nixpkgs/pkgs/build-support/trivial-builders.nix
deliciouslytyped a71e906e3a trivial-builders: refactor writeTextFile to be overridable
This fixes #126344, specifically with the goal of enabling overriding the
checkPhase argument. See `design notes` at the end for details.

This allows among other things, enabling bash extension for the `checkPhase`.
Previously using such bash extensions was prohibited by the `writeShellScript`
code because there was no way to enable the extension in the checker.

As an example:

```nix
(writeShellScript "foo" ''
  shopt -s extglob
  echo @(foo|bar)
'').overrideAttrs (old: {
  checkPhase = ''
    # use subshell to preserve outer environment
    (
      export BASHOPTS
      shopt -s extglob
      ${old.checkPhase}
    )
  '';
})
```

This commit also adds tests for this feature to `pkgs/tests/default.nix`,
under `trivial-overriding`. The test code is located at
`pkgs/build-support/trivial-builders/test-overriding.nix`.

Design notes:
-------------

Per discussion with @sternenseemann, the original approach of just wrapping
`writeTextFile` in `makeOverridable` had the issue that combined with `callPackage`
in the following form, would shadow the `.override` attribute of the `writeTextFile`:

```nix
with import <nixpkgs>;
callPackage ({writeShellScript}: writeShellScript "foo" "echo foo")
```

A better approach can be seen in this commit, where `checkPhase` is moved
from an argument of `writeTextFile`, which is substituted into `buildCommand`,
into an `mkDerivation` argument, which is substituted from the environment
and `eval`-ed. (see the source)

This way we can simple use `.overideAttrs` as usual, and this also makes
`checkPhase` a bit more conformant to `mkDerivation` naming, with respect to
phases generally being overridable attrs.

Co-authored-by: sterni <sternenseemann@systemli.org>
Co-authored-by: Naïm Favier <n@monade.li>
2021-06-18 01:39:59 +02:00

