[msan] Remove legacy PM pass

[MaskRay]

Summary

Using the legacy PM for the optimization pipeline was deprecated in 13.0.0.
Following recent changes to remove non-core features of the legacy
PM/optimization pipeline, remove MemorySanitizerLegacyPass.

I am going to wait a bit for

• Rust https://internals.rust-lang.org/t/llvms-legacy-pass-manager-passes-for-sanitizers-will-go-away/16473
• SwiftShader https://issuetracker.google.com/issues/229437380

llvm/bindings/go/llvm/InstrumentationBindings.h

 
 // FIXME: These bindings shouldn't be Go-specific and should eventually move to
 // a (somewhat) less stable collection of C APIs for use in creating bindings of
 // LLVM in other languages.
 
 void LLVMAddAddressSanitizerFunctionPass(LLVMPassManagerRef PM);
 void LLVMAddAddressSanitizerModulePass(LLVMPassManagerRef PM);
 void LLVMAddThreadSanitizerPass(LLVMPassManagerRef PM);
-void LLVMAddMemorySanitizerLegacyPassPass(LLVMPassManagerRef PM);
 void LLVMAddDataFlowSanitizerPass(LLVMPassManagerRef PM, int ABIListFilesNum,
                                   const char **ABIListFiles);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif

llvm/bindings/go/llvm/InstrumentationBindings.cpp

 void LLVMAddAddressSanitizerModulePass(LLVMPassManagerRef PM) {
   unwrap(PM)->add(createModuleAddressSanitizerLegacyPassPass());
 }
 
 void LLVMAddThreadSanitizerPass(LLVMPassManagerRef PM) {
   unwrap(PM)->add(createThreadSanitizerLegacyPassPass());
 }
 
-void LLVMAddMemorySanitizerLegacyPassPass(LLVMPassManagerRef PM) {
-  unwrap(PM)->add(createMemorySanitizerLegacyPassPass());
-}
-
 void LLVMAddDataFlowSanitizerPass(LLVMPassManagerRef PM,
                                   int ABIListFilesNum,
                                   const char **ABIListFiles) {
   std::vector<std::string> ABIListFilesVec;
   for (int i = 0; i != ABIListFilesNum; ++i) {
     ABIListFilesVec.push_back(ABIListFiles[i]);
   }
   unwrap(PM)->add(createDataFlowSanitizerLegacyPassPass(ABIListFilesVec));
 }

llvm/bindings/go/llvm/transforms_instrumentation.go

 func (pm PassManager) AddAddressSanitizerModulePass() {
   C.LLVMAddAddressSanitizerModulePass(pm.C)
 }
 
 func (pm PassManager) AddThreadSanitizerPass() {
   C.LLVMAddThreadSanitizerPass(pm.C)
 }
 
-func (pm PassManager) AddMemorySanitizerLegacyPassPass() {
-  C.LLVMAddMemorySanitizerLegacyPassPass(pm.C)
-}
-
 func (pm PassManager) AddDataFlowSanitizerPass(abilist []string) {
   abiliststrs := make([]*C.char, len(abilist))
   for i, arg := range abilist {
     abiliststrs[i] = C.CString(arg)
     defer C.free(unsafe.Pointer(abiliststrs[i]))
   }
   C.LLVMAddDataFlowSanitizerPass(pm.C, C.int(len(abilist)), &abiliststrs[0])
 }

llvm/include/llvm/InitializePasses.h

 void initializeMachineTraceMetricsPass(PassRegistry&);
 void initializeMachineVerifierPassPass(PassRegistry&);
 void initializeMemCpyOptLegacyPassPass(PassRegistry&);
 void initializeMemDepPrinterPass(PassRegistry&);
 void initializeMemDerefPrinterPass(PassRegistry&);
 void initializeMemoryDependenceWrapperPassPass(PassRegistry&);
 void initializeMemorySSAPrinterLegacyPassPass(PassRegistry&);
 void initializeMemorySSAWrapperPassPass(PassRegistry&);
-void initializeMemorySanitizerLegacyPassPass(PassRegistry&);
 void initializeMergeFunctionsLegacyPassPass(PassRegistry&);
 void initializeMergeICmpsLegacyPassPass(PassRegistry &);
 void initializeMergedLoadStoreMotionLegacyPassPass(PassRegistry&);
 void initializeMetaRenamerPass(PassRegistry&);
 void initializeModuleDebugInfoLegacyPrinterPass(PassRegistry &);
 void initializeModuleMemProfilerLegacyPassPass(PassRegistry &);
 void initializeModuleSummaryIndexWrapperPassPass(PassRegistry&);
 void initializeModuloScheduleTestPass(PassRegistry&);

llvm/include/llvm/Transforms/Instrumentation/MemorySanitizer.h

struct MemorySanitizerOptions {
   MemorySanitizerOptions(int TrackOrigins, bool Recover, bool Kernel,
                          bool EagerChecks);
   bool Kernel;
   int TrackOrigins;
   bool Recover;
   bool EagerChecks;
 };
 
