gnu/packages/patches/clang-7.0-libc-search-path.patch

   1 Clang attempts to guess file names based on the OS and distro (yes!),
   2 but unfortunately, that doesn't work for us.
   3
   4 This patch makes it easy to insert libc's $libdir so that Clang passes the
   5 correct absolute file name of crt1.o etc. to 'ld'.  It also disables all
   6 the distro-specific stuff and removes the hard-coded FHS directory names
   7 to make sure Clang also works on non-GuixSD systems.
   8
   9 --- a/lib/Driver/ToolChains/Linux.cpp
  10 +++ b/lib/Driver/ToolChains/Linux.cpp
  11 @@ -225,7 +225,9 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  12    PPaths.push_back(Twine(GCCInstallation.getParentLibPath() + "/../" +
  13                           GCCInstallation.getTriple().str() + "/bin")
  14                         .str());
  15 -
  16 +  // Comment out the distro-specific tweaks so that they don't bite when
  17 +  // using Guix on a foreign distro.
  18 +#if 0
  19    Distro Distro(D.getVFS());
  20
  21    if (Distro.IsAlpineLinux()) {
  22 @@ -284,6 +286,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  23
  24    if (IsAndroid || Distro.IsOpenSUSE())
  25      ExtraOpts.push_back("--enable-new-dtags");
  26 +#endif
  27
  28    // The selection of paths to try here is designed to match the patterns which
  29    // the GCC driver itself uses, as this is part of the GCC-compatible driver.
  30 @@ -342,7 +345,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  31      // the cross. Note that GCC does include some of these directories in some
  32      // configurations but this seems somewhere between questionable and simply
  33      // a bug.
  34 -    if (StringRef(LibPath).startswith(SysRoot)) {
  35 +    if (0) {
  36        addPathIfExists(D, LibPath + "/" + MultiarchTriple, Paths);
  37        addPathIfExists(D, LibPath + "/../" + OSLibDir, Paths);
  38      }
  39 @@ -361,6 +364,8 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  40    addPathIfExists(D, SysRoot + "/lib/" + MultiarchTriple, Paths);
  41    addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
  42
  43 +  // This requires the commented distro tweaks above.
  44 +#if 0
  45    if (IsAndroid) {
  46      // Android sysroots contain a library directory for each supported OS
  47      // version as well as some unversioned libraries in the usual multiarch
  48 @@ -389,10 +394,14 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  49      addPathIfExists(D, SysRoot + "/" + OSLibDir + "/" + ABIName, Paths);
  50      addPathIfExists(D, SysRoot + "/usr/" + OSLibDir + "/" + ABIName, Paths);
  51    }
  52 +#endif
  53
  54    // Try walking via the GCC triple path in case of biarch or multiarch GCC
  55    // installations with strange symlinks.
  56    if (GCCInstallation.isValid()) {
  57 +    // The following code would end up adding things like
  58 +    // "/usr/lib/x86_64-unknown-linux-gnu/../../lib64" to the search path.
  59 +#if 0
  60      addPathIfExists(D,
  61                      SysRoot + "/usr/lib/" + GCCInstallation.getTriple().str() +
  62                          "/../../" + OSLibDir,
  63 @@ -405,6 +414,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  64                               BiarchSibling.gccSuffix(),
  65                        Paths);
  66      }
  67 +#endif
  68
  69      // See comments above on the multilib variant for details of why this is
  70      // included even from outside the sysroot.
  71 @@ -429,8 +439,9 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  72    if (StringRef(D.Dir).startswith(SysRoot))
  73      addPathIfExists(D, D.Dir + "/../lib", Paths);
  74
  75 -  addPathIfExists(D, SysRoot + "/lib", Paths);
  76 -  addPathIfExists(D, SysRoot + "/usr/lib", Paths);
  77 +  // Add libc's lib/ directory to the search path, so that crt1.o, crti.o,
  78 +  // and friends can be found.
  79 +  addPathIfExists(D, "@GLIBC_LIBDIR@", Paths);
  80  }
  81
  82  bool Linux::HasNativeLLVMSupport() const { return true; }