* Print attributes in sorted order.

branch.  Also added a test for tryEval.

.gitignore

@@ -0,0 +1,262 @@
+# 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

@@ -1,17 +1,11 @@
 SUBDIRS = externals src scripts corepkgs doc misc tests
 EXTRA_DIST = substitute.mk nix.spec nix.spec.in bootstrap.sh \
-  svn-revision nix.conf.example NEWS
+  nix.conf.example NEWS version
 
 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
@@ -35,22 +29,18 @@ 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
 
-svn-revision:
-	svnversion . > svn-revision
-
-all-local: NEWS
-
-NEWS: doc/manual/NEWS.txt
+NEWS:
+	$(MAKE) -C doc/manual NEWS.txt
 	cp $(srcdir)/doc/manual/NEWS.txt NEWS

configure.ac

@@ -1,21 +1,8 @@
-AC_INIT(nix, 0.12)
+AC_INIT(nix, m4_esyscmd([echo -n $(cat ./version)$VERSION_SUFFIX]))
 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=0
-
-# 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
@@ -63,20 +50,51 @@ AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier (`cpu-os')])
 test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var
 
 
-# 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.])
+# Whether to produce a statically linked binary.  On Cygwin, this is
+# the default: dynamically linking against the ATerm DLL does work,
+# 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.
 
-    # Shared libraries don't work, currently.
+AC_ARG_ENABLE(static-nix, AC_HELP_STRING([--enable-static-nix],
+  [produce statically linked binaries]),
+  static_nix=$enableval, static_nix=no)
+
+if test "$sys_name" = cygwin; then
+   static_nix=yes
+fi
+
+if test "$static_nix" = yes; then
     AC_DISABLE_SHARED
     AC_ENABLE_STATIC
 fi
 
 
+# Windows-specific stuff.
+if test "$sys_name" = "cygwin"; then
+    # We cannot delete open files.
+    AC_DEFINE(CANNOT_DELETE_OPEN_FILES, 1, [Whether it is impossible to delete open files.])
+fi
+
+# Solaris-specific stuff.
+if test "$sys_name" = "sunos"; then
+    # Solaris requires -lsocket -lnsl for network functions
+    ADDITIONAL_NETWORK_LIBS="-lsocket -lnsl"
+    AC_SUBST(ADDITIONAL_NETWORK_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
@@ -85,8 +103,7 @@ AC_PROG_LIBTOOL
 
 
 # Use 64-bit file system calls so that we can support files > 2 GiB.
-CFLAGS="-D_FILE_OFFSET_BITS=64 $CFLAGS"
-CXXFLAGS="-D_FILE_OFFSET_BITS=64 $CXXFLAGS"
+AC_SYS_LARGEFILE
 
 
 # Check for pubsetbuf.
@@ -103,6 +120,8 @@ 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
@@ -111,12 +130,17 @@ 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 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])
+
+
 AC_DEFUN([NEED_PROG],
 [
 AC_PATH_PROG($1, $2)
@@ -130,11 +154,11 @@ NEED_PROG(bash, bash)
 NEED_PROG(patch, patch)
 AC_PATH_PROG(xmllint, xmllint, false)
 AC_PATH_PROG(xsltproc, xsltproc, false)
-AC_PATH_PROG(jing, jing, false) # needed because xmllint --relaxng seems broken
 AC_PATH_PROG(w3m, w3m, false)
 AC_PATH_PROG(flex, flex, false)
 AC_PATH_PROG(bison, bison, false)
 NEED_PROG(perl, perl)
+NEED_PROG(sed, sed)
 NEED_PROG(tar, tar)
 AC_PATH_PROG(dot, dot)
 AC_PATH_PROG(dblatex, dblatex)
@@ -179,48 +203,6 @@ AC_ARG_WITH(store-dir, AC_HELP_STRING([--with-store-dir=PATH],
   storedir=$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=)
@@ -250,7 +232,7 @@ 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)
@@ -272,15 +254,24 @@ AC_CHECK_FUNCS([setresuid setreuid lchown])
 
 # Nice to have, but not essential.
 AC_CHECK_FUNCS([strsignal])
+AC_CHECK_FUNCS([posix_fallocate])
 
 
-# This is needed if ATerm, Berkeley DB or bzip2 are static libraries,
+# This is needed if ATerm or bzip2 are static libraries,
 # and the Nix libraries are dynamic.
 if test "$(uname)" = "Darwin"; then
     LDFLAGS="-all_load $LDFLAGS"
 fi
 
 
+if test "$static_nix" = yes; then
+    # `-all-static' has to be added at the end of configure, because
+    # the C compiler doesn't know about -all-static (it's filtered out
+    # by libtool, but configure doesn't use libtool).
+    LDFLAGS="-all-static $LDFLAGS"
+fi
+
+
 AM_CONFIG_HEADER([config.h])
 AC_CONFIG_FILES([Makefile
    externals/Makefile

corepkgs/buildenv/builder.pl.in

@@ -29,10 +29,18 @@ 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$/ ||
             $srcFile =~ /\/nix-support$/ ||
             $srcFile =~ /\/perllocal.pod$/ ||
+            $srcFile =~ /\/easy-install.pth$/ ||
+            $srcFile =~ /\/site.py$/ ||
+            $srcFile =~ /\/site.pyc$/ ||
             $srcFile =~ /\/info\/dir$/ ||
             $srcFile =~ /\/log$/)
         {
@@ -160,4 +168,4 @@ while (scalar(keys %postponed) > 0) {
 print STDERR "created $symlinks symlinks in user environment\n";
 
 
-symlink($ENV{"manifest"}, "$out/manifest") or die "cannot create manifest";
+symlink($ENV{"manifest"}, "$out/manifest.nix") or die "cannot create manifest";

corepkgs/channels/unpack.sh.in

@@ -1,5 +1,8 @@
 #! @shell@ -e
 
+# Cygwin compatibility hack: bunzip2 expects cygwin.dll in $PATH.
+export PATH=@coreutils@
+
 @coreutils@/mkdir $out
 @coreutils@/mkdir $out/tmp
 cd $out/tmp
@@ -8,9 +11,15 @@ inputs=($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

doc/manual/Makefile.am

@@ -6,7 +6,12 @@ XSLTPROC = $(xsltproc) $(xmlflags) \
  --param xref.with.number.and.title 1 \
  --param toc.section.depth 3 \
  --param admon.style \'\' \
- --param callout.graphics.extension \'.gif\'
+ --param callout.graphics.extension \'.gif\' \
+ --param contrib.inline.enabled 0
+
+dblatex_opts = \
+ -P doc.collab.show=0 \
+ -P latex.output.revhistory=0
 
 # Note: we use GIF for now, since the PNGs shipped with Docbook aren't
 # transparent.
@@ -29,13 +34,9 @@ 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) --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
+	$(XMLLINT) --noout --nonet --xinclude --noxincludenode --relaxng $(docbookrng)/docbook.rng $<
 	touch $@
 
 version.txt:
@@ -50,7 +51,7 @@ manual.html: $(MANUAL_SRCS) manual.is-valid images
 
 manual.pdf: $(MANUAL_SRCS) manual.is-valid images
 	if test "$(dblatex)" != ""; then \
-		$(dblatex) manual.xml; \
+		$(dblatex) $(dblatex_opts) manual.xml; \
 	else \
 		echo "Please install dblatex and rerun configure."; \
 		exit 1; \
@@ -79,10 +80,14 @@ 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

@@ -77,18 +77,8 @@ 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.
-    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>
+    installations that don’t have the desired built-in
+    function.</para></listitem>
 
   </varlistentry>
 
@@ -334,6 +324,16 @@ 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>
 
@@ -364,6 +364,36 @@ 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

@@ -233,7 +233,17 @@ 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>false</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 file descriptor 3 one of the following responses (terminated
-  by a newline, <literal>"\n"</literal>):
+  out on standard error 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>
@@ -185,37 +185,12 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
   </para>
 
-  <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:
+  <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:
 
   <variablelist>
 
@@ -255,7 +230,9 @@ $ 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.</para>
+  <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>
 
   </listitem>
 

doc/manual/installation.xml

@@ -96,24 +96,15 @@ 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 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
+<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
 <filename>externals/Makefile.am</filename> for the precise URLs of
-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>
+this packages.  Alternatively, if you already have it installed, you
+can use <command>configure</command>'s <option>--with-bzip2</option>
 options to point to their respective locations.</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>
 
 
@@ -133,23 +124,32 @@ $ make install</screen>
 preceded by the command:
 
 <screen>
-$ ./bootstrap</screen>
+$ ./bootstrap.sh</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>/nix</filename>.  You can change this to any location you
-like.  You must have write permission to the
+<filename>/usr/local</filename>.  You can change this to any location
+you like.  You must have write permission to the
 <replaceable>prefix</replaceable> path.</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>
+<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>
 
-<para>If you want to rebuilt the documentation, pass the full path to
+<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
 the DocBook RELAX NG schemas and to the DocBook XSL stylesheets using
 the
 <option>--with-docbook-rng=<replaceable>path</replaceable></option>
@@ -160,27 +160,26 @@ options.</para>
 </section>
 
 
-<section><title>Installing from RPMs</title>
+<section><title>Installing a binary distribution</title>
 
-<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,
+<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,
 
 <screen>
-$ rpm -U nix-0.5pre664-1.i386.rpm</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>
 
 </para>
 
-<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:
+<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:
 
 <screen>
 $ rm -rf /nix/store
@@ -191,6 +190,7 @@ $ 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
@@ -203,6 +203,7 @@ 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

@@ -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://nix.cs.uu.nl/docs/papers.html">an up-to-date list
+xlink:href="http://nixos.org/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

@@ -17,6 +17,7 @@
         <orgname>Delft University of Technology</orgname>
         <orgdiv>Department of Software Technology</orgdiv>
       </affiliation>
+      <contrib>Author</contrib>
     </author>
 
     <copyright>
@@ -25,10 +26,11 @@
       <year>2006</year>
       <year>2007</year>
       <year>2008</year>
+      <year>2009</year>
       <holder>Eelco Dolstra</holder>
     </copyright>
 
-    <date>November 2008</date>
+    <date>September 2009</date>
     
   </info>
 
@@ -49,68 +51,29 @@
     
     <section>
       <title>Main commands</title>
-      <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>
+      <xi:include href="nix-env.xml" />
+      <xi:include href="nix-instantiate.xml" />
+      <xi:include href="nix-store.xml" />
     </section>
     
     <section>
       <title>Utilities</title>
-      <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>
+      <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>
-    
+
   </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

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

doc/manual/nix-channel.xml

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

doc/manual/nix-collect-garbage.xml

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

doc/manual/nix-copy-closure.xml

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

doc/manual/nix-env.xml

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

doc/manual/nix-hash.xml

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

doc/manual/nix-install-package.xml

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

doc/manual/nix-instantiate.xml

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

doc/manual/nix-lang-ref.xml

@@ -178,100 +178,5 @@
     </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

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

doc/manual/nix-pull.xml

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

doc/manual/nix-push.xml

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

doc/manual/nix-store.xml

@@ -1,6 +1,7 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
-          xmlns:xi="http://www.w3.org/2001/XInclude">
+          xmlns:xi="http://www.w3.org/2001/XInclude"
+          xml:id="sec-nix-store">
 
 <refmeta>
   <refentrytitle>nix-store</refentrytitle>
@@ -212,8 +213,6 @@ 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>
@@ -291,42 +290,6 @@ 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>
@@ -357,13 +320,6 @@ 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>
@@ -386,7 +342,7 @@ $ nix-store --gc --max-freed $((100 * 1024 * 1024))</screen>
 
 <cmdsynopsis>
   <command>nix-store</command>
-  <arg choice='plain'><option>--gc</option></arg>
+  <arg choice='plain'><option>--delete</option></arg>
   <arg><option>--ignore-liveness</option></arg>
   <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
 </cmdsynopsis>
@@ -448,6 +404,7 @@ 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>--roots</option></arg>
   </group>
   <arg><option>--use-output</option></arg>
   <arg><option>-u</option></arg>
@@ -630,12 +587,20 @@ 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 path <replaceable>paths</replaceable>.  Since the hash is
+    store paths <replaceable>paths</replaceable>.  Since the hash is
     stored in the Nix database, this is a fast
     operation.</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>
+
+  </varlistentry>
+
 </variablelist>
 
 </refsection>
@@ -713,6 +678,18 @@ $ 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

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

doc/manual/opt-common-syn.xml

@@ -24,6 +24,7 @@
 <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

@@ -251,14 +251,14 @@
 
 <programlisting>
 { # The system (e.g., `i686-linux') for which to build the packages.
-  system ? __currentSystem
+  system ? builtins.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>__currentSystem</literal></link>
+  linkend='builtin-currentSystem'><literal>builtins.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
@@ -305,6 +305,14 @@
 </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/releases/full-index-nixpkgs.html' />.</para>
+xlink:href='http://nixos.org/nixpkgs/download.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 section <xref linkend='sec-garbage-collection'
+garbage collector (see <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/releases/nixpkgs/nixpkgs-unstable/">Nix
+xlink:href="http://nixos.org/nixpkgs/">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
@@ -507,19 +507,16 @@ 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://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>
+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>
 
 <para>You can also install <literal>application/nix-package</literal>
 files from the command line directly.  See <xref

doc/manual/quick-start.xml

@@ -1,5 +1,6 @@
 <chapter xmlns="http://docbook.org/ns/docbook"
-         xmlns:xlink="http://www.w3.org/1999/xlink">
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-quick-start">
 
 <title>Quick Start</title>
 
@@ -10,9 +11,9 @@ to the following chapters.</para>
 
 <orderedlist>
 
-<listitem><para>Download a source tarball or RPM from <link
-xlink:href='http://nixos.org/'/>.  Build source
-distributions using the regular sequence:
+<listitem><para>Download a source tarball, RPM or Deb from <link
+xlink:href='http://nixos.org/'/>.  Build source distributions using
+the regular sequence:
         
 <screen>
 $ tar xvfj nix-<replaceable>version</replaceable>.tar.bz2
@@ -20,13 +21,21 @@ $ ./configure
 $ make
 $ make install <lineannotation>(as root)</lineannotation></screen>
 
-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
+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
 file).</para></listitem>
 
 <listitem><para>Subscribe to the Nix Packages channel.
@@ -99,7 +108,7 @@ 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://nix.cs.uu.nl/dist/nix/nixpkgs-unstable-latest/" />
+xlink:href="http://hydra.nixos.org/jobset/nixpkgs/trunk/channel/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

@@ -6,6 +6,167 @@
 
 
 
+<!--==================================================================-->
+
+<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-2'>
+  <callout arearefs='ex-subversion-nix-co-3'>
     <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 0 (00:00:00 1/1/1970
+  timestamp on all files in the build result to 1 (00:00:01 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

@@ -1,78 +1,3 @@
-# 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
@@ -107,11 +32,10 @@ install:
 endif
 
 
-all: build-db build-aterm build-bzip2
+all: build-bzip2
 
-EXTRA_DIST = $(DB).tar.gz $(ATERM).tar.bz2 $(BZIP2).tar.gz \
-  bdb-cygwin.patch
+EXTRA_DIST = $(BZIP2).tar.gz
 
 ext-clean:
-	$(RM) -f have-db build-db have-aterm build-aterm have-bzip2 build-bzip2
-	$(RM) -rf $(DB) $(ATERM) $(BZIP2)
+	$(RM) -f have-bzip2 build-bzip2
+	$(RM) -rf $(BZIP2)

externals/bdb-cygwin.patch

@@ -1,22 +0,0 @@
-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

@@ -21,12 +21,14 @@ syn match nixFuncArg "\zs\w\+\ze\s*:"
 syn region nixStringParam start=+\${+ end=+}+
 syn region nixMultiLineComment start=+/\*+ skip=+\\"+ end=+\*/+
 syn match  nixEndOfLineComment "#.*$"
-syn region nixString      start=+"+ skip=+\\"+ end=+"+ contains=nixStringParam
+syn region nixStringIndented start=+''+ skip=+'''\|''${\|"+ 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

@@ -154,21 +154,17 @@
 #build-chroot-dirs = /dev /dev/pts /proc
 
 
-### Option `system'
+### Option `build-cache-failure'
 #
-# 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.
+# 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/*'.
 #
 # Example:
-#   system = i686-darwin
-#system =
+#   build-cache-failure = true
+#build-cache-failure = false

release.nix

@@ -0,0 +1,206 @@
+{ nixpkgs ? ../nixpkgs }:
+
+let
+
+  jobs = rec {
+
+
+    tarball =
+      { nix ? {outPath = ./.; rev = 1234;}
+      , officialRelease ? false
+      }:
+
+      with import nixpkgs {};
+
+      releaseTools.sourceTarball {
+        name = "nix-tarball";
+        version = builtins.readFile ./version;
+        src = nix;
+        inherit officialRelease;
+
+        buildInputs =
+          [ curl bison flex2533 perl libxml2 libxslt w3m bzip2
+            tetex dblatex nukeReferences
+          ];
+
+        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
+
+          # 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" >> $out/nix-support/hydra-build-products
+        '';
+      };
+
+
+    build =
+      { tarball ? jobs.tarball {}
+      , system ? "i686-linux"
+      }:
+
+      with import nixpkgs {inherit system;};
+
+      releaseTools.nixBuild {
+        name = "nix";
+        src = tarball;
+
+        buildInputs = [curl perl bzip2 openssl];
+
+        configureFlags = ''
+          --disable-init-state
+          --with-bzip2=${bzip2}
+        '';
+      };
+
+
+    /*
+    static =
+      { tarball ? jobs.tarball {}
+      , system ? "i686-linux"
+      }:
+
+      with import nixpkgs {inherit system;};
+
+      releaseTools.binaryTarball {
+        name = "nix-static-tarball";
+        src = tarball;
+
+        buildInputs = [curl perl bzip2];
+
+        configureFlags = ''
+          --disable-init-state
+          --with-bzip2=${bzip2}
+          --enable-static-nix
+        '';
+      };
+    */
+
+      
+    coverage =
+      { tarball ? jobs.tarball {}
+      }:
+
+      with import nixpkgs {};
+
+      releaseTools.coverageAnalysis {
+        name = "nix-build";
+        src = tarball;
+
+        buildInputs = [
+          curl perl bzip2 openssl
+          # These are for "make check" only:
+          graphviz libxml2 libxslt
+        ];
+
+        configureFlags = ''
+          --disable-init-state --disable-shared
+          --with-bzip2=${bzip2}
+        '';
+
+        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:
+    { tarball ? jobs.tarball {}
+    }:
+
+    with import nixpkgs {inherit system;};
+
+    releaseTools.rpmBuild rec {
+      name = "nix-rpm-${diskImage.name}";
+      src = tarball;
+      diskImage = diskImageFun vmTools.diskImages;
+      memSize = 1024;
+      meta = { schedulingPriority = toString prio; };
+    };
+
+
+  makeDeb_i686 = makeDeb "i686-linux";
+  makeDeb_x86_64 = makeDeb "x86_64-linux";
+  
+  makeDeb =
+    system: diskImageFun: prio:
+    { tarball ? jobs.tarball {}
+    }:
+
+    with import nixpkgs {inherit system;};
+
+    releaseTools.debBuild {
+      name = "nix-deb";
+      src = tarball;
+      diskImage = diskImageFun vmTools.diskImages;
+      memSize = 1024;
+      meta = { schedulingPriority = toString prio; };
+      configureFlags = "--sysconfdir=/etc";
+      debRequires = ["curl"];
+    };
+
+
+in jobs

scripts/Makefile.am

@@ -15,6 +15,7 @@ install-exec-local: readmanifest.pm download-using-manifests.pl copy-from-other-
 	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix
 	$(INSTALL_DATA) readmanifest.pm $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL_DATA) readconfig.pm $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL_DATA) ssh.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 
@@ -31,6 +32,7 @@ EXTRA_DIST = nix-collect-garbage.in \
   nix-channel.in \
   readmanifest.pm.in \
   readconfig.pm.in \
+  ssh.pm \
   nix-build.in \
   download-using-manifests.pl.in \
   copy-from-other-stores.pl.in \

scripts/build-remote.pl.in

@@ -1,8 +1,10 @@
-#! @perl@ -w
+#! @perl@ -w -I@libexecdir@/nix
 
-use strict;
 use Fcntl ':flock';
 use English '-no_match_vars';
+use IO::Handle;
+use ssh qw/sshOpts openSSHConnection/;
+
 
 # General operation:
 #
@@ -21,18 +23,22 @@ use English '-no_match_vars';
 # The nice thing about this scheme is that if we die prematurely, the
 # locks are released automatically.
 