-// Insert MemorySanitizer instrumentation (detection of uninitialized reads)
-FunctionPass *
-createMemorySanitizerLegacyPassPass(MemorySanitizerOptions Options = {});
-
 /// A function pass for msan instrumentation.
 ///
 /// Instruments functions to detect unitialized reads. This function pass
 /// inserts calls to runtime library functions. If the functions aren't declared
 /// yet, the pass inserts the declarations. Otherwise the existing globals are
 /// used.
 struct MemorySanitizerPass : public PassInfoMixin<MemorySanitizerPass> {
   MemorySanitizerPass(MemorySanitizerOptions Options) : Options(Options) {}

llvm/lib/Transforms/Instrumentation/Instrumentation.cpp

void llvm::initializeInstrumentation(PassRegistry &Registry) {
   initializeMemProfilerLegacyPassPass(Registry);
   initializeModuleMemProfilerLegacyPassPass(Registry);
   initializeBoundsCheckingLegacyPassPass(Registry);
   initializeControlHeightReductionLegacyPassPass(Registry);
   initializeGCOVProfilerLegacyPassPass(Registry);
   initializeCGProfileLegacyPassPass(Registry);
   initializeInstrOrderFileLegacyPassPass(Registry);
   initializeInstrProfilingLegacyPassPass(Registry);
-  initializeMemorySanitizerLegacyPassPass(Registry);
   initializeHWAddressSanitizerLegacyPassPass(Registry);
   initializeThreadSanitizerLegacyPassPass(Registry);
   initializeModuleSanitizerCoverageLegacyPassPass(Registry);
   initializeDataFlowSanitizerLegacyPassPass(Registry);
 }
 
 /// LLVMInitializeInstrumentation - C binding for
 /// initializeInstrumentation.
 void LLVMInitializeInstrumentation(LLVMPassRegistryRef R) {
   initializeInstrumentation(*unwrap(R));
 }

llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp

getOrCreateSanitizerCtorAndInitFunctions(
           return;
         }
         Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName);
         Ctor->setComdat(MsanCtorComdat);
         appendToGlobalCtors(M, Ctor, 0, Ctor);
       });
 }
 
-/// A legacy function pass for msan instrumentation.
-///
-/// Instruments functions to detect uninitialized reads.
-struct MemorySanitizerLegacyPass : public FunctionPass {
-  // Pass identification, replacement for typeid.
-  static char ID;
-
-  MemorySanitizerLegacyPass(MemorySanitizerOptions Options = {})
-      : FunctionPass(ID), Options(Options) {
-    initializeMemorySanitizerLegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-  StringRef getPassName() const override { return "MemorySanitizerLegacyPass"; }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<TargetLibraryInfoWrapperPass>();
-  }
-
-  bool runOnFunction(Function &F) override {
-    return MSan->sanitizeFunction(
-        F, getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F));
-  }
-  bool doInitialization(Module &M) override;
-
-  Optional<MemorySanitizer> MSan;
-  MemorySanitizerOptions Options;
-};
-
 template <class T> T getOptOrDefault(const cl::opt<T> &Opt, T Default) {
   return (Opt.getNumOccurrences() > 0) ? Opt : Default;
 }
 
 } // end anonymous namespace
 
 MemorySanitizerOptions::MemorySanitizerOptions(int TO, bool R, bool K,
                                                bool EagerChecks)
void MemorySanitizerPass::printPipeline(
   if (Options.Kernel)
     OS << "kernel;";
   if (Options.EagerChecks)
     OS << "eager-checks;";
   OS << "track-origins=" << Options.TrackOrigins;
   OS << ">";
 }
 
-char MemorySanitizerLegacyPass::ID = 0;
-
-INITIALIZE_PASS_BEGIN(MemorySanitizerLegacyPass, "msan",
-                      "MemorySanitizer: detects uninitialized reads.", false,
-                      false)
-INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
-INITIALIZE_PASS_END(MemorySanitizerLegacyPass, "msan",
-                    "MemorySanitizer: detects uninitialized reads.", false,
-                    false)
-
-FunctionPass *
-llvm::createMemorySanitizerLegacyPassPass(MemorySanitizerOptions Options) {
-  return new MemorySanitizerLegacyPass(Options);
-}
-
 /// Create a non-const global initialized with the given string.
 ///
 /// Creates a writable global for Str so that we can pass it to the
 /// run-time lib. Runtime uses first 4 bytes of the string to store the
 /// frame ID, so the string needs to be mutable.
 static GlobalVariable *createPrivateNonConstGlobalForString(Module &M,
                                                             StringRef Str) {
   Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
if (Recover)
       M.getOrInsertGlobal("__msan_keep_going", IRB.getInt32Ty(), [&] {
         return new GlobalVariable(M, IRB.getInt32Ty(), true,
                                   GlobalValue::WeakODRLinkage,
                                   IRB.getInt32(Recover), "__msan_keep_going");
       });
 }
 }
 
-bool MemorySanitizerLegacyPass::doInitialization(Module &M) {
-  if (!Options.Kernel)
-    insertModuleCtor(M);
-  MSan.emplace(M, Options);
-  return true;
-}
-
 namespace {
 
 /// A helper class that handles instrumentation of VarArg
 /// functions on a particular platform.
 ///
 /// Implementations are expected to insert the instrumentation
 /// necessary to propagate argument shadow through VarArg function
 /// calls. Visit* methods are called during an InstVisitor pass over