[PATCH] D61460: Fix bug in getCompleteTypeIndex in codeview debug info

[Reid Kleckner via Phabricator via llvm-commits]

rnk added a comment.

This should have a test. I think you can use this C++ to start:

  struct Foo;
  extern "C" __declspec(allocator) Foo *alloc_foo();
  void escape(Foo*);
  void doit() {
    escape(alloc_foo());
    escape(alloc_foo());
    escape(alloc_foo());
  }

Before this change, the symbols would show the wrong type for the second and third heap alloc sites.



================
Comment at: llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp:2519-2521
+  auto InsertResult = CompleteTypeIndices.insert({CTy, TypeIndex()});
+  if (!InsertResult.second)
+    return InsertResult.first->second;
----------------
While we're here, please simplify this to just use `.find` since we can't use InsertResult below.


================
Comment at: llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp:2536-2539
   // Update the type index associated with this CompositeType.  This cannot
   // use the 'InsertResult' iterator above because it is potentially
   // invalidated by map insertions which can occur while lowering the class
   // type above.
----------------
If you do delete InsertResult, you should simplify this comment to just say that we need to re-do the hash lookup because complete type lowering may insert more complete types into the table.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D61460/new/

https://reviews.llvm.org/D61460