+
+# 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"} = "";
+
+
 my $loadIncreased = 0;
 
-my $amWilling = shift @ARGV;
-my $localSystem = shift @ARGV;
-my $neededSystem = shift @ARGV;
-my $drvPath = shift @ARGV;
+my ($amWilling, $localSystem, $neededSystem, $drvPath, $maxSilentTime) = @ARGV;
+$maxSilentTime = 0 unless defined $maxSilentTime;
 
 sub sendReply {
     my $reply = shift;
-    open OUT, ">&3" or die;
-    print OUT "$reply\n";
-    close OUT;
+    print STDERR "# $reply\n";
 }
 
 sub decline {
@@ -47,30 +53,26 @@ 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;
+my $canBuildLocally = $amWilling && ($localSystem eq $neededSystem);
 
 
 # Read the list of machines.
+my @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} = $4;
+    /^\s*(\S+)\s+(\S+)\s+(\S+)\s+(\d+)(\s+([0-9\.]+))?\s*$/ or die;
+    push @machines,
+        { hostName => $1
+        , systemTypes => [split(/,/, $2)]
+        , sshKeys => $3
+        , maxJobs => $4
+        , speedFactor => 1.0 * ($6 || 1)
+        , enabled => 1
+        };
 }
 
 close CONF;
@@ -82,90 +84,116 @@ 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}) {
-        $rightType = 1;
+sub openSlotLock {
+    my ($machine, $slot) = @_;
+    my $slotLockFn = "$currentLoad/" . (join '+', @{$machine->{systemTypes}}) . "-" . $machine->{hostName} . "-$slot";
+    my $slotLock = new IO::Handle;
+    open $slotLock, ">>$slotLockFn" or die;
+    return $slotLock;
+}
+    
 
-        # 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++;
+my $hostName;
+my $slotLock;
+
+while (1) {
+    
+    # Find all machine that can execute this build, i.e., that support
+    # builds for the given platform 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}}) {
+            $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};
         }
     }
-}
 
-close MAINLOCK;
-
-
-# Didn't find one?
-if (!defined $machine) {
-    if ($rightType) {
-        sendReply "postpone";
-        exit 0;
-    } else {
-        decline;
+    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";
+            exit 0;
+        } else {
+            decline;
+        }
+    }
+
+
+    # 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 if openSSHConnection $hostName;
+    
+    warn "unable to open SSH connection to $hostName, trying other available machines...\n";
+    $machine->{enabled} = 0;
 }
 
-# Yes we did, accept.
+
+# Tell Nix we've accepted the build.
 sendReply "accept";
-open IN, "<&4" or die;
-my $x = <IN>;
+my $x = <STDIN>;
 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"} = "";
-$ENV{"SSH_PASSWORD_FILE="} = "";
-$ENV{"SSH_ASKPASS="} = "";
-
-my $sshOpts = "-i $sshKeys{$machine} -x";
-
-# 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;
-    $ENV{"SSH_ASKPASS"} = "/tmp/writepass";
-
-    open WRITEPASS, ">/tmp/writepass" or die;
-    print WRITEPASS "#! /bin/sh\ncat \"\$SSH_PASSWORD_FILE\"";
-    close WRITEPASS;
-    chmod 0755, "/tmp/writepass" or die;
-}
+# Do the actual build.
+print STDERR "building `$drvPath' on `$hostName'\n";
 
 my $inputs = `cat inputs`; die if ($? != 0);
 $inputs =~ s/\n/ /g;
@@ -173,36 +201,40 @@ $inputs =~ s/\n/ /g;
 my $outputs = `cat outputs`; die if ($? != 0);
 $outputs =~ s/\n/ /g;
 
-print "COPYING INPUTS...\n";
+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: $?";
+system("NIX_SSHOPTS=\"@sshOpts\" @bindir@/nix-copy-closure $hostName $maybeSign $drvPath $inputs") == 0
+    or die "cannot copy inputs to $hostName: $?";
 
-print "BUILDING...\n";
+print "building...\n";
 
-system("ssh $sshOpts $machine 'nix-store -rvvK $drvPath'") == 0
-    or die "remote build on $machine failed: $?";
+my $buildFlags = "--max-silent-time $maxSilentTime";
 
-print "REMOTE BUILD DONE: $drvPath on $machine\n";
+# `-tt' forces allocation of a pseudo-terminal.  This is required to
+# make the remote nix-store process receive a signal when the
+# connection dies.  Without it, the remote process might continue to
+# run indefinitely (that is, until it next tries to write to
+# stdout/stderr).
+if (system("ssh $hostName @sshOpts -tt 'nix-store --realise $buildFlags $drvPath > /dev/null'") != 0) {
+    # If we couldn't run ssh or there was an ssh problem (indicated by
+    # exit code 255), then we return exit code 1; otherwise we assume
+    # that the builder failed, which we indicate to Nix using exit
+    # code 100.  It's important to distinguish between the two because
+    # the first is a transient failure and the latter is permanent.
+    my $res = $? == -1 || ($? >> 8) == 255 ? 1 : 100;
+    print STDERR "build of `$drvPath' on `$hostName' failed with exit code $?\n";
+    exit $res;
+}
+
+print "build of `$drvPath' on `$hostName' succeeded\n";
 
 foreach my $output (split '\n', $outputs) {
     my $maybeSignRemote = "";
     $maybeSignRemote = "--sign" if $UID != 0;
     
-    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: $?";
+    system("ssh $hostName @sshOpts 'nix-store --export $maybeSignRemote $output' | @bindir@/nix-store --import > /dev/null") == 0
+	or die "cannot copy $output from $hostName: $?";
 }

scripts/download-using-manifests.pl.in

@@ -9,7 +9,7 @@ my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
 
 STDOUT->autoflush(1);
 
-my $manifestDir = "@localstatedir@/nix/manifests";
+my $manifestDir = ($ENV{"NIX_MANIFESTS_DIR"} or "@localstatedir@/nix/manifests");
 my $logFile = "@localstatedir@/log/nix/downloads";
 
 
@@ -19,10 +19,15 @@ my %localPaths;
 my %patches;
 
 for my $manifest (glob "$manifestDir/*.nixmanifest") {
-    if (readManifest($manifest, \%narFiles, \%localPaths, \%patches) < 3) {
+    my $version = readManifest($manifest, \%narFiles, \%localPaths, \%patches);
+    if ($version < 3) {
         print STDERR "you have an old-style manifest `$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;
+    }
 }
 
 
@@ -68,7 +73,7 @@ if ($ARGV[0] eq "--query") {
 }
 
 elsif ($ARGV[0] ne "--substitute") {
-    die "syntax: $0 [--query-paths | --query-info PATHS... | --substitute PATH]\n";
+    die;
 }
 
 
@@ -80,8 +85,6 @@ my $targetPath = $ARGV[1];
 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";
 
@@ -185,13 +188,11 @@ while ($queueFront < scalar @queue) {
                 $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 "$$ rejecting $patch->{basePath}\n";
                     next;
                 }
             }
-#            print "  PATCH from $patch->{basePath}\n";
             addToQueue $patch->{basePath};
             addEdge $patch->{basePath}, $u, $patch->{size}, "patch", $patch;
         }
@@ -199,10 +200,12 @@ while ($queueFront < scalar @queue) {
         # Add NAR file edges to the start node.
         my $narFileList = $narFiles{$u};
         foreach my $narFile (@{$narFileList}) {
-#            print "  NAR from $narFile->{url}\n";
-            addEdge "start", $u, $narFile->{size}, "narfile", $narFile;
+            # !!! how to handle files whose size is not known in advance?
+            # For now, assume some arbitrary size (1 MB).
+            addEdge "start", $u, ($narFile->{size} || 1000000), "narfile", $narFile;
             if ($u eq $targetPath) {
-                print LOGFILE "$$ full-download-would-be $narFile->{size}\n";
+                my $size = $narFile->{size} || -1;
+                print LOGFILE "$$ full-download-would-be $size\n";
             }
         }
 
@@ -228,8 +231,6 @@ while (scalar @todo > 0) {
 
     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}) {
@@ -237,7 +238,6 @@ while (scalar @todo > 0) {
             # Store the edge; to edge->start is actually the
             # predecessor.
             $v_->{pred} = $edge; 
-#            print "  RELAX $edge->{end} $v_->{d}\n";
         }
     }
 }
@@ -259,20 +259,18 @@ while ($cur ne "start") {
 my $curStep = 1;
 my $maxStep = scalar @path;
 
-sub downloadFile {
-    my $url = shift;
-    my ($hashAlgo, $hash) = parseHash(shift);
+sub downloadFile { 
+    my $url = shift; 
     $ENV{"PRINT_PATH"} = 1;
     $ENV{"QUIET"} = 1;
-    $ENV{"NIX_HASH_ALGO"} = $hashAlgo;
-    my ($hash2, $path) = `$binDir/nix-prefetch-url '$url' '$hash'`;
+    my ($hash, $path) = `$binDir/nix-prefetch-url '$url'`;
     die "download of `$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};
@@ -302,7 +300,7 @@ while (scalar @path > 0) {
 
         # Download the patch.
         print "  downloading patch...\n";
-        my $patchPath = downloadFile "$patch->{url}", "$patch->{hash}";
+        my $patchPath = downloadFile "$patch->{url}";
 
         # Apply the patch to the NAR archive produced in step 1 (for
         # the already present path) or a later step (for patch sequences).
@@ -320,17 +318,20 @@ 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";
 
-        print LOGFILE "$$ narfile $narFile->{url} $narFile->{size} $v\n";
+        my $size = $narFile->{size} || -1;
+        print LOGFILE "$$ narfile $narFile->{url} $size $v\n";
         
         # Download the archive.
         print "  downloading archive...\n";
-        my $narFilePath = downloadFile "$narFile->{url}", "$narFile->{hash}";
+        my $narFilePath = downloadFile "$narFile->{url}";
 
         if ($curStep < $maxStep) {
             # The archive will be used a base to a patch.
@@ -342,11 +343,36 @@ while (scalar @path > 0) {
             system("@bunzip2@ < '$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/nix-build.in

@@ -12,6 +12,7 @@ my $outLink;
 my $drvLink;
 
 my $dryRun = 0;
+my $verbose = 0;
 
 my @instArgs = ();
 my @buildArgs = ();
@@ -77,7 +78,7 @@ EOF
 
     elsif ($arg eq "--attr" or $arg eq "-A") {
         $n++;
-        die "$0: `--attr' requires an argument\n" unless $n < scalar @ARGV;
+        die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
         push @instArgs, ("--attr", $ARGV[$n]);
     }
 
@@ -87,7 +88,21 @@ EOF
         $n += 2;
     }
 
-    elsif ($arg eq "--max-jobs" or $arg eq "-j" or $arg eq "--max-silent-time") {
+    elsif ($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") {
         $n++;
         die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
         push @buildArgs, ($arg, $ARGV[$n]);
@@ -98,6 +113,16 @@ 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;
+        $verbose = 1;
+    }
+    
     elsif (substr($arg, 0, 1) eq "-") {
         push @buildArgs, $arg;
     }
@@ -128,11 +153,14 @@ 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, $_;}
-    close DRVPATHS or exit 1;
+    if (!close DRVPATHS) {
+        die "nix-instantiate killed by signal " . ($? & 127) . "\n" if ($? & 127);
+        exit 1;
+    }
 
     foreach my $drvPath (@drvPaths) {
         my $target = readlink $drvPath or die "cannot read symlink `$drvPath'";
-        print STDERR "store derivation is $target\n";
+        print STDERR "derivation is $target\n" if $verbose;
     }
 
     # Build.
@@ -140,7 +168,10 @@ foreach my $expr (@exprs) {
     $pid = open(OUTPATHS, "-|") || exec "$binDir/nix-store", "--add-root", $outLink, "--indirect", "-rv",
         @buildArgs, @drvPaths;
     while (<OUTPATHS>) {chomp; push @outPaths, $_;}
-    close OUTPATHS or exit 1;
+    if (!close OUTPATHS) {
+        die "nix-store killed by signal " . ($? & 127) . "\n" if ($? & 127);
+        exit 1;
+    }
 
     next if $dryRun;
 

scripts/nix-channel.in

@@ -78,6 +78,9 @@ 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
@@ -85,11 +88,6 @@ 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";
@@ -125,15 +123,13 @@ sub update {
 
     my $rootFile = "$rootsDir/per-user/$userName/channels";
     
-    # Instantiate the Nix expression.
+    # Build the Nix expression.
     print "unpacking channel Nix expressions...\n";
-    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";
+    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";
     chomp $outPath;
 
     unlink "$rootFile.tmp";

scripts/nix-copy-closure.in

@@ -1,4 +1,6 @@
-#! @perl@ -w
+#! @perl@ -w -I@libexecdir@/nix
+
+use ssh;
 
 my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
 
@@ -14,12 +16,11 @@ EOF
 
 # Get the target host.
 my $sshHost;
-my @sshOpts = split ' ', ($ENV{"NIX_SSHOPTS"} or "");
 
 my $sign = 0;
 
-my $compressor = "cat";
-my $decompressor = "cat";
+my $compressor = "";
+my $decompressor = "";
 
 my $toMode = 1;
 
@@ -34,8 +35,8 @@ while (@ARGV) {
         $sign = 1;
     }
     elsif ($arg eq "--gzip") {
-        $compressor = "gzip";
-        $decompressor = "gunzip";
+        $compressor = "| gzip";
+        $decompressor = "gunzip |";
     }
     elsif ($arg eq "--from") {
         $toMode = 0;
@@ -52,40 +53,30 @@ while (@ARGV) {
 }
 
 
+openSSHConnection $sshHost or die "$0: unable to start SSH\n";
+
+
 if ($toMode) { # Copy TO the remote machine.
 
     my @allStorePaths;
-    my %storePathsSeen;
 
-    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;
+    # Get the closure of this path.
+    my $pid = open(READ, "$binDir/nix-store --query --requisites @storePaths|") or die;
     
-        while (<READ>) {
-            chomp;
-            die "bad: $_" unless /^\//;
-            if (!defined $storePathsSeen{$_}) {
-                push @allStorePaths, $_;
-                $storePathsSeen{$_} = 1;
-            }
-        }
-
-        close READ or die "nix-store failed: $?";
+    while (<READ>) {
+        chomp;
+        die "bad: $_" unless /^\//;
+        push @allStorePaths, $_;
     }
 
+    close READ or die "nix-store failed: $?";
+
 
     # Ask the remote host which paths are invalid.
-    open(READ, "ssh @sshOpts $sshHost nix-store --check-validity --print-invalid @allStorePaths|");
+    open(READ, "ssh $sshHost @sshOpts nix-store --check-validity --print-invalid @allStorePaths|");
     my @missing = ();
     while (<READ>) {
         chomp;
-        print STDERR "target machine needs $_\n";
         push @missing, $_;
     }
     close READ or die;
@@ -93,9 +84,11 @@ if ($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("nix-store --export $extraOpts @missing | $compressor | ssh @sshOpts $sshHost '$decompressor | nix-store --import'") == 0
+        system("nix-store --export $extraOpts @missing $compressor | ssh $sshHost @sshOpts '$decompressor nix-store --import'") == 0
             or die "copying store paths to remote machine `$sshHost' failed: $?";
     }
 
@@ -111,15 +104,11 @@ else { # Copy FROM the remote machine.
         "ssh @sshOpts $sshHost nix-store --query --requisites @storePaths|") or die;
     
     my @allStorePaths;
-    my %storePathsSeen;
 
     while (<READ>) {
         chomp;
         die "bad: $_" unless /^\//;
-        if (!defined $storePathsSeen{$_}) {
-            push @allStorePaths, $_;
-            $storePathsSeen{$_} = 1;
-        }
+        push @allStorePaths, $_;
     }
 
     close READ or die "nix-store on remote machine `$sshHost' failed: $?";
@@ -130,7 +119,6 @@ else { # Copy FROM the remote machine.
     my @missing = ();
     while (<READ>) {
         chomp;
-        print STDERR "local machine needs $_\n";
         push @missing, $_;
     }
     close READ or die;
@@ -138,10 +126,12 @@ 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("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: $?";
+        system("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: $?";
     }
 
 }

scripts/nix-http-export.cgi.in

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

scripts/nix-install-package.in

@@ -123,6 +123,11 @@ 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

@@ -21,7 +21,10 @@ if test -z "$url"; then
     exit 1
 fi
 
-name=$(basename "$url")
+# 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')
 if test -z "$name"; then echo "invalid url"; exit 1; fi
 
 
@@ -60,7 +63,7 @@ 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

@@ -8,21 +8,22 @@ 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 = $ENV{"NIX_LIBEXEC_DIR"};
-$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;
+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");
 
 
 # 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;
@@ -50,7 +51,7 @@ sub processURL {
 
     # First see if a bzipped manifest is available.
     if (system("@curl@ --fail --silent --head '$url'.bz2 > /dev/null") == 0) {
-        print "obtaining list of Nix archives at `$url.bz2'...\n";
+        print "fetching list of Nix archives at `$url.bz2'...\n";
         my $bzipped = downloadFile "$url.bz2";
 
         $manifest = "$tmpDir/MANIFEST";
@@ -68,10 +69,11 @@ sub processURL {
         print "obtaining list of Nix archives at `$url'...\n";
         $manifest = downloadFile $url;
     }
+
+    my $version = readManifest($manifest, \%narFiles, \%localPaths, \%patches);
     
-    if (readManifest($manifest, \%narFiles, \%localPaths, \%patches) < 3) {
-        die "`$url' is not manifest or it is too old (i.e., for Nix <= 0.7)\n";
-    }
+    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 ($skipWrongStore) {
         foreach my $path (keys %narFiles) {
@@ -90,11 +92,31 @@ 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 $finalPath = "$stateDir/manifests/$baseName-$hash.nixmanifest";
-    
-    system("@coreutils@/ln", "-sfn", "$manifest", "$finalPath") == 0
+    my $finalPath = "$manifestDir/$baseName-$hash.nixmanifest";
+
+    unlink $finalPath if -e $finalPath;
+        
+    symlink("$manifest", "$finalPath")
         or die "cannot link `$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

@@ -128,7 +128,7 @@ while (<READ>) {
 close READ or die "nix-instantiate failed: $?";
 
 
-# Realise the store expressions.
+# Build the derivations.
 print STDERR "creating archives...\n";
 
 my @narPaths;
@@ -140,12 +140,7 @@ while (scalar @tmp > 0) {
     my @tmp2 = @tmp[0..$n - 1];
     @tmp = @tmp[$n..scalar @tmp - 1];
 
