nixpkgs/pkgs/test/cc-wrapper/default.nix

{
  lib,
  stdenv,
  glibc,
  buildPackages,
}:

let
  # Sanitizers are not supported on Darwin.
  # Sanitizer headers aren't available in older libc++ stdenvs due to a bug
  sanitizersWorking =
    (stdenv.buildPlatform == stdenv.hostPlatform)
    && !stdenv.hostPlatform.isDarwin
    && !stdenv.hostPlatform.isMusl
    && (
      (stdenv.cc.isClang && lib.versionAtLeast (lib.getVersion stdenv.cc.name) "5.0.0")
      || (stdenv.cc.isGNU && stdenv.hostPlatform.isLinux)
    );
  staticLibc = lib.optionalString (stdenv.hostPlatform.libc == "glibc") "-L ${glibc.static}/lib";
  emulator = lib.optionalString (!stdenv.buildPlatform.canExecute stdenv.hostPlatform) (
    stdenv.hostPlatform.emulator buildPackages
  );
  isCxx = stdenv.cc.libcxx != null;
  libcxxStdenvSuffix = lib.optionalString isCxx "-libcxx";
  CC = "PATH= ${lib.getExe' stdenv.cc "${stdenv.cc.targetPrefix}cc"}";
  CXX = "PATH= ${lib.getExe' stdenv.cc "${stdenv.cc.targetPrefix}c++"}";
  READELF = "PATH= ${lib.getExe' stdenv.cc "${stdenv.cc.targetPrefix}readelf"}";
in
stdenv.mkDerivation {
  pname = "cc-wrapper-test-${stdenv.cc.cc.pname}${libcxxStdenvSuffix}";
  version = stdenv.cc.version;

  buildCommand = ''
    echo "Testing: ${stdenv.cc.name}" >&2
    echo "With libc: ${stdenv.cc.libc.name}" >&2
    set -o pipefail

    NIX_DEBUG=1 ${CC} -v
    NIX_DEBUG=1 ${CXX} -v

    echo "checking whether compiler builds valid C binaries... " >&2
    ${CC} -o cc-check ${./cc-main.c}
    ${emulator} ./cc-check

    echo "checking whether compiler builds valid C++ binaries... " >&2
    ${CXX} -o cxx-check ${./cxx-main.cc}
    ${emulator} ./cxx-check

    # test for https://github.com/NixOS/nixpkgs/issues/214524#issuecomment-1431745905
    # .../include/cxxabi.h:20:10: fatal error: '__cxxabi_config.h' file not found
    # in libcxxStdenv
    echo "checking whether cxxabi.h can be included... " >&2
    ${CXX} -o include-cxxabi ${./include-cxxabi.cc}
    ${emulator} ./include-cxxabi

    # cxx doesn't have libatomic.so
    ${lib.optionalString (!isCxx) ''
      # https://github.com/NixOS/nixpkgs/issues/91285
      echo "checking whether libatomic.so can be linked... " >&2
      ${CXX} -shared -o atomics.so ${./atomics.cc} -latomic ${
        lib.optionalString (stdenv.cc.isClang && lib.versionOlder stdenv.cc.version "6.0.0") "-std=c++17"
      }
      ${READELF} -d ./atomics.so | grep libatomic.so && echo "ok" >&2 || echo "failed" >&2
    ''}

    # Test that linking libc++ works, and statically.
    ${lib.optionalString isCxx ''
      echo "checking whether can link with libc++... " >&2
      NIX_DEBUG=1 ${CXX} ${./cxx-main.cc} -c -o cxx-main.o
      NIX_DEBUG=1 ${CC} cxx-main.o -lc++ -o cxx-main
      NIX_DEBUG=1 ${CC} cxx-main.o ${lib.getLib stdenv.cc.libcxx}/lib/libc++.a -o cxx-main-static
      ${emulator} ./cxx-main
      ${emulator} ./cxx-main-static
      rm cxx-main{,-static,.o}
    ''}

