Compare commits

..

10 Commits

Author SHA1 Message Date
Eelco Dolstra
a10da8466f * Option to turn off position information to test the impact on
maximal sharing.
2007-10-17 12:36:37 +00:00
Eelco Dolstra
e23d134b85 * Memoize the substitution function.
* Print some substitution statistics.
* Option to turn off the closed term optimization.
2007-10-15 12:08:31 +00:00
Eelco Dolstra
c3a79daaf3 * Short-circuiting of function call evaluation.
With maximal laziness, you would expect that a function like this

    fib = n:
      if n == 0 then 0 else
      if n == 1 then 1 else
      builtins.add (fib (builtins.sub n 1)) (fib (builtins.sub n 2));

  can be evaluated efficiently, because maximal laziness should
  implictly memoize the recursive calls to "fib".  However, non-strictness
  interferes with this: the argument "n" is generally not in a form
  that allows the memoization to work (e.g., it will be something like
  (20 - 1 - 2 - 2) rather than 15).  By the time that "n" is
  evaluated (in "if n == 0 ..."), we're already deep in the evaluation
  of the call.

  (Strictness solves this:

      builtins.add (strict fib (builtins.sub n 1)) (strict fib (builtins.sub n 2));

  but that's not a very nice approach.)

  With short-circuiting, the evaluator will check after evaluating a
  term, whether that term is the argument of a function call that
  we're currently evaluating.  If so, it will check to see if the same
  call but with the evaluated argument is in the normal form cache.

  For instance, after evaluating (20 - 1 - 2 - 2) to 15, if we see
  that "fib (20 - 1 - 2 - 2)" is currently being evaluated, we check
  to see if "fib 15" is in the normal form cache.  If so, we unwind
  the stack (by throwing an exception) up to the evalExpr call
  responsible for "fib (20 - 1 - 2 - 2)", which can then immediately
  return the normal form for "fib 15".  And indeed this makes "fib"
  run in O(n) time.

  The overhead for checking the active function calls (which isn't
  very smart yet) seems to be modest, about 2% for "nix-env -qa
  --drv-path --out-path" on Nixpkgs.
2007-10-12 17:53:47 +00:00
Eelco Dolstra
74ce938e18 * Simulate conventional laziness a bit better still by "allocating"
all local variables when entering a new scope.  I.e., don't do
  implicit let-floating.
2007-10-11 22:42:09 +00:00
Eelco Dolstra
981afe821c * Some hacks to simulate conventional laziness. 2007-10-11 21:58:37 +00:00
Eelco Dolstra
cd9d10d4e3 * Caching of parse results for fairer comparisons. 2007-10-11 20:02:08 +00:00
Eelco Dolstra
c1179badd5 * Playing with strictness. 2007-10-11 14:07:00 +00:00
Eelco Dolstra
3d14ed9270 * A primop for calling functions strictly (i.e. forcing evaluation of
argument).  Necessary to actually get memoisation of functions like
  "fib" with maximal laziness.
2007-10-11 14:06:43 +00:00
Eelco Dolstra
8e0488370d * Environment variable to disable normal form caching. 2007-10-11 12:09:06 +00:00
Eelco Dolstra
b57f8bd38d * PEPM related hacks. 2007-10-11 12:07:49 +00:00
66 changed files with 1396 additions and 3590 deletions

View File

@@ -5,7 +5,7 @@ AM_INIT_AUTOMAKE([dist-bzip2 foreign])
# Change to `1' to produce a `stable' release (i.e., the `preREVISION'
# suffix is not added).
STABLE=1
STABLE=0
# Put the revision number in the version.
if test "$STABLE" != "1"; then
@@ -99,19 +99,9 @@ static char buf[1024];]],
AC_LANG_POP(C++)
# Check for chroot support (requires chroot() and bind mounts).
AC_CHECK_FUNCS([chroot])
AC_CHECK_HEADERS([sys/param.h], [], [], [])
AC_CHECK_HEADERS([sys/mount.h], [], [],
[#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
# endif
])
# Check for <locale>
AC_LANG_PUSH(C++)
AC_CHECK_HEADERS([locale], [], [], [])
AC_CHECK_HEADERS([locale])
AC_LANG_POP(C++)
@@ -124,7 +114,7 @@ fi
])
NEED_PROG(curl, curl)
NEED_PROG(shell, bash)
NEED_PROG(shell, sh)
NEED_PROG(patch, patch)
AC_PATH_PROG(xmllint, xmllint, false)
AC_PATH_PROG(xsltproc, xsltproc, false)
@@ -135,7 +125,6 @@ AC_PATH_PROG(bison, bison, false)
NEED_PROG(perl, perl)
NEED_PROG(tar, tar)
AC_PATH_PROG(dot, dot)
AC_PATH_PROG(dblatex, dblatex)
AC_PATH_PROG(openssl_prog, openssl, openssl) # if not found, call openssl in $PATH
AC_SUBST(openssl_prog)
@@ -256,10 +245,6 @@ AM_CONDITIONAL(INIT_STATE, test "$init_state" = "yes")
AC_CHECK_FUNCS([setresuid setreuid lchown])
# Nice to have, but not essential.
AC_CHECK_FUNCS([strsignal])
# This is needed if ATerm, Berkeley DB or bzip2 are static libraries,
# and the Nix libraries are dynamic.
if test "$(uname)" = "Darwin"; then

View File

@@ -20,7 +20,7 @@ man1_MANS = nix-env.1 nix-build.1 nix-store.1 nix-instantiate.1 \
FIGURES = figures/user-environments.png
MANUAL_SRCS = manual.xml introduction.xml installation.xml \
package-management.xml writing-nix-expressions.xml builtins.xml \
package-management.xml writing-nix-expressions.xml \
build-farm.xml \
$(man1_MANS:.1=.xml) \
troubleshooting.xml bugs.xml opt-common.xml opt-common-syn.xml \
@@ -47,14 +47,6 @@ manual.html: $(MANUAL_SRCS) manual.is-valid images
$(XSLTPROC) --nonet --xinclude --output manual.html \
$(docbookxsl)/html/docbook.xsl manual.xml
manual.pdf: $(MANUAL_SRCS) manual.is-valid images
if test "$(dblatex)" != ""; then \
$(dblatex) manual.xml; \
else \
echo "Please install dblatex and rerun configure."; \
exit 1; \
fi
NEWS_OPTS = \
--stringparam generate.toc "article nop" \

View File

@@ -36,10 +36,10 @@ build farm, since:
builds, and Nix expressions are self-contained.</para></listitem>
<listitem><para>Nix will only rebuild things that have actually
changed. For instance, if the sources of a package haven't changed
between runs of the build farm, the package won't be rebuilt (unless
it was garbage-collected). Also, dependencies typically don't
change very often, so they only need to be built
changed. For instance, if the sources of a component haven't
changed between runs of the build farm, the component won't be
rebuild (unless it was garbage-collected). Also, dependencies
typically don't change very often, so they only need to be built
once.</para></listitem>
<listitem><para>The results of a Nix build farm can be made

View File

@@ -1,760 +0,0 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id='ssec-builtins'>
<title>Built-in functions</title>
<para>This section lists the functions and constants built into the
Nix expression evaluator. (The built-in function
<function>derivation</function> is discussed above.) Some built-ins,
such as <function>derivation</function>, are always in scope of every
Nix expression; you can just access them right away. But to prevent
polluting the namespace too much, most built-ins are not in scope.
Instead, you can access them through the <varname>builtins</varname>
built-in value, which is an attribute set that contains all built-in
functions and values. For instance, <function>derivation</function>
is also available as <function>builtins.derivation</function>.</para>
<variablelist>
<varlistentry><term><function>abort</function> <replaceable>s</replaceable></term>
<listitem><para>Abort Nix expression evaluation, print error
message <replaceable>s</replaceable>.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.add</function>
<replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
<listitem><para>Return the sum of the integers
<replaceable>e1</replaceable> and
<replaceable>e2</replaceable>.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.attrNames</function>
<replaceable>attrs</replaceable></term>
<listitem><para>Return the names of the attributes in the
attribute set <replaceable>attrs</replaceable> in a sorted list.
For instance, <literal>builtins.attrNames {y = 1; x =
"foo";}</literal> evaluates to <literal>["x" "y"]</literal>.
There is no built-in function <function>attrValues</function>, but
you can easily define it yourself:
<programlisting>
attrValues = attrs: map (name: builtins.getAttr name attrs) (builtins.attrNames attrs);</programlisting>
</para></listitem>
</varlistentry>
<varlistentry><term><function>baseNameOf</function> <replaceable>s</replaceable></term>
<listitem><para>Return the <emphasis>base name</emphasis> of the
string <replaceable>s</replaceable>, that is, everything following
the final slash in the string. This is similar to the GNU
<command>basename</command> command.</para></listitem>
</varlistentry>
<varlistentry><term><varname>builtins</varname></term>
<listitem><para>The attribute set <varname>builtins</varname>
contains all the built-in functions and values. You can use
<varname>builtins</varname> to test for the availability of
features in the Nix installation, e.g.,
<programlisting>
if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting>
This allows a Nix expression to fall back gracefully on older Nix
installations that dont 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> doesnt
exist. <literal>builtins.getEnv</literal>, on the other hand, is
safe since <literal>builtins</literal> always exists and attribute
selection is lazy, so its only performed if the test
succeeds.</para></listitem>
</varlistentry>
<varlistentry
xml:id='builtin-currentSystem'><term><varname>builtins.currentSystem</varname></term>
<listitem><para>The built-in value <varname>currentSystem</varname>
evaluates to the Nix platform identifier for the Nix installation
on which the expression is being evaluated, such as
<literal>"i686-linux"</literal> or
<literal>"powerpc-darwin"</literal>.</para></listitem>
</varlistentry>
<!--
<varlistentry><term><function>currentTime</function></term>
<listitem><para>The built-in value <varname>currentTime</varname>
returns the current system time in seconds since 00:00:00 1/1/1970
UTC. Due to the evaluation model of Nix expressions
(<emphasis>maximal laziness</emphasis>), it always yields the same
value within an execution of Nix.</para></listitem>
</varlistentry>
-->
<!--
<varlistentry><term><function>dependencyClosure</function></term>
<listitem><para>TODO</para></listitem>
</varlistentry>
-->
<varlistentry><term><function>derivation</function>
<replaceable>attrs</replaceable></term>
<listitem><para><function>derivation</function> is described in
<xref linkend='ssec-derivation' />.</para></listitem>
</varlistentry>
<varlistentry><term><function>dirOf</function> <replaceable>s</replaceable></term>
<listitem><para>Return the directory part of the string
<replaceable>s</replaceable>, that is, everything before the final
slash in the string. This is similar to the GNU
<command>dirname</command> command.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.filterSource</function>
<replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
<listitem>
<para>This function allows you to copy sources into the Nix
store while filtering certain files. For instance, suppose that
you want to use the directory <filename>source-dir</filename> as
an input to a Nix expression, e.g.
<programlisting>
stdenv.mkDerivation {
...
src = ./source-dir;
}
</programlisting>
However, if <filename>source-dir</filename> is a Subversion
working copy, then all those annoying <filename>.svn</filename>
subdirectories will also be copied to the store. Worse, the
contents of those directories may change a lot, causing lots of
spurious rebuilds. With <function>filterSource</function> you
can filter out the <filename>.svn</filename> directories:
<programlisting>
src = builtins.filterSource
(path: type: type != "directory" || baseNameOf path != ".svn")
./source-dir;
</programlisting>
</para>
<para>Thus, the first argument <replaceable>e1</replaceable>
must be a predicate function that is called for each regular
file, directory or symlink in the source tree
<replaceable>e2</replaceable>. If the function returns
<literal>true</literal>, the file is copied to the Nix store,
otherwise it is omitted. The function is called with two
arguments. The first is the full path of the file. The second
is a string that identifies the type of the file, which is
either <literal>"regular"</literal>,
<literal>"directory"</literal>, <literal>"symlink"</literal> or
<literal>"unknown"</literal> (for other kinds of files such as
device nodes or fifos — but note that those cannot be copied to
the Nix store, so if the predicate returns
<literal>true</literal> for them, the copy will fail).</para>
</listitem>
</varlistentry>
<varlistentry><term><function>builtins.getAttr</function>
<replaceable>s</replaceable> <replaceable>attrs</replaceable></term>
<listitem><para><function>getAttr</function> returns the attribute
named <replaceable>s</replaceable> from the attribute set
<replaceable>attrs</replaceable>. Evaluation aborts if the
attribute doesnt exist. This is a dynamic version of the
<literal>.</literal> operator, since <replaceable>s</replaceable>
is an expression rather than an identifier.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.getEnv</function>
<replaceable>s</replaceable></term>
<listitem><para><function>getEnv</function> returns the value of
the environment variable <replaceable>s</replaceable>, or an empty
string if the variable doesnt exist. This function should be
used with care, as it can introduce all sorts of nasty environment
dependencies in your Nix expression.</para>
<para><function>getEnv</function> is used in Nix Packages to
locate the file <filename>~/.nixpkgs/config.nix</filename>, which
contains user-local settings for Nix Packages. (That is, it does
a <literal>getEnv "HOME"</literal> to locate the users home
directory.)</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.hasAttr</function>
<replaceable>s</replaceable> <replaceable>attrs</replaceable></term>
<listitem><para><function>hasAttr</function> returns
<literal>true</literal> if the attribute set
<replaceable>attrs</replaceable> has an attribute named
<replaceable>s</replaceable>, and <literal>false</literal>
otherwise. This is a dynamic version of the <literal>?</literal>
operator, since <replaceable>s</replaceable> is an expression
rather than an identifier.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.head</function>
<replaceable>list</replaceable></term>
<listitem><para>Return the first element of a list; abort
evaluation if the argument isnt a list or is an empty list. You
can test whether a list is empty by comparing it with
<literal>[]</literal>.</para></listitem>
</varlistentry>
<varlistentry><term><function>import</function>
<replaceable>path</replaceable></term>
<listitem><para>Load, parse and return the Nix expression in the
file <replaceable>path</replaceable>. Evaluation aborts if the
file doesnt exist or contains an incorrect Nix
expression. <function>import</function> implements Nixs module
system: you can put any Nix expression (such as an attribute set
or a function) in a separate file, and use it from Nix expressions
in other files.</para>
<para>A Nix expression loaded by <function>import</function> must
not contain any <emphasis>free variables</emphasis> (identifiers
that are not defined in the Nix expression itself and are not
built-in). Therefore, it cannot refer to variables that are in
scope at the call site. For instance, if you have a calling
expression
<programlisting>
rec {
x = 123;
y = import ./foo.nix;
}</programlisting>
then the following <filename>foo.nix</filename> will give an
error:
<programlisting>
x + 456</programlisting>
since <varname>x</varname> is not in scope in
<filename>foo.nix</filename>. If you want <varname>x</varname>
to be available in <filename>foo.nix</filename>, you should pass
it as a function argument:
<programlisting>
rec {
x = 123;
y = import ./foo.nix x;
}</programlisting>
and
<programlisting>
x: x + 456</programlisting>
(The function argument doesnt have to be called
<varname>x</varname> in <filename>foo.nix</filename>; any name
would work.)</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.isAttrs</function>
<replaceable>e</replaceable></term>
<listitem><para>Return <literal>true</literal> if
<replaceable>e</replaceable> evaluates to an attribute set, and
<literal>false</literal> otherwise.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.isList</function>
<replaceable>e</replaceable></term>
<listitem><para>Return <literal>true</literal> if
<replaceable>e</replaceable> evaluates to a list, and
<literal>false</literal> otherwise.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.isFunction</function>
<replaceable>e</replaceable></term>
<listitem><para>Return <literal>true</literal> if
<replaceable>e</replaceable> evaluates to a function, and
<literal>false</literal> otherwise.</para></listitem>
</varlistentry>
<varlistentry><term><function>isNull</function>
<replaceable>e</replaceable></term>
<listitem><para>Return <literal>true</literal> if
<replaceable>e</replaceable> evaluates to <literal>null</literal>,
and <literal>false</literal> otherwise.</para>
<warning><para>This function is <emphasis>deprecated</emphasis>;
just write <literal>e == null</literal> instead.</para></warning>
</listitem>
</varlistentry>
<varlistentry><term><function>builtins.lessThan</function>
<replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
<listitem><para>Return <literal>true</literal> if the integer
<replaceable>e1</replaceable> is less than the integer
<replaceable>e2</replaceable>, and <literal>false</literal>
otherwise. Evaluation aborts if either
<replaceable>e1</replaceable> or <replaceable>e2</replaceable>
does not evaluate to an integer.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.listToAttrs</function>
<replaceable>e</replaceable></term>
<listitem><para>Construct an attribute set from a list specifying
the names and values of each attribute. Each element of the list
should be an attribute set consisting of a string-valued attribute
<varname>name</varname> specifying the name of the attribute, and
an attribute <varname>value</varname> specifying its value.
Example:
<programlisting>
builtins.listToAttrs [
{name = "foo"; value = 123;}
{name = "bar"; value = 456;}
]
</programlisting>
evaluates to
<programlisting>
{ foo = 123; bar = 456; }
</programlisting>
</para></listitem>
</varlistentry>
<varlistentry><term><function>map</function>
<replaceable>f</replaceable> <replaceable>list</replaceable></term>
<listitem><para>Apply the function <replaceable>f</replaceable> to
each element in the list <replaceable>list</replaceable>. For
example,
<programlisting>
map (x: "foo" + x) ["bar" "bla" "abc"]</programlisting>
evaluates to <literal>["foobar" "foobla"
"fooabc"]</literal>.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.pathExists</function>
<replaceable>path</replaceable></term>
<listitem><para>Return <literal>true</literal> if the path
<replaceable>path</replaceable> exists, and
<literal>false</literal> otherwise. One application of this
function is to conditionally include a Nix expression containing
user configuration:
<programlisting>
let
fileName = builtins.getEnv "CONFIG_FILE";
config =
if fileName != "" &amp;&amp; builtins.pathExists (builtins.toPath fileName)
then import (builtins.toPath fileName)
else { someSetting = false; }; <lineannotation># default configuration</lineannotation>
in config.someSetting</programlisting>
(Note that <envar>CONFIG_FILE</envar> must be an absolute path for
this to work.)</para></listitem>
</varlistentry>
<!--
<varlistentry><term><function>relativise</function></term>
<listitem><para>TODO</para></listitem>
</varlistentry>
-->
<varlistentry><term><function>builtins.readFile</function>
<replaceable>path</replaceable></term>
<listitem><para>Return the contents of the file
<replaceable>path</replaceable> as a string.</para></listitem>
</varlistentry>
<varlistentry><term><function>removeAttrs</function>
<replaceable>attrs</replaceable> <replaceable>list</replaceable></term>
<listitem><para>Remove the attributes listed in
<replaceable>list</replaceable> from the attribute set
<replaceable>attrs</replaceable>. The attributes dont have to
exist in <replaceable>attrs</replaceable>. For instance,
<screen>
removeAttrs { x = 1; y = 2; z = 3; } ["a" "x" "z"]</screen>
evaluates to <literal>{y = 2;}</literal>.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.stringLength</function>
<replaceable>e</replaceable></term>
<listitem><para>Return the length of the string
<replaceable>e</replaceable>. If <replaceable>e</replaceable> is
not a string, evaluation is aborted.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.sub</function>
<replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
<listitem><para>Return the difference between the integers
<replaceable>e1</replaceable> and
<replaceable>e2</replaceable>.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.substring</function>
<replaceable>start</replaceable> <replaceable>len</replaceable>
<replaceable>s</replaceable></term>
<listitem><para>Return the substring of
<replaceable>s</replaceable> from character position
<replaceable>start</replaceable> (zero-based) up to but not
including <replaceable>start + len</replaceable>. If
<replaceable>start</replaceable> is greater than the length of the
string, an empty string is returned, and if <replaceable>start +
len</replaceable> lies beyond the end of the string, only the
substring up to the end of the string is returned.
<replaceable>start</replaceable> must be
non-negative.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.tail</function>
<replaceable>list</replaceable></term>
<listitem><para>Return the second to last elements of a list;
abort evaluation if the argument isnt a list or is an empty
list.</para></listitem>
</varlistentry>
<varlistentry><term><function>throw</function>
<replaceable>s</replaceable></term>
<listitem><para>Throw an error message
<replaceable>s</replaceable>. This usually aborts Nix expression
evaluation, but in <command>nix-env -qa</command> and other
commands that try to evaluate a set of derivations to get
information about those derivations, a derivation that throws an
error is silently skipped (which is not the case for
<function>abort</function>).</para></listitem>
</varlistentry>
<varlistentry
xml:id='builtin-toFile'><term><function>builtins.toFile</function>
<replaceable>name</replaceable> <replaceable>s</replaceable></term>
<listitem><para>Store the string <replaceable>s</replaceable> in a
file in the Nix store and return its path. The file has suffix
<replaceable>name</replaceable>. This file can be used as an
input to derivations. One application is to write builders
“inline”. For instance, the following Nix expression combines
<xref linkend='ex-hello-nix' /> and <xref
linkend='ex-hello-builder' /> into one file:
<programlisting>
{stdenv, fetchurl, perl}:
stdenv.mkDerivation {
name = "hello-2.1.1";
builder = builtins.toFile "builder.sh" "
source $stdenv/setup
PATH=$perl/bin:$PATH
tar xvfz $src
cd hello-*
./configure --prefix=$out
make
make install
";
src = fetchurl {
url = http://nix.cs.uu.nl/dist/tarballs/hello-2.1.1.tar.gz;
md5 = "70c9ccf9fac07f762c24f2df2290784d";
};
inherit perl;
}</programlisting>
</para>
<para>It is even possible for one file to refer to another, e.g.,
<programlisting>
builder = let
configFile = builtins.toFile "foo.conf" "
# This is some dummy configuration file.
<replaceable>...</replaceable>
";
in builtins.toFile "builder.sh" "
source $stdenv/setup
<replaceable>...</replaceable>
cp ${configFile} $out/etc/foo.conf
";</programlisting>
Note that <literal>${configFile}</literal> is an antiquotation
(see <xref linkend='ssec-values' />), so the result of the
expression <literal>configFile</literal> (i.e., a path like
<filename>/nix/store/m7p7jfny445k...-foo.conf</filename>) will be
spliced into the resulting string.</para>
<para>It is however <emphasis>not</emphasis> allowed to have files
mutually referring to each other, like so:
<programlisting>
let
foo = builtins.toFile "foo" "...${bar}...";
bar = builtins.toFile "bar" "...${foo}...";
in foo</programlisting>
This is not allowed because it would cause a cyclic dependency in
the computation of the cryptographic hashes for
<varname>foo</varname> and <varname>bar</varname>.</para></listitem>
</varlistentry>
<varlistentry><term><function>builtins.toPath</function> <replaceable>s</replaceable></term>
<listitem><para>Convert the string value
<replaceable>s</replaceable> into a path value. The string
<replaceable>s</replaceable> must represent an absolute path
(i.e., must start with <literal>/</literal>). The path need not
exist. The resulting path is canonicalised, e.g.,
<literal>builtins.toPath "//foo/xyzzy/../bar/"</literal> returns
<literal>/foo/bar</literal>.</para></listitem>
</varlistentry>
<varlistentry><term><function>toString</function> <replaceable>e</replaceable></term>
<listitem><para>Convert the expression
<replaceable>e</replaceable> to a string.
<replaceable>e</replaceable> can be a string (in which case
<function>toString</function> is a no-op) or a path (e.g.,
<literal>toString /foo/bar</literal> yields
<literal>"/foo/bar"</literal>.</para></listitem>
</varlistentry>
<varlistentry xml:id='builtin-toXML'><term><function>builtins.toXML</function> <replaceable>e</replaceable></term>
<listitem><para>Return a string containing an XML representation
of <replaceable>e</replaceable>. The main application for
<function>toXML</function> is to communicate information with the
builder in a more structured format than plain environment
variables.</para>
<!-- TODO: more formally describe the schema of the XML
representation -->
<para><xref linkend='ex-toxml' /> shows an example where this is
the case. The builder is supposed to generate the configuration
file for a <link xlink:href='http://jetty.mortbay.org/'>Jetty
servlet container</link>. A servlet container contains a number
of servlets (<filename>*.war</filename> files) each exported under
a specific URI prefix. So the servlet configuration is a list of
attribute sets containing the <varname>path</varname> and
<varname>war</varname> of the servlet (<xref
linkend='ex-toxml-co-servlets' />). This kind of information is
difficult to communicate with the normal method of passing
information through an environment variable, which just
concatenates everything together into a string (which might just
work in this case, but wouldnt work if fields are optional or
contain lists themselves). Instead the Nix expression is
converted to an XML representation with
<function>toXML</function>, which is unambiguous and can easily be
processed with the appropriate tools. For instance, in the
example an XSLT stylesheet (<xref linkend='ex-toxml-co-stylesheet'
/>) is applied to it (<xref linkend='ex-toxml-co-apply' />) to
generate the XML configuration file for the Jetty server. The XML
representation produced from <xref linkend='ex-toxml-co-servlets'
/> by <function>toXML</function> is shown in <xref
linkend='ex-toxml-result' />.</para>
<para>Note that <xref linkend='ex-toxml' /> uses the <function
linkend='builtin-toFile'>toFile</function> built-in to write the
builder and the stylesheet “inline” in the Nix expression. The
path of the stylesheet is spliced into the builder at
<literal>xsltproc ${stylesheet}
<replaceable>...</replaceable></literal>.</para>
<example xml:id='ex-toxml'><title>Passing information to a builder
using <function>toXML</function></title>
<programlisting><![CDATA[
{stdenv, fetchurl, libxslt, jira, uberwiki}:
stdenv.mkDerivation (rec {
name = "web-server";
buildInputs = [libxslt];
builder = builtins.toFile "builder.sh" "
source $stdenv/setup
mkdir $out
echo $servlets | xsltproc ${stylesheet} - > $out/server-conf.xml]]> <co xml:id='ex-toxml-co-apply' /> <![CDATA[
";
stylesheet = builtins.toFile "stylesheet.xsl"]]> <co xml:id='ex-toxml-co-stylesheet' /> <![CDATA[
"<?xml version='1.0' encoding='UTF-8'?>
<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='1.0'>
<xsl:template match='/'>
<Configure>
<xsl:for-each select='/expr/list/attrs'>
<Call name='addWebApplication'>
<Arg><xsl:value-of select=\"attr[@name = 'path']/string/@value\" /></Arg>
<Arg><xsl:value-of select=\"attr[@name = 'war']/path/@value\" /></Arg>
</Call>
</xsl:for-each>
</Configure>
</xsl:template>
</xsl:stylesheet>
";
servlets = builtins.toXML []]> <co xml:id='ex-toxml-co-servlets' /> <![CDATA[
{ path = "/bugtracker"; war = jira + "/lib/atlassian-jira.war"; }
{ path = "/wiki"; war = uberwiki + "/uberwiki.war"; }
];
})]]></programlisting>
</example>
<example xml:id='ex-toxml-result'><title>XML representation produced by
<function>toXML</function></title>
<programlisting><![CDATA[<?xml version='1.0' encoding='utf-8'?>
<expr>
<list>
<attrs>
<attr name="path">
<string value="/bugtracker" />
</attr>
<attr name="war">
<path value="/nix/store/d1jh9pasa7k2...-jira/lib/atlassian-jira.war" />
</attr>
</attrs>
<attrs>
<attr name="path">
<string value="/wiki" />
</attr>
<attr name="war">
<path value="/nix/store/y6423b1yi4sx...-uberwiki/uberwiki.war" />
</attr>
</attrs>
</list>
</expr>]]></programlisting>
</example>
</listitem>
</varlistentry>
<varlistentry><term><function>builtins.trace</function>
<replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
<listitem><para>Evaluate <replaceable>e1</replaceable> and print its
abstract syntax representation on standard error. Then return
<replaceable>e2</replaceable>. This function is useful for
debugging.</para></listitem>
</varlistentry>
</variablelist>
</section>