-    # 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|")
+    my $pid = open(READ, "$binDir/nix-store --realise @tmp2|")
         or die "cannot run nix-store";
     while (<READ>) {
         chomp;

scripts/readmanifest.pm.in

@@ -2,10 +2,7 @@ use strict;
 
 
 sub addPatch {
-    my $patches = shift;
-    my $storePath = shift;
-    my $patch = shift;
-    my $allowConflicts = shift;
+    my ($patches, $storePath, $patch) = @_;
 
     $$patches{$storePath} = []
         unless defined $$patches{$storePath};
@@ -14,15 +11,9 @@ sub addPatch {
 
     my $found = 0;
     foreach my $patch2 (@{$patchList}) {
-        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;
-            }
-        }
+        $found = 1 if
+            $patch2->{url} eq $patch->{url} &&
+            $patch2->{basePath} eq $patch->{basePath};
     }
     
     push @{$patchList}, $patch if !$found;
@@ -32,12 +23,7 @@ sub addPatch {
 
 
 sub readManifest {
-    my $manifest = shift;
-    my $narFiles = shift;
-    my $localPaths = shift;
-    my $patches = shift;
-    my $allowConflicts = shift;
-    $allowConflicts = 0 unless defined $allowConflicts;
+    my ($manifest, $narFiles, $localPaths, $patches) = @_;
 
     open MANIFEST, "<$manifest"
         or die "cannot open `$manifest': $!";
@@ -98,15 +84,7 @@ sub readManifest {
 
                     my $found = 0;
                     foreach my $narFile (@{$narFileList}) {
-                        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;
-                            }
-                        }
+                        $found = 1 if $narFile->{url} eq $url;
                     }
                     if (!$found) {
                         push @{$narFileList},
@@ -124,7 +102,7 @@ sub readManifest {
                         , basePath => $basePath, baseHash => $baseHash
                         , narHash => $narHash, patchType => $patchType
                         , hashAlgo => $hashAlgo
-                        }, $allowConflicts;
+                        };
                 }
 
                 elsif ($type eq "localPath") {
@@ -171,12 +149,8 @@ sub readManifest {
 }
 
 
-sub writeManifest
-{
-    my $manifest = shift;
-    my $narFiles = shift;
-    my $patches = shift;
-    my $copySources = shift;
+sub writeManifest {
+    my ($manifest, $narFiles, $patches) = @_;
 
     open MANIFEST, ">$manifest.tmp"; # !!! check exclusive
 
@@ -190,9 +164,9 @@ sub writeManifest
             print MANIFEST "{\n";
             print MANIFEST "  StorePath: $storePath\n";
             print MANIFEST "  NarURL: $narFile->{url}\n";
-            print MANIFEST "  Hash: $narFile->{hash}\n";
+            print MANIFEST "  Hash: $narFile->{hash}\n" if defined $narFile->{hash};
             print MANIFEST "  NarHash: $narFile->{narHash}\n";
-            print MANIFEST "  Size: $narFile->{size}\n";
+            print MANIFEST "  Size: $narFile->{size}\n" if defined $narFile->{size};
             print MANIFEST "  References: $narFile->{references}\n"
                 if defined $narFile->{references} && $narFile->{references} ne "";
             print MANIFEST "  Deriver: $narFile->{deriver}\n"

scripts/ssh.pm

@@ -0,0 +1,47 @@
+use strict;
+use File::Temp qw(tempdir);
+
+our @sshOpts = split ' ', ($ENV{"NIX_SSHOPTS"} or "");
+
+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 SSH, "ssh $sshHost @sshOpts -M -N -o LocalCommand='echo started' -o PermitLocalCommand=yes |" or die;
+    while (<SSH>) {
+        chomp;
+        last if /started/;
+    }
+    
+    $sshStarted = 1;
+    return 1;
+}
+
+# Tell the master SSH client to exit.
+sub closeSSHConnection {
+    if ($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;

src/Makefile.am

@@ -1,5 +1,3 @@
 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

@@ -1,178 +0,0 @@
-#! /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

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

src/boost/Makefile.am

@@ -1,6 +1,6 @@
 SUBDIRS = format
 
-pkginclude_HEADERS = assert.hpp checked_delete.hpp format.hpp \
+nobase_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/libexpr/Makefile.am

@@ -2,27 +2,25 @@ 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 expr-to-xml.cc common-opts.cc \
+ get-drvs.cc attr-path.cc value-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 expr-to-xml.hh common-opts.hh \
- names.hh
+ get-drvs.hh attr-path.hh value-to-xml.hh common-opts.hh \
+ names.hh symbol-table.hh
 
 libexpr_la_LIBADD = ../libutil/libutil.la ../libstore/libstore.la \
  ../boost/format/libformat.la
 
-BUILT_SOURCES = nixexpr-ast.cc nixexpr-ast.hh \
+BUILT_SOURCES = \
  parser-tab.hh lexer-tab.hh parser-tab.cc lexer-tab.cc
 
-EXTRA_DIST = lexer.l parser.y nixexpr-ast.def nixexpr-ast.cc
+EXTRA_DIST = lexer.l parser.y
 
 AM_CXXFLAGS = \
- -I$(srcdir)/.. ${bdb_include} ${aterm_include} \
+ -I$(srcdir)/.. \
  -I$(srcdir)/../libutil -I$(srcdir)/../libstore
-AM_CFLAGS = \
- ${aterm_include}
 
 
 # Parser generation.
@@ -34,15 +32,6 @@ 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

@@ -1,23 +1,12 @@
 #include "attr-path.hh"
-#include "nixexpr-ast.hh"
 #include "util.hh"
 
 
 namespace nix {
 
 
-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)
+void findAlongAttrPath(EvalState & state, const string & attrPath,
+    const Bindings & autoArgs, Expr * e, Value & v)
 {
     Strings tokens = tokenizeString(attrPath, ".");
 
@@ -25,8 +14,10 @@ Expr findAlongAttrPath(EvalState & state, const string & attrPath,
         Error(format("attribute selection path `%1%' does not match expression") % attrPath);
 
     string curPath;
+
+    state.mkThunk_(v, e);
     
-    for (Strings::iterator i = tokens.begin(); i != tokens.end(); ++i) {
+    foreach (Strings::iterator, i, tokens) {
 
         if (!curPath.empty()) curPath += ".";
         curPath += *i;
@@ -38,7 +29,10 @@ Expr findAlongAttrPath(EvalState & state, const string & attrPath,
         if (string2Int(attr, attrIndex)) apType = apIndex;
 
         /* Evaluate the expression. */
-        e = evalExpr(state, autoCallFunction(evalExpr(state, e), autoArgs));
+        Value vTmp;
+        state.autoCallFunction(autoArgs, v, vTmp);
+        v = vTmp;
+        state.forceValue(v);
 
         /* It should evaluate to either an attribute set or an
            expression, according to what is specified in the
@@ -46,36 +40,31 @@ Expr findAlongAttrPath(EvalState & state, const string & attrPath,
 
         if (apType == apAttr) {
 
-            ATermMap attrs;
-
-            if (!isAttrs(state, e, attrs))
+            if (v.type != tAttrs)
                 throw TypeError(
                     format("the expression selected by the selection path `%1%' should be an attribute set but is %2%")
-                    % curPath % showType(e));
-                
-            e = attrs.get(toATerm(attr));
-            if (!e)
-                throw Error(format("attribute `%1%' in selection path `%2%' not found") % attr % curPath);
+                    % curPath % showType(v));
 
+            Bindings::iterator a = v.attrs->find(state.symbols.create(attr));
+            if (a == v.attrs->end())
+                throw Error(format("attribute `%1%' in selection path `%2%' not found") % attr % curPath);
+            v = a->second.value;
         }
 
         else if (apType == apIndex) {
 
-            ATermList es;
-            if (!matchList(e, es))
+            if (v.type != tList)
                 throw TypeError(
                     format("the expression selected by the selection path `%1%' should be a list but is %2%")
-                    % curPath % showType(e));
+                    % curPath % showType(v));
 
-            e = ATelementAt(es, attrIndex);
-            if (!e)
-                throw Error(format("list index %1% in selection path `%2%' not found") % attrIndex % curPath);
-            
+            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];
         }
         
     }
-    
-    return e;
 }
 
  

src/libexpr/attr-path.hh

@@ -10,8 +10,8 @@
 namespace nix {
 
     
-Expr findAlongAttrPath(EvalState & state, const string & attrPath,
-    const ATermMap & autoArgs, Expr e);
+void findAlongAttrPath(EvalState & state, const string & attrPath,
+    const Bindings & autoArgs, Expr * e, Value & v);
 
     
 }

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,
-    ATermMap & autoArgs)
+    Bindings & autoArgs)
 {
     if (arg != "--arg" && arg != "--argstr") return false;
 
@@ -19,11 +19,13 @@ bool parseOptionArg(const string & arg, Strings::iterator & i,
     string name = *i++;
     if (i == argsEnd) throw error;
     string value = *i++;
-    
-    Expr e = arg == "--arg"
-        ? parseExprFromString(state, value, absPath("."))
-        : makeStr(value);
-    autoArgs.set(toATerm(name), e);
+
+    Value & v(autoArgs[state.symbols.create(name)].value);
+
+    if (arg == "--arg")
+        state.mkThunk_( v, parseExprFromString(state, value, absPath(".")));
+    else
+        mkString(v, value);
     
     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,
-    ATermMap & autoArgs);
+    Bindings & autoArgs);
     
 }
 

src/libexpr/eval.hh

@@ -3,17 +3,165 @@
 
 #include <map>
 
-#include "aterm.hh"
 #include "nixexpr.hh"
+#include "symbol-table.hh"
 
 
 namespace nix {
 
 
 class Hash;
-    
+class EvalState;
+struct Env;
+struct Value;
+struct Attr;
+
+typedef std::map<Symbol, Attr> Bindings;
+
+
+typedef enum {
+    tInt = 1,
+    tBool,
+    tString,
+    tPath,
+    tNull,
+    tAttrs,
+    tList,
+    tThunk,
+    tApp,
+    tLambda,
+    tCopy,
+    tBlackhole,
+    tPrimOp,
+    tPrimOpApp,
+} ValueType;
+
+
+typedef void (* PrimOp) (EvalState & state, Value * * args, Value & v);
+
+
+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;
+        Value * val;
+        struct {
+            PrimOp fun;
+            char * name;
+            unsigned int arity;
+        } primOp;
+        struct {
+            Value * left, * right;
+            unsigned int argsLeft;
+        } primOpApp;
+    };
+};
+
+
+struct Env
+{
+    Env * up;
+    unsigned int prevWith; // nr of levels up to next `with' environment
+    Value values[0];
+};
+
+
+struct Attr
+{
+    Value value;
+    Pos * pos;
+    Attr() : pos(&noPos) { };
+};
+
+
+static inline void mkInt(Value & v, int n)
+{
+    v.type = tInt;
+    v.integer = n;
+}
+
+
+static inline void mkBool(Value & v, bool b)
+{
+    v.type = tBool;
+    v.boolean = b;
+}
+
+
+static inline void mkThunk(Value & v, Env & env, Expr * expr)
+{
+    v.type = tThunk;
+    v.thunk.env = &env;
+    v.thunk.expr = expr;
+}
+
+
+static inline void mkCopy(Value & v, Value & src)
+{
+    v.type = tCopy;
+    v.val = &src;
+}
+
+
+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);
+
 
-typedef std::map<Path, PathSet> DrvRoots;
 typedef std::map<Path, Hash> DrvHashes;
 
 /* Cache for calls to addToStore(); maps source paths to the store
@@ -22,73 +170,153 @@ typedef std::map<Path, Path> SrcToStore;
 
 struct EvalState;
 
-/* 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);
+
+std::ostream & operator << (std::ostream & str, Value & v);
 
 
-struct EvalState 
+class EvalState 
 {
-    ATermMap normalForms;
-    ATermMap primOps;
-    DrvRoots drvRoots;
+public:
     DrvHashes drvHashes; /* normalised derivation hashes */
+
+    SymbolTable symbols;
+
+    const Symbol sWith, sOutPath, sDrvPath, sType, sMeta, sName, sSystem;
+
+private:
     SrcToStore srcToStore; 
 
-    unsigned int nrEvaluated;
-    unsigned int nrCached;
+    bool allowUnsafeEquality;
 
+    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, PrimOp 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(const Bindings & args, Value & fun, Value & res);
+    
+    /* Allocation primitives. */
+    Value * allocValues(unsigned int count);
+    Env & allocEnv(unsigned int size);
+
+    void mkList(Value & v, unsigned int length);
+    void mkAttrs(Value & v);
+    void mkThunk_(Value & v, Expr * expr);
+    
+    void cloneAttrs(Value & src, Value & dst);
+
+    /* Print statistics. */
+    void printStats();
+
+private:
+    
+    unsigned long nrEnvs;
+    unsigned long nrValuesInEnvs;
+    unsigned long nrValues;
+    unsigned long nrListElems;
+    unsigned long nrEvaluated;
+    unsigned int recursionDepth;
+    unsigned int maxRecursionDepth;
+    char * deepestStack; /* for measuring stack usage */
+    
+    friend class RecursionCounter;
 };
 
 
-/* Evaluate an expression to normal form. */
-Expr evalExpr(EvalState & state, Expr e);
+/* Return a string representing the type of the value `v'. */
+string showType(const Value & v);
 
-/* 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

@@ -1,156 +0,0 @@
-#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

@@ -1,16 +0,0 @@
-#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

@@ -1,5 +1,4 @@
 #include "get-drvs.hh"
-#include "nixexpr-ast.hh"
 #include "util.hh"
 
 
@@ -8,17 +7,10 @@ namespace nix {
 
 string DrvInfo::queryDrvPath(EvalState & state) const
 {
-    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);
-        
+    if (drvPath == "" && attrs) {
+        Bindings::iterator i = attrs->find(state.sDrvPath);
         PathSet context;
-        (string &) drvPath = a ? coerceToPath(state, a, context) : "";
+        (string &) drvPath = i != attrs->end() ? state.coerceToPath(i->second.value, context) : "";
     }
     return drvPath;
 }
@@ -26,11 +18,10 @@ string DrvInfo::queryDrvPath(EvalState & state) const
 
 string DrvInfo::queryOutPath(EvalState & state) const
 {
-    if (outPath == "") {
-        Expr a = attrs->get(toATerm("outPath"));
-        if (!a) throw TypeError("output path missing");
+    if (outPath == "" && attrs) {
+        Bindings::iterator i = attrs->find(state.sOutPath);
         PathSet context;
-        (string &) outPath = coerceToPath(state, a, context);
+        (string &) outPath = i != attrs->end() ? state.coerceToPath(i->second.value, context) : "";
     }
     return outPath;
 }
@@ -38,93 +29,85 @@ string DrvInfo::queryOutPath(EvalState & state) const
 
 MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
 {
-    MetaInfo meta;
+    if (metaInfoRead) return meta;
     
-    Expr a = attrs->get(toATerm("meta"));
-    if (!a) return meta; /* fine, empty meta information */
+    (bool &) metaInfoRead = true;
+    
+    Bindings::iterator a = attrs->find(state.sMeta);
+    if (a == attrs->end()) return meta; /* fine, empty meta information */
 
-    ATermMap attrs2;
-    queryAllAttrs(evalExpr(state, a), attrs2);
+    state.forceAttrs(a->second.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. */
+    foreach (Bindings::iterator, i, *a->second.value.attrs) {
+        MetaValue value;
+        state.forceValue(i->second.value);
+        if (i->second.value.type == tString) {
+            value.type = MetaValue::tpString;
+            value.stringValue = i->second.value.string.s;
+        } else if (i->second.value.type == tInt) {
+            value.type = MetaValue::tpInt;
+            value.intValue = i->second.value.integer;
+        } else if (i->second.value.type == tList) {
+            value.type = MetaValue::tpStrings;
+            for (unsigned int j = 0; j < i->second.value.list.length; ++j)
+                value.stringValues.push_back(state.forceStringNoCtx(*i->second.value.list.elems[j]));
+        } else continue;
+        ((MetaInfo &) meta)[i->first] = value;
     }
 
     return meta;
 }
 
 
-string DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
+MetaValue DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
 {
     /* !!! evaluates all meta attributes => inefficient */
-    MetaInfo meta = queryMetaInfo(state);
-    MetaInfo::iterator i = meta.find(name);
-    return i == meta.end() ? "" : i->second;
+    return queryMetaInfo(state)[name];
 }
 
 
 void DrvInfo::setMetaInfo(const MetaInfo & 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));
+    metaInfoRead = true;
+    this->meta = meta;
 }
 
 
-/* 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;
+/* Cache for already considered attrsets. */
+typedef set<Bindings *> 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)
+/* 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)
 {
     try {
-        
-        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;
+        state.forceValue(v);
+        if (!state.isDerivation(v)) return true;
 
         /* Remove spurious duplicates (e.g., an attribute set like
            `rec { x = derivation {...}; y = x;}'. */
-        if (doneExprs.find(e) != doneExprs.end()) return false;
-        doneExprs.insert(e);
+        if (done.find(v.attrs) != done.end()) return false;
+        done.insert(v.attrs);
 
         DrvInfo drv;
     
-        a = attrs->get(toATerm("name"));
+        Bindings::iterator i = v.attrs->find(state.sName);
         /* !!! We really would like to have a decent back trace here. */
-        if (!a) throw TypeError("derivation name missing");
-        drv.name = evalStringNoCtx(state, a);
+        if (i == v.attrs->end()) throw TypeError("derivation name missing");
+        drv.name = state.forceStringNoCtx(i->second.value);
 
-        a = attrs->get(toATerm("system"));
-        if (!a)
+        i = v.attrs->find(state.sSystem);
+        if (i == v.attrs->end())
             drv.system = "unknown";
         else
-            drv.system = evalStringNoCtx(state, a);
+            drv.system = state.forceStringNoCtx(i->second.value);
 
-        drv.attrs = attrs;
+        drv.attrs = v.attrs;
 
         drv.attrPath = attrPath;
 
@@ -137,11 +120,11 @@ static bool getDerivation(EvalState & state, Expr e,
 }
 
 
-bool getDerivation(EvalState & state, Expr e, DrvInfo & drv)
+bool getDerivation(EvalState & state, Value & v, DrvInfo & drv)
 {
-    Exprs doneExprs;
+    Done done;
     DrvInfos drvs;
-    getDerivation(state, e, "", drvs, doneExprs);
+    getDerivation(state, v, "", drvs, done);
     if (drvs.size() != 1) return false;
     drv = drvs.front();
     return true;
@@ -154,83 +137,73 @@ static string addToPath(const string & s1, const string & s2)
 }
 
 
-static void getDerivations(EvalState & state, Expr e,
-    const string & pathPrefix, const ATermMap & autoArgs,
-    DrvInfos & drvs, Exprs & doneExprs)
+static void getDerivations(EvalState & state, Value & vIn,
+    const string & pathPrefix, const Bindings & autoArgs,
+    DrvInfos & drvs, Done & done)
 {
-    e = evalExpr(state, autoCallFunction(evalExpr(state, e), autoArgs));
-
+    Value v;
+    state.autoCallFunction(autoArgs, vIn, v);
+    
     /* Process the expression. */
-    ATermList es;
     DrvInfo drv;
 
-    if (!getDerivation(state, e, pathPrefix, drvs, doneExprs))
-        return;
+    if (!getDerivation(state, v, pathPrefix, drvs, done)) ;
 
-    if (matchAttrs(e, es)) {
-        ATermMap drvMap(ATgetLength(es));
-        queryAllAttrs(e, drvMap);
+    else if (v.type == tAttrs) {
 
         /* !!! undocumented hackery to support combining channels in
            nix-env.cc. */
-        bool combineChannels = drvMap.get(toATerm("_combineChannels"));
+        bool combineChannels = v.attrs->find(state.symbols.create("_combineChannels")) != v.attrs->end();
 
         /* 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, Expr> AttrsSorted;
-        AttrsSorted attrsSorted;
-        foreach (ATermMap::const_iterator, i, drvMap)
-            attrsSorted[aterm2String(i->key)] = i->value;
+        typedef std::map<string, Symbol> SortedSymbols;
+        SortedSymbols attrs;
+        foreach (Bindings::iterator, i, *v.attrs)
+            attrs.insert(std::pair<string, Symbol>(i->first, i->first));
 
-        foreach (AttrsSorted::iterator, i, attrsSorted) {
+        foreach (SortedSymbols::iterator, i, attrs) {
             startNest(nest, lvlDebug, format("evaluating attribute `%1%'") % i->first);
             string pathPrefix2 = addToPath(pathPrefix, i->first);
+            Value & v2((*v.attrs)[i->second].value);
             if (combineChannels)
-                getDerivations(state, i->second, pathPrefix2, autoArgs, drvs, doneExprs);
-            else if (getDerivation(state, i->second, pathPrefix2, drvs, doneExprs)) {
+                getDerivations(state, v2, pathPrefix2, autoArgs, drvs, done);
+            else if (getDerivation(state, v2, pathPrefix2, drvs, done)) {
                 /* If the value of this attribute is itself an
                    attribute set, should we recurse into it?  => Only
                    if it has a `recurseForDerivations = true'
                    attribute. */
-                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);
+                if (v2.type == tAttrs) {
+                    Bindings::iterator j = v2.attrs->find(state.symbols.create("recurseForDerivations"));
+                    if (j != v2.attrs->end() && state.forceBool(j->second.value))
+                        getDerivations(state, v2, pathPrefix2, autoArgs, drvs, done);
                 }
             }
         }
-        
-        return;
     }
 
