Revert "Revert "Fix LLVMgold plugin name/path for non-Linux.""

Summary:
Relanding https://reviews.llvm.org/D35739 which was reverted because
it broke the tests on non-Linux. The tests have been fixed to be
platform agnostic, and additional tests have been added to make sure
that the plugin has the correct extension on each platform
(%pluginext doesn't work in CHECK lines).

Reviewers: srhines, pirama

Reviewed By: srhines

Subscribers: emaste, mehdi_amini, eraman, cfe-commits

Differential Revision: https://reviews.llvm.org/D36769

llvm-svn: 310960

1 files changed, 14 insertions, 2 deletions

diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 1273b7aabc0..b9b5b2cbe6e 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -376,8 +376,20 @@ void tools::AddGoldPlugin(const ToolChain &ToolChain, const ArgList &Args,
   // as gold requires -plugin to come before any -plugin-opt that -Wl might
   // forward.
   CmdArgs.push_back("-plugin");
-  std::string Plugin =
-      ToolChain.getDriver().Dir + "/../lib" CLANG_LIBDIR_SUFFIX "/LLVMgold.so";
+
+#if defined(LLVM_ON_WIN32)
+  const char *Suffix = ".dll";
+#elif defined(__APPLE__)
+  const char *Suffix = ".dylib";
+#else
+  const char *Suffix = ".so";
+#endif
+
+  SmallString<1024> Plugin;
+  llvm::sys::path::native(Twine(ToolChain.getDriver().Dir) +
+                              "/../lib" CLANG_LIBDIR_SUFFIX "/LLVMgold" +
+                              Suffix,
+                          Plugin);
   CmdArgs.push_back(Args.MakeArgString(Plugin));
 
   // Try to pass driver level flags relevant to LTO code generation down to