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{ lib, stdenv, stdenvNoCC, lndir, runtimeShell }:
rec {
/* Run the shell command `buildCommand' to produce a store path named
* `name'. The attributes in `env' are added to the environment
* prior to running the command. By default `runCommand` runs in a
* stdenv with no compiler environment. `runCommandCC` uses the default
* stdenv, `pkgs.stdenv`.
*
* Examples:
* runCommand "name" {envVariable = true;} ''echo hello > $out''
* runCommandNoCC "name" {envVariable = true;} ''echo hello > $out'' # equivalent to prior
* runCommandCC "name" {} ''gcc -o myfile myfile.c; cp myfile $out'';
*
* The `*Local` variants force a derivation to be built locally,
* it is not substituted.
*
* This is intended for very cheap commands (<1s execution time).
* It saves on the network roundrip and can speed up a build.
*
* It is the same as adding the special fields
* `preferLocalBuild = true;`
* `allowSubstitutes = false;`
* to a derivations attributes.
*/
runCommand = runCommandNoCC;
runCommandLocal = runCommandNoCCLocal;
runCommandNoCC = name: env: runCommandWith {
stdenv = stdenvNoCC;
runLocal = false;
inherit name;
derivationArgs = env;
};
runCommandNoCCLocal = name: env: runCommandWith {
stdenv = stdenvNoCC;
runLocal = true;
inherit name;
derivationArgs = env;
};
runCommandCC = name: env: runCommandWith {
stdenv = stdenv;
runLocal = false;
inherit name;
derivationArgs = env;
};
# `runCommandCCLocal` left out on purpose.
# We shouldnt force the user to have a cc in scope.
/* Generalized version of the `runCommand`-variants
* which does customized behavior via a single
* attribute set passed as the first argument
* instead of having a lot of variants like
* `runCommand*`. Additionally it allows changing
* the used `stdenv` freely and has a more explicit
* approach to changing the arguments passed to
* `stdenv.mkDerivation`.
*/
runCommandWith =
let
# prevent infinite recursion for the default stdenv value
defaultStdenv = stdenv;
in
{ stdenv ? defaultStdenv
# which stdenv to use, defaults to a stdenv with a C compiler, pkgs.stdenv
, runLocal ? false
# whether to build this derivation locally instead of substituting
, derivationArgs ? {}
# extra arguments to pass to stdenv.mkDerivation
, name
# name of the resulting derivation
}: buildCommand:
stdenv.mkDerivation ({
name = lib.strings.sanitizeDerivationName name;
inherit buildCommand;
passAsFile = [ "buildCommand" ]
++ (derivationArgs.passAsFile or []);
}
// (lib.optionalAttrs runLocal {
preferLocalBuild = true;
allowSubstitutes = false;
})
// builtins.removeAttrs derivationArgs [ "passAsFile" ]);
/* Writes a text file to the nix store.
* The contents of text is added to the file in the store.
*
* Examples:
* # Writes my-file to /nix/store/<store path>
* writeTextFile {
* name = "my-file";
* text = ''
* Contents of File
* '';
* }
* # See also the `writeText` helper function below.
*
* # Writes executable my-file to /nix/store/<store path>/bin/my-file
* writeTextFile {
* name = "my-file";
* text = ''
* Contents of File
* '';
* executable = true;
* destination = "/bin/my-file";
* }
*/
writeTextFile =
{ name # the name of the derivation
, text
, executable ? false # run chmod +x ?
, destination ? "" # relative path appended to $out eg "/bin/foo"
, checkPhase ? "" # syntax checks, e.g. for scripts
}:
runCommand name
{ inherit text executable checkPhase;
passAsFile = [ "text" ];
# Pointless to do this on a remote machine.
preferLocalBuild = true;
allowSubstitutes = false;
}
''
n=$out${destination}
mkdir -p "$(dirname "$n")"
if [ -e "$textPath" ]; then
mv "$textPath" "$n"
else
echo -n "$text" > "$n"
fi
eval "$checkPhase"
(test -n "$executable" && chmod +x "$n") || true
'';
/*
* Writes a text file to nix store with no optional parameters available.
*
* Example:
* # Writes contents of file to /nix/store/<store path>
* writeText "my-file"
* ''
* Contents of File
* '';
*
*/
writeText = name: text: writeTextFile {inherit name text;};
/*
* Writes a text file to nix store in a specific directory with no
* optional parameters available.
*
* Example:
* # Writes contents of file to /nix/store/<store path>/share/my-file
* writeTextDir "share/my-file"
* ''
* Contents of File
* '';
*
*/
writeTextDir = path: text: writeTextFile {