-    if (matchList(e, es)) {
-        int n = 0;
-        for (ATermIterator i(es); i; ++i, ++n) {
+    else if (v.type == tList) {
+        for (unsigned int n = 0; n < v.list.length; ++n) {
             startNest(nest, lvlDebug,
                 format("evaluating list element"));
             string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
-            if (getDerivation(state, *i, pathPrefix2, drvs, doneExprs))
-                getDerivations(state, *i, pathPrefix2, autoArgs, drvs, doneExprs);
+            if (getDerivation(state, *v.list.elems[n], pathPrefix2, drvs, done))
+                getDerivations(state, *v.list.elems[n], pathPrefix2, autoArgs, drvs, done);
         }
-        return;
     }
 
-    throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
+    else throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
 }
 
 
-void getDerivations(EvalState & state, Expr e, const string & pathPrefix,
-    const ATermMap & autoArgs, DrvInfos & drvs)
+void getDerivations(EvalState & state, Value & v, const string & pathPrefix,
+    const Bindings & autoArgs, DrvInfos & drvs)
 {
-    Exprs doneExprs;
-    getDerivations(state, e, pathPrefix, autoArgs, drvs, doneExprs);
+    Done done;
+    getDerivations(state, v, pathPrefix, autoArgs, drvs, done);
 }
 
  

src/libexpr/get-drvs.hh

@@ -12,7 +12,16 @@
 namespace nix {
 
 
-typedef std::map<string, string> MetaInfo;
+struct MetaValue
+{
+    enum { tpNone, tpString, tpStrings, tpInt } type;
+    string stringValue;
+    Strings stringValues;
+    int intValue;
+};
+
+
+typedef std::map<string, MetaValue> MetaInfo;
 
 
 struct DrvInfo
@@ -20,21 +29,24 @@ struct DrvInfo
 private:
     string drvPath;
     string outPath;
+
+    bool metaInfoRead;
+    MetaInfo meta;
     
 public:
     string name;
     string attrPath; /* path towards the derivation */
     string system;
 
-    /* !!! 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;
+    /* !!! make this private */
+    Bindings * attrs;
+
+    DrvInfo() : metaInfoRead(false), attrs(0) { };
 
     string queryDrvPath(EvalState & state) const;
     string queryOutPath(EvalState & state) const;
     MetaInfo queryMetaInfo(EvalState & state) const;
-    string queryMetaInfo(EvalState & state, const string & name) const;
+    MetaValue queryMetaInfo(EvalState & state, const string & name) const;
 
     void setDrvPath(const string & s)
     {
@@ -53,13 +65,12 @@ public:
 typedef list<DrvInfo> DrvInfos;
 
 
-/* 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);
+/* 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);
 
-void getDerivations(EvalState & state, Expr e, const string & pathPrefix,
-    const ATermMap & autoArgs, DrvInfos & drvs);
+void getDerivations(EvalState & state, Value & v, const string & pathPrefix,
+    const Bindings & autoArgs, DrvInfos & drvs);
 
  
 }

src/libexpr/lexer.l

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

src/libexpr/nixexpr-ast.def

@@ -1,96 +0,0 @@
-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

@@ -1,407 +1,325 @@
 #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 (list<Inherited>::iterator, i, inherited)
+        str << "inherit " << i->first.name << "; ";
+    foreach (Attrs::iterator, i, attrs)
+        str << i->first << " = " << *i->second.first << "; ";
+    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 (list<ExprAttrs::Inherited>::iterator, i, attrs->inherited)
+        str << "inherit " << i->first.name << "; ";
+    foreach (ExprAttrs::Attrs::iterator, i, attrs->attrs)
+        str << i->first << " = " << *i->second.first << "; ";
+    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;
 
-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();
+        foreach (ExprAttrs::Attrs::iterator, i, attrs)
+            newEnv.vars[i->first] = displ++;
+
+        foreach (list<Inherited>::iterator, i, inherited) {
+            newEnv.vars[i->first.name] = displ++;
+            i->first.bind(env);
+        }
+
+        foreach (ExprAttrs::Attrs::iterator, i, attrs)
+            i->second.first->bindVars(newEnv);
+    }
+
+    else {
+        foreach (ExprAttrs::Attrs::iterator, i, attrs)
+            i->second.first->bindVars(env);
+
+        foreach (list<Inherited>::iterator, i, inherited)
+            i->first.bind(env);
+    }
 }
+
+void ExprList::bindVars(const StaticEnv & env)
+{
+    foreach (vector<Expr *>::iterator, i, elems)
+        (*i)->bindVars(env);
+}
+
+void ExprLambda::bindVars(const StaticEnv & env)
+{
+    StaticEnv newEnv(false, &env);
     
-
-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));
-        
-        e = (ATerm) ATmakeApplArray(fun, args);
-    }
-
-    else if (ATgetType(e) == AT_LIST) {
-        ATermList in = (ATermList) e;
-        ATermList out = ATempty;
-
-        for (ATermIterator i(in); i; ++i)
-            out = ATinsert(out, bottomupRewrite(f, *i));
-
-        e = (ATerm) ATreverse(out);
-    }
-
-    return f(e);
-}
-
-
-void queryAllAttrs(Expr e, ATermMap & attrs, bool withPos)
-{
-    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);
-    }
-}
-
-
-Expr queryAttr(Expr e, const string & name)
-{
-    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);
+    unsigned int displ = 0;
     
-    ATerm name, pos, value;
-    ATerm with, body;
-    ATermList rbnds, nrbnds;
-    Pattern pat;
+    if (!arg.empty()) newEnv.vars[arg] = displ++;
 
-    /* Closed terms don't have free variables, so we don't have to
-       check by definition. */
-    if (matchClosed(e, value)) return;
+    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);
+    }
+
+    body->bindVars(newEnv);
+}
+
+void ExprLet::bindVars(const StaticEnv & env)
+{
+    StaticEnv newEnv(false, &env);
     
-    else if (matchVar(e, name)) {
-        if (!defs.get(name))
-            throw EvalError(format("undefined variable `%1%'")
-                % aterm2String(name));
+    unsigned int displ = 0;
+
+    foreach (ExprAttrs::Attrs::iterator, i, attrs->attrs)
+        newEnv.vars[i->first] = displ++;
+
+    foreach (list<ExprAttrs::Inherited>::iterator, i, attrs->inherited) {
+        newEnv.vars[i->first.name] = displ++;
+        i->first.bind(env);
     }
 
-    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);
-    }
+    foreach (ExprAttrs::Attrs::iterator, i, attrs->attrs)
+        i->second.first->bindVars(newEnv);
     
-    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);
+    body->bindVars(newEnv);
 }
 
-
-void checkVarDefs(const ATermMap & defs, Expr e)
+void ExprWith::bindVars(const StaticEnv & env)
 {
-    set<Expr> done;
-    checkVarDefs2(done, defs, e);
-}
-
-
-struct Canonicalise : TermFun
-{
-    ATerm operator () (ATerm e)
-    {
-        /* Remove position info. */
-        ATerm path;
-        int line, column;
-        if (matchPos(e, path, line, column))
-            return makeNoPos();
-
-        /* 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);
+    /* 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;
         }
-        
-        return e;
-    }
-};
+    
+    attrs->bindVars(env);    
+    StaticEnv newEnv(true, &env);
+    body->bindVars(newEnv);
+}
 
-
-Expr canonicaliseExpr(Expr e)
+void ExprIf::bindVars(const StaticEnv & env)
 {
-    Canonicalise canonicalise;
-    return bottomupRewrite(canonicalise, e);
+    cond->bindVars(env);
+    then->bindVars(env);
+    else_->bindVars(env);
 }
 
-
-Expr makeBool(bool b)
+void ExprAssert::bindVars(const StaticEnv & env)
 {
-    return b ? eTrue : eFalse;
+    cond->bindVars(env);
+    body->bindVars(env);
 }
 
-
-bool matchStr(Expr e, string & s, PathSet & context)
+void ExprOpNot::bindVars(const StaticEnv & env)
 {
-    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;
+    e->bindVars(env);
 }
 
-
-Expr makeStr(const string & s, const PathSet & context)
+void ExprConcatStrings::bindVars(const StaticEnv & env)
 {
-    return makeStr(toATerm(s), toATermList(context));
+    foreach (vector<Expr *>::iterator, i, *es)
+        (*i)->bindVars(env);
 }
 
 
-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

@@ -3,119 +3,268 @@
 
 #include <map>
 
-#include "aterm-map.hh"
-#include "types.hh"
+#include "symbol-table.hh"
 
 
 namespace nix {
 
 
 MakeError(EvalError, Error)
+MakeError(ParseError, Error)
 MakeError(AssertionError, EvalError)
 MakeError(ThrownError, AssertionError)
 MakeError(Abort, EvalError)
 MakeError(TypeError, EvalError)
 
 
-/* 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;
+/* Position objects. */
 
-
-/* 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
+struct Pos
 {
-    ATermMap * map;
-    const Substitution * prev;
+    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) { };
+};
 
-    Substitution(const Substitution * prev, ATermMap * map)
-    {
-        this->prev = prev;
-        this->map = map;
-    }
+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
+{
+    string s;
+    ExprString(const string & 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;
     
-    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;
-    }
+    /* 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(const Symbol & name) : name(name) { };
+    void bind(const StaticEnv & env);
 };
 
-
-/* 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
+struct ExprVar : Expr
 {
-    virtual ~TermFun() { }
-    virtual ATerm operator () (ATerm e) = 0;
+    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;
+    typedef std::pair<Expr *, Pos> Attr;
+    typedef std::pair<VarRef, Pos> Inherited;
+    typedef std::map<Symbol, Attr> Attrs;
+    Attrs attrs;
+    list<Inherited> inherited;
+    std::map<Symbol, Pos> attrNames; // used during parsing
+    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)
+    {
+        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
+};
+
+struct ExprLet : Expr
+{
+    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
 };
-ATerm bottomupRewrite(TermFun & f, ATerm e);
 
 
-/* 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);
+/* 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) { };
+};
 
 
-/* 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

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

@@ -20,14 +20,13 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "aterm.hh"
 #include "util.hh"
     
+#include "nixexpr.hh"
+
 #include "parser-tab.hh"
 #include "lexer-tab.hh"
-
-#include "nixexpr.hh"
-#include "nixexpr-ast.hh"
+#define YYSTYPE YYSTYPE // workaround a bug in Bison 2.4
 
 
 using namespace nix;
@@ -38,39 +37,85 @@ namespace nix {
     
 struct ParseData 
 {
-    Expr result;
+    SymbolTable & symbols;
+    Expr * result;
     Path basePath;
     Path path;
     string error;
+    Symbol sLetBody;
+    ParseData(SymbolTable & symbols)
+        : symbols(symbols)
+        , sLetBody(symbols.create("<let-body>"))
+    { };
 };
 
 
-static Expr fixAttrs(int recursive, ATermList as)
+static string showAttrPath(const vector<Symbol> & attrPath)
 {
-    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);
+    string s;
+    foreach (vector<Symbol>::const_iterator, i, attrPath) {
+        if (!s.empty()) s += '.';
+        s += *i;
     }
-    if (recursive)
-        return makeRec(bs, cs);
-    else
-        return makeAttrs(bs);
+    return s;
 }
 
 
-static Expr stripIndentation(ATermList es)
+static void dupAttr(const vector<Symbol> & attrPath, const Pos & pos, const Pos & prevPos)
 {
-    if (es == ATempty) return makeStr("");
+    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::Attrs::iterator j = attrs->attrs.find(*i);
+        if (j != attrs->attrs.end()) {
+            ExprAttrs * attrs2 = dynamic_cast<ExprAttrs *>(j->second.first);
+            if (!attrs2 || n == attrPath.size()) dupAttr(attrPath, pos, j->second.second);
+            attrs = attrs2;
+        } else {
+            if (attrs->attrNames.find(*i) != attrs->attrNames.end())
+                dupAttr(attrPath, pos, attrs->attrNames[*i]);
+            attrs->attrNames[*i] = pos;
+            if (n == attrPath.size())
+                attrs->attrs[*i] = ExprAttrs::Attr(e, pos);
+            else {
+                ExprAttrs * nested = new ExprAttrs;
+                attrs->attrs[*i] = ExprAttrs::Attr(nested, pos);
+                attrs = nested;
+            }
+        }
+    }
+}
+
+
+static void addFormal(const Pos & pos, Formals * formals, const Formal & formal)
+{
+    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(vector<Expr *> & es)
+{
+    if (es.empty()) return new ExprString("");
     
     /* Figure out the minimum indentation.  Note that by design
        whitespace-only final lines are not taken into account.  (So
@@ -78,9 +123,9 @@ static Expr stripIndentation(ATermList es)
     bool atStartOfLine = true; /* = seen only whitespace in the current line */
     unsigned int minIndent = 1000000;
     unsigned int curIndent = 0;
-    ATerm e;
-    for (ATermIterator i(es); i; ++i) {
-        if (!matchIndStr(*i, e)) {
+    foreach (vector<Expr *>::iterator, i, es) {
+        ExprIndStr * e = dynamic_cast<ExprIndStr *>(*i);
+        if (!e) {
             /* Anti-quotations end the current start-of-line whitespace. */
             if (atStartOfLine) {
                 atStartOfLine = false;
@@ -88,12 +133,11 @@ static Expr stripIndentation(ATermList es)
             }
             continue;
         }
-        string s = aterm2String(e);
-        for (unsigned int j = 0; j < s.size(); ++j) {
+        for (unsigned int j = 0; j < e->s.size(); ++j) {
             if (atStartOfLine) {
-                if (s[j] == ' ')
+                if (e->s[j] == ' ')
                     curIndent++;
-                else if (s[j] == '\n') {
+                else if (e->s[j] == '\n') {
                     /* Empty line, doesn't influence minimum
                        indentation. */
                     curIndent = 0;
@@ -101,7 +145,7 @@ static Expr stripIndentation(ATermList es)
                     atStartOfLine = false;
                     if (curIndent < minIndent) minIndent = curIndent;
                 }
-            } else if (s[j] == '\n') {
+            } else if (e->s[j] == '\n') {
                 atStartOfLine = true;
                 curIndent = 0;
             }
@@ -109,52 +153,52 @@ static Expr stripIndentation(ATermList es)
     }
 
     /* Strip spaces from each line. */
-    ATermList es2 = ATempty;
+    vector<Expr *> * es2 = new vector<Expr *>;
     atStartOfLine = true;
     unsigned int curDropped = 0;
-    unsigned int n = ATgetLength(es);
-    for (ATermIterator i(es); i; ++i, --n) {
-        if (!matchIndStr(*i, e)) {
+    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) {
             atStartOfLine = false;
             curDropped = 0;
-            es2 = ATinsert(es2, *i);
+            es2->push_back(*i);
             continue;
         }
         
-        string s = aterm2String(e);
         string s2;
-        for (unsigned int j = 0; j < s.size(); ++j) {
+        for (unsigned int j = 0; j < e->s.size(); ++j) {
             if (atStartOfLine) {
-                if (s[j] == ' ') {
+                if (e->s[j] == ' ') {
                     if (curDropped++ >= minIndent)
-                        s2 += s[j];
+                        s2 += e->s[j];
                 }
-                else if (s[j] == '\n') {
+                else if (e->s[j] == '\n') {
                     curDropped = 0;
-                    s2 += s[j];
+                    s2 += e->s[j];
                 } else {
                     atStartOfLine = false;
                     curDropped = 0;
-                    s2 += s[j];
+                    s2 += e->s[j];
                 }
             } else {
-                s2 += s[j];
-                if (s[j] == '\n') atStartOfLine = true;
+                s2 += e->s[j];
+                if (e->s[j] == '\n') atStartOfLine = true;
             }
         }
 
         /* Remove the last line if it is empty and consists only of
            spaces. */
         if (n == 1) {
-            unsigned int p = s2.find_last_of('\n');
+            string::size_type 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 = ATinsert(es2, makeStr(s2));
+
+        es2->push_back(new ExprString(s2));
     }
 
-    return makeConcatStrings(ATreverse(es2));
+    return new ExprConcatStrings(es2);
 }
 
 
@@ -162,13 +206,12 @@ void backToString(yyscan_t scanner);
 void backToIndString(yyscan_t scanner);
 
 
-static Pos makeCurPos(YYLTYPE * loc, ParseData * data)
+static Pos makeCurPos(const YYLTYPE & loc, ParseData * data)
 {
-    return makePos(toATerm(data->path),
-        loc->first_line, loc->first_column);
+    return Pos(data->path, loc.first_line, loc.first_column);
 }
 
-#define CUR_POS makeCurPos(yylocp, data)
+#define CUR_POS makeCurPos(*yylocp, data)
 
 
 }
@@ -176,50 +219,43 @@ static Pos makeCurPos(YYLTYPE * loc, ParseData * data)
 
 void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * error)
 {
-    data->error = (format("%1%, at `%2%':%3%:%4%")
-        % error % data->path % loc->first_line % loc->first_column).str();
+    data->error = (format("%1%, at %2%")
+        % error % makeCurPos(*loc, data)).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 {
-  ATerm t;
-  ATermList ts;
-  struct {
-    ATermList formals;
-    bool ellipsis;
-  } formals;
+  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;
 }
 
-%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 <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 <formals> formals
-%token <t> ID INT STR IND_STR PATH URI
+%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 IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL
 %token DOLLAR_CURLY /* == ${ */
 %token IND_STRING_OPEN IND_STRING_CLOSE
@@ -243,239 +279,172 @@ start: expr { data->result = $1; };
 expr: expr_function;
 
 expr_function
-  : pattern ':' expr_function
-    { $$ = makeFunction($1, $3, CUR_POS); }
+  : ID ':' expr_function
+    { $$ = 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
+    { $$ = new ExprLambda(CUR_POS, data->symbols.create($1), true, $4, $7); }
   | ASSERT expr ';' expr_function
-    { $$ = makeAssert($2, $4, CUR_POS); }
+    { $$ = new ExprAssert(CUR_POS, $2, $4); }
   | WITH expr ';' expr_function
-    { $$ = makeWith($2, $4, CUR_POS); }
+    { $$ = new ExprWith(CUR_POS, $2, $4); }
   | LET binds IN expr_function
-    { $$ = makeSelect(fixAttrs(1, ATinsert($2, makeBind(toATerm("<let-body>"), $4, CUR_POS))), toATerm("<let-body>")); }
+    { $$ = new ExprLet($2, $4); }
   | expr_if
   ;
 
 expr_if
-  : IF expr THEN expr ELSE expr
-    { $$ = makeIf($2, $4, $6); }
+  : IF expr THEN expr ELSE expr { $$ = new ExprIf($2, $4, $6); }
   | expr_op
   ;
 
 expr_op
-  : '!' 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 { $$ = makeOpConcat($1, $3); }
+  : '!' expr_op %prec NEG { $$ = 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_app
   ;
 
 expr_app
   : expr_app expr_select
-    { $$ = makeCall($1, $2); }
+    { $$ = new ExprApp($1, $2); }
   | expr_select { $$ = $1; }
   ;
 
 expr_select
   : expr_select '.' ID
-    { $$ = makeSelect($1, $3); }
+    { $$ = new ExprSelect($1, data->symbols.create($3)); }
   | expr_simple { $$ = $1; }
   ;
 
 expr_simple
-  : ID { $$ = makeVar($1); }
-  | INT { $$ = makeInt(ATgetInt((ATermInt) $1)); }
+  : ID { $$ = new ExprVar(data->symbols.create($1)); }
+  | INT { $$ = new ExprInt($1); }
   | '"' string_parts '"' {
       /* For efficiency, and to simplify parse trees a bit. */
-      if ($2 == ATempty) $$ = makeStr(toATerm(""), ATempty);
-      else if (ATgetNext($2) == ATempty) $$ = ATgetFirst($2);
-      else $$ = makeConcatStrings(ATreverse($2));
+      if ($2->empty()) $$ = new ExprString("");
+      else if ($2->size() == 1) $$ = $2->front();
+      else $$ = new ExprConcatStrings($2);
   }
   | IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE {
-      $$ = stripIndentation(ATreverse($2));
+      $$ = stripIndentation(*$2);
   }
-  | PATH { $$ = makePath(toATerm(absPath(aterm2String($1), data->basePath))); }
-  | URI { $$ = makeStr($1, ATempty); }
+  | PATH { $$ = new ExprPath(absPath($1, data->basePath)); }
+  | URI { $$ = new ExprString($1); }
   | '(' expr ')' { $$ = $2; }
   /* Let expressions `let {..., body = ...}' are just desugared
      into `(rec {..., body = ...}).body'. */
   | LET '{' binds '}'
-    { $$ = makeSelect(fixAttrs(1, $3), toATerm("body")); }
+    { $3->recursive = true; $$ = new ExprSelect($3, data->symbols.create("body")); }
   | REC '{' binds '}'
-    { $$ = fixAttrs(1, $3); }
+    { $3->recursive = true; $$ = $3; }
   | '{' binds '}'
-    { $$ = fixAttrs(0, $2); }
-  | '[' expr_list ']' { $$ = makeList($2); }
+    { $$ = $2; }
+  | '[' expr_list ']' { $$ = $2; }
   ;
 
 string_parts
-  : string_parts STR { $$ = ATinsert($1, $2); }
-  | string_parts DOLLAR_CURLY expr '}' { backToString(scanner); $$ = ATinsert($1, $3); }
-  | { $$ = ATempty; }
+  : string_parts STR { $$ = $1; $1->push_back($2); }
+  | string_parts DOLLAR_CURLY expr '}' { backToString(scanner); $$ = $1; $1->push_back($3); }
+  | { $$ = new vector<Expr *>; }
   ;
 
 ind_string_parts
-  : 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); }
+  : 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 *>; }
   ;
 
 binds
-  : binds bind { $$ = ATinsert($1, $2); }
-  | { $$ = ATempty; }
+  : binds attrpath '=' expr ';' { $$ = $1; addAttr($$, *$2, $4, makeCurPos(@2, data)); }
+  | binds INHERIT ids ';'
+    { $$ = $1;
+      foreach (vector<Symbol>::iterator, i, *$3) {
+          if ($$->attrNames.find(*i) != $$->attrNames.end())
+              dupAttr(*i, makeCurPos(@3, data), $$->attrNames[*i]);
+          Pos pos = makeCurPos(@3, data);
+          $$->inherited.push_back(ExprAttrs::Inherited(*i, pos));
+          $$->attrNames[*i] = pos;
+      }
+    }
+  | binds INHERIT '(' expr ')' ids ';'
+    { $$ = $1;
+      /* !!! Should ensure sharing of the expression in $4. */
+      foreach (vector<Symbol>::iterator, i, *$6) {
+          if ($$->attrNames.find(*i) != $$->attrNames.end())
+              dupAttr(*i, makeCurPos(@6, data), $$->attrNames[*i]);
+          $$->attrs[*i] = ExprAttrs::Attr(new ExprSelect($4, *i), makeCurPos(@6, data));
+          $$->attrNames[*i] = makeCurPos(@6, data);
+      }}
+
+  | { $$ = new ExprAttrs; }
   ;
 
