gnu/packages/patches/clang-10.0-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-Guix systems.
   8
   9 diff --git a/lib/Driver/ToolChains/Linux.cpp b/lib/Driver/ToolChains/Linux.cpp
  10 index bff1ab10..79e1477e 100644
  11 --- a/lib/Driver/ToolChains/Linux.cpp
  12 +++ b/lib/Driver/ToolChains/Linux.cpp
  13 @@ -240,6 +240,9 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  14                           .str());
  15    }
  16
  17 +// Comment out the distro-specific tweaks so that they don't bite when
  18 +// using Guix on a foreign distro.
  19 +#if 0
  20    Distro Distro(D.getVFS(), Triple);
  21
  22    if (Distro.IsAlpineLinux() || Triple.isAndroid()) {
  23 @@ -306,6 +309,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  24
  25    if (IsAndroid || Distro.IsOpenSUSE())
  26      ExtraOpts.push_back("--enable-new-dtags");
  27 +#endif // Guix
  28
  29    // The selection of paths to try here is designed to match the patterns which
  30    // the GCC driver itself uses, as this is part of the GCC-compatible driver.
  31 @@ -363,7 +367,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  32      // the cross. Note that GCC does include some of these directories in some
  33      // configurations but this seems somewhere between questionable and simply
  34      // a bug.
  35 -    if (StringRef(LibPath).startswith(SysRoot)) {
  36 +    if (0) {
  37        addPathIfExists(D, LibPath + "/" + MultiarchTriple, Paths);
  38        addPathIfExists(D, LibPath + "/../" + OSLibDir, Paths);
  39      }
  40 @@ -382,6 +386,8 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  41    addPathIfExists(D, SysRoot + "/lib/" + MultiarchTriple, Paths);
  42    addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
  43
  44 +// This requires the commented distro tweaks above.
  45 +#if 0
  46    if (IsAndroid) {
  47      // Android sysroots contain a library directory for each supported OS
  48      // version as well as some unversioned libraries in the usual multiarch
  49 @@ -410,10 +416,15 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  50      addPathIfExists(D, SysRoot + "/" + OSLibDir + "/" + ABIName, Paths);
  51      addPathIfExists(D, SysRoot + "/usr/" + OSLibDir + "/" + ABIName, Paths);
  52    }
  53 +#endif
  54
  55    // Try walking via the GCC triple path in case of biarch or multiarch GCC
  56    // installations with strange symlinks.
  57    if (GCCInstallation.isValid()) {
  58 +
  59 +// The following code would end up adding things like
  60 +// "/usr/lib/x86_64-unknown-linux-gnu/../../lib64" to the search path.
  61 +#if 0
  62      addPathIfExists(D,
  63                      SysRoot + "/usr/lib/" + GCCInstallation.getTriple().str() +
  64                          "/../../" + OSLibDir,
  65 @@ -426,6 +437,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  66                               BiarchSibling.gccSuffix(),
  67                        Paths);
  68      }
  69 +#endif
  70
  71      // See comments above on the multilib variant for details of why this is
  72      // included even from outside the sysroot.
  73 @@ -450,8 +462,9 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
  74    if (StringRef(D.Dir).startswith(SysRoot))
  75      addPathIfExists(D, D.Dir + "/../lib", Paths);
  76
  77 -  addPathIfExists(D, SysRoot + "/lib", Paths);
  78 -  addPathIfExists(D, SysRoot + "/usr/lib", Paths);
  79 +  // Add libc's lib/ directory to the search path, so that crt1.o, crti.o,
  80 +  // and friends can be found.
  81 +  addPathIfExists(D, "@GLIBC_LIBDIR@", Paths);
  82  }
  83
  84  ToolChain::CXXStdlibType Linux::GetDefaultCXXStdlibType() const {