View File

@@ -118,123 +118,6 @@ env-keep-derivations = false
</varlistentry>
<varlistentry xml:id="conf-build-max-silent-time"><term><literal>build-max-silent-time</literal></term>
<listitem>
<para>This option defines the maximum number of seconds that a
builder can go without producing any data on standard output or
standard error. This is useful (for instance in a automated
build system) to catch builds that are stuck in an infinite
loop, or to catch remote builds that are hanging due to network
problems. It can be overriden using the <option
linkend="opt-max-silent-time">--max-silent-time</option> command
line switch.</para>
<para>The value <literal>0</literal> means that there is no
timeout. This is also the default.</para>
</listitem>
</varlistentry>
<varlistentry xml:id="conf-build-users-group"><term><literal>build-users-group</literal></term>
<listitem><para>This options specifies the Unix group containing
the Nix build user accounts. In multi-user Nix installations,
builds should not be performed by the Nix account since that would
allow users to arbitrarily modify the Nix store and database by
supplying specially crafted builders; and they cannot be performed
by the calling user since that would allow him/her to influence
the build result.</para>
<para>Therefore, if this option is non-empty and specifies a valid
group, builds will be performed under the user accounts that are a
member of the group specified here (as listed in
<filename>/etc/group</filename>). Those user accounts should not
be used for any other purpose!</para>
<para>Nix will never run two builds under the same user account at
the same time. This is to prevent an obvious security hole: a
malicious user writing a Nix expression that modifies the build
result of a legitimate Nix expression being built by another user.
Therefore it is good to have as many Nix build user accounts as
you can spare. (Remember: uids are cheap.)</para>
<para>The build users should have permission to create files in
the Nix store, but not delete them. Therefore,
<filename>/nix/store</filename> should be owned by the Nix
account, its group should be the group specified here, and its
mode should be <literal>1775</literal>.</para>
<para>If the build users group is empty, builds will be performed
under the uid of the Nix process (that is, the uid of the caller
if <envar>NIX_REMOTE</envar> is empty, the uid under which the Nix
daemon runs if <envar>NIX_REMOTE</envar> is
<literal>daemon</literal>, or the uid that owns the setuid
<command>nix-worker</command> program if <envar>NIX_REMOTE</envar>
is <literal>slave</literal>). Obviously, this should not be used
in multi-user settings with untrusted users.</para>
</listitem>
</varlistentry>
<varlistentry><term><literal>build-use-chroot</literal></term>
<listitem><para>If set to <literal>true</literal>, builds will be
performed in a <emphasis>chroot environment</emphasis>, i.e., the
build will be isolated from the normal file system hierarchy and
will only see the Nix store, the temporary build directory, and
the directories configured with the <link
linkend='conf-build-chroot-dirs'><literal>build-chroot-dirs</literal>
option</link> (such as <filename>/proc</filename> and
<filename>/dev</filename>). This is useful to prevent undeclared
dependencies on files in directories such as
<filename>/usr/bin</filename>.</para>
<para>The use of a chroot requires that Nix is run as root (but
you can still use the <link
linkend='conf-build-users-group'>“build users” feature</link> to
perform builds under different users than root). Currently,
chroot builds only work on Linux because Nix uses “bind mounts” to
make the Nix store and other directories available inside the
chroot.</para>
</listitem>
</varlistentry>
<varlistentry xml:id="conf-build-chroot-dirs"><term><literal>build-chroot-dirs</literal></term>
<listitem><para>When builds are performed in a chroot environment,
Nix will mount (using <command>mount --bind</command> on Linux)
some directories from the normal file system hierarchy inside the
chroot. These are the Nix store, the temporary build directory
(usually
<filename>/tmp/nix-<replaceable>pid</replaceable>-<replaceable>number</replaceable></filename>)
and the directories listed here. The default is <literal>dev
/proc</literal>. Files in <filename>/dev</filename> (such as
<filename>/dev/null</filename>) are needed by many builds, and
some files in <filename>/proc</filename> may also be needed
occasionally.</para>
<para>The value used on NixOS is
<programlisting>
build-use-chroot = /dev /proc /bin</programlisting>
to make the <filename>/bin/sh</filename> symlink available (which
is still needed by many builders).</para>
</listitem>
</varlistentry>
<varlistentry><term><literal>system</literal></term>
<listitem><para>This option specifies the canonical Nix system

View File

@@ -263,17 +263,6 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
</varlistentry>
<varlistentry xml:id="envar-remote"><term><envar>NIX_REMOTE</envar></term>
<listitem><para>This variable should be set to
<literal>daemon</literal> if you want to use the Nix daemon to
executed Nix operations, which is necessary in <link
linkend="ssec-multi-user">multi-user Nix installations</link>.
Otherwise, it should be left unset.</para></listitem>
</varlistentry>
</variablelist>

View File

@@ -74,9 +74,9 @@
<glossentry><glossterm>Nix expression</glossterm>
<glossdef><para>A high-level description of software packages and
<glossdef><para>A high-level description of software components and
compositions thereof. Deploying software using Nix entails writing
Nix expressions for your packages. Nix expressions are translated
Nix expressions for your components. Nix expressions are translated
to derivations that are stored in the Nix store. These derivations
can then be built.</para></glossdef>

View File

@@ -42,8 +42,9 @@ platforms as well.</para>
<section><title>Obtaining Nix</title>
<para>The easiest way to obtain Nix is to download a <link
xlink:href="http://nix.cs.uu.nl/">source distribution</link>. RPMs
for Red Hat, SuSE, and Fedora Core are also available.</para>
xlink:href="http://www.cs.uu.nl/groups/ST/Trace/Nix">source
distribution</link>. RPMs for Red Hat, SuSE, and Fedora Core are also
available.</para>
<para>Alternatively, the most recent sources of Nix can be obtained
from its <link
@@ -99,16 +100,14 @@ 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 Sleepycat's Berkeley DB, 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 Sleepycat's Berkeley DB and CWI's ATerm library. These
are included in the Nix source distribution. If you build from the
Subversion repository, you must download them yourself and place them
in the <filename>externals/</filename> directory. See
<filename>externals/Makefile.am</filename> for the precise URLs of
these packages. Alternatively, if you already have them installed,
you can use <command>configure</command>'s
<option>--with-bdb</option>, <option>--with-aterm</option> and
<option>--with-bzip2</option> options to point to their respective
you can use <command>configure</command>'s <option>--with-bdb</option>
and <option>--with-aterm</option> options to point to their respective
locations. Note that Berkeley DB <emphasis>must</emphasis> be version
4.5; other versions may not have compatible database formats.</para>
@@ -119,21 +118,19 @@ locations. Note that Berkeley DB <emphasis>must</emphasis> be version
<para>After unpacking or checking out the Nix sources, issue the
following commands:
</para>
<screen>
$ ./configure <replaceable>options...</replaceable>
$ make
$ make install</screen>
</para>
<para>When building from the Subversion repository, these should be
preceded by the command:
</para>
<screen>
$ ./bootstrap</screen>
</para>
$ ./boostrap</screen>
<para>The installation path can be specified by passing the
<option>--prefix=<replaceable>prefix</replaceable></option> to
@@ -160,32 +157,28 @@ options.</para>
<section><title>Installing from RPMs</title>
<para>RPM packages of Nix can be downloaded from <link
xlink:href="http://nix.cs.uu.nl/" />. 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>RPM packages of Nix can be downloaded from <uri
xlink:href="http://www.cs.uu.nl/groups/ST/Trace/Nix">http://www.cs.uu.nl/groups/ST/Trace/Nix</uri>.
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,
<command>rpm -U</command>. For example,</para>
<screen>
$ rpm -U nix-0.5pre664-1.i386.rpm</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:
auxiliary data:</para>
<screen>
$ rm -rf /nix/store
$ rm -rf /nix/var</screen>
</para>
</section>
@@ -194,7 +187,7 @@ $ rm -rf /nix/var</screen>
<para>You can install the latest stable version of Nix through Nix
itself by subscribing to the channel <link
xlink:href="http://nix.cs.uu.nl/dist/nix/channels-v3/nix-stable" />,
or the latest unstable version by subscribing to the channel <link
or the latest unstable version by subscribing to the channel<link
xlink:href="http://nix.cs.uu.nl/dist/nix/channels-v3/nix-unstable" />.
You can also do a <link linkend="sec-one-click">one-click
installation</link> by clicking on the package links at <link
@@ -238,215 +231,33 @@ class="username">root</systemitem> all the time.</para>
</section>
<section xml:id="ssec-multi-user"><title>Multi-user mode</title>
<section><title>Multi-user mode</title>
<para>To allow a Nix store to be shared safely among multiple users,
it is important that users are not able to run builders that modify
the Nix store or database in arbitrary ways, or that interfere with
builds started by other users. If they could do so, they could
install a Trojan horse in some package and compromise the accounts of
other users.</para>
<para></para>
<para>To prevent this, the Nix store and database are owned by some
privileged user (usually <literal>root</literal>) and builders are
executed under special user accounts (usually named
<literal>nixbld1</literal>, <literal>nixbld2</literal>, etc.). When a
unprivileged user runs a Nix command, actions that operate on the Nix
store (such as builds) are forwarded to a <emphasis>Nix
daemon</emphasis> running under the owner of the Nix store/database
that performs the operation.</para>
<!--
warning: the nix-builders group should contain *only* the Nix
builders, and nothing else. If the Nix account is compromised, you
can execute programs under the accounts in the nix-builders group, so
it obviously shouldnt contain any “real” user accounts. So dont use
an existing group like <literal>users</literal> — just create a new
one.
-->
<note><para>Multi-user mode has one important limitation: only
<systemitem class="username">root</systemitem> can run <command
linkend="sec-nix-pull">nix-pull</command> to register the availability
of pre-built binaries. However, those registrations are shared by all
users, so they still get the benefit from <command>nix-pull</command>s
done by <systemitem class="username">root</systemitem>.</para></note>
<section><title>Setting up the build users</title>
<para>The <emphasis>build users</emphasis> are the special UIDs under
which builds are performed. They should all be members of the
<emphasis>build users group</emphasis> (usually called
<literal>nixbld</literal>). This group should have no other members.
The build users should not be members of any other group.</para>
<para>Here is a typical <filename>/etc/group</filename> definition of
the build users group with 10 build users:
<programlisting>
nixbld:!:30000:nixbld1,nixbld2,nixbld3,nixbld4,nixbld5,nixbld6,nixbld7,nixbld8,nixbld9,nixbld10
</programlisting>
In this example the <literal>nixbld</literal> group has UID 30000, but
of course it can be anything that doesnt collide with an existing
group.</para>
<para>Here is the corresponding part of
<filename>/etc/passwd</filename>:
<programlisting>
nixbld1:x:30001:65534:Nix build user 1:/var/empty:/noshell
nixbld2:x:30002:65534:Nix build user 2:/var/empty:/noshell
nixbld3:x:30003:65534:Nix build user 3:/var/empty:/noshell
...
nixbld10:x:30010:65534:Nix build user 10:/var/empty:/noshell
</programlisting>
The home directory of the build users should not exist or should be an
empty directory to which they do not have write access.</para>
<para>The build users should have write access to the Nix store, but
they should not have the right to delete files. Thus the Nix stores
group should be the build users group, and it should have the sticky
bit turned on (like <filename>/tmp</filename>):
<screen>
$ chgrp nixbld /nix/store
$ chmod 1777 /nix/store
</screen>
</para>
<para>Finally, you should tell Nix to use the build users by
specifying the build users group in the <link
linkend="conf-build-users-group"><literal>build-users-group</literal>
option</link> in the <link linkend="sec-conf-file">Nix configuration
file</link> (<literal>/nix/etc/nix/nix.conf</literal>):
<programlisting>
build-users-group = nixbld
</programlisting>
</para>
of pre-built binaries. However, those registrations
<emphasis>are</emphasis> used by all users to speed up
builds.</para></note>
</section>
<section><title>Nix store/database owned by root</title>
<para>The simplest setup is to let <literal>root</literal> own the Nix
store and database. I.e.,
<screen>
$ chown -R root /nix/store /nix/var/nix</screen>
</para>
<para>The Nix daemon should be started as follows (as
<literal>root</literal>):
<screen>
$ nix-worker --daemon</screen>
Youll want to put that line somewhere in your systems boot
scripts.</para>
<para>To let unprivileged users use the daemon, they should set the
<link linkend="envar-remote"><envar>NIX_REMOTE</envar> environment
variable</link> to <literal>daemon</literal>. So you should put a
line like
<programlisting>
export NIX_REMOTE=daemon</programlisting>
into the users login scripts.</para>
</section>
<section><title>Nix store/database not owned by root</title>
<para>It is also possible to let the Nix store and database be owned
by a non-root user, which should be more secure<footnote><para>Note
however that even when the Nix daemon runs as root, not
<emphasis>that</emphasis> much code is executed as root: Nix
expression evaluation is performed by the calling (unprivileged) user,
and builds are performed under the special build user accounts. So
only the code that accesses the database and starts builds is executed
as <literal>root</literal>.</para></footnote>. Typically, this user
is a special account called <literal>nix</literal>, but it can be
named anything. It should own the Nix store and database:
<screen>
$ chown -R root /nix/store /nix/var/nix</screen>
and of course <command>nix-worker --daemon</command> should be started
under that user, e.g.,
<screen>
$ su - nix -c "exec /nix/bin/nix-worker --daemon"</screen>
</para>
<para>There is a catch, though: non-<literal>root</literal> users
cannot start builds under the build user accounts, since the
<function>setuid</function> system call is obviously privileged. To
allow a non-<literal>root</literal> Nix daemon to use the build user
feature, it calls a setuid-root helper program,
<command>nix-setuid-helper</command>. This program is installed in
<filename><replaceable>prefix</replaceable>/libexec/nix-setuid-helper</filename>.
To set the permissions properly (Nixs <command>make install</command>
doesnt do this, since we dont want to ship setuid-root programs
out-of-the-box):
<screen>
$ chown root.root /nix/libexec/nix-setuid-helper
$ chmod 4755 /nix/libexec/nix-setuid-helper
</screen>
(This example assumes that the Nix binaries are installed in
<filename>/nix</filename>.)</para>
<para>Of course, the <command>nix-setuid-helper</command> command
should not be usable by just anybody, since then anybody could run
commands under the Nix build user accounts. For that reason there is
a configuration file <filename>/etc/nix-setuid.conf</filename> that
restricts the use of the helper. This file should be a text file
containing precisely two lines, the first being the Nix daemon user
and the second being the build users group, e.g.,
<programlisting>
nix
nixbld
</programlisting>
The setuid-helper barfs if it is called by a user other than the one
specified on the first line, or if it is asked to execute a build
under a user who is not a member of the group specified on the second
line. The file <filename>/etc/nix-setuid.conf</filename> must be
owned by root, and must not be group- or world-writable. The
setuid-helper barfs if this is not the case.</para>
</section>
<section><title>Restricting access</title>
<para>To limit which users can perform Nix operations, you can use the
permissions on the directory
<filename>/nix/var/nix/daemon-socket</filename>. For instance, if you
want to restrict the use of Nix to the members of a group called
<literal>nix-users</literal>, do
<screen>
$ chgrp nix-users /nix/var/nix/daemon-socket
$ chmod ug=rwx,o= /nix/var/nix/daemon-socket
</screen>
This way, users who are not in the <literal>nix-users</literal> group
cannot connect to the Unix domain socket
<filename>/nix/var/nix/daemon-socket/socket</filename>, so they cannot
perform Nix operations.</para>
</section>
</section> <!-- end of multi-user -->
</section> <!-- end of security -->
</section> <!-- end of permissions section -->
<section><title>Using Nix</title>

