[hwasan] keep debug intrinsicts in AllocaInfo.

[fmayer]

check for interesting alloca

[fmayer]

naming

[eugenis]

LGTM
Add (NFC) to the title.

[fmayer]

fix bug

llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h

bool isStandardLifetime(const SmallVectorImpl<IntrinsicInst *> &LifetimeStart,
                         const DominatorTree *DT, size_t MaxLifetimes);
 
 Instruction *getUntagLocationIfFunctionExit(Instruction &Inst);
 
 struct AllocaInfo {
   AllocaInst *AI;
   SmallVector<IntrinsicInst *, 2> LifetimeStart;
   SmallVector<IntrinsicInst *, 2> LifetimeEnd;
+  SmallVector<DbgVariableIntrinsic *, 2> DbgVariableIntrinsics;
 };
 
 struct StackInfo {
   MapVector<AllocaInst *, AllocaInfo> AllocasToInstrument;
   SmallVector<Instruction *, 4> UnrecognizedLifetimes;
-  DenseMap<AllocaInst *, std::vector<DbgVariableIntrinsic *>> AllocaDbgMap;
   SmallVector<Instruction *, 8> RetVec;
   bool CallsReturnTwice = false;
 };
 
 class StackInfoBuilder {
 public:
   StackInfoBuilder(std::function<bool(const AllocaInst &)> IsInterestingAlloca)
       : IsInterestingAlloca(IsInterestingAlloca) {}

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

for (auto &KV : SInfo.AllocasToInstrument) {
     Value *Replacement = tagPointer(IRB, AI->getType(), AILong, Tag);
     std::string Name =
         AI->hasName() ? AI->getName().str() : "alloca." + itostr(N);
     Replacement->setName(Name + ".hwasan");
 
     AI->replaceUsesWithIf(Replacement,
                           [AILong](Use &U) { return U.getUser() != AILong; });
 
-    for (auto *DDI : SInfo.AllocaDbgMap.lookup(AI)) {
+    for (auto *DDI : Info.DbgVariableIntrinsics) {
       // Prepend "tag_offset, N" to the dwarf expression.
       // Tag offset logically applies to the alloca pointer, and it makes sense
       // to put it at the beginning of the expression.
       SmallVector<uint64_t, 8> NewOps = {dwarf::DW_OP_LLVM_tag_offset,
                                          retagMask(N)};
       for (size_t LocNo = 0; LocNo < DDI->getNumVariableLocationOps(); ++LocNo)
         if (DDI->getVariableLocationOp(LocNo) == AI)
           DDI->setExpression(DIExpression::appendOpsToArg(DDI->getExpression(),

llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp

if (II && (II->getIntrinsicID() == Intrinsic::lifetime_start ||
     if (II->getIntrinsicID() == Intrinsic::lifetime_start)
       Info.AllocasToInstrument[AI].LifetimeStart.push_back(II);
     else
       Info.AllocasToInstrument[AI].LifetimeEnd.push_back(II);
     return;
   }
   if (auto *DVI = dyn_cast<DbgVariableIntrinsic>(&Inst)) {
     for (Value *V : DVI->location_ops()) {
-      if (auto *Alloca = dyn_cast_or_null<AllocaInst>(V))
-        if (!Info.AllocaDbgMap.count(Alloca) ||
-            Info.AllocaDbgMap[Alloca].back() != DVI)
-          Info.AllocaDbgMap[Alloca].push_back(DVI);
+      if (auto *AI = dyn_cast_or_null<AllocaInst>(V)) {
+        if (!IsInterestingAlloca(*AI))
+          continue;
+        AllocaInfo &AInfo = Info.AllocasToInstrument[AI];
+        auto &DVIVec = AInfo.DbgVariableIntrinsics;
+        if (DVIVec.empty() || DVIVec.back() != DVI)
+          DVIVec.push_back(DVI);
+      }
     }
   }
   Instruction *ExitUntag = getUntagLocationIfFunctionExit(Inst);
   if (ExitUntag)
     Info.RetVec.push_back(ExitUntag);
 }
 
 } // namespace memtag
 } // namespace llvm