    ${lib.optionalString (stdenv.hostPlatform.isDarwin && stdenv.cc.isClang) ''
      echo "checking whether compiler can build with CoreFoundation.framework... " >&2
      mkdir -p foo/lib
      ${CC} -framework CoreFoundation -o core-foundation-check ${./core-foundation-main.c}
      ${emulator} ./core-foundation-check
    ''}


    ${lib.optionalString (!stdenv.hostPlatform.isDarwin) ''
      echo "checking whether compiler builds valid static C binaries... " >&2
      ${CC} ${staticLibc} -static -o cc-static ${./cc-main.c}
      ${emulator} ./cc-static
      ${lib.optionalString (stdenv.cc.isGNU && lib.versionAtLeast (lib.getVersion stdenv.cc.name) "8.0.0")
        ''
          echo "checking whether compiler builds valid static pie C binaries... " >&2
          ${CC} ${staticLibc} -static-pie -o cc-static-pie ${./cc-main.c}
          ${emulator} ./cc-static-pie
        ''
      }
    ''}

    ${
      # See: https://github.com/llvm/llvm-project/commit/ed1d07282cc9d8e4c25d585e03e5c8a1b6f63a74
      # `gcc` does not support this so we gate the test on `clang`
      lib.optionalString stdenv.cc.isClang ''
        echo "checking whether cc-wrapper accepts -- followed by positional (file) args..." >&2
        mkdir -p positional

        # Make sure `--` is not parsed as a "non flag arg"; we should get an
        # input file error here and *not* a linker error.
        { ! ${CC} --; } |& grep -q "no input files"

        # And that positional file args _must_ be files (this is just testing
        # that we remembered to put the `--` back in the args to the compiler):
        { ! ${CC} -c -- -o foo ${./foo.c}; } \
          |& grep -q "no such file or directory: '-o'"

        # Now check that we accept single and multiple positional file args:
        ${CC} -c -DVALUE=42 -o positional/foo.o -- ${./foo.c}
        ${CC} -o positional/main -- positional/foo.o ${./ldflags-main.c}
        ${emulator} ./positional/main
      ''
    }

    echo "checking whether compiler uses NIX_CFLAGS_COMPILE... " >&2
    mkdir -p foo/include
    cp ${./foo.c} foo/include/foo.h
    NIX_CFLAGS_COMPILE="-Ifoo/include -DVALUE=42" ${CC} -o cflags-check ${./cflags-main.c}
    ${emulator} ./cflags-check

    echo "checking whether compiler uses NIX_LDFLAGS... " >&2
    mkdir -p foo/lib
    ${CC} -shared \
      ${lib.optionalString stdenv.hostPlatform.isDarwin "-Wl,-install_name,@rpath/libfoo.dylib"} \
      -DVALUE=42 \
      -o foo/lib/libfoo${stdenv.hostPlatform.extensions.sharedLibrary} \
      ${./foo.c}

    NIX_LDFLAGS="-L$NIX_BUILD_TOP/foo/lib -rpath $NIX_BUILD_TOP/foo/lib" ${CC} -lfoo -o ldflags-check ${./ldflags-main.c}
    ${emulator} ./ldflags-check

    echo "Check whether -nostdinc and -nostdinc++ is handled correctly" >&2
    mkdir -p std-include
    cp ${./stdio.h} std-include/stdio.h
    NIX_DEBUG=1 ${CC} -I std-include -nostdinc -o nostdinc-main ${./nostdinc-main.c}
    ${emulator} ./nostdinc-main
    ${CXX} -I std-include -nostdinc++ -o nostdinc-main++ ${./nostdinc-main.c}
    ${emulator} ./nostdinc-main++

    ${lib.optionalString sanitizersWorking ''
      echo "checking whether sanitizers are fully functional... ">&2
      ${CC} -o sanitizers -fsanitize=address,undefined ${./sanitizers.c}
      ASAN_OPTIONS=use_sigaltstack=0 ${emulator} ./sanitizers
    ''}

    echo "Check whether CC and LD with NIX_X_USE_RESPONSE_FILE hardcodes all required binaries..." >&2
    NIX_CC_USE_RESPONSE_FILE=1 NIX_LD_USE_RESPONSE_FILE=1 ${CC} -v

    touch $out
  '';

  meta.platforms = lib.platforms.all;
}