[IR] Adds Instruction::setNoSanitizeMetadata()

[Enna1]

Summary

This patch adds a new method setNoSanitizeMetadata() for Instruction, and use it in SanitizerMetadata and SanitizerCoverage.

[Enna1]

update

[nickdesaulniers]

clang/lib/CodeGen/SanitizerMetadata.cpp

103

How about deleting this definition and updating the two call sites in:

1. clang/lib/CodeGen/ItaniumCXXABI.cpp
2. clang/lib/CodeGen/CodeGenFunction.cpp

[Enna1]

address review comments

[MaskRay]

LGTM.

llvm/include/llvm/IR/Instruction.h

353

Set.

Imperative sentences are more common in comments. Ignore Sets above that's inconsistent with other places in this file.

clang/lib/CodeGen/CodeGenFunction.cpp

 }
 
 void CodeGenFunction::InsertHelper(llvm::Instruction *I,
                                    const llvm::Twine &Name,
                                    llvm::BasicBlock *BB,
                                    llvm::BasicBlock::iterator InsertPt) const {
   LoopStack.InsertHelper(I);
   if (IsSanitizerScope)
-    CGM.getSanitizerMetadata()->disableSanitizerForInstruction(I);
+    I->setNoSanitizeMetadata();
 }
 
 void CGBuilderInserter::InsertHelper(
     llvm::Instruction *I, const llvm::Twine &Name, llvm::BasicBlock *BB,
     llvm::BasicBlock::iterator InsertPt) const {
   llvm::IRBuilderDefaultInserter::InsertHelper(I, Name, BB, InsertPt);
   if (CGF)
     CGF->InsertHelper(I, Name, BB, InsertPt);

clang/lib/CodeGen/ItaniumCXXABI.cpp

Address NumElementsPtr =
       CGF.Builder.CreateElementBitCast(CookiePtr, CGF.SizeTy);
   llvm::Instruction *SI = CGF.Builder.CreateStore(NumElements, NumElementsPtr);
 
   // Handle the array cookie specially in ASan.
   if (CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) && AS == 0 &&
       (expr->getOperatorNew()->isReplaceableGlobalAllocationFunction() ||
        CGM.getCodeGenOpts().SanitizeAddressPoisonCustomArrayCookie)) {
     // The store to the CookiePtr does not need to be instrumented.
-    CGM.getSanitizerMetadata()->disableSanitizerForInstruction(SI);
+    SI->setNoSanitizeMetadata();
     llvm::FunctionType *FTy =
         llvm::FunctionType::get(CGM.VoidTy, NumElementsPtr.getType(), false);
     llvm::FunctionCallee F =
         CGM.CreateRuntimeFunction(FTy, "__asan_poison_cxx_array_cookie");
     CGF.Builder.CreateCall(F, NumElementsPtr.getPointer());
   }
 
   // Finally, compute a pointer to the actual data buffer by skipping

clang/lib/CodeGen/SanitizerMetadata.h

public:
   SanitizerMetadata(CodeGenModule &CGM);
   void reportGlobal(llvm::GlobalVariable *GV, const VarDecl &D,
                     bool IsDynInit = false);
   void reportGlobal(llvm::GlobalVariable *GV, SourceLocation Loc,
                     StringRef Name, QualType Ty = {},
                     SanitizerMask NoSanitizeAttrMask = {},
                     bool IsDynInit = false);
   void disableSanitizerForGlobal(llvm::GlobalVariable *GV);
-  void disableSanitizerForInstruction(llvm::Instruction *I);
 };
 } // end namespace CodeGen
 } // end namespace clang
 
 #endif

clang/lib/CodeGen/SanitizerMetadata.cpp

void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV, const VarDecl &D,
   };
 
   reportGlobal(GV, D.getLocation(), OS.str(), D.getType(), getNoSanitizeMask(D),
                IsDynInit);
 }
 
 void SanitizerMetadata::disableSanitizerForGlobal(llvm::GlobalVariable *GV) {
   reportGlobal(GV, SourceLocation(), "", QualType(), SanitizerKind::All);
 }
-
-void SanitizerMetadata::disableSanitizerForInstruction(llvm::Instruction *I) {
-  I->setMetadata(llvm::LLVMContext::MD_nosanitize,
-                 llvm::MDNode::get(CGM.getLLVMContext(), std::nullopt));
-}

llvm/include/llvm/IR/Instruction.h

public:
   /// the existing node.
   void addAnnotationMetadata(SmallVector<StringRef> Annotations);
   /// Returns the AA metadata for this instruction.
   AAMDNodes getAAMetadata() const;
 
   /// Sets the AA metadata on this instruction from the AAMDNodes structure.
   void setAAMetadata(const AAMDNodes &N);
 
+  /// Sets the nosanitize metadata on this instruction.
+  void setNoSanitizeMetadata();
+
   /// Retrieve total raw weight values of a branch.
   /// Returns true on success with profile total weights filled in.
   /// Returns false if no metadata was found.
   bool extractProfTotalWeight(uint64_t &TotalVal) const;
 
