1 files changed, 33 insertions, 15 deletions

diff --git a/clang/lib/Driver/ToolChains/Hurd.cpp b/clang/lib/Driver/ToolChains/Hurd.cpp
index 72166ca9f359..a700d7b9064c 100644
--- a/clang/lib/Driver/ToolChains/Hurd.cpp
+++ b/clang/lib/Driver/ToolChains/Hurd.cpp
@@ -61,21 +61,35 @@ static StringRef getOSLibDir(const llvm::Triple &Triple, const ArgList &Args) {
   return Triple.isArch32Bit() ? "lib" : "lib64";
 }
 
-Hurd::Hurd(const Driver &D, const llvm::Triple &Triple,
-           const ArgList &Args)
+Hurd::Hurd(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
     : Generic_ELF(D, Triple, Args) {
+  GCCInstallation.init(Triple, Args);
+  Multilibs = GCCInstallation.getMultilibs();
+  SelectedMultilib = GCCInstallation.getMultilib();
   std::string SysRoot = computeSysRoot();
+  ToolChain::path_list &PPaths = getProgramPaths();
+
+  Generic_GCC::PushPPaths(PPaths);
+
+  // The selection of paths to try here is designed to match the patterns which
+  // the GCC driver itself uses, as this is part of the GCC-compatible driver.
+  // This was determined by running GCC in a fake filesystem, creating all
+  // possible permutations of these directories, and seeing which ones it added
+  // to the link paths.
   path_list &Paths = getFilePaths();
 
-  const std::string OSLibDir = getOSLibDir(Triple, Args);
+  const std::string OSLibDir = std::string(getOSLibDir(Triple, Args));
   const std::string MultiarchTriple = getMultiarchTriple(D, Triple, SysRoot);
 
 #ifdef ENABLE_LINKER_BUILD_ID
   ExtraOpts.push_back("--build-id");
 #endif
 
-  // If we are currently running Clang inside of the requested system root, add
-  // its parent library paths to those searched.
+  Generic_GCC::AddMultilibPaths(D, SysRoot, OSLibDir, MultiarchTriple, Paths);
+
+  // Similar to the logic for GCC above, if we currently running Clang inside
+  // of the requested system root, add its parent library paths to
+  // those searched.
   // FIXME: It's not clear whether we should use the driver's installed
   // directory ('Dir' below) or the ResourceDir.
   if (StringRef(D.Dir).startswith(SysRoot)) {
@@ -89,8 +103,11 @@ Hurd::Hurd(const Driver &D, const llvm::Triple &Triple,
   addPathIfExists(D, SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
   addPathIfExists(D, SysRoot + "/usr/lib/../" + OSLibDir, Paths);
 
-  // If we are currently running Clang inside of the requested system root, add
-  // its parent library path to those searched.
+  Generic_GCC::AddMultiarchPaths(D, SysRoot, OSLibDir, Paths);
+
+  // Similar to the logic for GCC above, if we are currently running Clang
+  // inside of the requested system root, add its parent library path to those
+  // searched.
   // FIXME: It's not clear whether we should use the driver's installed
   // directory ('Dir' below) or the ResourceDir.
   if (StringRef(D.Dir).startswith(SysRoot))
@@ -108,13 +125,6 @@ Tool *Hurd::buildAssembler() const {
   return new tools::gnutools::Assembler(*this);
 }
 
-std::string Hurd::computeSysRoot() const {
-  if (!getDriver().SysRoot.empty())
-    return getDriver().SysRoot;
-
-  return std::string();
-}
-
 std::string Hurd::getDynamicLinker(const ArgList &Args) const {
   if (getArch() == llvm::Triple::x86)
     return "/lib/ld.so";
@@ -149,7 +159,7 @@ void Hurd::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
     CIncludeDirs.split(Dirs, ":");
     for (StringRef Dir : Dirs) {
       StringRef Prefix =
-          llvm::sys::path::is_absolute(Dir) ? StringRef(SysRoot) : "";
+          llvm::sys::path::is_absolute(Dir) ? "" : StringRef(SysRoot);
       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + Dir);
     }
     return;
@@ -157,6 +167,9 @@ void Hurd::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 
   // Lacking those, try to detect the correct set of system includes for the
   // target triple.
+
+  AddMultilibIncludeArgs(DriverArgs, CC1Args);
+
   if (getTriple().getArch() == llvm::Triple::x86) {
     std::string Path = SysRoot + "/usr/include/i386-gnu";
     if (D.getVFS().exists(Path))
@@ -170,3 +183,8 @@ void Hurd::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 
   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
 }
+
+void Hurd::addExtraOpts(llvm::opt::ArgStringList &CmdArgs) const {
+  for (const auto &Opt : ExtraOpts)
+    CmdArgs.push_back(Opt.c_str());
+}