View File

@@ -1,304 +1,135 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-introduction">
xmlns:xlink="http://www.w3.org/1999/xlink">
<title>Introduction</title>
<section><title>About Nix</title>
<para>Nix is a <emphasis>purely functional package manager</emphasis>.
This means that it treats packages like values in purely functional
programming languages such as Haskell — they are built by functions
that dont have side-effects, and they never change after they have
been built. Nix stores packages in the <emphasis>Nix
store</emphasis>, usually the directory
<filename>/nix/store</filename>, where each package has its own unique
subdirectory such as
<programlisting>
/nix/store/r8vvq9kq18pz08v249h8my6r9vs7s0n3-firefox-2.0.0.1/
</programlisting>
where <literal>r8vvq9kq…</literal> is a unique identifier for the
package that captures all its dependencies (its a cryptographic hash
of the packages build dependency graph). This enables many powerful
features.</para>
<simplesect><title>Multiple versions</title>
<para>You can have multiple versions or variants of a package
installed at the same time. This is especially important when
different applications have dependencies on different versions of the
same package — it prevents the “DLL hell”. Because of the hashing
scheme, different versions of a package end up in different paths in
the Nix store, so they dont interfere with each other.</para>
<para>An important consequence is that operations like upgrading or
uninstalling an application cannot break other applications, since
these operations never “destructively” update or delete files that are
used by other packages.</para>
</simplesect>
<simplesect><title>Complete dependencies</title>
<para>Nix helps you make sure that package dependency specifications
are complete. In general, when youre making a package for a package
management system like RPM, you have to specify for each package what
its dependencies are, but there are no guarantees that this
specification is complete. If you forget a dependency, then the
package will build and work correctly on <emphasis>your</emphasis>
machine if you have the dependency installed, but not on the end
user's machine if it's not there.</para>
<para>Since Nix on the other hand doesnt install packages in “global”
locations like <filename>/usr/bin</filename> but in package-specific
directories, the risk of incomplete dependencies is greatly reduced.
This is because tools such as compilers dont search in per-packages
directories such as
<filename>/nix/store/5lbfaxb722zp…-openssl-0.9.8d/include</filename>,
so if a package builds correctly on your system, this is because you
specified the dependency explicitly.</para>
<para>Runtime dependencies are found by scanning binaries for the hash
parts of Nix store paths (such as <literal>r8vvq9kq…</literal>). This
sounds risky, but it works extremely well.</para>
</simplesect>
<simplesect><title>Multi-user support</title>
<para>Starting at version 0.11, Nix has multi-user support. This
means that non-privileged users can securely install software. Each
user can have a different <emphasis>profile</emphasis>, a set of
packages in the Nix store that appear in the users
<envar>PATH</envar>. If a user installs a package that another user
has already installed previously, the package wont be built or
downloaded a second time. At the same time, it is not possible for
one user to inject a Trojan horse into a package that might be used by
another user.</para>
<!--
<para>More details can be found in Section 3 of our <a
href="docs/papers.html#securesharing">ASE 2005 paper</a>.</para>
-->
</simplesect>
<simplesect><title>Atomic upgrades and rollbacks</title>
<para>Since package management operations never overwrite packages in
the Nix store but just add new versions in different paths, they are
<emphasis>atomic</emphasis>. So during a package upgrade, there is no
time window in which the package has some files from the old version
and some files from the new version — which would be bad because a
program might well crash if its started during that period.</para>
<para>And since package arent overwritten, the old versions are still
there after an upgrade. This means that you can <emphasis>roll
back</emphasis> to the old version:</para>
<screen>
$ nix-env --upgrade <replaceable>some-packages</replaceable>
$ nix-env --rollback
</screen>
</simplesect>
<simplesect><title>Garbage collection</title>
<para>When you install a package like this…
<screen>
$ nix-env --uninstall firefox
</screen>
the package isnt deleted from the system right away (after all, you
might want to do a rollback, or it might be in the profiles of other
users). Instead, unused packages can be deleted safely by running the
<emphasis>garbage collector</emphasis>:
<screen>
$ nix-collect-garbage
</screen>
This deletes all packages that arent in use by any user profile or by
a currently running program.</para>
</simplesect>
<simplesect><title>Functional package language</title>
<para>Packages are built from <emphasis>Nix expressions</emphasis>,
which is a simple functional language. A Nix expression describes
everything that goes into a package build action (a “derivation”):
other packages, sources, the build script, environment variables for
the build script, etc. Nix tries very hard to ensure that Nix
expressions are <emphasis>deterministic</emphasis>: building a Nix
expression twice should yield the same result.</para>
<para>Because its a functional language, its easy to support
building variants of a package: turn the Nix expression into a
function and call it any number of times with the appropriate
arguments. Due to the hashing scheme, variants dont conflict with
each other in the Nix store.</para>
</simplesect>
<simplesect><title>Transparent source/binary deployment</title>
<para>Nix expressions generally describe how to build a package from
source, so an installation action like
<screen>
$ nix-env --install firefox
</screen>
<emphasis>could</emphasis> cause quite a bit of build activity, as not
only Firefox but also all its dependencies (all the way up to the C
library and the compiler) would have to built, at least if they are
not already in the Nix store. This is a <emphasis>source deployment
model</emphasis>. For most users, building from source is not very
pleasant as it takes far too long. However, Nix can automatically
skip building from source and download a pre-built binary instead if
it knows about it. <emphasis>Nix channels</emphasis> provide Nix
expressions along with pre-built binaries.</para>
<!--
<para>source deployment model (like <a
href="http://www.gentoo.org/">Gentoo</a>) and a binary model (like
RPM)</para>
-->
</simplesect>
<simplesect><title>Binary patching</title>
<para>In addition to downloading binaries automatically if theyre
available, Nix can download binary deltas that patch an existing
package in the Nix store into a new version. This speeds up
upgrades.</para>
</simplesect>
<simplesect><title>Nix Packages collection</title>
<para>We provide a large set of Nix expressions containing hundreds of
existing Unix packages, the <emphasis>Nix Packages
collection</emphasis> (Nixpkgs).</para>
</simplesect>
<simplesect><title>Service deployment</title>
<para>Nix can be used not only for rolling out packages, but also
complete <emphasis>configurations</emphasis> of services. This is
done by treating all the static bits of a service (such as software
packages, configuration files, control scripts, static web pages,
etc.) as “packages” that can be built by Nix expressions. As a
result, all the features above apply to services as well: for
instance, you can roll back a web server configuration if a
configuration change turns out to be undesirable, you can easily have
multiple instances of a service (e.g., a test and production server),
and because the whole service is built in a purely functional way from
a Nix expression, it is repeatable so you can easily reproduce the
service on another machine.</para>
<!--
<para>You can read more about this in our <a
href="docs/papers.html#servicecm">SCM-12 paper</a>.</para>
-->
</simplesect>
<simplesect><title>Portability</title>
<para>Nix should run on most Unix systems, including Linux, FreeBSD and
Mac OS X. It is also supported on Windows using Cygwin.</para>
</simplesect>
<simplesect><title>NixOS</title>
<para>NixOS is a Linux distribution based on Nix. It uses Nix not
just for package management but also to manage the system
configuration (e.g., to build configuration files in
<filename>/etc</filename>). This means, among other things, that its
possible to easily roll back the entire configuration of the system to
an earlier state. Also, users can install software without root
privileges. For more information and downloads, see the <link
xlink:href="http://nix.cs.uu.nl/nixos/">NixOS homepage</link>.</para>
</simplesect>
<!-- other features:
- build farms
- reproducibility (Nix expressions allows whole configuration to be rebuilt)
-->
</section>
<section><title>About us</title>
<para>Nix was developed at the <link
xlink:href="http://www.cs.uu.nl/">Department of Information and
Computing Sciences</link>, Utrecht University by the <link
xlink:href="http://www.cs.uu.nl/wiki/Trace/WebHome">TraCE
project</link>. The project is funded by the Software Engineering
Research Program <link
xlink:href="http://www.jacquard.nl/">Jacquard</link> to improve the
support for variability in software systems.</para>
</section>
<section><title>About this manual</title>
<para>Nix is a system for the deployment of software. Software
deployment is concerned with the creation, distribution, and
management of software components (<quote>packages</quote>). Its main
features are:
<itemizedlist>
<listitem><para>It helps you make sure that dependency specifications
are complete. In general in a deployment system you have to specify
for each component what its dependencies are, but there are no
guarantees that this specification is complete. If you forget a
dependency, then the component will build and work correctly on
<emphasis>your</emphasis> machine if you have the dependency
installed, but not on the end user's machine if it's not
there.</para></listitem>
<listitem><para>It is possible to have <emphasis>multiple versions or
variants</emphasis> of a component installed at the same time. In
contrast, in systems such as RPM different versions of the same
package tend to install to the same location in the file system, so
installing one version will remove the other. This is especially
important if you want to use applications that have conflicting
requirements on different versions of a component (e.g., application A
requires version 1.0 of library X, while application B requires a
non-backwards compatible version 1.1).</para></listitem>
<listitem><para>Users can have different <quote>views</quote>
(<quote>profiles</quote> in Nix parlance) on the set of installed
applications in a system. For instance, one user can have version 1.0
of some package visible, while another is using version 1.1, and a
third doesn't use it at all.</para></listitem>
<listitem><para>It is possible to atomically
<emphasis>upgrade</emphasis> software. I.e., there is no time window
during an upgrade in which part of the old version and part of the new
version are simultaneously visible (which might well cause the
component to fail).</para></listitem>
<listitem><para>Likewise, it is possible to atomically roll back after
an install, upgrade, or uninstall action. That is, in a fast (O(1))
operation the previous configuration of the system can be restored.
This is because upgrade or uninstall actions don't actually remove
components from the system.</para></listitem>
<listitem><para>Unused components can be
<emphasis>garbage-collected</emphasis> automatically and safely: when
you remove an application from a profile, its dependencies will be
deleted by the garbage collector only if there are no other active
applications using them.</para></listitem>
<listitem><para>Nix supports both source-based deployment models
(where you distribute <emphasis>Nix expressions</emphasis> that tell
Nix how to build software from source) and binary-based deployment
models. The latter is more-or-less transparent: installation of
components is always based on Nix expressions, but if the expressions
have been built before and Nix knows that the resulting binaries are
available somewhere, it will use those instead.</para></listitem>
<listitem><para>Nix is flexible in the deployment policies that it
supports. There is a clear separation between the tools that
implement basic Nix <emphasis>mechanisms</emphasis> (e.g., building
Nix expressions), and the tools that implement various deployment
<emphasis>policies</emphasis>. For instance, there is a concept of
<quote>Nix channels</quote> that can be used to keep software
installations up-to-date automatically from a network source. This is
a policy that is implemented by a fairly short Perl script, which can
be adapted easily to achieve similar policies.</para></listitem>
<listitem><para>Nix component builds aim to be <quote>pure</quote>;
that is, unaffected by anything other than the declared dependencies.
This means that if a component was built successfully once, it can be
rebuilt again on another machine and the result will be the same. We
cannot <emphasis>guarantee</emphasis> this (e.g., if the build depends
on the time-of-day), but Nix (and the tools in the Nix Packages
collection) takes special care to help achieve this.</para></listitem>
<listitem><para>Nix expressions (the things that tell Nix how to build
components) are self-contained: they describe not just components but
complete compositions. In other words, Nix expressions also describe
how to build all the dependencies. This is in contrast to component
specification languages like RPM spec files, which might say that a
component X depends on some other component Y, but since it does not
describe <emphasis>exactly</emphasis> what Y is, the result of
building or running X might be different on different machines.
Combined with purity, self-containedness ensures that a component that
<quote>works</quote> on one machine also works on another, when
deployed using Nix.</para></listitem>
<listitem><para>The Nix expression language makes it easy to describe
variability in components (e.g., optional features or
dependencies).</para></listitem>
<listitem><para>Nix is ideal for building build farms that do
continuous builds of software from a version management system, since
it can take care of building all the dependencies as well. Also, Nix
only rebuilds components that have changed, so there are no
unnecessary builds. In addition, Nix can transparently distribute
build jobs over different machines, including different
platforms.</para></listitem>
<listitem><para>Nix can be used not only for software deployment, but
also for <emphasis>service deployment</emphasis>, such as the
deployment of a complete web server with all its configuration files,
static pages, software dependencies, and so on. Nix's advantages for
software deployment also apply here: for instance, the ability
trivially to have multiple configurations at the same time, or the
ability to do rollbacks.</para></listitem>
<listitem><para>Nix can efficiently upgrade between different versions
of a component through <emphasis>binary patching</emphasis>. If
patches are available on a server, and you try to install a new
version of some component, Nix will automatically apply a patch (or
sequence of patches), if available, to transform the installed
component into the new version.</para></listitem>
</itemizedlist>
</para>
<para>This manual tells you how to install and use Nix and how to
write Nix expressions for software not already in the Nix Packages
collection. It also discusses some advanced topics, such as setting
up a Nix-based build farm.</para>
up a Nix-based build farm, and doing service deployment using
Nix.</para>
</section>
<section><title>License</title>
<para>Nix is free software; you can redistribute it and/or modify it
under the terms of the <link
xlink:href="http://www.gnu.org/licenses/lgpl.html">GNU Lesser General
Public License</link> as published by the <link
xlink:href="http://www.fsf.org/">Free Software Foundation</link>;
either version 2.1 of the License, or (at your option) any later
version. Nix is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.</para>
</section>
<section><title>More information</title>
<para>Some background information on Nix can be found in a number of
papers. The ICSE 2004 paper <citetitle
<note><para>Some background information on Nix can be found in a
number of papers. The ICSE 2004 paper <citetitle
xlink:href='http://www.cs.uu.nl/~eelco/pubs/immdsd-icse2004-final.pdf'>Imposing
a Memory Management Discipline on Software Deployment</citetitle>
discusses the hashing mechanism used to ensure reliable dependency
@@ -310,27 +141,10 @@ gives a more general discussion of Nix from a system-administration
perspective. The CBSE 2005 paper <citetitle
xlink:href='http://www.cs.uu.nl/~eelco/pubs/eupfcdm-cbse2005-final.pdf'>Efficient
Upgrading in a Purely Functional Component Deployment Model
</citetitle> is about transparent patch deployment in Nix. The SCM-12
paper <citetitle
</citetitle> is about transparent patch deployment in Nix. Finally,
the SCM-12 paper <citetitle
xlink:href='http://www.cs.uu.nl/~eelco/pubs/servicecm-scm12-final.pdf'>
Service Configuration Management</citetitle> shows how services (e.g.,
web servers) can be deployed and managed through Nix. A short
overview of NixOS is given in the HotOS XI paper <citetitle
xlink:href="http://www.cs.uu.nl/~eelco/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
of Nix-related papers</link>.</para>
<para>Nix is the subject of Eelco Dolstras PhD thesis <citetitle
xlink:href="http://igitur-archive.library.uu.nl/dissertations/2006-0118-200031/index.htm">The
Purely Functional Software Deployment Model</citetitle>, which
contains most of the papers listed above.</para>
<para>Nix has a homepage at <link
xlink:href="http://nix.cs.uu.nl/"/>.</para>
</section>
web servers) can be deployed and managed through Nix.</para></note>
</chapter>

View File

@@ -19,7 +19,6 @@
<command>nix-build</command>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
<arg><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
<arg><option>--argstr</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--attr</option></arg>

View File

@@ -62,11 +62,11 @@ also <xref linkend="sec-channels" />.</para>
<varlistentry><term><option>--update</option></term>
<listitem><para>Downloads the Nix expressions of all subscribed
channels, makes them the default for <command>nix-env</command>
operations (by symlinking them in the directory
<filename>~/.nix-defexpr</filename>), and performs a
<command>nix-pull</command> on the manifests of all channels to
make pre-built binaries available.</para></listitem>
channels, makes the conjunction of these the default for
<command>nix-env</command> operations (by calling <command>nix-env
-I</command>), and performs a <command>nix-pull</command> on the
manifests of all channels to make pre-built binaries
available.</para></listitem>
</varlistentry>

View File

@@ -19,7 +19,13 @@
<command>nix-env</command>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
<arg><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
<arg><option>--argstr</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--attr</option></arg>
<arg choice='plain'><option>-A</option></arg>
</group>
<replaceable>attrPath</replaceable>
</arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--file</option></arg>
@@ -39,6 +45,9 @@
<replaceable>system</replaceable>
</arg>
<arg><option>--dry-run</option></arg>
<arg><option>--from-expression</option></arg>
<arg><option>-E</option></arg>
<arg><option>--from-profile</option> <replaceable>path</replaceable></arg>
<arg choice='plain'><replaceable>operation</replaceable></arg>
<arg rep='repeat'><replaceable>options</replaceable></arg>
<arg rep='repeat'><replaceable>arguments</replaceable></arg>
@@ -49,7 +58,7 @@
<refsection><title>Description</title>
<para>The command <command>nix-env</command> is used to manipulate Nix
user environments. User environments are sets of software packages
user environments. User environments are sets of software components
available to a user at some point in time. In other words, they are a
synthesised view of the programs available in the Nix store. There
may be many user environments: different users can have different
@@ -142,33 +151,13 @@ linkend="sec-common-options" />.</para>
<varlistentry><term><filename>~/.nix-defexpr</filename></term>
<listitem><para>A directory that contains the default Nix
expressions used by the <option>--install</option>,
<option>--upgrade</option>, and <option>--query
--available</option> operations to obtain derivations. The
<option>--file</option> option may be used to override this
default.</para>
<para>The Nix expressions in this directory are combined into a
single attribute set, with each file as an attribute that has the
name of the file. Thus, if <filename>~/.nix-defexpr</filename>
contains two files, <filename>foo</filename> and
<filename>bar</filename>, then the default Nix expression will
essentially be
<programlisting>
{
foo = import ~/.nix-defexpr/foo;
bar = import ~/.nix-defexpr/bar;
}</programlisting>
</para>
<para>The command <command>nix-channel</command> places symlinks
to the downloaded Nix expressions from each subscribed channel in
this directory.</para>
</listitem>
<!-- !!! .nix-defexpr can be a directory now -->
<listitem><para>The default Nix expression used by the
<option>--install</option>, <option>--upgrade</option>, and
<option>--query --available</option> operations to obtain
derivations. The <option>--file</option> option may be used to
override this default.</para></listitem>
</varlistentry>
@@ -201,7 +190,6 @@ linkend="sec-common-options" />.</para>
<arg choice='plain'><option>--install</option></arg>
<arg choice='plain'><option>-i</option></arg>
</group>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-inst-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
<group choice='opt'>
<arg choice='plain'><option>--preserve-installed</option></arg>
<arg choice='plain'><option>-P</option></arg>
@@ -233,21 +221,11 @@ number of possible ways:
<para>If there are multiple derivations matching a name in
<replaceable>args</replaceable> that have the same name (e.g.,
<literal>gcc-3.3.6</literal> and <literal>gcc-4.1.1</literal>), then
the derivation with the highest <emphasis>priority</emphasis> is
used. A derivation can define a priority by declaring the
<varname>meta.priority</varname> attribute. This attribute should
be a number, with a higher value denoting a lower priority. The
default priority is <literal>0</literal>.</para>
<para>If there are multiple matching derivations with the same
priority, then the derivation with the highest version will be
installed.</para>
<para>You can force the installation of multiple derivations with
the same name by being specific about the versions. For instance,
<literal>nix-env -i gcc-3.3.6 gcc-4.1.1</literal> will install both
version of GCC (and will probably cause a user environment
conflict!).</para></listitem>
only the highest version will be installed. You can force the
installation of multiple derivations with the same name by being
specific about the versions. For instance, <literal>nix-env -i
gcc-3.3.6 gcc-4.1.1</literal> will install both version of GCC (and
will probably cause a user environment conflict!).</para></listitem>
<listitem><para>If <link
linkend='opt-attr'><option>--attr</option></link>
@@ -294,15 +272,6 @@ number of possible ways:
<variablelist>
<varlistentry><term><option>--prebuild-only</option> / <option>-b</option></term>
<listitem><para>Use only derivations for which a substitute is
registered, i.e., there is a pre-built binary available that can
be downloaded in lieu of building the derivation. Thus, no
packages will be built from source.</para></listitem>
</varlistentry>
<varlistentry><term><option>--preserve-installed</option></term>
<term><option>-P</option></term>
@@ -418,7 +387,7 @@ the following paths will be substituted:
<!--######################################################################-->
<refsection xml:id="rsec-nix-env-upgrade"><title>Operation <option>--upgrade</option></title>
<refsection><title>Operation <option>--upgrade</option></title>
<refsection><title>Synopsis</title>
@@ -428,7 +397,6 @@ the following paths will be substituted:
<arg choice='plain'><option>--upgrade</option></arg>
<arg choice='plain'><option>-u</option></arg>
</group>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-inst-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
<group choice='opt'>
<arg choice='plain'><option>--lt</option></arg>
<arg choice='plain'><option>--leq</option></arg>
@@ -503,9 +471,6 @@ installed.</para>
</variablelist>
<para>For the other flags, see <option
linkend="rsec-nix-env-install">--install</option>.</para>
</refsection>
<refsection><title>Examples</title>
@@ -615,111 +580,6 @@ $ nix-env -e '*' <lineannotation>(remove everything)</lineannotation></screen>
<!--######################################################################-->
<refsection xml:id="rsec-nix-env-set-flag"><title>Operation <option>--set-flag</option></title>
<refsection><title>Synopsis</title>
<cmdsynopsis>
<command>nix-env</command>
<arg choice='plain'><option>--set-flag</option></arg>
<arg choice='plain'><replaceable>name</replaceable></arg>
<arg choice='plain'><replaceable>value</replaceable></arg>
<arg choice='plain' rep='repeat'><replaceable>drvnames</replaceable></arg>
</cmdsynopsis>
</refsection>
<refsection><title>Description</title>
<para>The <option>--set-flag</option> operation allows meta attributes
of installed packages to be modified. There are several attributes
that can be usefully modified, because they affect the behaviour of
<command>nix-env</command> or the user environment build
script:
<itemizedlist>
<listitem><para><varname>priority</varname> can be changed to
resolve filename clashes. The user environment build script uses
the <varname>meta.priority</varname> attribute of derivations to
resolve filename collisions between packages. Lower priority values
denote a higher priority. For instance, the GCC wrapper package and
the Binutils package in Nixpkgs both have a file
<filename>bin/ld</filename>, so previously if you tried to install
both you would get a collision. Now, on the other hand, the GCC
wrapper declares a higher priority than Binutils, so the formers
<filename>bin/ld</filename> is symlinked in the user
environment.</para></listitem>
<listitem><para><varname>keep</varname> can be set to
<literal>true</literal> to prevent the package from being upgraded
or replaced. This is useful if you want to hang on to an older
version of a package.</para></listitem>
<listitem><para><varname>active</varname> can be set to
<literal>false</literal> to “disable” the package. That is, no
symlinks will be generated to the files of the package, but it
remains part of the profile (so it wont be garbage-collected). It
can be set back to <literal>true</literal> to re-enable the
package.</para></listitem>
</itemizedlist>
</para>
</refsection>
<refsection><title>Examples</title>
<para>To prevent the currently installed Firefox from being upgraded:
<screen>
$ nix-env --set-flag keep true firefox</screen>
After this, <command>nix-env -u</command> will ignore Firefox.</para>
<para>To disable the currently installed Firefox, then install a new
Firefox while the old remains part of the profile:
<screen>
$ nix-env -q \*
firefox-2.0.0.9 <lineannotation>(the current one)</lineannotation>
$ nix-env --preserve-installed -i firefox-2.0.0.11
installing `firefox-2.0.0.11'
building path(s) `/nix/store/myy0y59q3ig70dgq37jqwg1j0rsapzsl-user-environment'
Collission between `/nix/store/<replaceable>...</replaceable>-firefox-2.0.0.11/bin/firefox'
and `/nix/store/<replaceable>...</replaceable>-firefox-2.0.0.9/bin/firefox'.
<lineannotation>(i.e., cant have two active at the same time)</lineannotation>
$ nix-env --set-flag active false firefox
setting flag on `firefox-2.0.0.9'
$ nix-env --preserve-installed -i firefox-2.0.0.11
installing `firefox-2.0.0.11'
$ nix-env -q \*
firefox-2.0.0.11 <lineannotation>(the enabled one)</lineannotation>
firefox-2.0.0.9 <lineannotation>(the disabled one)</lineannotation></screen>
</para>
<para>To make files from <literal>binutils</literal> take precedence
over files from <literal>gcc</literal>:
<screen>
$ nix-env --set-flag priority 5 binutils
$ nix-env --set-flag priority 10 gcc</screen>
</para>
</refsection>
</refsection>
<!--######################################################################-->
<refsection><title>Operation <option>--query</option></title>
@@ -732,14 +592,13 @@ $ nix-env --set-flag priority 10 gcc</screen>
<arg choice='plain'><option>--query</option></arg>
<arg choice='plain'><option>-q</option></arg>
</group>
<arg><option>--xml</option></arg>
<group choice='opt'>
<arg choice='plain'><option>--installed</option></arg>
<arg choice='plain'><option>--available</option></arg>
<arg choice='plain'><option>-a</option></arg>
</group>
<sbr />
<arg>
<group choice='req'>
<arg choice='plain'><option>--status</option></arg>
@@ -748,8 +607,8 @@ $ nix-env --set-flag priority 10 gcc</screen>
</arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--attr-path</option></arg>
<arg choice='plain'><option>-P</option></arg>
<arg choice='plain'><option>--attr</option></arg>
<arg choice='plain'><option>-A</option></arg>
</group>
</arg>
<arg><option>--no-name</option></arg>
@@ -763,28 +622,6 @@ $ nix-env --set-flag priority 10 gcc</screen>
<arg><option>--drv-path</option></arg>
<arg><option>--out-path</option></arg>
<arg><option>--description</option></arg>
<arg><option>--meta</option></arg>
<sbr />
<arg><option>--xml</option></arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--prebuilt-only</option></arg>
<arg choice='plain'><option>-b</option></arg>
</group>
</arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--attr</option></arg>
<arg choice='plain'><option>-A</option></arg>
</group>
<replaceable>attribute-path</replaceable>
</arg>
<sbr />
<arg choice='plain' rep='repeat'><replaceable>names</replaceable></arg>
</cmdsynopsis>
@@ -861,16 +698,6 @@ user environment elements, etc. -->
</varlistentry>
<varlistentry><term><option>--prebuild-only</option> / <option>-b</option></term>
<listitem><para>Show only derivations for which a substitute is
registered, i.e., there is a pre-built binary available that can
be downloaded in lieu of building the derivation. Thus, this
shows all packages that probably can be installed
quickly.</para></listitem>
</varlistentry>
<varlistentry><term><option>--status</option></term>
<term><option>-s</option></term>
@@ -890,8 +717,8 @@ user environment elements, etc. -->
</varlistentry>
<varlistentry><term><option>--attr-path</option></term>
<term><option>-P</option></term>
<varlistentry><term><option>--attr</option></term>
<term><option>-a</option></term>
<listitem><para>Print the <emphasis>attribute path</emphasis> of
the derivation, which can be used to unambiguously select it using
@@ -914,35 +741,35 @@ user environment elements, etc. -->
<listitem><para>Compare installed versions to available versions,
or vice versa (if <option>--available</option> is given). This is
useful for quickly seeing whether upgrades for installed
packages are available in a Nix expression. A column is added
components are available in a Nix expression. A column is added
with the following meaning:
<variablelist>
<varlistentry><term><literal>&lt;</literal> <replaceable>version</replaceable></term>
<listitem><para>A newer version of the package is available
<listitem><para>A newer version of the component is available
or installed.</para></listitem>
</varlistentry>
<varlistentry><term><literal>=</literal> <replaceable>version</replaceable></term>
<listitem><para>At most the same version of the package is
<listitem><para>At most the same version of the component is
available or installed.</para></listitem>
</varlistentry>
<varlistentry><term><literal>></literal> <replaceable>version</replaceable></term>
<listitem><para>Only older versions of the package are
<listitem><para>Only older versions of the component are
available or installed.</para></listitem>
</varlistentry>
<varlistentry><term><literal>- ?</literal></term>
<listitem><para>No version of the package is available or
<listitem><para>No version of the component is available or
installed.</para></listitem>
</varlistentry>
@@ -983,14 +810,6 @@ user environment elements, etc. -->
</varlistentry>
<varlistentry><term><option>--meta</option></term>
<listitem><para>Print all of the meta-attributes of the
derivation. This option is only available with
<option>--xml</option>.</para></listitem>
</varlistentry>
</variablelist>
</refsection>

