[NewPM] Add -fsanitize={memory,thread} handling to clang

[philip.pfaffe]

Summary

This is the missing bit to drive thread and memory sanitizers through clang using the new PassManager.

[chandlerc]

LGTM

clang/lib/CodeGen/BackendUtil.cpp

1016–1017

Add a FIXME about ASan?

Actually, if you don't mind, could you add code to detect ASan (and any other sanitizers you see in the parallel code) and emit a fatal error and put the FIXME there? I really should have done this to begin with. We should never *ignore* the flag.

Follow-up patch is probably better at that point, and include Richard or Reid on it to make sure its an acceptable way to handle the error.

I don't think we need to produce a full fledged diagnostic here -- this isn't related to the code at all, and this is essentially a "not implemented yet" as opposed to a useful thing for users.

clang/lib/CodeGen/BackendUtil.cpp

if (CodeGenOpts.OptimizationLevel == 0) {
         MPM.addPass(CanonicalizeAliasesPass());
         MPM.addPass(NameAnonGlobalPass());
       }
     } else {
       // Map our optimization levels into one of the distinct levels used to
       // configure the pipeline.
       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
 
       // Register callbacks to schedule sanitizer passes at the appropriate part of
       // the pipeline.
       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
         PB.registerScalarOptimizerLateEPCallback(
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
               FPM.addPass(BoundsCheckingPass());
             });
+      if (LangOpts.Sanitize.has(SanitizerKind::Memory))
+        PB.registerOptimizerLastEPCallback(
+            [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
+              FPM.addPass(MemorySanitizerPass());
+            });
+      if (LangOpts.Sanitize.has(SanitizerKind::Thread))
+        PB.registerOptimizerLastEPCallback(
+            [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
+              FPM.addPass(ThreadSanitizerPass());
+            });
       if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
         PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
           MPM.addPass(GCOVProfilerPass(*Options));
         });
 
       if (IsThinLTO) {
         MPM = PB.buildThinLTOPreLinkDefaultPipeline(
             Level, CodeGenOpts.DebugPassManager);