-bind
-  : ID '=' expr ';'
-    { $$ = makeBind($1, $3, CUR_POS); }
-  | INHERIT inheritsrc ids ';'
-    { $$ = makeInherit($2, $3, CUR_POS); }
+ids
+  : ids ID { $$ = $1; $1->push_back(data->symbols.create($2)); /* !!! dangerous */ }
+  | { $$ = new vector<Symbol>; }
   ;
 
-inheritsrc
-  : '(' expr ')' { $$ = $2; }
-  | { $$ = makeScope(); }
+attrpath
+  : attrpath '.' ID { $$ = $1; $1->push_back(data->symbols.create($3)); }
+  | ID { $$ = new vector<Symbol>; $$->push_back(data->symbols.create($1)); }
   ;
 
-ids: ids ID { $$ = ATinsert($1, $2); } | { $$ = ATempty; };
-
 expr_list
-  : 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; }
+  : expr_list expr_select { $$ = $1; $1->elems.push_back($2); /* !!! dangerous */ }
+  | { $$ = new ExprList; }
   ;
 
 formals
-  : formal ',' formals /* idem - right recursive */
-    { $$.formals = ATinsert($3.formals, $1); $$.ellipsis = $3.ellipsis; }
+  : formal ',' formals
+    { $$ = $3; addFormal(CUR_POS, $$, *$1); }
   | formal
-    { $$.formals = ATinsert(ATempty, $1); $$.ellipsis = false; }
+    { $$ = new Formals; addFormal(CUR_POS, $$, *$1); $$->ellipsis = false; }
   |
-    { $$.formals = ATempty; $$.ellipsis = false; }
+    { $$ = new Formals; $$->ellipsis = false; }
   | ELLIPSIS
-    { $$.formals = ATempty; $$.ellipsis = true; }
+    { $$ = new Formals; $$->ellipsis = true; }
   ;
 
 formal
-  : ID { $$ = makeFormal($1, makeNoDefaultValue()); }
-  | ID '?' expr { $$ = makeFormal($1, makeDefaultValue($3)); }
+  : ID { $$ = new Formal(data->symbols.create($1), 0); }
+  | ID '?' expr { $$ = new Formal(data->symbols.create($1), $3); }
   ;
   
 %%
 
 
-#include "eval.hh"  
-
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 
+#include <eval.hh>
+
 
 namespace nix {
       
 
-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)
+static Expr * parse(EvalState & state, const char * text,
+    const Path & path, const Path & basePath)
 {
     yyscan_t scanner;
-    ParseData data;
+    ParseData data(state.symbols);
     data.basePath = basePath;
     data.path = path;
 
@@ -484,30 +453,22 @@ static Expr parse(EvalState & state,
     int res = yyparse(scanner, &data);
     yylex_destroy(scanner);
     
-    if (res) throw EvalError(data.error);
+    if (res) throw ParseError(data.error);
 
     try {
-        checkVarDefs(state.primOps, data.result);
+        data.result->bindVars(state.staticBaseEnv);
     } catch (Error & e) {
-        throw EvalError(format("%1%, in `%2%'") % e.msg() % path);
+        throw ParseError(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;
@@ -529,7 +490,7 @@ 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

@@ -0,0 +1,81 @@
+#ifndef __SYMBOL_TABLE_H
+#define __SYMBOL_TABLE_H
+
+#include <map>
+#include <tr1/unordered_set>
+
+#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:
+    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:
+    typedef std::tr1::unordered_set<string> Symbols;
+    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

@@ -0,0 +1,161 @@
+#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->first);
+    
+    foreach (StringSet::iterator, i, names) {
+        Attr & a(attrs[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? */
+            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->second.value);
+                    if (a->second.value.type == tString)
+                        xmlAttrs["drvPath"] = drvPath = a->second.value.string.s;
+                }
+        
+                a = v.attrs->find(state.sOutPath);
+                if (a != v.attrs->end()) {
+                    if (strict) state.forceValue(a->second.value);
+                    if (a->second.value.type == tString)
+                        xmlAttrs["outPath"] = a->second.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

@@ -0,0 +1,17 @@
+#ifndef __VALUE_TO_XML_H
+#define __VALUE_TO_XML_H
+
+#include <string>
+#include <map>
+
+#include "nixexpr.hh"
+#include "eval.hh"
+
+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

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

src/libmain/shared.cc

@@ -13,8 +13,6 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include <aterm2.h>
-
 
 namespace nix {
 
@@ -87,21 +85,6 @@ 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 {
@@ -125,6 +108,9 @@ RemoveTempRoots::~RemoveTempRoots()
 }
 
 
+static bool showTrace = false;
+
+
 /* Initialize and reorder arguments, then call the actual argument
    processor. */
 static void initAndRun(int argc, char * * argv)
@@ -138,7 +124,6 @@ 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") {
@@ -153,23 +138,29 @@ static void initAndRun(int argc, char * * argv)
     maxSilentTime = queryIntSetting("build-max-silent-time", 0);
 
     /* Catch SIGINT. */
-    struct sigaction act, oact;
+    struct sigaction act;
     act.sa_handler = sigintHandler;
     sigfillset(&act.sa_mask);
     act.sa_flags = 0;
-    if (sigaction(SIGINT, &act, &oact))
+    if (sigaction(SIGINT, &act, 0))
         throw SysError("installing handler for SIGINT");
-    if (sigaction(SIGTERM, &act, &oact))
+    if (sigaction(SIGTERM, &act, 0))
         throw SysError("installing handler for SIGTERM");
-    if (sigaction(SIGHUP, &act, &oact))
+    if (sigaction(SIGHUP, &act, 0))
         throw SysError("installing handler for SIGHUP");
 
     /* Ignore SIGPIPE. */
     act.sa_handler = SIG_IGN;
     act.sa_flags = 0;
-    if (sigaction(SIGPIPE, &act, &oact))
+    if (sigaction(SIGPIPE, &act, 0))
         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
@@ -180,9 +171,6 @@ 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++);
@@ -193,7 +181,7 @@ 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] != '-') {
+        else if (arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && !isdigit(arg[1])) {
             for (unsigned int j = 1; j < arg.length(); j++)
                 if (isalpha(arg[j]))
                     remaining.push_back((string) "-" + arg[j]);
@@ -237,13 +225,22 @@ static void initAndRun(int argc, char * * argv)
         else if (arg == "--fallback")
             tryFallback = true;
         else if (arg == "--max-jobs" || arg == "-j")
-            maxBuildJobs = getIntArg(arg, i, args.end());
+            maxBuildJobs = getIntArg<unsigned int>(arg, i, args.end());
         else if (arg == "--readonly-mode")
             readOnlyMode = true;
         else if (arg == "--max-silent-time")
-            maxSilentTime = getIntArg(arg, i, args.end());
+            maxSilentTime = getIntArg<unsigned int>(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);
     }
 
@@ -328,10 +325,6 @@ 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));
@@ -359,7 +352,9 @@ int main(int argc, char * * argv)
             % e.what() % programId);
         return 1;
     } catch (BaseError & e) {
-        printMsg(lvlError, format("error: %1%") % e.msg());
+        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 1;
     } catch (std::exception & e) {
         printMsg(lvlError, format("error: %1%") % e.what());

src/libmain/shared.hh

@@ -22,22 +22,30 @@ 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);
 
-unsigned long long getIntArg(const string & opt,
-    Strings::iterator & i, const Strings::iterator & end);
+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;
+}
 
 /* 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 +2,15 @@ pkglib_LTLIBRARIES = libstore.la
 
 libstore_la_SOURCES = \
   store-api.cc local-store.cc remote-store.cc derivations.cc build.cc misc.cc \
-  globals.cc db.cc references.cc pathlocks.cc gc.cc upgrade-schema.cc \
+  globals.cc references.cc pathlocks.cc gc.cc \
   optimise-store.cc
 
 pkginclude_HEADERS = \
   store-api.hh local-store.hh remote-store.hh derivations.hh misc.hh \
-  globals.hh db.hh references.hh pathlocks.hh \
+  globals.hh references.hh pathlocks.hh \
   worker-protocol.hh
 
-libstore_la_LIBADD = ../libutil/libutil.la ../boost/format/libformat.la
-
-BUILT_SOURCES = derivations-ast.cc derivations-ast.hh
-
-EXTRA_DIST = derivations-ast.def derivations-ast.cc
+libstore_la_LIBADD = ../libutil/libutil.la ../boost/format/libformat.la @ADDITIONAL_NETWORK_LIBS@
 
 AM_CXXFLAGS = -Wall \
- -I$(srcdir)/.. ${bdb_include} ${aterm_include} -I$(srcdir)/../libutil
-
-derivations-ast.cc derivations-ast.hh: ../aterm-helper.pl derivations-ast.def
-	$(perl) $(srcdir)/../aterm-helper.pl derivations-ast.hh derivations-ast.cc < $(srcdir)/derivations-ast.def
+ -I$(srcdir)/.. -I$(srcdir)/../libutil

src/libstore/db.cc

@@ -1,474 +0,0 @@
-#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

@@ -1,107 +0,0 @@
-#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

@@ -1,10 +0,0 @@
-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

@@ -1,164 +1,167 @@
 #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());
-    for (DerivationInputs::const_iterator i = drv.inputDrvs.begin();
-         i != drv.inputDrvs.end(); ++i)
+    foreach (DerivationInputs::const_iterator, i, drv.inputDrvs)
         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 = atPrint(unparseDerivation(drv));
+    string contents = unparseDerivation(drv);
     return readOnlyMode
         ? computeStorePathForText(suffix, contents, references)
         : store->addTextToStore(suffix, contents, references);
 }
 
 
-static void checkPath(const string & s)
+static Path parsePath(std::istream & str)
 {
+    string s = parseString(str);
     if (s.size() == 0 || s[0] != '/')
         throw Error(format("bad path `%1%' in derivation") % s);
+    return s;
 }
     
 
-static void parseStrings(ATermList paths, StringSet & out, bool arePaths)
+static StringSet parseStrings(std::istream & str, bool arePaths)
 {
-    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);
-    }
+    StringSet res;
+    while (!endOfList(str))
+        res.insert(arePaths ? parsePath(str) : parseString(str));
+    return res;
 }
+    
 
-
-/* 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 parseDerivation(const string & s)
 {
     Derivation drv;
-    ATermList outs, inDrvs, inSrcs, args, bnds;
-    ATerm builder, platform;
+    std::istringstream str(s);
+    expect(str, "Derive([");
 
-    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);
+    /* Parse the list of outputs. */
+    while (!endOfList(str)) {
         DerivationOutput out;
-        out.path = aterm2String(path);
-        checkPath(out.path);
-        out.hashAlgo = aterm2String(hashAlgo);
-        out.hash = aterm2String(hash);
-        drv.outputs[aterm2String(id)] = 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;
     }
 
-    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;
+    /* 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;
     }
     
-    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);
-    }
-
+    expect(str, ")");
     return drv;
 }
 
 
-ATerm unparseDerivation(const Derivation & drv)
+static void printString(string & res, const string & s)
 {
-    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)));
+    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 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)));
+
+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 args = ATempty;
-    for (Strings::const_reverse_iterator i = drv.args.rbegin();
-         i != drv.args.rend(); ++i)
-        args = ATinsert(args, toATerm(*i));
+    s += ','; printString(s, drv.platform);
+    s += ','; printString(s, drv.builder);
+    s += ','; printStrings(s, drv.args.begin(), drv.args.end());
 
-    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);
+    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;
 }
 
 

src/libstore/derivations.hh

@@ -1,8 +1,6 @@
 #ifndef __DERIVATIONS_H
 #define __DERIVATIONS_H
 
-typedef struct _ATerm * ATerm;
-
 #include "hash.hh"
 
 #include <map>
@@ -53,17 +51,14 @@ 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(ATerm t);
+Derivation parseDerivation(const string & s);
 
-/* Parse a derivation. */
-ATerm unparseDerivation(const Derivation & drv);
+/* Print a derivation. */
+string unparseDerivation(const Derivation & drv);
 
 /* Check whether a file name ends with the extensions for
    derivations. */

src/libstore/gc.cc

@@ -7,6 +7,7 @@
 
 #include <functional>
 #include <queue>
+#include <algorithm>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -14,11 +15,6 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#ifdef __CYGWIN__
-#include <windows.h>
-#include <sys/cygwin.h>
-#endif
-
 
 namespace nix {
 
@@ -178,15 +174,6 @@ 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);
 
@@ -200,10 +187,6 @@ 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
         }
 
     }
@@ -216,14 +199,9 @@ 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
 }
 
 
@@ -247,25 +225,10 @@ static void readTempRoots(PathSet & tempRoots, FDs & fds)
     Strings tempRootFiles = readDirectory(
         (format("%1%/%2%") % nixStateDir % tempRootsDir).str());
 
-    for (Strings::iterator i = tempRootFiles.begin();
-         i != tempRootFiles.end(); ++i)
-    {
+    foreach (Strings::iterator, i, tempRootFiles) {
         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. */
@@ -277,7 +240,6 @@ 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. */
@@ -288,7 +250,6 @@ 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
@@ -328,7 +289,7 @@ static void findRoots(const Path & path, bool recurseSymlinks,
 
         if (S_ISDIR(st.st_mode)) {
             Strings names = readDirectory(path);
-            for (Strings::iterator i = names.begin(); i != names.end(); ++i)
+            foreach (Strings::iterator, i, names)
                 findRoots(path + "/" + *i, recurseSymlinks, deleteStale, roots);
         }
 
@@ -399,11 +360,11 @@ static void addAdditionalRoots(PathSet & roots)
 
     Strings paths = tokenizeString(result, "\n");
     
-    for (Strings::iterator i = paths.begin(); i != paths.end(); ++i) {
+    foreach (Strings::iterator, i, paths) {
         if (isInStore(*i)) {
             Path path = toStorePath(*i);
             if (roots.find(path) == roots.end() && store->isValidPath(path)) {
-                debug(format("found additional root `%1%'") % path);
+                debug(format("got additional root `%1%'") % path);
                 roots.insert(path);
             }
         }
@@ -421,8 +382,7 @@ static void dfsVisit(const PathSet & paths, const Path & path,
     if (store->isValidPath(path))
         store->queryReferences(path, references);
     
-    for (PathSet::iterator i = references.begin();
-         i != references.end(); ++i)
+    foreach (PathSet::iterator, i, references)
         /* 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())
@@ -436,156 +396,224 @@ Paths topoSortPaths(const PathSet & paths)
 {
     Paths sorted;
     PathSet visited;
-    for (PathSet::const_iterator i = paths.begin(); i != paths.end(); ++i)
+    foreach (PathSet::const_iterator, i, paths)
         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 { };
 
 
-void LocalStore::gcPath(const GCOptions & options, GCResults & results, 
-    const Path & path)
+struct LocalStore::GCState
 {
-    results.paths.insert(path);
+    GCOptions options;
+    GCResults & results;
+    PathSet roots;
+    PathSet tempRoots;
+    PathSet deleted;
+    PathSet live;
+    PathSet busy;
+    bool gcKeepOutputs;
+    bool gcKeepDerivations;
 
-    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
+    bool drvsIndexed;
+    typedef std::multimap<string, Path> DrvsByName;
+    DrvsByName drvsByName; // derivation paths hashed by name attribute
 
-    /* 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)
+    GCState(GCResults & results_) : results(results_), drvsIndexed(false)
     {
-        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);
     }
 };
 
 
-string showTime(const string & format, time_t t)
+static bool doDelete(GCOptions::GCAction action)
 {
-    char s[128];
-    strftime(s, sizeof s, format.c_str(), localtime(&t));
-    return string(s);
+    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();
+}
+
+
+/* Return all the derivations in the Nix store that have `path' as an
+   output.  This function assumes that derivations have the same name
+   as their outputs. */
+PathSet LocalStore::findDerivers(GCState & state, const Path & path)
+{
+    PathSet derivers;
+
+    Path deriver = queryDeriver(path);
+    if (deriver != "") derivers.insert(deriver);
+
+    if (!state.drvsIndexed) {
+        Paths entries = readDirectory(nixStore);
+        foreach (Paths::iterator, i, entries)
+            if (isDerivation(*i))
+                state.drvsByName.insert(std::pair<string, Path>(
+                        getNameOfStorePath(*i), nixStore + "/" + *i));
+        state.drvsIndexed = true;
+    }
+    
+    string name = getNameOfStorePath(path);
+
+    // Urgh, I should have used Haskell...
+    std::pair<GCState::DrvsByName::iterator, GCState::DrvsByName::iterator> range =
+        state.drvsByName.equal_range(name);
+
+    for (GCState::DrvsByName::iterator i = range.first; i != range.second; ++i)
+        if (isValidPath(i->second)) {
+            Derivation drv = derivationFromPath(i->second);
+            foreach (DerivationOutputs::iterator, j, drv.outputs)
+                if (j->second.path == path) derivers.insert(i->second);
+        }
+
+    return derivers;
+}
+
+    
+bool LocalStore::tryToDelete(GCState & state, const Path & path)
+{
+    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)) {
+            Derivation drv = derivationFromPath(path);
+            foreach (DerivationOutputs::iterator, i, drv.outputs)
+                if (!tryToDelete(state, i->second.path)) {
+                    printMsg(lvlDebug, format("cannot delete derivation `%1%' because its output is alive") % path);
+                    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
+           its deriver is not garbage.  !!! Nix does not reliably
+           store derivers, so we have to look at all derivations to
+           determine which of them derive `path'.  Since this makes
+           the garbage collector very slow to start on large Nix
+           stores, here we just look for all derivations that have the
+           same name as `path' (where the name is the part of the
+           filename after the hash, i.e. the `name' attribute of the
+           derivation).  This is somewhat hacky: currently, the
+           deriver of a path always has the same name as the output,
+           but this might change in the future. */
+        if (state.gcKeepOutputs) {
+            PathSet derivers = findDerivers(state, 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 (doDelete(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;
 }
 
 
 void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
 {
-    bool gcKeepOutputs =
-        queryBoolSetting("gc-keep-outputs", false);
-    bool gcKeepDerivations =
-        queryBoolSetting("gc-keep-derivations", true);
-    int gcKeepOutputsThreshold = 
-        queryIntSetting ("gc-keep-outputs-threshold", defaultGcLevel);
-
+    GCState state(results);
+    state.options = options;    
+    
+    state.gcKeepOutputs = queryBoolSetting("gc-keep-outputs", false);
+    state.gcKeepDerivations = queryBoolSetting("gc-keep-derivations", true);
+    
     /* Acquire the global GC root.  This prevents
        a) New roots from being added.
        b) Processes from creating new temporary root files. */
@@ -596,207 +624,60 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
     printMsg(lvlError, format("finding garbage collector roots..."));
     Roots rootMap = options.ignoreLiveness ? Roots() : nix::findRoots(true);
 
