* Tagged Nix 0.12.

.gitignore

@@ -1,262 +0,0 @@
-# START "git svn show-ignore"
-
-# /
-/Makefile
-/Makefile.in
-/aclocal.m4
-/autom4te.cache
-/config.*
-/configure
-/nix.spec
-/stamp-h1
-/svn-revision
-/NEWS
-/libtool
-
-# /config/
-/config/config.guess
-/config/config.sub
-/config/depcomp
-/config/install-sh
-/config/missing
-/config/mkinstalldirs
-/config/ltmain.sh
-
-# /corepkgs/
-/corepkgs/Makefile
-/corepkgs/Makefile.in
-
-# /corepkgs/buildenv/
-/corepkgs/buildenv/Makefile.in
-/corepkgs/buildenv/Makefile
-/corepkgs/buildenv/builder.pl
-
-# /corepkgs/channels/
-/corepkgs/channels/Makefile.in
-/corepkgs/channels/Makefile
-/corepkgs/channels/unpack.sh
-
-# /corepkgs/nar/
-/corepkgs/nar/Makefile
-/corepkgs/nar/Makefile.in
-/corepkgs/nar/nar.sh
-/corepkgs/nar/unnar.sh
-
-# /doc/
-/doc/Makefile
-/doc/Makefile.in
-
-# /doc/manual/
-/doc/manual/Makefile
-/doc/manual/Makefile.in
-/doc/manual/manual.html
-/doc/manual/manual.is-valid
-/doc/manual/*.1
-/doc/manual/*.8
-/doc/manual/images
-/doc/manual/version.txt
-/doc/manual/NEWS.html
-/doc/manual/NEWS.txt
-
-# /externals/
-/externals/Makefile
-/externals/Makefile.in
-/externals/aterm-*
-/externals/have-aterm
-/externals/build-aterm
-/externals/inst-aterm
-/externals/bzip2-*
-/externals/have-bzip2
-/externals/build-bzip2
-/externals/inst-bzip2
-
-# /make/examples/aterm/
-/make/examples/aterm/result*
-
-# /make/examples/aterm/aterm/
-/make/examples/aterm/aterm/*
-
-# /make/examples/aterm/test/
-/make/examples/aterm/test/*
-
-# /misc/
-/misc/Makefile.in
-/misc/Makefile
-
-# /misc/emacs/
-/misc/emacs/Makefile.in
-/misc/emacs/Makefile
-
-# /scripts/
-/scripts/Makefile
-/scripts/Makefile.in
-/scripts/nix-profile.sh
-/scripts/nix-pull
-/scripts/nix-push
-/scripts/nix-switch
-/scripts/nix-collect-garbage
-/scripts/nix-prefetch-url
-/scripts/nix-install-package
-/scripts/nix-channel
-/scripts/nix-build
-/scripts/nix-copy-closure
-/scripts/readmanifest.pm
-/scripts/readconfig.pm
-/scripts/download-using-manifests.pl
-/scripts/copy-from-other-stores.pl
-/scripts/generate-patches.pl
-/scripts/find-runtime-roots.pl
-/scripts/build-remote.pl
-
-# /src/
-/src/Makefile
-/src/Makefile.in
-
-# /src/bin2c/
-/src/bin2c/Makefile.in
-/src/bin2c/Makefile
-/src/bin2c/bin2c
-/src/bin2c/.deps
-/src/bin2c/.libs
-
-# /src/boost/
-/src/boost/Makefile
-/src/boost/Makefile.in
-
-# /src/boost/format/
-/src/boost/format/Makefile
-/src/boost/format/Makefile.in
-/src/boost/format/.deps
-/src/boost/format/libformat.a
-/src/boost/format/.libs
-
-# /src/bsdiff-4.3/
-/src/bsdiff-4.3/Makefile
-/src/bsdiff-4.3/Makefile.in
-/src/bsdiff-4.3/bsdiff
-/src/bsdiff-4.3/bspatch
-/src/bsdiff-4.3/.deps
-/src/bsdiff-4.3/.libs
-
-# /src/libexpr/
-/src/libexpr/Makefile
-/src/libexpr/Makefile.in
-/src/libexpr/.deps
-/src/libexpr/libexpr.a
-/src/libexpr/lexer-tab.cc
-/src/libexpr/lexer-tab.hh
-/src/libexpr/parser-tab.cc
-/src/libexpr/parser-tab.hh
-/src/libexpr/parser-tab.output
-/src/libexpr/nixexpr-ast.hh
-/src/libexpr/nixexpr-ast.cc
-/src/libexpr/.libs
-/src/libexpr/nix.tbl
-
-# /src/libmain/
-/src/libmain/Makefile
-/src/libmain/Makefile.in
-/src/libmain/.deps
-/src/libmain/libmain.a
-/src/libmain/.libs
-
-# /src/libstore/
-/src/libstore/Makefile
-/src/libstore/Makefile.in
-/src/libstore/.deps
-/src/libstore/libstore.a
-/src/libstore/derivations-ast.cc
-/src/libstore/derivations-ast.hh
-/src/libstore/.libs
-
-# /src/libutil/
-/src/libutil/Makefile
-/src/libutil/Makefile.in
-/src/libutil/.deps
-/src/libutil/libutil.a
-/src/libutil/.libs
-
-# /src/nix-env/
-/src/nix-env/Makefile.in
-/src/nix-env/Makefile
-/src/nix-env/.deps
-/src/nix-env/nix-env
-/src/nix-env/help.txt.hh
-/src/nix-env/.libs
-
-# /src/nix-hash/
-/src/nix-hash/Makefile
-/src/nix-hash/Makefile.in
-/src/nix-hash/.deps
-/src/nix-hash/.libs
-/src/nix-hash/nix-hash
-/src/nix-hash/help.txt.hh
-
-# /src/nix-instantiate/
-/src/nix-instantiate/Makefile.in
-/src/nix-instantiate/Makefile
-/src/nix-instantiate/.deps
-/src/nix-instantiate/nix-instantiate
-/src/nix-instantiate/help.txt.hh
-/src/nix-instantiate/.libs
-
-# /src/nix-log2xml/
-/src/nix-log2xml/Makefile.in
-/src/nix-log2xml/Makefile
-/src/nix-log2xml/.deps
-/src/nix-log2xml/nix-log2xml
-/src/nix-log2xml/test*.*
-/src/nix-log2xml/.libs
-/src/nix-log2xml/*.log
-/src/nix-log2xml/*.xml
-/src/nix-log2xml/*.html
-
-# /src/nix-setuid-helper/
-/src/nix-setuid-helper/Makefile.in
-/src/nix-setuid-helper/Makefile
-/src/nix-setuid-helper/.deps
-/src/nix-setuid-helper/nix-setuid-helper
-/src/nix-setuid-helper/help.txt.hh
-/src/nix-setuid-helper/.libs
-
-# /src/nix-store/
-/src/nix-store/Makefile
-/src/nix-store/Makefile.in
-/src/nix-store/.deps
-/src/nix-store/help.txt.hh
-/src/nix-store/nix-store
-/src/nix-store/.libs
-
-# /src/nix-worker/
-/src/nix-worker/Makefile.in
-/src/nix-worker/Makefile
-/src/nix-worker/.deps
-/src/nix-worker/nix-worker
-/src/nix-worker/help.txt.hh
-/src/nix-worker/.libs
-
-# /tests/
-/tests/Makefile
-/tests/Makefile.in
-/tests/test-tmp
-/tests/config.nix
-/tests/common.sh
-/tests/dummy
-
-# /tests/lang/
-/tests/lang/*.out
-/tests/lang/*.out.xml
-/tests/lang/*.ast
-
-# END "git svn show-ignore"
-
-*.lo
-*.la
-*.o
-*~
-
-# GNU Global
-GPATH
-GRTAGS
-GSYMS
-GTAGS

Makefile.am

@@ -1,13 +1,17 @@
 SUBDIRS = externals src scripts corepkgs doc misc tests
 EXTRA_DIST = substitute.mk nix.spec nix.spec.in bootstrap.sh \
-  nix.conf.example NEWS version
-
-pkginclude_HEADERS = config.h
+  svn-revision nix.conf.example NEWS
 
 include ./substitute.mk
 
 nix.spec: nix.spec.in
 
+rpm: nix.spec dist
+	rpm $(EXTRA_RPM_FLAGS) -ta $(distdir).tar.gz
+
+relname:
+	echo -n $(distdir) > relname
+
 install-data-local: init-state
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
 	$(INSTALL_DATA) $(srcdir)/nix.conf.example $(DESTDIR)$(sysconfdir)/nix
@@ -31,18 +35,22 @@ init-state:
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/profiles
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/gcroots
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/temproots
+	$(INSTALL) $(INIT_FLAGS) $(GROUP_WRITABLE) -d $(DESTDIR)$(localstatedir)/nix/gcroots/tmp
+	$(INSTALL) $(INIT_FLAGS) $(GROUP_WRITABLE) -d $(DESTDIR)$(localstatedir)/nix/gcroots/channels
 	ln -sfn $(localstatedir)/nix/profiles $(DESTDIR)$(localstatedir)/nix/gcroots/profiles
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/userpool
-	-$(INSTALL) $(INIT_FLAGS) -m 1777 -d $(DESTDIR)$(storedir)
+	$(INSTALL) $(INIT_FLAGS) -m 1777 -d $(DESTDIR)$(storedir)
 	$(INSTALL) $(INIT_FLAGS) $(GROUP_WRITABLE) -d $(DESTDIR)$(localstatedir)/nix/manifests
 	ln -sfn $(localstatedir)/nix/manifests $(DESTDIR)$(localstatedir)/nix/gcroots/manifests
 
 else
-
 init-state:
-
 endif
 
-NEWS:
-	$(MAKE) -C doc/manual NEWS.txt
+svn-revision:
+	svnversion . > svn-revision
+
+all-local: NEWS
+
+NEWS: doc/manual/NEWS.txt
 	cp $(srcdir)/doc/manual/NEWS.txt NEWS

aterm-gc.supp

@@ -115,35 +115,3 @@
    fun:*
    fun:AT_collect
 }
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:*
-   fun:*
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:*
-   fun:*
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:*
-   fun:*
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:*
-   fun:*
-   fun:mark_phase_young
-}

bootstrap.sh

@@ -1,5 +1,4 @@
 #! /bin/sh -e
-rm -f aclocal.m4
 mkdir -p config
 libtoolize --copy
 aclocal

configure.ac

@@ -1,8 +1,21 @@
-AC_INIT(nix, m4_esyscmd([echo -n $(cat ./version)$VERSION_SUFFIX]))
+AC_INIT(nix, 0.12)
 AC_CONFIG_SRCDIR(README)
 AC_CONFIG_AUX_DIR(config)
 AM_INIT_AUTOMAKE([dist-bzip2 foreign])
 
+# Change to `1' to produce a `stable' release (i.e., the `preREVISION'
+# suffix is not added).
+STABLE=1
+
+# Put the revision number in the version.
+if test "$STABLE" != "1"; then
+    if REVISION=`test -d $srcdir/.svn && svnversion -n $srcdir 2> /dev/null`; then
+        VERSION=${VERSION}pre${REVISION}
+    elif REVISION=`cat $srcdir/svn-revision 2> /dev/null`; then
+        VERSION=${VERSION}pre${REVISION}
+    fi
+fi
+
 AC_DEFINE_UNQUOTED(NIX_VERSION, ["$VERSION"], [Nix version.])
 
 AC_CANONICAL_HOST
@@ -10,8 +23,8 @@ AC_CANONICAL_HOST
 
 # Construct a Nix system name (like "i686-linux").
 AC_MSG_CHECKING([for the canonical Nix system name])
-cpu_name=$(uname -p | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ ' 'abcdefghijklmnopqrstuvwxyz_')
-machine_name=$(uname -m | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ ' 'abcdefghijklmnopqrstuvwxyz_')
+cpu_name=$(uname -p | tr 'A-Z ' 'a-z_')
+machine_name=$(uname -m | tr 'A-Z ' 'a-z_')
 
 case $machine_name in
     i*86)
@@ -30,7 +43,7 @@ case $machine_name in
         ;;
 esac
 
-sys_name=$(uname -s | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ ' 'abcdefghijklmnopqrstuvwxyz_')
+sys_name=$(uname -s | tr 'A-Z ' 'a-z_')
 
 case $sys_name in
     cygwin*)
@@ -50,52 +63,30 @@ AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier (`cpu-os')])
 test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var
 
 
-# Windows-specific stuff.  On Cygwin, dynamically linking against the
-# ATerm DLL works, except that it requires the ATerm "lib" directory
-# to be in $PATH, as Windows doesn't have anything like an RPATH
-# embedded in executable.  Since this is kind of annoying, we use
-# static libraries for now.
+# Windows-specific stuff.
 if test "$sys_name" = "cygwin"; then
+    # We cannot delete open files.
+    AC_DEFINE(CANNOT_DELETE_OPEN_FILES, 1, [Whether it is impossible to delete open files.])
+
+    # Shared libraries don't work, currently.
     AC_DISABLE_SHARED
     AC_ENABLE_STATIC
 fi
 
 
-# Solaris-specific stuff.
-if test "$sys_name" = "sunos"; then
-    # Solaris requires -lsocket -lnsl for network functions
-    LIBS="-lsocket -lnsl $LIBS"
-fi
-
-
 AC_PROG_CC
 AC_PROG_CXX
 
-# To build programs to be run in the build machine
-if test "$CC_FOR_BUILD" = ""; then
-    if test "$cross_compiling" = "yes"; then
-        AC_CHECK_PROGS(CC_FOR_BUILD, gcc cc)
-    else
-        CC_FOR_BUILD="$CC"
-    fi
-fi
-AC_SUBST([CC_FOR_BUILD])
 
 # We are going to use libtool.
 AC_DISABLE_STATIC
 AC_ENABLE_SHARED
 AC_PROG_LIBTOOL
 
-if test "$enable_shared" = yes; then
-   SUB_CONFIGURE_FLAGS="--enable-shared --disable-static"
-else
-   SUB_CONFIGURE_FLAGS="--enable-static --disable-shared"
-fi
-AC_SUBST(SUB_CONFIGURE_FLAGS)
-
 
 # Use 64-bit file system calls so that we can support files > 2 GiB.
-AC_SYS_LARGEFILE
+CFLAGS="-D_FILE_OFFSET_BITS=64 $CFLAGS"
+CXXFLAGS="-D_FILE_OFFSET_BITS=64 $CXXFLAGS"
 
 
 # Check for pubsetbuf.
@@ -112,8 +103,6 @@ AC_LANG_POP(C++)
 
 # Check for chroot support (requires chroot() and bind mounts).
 AC_CHECK_FUNCS([chroot])
-AC_CHECK_FUNCS([unshare])
-AC_CHECK_HEADERS([sched.h], [], [], [])
 AC_CHECK_HEADERS([sys/param.h], [], [], [])
 AC_CHECK_HEADERS([sys/mount.h], [], [],
 [#ifdef HAVE_SYS_PARAM_H
@@ -122,28 +111,12 @@ AC_CHECK_HEADERS([sys/mount.h], [], [],
 ])
 
 
-# Check for <locale>.
+# Check for <locale>
 AC_LANG_PUSH(C++)
 AC_CHECK_HEADERS([locale], [], [], [])
 AC_LANG_POP(C++)
 
 
-# Check for <err.h>.
-AC_CHECK_HEADER([err.h], [], [bsddiff_compat_include="-Icompat-include"])
-AC_SUBST([bsddiff_compat_include])
-
-
-# Check whether we have the personality() syscall, which allows us to
-# do i686-linux builds on x86_64-linux machines.
-AC_CHECK_HEADERS([sys/personality.h])
-
-
-# Check for tr1/unordered_set.
-AC_LANG_PUSH(C++)
-AC_CHECK_HEADERS([tr1/unordered_set], [], [], [])
-AC_LANG_POP(C++)
-
-
 AC_DEFUN([NEED_PROG],
 [
 AC_PATH_PROG($1, $2)
@@ -157,11 +130,11 @@ NEED_PROG(bash, bash)
 NEED_PROG(patch, patch)
 AC_PATH_PROG(xmllint, xmllint, false)
 AC_PATH_PROG(xsltproc, xsltproc, false)
+AC_PATH_PROG(jing, jing, false) # needed because xmllint --relaxng seems broken
 AC_PATH_PROG(w3m, w3m, false)
 AC_PATH_PROG(flex, flex, false)
 AC_PATH_PROG(bison, bison, false)
 NEED_PROG(perl, perl)
-NEED_PROG(sed, sed)
 NEED_PROG(tar, tar)
 AC_PATH_PROG(dot, dot)
 AC_PATH_PROG(dblatex, dblatex)
@@ -206,6 +179,48 @@ AC_ARG_WITH(store-dir, AC_HELP_STRING([--with-store-dir=PATH],
   storedir=$withval, storedir='/nix/store')
 AC_SUBST(storedir)
 
+AC_ARG_ENABLE(old-db-compat, AC_HELP_STRING([--disable-old-db-compat],
+  [disable support for converting from old Berkeley DB-based Nix stores]),
+  old_db_compat=$enableval, old_db_compat=yes)
+AM_CONDITIONAL(OLD_DB_COMPAT, test "$old_db_compat" = "yes")
+
+AC_ARG_WITH(bdb, AC_HELP_STRING([--with-bdb=PATH],
+  [prefix of Berkeley DB (for Nix <= 0.11 compatibility)]),
+  bdb=$withval, bdb=)
+AM_CONDITIONAL(HAVE_BDB, test -n "$bdb")
+if test -z "$bdb"; then
+  bdb_lib='-L${top_builddir}/externals/inst-bdb/lib -ldb_cxx'
+  bdb_include='-I${top_builddir}/externals/inst-bdb/include'
+else
+  bdb_lib="-L$bdb/lib -ldb_cxx"
+  bdb_include="-I$bdb/include"
+fi
+if test "$old_db_compat" = "no"; then
+  bdb_lib=
+  bdb_include=
+else
+  AC_DEFINE(OLD_DB_COMPAT, 1, [Whether to support converting from old Berkeley DB-based Nix stores.])
+fi
+AC_SUBST(bdb_lib)
+AC_SUBST(bdb_include)
+
+AC_ARG_WITH(aterm, AC_HELP_STRING([--with-aterm=PATH],
+  [prefix of CWI ATerm library]),
+  aterm=$withval, aterm=)
+AM_CONDITIONAL(HAVE_ATERM, test -n "$aterm")
+if test -z "$aterm"; then
+  aterm_lib='-L${top_builddir}/externals/inst-aterm/lib -lATerm'
+  aterm_include='-I${top_builddir}/externals/inst-aterm/include'
+  aterm_bin='${top_builddir}/externals/inst-aterm/bin'
+else
+  aterm_lib="-L$aterm/lib -lATerm"
+  aterm_include="-I$aterm/include"
+  aterm_bin="$aterm/bin"
+fi
+AC_SUBST(aterm_lib)
+AC_SUBST(aterm_include)
+AC_SUBST(aterm_bin)
+
 AC_ARG_WITH(openssl, AC_HELP_STRING([--with-openssl=PATH],
   [prefix of the OpenSSL library]),
   openssl=$withval, openssl=)
@@ -221,8 +236,6 @@ AC_ARG_WITH(bzip2, AC_HELP_STRING([--with-bzip2=PATH],
   [prefix of bzip2]),
   bzip2=$withval, bzip2=)
 AM_CONDITIONAL(HAVE_BZIP2, test -n "$bzip2")
-ATERM_VERSION=2.5
-AC_SUBST(ATERM_VERSION)
 if test -z "$bzip2"; then
   # Headers and libraries will be used from the temporary installation
   # in externals/inst-bzip2.
@@ -237,42 +250,14 @@ else
   bzip2_include="-I$bzip2/include"
   bzip2_bin="$bzip2/bin"
   bzip2_bin_test="$bzip2/bin"
-fi
+fi   
 AC_SUBST(bzip2_lib)
 AC_SUBST(bzip2_include)
 AC_SUBST(bzip2_bin)
 AC_SUBST(bzip2_bin_test)
 
-AC_ARG_WITH(sqlite, AC_HELP_STRING([--with-sqlite=PATH],
-  [prefix of SQLite]),
-  sqlite=$withval, sqlite=)
-AM_CONDITIONAL(HAVE_SQLITE, test -n "$sqlite")
-SQLITE_VERSION=3070500
-AC_SUBST(SQLITE_VERSION)
-if test -z "$sqlite"; then
-  sqlite_lib='${top_builddir}/externals/sqlite-autoconf-$(SQLITE_VERSION)/libsqlite3.la'
-  sqlite_include='-I${top_builddir}/externals/sqlite-autoconf-$(SQLITE_VERSION)'
-  sqlite_bin='${top_builddir}/externals/sqlite-autoconf-$(SQLITE_VERSION)'
-else
-  sqlite_lib="-L$sqlite/lib -lsqlite3"
-  sqlite_include="-I$sqlite/include"
-  sqlite_bin="$sqlite/bin"
-fi
-AC_SUBST(sqlite_lib)
-AC_SUBST(sqlite_include)
-AC_SUBST(sqlite_bin)
 
-# Whether to use the Boehm garbage collector.
-AC_ARG_ENABLE(gc, AC_HELP_STRING([--enable-gc],
-  [enable garbage collection in the Nix expression evaluator (requires Boehm GC)]),
-  gc=$enableval, gc=)
-if test -n "$gc"; then
-  PKG_CHECK_MODULES([BDW_GC], [bdw-gc])
-  boehmgc_lib="-L$boehmgc/lib -lgc"
-  CXXFLAGS="$BDW_GC_CFLAGS $CXXFLAGS"
-  AC_DEFINE(HAVE_BOEHMGC, 1, [Whether to use the Boehm garbage collector.])
-fi
-AC_SUBST(boehmgc_lib)
+AC_CHECK_LIB(pthread, pthread_mutex_init)
 
 
 AC_ARG_ENABLE(init-state, AC_HELP_STRING([--disable-init-state],
@@ -286,10 +271,10 @@ AC_CHECK_FUNCS([setresuid setreuid lchown])
 
 
 # Nice to have, but not essential.
-AC_CHECK_FUNCS([strsignal posix_fallocate nanosleep])
+AC_CHECK_FUNCS([strsignal])
 
 
-# This is needed if ATerm or bzip2 are static libraries,
+# This is needed if ATerm, Berkeley DB or bzip2 are static libraries,
 # and the Nix libraries are dynamic.
 if test "$(uname)" = "Darwin"; then
     LDFLAGS="-all_load $LDFLAGS"

corepkgs/buildenv/builder.pl.in

@@ -29,18 +29,10 @@ sub createLinks {
         $baseName =~ s/^.*\///g; # strip directory
         my $dstFile = "$dstDir/$baseName";
 
-        # The files below are special-cased so that they don't show up
-        # in user profiles, either because they are useless, or
-        # because they would cause pointless collisions (e.g., each
-        # Python package brings its own
-        # `$out/lib/pythonX.Y/site-packages/easy-install.pth'.)
         # Urgh, hacky...
-        if ($srcFile =~ /\/propagated-build-inputs$/ ||
+	if ($srcFile =~ /\/propagated-build-inputs$/ ||
             $srcFile =~ /\/nix-support$/ ||
             $srcFile =~ /\/perllocal.pod$/ ||
-            $srcFile =~ /\/easy-install.pth$/ ||
-            $srcFile =~ /\/site.py$/ ||
-            $srcFile =~ /\/site.pyc$/ ||
             $srcFile =~ /\/info\/dir$/ ||
             $srcFile =~ /\/log$/)
         {
@@ -168,4 +160,4 @@ while (scalar(keys %postponed) > 0) {
 print STDERR "created $symlinks symlinks in user environment\n";
 
 
-symlink($ENV{"manifest"}, "$out/manifest.nix") or die "cannot create manifest";
+symlink($ENV{"manifest"}, "$out/manifest") or die "cannot create manifest";

corepkgs/buildenv/default.nix

@@ -11,8 +11,4 @@ derivation {
   paths = derivations;
   active = map (x: if x ? meta && x.meta ? active then x.meta.active else "true") derivations;
   priority = map (x: if x ? meta && x.meta ? priority then x.meta.priority else "5") derivations;
-
-  # Building user environments remotely just causes huge amounts of
-  # network traffic, so don't do that.
-  preferLocalBuild = true;
 }

corepkgs/channels/unpack.sh.in

@@ -1,8 +1,5 @@
 #! @shell@ -e
 
-# Cygwin compatibility hack: bunzip2 expects cygwin.dll in $PATH.
-export PATH=@coreutils@
-
 @coreutils@/mkdir $out
 @coreutils@/mkdir $out/tmp
 cd $out/tmp
@@ -11,15 +8,9 @@ inputs=($inputs)
 for ((n = 0; n < ${#inputs[*]}; n += 2)); do
     channelName=${inputs[n]}
     channelTarball=${inputs[n+1]}
-    
     echo "unpacking channel $channelName"
-    
     @bunzip2@ < $channelTarball | @tar@ xf -
 
-    if test -e */channel-name; then
-        channelName="$(@coreutils@/cat */channel-name)"
-    fi
-
     nr=1
     attrName=$(echo $channelName | @tr@ -- '- ' '__')
     dirName=$attrName

corepkgs/nar/nar.sh.in

@@ -7,6 +7,8 @@ dst=$out/tmp.nar.bz2
 
 @bzip2@ < tmp > $dst
 
+@bindir@/nix-hash -vvvvv --flat --type $hashAlgo --base32 tmp > $out/nar-hash
+
 @bindir@/nix-hash --flat --type $hashAlgo --base32 $dst > $out/narbz2-hash
 
 @coreutils@/mv $out/tmp.nar.bz2 $out/$(@coreutils@/cat $out/narbz2-hash).nar.bz2

doc/manual/Makefile.am

@@ -6,12 +6,7 @@ XSLTPROC = $(xsltproc) $(xmlflags) \
  --param xref.with.number.and.title 1 \
  --param toc.section.depth 3 \
  --param admon.style \'\' \
- --param callout.graphics.extension \'.gif\' \
- --param contrib.inline.enabled 0
-
-dblatex_opts = \
- -P doc.collab.show=0 \
- -P latex.output.revhistory=0
+ --param callout.graphics.extension \'.gif\'
 
 # Note: we use GIF for now, since the PNGs shipped with Docbook aren't
 # transparent.
@@ -34,9 +29,13 @@ MANUAL_SRCS = manual.xml introduction.xml installation.xml \
  conf-file.xml release-notes.xml \
  style.css images
 
-# Note: RelaxNG validation requires xmllint >= 2.7.4.
 manual.is-valid: $(MANUAL_SRCS) version.txt
-	$(XMLLINT) --noout --nonet --xinclude --noxincludenode --relaxng $(docbookrng)/docbook.rng $<
+#	$(XMLLINT) --xinclude $< | $(XMLLINT) --noout --nonet --relaxng $(docbookrng)/docbook.rng -
+	if test "$(jing)" != "false"; then \
+		$(XMLLINT) --xinclude $< | $(jing) $(docbookrng)/docbook.rng /dev/fd/0; \
+	else \
+		echo "Not validating."; \
+	fi
 	touch $@
 
 version.txt:
@@ -51,7 +50,7 @@ manual.html: $(MANUAL_SRCS) manual.is-valid images
 
 manual.pdf: $(MANUAL_SRCS) manual.is-valid images
 	if test "$(dblatex)" != ""; then \
-		$(dblatex) $(dblatex_opts) manual.xml; \
+		$(dblatex) manual.xml; \
 	else \
 		echo "Please install dblatex and rerun configure."; \
 		exit 1; \
@@ -80,14 +79,10 @@ all-local: manual.html NEWS.html NEWS.txt
 install-data-local: manual.html
 	$(INSTALL) -d $(DESTDIR)$(docdir)/manual
 	$(INSTALL_DATA) manual.html $(DESTDIR)$(docdir)/manual
-	ln -sf manual.html $(DESTDIR)$(docdir)/manual/index.html
 	$(INSTALL_DATA) style.css $(DESTDIR)$(docdir)/manual
 	cp -r images $(DESTDIR)$(docdir)/manual/images
 	$(INSTALL) -d $(DESTDIR)$(docdir)/manual/figures
 	$(INSTALL_DATA) $(FIGURES) $(DESTDIR)$(docdir)/manual/figures
-	$(INSTALL) -d $(DESTDIR)$(docdir)/release-notes
-	$(INSTALL_DATA) NEWS.html $(DESTDIR)$(docdir)/release-notes/index.html
-	$(INSTALL_DATA) style.css $(DESTDIR)$(docdir)/release-notes/
 
 images:
 	mkdir images

doc/manual/builtins.xml

@@ -77,8 +77,18 @@ attrValues = attrs: map (name: builtins.getAttr name attrs) (builtins.attrNames
 if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting>
 
     This allows a Nix expression to fall back gracefully on older Nix
-    installations that don’t have the desired built-in
-    function.</para></listitem>
+    installations that don’t have the desired built-in function.
+    However, in that case you should not write
+
+<programlisting>
+if builtins ? getEnv then __getEnv "PATH" else ""</programlisting>
+
+    This Nix expression will trigger an “undefined variable” error on
+    older Nix versions since <function>__getEnv</function> doesn’t
+    exist.  <literal>builtins.getEnv</literal>, on the other hand, is
+    safe since <literal>builtins</literal> always exists and attribute
+    selection is lazy, so it’s only performed if the test
+    succeeds.</para></listitem>
 
   </varlistentry>
 
@@ -324,16 +334,6 @@ x: x + 456</programlisting>
   </varlistentry>
 
   
-  <varlistentry><term><function>builtins.intersectAttrs</function>
-  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
-
-    <listitem><para>Return an attribute set consisting of the
-    attributes in the set <replaceable>e2</replaceable> that also
-    exist in the set <replaceable>e1</replaceable>.</para></listitem>
-
-  </varlistentry>
-        
-    
   <varlistentry><term><function>builtins.isAttrs</function>
   <replaceable>e</replaceable></term>
 
@@ -364,36 +364,6 @@ x: x + 456</programlisting>
   </varlistentry>
 
   
-  <varlistentry><term><function>builtins.isString</function>
-  <replaceable>e</replaceable></term>
-
-    <listitem><para>Return <literal>true</literal> if
-    <replaceable>e</replaceable> evaluates to a string, and
-    <literal>false</literal> otherwise.</para></listitem>
-
-  </varlistentry>
-
-  
-  <varlistentry><term><function>builtins.isInt</function>
-  <replaceable>e</replaceable></term>
-
-    <listitem><para>Return <literal>true</literal> if
-    <replaceable>e</replaceable> evaluates to a int, and
-    <literal>false</literal> otherwise.</para></listitem>
-
-  </varlistentry>
-
-  
-  <varlistentry><term><function>builtins.isBool</function>
-  <replaceable>e</replaceable></term>
-
-    <listitem><para>Return <literal>true</literal> if
-    <replaceable>e</replaceable> evaluates to a bool, and
-    <literal>false</literal> otherwise.</para></listitem>
-
-  </varlistentry>
-
-  
   <varlistentry><term><function>isNull</function>
   <replaceable>e</replaceable></term>
 

doc/manual/conf-file.xml

@@ -97,25 +97,6 @@ env-keep-derivations = false
   </varlistentry>
 
 
-  <varlistentry xml:id="conf-build-cores"><term><literal>build-cores</literal></term>
-
-    <listitem><para>Sets the value of the
-    <envar>NIX_BUILD_CORES</envar> environment variable in the
-    invocation of builders.  Builders can use this variable at their
-    discretion to control the maximum amount of parallelism.  For
-    instance, in Nixpkgs, if the derivation attribute
-    <varname>enableParallelBuilding</varname> is set to
-    <literal>true</literal>, the builder passes the
-    <option>-j<replaceable>N</replaceable></option> flag to GNU Make.
-    It can be overriden using the <option
-    linkend='opt-cores'>--cores</option> command line switch and
-    defaults to <literal>1</literal>.  The value <literal>0</literal>
-    means that the builder should use all available CPU cores in the
-    system.</para></listitem>
-
-  </varlistentry>
-
-
   <varlistentry xml:id="conf-build-max-silent-time"><term><literal>build-max-silent-time</literal></term>
 
     <listitem>
@@ -252,17 +233,7 @@ build-use-chroot = /dev /proc /bin</programlisting>
     <filename>configure</filename> at build time.</para></listitem>
 
   </varlistentry>
-
-
-  <varlistentry><term><literal>fsync-metadata</literal></term>
-
-    <listitem><para>If set to <literal>true</literal>, changes to the
-    Nix store metadata (in <filename>/nix/var/nix/db</filename>) are
-    synchronously flushed to disk.  This improves robustness in case
-    of system crashes, but reduces performance.  The default is
-    <literal>true</literal>.</para></listitem>
-
-  </varlistentry>
+  
     
 </variablelist>
 

doc/manual/env-common.xml

@@ -151,12 +151,12 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
   <para>On the basis of this information, and whatever persistent
   state the build hook keeps about other machines and their current
   load, it has to decide what to do with the build.  It should print
-  out on standard error one of the following responses (terminated by
-  a newline, <literal>"\n"</literal>):
+  out on file descriptor 3 one of the following responses (terminated
+  by a newline, <literal>"\n"</literal>):
 
   <variablelist>
 
-    <varlistentry><term><literal># decline</literal></term>
+    <varlistentry><term><literal>decline</literal></term>
 
       <listitem><para>The build hook is not willing or able to perform
       the build; the calling Nix process should do the build itself,
@@ -164,7 +164,7 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
     </varlistentry>
 
-    <varlistentry><term><literal># postpone</literal></term>
+    <varlistentry><term><literal>postpone</literal></term>
 
       <listitem><para>The build hook cannot perform the build now, but
       can do so in the future (e.g., because all available build slots
@@ -174,7 +174,7 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
     </varlistentry>
 
-    <varlistentry><term><literal># accept</literal></term>
+    <varlistentry><term><literal>accept</literal></term>
 
       <listitem><para>The build hook has accepted the
       build.</para></listitem>
@@ -185,12 +185,37 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
   </para>
 
-  <para>After sending <literal># accept</literal>, the hook should
-  read one line from standard input, which will be the string
-  <literal>okay</literal>.  It can then proceed with the build.
-  Before sending <literal>okay</literal>, Nix will store in the hook’s
-  current directory a number of text files that contain information
-  about the derivation:
+  <para>If the build hook accepts the build, it is possible that it is
+  no longer necessary to do the build because some other process has
+  performed the build in the meantime.  To prevent races, the hook
+  must read from file descriptor 4 a single line that tells it whether
+  to continue:
+
+  <variablelist>
+
+    <varlistentry><term><literal>cancel</literal></term>
+
+      <listitem><para>The build has already been done, so the hook
+      should exit.</para></listitem>
+
+    </varlistentry>
+  
+    <varlistentry><term><literal>okay</literal></term>
+
+      <listitem><para>The hook should proceed with the build.  At this
+      point, the calling Nix process has acquired locks on the output
+      path, so no other Nix process will perform the
+      build.</para></listitem>
+
+    </varlistentry>
+
+  </variablelist>
+
+  </para>
+
+  <para>If the hook has been told to proceed, Nix will store in the
+  hook’s current directory a number of text files that contain
+  information about the derivation:
 
   <variablelist>
 
@@ -230,9 +255,7 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
   <para>The hook should copy the inputs to the remote machine,
   register the validity of the inputs, perform the remote build, and
   copy the outputs back to the local machine.  An exit code other than
-  <literal>0</literal> indicates that the hook has failed.  An exit
-  code equal to 100 means that the remote build failed (as opposed to,
-  e.g., a network error).</para>
+  <literal>0</literal> indicates that the hook has failed.</para>
 
   </listitem>
 
@@ -271,17 +294,6 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
 </varlistentry>
 
-
-<varlistentry><term><envar>GC_INITIAL_HEAP_SIZE</envar></term>
-
-  <listitem><para>If Nix has been configured to use the Boehm garbage
-  collector, this variable sets the initial size of the heap in bytes.
-  It defaults to 384 MiB.  Setting it to a low value reduces memory
-  consumption, but will increase runtime due to the overhead of
-  garbage collection.</para></listitem>
-
-</varlistentry>
-
     
 </variablelist>
 

doc/manual/installation.xml

@@ -96,21 +96,23 @@ ubiquitous 2.5.4a won't.  Note that these are only required if you
 modify the parser or when you are building from the Subversion
 repository.</para>
 
-<para>Nix uses the bzip2 compressor (including the bzip2 library).  It
-is included in the Nix source distribution.  If you build from the
-Subversion repository, you must download it yourself and place it in
-the <filename>externals/</filename> directory.  See
+<para>Nix uses CWI's ATerm library and the bzip2 compressor (including
+the bzip2 library).  These are included in the Nix source
+distribution.  If you build from the Subversion repository, you must
+download them yourself and place them in the
+<filename>externals/</filename> directory.  See
 <filename>externals/Makefile.am</filename> for the precise URLs of
-this packages.  Alternatively, if you already have it installed, you
-can use <command>configure</command>'s <option>--with-bzip2</option>
+these packages.  Alternatively, if you already have them installed,
+you can use <command>configure</command>'s
+<option>--with-aterm</option> and <option>--with-bzip2</option>
 options to point to their respective locations.</para>
 
-<para>Nix can optionally use the <link
-xlink:href="http://www.hpl.hp.com/personal/Hans_Boehm/gc/">Boehm
-garbage collector</link> to reduce the evaluator’s memory consumption.
-To enable it, install <literal>pkgconfig</literal> and the Boehm
-garbage collector, and pass the flag <option>--enable-gc</option> to
-<command>configure</command>.</para>
+<para>If you want to be able to upgrade Nix stores from before version
+0.12pre12020, you need Sleepycat's Berkeley DB version version 4.5.
+(Other versions may not have compatible database formats.).  Berkeley
+DB 4.5 is included in the Nix source distribution.  If you do not need
+this ability, you can build Nix with the
+<option>--disable-old-db-compat</option> configure option.</para>
 
 </section>
 
@@ -131,32 +133,23 @@ $ make install</screen>
 preceded by the command:
 
 <screen>
-$ ./bootstrap.sh</screen>
+$ ./bootstrap</screen>
 
 </para>
 
 <para>The installation path can be specified by passing the
 <option>--prefix=<replaceable>prefix</replaceable></option> to
 <command>configure</command>.  The default installation directory is
-<filename>/usr/local</filename>.  You can change this to any location
-you like.  You must have write permission to the
+<filename>/nix</filename>.  You can change this to any location you
+like.  You must have write permission to the
 <replaceable>prefix</replaceable> path.</para>
 
-<para>Nix keeps its <emphasis>store</emphasis> (the place where
-packages are stored) in <filename>/nix/store</filename> by default.
-This can be changed using
-<option>--with-store-dir=<replaceable>path</replaceable></option>.</para>
+<warning><para>It is best <emphasis>not</emphasis> to change the
+installation prefix from its default, since doing so makes it
+impossible to use pre-built binaries from the standard Nixpkgs
+channels.</para></warning>
 
-<warning><para>It is best <emphasis>not</emphasis> to change the Nix
-store from its default, since doing so makes it impossible to use
-pre-built binaries from the standard Nixpkgs channels — that is, all
-packages will need to be built from source.</para></warning>
-
-<para>Nix keeps state (such as its database and log files) in
-<filename>/nix/var</filename> by default.  This can be changed using
-<option>--localstatedir=<replaceable>path</replaceable></option>.</para>
-
-<para>If you want to rebuild the documentation, pass the full path to
+<para>If you want to rebuilt the documentation, pass the full path to
 the DocBook RELAX NG schemas and to the DocBook XSL stylesheets using
 the
 <option>--with-docbook-rng=<replaceable>path</replaceable></option>
@@ -167,26 +160,27 @@ options.</para>
 </section>
 
 
-<section><title>Installing a binary distribution</title>
+<section><title>Installing from RPMs</title>
 
-<para>RPM and Deb packages of Nix for a number of different versions
-of Fedora, openSUSE, Debian and Ubuntu can be downloaded from <link
-xlink:href="http://nixos.org/" />.  Once downloaded, the RPMs can be
-installed or upgraded using <command>rpm -U</command>.  For example,
+<para>RPM packages of Nix can be downloaded from <link
+xlink:href="http://nixos.org/" />.  These RPMs should work for most
+fairly recent releases of SuSE and Red Hat Linux.  They have been
+known to work work on SuSE Linux 8.1 and 9.0, and Red Hat 9.0.  In
+fact, it should work on any RPM-based Linux distribution based on
+<literal>glibc</literal> 2.3 or later.</para>
+
+<para>Once downloaded, the RPMs can be installed or upgraded using
+<command>rpm -U</command>.  For example,
 
 <screen>
-$ rpm -U nix-0.13pre18104-1.i386.rpm</screen>
-
-Likewise, for a Deb package:
-
-<screen>
-$ dpkg -i nix_0.13pre18104-1_amd64.deb</screen>
+$ rpm -U nix-0.5pre664-1.i386.rpm</screen>
 
 </para>
 
-<para>Nix can be uninstalled using <command>rpm -e nix</command> or
-<command>dpkg -r nix</command>.  After this you should manually remove
-the Nix store and other auxiliary data, if desired:
+<para>The RPMs install into the directory <filename>/nix</filename>.
+Nix can be uninstalled using <command>rpm -e nix</command>.  After
+this it will be necessary to manually remove the Nix store and other
+auxiliary data:
 
 <screen>
 $ rm -rf /nix/store
@@ -197,7 +191,6 @@ $ rm -rf /nix/var</screen>
 </section>
 
 
-<!-- TODO: should be updated
 <section><title>Upgrading Nix through Nix</title>
 
 <para>You can install the latest stable version of Nix through Nix
@@ -210,7 +203,6 @@ installation</link> by clicking on the package links at <link
 xlink:href="http://nixos.org/releases/full-index-nix.html" />.</para>
 
 </section>
--->
 
 
 <section><title>Security</title>

doc/manual/introduction.xml

@@ -113,7 +113,7 @@ $ nix-env --rollback
 
 <simplesect><title>Garbage collection</title>
 
-<para>When you uninstall a package like this…
+<para>When you install a package like this…
 
 <screen>
 $ nix-env --uninstall firefox
@@ -320,7 +320,7 @@ overview of NixOS is given in the HotOS XI paper <citetitle
 xlink:href="http://www.st.ewi.tudelft.nl/~dolstra/pubs/hotos-final.pdf">Purely
 Functional System Configuration Management</citetitle>.  The Nix
 homepage has <link
-xlink:href="http://nixos.org/docs/papers.html">an up-to-date list
+xlink:href="http://nix.cs.uu.nl/docs/papers.html">an up-to-date list
 of Nix-related papers</link>.</para>
 
 <para>Nix is the subject of Eelco Dolstra’s PhD thesis <citetitle

doc/manual/manual.xml

@@ -17,7 +17,6 @@
         <orgname>Delft University of Technology</orgname>
         <orgdiv>Department of Software Technology</orgdiv>
       </affiliation>
-      <contrib>Author</contrib>
     </author>
 
     <copyright>
@@ -26,12 +25,10 @@
       <year>2006</year>
       <year>2007</year>
       <year>2008</year>
-      <year>2009</year>
-      <year>2010</year>
       <holder>Eelco Dolstra</holder>
     </copyright>
 
-    <date>August 2010</date>
+    <date>November 2008</date>
     
   </info>
 
@@ -52,29 +49,68 @@
     
     <section>
       <title>Main commands</title>
-      <xi:include href="nix-env.xml" />
-      <xi:include href="nix-instantiate.xml" />
-      <xi:include href="nix-store.xml" />
+      <section xml:id="sec-nix-env">
+        <title>nix-env</title>
+        <xi:include href="nix-env.xml" />
+      </section>
+      <section xml:id="sec-nix-instantiate">
+        <title>nix-instantiate</title>
+        <xi:include href="nix-instantiate.xml" />
+      </section>
+      <section xml:id="sec-nix-store">
+        <title>nix-store</title>
+        <xi:include href="nix-store.xml" />
+      </section>
     </section>
     
     <section>
       <title>Utilities</title>
-      <xi:include href="nix-build.xml" />
-      <xi:include href="nix-channel.xml" />
-      <xi:include href="nix-collect-garbage.xml" />
-      <xi:include href="nix-copy-closure.xml" />
-      <xi:include href="nix-hash.xml" />
-      <xi:include href="nix-install-package.xml" />
-      <xi:include href="nix-prefetch-url.xml" />
-      <xi:include href="nix-pull.xml" />
-      <xi:include href="nix-push.xml" />
-      <xi:include href="nix-worker.xml" />
+      <section xml:id="sec-nix-build">
+        <title>nix-build</title>
+        <xi:include href="nix-build.xml" />
+      </section>
+      <section xml:id="sec-nix-channel">
+        <title>nix-channel</title>
+        <xi:include href="nix-channel.xml" />
+      </section>
+      <section xml:id="sec-nix-collect-garbage">
+        <title>nix-collect-garbage</title>
+        <xi:include href="nix-collect-garbage.xml" />
+      </section>
+      <section xml:id="sec-nix-copy-closure">
+        <title>nix-copy-closure</title>
+        <xi:include href="nix-copy-closure.xml" />
+      </section>
+      <section xml:id="sec-nix-hash">
+        <title>nix-hash</title>
+        <xi:include href="nix-hash.xml" />
+      </section>
+      <section xml:id="sec-nix-install-package">
+        <title>nix-install-package</title>
+        <xi:include href="nix-install-package.xml" />
+      </section>
+      <section xml:id="sec-nix-prefetch-url">
+        <title>nix-prefetch-url</title>
+        <xi:include href="nix-prefetch-url.xml" />
+      </section>
+      <section xml:id="sec-nix-pull">
+        <title>nix-pull</title>
+        <xi:include href="nix-pull.xml" />
+      </section>
+      <section xml:id="sec-nix-push">
+        <title>nix-push</title>
+        <xi:include href="nix-push.xml" />
+      </section>
+      <section xml:id="sec-nix-worker">
+        <title>nix-worker</title>
+        <xi:include href="nix-worker.xml" />
+      </section>
     </section>
-
+    
   </appendix>
 
   <xi:include href="troubleshooting.xml" />
-  <!-- <xi:include href="bugs.xml" /> -->
+  <xi:include href="bugs.xml" />
   <xi:include href="glossary.xml" />
 
