r223086 - Make -fuse-ld=lld work properly on Windows.

[Zachary Turner]

Author: zturner
Date: Mon Dec  1 17:06:47 2014
New Revision: 223086

URL: http://llvm.org/viewvc/llvm-project?rev=223086&view=rev
Log:
Make -fuse-ld=lld work properly on Windows.

Using lld on Windows requires calling link-lld.exe instead of
lld.exe.  This patch puts this knowledge into clang so that when
using the GCC style clang driver, it can properly delegate to
lld.

Differential Revision: http://reviews.llvm.org/D6428
Reviewed by: Reid Kleckner, Rui Ueyama

Modified:
    cfe/trunk/lib/Driver/MSVCToolChain.cpp
    cfe/trunk/lib/Driver/Tools.cpp

Modified: cfe/trunk/lib/Driver/MSVCToolChain.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/MSVCToolChain.cpp?rev=223086&r1=223085&r2=223086&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/MSVCToolChain.cpp (original)
+++ cfe/trunk/lib/Driver/MSVCToolChain.cpp Mon Dec  1 17:06:47 2014
@@ -43,6 +43,9 @@ using namespace llvm::opt;
 MSVCToolChain::MSVCToolChain(const Driver &D, const llvm::Triple& Triple,
                              const ArgList &Args)
   : ToolChain(D, Triple, Args) {
+  getProgramPaths().push_back(getDriver().getInstalledDir());
+  if (getDriver().getInstalledDir() != getDriver().Dir)
+    getProgramPaths().push_back(getDriver().Dir);
 }
 
 Tool *MSVCToolChain::buildLinker() const {

Modified: cfe/trunk/lib/Driver/Tools.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=223086&r1=223085&r2=223086&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Mon Dec  1 17:06:47 2014
@@ -7982,10 +7982,26 @@ void visualstudio::Link::ConstructJob(Co
     A.renderAsInput(Args, CmdArgs);
   }
 
-  // It's not sufficient to just use link from the program PATH, because other
-  // environments like GnuWin32 install their own link.exe which may come first.
-  llvm::SmallString<128> linkPath(FindVisualStudioExecutable(
-      getToolChain(), "link.exe", C.getDriver().getClangProgramPath()));
+  // We need to special case some linker paths.  In the case of lld, we need to
+  // translate 'lld' into 'lld-link', and in the case of the regular msvc
+  // linker, we need to use a special search algorithm.
+  llvm::SmallString<128> linkPath;
+  StringRef Linker = Args.getLastArgValue(options::OPT_fuse_ld_EQ, "link");
+  if (Linker.equals_lower("lld"))
+    Linker = "lld-link";
+
+  if (Linker.equals_lower("link")) {
+    // If we're using the MSVC linker, it's not sufficient to just use link
+    // from the program PATH, because other environments like GnuWin32 install
+    // their own link.exe which may come first.
+    linkPath = FindVisualStudioExecutable(getToolChain(), "link.exe",
+                                          C.getDriver().getClangProgramPath());
+  } else {
+    linkPath = Linker;
+    llvm::sys::path::replace_extension(linkPath, "exe");
+    linkPath = getToolChain().GetProgramPath(linkPath.c_str());
+  }
+
   const char *Exec = Args.MakeArgString(linkPath);
   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs));
 }