-    PathSet roots;
-    for (Roots::iterator i = rootMap.begin(); i != rootMap.end(); ++i)
-        roots.insert(i->second);
+    foreach (Roots::iterator, i, rootMap) state.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(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;
-    }
+        addAdditionalRoots(state.roots);
 
     /* 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(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);
+    readTempRoots(state.tempRoots, fds);
+    state.roots.insert(state.tempRoots.begin(), state.tempRoots.end());
 
     /* After this point the set of roots or temporary roots cannot
        increase, since we hold locks on everything.  So everything
-       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);
-        }
-    }
+       that is not reachable from `roots'. */
+
+    /* Now either delete all garbage paths, or just the specified
+       paths (for gcDeleteSpecific). */
+
+    if (options.action == GCOptions::gcDeleteSpecific) {
 
-    else {
         foreach (PathSet::iterator, i, options.pathsToDelete) {
             assertStorePath(*i);
-            storePaths.insert(*i);
-            if (livePaths.find(*i) != livePaths.end())
+            if (!tryToDelete(state, *i))
                 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);
-        }
-    }
-
-    if (options.action == GCOptions::gcReturnDead) {
-        results.paths.insert(storePaths.begin(), storePaths.end());
-        return;
-    }
-
-    /* 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..."));
-            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) {
-    }
+    } 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 (doDelete(state.options.action))
+            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) {
+        }
+    }        
 }
 
 

src/libstore/globals.cc

@@ -16,7 +16,6 @@ string nixDBPath = "/UNINIT";
 string nixConfDir = "/UNINIT";
 string nixLibexecDir = "/UNINIT";
 string nixBinDir = "/UNINIT";
-string nixChrootsDir = "/UNINIT";
 
 bool keepFailed = false;
 bool keepGoing = false;
@@ -25,7 +24,7 @@ Verbosity buildVerbosity = lvlInfo;
 unsigned int maxBuildJobs = 1;
 bool readOnlyMode = false;
 string thisSystem = "unset";
-unsigned int maxSilentTime = 0;
+time_t maxSilentTime = 0;
 Paths substituters;
 bool useBuildHook = true;
 bool printBuildTrace = false;
@@ -35,6 +34,9 @@ static bool settingsRead = false;
 
 static std::map<string, Strings> settings;
 
+/* Overriden settings. */
+std::map<string, Strings> settingsCmdline;
+
 
 string & at(Strings & ss, unsigned int n)
 {
@@ -74,6 +76,8 @@ static void readSettings()
         advance(i, 2);
         settings[name] = Strings(i, tokens.end());
     };
+
+    settings.insert(settingsCmdline.begin(), settingsCmdline.end());
     
     settingsRead = true;
 }
@@ -119,6 +123,13 @@ unsigned int queryIntSetting(const string & name, unsigned int def)
 }
 
 
+void overrideSetting(const string & name, const Strings & value)
+{
+    if (settingsRead) settings[name] = value;
+    settingsCmdline[name] = value;
+}
+
+
 void reloadSettings()
 {
     settingsRead = false;

src/libstore/globals.hh

@@ -35,12 +35,6 @@ extern string nixLibexecDir;
 /* nixBinDir is the directory where the main programs are stored. */
 extern string nixBinDir;
 
-/* nixChrootsDir is the directory where we create chroot environments
-   (when chroot builds are enabled).  We don't put these under /tmp to
-   prevent "rm -rf /tmp" from recursing into /nix/store via the bind
-   mounts in the chroots. */
-extern string nixChrootsDir;
-
 
 /* Misc. global flags. */
 
@@ -71,7 +65,7 @@ extern string thisSystem;
 /* The maximum time in seconds that a builer can go without producing
    any output on stdout/stderr before it is killed.  0 means
    infinity. */
-extern unsigned int maxSilentTime;
+extern time_t maxSilentTime;
 
 /* The substituters.  There are programs that can somehow realise a
    store path without building, e.g., by downloading it or copying it
@@ -107,6 +101,8 @@ bool queryBoolSetting(const string & name, bool def);
 
 unsigned int queryIntSetting(const string & name, unsigned int def);
 
+void overrideSetting(const string & name, const Strings & value);
+
 void reloadSettings();
 
     

src/libstore/local-store.cc

@@ -3,8 +3,6 @@
 #include "globals.hh"
 #include "archive.hh"
 #include "pathlocks.hh"
-#include "aterm.hh"
-#include "derivations-ast.hh"
 #include "worker-protocol.hh"
     
 #include <iostream>
@@ -16,6 +14,7 @@
 #include <utime.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <stdio.h>
 
 
 namespace nix {
@@ -47,6 +46,21 @@ LocalStore::LocalStore()
     
     if (readOnlyMode) return;
 
+    /* Create missing state directories if they don't already exist. */
+    createDirs(nixStore);
+    createDirs(nixDBPath + "/info");
+    createDirs(nixDBPath + "/referrer");
+    createDirs(nixDBPath + "/failed");
+    Path profilesDir = nixStateDir + "/profiles";
+    createDirs(nixStateDir + "/profiles");
+    createDirs(nixStateDir + "/temproots");
+    Path gcRootsDir = nixStateDir + "/gcroots";
+    if (!pathExists(gcRootsDir)) {
+        createDirs(gcRootsDir);
+        if (symlink(profilesDir.c_str(), (gcRootsDir + "/profiles").c_str()) == -1)
+            throw SysError(format("creating symlink to `%1%'") % profilesDir);
+    }
+  
     checkStoreNotSymlink();
 
     try {
@@ -62,10 +76,7 @@ LocalStore::LocalStore()
         printMsg(lvlError, "waiting for the big Nix store lock...");
         lockFile(globalLock, ltRead, true);
     }
-
-    createDirs(nixDBPath + "/info");
-    createDirs(nixDBPath + "/referrer");
-
+    
     int curSchema = getSchema();
     if (curSchema > nixSchemaVersion)
         throw Error(format("current Nix store schema is version %1%, but I only support %2%")
@@ -76,6 +87,8 @@ LocalStore::LocalStore()
     }
     if (curSchema == 1) throw Error("your Nix store is no longer supported");
     if (curSchema < nixSchemaVersion) upgradeStore12();
+
+    doFsync = queryBoolSetting("fsync-metadata", false);
 }
 
 
@@ -85,8 +98,8 @@ LocalStore::~LocalStore()
         flushDelayedUpdates();
 
         foreach (RunningSubstituters::iterator, i, runningSubstituters) {
-            i->second.toBuf.reset();
-            i->second.to.reset();
+            i->second.to.close();
+            i->second.from.close();
             i->second.pid.wait(true);
         }
                 
@@ -108,23 +121,6 @@ int LocalStore::getSchema()
 }
 
 
-void copyPath(const Path & src, const Path & dst, PathFilter & filter)
-{
-    debug(format("copying `%1%' to `%2%'") % src % dst);
-
-    /* Dump an archive of the path `src' into a string buffer, then
-       restore the archive to `dst'.  This is not a very good method
-       for very large paths, but `copyPath' is mainly used for small
-       files. */ 
-
-    StringSink sink;
-    dumpPath(src, sink, filter);
-
-    StringSource source(sink.s);
-    restorePath(dst, source);
-}
-
-
 void canonicalisePathMetaData(const Path & path, bool recurse)
 {
     checkInterrupt();
@@ -167,7 +163,7 @@ void canonicalisePathMetaData(const Path & path, bool recurse)
         if (st.st_mtime != 0) {
             struct utimbuf utimbuf;
             utimbuf.actime = st.st_atime;
-            utimbuf.modtime = 0;
+            utimbuf.modtime = 1; /* 1 second into the epoch */
             if (utime(path.c_str(), &utimbuf) == -1) 
                 throw SysError(format("changing modification time of `%1%'") % path);
         }
@@ -176,7 +172,7 @@ void canonicalisePathMetaData(const Path & path, bool recurse)
 
     if (recurse && S_ISDIR(st.st_mode)) {
         Strings names = readDirectory(path);
-	for (Strings::iterator i = names.begin(); i != names.end(); ++i)
+	foreach (Strings::iterator, i, names)
 	    canonicalisePathMetaData(path + "/" + *i, true);
     }
 }
@@ -213,13 +209,20 @@ static Path referrersFileFor(const Path & path)
 }
 
 
+static Path failedFileFor(const Path & path)
+{
+    string baseName = baseNameOf(path);
+    return (format("%1%/failed/%2%") % nixDBPath % baseName).str();
+}
+
+
 static Path tmpFileForAtomicUpdate(const Path & path)
 {
     return (format("%1%/.%2%.%3%") % dirOf(path) % getpid() % baseNameOf(path)).str();
 }
 
 
-static void appendReferrer(const Path & from, const Path & to, bool lock)
+void LocalStore::appendReferrer(const Path & from, const Path & to, bool lock)
 {
     Path referrersFile = referrersFileFor(from);
     
@@ -234,6 +237,8 @@ static void appendReferrer(const Path & from, const Path & to, bool lock)
     
     string s = " " + to;
     writeFull(fd, (const unsigned char *) s.c_str(), s.size());
+
+    if (doFsync) fsync(fd);
 }
 
 
@@ -264,6 +269,8 @@ void LocalStore::rewriteReferrers(const Path & path, bool purge, PathSet referre
     
     writeFull(fd, (const unsigned char *) s.c_str(), s.size());
 
+    if (doFsync) fsync(fd);
+    
     fd.close(); /* for Windows; can't rename open file */
 
     if (rename(tmpFile.c_str(), referrersFile.c_str()) == -1)
@@ -332,6 +339,8 @@ void LocalStore::registerValidPath(const ValidPathInfo & info, bool ignoreValidi
             appendReferrer(*i, info.path, false);
     }
 
+    assert(info.hash.type == htSHA256);
+
     string s = (format(
         "Hash: sha256:%1%\n"
         "References: %2%\n"
@@ -342,7 +351,7 @@ void LocalStore::registerValidPath(const ValidPathInfo & info, bool ignoreValidi
 
     /* Atomically rewrite the info file. */
     Path tmpFile = tmpFileForAtomicUpdate(infoFile);
-    writeFile(tmpFile, s);
+    writeFile(tmpFile, s, doFsync);
     if (rename(tmpFile.c_str(), infoFile.c_str()) == -1)
         throw SysError(format("cannot rename `%1%' to `%2%'") % tmpFile % infoFile);
 
@@ -350,6 +359,20 @@ void LocalStore::registerValidPath(const ValidPathInfo & info, bool ignoreValidi
 }
 
 
+void LocalStore::registerFailedPath(const Path & path)
+{
+    /* Write an empty file in the .../failed directory to denote the
+       failure of the builder for `path'. */
+    writeFile(failedFileFor(path), "");
+}
+
+
+bool LocalStore::hasPathFailed(const Path & path)
+{
+    return pathExists(failedFileFor(path));
+}
+
+
 Hash parseHashField(const Path & path, const string & s)
 {
     string::size_type colon = s.find(':');
@@ -364,13 +387,16 @@ Hash parseHashField(const Path & path, const string & s)
 }
 
 
-ValidPathInfo LocalStore::queryPathInfo(const Path & path)
+ValidPathInfo LocalStore::queryPathInfo(const Path & path, bool ignoreErrors)
 {
     ValidPathInfo res;
     res.path = path;
 
     assertStorePath(path);
 
+    if (!isValidPath(path))
+        throw Error(format("path `%1%' is not valid") % path);
+
     std::map<Path, ValidPathInfo>::iterator lookup = pathInfoCache.find(path);
     if (lookup != pathInfoCache.end()) return lookup->second;
     
@@ -383,9 +409,13 @@ ValidPathInfo LocalStore::queryPathInfo(const Path & path)
     /* Parse it. */
     Strings lines = tokenizeString(info, "\n");
 
-    for (Strings::iterator i = lines.begin(); i != lines.end(); ++i) {
-        unsigned int p = i->find(':');
-        if (p == string::npos) continue; /* bad line */
+    foreach (Strings::iterator, i, lines) {
+        string::size_type p = i->find(':');
+        if (p == string::npos) {
+            if (!ignoreErrors)
+                throw Error(format("corrupt line in `%1%': %2%") % infoFile % *i);
+            continue; /* bad line */
+        }
         string name(*i, 0, p);
         string value(*i, p + 2);
         if (name == "References") {
@@ -394,7 +424,12 @@ ValidPathInfo LocalStore::queryPathInfo(const Path & path)
         } else if (name == "Deriver") {
             res.deriver = value;
         } else if (name == "Hash") {
-            res.hash = parseHashField(path, value);
+            try {
+                res.hash = parseHashField(path, value);
+            } catch (Error & e) {
+                if (!ignoreErrors) throw;
+                printMsg(lvlError, format("cannot parse hash field in `%1%': %2%") % infoFile % e.msg());
+            }
         } else if (name == "Registered-At") {
             int n = 0;
             string2Int(value, n);
@@ -411,7 +446,22 @@ bool LocalStore::isValidPath(const Path & path)
     /* Files in the info directory starting with a `.' are temporary
        files. */
     if (baseNameOf(path).at(0) == '.') return false;
-    return pathExists(infoFileFor(path));
+
+    /* A path is valid if its info file exists and has a non-zero
+       size.  (The non-zero size restriction is to be robust to
+       certain kinds of filesystem corruption, particularly with
+       ext4.) */
+    Path infoFile = infoFileFor(path);
+
+    struct stat st;
+    if (lstat(infoFile.c_str(), &st)) {
+        if (errno == ENOENT) return false;
+        throw SysError(format("getting status of `%1%'") % infoFile);
+    }
+
+    if (st.st_size == 0) return false;
+    
+    return true;
 }
 
 
@@ -419,7 +469,7 @@ PathSet LocalStore::queryValidPaths()
 {
     PathSet paths;
     Strings entries = readDirectory(nixDBPath + "/info");
-    for (Strings::iterator i = entries.begin(); i != entries.end(); ++i)
+    foreach (Strings::iterator, i, entries)
         if (i->at(0) != '.') paths.insert(nixStore + "/" + *i);
     return paths;
 }
@@ -454,7 +504,7 @@ bool LocalStore::queryReferrersInternal(const Path & path, PathSet & referrers)
 
     Paths refs = tokenizeString(readFile(fd), " ");
 
-    for (Paths::iterator i = refs.begin(); i != refs.end(); ++i)
+    foreach (Paths::iterator, i, refs)
         /* Referrers can be invalid (see registerValidPath() for the
            invariant), so we only return one if it is valid. */
         if (isStorePath(*i) && isValidPath(*i)) referrers.insert(*i); else allValid = false;
@@ -495,6 +545,13 @@ void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter &
 
     case 0: /* child */
         try {
+            /* Hack to let "make check" succeed on Darwin.  The
+               libtool wrapper script sets DYLD_LIBRARY_PATH to our
+               libutil (among others), but Perl also depends on a
+               library named libutil.  As a result, substituters
+               written in Perl (i.e. all of them) fail. */
+            unsetenv("DYLD_LIBRARY_PATH");
+            
             fromPipe.readSide.close();
             toPipe.writeSide.close();
             if (dup2(toPipe.readSide, STDIN_FILENO) == -1)
@@ -512,23 +569,16 @@ void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter &
 
     /* Parent. */
     
-    toPipe.readSide.close();
-    fromPipe.writeSide.close();
-
-    run.toBuf = boost::shared_ptr<stdio_filebuf>(new stdio_filebuf(toPipe.writeSide.borrow(), std::ios_base::out));
-    run.to = boost::shared_ptr<std::ostream>(new std::ostream(&*run.toBuf));
-
-    run.fromBuf = boost::shared_ptr<stdio_filebuf>(new stdio_filebuf(fromPipe.readSide.borrow(), std::ios_base::in));
-    run.from = boost::shared_ptr<std::istream>(new std::istream(&*run.fromBuf));
+    run.to = toPipe.writeSide.borrow();
+    run.from = fromPipe.readSide.borrow();
 }
 
 
-template<class T> T getIntLine(std::istream & str)
+template<class T> T getIntLine(int fd)
 {
-    string s;
+    string s = readLine(fd);
     T res;
-    getline(str, s);
-    if (!str || !string2Int(s, res)) throw Error("integer expected from stream");
+    if (!string2Int(s, res)) throw Error("integer expected from stream");
     return res;
 }
 
@@ -538,10 +588,8 @@ bool LocalStore::hasSubstitutes(const Path & path)
     foreach (Paths::iterator, i, substituters) {
         RunningSubstituter & run(runningSubstituters[*i]);
         startSubstituter(*i, run);
-
-        *run.to << "have\n" << path << "\n" << std::flush;
-
-        if (getIntLine<int>(*run.from)) return true;
+        writeLine(run.to, "have\n" + path);
+        if (getIntLine<int>(run.from)) return true;
     }
 
     return false;
@@ -554,19 +602,19 @@ bool LocalStore::querySubstitutablePathInfo(const Path & substituter,
     RunningSubstituter & run(runningSubstituters[substituter]);
     startSubstituter(substituter, run);
 
-    *run.to << "info\n" << path << "\n" << std::flush;
-        
-    if (!getIntLine<int>(*run.from)) return false;
+    writeLine(run.to, "info\n" + path);
+
+    if (!getIntLine<int>(run.from)) return false;
     
-    getline(*run.from, info.deriver);
+    info.deriver = readLine(run.from);
     if (info.deriver != "") assertStorePath(info.deriver);
-    int nrRefs = getIntLine<int>(*run.from);
+    int nrRefs = getIntLine<int>(run.from);
     while (nrRefs--) {
-        Path p; getline(*run.from, p);
+        Path p = readLine(run.from);
         assertStorePath(p);
         info.references.insert(p);
     }
-    info.downloadSize = getIntLine<long long>(*run.from);
+    info.downloadSize = getIntLine<long long>(run.from);
     
     return true;
 }
@@ -595,8 +643,7 @@ static void dfsVisit(std::map<Path, ValidPathInfo> & infos,
 
     ValidPathInfo & info(infos[path]);
     
-    for (PathSet::iterator i = info.references.begin();
-         i != info.references.end(); ++i)
+    foreach (PathSet::iterator, i, info.references)
         if (infos.find(*i) != infos.end())
             dfsVisit(infos, *i, visited, sorted);
 
@@ -611,15 +658,15 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
     /* Sort the paths topologically under the references relation, so
        that if path A is referenced by B, then A is registered before
        B. */
-    for (ValidPathInfos::const_iterator i = infos.begin(); i != infos.end(); ++i)
+    foreach (ValidPathInfos::const_iterator, i, infos)
         infosMap[i->path] = *i;
 
     PathSet visited;
     Paths sorted;
-    for (ValidPathInfos::const_iterator i = infos.begin(); i != infos.end(); ++i)
+    foreach (ValidPathInfos::const_iterator, i, infos)
         dfsVisit(infosMap, i->path, visited, sorted);
 
-    for (Paths::iterator i = sorted.begin(); i != sorted.end(); ++i)
+    foreach (Paths::iterator, i, sorted)
         registerValidPath(infosMap[*i]);
 }
 