inherit text;
name = builtins.baseNameOf path;
destination = "/${path}";
};
/*
* Writes a text file to /nix/store/<store path> and marks the file as
* executable.
*
* If passed as a build input, will be used as a setup hook. This makes setup
* hooks more efficient to create: you don't need a derivation that copies
* them to $out/nix-support/setup-hook, instead you can use the file as is.
*
* Example:
* # Writes my-file to /nix/store/<store path> and makes executable
* writeScript "my-file"
* ''
* Contents of File
* '';
*
*/
writeScript = name: text: writeTextFile {inherit name text; executable = true;};
/*
* Writes a text file to /nix/store/<store path>/bin/<name> and
* marks the file as executable.
*
* Example:
* # Writes my-file to /nix/store/<store path>/bin/my-file and makes executable.
* writeScriptBin "my-file"
* ''
* Contents of File
* '';
*
*/
writeScriptBin = name: text: writeTextFile {inherit name text; executable = true; destination = "/bin/${name}";};
/*
* Similar to writeScript. Writes a Shell script and checks its syntax.
* Automatically includes interpreter above the contents passed.
*
* Example:
* # Writes my-file to /nix/store/<store path> and makes executable.
* writeShellScript "my-file"
* ''
* Contents of File
* '';
*
*/
writeShellScript = name: text:
writeTextFile {
inherit name;
executable = true;
text = ''
#!${runtimeShell}
${text}
'';
checkPhase = ''
${stdenv.shell} -n $out
'';
};
/*
* Similar to writeShellScript and writeScriptBin.
* Writes an executable Shell script to /nix/store/<store path>/bin/<name> and checks its syntax.
* Automatically includes interpreter above the contents passed.
*
* Example:
* # Writes my-file to /nix/store/<store path>/bin/my-file and makes executable.
* writeShellScriptBin "my-file"
* ''
* Contents of File
* '';
*
*/
writeShellScriptBin = name : text :
writeTextFile {
inherit name;
executable = true;
destination = "/bin/${name}";
text = ''
#!${runtimeShell}
${text}
'';
checkPhase = ''
${stdenv.shell} -n $out/bin/${name}
'';
};
# Create a C binary
writeCBin = name: code:
runCommandCC name
{
inherit name code;
executable = true;
passAsFile = ["code"];
# Pointless to do this on a remote machine.
preferLocalBuild = true;
allowSubstitutes = false;
}
''
n=$out/bin/$name
mkdir -p "$(dirname "$n")"
mv "$codePath" code.c
$CC -x c code.c -o "$n"
'';
/*
* Create a forest of symlinks to the files in `paths'.
*
* This creates a single derivation that replicates the directory structure
* of all the input paths.
*
* BEWARE: it may not "work right" when the passed paths contain symlinks to directories.
*
* Examples:
* # adds symlinks of hello to current build.
* symlinkJoin { name = "myhello"; paths = [ pkgs.hello ]; }
*
* # adds symlinks of hello and stack to current build and prints "links added"
* symlinkJoin { name = "myexample"; paths = [ pkgs.hello pkgs.stack ]; postBuild = "echo links added"; }
*
* This creates a derivation with a directory structure like the following:
*
* /nix/store/sglsr5g079a5235hy29da3mq3hv8sjmm-myexample
* |-- bin
* | |-- hello -> /nix/store/qy93dp4a3rqyn2mz63fbxjg228hffwyw-hello-2.10/bin/hello
* | `-- stack -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/bin/stack
* `-- share
* |-- bash-completion
* | `-- completions
* | `-- stack -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/share/bash-completion/completions/stack
* |-- fish
* | `-- vendor_completions.d
* | `-- stack.fish -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/share/fish/vendor_completions.d/stack.fish
* ...
*
* symlinkJoin and linkFarm are similar functions, but they output
* derivations with different structure.
*
* symlinkJoin is used to create a derivation with a familiar directory
* structure (top-level bin/, share/, etc), but with all actual files being symlinks to
* the files in the input derivations.
*
* symlinkJoin is used many places in nixpkgs to create a single derivation
* that appears to contain binaries, libraries, documentation, etc from
* multiple input derivations.
*
* linkFarm is instead used to create a simple derivation with symlinks to
* other derivations. A derivation created with linkFarm is often used in CI
* as a easy way to build multiple derivations at once.
*/
symlinkJoin =
args_@{ name
, paths
, preferLocalBuild ? true