   <appendix>

doc/manual/nix-build.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-build">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
 <refmeta>
   <refentrytitle>nix-build</refentrytitle>

doc/manual/nix-channel.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-channel">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-channel</refentrytitle>

doc/manual/nix-collect-garbage.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-collect-garbage">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-collect-garbage</refentrytitle>

doc/manual/nix-copy-closure.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-copy-closure">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
 <refmeta>
   <refentrytitle>nix-copy-closure</refentrytitle>

doc/manual/nix-env.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-env">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-env</refentrytitle>

doc/manual/nix-hash.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-hash">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-hash</refentrytitle>

doc/manual/nix-install-package.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-install-package">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-install-package</refentrytitle>

doc/manual/nix-instantiate.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-instantiate">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-instantiate</refentrytitle>

doc/manual/nix-lang-ref.xml

@@ -178,5 +178,100 @@
     </productionset>
     
   </sect1>
+  
+
+
+  <sect1>
+    <title>Semantics</title>
+
+
+    
+    <sect2>
+      <title>Built-in functions</title>
+
+      <para>
+        The Nix language provides the following built-in function
+        (<quote>primops</quote>):
+      </para>
+
+      <variablelist>
+
+        <varlistentry>
+          <term><function>import</function>
+          <replaceable>e</replaceable></term>
+          <listitem>
+            <para>
+              Evaluates the expression <replaceable>e</replaceable>,
+              which must yield a path value.  The Nix expression
+              stored at this path in the file system is then read,
+              parsed, and evaluated.  Returns the result of the
+              evaluation of the Nix expression just read.
+            </para>
+
+            <para>
+              Example: <literal>import ./foo.nix</literal> evaluates
+              the expression stored in <filename>foo.nix</filename>
+              (in the directory containing the expression in which the
+              <function>import</function> occurs).
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><function>derivation</function>
+          <replaceable>e</replaceable></term>
+          <listitem>
+            <para>
+              Evaluates the expression <replaceable>e</replaceable>,
+              which must yield an attribute set.  [...]
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><function>baseNameOf</function>
+          <replaceable>e</replaceable></term>
+          <listitem>
+            <para>
+              Evaluates the expression <replaceable>e</replaceable>,
+              which must yield a string value, and returns a string
+              representing its <emphasis>base name</emphasis>.  This
+              is the substring following the last path separator
+              (<literal>/</literal>).
+            </para>
+
+            <para>
+              Example: <literal>baseNameOf "/foo/bar"</literal>
+              returns <literal>"bar"</literal>, and
+              <literal>baseNameOf "/foo/bar/"</literal> returns
+              <literal>""</literal>.
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><function>toString</function>
+          <replaceable>e</replaceable></term>
+          <listitem>
+            <para>
+              Evaluates the expression <replaceable>e</replaceable>
+              and coerces it into a string, if possible.  Only
+              strings, paths, and URIs can be so coerced.
+            </para>
+
+            <para>
+              Example: <literal>toString
+              http://www.cs.uu.nl/</literal> returns
+              <literal>"http://www.cs.uu.nl/"</literal>.
+            </para>
+          </listitem>
+        </varlistentry>
+            
+      </variablelist>
+
+    </sect2>
+
+  </sect1>
+  
 
 </appendix>

doc/manual/nix-prefetch-url.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-prefetch-url">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
 <refmeta>
   <refentrytitle>nix-prefetch-url</refentrytitle>

doc/manual/nix-pull.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-pull">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
 <refmeta>
   <refentrytitle>nix-pull</refentrytitle>

doc/manual/nix-push.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-push">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
 <refmeta>
   <refentrytitle>nix-push</refentrytitle>
@@ -120,7 +119,7 @@ dependencies used in the build, such as compilers).</para>
 dependencies, we can do:
       
 <screen>
-$ nix-push <replaceable>urls</replaceable> $(nix-store -r $(nix-instantiate foo.nix))</screen>
+$ nix-push <replaceable>urls</replaceable> $(nix-instantiate $(nix-store -r foo.nix))</screen>
     
 </para>
 

doc/manual/nix-store.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-store">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
 <refmeta>
   <refentrytitle>nix-store</refentrytitle>
@@ -213,6 +212,8 @@ linkend="sec-nix-build"><command>nix-build</command></link> does.</para>
   </group>
   <arg><option>--max-freed</option> <replaceable>bytes</replaceable></arg>
   <arg><option>--max-links</option> <replaceable>nrlinks</replaceable></arg>
+  <arg><option>--max-atime</option> <replaceable>atime</replaceable></arg>
+  <arg><option>--use-atime</option></arg>
 </cmdsynopsis>
 
 </refsection>
@@ -290,6 +291,42 @@ options control what gets deleted and in what order:
     
   </varlistentry>
 
+  <varlistentry><term><option>--max-atime</option> <replaceable>atime</replaceable></term>
+  
+    <listitem><para>Only delete a store path if its last-accessed time
+    is less than <replaceable>atime</replaceable>.  This allows you to
+    garbage-collect only packages that haven’t been used recently.
+    The time is expressed as the number of seconds in the Unix epoch,
+    i.e., since 1970-01-01 00:00:00 UTC.  An easy way to convert to
+    this format is <literal>date +%s -d "<replaceable>date
+    specification</replaceable>"</literal>.</para>
+
+    <para>For directories, the last-accessed time is the highest
+    last-accessed time of any regular file in the directory (or in any
+    of its subdirectories).  That is, the <literal>atime</literal>
+    field maintained by the filesystem is ignored for directories.
+    This is because operations such as rebuilding the
+    <command>locate</command> database tend to update the
+    <literal>atime</literal> values of all directories, so they’re not
+    a useful indicator of whether a package was recently used.</para>
+
+    <para>Note that <command>nix-store --optimise</command> reads all
+    regular files in the Nix store, and so causes all last-accessed
+    times to be set to the present time.  This makes
+    <option>--max-atime</option> ineffective (for a while at
+    least).</para></listitem>
+    
+  </varlistentry>
+
+  <varlistentry><term><option>--use-atime</option></term>
+
+    <listitem><para>Delete store paths in order of ascending
+    last-accessed time.  This is useful in conjunction with the other
+    options to delete only the least recently used
+    packages.</para></listitem>
+
+  </varlistentry>
+  
 </variablelist>
 
 </para>
@@ -320,6 +357,13 @@ deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv'
 
 </para>
 
+<para>To delete unreachable paths not accessed in the last two months:
+
+<screen>
+$ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")</screen>
+
+</para>
+
 <para>To delete at least 100 MiBs of unreachable paths:
 
 <screen>
@@ -342,7 +386,7 @@ $ nix-store --gc --max-freed $((100 * 1024 * 1024))</screen>
 
 <cmdsynopsis>
   <command>nix-store</command>
-  <arg choice='plain'><option>--delete</option></arg>
+  <arg choice='plain'><option>--gc</option></arg>
   <arg><option>--ignore-liveness</option></arg>
   <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
 </cmdsynopsis>
@@ -404,8 +448,6 @@ error: cannot delete path `/nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4'
     <arg choice='plain'><option>--tree</option></arg>
     <arg choice='plain'><option>--binding</option> <replaceable>name</replaceable></arg>
     <arg choice='plain'><option>--hash</option></arg>
-    <arg choice='plain'><option>--size</option></arg>
-    <arg choice='plain'><option>--roots</option></arg>
   </group>
   <arg><option>--use-output</option></arg>
   <arg><option>-u</option></arg>
@@ -588,29 +630,9 @@ query is applied to the target of the symlink.</para>
   <varlistentry><term><option>--hash</option></term>
   
     <listitem><para>Prints the SHA-256 hash of the contents of the
-    store paths <replaceable>paths</replaceable> (that is, the hash of
-    the output of <command>nix-store --dump</command> on the given
-    paths).  Since the hash is stored in the Nix database, this is a
-    fast operation.</para></listitem>
-
-  </varlistentry>
-
-  <varlistentry><term><option>--size</option></term>
-  
-    <listitem><para>Prints the size in bytes of the contents of the
-    store paths <replaceable>paths</replaceable> — to be precise, the
-    size of the output of <command>nix-store --dump</command> on the
-    given paths.  Note that the actual disk space required by the
-    store paths may be higher, especially on filesystems with large
-    cluster sizes.</para></listitem>
-
-  </varlistentry>
-
-  <varlistentry><term><option>--roots</option></term>
-  
-    <listitem><para>Prints the garbage collector roots that point,
-    directly or indirectly, at the store paths
-    <replaceable>paths</replaceable>.</para></listitem>
+    store path <replaceable>paths</replaceable>.  Since the hash is
+    stored in the Nix database, this is a fast
+    operation.</para></listitem>
 
   </varlistentry>
 
@@ -691,18 +713,6 @@ $ gv graph.ps</screen>
 
 </para>
 
-<para>Show every garbage collector root that points to a store path
-that depends on <command>svn</command>:
-
-<screen>
-$ nix-store -q --roots $(which svn)
-/nix/var/nix/profiles/default-81-link
-/nix/var/nix/profiles/default-82-link
-/nix/var/nix/profiles/per-user/eelco/profile-97-link
-</screen>
-
-</para>
-
 </refsection>
 
 

doc/manual/nix-worker.xml

@@ -1,7 +1,6 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-nix-worker">
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
 <refmeta>
   <refentrytitle>nix-worker</refentrytitle>

doc/manual/opt-common-syn.xml

@@ -13,10 +13,6 @@
   </group>
   <replaceable>number</replaceable>
 </arg>
-<arg>
-  <arg><option>--cores</option></arg>
-  <replaceable>number</replaceable>
-</arg>
 <arg>
   <arg><option>--max-silent-time</option></arg>
   <replaceable>number</replaceable>
@@ -28,7 +24,6 @@
 <arg><option>--fallback</option></arg>
 <arg><option>--readonly-mode</option></arg>
 <arg><option>--log-type</option> <replaceable>type</replaceable></arg>
-<arg><option>--show-trace</option></arg>
 <sbr />
 
 </nop>

doc/manual/opt-common.xml

@@ -98,25 +98,7 @@
   linkend='conf-build-max-jobs'><literal>build-max-jobs</literal></link>
   configuration setting, which itself defaults to
   <literal>1</literal>.  A higher value is useful on SMP systems or to
-  exploit I/O latency.</para></listitem>
-  
-</varlistentry>
-
-
-<varlistentry xml:id="opt-cores"><term><option>--cores</option></term>
-
-  <listitem><para>Sets the value of the <envar>NIX_BUILD_CORES</envar>
-  environment variable in the invocation of builders.  Builders can
-  use this variable at their discretion to control the maximum amount
-  of parallelism.  For instance, in Nixpkgs, if the derivation
-  attribute <varname>enableParallelBuilding</varname> is set to
-  <literal>true</literal>, the builder passes the
-  <option>-j<replaceable>N</replaceable></option> flag to GNU Make.
-  It defaults to the value of the <link
-  linkend='conf-build-cores'><literal>build-cores</literal></link>
-  configuration setting, if set, or <literal>1</literal> otherwise.
-  The value <literal>0</literal> means that the builder should use all
-  available CPU cores in the system.</para></listitem>
+  exploit I/O latency.  </para></listitem>
   
 </varlistentry>
 
@@ -269,14 +251,14 @@
 
 <programlisting>
 { # The system (e.g., `i686-linux') for which to build the packages.
-  system ? builtins.currentSystem
+  system ? __currentSystem
   <replaceable>...</replaceable>
 }: <replaceable>...</replaceable></programlisting>
 
   So if you call this Nix expression (e.g., when you do
   <literal>nix-env -i <replaceable>pkgname</replaceable></literal>),
   the function will be called automatically using the value <link
-  linkend='builtin-currentSystem'><literal>builtins.currentSystem</literal></link>
+  linkend='builtin-currentSystem'><literal>__currentSystem</literal></link>
   for the <literal>system</literal> argument.  You can override this
   using <option>--arg</option>, e.g., <literal>nix-env -i
   <replaceable>pkgname</replaceable> --arg system
@@ -323,14 +305,6 @@
 </varlistentry>
 
 
-<varlistentry><term><option>--show-trace</option></term>
-  
-  <listitem><para>Causes Nix to print out a stack trace in case of Nix
-  expression evaluation errors.</para></listitem>
-  
-</varlistentry>
-
-
 </variablelist>
 
 

doc/manual/package-management.xml

@@ -38,7 +38,7 @@ to end-user applications like Mozilla Firefox.  (Nix is however not
 tied to the Nix Package collection; you could write your own Nix
 expressions based on it, or completely new ones.)  You can download
 the latest version from <link
-xlink:href='http://nixos.org/nixpkgs/download.html' />.</para>
+xlink:href='http://nixos.org/releases/full-index-nixpkgs.html' />.</para>
 
 <para>Assuming that you have downloaded and unpacked a release of Nix
 Packages, you can view the set of available packages in the release:
@@ -331,7 +331,7 @@ default profile, respectively.  If the profile doesn’t exist, it will
 be created automatically.  You should be careful about storing a
 profile in another location than the <filename>profiles</filename>
 directory, since otherwise it might not be used as a root of the
-garbage collector (see <xref linkend='sec-garbage-collection'
+garbage collector (see section <xref linkend='sec-garbage-collection'
 />).</para>
 
 <para>All <command>nix-env</command> operations work on the profile
@@ -496,7 +496,7 @@ available in the subscribed channels.</para>
 
 <para>Often, when you want to install a specific package (e.g., from
 the <link
-xlink:href="http://nixos.org/nixpkgs/">Nix
+xlink:href="http://nixos.org/releases/nixpkgs/nixpkgs-unstable/">Nix
 Packages collection</link>), subscribing to a channel is a bit
 cumbersome.  And channels don’t help you at all if you want to install
 an older version of a package than the one provided by the current
@@ -507,16 +507,19 @@ click on it, and it will be installed with all the necessary
 dependencies.</para>
 
 <para>For instance, you can go to <link
-xlink:href="http://hydra.nixos.org/jobset/nixpkgs/trunk/channel/latest"
-/> and click on any link for the individual packages for your
-platform.  The first time you do this, your browser will ask what to
-do with <literal>application/nix-package</literal> files.  You should
-open them with <filename>/nix/bin/nix-install-package</filename>.
-This will open a window that asks you to confirm that you want to
-install the package.  When you answer <literal>Y</literal>, the
-package and all its dependencies will be installed.  This is a binary
-deployment mechanism — you get packages pre-compiled for the selected
-platform type.</para>
+xlink:href="http://nixos.org/releases/nixpkgs/nixpkgs-unstable/" /> —
+or to any older release of Nix Packages — and click on any link for
+the individual packages for your platform (say, <link
+xlink:href='http://nix.cs.uu.nl/dist/nix/nixpkgs-0.10pre6622/pkgs/subversion-1.4.0-i686-linux.nixpkg'><literal>subversion-1.4.0</literal>
+for <literal>i686-linux</literal></link>).  The first time you do
+this, your browser will ask what to do with
+<literal>application/nix-package</literal> files.  You should open
+them with <filename>/nix/bin/nix-install-package</filename>.  This
+will open a window that asks you to confirm that you want to install
+the package.  When you answer <literal>Y</literal>, the package and
+all its dependencies will be installed.  This is a binary deployment
+mechanism — you get packages pre-compiled for the selected platform
+type.</para>
 
 <para>You can also install <literal>application/nix-package</literal>
 files from the command line directly.  See <xref

doc/manual/quick-start.xml

@@ -1,6 +1,5 @@
 <chapter xmlns="http://docbook.org/ns/docbook"
-         xmlns:xlink="http://www.w3.org/1999/xlink"
-         xml:id="chap-quick-start">
+         xmlns:xlink="http://www.w3.org/1999/xlink">
 
 <title>Quick Start</title>
 
@@ -11,9 +10,9 @@ to the following chapters.</para>
 
 <orderedlist>
 
-<listitem><para>Download a source tarball, RPM or Deb from <link
-xlink:href='http://nixos.org/'/>.  Build source distributions using
-the regular sequence:
+<listitem><para>Download a source tarball or RPM from <link
+xlink:href='http://nixos.org/'/>.  Build source
+distributions using the regular sequence:
         
 <screen>
 $ tar xvfj nix-<replaceable>version</replaceable>.tar.bz2
@@ -21,21 +20,13 @@ $ ./configure
 $ make
 $ make install <lineannotation>(as root)</lineannotation></screen>
 
-This will install the Nix binaries in <filename>/usr/local</filename>
-and keep the Nix store and other state in <filename>/nix</filename>.
-You can change the former by specifying
-<option>--prefix=<replaceable>path</replaceable></option>.  The
-location of the store can be changed using
-<option>--with-store-dir=<replaceable>path</replaceable></option>.
-However, you shouldn't change the store location, if at all possible,
-since that will make it impossible to use pre-built binaries from the
-Nixpkgs channel and other channels.  The location of the state can be
-changed using
-<option>--localstatedir=<replaceable>path</replaceable>.</option></para></listitem>
-
-<listitem><para>You should add
-<filename><replaceable>prefix</replaceable>/etc/profile.d/nix.sh</filename>
-to your <filename>~/.bashrc</filename> (or some other login
+This will install Nix in <filename>/nix</filename>.  You shouldn't
+change the prefix if at all possible since that will make it
+impossible to use pre-built binaries from the Nixpkgs channel and
+other channels.  Alternatively, you could grab an RPM if you're on an
+RPM-based system.  You should also add
+<filename>/nix/etc/profile.d/nix.sh</filename> to your
+<filename>~/.bashrc</filename> (or some other login
 file).</para></listitem>
 
 <listitem><para>Subscribe to the Nix Packages channel.
@@ -60,7 +51,7 @@ available remotely.</para></listitem>
 in the channel:
 
 <screen>
-$ nix-env -qa \*
+$ nix-env -qa ’*’ <lineannotation>(mind the quotes!)</lineannotation>
 docbook-xml-4.2
 firefox-1.0pre-PR-0.10.1
 hello-2.1.1
@@ -108,7 +99,7 @@ numbers).</para></listitem>
 
 <listitem><para>You can also install specific packages directly from
 your web browser.  For instance, you can go to <link
-xlink:href="http://hydra.nixos.org/jobset/nixpkgs/trunk/channel/latest" />
+xlink:href="http://nix.cs.uu.nl/dist/nix/nixpkgs-unstable-latest/" />
 and click on any link for the individual packages for your platform.
 Associate <literal>application/nix-package</literal> with the program
 <filename>/nix/bin/nix-install-package</filename>.  A window should

doc/manual/release-notes.xml

@@ -6,241 +6,6 @@
 
 
 
-<!--==================================================================-->
-
-<section xml:id="ssec-relnotes-1.0"><title>Release 1.0 (TBA)</title>
-
-<para>This release has the following improvements:</para>
-
-<itemizedlist>
-
-  <listitem>
-    <para>Nix can now optionally use the Boehm garbage collector.
-    This significantly reduces the Nix evaluator’s memory footprint,
-    especially when evaluating large NixOS system configurations.  It
-    can be enabled using the <option>--enable-gc</option> configure
-    option.</para>
-  </listitem>
-
-</itemizedlist>
-
-</section>
-
-
-<!--==================================================================-->
-
-<section xml:id="ssec-relnotes-0.16"><title>Release 0.16 (August 17, 2010)</title>
-
-<para>This release has the following improvements:</para>
-
-<itemizedlist>
-
-  <listitem>
-    <para>The Nix expression evaluator is now much faster in most
-    cases: typically, <link
-    xlink:href="http://www.mail-archive.com/nix-dev@cs.uu.nl/msg04113.html">3
-    to 8 times compared to the old implementation</link>.  It also
-    uses less memory.  It no longer depends on the ATerm
-    library.</para>
-  </listitem>
-
-  <listitem>
-    <para>
-      Support for configurable parallelism inside builders.  Build
-      scripts have always had the ability to perform multiple build
-      actions in parallel (for instance, by running <command>make -j
-      2</command>), but this was not desirable because the number of
-      actions to be performed in parallel was not configurable.  Nix
-      now has an option <option>--cores
-      <replaceable>N</replaceable></option> as well as a configuration
-      setting <varname>build-cores =
-      <replaceable>N</replaceable></varname> that causes the
-      environment variable <envar>NIX_BUILD_CORES</envar> to be set to
-      <replaceable>N</replaceable> when the builder is invoked.  The
-      builder can use this at its discretion to perform a parallel
-      build, e.g., by calling <command>make -j
-      <replaceable>N</replaceable></command>.  In Nixpkgs, this can be
-      enabled on a per-package basis by setting the derivation
-      attribute <varname>enableParallelBuilding</varname> to
-      <literal>true</literal>.
-    </para>
-  </listitem>
-
-  <listitem>
-    <para><command>nix-store -q</command> now supports XML output
-    through the <option>--xml</option> flag.</para>
-  </listitem>
-
-  <listitem>
-    <para>Several bug fixes.</para>
-  </listitem>
-
-</itemizedlist>
-
-</section>
-
-
-<!--==================================================================-->
-
-<section xml:id="ssec-relnotes-0.15"><title>Release 0.15 (March 17, 2010)</title>
-
-<para>This is a bug-fix release.  Among other things, it fixes
-building on Mac OS X (Snow Leopard), and improves the contents of
-<filename>/etc/passwd</filename> and <filename>/etc/group</filename>
-in <literal>chroot</literal> builds.</para>
-
-</section>
-
-
-<!--==================================================================-->
-
-<section xml:id="ssec-relnotes-0.14"><title>Release 0.14 (February 4, 2010)</title>
-
-<para>This release has the following improvements:</para>
-
-<itemizedlist>
-
-  <listitem>
-    <para>The garbage collector now starts deleting garbage much
-    faster than before.  It no longer determines liveness of all paths
-    in the store, but does so on demand.</para>
-  </listitem>
-
-  <listitem>
-    <para>Added a new operation, <command>nix-store --query
-    --roots</command>, that shows the garbage collector roots that
-    directly or indirectly point to the given store paths.</para>
-  </listitem>
-
-  <listitem>
-    <para>Removed support for converting Berkeley DB-based Nix
-    databases to the new schema.</para>
-  </listitem>
-
-  <listitem>
-    <para>Removed the <option>--use-atime</option> and
-    <option>--max-atime</option> garbage collector options.  They were
-    not very useful in practice.</para>
-  </listitem>
-
-  <listitem>
-    <para>On Windows, Nix now requires Cygwin 1.7.x.</para>
-  </listitem>
-
-  <listitem>
-    <para>A few bug fixes.</para>
-  </listitem>
-
-</itemizedlist>
-
-</section>
-
-
-<!--==================================================================-->
-
-<section xml:id="ssec-relnotes-0.13"><title>Release 0.13 (November 5,
-2009)</title>
-
-<para>This is primarily a bug fix release.  It has some new
-features:</para>
-
-<itemizedlist>
-
-  <listitem>
-    <para>Syntactic sugar for writing nested attribute sets.  Instead of
-
-<programlisting>
-{
-  foo = {
-    bar = 123;
-    xyzzy = true;
-  };
-  a = { b = { c = "d"; }; };
-}
-</programlisting>
-
-    you can write
-
-<programlisting>
-{
-  foo.bar = 123;
-  foo.xyzzy = true;
-  a.b.c = "d";
-}
-</programlisting>
-
-    This is useful, for instance, in NixOS configuration files.</para>
-    
-  </listitem>
-
-  <listitem>
-    <para>Support for Nix channels generated by Hydra, the Nix-based
-    continuous build system.  (Hydra generates NAR archives on the
-    fly, so the size and hash of these archives isn’t known in
-    advance.)</para>
-  </listitem>
-
-  <listitem>
-    <para>Support <literal>i686-linux</literal> builds directly on
-    <literal>x86_64-linux</literal> Nix installations.  This is
-    implemented using the <function>personality()</function> syscall,
-    which causes <command>uname</command> to return
-    <literal>i686</literal> in child processes.</para>
-  </listitem>
-  
-  <listitem>
-    <para>Various improvements to the <literal>chroot</literal>
-    support.  Building in a <literal>chroot</literal> works quite well
-    now.</para>
-  </listitem>
-
-  <listitem>
-    <para>Nix no longer blocks if it tries to build a path and another
-    process is already building the same path.  Instead it tries to
-    build another buildable path first.  This improves
-    parallelism.</para>
-  </listitem>
-
-  <listitem>
-    <para>Support for large (> 4 GiB) files in NAR archives.</para>
-  </listitem>
-    
-  <listitem>
-    <para>Various (performance) improvements to the remote build
-    mechanism.</para>
-  </listitem>
-    
-  <listitem>
-    <para>New primops: <varname>builtins.addErrorContext</varname> (to
-    add a string to stack traces — useful for debugging),
-    <varname>builtins.isBool</varname>,
-    <varname>builtins.isString</varname>,
-    <varname>builtins.isInt</varname>,
-    <varname>builtins.intersectAttrs</varname>.</para>
-  </listitem>
-
-  <listitem>
-    <para>OpenSolaris support (Sander van der Burg).</para>
-  </listitem>
-
-  <listitem>
-    <para>Stack traces are no longer displayed unless the
-    <option>--show-trace</option> option is used.</para>
-  </listitem>
-
-  <listitem>
-    <para>The scoping rules for <literal>inherit
-    (<replaceable>e</replaceable>) ...</literal> in recursive
-    attribute sets have changed.  The expression
-    <replaceable>e</replaceable> can now refer to the attributes
-    defined in the containing set.</para>
-  </listitem>
-
-</itemizedlist>
-
-</section>
-
-
 <!--==================================================================-->
 
 <section xml:id="ssec-relnotes-0.12"><title>Release 0.12 (November 20,

doc/manual/writing-nix-expressions.xml

@@ -1106,7 +1106,7 @@ used in the Nix expression for Subversion.</para>
     incompatibility might occur.</para>
   </callout>
 
-  <callout arearefs='ex-subversion-nix-co-3'>
+  <callout arearefs='ex-subversion-nix-co-2'>
     <para>This assertion says that in order for Subversion to have SSL
     support (so that it can access <literal>https</literal> URLs), an
     OpenSSL library must be passed.  Additionally, it says that
@@ -1432,7 +1432,7 @@ command-line argument.  See <xref linkend='sec-standard-environment'
   inputs.</para></listitem>
 
   <listitem><para>After the build, Nix sets the last-modified
-  timestamp on all files in the build result to 1 (00:00:01 1/1/1970
+  timestamp on all files in the build result to 0 (00:00:00 1/1/1970
   UTC), sets the group to the default group, and sets the mode of the
   file to 0444 or 0555 (i.e., read-only, with execute permission
   enabled if the file was originally executable).  Note that possible

externals/Makefile.am

@@ -1,3 +1,78 @@
+# Berkeley DB
+
+DB = db-4.5.20
+
+if OLD_DB_COMPAT
+
+$(DB).tar.gz:
+	@echo "Nix requires Berkeley DB to build."
+	@echo "Please download version 4.5.20 from"
+	@echo "  http://download-east.oracle.com/berkeley-db/db-4.5.20.tar.gz"
+	@echo "and place it in the externals/ directory."
+	false
+
+$(DB): $(DB).tar.gz
+	gunzip < $(srcdir)/$(DB).tar.gz | tar xvf -
+	(cd $(DB) && $(patch) -p1) < $(srcdir)/bdb-cygwin.patch
+
+have-db:
+	$(MAKE) $(DB)
+	touch have-db
+
+if HAVE_BDB
+build-db:
+else
+build-db: have-db
+	(pfx=`pwd` && \
+	cd $(DB)/build_unix && \
+	CC="$(CC)" CXX="$(CXX)" CFLAGS="$(CFLAGS)" CXXFLAGS="$(CXXFLAGS)" \
+	 ../dist/configure --prefix=$$pfx/inst-bdb \
+	 --enable-cxx --disable-shared --disable-cryptography \
+         --disable-replication --disable-verify && \
+	$(MAKE) && \
+	$(MAKE) install_include install_lib)
+	touch build-db
+endif
+
+else
+
+build-db:
+
+endif
+
+
+# CWI ATerm
+
+ATERM = aterm-2.4.2-fixes-r2
+
+$(ATERM).tar.bz2:
+	@echo "Nix requires the CWI ATerm library to build."
+	@echo "Please download version 2.4.2-fixes-r2 from"
+	@echo "  http://losser.st-lab.cs.uu.nl/~eelco/dist/aterm-2.4.2-fixes-r2.tar.bz2"
+	@echo "and place it in the externals/ directory."
+	false
+
+$(ATERM): $(ATERM).tar.bz2
+	bunzip2 < $(srcdir)/$(ATERM).tar.bz2 | tar xvf -
+
+have-aterm:
+	$(MAKE) $(ATERM)
+	touch have-aterm
+
+if HAVE_ATERM
+build-aterm:
+else
+build-aterm: have-aterm
+	(pfx=`pwd` && \
+	cd $(ATERM) && \
+	CC="$(CC)" ./configure --prefix=$$pfx/inst-aterm \
+	  --disable-shared --enable-static && \
+	$(MAKE) && \
+	$(MAKE) install)
+	touch build-aterm
+endif
+
+
 # bzip2
 
 BZIP2 = bzip2-1.0.5
@@ -12,56 +87,31 @@ $(BZIP2).tar.gz:
 $(BZIP2): $(BZIP2).tar.gz
 	gunzip < $(srcdir)/$(BZIP2).tar.gz | tar xvf -
 
+have-bzip2:
+	$(MAKE) $(BZIP2)
+	touch have-bzip2
+
 if HAVE_BZIP2
 build-bzip2:
 else
-build-bzip2: $(BZIP2)
-	(cd $(BZIP2) && \
-	$(MAKE) CC="$(CC)" && \
-	$(MAKE) install PREFIX=$(abs_builddir)/inst-bzip2)
+build-bzip2: have-bzip2
+	(pfx=`pwd` && \
+	cd $(BZIP2) && \
+	$(MAKE) && \
+	$(MAKE) install PREFIX=$$pfx/inst-bzip2)
 	touch build-bzip2
 
-install-exec-local:: build-bzip2
+install:
 	mkdir -p $(DESTDIR)${bzip2_bin}
 	$(INSTALL_PROGRAM) $(bzip2_bin_test)/bzip2 $(bzip2_bin_test)/bunzip2 $(DESTDIR)${bzip2_bin}
 endif
 
 
-# SQLite
+all: build-db build-aterm build-bzip2
 
-SQLITE = sqlite-autoconf-$(SQLITE_VERSION)
-SQLITE_TAR = sqlite-autoconf-$(SQLITE_VERSION).tar.gz
+EXTRA_DIST = $(DB).tar.gz $(ATERM).tar.bz2 $(BZIP2).tar.gz \
+  bdb-cygwin.patch
 
-$(SQLITE_TAR):
-	@echo "Nix requires the SQLite library to build."
-	@echo "Please download version $(SQLITE_VERSION) from"
-	@echo "  http://www.sqlite.org/$(SQLITE_TAR)"
-	@echo "and place it in the externals/ directory."
-	false
-
-$(SQLITE): $(SQLITE_TAR)
-	gzip -d < $(srcdir)/$(SQLITE_TAR) | tar xvf -
-
-if HAVE_SQLITE
-build-sqlite:
-else
-build-sqlite: $(SQLITE)
-	(cd $(SQLITE) && \
-	CC="$(CC)" CFLAGS="-DSQLITE_ENABLE_COLUMN_METADATA=1" ./configure --disable-static --prefix=$(pkglibdir)/dummy --libdir=${pkglibdir} $(SUB_CONFIGURE_FLAGS) && \
-	$(MAKE) )
-	touch build-sqlite
-
-install-exec-local:: build-sqlite
-	cd $(SQLITE) && $(MAKE) install
-	rm -rf "$(DESTDIR)/$(pkglibdir)/dummy"
-endif
-
-
-all: build-bzip2 build-sqlite
-
-EXTRA_DIST = $(BZIP2).tar.gz $(SQLITE_TAR)
-
-clean:
-	$(RM) -f build-bzip2 build-sqlite
-	$(RM) -rf $(BZIP2) $(SQLITE)
-	$(RM) -rf inst-bzip2
+ext-clean:
+	$(RM) -f have-db build-db have-aterm build-aterm have-bzip2 build-bzip2
+	$(RM) -rf $(DB) $(ATERM) $(BZIP2)

externals/bdb-cygwin.patch

@@ -0,0 +1,22 @@
+diff -rc db-4.5.20-orig/os/os_flock.c db-4.5.20/os/os_flock.c
+*** db-4.5.20-orig/os/os_flock.c	2006-10-13 12:36:12.000000000 +0200
+--- db-4.5.20/os/os_flock.c	2006-10-13 12:40:11.000000000 +0200
+***************
+*** 30,35 ****
+--- 30,44 ----
+  
+  	DB_ASSERT(dbenv, F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
+  
++ #ifdef __CYGWIN__
++ 	/*
++ 	 * Windows file locking interferes with read/write operations, so we
++ 	 * map the ranges to an area past the end of the file.
++ 	 */
++ 	DB_ASSERT(dbenv, offset < (off_t) 1 << 62);
++ 	offset += (off_t) 1 << 62;
++ #endif
++ 
+  	fl.l_start = offset;
+  	fl.l_len = 1;
+  	fl.l_type = acquire ? F_WRLCK : F_UNLCK;
+Only in db-4.5.20/os: os_flock.c~

misc/emacs/nix-mode.el

@@ -76,10 +76,10 @@ The hook `nix-mode-hook' is run when Nix mode is started.
     ("\\<baseNameOf\\>" . font-lock-builtin-face)
     ("\\<toString\\>" . font-lock-builtin-face)
     ("\\<isNull\\>" . font-lock-builtin-face)
+    ("\\<\\([a-zA-Z_][a-zA-Z0-9_']*\\)[ \t]*="
+     (1 font-lock-variable-name-face nil nil))
     ("[a-zA-Z][a-zA-Z0-9\\+-\\.]*:[a-zA-Z0-9%/\\?:@&=\\+\\$,_\\.!~\\*'-]+"
      . font-lock-constant-face)
-    ("\\<\\([a-zA-Z_][a-zA-Z0-9_'\.]*\\)[ \t]*="
-     (1 font-lock-variable-name-face nil nil))
     ("[a-zA-Z0-9._\\+-]*\\(/[a-zA-Z0-9._\\+-]+\\)+"
      . font-lock-constant-face)
     ))

misc/vim/syntax/nix.vim

@@ -21,14 +21,12 @@ syn match nixFuncArg "\zs\w\+\ze\s*:"
 syn region nixStringParam start=+\${+ end=+}+
 syn region nixMultiLineComment start=+/\*+ skip=+\\"+ end=+\*/+
 syn match  nixEndOfLineComment "#.*$"
-syn region nixStringIndented start=+''+ skip=+'''\|''${\|"+ end=+''+ contains=nixStringParam
-syn region nixString         start=+"+ skip=+\\"+ end=+"+ contains=nixStringParam
+syn region nixString      start=+"+ skip=+\\"+ end=+"+ contains=nixStringParam
 
 hi def link nixKeyword       Keyword
 hi def link nixConditional   Conditional
 hi def link nixBrace         Special
 hi def link nixString        String
-hi def link nixStringIndented String
 hi def link nixBuiltin       Special
 hi def link nixStringParam   Macro
 hi def link nixMultiLineComment Comment

nix.conf.example

@@ -59,17 +59,6 @@
 #build-max-jobs = 1
 
 
-### Option `build-cores'
-#
-# This option defines the number of CPU cores to utilize in parallel
-# within a build job, i.e. by passing an appropriate `-jN' flag to GNU
-# Make. The default is 1, meaning that parallel building within jobs
-# is disabled.  Passing the special value `0' causes Nix to try and
-# auto-detect the number of available cores on the local host.  This
-# setting can be overridden using the `--cores' command line switch.
-#build-cores = 1
-
-
 ### Option `build-max-silent-time'
 #
 # This option defines the maximum number of seconds that a builder can
@@ -165,17 +154,21 @@
 #build-chroot-dirs = /dev /dev/pts /proc
 
 
-### Option `build-cache-failure'
+### Option `system'
 #
-# If this option is enabled, Nix will do negative caching; that is, it
-# will remember failed builds, and won't attempt to try to build them
-# again if you ask for it.  Negative caching is disabled by default
-# because Nix cannot distinguish between permanent build errors (e.g.,
-# a syntax error in a source file) and transient build errors (e.g., a
-# full disk), as they both cause the builder to return a non-zero exit
-# code.  You can clear the cache by doing `rm -f
-# /nix/var/nix/db/failed/*'.
+# This option specifies the canonical Nix system name of the current
+# installation, such as `i686-linux' or `powerpc-darwin'.  Nix can
+# only build derivations whose `system' attribute equals the value
+# specified here.  In general, it never makes sense to modify this
+# value from its default, since you can use it to `lie' about the
+# platform you are building on (e.g., perform a Mac OS build on a
+# Linux machine; the result would obviously be wrong).  It only makes
+# sense if the Nix binaries can run on multiple platforms, e.g.,
+# `universal binaries' that run on `powerpc-darwin' and `i686-darwin'.
+#
+# It defaults to the canonical Nix system name detected by `configure'
+# at build time.
 #
 # Example:
-#   build-cache-failure = true
-#build-cache-failure = false
+#   system = i686-darwin
+#system =

release.nix

@@ -1,177 +0,0 @@
-{ nixpkgs ? ../nixpkgs
-, nix ? { outPath = ./.; rev = 1234; }
-, officialRelease ? false
-}:
-
-let
-
-  jobs = rec {
-
-
-    tarball =
-      with import nixpkgs {};
-
-      releaseTools.sourceTarball {
-        name = "nix-tarball";
-        version = builtins.readFile ./version;
-        src = nix;
-        inherit officialRelease;
-
-        buildInputs =
-          [ curl bison24 flex2535 perl libxml2 libxslt w3m bzip2
-            tetex dblatex nukeReferences pkgconfig
-          ];
-
-        configureFlags = ''
-          --with-docbook-rng=${docbook5}/xml/rng/docbook
-          --with-docbook-xsl=${docbook5_xsl}/xml/xsl/docbook
-          --with-xml-flags=--nonet
-        '';
-
-        # Include the Bzip2 tarball in the distribution.
-        preConfigure = ''
-          stripHash ${bzip2.src}
-          cp -pv ${bzip2.src} externals/$strippedName
-
-          stripHash ${sqlite.src}
-          cp -pv ${sqlite.src} externals/$strippedName
-
-          # TeX needs a writable font cache.
-          export VARTEXFONTS=$TMPDIR/texfonts
-        '';
-
-        preDist = ''
-          make -C doc/manual install prefix=$out
-          
-          make -C doc/manual manual.pdf prefix=$out
-          cp doc/manual/manual.pdf $out/manual.pdf
-
-          # The PDF containes filenames of included graphics (see
-          # http://www.tug.org/pipermail/pdftex/2007-August/007290.html).
-          # This causes a retained dependency on dblatex, which Hydra
-          # doesn't like (the output of the tarball job is distributed
-          # to Windows and Macs, so there should be no Linux binaries
-          # in the closure).
-          nuke-refs $out/manual.pdf
-          
-          echo "doc manual $out/share/doc/nix/manual" >> $out/nix-support/hydra-build-products
-          echo "doc-pdf manual $out/manual.pdf" >> $out/nix-support/hydra-build-products
-          echo "doc release-notes $out/share/doc/nix/release-notes" >> $out/nix-support/hydra-build-products
-        '';
-      };
-
-
-    build =
-      { system ? "i686-linux" }:
-
-      with import nixpkgs { inherit system; };
-
-      releaseTools.nixBuild {
-        name = "nix";
-        src = tarball;
-
-        buildInputs = [ curl perl bzip2 openssl pkgconfig boehmgc ];
-
-        configureFlags = ''
-          --disable-init-state
-          --with-bzip2=${bzip2} --with-sqlite=${sqlite}
-          --enable-gc
-        '';
-      };
-
-
-    coverage =
-      with import nixpkgs { system = "x86_64-linux"; };
-
-      releaseTools.coverageAnalysis {
-        name = "nix-build";
-        src = tarball;
-
-        buildInputs =
-          [ curl perl bzip2 openssl
-            # These are for "make check" only:
-            graphviz libxml2 libxslt
-          ];
-
-        configureFlags = ''
-          --disable-init-state --disable-shared
-          --with-bzip2=${bzip2} --with-sqlite=${sqlite}
-        '';
-
-        lcovFilter = [ "*/boost/*" "*-tab.*" ];
-
-        # We call `dot', and even though we just use it to
-        # syntax-check generated dot files, it still requires some
-        # fonts.  So provide those.
-        FONTCONFIG_FILE = texFunctions.fontsConf;
-      };
-
-      
-    rpm_fedora5i386 = makeRPM_i686 (diskImages: diskImages.fedora5i386) 10;
-    rpm_fedora9i386 = makeRPM_i686 (diskImages: diskImages.fedora9i386) 20;
-    rpm_fedora9x86_64 = makeRPM_x86_64 (diskImages: diskImages.fedora9x86_64) 20;
-    rpm_fedora10i386 = makeRPM_i686 (diskImages: diskImages.fedora10i386) 30;
-    rpm_fedora10x86_64 = makeRPM_x86_64 (diskImages: diskImages.fedora10x86_64) 30;
-    rpm_fedora11i386 = makeRPM_i686 (diskImages: diskImages.fedora11i386) 40;
-    rpm_fedora11x86_64 = makeRPM_x86_64 (diskImages: diskImages.fedora11x86_64) 40;
-    rpm_fedora12i386 = makeRPM_i686 (diskImages: diskImages.fedora12i386) 50;
-    rpm_fedora12x86_64 = makeRPM_x86_64 (diskImages: diskImages.fedora12x86_64) 50;
-    rpm_opensuse103i386 = makeRPM_i686 (diskImages: diskImages.opensuse103i386) 40;
-    rpm_opensuse110i386 = makeRPM_i686 (diskImages: diskImages.opensuse110i386) 50;
-    rpm_opensuse110x86_64 = makeRPM_x86_64 (diskImages: diskImages.opensuse110x86_64) 50;
-
-    
-    deb_debian40i386 = makeDeb_i686 (diskImages: diskImages.debian40i386) 40;
-    deb_debian40x86_64 = makeDeb_x86_64 (diskImages: diskImages.debian40x86_64) 40;
-    deb_debian50i386 = makeDeb_i686 (diskImages: diskImages.debian50i386) 50;
-    deb_debian50x86_64 = makeDeb_x86_64 (diskImages: diskImages.debian50x86_64) 50;
-    deb_ubuntu804i386 = makeDeb_i686 (diskImages: diskImages.ubuntu804i386) 20;
-    deb_ubuntu804x86_64 = makeDeb_x86_64 (diskImages: diskImages.ubuntu804x86_64) 20;
-    deb_ubuntu810i386 = makeDeb_i686 (diskImages: diskImages.ubuntu810i386) 30;
-    deb_ubuntu810x86_64 = makeDeb_x86_64 (diskImages: diskImages.ubuntu810x86_64) 30;
-    deb_ubuntu904i386 = makeDeb_i686 (diskImages: diskImages.ubuntu904i386) 40;
-    deb_ubuntu904x86_64 = makeDeb_x86_64 (diskImages: diskImages.ubuntu904x86_64) 40;
-    deb_ubuntu910i386 = makeDeb_i686 (diskImages: diskImages.ubuntu910i386) 50;
-    deb_ubuntu910x86_64 = makeDeb_x86_64 (diskImages: diskImages.ubuntu910x86_64) 50;
-
-
-  };
-
-
-  makeRPM_i686 = makeRPM "i686-linux";
-  makeRPM_x86_64 = makeRPM "x86_64-linux";
-
-  makeRPM = 
-    system: diskImageFun: prio:
-
-    with import nixpkgs { inherit system; };
-
-    releaseTools.rpmBuild rec {
-      name = "nix-rpm-${diskImage.name}";
-      src = jobs.tarball;
-      diskImage = diskImageFun vmTools.diskImages;
-      memSize = 1024;
-      meta.schedulingPriority = prio;
-    };
-
-
-  makeDeb_i686 = makeDeb "i686-linux";
-  makeDeb_x86_64 = makeDeb "x86_64-linux";
-  
-  makeDeb =
-    system: diskImageFun: prio:
-
-    with import nixpkgs { inherit system; };
-
-    releaseTools.debBuild {
-      name = "nix-deb";
-      src = jobs.tarball;
-      diskImage = diskImageFun vmTools.diskImages;
-      memSize = 1024;
-      meta.schedulingPriority = prio;
-      configureFlags = "--sysconfdir=/etc";
-      debRequires = [ "curl" ];
-    };
-
-
-in jobs