View File

@@ -779,178 +779,4 @@ archive is read from standard input.</para>
</refsection>
<!--######################################################################-->
<refsection xml:id='refsec-nix-store-export'><title>Operation <option>--export</option></title>
<refsection>
<title>Synopsis</title>
<cmdsynopsis>
<command>nix-store</command>
<arg choice='plain'><option>--export</option></arg>
<arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
</cmdsynopsis>
</refsection>
<refsection><title>Description</title>
<para>The operation <option>--export</option> writes a serialisation
of the specified store paths to standard output in a format that can
be imported into another Nix store with <command
linkend="refsec-nix-store-import">nix-store --import</command>. This
is like <command linkend="refsec-nix-store-dump">nix-store
--dump</command>, except that the NAR archive produced by that command
doesnt contain the necessary meta-information to allow it to be
imported into another Nix store (namely, the set of references of the
path).</para>
<para>This command does not produce a <emphasis>closure</emphasis> of
the specified paths, so if a store path references other store paths
that are missing in the target Nix store, the import will fail. To
copy a whole closure, do something like
<screen>
$ nix-store --export $(nix-store -qR <replaceable>paths</replaceable>) > out</screen>
</para>
<para>For an example of how <option>--export</option> and
<option>--import</option> can be used, see the source of the <command
linkend="sec-nix-copy-closure">nix-copy-closure</command>
command.</para>
</refsection>
</refsection>
<!--######################################################################-->
<refsection xml:id='refsec-nix-store-import'><title>Operation <option>--import</option></title>
<refsection>
<title>Synopsis</title>
<cmdsynopsis>
<command>nix-store</command>
<arg choice='plain'><option>--import</option></arg>
</cmdsynopsis>
</refsection>
<refsection><title>Description</title>
<para>The operation <option>--export</option> reads a serialisation of
a set of store paths produced by <command
linkend="refsec-nix-store-export">nix-store --import</command> from
standard input and adds those store paths to the Nix store. Paths
that already exist in the Nix store are ignored. If a path refers to
another path that doesnt exist in the Nix store, the import
fails.</para>
</refsection>
</refsection>
<!--######################################################################-->
<refsection><title>Operation <option>--optimise</option></title>
<refsection>
<title>Synopsis</title>
<cmdsynopsis>
<command>nix-store</command>
<arg choice='plain'><option>--optimise</option></arg>
</cmdsynopsis>
</refsection>
<refsection><title>Description</title>
<para>The operation <option>--optimise</option> reduces Nix store disk
space usage by finding identical files in the store and hard-linking
them to each other. It typically reduces the size of the store by
something like 25-35%. Only regular files and symlinks are
hard-linked in this manner. Files are considered identical when they
have the same NAR archive serialisation: that is, regular files must
have the same contents and permission (executable or non-executable),
and symlinks must have the same contents.</para>
<para>After completion, or when the command is interrupted, a report
on the achieved savings is printed on standard error.</para>
<para>Use <option>-vv</option> or <option>-vvv</option> to get some
progress indication.</para>
</refsection>
<refsection><title>Example</title>
<screen>
$ nix-store --optimise
hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1'
<replaceable>...</replaceable>
541838819 bytes (516.74 MiB) freed by hard-linking 54143 files;
there are 114486 files with equal contents out of 215894 files in total
</screen>
</refsection>
</refsection>
<!--######################################################################-->
<refsection><title>Operation <option>--read-log</option></title>
<refsection>
<title>Synopsis</title>
<cmdsynopsis>
<command>nix-store</command>
<group choice='req'>
<arg choice='plain'><option>--read-log</option></arg>
<arg choice='plain'><option>-l</option></arg>
</group>
<arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
</cmdsynopsis>
</refsection>
<refsection><title>Description</title>
<para>The operation <option>--read-log</option> prints the build log
of the specified store paths on standard output. The build log is
whatever the builder of a derivation wrote to standard output and
standard error. If a store path is not a derivation, the deriver of
the store path is used.</para>
<para>Build logs are kept in
<filename>/nix/var/log/nix/drvs</filename>. However, there is no
guarantee that a build log is available for any particular store
path. For instance, if the path was downloaded as a pre-built binary
through a substitute, then the log is unavailable.</para>
</refsection>
<refsection><title>Example</title>
<screen>
$ nix-store -l $(which ktorrent)
building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1
unpacking sources
unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz
ktorrent-2.2.1/
ktorrent-2.2.1/NEWS
<replaceable>...</replaceable>
</screen>
</refsection>
</refsection>
<!-- TODO: export, import operations -->
</refentry>

View File

@@ -13,10 +13,6 @@
</group>
<replaceable>number</replaceable>
</arg>
<arg>
<arg><option>--max-silent-time</option></arg>
<replaceable>number</replaceable>
</arg>
<arg><option>--keep-going</option></arg>
<arg><option>-k</option></arg>
<arg><option>--keep-failed</option></arg>

View File

@@ -103,17 +103,6 @@
</varlistentry>
<varlistentry xml:id="opt-max-silent-time"><term><option>--max-silent-time</option></term>
<listitem><para>Sets the maximum number of seconds that a builder
can go without producing any data on standard output or standard
error. The default is specified by the <link
linkend='conf-build-max-silent-time'><literal>build-max-silent-time</literal></link>
configuration setting. <literal>0</literal> means no
time-out.</para></listitem>
</varlistentry>
<varlistentry><term><option>--keep-going</option></term>
<term><option>-k</option></term>
@@ -268,17 +257,6 @@
</varlistentry>
<varlistentry><term><option>--argstr</option> <replaceable>name</replaceable> <replaceable>value</replaceable></term>
<listitem><para>This option is like <option>--arg</option>, only the
value is not a Nix expression but a string. So instead of
<literal>--arg system \"i686-linux\"</literal> (the outer quotes are
to keep the shell happy) you can say <literal>--argstr system
i686-linux</literal>.</para></listitem>
</varlistentry>
<varlistentry xml:id="opt-attr"><term><option>--attr</option> / <option>-A</option>
<replaceable>attrPath</replaceable></term>

View File

@@ -1,22 +0,0 @@
<nop xmlns="http://docbook.org/ns/docbook">
<arg>
<group choice='req'>
<arg choice='plain'><option>--prebuilt-only</option></arg>
<arg choice='plain'><option>-b</option></arg>
</group>
</arg>
<arg>
<group choice='req'>
<arg choice='plain'><option>--attr</option></arg>
<arg choice='plain'><option>-A</option></arg>
</group>
</arg>
<arg><option>--from-expression</option></arg>
<arg><option>-E</option></arg>
<arg><option>--from-profile</option> <replaceable>path</replaceable></arg>
</nop>

View File

@@ -6,9 +6,9 @@
<para>This chapter discusses how to do package management with Nix,
i.e., how to obtain, install, upgrade, and erase packages. This is
i.e., how to obtain, install, upgrade, and erase components. This is
the “users” perspective of the Nix system — people
who want to <emphasis>create</emphasis> packages should consult
who want to <emphasis>create</emphasis> components should consult
<xref linkend='chap-writing-nix-expressions' />.</para>
@@ -16,8 +16,8 @@ who want to <emphasis>create</emphasis> packages should consult
<para>The main command for package management is <link
linkend="sec-nix-env"><command>nix-env</command></link>. You can use
it to install, upgrade, and erase packages, and to query what
packages are installed or are available for installation.</para>
it to install, upgrade, and erase components, and to query what
components are installed or are available for installation.</para>
<para>In Nix, different users can have different “views”
on the set of installed applications. That is, there might be lots of
@@ -30,10 +30,10 @@ environment</emphasis>, which is just a directory tree consisting of
symlinks to the files of the active applications. </para>
<para>Components are installed from a set of <emphasis>Nix
expressions</emphasis> that tell Nix how to build those packages,
expressions</emphasis> that tell Nix how to build those components,
including, if necessary, their dependencies. There is a collection of
Nix expressions called the Nix Package collection that contains
packages ranging from basic development stuff such as GCC and Glibc,
components ranging from basic development stuff such as GCC and Glibc,
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
@@ -41,7 +41,7 @@ the latest version from <link
xlink:href='http://nix.cs.uu.nl/dist/nix' />.</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:
Packages, you can view the set of available components in the release:
<screen>
$ nix-env -qaf nixpkgs-<replaceable>version</replaceable> '*'
@@ -74,7 +74,7 @@ gcc-4.1.1</screen>
</para>
<para>It is also possible to see the <emphasis>status</emphasis> of
available packages, i.e., whether they are installed into the user
available components, i.e., whether they are installed into the user
environment and/or present in the system:
<screen>
@@ -86,24 +86,24 @@ IPS bison-1.875d
...</screen>
The first character (<literal>I</literal>) indicates whether the
package is installed in your current user environment. The second
component is installed in your current user environment. The second
(<literal>P</literal>) indicates whether it is present on your system
(in which case installing it into your user environment would be a
very quick operation). The last one (<literal>S</literal>) indicates
whether there is a so-called <emphasis>substitute</emphasis> for the
package, which is Nixs mechanism for doing binary deployment. It
just means that Nix knows that it can fetch a pre-built package from
component, which is Nixs mechanism for doing binary deployment. It
just means that Nix knows that it can fetch a pre-built component from
somewhere (typically a network server) instead of building it
locally.</para>
<para>So now that we have a set of Nix expressions we can build the
packages contained in them. This is done using <literal>nix-env
components contained in them. This is done using <literal>nix-env
-i</literal>. For instance,
<screen>
$ nix-env -f nixpkgs-<replaceable>version</replaceable> -i subversion</screen>
will install the package called <literal>subversion</literal> (which
will install the component called <literal>subversion</literal> (which
is, of course, the <link
xlink:href='http://subversion.tigris.org/'>Subversion version
management system</link>).</para>
@@ -112,7 +112,7 @@ management system</link>).</para>
Subversion and all its dependencies. This will take quite a while —
typically an hour or two on modern machines. Fortunately, there is a
faster way (so do a Ctrl-C on that install operation!): you just need
to tell Nix that pre-built binaries of all those packages are
to tell Nix that pre-built binaries of all those components are
available somewhere. This is done using the
<command>nix-pull</command> command, which must be supplied with a URL
containing a <emphasis>manifest</emphasis> describing what binaries
@@ -153,7 +153,7 @@ expressions, use <parameter>-i</parameter> instead of
<parameter>-u</parameter>; <parameter>-i</parameter> will remove
whatever version is already installed.</para>
<para>You can also upgrade all packages for which there are newer
<para>You can also upgrade all components for which there are newer
versions:
<screen>
@@ -199,19 +199,19 @@ set.</para></footnote></para>
implementing the ability to allow different users to have different
configurations, and to do atomic upgrades and rollbacks. To
understand how they work, its useful to know a bit about how Nix
works. In Nix, packages are stored in unique locations in the
works. In Nix, components are stored in unique locations in the
<emphasis>Nix store</emphasis> (typically,
<filename>/nix/store</filename>). For instance, a particular version
of the Subversion package might be stored in a directory
of the Subversion component might be stored in a directory
<filename>/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3/</filename>,
while another version might be stored in
<filename>/nix/store/5mq2jcn36ldlmh93yj1n8s9c95pj7c5s-subversion-1.1.2</filename>.
The long strings prefixed to the directory names are cryptographic
hashes<footnote><para>160-bit truncations of SHA-256 hashes encoded in
a base-32 notation, to be precise.</para></footnote> of
<emphasis>all</emphasis> inputs involved in building the package
<emphasis>all</emphasis> inputs involved in building the component
sources, dependencies, compiler flags, and so on. So if two
packages differ in any way, they end up in different locations in
components differ in any way, they end up in different locations in
the file system, so they dont interfere with each other. <xref
linkend='fig-user-environments' /> shows a part of a typical Nix
store.</para>
@@ -231,12 +231,12 @@ $ /nix/store/dpmvp969yhdq...-subversion-1.1.3/bin/svn</screen>
every time you want to run Subversion. Of course we could set up the
<envar>PATH</envar> environment variable to include the
<filename>bin</filename> directory of every package we want to use,
<filename>bin</filename> directory of every component we want to use,
but this is not very convenient since changing <envar>PATH</envar>
doesnt take effect for already existing processes. The solution Nix
uses is to create directory trees of symlinks to
<emphasis>activated</emphasis> packages. These are called
<emphasis>user environments</emphasis> and they are packages
<emphasis>activated</emphasis> components. These are called
<emphasis>user environments</emphasis> and they are components
themselves (though automatically generated by
<command>nix-env</command>), so they too reside in the Nix store. For
instance, in <xref linkend='fig-user-environments' /> the user
@@ -285,8 +285,8 @@ operation, a new user environment and generation link are created
based on the current one, and finally the <filename>default</filename>
symlink is made to point at the new generation. This last step is
atomic on Unix, which explains how we can do atomic upgrades. (Note
that the building/installing of new packages doesnt interfere in
any way with old packages, since they are stored in different
that the building/installing of new components doesnt interfere in
any way with old components, since they are stored in different
locations in the Nix store.)</para>
<para>If you find that you want to undo a <command>nix-env</command>
@@ -352,18 +352,18 @@ This will <emphasis>not</emphasis> change the
<para><command>nix-env</command> operations such as upgrades
(<option>-u</option>) and uninstall (<option>-e</option>) never
actually delete packages from the system. All they do (as shown
actually delete components from the system. All they do (as shown
above) is to create a new user environment that no longer contains
symlinks to the “deleted” packages.</para>
symlinks to the “deleted” components.</para>
<para>Of course, since disk space is not infinite, unused packages
<para>Of course, since disk space is not infinite, unused components
should be removed at some point. You can do this by running the Nix
garbage collector. It will remove from the Nix store any package
garbage collector. It will remove from the Nix store any component
not used (directly or indirectly) by any generation of any
profile.</para>
<para>Note however that as long as old generations reference a
package, it will not be deleted. After all, we wouldnt be able to
component, it will not be deleted. After all, we wouldnt be able to
do a rollback otherwise. So in order for garbage collection to be
effective, you should also delete (some) old generations. Of course,
this should only be done if you are certain that you will not need to
@@ -486,7 +486,7 @@ makes the union of each channels Nix expressions the default for
<screen>
$ nix-env -u '*'</screen>
to upgrade all packages in your profile to the latest versions
to upgrade all components in your profile to the latest versions
available in the subscribed channels.</para>
</section>

View File

@@ -11,7 +11,7 @@ to the following chapters.</para>
<orderedlist>
<listitem><para>Download a source tarball or RPM from <link
xlink:href='http://nix.cs.uu.nl/'/>. Build source
xlink:href='http://www.cs.uu.nl/groups/ST/Trace/Nix'/>. Build source
distributions using the regular sequence:
<screen>
@@ -22,9 +22,8 @@ $ 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
impossible to use our pre-built components. Alternatively, you could
grab an RPM if you're on an RPM-based system. You should also add
<filename>/nix/etc/profile.d/nix.sh</filename> to your
<filename>~/.bashrc</filename> (or some other login
file).</para></listitem>
@@ -41,14 +40,14 @@ $ nix-channel --add \
<screen>
$ nix-channel --update</screen>
Note that this in itself doesn't download any packages, it just
Note that this in itself doesn't download any components, it just
downloads the Nix expressions that build them and stores them
somewhere (under <filename>~/.nix-defexpr</filename>, in case you're
curious). Also, it registers the fact that pre-built binaries are
available remotely.</para></listitem>
<listitem><para>See what installable packages are currently available
in the channel:
<listitem><para>See what installable components are currently
available in the channel:
<screen>
$ nix-env -qa * <lineannotation>(mind the quotes!)</lineannotation>
@@ -60,13 +59,13 @@ libxslt-1.1.0
</para></listitem>
<listitem><para>Install some packages from the channel:
<listitem><para>Install some components from the channel:
<screen>
$ nix-env -i hello firefox <replaceable>...</replaceable> </screen>
This should download pre-built packages; it should not build them
locally (if it does, something went wrong).</para></listitem>
This should download the pre-built components; it should not build
them locally (if it does, something went wrong).</para></listitem>
<listitem><para>Test that they work:
@@ -93,8 +92,8 @@ $ nix-env -e hello</screen>
$ nix-channel --update
$ nix-env -u '*'</screen>
The latter command will upgrade each installed package for which there
is a “newer” version (as determined by comparing the version
The latter command will upgrade each installed component for which
there is a “newer” version (as determined by comparing the version
numbers).</para></listitem>
<listitem><para>You can also install specific packages directly from
@@ -108,7 +107,7 @@ appear asking you whether its okay to install the package. Say
installed.</para></listitem>
<listitem><para>If you're unhappy with the result of a
<command>nix-env</command> action (e.g., an upgraded package turned
<command>nix-env</command> action (e.g., an upgraded component turned
out not to work properly), you can go back:
<screen>
@@ -125,7 +124,7 @@ $ nix-collect-garbage -d</screen>
<!--
The first command deletes old “generations” of your profile (making
rollbacks impossible, but also making the packages in those old
rollbacks impossible, but also making the components in those old
generations available for garbage collection), while the second
command actually deletes them.-->

