[clang] [MinGW] Add the compiler rt libdirs to the search path

This matches what is done for MSVC in
b8000c0ce84541c5b5535419234fb65ce77d6756. Since that commit, compiler
rt sanitizer libraries aren't linked to with absolute path on windows,
but using their basenames, requiring the libdirs to be passed to
the linker.

This fixes undefined behaviour sanitizer on MinGW after
b8000c0ce84541c5b5535419234fb65ce77d6756.

Differential Revision: https://reviews.llvm.org/D79076

diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp
index 6139764..ce01c88 100644 (file)
--- a/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -18,6 +18,7 @@
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/VirtualFileSystem.h"
 #include <system_error>
 
 using namespace clang::diag;
@@ -198,6 +199,17 @@ void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   Args.AddAllArgs(CmdArgs, options::OPT_L);
   TC.AddFilePathLibArgs(Args, CmdArgs);
+
+  // Add the compiler-rt library directories if they exist to help
+  // the linker find the various sanitizer, builtin, and profiling runtimes.
+  for (const auto &LibPath : TC.getLibraryPaths()) {
+    if (TC.getVFS().exists(LibPath))
+      CmdArgs.push_back(Args.MakeArgString("-L" + LibPath));
+  }
+  auto CRTPath = TC.getCompilerRTPath();
+  if (TC.getVFS().exists(CRTPath))
+    CmdArgs.push_back(Args.MakeArgString("-L" + CRTPath));
+
   AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
 
   // TODO: Add profile stuff here