scripts/GeneratePatches.pm.in

@@ -1,334 +0,0 @@
-#! @perl@ -w -I@libexecdir@/nix
-
-use strict;
-use File::Temp qw(tempdir);
-
-
-# Some patch generations options.
-
-# Max size of NAR archives to generate patches for.
-my $maxNarSize = $ENV{"NIX_MAX_NAR_SIZE"};
-$maxNarSize = 160 * 1024 * 1024 if !defined $maxNarSize;
-
-# If patch is bigger than this fraction of full archive, reject.
-my $maxPatchFraction = $ENV{"NIX_PATCH_FRACTION"};
-$maxPatchFraction = 0.60 if !defined $maxPatchFraction;
-
-my $timeLimit = $ENV{"NIX_BSDIFF_TIME_LIMIT"};
-$timeLimit = 180 if !defined $timeLimit;
-
-my $hashAlgo = "sha256";
-
-
-sub findOutputPaths {
-    my $narFiles = shift;
-
-    my %outPaths;
-    
-    foreach my $p (keys %{$narFiles}) {
-
-        # Ignore derivations.
-        next if ($p =~ /\.drv$/);
-        
-        # Ignore builders (too much ambiguity -- they're all called
-        # `builder.sh').
-        next if ($p =~ /\.sh$/);
-        next if ($p =~ /\.patch$/);
-        
-        # Don't bother including tar files etc.
-        next if ($p =~ /\.tar$/ || $p =~ /\.tar\.(gz|bz2|Z|lzma|xz)$/ || $p =~ /\.zip$/ || $p =~ /\.bin$/ || $p =~ /\.tgz$/ || $p =~ /\.rpm$/ || $p =~ /cvs-export$/ || $p =~ /fetchhg$/);
-
-        $outPaths{$p} = 1;
-    }
-
-    return %outPaths;
-}
-
-
-sub getNameVersion {
-    my $p = shift;
-    $p =~ /\/[0-9a-z]+((?:-[a-zA-Z][^\/-]*)+)([^\/]*)$/;
-    my $name = $1;
-    my $version = $2;
-    return undef unless defined $name && defined $version;
-    $name =~ s/^-//;
-    $version =~ s/^-//;
-    return ($name, $version);
-}
-
-
-# A quick hack to get a measure of the `distance' between two
-# versions: it's just the position of the first character that differs
-# (or 999 if they are the same).
-sub versionDiff {
-    my $s = shift;
-    my $t = shift;
-    my $i;
-    return 999 if $s eq $t;
-    for ($i = 0; $i < length $s; $i++) {
-        return $i if $i >= length $t or
-            substr($s, $i, 1) ne substr($t, $i, 1);
-    }
-    return $i;
-}
-
-
-sub getNarBz2 {
-    my $narPath = shift;
-    my $narFiles = shift;
-    my $storePath = shift;
-    
-    my $narFileList = $$narFiles{$storePath};
-    die "missing path $storePath" unless defined $narFileList;
-
-    my $narFile = @{$narFileList}[0];
-    die unless defined $narFile;
-
-    $narFile->{url} =~ /\/([^\/]+)$/;
-    die unless defined $1;
-    return "$narPath/$1";
-}
-
-
-sub containsPatch {
-    my $patches = shift;
-    my $storePath = shift;
-    my $basePath = shift;
-    my $patchList = $$patches{$storePath};
-    return 0 if !defined $patchList;
-    my $found = 0;
-    foreach my $patch (@{$patchList}) {
-        # !!! baseHash might differ
-        return 1 if $patch->{basePath} eq $basePath;
-    }
-    return 0;
-}
-
-
-sub generatePatches {
-    my ($srcNarFiles, $dstNarFiles, $srcPatches, $dstPatches, $narPath, $patchesPath, $patchesURL, $tmpDir) = @_;
-
-    my %srcOutPaths = findOutputPaths $srcNarFiles;
-    my %dstOutPaths = findOutputPaths $dstNarFiles;
-
-    # For each output path in the destination, see if we need to / can
-    # create a patch.
-
-    print STDERR "creating patches...\n";
-
-    foreach my $p (keys %dstOutPaths) {
-
-        # If exactly the same path already exists in the source, skip it.
-        next if defined $srcOutPaths{$p};
-    
-        print "  $p\n";
-
-        # If not, then we should find the paths in the source that are
-        # `most' likely to be present on a system that wants to
-        # install this path.
-
-        (my $name, my $version) = getNameVersion $p;
-        next unless defined $name && defined $version;
-
-        my @closest = ();
-        my $closestVersion;
-        my $minDist = -1; # actually, larger means closer
-
-        # Find all source paths with the same name.
-
-        foreach my $q (keys %srcOutPaths) {
-            (my $name2, my $version2) = getNameVersion $q;
-            next unless defined $name2 && defined $version2;
-
-            if ($name eq $name2) {
-
-                my $srcSystem = @{$$dstNarFiles{$p}}[0]->{system};
-                my $dstSystem = @{$$srcNarFiles{$q}}[0]->{system};
-                if (defined $srcSystem && defined $dstSystem && $srcSystem ne $dstSystem) {
-                    print "    SKIPPING $q due to different systems ($srcSystem vs. $dstSystem)\n";
-                    next;
-                }
-
-                # If the sizes differ too much, then skip.  This
-                # disambiguates between, e.g., a real component and a
-                # wrapper component (cf. Firefox in Nixpkgs).
-                my $srcSize = @{$$srcNarFiles{$q}}[0]->{size};
-                my $dstSize = @{$$dstNarFiles{$p}}[0]->{size};
-                my $ratio = $srcSize / $dstSize;
-                $ratio = 1 / $ratio if $ratio < 1;
-                # print "  SIZE $srcSize $dstSize $ratio $q\n";
-
-                if ($ratio >= 3) {
-                    print "    SKIPPING $q due to size ratio $ratio ($srcSize vs. $dstSize)\n";
-                    next;
-                }
-
-                # If there are multiple matching names, include the
-                # ones with the closest version numbers.
-                my $dist = versionDiff $version, $version2;
-                if ($dist > $minDist) {
-                    $minDist = $dist;
-                    @closest = ($q);
-                    $closestVersion = $version2;
-                } elsif ($dist == $minDist) {
-                    push @closest, $q;
-                }
-            }
-        }
-
-        if (scalar(@closest) == 0) {
-            print "    NO BASE: $p\n";
-            next;
-        }
-
-        foreach my $closest (@closest) {
-
-            # Generate a patch between $closest and $p.
-            print STDERR "  $p <- $closest\n";
-
-            # If the patch already exists, skip it.
-            if (containsPatch($srcPatches, $p, $closest) ||
-                containsPatch($dstPatches, $p, $closest))
-            {
-                print "    skipping, already exists\n";
-                next;
-            }
-
-            my $srcNarBz2 = getNarBz2 $narPath, $srcNarFiles, $closest;
-            my $dstNarBz2 = getNarBz2 $narPath, $dstNarFiles, $p;
-
-            if (! -f $srcNarBz2) {
-                warn "patch source archive $srcNarBz2 is missing\n";
-                next;
-            }
-
-            system("@bunzip2@ < $srcNarBz2 > $tmpDir/A") == 0
-                or die "cannot unpack $srcNarBz2";
-
-            if ((stat "$tmpDir/A")[7] >= $maxNarSize) {
-                print "    skipping, source is too large\n";
-                next;
-            }
-        
-            system("@bunzip2@ < $dstNarBz2 > $tmpDir/B") == 0
-                or die "cannot unpack $dstNarBz2";
-
-            if ((stat "$tmpDir/B")[7] >= $maxNarSize) {
-                print "    skipping, destination is too large\n";
-                next;
-            }
-        
-            my $time1 = time();
-            my $res = system("ulimit -t $timeLimit; @libexecdir@/bsdiff $tmpDir/A $tmpDir/B $tmpDir/DIFF");
-            my $time2 = time();
-            if ($res) {
-                warn "binary diff computation aborted after ", $time2 - $time1, " seconds\n";
-                next;
-            }
-
-            my $baseHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpDir/A` or die;
-            chomp $baseHash;
-
-            my $narHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpDir/B` or die;
-            chomp $narHash;
-
-            my $narDiffHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpDir/DIFF` or die;
-            chomp $narDiffHash;
-
-            my $narDiffSize = (stat "$tmpDir/DIFF")[7];
-            my $dstNarBz2Size = (stat $dstNarBz2)[7];
-
-            print "    size $narDiffSize; full size $dstNarBz2Size; ", $time2 - $time1, " seconds\n";
-        
-            if ($narDiffSize >= $dstNarBz2Size) {
-                print "    rejecting; patch bigger than full archive\n";
-                next;
-            }
-    
-            if ($narDiffSize / $dstNarBz2Size >= $maxPatchFraction) {
-                print "    rejecting; patch too large relative to full archive\n";
-                next;
-            }
-    
-            my $finalName = "$narDiffHash.nar-bsdiff";
-
-            if (-e "$patchesPath/$finalName") {
-                print "    not copying, already exists\n";
-            }
-
-            else {
-                system("cp '$tmpDir/DIFF' '$patchesPath/$finalName.tmp'") == 0
-                    or die "cannot copy diff";
-                rename("$patchesPath/$finalName.tmp", "$patchesPath/$finalName")
-                    or die "cannot rename $patchesPath/$finalName.tmp";
-            }
-        
-            # Add the patch to the manifest.
-            addPatch $dstPatches, $p,
-                { url => "$patchesURL/$finalName", hash => "$hashAlgo:$narDiffHash"
-                , size => $narDiffSize, basePath => $closest, baseHash => "$hashAlgo:$baseHash"
-                , narHash => "$hashAlgo:$narHash", patchType => "nar-bsdiff"
-                };
-        }
-    }
-}
-
-
-# Propagate useful patches from $srcPatches to $dstPatches.  A patch
-# is useful if it produces either paths in the $dstNarFiles or paths
-# that can be used as the base for other useful patches.
-sub propagatePatches {
-    my ($srcPatches, $dstNarFiles, $dstPatches) = @_;
-
-    print STDERR "propagating patches...\n";
-
-    my $changed;
-    do {
-        # !!! we repeat this to reach the transitive closure; inefficient
-        $changed = 0;
-
-        print STDERR "loop\n";
-
-        my %dstBasePaths;
-        foreach my $q (keys %{$dstPatches}) {
-            foreach my $patch (@{$$dstPatches{$q}}) {
-                $dstBasePaths{$patch->{basePath}} = 1;
-            }
-        }
-
-        foreach my $p (keys %{$srcPatches}) {
-            my $patchList = $$srcPatches{$p};
-
-            my $include = 0;
-
-            # Is path $p included in the destination?  If so, include
-            # patches that produce it.
-            $include = 1 if defined $$dstNarFiles{$p};
-
-            # Is path $p a path that serves as a base for paths in the
-            # destination?  If so, include patches that produce it.
-            # !!! check baseHash
-            $include = 1 if defined $dstBasePaths{$p};
-
-            if ($include) {
-                foreach my $patch (@{$patchList}) {
-                    $changed = 1 if addPatch $dstPatches, $p, $patch;
-                }
-            }
-        
-        }
-    
-    } while $changed;
-}
-
-
-# Add all new patches in $srcPatches to $dstPatches.
-sub copyPatches {
-    my ($srcPatches, $dstPatches) = @_;
-    foreach my $p (keys %{$srcPatches}) {
-        addPatch $dstPatches, $p, $_ foreach @{$$srcPatches{$p}};
-    }
-}
-
-
-return 1;

scripts/Makefile.am

@@ -1,23 +1,22 @@
 bin_SCRIPTS = nix-collect-garbage \
   nix-pull nix-push nix-prefetch-url \
   nix-install-package nix-channel nix-build \
-  nix-copy-closure nix-generate-patches
+  nix-copy-closure 
 
-noinst_SCRIPTS = nix-profile.sh GeneratePatches.pm \
+noinst_SCRIPTS = nix-profile.sh generate-patches.pl \
   find-runtime-roots.pl build-remote.pl nix-reduce-build \
   copy-from-other-stores.pl nix-http-export.cgi
 
-nix-pull nix-push: NixManifest.pm NixConfig.pm download-using-manifests.pl
+nix-pull nix-push: readmanifest.pm readconfig.pm download-using-manifests.pl
 
-install-exec-local: NixManifest.pm GeneratePatches.pm download-using-manifests.pl copy-from-other-stores.pl find-runtime-roots.pl
+install-exec-local: readmanifest.pm download-using-manifests.pl copy-from-other-stores.pl find-runtime-roots.pl
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/profile.d
 	$(INSTALL_PROGRAM) nix-profile.sh $(DESTDIR)$(sysconfdir)/profile.d/nix.sh
 	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix
-	$(INSTALL_DATA) NixManifest.pm $(DESTDIR)$(libexecdir)/nix 
-	$(INSTALL_DATA) NixConfig.pm $(DESTDIR)$(libexecdir)/nix 
-	$(INSTALL_DATA) SSH.pm $(DESTDIR)$(libexecdir)/nix 
-	$(INSTALL_DATA) GeneratePatches.pm $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL_DATA) readmanifest.pm $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL_DATA) readconfig.pm $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL_PROGRAM) find-runtime-roots.pl $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL_PROGRAM) generate-patches.pl $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL_PROGRAM) build-remote.pl $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix/substituters
 	$(INSTALL_PROGRAM) download-using-manifests.pl $(DESTDIR)$(libexecdir)/nix/substituters
@@ -30,16 +29,14 @@ EXTRA_DIST = nix-collect-garbage.in \
   nix-pull.in nix-push.in nix-profile.sh.in \
   nix-prefetch-url.in nix-install-package.in \
   nix-channel.in \
-  NixManifest.pm.in \
-  NixConfig.pm.in \
-  SSH.pm \
-  GeneratePatches.pm.in \
+  readmanifest.pm.in \
+  readconfig.pm.in \
   nix-build.in \
   download-using-manifests.pl.in \
   copy-from-other-stores.pl.in \
+  generate-patches.pl.in \
   nix-copy-closure.in \
   find-runtime-roots.pl.in \
   build-remote.pl.in \
   nix-reduce-build.in \
-  nix-http-export.cgi.in \
-  nix-generate-patches.in
+  nix-http-export.cgi.in 

scripts/SSH.pm

@@ -1,52 +0,0 @@
-use strict;
-use File::Temp qw(tempdir);
-
-our @sshOpts = split ' ', ($ENV{"NIX_SSHOPTS"} or "");
-
-push @sshOpts, "-x";
-
-my $sshStarted = 0;
-my $sshHost;
-
-# Open a master SSH connection to `host', unless there already is a
-# running master connection (as determined by `-O check').
-sub openSSHConnection {
-    my ($host) = @_;
-    die if $sshStarted;
-    $sshHost = $host;
-    return 1 if system("ssh $sshHost @sshOpts -O check 2> /dev/null") == 0;
-
-    my $tmpDir = tempdir("nix-ssh.XXXXXX", CLEANUP => 1, TMPDIR => 1)
-        or die "cannot create a temporary directory";
-    
-    push @sshOpts, "-S", "$tmpDir/control";
-
-    # Start the master.  We can't use the `-f' flag (fork into
-    # background after establishing the connection) because then the
-    # child continues to run if we are killed.  So instead make SSH
-    # print "started" when it has established the connection, and wait
-    # until we see that.
-    open SSHPIPE, "ssh $sshHost @sshOpts -M -N -o LocalCommand='echo started' -o PermitLocalCommand=yes |" or die;
-
-    while (<SSHPIPE>) {
-        chomp;
-        if ($_ eq "started") {
-            $sshStarted = 1;
-            return 1;
-        }
-    }
-
-    return 0;
-}
-
-# Tell the master SSH client to exit.
-sub closeSSHConnection {
-    if ($sshStarted) {
-        system("ssh $sshHost @sshOpts -O exit 2> /dev/null") == 0
-            or warn "unable to stop SSH master: $?";
-    }
-}
-
-END { my $saved = $?; closeSSHConnection; $? = $saved; }
-
-return 1;

scripts/build-remote.pl.in

@@ -1,11 +1,8 @@
-#! @perl@ -w -I@libexecdir@/nix
+#! @perl@ -w
 
+use strict;
 use Fcntl ':flock';
 use English '-no_match_vars';
-use IO::Handle;
-use SSH qw/sshOpts openSSHConnection/;
-no warnings('once');
-
 
 # General operation:
 #
@@ -24,246 +21,188 @@ no warnings('once');
 # The nice thing about this scheme is that if we die prematurely, the
 # locks are released automatically.
 
+my $loadIncreased = 0;
+
+my $amWilling = shift @ARGV;
+my $localSystem = shift @ARGV;
+my $neededSystem = shift @ARGV;
+my $drvPath = shift @ARGV;
+
+sub sendReply {
+    my $reply = shift;
+    open OUT, ">&3" or die;
+    print OUT "$reply\n";
+    close OUT;
+}
+
+sub decline {
+    sendReply "decline";
+    exit 0;
+}
+
+my $currentLoad = $ENV{"NIX_CURRENT_LOAD"};
+decline unless defined $currentLoad;
+mkdir $currentLoad, 0777 or die unless -d $currentLoad;
+
+my $conf = $ENV{"NIX_REMOTE_SYSTEMS"};
+decline if !defined $conf || ! -e $conf;
+
+# Decline if the local system can do the build.
+decline if $amWilling && ($localSystem eq $neededSystem);
+
+
+# Otherwise find a willing remote machine.
+my %machines;
+my %systemTypes;
+my %sshKeys;
+my %maxJobs;
+my %curJobs;
+
+
+# Read the list of machines.
+open CONF, "< $conf" or die;
+
+while (<CONF>) {
+    chomp;
+    s/\#.*$//g;
+    next if /^\s*$/;
+    /^\s*(\S+)\s+(\S+)\s+(\S+)\s+(\d+)\s*$/ or die;
+    $machines{$1} = "";
+    $systemTypes{$1} = $2;
+    $sshKeys{$1} = $3;
+    $maxJobs{$1} = $4;
+}
+
+close CONF;
+
+
+# Acquire the exclusive lock on $currentLoad/main-lock.
+my $mainLock = "$currentLoad/main-lock";
+open MAINLOCK, ">>$mainLock" or die;
+flock(MAINLOCK, LOCK_EX) or die;
+
+
+# Find a suitable system.
+my $rightType = 0;
+my $machine;
+LOOP: foreach my $cur (keys %machines) {
+    if ($neededSystem eq $systemTypes{$cur}) {
+        $rightType = 1;
+
+        # We have a machine of the right type.  Try to get a lock on
+        # one of the machine's lock files.
+        my $slot = 0;
+        while ($slot < $maxJobs{$cur}) {
+            my $slotLock = "$currentLoad/$cur-$slot";
+            open SLOTLOCK, ">>$slotLock" or die;
+            if (flock(SLOTLOCK, LOCK_EX | LOCK_NB)) {
+                $machine = $cur;
+                last LOOP;
+            }                
+            close SLOTLOCK;
+            $slot++;
+        }
+    }
+}
+
+close MAINLOCK;
+
+
+# Didn't find one?
+if (!defined $machine) {
+    if ($rightType) {
+        sendReply "postpone";
+        exit 0;
+    } else {
+        decline;
+    }
+}
+
+# Yes we did, accept.
+sendReply "accept";
+open IN, "<&4" or die;
+my $x = <IN>;
+chomp $x;
+#print "got $x\n";  
+close IN;
+
+if ($x ne "okay") {
+    exit 0;
+}
+
+
+# Do the actual job.
+print "BUILDING REMOTE: $drvPath on $machine\n";
 
 # Make sure that we don't get any SSH passphrase or host key popups -
 # if there is any problem it should fail, not do something
 # interactive.
 $ENV{"DISPLAY"} = "";
-$ENV{"SSH_ASKPASS"} = "";
+$ENV{"SSH_PASSWORD_FILE="} = "";
+$ENV{"SSH_ASKPASS="} = "";
 
+my $sshOpts = "-i $sshKeys{$machine} -x";
 
-sub sendReply {
-    my $reply = shift;
-    print STDERR "# $reply\n";
+# Hack to support Cygwin: if we login without a password, we don't
+# have exactly the same right as when we do.  This causes the
+# Microsoft C compiler to fail with certain flags:
+#
+#   http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=99676
+#
+# So as a workaround, we pass a verbatim password.  ssh tries to makes
+# this very hard; the trick is to make it call SSH_ASKPASS to get the
+# password.  (It only calls this command when there is no controlling
+# terminal, but Nix ensures that is is the case.  When doing this
+# manually, use setsid(1).)
+if ($sshKeys{$machine} =~ /^password:/) {
+    my $passwordFile = $sshKeys{$machine};
+    $passwordFile =~ s/^password://;
+    $sshOpts = "ssh -x";
+    $ENV{"SSH_PASSWORD_FILE"} = $passwordFile;
+    $ENV{"SSH_ASKPASS"} = "/tmp/writepass";
+
+    open WRITEPASS, ">/tmp/writepass" or die;
+    print WRITEPASS "#! /bin/sh\ncat \"\$SSH_PASSWORD_FILE\"";
+    close WRITEPASS;
+    chmod 0755, "/tmp/writepass" or die;
 }
 
-sub all { $_ || return 0 for @_; 1 }
+my $inputs = `cat inputs`; die if ($? != 0);
+$inputs =~ s/\n/ /g;
 
+my $outputs = `cat outputs`; die if ($? != 0);
+$outputs =~ s/\n/ /g;
 
-# Initialisation.
-my $loadIncreased = 0;
-
-my ($localSystem, $maxSilentTime, $printBuildTrace) = @ARGV;
-$maxSilentTime = 0 unless defined $maxSilentTime;
-
-my $currentLoad = $ENV{"NIX_CURRENT_LOAD"};
-my $conf = $ENV{"NIX_REMOTE_SYSTEMS"};
-
-
-sub openSlotLock {
-    my ($machine, $slot) = @_;
-    my $slotLockFn = "$currentLoad/" . (join '+', @{$machine->{systemTypes}}) . "-" . $machine->{hostName} . "-$slot";
-    my $slotLock = new IO::Handle;
-    open $slotLock, ">>$slotLockFn" or die;
-    return $slotLock;
-}
-
-
-# Read the list of machines.
-my @machines;
-if (defined $conf && -e $conf) {
-    open CONF, "< $conf" or die;
-    while (<CONF>) {
-        chomp;
-        s/\#.*$//g;
-        next if /^\s*$/;
-        my @tokens = split /\s/, $_;
-        push @machines,
-            { hostName => $tokens[0]
-            , systemTypes => [ split(/,/, $tokens[1]) ]
-            , sshKeys => $tokens[2]
-            , maxJobs => int($tokens[3])
-            , speedFactor => 1.0 * (defined $tokens[4] ? int($tokens[4]) : 1)
-            , features => [ split(/,/, $tokens[5] || "") ]
-            , enabled => 1
-            };
-    }
-    close CONF;
-}
-
-
-
-# Wait for the calling process to ask us whether we can build some derivation.
-my ($drvPath, $hostName, $slotLock);
-
-REQ: while (1) {
-    $_ = <STDIN> || exit 0;
-    my ($amWilling, $neededSystem);
-    ($amWilling, $neededSystem, $drvPath, $requiredFeatures) = split;
-    my @requiredFeatures = split /,/, $requiredFeatures;
-
-    my $canBuildLocally = $amWilling && ($localSystem eq $neededSystem);
-
-    if (!defined $currentLoad) {
-        sendReply "decline";
-        next;
-    }
-    
-    # Acquire the exclusive lock on $currentLoad/main-lock.
-    mkdir $currentLoad, 0777 or die unless -d $currentLoad;
-    my $mainLock = "$currentLoad/main-lock";
-    open MAINLOCK, ">>$mainLock" or die;
-    flock(MAINLOCK, LOCK_EX) or die;
-    
-    
-    while (1) {
-        # Find all machine that can execute this build, i.e., that
-        # support builds for the given platform and features, and are
-        # not at their job limit.
-        my $rightType = 0;
-        my @available = ();
-        LOOP: foreach my $cur (@machines) {
-            if ($cur->{enabled}
-                && (grep { $neededSystem eq $_ } @{$cur->{systemTypes}})
-                && all(map { my $f = $_; 0 != grep { $f eq $_ } @{$cur->{features}} } @requiredFeatures))
-            {
-                $rightType = 1;
-
-                # We have a machine of the right type.  Determine the load on
-                # the machine.
-                my $slot = 0;
-                my $load = 0;
-                my $free;
-                while ($slot < $cur->{maxJobs}) {
-                    my $slotLock = openSlotLock($cur, $slot);
-                    if (flock($slotLock, LOCK_EX | LOCK_NB)) {
-                        $free = $slot unless defined $free;
-                        flock($slotLock, LOCK_UN) or die;
-                    } else {
-                        $load++;
-                    }
-                    close $slotLock;
-                    $slot++;
-                }
-                
-                push @available, { machine => $cur, load => $load, free => $free }
-                if $load < $cur->{maxJobs};
-            }
-        }
-
-        if (defined $ENV{NIX_DEBUG_HOOK}) {
-            print STDERR "load on " . $_->{machine}->{hostName} . " = " . $_->{load} . "\n"
-                foreach @available;
-        }
-
-
-        # Didn't find any available machine?  Then decline or postpone.
-        if (scalar @available == 0) {
-            # Postpone if we have a machine of the right type, except
-            # if the local system can and wants to do the build.
-            if ($rightType && !$canBuildLocally) {
-                sendReply "postpone";
-            } else {
-                sendReply "decline";                
-            }
-            close MAINLOCK;
-            next REQ;
-        }
-
-
-        # Prioritise the available machines as follows:
-        # - First by load divided by speed factor, rounded to the nearest
-        #   integer.  This causes fast machines to be preferred over slow
-        #   machines with similar loads.
-        # - Then by speed factor.
-        # - Finally by load.
-        sub lf { my $x = shift; return int($x->{load} / $x->{machine}->{speedFactor} + 0.4999); }
-        @available = sort
-            { lf($a) <=> lf($b)
-                  || $b->{machine}->{speedFactor} <=> $a->{machine}->{speedFactor}
-                  || $a->{load} <=> $b->{load}
-            } @available;
-
-
-        # Select the best available machine and lock a free slot.
-        my $selected = $available[0]; 
-        my $machine = $selected->{machine};
-        
-        $slotLock = openSlotLock($machine, $selected->{free});
-        flock($slotLock, LOCK_EX | LOCK_NB) or die;
-        utime undef, undef, $slotLock;
-
-        close MAINLOCK;
-
-
-        # Connect to the selected machine.
-        @sshOpts = ("-i", $machine->{sshKeys}, "-x");
-        $hostName = $machine->{hostName};
-        last REQ if openSSHConnection $hostName;
-    
-        warn "unable to open SSH connection to $hostName, trying other available machines...\n";
-        $machine->{enabled} = 0;
-    }
-}
-
-
-# Tell Nix we've accepted the build.
-sendReply "accept";
-my @inputs = split /\s/, readline(STDIN);
-my @outputs = split /\s/, readline(STDIN);
-
-
-print STDERR "building `$drvPath' on `$hostName'\n";
-print STDERR "@ build-remote $drvPath $hostName\n" if $printBuildTrace;
-
+print "COPYING INPUTS...\n";
 
 my $maybeSign = "";
 $maybeSign = "--sign" if -e "/nix/etc/nix/signing-key.sec";
 
+system("NIX_SSHOPTS=\"$sshOpts\" nix-copy-closure $machine $maybeSign $drvPath $inputs") == 0
+    or die "cannot copy inputs to $machine: $?";
 
-# Register the derivation as a temporary GC root.  Note that $PPID is
-# the PID of the remote SSH process, which, due to the use of a
-# persistant SSH connection, should be the same across all remote
-# command invocations for this session.
-my $rootsDir = "@localstatedir@/nix/gcroots/tmp";
-system("ssh $hostName @sshOpts 'mkdir -m 1777 -p $rootsDir; ln -sfn $drvPath $rootsDir/\$PPID.drv'");
+print "BUILDING...\n";
 
-sub removeRoots {
-    system("ssh $hostName @sshOpts 'rm -f $rootsDir/\$PPID.drv $rootsDir/\$PPID.out'");
-}
+system("ssh $sshOpts $machine 'nix-store -rvvK $drvPath'") == 0
+    or die "remote build on $machine failed: $?";
 
+print "REMOTE BUILD DONE: $drvPath on $machine\n";
 
-# Copy the derivation and its dependencies to the build machine.
-system("NIX_SSHOPTS=\"@sshOpts\" @bindir@/nix-copy-closure $hostName $maybeSign $drvPath @inputs") == 0
-    or die "cannot copy inputs to $hostName: $?";
-
-
-# Perform the build.
-my $buildFlags = "--max-silent-time $maxSilentTime --fallback --add-root $rootsDir/\$PPID.out --option verbosity 0";
-
-# We let the remote side kill its process group when the connection is
-# closed unexpectedly.  This is necessary to ensure that no processes
-# are left running on the remote system if the local Nix process is
-# killed.  (SSH itself doesn't kill child processes if the connection
-# is interrupted unless the `-tt' flag is used to force a pseudo-tty,
-# in which case every child receives SIGHUP; however, `-tt' doesn't
-# work on some platforms when connection sharing is used.)
-pipe STDIN, DUMMY; # make sure we have a readable STDIN
-if (system("ssh $hostName @sshOpts '(read; kill -INT -\$\$) <&0 & nix-store -r $drvPath $buildFlags > /dev/null' 2>&4") != 0) {
-    # Note that if we get exit code 100 from `nix-store -r', it
-    # denotes a permanent build failure (as opposed to an SSH problem
-    # or a temporary Nix problem).  We propagate this to the caller to
-    # allow it to distinguish between transient and permanent
-    # failures.
-    my $res = $? >> 8;
-    print STDERR "build of `$drvPath' on `$hostName' failed with exit code $res\n";
-    removeRoots;
-    exit $res;
-}
-
-#print "build of `$drvPath' on `$hostName' succeeded\n";
-
-
-# Copy the output from the build machine.
-foreach my $output (@outputs) {
+foreach my $output (split '\n', $outputs) {
     my $maybeSignRemote = "";
     $maybeSignRemote = "--sign" if $UID != 0;
     
-    system("ssh $hostName @sshOpts 'nix-store --export $maybeSignRemote $output'" .
-           "| NIX_HELD_LOCKS=$output @bindir@/nix-store --import > /dev/null") == 0
-	or die "cannot copy $output from $hostName: $?";
+    system("ssh $sshOpts $machine 'nix-store --export $maybeSignRemote $output' > dump") == 0
+	or die "cannot copy $output from $machine: $?";
+
+    # This doesn't work yet, since the caller has a lock on the output
+    # path.  We should move towards lock-free invocation of build
+    # hooks and substitutes.
+    #system("nix-store --import < dump") == 0
+    #    or die "cannot import $output: $?";
+
+    # Hack: skip the first 8 bytes (the nix-store --export next
+    # archive marker).  The archive follows.
+    system("(dd bs=1 count=8 of=/dev/null && cat) < dump | nix-store --restore $output") == 0
+	or die "cannot restore $output: $?";
 }
-
-
-# Get rid of the temporary GC roots.
-removeRoots;

scripts/copy-from-other-stores.pl.in

@@ -17,19 +17,25 @@ foreach my $dir (@remoteStoresAll) {
 }
 
 
-$ENV{"NIX_REMOTE"} = "";
-
-
 sub findStorePath {
     my $storePath = shift;
+    
+    my $storePathName = basename $storePath;
+    
     foreach my $store (@remoteStores) {
-        my $sourcePath = "$store/store/" . basename $storePath;
-        next unless -e $sourcePath || -l $sourcePath;
-        $ENV{"NIX_DB_DIR"} = "$store/var/nix/db";
-        return ($store, $sourcePath) if
-            system("@bindir@/nix-store --check-validity $storePath") == 0;
+        # Determine whether $storePath exists by looking for the
+        # existence of the info file, and if so, get store path info
+        # from that file.  This rather breaks abstraction: we should
+        # be using `nix-store' for that.  But right now there is no
+        # good way to tell nix-store to access a store mounted under a
+        # different location (there's $NIX_STORE, but that only works
+        # if the remote store is mounted under its "real" location).
+        my $infoFile = "$store/var/nix/db/info/$storePathName";
+        my $storePath2 = "$store/store/$storePathName";
+        if (-f $infoFile && -e $storePath2) {
+            return ($infoFile, $storePath2);
+        }
     }
-    return undef;
 }
 
 
@@ -40,38 +46,37 @@ if ($ARGV[0] eq "--query") {
 
         if ($cmd eq "have") {
             my $storePath = <STDIN>; chomp $storePath;
-            print STDOUT (defined findStorePath($storePath) ? "1\n" : "0\n");
+            (my $infoFile) = findStorePath $storePath;
+            print STDOUT ($infoFile ? "1\n" : "0\n");
         }
 
         elsif ($cmd eq "info") {
             my $storePath = <STDIN>; chomp $storePath;
-            my ($store, $sourcePath) = findStorePath($storePath);
-            if (!defined $store) {
+            (my $infoFile) = findStorePath $storePath;
+            if (!$infoFile) {
                 print "0\n";
                 next; # not an error
             }
             print "1\n";
 
-            $ENV{"NIX_DB_DIR"} = "$store/var/nix/db";
-            
-            my $deriver = `@bindir@/nix-store --query --deriver $storePath`;
-            die "cannot query deriver of `$storePath'" if $? != 0;
-            chomp $deriver;
-            $deriver = "" if $deriver eq "unknown-deriver";
+            my $deriver = "";
+            my @references = ();
 
-            my @references = split "\n",
-                `@bindir@/nix-store --query --references $storePath`;
-            die "cannot query references of `$storePath'" if $? != 0;
-
-            my $narSize = `@bindir@/nix-store --query --size $storePath`;
-            die "cannot query size of `$storePath'" if $? != 0;
-            chomp $narSize;
+            open INFO, "<$infoFile" or die "cannot read info file $infoFile\n";
+            while (<INFO>) {
+                chomp;
+                /^([\w-]+): (.*)$/ or die "bad info file";
+                my $key = $1;
+                my $value = $2;
+                if ($key eq "Deriver") { $deriver = $value; }
+                elsif ($key eq "References") { @references = split ' ', $value; }
+            }
+            close INFO;
 
             print "$deriver\n";
             print scalar @references, "\n";
             print "$_\n" foreach @references;
-            print "$narSize\n";
-            print "$narSize\n";
+            print "0\n"; # !!! showing size not supported (yet)
         }
 
         else { die "unknown command `$cmd'"; }
@@ -82,8 +87,8 @@ if ($ARGV[0] eq "--query") {
 elsif ($ARGV[0] eq "--substitute") {
     die unless scalar @ARGV == 2;
     my $storePath = $ARGV[1];
-    my ($store, $sourcePath) = findStorePath $storePath;
-    die unless $store;
+    (my $infoFile, my $sourcePath) = findStorePath $storePath;
+    die unless $infoFile;
     print "\n*** Copying `$storePath' from `$sourcePath'\n\n";
     system("$binDir/nix-store --dump $sourcePath | $binDir/nix-store --restore $storePath") == 0
         or die "cannot copy `$sourcePath' to `$storePath'";

scripts/download-using-manifests.pl.in

@@ -1,7 +1,7 @@
 #! @perl@ -w -I@libexecdir@/nix
 
 use strict;
-use NixManifest;
+use readmanifest;
 use POSIX qw(strftime);
 use File::Temp qw(tempdir);
 
@@ -9,13 +9,9 @@ my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
 
 STDOUT->autoflush(1);
 
-my $manifestDir = ($ENV{"NIX_MANIFESTS_DIR"} or "@localstatedir@/nix/manifests");
+my $manifestDir = "@localstatedir@/nix/manifests";
 my $logFile = "@localstatedir@/log/nix/downloads";
 
-# For queries, skip expensive calls to nix-hash etc.  We're just
-# estimating the expected download size.
-my $fast = 1;
-
 
 # Load all manifests.
 my %narFiles;
@@ -23,160 +19,10 @@ my %localPaths;
 my %patches;
 
 for my $manifest (glob "$manifestDir/*.nixmanifest") {
-    my $version = readManifest($manifest, \%narFiles, \%localPaths, \%patches);
-    if ($version < 3) {
+    if (readManifest($manifest, \%narFiles, \%localPaths, \%patches) < 3) {
         print STDERR "you have an old-style manifest `$manifest'; please delete it\n";
         exit 1;
     }
-    if ($version >= 10) {
-        print STDERR "manifest `$manifest' is too new; please delete it or upgrade Nix\n";
-        exit 1;
-    }
-}
-
-
-sub isValidPath {
-    my $p = shift;
-    if ($fast) {
-        return -e $p;
-    } else {
-        return system("$binDir/nix-store --check-validity '$p' 2> /dev/null") == 0;
-    }
-}
-
-
-sub parseHash {
-    my $hash = shift;
-    if ($hash =~ /^(.+):(.+)$/) {
-        return ($1, $2);
-    } else {
-        return ("md5", $hash);
-    }
-}
-
-
-# Compute the most efficient sequence of downloads to produce the
-# given path.
-sub computeSmallestDownload {
-    my $targetPath = shift;
-    
-    # Build a graph of all store paths that might contribute to the
-    # construction of $targetPath, and the special node "start".  The
-    # edges are either patch operations, or downloads of full NAR
-    # files.  The latter edges only occur between "start" and a store
-    # path.
-    my %graph;
-
-    $graph{"start"} = {d => 0, pred => undef, edges => []};
-
-    my @queue = ();
-    my $queueFront = 0;
-    my %done;
-
-    sub addNode {
-        my $graph = shift;
-        my $u = shift;
-        $$graph{$u} = {d => 999999999999, pred => undef, edges => []}
-            unless defined $$graph{$u};
-    }
-
-    sub addEdge {
-        my $graph = shift;
-        my $u = shift;
-        my $v = shift;
-        my $w = shift;
-        my $type = shift;
-        my $info = shift;
-        addNode $graph, $u;
-        push @{$$graph{$u}->{edges}},
-            {weight => $w, start => $u, end => $v, type => $type, info => $info};
-        my $n = scalar @{$$graph{$u}->{edges}};
-    }
-
-    push @queue, $targetPath;
-
-    while ($queueFront < scalar @queue) {
-        my $u = $queue[$queueFront++];
-        next if defined $done{$u};
-        $done{$u} = 1;
-
-        addNode \%graph, $u;
-
-        # If the path already exists, it has distance 0 from the
-        # "start" node.
-        if (isValidPath($u)) {
-            addEdge \%graph, "start", $u, 0, "present", undef;
-        }
-
-        else {
-
-            # Add patch edges.
-            my $patchList = $patches{$u};
-            foreach my $patch (@{$patchList}) {
-                if (isValidPath($patch->{basePath})) {
-                    # !!! this should be cached
-                    my ($baseHashAlgo, $baseHash) = parseHash $patch->{baseHash};
-                    my $format = "--base32";
-                    $format = "" if $baseHashAlgo eq "md5";
-                    my $hash = $fast && $baseHashAlgo eq "sha256"
-                        ? `$binDir/nix-store -q --hash "$patch->{basePath}"`
-                        : `$binDir/nix-hash --type '$baseHashAlgo' $format "$patch->{basePath}"`;
-                    chomp $hash;
-                    $hash =~ s/.*://;
-                    next if $hash ne $baseHash;
-                }
-                push @queue, $patch->{basePath};
-                addEdge \%graph, $patch->{basePath}, $u, $patch->{size}, "patch", $patch;
-            }
-
-            # Add NAR file edges to the start node.
-            my $narFileList = $narFiles{$u};
-            foreach my $narFile (@{$narFileList}) {
-                # !!! how to handle files whose size is not known in advance?
-                # For now, assume some arbitrary size (1 MB).
-                addEdge \%graph, "start", $u, ($narFile->{size} || 1000000), "narfile", $narFile;
-            }
-        }
-    }
-
-
-    # Run Dijkstra's shortest path algorithm to determine the shortest
-    # sequence of download and/or patch actions that will produce
-    # $targetPath.
-
-    my @todo = keys %graph;
-
-    while (scalar @todo > 0) {
-
-        # Remove the closest element from the todo list.
-        # !!! inefficient, use a priority queue
-        @todo = sort { -($graph{$a}->{d} <=> $graph{$b}->{d}) } @todo;
-        my $u = pop @todo;
-
-        my $u_ = $graph{$u};
-
-        foreach my $edge (@{$u_->{edges}}) {
-            my $v_ = $graph{$edge->{end}};
-            if ($v_->{d} > $u_->{d} + $edge->{weight}) {
-                $v_->{d} = $u_->{d} + $edge->{weight};
-                # Store the edge; to edge->start is actually the
-                # predecessor.
-                $v_->{pred} = $edge; 
-            }
-        }
-    }
-
-
-    # Retrieve the shortest path from "start" to $targetPath.
-    my @path = ();
-    my $cur = $targetPath;
-    return () unless defined $graph{$targetPath}->{pred};
-    while ($cur ne "start") {
-        push @path, $graph{$cur}->{pred};
-        $cur = $graph{$cur}->{pred}->{start};
-    }
-
-    return @path;
 }
 
 
@@ -195,7 +41,6 @@ if ($ARGV[0] eq "--query") {
 
         elsif ($cmd eq "info") {
             my $storePath = <STDIN>; chomp $storePath;
-
             my $info;
             if (defined $narFiles{$storePath}) {
                 $info = @{$narFiles{$storePath}}[0];
@@ -207,32 +52,13 @@ if ($ARGV[0] eq "--query") {
                 print "0\n";
                 next; # not an error
             }
-
             print "1\n";
             print "$info->{deriver}\n";
             my @references = split " ", $info->{references};
             print scalar @references, "\n";
             print "$_\n" foreach @references;
-
-            my @path = computeSmallestDownload $storePath;
-            
-            my $downloadSize = 0;
-            while (scalar @path > 0) {
-                my $edge = pop @path;
-                my $u = $edge->{start};
-                my $v = $edge->{end};
-                if ($edge->{type} eq "patch") {
-                    $downloadSize += $edge->{info}->{size} || 0;
-                }
-                elsif ($edge->{type} eq "narfile") {
-                    $downloadSize += $edge->{info}->{size} || 0;
-                }
-            }
-                
-            print "$downloadSize\n";
-            
-            my $narSize = $info->{narSize} || 0;
-            print "$narSize\n";
+            my $size = $info->{size} || 0;
+            print "$size\n";
         }
         
         else { die "unknown command `$cmd'"; }
@@ -242,19 +68,20 @@ if ($ARGV[0] eq "--query") {
 }
 
 elsif ($ARGV[0] ne "--substitute") {
-    die;
+    die "syntax: $0 [--query-paths | --query-info PATHS... | --substitute PATH]\n";
 }
 
 
 die unless scalar @ARGV == 2;
 my $targetPath = $ARGV[1];
-$fast = 0;
 
 
 # Create a temporary directory.
 my $tmpDir = tempdir("nix-download.XXXXXX", CLEANUP => 1, TMPDIR => 1)
     or die "cannot create a temporary directory";
 
+chdir $tmpDir or die "cannot change to `$tmpDir': $!";
+
 my $tmpNar = "$tmpDir/nar";
 my $tmpNar2 = "$tmpDir/nar2";
 
@@ -280,9 +107,151 @@ foreach my $localPath (@{$localPathList}) {
 }
 
 
-# Compute the shortest path.
-my @path = computeSmallestDownload $targetPath;
-die "don't know how to produce $targetPath\n" if scalar @path == 0;
+# Build a graph of all store paths that might contribute to the
+# construction of $targetPath, and the special node "start".  The
+# edges are either patch operations, or downloads of full NAR files.
+# The latter edges only occur between "start" and a store path.
+
+my %graph;
+
+$graph{"start"} = {d => 0, pred => undef, edges => []};
+
+my @queue = ();
+my $queueFront = 0;
+my %done;
+
+sub addToQueue {
+    my $v = shift;
+    return if defined $done{$v};
+    $done{$v} = 1;
+    push @queue, $v;
+}
+
+sub addNode {
+    my $u = shift;
+    $graph{$u} = {d => 999999999999, pred => undef, edges => []}
+        unless defined $graph{$u};
+}
+
+sub addEdge {
+    my $u = shift;
+    my $v = shift;
+    my $w = shift;
+    my $type = shift;
+    my $info = shift;
+    addNode $u;
+    push @{$graph{$u}->{edges}},
+        {weight => $w, start => $u, end => $v, type => $type, info => $info};
+    my $n = scalar @{$graph{$u}->{edges}};
+}
+
+addToQueue $targetPath;
+
+sub isValidPath {
+    my $p = shift;
+    return system("$binDir/nix-store --check-validity '$p' 2> /dev/null") == 0;
+}
+
+sub parseHash {
+    my $hash = shift;
+    if ($hash =~ /^(.+):(.+)$/) {
+        return ($1, $2);
+    } else {
+        return ("md5", $hash);
+    }
+}
+
+while ($queueFront < scalar @queue) {
+    my $u = $queue[$queueFront++];
+#    print "$u\n";
+
+    addNode $u;
+
+    # If the path already exists, it has distance 0 from the "start"
+    # node.
+    if (isValidPath($u)) {
+        addEdge "start", $u, 0, "present", undef;
+    }
+
+    else {
+
+        # Add patch edges.
+        my $patchList = $patches{$u};
+        foreach my $patch (@{$patchList}) {
+            if (isValidPath($patch->{basePath})) {
+                # !!! this should be cached
+                my ($baseHashAlgo, $baseHash) = parseHash $patch->{baseHash};
+                my $format = "--base32";
+                $format = "" if $baseHashAlgo eq "md5";
+                my $hash = `$binDir/nix-hash --type '$baseHashAlgo' $format "$patch->{basePath}"`;
+                chomp $hash;
+#                print "  MY HASH is $hash\n";
+                if ($hash ne $baseHash) {
+                    print LOGFILE "$$ rejecting $patch->{basePath}\n";
+                    next;
+                }
+            }
+#            print "  PATCH from $patch->{basePath}\n";
+            addToQueue $patch->{basePath};
+            addEdge $patch->{basePath}, $u, $patch->{size}, "patch", $patch;
+        }
+
+        # Add NAR file edges to the start node.
+        my $narFileList = $narFiles{$u};
+        foreach my $narFile (@{$narFileList}) {
+#            print "  NAR from $narFile->{url}\n";
+            addEdge "start", $u, $narFile->{size}, "narfile", $narFile;
+            if ($u eq $targetPath) {
+                print LOGFILE "$$ full-download-would-be $narFile->{size}\n";
+            }
+        }
+
+    }
+}
+
+
+# Run Dijkstra's shortest path algorithm to determine the shortest
+# sequence of download and/or patch actions that will produce
+# $targetPath.
+
+sub byDistance { # sort by distance, reversed
+    return -($graph{$a}->{d} <=> $graph{$b}->{d});
+}
+
+my @todo = keys %graph;
+
+while (scalar @todo > 0) {
+
+    # Remove the closest element from the todo list.
+    @todo = sort byDistance @todo;
+    my $u = pop @todo;
+
+    my $u_ = $graph{$u};
+
+#    print "IN $u $u_->{d}\n";
+
+    foreach my $edge (@{$u_->{edges}}) {
+        my $v_ = $graph{$edge->{end}};
+        if ($v_->{d} > $u_->{d} + $edge->{weight}) {
+            $v_->{d} = $u_->{d} + $edge->{weight};
+            # Store the edge; to edge->start is actually the
+            # predecessor.
+            $v_->{pred} = $edge; 
+#            print "  RELAX $edge->{end} $v_->{d}\n";
+        }
+    }
+}
+
+
+# Retrieve the shortest path from "start" to $targetPath.
+my @path = ();
+my $cur = $targetPath;
+die "don't know how to produce $targetPath\n"
+    unless defined $graph{$targetPath}->{pred};
+while ($cur ne "start") {
+    push @path, $graph{$cur}->{pred};
+    $cur = $graph{$cur}->{pred}->{start};
+}
 
 
 # Traverse the shortest path, perform the actions described by the
@@ -290,18 +259,20 @@ die "don't know how to produce $targetPath\n" if scalar @path == 0;
 my $curStep = 1;
 my $maxStep = scalar @path;
 
-sub downloadFile { 
-    my $url = shift; 
+sub downloadFile {
+    my $url = shift;
+    my ($hashAlgo, $hash) = parseHash(shift);
     $ENV{"PRINT_PATH"} = 1;
     $ENV{"QUIET"} = 1;
-    my ($hash, $path) = `$binDir/nix-prefetch-url '$url'`;
+    $ENV{"NIX_HASH_ALGO"} = $hashAlgo;
+    my ($hash2, $path) = `$binDir/nix-prefetch-url '$url' '$hash'`;
     die "download of `$url' failed" unless $? == 0;
+    chomp $hash2;
     chomp $path;
+    die "hash mismatch, expected $hash, got $hash2" if $hash ne $hash2;
     return $path;
 }
 
-my $finalNarHash;
-
 while (scalar @path > 0) {
     my $edge = pop @path;
     my $u = $edge->{start};
@@ -331,7 +302,7 @@ while (scalar @path > 0) {
 
         # Download the patch.
         print "  downloading patch...\n";
-        my $patchPath = downloadFile "$patch->{url}";
+        my $patchPath = downloadFile "$patch->{url}", "$patch->{hash}";
 
         # Apply the patch to the NAR archive produced in step 1 (for
         # the already present path) or a later step (for patch sequences).
@@ -349,20 +320,17 @@ while (scalar @path > 0) {
             system("$binDir/nix-store --restore $v < $tmpNar2") == 0
                 or die "cannot unpack $tmpNar2 into `$v'";
         }
-
-        $finalNarHash = $patch->{narHash};
     }
 
     elsif ($edge->{type} eq "narfile") {
         my $narFile = $edge->{info};
         print "downloading `$narFile->{url}' into `$v'\n";
 
-        my $size = $narFile->{size} || -1;
-        print LOGFILE "$$ narfile $narFile->{url} $size $v\n";
+        print LOGFILE "$$ narfile $narFile->{url} $narFile->{size} $v\n";
         