View File

@@ -8,258 +8,115 @@
<!--==================================================================-->
<section xml:id="ssec-relnotes-0.11"><title>Release 0.11 (December 31,
2007)</title>
<para>Nix 0.11 has many improvements over the previous stable release.
The most important improvement is secure multi-user support. It also
features many usability enhancements and language extensions, many of
them prompted by NixOS, the purely functional Linux distribution based
on Nix. Here is an (incomplete) list:</para>
<section xml:id="ssec-relnotes-0.11"><title>Release 0.11 (TBA)</title>
<itemizedlist>
<listitem><para>Secure multi-user support. A single Nix store can
now be shared between multiple (possible untrusted) users. This is
an important feature for NixOS, where it allows non-root users to
install software. The old setuid method for sharing a store between
multiple users has been removed. Details for setting up a
multi-user store can be found in the manual.</para></listitem>
<listitem><para>TODO: multi-user support. The old setuid method for
sharing a store between multiple users has been
removed.</para></listitem>
<listitem><para>The new command <command>nix-copy-closure</command>
gives you an easy and efficient way to exchange software between
machines. It copies the missing parts of the closure of a set of
store path to or from a remote machine via
<command>ssh</command>.</para></listitem>
store path to or from a remote machine.</para></listitem>
<listitem><para>A new kind of string literal: strings between double
single-quotes (<literal>''</literal>) have indentation
“intelligently” removed. This allows large strings (such as shell
scripts or configuration file fragments in NixOS) to cleanly follow
the indentation of the surrounding expression. It also requires
much less escaping, since <literal>''</literal> is less common in
most languages than <literal>"</literal>.</para></listitem>
<listitem><para><command>nix-env</command> <option>--set</option>
modifies the current generation of a profile so that it contains
exactly the specified derivation, and nothing else. For example,
<literal>nix-env -p /nix/var/nix/profiles/browser --set
firefox</literal> lets the profile named
<filename>browser</filename> contain just Firefox.</para></listitem>
<listitem><para><command>nix-env</command> now maintains
meta-information about installed packages in profiles. The
meta-information is the contents of the <varname>meta</varname>
attribute of derivations, such as <varname>description</varname> or
<varname>homepage</varname>. The command <literal>nix-env -q --xml
--meta</literal> shows all meta-information.</para></listitem>
<listitem><para><command>nix-prefetch-url</command> now by default
computes the SHA-256 hash of the file instead of the MD5 hash. In
calls to <function>fetchurl</function> you should pass an
<literal>sha256</literal> attribute instead of
<literal>md5</literal>. You can pass either a hexadecimal or a
base-32 encoding of the hash.</para></listitem>
<listitem><para><command>nix-env</command> now uses the
<varname>meta.priority</varname> attribute of derivations to resolve
filename collisions between packages. Lower priority values denote
a higher priority. For instance, the GCC wrapper package and the
Binutils package in Nixpkgs both have a file
<filename>bin/ld</filename>, so previously if you tried to install
both you would get a collision. Now, on the other hand, the GCC
wrapper declares a higher priority than Binutils, so the formers
<filename>bin/ld</filename> is symlinked in the user
environment.</para></listitem>
<listitem><para><command>nix-env -i / -u</command>: instead of
breaking package ties by version, break them by priority and version
number. That is, if there are multiple packages with the same name,
then pick the package with the highest priority, and only use the
version if there are multiple packages with the same
priority.</para>
<para>This makes it possible to mark specific versions/variant in
Nixpkgs more or less desirable than others. A typical example would
be a beta version of some package (e.g.,
<literal>gcc-4.2.0rc1</literal>) which should not be installed even
though it is the highest version, except when it is explicitly
selected (e.g., <literal>nix-env -i
gcc-4.2.0rc1</literal>).</para></listitem>
<listitem><para><command>nix-env --set-flag</command> allows meta
attributes of installed packages to be modified. There are several
attributes that can be usefully modified, because they affect the
behaviour of <command>nix-env</command> or the user environment
build script:
<itemizedlist>
<listitem><para><varname>meta.priority</varname> can be changed
to resolve filename clashes (see above).</para></listitem>
<listitem><para><varname>meta.keep</varname> can be set to
<literal>true</literal> to prevent the package from being
upgraded or replaced. Useful if you want to hang on to an older
version of a package.</para></listitem>
<listitem><para><varname>meta.active</varname> can be set to
<literal>false</literal> to “disable” the package. That is, no
symlinks will be generated to the files of the package, but it
remains part of the profile (so it wont be garbage-collected).
Set it back to <literal>true</literal> to re-enable the
package.</para></listitem>
</itemizedlist>
</para></listitem>
<listitem><para><command>nix-env -q</command> now has a flag
<option>--prebuilt-only</option> (<option>-b</option>) that causes
<command>nix-env</command> to show only those derivations whose
output is already in the Nix store or that can be substituted (i.e.,
downloaded from somewhere). In other words, it shows the packages
that can be installed “quickly”, i.e., dont need to be built from
source. The <option>-b</option> flag is also available in
<command>nix-env -i</command> and <command>nix-env -u</command> to
filter out derivations for which no pre-built binary is
available.</para></listitem>
<listitem><para>The new option <option>--argstr</option> (in
<command>nix-env</command>, <command>nix-instantiate</command> and
<command>nix-build</command>) is like <option>--arg</option>, except
that the value is a string. For example, <literal>--argstr system
i686-linux</literal> is equivalent to <literal>--arg system
\"i686-linux\"</literal> (note that <option>--argstr</option>
prevents annoying quoting around shell arguments).</para></listitem>
<listitem><para><command>nix-store</command> has a new operation
<option>--read-log</option> (<option>-l</option>)
<parameter>paths</parameter> that shows the build log of the given
paths.</para></listitem>
<!--
<listitem><para>TODO: <varname>allowedReferences</varname> for
checking the set of references in the output of a
derivation.</para></listitem>
<listitem><para>TODO: semantic cleanups of string concatenation
etc. (mostly in r6740).</para></listitem>
-->
<listitem><para>Nix now uses Berkeley DB 4.5. The database is
upgraded automatically, but you should be careful not to use old
versions of Nix that still use Berkeley DB 4.4.</para></listitem>
<listitem><para>TODO: now using Berkeley DB 4.5.</para></listitem>
<!-- foo
<listitem><para>TODO: option <option>- -reregister</option> in
<command>nix-store - -register-validity</command>.</para></listitem>
-->
<listitem><para>TODO: option <option>--reregister</option> in
<command>nix-store --register-validity</command>.</para></listitem>
<listitem><para>The option <option>--max-silent-time</option>
(corresponding to the configuration setting
<literal>build-max-silent-time</literal>) allows you to set a
timeout on builds — if a build produces no output on
<literal>stdout</literal> or <literal>stderr</literal> for the given
number of seconds, it is terminated. This is useful for recovering
automatically from builds that are stuck in an infinite
loop.</para></listitem>
<listitem><para>TODO: magic <varname>exportReferencesGraph</varname>
attribute.</para></listitem>
<listitem><para><command>nix-channel</command>: each subscribed
channel is its own attribute in the top-level expression generated
for the channel. This allows disambiguation (e.g. <literal>nix-env
-i -A nixpkgs_unstable.firefox</literal>).</para></listitem>
<listitem><para>TODO: option <option>--max-silent-time</option>,
configuration setting
<literal>build-max-silent-time</literal>.</para></listitem>
<listitem><para>The substitutes table has been removed from the
database. This makes operations such as <command>nix-pull</command>
and <command>nix-channel --update</command> much, much
faster.</para></listitem>
<listitem><para>TODO: <command>nix-env</command>
<option>--set</option>.</para></listitem>
<listitem><para>TODO: <option>--argstr</option>.</para></listitem>
<listitem><para><command>nix-pull</command> now supports
bzip2-compressed manifests. This speeds up
channels.</para></listitem>
<listitem><para>TODO: <command>nix-env</command> now maintains meta
info about installed packages in user environments. <option>-q
--xml --meta</option> to show all meta info.</para></listitem>
<listitem><para>TODO: <command>nix-env</command>
<option>--set-flag</option>. Specific flags:
<literal>active</literal>, <literal>priority</literal>,
<literal>keep</literal>.</para></listitem>
<listitem><para>TODO: <command>nix-env</command> <option>-i</option>
/ <option>-u</option> take package priorities into
account.</para></listitem>
<listitem><para><command>nix-env -q</command> now has a flag
<option>--prebuilt-only</option> (<option>-b</option>) that causes
<command>nix-env</command> to show only those derivations whose
output is already in the Nix store or that can be substituted (i.e.,
downloaded from somewhere). In other words, it shows the packages
that can be installed “quickly”, i.e., dont need to be built from
source.</para></listitem>
<listitem><para>TODO: new built-ins
<function>builtins.attrNames</function>,
<function>builtins.filterSource</function>,
<function>builtins.sub</function>,
<function>builtins.stringLength</function>,
<function>builtins.substring</function>.</para></listitem>
<listitem><para>TODO: each subscribed channel is its own attribute
in the top-level expression generated for the channel, this allows
disambiguation (<command>nix-env -qaA</command>).</para></listitem>
<listitem><para>TODO: substitutes table is gone, registering
substitutes is now much faster.</para></listitem>
<listitem><para><command>nix-prefetch-url</command> now has a
limited form of caching. This is used by
<command>nix-channel</command> to prevent unnecessary downloads when
the channel hasnt changed.</para></listitem>
<listitem><para><command>nix-prefetch-url</command> now by default
computes the SHA-256 hash of the file instead of the MD5 hash. In
calls to <function>fetchurl</function> you should pass the
<literal>sha256</literal> attribute instead of
<literal>md5</literal>. You can pass either a hexadecimal or a
base-32 encoding of the hash.</para></listitem>
<listitem><para>Nix can now perform builds in an automatically
generated “chroot”. This prevents a builder from accessing stuff
outside of the Nix store, and thus helps ensure purity. This is an
experimental feature.</para></listitem>
<listitem><para>The new command <command>nix-store
--optimise</command> reduces Nix store disk space usage by finding
identical files in the store and hard-linking them to each other.
It typically reduces the size of the store by something like
25-35%.</para></listitem>
<listitem><para><filename>~/.nix-defexpr</filename> can now be a
directory, in which case the Nix expressions in that directory are
combined into an attribute set, with the file names used as the
names of the attributes. The command <command>nix-env
--import</command> (which set the
<filename>~/.nix-defexpr</filename> symlink) is
removed.</para></listitem>
<listitem><para>Derivations can specify the new special attribute
<varname>allowedReferences</varname> to enforce that the references
in the output of a derivation are a subset of a declared set of
paths. For example, if <varname>allowedReferences</varname> is an
empty list, then the output must not have any references. This is
used in NixOS to check that generated files such as initial ramdisks
for booting Linux dont have any dependencies.</para></listitem>
<listitem><para>The new attribute
<varname>exportReferencesGraph</varname> allows builders access to
the references graph of their inputs. This is used in NixOS for
tasks such as generating ISO-9660 images that contain a Nix store
populated with the closure of certain paths.</para></listitem>
<listitem><para>Fixed-output derivations (like
<function>fetchurl</function>) can define the attribute
<varname>impureEnvVars</varname> to allow external environment
variables to be passed to builders. This is used in Nixpkgs to
support proxy configuration, among other things.</para></listitem>
<listitem><para>Several new built-in functions:
<function>builtins.attrNames</function>,
<function>builtins.filterSource</function>,
<function>builtins.isAttrs</function>,
<function>builtins.isFunction</function>,
<function>builtins.listToAttrs</function>,
<function>builtins.stringLength</function>,
<function>builtins.sub</function>,
<function>builtins.substring</function>,
<function>throw</function>,
<function>builtins.trace</function>,
<function>builtins.readFile</function>.</para></listitem>
</itemizedlist>

View File

@@ -46,11 +46,6 @@ h3 /* subsections */
font-size: 125%;
}
div.simplesect h2
{
font-size: 110%;
}
div.appendix h3
{
font-size: 150%;

View File

@@ -4,9 +4,7 @@
<title>Troubleshooting</title>
<para>This section provides solutions for some common problems. See
the <link xlink:href="https://bugs.cs.uu.nl/browse/NIX">Nix
bug tracker</link> for a list of currently known issues.</para>
<para>This section provides solutions for some common problems.</para>
<section><title>Berkeley DB: <quote>Cannot allocate memory</quote></title>
@@ -79,46 +77,6 @@ $ nix-store --verify</screen>
</section>
<section><title>Berkeley DB out of locks</title>
<para>It is possible, especially in <command>nix-store
--verify</command> or when running the garbage collector, to run out
of Berkeley DB locks, like this:
<screen>
$ nix-store --verify
checking path existence
checking path realisability
checking the derivers table
checking the references table
Berkeley DB error: Lock table is out of available object entries
error: Db::get: Cannot allocate memory</screen>
</para>
<para>A workaround is to increase the number of locks that Berkeley DB
allocates. (The real solution would be for Nix to not use so many
locks.) This can be done by putting the following in the file
<filename>/nix/var/nix/db/<link
xlink:href="http://www.oracle.com/technology/documentation/berkeley-db/db/ref/env/db_config.html">DB_CONFIG</link></filename>:
<programlisting>
set_lk_max_locks 100000
set_lk_max_lockers 100000
set_lk_max_objects 100000
</programlisting>
(Increase these numbers if necessary.) Then make sure that there are
no running Nix processes and delete the Berkeley DB environment:
<screen>
$ rm /nix/var/nix/db/__db.*</screen>
The Berkeley DB environment is automatically recreated with the new
limits when you run any Nix command.</para>
</section>
<section><title>Collisions in <command>nix-env</command></title>

File diff suppressed because it is too large Load Diff

View File

@@ -1,35 +0,0 @@
" Vim syntax file
" Language: nix
" Maintainer: Marc Weber <marco-oweber@gmx.de>
" Modify and commit if you feel that way
" Last Change: 2007 Dec
" Quit when a (custom) syntax file was already loaded
if exists("b:current_syntax")
finish
endif
syn keyword nixKeyword let throw inherit import true false null with
syn keyword nixConditional if else then
syn keyword nixBrace ( ) { } =
syn keyword nixBuiltin __currentSystem __currentTime __isFunction __getEnv __trace __toPath __pathExists
\ __readFile __toXML __toFile __filterSource __attrNames __getAttr __hasAttr __isAttrs __listToAttrs __isList
\ __head __tail __add __sub __lessThan __substring __stringLength
syn match nixAttr "\w\+\ze\s*="
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
hi def link nixKeyword Keyword
hi def link nixConditional Conditional
hi def link nixBrace Special
hi def link nixString String
hi def link nixBuiltin Special
hi def link nixStringParam Macro
hi def link nixMultiLineComment Comment
hi def link nixEndOfLineComment Comment
hi def link nixAttr Identifier
hi def link nixFuncArg Identifier

View File

@@ -80,7 +80,7 @@
### Option `build-max-silent-time'
#
# This option defines the maximum number of seconds that a builder can
# This option defines the maximum number of seconds that builder can
# go without producing any data on standard output or standard error.
# This is useful (for instance in a automated build system) to catch
# builds that are stuck in an infinite loop, or to catch remote builds
@@ -135,44 +135,6 @@
#build-users-group =
### Option `build-use-chroot'
#
# If set to `true', builds will be performed in a chroot environment,
# i.e., the build will be isolated from the normal file system
# hierarchy and will only see the Nix store, the temporary build
# directory, and the directories configured with the
# `build-chroot-dirs' option (such as /proc and /dev). This is useful
# to prevent undeclared dependencies on files in directories such as
# /usr/bin.
#
# The use of a chroot requires that Nix is run as root (but you can
# still use the "build users" feature to perform builds under
# different users than root). Currently, chroot builds only work on
# Linux because Nix uses "bind mounts" to make the Nix store and other
# directories available inside the chroot.
#
# The default is `false'.
#
# Example:
# build-use-chroot = true
#build-use-chroot = false
### Option `build-chroot-dirs'
#
# When builds are performed in a chroot environment, Nix will mount
# (using `mount --bind' on Linux) some directories from the normal
# file system hierarchy inside the chroot. These are the Nix store,
# the temporary build directory (usually /tmp/nix-<pid>-<number>) and
# the directories listed here. The default is "/dev /proc". Files
# in /dev (such as /dev/null) are needed by many builds, and some
# files in /proc may also be needed occasionally.
#
# Example:
# build-use-chroot = /dev /proc /bin
#build-chroot-dirs = /dev /proc
### Option `system'
#
# This option specifies the canonical Nix system name of the current

View File

@@ -4,8 +4,7 @@ bin_SCRIPTS = nix-collect-garbage \
nix-pack-closure nix-unpack-closure \
nix-copy-closure
noinst_SCRIPTS = nix-profile.sh generate-patches.pl \
find-runtime-roots.pl build-remote.pl
noinst_SCRIPTS = nix-profile.sh generate-patches.pl find-runtime-roots.pl
nix-pull nix-push: readmanifest.pm readconfig.pm download-using-manifests.pl
@@ -18,7 +17,6 @@ install-exec-local: readmanifest.pm download-using-manifests.pl find-runtime-roo
$(INSTALL_PROGRAM) download-using-manifests.pl $(DESTDIR)$(libexecdir)/nix
$(INSTALL_PROGRAM) find-runtime-roots.pl $(DESTDIR)$(libexecdir)/nix
$(INSTALL_PROGRAM) generate-patches.pl $(DESTDIR)$(libexecdir)/nix
$(INSTALL_PROGRAM) build-remote.pl $(DESTDIR)$(libexecdir)/nix
$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
include ../substitute.mk
@@ -34,5 +32,4 @@ EXTRA_DIST = nix-collect-garbage.in \
generate-patches.pl.in \
nix-pack-closure.in nix-unpack-closure.in \
nix-copy-closure.in \
find-runtime-roots.pl.in \
build-remote.pl.in
find-runtime-roots.pl.in

View File

@@ -1,208 +0,0 @@
#! @perl@ -w
use strict;
use Fcntl ':flock';
use English '-no_match_vars';
# General operation:
#
# Try to find a free machine of type $neededSystem. We do this as
# follows:
# - We acquire an exclusive lock on $currentLoad/main-lock.
# - For each machine $machine of type $neededSystem and for each $slot
# less than the maximum load for that machine, we try to get an
# exclusive lock on $currentLoad/$machine-$slot (without blocking).
# If we get such a lock, we send "accept" to the caller. Otherwise,
# we send "postpone" and exit.
# - We release the exclusive lock on $currentLoad/main-lock.
# - We perform the build on $neededSystem.
# - We release the exclusive lock on $currentLoad/$machine-$slot.
#
# The nice thing about this scheme is that if we die prematurely, the
# locks are released automatically.
my $loadIncreased = 0;
my $amWilling = shift @ARGV;
my $localSystem = shift @ARGV;
my $neededSystem = shift @ARGV;
my $drvPath = shift @ARGV;
sub sendReply {
my $reply = shift;
open OUT, ">&3" or die;
print OUT "$reply\n";
close OUT;
}
sub decline {
sendReply "decline";
exit 0;
}
my $currentLoad = $ENV{"NIX_CURRENT_LOAD"};
decline unless defined $currentLoad;
mkdir $currentLoad, 0777 or die unless -d $currentLoad;
my $conf = $ENV{"NIX_REMOTE_SYSTEMS"};
decline if !defined $conf || ! -e $conf;
# Decline if the local system can do the build.
decline if $amWilling && ($localSystem eq $neededSystem);
# Otherwise find a willing remote machine.
my %machines;
my %systemTypes;
my %sshKeys;
my %maxJobs;
my %curJobs;
# Read the list of machines.
open CONF, "< $conf" or die;
while (<CONF>) {
chomp;
s/\#.*$//g;
next if /^\s*$/;
/^\s*(\S+)\s+(\S+)\s+(\S+)\s+(\d+)\s*$/ or die;
$machines{$1} = "";
$systemTypes{$1} = $2;
$sshKeys{$1} = $3;
$maxJobs{$1} = $4;
}
close CONF;
# Acquire the exclusive lock on $currentLoad/main-lock.
my $mainLock = "$currentLoad/main-lock";
open MAINLOCK, ">>$mainLock" or die;
flock(MAINLOCK, LOCK_EX) or die;
# Find a suitable system.
my $rightType = 0;
my $machine;
LOOP: foreach my $cur (keys %machines) {
if ($neededSystem eq $systemTypes{$cur}) {
$rightType = 1;
# We have a machine of the right type. Try to get a lock on
# one of the machine's lock files.
my $slot = 0;
while ($slot < $maxJobs{$cur}) {
my $slotLock = "$currentLoad/$cur-$slot";
open SLOTLOCK, ">>$slotLock" or die;
if (flock(SLOTLOCK, LOCK_EX | LOCK_NB)) {
$machine = $cur;
last LOOP;
}
close SLOTLOCK;
$slot++;
}
}
}
close MAINLOCK;
# Didn't find one?
if (!defined $machine) {
if ($rightType) {
sendReply "postpone";
exit 0;
} else {
decline;
}
}
# Yes we did, accept.
sendReply "accept";
open IN, "<&4" or die;
my $x = <IN>;
chomp $x;
#print "got $x\n";
close IN;
if ($x ne "okay") {
exit 0;
}
# Do the actual job.
print "BUILDING REMOTE: $drvPath on $machine\n";
# Make sure that we don't get any SSH passphrase or host key popups -
# if there is any problem it should fail, not do something
# interactive.
$ENV{"DISPLAY"} = "";
$ENV{"SSH_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;
}
my $inputs = `cat inputs`; die if ($? != 0);
$inputs =~ s/\n/ /g;
my $outputs = `cat outputs`; die if ($? != 0);
$outputs =~ s/\n/ /g;
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: $?";
print "BUILDING...\n";
system("ssh $sshOpts $machine 'nix-store -rvvK $drvPath'") == 0
or die "remote build on $machine failed: $?";
print "REMOTE BUILD DONE: $drvPath on $machine\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: $?";
}

View File

@@ -19,6 +19,8 @@ chdir $tmpDir or die "cannot change to `$tmpDir': $!";
my $tmpNar = "$tmpDir/nar";
my $tmpNar2 = "$tmpDir/nar2";
END { unlink $tmpNar; unlink $tmpNar2; rmdir $tmpDir; }
# Load all manifests.
my %narFiles;

View File

@@ -77,9 +77,9 @@ EOF
push @instArgs, ("--attr", $ARGV[$n]);
}
elsif ($arg eq "--arg" || $arg eq "--argstr") {
die "$0: `$arg' requires two arguments\n" unless $n + 2 < scalar @ARGV;
push @instArgs, ($arg, $ARGV[$n + 1], $ARGV[$n + 2]);
elsif ($arg eq "--arg") {
die "$0: `--arg' requires two arguments\n" unless $n + 2 < scalar @ARGV;
push @instArgs, ("--arg", $ARGV[$n + 1], $ARGV[$n + 2]);
$n += 2;
}

View File

@@ -6,7 +6,7 @@ $binDir = "@bindir@" unless defined $binDir;
if (scalar @ARGV < 1) {
print STDERR <<EOF
Usage: nix-copy-closure [--from | --to] HOSTNAME [--sign] [--gzip] PATHS...
Usage: nix-copy-closure [--from | --to] HOSTNAME [--sign] PATHS...
EOF
;
exit 1;

View File

@@ -36,28 +36,6 @@ if test -n "$expHash"; then
fi
mkTempDir() {
local i=0
while true; do
if test -z "$TMPDIR"; then TMPDIR=/tmp; fi
tmpPath=$TMPDIR/nix-prefetch-url-$$-$i
if mkdir "$tmpPath"; then break; fi
# !!! to bad we can't check for ENOENT in mkdir, so this check
# is slightly racy (it bombs out if somebody just removed
# $tmpPath...).
if ! test -e "$tmpPath"; then exit 1; fi
i=$((i + 1))
done
trap removeTempDir EXIT SIGINT SIGQUIT
}
removeTempDir() {
if test -n "$tmpPath"; then
rm -rf "$tmpPath" || true
fi
}
doDownload() {
@curl@ $cacheFlags --fail -# --location --max-redirs 20 --disable-epsv \
--cookie-jar $tmpPath/cookies "$url" -o $tmpFile
@@ -68,8 +46,9 @@ doDownload() {
# download the file and add it to the store.
if test -z "$finalPath"; then
mkTempDir
tmpPath=/tmp/nix-prefetch-url-$$ # !!! security?
tmpFile=$tmpPath/$name
mkdir $tmpPath # !!! retry if tmpPath already exists
# Optionally do timestamp-based caching of the download.
# Actually, the only thing that we cache in $NIX_DOWNLOAD_CACHE is
@@ -119,6 +98,8 @@ if test -z "$finalPath"; then
# Add the downloaded file to the Nix store.
finalPath=$(@bindir@/nix-store --add-fixed "$hashType" $tmpFile)
if test -n "$tmpPath"; then rm -rf $tmpPath || true; fi
if test -n "$expHash" -a "$expHash" != "$hash"; then
echo "hash mismatch for URL \`$url'" >&2
exit 1

View File

@@ -116,9 +116,9 @@ print NIX "]";
close NIX;
# Instantiate store derivations from the Nix expression.
# Instantiate store expressions from the Nix expression.
my @storeExprs;
print STDERR "instantiating store derivations...\n";
print STDERR "instantiating store expressions...\n";
my $pid = open(READ, "$binDir/nix-instantiate $nixExpr|")
or die "cannot run nix-instantiate";
while (<READ>) {
@@ -146,7 +146,7 @@ while (scalar @tmp > 0) {
# 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;