   /// Set the debug location information for this instruction.
   void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); }
 

llvm/lib/IR/Metadata.cpp

 
 void Instruction::setAAMetadata(const AAMDNodes &N) {
   setMetadata(LLVMContext::MD_tbaa, N.TBAA);
   setMetadata(LLVMContext::MD_tbaa_struct, N.TBAAStruct);
   setMetadata(LLVMContext::MD_alias_scope, N.Scope);
   setMetadata(LLVMContext::MD_noalias, N.NoAlias);
 }
 
+void Instruction::setNoSanitizeMetadata() {
+  setMetadata(llvm::LLVMContext::MD_nosanitize,
+              llvm::MDNode::get(getContext(), std::nullopt));
+}
+
 MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
   // Handle 'dbg' as a special case since it is not stored in the hash table.
   if (KindID == LLVMContext::MD_dbg)
     return DbgLoc.getAsMDNode();
   return Value::getMetadata(KindID);
 }
 
 void Instruction::getAllMetadataImpl(

llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp

private:
   void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx,
                              bool IsLeafFunc = true);
   Function *CreateInitCallsForSections(Module &M, const char *CtorName,
                                        const char *InitFunctionName, Type *Ty,
                                        const char *Section);
   std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section,
                                                 Type *Ty);
 
-  void SetNoSanitizeMetadata(Instruction *I) {
-    I->setMetadata(LLVMContext::MD_nosanitize, MDNode::get(*C, std::nullopt));
-  }
-
   std::string getSectionName(const std::string &Section) const;
   std::string getSectionStart(const std::string &Section) const;
   std::string getSectionEnd(const std::string &Section) const;
   FunctionCallee SanCovTracePCIndir;
   FunctionCallee SanCovTracePC, SanCovTracePCGuard;
   std::array<FunctionCallee, 4> SanCovTraceCmpFunction;
   std::array<FunctionCallee, 4> SanCovTraceConstCmpFunction;
   std::array<FunctionCallee, 5> SanCovLoadFunction;
void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
   }
   if (Options.Inline8bitCounters) {
     auto CounterPtr = IRB.CreateGEP(
         Function8bitCounterArray->getValueType(), Function8bitCounterArray,
         {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)});
     auto Load = IRB.CreateLoad(Int8Ty, CounterPtr);
     auto Inc = IRB.CreateAdd(Load, ConstantInt::get(Int8Ty, 1));
     auto Store = IRB.CreateStore(Inc, CounterPtr);
-    SetNoSanitizeMetadata(Load);
-    SetNoSanitizeMetadata(Store);
+    Load->setNoSanitizeMetadata();
+    Store->setNoSanitizeMetadata();
   }
   if (Options.InlineBoolFlag) {
     auto FlagPtr = IRB.CreateGEP(
         FunctionBoolArray->getValueType(), FunctionBoolArray,
         {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)});
     auto Load = IRB.CreateLoad(Int1Ty, FlagPtr);
     auto ThenTerm =
         SplitBlockAndInsertIfThen(IRB.CreateIsNull(Load), &*IP, false);
     IRBuilder<> ThenIRB(ThenTerm);
     auto Store = ThenIRB.CreateStore(ConstantInt::getTrue(Int1Ty), FlagPtr);
-    SetNoSanitizeMetadata(Load);
-    SetNoSanitizeMetadata(Store);
+    Load->setNoSanitizeMetadata();
+    Store->setNoSanitizeMetadata();
   }
   if (Options.StackDepth && IsEntryBB && !IsLeafFunc) {
     // Check stack depth.  If it's the deepest so far, record it.
     Module *M = F.getParent();
     Function *GetFrameAddr = Intrinsic::getDeclaration(
         M, Intrinsic::frameaddress,
         IRB.getInt8PtrTy(M->getDataLayout().getAllocaAddrSpace()));
     auto FrameAddrPtr =
         IRB.CreateCall(GetFrameAddr, {Constant::getNullValue(Int32Ty)});
     auto FrameAddrInt = IRB.CreatePtrToInt(FrameAddrPtr, IntptrTy);
     auto LowestStack = IRB.CreateLoad(IntptrTy, SanCovLowestStack);
     auto IsStackLower = IRB.CreateICmpULT(FrameAddrInt, LowestStack);
     auto ThenTerm = SplitBlockAndInsertIfThen(IsStackLower, &*IP, false);
     IRBuilder<> ThenIRB(ThenTerm);
     auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack);
-    SetNoSanitizeMetadata(LowestStack);
-    SetNoSanitizeMetadata(Store);
+    LowestStack->setNoSanitizeMetadata();
+    Store->setNoSanitizeMetadata();
   }
 }
 
 std::string
 ModuleSanitizerCoverage::getSectionName(const std::string &Section) const {
   if (TargetTriple.isOSBinFormatCOFF()) {
     if (Section == SanCovCountersSectionName)
       return ".SCOV$CM";