         # Download the archive.
         print "  downloading archive...\n";
-        my $narFilePath = downloadFile "$narFile->{url}";
+        my $narFilePath = downloadFile "$narFile->{url}", "$narFile->{hash}";
 
         if ($curStep < $maxStep) {
             # The archive will be used a base to a patch.
@@ -374,36 +342,11 @@ while (scalar @path > 0) {
             system("@bunzip2@ < '$narFilePath' | $binDir/nix-store --restore '$v'") == 0
                 or die "cannot unpack `$narFilePath' into `$v'";
         }
-
-        $finalNarHash = $narFile->{narHash};
     }
 
     $curStep++;
 }
 
 
-# Make sure that the hash declared in the manifest matches what we
-# downloaded and unpacked.
-
-if (defined $finalNarHash) {
-    my ($hashAlgo, $hash) = parseHash $finalNarHash;
-
-    # The hash in the manifest can be either in base-16 or base-32.
-    # Handle both.
-    my $extraFlag =
-        ($hashAlgo eq "sha256" && length($hash) != 64)
-        ? "--base32" : "";
-    
-    my $hash2 = `@bindir@/nix-hash --type $hashAlgo $extraFlag $targetPath`
-        or die "cannot compute hash of path `$targetPath'";
-    chomp $hash2;
-    
-    die "hash mismatch in downloaded path $targetPath; expected $hash, got $hash2"
-        if $hash ne $hash2;
-} else {
-    die "cannot check integrity of the downloaded path since its hash is not known";
-}
-
-
 print LOGFILE "$$ success\n";
 close LOGFILE;

scripts/generate-patches.pl.in

@@ -0,0 +1,408 @@
+#! @perl@ -w -I@libexecdir@/nix
+
+use strict;
+use File::Temp qw(tempdir);
+use readmanifest;
+
+
+# Some patch generations options.
+
+# Max size of NAR archives to generate patches for.
+my $maxNarSize = $ENV{"NIX_MAX_NAR_SIZE"};
+$maxNarSize = 100 * 1024 * 1024 if !defined $maxNarSize;
+
+# If patch is bigger than this fraction of full archive, reject.
+my $maxPatchFraction = $ENV{"NIX_PATCH_FRACTION"};
+$maxPatchFraction = 0.60 if !defined $maxPatchFraction;
+
+
+die unless scalar @ARGV == 5;
+
+my $hashAlgo = "sha256";
+
+my $cacheDir = $ARGV[0];
+my $patchesDir = $ARGV[1];
+my $patchesURL = $ARGV[2];
+my $srcDir = $ARGV[3];
+my $dstDir = $ARGV[4];
+
+my $tmpDir = tempdir("nix-generate-patches.XXXXXX", CLEANUP => 1, TMPDIR => 1)
+    or die "cannot create a temporary directory";
+
+print "TEMP = $tmpDir\n";
+
+#END { rmdir $tmpDir; }
+
+my %srcNarFiles;
+my %srcLocalPaths;
+my %srcPatches;
+
+my %dstNarFiles;
+my %dstLocalPaths;
+my %dstPatches;
+
+readManifest "$srcDir/MANIFEST",
+    \%srcNarFiles, \%srcLocalPaths, \%srcPatches;
+
+readManifest "$dstDir/MANIFEST",
+    \%dstNarFiles, \%dstLocalPaths, \%dstPatches;
+
+
+sub findOutputPaths {
+    my $narFiles = shift;
+
+    my %outPaths;
+    
+    foreach my $p (keys %{$narFiles}) {
+
+        # Ignore store expressions.
+        next if ($p =~ /\.store$/);
+        next if ($p =~ /\.drv$/);
+        
+        # Ignore builders (too much ambiguity -- they're all called
+        # `builder.sh').
+        next if ($p =~ /\.sh$/);
+        next if ($p =~ /\.patch$/);
+        
+        # Don't bother including tar files etc.
+        next if ($p =~ /\.tar\.(gz|bz2)$/ || $p =~ /\.zip$/ || $p =~ /\.bin$/);
+
+        $outPaths{$p} = 1;
+    }
+
+    return %outPaths;
+}
+
+print "finding src output paths...\n";
+my %srcOutPaths = findOutputPaths \%srcNarFiles;
+
+print "finding dst output paths...\n";
+my %dstOutPaths = findOutputPaths \%dstNarFiles;
+
+
+sub getNameVersion {
+    my $p = shift;
+    $p =~ /\/[0-9a-z]+((?:-[a-zA-Z][^\/-]*)+)([^\/]*)$/;
+    my $name = $1;
+    my $version = $2;
+    $name =~ s/^-//;
+    $version =~ s/^-//;
+    return ($name, $version);
+}
+
+
+# A quick hack to get a measure of the `distance' between two
+# versions: it's just the position of the first character that differs
+# (or 999 if they are the same).
+sub versionDiff {
+    my $s = shift;
+    my $t = shift;
+    my $i;
+    return 999 if $s eq $t;
+    for ($i = 0; $i < length $s; $i++) {
+        return $i if $i >= length $t or
+            substr($s, $i, 1) ne substr($t, $i, 1);
+    }
+    return $i;
+}
+
+
+sub getNarBz2 {
+    my $narFiles = shift;
+    my $storePath = shift;
+    
+    my $narFileList = $$narFiles{$storePath};
+    die "missing store expression $storePath" unless defined $narFileList;
+
+    my $narFile = @{$narFileList}[0];
+    die unless defined $narFile;
+
+    $narFile->{url} =~ /\/([^\/]+)$/;
+    die unless defined $1;
+    return "$cacheDir/$1";
+}
+
+
+sub containsPatch {
+    my $patches = shift;
+    my $storePath = shift;
+    my $basePath = shift;
+    my $patchList = $$patches{$storePath};
+    return 0 if !defined $patchList;
+    my $found = 0;
+    foreach my $patch (@{$patchList}) {
+        # !!! baseHash might differ
+        return 1 if $patch->{basePath} eq $basePath;
+    }
+    return 0;
+}
+
+
+# Compute the "weighted" number of uses of a path in the build graph.
+sub computeUses {
+    my $narFiles = shift;
+    my $path = shift;
+
+    # Find the deriver of $path.
+    return 1 unless defined $$narFiles{$path};
+    my $deriver = @{$$narFiles{$path}}[0]->{deriver};
+    return 1 unless defined $deriver && $deriver ne "";
+
+#    print "  DERIVER $deriver\n";
+
+    # Optimisation: build the referrers graph from the references
+    # graph.
+    my %referrers;
+    foreach my $q (keys %{$narFiles}) {
+        my @refs = split " ", @{$$narFiles{$q}}[0]->{references};
+        foreach my $r (@refs) {
+            $referrers{$r} = [] unless defined $referrers{$r};
+            push @{$referrers{$r}}, $q;
+        }
+    }
+
+    # Determine the shortest path from $deriver to all other reachable
+    # paths in the `referrers' graph.
+
+    my %dist;
+    $dist{$deriver} = 0;
+
+    my @queue = ($deriver);
+    my $pos = 0;
+    
+    while ($pos < scalar @queue) {
+        my $p = $queue[$pos];
+        $pos++;
+
+        foreach my $q (@{$referrers{$p}}) {
+            if (!defined $dist{$q}) {
+                $dist{$q} = $dist{$p} + 1;
+#                print "    $q $dist{$q}\n";
+                push @queue, $q;
+            }
+        }
+    }
+
+    my $wuse = 1.0;
+    foreach my $user (keys %dist) {
+        next if $user eq $deriver;
+#        print "    $user $dist{$user}\n";
+        $wuse += 1.0 / 2.0**$dist{$user};
+    }
+
+#    print "    XXX $path $wuse\n";
+    
+    return $wuse;
+}
+
+
+# For each output path in the destination, see if we need to / can
+# create a patch.
+
+print "creating patches...\n";
+
+foreach my $p (keys %dstOutPaths) {
+
+    # If exactly the same path already exists in the source, skip it.
+    next if defined $srcOutPaths{$p};
+    
+    print "  $p\n";
+
+    # If not, then we should find the paths in the source that are
+    # `most' likely to be present on a system that wants to install
+    # this path.
+
+    (my $name, my $version) = getNameVersion $p;
+
+    my @closest = ();
+    my $closestVersion;
+    my $minDist = -1; # actually, larger means closer
+
+    # Find all source paths with the same name.
+
+    foreach my $q (keys %srcOutPaths) {
+        (my $name2, my $version2) = getNameVersion $q;
+        if ($name eq $name2) {
+
+            # If the sizes differ too much, then skip.  This
+            # disambiguates between, e.g., a real component and a
+            # wrapper component (cf. Firefox in Nixpkgs).
+            my $srcSize = @{$srcNarFiles{$q}}[0]->{size};
+            my $dstSize = @{$dstNarFiles{$p}}[0]->{size};
+            my $ratio = $srcSize / $dstSize;
+            $ratio = 1 / $ratio if $ratio < 1;
+#            print "  SIZE $srcSize $dstSize $ratio $q\n";
+
+            if ($ratio >= 3) {
+                print "  SKIPPING $q due to size ratio $ratio ($srcSize $dstSize)\n";
+                next;
+            }
+
+            # If the numbers of weighted uses differ too much, then
+            # skip.  This disambiguates between, e.g., the bootstrap
+            # GCC and the final GCC in Nixpkgs.
+            my $srcUses = computeUses \%srcNarFiles, $q;
+            my $dstUses = computeUses \%dstNarFiles, $p;
+            $ratio = $srcUses / $dstUses;
+            $ratio = 1 / $ratio if $ratio < 1;
+            print "  USE $srcUses $dstUses $ratio $q\n";
+            
+#            if ($ratio >= 2) {
+#                print "  SKIPPING $q due to use ratio $ratio ($srcUses $dstUses)\n";
+#                next;
+#            }
+
+            # If there are multiple matching names, include the ones
+            # with the closest version numbers.
+            my $dist = versionDiff $version, $version2;
+            if ($dist > $minDist) {
+                $minDist = $dist;
+                @closest = ($q);
+                $closestVersion = $version2;
+            } elsif ($dist == $minDist) {
+                push @closest, $q;
+            }
+        }
+    }
+
+    if (scalar(@closest) == 0) {
+        print "  NO BASE: $p\n";
+        next;
+    }
+
+    foreach my $closest (@closest) {
+
+        # Generate a patch between $closest and $p.
+        print "  $p <- $closest\n";
+
+        # If the patch already exists, skip it.
+        if (containsPatch(\%srcPatches, $p, $closest) ||
+            containsPatch(\%dstPatches, $p, $closest))
+        {
+            print "    skipping, already exists\n";
+            next;
+        }
+
+#        next;
+        
+        my $srcNarBz2 = getNarBz2 \%srcNarFiles, $closest;
+        my $dstNarBz2 = getNarBz2 \%dstNarFiles, $p;
+
+        system("@bunzip2@ < $srcNarBz2 > $tmpDir/A") == 0
+            or die "cannot unpack $srcNarBz2";
+
+        if ((stat "$tmpDir/A")[7] >= $maxNarSize) {
+            print "    skipping, source is too large\n";
+            next;
+        }
+        
+        system("@bunzip2@ < $dstNarBz2 > $tmpDir/B") == 0
+            or die "cannot unpack $dstNarBz2";
+
+        if ((stat "$tmpDir/B")[7] >= $maxNarSize) {
+            print "    skipping, destination is too large\n";
+            next;
+        }
+        
+        system("@libexecdir@/bsdiff $tmpDir/A $tmpDir/B $tmpDir/DIFF") == 0
+            or die "cannot compute binary diff";
+
+        my $baseHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpDir/A` or die;
+        chomp $baseHash;
+
+        my $narHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpDir/B` or die;
+        chomp $narHash;
+
+        my $narDiffHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpDir/DIFF` or die;
+        chomp $narDiffHash;
+
+        my $narDiffSize = (stat "$tmpDir/DIFF")[7];
+        my $dstNarBz2Size = (stat $dstNarBz2)[7];
+
+        print "    size $narDiffSize; full size $dstNarBz2Size\n";
+        
+        if ($narDiffSize >= $dstNarBz2Size) {
+            print "    rejecting; patch bigger than full archive\n";
+            next;
+        }
+    
+        if ($narDiffSize / $dstNarBz2Size >= $maxPatchFraction) {
+            print "    rejecting; patch too large relative to full archive\n";
+            next;
+        }
+    
+        my $finalName =
+            "$narDiffHash.nar-bsdiff";
+
+        if (-e "$patchesDir/$finalName") {
+            print "    not copying, already exists\n";
+        }
+
+        else {
+
+            system("cp '$tmpDir/DIFF' '$patchesDir/$finalName.tmp'") == 0
+                or die "cannot copy diff";
+            
+            rename("$patchesDir/$finalName.tmp", "$patchesDir/$finalName")
+                or die "cannot rename $patchesDir/$finalName.tmp";
+            
+        }
+        
+        # Add the patch to the manifest.
+        addPatch \%dstPatches, $p,
+            { url => "$patchesURL/$finalName", hash => "$hashAlgo:$narDiffHash"
+            , size => $narDiffSize, basePath => $closest, baseHash => "$hashAlgo:$baseHash"
+            , narHash => "$hashAlgo:$narHash", patchType => "nar-bsdiff"
+            }, 0;
+    }
+}
+
+
+# Add in any potentially useful patches in the source (namely, those
+# patches that produce either paths in the destination or paths that
+# can be used as the base for other useful patches).
+
+print "propagating patches...\n";
+
+my $changed;
+do {
+    # !!! we repeat this to reach the transitive closure; inefficient
+    $changed = 0;
+
+    print "loop\n";
+
+    my %dstBasePaths;
+    foreach my $q (keys %dstPatches) {
+	foreach my $patch (@{$dstPatches{$q}}) {
+	    $dstBasePaths{$patch->{basePath}} = 1;
+	}
+    }
+
+    foreach my $p (keys %srcPatches) {
+        my $patchList = $srcPatches{$p};
+
+        my $include = 0;
+
+        # Is path $p included in the destination?  If so, include
+        # patches that produce it.
+        $include = 1 if defined $dstNarFiles{$p};
+
+        # Is path $p a path that serves as a base for paths in the
+        # destination?  If so, include patches that produce it.
+	# !!! check baseHash
+        $include = 1 if defined $dstBasePaths{$p};
+
+        if ($include) {
+            foreach my $patch (@{$patchList}) {
+                $changed = 1 if addPatch \%dstPatches, $p, $patch;
+            }
+        }
+        
+    }
+    
+} while $changed;
+
+
+# Rewrite the manifest of the destination (with the new patches).
+writeManifest "$dstDir/MANIFEST",
+    \%dstNarFiles, \%dstPatches;

scripts/nix-build.in

@@ -12,7 +12,6 @@ my $outLink;
 my $drvLink;
 
 my $dryRun = 0;
-my $verbose = 0;
 
 my @instArgs = ();
 my @buildArgs = ();
@@ -78,7 +77,7 @@ EOF
 
     elsif ($arg eq "--attr" or $arg eq "-A") {
         $n++;
-        die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
+        die "$0: `--attr' requires an argument\n" unless $n < scalar @ARGV;
         push @instArgs, ("--attr", $ARGV[$n]);
     }
 
@@ -88,21 +87,7 @@ EOF
         $n += 2;
     }
 
-    elsif ($arg eq "--log-type") {
-        $n++;
-        die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
-        push @instArgs, ($arg, $ARGV[$n]);
-        push @buildArgs, ($arg, $ARGV[$n]);
-    }
-
-    elsif ($arg eq "--option") {
-        die "$0: `$arg' requires two arguments\n" unless $n + 2 < scalar @ARGV;
-        push @instArgs, ($arg, $ARGV[$n + 1], $ARGV[$n + 2]);
-        push @buildArgs, ($arg, $ARGV[$n + 1], $ARGV[$n + 2]);
-        $n += 2;
-    }
-
-    elsif ($arg eq "--max-jobs" or $arg eq "-j" or $arg eq "--max-silent-time" or $arg eq "--log-type" or $arg eq "--cores") {
+    elsif ($arg eq "--max-jobs" or $arg eq "-j" or $arg eq "--max-silent-time") {
         $n++;
         die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
         push @buildArgs, ($arg, $ARGV[$n]);
@@ -113,21 +98,6 @@ EOF
         $dryRun = 1;
     }
     
-    elsif ($arg eq "--show-trace") {
-        push @instArgs, $arg;
-    }
-    
-    elsif ($arg eq "--verbose" or substr($arg, 0, 2) eq "-v") {
-        push @buildArgs, $arg;
-        push @instArgs, $arg;
-        $verbose = 1;
-    }
-    
-    elsif ($arg eq "--quiet") {
-        push @buildArgs, $arg;
-        push @instArgs, $arg;
-    }
-    
     elsif (substr($arg, 0, 1) eq "-") {
         push @buildArgs, $arg;
     }
@@ -158,25 +128,19 @@ foreach my $expr (@exprs) {
     # !!! would prefer the perl 5.8.0 pipe open feature here.
     my $pid = open(DRVPATHS, "-|") || exec "$binDir/nix-instantiate", "--add-root", $drvLink, "--indirect", @instArgs, $expr;
     while (<DRVPATHS>) {chomp; push @drvPaths, $_;}
-    if (!close DRVPATHS) {
-        die "nix-instantiate killed by signal " . ($? & 127) . "\n" if ($? & 127);
-        exit 1;
-    }
+    close DRVPATHS or exit 1;
 
     foreach my $drvPath (@drvPaths) {
         my $target = readlink $drvPath or die "cannot read symlink `$drvPath'";
-        print STDERR "derivation is $target\n" if $verbose;
+        print STDERR "store derivation is $target\n";
     }
 
     # Build.
     my @outPaths;
-    $pid = open(OUTPATHS, "-|") || exec "$binDir/nix-store", "--add-root", $outLink, "--indirect", "-r",
+    $pid = open(OUTPATHS, "-|") || exec "$binDir/nix-store", "--add-root", $outLink, "--indirect", "-rv",
         @buildArgs, @drvPaths;
     while (<OUTPATHS>) {chomp; push @outPaths, $_;}
-    if (!close OUTPATHS) {
-        die "nix-store killed by signal " . ($? & 127) . "\n" if ($? & 127);
-        exit 1;
-    }
+    close OUTPATHS or exit 1;
 
     next if $dryRun;
 

scripts/nix-channel.in

@@ -78,9 +78,6 @@ sub removeChannel {
 sub update {
     readChannels;
 
-    # Create the manifests directory if it doesn't exist.
-    mkdir "$stateDir/manifests", 0755 unless -e "$stateDir/manifests";
-
     # Do we have write permission to the manifests directory?  If not,
     # then just skip pulling the manifest and just download the Nix
     # expressions.  If the user is a non-privileged user in a
@@ -88,6 +85,11 @@ sub update {
     # source.
     if (-W "$stateDir/manifests") {
 
+        # Remove all the old manifests.
+        for my $manifest (glob "$stateDir/manifests/*.nixmanifest") {
+            unlink $manifest or die "cannot remove `$manifest': $!";
+        }
+
         # Pull cache manifests.
         foreach my $url (@channels) {
             #print "pulling cache manifest from `$url'\n";
@@ -123,13 +125,15 @@ sub update {
 
     my $rootFile = "$rootsDir/per-user/$userName/channels";
     
-    # Build the Nix expression.
+    # Instantiate the Nix expression.
     print "unpacking channel Nix expressions...\n";
-    my $outPath = `\\
-        @bindir@/nix-build --out-link '$rootFile' --drv-link '$rootFile'.tmp \\
-        @datadir@/nix/corepkgs/channels/unpack.nix \\
-        --argstr system @system@ --arg inputs '$inputs'`
-        or die "cannot unpack the channels";
+    my $storeExpr = `@bindir@/nix-instantiate --add-root '$rootFile'.tmp @datadir@/nix/corepkgs/channels/unpack.nix --argstr system @system@ --arg inputs '$inputs'`
+        or die "cannot instantiate Nix expression";
+    chomp $storeExpr;
+
+    # Build the resulting derivation.
+    my $outPath = `@bindir@/nix-store --add-root '$rootFile' -r '$storeExpr'`
+        or die "cannot realise store expression";
     chomp $outPath;
 
     unlink "$rootFile.tmp";

scripts/nix-copy-closure.in

@@ -1,6 +1,4 @@
-#! @perl@ -w -I@libexecdir@/nix
-
-use SSH;
+#! @perl@ -w
 
 my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
 
@@ -16,11 +14,12 @@ EOF
 
 # Get the target host.
 my $sshHost;
+my @sshOpts = split ' ', ($ENV{"NIX_SSHOPTS"} or "");
 
 my $sign = 0;
 
-my $compressor = "";
-my $decompressor = "";
+my $compressor = "cat";
+my $decompressor = "cat";
 
 my $toMode = 1;
 
@@ -35,8 +34,8 @@ while (@ARGV) {
         $sign = 1;
     }
     elsif ($arg eq "--gzip") {
-        $compressor = "| gzip";
-        $decompressor = "gunzip |";
+        $compressor = "gzip";
+        $decompressor = "gunzip";
     }
     elsif ($arg eq "--from") {
         $toMode = 0;
@@ -53,30 +52,40 @@ while (@ARGV) {
 }
 
 
-openSSHConnection $sshHost or die "$0: unable to start SSH\n";
-
-
 if ($toMode) { # Copy TO the remote machine.
 
     my @allStorePaths;
+    my %storePathsSeen;
 
-    # Get the closure of this path.
-    my $pid = open(READ, "set -f; $binDir/nix-store --query --requisites @storePaths|") or die;
+    foreach my $storePath (@storePaths) {
+        # $arg might be a symlink to the store, so resolve it.
+        my $storePath2 = (`$binDir/nix-store --query --resolve '$storePath'`
+            or die "cannot resolve `$storePath'");
+        chomp $storePath2;
+
+        # Get the closure of this path.
+        my $pid = open(READ,
+            "$binDir/nix-store --query --requisites '$storePath2'|") or die;
     
-    while (<READ>) {
-        chomp;
-        die "bad: $_" unless /^\//;
-        push @allStorePaths, $_;
-    }
+        while (<READ>) {
+            chomp;
+            die "bad: $_" unless /^\//;
+            if (!defined $storePathsSeen{$_}) {
+                push @allStorePaths, $_;
+                $storePathsSeen{$_} = 1;
+            }
+        }
 
-    close READ or die "nix-store failed: $?";
+        close READ or die "nix-store failed: $?";
+    }
 
 
     # Ask the remote host which paths are invalid.
-    open(READ, "set -f; ssh $sshHost @sshOpts nix-store --check-validity --print-invalid @allStorePaths|");
+    open(READ, "ssh @sshOpts $sshHost nix-store --check-validity --print-invalid @allStorePaths|");
     my @missing = ();
     while (<READ>) {
         chomp;
+        print STDERR "target machine needs $_\n";
         push @missing, $_;
     }
     close READ or die;
@@ -84,11 +93,9 @@ if ($toMode) { # Copy TO the remote machine.
 
     # Export the store paths and import them on the remote machine.
     if (scalar @missing > 0) {
-        print STDERR "copying these missing paths:\n";
-        print STDERR "  $_\n" foreach @missing;
         my $extraOpts = "";
         $extraOpts .= "--sign" if $sign == 1;
-        system("set -f; nix-store --export $extraOpts @missing $compressor | ssh $sshHost @sshOpts '$decompressor nix-store --import'") == 0
+        system("nix-store --export $extraOpts @missing | $compressor | ssh @sshOpts $sshHost '$decompressor | nix-store --import'") == 0
             or die "copying store paths to remote machine `$sshHost' failed: $?";
     }
 
@@ -101,24 +108,29 @@ else { # Copy FROM the remote machine.
     # machine.  Paths are assumed to be store paths; there is no
     # resolution (following of symlinks).
     my $pid = open(READ,
-        "set -f; ssh @sshOpts $sshHost nix-store --query --requisites @storePaths|") or die;
+        "ssh @sshOpts $sshHost nix-store --query --requisites @storePaths|") or die;
     
     my @allStorePaths;
+    my %storePathsSeen;
 
     while (<READ>) {
         chomp;
         die "bad: $_" unless /^\//;
-        push @allStorePaths, $_;
+        if (!defined $storePathsSeen{$_}) {
+            push @allStorePaths, $_;
+            $storePathsSeen{$_} = 1;
+        }
     }
 
     close READ or die "nix-store on remote machine `$sshHost' failed: $?";
 
 
     # What paths are already valid locally?
-    open(READ, "set -f; @bindir@/nix-store --check-validity --print-invalid @allStorePaths|");
+    open(READ, "@bindir@/nix-store --check-validity --print-invalid @allStorePaths|");
     my @missing = ();
     while (<READ>) {
         chomp;
+        print STDERR "local machine needs $_\n";
         push @missing, $_;
     }
     close READ or die;
@@ -126,12 +138,10 @@ else { # Copy FROM the remote machine.
 
     # Export the store paths on the remote machine and import them on locally.
     if (scalar @missing > 0) {
-        print STDERR "copying these missing paths:\n";
-        print STDERR "  $_\n" foreach @missing;
         my $extraOpts = "";
         $extraOpts .= "--sign" if $sign == 1;
-        system("set -f; ssh $sshHost @sshOpts 'nix-store --export $extraOpts @missing $compressor' | $decompressor @bindir@/nix-store --import") == 0
-            or die "copying store paths from remote machine `$sshHost' failed: $?";
+        system("ssh @sshOpts $sshHost 'nix-store --export $extraOpts @missing | $compressor' | $decompressor | @bindir@/nix-store --import") == 0
+            or die "copying store paths to remote machine `$sshHost' failed: $?";
     }
 
 }

scripts/nix-generate-patches.in

@@ -1,42 +0,0 @@
-#! @perl@ -w -I@libexecdir@/nix
-
-use strict;
-use File::Temp qw(tempdir);
-use NixManifest;
-use GeneratePatches;
-
-if (scalar @ARGV != 5) {
-    print STDERR <<EOF;
-Usage: nix-generate-patches NAR-DIR PATCH-DIR PATCH-URI OLD-MANIFEST NEW-MANIFEST
-
-This command generates binary patches between NAR files listed in
-OLD-MANIFEST and NEW-MANIFEST.  The patches are written to the
-directory PATCH-DIR, and the prefix PATCH-URI is used to generate URIs
-for the patches.  The patches are added to NEW-MANIFEST.  All NARs are
-required to exist in NAR-DIR.  Patches are generated between
-succeeding versions of packages with the same name.
-EOF
-    exit 1;
-}
-
-my $narPath = $ARGV[0];
-my $patchesPath = $ARGV[1];
-my $patchesURL = $ARGV[2];
-my $srcManifest = $ARGV[3];
-my $dstManifest = $ARGV[4];
-
-my (%srcNarFiles, %srcLocalPaths, %srcPatches);
-readManifest $srcManifest, \%srcNarFiles, \%srcLocalPaths, \%srcPatches;
-
-my (%dstNarFiles, %dstLocalPaths, %dstPatches);
-readManifest $dstManifest, \%dstNarFiles, \%dstLocalPaths, \%dstPatches;
-
-my $tmpDir = tempdir("nix-generate-patches.XXXXXX", CLEANUP => 1, TMPDIR => 1)
-    or die "cannot create a temporary directory";
-
-generatePatches \%srcNarFiles, \%dstNarFiles, \%srcPatches, \%dstPatches,
-    $narPath, $patchesPath, $patchesURL, $tmpDir;
-
-propagatePatches \%srcPatches, \%dstNarFiles, \%dstPatches;
-
-writeManifest $dstManifest, \%dstNarFiles, \%dstPatches;

scripts/nix-http-export.cgi.in

@@ -12,8 +12,7 @@ needed_path="?$QUERY_STRING"
 needed_path="${needed_path#*[?&]needed_path=}"
 needed_path="${needed_path%%&*}"
 #needed_path="$(echo $needed_path  | ./unhttp)"
-needed_path="${needed_path//%2B/+}"
-needed_path="${needed_path//%3D/=}"
+needed_path="$(echo $needed_path  | sed -e 's/%2B/+/g; s/%3D/=/g')"
 
 echo needed_path: "$needed_path" >&2
 

scripts/nix-install-package.in

@@ -123,11 +123,6 @@ if ($interactive) {
 }
 
 
-# Store the manifest in the temporary directory so that we don't
-# pollute /nix/var/nix/manifests.
-$ENV{NIX_MANIFESTS_DIR} = $tmpDir;
-
-
 print "\nPulling manifests...\n";
 system("$binDir/nix-pull", $manifestURL) == 0
     or barf "nix-pull failed: $?";

scripts/nix-prefetch-url.in

@@ -21,10 +21,7 @@ if test -z "$url"; then
     exit 1
 fi
 
-# Handle escaped characters in the URI.  `+', `=' and `?' are the only
-# characters that are valid in Nix store path names but have a special
-# meaning in URIs.
-name=$(basename "$url" | @sed@ -e 's/%2b/+/g' -e 's/%3d/=/g' -e 's/%3f/\?/g')
+name=$(basename "$url")
 if test -z "$name"; then echo "invalid url"; exit 1; fi
 
 
@@ -63,7 +60,7 @@ removeTempDir() {
 
 
 doDownload() {
-    @curl@ $cacheFlags --fail --location --max-redirs 20 --disable-epsv \
+    @curl@ $cacheFlags --fail -# --location --max-redirs 20 --disable-epsv \
         --cookie-jar $tmpPath/cookies "$url" -o $tmpFile
 }
 

scripts/nix-pull.in

@@ -2,28 +2,27 @@
 
 use strict;
 use File::Temp qw(tempdir);
-use NixManifest;
+use readmanifest;
 
 my $tmpDir = tempdir("nix-pull.XXXXXX", CLEANUP => 1, TMPDIR => 1)
     or die "cannot create a temporary directory";
 
 my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
-my $libexecDir = ($ENV{"NIX_LIBEXEC_DIR"} or "@libexecdir@");
-my $storeDir = ($ENV{"NIX_STORE_DIR"} or "@storedir@");
-my $stateDir = ($ENV{"NIX_STATE_DIR"} or "@localstatedir@/nix");
-my $manifestDir = ($ENV{"NIX_MANIFESTS_DIR"} or "$stateDir/manifests");
+
+my $libexecDir = $ENV{"NIX_LIBEXEC_DIR"};
+$libexecDir = "@libexecdir@" unless defined $libexecDir;
+
+my $stateDir = $ENV{"NIX_STATE_DIR"};
+$stateDir = "@localstatedir@/nix" unless defined $stateDir;
+
+my $storeDir = $ENV{"NIX_STORE_DIR"};
+$storeDir = "@storedir@" unless defined $storeDir;
 
 
 # Prevent access problems in shared-stored installations.
 umask 0022;
 
 
-# Create the manifests directory if it doesn't exist.
-if (! -e $manifestDir) {
-    mkdir $manifestDir, 0755 or die "cannot create directory `$manifestDir'";
-}
-
-
 # Process the URLs specified on the command line.
 my %narFiles;
 my %localPaths;
@@ -51,7 +50,7 @@ sub processURL {
 
     # First see if a bzipped manifest is available.
     if (system("@curl@ --fail --silent --head '$url'.bz2 > /dev/null") == 0) {
-        print "fetching list of Nix archives at `$url.bz2'...\n";
+        print "obtaining list of Nix archives at `$url.bz2'...\n";
         my $bzipped = downloadFile "$url.bz2";
 
         $manifest = "$tmpDir/MANIFEST";
@@ -69,11 +68,10 @@ sub processURL {
         print "obtaining list of Nix archives at `$url'...\n";
         $manifest = downloadFile $url;
     }
-
-    my $version = readManifest($manifest, \%narFiles, \%localPaths, \%patches);
     
-    die "`$url' is not a manifest or it is too old (i.e., for Nix <= 0.7)\n" if $version < 3;
-    die "manifest `$url' is too new\n" if $version >= 5;
+    if (readManifest($manifest, \%narFiles, \%localPaths, \%patches) < 3) {
+        die "`$url' is not manifest or it is too old (i.e., for Nix <= 0.7)\n";
+    }
 
     if ($skipWrongStore) {
         foreach my $path (keys %narFiles) {
@@ -92,31 +90,11 @@ sub processURL {
     my $hash = `$binDir/nix-hash --flat '$manifest'`
         or die "cannot hash `$manifest'";
     chomp $hash;
-
-    my $urlFile = "$manifestDir/$baseName-$hash.url";
-    open URL, ">$urlFile" or die "cannot create `$urlFile'";
-    print URL "$url";
-    close URL;
     
-    my $finalPath = "$manifestDir/$baseName-$hash.nixmanifest";
-
-    unlink $finalPath if -e $finalPath;
-        
-    symlink("$manifest", "$finalPath")
+    my $finalPath = "$stateDir/manifests/$baseName-$hash.nixmanifest";
+    
+    system("@coreutils@/ln", "-sfn", "$manifest", "$finalPath") == 0
         or die "cannot link `$finalPath to `$manifest'";
-
-    # Delete all old manifests downloaded from this URL.
-    for my $urlFile2 (glob "$manifestDir/*.url") {
-        next if $urlFile eq $urlFile2;
-        open URL, "<$urlFile2" or die;
-        my $url2 = <URL>;
-        chomp $url2;
-        close URL;
-        next unless $url eq $url2;
-        my $base = $urlFile2; $base =~ s/.url$//;
-        unlink "${base}.url";
-        unlink "${base}.nixmanifest";
-    }
 }
 
 while (@ARGV) {

scripts/nix-push.in

@@ -2,7 +2,7 @@
 
 use strict;
 use File::Temp qw(tempdir);
-use NixManifest;
+use readmanifest;
 
 my $hashAlgo = "sha256";
 
@@ -128,7 +128,7 @@ while (<READ>) {
 close READ or die "nix-instantiate failed: $?";
 
 
-# Build the derivations.
+# Realise the store expressions.
 print STDERR "creating archives...\n";
 
 my @narPaths;
@@ -140,7 +140,12 @@ while (scalar @tmp > 0) {
     my @tmp2 = @tmp[0..$n - 1];
     @tmp = @tmp[$n..scalar @tmp - 1];
 
-    my $pid = open(READ, "$binDir/nix-store --realise @tmp2|")
+    # Note: we disable build hooks because of the impure path
+    # reference (see above).  Even if that is fixed, using a hook
+    # probably wouldn't make that much sense; pumping lots of data
+    # around just to compress them won't gain that much.
+    $ENV{"NIX_BUILD_HOOK"} = "";
+    my $pid = open(READ, "$binDir/nix-store --no-build-hook --realise @tmp2|")
         or die "cannot run nix-store";
     while (<READ>) {
         chomp;
@@ -172,6 +177,12 @@ for (my $n = 0; $n < scalar @storePaths; $n++) {
     $narbz2Hash =~ /^[0-9a-z]+$/ or die "invalid hash";
     close HASH;
 
+    open HASH, "$narDir/nar-hash" or die "cannot open nar-hash";
+    my $narHash = <HASH>;
+    chomp $narHash;
+    $narHash =~ /^[0-9a-z]+$/ or die "invalid hash";
+    close HASH;
+    
     my $narName = "$narbz2Hash.nar.bz2";
 
     my $narFile = "$narDir/$narName";
@@ -189,14 +200,6 @@ for (my $n = 0; $n < scalar @storePaths; $n++) {
     chomp $deriver;
     $deriver = "" if $deriver eq "unknown-deriver";
 
-    my $narHash = `$binDir/nix-store --query --hash '$storePath'`;
-    die "cannot query hash for `$storePath'" if $? != 0;
-    chomp $narHash;
-
-    my $narSize = `$binDir/nix-store --query --size '$storePath'`;
-    die "cannot query size for `$storePath'" if $? != 0;
-    chomp $narSize;
-
     my $url;
     if ($localCopy) {
         $url = "$targetArchivesUrl/$narName";
@@ -207,8 +210,7 @@ for (my $n = 0; $n < scalar @storePaths; $n++) {
         { url => $url
         , hash => "$hashAlgo:$narbz2Hash"
         , size => $narbz2Size
-        , narHash => "$narHash"
-        , narSize => $narSize
+        , narHash => "$hashAlgo:$narHash"
         , references => $references
         , deriver => $deriver
         }

scripts/readmanifest.pm.in

@@ -2,7 +2,10 @@ use strict;
 
 
 sub addPatch {
-    my ($patches, $storePath, $patch) = @_;
+    my $patches = shift;
+    my $storePath = shift;
+    my $patch = shift;
+    my $allowConflicts = shift;
 
     $$patches{$storePath} = []
         unless defined $$patches{$storePath};
@@ -11,9 +14,15 @@ sub addPatch {
 
     my $found = 0;
     foreach my $patch2 (@{$patchList}) {
-        $found = 1 if
-            $patch2->{url} eq $patch->{url} &&
-            $patch2->{basePath} eq $patch->{basePath};
+        if ($patch2->{url} eq $patch->{url}) {
+            if ($patch2->{hash} eq $patch->{hash}) {
+                $found = 1 if ($patch2->{basePath} eq $patch->{basePath});
+            } else {
+                die "conflicting hashes for URL $patch->{url}, " .
+                    "namely $patch2->{hash} and $patch->{hash}"
+                    unless $allowConflicts;
+            }
+        }
     }
     
     push @{$patchList}, $patch if !$found;
@@ -23,7 +32,12 @@ sub addPatch {
 
 
 sub readManifest {
-    my ($manifest, $narFiles, $localPaths, $patches) = @_;
+    my $manifest = shift;
+    my $narFiles = shift;
+    my $localPaths = shift;
+    my $patches = shift;
+    my $allowConflicts = shift;
+    $allowConflicts = 0 unless defined $allowConflicts;
 
     open MANIFEST, "<$manifest"
         or die "cannot open `$manifest': $!";
@@ -33,8 +47,18 @@ sub readManifest {
 
     my $manifestVersion = 2;
 
-    my ($storePath, $url, $hash, $size, $basePath, $baseHash, $patchType);
-    my ($narHash, $narSize, $references, $deriver, $hashAlgo, $copyFrom, $system);
+    my $storePath;
+    my $url;
+    my $hash;
+    my $size;
+    my $basePath;
+    my $baseHash;
+    my $patchType;
+    my $narHash;
+    my $references;
+    my $deriver;
+    my $hashAlgo;
+    my $copyFrom;
 
     while (<MANIFEST>) {
         chomp;
@@ -52,11 +76,9 @@ sub readManifest {
                 undef $hash;
                 undef $size;
                 undef $narHash;
-                undef $narSize;
                 undef $basePath;
                 undef $baseHash;
                 undef $patchType;
-                undef $system;
                 $references = "";
                 $deriver = "";
                 $hashAlgo = "md5";
@@ -76,15 +98,21 @@ sub readManifest {
 
                     my $found = 0;
                     foreach my $narFile (@{$narFileList}) {
-                        $found = 1 if $narFile->{url} eq $url;
+                        if ($narFile->{url} eq $url) {
+                            if ($narFile->{hash} eq $hash) {
+                                $found = 1;
+                            } else {
+                                die "conflicting hashes for URL $url, " .
+                                    "namely $narFile->{hash} and $hash"
+                                    unless $allowConflicts;
+                            }
+                        }
                     }
                     if (!$found) {
                         push @{$narFileList},
                             { url => $url, hash => $hash, size => $size
-                            , narHash => $narHash, narSize => $narSize
-                            , references => $references
+                            , narHash => $narHash, references => $references
                             , deriver => $deriver, hashAlgo => $hashAlgo
-                            , system => $system
                             };
                     }
                 
@@ -94,9 +122,9 @@ sub readManifest {
                     addPatch $patches, $storePath,
                         { url => $url, hash => $hash, size => $size
                         , basePath => $basePath, baseHash => $baseHash
-                        , narHash => $narHash, narSize => $narSize
-                        , patchType => $patchType, hashAlgo => $hashAlgo
-                        };
+                        , narHash => $narHash, patchType => $patchType
+                        , hashAlgo => $hashAlgo
+                        }, $allowConflicts;
                 }
 
                 elsif ($type eq "localPath") {
@@ -126,11 +154,9 @@ sub readManifest {
             elsif (/^\s*BaseHash:\s*(\S+)\s*$/) { $baseHash = $1; }
             elsif (/^\s*Type:\s*(\S+)\s*$/) { $patchType = $1; }
             elsif (/^\s*NarHash:\s*(\S+)\s*$/) { $narHash = $1; }
-            elsif (/^\s*NarSize:\s*(\d+)\s*$/) { $narSize = $1; }
             elsif (/^\s*References:\s*(.*)\s*$/) { $references = $1; }
             elsif (/^\s*Deriver:\s*(\S+)\s*$/) { $deriver = $1; }
             elsif (/^\s*ManifestVersion:\s*(\d+)\s*$/) { $manifestVersion = $1; }
-            elsif (/^\s*System:\s*(\S+)\s*$/) { $system = $1; }
 
             # Compatibility;
             elsif (/^\s*NarURL:\s*(\S+)\s*$/) { $url = $1; }
@@ -145,8 +171,12 @@ sub readManifest {
 }
 
 
-sub writeManifest {
-    my ($manifest, $narFiles, $patches, $noCompress) = @_;
+sub writeManifest
+{
+    my $manifest = shift;
+    my $narFiles = shift;
+    my $patches = shift;
+    my $copySources = shift;
 
     open MANIFEST, ">$manifest.tmp"; # !!! check exclusive
 
@@ -160,15 +190,13 @@ sub writeManifest {
             print MANIFEST "{\n";
             print MANIFEST "  StorePath: $storePath\n";
             print MANIFEST "  NarURL: $narFile->{url}\n";
-            print MANIFEST "  Hash: $narFile->{hash}\n" if defined $narFile->{hash};
-            print MANIFEST "  Size: $narFile->{size}\n" if defined $narFile->{size};
+            print MANIFEST "  Hash: $narFile->{hash}\n";
             print MANIFEST "  NarHash: $narFile->{narHash}\n";
-            print MANIFEST "  NarSize: $narFile->{narSize}\n" if $narFile->{narSize};
+            print MANIFEST "  Size: $narFile->{size}\n";
             print MANIFEST "  References: $narFile->{references}\n"
                 if defined $narFile->{references} && $narFile->{references} ne "";
             print MANIFEST "  Deriver: $narFile->{deriver}\n"
                 if defined $narFile->{deriver} && $narFile->{deriver} ne "";
-            print MANIFEST "  System: $narFile->{system}\n" if defined $narFile->{system};
             print MANIFEST "}\n";
         }
     }
@@ -180,9 +208,8 @@ sub writeManifest {
             print MANIFEST "  StorePath: $storePath\n";
             print MANIFEST "  NarURL: $patch->{url}\n";
             print MANIFEST "  Hash: $patch->{hash}\n";
-            print MANIFEST "  Size: $patch->{size}\n";
             print MANIFEST "  NarHash: $patch->{narHash}\n";
-            print MANIFEST "  NarSize: $patch->{narSize}\n" if $patch->{narSize};
+            print MANIFEST "  Size: $patch->{size}\n";
             print MANIFEST "  BasePath: $patch->{basePath}\n";
             print MANIFEST "  BaseHash: $patch->{baseHash}\n";
             print MANIFEST "  Type: $patch->{patchType}\n";
@@ -198,13 +225,11 @@ sub writeManifest {
 
 
     # Create a bzipped manifest.
-    unless (defined $noCompress) {
-	system("@bzip2@ < $manifest > $manifest.bz2.tmp") == 0
-	    or die "cannot compress manifest";
+    system("@bzip2@ < $manifest > $manifest.bz2.tmp") == 0
+        or die "cannot compress manifest";
 
-	rename("$manifest.bz2.tmp", "$manifest.bz2")
-	    or die "cannot rename $manifest.bz2.tmp: $!";
-    }
+    rename("$manifest.bz2.tmp", "$manifest.bz2")
+        or die "cannot rename $manifest.bz2.tmp: $!";
 }
 