@@ -670,16 +717,12 @@ void LocalStore::invalidatePath(const Path & path)
 }
 
 
-Path LocalStore::addToStore(const Path & _srcPath, bool fixed,
-    bool recursive, string hashAlgo, PathFilter & filter)
+Path LocalStore::addToStoreFromDump(const string & dump, const string & name,
+    bool recursive, HashType hashAlgo)
 {
-    Path srcPath(absPath(_srcPath));
-    debug(format("adding `%1%' to the store") % srcPath);
+    Hash h = hashString(hashAlgo, dump);
 
-    std::pair<Path, Hash> pr =
-        computeStorePathForPath(srcPath, fixed, recursive, hashAlgo, filter);
-    Path & dstPath(pr.first);
-    Hash & h(pr.second);
+    Path dstPath = makeFixedOutputPath(recursive, hashAlgo, h, name);
 
     addTempRoot(dstPath);
 
@@ -694,16 +737,22 @@ Path LocalStore::addToStore(const Path & _srcPath, bool fixed,
 
             if (pathExists(dstPath)) deletePathWrapped(dstPath);
 
-            copyPath(srcPath, dstPath, filter);
-
-            Hash h2 = hashPath(htSHA256, dstPath, filter);
-            if (h != h2)
-                throw Error(format("contents of `%1%' changed while copying it to `%2%' (%3% -> %4%)")
-                    % srcPath % dstPath % printHash(h) % printHash(h2));
+            if (recursive) {
+                StringSource source(dump);
+                restorePath(dstPath, source);
+            } else
+                writeFile(dstPath, dump);
 
             canonicalisePathMetaData(dstPath);
-            
-            registerValidPath(dstPath, h, PathSet(), "");
+
+            /* Register the SHA-256 hash of the NAR serialisation of
+               the path in the database.  We may just have computed it
+               above (if called with recursive == true and hashAlgo ==
+               sha256); otherwise, compute it here. */
+            registerValidPath(dstPath,
+                (recursive && hashAlgo == htSHA256) ? h :
+                (recursive ? hashString(htSHA256, dump) : hashPath(htSHA256, dstPath)),
+                PathSet(), "");
         }
 
         outputLock.setDeletion(true);
@@ -713,10 +762,29 @@ Path LocalStore::addToStore(const Path & _srcPath, bool fixed,
 }
 
 
-Path LocalStore::addTextToStore(const string & suffix, const string & s,
+Path LocalStore::addToStore(const Path & _srcPath,
+    bool recursive, HashType hashAlgo, PathFilter & filter)
+{
+    Path srcPath(absPath(_srcPath));
+    debug(format("adding `%1%' to the store") % srcPath);
+
+    /* Read the whole path into memory. This is not a very scalable
+       method for very large paths, but `copyPath' is mainly used for
+       small files. */
+    StringSink sink;
+    if (recursive) 
+        dumpPath(srcPath, sink, filter);
+    else
+        sink.s = readFile(srcPath);
+
+    return addToStoreFromDump(sink.s, baseNameOf(srcPath), recursive, hashAlgo);
+}
+
+
+Path LocalStore::addTextToStore(const string & name, const string & s,
     const PathSet & references)
 {
-    Path dstPath = computeStorePathForText(suffix, s, references);
+    Path dstPath = computeStorePathForText(name, s, references);
     
     addTempRoot(dstPath);
 
@@ -728,7 +796,7 @@ Path LocalStore::addTextToStore(const string & suffix, const string & s,
 
             if (pathExists(dstPath)) deletePathWrapped(dstPath);
 
-            writeStringToFile(dstPath, s);
+            writeFile(dstPath, s);
 
             canonicalisePathMetaData(dstPath);
             
@@ -807,7 +875,7 @@ void LocalStore::exportPath(const Path & path, bool sign,
         Path tmpDir = createTempDir();
         AutoDelete delTmp(tmpDir);
         Path hashFile = tmpDir + "/hash";
-        writeStringToFile(hashFile, printHash(hash));
+        writeFile(hashFile, printHash(hash));
 
         Path secretKey = nixConfDir + "/signing-key.sec";
         checkSecrecy(secretKey);
@@ -854,7 +922,7 @@ Path LocalStore::importPath(bool requireSignature, Source & source)
        store path follows the archive data proper), and besides, we
        don't know yet whether the signature is valid. */
     Path tmpDir = createTempDir(nixStore);
-    AutoDelete delTmp(tmpDir);
+    AutoDelete delTmp(tmpDir); /* !!! could be GC'ed! */
     Path unpacked = tmpDir + "/unpacked";
 
     restorePath(unpacked, hashAndReadSource);
@@ -883,7 +951,7 @@ Path LocalStore::importPath(bool requireSignature, Source & source)
 
         if (requireSignature) {
             Path sigFile = tmpDir + "/sig";
-            writeStringToFile(sigFile, signature);
+            writeFile(sigFile, signature);
 
             Strings args;
             args.push_back("rsautl");
@@ -913,7 +981,14 @@ Path LocalStore::importPath(bool requireSignature, Source & source)
 
     if (!isValidPath(dstPath)) {
 
-        PathLocks outputLock(singleton<PathSet, Path>(dstPath));
+        PathLocks outputLock;
+
+        /* Lock the output path.  But don't lock if we're being called
+           from a build hook (whose parent process already acquired a
+           lock on this path). */
+        Strings locksHeld = tokenizeString(getEnv("NIX_HELD_LOCKS"));
+        if (find(locksHeld.begin(), locksHeld.end(), dstPath) == locksHeld.end())
+            outputLock.lockPaths(singleton<PathSet, Path>(dstPath));
 
         if (!isValidPath(dstPath)) {
 
@@ -971,7 +1046,7 @@ void LocalStore::verifyStore(bool checkContents)
 
     PathSet validPaths2 = queryValidPaths(), validPaths;
     
-    for (PathSet::iterator i = validPaths2.begin(); i != validPaths2.end(); ++i) {
+    foreach (PathSet::iterator, i, validPaths2) {
         checkInterrupt();
         if (!isStorePath(*i)) {
             printMsg(lvlError, format("path `%1%' is not in the Nix store") % *i);
@@ -979,8 +1054,18 @@ void LocalStore::verifyStore(bool checkContents)
         } else if (!pathExists(*i)) {
             printMsg(lvlError, format("path `%1%' disappeared") % *i);
             invalidatePath(*i);
-        } else
-            validPaths.insert(*i);
+        } else {
+            Path infoFile = infoFileFor(*i);
+            struct stat st;
+            if (lstat(infoFile.c_str(), &st))
+                throw SysError(format("getting status of `%1%'") % infoFile);
+            if (st.st_size == 0) {
+                printMsg(lvlError, format("removing corrupt info file `%1%'") % infoFile);
+                if (unlink(infoFile.c_str()) == -1)
+                    throw SysError(format("unlinking `%1%'") % infoFile);
+            }
+            else validPaths.insert(*i);
+        }
     }
 
 
@@ -989,26 +1074,25 @@ void LocalStore::verifyStore(bool checkContents)
 
     std::map<Path, PathSet> referrersCache;
     
-    for (PathSet::iterator i = validPaths.begin(); i != validPaths.end(); ++i) {
+    foreach (PathSet::iterator, i, validPaths) {
         bool update = false;
-        ValidPathInfo info = queryPathInfo(*i);
+        ValidPathInfo info = queryPathInfo(*i, true);
 
         /* Check the references: each reference should be valid, and
            it should have a matching referrer. */
-        for (PathSet::iterator j = info.references.begin();
-             j != info.references.end(); ++j)
-        {
-            if (referrersCache.find(*j) == referrersCache.end())
-                queryReferrers(*j, referrersCache[*j]);
-            if (referrersCache[*j].find(*i) == referrersCache[*j].end()) {
-                printMsg(lvlError, format("adding missing referrer mapping from `%1%' to `%2%'")
-                    % *j % *i);
-                appendReferrer(*j, *i, true);
-            }
+        foreach (PathSet::iterator, j, info.references) {
             if (validPaths.find(*j) == validPaths.end()) {
                 printMsg(lvlError, format("incomplete closure: `%1%' needs missing `%2%'")
                     % *i % *j);
                 /* nothing we can do about it... */
+            } else {
+                if (referrersCache.find(*j) == referrersCache.end())
+                    queryReferrers(*j, referrersCache[*j]);
+                if (referrersCache[*j].find(*i) == referrersCache[*j].end()) {
+                    printMsg(lvlError, format("adding missing referrer mapping from `%1%' to `%2%'")
+                        % *j % *i);
+                    appendReferrer(*j, *i, true);
+                }
             }
         }
 
@@ -1020,7 +1104,11 @@ void LocalStore::verifyStore(bool checkContents)
         }
 
         /* Check the content hash (optionally - slow). */
-        if (checkContents) {
+        if (info.hash.hashSize == 0) {
+            printMsg(lvlError, format("re-hashing `%1%'") % *i);
+            info.hash = hashPath(htSHA256, *i);
+            update = true;
+        } else if (checkContents) {
             debug(format("checking contents of `%1%'") % *i);
             Hash current = hashPath(info.hash.type, *i);
             if (current != info.hash) {
@@ -1042,10 +1130,12 @@ void LocalStore::verifyStore(bool checkContents)
     std::map<Path, PathSet> referencesCache;
     
     Strings entries = readDirectory(nixDBPath + "/referrer");
-    for (Strings::iterator i = entries.begin(); i != entries.end(); ++i) {
+    foreach (Strings::iterator, i, entries) {
         Path from = nixStore + "/" + *i;
         
         if (validPaths.find(from) == validPaths.end()) {
+            /* !!! This removes lock files as well.  Need to check
+               whether that's okay. */
             printMsg(lvlError, format("removing referrers file for invalid `%1%'") % from);
             Path p = referrersFileFor(from);
             if (unlink(p.c_str()) == -1)
@@ -1064,7 +1154,7 @@ void LocalStore::verifyStore(bool checkContents)
 
         /* Each referrer should have a matching reference. */
         PathSet referrersNew;
-        for (PathSet::iterator j = referrers.begin(); j != referrers.end(); ++j) {
+        foreach (PathSet::iterator, j, referrers) {
             if (referencesCache.find(*j) == referencesCache.end())
                 queryReferences(*j, referencesCache[*j]);
             if (referencesCache[*j].find(from) == referencesCache[*j].end()) {
@@ -1079,4 +1169,16 @@ void LocalStore::verifyStore(bool checkContents)
 }
 
 
+/* Upgrade from schema 4 (Nix 0.11) to schema 5 (Nix >= 0.12).  The
+   old schema uses Berkeley DB, the new one stores store path
+   meta-information in files. */
+void LocalStore::upgradeStore12()
+{
+    throw Error(
+        "Your Nix store has a database in Berkeley DB format,\n"
+        "which is no longer supported. To convert to the new format,\n"
+        "please upgrade Nix to version 0.12 first.");
+}
+
+
 }

src/libstore/local-store.hh

@@ -3,8 +3,6 @@
 
 #include <string>
 
-#include <ext/stdio_filebuf.h>
-
 #include "store-api.hh"
 #include "util.hh"
 
@@ -36,15 +34,10 @@ struct OptimiseStats
 };
 
 
-typedef __gnu_cxx::stdio_filebuf<char> stdio_filebuf;
-
-
 struct RunningSubstituter
 {
     Pid pid;
-    boost::shared_ptr<stdio_filebuf> toBuf, fromBuf;
-    boost::shared_ptr<std::ostream> to;
-    boost::shared_ptr<std::istream> from;
+    AutoCloseFD to, from;
 };
 
 
@@ -89,11 +82,18 @@ public:
     bool querySubstitutablePathInfo(const Path & substituter,
         const Path & path, SubstitutablePathInfo & info);
     
-    Path addToStore(const Path & srcPath, bool fixed = false,
-        bool recursive = false, string hashAlgo = "",
+    Path addToStore(const Path & srcPath,
+        bool recursive = true, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter);
 
-    Path addTextToStore(const string & suffix, const string & s,
+    /* Like addToStore(), but the contents of the path are contained
+       in `dump', which is either a NAR serialisation (if recursive ==
+       true) or simply the contents of a regular file (if recursive ==
+       false). */
+    Path addToStoreFromDump(const string & dump, const string & name,
+        bool recursive = true, HashType hashAlgo = htSHA256);
+
+    Path addTextToStore(const string & name, const string & s,
         const PathSet & references);
 
     void exportPath(const Path & path, bool sign,
@@ -137,6 +137,13 @@ public:
 
     void registerValidPaths(const ValidPathInfos & infos);
 
+    /* Register that the build of a derivation with output `path' has
+       failed. */
+    void registerFailedPath(const Path & path);
+
+    /* Query whether `path' previously failed to build. */
+    bool hasPathFailed(const Path & path);
+
 private:
 
     Path schemaPath;
@@ -151,12 +158,17 @@ private:
     /* Store paths for which the referrers file must be purged. */
     PathSet delayedUpdates;
 
+    /* Whether to do an fsync() after writing Nix metadata. */
+    bool doFsync;
+
     int getSchema();
 
     void registerValidPath(const ValidPathInfo & info, bool ignoreValidity = false);
 
-    ValidPathInfo queryPathInfo(const Path & path);
+    ValidPathInfo queryPathInfo(const Path & path, bool ignoreErrors = false);
 
+    void appendReferrer(const Path & from, const Path & to, bool lock);
+    
     void rewriteReferrers(const Path & path, bool purge, PathSet referrers);
 
     void flushDelayedUpdates();
@@ -167,24 +179,24 @@ private:
     
     void upgradeStore12();
 
-    void gcPath(const GCOptions & options, GCResults & results,
-        const Path & path);
-
-    void gcPathRecursive(const GCOptions & options,
-        GCResults & results, PathSet & done, const Path & path);
+    struct GCState;
 
+    bool tryToDelete(GCState & state, const Path & path);
+    
+    PathSet findDerivers(GCState & state, const Path & path);
+    
+    bool isActiveTempFile(const GCState & state,
+        const Path & path, const string & suffix);
+        
     void startSubstituter(const Path & substituter,
         RunningSubstituter & runningSubstituter);
 };
 
 
-/* Copy a path recursively. */
-void copyPath(const Path & src, const Path & dst);
-
 /* "Fix", or canonicalise, the meta-data of the files in a store path
    after it has been built.  In particular:
-   - the last modification date on each file is set to 0 (i.e.,
-     00:00:00 1/1/1970 UTC)
+   - the last modification date on each file is set to 1 (i.e.,
+     00:00:01 1/1/1970 UTC)
    - the permissions are set of 444 or 555 (i.e., read-only with or
      without execute permission; setuid bits etc. are cleared)
    - the owner and group are set to the Nix user and group, if we're

src/libstore/misc.cc

@@ -2,8 +2,6 @@
 #include "store-api.hh"
 #include "local-store.hh"
 
-#include <aterm2.h>
-
 
 namespace nix {
 
@@ -12,14 +10,12 @@ Derivation derivationFromPath(const Path & drvPath)
 {
     assertStorePath(drvPath);
     store->ensurePath(drvPath);
-    ATerm t = ATreadFromNamedFile(drvPath.c_str());
-    if (!t) throw Error(format("cannot read aterm from `%1%'") % drvPath);
-    return parseDerivation(t);
+    return parseDerivation(readFile(drvPath));
 }
 
 
 void computeFSClosure(const Path & storePath,
-    PathSet & paths, bool flipDirection)
+    PathSet & paths, bool flipDirection, bool includeOutputs)
 {
     if (paths.find(storePath) != paths.end()) return;
     paths.insert(storePath);
@@ -30,16 +26,21 @@ void computeFSClosure(const Path & storePath,
     else
         store->queryReferences(storePath, references);
 
-    for (PathSet::iterator i = references.begin();
-         i != references.end(); ++i)
-        computeFSClosure(*i, paths, flipDirection);
+    if (includeOutputs && isDerivation(storePath)) {
+        Derivation drv = derivationFromPath(storePath);
+        foreach (DerivationOutputs::iterator, i, drv.outputs)
+            if (store->isValidPath(i->second.path))
+                computeFSClosure(i->second.path, paths, flipDirection, true);
+    }
+
+    foreach (PathSet::iterator, i, references)
+        computeFSClosure(*i, paths, flipDirection, includeOutputs);
 }
 
 
 Path findOutput(const Derivation & drv, string id)
 {
-    for (DerivationOutputs::const_iterator i = drv.outputs.begin();
-         i != drv.outputs.end(); ++i)
+    foreach (DerivationOutputs::const_iterator, i, drv.outputs)
         if (i->first == id) return i->second.path;
     throw Error(format("derivation has no output `%1%'") % id);
 }
@@ -67,20 +68,17 @@ void queryMissing(const PathSet & targets,
             Derivation drv = derivationFromPath(p);
 
             bool mustBuild = false;
-            for (DerivationOutputs::iterator i = drv.outputs.begin();
-                 i != drv.outputs.end(); ++i)
+            foreach (DerivationOutputs::iterator, i, drv.outputs)
                 if (!store->isValidPath(i->second.path) && !store->hasSubstitutes(i->second.path))
                     mustBuild = true;
 
             if (mustBuild) {
                 willBuild.insert(p);
                 todo.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
-                for (DerivationInputs::iterator i = drv.inputDrvs.begin();
-                     i != drv.inputDrvs.end(); ++i)
+                foreach (DerivationInputs::iterator, i, drv.inputDrvs)
                     todo.insert(i->first);
             } else 
-                for (DerivationOutputs::iterator i = drv.outputs.begin();
-                     i != drv.outputs.end(); ++i)
+                foreach (DerivationOutputs::iterator, i, drv.outputs)
                     todo.insert(i->second.path);
         }
 

src/libstore/misc.hh

@@ -19,7 +19,8 @@ Derivation derivationFromPath(const Path & drvPath);
    `referrers' relation instead of the `references' relation is
    returned. */
 void computeFSClosure(const Path & storePath,
-    PathSet & paths, bool flipDirection = false);
+    PathSet & paths, bool flipDirection = false,
+    bool includeOutputs = false);
 
 /* Return the path corresponding to the output identifier `id' in the
    given derivation. */

src/libstore/optimise-store.cc

@@ -5,6 +5,7 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #include <errno.h>
+#include <stdio.h>
 
 
 namespace nix {
@@ -131,7 +132,7 @@ static void hashAndLink(bool dryRun, HashToPath & hashToPath,
 
     if (S_ISDIR(st.st_mode)) {
         Strings names = readDirectory(path);
-	for (Strings::iterator i = names.begin(); i != names.end(); ++i)
+	foreach (Strings::iterator, i, names)
 	    hashAndLink(dryRun, hashToPath, stats, path + "/" + *i);
     }
 }
@@ -143,7 +144,7 @@ void LocalStore::optimiseStore(bool dryRun, OptimiseStats & stats)
 
     PathSet paths = queryValidPaths();
 
-    for (PathSet::iterator i = paths.begin(); i != paths.end(); ++i) {
+    foreach (PathSet::iterator, i, paths) {
         addTempRoot(*i);
         if (!isValidPath(*i)) continue; /* path was GC'ed, probably */
         startNest(nest, lvlChatty, format("hashing files in `%1%'") % *i);

src/libstore/pathlocks.cc

@@ -8,11 +8,6 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
-#ifdef __CYGWIN__
-#include <windows.h>
-#include <sys/cygwin.h>
-#endif
-
 
 namespace nix {
 
@@ -21,72 +16,24 @@ int openLockFile(const Path & path, bool create)
 {
     AutoCloseFD fd;
 
