[coroutines] Fix invalid source range in co_await call expressions.

Summary:
Currently an invalid source range is generated for the member call expressions of `co_await`. The end location of the call expression is the `co_await` token loc, while the start is the location of the operand. This causes crashes when the source range is used to produce diagnostics.

This patch fixes the issues by using the expression location instead of the token location when building the member calls.

Reviewers: GorNishanov, rsmith, vsk, aaron.ballman

Reviewed By: vsk

Subscribers: cfe-commits, modocache

Differential Revision: https://reviews.llvm.org/D44915

llvm-svn: 328606

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
index e4cb4cf059f..95758baff4a 100644
--- a/clang/lib/Sema/SemaCoroutine.cpp
+++ b/clang/lib/Sema/SemaCoroutine.cpp
@@ -708,9 +708,14 @@ ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *E,
   if (E->getValueKind() == VK_RValue)
     E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
 
+  // The location of the `co_await` token cannot be used when constructing
+  // the member call expressions since it's before the location of `Expr`, which
+  // is used as the start of the member call expression.
+  SourceLocation CallLoc = E->getExprLoc();
+
   // Build the await_ready, await_suspend, await_resume calls.
   ReadySuspendResumeResult RSS =
-      buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
+      buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
   if (RSS.IsInvalid)
     return ExprError();