 

src/Makefile.am

@@ -1,3 +1,5 @@
 SUBDIRS = bin2c boost libutil libstore libmain nix-store nix-hash \
  libexpr nix-instantiate nix-env nix-worker nix-setuid-helper \
  nix-log2xml bsdiff-4.3
+
+EXTRA_DIST = aterm-helper.pl

src/aterm-helper.pl

@@ -0,0 +1,178 @@
+#! /usr/bin/perl -w
+
+# This program generates C/C++ code for efficiently manipulating
+# ATerms.  It generates functions to build and match ATerms according
+# to a set of constructor definitions defined in a file read from
+# standard input.  A constructor is defined by a line with the
+# following format:
+#
+#   SYM | ARGS | TYPE | FUN?
+#
+# where SYM is the name of the constructor, ARGS is a
+# whitespace-separated list of argument types, TYPE is the type of the
+# resulting ATerm (which should be `ATerm' or a type synonym for
+# `ATerm'), and the optional FUN is used to construct the names of the
+# build and match functions (it defaults to SYM; overriding it is
+# useful if there are overloaded constructors, e.g., with different
+# arities).  Note that SYM may be empty.
+#
+# A line of the form
+#
+#   VAR = EXPR
+#
+# causes a ATerm variable to be generated that is initialised to the
+# value EXPR.
+#
+# Finally, a line of the form
+#
+#   init NAME
+#
+# causes the initialisation function to be called `NAME'.  This
+# function must be called before any of the build/match functions or
+# the generated variables are used.
+
+die if scalar @ARGV != 2;
+
+my $syms = "";
+my $init = "";
+my $initFun = "init";
+
+open HEADER, ">$ARGV[0]";
+open IMPL, ">$ARGV[1]";
+
+print HEADER "#include <aterm2.h>\n";
+print HEADER "#ifdef __cplusplus\n";
+print HEADER "namespace nix {\n";
+print HEADER "#endif\n\n\n";
+print IMPL "namespace nix {\n";
+
+while (<STDIN>) {
+    s/\#.*//;
+    next if (/^\s*$/);
+    
+    if (/^\s*(\w*)\s*\|([^\|]*)\|\s*(\w+)\s*\|\s*(\w+)?/) {
+        my $const = $1;
+        my @types = split ' ', $2;
+        my $result = $3;
+        my $funname = $4;
+        $funname = $const unless defined $funname;
+
+        my $formals = "";
+        my $formals2 = "";
+        my $args = "";
+        my $unpack = "";
+        my $n = 1;
+        foreach my $type (@types) {
+            my $realType = $type;
+            $args .= ", ";
+            if ($type eq "string") {
+#                $args .= "(ATerm) ATmakeAppl0(ATmakeAFun((char *) e$n, 0, ATtrue))";
+#                $type = "const char *";
+                $type = "ATerm";
+                $args .= "e$n";
+                # !!! in the matcher, we should check that the
+                # argument is a string (i.e., a nullary application).
+            } elsif ($type eq "int") {
+                $args .= "(ATerm) ATmakeInt(e$n)";
+            } elsif ($type eq "ATermList" || $type eq "ATermBlob") {
+                $args .= "(ATerm) e$n";
+            } else {
+                $args .= "e$n";
+            }
+            $formals .= ", " if $formals ne "";
+            $formals .= "$type e$n";
+            $formals2 .= ", ";
+            $formals2 .= "$type & e$n";
+            my $m = $n - 1;
+            # !!! more checks here
+            if ($type eq "int") {
+                $unpack .= "    e$n = ATgetInt((ATermInt) ATgetArgument(e, $m));\n";
+            } elsif ($type eq "ATermList") {
+                $unpack .= "    e$n = (ATermList) ATgetArgument(e, $m);\n";
+            } elsif ($type eq "ATermBlob") {
+                $unpack .= "    e$n = (ATermBlob) ATgetArgument(e, $m);\n";
+            } elsif ($realType eq "string") {
+                $unpack .= "    e$n = ATgetArgument(e, $m);\n";
+                $unpack .= "    if (ATgetType(e$n) != AT_APPL) return false;\n";
+            } else {
+                $unpack .= "    e$n = ATgetArgument(e, $m);\n";
+            }
+            $n++;
+        }
+
+        my $arity = scalar @types;
+
+        print HEADER "extern AFun sym$funname;\n\n";
+        
+        print IMPL "AFun sym$funname = 0;\n";
+        
+        if ($arity == 0) {
+            print HEADER "extern ATerm const$funname;\n\n";
+            print IMPL "ATerm const$funname = 0;\n";
+        }
+        
+        print HEADER "static inline $result make$funname($formals) __attribute__ ((pure, nothrow));\n";
+        print HEADER "static inline $result make$funname($formals) {\n";
+        if ($arity == 0) {
+            print HEADER "    return const$funname;\n";
+        }
+        elsif ($arity <= 6) {
+            print HEADER "    return (ATerm) ATmakeAppl$arity(sym$funname$args);\n";
+        } else {
+            $args =~ s/^,//;
+            print HEADER "    ATerm array[$arity] = {$args};\n";
+            print HEADER "    return (ATerm) ATmakeApplArray(sym$funname, array);\n";
+        }
+        print HEADER "}\n\n";
+
+        print HEADER "#ifdef __cplusplus\n";
+        print HEADER "static inline bool match$funname(ATerm e$formals2) {\n";
+        print HEADER "    if (ATgetType(e) != AT_APPL || (AFun) ATgetAFun(e) != sym$funname) return false;\n";
+        print HEADER "$unpack";
+        print HEADER "    return true;\n";
+        print HEADER "}\n";
+        print HEADER "#endif\n\n\n";
+
+        $init .= "    sym$funname = ATmakeAFun(\"$const\", $arity, ATfalse);\n";
+        $init .= "    ATprotectAFun(sym$funname);\n";
+        if ($arity == 0) {
+            $init .= "    const$funname = (ATerm) ATmakeAppl0(sym$funname);\n";
+            $init .= "    ATprotect(&const$funname);\n";
+        }
+    }
+
+    elsif (/^\s*(\w+)\s*=\s*(.*)$/) {
+        my $name = $1;
+        my $value = $2;
+        print HEADER "extern ATerm $name;\n";
+        print IMPL "ATerm $name = 0;\n";
+        $init .= "    $name = $value;\n";
+    }
+
+    elsif (/^\s*init\s+(\w+)\s*$/) {
+        $initFun = $1;
+    }
+
+    else {
+        die "bad line: `$_'";
+    }
+}
+
+print HEADER "void $initFun();\n\n";
+
+print HEADER "static inline const char * aterm2String(ATerm t) {\n";
+print HEADER "    return (const char *) ATgetName(ATgetAFun(t));\n";
+print HEADER "}\n\n";
+
+print IMPL "\n";
+print IMPL "void $initFun() {\n";
+print IMPL "$init";
+print IMPL "}\n";
+
+print HEADER "#ifdef __cplusplus\n";
+print HEADER "}\n";
+print HEADER "#endif\n\n\n";
+print IMPL "}\n";
+
+close HEADER;
+close IMPL;

src/bin2c/Makefile.am

@@ -1,6 +1,3 @@
 noinst_PROGRAMS = bin2c
 
 bin2c_SOURCES = bin2c.c
-
-bin2c$(EXEEXT): bin2c.c
-	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o bin2c bin2c.c

src/bin2c/bin2c.c

@@ -14,10 +14,10 @@ int main(int argc, char * * argv)
 {
     int c;
     if (argc != 2) abort();
-    print("static unsigned char %s[] = { ", argv[1]);
+    print("static unsigned char %s[] = {", argv[1]);
     while ((c = getchar()) != EOF) {
         print("0x%02x, ", (unsigned char) c);
     }
-    print("0 };\n");
+    print("};\n");
     return 0;
 }

src/boost/Makefile.am

@@ -1,6 +1,6 @@
 SUBDIRS = format
 
-nobase_pkginclude_HEADERS = assert.hpp checked_delete.hpp format.hpp \
+pkginclude_HEADERS = assert.hpp checked_delete.hpp format.hpp \
  shared_ptr.hpp weak_ptr.hpp throw_exception.hpp \
  enable_shared_from_this.hpp \
  detail/shared_count.hpp detail/workaround.hpp

src/bsdiff-4.3/Makefile.am

@@ -1,5 +1,3 @@
-EXTRA_DIST = compat-include
-
 libexec_PROGRAMS = bsdiff bspatch
 
 bsdiff_SOURCES = bsdiff.c
@@ -10,4 +8,4 @@ bspatch_SOURCES = bspatch.c
 
 bspatch_LDADD = ${bzip2_lib}
 
-AM_CFLAGS = -O3 ${bzip2_include} ${bsddiff_compat_include}
+AM_CFLAGS = -O3 ${bzip2_include}

src/bsdiff-4.3/bsdiff.c

@@ -277,7 +277,6 @@ int main(int argc,char *argv[])
 		for(scsc=scan+=len;scan<newsize;scan++) {
 			len=search(I,old,oldsize,new+scan,newsize-scan,
 					0,oldsize,&pos);
-			if (len > 64 * 1024) break;
 
 			for(;scsc<scan+len;scsc++)
 			if((scsc+lastoffset<oldsize) &&

src/bsdiff-4.3/compat-include/err.h

@@ -1,12 +0,0 @@
-/* Simulate BSD's <err.h> functionality. */
-
-#ifndef COMPAT_ERR_H_INCLUDED
-#define COMPAT_ERR_H_INCLUDED 1
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#define err(rc,...)  do { fprintf(stderr,__VA_ARGS__); exit(rc); } while(0)
-#define errx(rc,...) do { fprintf(stderr,__VA_ARGS__); exit(rc); } while(0)
-
-#endif

src/libexpr/Makefile.am

@@ -2,25 +2,27 @@ pkglib_LTLIBRARIES = libexpr.la
 
 libexpr_la_SOURCES = \
  nixexpr.cc eval.cc primops.cc lexer-tab.cc parser-tab.cc \
- get-drvs.cc attr-path.cc value-to-xml.cc common-opts.cc \
+ get-drvs.cc attr-path.cc expr-to-xml.cc common-opts.cc \
  names.cc
 
 pkginclude_HEADERS = \
  nixexpr.hh eval.hh parser.hh lexer-tab.hh parser-tab.hh \
- get-drvs.hh attr-path.hh value-to-xml.hh common-opts.hh \
- names.hh symbol-table.hh
+ get-drvs.hh attr-path.hh expr-to-xml.hh common-opts.hh \
+ names.hh
 
 libexpr_la_LIBADD = ../libutil/libutil.la ../libstore/libstore.la \
- ../boost/format/libformat.la @boehmgc_lib@
+ ../boost/format/libformat.la
 
-BUILT_SOURCES = \
+BUILT_SOURCES = nixexpr-ast.cc nixexpr-ast.hh \
  parser-tab.hh lexer-tab.hh parser-tab.cc lexer-tab.cc
 
-EXTRA_DIST = lexer.l parser.y
+EXTRA_DIST = lexer.l parser.y nixexpr-ast.def nixexpr-ast.cc
 
 AM_CXXFLAGS = \
- -I$(srcdir)/.. \
+ -I$(srcdir)/.. ${bdb_include} ${aterm_include} \
  -I$(srcdir)/../libutil -I$(srcdir)/../libstore
+AM_CFLAGS = \
+ ${aterm_include}
 
 
 # Parser generation.
@@ -32,6 +34,15 @@ lexer-tab.cc lexer-tab.hh: lexer.l
 	$(flex) --outfile lexer-tab.cc --header-file=lexer-tab.hh $(srcdir)/lexer.l 
 
 
+# ATerm helper function generation.
+
+nixexpr-ast.cc nixexpr-ast.hh: ../aterm-helper.pl nixexpr-ast.def
+	$(perl) $(srcdir)/../aterm-helper.pl nixexpr-ast.hh nixexpr-ast.cc < $(srcdir)/nixexpr-ast.def
+
+
+CLEANFILES =
+
+
 # SDF stuff (not built by default).
 nix.tbl: nix.sdf
 	sdf2table -m Nix -s -i nix.sdf -o nix.tbl

src/libexpr/attr-path.cc

@@ -1,13 +1,23 @@
 #include "attr-path.hh"
+#include "nixexpr-ast.hh"
 #include "util.hh"
 
 
 namespace nix {
 
 
-// !!! Shouldn't we return a pointer to a Value?
-void findAlongAttrPath(EvalState & state, const string & attrPath,
-    Bindings & autoArgs, Expr * e, Value & v)
+bool isAttrs(EvalState & state, Expr e, ATermMap & attrs)
+{
+    e = evalExpr(state, e);
+    ATermList dummy;
+    if (!matchAttrs(e, dummy)) return false;
+    queryAllAttrs(e, attrs, false);
+    return true;
+}
+
+
+Expr findAlongAttrPath(EvalState & state, const string & attrPath,
+    const ATermMap & autoArgs, Expr e)
 {
     Strings tokens = tokenizeString(attrPath, ".");
 
@@ -15,10 +25,8 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
         Error(format("attribute selection path `%1%' does not match expression") % attrPath);
 
     string curPath;
-
-    state.mkThunk_(v, e);
     
-    foreach (Strings::iterator, i, tokens) {
+    for (Strings::iterator i = tokens.begin(); i != tokens.end(); ++i) {
 
         if (!curPath.empty()) curPath += ".";
         curPath += *i;
@@ -30,10 +38,7 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
         if (string2Int(attr, attrIndex)) apType = apIndex;
 
         /* Evaluate the expression. */
-        Value vTmp;
-        state.autoCallFunction(autoArgs, v, vTmp);
-        v = vTmp;
-        state.forceValue(v);
+        e = evalExpr(state, autoCallFunction(evalExpr(state, e), autoArgs));
 
         /* It should evaluate to either an attribute set or an
            expression, according to what is specified in the
@@ -41,31 +46,36 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
 
         if (apType == apAttr) {
 
-            if (v.type != tAttrs)
+            ATermMap attrs;
+
+            if (!isAttrs(state, e, attrs))
                 throw TypeError(
                     format("the expression selected by the selection path `%1%' should be an attribute set but is %2%")
-                    % curPath % showType(v));
-
-            Bindings::iterator a = v.attrs->find(state.symbols.create(attr));
-            if (a == v.attrs->end())
+                    % curPath % showType(e));
+                
+            e = attrs.get(toATerm(attr));
+            if (!e)
                 throw Error(format("attribute `%1%' in selection path `%2%' not found") % attr % curPath);
-            v = *a->value;
+
         }
 
         else if (apType == apIndex) {
 
-            if (v.type != tList)
+            ATermList es;
+            if (!matchList(e, es))
                 throw TypeError(
                     format("the expression selected by the selection path `%1%' should be a list but is %2%")
-                    % curPath % showType(v));
+                    % curPath % showType(e));
 
-            if (attrIndex >= v.list.length)
-                throw Error(format("list index %1% in selection path `%2%' is out of range") % attrIndex % curPath);
-
-            v = *v.list.elems[attrIndex];
+            e = ATelementAt(es, attrIndex);
+            if (!e)
+                throw Error(format("list index %1% in selection path `%2%' not found") % attrIndex % curPath);
+            
         }
         
     }
+    
+    return e;
 }
 
  

src/libexpr/attr-path.hh

@@ -1,17 +1,17 @@
 #ifndef __ATTR_PATH_H
 #define __ATTR_PATH_H
 
-#include "eval.hh"
-
 #include <string>
 #include <map>
 
+#include "eval.hh"
+
 
 namespace nix {
 
     
-void findAlongAttrPath(EvalState & state, const string & attrPath,
-    Bindings & autoArgs, Expr * e, Value & v);
+Expr findAlongAttrPath(EvalState & state, const string & attrPath,
+    const ATermMap & autoArgs, Expr e);
 
     
 }

src/libexpr/common-opts.cc

@@ -9,7 +9,7 @@ namespace nix {
 
 bool parseOptionArg(const string & arg, Strings::iterator & i,
     const Strings::iterator & argsEnd, EvalState & state,
-    Bindings & autoArgs)
+    ATermMap & autoArgs)
 {
     if (arg != "--arg" && arg != "--argstr") return false;
 
@@ -19,18 +19,12 @@ bool parseOptionArg(const string & arg, Strings::iterator & i,
     string name = *i++;
     if (i == argsEnd) throw error;
     string value = *i++;
-
-    /* !!! check for duplicates! */
-    Value * v = state.allocValue();
-    autoArgs.push_back(Attr(state.symbols.create(name), v));
-
-    if (arg == "--arg")
-        state.mkThunk_(*v, parseExprFromString(state, value, absPath(".")));
-    else
-        mkString(*v, value);
-
-    autoArgs.sort(); // !!! inefficient
-
+    
+    Expr e = arg == "--arg"
+        ? parseExprFromString(state, value, absPath("."))
+        : makeStr(value);
+    autoArgs.set(toATerm(name), e);
+    
     return true;
 }
 

src/libexpr/common-opts.hh

@@ -9,7 +9,7 @@ namespace nix {
 /* Some common option parsing between nix-env and nix-instantiate. */
 bool parseOptionArg(const string & arg, Strings::iterator & i,
     const Strings::iterator & argsEnd, EvalState & state,
-    Bindings & autoArgs);
+    ATermMap & autoArgs);
     
 }
 

src/libexpr/eval.hh

@@ -1,193 +1,19 @@
 #ifndef __EVAL_H
 #define __EVAL_H
 
-#include "nixexpr.hh"
-#include "symbol-table.hh"
-#include "hash.hh"
-
 #include <map>
 
-#if HAVE_BOEHMGC
-#include <gc/gc_allocator.h>
-#endif
+#include "aterm.hh"
+#include "nixexpr.hh"
 
 
 namespace nix {
 
 
-class EvalState;
-struct Env;
-struct Value;
-struct Attr;
-
-
-/* Attribute sets are represented as a vector of attributes, sorted by
-   symbol (i.e. pointer to the attribute name in the symbol table). */
-#if HAVE_BOEHMGC
-typedef std::vector<Attr, gc_allocator<Attr> > BindingsBase;
-#else
-typedef std::vector<Attr> BindingsBase;
-#endif
-
-
-class Bindings : public BindingsBase
-{
-public:
-    iterator find(const Symbol & name);
-    void sort();
-};
-
-
-typedef enum {
-    tInt = 1,
-    tBool,
-    tString,
-    tPath,
-    tNull,
-    tAttrs,
-    tList,
-    tThunk,
-    tApp,
-    tLambda,
-    tBlackhole,
-    tPrimOp,
-    tPrimOpApp,
-} ValueType;
-
-
-typedef void (* PrimOpFun) (EvalState & state, Value * * args, Value & v);
-
-
-struct PrimOp
-{
-    PrimOpFun fun;
-    unsigned int arity;
-    Symbol name;
-    PrimOp(PrimOpFun fun, unsigned int arity, Symbol name)
-        : fun(fun), arity(arity), name(name) { }
-};
-
-
-struct Value
-{
-    ValueType type;
-    union 
-    {
-        int integer;
-        bool boolean;
-        
-        /* Strings in the evaluator carry a so-called `context' (the
-           ATermList) which is a list of strings representing store
-           paths.  This is to allow users to write things like
-
-             "--with-freetype2-library=" + freetype + "/lib"
-
-           where `freetype' is a derivation (or a source to be copied
-           to the store).  If we just concatenated the strings without
-           keeping track of the referenced store paths, then if the
-           string is used as a derivation attribute, the derivation
-           will not have the correct dependencies in its inputDrvs and
-           inputSrcs.
-
-           The semantics of the context is as follows: when a string
-           with context C is used as a derivation attribute, then the
-           derivations in C will be added to the inputDrvs of the
-           derivation, and the other store paths in C will be added to
-           the inputSrcs of the derivations.
-
-           For canonicity, the store paths should be in sorted order. */
-        struct {
-            const char * s;
-            const char * * context; // must be in sorted order
-        } string;
-        
-        const char * path;
-        Bindings * attrs;
-        struct {
-            unsigned int length;
-            Value * * elems;
-        } list;
-        struct {
-            Env * env;
-            Expr * expr;
-        } thunk;
-        struct {
-            Value * left, * right;
-        } app;
-        struct {
-            Env * env;
-            ExprLambda * fun;
-        } lambda;
-        PrimOp * primOp;
-        struct {
-            Value * left, * right;
-        } primOpApp;
-    };
-};
-
-
-struct Env
-{
-    Env * up;
-    unsigned int prevWith; // nr of levels up to next `with' environment
-    Value * values[0];
-};
-
-
-struct Attr
-{
-    Symbol name;
-    Value * value;
-    Pos * pos;
-    Attr(Symbol name, Value * value, Pos * pos = &noPos)
-        : name(name), value(value), pos(pos) { };
-    Attr() : pos(&noPos) { };
-    bool operator < (const Attr & a) const
-    {
-        return name < a.name;
-    }
-};
-
-
-/* After overwriting an app node, be sure to clear pointers in the
-   Value to ensure that the target isn't kept alive unnecessarily. */
-static inline void clearValue(Value & v)
-{
-    v.app.right = 0;
-}
-
-
-static inline void mkInt(Value & v, int n)
-{
-    clearValue(v);
-    v.type = tInt;
-    v.integer = n;
-}
-
-
-static inline void mkBool(Value & v, bool b)
-{
-    clearValue(v);
-    v.type = tBool;
-    v.boolean = b;
-}
-
-
-static inline void mkApp(Value & v, Value & left, Value & right)
-{
-    v.type = tApp;
-    v.app.left = &left;
-    v.app.right = &right;
-}
-
-
-void mkString(Value & v, const char * s);
-void mkString(Value & v, const string & s, const PathSet & context = PathSet());
-void mkPath(Value & v, const char * s);
-
-void copyContext(const Value & v, PathSet & context);
-
+class Hash;
+    
 
+typedef std::map<Path, PathSet> DrvRoots;
 typedef std::map<Path, Hash> DrvHashes;
 
 /* Cache for calls to addToStore(); maps source paths to the store
@@ -196,160 +22,73 @@ typedef std::map<Path, Path> SrcToStore;
 
 struct EvalState;
 
-
-std::ostream & operator << (std::ostream & str, const Value & v);
+/* Note: using a ATermVector is safe here, since when we call a primop
+   we also have an ATermList on the stack. */
+typedef Expr (* PrimOp) (EvalState &, const ATermVector & args);
 
 
-class EvalState 
+struct EvalState 
 {
-public:
+    ATermMap normalForms;
+    ATermMap primOps;
+    DrvRoots drvRoots;
     DrvHashes drvHashes; /* normalised derivation hashes */
-
-    SymbolTable symbols;
-
-    const Symbol sWith, sOutPath, sDrvPath, sType, sMeta, sName,
-        sSystem, sOverrides;
-
-private:
     SrcToStore srcToStore; 
 
-    bool allowUnsafeEquality;
+    unsigned int nrEvaluated;
+    unsigned int nrCached;
 
-    std::map<Path, Expr *> parseTrees;
-
-public:
-    
     EvalState();
-    ~EvalState();
-
-    /* Evaluate an expression read from the given file to normal
-       form. */
-    void evalFile(const Path & path, Value & v);
-
-    /* Evaluate an expression to normal form, storing the result in
-       value `v'. */
-    void eval(Expr * e, Value & v);
-    void eval(Env & env, Expr * e, Value & v);
-
-    /* Evaluation the expression, then verify that it has the expected
-       type. */
-    bool evalBool(Env & env, Expr * e);
-    void evalAttrs(Env & env, Expr * e, Value & v);
-
-    /* If `v' is a thunk, enter it and overwrite `v' with the result
-       of the evaluation of the thunk.  If `v' is a delayed function
-       application, call the function and overwrite `v' with the
-       result.  Otherwise, this is a no-op. */
-    void forceValue(Value & v);
-
-    /* Force a value, then recursively force list elements and
-       attributes. */
-    void strictForceValue(Value & v);
-
-    /* Force `v', and then verify that it has the expected type. */
-    int forceInt(Value & v);
-    bool forceBool(Value & v);
-    void forceAttrs(Value & v);
-    void forceList(Value & v);
-    void forceFunction(Value & v); // either lambda or primop
-    string forceString(Value & v);
-    string forceString(Value & v, PathSet & context);
-    string forceStringNoCtx(Value & v);
-
-    /* Return true iff the value `v' denotes a derivation (i.e. a
-       set with attribute `type = "derivation"'). */
-    bool isDerivation(Value & v);
-
-    /* String coercion.  Converts strings, paths and derivations to a
-       string.  If `coerceMore' is set, also converts nulls, integers,
-       booleans and lists to a string.  If `copyToStore' is set,
-       referenced paths are copied to the Nix store as a side effect.q */
-    string coerceToString(Value & v, PathSet & context,
-        bool coerceMore = false, bool copyToStore = true);
-
-    /* Path coercion.  Converts strings, paths and derivations to a
-       path.  The result is guaranteed to be a canonicalised, absolute
-       path.  Nothing is copied to the store. */
-    Path coerceToPath(Value & v, PathSet & context);
-
-private:
-
-    /* The base environment, containing the builtin functions and
-       values. */
-    Env & baseEnv;
-
-    unsigned int baseEnvDispl;
-
-public:
-    
-    /* The same, but used during parsing to resolve variables. */
-    StaticEnv staticBaseEnv; // !!! should be private
-
-private:
-    
-    void createBaseEnv();
-    
-    void addConstant(const string & name, Value & v);
 
+    void addPrimOps();
     void addPrimOp(const string & name,
-        unsigned int arity, PrimOpFun primOp);
-
-    Value * lookupVar(Env * env, const VarRef & var);
-    
-    friend class ExprVar;
-    friend class ExprAttrs;
-    friend class ExprLet;
-
-public:
-    
-    /* Do a deep equality test between two values.  That is, list
-       elements and attributes are compared recursively. */
-    bool eqValues(Value & v1, Value & v2);
-
-    void callFunction(Value & fun, Value & arg, Value & v);
-
-    /* Automatically call a function for which each argument has a
-       default value or has a binding in the `args' map. */
-    void autoCallFunction(Bindings & args, Value & fun, Value & res);
-    
-    /* Allocation primitives. */
-    Value * allocValue();
-    Env & allocEnv(unsigned int size);
-
-    Value * allocAttr(Value & vAttrs, const Symbol & name);
-
-    void mkList(Value & v, unsigned int length);
-    void mkAttrs(Value & v, unsigned int expected);
-    void mkThunk_(Value & v, Expr * expr);
-
-    Value * maybeThunk(Env & env, Expr * expr);
-    
-    /* Print statistics. */
-    void printStats();
-
-private:
-    
-    unsigned long nrEnvs;
-    unsigned long nrValuesInEnvs;
-    unsigned long nrValues;
-    unsigned long nrListElems;
-    unsigned long nrEvaluated;
-    unsigned long nrAttrsets;
-    unsigned long nrOpUpdates;
-    unsigned long nrOpUpdateValuesCopied;
-    unsigned int recursionDepth;
-    unsigned int maxRecursionDepth;
-    char * deepestStack; /* for measuring stack usage */
-    
-    friend class RecursionCounter;
-    friend class ExprOpUpdate;
+        unsigned int arity, PrimOp primOp);
 };
 
 
-/* Return a string representing the type of the value `v'. */
-string showType(const Value & v);
+/* Evaluate an expression to normal form. */
+Expr evalExpr(EvalState & state, Expr e);
 
+/* Evaluate an expression read from the given file to normal form. */
+Expr evalFile(EvalState & state, const Path & path);
 
+/* Evaluate an expression, and recursively evaluate list elements and
+   attributes.  If `canonicalise' is true, we remove things like
+   position information and make sure that attribute sets are in
+   sorded order. */
+Expr strictEvalExpr(EvalState & state, Expr e);
+
+/* Specific results. */
+string evalString(EvalState & state, Expr e, PathSet & context);
+string evalStringNoCtx(EvalState & state, Expr e);
+int evalInt(EvalState & state, Expr e);
+bool evalBool(EvalState & state, Expr e);
+ATermList evalList(EvalState & state, Expr e);
+
+/* Flatten nested lists into a single list (or expand a singleton into
+   a list). */
+ATermList flattenList(EvalState & state, Expr e);
+
+/* String coercion.  Converts strings, paths and derivations to a
+   string.  If `coerceMore' is set, also converts nulls, integers,
+   booleans and lists to a string. */
+string coerceToString(EvalState & state, Expr e, PathSet & context,
+    bool coerceMore = false, bool copyToStore = true);
+
+/* Path coercion.  Converts strings, paths and derivations to a path.
+   The result is guaranteed to be an canonicalised, absolute path.
+   Nothing is copied to the store. */
+Path coerceToPath(EvalState & state, Expr e, PathSet & context);
+
+/* Automatically call a function for which each argument has a default
+   value or has a binding in the `args' map.  Note: result is a call,
+   not a normal form; it should be evaluated by calling evalExpr(). */
+Expr autoCallFunction(Expr e, const ATermMap & args);
+
+/* Print statistics. */
+void printEvalStats(EvalState & state);
+
+ 
 }
 
 

src/libexpr/expr-to-xml.cc

@@ -0,0 +1,156 @@
+#include "expr-to-xml.hh"
+#include "xml-writer.hh"
+#include "nixexpr-ast.hh"
+#include "aterm.hh"
+#include "util.hh"
+
+#include <cstdlib>
+
+
+namespace nix {
+
+    
+static XMLAttrs singletonAttrs(const string & name, const string & value)
+{
+    XMLAttrs attrs;
+    attrs[name] = value;
+    return attrs;
+}
+
+
+/* set<Expr> is safe because all the expressions are also reachable
+   from the stack, therefore can't be garbage-collected. */
+typedef set<Expr> ExprSet;
+
+
+static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context,
+    ExprSet & drvsSeen);
+
+
+static void showAttrs(const ATermMap & attrs, XMLWriter & doc,
+    PathSet & context, ExprSet & drvsSeen)
+{
+    StringSet names;
+    for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i)
+        names.insert(aterm2String(i->key));
+    for (StringSet::iterator i = names.begin(); i != names.end(); ++i) {
+        XMLOpenElement _(doc, "attr", singletonAttrs("name", *i));
+        printTermAsXML(attrs.get(toATerm(*i)), doc, context, drvsSeen);
+    }
+}
+
+
+static void printPatternAsXML(Pattern pat, XMLWriter & doc)
+{
+    ATerm name;
+    ATermList formals;
+    Pattern pat1, pat2;
+    ATermBool ellipsis;
+    if (matchVarPat(pat, name))
+        doc.writeEmptyElement("varpat", singletonAttrs("name", aterm2String(name)));
+    else if (matchAttrsPat(pat, formals, ellipsis)) {
+        XMLOpenElement _(doc, "attrspat");
+        for (ATermIterator i(formals); i; ++i) {
+            Expr name; ATerm dummy;
+            if (!matchFormal(*i, name, dummy)) abort();
+            doc.writeEmptyElement("attr", singletonAttrs("name", aterm2String(name)));
+        }
+        if (ellipsis == eTrue) doc.writeEmptyElement("ellipsis");
+    }
+    else if (matchAtPat(pat, pat1, pat2)) {
+        XMLOpenElement _(doc, "at");
+        printPatternAsXML(pat1, doc);
+        printPatternAsXML(pat2, doc);
+    }
+}
+
+
+static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context,
+    ExprSet & drvsSeen)
+{
+    XMLAttrs attrs;
+    string s;
+    ATerm s2;
+    int i;
+    ATermList as, es;
+    ATerm pat, body, pos;
+
+    checkInterrupt();
+
+    if (matchStr(e, s, context)) /* !!! show the context? */
+        doc.writeEmptyElement("string", singletonAttrs("value", s));
+
+    else if (matchPath(e, s2))
+        doc.writeEmptyElement("path", singletonAttrs("value", aterm2String(s2)));
+
+    else if (matchNull(e))
+        doc.writeEmptyElement("null");
+
+    else if (matchInt(e, i))
+        doc.writeEmptyElement("int", singletonAttrs("value", (format("%1%") % i).str()));
+
+    else if (e == eTrue)
+        doc.writeEmptyElement("bool", singletonAttrs("value", "true"));
+
+    else if (e == eFalse)
+        doc.writeEmptyElement("bool", singletonAttrs("value", "false"));
+
+    else if (matchAttrs(e, as)) {
+        ATermMap attrs;
+        queryAllAttrs(e, attrs);
+
+        Expr a = attrs.get(toATerm("type"));
+        if (a && matchStr(a, s, context) && s == "derivation") {
+
+            XMLAttrs xmlAttrs;
+            Path outPath, drvPath;
+            
+            a = attrs.get(toATerm("drvPath"));
+            if (matchStr(a, drvPath, context))
+                xmlAttrs["drvPath"] = drvPath;
+        
+            a = attrs.get(toATerm("outPath"));
+            if (matchStr(a, outPath, context))
+                xmlAttrs["outPath"] = outPath;
+        
+            XMLOpenElement _(doc, "derivation", xmlAttrs);
+
+            if (drvsSeen.find(e) == drvsSeen.end()) {
+                drvsSeen.insert(e);
+                showAttrs(attrs, doc, context, drvsSeen);
+            } else
+                doc.writeEmptyElement("repeated");
+        }
+
+        else {
+            XMLOpenElement _(doc, "attrs");
+            showAttrs(attrs, doc, context, drvsSeen);
+        }
+    }
+
+    else if (matchList(e, es)) {
+        XMLOpenElement _(doc, "list");
+        for (ATermIterator i(es); i; ++i)
+            printTermAsXML(*i, doc, context, drvsSeen);
+    }
+
+    else if (matchFunction(e, pat, body, pos)) {
+        XMLOpenElement _(doc, "function");
+        printPatternAsXML(pat, doc);
+    }
+
+    else
+        doc.writeEmptyElement("unevaluated");
+}
+
+
+void printTermAsXML(Expr e, std::ostream & out, PathSet & context)
+{
+    XMLWriter doc(true, out);
+    XMLOpenElement root(doc, "expr");
+    ExprSet drvsSeen;    
+    printTermAsXML(e, doc, context, drvsSeen);
+}
+
+ 
+}

src/libexpr/expr-to-xml.hh

@@ -0,0 +1,16 @@
+#ifndef __EXPR_TO_XML_H
+#define __EXPR_TO_XML_H
+
+#include <string>
+#include <map>
+
+#include "nixexpr.hh"
+#include "aterm.hh"
+
+namespace nix {
+
+void printTermAsXML(Expr e, std::ostream & out, PathSet & context);
+    
+}
+
+#endif /* !__EXPR_TO_XML_H */

src/libexpr/get-drvs.cc

@@ -1,4 +1,5 @@
 #include "get-drvs.hh"
+#include "nixexpr-ast.hh"
 #include "util.hh"
 
 
@@ -7,10 +8,17 @@ namespace nix {
 
 string DrvInfo::queryDrvPath(EvalState & state) const
 {
-    if (drvPath == "" && attrs) {
-        Bindings::iterator i = attrs->find(state.sDrvPath);
+    if (drvPath == "") {
+        Expr a = attrs->get(toATerm("drvPath"));
+
+        /* Backwards compatibility hack with user environments made by
+           Nix <= 0.10: these contain illegal Path("") expressions. */
+        ATerm t;
+        if (a && matchPath(evalExpr(state, a), t))
+            return aterm2String(t);
+        
         PathSet context;
-        (string &) drvPath = i != attrs->end() ? state.coerceToPath(*i->value, context) : "";
+        (string &) drvPath = a ? coerceToPath(state, a, context) : "";
     }
     return drvPath;
 }
@@ -18,10 +26,11 @@ string DrvInfo::queryDrvPath(EvalState & state) const
 
 string DrvInfo::queryOutPath(EvalState & state) const
 {
-    if (outPath == "" && attrs) {
-        Bindings::iterator i = attrs->find(state.sOutPath);
+    if (outPath == "") {
+        Expr a = attrs->get(toATerm("outPath"));
+        if (!a) throw TypeError("output path missing");
         PathSet context;
-        (string &) outPath = i != attrs->end() ? state.coerceToPath(*i->value, context) : "";
+        (string &) outPath = coerceToPath(state, a, context);
     }
     return outPath;
 }
@@ -29,85 +38,93 @@ string DrvInfo::queryOutPath(EvalState & state) const
 
 MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
 {
-    if (metaInfoRead) return meta;
+    MetaInfo meta;
     
-    (bool &) metaInfoRead = true;
-    
-    Bindings::iterator a = attrs->find(state.sMeta);
-    if (a == attrs->end()) return meta; /* fine, empty meta information */
+    Expr a = attrs->get(toATerm("meta"));
+    if (!a) return meta; /* fine, empty meta information */
 
-    state.forceAttrs(*a->value);
+    ATermMap attrs2;
+    queryAllAttrs(evalExpr(state, a), attrs2);
 
-    foreach (Bindings::iterator, i, *a->value->attrs) {
-        MetaValue value;
-        state.forceValue(*i->value);
-        if (i->value->type == tString) {
-            value.type = MetaValue::tpString;
-            value.stringValue = i->value->string.s;
-        } else if (i->value->type == tInt) {
-            value.type = MetaValue::tpInt;
-            value.intValue = i->value->integer;
-        } else if (i->value->type == tList) {
-            value.type = MetaValue::tpStrings;
-            for (unsigned int j = 0; j < i->value->list.length; ++j)
-                value.stringValues.push_back(state.forceStringNoCtx(*i->value->list.elems[j]));
-        } else continue;
-        ((MetaInfo &) meta)[i->name] = value;
+    for (ATermMap::const_iterator i = attrs2.begin(); i != attrs2.end(); ++i) {
+        Expr e = evalExpr(state, i->value);
+        string s;
+        PathSet context;
+        if (matchStr(e, s, context))
+            meta[aterm2String(i->key)] = s;
+        /* For future compatibility, ignore attribute values that are
+           not strings. */
     }
 
     return meta;
 }
 
 
-MetaValue DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
+string DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
 {
     /* !!! evaluates all meta attributes => inefficient */
-    return queryMetaInfo(state)[name];
+    MetaInfo meta = queryMetaInfo(state);
+    MetaInfo::iterator i = meta.find(name);
+    return i == meta.end() ? "" : i->second;
 }
 
 
 void DrvInfo::setMetaInfo(const MetaInfo & meta)
 {
-    metaInfoRead = true;
-    this->meta = meta;
+    ATermMap metaAttrs;
+    for (MetaInfo::const_iterator i = meta.begin(); i != meta.end(); ++i)
+        metaAttrs.set(toATerm(i->first),
+            makeAttrRHS(makeStr(i->second), makeNoPos()));
+    attrs->set(toATerm("meta"), makeAttrs(metaAttrs));
 }
 
 
-/* Cache for already considered attrsets. */
-typedef set<Bindings *> Done;
+/* Cache for already evaluated derivations.  Usually putting ATerms in
+   a STL container is unsafe (they're not scanning for GC roots), but
+   here it doesn't matter; everything in this set is reachable from
+   the stack as well. */
+typedef set<Expr> Exprs;
 
 
-/* Evaluate value `v'.  If it evaluates to an attribute set of type
-   `derivation', then put information about it in `drvs' (unless it's
-   already in `doneExprs').  The result boolean indicates whether it
-   makes sense for the caller to recursively search for derivations in
-   `v'. */
-static bool getDerivation(EvalState & state, Value & v,
-    const string & attrPath, DrvInfos & drvs, Done & done)
+/* Evaluate expression `e'.  If it evaluates to an attribute set of
+   type `derivation', then put information about it in `drvs' (unless
+   it's already in `doneExprs').  The result boolean indicates whether
+   it makes sense for the caller to recursively search for derivations
+   in `e'. */
+static bool getDerivation(EvalState & state, Expr e,
+    const string & attrPath, DrvInfos & drvs, Exprs & doneExprs)
 {
     try {
-        state.forceValue(v);
-        if (!state.isDerivation(v)) return true;
+        
+        ATermList es;
+        e = evalExpr(state, e);
+        if (!matchAttrs(e, es)) return true;
+
+        boost::shared_ptr<ATermMap> attrs(new ATermMap());
+        queryAllAttrs(e, *attrs, false);
+        
+        Expr a = attrs->get(toATerm("type"));
+        if (!a || evalStringNoCtx(state, a) != "derivation") return true;
 
         /* Remove spurious duplicates (e.g., an attribute set like
            `rec { x = derivation {...}; y = x;}'. */
-        if (done.find(v.attrs) != done.end()) return false;
-        done.insert(v.attrs);
+        if (doneExprs.find(e) != doneExprs.end()) return false;
+        doneExprs.insert(e);
 
         DrvInfo drv;
     
-        Bindings::iterator i = v.attrs->find(state.sName);
+        a = attrs->get(toATerm("name"));
         /* !!! We really would like to have a decent back trace here. */
-        if (i == v.attrs->end()) throw TypeError("derivation name missing");
-        drv.name = state.forceStringNoCtx(*i->value);
+        if (!a) throw TypeError("derivation name missing");
+        drv.name = evalStringNoCtx(state, a);
 
-        Bindings::iterator i2 = v.attrs->find(state.sSystem);
-        if (i2 == v.attrs->end())
+        a = attrs->get(toATerm("system"));
+        if (!a)
             drv.system = "unknown";
         else
-            drv.system = state.forceStringNoCtx(*i2->value);
+            drv.system = evalStringNoCtx(state, a);
 
-        drv.attrs = v.attrs;
+        drv.attrs = attrs;
 
         drv.attrPath = attrPath;
 
@@ -120,11 +137,11 @@ static bool getDerivation(EvalState & state, Value & v,
 }
 
 
-bool getDerivation(EvalState & state, Value & v, DrvInfo & drv)
+bool getDerivation(EvalState & state, Expr e, DrvInfo & drv)
 {
-    Done done;
+    Exprs doneExprs;
     DrvInfos drvs;
-    getDerivation(state, v, "", drvs, done);
+    getDerivation(state, e, "", drvs, doneExprs);
     if (drvs.size() != 1) return false;
     drv = drvs.front();
     return true;
@@ -137,73 +154,83 @@ static string addToPath(const string & s1, const string & s2)
 }
 
 
-static void getDerivations(EvalState & state, Value & vIn,
-    const string & pathPrefix, Bindings & autoArgs,
-    DrvInfos & drvs, Done & done)
+static void getDerivations(EvalState & state, Expr e,
+    const string & pathPrefix, const ATermMap & autoArgs,
+    DrvInfos & drvs, Exprs & doneExprs)
 {
-    Value v;
-    state.autoCallFunction(autoArgs, vIn, v);
-    
+    e = evalExpr(state, autoCallFunction(evalExpr(state, e), autoArgs));
+
     /* Process the expression. */
+    ATermList es;
     DrvInfo drv;
 
-    if (!getDerivation(state, v, pathPrefix, drvs, done)) ;
+    if (!getDerivation(state, e, pathPrefix, drvs, doneExprs))
+        return;
 
-    else if (v.type == tAttrs) {
+    if (matchAttrs(e, es)) {
+        ATermMap drvMap(ATgetLength(es));
+        queryAllAttrs(e, drvMap);
 
         /* !!! undocumented hackery to support combining channels in
            nix-env.cc. */
-        bool combineChannels = v.attrs->find(state.symbols.create("_combineChannels")) != v.attrs->end();
+        bool combineChannels = drvMap.get(toATerm("_combineChannels"));
 
         /* Consider the attributes in sorted order to get more
            deterministic behaviour in nix-env operations (e.g. when
            there are names clashes between derivations, the derivation
            bound to the attribute with the "lower" name should take
            precedence). */
-        typedef std::map<string, Symbol> SortedSymbols;
-        SortedSymbols attrs;
-        foreach (Bindings::iterator, i, *v.attrs)
-            attrs.insert(std::pair<string, Symbol>(i->name, i->name));
+        typedef std::map<string, Expr> AttrsSorted;
+        AttrsSorted attrsSorted;
+        foreach (ATermMap::const_iterator, i, drvMap)
+            attrsSorted[aterm2String(i->key)] = i->value;
 
-        foreach (SortedSymbols::iterator, i, attrs) {
+        foreach (AttrsSorted::iterator, i, attrsSorted) {
             startNest(nest, lvlDebug, format("evaluating attribute `%1%'") % i->first);
             string pathPrefix2 = addToPath(pathPrefix, i->first);
-            Value & v2(*v.attrs->find(i->second)->value);
             if (combineChannels)
-                getDerivations(state, v2, pathPrefix2, autoArgs, drvs, done);
-            else if (getDerivation(state, v2, pathPrefix2, drvs, done)) {
+                getDerivations(state, i->second, pathPrefix2, autoArgs, drvs, doneExprs);
+            else if (getDerivation(state, i->second, pathPrefix2, drvs, doneExprs)) {
                 /* If the value of this attribute is itself an
                    attribute set, should we recurse into it?  => Only
                    if it has a `recurseForDerivations = true'
                    attribute. */
-                if (v2.type == tAttrs) {
-                    Bindings::iterator j = v2.attrs->find(state.symbols.create("recurseForDerivations"));
-                    if (j != v2.attrs->end() && state.forceBool(*j->value))
-                        getDerivations(state, v2, pathPrefix2, autoArgs, drvs, done);
+                ATermList es;
+                Expr e = evalExpr(state, i->second), e2;
+                if (matchAttrs(e, es)) {
+                    ATermMap attrs(ATgetLength(es));
+                    queryAllAttrs(e, attrs, false);
+                    if (((e2 = attrs.get(toATerm("recurseForDerivations")))
+                            && evalBool(state, e2)))
+                        getDerivations(state, e, pathPrefix2, autoArgs, drvs, doneExprs);
                 }
             }
         }
+        
+        return;
     }
 
-    else if (v.type == tList) {
-        for (unsigned int n = 0; n < v.list.length; ++n) {
+    if (matchList(e, es)) {
+        int n = 0;
+        for (ATermIterator i(es); i; ++i, ++n) {
             startNest(nest, lvlDebug,
                 format("evaluating list element"));
             string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
-            if (getDerivation(state, *v.list.elems[n], pathPrefix2, drvs, done))
-                getDerivations(state, *v.list.elems[n], pathPrefix2, autoArgs, drvs, done);
+            if (getDerivation(state, *i, pathPrefix2, drvs, doneExprs))
+                getDerivations(state, *i, pathPrefix2, autoArgs, drvs, doneExprs);
         }
+        return;
     }
 
-    else throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
+    throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
 }
 
 
-void getDerivations(EvalState & state, Value & v, const string & pathPrefix,
-    Bindings & autoArgs, DrvInfos & drvs)
+void getDerivations(EvalState & state, Expr e, const string & pathPrefix,
+    const ATermMap & autoArgs, DrvInfos & drvs)
 {
-    Done done;
-    getDerivations(state, v, pathPrefix, autoArgs, drvs, done);
+    Exprs doneExprs;
+    getDerivations(state, e, pathPrefix, autoArgs, drvs, doneExprs);
 }
 
  

src/libexpr/get-drvs.hh

@@ -1,27 +1,18 @@
 #ifndef __GET_DRVS_H
 #define __GET_DRVS_H
 
-#include "eval.hh"
-
 #include <string>
 #include <map>
 
 #include <boost/shared_ptr.hpp>
 
+#include "eval.hh"
+
 
 namespace nix {
 
 
-struct MetaValue
-{
-    enum { tpNone, tpString, tpStrings, tpInt } type;
-    string stringValue;
-    Strings stringValues;
-    int intValue;
-};
-
-
-typedef std::map<string, MetaValue> MetaInfo;
+typedef std::map<string, string> MetaInfo;
 
 
 struct DrvInfo
@@ -29,24 +20,21 @@ struct DrvInfo
 private:
     string drvPath;
     string outPath;
-
-    bool metaInfoRead;
-    MetaInfo meta;
     
 public:
     string name;
     string attrPath; /* path towards the derivation */
     string system;
 
-    /* !!! make this private */
-    Bindings * attrs;
-
-    DrvInfo() : metaInfoRead(false), attrs(0) { };
+    /* !!! these should really be hidden, and setMetaInfo() should
+       make a copy since the ATermMap can be shared between multiple
+       DrvInfos. */
+    boost::shared_ptr<ATermMap> attrs;
 
     string queryDrvPath(EvalState & state) const;
     string queryOutPath(EvalState & state) const;
     MetaInfo queryMetaInfo(EvalState & state) const;
-    MetaValue queryMetaInfo(EvalState & state, const string & name) const;
+    string queryMetaInfo(EvalState & state, const string & name) const;
 
     void setDrvPath(const string & s)
     {
@@ -62,19 +50,16 @@ public:
 };
 
 
-#if HAVE_BOEHMGC
-typedef list<DrvInfo, traceable_allocator<DrvInfo> > DrvInfos;
-#else
 typedef list<DrvInfo> DrvInfos;
-#endif
 
 
-/* If value `v' denotes a derivation, store information about the
-   derivation in `drv' and return true.  Otherwise, return false. */
-bool getDerivation(EvalState & state, Value & v, DrvInfo & drv);
+/* Evaluate expression `e'.  If it evaluates to a derivation, store
+   information about the derivation in `drv' and return true.
+   Otherwise, return false. */
+bool getDerivation(EvalState & state, Expr e, DrvInfo & drv);
 
-void getDerivations(EvalState & state, Value & v, const string & pathPrefix,
-    Bindings & autoArgs, DrvInfos & drvs);
+void getDerivations(EvalState & state, Expr e, const string & pathPrefix,
+    const ATermMap & autoArgs, DrvInfos & drvs);
 
  
 }

src/libexpr/lexer.l

@@ -8,7 +8,9 @@
 
 
 %{
+#include "aterm.hh"
 #include "nixexpr.hh"
+#include "nixexpr-ast.hh"
 #define BISON_HEADER_HACK
 #include "parser-tab.hh"
 
@@ -19,16 +21,13 @@ namespace nix {
     
 static void initLoc(YYLTYPE * loc)
 {
-    loc->first_line = loc->last_line = 1;
-    loc->first_column = loc->last_column = 1;
+    loc->first_line = 1;
+    loc->first_column = 1;
 }
 
     
 static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
 {
-    loc->first_line = loc->last_line;
-    loc->first_column = loc->last_column;
-
     while (len--) {
        switch (*s++) {
        case '\r':
@@ -36,17 +35,17 @@ static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
                s++;
            /* fall through */
        case '\n': 
-           ++loc->last_line;
-           loc->last_column = 1;
+           ++loc->first_line;
+           loc->first_column = 1;
            break;
        default:
-           ++loc->last_column;
+           ++loc->first_column;
        }
     }
 }
 
