[tsan,msan] Insert module constructors in a module pass

Summary:
If we insert them from function pass some analysis may be missing or invalid.
Fixes PR42877.

Reviewers: eugenis, leonardchan

Reviewed By: leonardchan

Subscribers: hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D68832

llvm-svn: 374481

1 files changed, 27 insertions, 25 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
index 643a03783e7..ac274a155a8 100644
--- a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
@@ -92,11 +92,10 @@ namespace {
 /// ensures the __tsan_init function is in the list of global constructors for
 /// the module.
 struct ThreadSanitizer {
-  ThreadSanitizer(Module &M);
   bool sanitizeFunction(Function &F, const TargetLibraryInfo &TLI);
 
 private:
-  void initializeCallbacks(Module &M);
+  void initialize(Module &M);
   bool instrumentLoadOrStore(Instruction *I, const DataLayout &DL);
   bool instrumentAtomic(Instruction *I, const DataLayout &DL);
   bool instrumentMemIntrinsic(Instruction *I);
@@ -108,8 +107,6 @@ private:
   void InsertRuntimeIgnores(Function &F);
 
   Type *IntptrTy;
-  IntegerType *OrdTy;
-  // Callbacks to run-time library are computed in doInitialization.
   FunctionCallee TsanFuncEntry;
   FunctionCallee TsanFuncExit;
   FunctionCallee TsanIgnoreBegin;
@@ -130,7 +127,6 @@ private:
   FunctionCallee TsanVptrUpdate;
   FunctionCallee TsanVptrLoad;
   FunctionCallee MemmoveFn, MemcpyFn, MemsetFn;
-  Function *TsanCtorFunction;
 };
 
 struct ThreadSanitizerLegacyPass : FunctionPass {
@@ -143,16 +139,32 @@ struct ThreadSanitizerLegacyPass : FunctionPass {
 private:
   Optional<ThreadSanitizer> TSan;
 };
+
+void insertModuleCtor(Module &M) {
+  getOrCreateSanitizerCtorAndInitFunctions(
+      M, kTsanModuleCtorName, kTsanInitName, /*InitArgTypes=*/{},
+      /*InitArgs=*/{},
+      // This callback is invoked when the functions are created the first
+      // time. Hook them into the global ctors list in that case:
+      [&](Function *Ctor, FunctionCallee) { appendToGlobalCtors(M, Ctor, 0); });
+}
+
 }  // namespace
 
 PreservedAnalyses ThreadSanitizerPass::run(Function &F,
                                            FunctionAnalysisManager &FAM) {
-  ThreadSanitizer TSan(*F.getParent());
+  ThreadSanitizer TSan;
   if (TSan.sanitizeFunction(F, FAM.getResult<TargetLibraryAnalysis>(F)))
     return PreservedAnalyses::none();
   return PreservedAnalyses::all();
 }
 
+PreservedAnalyses ThreadSanitizerPass::run(Module &M,
+                                           ModuleAnalysisManager &MAM) {
+  insertModuleCtor(M);
+  return PreservedAnalyses::none();
+}
+
 char ThreadSanitizerLegacyPass::ID = 0;
 INITIALIZE_PASS_BEGIN(ThreadSanitizerLegacyPass, "tsan",
                       "ThreadSanitizer: detects data races.", false, false)
@@ -169,7 +181,8 @@ void ThreadSanitizerLegacyPass::getAnalysisUsage(AnalysisUsage &AU) const {
 }
 
 bool ThreadSanitizerLegacyPass::doInitialization(Module &M) {
-  TSan.emplace(M);
+  insertModuleCtor(M);
+  TSan.emplace();
   return true;
 }
 
@@ -183,7 +196,10 @@ FunctionPass *llvm::createThreadSanitizerLegacyPassPass() {
   return new ThreadSanitizerLegacyPass();
 }
 
-void ThreadSanitizer::initializeCallbacks(Module &M) {
+void ThreadSanitizer::initialize(Module &M) {
+  const DataLayout &DL = M.getDataLayout();
+  IntptrTy = DL.getIntPtrType(M.getContext());
+
   IRBuilder<> IRB(M.getContext());
   AttributeList Attr;
   Attr = Attr.addAttribute(M.getContext(), AttributeList::FunctionIndex,
@@ -197,7 +213,7 @@ void ThreadSanitizer::initializeCallbacks(Module &M) {
                                           IRB.getVoidTy());
   TsanIgnoreEnd =
       M.getOrInsertFunction("__tsan_ignore_thread_end", Attr, IRB.getVoidTy());
-  OrdTy = IRB.getInt32Ty();
+  IntegerType *OrdTy = IRB.getInt32Ty();
   for (size_t i = 0; i < kNumberOfAccessSizes; ++i) {
     const unsigned ByteSize = 1U << i;
     const unsigned BitSize = ByteSize * 8;
@@ -280,20 +296,6 @@ void ThreadSanitizer::initializeCallbacks(Module &M) {
                             IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy);
 }
 
-ThreadSanitizer::ThreadSanitizer(Module &M) {
-  const DataLayout &DL = M.getDataLayout();
-  IntptrTy = DL.getIntPtrType(M.getContext());
-  std::tie(TsanCtorFunction, std::ignore) =
-      getOrCreateSanitizerCtorAndInitFunctions(
-          M, kTsanModuleCtorName, kTsanInitName, /*InitArgTypes=*/{},
-          /*InitArgs=*/{},
-          // This callback is invoked when the functions are created the first
-          // time. Hook them into the global ctors list in that case:
-          [&](Function *Ctor, FunctionCallee) {
-            appendToGlobalCtors(M, Ctor, 0);
-          });
-}
-
 static bool isVtableAccess(Instruction *I) {
   if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
     return Tag->isTBAAVtableAccess();
@@ -436,9 +438,9 @@ bool ThreadSanitizer::sanitizeFunction(Function &F,
                                        const TargetLibraryInfo &TLI) {
   // This is required to prevent instrumenting call to __tsan_init from within
   // the module constructor.
-  if (&F == TsanCtorFunction)
+  if (F.getName() == kTsanModuleCtorName)
     return false;
-  initializeCallbacks(*F.getParent());
+  initialize(*F.getParent());
   SmallVector<Instruction*, 8> AllLoadsAndStores;
   SmallVector<Instruction*, 8> LocalLoadsAndStores;
   SmallVector<Instruction*, 8> AtomicAccesses;