[clang] [clang-tools-extra] [coroutines] Do not check coroutine wrappers for skipped function bodies (PR #76729)

[Ilya Biryukov via cfe-commits]

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@@ -15845,7 +15845,7 @@ static void diagnoseImplicitlyRetainedSelf(Sema &S) {
 }
 
 void Sema::CheckCoroutineWrapper(FunctionDecl *FD) {
-  if (!FD)
+  if (!FD || FD->hasSkippedBody())
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ilya-biryukov wrote:

Suggestion: a comment would be appropriate here, e.g. `// if we skip function body, we can't tell if a function is a coroutine`.

More serious request is to move this check up the call stack where we inspect `FSI` and call `isCoroutine()`. `CheckCoroutineWrapper` does not even look if the function is a coroutine or not, it merely looks at an attribute, which is available even if we skip the function body.

It's the calling code that should make sure `CheckCoroutineWrapper` should not be called for coroutines, so it's caller's responsibility to ensure this function is not called when it can't tell if a function is a coroutine or not.


https://github.com/llvm/llvm-project/pull/76729