View File

@@ -36,7 +36,6 @@ __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
static off_t offtin(u_char *buf)
{

View File

@@ -1,3 +1,5 @@
#include <iostream>
#include "eval.hh"
#include "parser.hh"
#include "hash.hh"
@@ -13,6 +15,19 @@
namespace nix {
int cacheTerms;
bool shortCircuit;
bool closedTerms; // don't substitute under terms known to be closed
bool substCache; // memoization of the term substitution function
bool posInfo; // attach position info to functions, assertions, attributes
#define maxActiveCalls 4096
ATerm activeCalls[maxActiveCalls];
unsigned int activeCallsCount = 0;
EvalState::EvalState()
@@ -23,6 +38,15 @@ EvalState::EvalState()
initNixExprHelpers();
addPrimOps();
if (!string2Int(getEnv("NIX_TERM_CACHE"), cacheTerms)) cacheTerms = 1;
shortCircuit = getEnv("NIX_SHORT_CIRCUIT", "0") == "1";
strictMode = getEnv("NIX_STRICT", "0") == "1";
closedTerms = getEnv("NIX_CLOSED_TERMS", "1") == "1";
substCache = getEnv("NIX_SUBST_CACHE", "1") == "1";
posInfo = getEnv("NIX_POS_INFO", "1") == "1";
ATprotectMemory(activeCalls, maxActiveCalls);
}
@@ -69,6 +93,19 @@ LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2,
}
Expr speculativeEval(EvalState & state, Expr e)
{
if (!state.strictMode) return e;
try {
return evalExpr(state, e);
} catch (EvalError & err) {
/* ignore, pass the original arg and depend on
laziness */
return e;
}
}
/* Substitute an argument set into the body of a function. */
static Expr substArgs(EvalState & state,
Expr body, ATermList formals, Expr arg)
@@ -80,7 +117,7 @@ static Expr substArgs(EvalState & state,
ATermMap args;
queryAllAttrs(arg, args);
for (ATermMap::const_iterator i = args.begin(); i != args.end(); ++i)
subs.set(i->key, i->value);
subs.set(i->key, speculativeEval(state, i->value));
/* Get the formal arguments. */
ATermVector defsUsed;
@@ -389,7 +426,7 @@ Expr autoCallFunction(Expr e, const ATermMap & args)
Expr name, def, value; ATerm values, def2;
if (!matchFormal(*i, name, values, def2)) abort();
if ((value = args.get(name)))
actualArgs.set(name, makeAttrRHS(value, makeNoPos()));
actualArgs.set(name, makeAttrRHS(allocCell(value), makeNoPos()));
else if (!matchDefaultValue(def2, def))
throw TypeError(format("cannot auto-call a function that has an argument without a default value (`%1%')")
% aterm2String(name));
@@ -457,7 +494,7 @@ LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg))
else if (matchFunction(fun, formals, body, pos)) {
arg = evalExpr(state, arg);
try {
return evalExpr(state, substArgs(state, body, formals, arg));
return evalExpr(state, substArgs(state, allocCells(body), formals, arg));
} catch (Error & e) {
addErrorPrefix(e, "while evaluating the function at %1%:\n",
showPos(pos));
@@ -467,9 +504,10 @@ LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg))
else if (matchFunction1(fun, name, body, pos)) {
try {
arg = speculativeEval(state, arg);
ATermMap subs(1);
subs.set(name, arg);
return evalExpr(state, substitute(Substitution(0, &subs), body));
subs.set(name, allocCell(arg));
return evalExpr(state, substitute(Substitution(0, &subs), allocCells(body)));
} catch (Error & e) {
addErrorPrefix(e, "while evaluating the function at %1%:\n",
showPos(pos));
@@ -624,6 +662,10 @@ Expr evalExpr2(EvalState & state, Expr e)
Expr e1, e2, e3;
ATerm name, pos;
int bla;
if (matchCell(e, bla, e1)) e = e1;
AFun sym = ATgetAFun(e);
/* Normal forms. */
@@ -715,41 +757,141 @@ Expr evalExpr2(EvalState & state, Expr e)
if (matchOpConcat(e, e1, e2)) return evalOpConcat(state, e1, e2);
/* Barf. */
//printMsg(lvlError, format("%1%") % e);
abort();
}
class ShortCircuit
{
};
unsigned int fnord;
void maybeShortCircuit(EvalState & state, Expr e, Expr nf)
{
for (unsigned int i = 0; i < activeCallsCount; ++i) {
Expr fun, arg;
if (!matchCall(activeCalls[i], fun, arg)) abort();
if (arg == e) {
//printMsg(lvlError, format("blaat"));
//printMsg(lvlError, format("blaat %1% %2% %3%") % fun % arg % e);
Expr res = state.normalForms.get(makeCall(fun, nf));
if (res) {
fnord++;
//printMsg(lvlError, format("blaat"));
throw ShortCircuit();
}
}
}
}
Expr evalExpr(EvalState & state, Expr e)
{
checkInterrupt();
#if 0
#if 1
startNest(nest, lvlVomit,
format("evaluating expression: %1%") % e);
#endif
state.nrEvaluated++;
if (cacheTerms == 0) return evalExpr2(state, e);
if (cacheTerms == 2) {
int pseudoAddr;
Expr e2;
if (!matchCell(e, pseudoAddr, e2)) return evalExpr2(state, e);
}
/* Consult the memo table to quickly get the normal form of
previously evaluated expressions. */
Expr nf = state.normalForms.get(e);
if (nf) {
if (nf == makeBlackHole())
throwEvalError("infinite recursion encountered");
//if (nf == makeBlackHole())
// throwEvalError("infinite recursion encountered");
state.nrCached++;
return nf;
}
/* Otherwise, evaluate and memoize. */
state.normalForms.set(e, makeBlackHole());
try {
nf = evalExpr2(state, e);
} catch (Error & err) {
state.normalForms.remove(e);
throw;
Expr fun, arg;
if (shortCircuit && matchCall(e, fun, arg)) {
#if 0
Expr arg2 = state.normalForms.get(arg);
if (arg2) { /* the evaluated argument is now known */
//printMsg(lvlError, "foo");
/* do we know the result of the same function called
with the evaluated argument? */
Expr res = state.normalForms.get(makeCall(fun, arg2));
if (res) { /* woohoo! */
printMsg(lvlError, "dingdong");
state.normalForms.set(e, res);
return res;
}
}
#endif
assert(activeCallsCount < maxActiveCalls);
activeCalls[activeCallsCount++] = e;
//state.normalForms.set(e, makeBlackHole());
try {
nf = evalExpr2(state, e);
}
catch (ShortCircuit & exception) {
//printMsg(lvlError, "catch!");
Expr arg2 = state.normalForms.get(arg);
if (arg2) { /* the evaluated argument is now known */
/* do we know the result of the same function called
with the evaluated argument? */
Expr res = state.normalForms.get(makeCall(fun, arg2));
if (res) { /* woohoo! */
//printMsg(lvlError, "woohoo!");
//printMsg(lvlError, format("woohoo! %1% %2% %3% %4%") % fun % arg % arg2 % res);
activeCallsCount--;
state.normalForms.set(e, res);
maybeShortCircuit(state, e, res);
return res;
}
}
activeCallsCount--;
state.normalForms.remove(e);
throw; /* not for us */
}
catch (...) {
activeCallsCount--;
state.normalForms.remove(e);
throw;
}
activeCallsCount--;
state.normalForms.set(e, nf);
Expr arg2 = state.normalForms.get(arg);
if (arg2) state.normalForms.set(makeCall(fun, arg2), nf);
maybeShortCircuit(state, e, nf);
return nf;
}
else {
/* Otherwise, evaluate and memoize. */
//state.normalForms.set(e, makeBlackHole());
try {
nf = evalExpr2(state, e);
} catch (...) {
state.normalForms.remove(e);
throw;
}
state.normalForms.set(e, nf);
if (shortCircuit) maybeShortCircuit(state, e, nf);
return nf;
}
state.normalForms.set(e, nf);
return nf;
}
@@ -845,16 +987,24 @@ extern "C" {
unsigned long AT_calcAllocatedSize();
}
unsigned int substs = 0;
unsigned int substsCached = 0;
void printEvalStats(EvalState & state)
{
char x;
bool showStats = getEnv("NIX_SHOW_STATS", "0") != "0";
printMsg(lvlError, format("FNORD %1%") % fnord);
printMsg(showStats ? lvlInfo : lvlDebug,
format("evaluated %1% expressions, %2% cache hits, %3%%% efficiency, used %4% ATerm bytes, used %5% bytes of stack space")
format("evaluated %1% expressions, %2% cache hits, %3%%% efficiency, used %4% ATerm bytes, used %5% bytes of stack space, %6% substitutions (%7% cached)")
% state.nrEvaluated % state.nrCached
% ((float) state.nrCached / (float) state.nrEvaluated * 100)
% AT_calcAllocatedSize()
% (&x - deepestStack));
% (&x - deepestStack)
% substs
% substsCached);
if (showStats)
printATermMapStats();
}

View File

@@ -27,6 +27,9 @@ struct EvalState;
typedef Expr (* PrimOp) (EvalState &, const ATermVector & args);
extern int cacheTerms; // 0 = don't, 1 = do, 2 = "cell" terms only
struct EvalState
{
ATermMap normalForms;
@@ -38,6 +41,10 @@ struct EvalState
unsigned int nrEvaluated;
unsigned int nrCached;
bool strictMode;
ATermMap parsings; /* path -> expr mapping */
EvalState();
void addPrimOps();

View File

@@ -4,7 +4,6 @@
%x STRING
%x IND_STRING
%{
@@ -123,26 +122,6 @@ inherit { return INHERIT; }
<STRING>\" { BEGIN(INITIAL); return '"'; }
<STRING>. return yytext[0]; /* just in case: shouldn't be reached */
\'\'(\ *\n)? { BEGIN(IND_STRING); return IND_STRING_OPEN; }
<IND_STRING>([^\$\']|\$[^\{\']|\'[^\'])+ {
yylval->t = makeIndStr(toATerm(yytext));
return IND_STR;
}
<IND_STRING>\'\'\$ {
yylval->t = makeIndStr(toATerm("$"));
return IND_STR;
}
<IND_STRING>\'\'\' {
yylval->t = makeIndStr(toATerm("''"));
return IND_STR;
}
<IND_STRING>\'\'\\. {
yylval->t = unescapeStr(yytext + 2);
return IND_STR;
}
<IND_STRING>\$\{ { BEGIN(INITIAL); return DOLLAR_CURLY; }
<IND_STRING>\'\' { BEGIN(INITIAL); return IND_STRING_CLOSE; }
<IND_STRING>. 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 */ }
@@ -169,10 +148,4 @@ void backToString(yyscan_t scanner)
BEGIN(STRING);
}
void backToIndString(yyscan_t scanner)
{
struct yyguts_t * yyg = (struct yyguts_t *) scanner;
BEGIN(IND_STRING);
}
}

View File

@@ -46,9 +46,6 @@ Int | int | Expr |
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
@@ -76,6 +73,8 @@ Inherit | Expr ATermList Pos | ATerm |
Scope | | Expr |
Cell | int Expr | Expr |
Formal | string ValidValues DefaultValue | ATerm |
ValidValues | ATermList | ValidValues |

View File

@@ -2,6 +2,7 @@
#include "derivations.hh"
#include "util.hh"
#include "aterm.hh"
#include "eval.hh" // !!! urgh
#include "nixexpr-ast.hh"
#include "nixexpr-ast.cc"
@@ -108,7 +109,16 @@ Expr makeAttrs(const ATermMap & attrs)
}
Expr substitute(const Substitution & subs, Expr e)
extern unsigned int substs;
extern unsigned int substsCached;
extern bool closedTerms;
extern bool substCache;
static Expr substitute(ATermMap & done, const Substitution & subs, Expr e);
static Expr substitute2(ATermMap & done, const Substitution & subs, Expr e)
{
checkInterrupt();
@@ -116,19 +126,20 @@ Expr substitute(const Substitution & subs, Expr e)
ATerm name, pos, e2;
substs++;
/* As an optimisation, don't substitute in subterms known to be
closed. */
if (matchClosed(e, e2)) return e;
if (closedTerms && 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;
return sub ? ((!closedTerms || matchClosed(sub, wrapped)) ? sub : makeClosed(sub)) : e;
}
/* In case of a function, filter out all variables bound by this
@@ -140,18 +151,30 @@ Expr substitute(const Substitution & subs, Expr e)
for (ATermIterator i(formals); i; ++i) {
ATerm d1, d2;
if (!matchFormal(*i, name, d1, d2)) abort();
map.set(name, makeRemoved());
if (subs.lookup(name))
map.set(name, constRemoved);
}
if (map.size() == 0)
return makeFunction(
(ATermList) substitute(done, subs, (ATerm) formals),
substitute(done, subs, body), pos);
else {
Substitution subs2(&subs, &map);
ATermMap done2(128);
return makeFunction(
(ATermList) substitute(done2, subs2, (ATerm) formals),
substitute(done2, subs2, body), pos);
}
Substitution subs2(&subs, &map);
return makeFunction(
(ATermList) substitute(subs2, (ATerm) formals),
substitute(subs2, body), pos);
}
if (matchFunction1(e, name, body, pos)) {
ATermMap map(1);
map.set(name, makeRemoved());
return makeFunction1(name, substitute(Substitution(&subs, &map), body), pos);
if (subs.lookup(name)) {
ATermMap map(1);
map.set(name, constRemoved);
ATermMap done2(128);
return makeFunction1(name, substitute(done2, Substitution(&subs, &map), body), pos);
} else
return makeFunction1(name, substitute(done, subs, body), pos);
}
/* Idem for a mutually recursive attribute set. */
@@ -159,14 +182,21 @@ Expr substitute(const Substitution & subs, Expr e)
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 */
if (matchBind(*i, name, e2, pos) && subs.lookup(name))
map.set(name, constRemoved);
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 (matchBind(*i, name, e2, pos) && subs.lookup(name))
map.set(name, constRemoved);
if (map.size() == 0)
return makeRec(
(ATermList) substitute(done, subs, (ATerm) rbnds),
(ATermList) substitute(done, subs, (ATerm) nrbnds));
else {
ATermMap done2(128);
return makeRec(
(ATermList) substitute(done2, Substitution(&subs, &map), (ATerm) rbnds),
(ATermList) substitute(done, subs, (ATerm) nrbnds));
}
}
if (ATgetType(e) == AT_APPL) {
@@ -177,7 +207,73 @@ Expr substitute(const Substitution & subs, Expr e)
for (int i = 0; i < arity; ++i) {
ATerm arg = ATgetArgument(e, i);
args[i] = substitute(subs, arg);
args[i] = substitute(done, 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);
bool changed = false;
for (unsigned int j = 0; i; ++i, ++j) {
es[j] = substitute(done, subs, *i);
if (es[j] != *i) changed = true;
}
if (!changed) return e;
ATermList out = ATempty;
for (unsigned int j = len; j; --j)
out = ATinsert(out, es[j - 1]);
return (ATerm) out;
}
return e;
}
static Expr substitute(ATermMap & done, const Substitution & subs, Expr e)
{
Expr res = done[e];
if (substCache && res) {
substsCached++;
return res;
}
res = substitute2(done, subs, e);
done.set(e, res);
return res;
}
Expr substitute(const Substitution & subs, Expr e)
{
ATermMap done(256);
return substitute(done, subs, e);
}
Expr allocCells(Expr e)
{
checkInterrupt();
ATerm e2;
if (matchClosed(e, e2)) return e;
int i;
if (matchCell(e, i, e2))
return allocCell(allocCells(e2));
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] = allocCells(arg);
if (args[i] != arg) changed = true;
}
@@ -189,7 +285,7 @@ Expr substitute(const Substitution & subs, Expr e)
ATerm es[len];
ATermIterator i((ATermList) e);
for (unsigned int j = 0; i; ++i, ++j)
es[j] = substitute(subs, *i);
es[j] = allocCells(*i);
ATermList out = ATempty;
for (unsigned int j = len; j; --j)
out = ATinsert(out, es[j - 1]);
@@ -399,5 +495,18 @@ string showValue(Expr e)
return "<unknown>";
}
static unsigned int cellCount = 0;
Expr allocCell(Expr e)
{
if (cacheTerms != 2) return e;
int i;
Expr e2;
if (matchCell(e, i, e2)) return e;
return makeCell(cellCount++, e);
}
}

View File

@@ -34,6 +34,9 @@ typedef ATerm Pos;
typedef vector<ATerm> ATermVector;
extern Expr constRemoved;
/* 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
@@ -53,7 +56,8 @@ struct Substitution
{
Expr x;
for (const Substitution * s(this); s; s = s->prev)
if ((x = s->map->get(name))) return x;
if ((x = s->map->get(name)))
return x == constRemoved ? 0 : x;
return 0;
}
};
@@ -116,6 +120,11 @@ string showType(Expr e);
string showValue(Expr e);
Expr allocCell(Expr e); // make an updateable cell (for simulating conventional laziness)
Expr allocCells(Expr e); // re-allocate all cells in e
}

View File

@@ -57,7 +57,7 @@ static Expr fixAttrs(int recursive, ATermList as)
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));
*is = ATinsert(*is, makeBind(*j, allocCell(rhs), pos));
}
} else bs = ATinsert(bs, *i);
}
@@ -68,104 +68,15 @@ static Expr fixAttrs(int recursive, ATermList as)
}
static Expr stripIndentation(ATermList es)
{
if (es == ATempty) return makeStr("");
/* Figure out the minimum indentation. Note that by design
whitespace-only final lines are not taken into account. (So
the " " in "\n ''" is ignored, but the " " in "\n foo''" is.) */
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)) {
/* Anti-quotations end the current start-of-line whitespace. */
if (atStartOfLine) {
atStartOfLine = false;
if (curIndent < minIndent) minIndent = curIndent;
}
continue;
}
string s = aterm2String(e);
for (unsigned int j = 0; j < s.size(); ++j) {
if (atStartOfLine) {
if (s[j] == ' ')
curIndent++;
else if (s[j] == '\n') {
/* Empty line, doesn't influence minimum
indentation. */
curIndent = 0;
} else {
atStartOfLine = false;
if (curIndent < minIndent) minIndent = curIndent;
}
} else if (s[j] == '\n') {
atStartOfLine = true;
curIndent = 0;
}
}
}
/* Strip spaces from each line. */
ATermList es2 = ATempty;
atStartOfLine = true;
unsigned int curDropped = 0;
unsigned int n = ATgetLength(es);
for (ATermIterator i(es); i; ++i, --n) {
if (!matchIndStr(*i, e)) {
atStartOfLine = false;
curDropped = 0;
es2 = ATinsert(es2, *i);
continue;
}
string s = aterm2String(e);
string s2;
for (unsigned int j = 0; j < s.size(); ++j) {
if (atStartOfLine) {
if (s[j] == ' ') {
if (curDropped++ >= minIndent)
s2 += s[j];
}
else if (s[j] == '\n') {
curDropped = 0;
s2 += s[j];
} else {
atStartOfLine = false;
curDropped = 0;
s2 += s[j];
}
} else {
s2 += s[j];
if (s[j] == '\n') atStartOfLine = true;
}
}
/* Remove the last line if it is empty and consists only of
spaces. */
if (n == 1) {
unsigned int p = s2.find_last_of('\n');
if (p != string::npos && s2.find_first_not_of(' ', p + 1) == string::npos)
s2 = string(s2, 0, p + 1);
}
es2 = ATinsert(es2, makeStr(s2));
}
return makeConcatStrings(ATreverse(es2));
}
void backToString(yyscan_t scanner);
void backToIndString(yyscan_t scanner);
extern bool posInfo;
static Pos makeCurPos(YYLTYPE * loc, ParseData * data)
{
return makePos(toATerm(data->path),
loc->first_line, loc->first_column);
return posInfo ? makePos(toATerm(data->path),
loc->first_line, loc->first_column) : makeNoPos();
}
#define CUR_POS makeCurPos(yylocp, data)
@@ -212,11 +123,10 @@ static void freeAndUnprotect(void * p)
%type <t> start expr expr_function expr_if expr_op
%type <t> expr_app expr_select expr_simple bind inheritsrc formal
%type <ts> binds ids expr_list formals string_parts ind_string_parts
%token <t> ID INT STR IND_STR PATH URI
%type <ts> binds ids expr_list formals string_parts
%token <t> ID INT STR PATH URI
%token IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL
%token DOLLAR_CURLY /* == ${ */
%token IND_STRING_OPEN IND_STRING_CLOSE
%nonassoc IMPL
%left OR
@@ -291,9 +201,6 @@ expr_simple
else if (ATgetNext($2) == ATempty) $$ = ATgetFirst($2);
else $$ = makeConcatStrings(ATreverse($2));
}
| IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE {
$$ = stripIndentation(ATreverse($2));
}
| PATH { $$ = makePath(toATerm(absPath(aterm2String($1), data->basePath))); }
| URI { $$ = makeStr($1, ATempty); }
| '(' expr ')' { $$ = $2; }
@@ -314,12 +221,6 @@ string_parts
| { $$ = ATempty; }
;
ind_string_parts
: ind_string_parts IND_STR { $$ = ATinsert($1, $2); }
| ind_string_parts DOLLAR_CURLY expr '}' { backToIndString(scanner); $$ = ATinsert($1, $3); }
| { $$ = ATempty; }
;
binds
: binds bind { $$ = ATinsert($1, $2); }
| { $$ = ATempty; }
@@ -327,7 +228,7 @@ binds
bind
: ID '=' expr ';'
{ $$ = makeBind($1, $3, CUR_POS); }
{ $$ = makeBind($1, allocCell($3), CUR_POS); }
| INHERIT inheritsrc ids ';'
{ $$ = makeInherit($2, $3, CUR_POS); }
;
@@ -484,8 +385,13 @@ Expr parseExprFromFile(EvalState & state, Path path)
if (S_ISDIR(st.st_mode))
path = canonPath(path + "/default.nix");
Expr cached = state.parsings.get(toATerm(path));
if (cached) return cached;
/* Read and parse the input file. */
return parse(state, readFile(path).c_str(), path, dirOf(path));
cached = parse(state, readFile(path).c_str(), path, dirOf(path));
state.parsings.set(toATerm(path), cached);
return cached;
}

