[Mlir-commits] [mlir] [MLIR][LLVM] Recursion importer handle repeated self-references (PR #87295)

[Billy Zhu]

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@@ -216,18 +216,15 @@ DebugTranslation::translateImpl(DIGlobalVariableAttr attr) {
 llvm::DIType *
 DebugTranslation::translateRecursive(DIRecursiveTypeAttrInterface attr) {
   DistinctAttr recursiveId = attr.getRecId();
-  if (attr.isRecSelf()) {
-    auto *iter = recursiveTypeMap.find(recursiveId);
-    assert(iter != recursiveTypeMap.end() && "unbound DI recursive self type");
+  if (auto *iter = recursiveTypeMap.find(recursiveId);
+      iter != recursiveTypeMap.end()) {
     return iter->second;
+  } else {
+    assert(!attr.isRecSelf() && "unbound DI recursive self type");
   }
 
   auto setRecursivePlaceholder = [&](llvm::DIType *placeholder) {
-    [[maybe_unused]] auto [iter, inserted] =
-        recursiveTypeMap.try_emplace(recursiveId, placeholder);
-    (void)iter;
-    (void)inserted;
-    assert(inserted && "illegal reuse of recursive id");
+    recursiveTypeMap.try_emplace(recursiveId, placeholder);
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zyx-billy wrote:

oof 🤦 thanks for the test case. I think the emplace here is guaranteed to insert because the check above will return if the recId is found in the map. I see that this use-after-free is the temporary that was created, and then RAUW'ed, but referenced again. I'm afraid we might have just exposed an existing issue with the exporter? Let me take a closer look 👀 ...

https://github.com/llvm/llvm-project/pull/87295