 
-static Expr * unescapeStr(SymbolTable & symbols, const char * s)
+static Expr unescapeStr(const char * s)
 {
     string t;
     char c;
@@ -66,7 +65,7 @@ static Expr * unescapeStr(SymbolTable & symbols, const char * s)
         }
         else t += c;
     }
-    return new ExprString(symbols.create(t));
+    return makeStr(toATerm(t), ATempty);
 }
 
  
@@ -106,20 +105,19 @@ inherit     { return INHERIT; }
 \/\/        { return UPDATE; }
 \+\+        { return CONCAT; }
 
-{ID}        { yylval->id = strdup(yytext); return ID; }
+{ID}        { yylval->t = toATerm(yytext); return ID; /* !!! alloc */ }
 {INT}       { int n = atoi(yytext); /* !!! overflow */
-              yylval->n = n;
+              yylval->t = ATmake("<int>", n);
               return INT;
             }
 
 \"          { BEGIN(STRING); return '"'; }
 <STRING>([^\$\"\\]|\$[^\{\"]|\\.)+ {
-              /* !!! Not quite right: we want a follow restriction on
-                 "$", it shouldn't be followed by a "{".  Right now
-                 "$\"" will be consumed as part of a string, rather
-                 than a "$" followed by the string terminator.
-                 Disallow "$\"" for now. */
-              yylval->e = unescapeStr(data->symbols, yytext);
+/* !!! Not quite right: we want a follow restriction on "$", it
+   shouldn't be followed by a "{".  Right now "$\"" will be consumed
+   as part of a string, rather than a "$" followed by the string
+   terminator.  Disallow "$\"" for now. */
+              yylval->t = unescapeStr(yytext); /* !!! alloc */ 
               return STR;
             }
 <STRING>\$\{  { BEGIN(INITIAL); return DOLLAR_CURLY; }
@@ -128,31 +126,31 @@ inherit     { return INHERIT; }
 
 \'\'(\ *\n)?     { BEGIN(IND_STRING); return IND_STRING_OPEN; }
 <IND_STRING>([^\$\']|\$[^\{\']|\'[^\'\$])+ {
-                   yylval->e = new ExprIndStr(yytext);
+                   yylval->t = makeIndStr(toATerm(yytext));
                    return IND_STR;
                  }
 <IND_STRING>\'\'\$ {
-                   yylval->e = new ExprIndStr("$");
+                   yylval->t = makeIndStr(toATerm("$"));
                    return IND_STR;
                  }
 <IND_STRING>\'\'\' {
-                   yylval->e = new ExprIndStr("''");
+                   yylval->t = makeIndStr(toATerm("''"));
                    return IND_STR;
                  }
 <IND_STRING>\'\'\\. {
-                   yylval->e = unescapeStr(data->symbols, yytext + 2);
+                   yylval->t = unescapeStr(yytext + 2);
                    return IND_STR;
                  }
 <IND_STRING>\$\{ { BEGIN(INITIAL); return DOLLAR_CURLY; }
 <IND_STRING>\'\' { BEGIN(INITIAL); return IND_STRING_CLOSE; }
 <IND_STRING>\'   {
-                   yylval->e = new ExprIndStr("'");
+                   yylval->t = makeIndStr(toATerm("'"));
                    return IND_STR;
                  }
 <IND_STRING>.    return yytext[0]; /* just in case: shouldn't be reached */
 
-{PATH}      { yylval->path = strdup(yytext); return PATH; }
-{URI}       { yylval->uri = strdup(yytext); return URI; }
+{PATH}      { yylval->t = toATerm(yytext); return PATH; /* !!! alloc */ }
+{URI}       { yylval->t = toATerm(yytext); return URI; /* !!! alloc */ }
 
 [ \t\r\n]+    /* eat up whitespace */
 \#[^\r\n]*    /* single-line comments */

src/libexpr/nixexpr-ast.def

@@ -0,0 +1,96 @@
+init initNixExprHelpers
+
+Pos | string int int | Pos |
+NoPos | | Pos |
+
+Function | Pattern Expr Pos | Expr |
+Assert | Expr Expr Pos | Expr |
+With | Expr Expr Pos | Expr |
+If | Expr Expr Expr | Expr |
+OpNot | Expr | Expr |
+OpEq | Expr Expr | Expr |
+OpNEq | Expr Expr | Expr |
+OpAnd | Expr Expr | Expr |
+OpOr | Expr Expr | Expr |
+OpImpl | Expr Expr | Expr |
+OpUpdate | Expr Expr | Expr |
+SubPath | Expr Expr | Expr |
+OpHasAttr | Expr string | Expr |
+OpPlus | Expr Expr | Expr |
+OpConcat | Expr Expr | Expr |
+ConcatStrings | ATermList | Expr |
+Call | Expr Expr | Expr |
+Select | Expr string | Expr |
+Var | string | Expr |
+Int | int | Expr |
+
+# Strings in the evaluator carry a so-called `context' (the ATermList)
+# which is a list of strings representing store paths.  This is to
+# allow users to write things like
+#
+#   "--with-freetype2-library=" + freetype + "/lib"
+#
+# where `freetype' is a derivation (or a source to be copied to the
+# store).  If we just concatenated the strings without keeping track
+# of the referenced store paths, then if the string is used as a
+# derivation attribute, the derivation will not have the correct
+# dependencies in its inputDrvs and inputSrcs.
+#
+# The semantics of the context is as follows: when a string with
+# context C is used as a derivation attribute, then the derivations in
+# C will be added to the inputDrvs of the derivation, and the other
+# store paths in C will be added to the inputSrcs of the derivations.
+#
+# For canonicity, the store paths should be in sorted order.
+Str | string ATermList | Expr |
+Str | string | Expr | ObsoleteStr
+
+# Internal to the parser, doesn't occur in ASTs.
+IndStr | string | Expr |
+
+# A path is a reference to a file system object that is to be copied
+# to the Nix store when used as a derivation attribute.  When it is
+# concatenated to a string (i.e., `str + path'), it is also copied and
+# the resulting store path is concatenated to the string (with the
+# store path in the context).  If a string or path is concatenated to
+# a path (i.e., `path + str' or `path + path'), the result is a new
+# path (if the right-hand side is a string, the context must be
+# empty).
+Path | string | Expr |
+
+List | ATermList | Expr |
+BlackHole | | Expr |
+Undefined | | Expr |
+Removed | | Expr |
+PrimOp | int ATermBlob ATermList | Expr |
+Attrs | ATermList | Expr |
+Closed | Expr | Expr |
+Rec | ATermList ATermList | Expr |
+Bool | ATermBool | Expr |
+Null | | Expr |
+
+Bind | string Expr Pos | ATerm |
+Bind | string Expr | ATerm | ObsoleteBind
+Inherit | Expr ATermList Pos | ATerm |
+
+Scope | | Expr |
+
+VarPat | string | Pattern |
+AttrsPat | ATermList ATermBool | Pattern | # bool = `...'
+AtPat | Pattern Pattern | Pattern |
+
+Formal | string DefaultValue | ATerm |
+
+DefaultValue | Expr | DefaultValue |
+NoDefaultValue | | DefaultValue |
+
+True | | ATermBool |
+False | | ATermBool |
+
+PrimOpDef | int ATermBlob | ATerm |
+
+AttrRHS | Expr Pos | ATerm |
+
+eTrue = makeBool(makeTrue())
+eFalse = makeBool(makeFalse())
+sOverrides = toATerm("__overrides")

src/libexpr/nixexpr.cc

@@ -1,314 +1,407 @@
 #include "nixexpr.hh"
 #include "derivations.hh"
 #include "util.hh"
+#include "aterm.hh"
+
+#include "nixexpr-ast.hh"
+#include "nixexpr-ast.cc"
 
 #include <cstdlib>
 
 
 namespace nix {
-
-
-/* Displaying abstract syntax trees. */
-
-std::ostream & operator << (std::ostream & str, Expr & e)
-{
-    e.show(str);
-    return str;
-}
-
-void Expr::show(std::ostream & str)
-{
-    abort();
-}
-
-void ExprInt::show(std::ostream & str)
-{
-    str << n;
-}
-
-void ExprString::show(std::ostream & str)
-{
-    str << "\"" << s << "\""; // !!! escaping
-}
-
-void ExprPath::show(std::ostream & str)
-{
-    str << s;
-}
-
-void ExprVar::show(std::ostream & str)
-{
-    str << info.name;
-}
-
-void ExprSelect::show(std::ostream & str)
-{
-    str << "(" << *e << ")." << name;
-}
-
-void ExprOpHasAttr::show(std::ostream & str)
-{
-    str << "(" << *e << ") ? " << name;
-}
-
-void ExprAttrs::show(std::ostream & str)
-{
-    if (recursive) str << "rec ";
-    str << "{ ";
-    foreach (AttrDefs::iterator, i, attrs)
-        if (i->second.inherited)
-            str << "inherit " << i->first << " " << "; ";
-        else
-            str << i->first << " = " << *i->second.e << "; ";
-    str << "}";
-}
-
-void ExprList::show(std::ostream & str)
-{
-    str << "[ ";
-    foreach (vector<Expr *>::iterator, i, elems)
-        str << "(" << **i << ") ";
-    str << "]";
-}
-
-void ExprLambda::show(std::ostream & str)
-{
-    str << "(";
-    if (matchAttrs) {
-        str << "{ ";
-        bool first = true;
-        foreach (Formals::Formals_::iterator, i, formals->formals) {
-            if (first) first = false; else str << ", ";
-            str << i->name;
-            if (i->def) str << " ? " << *i->def;
-        }
-        str << " }";
-        if (!arg.empty()) str << " @ ";
-    }
-    if (!arg.empty()) str << arg;
-    str << ": " << *body << ")";
-}
-
-void ExprLet::show(std::ostream & str)
-{
-    str << "let ";
-    foreach (ExprAttrs::AttrDefs::iterator, i, attrs->attrs)
-        if (i->second.inherited)
-            str << "inherit " << i->first << "; ";
-        else
-            str << i->first << " = " << *i->second.e << "; ";
-    str << "in " << *body;
-}
-
-void ExprWith::show(std::ostream & str)
-{
-    str << "with " << *attrs << "; " << *body;
-}
-
-void ExprIf::show(std::ostream & str)
-{
-    str << "if " << *cond << " then " << *then << " else " << *else_;
-}
-
-void ExprAssert::show(std::ostream & str)
-{
-    str << "assert " << *cond << "; " << *body;
-}
-
-void ExprOpNot::show(std::ostream & str)
-{
-    str << "! " << *e;
-}
-
-void ExprConcatStrings::show(std::ostream & str)
-{
-    bool first = true;
-    foreach (vector<Expr *>::iterator, i, *es) {
-        if (first) first = false; else str << " + ";
-        str << **i;
-    }
-}
-
-
-std::ostream & operator << (std::ostream & str, const Pos & pos)
-{
-    if (!pos.line)
-        str << "undefined position";
-    else
-        str << (format("`%1%:%2%:%3%'") % pos.file % pos.line % pos.column).str();
-    return str;
-}
-
-
-Pos noPos;
-
-
-/* Computing levels/displacements for variables. */
-
-void Expr::bindVars(const StaticEnv & env)
-{
-    abort();
-}
-
-void ExprInt::bindVars(const StaticEnv & env)
-{
-}
-
-void ExprString::bindVars(const StaticEnv & env)
-{
-}
-
-void ExprPath::bindVars(const StaticEnv & env)
-{
-}
-
-void VarRef::bind(const StaticEnv & env)
-{
-    /* Check whether the variable appears in the environment.  If so,
-       set its level and displacement. */
-    const StaticEnv * curEnv;
-    unsigned int level;
-    int withLevel = -1;
-    for (curEnv = &env, level = 0; curEnv; curEnv = curEnv->up, level++) {
-        if (curEnv->isWith) {
-            if (withLevel == -1) withLevel = level;
-        } else {
-            StaticEnv::Vars::const_iterator i = curEnv->vars.find(name);
-            if (i != curEnv->vars.end()) {
-                fromWith = false;
-                this->level = level;
-                displ = i->second;
-                return;
-            }
-        }
-    }
-
-    /* Otherwise, the variable must be obtained from the nearest
-       enclosing `with'.  If there is no `with', then we can issue an
-       "undefined variable" error now. */
-    if (withLevel == -1) throw EvalError(format("undefined variable `%1%'") % name);
-
-    fromWith = true;
-    this->level = withLevel;
-}
-
-void ExprVar::bindVars(const StaticEnv & env)
-{
-    info.bind(env);
-}
-
-void ExprSelect::bindVars(const StaticEnv & env)
-{
-    e->bindVars(env);
-}
-
-void ExprOpHasAttr::bindVars(const StaticEnv & env)
-{
-    e->bindVars(env);
-}
-
-void ExprAttrs::bindVars(const StaticEnv & env)
-{
-    if (recursive) {
-        StaticEnv newEnv(false, &env);
     
-        unsigned int displ = 0;
-        foreach (AttrDefs::iterator, i, attrs)
-            newEnv.vars[i->first] = i->second.displ = displ++;
+
+string showPos(ATerm pos)
+{
+    ATerm path;
+    int line, column;
+    if (matchNoPos(pos)) return "undefined position";
+    if (!matchPos(pos, path, line, column))
+        throw badTerm("position expected", pos);
+    return (format("`%1%', line %2%") % aterm2String(path) % line).str();
+}
+    
+
+ATerm bottomupRewrite(TermFun & f, ATerm e)
+{
+    checkInterrupt();
+
+    if (ATgetType(e) == AT_APPL) {
+        AFun fun = ATgetAFun(e);
+        int arity = ATgetArity(fun);
+        ATerm args[arity];
+
+        for (int i = 0; i < arity; ++i)
+            args[i] = bottomupRewrite(f, ATgetArgument(e, i));
         
-        foreach (AttrDefs::iterator, i, attrs)
-            if (i->second.inherited) i->second.var.bind(env);
-            else i->second.e->bindVars(newEnv);
+        e = (ATerm) ATmakeApplArray(fun, args);
     }
 
-    else
-        foreach (AttrDefs::iterator, i, attrs)
-            if (i->second.inherited) i->second.var.bind(env);
-            else i->second.e->bindVars(env);
-}
+    else if (ATgetType(e) == AT_LIST) {
+        ATermList in = (ATermList) e;
+        ATermList out = ATempty;
 
-void ExprList::bindVars(const StaticEnv & env)
-{
-    foreach (vector<Expr *>::iterator, i, elems)
-        (*i)->bindVars(env);
-}
+        for (ATermIterator i(in); i; ++i)
+            out = ATinsert(out, bottomupRewrite(f, *i));
 
-void ExprLambda::bindVars(const StaticEnv & env)
-{
-    StaticEnv newEnv(false, &env);
-    
-    unsigned int displ = 0;
-    
-    if (!arg.empty()) newEnv.vars[arg] = displ++;
-
-    if (matchAttrs) {
-        foreach (Formals::Formals_::iterator, i, formals->formals)
-            newEnv.vars[i->name] = displ++;
-
-        foreach (Formals::Formals_::iterator, i, formals->formals)
-            if (i->def) i->def->bindVars(newEnv);
+        e = (ATerm) ATreverse(out);
     }
 
-    body->bindVars(newEnv);
+    return f(e);
 }
 
-void ExprLet::bindVars(const StaticEnv & env)
+
+void queryAllAttrs(Expr e, ATermMap & attrs, bool withPos)
 {
-    StaticEnv newEnv(false, &env);
-    
-    unsigned int displ = 0;
-    foreach (ExprAttrs::AttrDefs::iterator, i, attrs->attrs)
-        newEnv.vars[i->first] = i->second.displ = displ++;
-    
-    foreach (ExprAttrs::AttrDefs::iterator, i, attrs->attrs)
-        if (i->second.inherited) i->second.var.bind(env);
-        else i->second.e->bindVars(newEnv);
-    
-    body->bindVars(newEnv);
+    ATermList bnds;
+    if (!matchAttrs(e, bnds))
+        throw TypeError(format("value is %1% while an attribute set was expected") % showType(e));
+
+    for (ATermIterator i(bnds); i; ++i) {
+        ATerm name;
+        Expr e;
+        ATerm pos;
+        if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
+        attrs.set(name, withPos ? makeAttrRHS(e, pos) : e);
+    }
 }
 
-void ExprWith::bindVars(const StaticEnv & env)
+
+Expr queryAttr(Expr e, const string & name)
 {
-    /* Does this `with' have an enclosing `with'?  If so, record its
-       level so that `lookupVar' can look up variables in the previous
-       `with' if this one doesn't contain the desired attribute. */
-    const StaticEnv * curEnv;
-    unsigned int level;
-    prevWith = 0;
-    for (curEnv = &env, level = 1; curEnv; curEnv = curEnv->up, level++)
-        if (curEnv->isWith) {
-            prevWith = level;
-            break;
+    ATerm dummy;
+    return queryAttr(e, name, dummy);
+}
+
+
+Expr queryAttr(Expr e, const string & name, ATerm & pos)
+{
+    ATermList bnds;
+    if (!matchAttrs(e, bnds))
+        throw TypeError(format("value is %1% while an attribute set was expected") % showType(e));
+
+    for (ATermIterator i(bnds); i; ++i) {
+        ATerm name2, pos2;
+        Expr e;
+        if (!matchBind(*i, name2, e, pos2))
+            abort(); /* can't happen */
+        if (aterm2String(name2) == name) {
+            pos = pos2;
+            return e;
         }
+    }
+
+    return 0;
+}
+
+
+Expr makeAttrs(const ATermMap & attrs)
+{
+    ATermList bnds = ATempty;
+    for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i) {
+        Expr e;
+        ATerm pos;
+        if (!matchAttrRHS(i->value, e, pos))
+            abort(); /* can't happen */
+        bnds = ATinsert(bnds, makeBind(i->key, e, pos));
+    }
+    return makeAttrs(bnds);
+}
+
+
+static void varsBoundByPattern(ATermMap & map, Pattern pat)
+{
+    ATerm name;
+    ATermList formals;
+    Pattern pat1, pat2;
+    ATermBool ellipsis;
+    /* Use makeRemoved() so that it can be used directly in
+       substitute(). */
+    if (matchVarPat(pat, name))
+        map.set(name, makeRemoved());
+    else if (matchAttrsPat(pat, formals, ellipsis)) { 
+        for (ATermIterator i(formals); i; ++i) {
+            ATerm d1;
+            if (!matchFormal(*i, name, d1)) abort();
+            map.set(name, makeRemoved());
+        }
+    }
+    else if (matchAtPat(pat, pat1, pat2)) {
+        varsBoundByPattern(map, pat1);
+        varsBoundByPattern(map, pat2);
+    }
+    else abort();
+}
+
+
+Expr substitute(const Substitution & subs, Expr e)
+{
+    checkInterrupt();
+
+    //if (subs.size() == 0) return e;
+
+    ATerm name, pos, e2;
+
+    /* As an optimisation, don't substitute in subterms known to be
+       closed. */
+    if (matchClosed(e, e2)) return e;
+
+    if (matchVar(e, name)) {
+        Expr sub = subs.lookup(name);
+        if (sub == makeRemoved()) sub = 0;
+        Expr wrapped;
+        /* Add a "closed" wrapper around terms that aren't already
+           closed.  The check is necessary to prevent repeated
+           wrapping, e.g., closed(closed(closed(...))), which kills
+           caching. */
+        return sub ? (matchClosed(sub, wrapped) ? sub : makeClosed(sub)) : e;
+    }
+
+    /* In case of a function, filter out all variables bound by this
+       function. */
+    Pattern pat;
+    ATerm body;
+    if (matchFunction(e, pat, body, pos)) {
+        ATermMap map(16);
+        varsBoundByPattern(map, pat);
+        Substitution subs2(&subs, &map);
+        return makeFunction(
+            (Pattern) substitute(subs2, (Expr) pat),
+            substitute(subs2, body), pos);
+    }
+
+    /* Idem for a mutually recursive attribute set. */
+    ATermList rbnds, nrbnds;
+    if (matchRec(e, rbnds, nrbnds)) {
+        ATermMap map(ATgetLength(rbnds) + ATgetLength(nrbnds));
+        for (ATermIterator i(rbnds); i; ++i)
+            if (matchBind(*i, name, e2, pos)) map.set(name, makeRemoved());
+            else abort(); /* can't happen */
+        for (ATermIterator i(nrbnds); i; ++i)
+            if (matchBind(*i, name, e2, pos)) map.set(name, makeRemoved());
+            else abort(); /* can't happen */
+        return makeRec(
+            (ATermList) substitute(Substitution(&subs, &map), (ATerm) rbnds),
+            (ATermList) substitute(subs, (ATerm) nrbnds));
+    }
+
+    if (ATgetType(e) == AT_APPL) {
+        AFun fun = ATgetAFun(e);
+        int arity = ATgetArity(fun);
+        ATerm args[arity];
+        bool changed = false;
+
+        for (int i = 0; i < arity; ++i) {
+            ATerm arg = ATgetArgument(e, i);
+            args[i] = substitute(subs, arg);
+            if (args[i] != arg) changed = true;
+        }
+        
+        return changed ? (ATerm) ATmakeApplArray(fun, args) : e;
+    }
+
+    if (ATgetType(e) == AT_LIST) {
+        unsigned int len = ATgetLength((ATermList) e);
+        ATerm es[len];
+        ATermIterator i((ATermList) e);
+        for (unsigned int j = 0; i; ++i, ++j)
+            es[j] = substitute(subs, *i);
+        ATermList out = ATempty;
+        for (unsigned int j = len; j; --j)
+            out = ATinsert(out, es[j - 1]);
+        return (ATerm) out;
+    }
+
+    return e;
+}
+
+
+/* We use memoisation to prevent exponential complexity on heavily
+   shared ATerms (remember, an ATerm is a graph, not a tree!).  Note
+   that using an STL set is fine here wrt to ATerm garbage collection
+   since all the ATerms in the set are already reachable from
+   somewhere else. */
+static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e)
+{
+    if (done.find(e) != done.end()) return;
+    done.insert(e);
     
-    attrs->bindVars(env);    
-    StaticEnv newEnv(true, &env);
-    body->bindVars(newEnv);
+    ATerm name, pos, value;
+    ATerm with, body;
+    ATermList rbnds, nrbnds;
+    Pattern pat;
+
+    /* Closed terms don't have free variables, so we don't have to
+       check by definition. */
+    if (matchClosed(e, value)) return;
+    
+    else if (matchVar(e, name)) {
+        if (!defs.get(name))
+            throw EvalError(format("undefined variable `%1%'")
+                % aterm2String(name));
+    }
+
+    else if (matchFunction(e, pat, body, pos)) {
+        ATermMap defs2(defs);
+        varsBoundByPattern(defs2, pat);
+        set<Expr> done2;
+        checkVarDefs2(done2, defs2, pat);
+        checkVarDefs2(done2, defs2, body);
+    }
+        
+    else if (matchRec(e, rbnds, nrbnds)) {
+        checkVarDefs2(done, defs, (ATerm) nrbnds);
+        ATermMap defs2(defs);
+        for (ATermIterator i(rbnds); i; ++i) {
+            if (!matchBind(*i, name, value, pos)) abort(); /* can't happen */
+            defs2.set(name, (ATerm) ATempty);
+        }
+        for (ATermIterator i(nrbnds); i; ++i) {
+            if (!matchBind(*i, name, value, pos)) abort(); /* can't happen */
+            defs2.set(name, (ATerm) ATempty);
+        }
+        set<Expr> done2;
+        checkVarDefs2(done2, defs2, (ATerm) rbnds);
+    }
+
+    else if (matchWith(e, with, body, pos)) {
+        /* We can't check the body without evaluating the definitions
+           (which is an arbitrary expression), so we don't do that
+           here but only when actually evaluating the `with'. */
+        checkVarDefs2(done, defs, with);
+    }
+    
+    else if (ATgetType(e) == AT_APPL) {
+        int arity = ATgetArity(ATgetAFun(e));
+        for (int i = 0; i < arity; ++i)
+            checkVarDefs2(done, defs, ATgetArgument(e, i));
+    }
+
+    else if (ATgetType(e) == AT_LIST)
+        for (ATermIterator i((ATermList) e); i; ++i)
+            checkVarDefs2(done, defs, *i);
 }
 
-void ExprIf::bindVars(const StaticEnv & env)
+
+void checkVarDefs(const ATermMap & defs, Expr e)
 {
-    cond->bindVars(env);
-    then->bindVars(env);
-    else_->bindVars(env);
+    set<Expr> done;
+    checkVarDefs2(done, defs, e);
 }
 
-void ExprAssert::bindVars(const StaticEnv & env)
+
+struct Canonicalise : TermFun
 {
-    cond->bindVars(env);
-    body->bindVars(env);
-}
+    ATerm operator () (ATerm e)
+    {
+        /* Remove position info. */
+        ATerm path;
+        int line, column;
+        if (matchPos(e, path, line, column))
+            return makeNoPos();
 
-void ExprOpNot::bindVars(const StaticEnv & env)
+        /* Sort attribute sets. */
+        ATermList _;
+        if (matchAttrs(e, _)) {
+            ATermMap attrs;
+            queryAllAttrs(e, attrs);
+            StringSet names;
+            for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i)
+                names.insert(aterm2String(i->key));
+
+            ATermList attrs2 = ATempty;
+            for (StringSet::reverse_iterator i = names.rbegin(); i != names.rend(); ++i)
+                attrs2 = ATinsert(attrs2,
+                    makeBind(toATerm(*i), attrs.get(toATerm(*i)), makeNoPos()));
+
+            return makeAttrs(attrs2);
+        }
+        
+        return e;
+    }
+};
+
+
+Expr canonicaliseExpr(Expr e)
 {
-    e->bindVars(env);
+    Canonicalise canonicalise;
+    return bottomupRewrite(canonicalise, e);
 }
 
-void ExprConcatStrings::bindVars(const StaticEnv & env)
+
+Expr makeBool(bool b)
 {
-    foreach (vector<Expr *>::iterator, i, *es)
-        (*i)->bindVars(env);
+    return b ? eTrue : eFalse;
 }
 
 
+bool matchStr(Expr e, string & s, PathSet & context)
+{
+    ATermList l;
+    ATerm s_;
+
+    if (!matchStr(e, s_, l)) return false;
+
+    s = aterm2String(s_);
+
+    for (ATermIterator i(l); i; ++i)
+        context.insert(aterm2String(*i));
+
+    return true;
+}
+
+
+Expr makeStr(const string & s, const PathSet & context)
+{
+    return makeStr(toATerm(s), toATermList(context));
+}
+
+
+string showType(Expr e)
+{
+    ATerm t1, t2;
+    ATermList l1;
+    ATermBlob b1;
+    int i1;
+    Pattern p1;
+    if (matchStr(e, t1, l1)) return "a string";
+    if (matchPath(e, t1)) return "a path";
+    if (matchNull(e)) return "null";
+    if (matchInt(e, i1)) return "an integer";
+    if (matchBool(e, t1)) return "a boolean";
+    if (matchFunction(e, p1, t1, t2)) return "a function";
+    if (matchAttrs(e, l1)) return "an attribute set";
+    if (matchList(e, l1)) return "a list";
+    if (matchPrimOp(e, i1, b1, l1)) return "a partially applied built-in function";
+    return "an unknown type";
+}
+
+
+string showValue(Expr e)
+{
+    PathSet context;
+    string s;
+    ATerm s2;
+    int i;
+    if (matchStr(e, s, context)) {
+        string u;
+        for (string::iterator i = s.begin(); i != s.end(); ++i)
+            if (*i == '\"' || *i == '\\') u += "\\" + *i;
+            else if (*i == '\n') u += "\\n";
+            else if (*i == '\r') u += "\\r";
+            else if (*i == '\t') u += "\\t";
+            else u += *i;
+        return "\"" + u + "\"";
+    }
+    if (matchPath(e, s2)) return aterm2String(s2);
+    if (matchNull(e)) return "null";
+    if (matchInt(e, i)) return (format("%1%") % i).str();
+    if (e == eTrue) return "true";
+    if (e == eFalse) return "false";
+    /* !!! incomplete */
+    return "<unknown>";
+}
+
+ 
 }

src/libexpr/nixexpr.hh

@@ -1,278 +1,121 @@
 #ifndef __NIXEXPR_H
 #define __NIXEXPR_H
 
-#include "symbol-table.hh"
-
 #include <map>
 
+#include "aterm-map.hh"
+#include "types.hh"
+
 
 namespace nix {
 
 
 MakeError(EvalError, Error)
-MakeError(ParseError, Error)
 MakeError(AssertionError, EvalError)
 MakeError(ThrownError, AssertionError)
 MakeError(Abort, EvalError)
 MakeError(TypeError, EvalError)
-MakeError(ImportError, EvalError) // error building an imported derivation
 
 
-/* Position objects. */
+/* Nix expressions are represented as ATerms.  The maximal sharing
+   property of the ATerm library allows us to implement caching of
+   normals forms efficiently. */
+typedef ATerm Expr;
+typedef ATerm DefaultValue;
+typedef ATerm Pos;
+typedef ATerm Pattern;
+typedef ATerm ATermBool;
 
-struct Pos
+
+/* A STL vector of ATerms.  Should be used with great care since it's
+   stored on the heap, and the elements are therefore not roots to the
+   ATerm garbage collector. */
+typedef vector<ATerm> ATermVector;
+
+
+/* A substitution is a linked list of ATermMaps that map names to
+   identifiers.  We use a list of ATermMaps rather than a single to
+   make it easy to grow or shrink a substitution when entering a
+   scope. */
+struct Substitution
 {
-    string file;
-    unsigned int line, column;
-    Pos() : line(0), column(0) { };
-    Pos(const string & file, unsigned int line, unsigned int column)
-        : file(file), line(line), column(column) { };
-};
+    ATermMap * map;
+    const Substitution * prev;
 
-extern Pos noPos;
-
-std::ostream & operator << (std::ostream & str, const Pos & pos);
-
-
-struct Env;
-struct Value;
-struct EvalState;
-struct StaticEnv;
-
-
-/* Abstract syntax of Nix expressions. */
-
-struct Expr
-{
-    virtual void show(std::ostream & str);
-    virtual void bindVars(const StaticEnv & env);
-    virtual void eval(EvalState & state, Env & env, Value & v);
-};
-
-std::ostream & operator << (std::ostream & str, Expr & e);
-
-#define COMMON_METHODS \
-    void show(std::ostream & str); \
-    void eval(EvalState & state, Env & env, Value & v); \
-    void bindVars(const StaticEnv & env);
-
-struct ExprInt : Expr
-{
-    int n;
-    ExprInt(int n) : n(n) { };
-    COMMON_METHODS
-};
-
-struct ExprString : Expr
-{
-    Symbol s;
-    ExprString(const Symbol & s) : s(s) { };
-    COMMON_METHODS
-};
-
-/* Temporary class used during parsing of indented strings. */
-struct ExprIndStr : Expr
-{
-    string s;
-    ExprIndStr(const string & s) : s(s) { };
-};
-
-struct ExprPath : Expr
-{
-    string s;
-    ExprPath(const string & s) : s(s) { };
-    COMMON_METHODS
-};
-
-struct VarRef
-{
-    Symbol name;
-
-    /* Whether the variable comes from an environment (e.g. a rec, let
-       or function argument) or from a "with". */
-    bool fromWith;
-    
-    /* In the former case, the value is obtained by going `level'
-       levels up from the current environment and getting the
-       `displ'th value in that environment.  In the latter case, the
-       value is obtained by getting the attribute named `name' from
-       the attribute set stored in the environment that is `level'
-       levels up from the current one.*/
-    unsigned int level;
-    unsigned int displ;
-
-    VarRef() { };
-    VarRef(const Symbol & name) : name(name) { };
-    void bind(const StaticEnv & env);
-};
-
-struct ExprVar : Expr
-{
-    VarRef info;
-    ExprVar(const Symbol & name) : info(name) { };
-    COMMON_METHODS
-};
-
-struct ExprSelect : Expr
-{
-    Expr * e;
-    Symbol name;
-    ExprSelect(Expr * e, const Symbol & name) : e(e), name(name) { };
-    COMMON_METHODS
-};
-
-struct ExprOpHasAttr : Expr
-{
-    Expr * e;
-    Symbol name;
-    ExprOpHasAttr(Expr * e, const Symbol & name) : e(e), name(name) { };
-    COMMON_METHODS
-};
-
-struct ExprAttrs : Expr
-{
-    bool recursive;
-    struct AttrDef {
-        bool inherited;
-        Expr * e; // if not inherited
-        VarRef var; // if inherited
-        Pos pos;
-        unsigned int displ; // displacement
-        AttrDef(Expr * e, const Pos & pos) : inherited(false), e(e), pos(pos) { };
-        AttrDef(const Symbol & name, const Pos & pos) : inherited(true), var(name), pos(pos) { };
-        AttrDef() { };
-    };
-    typedef std::map<Symbol, AttrDef> AttrDefs;
-    AttrDefs attrs;
-    ExprAttrs() : recursive(false) { };
-    COMMON_METHODS
-};
-
-struct ExprList : Expr
-{
-    std::vector<Expr *> elems;
-    ExprList() { };
-    COMMON_METHODS
-};
-
-struct Formal
-{
-    Symbol name;
-    Expr * def;
-    Formal(const Symbol & name, Expr * def) : name(name), def(def) { };
-};
-
-struct Formals
-{
-    typedef std::list<Formal> Formals_;
-    Formals_ formals;
-    std::set<Symbol> argNames; // used during parsing
-    bool ellipsis;
-};
-
-struct ExprLambda : Expr
-{
-    Pos pos;
-    Symbol arg;
-    bool matchAttrs;
-    Formals * formals;
-    Expr * body;
-    ExprLambda(const Pos & pos, const Symbol & arg, bool matchAttrs, Formals * formals, Expr * body)
-        : pos(pos), arg(arg), matchAttrs(matchAttrs), formals(formals), body(body)
+    Substitution(const Substitution * prev, ATermMap * map)
     {
-        if (!arg.empty() && formals && formals->argNames.find(arg) != formals->argNames.end())
-            throw ParseError(format("duplicate formal function argument `%1%' at %2%")
-                % arg % pos);
-    };
-    COMMON_METHODS
+        this->prev = prev;
+        this->map = map;
+    }
+    
+    Expr lookup(Expr name) const
+    {
+        Expr x;
+        for (const Substitution * s(this); s; s = s->prev)
+            if ((x = s->map->get(name))) return x;
+        return 0;
+    }
 };
 
-struct ExprLet : Expr
+
+/* Show a position. */
+string showPos(ATerm pos);
+
+/* Generic bottomup traversal over ATerms.  The traversal first
+   recursively descends into subterms, and then applies the given term
+   function to the resulting term. */
+struct TermFun
 {
-    ExprAttrs * attrs;
-    Expr * body;
-    ExprLet(ExprAttrs * attrs, Expr * body) : attrs(attrs), body(body) { };
-    COMMON_METHODS
-};
-
-struct ExprWith : Expr
-{
-    Pos pos;
-    Expr * attrs, * body;
-    unsigned int prevWith;
-    ExprWith(const Pos & pos, Expr * attrs, Expr * body) : pos(pos), attrs(attrs), body(body) { };
-    COMMON_METHODS
-};
-
-struct ExprIf : Expr
-{
-    Expr * cond, * then, * else_;
-    ExprIf(Expr * cond, Expr * then, Expr * else_) : cond(cond), then(then), else_(else_) { };
-    COMMON_METHODS
-};
-
-struct ExprAssert : Expr
-{
-    Pos pos;
-    Expr * cond, * body;
-    ExprAssert(const Pos & pos, Expr * cond, Expr * body) : pos(pos), cond(cond), body(body) { };
-    COMMON_METHODS
-};
-
-struct ExprOpNot : Expr
-{
-    Expr * e;
-    ExprOpNot(Expr * e) : e(e) { };
-    COMMON_METHODS
-};
-
-#define MakeBinOp(name, s) \
-    struct Expr##name : Expr \
-    { \
-        Expr * e1, * e2; \
-        Expr##name(Expr * e1, Expr * e2) : e1(e1), e2(e2) { }; \
-        void show(std::ostream & str) \
-        { \
-            str << *e1 << " " s " " << *e2; \
-        } \
-        void bindVars(const StaticEnv & env) \
-        { \
-            e1->bindVars(env); e2->bindVars(env); \
-        } \
-        void eval(EvalState & state, Env & env, Value & v); \
-    };
-
-MakeBinOp(App, "")
-MakeBinOp(OpEq, "==")
-MakeBinOp(OpNEq, "!=")
-MakeBinOp(OpAnd, "&&")
-MakeBinOp(OpOr, "||")
-MakeBinOp(OpImpl, "->")
-MakeBinOp(OpUpdate, "//")
-MakeBinOp(OpConcatLists, "++")
-
-struct ExprConcatStrings : Expr
-{
-    vector<Expr *> * es;
-    ExprConcatStrings(vector<Expr *> * es) : es(es) { };
-    COMMON_METHODS
+    virtual ~TermFun() { }
+    virtual ATerm operator () (ATerm e) = 0;
 };
+ATerm bottomupRewrite(TermFun & f, ATerm e);
 
 
-/* Static environments are used to map variable names onto (level,
-   displacement) pairs used to obtain the value of the variable at
-   runtime. */
-struct StaticEnv
-{
-    bool isWith;
-    const StaticEnv * up;
-    typedef std::map<Symbol, unsigned int> Vars;
-    Vars vars;
-    StaticEnv(bool isWith, const StaticEnv * up) : isWith(isWith), up(up) { };
-};
+/* Query all attributes in an attribute set expression.  The
+   expression must be in normal form. */
+void queryAllAttrs(Expr e, ATermMap & attrs, bool withPos = false);
+
+/* Query a specific attribute from an attribute set expression.  The
+   expression must be in normal form. */
+Expr queryAttr(Expr e, const string & name);
+Expr queryAttr(Expr e, const string & name, ATerm & pos);
+
+/* Create an attribute set expression from an Attrs value. */
+Expr makeAttrs(const ATermMap & attrs);
 
 
+/* Perform a set of substitutions on an expression. */
+Expr substitute(const Substitution & subs, Expr e);
 
+
+/* Check whether all variables are defined in the given expression.
+   Throw an exception if this isn't the case. */
+void checkVarDefs(const ATermMap & def, Expr e);
+
+
+/* Canonicalise a Nix expression by sorting attributes and removing
+   location information. */
+Expr canonicaliseExpr(Expr e);
+
+
+/* Create an expression representing a boolean. */
+Expr makeBool(bool b);
+
+
+/* Manipulation of Str() nodes.  Note: matchStr() does not clear
+   context!  */
+bool matchStr(Expr e, string & s, PathSet & context);
+
+Expr makeStr(const string & s, const PathSet & context = PathSet());
+
+
+/* Showing types, values. */
+string showType(Expr e);
+
+string showValue(Expr e);
+
+ 
 }
 
 

src/libexpr/parser.hh

@@ -8,11 +8,12 @@ namespace nix {
 
 
 /* Parse a Nix expression from the specified file.  If `path' refers
-   to a directory, then "/default.nix" is appended. */
-Expr * parseExprFromFile(EvalState & state, Path path);
+   to a directory, the "/default.nix" is appended. */
+Expr parseExprFromFile(EvalState & state, Path path);
 
 /* Parse a Nix expression from the specified string. */
-Expr * parseExprFromString(EvalState & state, const string & s, const Path & basePath);
+Expr parseExprFromString(EvalState & state, const string & s,
+    const Path & basePath);
 
 
 }

src/libexpr/parser.y

@@ -7,126 +7,70 @@
 %parse-param { yyscan_t scanner }
 %parse-param { ParseData * data }
 %lex-param { yyscan_t scanner }
-%lex-param { ParseData * data }
 
-%code requires {
-    
-#ifndef BISON_HEADER
-#define BISON_HEADER
-    
-#include "util.hh"
-    
-#include "nixexpr.hh"
-
-namespace nix {
-
-    struct ParseData 
-    {
-        SymbolTable & symbols;
-        Expr * result;
-        Path basePath;
-        Path path;
-        string error;
-        Symbol sLetBody;
-        ParseData(SymbolTable & symbols)
-            : symbols(symbols)
-            , sLetBody(symbols.create("<let-body>"))
-            { };
-    };
-    
-}
-
-#define YY_DECL int yylex \
-    (YYSTYPE * yylval_param, YYLTYPE * yylloc_param, yyscan_t yyscanner, nix::ParseData * data)
-
-#endif
-
-}
 
 %{
-
-#include "parser-tab.hh"
-#include "lexer-tab.hh"
-#define YYSTYPE YYSTYPE // workaround a bug in Bison 2.4
-
+/* Newer versions of Bison copy the declarations below to
+   parser-tab.hh, which sucks bigtime since lexer.l doesn't want that
+   stuff.  So allow it to be excluded. */
+#ifndef BISON_HEADER_HACK
+#define BISON_HEADER_HACK
+    
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-YY_DECL;
+#include "aterm.hh"
+#include "util.hh"
+    
+#include "parser-tab.hh"
+#include "lexer-tab.hh"
+
+#include "nixexpr.hh"
+#include "nixexpr-ast.hh"
+
 
 using namespace nix;
 
 
 namespace nix {
+
     
-
-static string showAttrPath(const vector<Symbol> & attrPath)
+struct ParseData 
 {
-    string s;
-    foreach (vector<Symbol>::const_iterator, i, attrPath) {
-        if (!s.empty()) s += '.';
-        s += *i;
-    }
-    return s;
-}
+    Expr result;
+    Path basePath;
+    Path path;
+    string error;
+};
 
 
-static void dupAttr(const vector<Symbol> & attrPath, const Pos & pos, const Pos & prevPos)
+static Expr fixAttrs(int recursive, ATermList as)
 {
-    throw ParseError(format("attribute `%1%' at %2% already defined at %3%")
-        % showAttrPath(attrPath) % pos % prevPos);
-}
- 
-
-static void dupAttr(Symbol attr, const Pos & pos, const Pos & prevPos)
-{
-    vector<Symbol> attrPath; attrPath.push_back(attr);
-    throw ParseError(format("attribute `%1%' at %2% already defined at %3%")
-        % showAttrPath(attrPath) % pos % prevPos);
-}
- 
-
-static void addAttr(ExprAttrs * attrs, const vector<Symbol> & attrPath,
-    Expr * e, const Pos & pos)
-{
-    unsigned int n = 0;
-    foreach (vector<Symbol>::const_iterator, i, attrPath) {
-        n++;
-        ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(*i);
-        if (j != attrs->attrs.end()) {
-            if (!j->second.inherited) {
-                ExprAttrs * attrs2 = dynamic_cast<ExprAttrs *>(j->second.e);
-                if (!attrs2 || n == attrPath.size()) dupAttr(attrPath, pos, j->second.pos);
-                attrs = attrs2;
-            } else
-                dupAttr(attrPath, pos, j->second.pos);
-        } else {
-            if (n == attrPath.size())
-                attrs->attrs[*i] = ExprAttrs::AttrDef(e, pos);
-            else {
-                ExprAttrs * nested = new ExprAttrs;
-                attrs->attrs[*i] = ExprAttrs::AttrDef(nested, pos);
-                attrs = nested;
+    ATermList bs = ATempty, cs = ATempty;
+    ATermList * is = recursive ? &cs : &bs;
+    for (ATermIterator i(as); i; ++i) {
+        ATermList names;
+        Expr src;
+        ATerm pos;
+        if (matchInherit(*i, src, names, pos)) {
+            bool fromScope = matchScope(src);
+            for (ATermIterator j(names); j; ++j) {
+                Expr rhs = fromScope ? makeVar(*j) : makeSelect(src, *j);
+                *is = ATinsert(*is, makeBind(*j, rhs, pos));
             }
-        }
+        } else bs = ATinsert(bs, *i);
     }
+    if (recursive)
+        return makeRec(bs, cs);
+    else
+        return makeAttrs(bs);
 }
 
 
-static void addFormal(const Pos & pos, Formals * formals, const Formal & formal)
+static Expr stripIndentation(ATermList es)
 {
-    if (formals->argNames.find(formal.name) != formals->argNames.end())
-        throw ParseError(format("duplicate formal function argument `%1%' at %2%")
-            % formal.name % pos);
-    formals->formals.push_front(formal);
-    formals->argNames.insert(formal.name);
-}
-
-
-static Expr * stripIndentation(SymbolTable & symbols, vector<Expr *> & es)
-{
-    if (es.empty()) return new ExprString(symbols.create(""));
+    if (es == ATempty) return makeStr("");
     
     /* Figure out the minimum indentation.  Note that by design
        whitespace-only final lines are not taken into account.  (So
@@ -134,9 +78,9 @@ static Expr * stripIndentation(SymbolTable & symbols, vector<Expr *> & es)
     bool atStartOfLine = true; /* = seen only whitespace in the current line */
     unsigned int minIndent = 1000000;
     unsigned int curIndent = 0;
-    foreach (vector<Expr *>::iterator, i, es) {
-        ExprIndStr * e = dynamic_cast<ExprIndStr *>(*i);
-        if (!e) {
+    ATerm e;
+    for (ATermIterator i(es); i; ++i) {
+        if (!matchIndStr(*i, e)) {
             /* Anti-quotations end the current start-of-line whitespace. */
             if (atStartOfLine) {
                 atStartOfLine = false;
@@ -144,11 +88,12 @@ static Expr * stripIndentation(SymbolTable & symbols, vector<Expr *> & es)
             }
             continue;
         }
-        for (unsigned int j = 0; j < e->s.size(); ++j) {
+        string s = aterm2String(e);
+        for (unsigned int j = 0; j < s.size(); ++j) {
             if (atStartOfLine) {
-                if (e->s[j] == ' ')
+                if (s[j] == ' ')
                     curIndent++;
-                else if (e->s[j] == '\n') {
+                else if (s[j] == '\n') {
                     /* Empty line, doesn't influence minimum
                        indentation. */
                     curIndent = 0;
@@ -156,7 +101,7 @@ static Expr * stripIndentation(SymbolTable & symbols, vector<Expr *> & es)
                     atStartOfLine = false;
                     if (curIndent < minIndent) minIndent = curIndent;
                 }
-            } else if (e->s[j] == '\n') {
+            } else if (s[j] == '\n') {
                 atStartOfLine = true;
                 curIndent = 0;
             }
@@ -164,52 +109,52 @@ static Expr * stripIndentation(SymbolTable & symbols, vector<Expr *> & es)
     }
 
     /* Strip spaces from each line. */
-    vector<Expr *> * es2 = new vector<Expr *>;
+    ATermList es2 = ATempty;
     atStartOfLine = true;
     unsigned int curDropped = 0;
-    unsigned int n = es.size();
-    for (vector<Expr *>::iterator i = es.begin(); i != es.end(); ++i, --n) {
-        ExprIndStr * e = dynamic_cast<ExprIndStr *>(*i);
-        if (!e) {
+    unsigned int n = ATgetLength(es);
+    for (ATermIterator i(es); i; ++i, --n) {
+        if (!matchIndStr(*i, e)) {
             atStartOfLine = false;
             curDropped = 0;
-            es2->push_back(*i);
+            es2 = ATinsert(es2, *i);
             continue;
         }
         