View File

@@ -296,19 +296,18 @@ static Expr prim_getEnv(EvalState & state, const ATermVector & args)
return makeStr(getEnv(name));
}
/* Evaluate the first expression, and print its abstract syntax tree
on standard error. Then return the second expression. Useful for
debugging.
/* for debugging purposes. print the first arg on stdout (perhaps stderr should be used?)
* and return the second
*/
static Expr prim_trace(EvalState & state, const ATermVector & args)
{
Expr e = evalExpr(state, args[0]);
printMsg(lvlError, format("trace: %1%") % e);
//string str = evalStringNoCtx(state, args[0]);
Expr a = evalExpr(state, args[0]);
printf("traced value: %s\n", atPrint(a).c_str());
return evalExpr(state, args[1]);
}
static Expr prim_relativise(EvalState & state, const ATermVector & args)
{
PathSet context; /* !!! what to do? */
@@ -565,7 +564,7 @@ static Expr prim_derivationLazy(EvalState & state, const ATermVector & args)
attrs.set(toATerm("type"),
makeAttrRHS(makeStr("derivation"), makeNoPos()));
Expr drvStrict = makeCall(makeVar(toATerm("derivation!")), eAttrs);
Expr drvStrict = allocCell(makeCall(makeVar(toATerm("derivation!")), eAttrs));
attrs.set(toATerm("outPath"),
makeAttrRHS(makeSelect(drvStrict, toATerm("outPath")), makeNoPos()));
@@ -622,17 +621,6 @@ static Expr prim_dirOf(EvalState & state, const ATermVector & args)
}
/* Return the contents of a file as a string. */
static Expr prim_readFile(EvalState & state, const ATermVector & args)
{
PathSet context;
Path path = coerceToPath(state, args[0], context);
if (!context.empty())
throw EvalError(format("string `%1%' cannot refer to other paths") % path);
return makeStr(readFile(path));
}
/*************************************************************
* Creating files
*************************************************************/
@@ -785,7 +773,7 @@ static Expr prim_listToAttrs(EvalState & state, const ATermVector & args)
Expr e = evalExpr(state, makeSelect(evaledExpr, toATerm("name")));
string attr = evalStringNoCtx(state,e);
Expr r = makeSelect(evaledExpr, toATerm("value"));
res.set(toATerm(attr), makeAttrRHS(r, makeNoPos()));
res.set(toATerm(attr), makeAttrRHS(allocCell(r), makeNoPos()));
}
else
throw TypeError(format("list element in `listToAttrs' is %s, expected a set { name = \"<name>\"; value = <value>; }")
@@ -800,7 +788,6 @@ static Expr prim_listToAttrs(EvalState & state, const ATermVector & args)
}
}
static Expr prim_removeAttrs(EvalState & state, const ATermVector & args)
{
ATermMap attrs;
@@ -815,7 +802,6 @@ static Expr prim_removeAttrs(EvalState & state, const ATermVector & args)
return makeAttrs(attrs);
}
/* Determine whether the argument is a list. */
static Expr prim_isAttrs(EvalState & state, const ATermVector & args)
{
@@ -823,7 +809,6 @@ static Expr prim_isAttrs(EvalState & state, const ATermVector & args)
return makeBool(matchAttrs(evalExpr(state, args[0]), list));
}
/*************************************************************
* Lists
*************************************************************/
@@ -917,8 +902,8 @@ static Expr prim_toString(EvalState & state, const ATermVector & args)
}
/* `substring start len str' returns the substring of `str' starting
at character position `min(start, stringLength str)' inclusive and
/* `substr start len str' returns the substring of `str' starting at
character position `min(start, stringLength str)' inclusive and
ending at `min(start + len, stringLength str)'. `start' must be
non-negative. */
static Expr prim_substring(EvalState & state, const ATermVector & args)
@@ -942,6 +927,17 @@ static Expr prim_stringLength(EvalState & state, const ATermVector & args)
}
/*************************************************************
* Strictness
*************************************************************/
static Expr prim_strict(EvalState & state, const ATermVector & args)
{
return evalExpr(state, makeCall(args[0], evalExpr(state, args[1])));
}
/*************************************************************
* Primop registration
*************************************************************/
@@ -979,7 +975,6 @@ void EvalState::addPrimOps()
addPrimOp("__pathExists", 1, prim_pathExists);
addPrimOp("baseNameOf", 1, prim_baseNameOf);
addPrimOp("dirOf", 1, prim_dirOf);
addPrimOp("__readFile", 1, prim_readFile);
// Creating files
addPrimOp("__toXML", 1, prim_toXML);
@@ -1009,6 +1004,9 @@ void EvalState::addPrimOps()
addPrimOp("toString", 1, prim_toString);
addPrimOp("__substring", 3, prim_substring);
addPrimOp("__stringLength", 1, prim_stringLength);
// Strictness
addPrimOp("strict", 2, prim_strict);
}

View File

@@ -212,8 +212,6 @@ static void initAndRun(int argc, char * * argv)
readOnlyMode = true;
else if (arg == "--max-silent-time")
maxSilentTime = getIntArg(arg, i, args.end());
else if (arg == "--no-build-hook")
useBuildHook = false;
else remaining.push_back(arg);
}

View File

@@ -25,19 +25,6 @@
#include <grp.h>
/* Includes required for chroot support. */
#include "config.h"
#if HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#if HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
#define CHROOT_ENABLED HAVE_CHROOT && HAVE_SYS_MOUNT_H && defined(MS_BIND)
namespace nix {
using std::map;
@@ -596,89 +583,6 @@ void deletePathWrapped(const Path & path)
//////////////////////////////////////////////////////////////////////
/* Helper RAII class for automatically unmounting bind-mounts in
chroots. */
struct BindMount
{
Path source, target;
Paths created;
BindMount()
{
}
BindMount(const Path & source, const Path & target)
{
bind(source, target);
}
~BindMount()
{
try {
unbind();
} catch (...) {
ignoreException();
}
}
void bind(const Path & source, const Path & target)
{
#if CHROOT_ENABLED
debug(format("bind mounting `%1%' to `%2%'") % source % target);
this->source = source;
this->target = target;
created = createDirs(target);
if (mount(source.c_str(), target.c_str(), "", MS_BIND, 0) == -1)
throw SysError(format("bind mount from `%1%' to `%2%' failed") % source % target);
#endif
}
void unbind()
{
#if CHROOT_ENABLED
if (source == "") return;
debug(format("unmount bind-mount `%1%'") % target);
/* Urgh. Unmount sometimes doesn't succeed right away because
the mount point is still busy. It shouldn't be, because
we've killed all the build processes by now (at least when
using a build user; see the check in killUser()). But
maybe this is because those processes are still zombies and
are keeping some kernel structures busy (open files,
current directories, etc.). So retry a few times
(actually, a 1 second sleep is almost certainly enough for
the zombies to be cleaned up). */
unsigned int tries = 0;
while (umount(target.c_str()) == -1) {
if (errno == EBUSY && ++tries < 10) {
printMsg(lvlError, format("unmounting `%1%' failed, retrying after 1 second...") % target);
sleep(1);
}
else
throw SysError(format("unmounting bind-mount `%1%' failed") % target);
}
/* Get rid of the directories for the mount point created in
bind(). */
for (Paths::reverse_iterator i = created.rbegin(); i != created.rend(); ++i) {
debug(format("deleting `%1%'") % *i);
if (remove(i->c_str()) == -1)
throw SysError(format("cannot unlink `%1%'") % *i);
}
source = "";
#endif
}
};
//////////////////////////////////////////////////////////////////////
class DerivationGoal : public Goal
{
private:
@@ -719,17 +623,6 @@ private:
Pipe toHook;
Pipe fromHook;
/* Whether we're currently doing a chroot build. */
bool useChroot;
/* A RAII object to delete the chroot directory. */
boost::shared_ptr<AutoDelete> autoDelChroot;
/* In chroot builds, the list of bind mounts currently active.
The destructor of BindMount will cause the binds to be
unmounted. */
list<boost::shared_ptr<BindMount> > bindMounts;
typedef void (DerivationGoal::*GoalState)();
GoalState state;
@@ -785,7 +678,7 @@ private:
void openLogFile();
/* Common initialisation to be performed in child processes (i.e.,
both in builders and in build hooks). */
both in builders and in build hooks. */
void initChild();
/* Delete the temporary directory, if we have one. */
@@ -1131,9 +1024,6 @@ void DerivationGoal::buildDone()
deleteTmpDir(true);
/* In chroot builds, unmount the bind mounts ASAP. */
bindMounts.clear(); /* the destructors will do the rest */
/* Compute the FS closure of the outputs and register them as
being valid. */
computeClosure();
@@ -1247,7 +1137,6 @@ static string makeValidityRegistration(const PathSet & paths,
DerivationGoal::HookReply DerivationGoal::tryBuildHook()
{
if (!useBuildHook) return rpDecline;
Path buildHook = getEnv("NIX_BUILD_HOOK");
if (buildHook == "") return rpDecline;
buildHook = absPath(buildHook);
@@ -1284,7 +1173,7 @@ DerivationGoal::HookReply DerivationGoal::tryBuildHook()
throw SysError(format("executing `%1%'") % buildHook);
} catch (std::exception & e) {
std::cerr << format("build hook error: %1%") % e.what() << std::endl;
std::cerr << format("build hook error: %1%\n") % e.what();
}
quickExit(1);
}
@@ -1619,44 +1508,6 @@ void DerivationGoal::startBuilder()
makeValidityRegistration(refs, false));
}
// The same for derivations
s = drv.env["exportBuildReferencesGraph"];
ss = tokenizeString(s);
if (ss.size() % 2 != 0)
throw BuildError(format("odd number of tokens in `exportReferencesGraph': `%1%'") % s);
for (Strings::iterator i = ss.begin(); i != ss.end(); ) {
string fileName = *i++;
checkStoreName(fileName); /* !!! abuse of this function */
/* Check that the store path is valid. */
Path storePath = *i++;
if (!isInStore(storePath))
throw BuildError(format("`exportReferencesGraph' contains a non-store path `%1%'")
% storePath);
storePath = toStorePath(storePath);
if (!store->isValidPath(storePath))
throw BuildError(format("`exportReferencesGraph' contains an invalid path `%1%'")
% storePath);
/* Write closure info to `fileName'. */
PathSet refs1,refs;
computeFSClosure(storePath, refs1);
for (PathSet::iterator j = refs1.begin(); j != refs1.end() ; j++) {
refs.insert (*j);
if (isDerivation (*j)) {
Derivation deriv = derivationFromPath (*j);
for (DerivationOutputs::iterator k=deriv.outputs.begin();
k != deriv.outputs.end(); k++) {
refs.insert(k->second.path);
}
}
}
/* !!! in secure Nix, the writing should be done on the
build uid for security (maybe). */
writeStringToFile(tmpDir + "/" + fileName,
makeValidityRegistration(refs, false));
}
/* If `build-users-group' is not empty, then we have to build as
one of the members of that group. */
@@ -1693,56 +1544,6 @@ void DerivationGoal::startBuilder()
% buildUser.getGID() % nixStore);
}
/* Are we doing a chroot build? */
useChroot = queryBoolSetting("build-use-chroot", false);
Path tmpRootDir;
if (useChroot) {
#if CHROOT_ENABLED
/* Create a temporary directory in which we set up the chroot
environment using bind-mounts.
!!! Big danger here: since we're doing this in /tmp, there
is a risk that the admin does something like "rm -rf
/tmp/chroot-nix-*" to clean up aborted builds, and if some
of the bind-mounts are still active, then "rm -rf" will
happily recurse into those mount points (thereby deleting,
say, /nix/store). Ideally, tmpRootDir should be created in
some special location (maybe in /nix/var/nix) where Nix
takes care of unmounting / deleting old chroots
automatically. */
tmpRootDir = createTempDir("", "chroot-nix");
/* Clean up the chroot directory automatically, but don't
recurse; that would be very very bad if the unmount of a
bind-mount fails. Instead BindMount::unbind() unmounts and
deletes exactly those directories that it created to
produce the mount point, so that after all the BindMount
destructors have run, tmpRootDir should be empty. */
autoDelChroot = boost::shared_ptr<AutoDelete>(new AutoDelete(tmpRootDir, false));
printMsg(lvlChatty, format("setting up chroot environment in `%1%'") % tmpRootDir);
Paths defaultDirs;
defaultDirs.push_back("/dev");
defaultDirs.push_back("/proc");
Paths dirsInChroot = querySetting("build-chroot-dirs", defaultDirs);
dirsInChroot.push_front(nixStore);
dirsInChroot.push_front(tmpDir);
/* Push BindMounts at the front of the list so that they get
unmounted in LIFO order. (!!! Does the C++ standard
guarantee that list elements are destroyed in order?) */
for (Paths::iterator i = dirsInChroot.begin(); i != dirsInChroot.end(); ++i)
bindMounts.push_front(boost::shared_ptr<BindMount>(new BindMount(*i, tmpRootDir + *i)));
#else
throw Error("chroot builds are not supported on this platform");
#endif
}
/* Run the builder. */
printMsg(lvlChatty, format("executing builder `%1%'") %
@@ -1768,17 +1569,6 @@ void DerivationGoal::startBuilder()
try { /* child */
#if CHROOT_ENABLED
/* If building in a chroot, do the chroot right away.
initChild() will do a chdir() to the temporary build
directory to make sure the current directory is in the
chroot. (Actually the order doesn't matter, since due
to the bind mount tmpDir and tmpRootDit/tmpDir are the
same directories.) */
if (useChroot && chroot(tmpRootDir.c_str()) == -1)
throw SysError(format("cannot change root directory to `%1%'") % tmpRootDir);
#endif
initChild();
/* Fill in the environment. */
@@ -1842,7 +1632,7 @@ void DerivationGoal::startBuilder()
% drv.builder);
} catch (std::exception & e) {
std::cerr << format("build error: %1%") % e.what() << std::endl;
std::cerr << format("build error: %1%\n") % e.what();
}
quickExit(1);
}
@@ -2353,7 +2143,7 @@ void SubstitutionGoal::tryToRun()
throw SysError(format("executing `%1%'") % sub);
} catch (std::exception & e) {
std::cerr << format("substitute error: %1%") % e.what() << std::endl;
std::cerr << format("substitute error: %1%\n") % e.what();
}
quickExit(1);
}

View File

@@ -26,8 +26,6 @@ static string gcLockName = "gc.lock";
static string tempRootsDir = "temproots";
static string gcRootsDir = "gcroots";
static const int defaultGcLevel = 1000;
/* Acquire the global GC lock. This is used to prevent new Nix
processes from starting after the temporary root files have been
@@ -447,8 +445,6 @@ void LocalStore::collectGarbage(GCAction action, const PathSet & pathsToDelete,
queryBoolSetting("gc-keep-outputs", false);
bool gcKeepDerivations =
queryBoolSetting("gc-keep-derivations", true);
int gcKeepOutputsThreshold =
queryIntSetting ("gc-keep-outputs-threshold", defaultGcLevel);
/* Acquire the global GC root. This prevents
a) New roots from being added.
@@ -500,17 +496,10 @@ void LocalStore::collectGarbage(GCAction action, const PathSet & pathsToDelete,
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 (store->isValidPath(j->second.path))
computeFSClosure(j->second.path, livePaths);
for (DerivationOutputs::iterator j = drv.outputs.begin();
j != drv.outputs.end(); ++j)
if (store->isValidPath(j->second.path))
computeFSClosure(j->second.path, livePaths);
}
}

View File

@@ -26,7 +26,6 @@ bool readOnlyMode = false;
string thisSystem = "unset";
unsigned int maxSilentTime = 0;
Paths substituters;
bool useBuildHook = true;
static bool settingsRead = false;

View File

@@ -72,10 +72,6 @@ extern unsigned int maxSilentTime;
from a CD. */
extern Paths substituters;
/* Whether to use build hooks (for distributed builds). Sometimes
users want to disable this from the command-line. */
extern bool useBuildHook;
Strings querySetting(const string & name, const Strings & def);

View File

@@ -59,7 +59,7 @@ RemoteStore::RemoteStore()
unsigned int magic = readInt(from);
if (magic != WORKER_MAGIC_2) throw Error("protocol mismatch");
daemonVersion = readInt(from);
unsigned int daemonVersion = readInt(from);
if (GET_PROTOCOL_MAJOR(daemonVersion) != GET_PROTOCOL_MAJOR(PROTOCOL_VERSION))
throw Error("Nix daemon protocol version not supported");
writeInt(PROTOCOL_VERSION, to);
@@ -169,8 +169,6 @@ void RemoteStore::setOptions()
writeInt(verbosity, to);
writeInt(maxBuildJobs, to);
writeInt(maxSilentTime, to);
if (GET_PROTOCOL_MINOR(daemonVersion) >= 2)
writeInt(useBuildHook, to);
processStderr();
}
@@ -232,9 +230,7 @@ Path RemoteStore::queryDeriver(const Path & path)
writeInt(wopQueryDeriver, to);
writeString(path, to);
processStderr();
Path drvPath = readString(from);
if (drvPath != "") assertStorePath(drvPath);
return drvPath;
return readStorePath(from);
}

View File

@@ -71,7 +71,6 @@ private:
FdSink to;
FdSource from;
Pid child;
unsigned int daemonVersion;
void processStderr(Sink * sink = 0, Source * source = 0);

View File

@@ -48,26 +48,6 @@ Path toStorePath(const Path & path)
}
Path followLinksToStore(const Path & _path)
{
Path path = absPath(_path);
while (!isInStore(path)) {
if (!isLink(path)) break;
string target = readLink(path);
path = absPath(target, dirOf(path));
}
if (!isInStore(path))
throw Error(format("path `%1%' is not in the Nix store") % path);
return path;
}
Path followLinksToStorePath(const Path & path)
{
return toStorePath(followLinksToStore(path));
}
void checkStoreName(const string & name)
{
string validChars = "+-._?=";

View File

@@ -174,21 +174,11 @@ bool isStorePath(const Path & path);
void checkStoreName(const string & name);
/* Chop off the parts after the top-level store name, e.g.,
/nix/store/abcd-foo/bar => /nix/store/abcd-foo. */
Path toStorePath(const Path & path);
/* Follow symlinks until we end up with a path in the Nix store. */
Path followLinksToStore(const Path & path);
/* Same as followLinksToStore(), but apply toStorePath() to the
result. */
Path followLinksToStorePath(const Path & path);
/* Constructs a unique store path name. */
Path makeStorePath(const string & type,
const Hash & hash, const string & suffix);

View File

@@ -8,9 +8,8 @@ namespace nix {
#define WORKER_MAGIC_1 0x6e697863
#define WORKER_MAGIC_2 0x6478696f
#define PROTOCOL_VERSION 0x102
#define PROTOCOL_VERSION 0x101
#define GET_PROTOCOL_MAJOR(x) ((x) & 0xff00)
#define GET_PROTOCOL_MINOR(x) ((x) & 0x00ff)
typedef enum {

View File

@@ -8,7 +8,6 @@
#include <cerrno>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <sys/stat.h>
#include <sys/wait.h>
@@ -106,7 +105,8 @@ Path canonPath(const Path & path, bool resolveSymlinks)
/* If s points to a symlink, resolve it and restart (since
the symlink target might contain new symlinks). */
if (resolveSymlinks && isLink(s)) {
if (++followCount >= maxFollow)
followCount++;
if (followCount >= maxFollow)
throw Error(format("infinite symlink recursion in path `%1%'") % path);
temp = absPath(readLink(s), dirOf(s))
+ string(i, end);
@@ -318,19 +318,19 @@ void makePathReadOnly(const Path & path)
}
static Path tempName(const Path & tmpRoot, const Path & prefix)
static Path tempName(const Path & tmpRoot)
{
static int counter = 0;
Path tmpRoot2 = canonPath(tmpRoot.empty() ? getEnv("TMPDIR", "/tmp") : tmpRoot, true);
return (format("%1%/%2%-%3%-%4%") % tmpRoot2 % prefix % getpid() % counter++).str();
return (format("%1%/nix-%2%-%3%") % tmpRoot2 % getpid() % counter++).str();
}
Path createTempDir(const Path & tmpRoot, const Path & prefix)
Path createTempDir(const Path & tmpRoot)
{
while (1) {
checkInterrupt();
Path tmpDir = tempName(tmpRoot, prefix);
Path tmpDir = tempName(tmpRoot);
if (mkdir(tmpDir.c_str(), 0777) == 0) {
/* Explicitly set the group of the directory. This is to
work around around problems caused by BSD's group
@@ -350,16 +350,13 @@ Path createTempDir(const Path & tmpRoot, const Path & prefix)
}
Paths createDirs(const Path & path)
void createDirs(const Path & path)
{
if (path == "/") return Paths();
Paths created = createDirs(dirOf(path));
if (!pathExists(path)) {
if (path == "/") return;
createDirs(dirOf(path));
if (!pathExists(path))
if (mkdir(path.c_str(), 0777) == -1)
throw SysError(format("creating directory `%1%'") % path);
created.push_back(path);
}
return created;
}
@@ -512,25 +509,14 @@ string drainFD(int fd)
//////////////////////////////////////////////////////////////////////
AutoDelete::AutoDelete(const string & p, bool recursive) : path(p)
AutoDelete::AutoDelete(const string & p) : path(p)
{
del = true;
this->recursive = recursive;
}
AutoDelete::~AutoDelete()
{
try {
if (del)
if (recursive)
deletePath(path);
else {
if (remove(path.c_str()) == -1)
throw SysError(format("cannot unlink `%1%'") % path);
}
} catch (...) {
ignoreException();
}
if (del) deletePath(path);
}
void AutoDelete::cancel()
@@ -766,10 +752,10 @@ void killUser(uid_t uid)
if (errno != EINTR)
throw SysError(format("cannot kill processes for uid `%1%'") % uid);
}
} catch (std::exception & e) {
std::cerr << format("killing processes beloging to uid `%1%': %1%")
% uid % e.what() << std::endl;
std::cerr << format("killing processes beloging to uid `%1%': %1%\n")
% uid % e.what();
quickExit(1);
}
quickExit(0);
@@ -961,15 +947,8 @@ string statusToString(int status)
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
if (WIFEXITED(status))
return (format("failed with exit code %1%") % WEXITSTATUS(status)).str();
else if (WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
#if HAVE_STRSIGNAL
const char * description = strsignal(sig);
return (format("failed due to signal %1% (%2%)") % sig % description).str();
#else
return (format("failed due to signal %1%") % sig).str();
#endif
}
else if (WIFSIGNALED(status))
return (format("failed due to signal %1%") % WTERMSIG(status)).str();
else
return "died abnormally";
} else return "succeeded";

View File

@@ -70,11 +70,10 @@ void deletePath(const Path & path, unsigned long long & bytesFreed);
void makePathReadOnly(const Path & path);
/* Create a temporary directory. */
Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix");
Path createTempDir(const Path & tmpRoot = "");
/* Create a directory and all its parents, if necessary. Returns the
list of created directories, in order of creation. */
Paths createDirs(const Path & path);
/* Create a directory and all its parents, if necessary. */
void createDirs(const Path & path);
/* Create a file and write the given text to it. The file is written
in binary mode (i.e., no end-of-line conversions). The path should
@@ -167,9 +166,8 @@ class AutoDelete
{
Path path;
bool del;
bool recursive;
public:
AutoDelete(const Path & p, bool recursive = true);
AutoDelete(const Path & p);
~AutoDelete();
void cancel();
};

