[PATCH] D82415: [Coroutines] Special handle __builtin_coro_resume for final_suspend nothrow check

[Xun Li via Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
lxfind marked an inline comment as done.
Closed by commit rG366159566df3: [Coroutines] Special handle __builtin_coro_resume for final_suspend nothrow… (authored by lxfind).

Changed prior to commit:
  https://reviews.llvm.org/D82415?vs=272910&id=273466#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82415/new/

https://reviews.llvm.org/D82415

Files:
  clang/lib/Sema/SemaCoroutine.cpp


Index: clang/lib/Sema/SemaCoroutine.cpp
===================================================================
--- clang/lib/Sema/SemaCoroutine.cpp
+++ clang/lib/Sema/SemaCoroutine.cpp
@@ -614,6 +614,17 @@
     // In the case of dtor, the call to dtor is implicit and hence we should
     // pass nullptr to canCalleeThrow.
     if (Sema::canCalleeThrow(S, IsDtor ? nullptr : cast<Expr>(E), D)) {
+      if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
+        // co_await promise.final_suspend() could end up calling
+        // __builtin_coro_resume for symmetric transfer if await_suspend()
+        // returns a handle. In that case, even __builtin_coro_resume is not
+        // declared as noexcept and may throw, it does not throw _into_ the
+        // coroutine that just suspended, but rather throws back out from
+        // whoever called coroutine_handle::resume(), hence we claim that
+        // logically it does not throw.
+        if (FD->getBuiltinID() == Builtin::BI__builtin_coro_resume)
+          return;
+      }
       if (ThrowingDecls.empty()) {
         // First time seeing an error, emit the error message.
         S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(),


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