build-support/cc-wrapper: add libstdc++fs into default library path for clang

After https://github.com/NixOS/nixpkgs/pull/210004 `usbmuxd2` started
failing to build as:

    usbmuxd2-unstable> .../ld: cannot find -lstdc++fs: No such file or directory
    usbmuxd2-unstable> clang-11: error: linker command failed with exit code 1 (use -v to see invocation)

This started happening because #210004 exposed a long-standing bug in
`gcc` derivation: `cc.lib` is missing `libstdc++fs` library:

    $ find $(nix-build --no-link -A stdenv.cc.cc.lib) | fgrep libstdc | unnix

    /<<NIX>>/gcc-11.3.0-lib/lib/libstdc++fs.la

    /<<NIX>>/gcc-11.3.0-lib/lib/libstdc++.la
    /<<NIX>>/gcc-11.3.0-lib/lib/libstdc++.so.6.0.29
    /<<NIX>>/gcc-11.3.0-lib/lib/libstdc++.so
    /<<NIX>>/gcc-11.3.0-lib/lib/libstdc++.so.6

It was not moved from `cc.out` output:

    $ find $(nix-build --no-link -A stdenv.cc.cc) | fgrep libstdc | unnix
    /<<NIX>>/gcc-11.3.0/lib/libstdc++.a
    /<<NIX>>/gcc-11.3.0/lib/libstdc++fs.a

This change adds `cc` library lookup path back to `staging-next` until
`gcc` is fixed.`
This commit is contained in:
Sergei Trofimovich 2023-01-27 21:30:14 +00:00
parent 8291dfb1b4
commit 4763533cca

View file

@ -321,6 +321,11 @@ stdenv.mkDerivation {
&& !(stdenv.targetPlatform.useLLVM or false)
&& gccForLibs != null) ''
echo "--gcc-toolchain=${gccForLibs}" >> $out/nix-support/cc-cflags
# Pull in 'cc.out' target to get 'libstdc++fs.a'. It should be in
# 'cc.lib'. But it's a gcc package bug.
# TODO(trofi): remove once gcc is fixed to move libraries to .lib output.
echo "-L${gccForLibs}/${optionalString (targetPlatform != hostPlatform) "/${targetPlatform.config}"}/lib" >> $out/nix-support/cc-ldflags
''
##