[compiler-rt] [llvm] [Asan] Add "funclet" OpBundle to generated runtime calls if required by EH personality (PR #82533)

[Reid Kleckner via llvm-commits]

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@@ -642,6 +643,70 @@ static uint64_t GetCtorAndDtorPriority(Triple &TargetTriple) {
 }
 
 namespace {
+/// Helper RAII class to keep track of the inserted asan runtime calls during a
+/// pass on a single Function. Upon end of scope, detects and applies the
+/// required funclet OpBundle.
+class RuntimeCallInserter {
+  Function *OwnerFn = nullptr;
+  bool TrackInsertedCalls = false;
+  std::vector<CallInst *> InsertedCalls;
+
+public:
+  RuntimeCallInserter(Function &Fn) : OwnerFn(&Fn) {
+    if (Fn.hasPersonalityFn()) {
+      auto Personality = classifyEHPersonality(Fn.getPersonalityFn());
+      if (isScopedEHPersonality(Personality))
+        TrackInsertedCalls = true;
+    }
+  }
+
+  ~RuntimeCallInserter() {
+    if (!TrackInsertedCalls || InsertedCalls.empty())
+      return;
+
+    DenseMap<BasicBlock *, ColorVector> BlockColors = colorEHFunclets(*OwnerFn);
+    for (CallInst *CI : InsertedCalls) {
+      BasicBlock *BB = CI->getParent();
+      assert(BB && "Instruction doesn't belong to a BasicBlock");
+      assert(BB->getParent() == OwnerFn &&
+             "Instruction doesn't belong to the expected Function!");
+
+      ColorVector &Colors = BlockColors[BB];
+      // funclet opbundles are only valid in monochromatic BBs.
+      // Note that unreachable BBs are seen as colorless by colorEHFunclets()
+      // and will be DCE'ed later.
+      if (Colors.size() != 1) {
+        OwnerFn->getContext().emitError(
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rnk wrote:

Seems like a reasonable strategy. It's a little janky, but probably less user hostile than the current emergent behavior.

https://github.com/llvm/llvm-project/pull/82533