, allowSubstitutes ? false
, postBuild ? ""
, ...
}:
let
args = removeAttrs args_ [ "name" "postBuild" ]
// {
inherit preferLocalBuild allowSubstitutes;
passAsFile = [ "paths" ];
}; # pass the defaults
in runCommand name args
''
mkdir -p $out
for i in $(cat $pathsPath); do
${lndir}/bin/lndir -silent $i $out
done
${postBuild}
'';
/*
* Quickly create a set of symlinks to derivations.
*
* This creates a simple derivation with symlinks to all inputs.
*
* entries is a list of attribute sets like
* { name = "name" ; path = "/nix/store/..."; }
*
* Example:
*
* # Symlinks hello and stack paths in store to current $out/hello-test and
* # $out/foobar.
* linkFarm "myexample" [ { name = "hello-test"; path = pkgs.hello; } { name = "foobar"; path = pkgs.stack; } ]
*
* This creates a derivation with a directory structure like the following:
*
* /nix/store/qc5728m4sa344mbks99r3q05mymwm4rw-myexample
* |-- foobar -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1
* `-- hello-test -> /nix/store/qy93dp4a3rqyn2mz63fbxjg228hffwyw-hello-2.10
*
* See the note on symlinkJoin for the difference between linkFarm and symlinkJoin.
*/
linkFarm = name: entries: runCommand name { preferLocalBuild = true; allowSubstitutes = false; }
''mkdir -p $out
cd $out
${lib.concatMapStrings (x: ''
mkdir -p "$(dirname ${lib.escapeShellArg x.name})"
ln -s ${lib.escapeShellArg x.path} ${lib.escapeShellArg x.name}
'') entries}
'';
/*
* Easily create a linkFarm from a set of derivations.
*
* This calls linkFarm with a list of entries created from the list of input
* derivations. It turns each input derivation into an attribute set
* like { name = drv.name ; path = drv }, and passes this to linkFarm.
*
* Example:
*
* # Symlinks the hello, gcc, and ghc derivations in $out
* linkFarmFromDrvs "myexample" [ pkgs.hello pkgs.gcc pkgs.ghc ]
*
* This creates a derivation with a directory structure like the following:
*
* /nix/store/m3s6wkjy9c3wy830201bqsb91nk2yj8c-myexample
* |-- gcc-wrapper-9.2.0 -> /nix/store/fqhjxf9ii4w4gqcsx59fyw2vvj91486a-gcc-wrapper-9.2.0
* |-- ghc-8.6.5 -> /nix/store/gnf3s07bglhbbk4y6m76sbh42siym0s6-ghc-8.6.5
* `-- hello-2.10 -> /nix/store/k0ll91c4npk4lg8lqhx00glg2m735g74-hello-2.10
*/
linkFarmFromDrvs = name: drvs:
let mkEntryFromDrv = drv: { name = drv.name; path = drv; };
in linkFarm name (map mkEntryFromDrv drvs);
/*
* Make a package that just contains a setup hook with the given contents.
* This setup hook will be invoked by any package that includes this package
* as a buildInput. Optionally takes a list of substitutions that should be
* applied to the resulting script.
*
* Examples:
* # setup hook that depends on the hello package and runs ./myscript.sh
* myhellohook = makeSetupHook { deps = [ hello ]; } ./myscript.sh;
*
* # wrotes a setup hook where @bash@ myscript.sh is substituted for the
* # bash interpreter.
* myhellohookSub = makeSetupHook {
* deps = [ hello ];
* substitutions = { bash = "${pkgs.bash}/bin/bash"; };
* } ./myscript.sh;
*/
makeSetupHook = { name ? "hook", deps ? [], substitutions ? {} }: script:
runCommand name substitutions
(''
mkdir -p $out/nix-support
cp ${script} $out/nix-support/setup-hook
'' + lib.optionalString (deps != []) ''
printWords ${toString deps} > $out/nix-support/propagated-build-inputs
'' + lib.optionalString (substitutions != {}) ''
substituteAll ${script} $out/nix-support/setup-hook
'');
# Write the references (i.e. the runtime dependencies in the Nix store) of `path' to a file.
writeReferencesToFile = path: runCommand "runtime-deps"
{
exportReferencesGraph = ["graph" path];
}
''
touch $out
while read path; do
echo $path >> $out
read dummy
read nrRefs
for ((i = 0; i < nrRefs; i++)); do read ref; done
done < graph
'';
/*
Write the set of references to a file, that is, their immediate dependencies.
This produces the equivalent of `nix-store -q --references`.
*/
writeDirectReferencesToFile = path: runCommand "runtime-references"
{
exportReferencesGraph = ["graph" path];
inherit path;
}
''
touch ./references
while read p; do
read dummy
read nrRefs
if [[ $p == $path ]]; then
for ((i = 0; i < nrRefs; i++)); do
read ref;
echo $ref >>./references
done
else
for ((i = 0; i < nrRefs; i++)); do
read ref;
done
fi
done < graph
sort ./references >$out
'';