View File

@@ -9,7 +9,6 @@ Operations:
--set: create a user environment containing a single derivation
--uninstall / -e: remove derivations from the user environment
--query / -q: perform a query on an environment or Nix expression
--set-flag NAME VALUE: set derivation meta-attribute to given value
The previous operations take a list of derivation names. The special
name `*' may be used to indicate all derivations.
@@ -21,6 +20,8 @@ name `*' may be used to indicate all derivations.
--delete-generations GENERATIONS...: deleted listed generations,
`old' for all non-current generations
--import / -I FILE: set default Nix expression
--version: output version information
--help: display help
@@ -54,7 +55,7 @@ Query flags:
--xml: show output in XML format
--status / -s: print installed/present status
--no-name: hide derivation names
--attr-path / -P: shows the unambiguous attribute name of the
--attr / -A: shows the unambiguous attribute name of the
derivation which can be used when installing with -A
--system: print the platform type of the derivation
--compare-versions / -c: compare version to available or installed
@@ -62,6 +63,8 @@ Query flags:
--out-path: print path of derivation output
--description: print description
--meta: print all meta attributes (only with --xml)
--prebuilt-only: only show derivations whose prebuilt binaries are
available on this machine or are downloadable
Options:
@@ -71,5 +74,3 @@ Options:
--keep-failed / -K: keep temporary directories of failed builds
--preserve-installed: do not replace currently installed versions in `-i'
--system-filter SYSTEM: only use derivations for specified platform
--prebuilt-only / -b: only use derivations whose prebuilt binaries are
available on this machine or are downloadable

View File

@@ -47,9 +47,8 @@ struct InstallSourceInfo
Path nixExprPath; /* for srcNixExprDrvs, srcNixExprs */
Path profile; /* for srcProfile */
string systemFilter; /* for srcNixExprDrvs */
bool prebuiltOnly;
ATermMap autoArgs;
InstallSourceInfo() : prebuiltOnly(false) { };
InstallSourceInfo() : autoArgs() { };
};
@@ -95,8 +94,6 @@ static bool parseInstallSourceOptions(Globals & globals,
}
else if (arg == "--attr" || arg == "-A")
globals.instSource.type = srcAttrPath;
else if (arg == "--prebuilt-only" || arg == "-b")
globals.instSource.prebuiltOnly = true;
else return false;
return true;
}
@@ -322,16 +319,9 @@ static int comparePriorities(EvalState & state,
}
static bool isPrebuilt(EvalState & state, const DrvInfo & elem)
{
return
store->isValidPath(elem.queryOutPath(state)) ||
store->hasSubstitutes(elem.queryOutPath(state));
}
static DrvInfos filterBySelector(EvalState & state, const DrvInfos & allElems,
const Strings & args, bool newestOnly, bool prebuiltOnly)
static DrvInfos filterBySelector(EvalState & state,
const DrvInfos & allElems,
const Strings & args, bool newestOnly)
{
DrvNames selectors = drvNamesFromArgs(args);
@@ -350,8 +340,7 @@ static DrvInfos filterBySelector(EvalState & state, const DrvInfos & allElems,
DrvName drvName(j->name);
if (i->matches(drvName)) {
i->hits++;
if (!prebuiltOnly || isPrebuilt(state, *j))
matches.push_back(std::pair<DrvInfo, unsigned int>(*j, n));
matches.push_back(std::pair<DrvInfo, unsigned int>(*j, n));
}
}
@@ -410,7 +399,7 @@ static DrvInfos filterBySelector(EvalState & state, const DrvInfos & allElems,
/* Check that all selectors have been used. */
for (DrvNames::iterator i = selectors.begin();
i != selectors.end(); ++i)
if (i->hits == 0 && i->fullName != "*")
if (i->hits == 0)
throw Error(format("selector `%1%' matches no derivations")
% i->fullName);
@@ -418,18 +407,12 @@ static DrvInfos filterBySelector(EvalState & state, const DrvInfos & allElems,
}
static bool isPath(const string & s)
{
return s.find('/') != string::npos;
}
static void queryInstSources(EvalState & state,
const InstallSourceInfo & instSource, const Strings & args,
DrvInfos & elems, bool newestOnly)
{
InstallSourceType type = instSource.type;
if (type == srcUnknown && args.size() > 0 && isPath(args.front()))
if (type == srcUnknown && args.size() > 0 && args.front()[0] == '/')
type = srcStorePaths;
switch (type) {
@@ -446,8 +429,7 @@ static void queryInstSources(EvalState & state,
loadDerivations(state, instSource.nixExprPath,
instSource.systemFilter, instSource.autoArgs, "", allElems);
elems = filterBySelector(state, allElems, args,
newestOnly, instSource.prebuiltOnly);
elems = filterBySelector(state, allElems, args, newestOnly);
break;
}
@@ -481,23 +463,23 @@ static void queryInstSources(EvalState & state,
for (Strings::const_iterator i = args.begin();
i != args.end(); ++i)
{
Path path = followLinksToStorePath(*i);
assertStorePath(*i);
DrvInfo elem;
elem.attrs = boost::shared_ptr<ATermMap>(new ATermMap(0)); /* ugh... */
string name = baseNameOf(path);
string name = baseNameOf(*i);
string::size_type dash = name.find('-');
if (dash != string::npos)
name = string(name, dash + 1);
if (isDerivation(path)) {
elem.setDrvPath(path);
elem.setOutPath(findOutput(derivationFromPath(path), "out"));
if (isDerivation(*i)) {
elem.setDrvPath(*i);
elem.setOutPath(findOutput(derivationFromPath(*i), "out"));
if (name.size() >= drvExtension.size() &&
string(name, name.size() - drvExtension.size()) == drvExtension)
name = string(name, 0, name.size() - drvExtension.size());
}
else elem.setOutPath(path);
else elem.setOutPath(*i);
elem.name = name;
@@ -513,7 +495,7 @@ static void queryInstSources(EvalState & state,
case srcProfile: {
elems = filterBySelector(state,
queryInstalled(state, instSource.profile),
args, newestOnly, instSource.prebuiltOnly);
args, newestOnly);
break;
}
@@ -817,7 +799,7 @@ static void opSet(Globals & globals,
}
static void uninstallDerivations(Globals & globals, Strings & selectors,
static void uninstallDerivations(Globals & globals, DrvNames & selectors,
Path & profile)
{
PathLocks lock;
@@ -830,13 +812,11 @@ static void uninstallDerivations(Globals & globals, Strings & selectors,
{
DrvName drvName(i->name);
bool found = false;
for (Strings::iterator j = selectors.begin(); j != selectors.end(); ++j)
/* !!! the repeated calls to followLinksToStorePath() are
expensive, should pre-compute them. */
if ((isPath(*j) && i->queryOutPath(globals.state) == followLinksToStorePath(*j))
|| DrvName(*j).matches(drvName))
{
printMsg(lvlInfo, format("uninstalling `%1%'") % i->name);
for (DrvNames::iterator j = selectors.begin();
j != selectors.end(); ++j)
if (j->matches(drvName)) {
printMsg(lvlInfo,
format("uninstalling `%1%'") % i->name);
found = true;
break;
}
@@ -855,7 +835,11 @@ static void opUninstall(Globals & globals,
{
if (opFlags.size() > 0)
throw UsageError(format("unknown flag `%1%'") % opFlags.front());
uninstallDerivations(globals, opArgs, globals.profile);
DrvNames drvNames = drvNamesFromArgs(opArgs);
uninstallDerivations(globals, drvNames,
globals.profile);
}
@@ -1015,7 +999,7 @@ static void opQuery(Globals & globals,
DrvInfos elems = filterBySelector(globals.state,
source == sInstalled ? installedElems : availElems,
remaining, false, prebuiltOnly);
remaining, false);
DrvInfos & otherElems(source == sInstalled ? availElems : installedElems);
@@ -1056,6 +1040,12 @@ static void opQuery(Globals & globals,
/* For XML output. */
XMLAttrs attrs;
if (prebuiltOnly) {
if (!store->isValidPath(i->queryOutPath(globals.state)) &&
!store->hasSubstitutes(i->queryOutPath(globals.state)))
continue;
}
if (printStatus) {
bool hasSubs = store->hasSubstitutes(i->queryOutPath(globals.state));
bool isInstalled = installed.find(i->queryOutPath(globals.state)) != installed.end();

View File

@@ -16,13 +16,8 @@ Operations:
--gc: run the garbage collector
--dump: dump a path as a Nix archive, forgetting dependencies
--restore: restore a path from a Nix archive, without
registering validity
--export: export a path as a Nix archive, marking dependencies
--import: import a path from a Nix archive, and register as
valid
--dump: dump a path as a Nix archive
--restore: restore a path from a Nix archive
--init: initialise the Nix database
--verify: verify Nix structures

View File

@@ -31,6 +31,18 @@ static int rootNr = 0;
static bool indirectRoot = false;
static Path fixPath(Path path)
{
path = absPath(path);
while (!isInStore(path)) {
if (!isLink(path)) break;
string target = readLink(path);
path = absPath(target, dirOf(path));
}
return toStorePath(path);
}
static Path useDeriver(Path path)
{
if (!isDerivation(path)) {
@@ -74,7 +86,7 @@ static void opRealise(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
*i = followLinksToStorePath(*i);
*i = fixPath(*i);
if (opArgs.size() > 1) {
PathSet drvPaths;
@@ -284,7 +296,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
*i = followLinksToStorePath(*i);
*i = fixPath(*i);
if (forceRealise) realisePath(*i);
Derivation drv = derivationFromPath(*i);
cout << format("%1%\n") % findOutput(drv, "out");
@@ -300,7 +312,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
Path path = maybeUseOutput(followLinksToStorePath(*i), useOutput, forceRealise);
Path path = maybeUseOutput(fixPath(*i), useOutput, forceRealise);
if (query == qRequisites)
storePathRequisites(path, includeOutputs, paths);
else if (query == qReferences) store->queryReferences(path, paths);
@@ -318,7 +330,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
Path deriver = store->queryDeriver(followLinksToStorePath(*i));
Path deriver = store->queryDeriver(fixPath(*i));
cout << format("%1%\n") %
(deriver == "" ? "unknown-deriver" : deriver);
}
@@ -328,7 +340,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
Path path = useDeriver(followLinksToStorePath(*i));
Path path = useDeriver(fixPath(*i));
Derivation drv = derivationFromPath(path);
StringPairs::iterator j = drv.env.find(bindingName);
if (j == drv.env.end())
@@ -342,7 +354,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
Path path = maybeUseOutput(followLinksToStorePath(*i), useOutput, forceRealise);
Path path = maybeUseOutput(fixPath(*i), useOutput, forceRealise);
Hash hash = store->queryPathHash(path);
assert(hash.type == htSHA256);
cout << format("sha256:%1%\n") % printHash32(hash);
@@ -353,7 +365,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
PathSet done;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
printTree(followLinksToStorePath(*i), "", "", done);
printTree(fixPath(*i), "", "", done);
break;
}
@@ -361,7 +373,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
PathSet roots;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
roots.insert(maybeUseOutput(followLinksToStorePath(*i), useOutput, forceRealise));
roots.insert(maybeUseOutput(fixPath(*i), useOutput, forceRealise));
printDotGraph(roots);
break;
}
@@ -369,7 +381,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
case qResolve: {
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
cout << format("%1%\n") % followLinksToStorePath(*i);
cout << format("%1%\n") % fixPath(*i);
break;
}
@@ -386,7 +398,7 @@ static void opReadLog(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
Path path = useDeriver(followLinksToStorePath(*i));
Path path = useDeriver(fixPath(*i));
Path logPath = (format("%1%/%2%/%3%") %
nixLogDir % drvsLogDir % baseNameOf(path)).str();
@@ -444,7 +456,7 @@ static void opCheckValidity(Strings opFlags, Strings opArgs)
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
{
Path path = followLinksToStorePath(*i);
Path path = fixPath(*i);
if (!store->isValidPath(path))
if (printInvalid)
cout << format("%1%\n") % path;
@@ -519,7 +531,7 @@ static void opDelete(Strings opFlags, Strings opArgs)
PathSet pathsToDelete;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
pathsToDelete.insert(followLinksToStorePath(*i));
pathsToDelete.insert(fixPath(*i));
PathSet dummy;
PrintFreed freed(true, false);
@@ -572,17 +584,12 @@ static void opExport(Strings opFlags, Strings opArgs)
static void opImport(Strings opFlags, Strings opArgs)
{
bool requireSignature = false;
for (Strings::iterator i = opFlags.begin();
i != opFlags.end(); ++i)
if (*i == "--require-signature") requireSignature = true;
else throw UsageError(format("unknown flag `%1%'") % *i);
if (!opFlags.empty()) throw UsageError("unknown flag");
if (!opArgs.empty()) throw UsageError("no arguments expected");
FdSource source(STDIN_FILENO);
while (readInt(source) == 1)
cout << format("%1%\n") % store->importPath(requireSignature, source) << std::flush;
cout << format("%1%\n") % store->importPath(false, source) << std::flush;
}

View File

@@ -223,8 +223,7 @@ struct TunnelSource : Source
};
static void performOp(unsigned int clientVersion,
Source & from, Sink & to, unsigned int op)
static void performOp(Source & from, Sink & to, unsigned int op)
{
switch (op) {
@@ -423,8 +422,6 @@ static void performOp(unsigned int clientVersion,
verbosity = (Verbosity) readInt(from);
maxBuildJobs = readInt(from);
maxSilentTime = readInt(from);
if (GET_PROTOCOL_MINOR(clientVersion) >= 2)
useBuildHook = readInt(from) != 0;
startWork();
stopWork();
break;
@@ -495,7 +492,7 @@ static void processConnection()
opCount++;
try {
performOp(clientVersion, from, to, op);
performOp(from, to, op);
} catch (Error & e) {
stopWork(false, e.msg());
}

1
tests/dummy Normal file
View File

@@ -0,0 +1 @@
Hello World

View File

@@ -1,7 +1,7 @@
source common.sh
try () {
printf "%s" "$2" > $TEST_ROOT/vector
echo -n "$2" > $TEST_ROOT/vector
hash=$($nixhash $EXTRA --flat --type "$1" $TEST_ROOT/vector)
if test "$hash" != "$3"; then
echo "hash $1, expected $3, got $hash"

View File

@@ -77,20 +77,6 @@ sed "s|^$|PATH='$PATH'|" < $NIX_DATA_DIR/nix/corepkgs/nar/nar.sh > tmp
chmod +x tmp
mv tmp $NIX_DATA_DIR/nix/corepkgs/nar/nar.sh
# An uberhack for Mac OS X 10.5: download-using-manifests uses Perl,
# and Perl links against Darwin's libutil.dylib (in /usr/lib), but
# when running "make check", the libtool wrapper script around the Nix
# binaries sets DYLD_LIBRARY_PATH so that Perl finds Nix's (completely
# different) libutil --- so it barfs. So generate a shell wrapper
# around download-using-manifests that clears DYLD_LIBRARY_PATH.
mv $NIX_BIN_DIR/nix/download-using-manifests.pl $NIX_BIN_DIR/nix/download-using-manifests.pl.real
cat > $NIX_BIN_DIR/nix/download-using-manifests.pl <<EOF
#! $SHELL -e
export DYLD_LIBRARY_PATH=
exec $NIX_BIN_DIR/nix/download-using-manifests.pl.real "\$@"
EOF
chmod +x $NIX_BIN_DIR/nix/download-using-manifests.pl
# Initialise the database.
$nixstore --init

View File

@@ -1 +0,0 @@
Str("This is an indented multi-line string\nliteral. An amount of whitespace at\nthe start of each line matching the minimum\nindentation of all lines in the string\nliteral together will be removed. Thus,\nin this case four spaces will be\nstripped from each line, even though\n THIS LINE is indented six spaces.\n\nAlso, empty lines don't count in the\ndetermination of the indentation level (the\nprevious empty line has indentation 0, but\nit doesn't matter).\nIf the string starts with whitespace\n followed by a newline, it's stripped, but\n that's not the case here. Two spaces are\n stripped because of the \" \" at the start. \nThis line is indented\na bit further.\nAnti-quotations, like so, are\nalso allowed.\n The \\ is not special here.\n' can be followed by any character except another ', e.g. 'x'.\nLikewise for $, e.g. $$ or $varName.\nBut ' followed by ' is special, as is $ followed by {.\nIf you want them, use anti-quotations: '', ${.\n Tabs are not interpreted as whitespace (since we can't guess\n what tab settings are intended), so don't use them.\n\tThis line starts with a space and a tab, so only one\n space will be stripped from each line.\nAlso note that if the last line (just before the closing ' ')\nconsists only of whitespace, it's ignored. But here there is\nsome non-whitespace stuff, so the line isn't removed. \nThis shows a hacky way to preserve an empty line after the start.\nBut there's no reason to do so: you could just repeat the empty\nline.\n Similarly you can force an indentation level,\n in this case to 2 spaces. This works because the anti-quote\n is significant (not whitespace).\nstart on network-interfaces\n\nstart script\n\n rm -f /var/run/opengl-driver\n ln -sf 123 /var/run/opengl-driver\n\n rm -f /var/log/slim.log\n \nend script\n\nenv SLIM_CFGFILE=abc\nenv SLIM_THEMESDIR=def\nenv FONTCONFIG_FILE=/etc/fonts/fonts.conf \t\t\t\t# !!! cleanup\nenv XKB_BINDIR=foo/bin \t\t\t\t# Needed for the Xkb extension.\nenv LD_LIBRARY_PATH=libX11/lib:libXext/lib:/usr/lib/ # related to xorg-sys-opengl - needed to load libglx for (AI)GLX support (for compiz)\n\nenv XORG_DRI_DRIVER_PATH=nvidiaDrivers/X11R6/lib/modules/drivers/ \n\nexec slim/bin/slim\nEscaping of ' followed by ': ''\nEscaping of $ followed by {: ${\nAnd finally to interpret \\n etc. as in a string: \n, \r, \t.\n",[])

View File

@@ -1,113 +0,0 @@
let
s1 = ''
This is an indented multi-line string
literal. An amount of whitespace at
the start of each line matching the minimum
indentation of all lines in the string
literal together will be removed. Thus,
in this case four spaces will be
stripped from each line, even though
THIS LINE is indented six spaces.
Also, empty lines don't count in the
determination of the indentation level (the
previous empty line has indentation 0, but
it doesn't matter).
'';
s2 = '' If the string starts with whitespace
followed by a newline, it's stripped, but
that's not the case here. Two spaces are
stripped because of the " " at the start.
'';
s3 = ''
This line is indented
a bit further.
''; # indentation of last line doesn't count if it's empty
s4 = ''
Anti-quotations, like ${if true then "so" else "not so"}, are
also allowed.
'';
s5 = ''
The \ is not special here.
' can be followed by any character except another ', e.g. 'x'.
Likewise for $, e.g. $$ or $varName.
But ' followed by ' is special, as is $ followed by {.
If you want them, use anti-quotations: ${"''"}, ${"\${"}.
'';
s6 = ''
Tabs are not interpreted as whitespace (since we can't guess
what tab settings are intended), so don't use them.
This line starts with a space and a tab, so only one
space will be stripped from each line.
'';
s7 = ''
Also note that if the last line (just before the closing ' ')
consists only of whitespace, it's ignored. But here there is
some non-whitespace stuff, so the line isn't removed. '';
s8 = '' ${""}
This shows a hacky way to preserve an empty line after the start.
But there's no reason to do so: you could just repeat the empty
line.
'';
s9 = ''
${""} Similarly you can force an indentation level,
in this case to 2 spaces. This works because the anti-quote
is significant (not whitespace).
'';
s10 = ''
'';
s11 = '''';
s12 = '' '';
s13 = ''
start on network-interfaces
start script
rm -f /var/run/opengl-driver
${if true
then "ln -sf 123 /var/run/opengl-driver"
else if true
then "ln -sf 456 /var/run/opengl-driver"
else ""
}
rm -f /var/log/slim.log
end script
env SLIM_CFGFILE=${"abc"}
env SLIM_THEMESDIR=${"def"}
env FONTCONFIG_FILE=/etc/fonts/fonts.conf # !!! cleanup
env XKB_BINDIR=${"foo"}/bin # Needed for the Xkb extension.
env LD_LIBRARY_PATH=${"libX11"}/lib:${"libXext"}/lib:/usr/lib/ # related to xorg-sys-opengl - needed to load libglx for (AI)GLX support (for compiz)
${if true
then "env XORG_DRI_DRIVER_PATH=${"nvidiaDrivers"}/X11R6/lib/modules/drivers/"
else if true
then "env XORG_DRI_DRIVER_PATH=${"mesa"}/lib/modules/dri"
else ""
}
exec ${"slim"}/bin/slim
'';
s14 = ''
Escaping of ' followed by ': '''
Escaping of $ followed by {: ''${
And finally to interpret \n etc. as in a string: ''\n, ''\r, ''\t.
'';
in s1 + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10 + s11 + s12 + s13 + s14

View File

@@ -1 +0,0 @@
Str("builtins.readFile ./eval-okay-readfile.nix\n",[])

View File

@@ -1 +0,0 @@
builtins.readFile ./eval-okay-readfile.nix

View File

@@ -18,9 +18,6 @@ if test "$text" != "Hello World!"; then exit 1; fi
$nixstore --delete $outPath
if test -e $outPath/hello; then false; fi
echo 'Hello World' > ./dummy
outPath="$(NIX_STORE_DIR=/foo $nixinstantiate --readonly-mode hash-check.nix)"
if test "$outPath" != "/foo/lfy1s6ca46rm5r6w4gg9hc0axiakjcnm-dependencies.drv"; then
echo "hashDerivationModulo appears broken, got $outPath"
exit 1
if test "$(NIX_STORE_DIR=/foo $nixinstantiate --readonly-mode hash-check.nix)" != "/foo/bbfambd3ksry4ylik1772pn2qyw1k296-dependencies.drv"; then
echo "hashDerivationModulo appears broken"
fi

View File

@@ -2,8 +2,6 @@ source common.sh
clearProfiles
set -x
# Query installed: should be empty.
test "$($nixenv -p $profiles/test -q '*' | wc -l)" -eq 0
@@ -73,15 +71,6 @@ echo $outPath10
$nixenv -p $profiles/test -i "$outPath10"
$nixenv -p $profiles/test -q '*' | grep -q foo-1.0
# Uninstall foo-1.0, using a symlink to its store path.
ln -sfn $outPath10/bin/foo $TEST_ROOT/symlink
$nixenv -p $profiles/test -e $TEST_ROOT/symlink
if $nixenv -p $profiles/test -q '*' | grep -q foo; then false; fi
# Install foo-1.0, now using a symlink to its store path.
$nixenv -p $profiles/test -i $TEST_ROOT/symlink
$nixenv -p $profiles/test -q '*' | grep -q foo
# Delete all old generations.
$nixenv -p $profiles/test --delete-generations old