-#ifdef __CYGWIN__
-    /* On Cygwin we have to open the lock file without "DELETE"
-       sharing mode; otherwise Windows will allow open lock files to
-       be deleted (which is almost but not quite what Unix does). */
-    char win32Path[MAX_PATH + 1];
-    cygwin_conv_to_full_win32_path(path.c_str(), win32Path);
-
-    SECURITY_ATTRIBUTES sa; /* required, otherwise inexplicably bad shit happens */
-    sa.nLength = sizeof sa;
-    sa.lpSecurityDescriptor = 0;
-    sa.bInheritHandle = TRUE;
-    HANDLE h = CreateFile(win32Path, GENERIC_READ | GENERIC_WRITE,
-        FILE_SHARE_READ | FILE_SHARE_WRITE, &sa, 
-        (create ? OPEN_ALWAYS : OPEN_EXISTING), 
-        FILE_ATTRIBUTE_NORMAL, 0);
-    if (h == INVALID_HANDLE_VALUE) {
-        if (create || GetLastError() != ERROR_FILE_NOT_FOUND)
-            throw Error(format("opening lock file `%1%'") % path);
-        fd = -1;
-    }
-    else
-        fd = cygwin_attach_handle_to_fd((char *) path.c_str(), -1, h, 1, O_RDWR);
-#else        
     fd = open(path.c_str(), O_RDWR | (create ? O_CREAT : 0), 0666);
     if (fd == -1 && (create || errno != ENOENT))
         throw SysError(format("opening lock file `%1%'") % path);
-#endif
 
     return fd.borrow();
 }
 
 
-void deleteLockFilePreClose(const Path & path, int fd)
+void deleteLockFile(const Path & path, int fd)
 {
-#ifndef __CYGWIN__
     /* Get rid of the lock file.  Have to be careful not to introduce
-       races. */
-    /* On Unix, write a (meaningless) token to the file to indicate to
+       races.  Write a (meaningless) token to the file to indicate to
        other processes waiting on this lock that the lock is stale
        (deleted). */
     unlink(path.c_str());
     writeFull(fd, (const unsigned char *) "d", 1);
     /* Note that the result of unlink() is ignored; removing the lock
        file is an optimisation, not a necessity. */
-#endif
-}
-
-
-void deleteLockFilePostClose(const Path & path)
-{
-#ifdef __CYGWIN__
-    /* On Windows, just try to delete the lock file.  This will fail
-       if anybody still has the file open.  We cannot use unlink()
-       here, because Cygwin emulates Unix semantics of allowing an
-       open file to be deleted (but fakes it - the file isn't actually
-       deleted until later, so a file with the same name cannot be
-       created in the meantime). */
-    char win32Path[MAX_PATH + 1];
-    cygwin_conv_to_full_win32_path(path.c_str(), win32Path);
-    if (DeleteFile(win32Path))
-        debug(format("delete of `%1%' succeeded") % path.c_str());
-    else
-        /* Not an error: probably means that the lock is still opened
-           by someone else. */
-        debug(format("delete of `%1%' failed: %2%") % path.c_str() % GetLastError());
-#endif
 }
 
 
@@ -141,9 +88,9 @@ PathLocks::PathLocks(const PathSet & paths, const string & waitMsg)
 }
 
 
-void PathLocks::lockPaths(const PathSet & _paths, const string & waitMsg)
+bool PathLocks::lockPaths(const PathSet & _paths,
+    const string & waitMsg, bool wait)
 {
-    /* May be called only once! */
     assert(fds.empty());
     
     /* Note that `fds' is built incrementally so that the destructor
@@ -155,7 +102,7 @@ void PathLocks::lockPaths(const PathSet & _paths, const string & waitMsg)
     paths.sort();
     
     /* Acquire the lock for each path. */
-    for (Paths::iterator i = paths.begin(); i != paths.end(); i++) {
+    foreach (Paths::iterator, i, paths) {
         checkInterrupt();
         Path path = *i;
         Path lockPath = path + ".lock";
@@ -174,8 +121,15 @@ void PathLocks::lockPaths(const PathSet & _paths, const string & waitMsg)
 
             /* Acquire an exclusive lock. */
             if (!lockFile(fd, ltWrite, false)) {
-                if (waitMsg != "") printMsg(lvlError, waitMsg);
-                lockFile(fd, ltWrite, true);
+                if (wait) {
+                    if (waitMsg != "") printMsg(lvlError, waitMsg);
+                    lockFile(fd, ltWrite, true);
+                } else {
+                    /* Failed to lock this path; release all other
+                       locks. */
+                    unlock();
+                    return false;
+                }
             }
 
             debug(format("lock acquired on `%1%'") % lockPath);
@@ -199,23 +153,31 @@ void PathLocks::lockPaths(const PathSet & _paths, const string & waitMsg)
         fds.push_back(FDPair(fd.borrow(), lockPath));
         lockedPaths.insert(lockPath);
     }
+
+    return true;
 }
 
 
 PathLocks::~PathLocks()
 {
-    for (list<FDPair>::iterator i = fds.begin(); i != fds.end(); i++) {
-        if (deletePaths) deleteLockFilePreClose(i->second, i->first);
+    unlock();
+}
+
+
+void PathLocks::unlock()
+{
+    foreach (list<FDPair>::iterator, i, fds) {
+        if (deletePaths) deleteLockFile(i->second, i->first);
 
         lockedPaths.erase(i->second);
         if (close(i->first) == -1)
             printMsg(lvlError,
                 format("error (ignored): cannot close lock file on `%1%'") % i->second);
 
-	if (deletePaths) deleteLockFilePostClose(i->second);
-
         debug(format("lock released on `%1%'") % i->second);
     }
+
+    fds.clear();
 }
 
 

src/libstore/pathlocks.hh

@@ -12,10 +12,8 @@ namespace nix {
    because it doesn't exist.  Any other error throws an exception. */
 int openLockFile(const Path & path, bool create);
 
-/* Delete an open lock file.  Both must be called to be fully portable
-   between Unix and Windows. */
-void deleteLockFilePreClose(const Path & path, int fd);
-void deleteLockFilePostClose(const Path & path);
+/* Delete an open lock file. */
+void deleteLockFile(const Path & path, int fd);
 
 enum LockType { ltRead, ltWrite, ltNone };
 
@@ -33,9 +31,11 @@ public:
     PathLocks();
     PathLocks(const PathSet & paths,
         const string & waitMsg = "");
-    void lockPaths(const PathSet & _paths,
-        const string & waitMsg = "");
+    bool lockPaths(const PathSet & _paths,
+        const string & waitMsg = "",
+        bool wait = true);
     ~PathLocks();
+    void unlock();
     void setDeletion(bool deletePaths);
 };
 

src/libstore/references.cc

@@ -1,17 +1,10 @@
 #include "references.hh"
 #include "hash.hh"
 #include "util.hh"
+#include "archive.hh"
 
-#include <cerrno>
-#include <cstring>
-#include <cstdlib>
 #include <map>
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <dirent.h>
-#include <fcntl.h>
+#include <cstdlib>
 
 
 namespace nix {
@@ -20,8 +13,8 @@ namespace nix {
 static unsigned int refLength = 32; /* characters */
 
 
-static void search(size_t len, const unsigned char * s,
-    StringSet & ids, StringSet & seen)
+static void search(const unsigned char * s, unsigned int len, 
+    StringSet & hashes, StringSet & seen)
 {
     static bool initialised = false;
     static bool isBase32[256];
@@ -43,93 +36,60 @@ static void search(size_t len, const unsigned char * s,
             }
         if (!match) continue;
         string ref((const char *) s + i, refLength);
-        if (ids.find(ref) != ids.end()) {
+        if (hashes.find(ref) != hashes.end()) {
             debug(format("found reference to `%1%' at offset `%2%'")
                   % ref % i);
             seen.insert(ref);
-            ids.erase(ref);
+            hashes.erase(ref);
         }
         ++i;
     }
 }
 
 
-void checkPath(const string & path,
-    StringSet & ids, StringSet & seen)
+struct RefScanSink : Sink
 {
-    checkInterrupt();
+    HashSink hashSink;
+    StringSet hashes;
+    StringSet seen;
+
+    string tail;
+
+    RefScanSink() : hashSink(htSHA256) { }
     
-    debug(format("checking `%1%'") % path);
+    void operator () (const unsigned char * data, unsigned int len);
+};
 
-    struct stat st;
-    if (lstat(path.c_str(), &st))
-        throw SysError(format("getting attributes of path `%1%'") % path);
 
-    if (S_ISDIR(st.st_mode)) {
-        Strings names = readDirectory(path);
-	for (Strings::iterator i = names.begin(); i != names.end(); i++) {
-            search(i->size(), (const unsigned char *) i->c_str(), ids, seen);
-            checkPath(path + "/" + *i, ids, seen);
-        }
-    }
+void RefScanSink::operator () (const unsigned char * data, unsigned int len)
+{
+    hashSink(data, len);
 
-    else if (S_ISREG(st.st_mode)) {
-        
-        AutoCloseFD fd = open(path.c_str(), O_RDONLY);
-        if (fd == -1) throw SysError(format("opening file `%1%'") % path);
+    /* It's possible that a reference spans the previous and current
+       fragment, so search in the concatenation of the tail of the
+       previous fragment and the start of the current fragment. */
+    string s = tail + string((const char *) data, len > refLength ? refLength : len);
+    search((const unsigned char *) s.c_str(), s.size(), hashes, seen);
 
-        size_t bufSize = 1024 * 1024;
-        assert(refLength <= bufSize);
-        unsigned char * buf = new unsigned char[bufSize];
+    search(data, len, hashes, seen);
 
-        size_t left = st.st_size;
-        bool firstBlock = true;
-        
-        while (left > 0) {
-            checkInterrupt();
-            
-            size_t read = left > bufSize ? bufSize : left;
-            size_t copiedBytes = 0;
-
-            if (!firstBlock) {
-                /* Move the last (refLength - 1) bytes from the last
-                   block to the start of the buffer to deal with
-                   references that cross block boundaries. */
-                copiedBytes = refLength - 1;
-                if (read + copiedBytes > bufSize)
-                    read -= copiedBytes;
-                memcpy(buf, buf + (bufSize - copiedBytes), copiedBytes);
-            }
-            firstBlock = false;
-
-            readFull(fd, buf + copiedBytes, read);
-            left -= read;
-
-            search(copiedBytes + read, buf, ids, seen);
-        }
-        
-        delete[] buf; /* !!! autodelete */
-    }
-    
-    else if (S_ISLNK(st.st_mode)) {
-        string target = readLink(path);
-        search(target.size(), (const unsigned char *) target.c_str(), ids, seen);
-    }
-    
-    else throw Error(format("unknown file type: %1%") % path);
+    unsigned int tailLen = len <= refLength ? len : refLength;
+    tail =
+        string(tail, tail.size() < refLength - tailLen ? 0 : tail.size() - (refLength - tailLen)) +
+        string((const char *) data + len - tailLen, tailLen);
 }
 
 
-PathSet scanForReferences(const string & path, const PathSet & paths)
+PathSet scanForReferences(const string & path,
+    const PathSet & refs, Hash & hash)
 {
+    RefScanSink sink;
     std::map<string, Path> backMap;
-    StringSet ids;
-    StringSet seen;
 
     /* For efficiency (and a higher hit rate), just search for the
        hash part of the file name.  (This assumes that all references
        have the form `HASH-bla'). */
-    for (PathSet::const_iterator i = paths.begin(); i != paths.end(); i++) {
+    foreach (PathSet::const_iterator, i, refs) {
         string baseName = baseNameOf(*i);
         string::size_type pos = baseName.find('-');
         if (pos == string::npos)
@@ -138,21 +98,25 @@ PathSet scanForReferences(const string & path, const PathSet & paths)
         assert(s.size() == refLength);
         assert(backMap.find(s) == backMap.end());
         // parseHash(htSHA256, s);
-        ids.insert(s);
+        sink.hashes.insert(s);
         backMap[s] = *i;
     }
 
-    checkPath(path, ids, seen);
+    /* Look for the hashes in the NAR dump of the path. */
+    dumpPath(path, sink);
 
+    /* Map the hashes found back to their store paths. */
     PathSet found;
-    for (StringSet::iterator i = seen.begin(); i != seen.end(); i++) {
+    foreach (StringSet::iterator, i, sink.seen) {
         std::map<string, Path>::iterator j;
         if ((j = backMap.find(*i)) == backMap.end()) abort();
         found.insert(j->second);
     }
 
+    hash = sink.hashSink.finish();
+        
     return found;
 }
 
- 
+
 }

src/libstore/references.hh

@@ -2,10 +2,12 @@
 #define __REFERENCES_H
 
 #include "types.hh"
+#include "hash.hh"
 
 namespace nix {
 
-PathSet scanForReferences(const Path & path, const PathSet & refs);
+PathSet scanForReferences(const Path & path, const PathSet & refs,
+    Hash & hash);
     
 }
 

src/libstore/remote-store.cc

@@ -29,14 +29,22 @@ Path readStorePath(Source & from)
 PathSet readStorePaths(Source & from)
 {
     PathSet paths = readStringSet(from);
-    for (PathSet::iterator i = paths.begin(); i != paths.end(); ++i)
-        assertStorePath(*i);
+    foreach (PathSet::iterator, i, paths) assertStorePath(*i);
     return paths;
 }
 
 
 RemoteStore::RemoteStore()
 {
+    initialised = false;
+}
+
+
+void RemoteStore::openConnection()
+{
+    if (initialised) return;
+    initialised = true;
+
     string remoteMode = getEnv("NIX_REMOTE");
 
     if (remoteMode == "slave")
@@ -64,8 +72,8 @@ RemoteStore::RemoteStore()
             throw Error("Nix daemon protocol version not supported");
         writeInt(PROTOCOL_VERSION, to);
         processStderr();
-
-    } catch (Error & e) {
+    }
+    catch (Error & e) {
         throw Error(format("cannot start worker (%1%)")
             % e.msg());
     }
@@ -194,6 +202,7 @@ void RemoteStore::setOptions()
 
 bool RemoteStore::isValidPath(const Path & path)
 {
+    openConnection();
     writeInt(wopIsValidPath, to);
     writeString(path, to);
     processStderr();
@@ -204,12 +213,14 @@ bool RemoteStore::isValidPath(const Path & path)
 
 PathSet RemoteStore::queryValidPaths()
 {
+    openConnection();
     throw Error("not implemented");
 }
 
 
 bool RemoteStore::hasSubstitutes(const Path & path)
 {
+    openConnection();
     writeInt(wopHasSubstitutes, to);
     writeString(path, to);
     processStderr();
@@ -221,6 +232,7 @@ bool RemoteStore::hasSubstitutes(const Path & path)
 bool RemoteStore::querySubstitutablePathInfo(const Path & path,
     SubstitutablePathInfo & info)
 {
+    openConnection();
     if (GET_PROTOCOL_MINOR(daemonVersion) < 3) return false;
     writeInt(wopQuerySubstitutablePathInfo, to);
     writeString(path, to);
@@ -237,6 +249,7 @@ bool RemoteStore::querySubstitutablePathInfo(const Path & path,
 
 Hash RemoteStore::queryPathHash(const Path & path)
 {
+    openConnection();
     writeInt(wopQueryPathHash, to);
     writeString(path, to);
     processStderr();
@@ -248,6 +261,7 @@ Hash RemoteStore::queryPathHash(const Path & path)
 void RemoteStore::queryReferences(const Path & path,
     PathSet & references)
 {
+    openConnection();
     writeInt(wopQueryReferences, to);
     writeString(path, to);
     processStderr();
@@ -259,6 +273,7 @@ void RemoteStore::queryReferences(const Path & path,
 void RemoteStore::queryReferrers(const Path & path,
     PathSet & referrers)
 {
+    openConnection();
     writeInt(wopQueryReferrers, to);
     writeString(path, to);
     processStderr();
@@ -269,6 +284,7 @@ void RemoteStore::queryReferrers(const Path & path,
 
 Path RemoteStore::queryDeriver(const Path & path)
 {
+    openConnection();
     writeInt(wopQueryDeriver, to);
     writeString(path, to);
     processStderr();
@@ -278,27 +294,31 @@ Path RemoteStore::queryDeriver(const Path & path)
 }
 
 
-Path RemoteStore::addToStore(const Path & _srcPath, bool fixed,
-    bool recursive, string hashAlgo, PathFilter & filter)
+Path RemoteStore::addToStore(const Path & _srcPath,
+    bool recursive, HashType hashAlgo, PathFilter & filter)
 {
+    openConnection();
+    
     Path srcPath(absPath(_srcPath));
     
     writeInt(wopAddToStore, to);
     writeString(baseNameOf(srcPath), to);
-    writeInt(fixed ? 1 : 0, to);
+    /* backwards compatibility hack */
+    writeInt((hashAlgo == htSHA256 && recursive) ? 0 : 1, to);
     writeInt(recursive ? 1 : 0, to);
-    writeString(hashAlgo, to);
+    writeString(printHashType(hashAlgo), to);
     dumpPath(srcPath, to, filter);
     processStderr();
     return readStorePath(from);
 }
 
 
-Path RemoteStore::addTextToStore(const string & suffix, const string & s,
+Path RemoteStore::addTextToStore(const string & name, const string & s,
     const PathSet & references)
 {
+    openConnection();
     writeInt(wopAddTextToStore, to);
-    writeString(suffix, to);
+    writeString(name, to);
     writeString(s, to);
     writeStringSet(references, to);
     
@@ -310,6 +330,7 @@ Path RemoteStore::addTextToStore(const string & suffix, const string & s,
 void RemoteStore::exportPath(const Path & path, bool sign,
     Sink & sink)
 {
+    openConnection();
     writeInt(wopExportPath, to);
     writeString(path, to);
     writeInt(sign ? 1 : 0, to);
@@ -320,10 +341,10 @@ void RemoteStore::exportPath(const Path & path, bool sign,
 
 Path RemoteStore::importPath(bool requireSignature, Source & source)
 {
+    openConnection();
     writeInt(wopImportPath, to);
     /* We ignore requireSignature, since the worker forces it to true
-       anyway. */
-    
+       anyway. */    
     processStderr(0, &source);
     return readStorePath(from);
 }
@@ -331,6 +352,7 @@ Path RemoteStore::importPath(bool requireSignature, Source & source)
 
 void RemoteStore::buildDerivations(const PathSet & drvPaths)
 {
+    openConnection();
     writeInt(wopBuildDerivations, to);
     writeStringSet(drvPaths, to);
     processStderr();
@@ -340,6 +362,7 @@ void RemoteStore::buildDerivations(const PathSet & drvPaths)
 
 void RemoteStore::ensurePath(const Path & path)
 {
+    openConnection();
     writeInt(wopEnsurePath, to);
     writeString(path, to);
     processStderr();
@@ -349,6 +372,7 @@ void RemoteStore::ensurePath(const Path & path)
 
 void RemoteStore::addTempRoot(const Path & path)
 {
+    openConnection();
     writeInt(wopAddTempRoot, to);
     writeString(path, to);
     processStderr();
@@ -358,6 +382,7 @@ void RemoteStore::addTempRoot(const Path & path)
 
 void RemoteStore::addIndirectRoot(const Path & path)
 {
+    openConnection();
     writeInt(wopAddIndirectRoot, to);
     writeString(path, to);
     processStderr();
@@ -367,6 +392,7 @@ void RemoteStore::addIndirectRoot(const Path & path)
 
 void RemoteStore::syncWithGC()
 {
+    openConnection();
     writeInt(wopSyncWithGC, to);
     processStderr();
     readInt(from);
@@ -375,6 +401,7 @@ void RemoteStore::syncWithGC()
 
 Roots RemoteStore::findRoots()
 {
+    openConnection();
     writeInt(wopFindRoots, to);
     processStderr();
     unsigned int count = readInt(from);
@@ -390,12 +417,19 @@ Roots RemoteStore::findRoots()
 
 void RemoteStore::collectGarbage(const GCOptions & options, GCResults & results)
 {
+    openConnection();
+    
     writeInt(wopCollectGarbage, to);
     writeInt(options.action, to);
     writeStringSet(options.pathsToDelete, to);
     writeInt(options.ignoreLiveness, to);
     writeLongLong(options.maxFreed, to);
     writeInt(options.maxLinks, to);
+    if (GET_PROTOCOL_MINOR(daemonVersion) >= 5) {
+        /* removed options */
+        writeInt(0, to);
+        writeInt(0, to);
+    }
     
     processStderr();
     

src/libstore/remote-store.hh

@@ -42,11 +42,11 @@ public:
     bool querySubstitutablePathInfo(const Path & path,
         SubstitutablePathInfo & info);
     
-    Path addToStore(const Path & srcPath, bool fixed = false,
-        bool recursive = false, string hashAlgo = "",
+    Path addToStore(const Path & srcPath,
+        bool recursive = true, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter);
 
-    Path addTextToStore(const string & suffix, const string & s,
+    Path addTextToStore(const string & name, const string & s,
         const PathSet & references);
 
     void exportPath(const Path & path, bool sign,
@@ -74,6 +74,9 @@ private:
     FdSource from;
     Pid child;
     unsigned int daemonVersion;
+    bool initialised;
+
+    void openConnection();
 
     void processStderr(Sink * sink = 0, Source * source = 0);