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

Zachary Turner · Zachary Turner · commit 719f58c22880 · 2014-12-01T23:06:47.000Z
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 llvm-svn: 223086
diff --git a/clang/lib/Driver/MSVCToolChain.cpp b/clang/lib/Driver/MSVCToolChain.cpp
@@ -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 {
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
@@ -7982,10 +7982,26 @@ void visualstudio::Link::ConstructJob(Compilation &C, const JobAction &JA,
     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));
 }

Original file line number	Diff line number	Diff line change
`@@ -43,6 +43,9 @@ using namespace llvm::opt;`
`43`	`43`	`MSVCToolChain::MSVCToolChain(const Driver &D, const llvm::Triple& Triple,`
`44`	`44`	`const ArgList &Args)`
`45`	`45`	`: ToolChain(D, Triple, Args) {`
	`46`	`+ getProgramPaths().push_back(getDriver().getInstalledDir());`
	`47`	`+ if (getDriver().getInstalledDir() != getDriver().Dir)`
	`48`	`+ getProgramPaths().push_back(getDriver().Dir);`
`46`	`49`	`}`
`47`	`50`
`48`	`51`	`Tool *MSVCToolChain::buildLinker() const {`