+        string s = aterm2String(e);
         string s2;
-        for (unsigned int j = 0; j < e->s.size(); ++j) {
+        for (unsigned int j = 0; j < s.size(); ++j) {
             if (atStartOfLine) {
-                if (e->s[j] == ' ') {
+                if (s[j] == ' ') {
                     if (curDropped++ >= minIndent)
-                        s2 += e->s[j];
+                        s2 += s[j];
                 }
-                else if (e->s[j] == '\n') {
+                else if (s[j] == '\n') {
                     curDropped = 0;
-                    s2 += e->s[j];
+                    s2 += s[j];
                 } else {
                     atStartOfLine = false;
                     curDropped = 0;
-                    s2 += e->s[j];
+                    s2 += s[j];
                 }
             } else {
-                s2 += e->s[j];
-                if (e->s[j] == '\n') atStartOfLine = true;
+                s2 += s[j];
+                if (s[j] == '\n') atStartOfLine = true;
             }
         }
 
         /* Remove the last line if it is empty and consists only of
            spaces. */
         if (n == 1) {
-            string::size_type p = s2.find_last_of('\n');
+            unsigned int p = s2.find_last_of('\n');
             if (p != string::npos && s2.find_first_not_of(' ', p + 1) == string::npos)
                 s2 = string(s2, 0, p + 1);
         }
-
-        es2->push_back(new ExprString(symbols.create(s2)));
+            
+        es2 = ATinsert(es2, makeStr(s2));
     }
 
-    return new ExprConcatStrings(es2);
+    return makeConcatStrings(ATreverse(es2));
 }
 
 
@@ -217,12 +162,13 @@ void backToString(yyscan_t scanner);
 void backToIndString(yyscan_t scanner);
 
 
-static Pos makeCurPos(const YYLTYPE & loc, ParseData * data)
+static Pos makeCurPos(YYLTYPE * loc, ParseData * data)
 {
-    return Pos(data->path, loc.first_line, loc.first_column);
+    return makePos(toATerm(data->path),
+        loc->first_line, loc->first_column);
 }
 
-#define CUR_POS makeCurPos(*yylocp, data)
+#define CUR_POS makeCurPos(yylocp, data)
 
 
 }
@@ -230,40 +176,50 @@ static Pos makeCurPos(const YYLTYPE & loc, ParseData * data)
 
 void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * error)
 {
-    data->error = (format("%1%, at %2%")
-        % error % makeCurPos(*loc, data)).str();
+    data->error = (format("%1%, at `%2%':%3%:%4%")
+        % error % data->path % loc->first_line % loc->first_column).str();
 }
 
 
+/* Make sure that the parse stack is scanned by the ATerm garbage
+   collector. */
+static void * mallocAndProtect(size_t size)
+{
+    void * p = malloc(size);
+    if (p) ATprotectMemory(p, size);
+    return p;
+}
+
+static void freeAndUnprotect(void * p)
+{
+    ATunprotectMemory(p);
+    free(p);
+}
+
+#define YYMALLOC mallocAndProtect
+#define YYFREE freeAndUnprotect
+
+
+#endif
+
+
 %}
 
 %union {
-  nix::Expr * e;
-  nix::ExprList * list;
-  nix::ExprAttrs * attrs;
-  nix::Formals * formals;
-  nix::Formal * formal;
-  int n;
-  char * id; // !!! -> Symbol
-  char * path;
-  char * uri;
-  std::vector<nix::Symbol> * ids;
-  std::vector<nix::Expr *> * string_parts;
+  ATerm t;
+  ATermList ts;
+  struct {
+    ATermList formals;
+    bool ellipsis;
+  } formals;
 }
 
-%type <e> start expr expr_function expr_if expr_op
-%type <e> expr_app expr_select expr_simple
-%type <list> expr_list
-%type <attrs> binds
+%type <t> start expr expr_function expr_if expr_op
+%type <t> expr_app expr_select expr_simple bind inheritsrc formal
+%type <t> pattern pattern2
+%type <ts> binds ids expr_list string_parts ind_string_parts
 %type <formals> formals
-%type <formal> formal
-%type <ids> ids attrpath
-%type <string_parts> string_parts ind_string_parts
-%token <id> ID ATTRPATH
-%token <e> STR IND_STR
-%token <n> INT
-%token <path> PATH
-%token <uri> URI
+%token <t> ID INT STR IND_STR PATH URI
 %token IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL
 %token DOLLAR_CURLY /* == ${ */
 %token IND_STRING_OPEN IND_STRING_CLOSE
@@ -287,170 +243,239 @@ start: expr { data->result = $1; };
 expr: expr_function;
 
 expr_function
-  : ID ':' expr_function
-    { $$ = new ExprLambda(CUR_POS, data->symbols.create($1), false, 0, $3); }
-  | '{' formals '}' ':' expr_function
-    { $$ = new ExprLambda(CUR_POS, data->symbols.create(""), true, $2, $5); }
-  | '{' formals '}' '@' ID ':' expr_function
-    { $$ = new ExprLambda(CUR_POS, data->symbols.create($5), true, $2, $7); }
-  | ID '@' '{' formals '}' ':' expr_function
-    { $$ = new ExprLambda(CUR_POS, data->symbols.create($1), true, $4, $7); }
+  : pattern ':' expr_function
+    { $$ = makeFunction($1, $3, CUR_POS); }
   | ASSERT expr ';' expr_function
-    { $$ = new ExprAssert(CUR_POS, $2, $4); }
+    { $$ = makeAssert($2, $4, CUR_POS); }
   | WITH expr ';' expr_function
-    { $$ = new ExprWith(CUR_POS, $2, $4); }
+    { $$ = makeWith($2, $4, CUR_POS); }
   | LET binds IN expr_function
-    { $$ = new ExprLet($2, $4); }
+    { $$ = makeSelect(fixAttrs(1, ATinsert($2, makeBind(toATerm("<let-body>"), $4, CUR_POS))), toATerm("<let-body>")); }
   | expr_if
   ;
 
 expr_if
-  : IF expr THEN expr ELSE expr { $$ = new ExprIf($2, $4, $6); }
+  : IF expr THEN expr ELSE expr
+    { $$ = makeIf($2, $4, $6); }
   | expr_op
   ;
 
 expr_op
-  : '!' expr_op %prec NEG { $$ = new ExprOpNot($2); }
-  | expr_op EQ expr_op { $$ = new ExprOpEq($1, $3); }
-  | expr_op NEQ expr_op { $$ = new ExprOpNEq($1, $3); }
-  | expr_op AND expr_op { $$ = new ExprOpAnd($1, $3); }
-  | expr_op OR expr_op { $$ = new ExprOpOr($1, $3); }
-  | expr_op IMPL expr_op { $$ = new ExprOpImpl($1, $3); }
-  | expr_op UPDATE expr_op { $$ = new ExprOpUpdate($1, $3); }
-  | expr_op '?' ID { $$ = new ExprOpHasAttr($1, data->symbols.create($3)); }
-  | expr_op '+' expr_op
-    { vector<Expr *> * l = new vector<Expr *>;
-      l->push_back($1);
-      l->push_back($3);
-      $$ = new ExprConcatStrings(l);
-    }
-  | expr_op CONCAT expr_op { $$ = new ExprOpConcatLists($1, $3); }
+  : '!' expr_op %prec NEG { $$ = makeOpNot($2); }
+  | expr_op EQ expr_op { $$ = makeOpEq($1, $3); }
+  | expr_op NEQ expr_op { $$ = makeOpNEq($1, $3); }
+  | expr_op AND expr_op { $$ = makeOpAnd($1, $3); }
+  | expr_op OR expr_op { $$ = makeOpOr($1, $3); }
+  | expr_op IMPL expr_op { $$ = makeOpImpl($1, $3); }
+  | expr_op UPDATE expr_op { $$ = makeOpUpdate($1, $3); }
+  | expr_op '~' expr_op { $$ = makeSubPath($1, $3); }
+  | expr_op '?' ID { $$ = makeOpHasAttr($1, $3); }
+  | expr_op '+' expr_op { $$ = makeOpPlus($1, $3); }
+  | expr_op CONCAT expr_op { $$ = makeOpConcat($1, $3); }
   | expr_app
   ;
 
 expr_app
   : expr_app expr_select
-    { $$ = new ExprApp($1, $2); }
+    { $$ = makeCall($1, $2); }
   | expr_select { $$ = $1; }
   ;
 
 expr_select
   : expr_select '.' ID
-    { $$ = new ExprSelect($1, data->symbols.create($3)); }
+    { $$ = makeSelect($1, $3); }
   | expr_simple { $$ = $1; }
   ;
 
 expr_simple
-  : ID { $$ = new ExprVar(data->symbols.create($1)); }
-  | INT { $$ = new ExprInt($1); }
+  : ID { $$ = makeVar($1); }
+  | INT { $$ = makeInt(ATgetInt((ATermInt) $1)); }
   | '"' string_parts '"' {
       /* For efficiency, and to simplify parse trees a bit. */
-      if ($2->empty()) $$ = new ExprString(data->symbols.create(""));
-      else if ($2->size() == 1) $$ = $2->front();
-      else $$ = new ExprConcatStrings($2);
+      if ($2 == ATempty) $$ = makeStr(toATerm(""), ATempty);
+      else if (ATgetNext($2) == ATempty) $$ = ATgetFirst($2);
+      else $$ = makeConcatStrings(ATreverse($2));
   }
   | IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE {
-      $$ = stripIndentation(data->symbols, *$2);
+      $$ = stripIndentation(ATreverse($2));
   }
-  | PATH { $$ = new ExprPath(absPath($1, data->basePath)); }
-  | URI { $$ = new ExprString(data->symbols.create($1)); }
+  | PATH { $$ = makePath(toATerm(absPath(aterm2String($1), data->basePath))); }
+  | URI { $$ = makeStr($1, ATempty); }
   | '(' expr ')' { $$ = $2; }
   /* Let expressions `let {..., body = ...}' are just desugared
      into `(rec {..., body = ...}).body'. */
   | LET '{' binds '}'
-    { $3->recursive = true; $$ = new ExprSelect($3, data->symbols.create("body")); }
+    { $$ = makeSelect(fixAttrs(1, $3), toATerm("body")); }
   | REC '{' binds '}'
-    { $3->recursive = true; $$ = $3; }
+    { $$ = fixAttrs(1, $3); }
   | '{' binds '}'
-    { $$ = $2; }
-  | '[' expr_list ']' { $$ = $2; }
+    { $$ = fixAttrs(0, $2); }
+  | '[' expr_list ']' { $$ = makeList($2); }
   ;
 
 string_parts
-  : string_parts STR { $$ = $1; $1->push_back($2); }
-  | string_parts DOLLAR_CURLY expr '}' { backToString(scanner); $$ = $1; $1->push_back($3); }
-  | { $$ = new vector<Expr *>; }
+  : string_parts STR { $$ = ATinsert($1, $2); }
+  | string_parts DOLLAR_CURLY expr '}' { backToString(scanner); $$ = ATinsert($1, $3); }
+  | { $$ = ATempty; }
   ;
 
 ind_string_parts
-  : ind_string_parts IND_STR { $$ = $1; $1->push_back($2); }
-  | ind_string_parts DOLLAR_CURLY expr '}' { backToIndString(scanner); $$ = $1; $1->push_back($3); }
-  | { $$ = new vector<Expr *>; }
+  : ind_string_parts IND_STR { $$ = ATinsert($1, $2); }
+  | ind_string_parts DOLLAR_CURLY expr '}' { backToIndString(scanner); $$ = ATinsert($1, $3); }
+  | { $$ = ATempty; }
+  ;
+
+pattern
+  : pattern2 '@' pattern { $$ = makeAtPat($1, $3); }
+  | pattern2
+  ;
+
+pattern2
+  : ID { $$ = makeVarPat($1); }
+  | '{' formals '}' { $$ = makeAttrsPat($2.formals, $2.ellipsis ? eTrue : eFalse); }
   ;
 
 binds
-  : binds attrpath '=' expr ';' { $$ = $1; addAttr($$, *$2, $4, makeCurPos(@2, data)); }
-  | binds INHERIT ids ';'
-    { $$ = $1;
-      foreach (vector<Symbol>::iterator, i, *$3) {
-          if ($$->attrs.find(*i) != $$->attrs.end())
-              dupAttr(*i, makeCurPos(@3, data), $$->attrs[*i].pos);
-          Pos pos = makeCurPos(@3, data);
-          $$->attrs[*i] = ExprAttrs::AttrDef(*i, pos);
-      }
-    }
-  | binds INHERIT '(' expr ')' ids ';'
-    { $$ = $1;
-      /* !!! Should ensure sharing of the expression in $4. */
-      foreach (vector<Symbol>::iterator, i, *$6) {
-          if ($$->attrs.find(*i) != $$->attrs.end())
-              dupAttr(*i, makeCurPos(@6, data), $$->attrs[*i].pos);
-          $$->attrs[*i] = ExprAttrs::AttrDef(new ExprSelect($4, *i), makeCurPos(@6, data));
-      }}
-
-  | { $$ = new ExprAttrs; }
+  : binds bind { $$ = ATinsert($1, $2); }
+  | { $$ = ATempty; }
   ;
 
-ids
-  : ids ID { $$ = $1; $1->push_back(data->symbols.create($2)); /* !!! dangerous */ }
-  | { $$ = new vector<Symbol>; }
+bind
+  : ID '=' expr ';'
+    { $$ = makeBind($1, $3, CUR_POS); }
+  | INHERIT inheritsrc ids ';'
+    { $$ = makeInherit($2, $3, CUR_POS); }
   ;
 
-attrpath
-  : attrpath '.' ID { $$ = $1; $1->push_back(data->symbols.create($3)); }
-  | ID { $$ = new vector<Symbol>; $$->push_back(data->symbols.create($1)); }
+inheritsrc
+  : '(' expr ')' { $$ = $2; }
+  | { $$ = makeScope(); }
   ;
 
+ids: ids ID { $$ = ATinsert($1, $2); } | { $$ = ATempty; };
+
 expr_list
-  : expr_list expr_select { $$ = $1; $1->elems.push_back($2); /* !!! dangerous */ }
-  | { $$ = new ExprList; }
+  : expr_select expr_list { $$ = ATinsert($2, $1); }
+    /* yes, this is right-recursive, but it doesn't matter since
+       otherwise we would need ATreverse which requires unbounded
+       stack space */
+  | { $$ = ATempty; }
   ;
 
 formals
-  : formal ',' formals
-    { $$ = $3; addFormal(CUR_POS, $$, *$1); }
+  : formal ',' formals /* idem - right recursive */
+    { $$.formals = ATinsert($3.formals, $1); $$.ellipsis = $3.ellipsis; }
   | formal
-    { $$ = new Formals; addFormal(CUR_POS, $$, *$1); $$->ellipsis = false; }
+    { $$.formals = ATinsert(ATempty, $1); $$.ellipsis = false; }
   |
-    { $$ = new Formals; $$->ellipsis = false; }
+    { $$.formals = ATempty; $$.ellipsis = false; }
   | ELLIPSIS
-    { $$ = new Formals; $$->ellipsis = true; }
+    { $$.formals = ATempty; $$.ellipsis = true; }
   ;
 
 formal
-  : ID { $$ = new Formal(data->symbols.create($1), 0); }
-  | ID '?' expr { $$ = new Formal(data->symbols.create($1), $3); }
+  : ID { $$ = makeFormal($1, makeNoDefaultValue()); }
+  | ID '?' expr { $$ = makeFormal($1, makeDefaultValue($3)); }
   ;
   
 %%
 
 
+#include "eval.hh"  
+
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 
-#include <eval.hh>
-
 
 namespace nix {
       
 
-static Expr * parse(EvalState & state, const char * text,
-    const Path & path, const Path & basePath)
+static void checkAttrs(ATermMap & names, ATermList bnds)
+{
+    for (ATermIterator i(bnds); i; ++i) {
+        ATerm name;
+        Expr e;
+        ATerm pos;
+        if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
+        if (names.get(name))
+            throw EvalError(format("duplicate attribute `%1%' at %2%")
+                % aterm2String(name) % showPos(pos));
+        names.set(name, name);
+    }
+}
+
+
+static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat)
+{
+    ATerm name;
+    ATermList formals;
+    Pattern pat1, pat2;
+    ATermBool ellipsis;
+    if (matchVarPat(pat, name)) {
+        if (map.get(name))
+            throw EvalError(format("duplicate formal function argument `%1%' at %2%")
+                % aterm2String(name) % showPos(pos));
+        map.set(name, name);
+    }
+    else if (matchAttrsPat(pat, formals, ellipsis)) { 
+        for (ATermIterator i(formals); i; ++i) {
+            ATerm d1;
+            if (!matchFormal(*i, name, d1)) abort();
+            if (map.get(name))
+                throw EvalError(format("duplicate formal function argument `%1%' at %2%")
+                    % aterm2String(name) % showPos(pos));
+            map.set(name, name);
+        }
+    }
+    else if (matchAtPat(pat, pat1, pat2)) {
+        checkPatternVars(pos, map, pat1);
+        checkPatternVars(pos, map, pat2);
+    }
+    else abort();
+}
+
+
+static void checkAttrSets(ATerm e)
+{
+    ATerm pat, body, pos;
+    if (matchFunction(e, pat, body, pos)) {
+        ATermMap map(16);
+        checkPatternVars(pos, map, pat);
+    }
+
+    ATermList bnds;
+    if (matchAttrs(e, bnds)) {
+        ATermMap names(ATgetLength(bnds));
+        checkAttrs(names, bnds);
+    }
+    
+    ATermList rbnds, nrbnds;
+    if (matchRec(e, rbnds, nrbnds)) {
+        ATermMap names(ATgetLength(rbnds) + ATgetLength(nrbnds));
+        checkAttrs(names, rbnds);
+        checkAttrs(names, nrbnds);
+    }
+    
+    if (ATgetType(e) == AT_APPL) {
+        int arity = ATgetArity(ATgetAFun(e));
+        for (int i = 0; i < arity; ++i)
+            checkAttrSets(ATgetArgument(e, i));
+    }
+
+    else if (ATgetType(e) == AT_LIST)
+        for (ATermIterator i((ATermList) e); i; ++i)
+            checkAttrSets(*i);
+}
+
+
+static Expr parse(EvalState & state,
+    const char * text, const Path & path,
+    const Path & basePath)
 {
     yyscan_t scanner;
-    ParseData data(state.symbols);
+    ParseData data;
     data.basePath = basePath;
     data.path = path;
 
@@ -459,22 +484,30 @@ static Expr * parse(EvalState & state, const char * text,
     int res = yyparse(scanner, &data);
     yylex_destroy(scanner);
     
-    if (res) throw ParseError(data.error);
+    if (res) throw EvalError(data.error);
 
     try {
-        data.result->bindVars(state.staticBaseEnv);
+        checkVarDefs(state.primOps, data.result);
     } catch (Error & e) {
-        throw ParseError(format("%1%, in `%2%'") % e.msg() % path);
+        throw EvalError(format("%1%, in `%2%'") % e.msg() % path);
     }
     
+    checkAttrSets(data.result);
+
     return data.result;
 }
 
 
-Expr * parseExprFromFile(EvalState & state, Path path)
+Expr parseExprFromFile(EvalState & state, Path path)
 {
     assert(path[0] == '/');
 
+#if 0
+    /* Perhaps this is already an imploded parse tree? */
+    Expr e = ATreadFromNamedFile(path.c_str());
+    if (e) return e;
+#endif
+
     /* If `path' is a symlink, follow it.  This is so that relative
        path references work. */
     struct stat st;
@@ -486,6 +519,8 @@ Expr * parseExprFromFile(EvalState & state, Path path)
     }
 
     /* If `path' refers to a directory, append `/default.nix'. */
+    if (stat(path.c_str(), &st))
+        throw SysError(format("getting status of `%1%'") % path);
     if (S_ISDIR(st.st_mode))
         path = canonPath(path + "/default.nix");
 
@@ -494,7 +529,7 @@ Expr * parseExprFromFile(EvalState & state, Path path)
 }
 
 
-Expr * parseExprFromString(EvalState & state,
+Expr parseExprFromString(EvalState & state,
     const string & s, const Path & basePath)
 {
     return parse(state, s.c_str(), "(string)", basePath);

src/libexpr/symbol-table.hh

@@ -1,92 +0,0 @@
-#ifndef __SYMBOL_TABLE_H
-#define __SYMBOL_TABLE_H
-
-#include "config.h"
-
-#include <map>
-
-#if HAVE_TR1_UNORDERED_SET
-#include <tr1/unordered_set>
-#endif
-
-#include "types.hh"
-
-namespace nix {
-
-/* Symbol table used by the parser and evaluator to represent and look
-   up identifiers and attribute sets efficiently.
-   SymbolTable::create() converts a string into a symbol.  Symbols
-   have the property that they can be compared efficiently (using a
-   pointer equality test), because the symbol table stores only one
-   copy of each string. */
-
-class Symbol
-{
-private:
-    const string * s; // pointer into SymbolTable
-    Symbol(const string * s) : s(s) { };
-    friend class SymbolTable;
-
-public:
-    Symbol() : s(0) { };
-    
-    bool operator == (const Symbol & s2) const
-    {
-        return s == s2.s;
-    }
-    
-    bool operator != (const Symbol & s2) const
-    {
-        return s != s2.s;
-    }
-    
-    bool operator < (const Symbol & s2) const
-    {
-        return s < s2.s;
-    }
-
-    operator const string & () const
-    {
-        return *s;
-    }
-
-    bool empty() const
-    {
-        return s->empty();
-    }
-
-    friend std::ostream & operator << (std::ostream & str, const Symbol & sym);
-};
-
-inline std::ostream & operator << (std::ostream & str, const Symbol & sym)
-{
-    str << *sym.s;
-    return str;
-}
-
-class SymbolTable
-{
-private:
-#if HAVE_TR1_UNORDERED_SET 
-    typedef std::tr1::unordered_set<string> Symbols;
-#else
-    typedef std::set<string> Symbols;
-#endif
-    Symbols symbols;
-
-public:
-    Symbol create(const string & s)
-    {
-        std::pair<Symbols::iterator, bool> res = symbols.insert(s);
-        return Symbol(&*res.first);
-    }
-
-    unsigned int size() const
-    {
-        return symbols.size();
-    }
-};
-
-}
-
-#endif /* !__SYMBOL_TABLE_H */

src/libexpr/value-to-xml.cc

@@ -1,162 +0,0 @@
-#include "value-to-xml.hh"
-#include "xml-writer.hh"
-#include "util.hh"
-
-#include <cstdlib>
-
-
-namespace nix {
-
-    
-static XMLAttrs singletonAttrs(const string & name, const string & value)
-{
-    XMLAttrs attrs;
-    attrs[name] = value;
-    return attrs;
-}
-
-
-static void printValueAsXML(EvalState & state, bool strict, bool location,
-    Value & v, XMLWriter & doc, PathSet & context, PathSet & drvsSeen);
-
-
-static void posToXML(XMLAttrs & xmlAttrs, const Pos & pos)
-{
-    xmlAttrs["path"] = pos.file;
-    xmlAttrs["line"] = (format("%1%") % pos.line).str();
-    xmlAttrs["column"] = (format("%1%") % pos.column).str();
-}
-
-
-static void showAttrs(EvalState & state, bool strict, bool location,
-    Bindings & attrs, XMLWriter & doc, PathSet & context, PathSet & drvsSeen)
-{
-    StringSet names;
-    
-    foreach (Bindings::iterator, i, attrs)
-        names.insert(i->name);
-    
-    foreach (StringSet::iterator, i, names) {
-        Attr & a(*attrs.find(state.symbols.create(*i)));
-        
-        XMLAttrs xmlAttrs;
-        xmlAttrs["name"] = *i;
-        if (location && a.pos != &noPos) posToXML(xmlAttrs, *a.pos);
-        
-        XMLOpenElement _(doc, "attr", xmlAttrs);
-        printValueAsXML(state, strict, location,
-            *a.value, doc, context, drvsSeen);
-    }
-}
-
-
-static void printValueAsXML(EvalState & state, bool strict, bool location,
-    Value & v, XMLWriter & doc, PathSet & context, PathSet & drvsSeen)
-{
-    checkInterrupt();
-
-    if (strict) state.forceValue(v);
-        
-    switch (v.type) {
-
-        case tInt:
-            doc.writeEmptyElement("int", singletonAttrs("value", (format("%1%") % v.integer).str()));
-            break;
-
-        case tBool:
-            doc.writeEmptyElement("bool", singletonAttrs("value", v.boolean ? "true" : "false"));
-            break;
-
-        case tString:
-            /* !!! show the context? */
-            copyContext(v, context);
-            doc.writeEmptyElement("string", singletonAttrs("value", v.string.s));
-            break;
-
-        case tPath:
-            doc.writeEmptyElement("path", singletonAttrs("value", v.path));
-            break;
-
-        case tNull:
-            doc.writeEmptyElement("null");
-            break;
-
-        case tAttrs:
-            if (state.isDerivation(v)) {
-                XMLAttrs xmlAttrs;
-            
-                Bindings::iterator a = v.attrs->find(state.symbols.create("derivation"));
-
-                Path drvPath;
-                a = v.attrs->find(state.sDrvPath);
-                if (a != v.attrs->end()) {
-                    if (strict) state.forceValue(*a->value);
-                    if (a->value->type == tString)
-                        xmlAttrs["drvPath"] = drvPath = a->value->string.s;
-                }
-        
-                a = v.attrs->find(state.sOutPath);
-                if (a != v.attrs->end()) {
-                    if (strict) state.forceValue(*a->value);
-                    if (a->value->type == tString)
-                        xmlAttrs["outPath"] = a->value->string.s;
-                }
-
-                XMLOpenElement _(doc, "derivation", xmlAttrs);
-
-                if (drvPath != "" && drvsSeen.find(drvPath) == drvsSeen.end()) {
-                    drvsSeen.insert(drvPath);
-                    showAttrs(state, strict, location, *v.attrs, doc, context, drvsSeen);
-                } else
-                    doc.writeEmptyElement("repeated");
-            }
-
-            else {
-                XMLOpenElement _(doc, "attrs");
-                showAttrs(state, strict, location, *v.attrs, doc, context, drvsSeen);
-            }
-            
-            break;
-
-        case tList: {
-            XMLOpenElement _(doc, "list");
-            for (unsigned int n = 0; n < v.list.length; ++n)
-                printValueAsXML(state, strict, location, *v.list.elems[n], doc, context, drvsSeen);
-            break;
-        }
-
-        case tLambda: {
-            XMLAttrs xmlAttrs;
-            if (location) posToXML(xmlAttrs, v.lambda.fun->pos);
-            XMLOpenElement _(doc, "function", xmlAttrs);
-            
-            if (v.lambda.fun->matchAttrs) {
-                XMLAttrs attrs;
-                if (!v.lambda.fun->arg.empty()) attrs["name"] = v.lambda.fun->arg;
-                if (v.lambda.fun->formals->ellipsis) attrs["ellipsis"] = "1";
-                XMLOpenElement _(doc, "attrspat", attrs);
-                foreach (Formals::Formals_::iterator, i, v.lambda.fun->formals->formals)
-                    doc.writeEmptyElement("attr", singletonAttrs("name", i->name));
-            } else
-                doc.writeEmptyElement("varpat", singletonAttrs("name", v.lambda.fun->arg));
-            
-            break;
-        }
-
-        default:
-            doc.writeEmptyElement("unevaluated");
-    }
-}
-
-
-void printValueAsXML(EvalState & state, bool strict, bool location,
-    Value & v, std::ostream & out, PathSet & context)
-{
-    XMLWriter doc(true, out);
-    XMLOpenElement root(doc, "expr");
-    PathSet drvsSeen;    
-    printValueAsXML(state, strict, location, v, doc, context, drvsSeen);
-}
-
- 
-}

src/libexpr/value-to-xml.hh

@@ -1,17 +0,0 @@
-#ifndef __VALUE_TO_XML_H
-#define __VALUE_TO_XML_H
-
-#include "nixexpr.hh"
-#include "eval.hh"
-
-#include <string>
-#include <map>
-
-namespace nix {
-
-void printValueAsXML(EvalState & state, bool strict, bool location,
-    Value & v, std::ostream & out, PathSet & context);
-    
-}
-
-#endif /* !__VALUE_TO_XML_H */

src/libmain/Makefile.am

@@ -1,10 +1,6 @@
 pkglib_LTLIBRARIES = libmain.la
 
-libmain_la_SOURCES = shared.cc
-
-libmain_la_LIBADD = ../libstore/libstore.la @boehmgc_lib@
-
-pkginclude_HEADERS = shared.hh
+libmain_la_SOURCES = shared.cc shared.hh
 
 AM_CXXFLAGS = \
  -DNIX_STORE_DIR=\"$(storedir)\" \
@@ -15,5 +11,5 @@ AM_CXXFLAGS = \
  -DNIX_LIBEXEC_DIR=\"$(libexecdir)\" \
  -DNIX_BIN_DIR=\"$(bindir)\" \
  -DNIX_VERSION=\"$(VERSION)\" \
- -I$(srcdir)/.. -I$(srcdir)/../libutil \
+ -I$(srcdir)/.. ${aterm_include} -I$(srcdir)/../libutil \
  -I$(srcdir)/../libstore

src/libmain/shared.cc

@@ -13,9 +13,7 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#if HAVE_BOEHMGC
-#include <gc/gc.h>
-#endif
+#include <aterm2.h>
 
 
 namespace nix {
@@ -54,26 +52,25 @@ void printGCWarning()
 
 void printMissing(const PathSet & paths)
 {
-    unsigned long long downloadSize, narSize;
+    unsigned long long downloadSize;
     PathSet willBuild, willSubstitute, unknown;
-    queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize, narSize);
+    queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize);
 
     if (!willBuild.empty()) {
-        printMsg(lvlInfo, format("these derivations will be built:"));
+        printMsg(lvlInfo, format("the following derivations will be built:"));
         foreach (PathSet::iterator, i, willBuild)
             printMsg(lvlInfo, format("  %1%") % *i);
     }
 
     if (!willSubstitute.empty()) {
-        printMsg(lvlInfo, format("these paths will be downloaded/copied (%.2f MiB download, %.2f MiB unpacked):")
-            % (downloadSize / (1024.0 * 1024.0))
-            % (narSize / (1024.0 * 1024.0)));
+        printMsg(lvlInfo, format("the following paths will be downloaded/copied (%.2f MiB):") %
+            (downloadSize / (1024.0 * 1024.0)));
         foreach (PathSet::iterator, i, willSubstitute)
             printMsg(lvlInfo, format("  %1%") % *i);
     }
 
     if (!unknown.empty()) {
-        printMsg(lvlInfo, format("don't know how to build these paths%1%:")
+        printMsg(lvlInfo, format("don't know how to build the following paths%1%:")
             % (readOnlyMode ? " (may be caused by read-only store access)" : ""));
         foreach (PathSet::iterator, i, unknown)
             printMsg(lvlInfo, format("  %1%") % *i);
@@ -90,6 +87,21 @@ static void setLogType(string lt)
 }
 
 
+unsigned long long getIntArg(const string & opt,
+    Strings::iterator & i, const Strings::iterator & end)
+{
+    ++i;
+    if (i == end) throw UsageError(format("`%1%' requires an argument") % opt);
+    long long n;
+    if (!string2Int(*i, n) || n < 0)
+        throw UsageError(format("`%1%' requires a non-negative integer") % opt);
+    return n;
+}
+
+
+void initDerivationsHelpers();
+
+
 static void closeStore()
 {
     try {
@@ -113,9 +125,6 @@ RemoveTempRoots::~RemoveTempRoots()
 }
 
 
-static bool showTrace = false;
-
-
 /* Initialize and reorder arguments, then call the actual argument
    processor. */
 static void initAndRun(int argc, char * * argv)
@@ -129,6 +138,7 @@ static void initAndRun(int argc, char * * argv)
     nixConfDir = canonPath(getEnv("NIX_CONF_DIR", NIX_CONF_DIR));
     nixLibexecDir = canonPath(getEnv("NIX_LIBEXEC_DIR", NIX_LIBEXEC_DIR));
     nixBinDir = canonPath(getEnv("NIX_BIN_DIR", NIX_BIN_DIR));
+    nixChrootsDir = canonPath(getEnv("NIX_CHROOTS_DIR", nixStateDir + "/chroots"));
 
     string subs = getEnv("NIX_SUBSTITUTERS", "default");
     if (subs == "default") {
@@ -140,33 +150,26 @@ static void initAndRun(int argc, char * * argv)
     /* Get some settings from the configuration file. */
     thisSystem = querySetting("system", SYSTEM);
     maxBuildJobs = queryIntSetting("build-max-jobs", 1);
-    buildCores = queryIntSetting("build-cores", 1);
     maxSilentTime = queryIntSetting("build-max-silent-time", 0);
 
     /* Catch SIGINT. */
-    struct sigaction act;
+    struct sigaction act, oact;
     act.sa_handler = sigintHandler;
     sigfillset(&act.sa_mask);
     act.sa_flags = 0;
-    if (sigaction(SIGINT, &act, 0))
+    if (sigaction(SIGINT, &act, &oact))
         throw SysError("installing handler for SIGINT");
-    if (sigaction(SIGTERM, &act, 0))
+    if (sigaction(SIGTERM, &act, &oact))
         throw SysError("installing handler for SIGTERM");
-    if (sigaction(SIGHUP, &act, 0))
+    if (sigaction(SIGHUP, &act, &oact))
         throw SysError("installing handler for SIGHUP");
 
     /* Ignore SIGPIPE. */
     act.sa_handler = SIG_IGN;
     act.sa_flags = 0;
-    if (sigaction(SIGPIPE, &act, 0))
+    if (sigaction(SIGPIPE, &act, &oact))
         throw SysError("ignoring SIGPIPE");
 
-    /* Reset SIGCHLD to its default. */
-    act.sa_handler = SIG_DFL;
-    act.sa_flags = 0;
-    if (sigaction(SIGCHLD, &act, 0))
-        throw SysError("resetting SIGCHLD");
-
     /* There is no privacy in the Nix system ;-)  At least not for
        now.  In particular, store objects should be readable by
        everybody.  This prevents nasty surprises when using a shared
@@ -177,6 +180,9 @@ static void initAndRun(int argc, char * * argv)
     string lt = getEnv("NIX_LOG_TYPE");
     if (lt != "") setLogType(lt);
 
+    /* ATerm stuff.  !!! find a better place to put this */
+    initDerivationsHelpers();
+    
     /* Put the arguments in a vector. */
     Strings args, remaining;
     while (argc--) args.push_back(*argv++);
@@ -187,7 +193,7 @@ static void initAndRun(int argc, char * * argv)
     for (Strings::iterator i = args.begin(); i != args.end(); ++i) {
         string arg = *i;
         if (string(arg, 0, 4) == "-at-") ;
-        else if (arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && !isdigit(arg[1])) {
+        else if (arg.length() > 2 && arg[0] == '-' && arg[1] != '-') {
             for (unsigned int j = 1; j < arg.length(); j++)
                 if (isalpha(arg[j]))
                     remaining.push_back((string) "-" + arg[j]);
@@ -201,16 +207,17 @@ static void initAndRun(int argc, char * * argv)
     remaining.clear();
 
     /* Process default options. */
-    int verbosityDelta = 0;
     for (Strings::iterator i = args.begin(); i != args.end(); ++i) {
         string arg = *i;
-        if (arg == "--verbose" || arg == "-v") verbosityDelta++;
-        else if (arg == "--quiet") verbosityDelta--;
+        if (arg == "--verbose" || arg == "-v")
+            verbosity = (Verbosity) ((int) verbosity + 1);
         else if (arg == "--log-type") {
             ++i;
             if (i == args.end()) throw UsageError("`--log-type' requires an argument");
             setLogType(*i);
         }
+        else if (arg == "--build-output" || arg == "-B")
+            ; /* !!! obsolete - remove eventually */
         else if (arg == "--no-build-output" || arg == "-Q")
             buildVerbosity = lvlVomit;
         else if (arg == "--print-build-trace")
@@ -230,30 +237,16 @@ static void initAndRun(int argc, char * * argv)
         else if (arg == "--fallback")
             tryFallback = true;
         else if (arg == "--max-jobs" || arg == "-j")
-            maxBuildJobs = getIntArg<unsigned int>(arg, i, args.end());
-        else if (arg == "--cores")
-            buildCores = getIntArg<unsigned int>(arg, i, args.end());
+            maxBuildJobs = getIntArg(arg, i, args.end());
         else if (arg == "--readonly-mode")
             readOnlyMode = true;
         else if (arg == "--max-silent-time")
-            maxSilentTime = getIntArg<unsigned int>(arg, i, args.end());
+            maxSilentTime = getIntArg(arg, i, args.end());
         else if (arg == "--no-build-hook")
             useBuildHook = false;
-        else if (arg == "--show-trace")
-            showTrace = true;
-        else if (arg == "--option") {
-            ++i; if (i == args.end()) throw UsageError("`--option' requires two arguments");
-            string name = *i;
-            ++i; if (i == args.end()) throw UsageError("`--option' requires two arguments");
-            string value = *i;
-            overrideSetting(name, tokenizeString(value));
-        }
         else remaining.push_back(arg);
     }
 
-    verbosityDelta += queryIntSetting("verbosity", lvlInfo);
-    verbosity = (Verbosity) (verbosityDelta < 0 ? 0 : verbosityDelta);
-    
     /* Automatically clean up the temporary roots file when we
        exit. */
     RemoveTempRoots removeTempRoots __attribute__((unused));
@@ -321,14 +314,6 @@ static void setuidInit()
 }
 
 
-/* Called when the Boehm GC runs out of memory. */
-static void * oomHandler(size_t requested)
-{
-    /* Convert this to a proper C++ exception. */
-    throw std::bad_alloc();
-}
-
-
 }
 
 
@@ -343,6 +328,10 @@ int main(int argc, char * * argv)
     if (argc == 0) abort();
     setuidInit();
     
+    /* ATerm setup. */
+    ATerm bottomOfStack;
+    ATinit(argc, argv, &bottomOfStack);
+
     /* Turn on buffering for cerr. */
 #if HAVE_PUBSETBUF
     std::cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));
@@ -350,26 +339,6 @@ int main(int argc, char * * argv)
 
     std::ios::sync_with_stdio(false);
 
-#if HAVE_BOEHMGC
-    /* Initialise the Boehm garbage collector.  This isn't necessary
-       on most platforms, but for portability we do it anyway. */
-    GC_INIT();
-
-    GC_oom_fn = oomHandler;
-
-    /* Set the initial heap size to something fairly big (384 MiB) so
-       that in most cases we don't need to garbage collect at all.
-       (Collection has a fairly significant overhead, some.)  The heap
-       size can be overriden through libgc's GC_INITIAL_HEAP_SIZE
-       environment variable.  We should probably also provide a
-       nix.conf setting for this.  Note that GC_expand_hp() causes a
-       lot of virtual, but not physical (resident) memory to be
-       allocated.  This might be a problem on systems that don't
-       overcommit. */
-    if (!getenv("GC_INITIAL_HEAP_SIZE"))
-        GC_expand_hp(384 * 1024 * 1024);
-#endif
-
     try {
         try {
             initAndRun(argc, argv);
@@ -390,10 +359,8 @@ int main(int argc, char * * argv)
             % e.what() % programId);
         return 1;
     } catch (BaseError & e) {
-        printMsg(lvlError, format("error: %1%%2%") % (showTrace ? e.prefix() : "") % e.msg());
-        if (e.prefix() != "" && !showTrace)
-            printMsg(lvlError, "(use `--show-trace' to show detailed location information)");
-        return e.status;
+        printMsg(lvlError, format("error: %1%") % e.msg());
+        return 1;
     } catch (std::exception & e) {
         printMsg(lvlError, format("error: %1%") % e.what());
         return 1;

src/libmain/shared.hh

@@ -1,7 +1,7 @@
 #ifndef __SHARED_H
 #define __SHARED_H
 
-#include "util.hh"
+#include "types.hh"
 
 #include <signal.h>
 
@@ -22,30 +22,22 @@ extern std::string programId;
 
 namespace nix {
 
-MakeError(UsageError, nix::Error);
-
 /* Ugh.  No better place to put this. */
 Path makeRootName(const Path & gcRoot, int & counter);
 void printGCWarning();
 
 void printMissing(const PathSet & paths);
 
-template<class N> N getIntArg(const string & opt,
-    Strings::iterator & i, const Strings::iterator & end)
-{
-    ++i;
-    if (i == end) throw UsageError(format("`%1%' requires an argument") % opt);
-    N n;
-    if (!string2Int(*i, n))
-        throw UsageError(format("`%1%' requires an integer argument") % opt);
-    return n;
-}
+unsigned long long getIntArg(const string & opt,
+    Strings::iterator & i, const Strings::iterator & end);
 
 /* Whether we're running setuid. */
 extern bool setuidMode;
 
 extern volatile ::sig_atomic_t blockInt;
 
+MakeError(UsageError, nix::Error);
+
 struct RemoveTempRoots 
 {
     ~RemoveTempRoots();    

src/libstore/Makefile.am

@@ -2,22 +2,22 @@ pkglib_LTLIBRARIES = libstore.la
 
 libstore_la_SOURCES = \
   store-api.cc local-store.cc remote-store.cc derivations.cc build.cc misc.cc \
-  globals.cc references.cc pathlocks.cc gc.cc \
+  globals.cc db.cc references.cc pathlocks.cc gc.cc upgrade-schema.cc \
   optimise-store.cc
 
 pkginclude_HEADERS = \
   store-api.hh local-store.hh remote-store.hh derivations.hh misc.hh \
-  globals.hh references.hh pathlocks.hh \
+  globals.hh db.hh references.hh pathlocks.hh \
   worker-protocol.hh
 
-libstore_la_LIBADD = ../libutil/libutil.la ../boost/format/libformat.la ${aterm_lib} ${sqlite_lib}
+libstore_la_LIBADD = ../libutil/libutil.la ../boost/format/libformat.la
 
-EXTRA_DIST = schema.sql
+BUILT_SOURCES = derivations-ast.cc derivations-ast.hh
+
+EXTRA_DIST = derivations-ast.def derivations-ast.cc
 
 AM_CXXFLAGS = -Wall \
- ${sqlite_include} -I$(srcdir)/.. -I$(srcdir)/../libutil
+ -I$(srcdir)/.. ${bdb_include} ${aterm_include} -I$(srcdir)/../libutil
 
