[clang] [Clang] Propagate elide safe context through [[clang::coro_must_await]] (PR #108474)

[Adrian Vogelsgesang via cfe-commits]

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@@ -880,14 +898,12 @@ ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *Operand,
   }
 
   auto *RD = Promise->getType()->getAsCXXRecordDecl();
-  bool AwaitElidable =
-      isCoroAwaitElidableCall(Operand) &&
-      isAttributedCoroAwaitElidable(
-          getCurFunctionDecl(/*AllowLambda=*/true)->getReturnType());
-
-  if (AwaitElidable)
-    if (auto *Call = dyn_cast<CallExpr>(Operand->IgnoreImplicit()))
-      Call->setCoroElideSafe();
+
+  bool CurFnAwaitElidable = isAttributedCoroAwaitElidable(
+      getCurFunctionDecl(/*AllowLambda=*/true)->getReturnType());
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vogelsgesang wrote:

ah, I see. So after this patch, we could actually check `await_transform` and also `operator co_await` and thereby get rid of the `CurFnAwaitElidable` check? Such that a `ElideableTask` coawaited within a NonElidableTask (as discussed in the other thread) would become elideable?

https://github.com/llvm/llvm-project/pull/108474