/* Print an error message if the file with the specified name and
* hash doesn't exist in the Nix store. This function should only
* be used by non-redistributable software with an unfree license
* that we need to require the user to download manually. It produces
* packages that cannot be built automatically.
*
* Examples:
*
* requireFile {
* name = "my-file";
* url = "http://example.com/download/";
* sha256 = "ffffffffffffffffffffffffffffffffffffffffffffffffffff";
* }
*/
requireFile = { name ? null
, sha256 ? null
, sha1 ? null
, url ? null
, message ? null
, hashMode ? "flat"
} :
assert (message != null) || (url != null);
assert (sha256 != null) || (sha1 != null);
assert (name != null) || (url != null);
let msg =
if message != null then message
else ''
Unfortunately, we cannot download file ${name_} automatically.
Please go to ${url} to download it yourself, and add it to the Nix store
using either
nix-store --add-fixed ${hashAlgo} ${name_}
or
nix-prefetch-url --type ${hashAlgo} file:///path/to/${name_}
'';
hashAlgo = if sha256 != null then "sha256" else "sha1";
hash = if sha256 != null then sha256 else sha1;
name_ = if name == null then baseNameOf (toString url) else name;
in
stdenvNoCC.mkDerivation {
name = name_;
outputHashMode = hashMode;
outputHashAlgo = hashAlgo;
outputHash = hash;
preferLocalBuild = true;
allowSubstitutes = false;
builder = writeScript "restrict-message" ''
source ${stdenvNoCC}/setup
cat <<_EOF_
***
${msg}
***
_EOF_
exit 1
'';
};
# Copy a path to the Nix store.
# Nix automatically copies files to the store before stringifying paths.
# If you need the store path of a file, ${copyPathToStore <path>} can be
# shortened to ${<path>}.
copyPathToStore = builtins.filterSource (p: t: true);
# Copy a list of paths to the Nix store.
copyPathsToStore = builtins.map copyPathToStore;
/* Applies a list of patches to a source directory.
*
* Examples:
*
* # Patching nixpkgs:
* applyPatches {
* src = pkgs.path;
* patches = [
* (pkgs.fetchpatch {
* url = "https://github.com/NixOS/nixpkgs/commit/1f770d20550a413e508e081ddc08464e9d08ba3d.patch";
* sha256 = "1nlzx171y3r3jbk0qhvnl711kmdk57jlq4na8f8bs8wz2pbffymr";
* })
* ];
* }
*/
applyPatches =
{ src
, name ? (if builtins.typeOf src == "path"
then builtins.baseNameOf src
else
if builtins.isAttrs src && builtins.hasAttr "name" src
then src.name
else throw "applyPatches: please supply a `name` argument because a default name can only be computed when the `src` is a path or is an attribute set with a `name` attribute."
) + "-patched"
, patches ? []
, postPatch ? ""
}: stdenvNoCC.mkDerivation {
inherit name src patches postPatch;
preferLocalBuild = true;
allowSubstitutes = false;
phases = "unpackPhase patchPhase installPhase";
installPhase = "cp -R ./ $out";
};
/* An immutable file in the store with a length of 0 bytes. */
emptyFile = runCommand "empty-file" {
outputHashAlgo = "sha256";
outputHashMode = "recursive";
outputHash = "0ip26j2h11n1kgkz36rl4akv694yz65hr72q4kv4b3lxcbi65b3p";
preferLocalBuild = true;
} "touch $out";
/* An immutable empty directory in the store. */
emptyDirectory = runCommand "empty-directory" {
outputHashAlgo = "sha256";
outputHashMode = "recursive";
outputHash = "0sjjj9z1dhilhpc8pq4154czrb79z9cm044jvn75kxcjv6v5l2m5";
preferLocalBuild = true;
} "mkdir $out";
/* Checks the command output contains the specified version
*
* Although simplistic, this test assures that the main program
* can run. While there's no substitute for a real test case,
* it does catch dynamic linking errors and such. It also provides
* some protection against accidentally building the wrong version,
* for example when using an 'old' hash in a fixed-output derivation.
*
* Examples:
*
* passthru.tests.version = testVersion { package = hello; };
*
* passthru.tests.version = testVersion {
* package = seaweedfs;
* command = "weed version";
* };
*
* passthru.tests.version = testVersion {
* package = key;
* command = "KeY --help";
* # Wrong '2.5' version in the code. Drop on next version.
* version = "2.5";
* };
*/
testVersion =
{ package,
command ? "${package.meta.mainProgram or package.pname or package.name} --version",
version ? package.version,
}: runCommand "test-version" { nativeBuildInputs = [ package ]; meta.timeout = 60; } ''
${command} | grep -Fw ${version}
touch $out
'';
}