-local-store.lo: schema.sql.hh
-
-%.sql.hh: %.sql
-	../bin2c/bin2c schema < $< > $@ || (rm $@ && exit 1)
+derivations-ast.cc derivations-ast.hh: ../aterm-helper.pl derivations-ast.def
+	$(perl) $(srcdir)/../aterm-helper.pl derivations-ast.hh derivations-ast.cc < $(srcdir)/derivations-ast.def

src/libstore/db.cc

@@ -0,0 +1,474 @@
+#include "config.h"
+
+#ifdef OLD_DB_COMPAT
+
+#include "db.hh"
+#include "util.hh"
+#include "pathlocks.hh"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <memory>
+
+#include <db_cxx.h>
+
+
+namespace nix {
+
+
+/* Wrapper class to ensure proper destruction. */
+class DestroyDbc 
+{
+    Dbc * dbc;
+public:
+    DestroyDbc(Dbc * _dbc) : dbc(_dbc) { }
+    ~DestroyDbc() { dbc->close(); /* close() frees dbc */ }
+};
+
+
+class DestroyDbEnv
+{
+    DbEnv * dbenv;
+public:
+    DestroyDbEnv(DbEnv * _dbenv) : dbenv(_dbenv) { }
+    ~DestroyDbEnv() {
+        if (dbenv) {
+            if (dbenv->get_DB_ENV()) dbenv->close(0);
+            delete dbenv;
+        }
+    }
+    void release() { dbenv = 0; };
+};
+
+
+static void rethrow(DbException & e)
+{
+    throw Error(e.what());
+}
+
+
+Transaction::Transaction()
+    : txn(0)
+{
+}
+
+
+Transaction::Transaction(Database & db)
+    : txn(0)
+{
+    begin(db);
+}
+
+
+Transaction::~Transaction()
+{
+    if (txn) abort();
+}
+
+
+void Transaction::begin(Database & db)
+{
+    assert(txn == 0);
+    db.requireEnv();
+    try {
+        db.env->txn_begin(0, &txn, 0);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void Transaction::commit()
+{
+    if (!txn) throw Error("commit called on null transaction");
+    debug(format("committing transaction %1%") % (void *) txn);
+    DbTxn * txn2 = txn;
+    txn = 0;
+    try {
+        txn2->commit(0);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void Transaction::abort()
+{
+    if (!txn) throw Error("abort called on null transaction");
+    debug(format("aborting transaction %1%") % (void *) txn);
+    DbTxn * txn2 = txn;
+    txn = 0;
+    try {
+        txn2->abort();
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void Transaction::moveTo(Transaction & t)
+{
+    if (t.txn) throw Error("target txn already exists");
+    t.txn = txn;
+    txn = 0;
+}
+
+
+void Database::requireEnv()
+{
+    checkInterrupt();
+    if (!env) throw Error("database environment is not open "
+        "(maybe you don't have sufficient permission?)");
+}
+
+
+Db * Database::getDb(TableId table)
+{
+    if (table == 0)
+        throw Error("database table is not open "
+            "(maybe you don't have sufficient permission?)");
+    std::map<TableId, Db *>::iterator i = tables.find(table);
+    if (i == tables.end())
+        throw Error("unknown table id");
+    return i->second;
+}
+
+
+Database::Database()
+    : env(0)
+    , nextId(1)
+{
+}
+
+
+Database::~Database()
+{
+    close();
+}
+
+
+void openEnv(DbEnv * & env, const string & path, u_int32_t flags)
+{
+    try {
+        createDirs(path);
+    } catch (SysError & e) {
+        if (e.errNo == EPERM || e.errNo == EACCES)
+            throw DbNoPermission(format("cannot create the Nix database in `%1%'") % path);
+        else
+            throw;
+    }
+        
+    try {
+        env->open(path.c_str(),
+            DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN |
+            DB_CREATE | flags,
+            0666);
+    } catch (DbException & e) {
+        printMsg(lvlError, format("environment open failed: %1%") % e.what());
+        throw;
+    }
+}
+
+
+static int my_fsync(int fd)
+{
+    return 0;
+}
+
+
+static void errorPrinter(const DbEnv * env, const char * errpfx, const char * msg)
+{
+    printMsg(lvlError, format("Berkeley DB error: %1%") % msg);
+}
+
+
+static void messagePrinter(const DbEnv * env, const char * msg)
+{
+    printMsg(lvlError, format("Berkeley DB message: %1%") % msg);
+}
+
+
+void Database::open2(const string & path, bool removeOldEnv)
+{
+    if (env) throw Error(format("environment already open"));
+
+    debug(format("opening database environment"));
+
+
+    /* Create the database environment object. */
+    DbEnv * env = new DbEnv(0);
+    DestroyDbEnv deleteEnv(env);
+
+    env->set_errcall(errorPrinter);
+    env->set_msgcall(messagePrinter);
+    if (getEnv("NIX_DEBUG_DB_REGISTER") == "1")
+        env->set_verbose(DB_VERB_REGISTER, 1);
+    env->set_verbose(DB_VERB_RECOVERY, 1);
+    
+    /* Smaller log files. */
+    env->set_lg_bsize(32 * 1024); /* default */
+    env->set_lg_max(256 * 1024); /* must be > 4 * lg_bsize */
+    
+    /* Write the log, but don't sync.  This protects transactions
+       against application crashes, but if the system crashes, some
+       transactions may be undone.  An acceptable risk, I think. */
+    env->set_flags(DB_TXN_WRITE_NOSYNC | DB_LOG_AUTOREMOVE, 1);
+    
+    /* Increase the locking limits.  If you ever get `Dbc::get: Cannot
+       allocate memory' or similar, especially while running
+       `nix-store --verify', just increase the following number, then
+       run db_recover on the database to remove the existing DB
+       environment (since changes only take effect on new
+       environments). */
+    env->set_lk_max_locks(10000);
+    env->set_lk_max_lockers(10000);
+    env->set_lk_max_objects(10000);
+    env->set_lk_detect(DB_LOCK_DEFAULT);
+    
+    /* Dangerous, probably, but from the docs it *seems* that BDB
+       shouldn't sync when DB_TXN_WRITE_NOSYNC is used, but it still
+       fsync()s sometimes. */
+    db_env_set_func_fsync(my_fsync);
+
+    
+    if (removeOldEnv) {
+        printMsg(lvlError, "removing old Berkeley DB database environment...");
+        env->remove(path.c_str(), DB_FORCE);
+        return;
+    }
+
+    openEnv(env, path, DB_REGISTER | DB_RECOVER);
+
+    deleteEnv.release();
+    this->env = env;
+}
+
+
+void Database::open(const string & path)
+{
+    try {
+
+        open2(path, false);
+        
+    } catch (DbException e) {
+        
+        if (e.get_errno() == DB_VERSION_MISMATCH) {
+            /* Remove the environment while we are holding the global
+               lock.  If things go wrong there, we bail out.
+               !!! argh, we abolished the global lock :-( */
+            open2(path, true);
+
+            /* Try again. */
+            open2(path, false);
+
+            /* Force a checkpoint, as per the BDB docs. */
+            env->txn_checkpoint(DB_FORCE, 0, 0);
+
+            printMsg(lvlError, "database succesfully upgraded to new version");
+        }
+
+#if 0        
+        else if (e.get_errno() == DB_RUNRECOVERY) {
+            /* If recovery is needed, do it. */
+            printMsg(lvlError, "running recovery...");
+            open2(path, false, true);
+        }
+#endif        
+        
+        else
+            rethrow(e);
+    }
+}
+
+
+void Database::close()
+{
+    if (!env) return;
+
+    /* Close the database environment. */
+    debug(format("closing database environment"));
+
+    try {
+
+        for (std::map<TableId, Db *>::iterator i = tables.begin();
+             i != tables.end(); )
+        {
+            std::map<TableId, Db *>::iterator j = i;
+            ++j;
+            closeTable(i->first);
+            i = j;
+        }
+
+        /* Do a checkpoint every 128 kilobytes, or every 5 minutes. */
+        env->txn_checkpoint(128, 5, 0);
+        
+        env->close(0);
+
+    } catch (DbException e) { rethrow(e); }
+
+    delete env;
+
+    env = 0;
+}
+
+
+TableId Database::openTable(const string & tableName, bool sorted)
+{
+    requireEnv();
+    TableId table = nextId++;
+
+    try {
+
+        Db * db = new Db(env, 0);
+
+        try {
+            db->open(0, tableName.c_str(), 0, 
+                sorted ? DB_BTREE : DB_HASH,
+                DB_CREATE | DB_AUTO_COMMIT, 0666);
+        } catch (...) {
+            delete db;
+            throw;
+        }
+
+        tables[table] = db;
+
+    } catch (DbException e) { rethrow(e); }
+
+    return table;
+}
+
+
+void Database::closeTable(TableId table)
+{
+    try {
+        Db * db = getDb(table);
+        db->close(DB_NOSYNC);
+        delete db;
+        tables.erase(table);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void Database::deleteTable(const string & table)
+{
+    try {
+        env->dbremove(0, table.c_str(), 0, DB_AUTO_COMMIT);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+bool Database::queryString(const Transaction & txn, TableId table, 
+    const string & key, string & data)
+{
+    checkInterrupt();
+
+    try {
+        Db * db = getDb(table);
+
+        Dbt kt((void *) key.c_str(), key.length());
+        Dbt dt;
+
+        int err = db->get(txn.txn, &kt, &dt, 0);
+        if (err) return false;
+
+        if (!dt.get_data())
+            data = "";
+        else
+            data = string((char *) dt.get_data(), dt.get_size());
+    
+    } catch (DbException e) { rethrow(e); }
+
+    return true;
+}
+
+
+bool Database::queryStrings(const Transaction & txn, TableId table, 
+    const string & key, Strings & data)
+{
+    string d;
+    if (!queryString(txn, table, key, d))
+        return false;
+    data = unpackStrings(d);
+    return true;
+}
+
+
+void Database::setString(const Transaction & txn, TableId table,
+    const string & key, const string & data)
+{
+    checkInterrupt();
+    try {
+        Db * db = getDb(table);
+        Dbt kt((void *) key.c_str(), key.length());
+        Dbt dt((void *) data.c_str(), data.length());
+        db->put(txn.txn, &kt, &dt, 0);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void Database::setStrings(const Transaction & txn, TableId table,
+    const string & key, const Strings & data, bool deleteEmpty)
+{
+    if (deleteEmpty && data.size() == 0)
+        delPair(txn, table, key);
+    else
+        setString(txn, table, key, packStrings(data));
+}
+
+
+void Database::delPair(const Transaction & txn, TableId table,
+    const string & key)
+{
+    checkInterrupt();
+    try {
+        Db * db = getDb(table);
+        Dbt kt((void *) key.c_str(), key.length());
+        db->del(txn.txn, &kt, 0);
+        /* Non-existence of a pair with the given key is not an
+           error. */
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void Database::enumTable(const Transaction & txn, TableId table,
+    Strings & keys, const string & keyPrefix)
+{
+    try {
+        Db * db = getDb(table);
+
+        Dbc * dbc;
+        db->cursor(txn.txn, &dbc, 0);
+        DestroyDbc destroyDbc(dbc);
+
+        Dbt kt, dt;
+        u_int32_t flags = DB_NEXT;
+
+        if (!keyPrefix.empty()) {
+            flags = DB_SET_RANGE;
+            kt = Dbt((void *) keyPrefix.c_str(), keyPrefix.size());
+        }
+
+        while (dbc->get(&kt, &dt, flags) != DB_NOTFOUND) {
+            checkInterrupt();
+            string data((char *) kt.get_data(), kt.get_size());
+            if (!keyPrefix.empty() &&
+                string(data, 0, keyPrefix.size()) != keyPrefix)
+                break;
+            keys.push_back(data);
+            flags = DB_NEXT;
+        }
+
+    } catch (DbException e) { rethrow(e); }
+}
+
+ 
+void Database::clearTable(const Transaction & txn, TableId table)
+{
+    try {
+        Db * db = getDb(table);
+        u_int32_t count;
+        db->truncate(txn.txn, &count, 0);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+}
+
+#endif

src/libstore/db.hh

@@ -0,0 +1,107 @@
+#ifndef __DB_H
+#define __DB_H
+
+#include "types.hh"
+
+#include <map>
+
+
+/* Defined externally. */
+class DbTxn;
+class DbEnv;
+class Db;
+
+
+namespace nix {
+
+
+class Database;
+
+
+class Transaction
+{
+    friend class Database;
+
+private:
+    DbTxn * txn;
+    
+public:
+    Transaction();
+    Transaction(Database & _db);
+    ~Transaction();
+
+    void begin(Database & db);
+    void abort();
+    void commit();
+
+    void moveTo(Transaction & t);
+};
+
+
+#define noTxn Transaction()
+
+
+typedef unsigned int TableId; /* table handles */
+
+
+class Database
+{
+    friend class Transaction;
+
+private:
+    DbEnv * env;
+
+    TableId nextId;
+    std::map<TableId, Db *> tables;
+
+    void requireEnv();
+
+    Db * getDb(TableId table);
+
+    void open2(const string & path, bool removeOldEnv);
+    
+public:
+    Database();
+    ~Database();
+    
+    void open(const string & path);
+    void close();
+
+    TableId openTable(const string & table, bool sorted = false);
+    void closeTable(TableId table);
+    void deleteTable(const string & table);
+
+    bool queryString(const Transaction & txn, TableId table, 
+        const string & key, string & data);
+
+    bool queryStrings(const Transaction & txn, TableId table, 
+        const string & key, Strings & data);
+
+    void setString(const Transaction & txn, TableId table,
+        const string & key, const string & data);
+
+    void setStrings(const Transaction & txn, TableId table,
+        const string & key, const Strings & data,
+        bool deleteEmpty = true);
+
+    void delPair(const Transaction & txn, TableId table,
+        const string & key);
+
+    void enumTable(const Transaction & txn, TableId table,
+        Strings & keys, const string & keyPrefix = "");
+
+    void clearTable(const Transaction & txn, TableId table);
+};
+
+
+class DbNoPermission : public Error
+{
+public:
+    DbNoPermission(const format & f) : Error(f) { };
+};
+
+ 
+}
+
+
+#endif /* !__DB_H */

src/libstore/derivations-ast.def

@@ -0,0 +1,10 @@
+init initDerivationsHelpers
+
+Derive | ATermList ATermList ATermList string string ATermList ATermList | ATerm |
+
+| string string | ATerm | EnvBinding |
+| string ATermList | ATerm | DerivationInput |
+| string string string string | ATerm | DerivationOutput |
+
+Closure | ATermList ATermList | ATerm | OldClosure |
+| string ATermList | ATerm | OldClosureElem |

src/libstore/derivations.cc

@@ -1,167 +1,164 @@
 #include "derivations.hh"
 #include "store-api.hh"
+#include "aterm.hh"
 #include "globals.hh"
 #include "util.hh"
 
+#include "derivations-ast.hh"
+#include "derivations-ast.cc"
+
 
 namespace nix {
 
 
+Hash hashTerm(ATerm t)
+{
+    return hashString(htSHA256, atPrint(t));
+}
+
+
 Path writeDerivation(const Derivation & drv, const string & name)
 {
     PathSet references;
     references.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
-    foreach (DerivationInputs::const_iterator, i, drv.inputDrvs)
+    for (DerivationInputs::const_iterator i = drv.inputDrvs.begin();
+         i != drv.inputDrvs.end(); ++i)
         references.insert(i->first);
     /* Note that the outputs of a derivation are *not* references
        (that can be missing (of course) and should not necessarily be
        held during a garbage collection). */
     string suffix = name + drvExtension;
-    string contents = unparseDerivation(drv);
+    string contents = atPrint(unparseDerivation(drv));
     return readOnlyMode
         ? computeStorePathForText(suffix, contents, references)
         : store->addTextToStore(suffix, contents, references);
 }
 
 
-static Path parsePath(std::istream & str)
+static void checkPath(const string & s)
 {
-    string s = parseString(str);
     if (s.size() == 0 || s[0] != '/')
         throw Error(format("bad path `%1%' in derivation") % s);
-    return s;
 }
     
 
-static StringSet parseStrings(std::istream & str, bool arePaths)
+static void parseStrings(ATermList paths, StringSet & out, bool arePaths)
 {
-    StringSet res;
-    while (!endOfList(str))
-        res.insert(arePaths ? parsePath(str) : parseString(str));
-    return res;
+    for (ATermIterator i(paths); i; ++i) {
+        if (ATgetType(*i) != AT_APPL)
+            throw badTerm("not a path", *i);
+        string s = aterm2String(*i);
+        if (arePaths) checkPath(s);
+        out.insert(s);
+    }
 }
-    
 
-Derivation parseDerivation(const string & s)
+
+/* Shut up warnings. */
+void throwBadDrv(ATerm t) __attribute__ ((noreturn));
+
+void throwBadDrv(ATerm t) 
+{
+    throw badTerm("not a valid derivation", t);
+}
+
+
+Derivation parseDerivation(ATerm t)
 {
     Derivation drv;
-    std::istringstream str(s);
-    expect(str, "Derive([");
+    ATermList outs, inDrvs, inSrcs, args, bnds;
+    ATerm builder, platform;
 
-    /* Parse the list of outputs. */
-    while (!endOfList(str)) {
+    if (!matchDerive(t, outs, inDrvs, inSrcs, platform, builder, args, bnds))
+        throwBadDrv(t);
+
+    for (ATermIterator i(outs); i; ++i) {
+        ATerm id, path, hashAlgo, hash;
+        if (!matchDerivationOutput(*i, id, path, hashAlgo, hash))
+            throwBadDrv(t);
         DerivationOutput out;
-        expect(str, "("); string id = parseString(str);
-        expect(str, ","); out.path = parsePath(str);
-        expect(str, ","); out.hashAlgo = parseString(str);
-        expect(str, ","); out.hash = parseString(str);
-        expect(str, ")");
-        drv.outputs[id] = out;
+        out.path = aterm2String(path);
+        checkPath(out.path);
+        out.hashAlgo = aterm2String(hashAlgo);
+        out.hash = aterm2String(hash);
+        drv.outputs[aterm2String(id)] = out;
     }
 
-    /* Parse the list of input derivations. */
-    expect(str, ",[");
-    while (!endOfList(str)) {
-        expect(str, "(");
-        Path drvPath = parsePath(str);
-        expect(str, ",[");
-        drv.inputDrvs[drvPath] = parseStrings(str, false);
-        expect(str, ")");
-    }
-
-    expect(str, ",["); drv.inputSrcs = parseStrings(str, true);
-    expect(str, ","); drv.platform = parseString(str);
-    expect(str, ","); drv.builder = parseString(str);
-
-    /* Parse the builder arguments. */
-    expect(str, ",[");
-    while (!endOfList(str))
-        drv.args.push_back(parseString(str));
-
-    /* Parse the environment variables. */
-    expect(str, ",[");
-    while (!endOfList(str)) {
-        expect(str, "("); string name = parseString(str);
-        expect(str, ","); string value = parseString(str);
-        expect(str, ")");
-        drv.env[name] = value;
+    for (ATermIterator i(inDrvs); i; ++i) {
+        ATerm drvPath;
+        ATermList ids;
+        if (!matchDerivationInput(*i, drvPath, ids))
+            throwBadDrv(t);
+        Path drvPath2 = aterm2String(drvPath);
+        checkPath(drvPath2);
+        StringSet ids2;
+        parseStrings(ids, ids2, false);
+        drv.inputDrvs[drvPath2] = ids2;
     }
     
-    expect(str, ")");
+    parseStrings(inSrcs, drv.inputSrcs, true);
+
+    drv.builder = aterm2String(builder);
+    drv.platform = aterm2String(platform);
+    
+    for (ATermIterator i(args); i; ++i) {
+        if (ATgetType(*i) != AT_APPL)
+            throw badTerm("string expected", *i);
+        drv.args.push_back(aterm2String(*i));
+    }
+
+    for (ATermIterator i(bnds); i; ++i) {
+        ATerm s1, s2;
+        if (!matchEnvBinding(*i, s1, s2))
+            throw badTerm("tuple of strings expected", *i);
+        drv.env[aterm2String(s1)] = aterm2String(s2);
+    }
+
     return drv;
 }
 
 
-static void printString(string & res, const string & s)
+ATerm unparseDerivation(const Derivation & drv)
 {
-    res += '"';
-    for (const char * i = s.c_str(); *i; i++)
-        if (*i == '\"' || *i == '\\') { res += "\\"; res += *i; }
-        else if (*i == '\n') res += "\\n";
-        else if (*i == '\r') res += "\\r";
-        else if (*i == '\t') res += "\\t";
-        else res += *i;
-    res += '"';
-}
+    ATermList outputs = ATempty;
+    for (DerivationOutputs::const_reverse_iterator i = drv.outputs.rbegin();
+         i != drv.outputs.rend(); ++i)
+        outputs = ATinsert(outputs,
+            makeDerivationOutput(
+                toATerm(i->first),
+                toATerm(i->second.path),
+                toATerm(i->second.hashAlgo),
+                toATerm(i->second.hash)));
 
-
-template<class ForwardIterator>
-static void printStrings(string & res, ForwardIterator i, ForwardIterator j)
-{
-    res += '[';
-    bool first = true;
-    for ( ; i != j; ++i) {
-        if (first) first = false; else res += ',';
-        printString(res, *i);
-    }
-    res += ']';
-}
-
-
-string unparseDerivation(const Derivation & drv)
-{
-    string s;
-    s.reserve(65536);
-    s += "Derive([";
-
-    bool first = true;
-    foreach (DerivationOutputs::const_iterator, i, drv.outputs) {
-        if (first) first = false; else s += ',';
-        s += '('; printString(s, i->first);
-        s += ','; printString(s, i->second.path);
-        s += ','; printString(s, i->second.hashAlgo);
-        s += ','; printString(s, i->second.hash);
-        s += ')';
-    }
-
-    s += "],[";
-    first = true;
-    foreach (DerivationInputs::const_iterator, i, drv.inputDrvs) {
-        if (first) first = false; else s += ',';
-        s += '('; printString(s, i->first);
-        s += ','; printStrings(s, i->second.begin(), i->second.end());
-        s += ')';
-    }
-
-    s += "],";
-    printStrings(s, drv.inputSrcs.begin(), drv.inputSrcs.end());
+    ATermList inDrvs = ATempty;
+    for (DerivationInputs::const_reverse_iterator i = drv.inputDrvs.rbegin();
+         i != drv.inputDrvs.rend(); ++i)
+        inDrvs = ATinsert(inDrvs,
+            makeDerivationInput(
+                toATerm(i->first),
+                toATermList(i->second)));
     
-    s += ','; printString(s, drv.platform);
-    s += ','; printString(s, drv.builder);
-    s += ','; printStrings(s, drv.args.begin(), drv.args.end());
+    ATermList args = ATempty;
+    for (Strings::const_reverse_iterator i = drv.args.rbegin();
+         i != drv.args.rend(); ++i)
+        args = ATinsert(args, toATerm(*i));
 
-    s += ",[";
-    first = true;
-    foreach (StringPairs::const_iterator, i, drv.env) {
-        if (first) first = false; else s += ',';
-        s += '('; printString(s, i->first);
-        s += ','; printString(s, i->second);
-        s += ')';
-    }
-    
-    s += "])";
-    
-    return s;
+    ATermList env = ATempty;
+    for (StringPairs::const_reverse_iterator i = drv.env.rbegin();
+         i != drv.env.rend(); ++i)
+        env = ATinsert(env,
+            makeEnvBinding(
+                toATerm(i->first),
+                toATerm(i->second)));
+
+    return makeDerive(
+        outputs,
+        inDrvs,
+        toATermList(drv.inputSrcs),
+        toATerm(drv.platform),
+        toATerm(drv.builder),
+        args,
+        env);
 }
 
 

src/libstore/derivations.hh

@@ -1,9 +1,11 @@
 #ifndef __DERIVATIONS_H
 #define __DERIVATIONS_H
 
-#include <map>
+typedef struct _ATerm * ATerm;
 
-#include "types.hh"
+#include "hash.hh"
+
+#include <map>
 
 
 namespace nix {
@@ -51,14 +53,17 @@ struct Derivation
 };
 
 
+/* Hash an aterm. */
+Hash hashTerm(ATerm t);
+
 /* Write a derivation to the Nix store, and return its path. */
 Path writeDerivation(const Derivation & drv, const string & name);
 
 /* Parse a derivation. */
-Derivation parseDerivation(const string & s);
+Derivation parseDerivation(ATerm t);
 
-/* Print a derivation. */
-string unparseDerivation(const Derivation & drv);
+/* Parse a derivation. */
+ATerm unparseDerivation(const Derivation & drv);
 
 /* Check whether a file name ends with the extensions for
    derivations. */

src/libstore/gc.cc

@@ -1,12 +1,12 @@
 #include "globals.hh"
 #include "misc.hh"
+#include "pathlocks.hh"
 #include "local-store.hh"
 
 #include <boost/shared_ptr.hpp>
 
 #include <functional>
 #include <queue>
-#include <algorithm>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -14,6 +14,11 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#ifdef __CYGWIN__
+#include <windows.h>
+#include <sys/cygwin.h>
+#endif
+
 
 namespace nix {
 
@@ -30,7 +35,7 @@ static const int defaultGcLevel = 1000;
    read.  To be precise: when they try to create a new temporary root
    file, they will block until the garbage collector has finished /
    yielded the GC lock. */
-int LocalStore::openGCLock(LockType lockType)
+static int openGCLock(LockType lockType)
 {
     Path fnGCLock = (format("%1%/%2%")
         % nixStateDir % gcLockName).str();
@@ -126,7 +131,7 @@ Path addPermRoot(const Path & _storePath, const Path & _gcRoot,
        Instead of reading all the roots, it would be more efficient to
        check if the root is in a directory in or linked from the
        gcroots directory. */
-    if (queryBoolSetting("gc-check-reachability", false)) {
+    if (queryBoolSetting("gc-check-reachability", true)) {
         Roots roots = store->findRoots();
         if (roots.find(gcRoot) == roots.end())
             printMsg(lvlError, 
@@ -135,7 +140,7 @@ Path addPermRoot(const Path & _storePath, const Path & _gcRoot,
                     "therefore, `%2%' might be removed by the garbage collector")
                 % gcRoot % storePath);
     }
-
+        
     /* Grab the global GC root, causing us to block while a GC is in
        progress.  This prevents the set of permanent roots from
        increasing while a GC is in progress. */
@@ -173,6 +178,15 @@ void LocalStore::addTempRoot(const Path & path)
 
             fdGCLock.close();
       
+	    /* Note that on Cygwin a lot of the following complexity
+	       is unnecessary, since we cannot delete open lock
+	       files.  If we have the lock file open, then it's valid;
+	       if we can delete it, then it wasn't in use any more. 
+
+	       Also note that on Cygwin we cannot "upgrade" a lock
+	       from a read lock to a write lock. */
+
+#ifndef __CYGWIN__
             debug(format("acquiring read lock on `%1%'") % fnTempRoots);
             lockFile(fdTempRoots, ltRead, true);
 
@@ -186,6 +200,10 @@ void LocalStore::addTempRoot(const Path & path)
             /* The garbage collector deleted this file before we could
                get a lock.  (It won't delete the file after we get a
                lock.)  Try again. */
+
+#else
+            break;
+#endif
         }
 
     }
@@ -198,9 +216,14 @@ void LocalStore::addTempRoot(const Path & path)
     string s = path + '\0';
     writeFull(fdTempRoots, (const unsigned char *) s.c_str(), s.size());
 
+#ifndef __CYGWIN__
     /* Downgrade to a read lock. */
     debug(format("downgrading to read lock on `%1%'") % fnTempRoots);
     lockFile(fdTempRoots, ltRead, true);
+#else
+    debug(format("releasing write lock on `%1%'") % fnTempRoots);
+    lockFile(fdTempRoots, ltNone, true);
+#endif
 }
 
 
@@ -224,10 +247,25 @@ static void readTempRoots(PathSet & tempRoots, FDs & fds)
     Strings tempRootFiles = readDirectory(
         (format("%1%/%2%") % nixStateDir % tempRootsDir).str());
 
-    foreach (Strings::iterator, i, tempRootFiles) {
+    for (Strings::iterator i = tempRootFiles.begin();
+         i != tempRootFiles.end(); ++i)
+    {
         Path path = (format("%1%/%2%/%3%") % nixStateDir % tempRootsDir % *i).str();
 
         debug(format("reading temporary root file `%1%'") % path);
+
+#ifdef __CYGWIN__
+	/* On Cygwin we just try to delete the lock file. */
+	char win32Path[MAX_PATH];
+	cygwin_conv_to_full_win32_path(path.c_str(), win32Path);
+	if (DeleteFile(win32Path)) {
+            printMsg(lvlError, format("removed stale temporary roots file `%1%'")
+                % path);
+            continue;
+        } else
+            debug(format("delete of `%1%' failed: %2%") % path % GetLastError());
+#endif
+
         FDPtr fd(new AutoCloseFD(open(path.c_str(), O_RDWR, 0666)));
         if (*fd == -1) {
             /* It's okay if the file has disappeared. */
@@ -239,6 +277,7 @@ static void readTempRoots(PathSet & tempRoots, FDs & fds)
         //FDPtr fd(new AutoCloseFD(openLockFile(path, false)));
         //if (*fd == -1) continue;
 
+#ifndef __CYGWIN__
         /* Try to acquire a write lock without blocking.  This can
            only succeed if the owning process has died.  In that case
            we don't care about its temporary roots. */
@@ -249,6 +288,7 @@ static void readTempRoots(PathSet & tempRoots, FDs & fds)
             writeFull(*fd, (const unsigned char *) "d", 1);
             continue;
         }
+#endif
 
         /* Acquire a read lock.  This will prevent the owning process
            from upgrading to a write lock, therefore it will block in
@@ -288,7 +328,7 @@ static void findRoots(const Path & path, bool recurseSymlinks,
 
         if (S_ISDIR(st.st_mode)) {
             Strings names = readDirectory(path);
-            foreach (Strings::iterator, i, names)
+            for (Strings::iterator i = names.begin(); i != names.end(); ++i)
                 findRoots(path + "/" + *i, recurseSymlinks, deleteStale, roots);
         }
 
@@ -359,11 +399,11 @@ static void addAdditionalRoots(PathSet & roots)
 
     Strings paths = tokenizeString(result, "\n");
     
-    foreach (Strings::iterator, i, paths) {
+    for (Strings::iterator i = paths.begin(); i != paths.end(); ++i) {
         if (isInStore(*i)) {
             Path path = toStorePath(*i);
             if (roots.find(path) == roots.end() && store->isValidPath(path)) {
-                debug(format("got additional root `%1%'") % path);
+                debug(format("found additional root `%1%'") % path);
                 roots.insert(path);
             }
         }
@@ -381,7 +421,8 @@ static void dfsVisit(const PathSet & paths, const Path & path,
     if (store->isValidPath(path))
         store->queryReferences(path, references);
     
-    foreach (PathSet::iterator, i, references)
+    for (PathSet::iterator i = references.begin();
+         i != references.end(); ++i)
         /* Don't traverse into paths that don't exist.  That can
            happen due to substitutes for non-existent paths. */
         if (*i != path && paths.find(*i) != paths.end())
@@ -395,185 +436,156 @@ Paths topoSortPaths(const PathSet & paths)
 {
     Paths sorted;
     PathSet visited;
-    foreach (PathSet::const_iterator, i, paths)
+    for (PathSet::const_iterator i = paths.begin(); i != paths.end(); ++i)
         dfsVisit(paths, *i, visited, sorted);
     return sorted;
 }
 
 
+static time_t lastFileAccessTime(const Path & path)
+{
+    checkInterrupt();
+    
+    struct stat st;
+    if (lstat(path.c_str(), &st) == -1)
+        throw SysError(format("statting `%1%'") % path);
+
+    if (S_ISDIR(st.st_mode)) {
+        time_t last = 0;
+	Strings names = readDirectory(path);
+	for (Strings::iterator i = names.begin(); i != names.end(); ++i) {
+            time_t t = lastFileAccessTime(path + "/" + *i);
+            if (t > last) last = t;
+        }
+        return last;
+    }
+
+    else if (S_ISLNK(st.st_mode)) return 0;
+
+    else return st.st_atime;
+}
+
+
 struct GCLimitReached { };
 
 
-struct LocalStore::GCState
+void LocalStore::gcPath(const GCOptions & options, GCResults & results, 
+    const Path & path)
 {
-    GCOptions options;
-    GCResults & results;
-    PathSet roots;
-    PathSet tempRoots;
-    PathSet deleted;
-    PathSet live;
-    PathSet busy;
-    bool gcKeepOutputs;
-    bool gcKeepDerivations;
-    GCState(GCResults & results_) : results(results_)
+    results.paths.insert(path);
+
+    if (!pathExists(path)) return;
+                
+#ifndef __CYGWIN__
+    AutoCloseFD fdLock;
+        
+    /* Only delete a lock file if we can acquire a write lock on it.
+       That means that it's either stale, or the process that created
+       it hasn't locked it yet.  In the latter case the other process
+       will detect that we deleted the lock, and retry (see
+       pathlocks.cc). */
+    if (path.size() >= 5 && string(path, path.size() - 5) == ".lock") {
+        fdLock = openLockFile(path, false);
+        if (fdLock != -1 && !lockFile(fdLock, ltWrite, false)) {
+            debug(format("skipping active lock `%1%'") % path);
+            return;
+        }
+    }
+#endif
+
+    /* Okay, it's safe to delete. */
+    unsigned long long bytesFreed, blocksFreed;
+    deleteFromStore(path, bytesFreed, blocksFreed);
+    results.bytesFreed += bytesFreed;
+    results.blocksFreed += blocksFreed;
+
+    if (results.bytesFreed > options.maxFreed) {
+        printMsg(lvlInfo, format("deleted more than %1% bytes; stopping") % options.maxFreed);
+        throw GCLimitReached();
+    }
+
+    if (options.maxLinks) {
+        struct stat st;
+        if (stat(nixStore.c_str(), &st) == -1)
+            throw SysError(format("statting `%1%'") % nixStore);
+        if (st.st_nlink < options.maxLinks) {
+            printMsg(lvlInfo, format("link count on the store has dropped below %1%; stopping") % options.maxLinks);
+            throw GCLimitReached();
+        }
+    }
+
+#ifndef __CYGWIN__
+    if (fdLock != -1)
+        /* Write token to stale (deleted) lock file. */
+        writeFull(fdLock, (const unsigned char *) "d", 1);
+#endif
+}
+
+
+void LocalStore::gcPathRecursive(const GCOptions & options,
+    GCResults & results, PathSet & done, const Path & path)
+{
+    if (done.find(path) != done.end()) return;
+    done.insert(path);
+
+    startNest(nest, lvlDebug, format("looking at `%1%'") % path);
+        
+    /* Delete all the referrers first.  They must be garbage too,
+       since if they were live, then the current path would also be
+       live.  Note that deleteFromStore() below still makes sure that
+       the referrer set has become empty, just in case.  (However that
+       doesn't guard against deleting top-level paths that are only
+       reachable from GC roots.) */
+    PathSet referrers;
+    if (isValidPath(path))
+        queryReferrers(path, referrers);
+    foreach (PathSet::iterator, i, referrers)
+        if (*i != path) gcPathRecursive(options, results, done, *i);
+
+    printMsg(lvlInfo, format("deleting `%1%'") % path);
+            
+    gcPath(options, results, path);
+}
+
+
+struct CachingAtimeComparator : public std::binary_function<Path, Path, bool> 
+{
+    std::map<Path, time_t> cache;
+
+    time_t lookup(const Path & p)
     {
+        std::map<Path, time_t>::iterator i = cache.find(p);
+        if (i != cache.end()) return i->second;
+        debug(format("computing atime of `%1%'") % p);
+        cache[p] = lastFileAccessTime(p);
+        assert(cache.find(p) != cache.end());
+        return cache[p];
+    }
+        
+    bool operator () (const Path & p1, const Path & p2)
+    {
+        return lookup(p2) < lookup(p1);
     }
 };
 
 
-static bool shouldDelete(GCOptions::GCAction action)
+string showTime(const string & format, time_t t)
 {
-    return action == GCOptions::gcDeleteDead
-        || action == GCOptions::gcDeleteSpecific;
-}
-
-
-bool LocalStore::isActiveTempFile(const GCState & state,
-    const Path & path, const string & suffix)
-{
-    return hasSuffix(path, suffix)
-        && state.tempRoots.find(string(path, 0, path.size() - suffix.size())) != state.tempRoots.end();
-}
-
-    
-bool LocalStore::tryToDelete(GCState & state, const Path & path)
-{
-    checkInterrupt();
-    
-    if (!pathExists(path)) return true;
-    if (state.deleted.find(path) != state.deleted.end()) return true;
-    if (state.live.find(path) != state.live.end()) return false;
-
-    startNest(nest, lvlDebug, format("considering whether to delete `%1%'") % path);
-
-    if (state.roots.find(path) != state.roots.end()) {
-        printMsg(lvlDebug, format("cannot delete `%1%' because it's a root") % path);
-        goto isLive;
-    }
-
-    if (isValidPath(path)) {
-
-        /* Recursively try to delete the referrers of this path.  If
-           any referrer can't be deleted, then this path can't be
-           deleted either. */
-        PathSet referrers;
-        queryReferrers(path, referrers);
-        foreach (PathSet::iterator, i, referrers)
-            if (*i != path && !tryToDelete(state, *i)) {
-                printMsg(lvlDebug, format("cannot delete `%1%' because it has live referrers") % path);
-                goto isLive;
-            }
-
-        /* If gc-keep-derivations is set and this is a derivation,
-           then don't delete the derivation if any of the outputs are
-           live. */
-        if (state.gcKeepDerivations && isDerivation(path)) {
-            PathSet outputs = queryDerivationOutputs(path);
-            foreach (PathSet::iterator, i, outputs)
-                if (!tryToDelete(state, *i)) {
-                    printMsg(lvlDebug, format("cannot delete derivation `%1%' because its output `%2%' is alive") % path % *i);
-                    goto isLive;
-                }
-        }
-
-        /* If gc-keep-derivations and gc-keep-outputs are both set,
-           it's possible that the path has already been deleted (due
-           to the recursion below), so bail out. */
-        if (!pathExists(path)) return true;
-
-        /* If gc-keep-outputs is set, then don't delete this path if
-           there are derivers of this path that are not garbage. */
-        if (state.gcKeepOutputs) {
-            PathSet derivers = queryValidDerivers(path);
-            foreach (PathSet::iterator, deriver, derivers) {
-                /* Break an infinite recursion if gc-keep-derivations
-                   and gc-keep-outputs are both set by tentatively
-                   assuming that this path is garbage.  This is a safe
-                   assumption because at this point, the only thing
-                   that can prevent it from being garbage is the
-                   deriver.  Since tryToDelete() works "upwards"
-                   through the dependency graph, it won't encouter
-                   this path except in the call to tryToDelete() in
-                   the gc-keep-derivation branch. */
-                state.deleted.insert(path);
-                if (!tryToDelete(state, *deriver)) {
-                    state.deleted.erase(path);
-                    printMsg(lvlDebug, format("cannot delete `%1%' because its deriver `%2%' is alive") % path % *deriver);
-                    goto isLive;
-                }
-            }
-        }
-    }
-
-    else {
-
-        /* A lock file belonging to a path that we're building right
-           now isn't garbage. */
-        if (isActiveTempFile(state, path, ".lock")) return false;
-
-        /* Don't delete .chroot directories for derivations that are
-           currently being built. */
-        if (isActiveTempFile(state, path, ".chroot")) return false;
-
-    }
-
-    /* The path is garbage, so delete it. */
-    if (shouldDelete(state.options.action)) {
-        printMsg(lvlInfo, format("deleting `%1%'") % path);
-
-        unsigned long long bytesFreed, blocksFreed;
-        deleteFromStore(path, bytesFreed, blocksFreed);
-        state.results.bytesFreed += bytesFreed;
-        state.results.blocksFreed += blocksFreed;
-
-        if (state.options.maxFreed && state.results.bytesFreed > state.options.maxFreed) {
-            printMsg(lvlInfo, format("deleted more than %1% bytes; stopping") % state.options.maxFreed);
-            throw GCLimitReached();
-        }
-
-        if (state.options.maxLinks) {
-            struct stat st;
-            if (stat(nixStore.c_str(), &st) == -1)
-                throw SysError(format("statting `%1%'") % nixStore);
-            if (st.st_nlink < state.options.maxLinks) {
-                printMsg(lvlInfo, format("link count on the store has dropped below %1%; stopping") % state.options.maxLinks);
-                throw GCLimitReached();
-            }
-        }
-        
-    } else
-        printMsg(lvlTalkative, format("would delete `%1%'") % path);
-    
-    state.deleted.insert(path);
-    if (state.options.action != GCOptions::gcReturnLive)
-        state.results.paths.insert(path);
-    return true;
-
- isLive:
-    state.live.insert(path);
-    if (state.options.action == GCOptions::gcReturnLive)
-        state.results.paths.insert(path);
-    return false;
+    char s[128];
+    strftime(s, sizeof s, format.c_str(), localtime(&t));
+    return string(s);
 }
 
 
 void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
 {
-    GCState state(results);
-    state.options = options;    
-    
-    state.gcKeepOutputs = queryBoolSetting("gc-keep-outputs", false);
-    state.gcKeepDerivations = queryBoolSetting("gc-keep-derivations", true);
+    bool gcKeepOutputs =
+        queryBoolSetting("gc-keep-outputs", false);
+    bool gcKeepDerivations =
+        queryBoolSetting("gc-keep-derivations", true);
+    int gcKeepOutputsThreshold = 
+        queryIntSetting ("gc-keep-outputs-threshold", defaultGcLevel);
 
-    /* Using `--ignore-liveness' with `--delete' can have unintended
-       consequences if `gc-keep-outputs' or `gc-keep-derivations' are
-       true (the garbage collector will recurse into deleting the
-       outputs or derivers, respectively).  So disable them. */
-    if (options.action == GCOptions::gcDeleteSpecific && options.ignoreLiveness) {
-        state.gcKeepOutputs = false;
-        state.gcKeepDerivations = false;
-    }
-    
     /* Acquire the global GC root.  This prevents
        a) New roots from being added.
        b) Processes from creating new temporary root files. */
@@ -584,60 +596,207 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
     printMsg(lvlError, format("finding garbage collector roots..."));
     Roots rootMap = options.ignoreLiveness ? Roots() : nix::findRoots(true);
 
-    foreach (Roots::iterator, i, rootMap) state.roots.insert(i->second);
+    PathSet roots;
+    for (Roots::iterator i = rootMap.begin(); i != rootMap.end(); ++i)
+        roots.insert(i->second);
 
     /* Add additional roots returned by the program specified by the
        NIX_ROOT_FINDER environment variable.  This is typically used
        to add running programs to the set of roots (to prevent them
        from being garbage collected). */
     if (!options.ignoreLiveness)
-        addAdditionalRoots(state.roots);
+        addAdditionalRoots(roots);
+
+    if (options.action == GCOptions::gcReturnRoots) {
+        results.paths = roots;
+        return;
+    }
+
+    /* Determine the live paths which is just the closure of the
+       roots under the `references' relation. */
+    printMsg(lvlError, format("computing live paths..."));
+    PathSet livePaths;
+    for (PathSet::const_iterator i = roots.begin(); i != roots.end(); ++i)
+        computeFSClosure(canonPath(*i), livePaths);
+
+    if (gcKeepDerivations) {
+        for (PathSet::iterator i = livePaths.begin();
+             i != livePaths.end(); ++i)
+        {
+            /* Note that the deriver need not be valid (e.g., if we
+               previously ran the collector with `gcKeepDerivations'
+               turned off). */
+            Path deriver = queryDeriver(*i);
+            if (deriver != "" && isValidPath(deriver))
+                computeFSClosure(deriver, livePaths);
+        }
+    }
+
+    if (gcKeepOutputs) {
+        /* Hmz, identical to storePathRequisites in nix-store. */
+        for (PathSet::iterator i = livePaths.begin();
+             i != livePaths.end(); ++i)
+            if (isDerivation(*i)) {
+                Derivation drv = derivationFromPath(*i);
+
+		string gcLevelStr = drv.env["__gcLevel"];
+		int gcLevel;
+		if (!string2Int(gcLevelStr, gcLevel))
+		    gcLevel = defaultGcLevel;
+		
+		if (gcLevel >= gcKeepOutputsThreshold)    
+		    for (DerivationOutputs::iterator j = drv.outputs.begin();
+                         j != drv.outputs.end(); ++j)
+			if (isValidPath(j->second.path))
+			    computeFSClosure(j->second.path, livePaths);
+            }
+    }
+
+    if (options.action == GCOptions::gcReturnLive) {
+        results.paths = livePaths;
+        return;
+    }
 
     /* Read the temporary roots.  This acquires read locks on all
        per-process temporary root files.  So after this point no paths
        can be added to the set of temporary roots. */
+    PathSet tempRoots;
     FDs fds;
-    readTempRoots(state.tempRoots, fds);
-    state.roots.insert(state.tempRoots.begin(), state.tempRoots.end());
+    readTempRoots(tempRoots, fds);
+
+    /* Close the temporary roots.  Note that we *cannot* do this in
+       readTempRoots(), because there we may not have all locks yet,
+       meaning that an invalid path can become valid (and thus add to
+       the references graph) after we have added it to the closure
+       (and computeFSClosure() assumes that the presence of a path
+       means that it has already been closed). */
+    PathSet tempRootsClosed;
+    for (PathSet::iterator i = tempRoots.begin(); i != tempRoots.end(); ++i)
+        if (isValidPath(*i))
+            computeFSClosure(*i, tempRootsClosed);
+        else
+            tempRootsClosed.insert(*i);
 
     /* After this point the set of roots or temporary roots cannot
        increase, since we hold locks on everything.  So everything
-       that is not reachable from `roots'. */
-
-    /* Now either delete all garbage paths, or just the specified
-       paths (for gcDeleteSpecific). */
-
-    if (options.action == GCOptions::gcDeleteSpecific) {
+       that is not currently in in `livePaths' or `tempRootsClosed'
+       can be deleted. */
+    
+    /* Read the Nix store directory to find all currently existing
+       paths and filter out all live paths. */
+    printMsg(lvlError, format("reading the Nix store..."));
+    PathSet storePaths;
+    
+    if (options.action != GCOptions::gcDeleteSpecific) {
+        Paths entries = readDirectory(nixStore);
+        foreach (Paths::iterator, i, entries) {
+            Path path = canonPath(nixStore + "/" + *i);
+            if (livePaths.find(path) == livePaths.end() &&
+                tempRootsClosed.find(path) == tempRootsClosed.end())
+                storePaths.insert(path);
+        }
+    }
 
+    else {
         foreach (PathSet::iterator, i, options.pathsToDelete) {
             assertStorePath(*i);
-            if (!tryToDelete(state, *i))
+            storePaths.insert(*i);
+            if (livePaths.find(*i) != livePaths.end())
                 throw Error(format("cannot delete path `%1%' since it is still alive") % *i);
+            if (tempRootsClosed.find(*i) != tempRootsClosed.end())
+                throw Error(format("cannot delete path `%1%' since it is temporarily in use") % *i);
         }
-        
-    } else {
-        
-        printMsg(lvlError, format("reading the Nix store..."));
-        Paths entries = readDirectory(nixStore);
+    }
 
-        /* Randomise the order in which we delete entries to make the
-           collector less biased towards deleting paths that come
-           alphabetically first (e.g. /nix/store/000...).  This
-           matters when using --max-freed etc. */
-        vector<Path> entries_(entries.begin(), entries.end());
-        random_shuffle(entries_.begin(), entries_.end());
+    if (options.action == GCOptions::gcReturnDead) {
+        results.paths.insert(storePaths.begin(), storePaths.end());
+        return;
+    }
 
-        if (shouldDelete(state.options.action))
+    /* Delete all dead store paths (or until one of the stop
+       conditions is reached). */
+
+    PathSet done;
+    try {
+
+        if (!options.useAtime) {
+            /* Delete the paths, respecting the partial ordering
+               determined by the references graph. */
             printMsg(lvlError, format("deleting garbage..."));
-        else
-            printMsg(lvlError, format("determining live/dead paths..."));
-    
-        try {
-            foreach (vector<Path>::iterator, i, entries_)
-                tryToDelete(state, canonPath(nixStore + "/" + *i));
-        } catch (GCLimitReached & e) {
+            foreach (PathSet::iterator, i, storePaths)
+                gcPathRecursive(options, results, done, *i);
         }
-    }        
+
+        else {
+
+            /* Delete in order of ascending last access time, still
+               maintaining the partial ordering of the reference
+               graph.  Note that we can't use a topological sort for
+               this because that takes time O(V+E), and in this case
+               E=O(V^2) (i.e. the graph is dense because of the edges
+               due to the atime ordering).  So instead we put all
+               deletable paths in a priority queue (ordered by atime),
+               and after deleting a path, add additional paths that
+               have become deletable to the priority queue. */
+
+            CachingAtimeComparator atimeComp;
+
+            /* Create a priority queue that orders paths by ascending
+               atime.  This is why C++ needs type inferencing... */
+            std::priority_queue<Path, vector<Path>, binary_function_ref_adapter<CachingAtimeComparator> > prioQueue =
+                std::priority_queue<Path, vector<Path>, binary_function_ref_adapter<CachingAtimeComparator> >(binary_function_ref_adapter<CachingAtimeComparator>(&atimeComp));
+
+           /* Initially put the paths that are invalid or have no
+              referrers into the priority queue. */
+            printMsg(lvlError, format("finding deletable paths..."));
+            foreach (PathSet::iterator, i, storePaths) {
+                checkInterrupt();
+                /* We can safely delete a path if it's invalid or
+                   it has no referrers.  Note that all the invalid
+                   paths will be deleted in the first round. */
+                if (isValidPath(*i)) {
+                    if (queryReferrersNoSelf(*i).empty()) prioQueue.push(*i);
+                } else prioQueue.push(*i);
+            }
+
+            debug(format("%1% initially deletable paths") % prioQueue.size());
+
+            /* Now delete everything in the order of the priority
+               queue until nothing is left. */
+            printMsg(lvlError, format("deleting garbage..."));
+            while (!prioQueue.empty()) {
+                checkInterrupt();
+                Path path = prioQueue.top(); prioQueue.pop();
+
+                if (options.maxAtime != (time_t) -1 &&
+                    atimeComp.lookup(path) > options.maxAtime)
+                    continue;
+                
+                printMsg(lvlInfo, format("deleting `%1%' (last accessed %2%)") % path % showTime("%F %H:%M:%S", atimeComp.lookup(path)));
+
+                PathSet references;
+                if (isValidPath(path)) references = queryReferencesNoSelf(path);
+
+                gcPath(options, results, path);
+
+                /* For each reference of the current path, see if the
+                   reference has now become deletable (i.e. is in the
+                   set of dead paths and has no referrers left).  If
+                   so add it to the priority queue. */
+                foreach (PathSet::iterator, i, references) {
+                    if (storePaths.find(*i) != storePaths.end() &&
+                        queryReferrersNoSelf(*i).empty())
+                    {
+                        debug(format("path `%1%' has become deletable") % *i);
+                        prioQueue.push(*i);
+                    }
+                }
+            }
+            
+        }
+        
+    } catch (GCLimitReached & e) {
+    }
 }