[clang] [coroutines][coro_lifetimebound] Detect lifetime issues with lambda captures (PR #77066)

[Chuanqi Xu via cfe-commits]

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@@ -15845,8 +15845,10 @@ void Sema::CheckCoroutineWrapper(FunctionDecl *FD) {
   RecordDecl *RD = FD->getReturnType()->getAsRecordDecl();
   if (!RD || !RD->getUnderlyingDecl()->hasAttr<CoroReturnTypeAttr>())
     return;
-  // Allow `get_return_object()`.
-  if (FD->getDeclName().isIdentifier() &&
+  // Allow some_promise_type::get_return_object().
+  // Since we are still in the promise definition, we can only do this
+  // heuristically as the promise may not be yet associated to a coroutine.
+  if (isa<CXXMethodDecl>(FD) && FD->getDeclName().isIdentifier() &&
       FD->getName().equals("get_return_object") && FD->param_empty())
     return;
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ChuanqiXu9 wrote:

> I do not think that would work either. For example, consider TUs with only promise definitions and no coroutine definitions. These attr would not be available even in the end of TU.

Oh, yeah. I didn't think about modules : ).

>  @ChuanqiXu9 is it fine to add attributes to existing functions conditioned on how they are used rather than how they are defined?

Then it is troublesome to use this attribute, which violates our intention.

https://github.com/llvm/llvm-project/pull/77066