nixpkgs/pkgs/build-support/rust/rustc-wrapper/default.nix
Alyssa Ross 0852f8eb84
rustc: expose platform lists
Previously, it wasn't possible to access the list of platforms we can
build Rust programs for outside of buildRustPackage.  This was a
problem for packages that have optional Rust components, like
gstreamer or Meson, as there was no way to only build the Rust parts
for supported platforms.  Now it's possible to get that information
from rustc's passthru.
2024-09-03 17:47:27 +02:00

55 lines
2.1 KiB
Nix

{ lib, runCommand, rustc-unwrapped, sysroot ? null }:
runCommand "${rustc-unwrapped.pname}-wrapper-${rustc-unwrapped.version}" {
preferLocalBuild = true;
strictDeps = true;
inherit (rustc-unwrapped) outputs;
env = {
sysroot = lib.optionalString (sysroot != null) "--sysroot ${sysroot}";
# Upstream rustc still assumes that musl = static[1]. The fix for
# this is to disable crt-static by default for non-static musl
# targets.
#
# Even though Cargo will build build.rs files for the build platform,
# cross-compiling _from_ musl appears to work fine, so we only need
# to do this when rustc's target platform is dynamically linked musl.
#
# [1]: https://github.com/rust-lang/compiler-team/issues/422
#
# WARNING: using defaultArgs is dangerous, as it will apply to all
# targets used by this compiler (host and target). This means
# that it can't be used to set arguments that should only be
# applied to the target. It's fine to do this for -crt-static,
# because rustc does not support +crt-static host platforms
# anyway.
defaultArgs = lib.optionalString
(with rustc-unwrapped.stdenv.targetPlatform; isMusl && !isStatic)
"-C target-feature=-crt-static";
};
passthru = {
inherit (rustc-unwrapped)
pname version src llvm llvmPackages
tier1TargetPlatforms targetPlatforms badTargetPlatforms;
unwrapped = rustc-unwrapped;
};
meta = rustc-unwrapped.meta // {
description = "${rustc-unwrapped.meta.description} (wrapper script)";
priority = 10;
};
} ''
mkdir -p $out/bin
ln -s ${rustc-unwrapped}/bin/* $out/bin
rm $out/bin/{rustc,rustdoc}
prog=${rustc-unwrapped}/bin/rustc extraFlagsVar=NIX_RUSTFLAGS \
substituteAll ${./rustc-wrapper.sh} $out/bin/rustc
prog=${rustc-unwrapped}/bin/rustdoc extraFlagsVar=NIX_RUSTDOCFLAGS \
substituteAll ${./rustc-wrapper.sh} $out/bin/rustdoc
chmod +x $out/bin/{rustc,rustdoc}
${lib.concatMapStrings (output: "ln -s ${rustc-unwrapped.${output}} \$${output}\n")
(lib.remove "out" rustc-unwrapped.outputs)}
''