[clang] 2ee2b6a - [Coroutines] Clear FirstVLALoc in time

[Chuanqi Xu via cfe-commits]

Author: Chuanqi Xu
Date: 2024-06-26T13:25:06+08:00
New Revision: 2ee2b6aa7a3d9ba6ba13f6881b25e26d7d12c823

URL: https://github.com/llvm/llvm-project/commit/2ee2b6aa7a3d9ba6ba13f6881b25e26d7d12c823
DIFF: https://github.com/llvm/llvm-project/commit/2ee2b6aa7a3d9ba6ba13f6881b25e26d7d12c823.diff

LOG: [Coroutines] Clear FirstVLALoc in time

Unlike other *Loc member in FunctionScopeInfo, we didn't clear
FirstVLALoc in 'FunctionScopeInfo::Clear()'. Then it will be
problematic for the following case:

```
void bar(int n) {
  int array[n];
  return;
}

coroutine foo(int n) {
  co_return;
}
```

When we parse `foo`, the FirstVLALoc is still valid, then the compiler
will report `vla in coroutine` error in bar, which is super odd. After
this patch, we can fix this.

Added: 
    

Modified: 
    clang/lib/Sema/ScopeInfo.cpp
    clang/test/SemaCXX/coroutine-vla.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/ScopeInfo.cpp b/clang/lib/Sema/ScopeInfo.cpp
index ce90451f2613b..12fb706072723 100644
--- a/clang/lib/Sema/ScopeInfo.cpp
+++ b/clang/lib/Sema/ScopeInfo.cpp
@@ -39,6 +39,7 @@ void FunctionScopeInfo::Clear() {
   FirstReturnLoc = SourceLocation();
   FirstCXXOrObjCTryLoc = SourceLocation();
   FirstSEHTryLoc = SourceLocation();
+  FirstVLALoc = SourceLocation();
   FoundImmediateEscalatingExpression = false;
 
   // Coroutine state

diff  --git a/clang/test/SemaCXX/coroutine-vla.cpp b/clang/test/SemaCXX/coroutine-vla.cpp
index 176e35f346e2b..996c89025e2ad 100644
--- a/clang/test/SemaCXX/coroutine-vla.cpp
+++ b/clang/test/SemaCXX/coroutine-vla.cpp
@@ -16,6 +16,12 @@ struct promise
     void unhandled_exception();
 };
 
+// Test that we won't report the error incorrectly.
+void bar(int n) {
+  int array[n];
+  return;
+}
+
 coroutine foo(int n) {
   int array[n]; // expected-error {{variable length arrays in a coroutine are not supported}}
   co_return;