[clang] [clang] Fix null dereference on return in lambda attribute statement expr (PR #66643)

[Piotr Fusik via cfe-commits]

https://github.com/pfusik created https://github.com/llvm/llvm-project/pull/66643

Fixes https://github.com/llvm/llvm-project/issues/48527

>From ea731b4d3d553f42cbaaec2079adeec3927b4150 Mon Sep 17 00:00:00 2001
From: Piotr Fusik <piotr at fusion-lang.org>
Date: Mon, 18 Sep 2023 15:10:58 +0200
Subject: [PATCH] [clang] Fix null dereference on return in lambda attribute
 statement expr

Fixes https://github.com/llvm/llvm-project/issues/48527
---
 clang/lib/Sema/SemaStmt.cpp    |  2 ++
 clang/test/SemaCXX/gh48527.cpp | 10 ++++++++++
 2 files changed, 12 insertions(+)
 create mode 100644 clang/test/SemaCXX/gh48527.cpp

diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 7cc509542d5381d..10adfbc406dfbb5 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -3577,6 +3577,8 @@ StmtResult Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc,
   CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
   QualType FnRetType = CurCap->ReturnType;
   LambdaScopeInfo *CurLambda = dyn_cast<LambdaScopeInfo>(CurCap);
+  if (CurLambda && CurLambda->CallOperator->getType().isNull())
+    return StmtError();
   bool HasDeducedReturnType =
       CurLambda && hasDeducedReturnType(CurLambda->CallOperator);
 
diff --git a/clang/test/SemaCXX/gh48527.cpp b/clang/test/SemaCXX/gh48527.cpp
new file mode 100644
index 000000000000000..420c35be37f5191
--- /dev/null
+++ b/clang/test/SemaCXX/gh48527.cpp
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+int main() { // expected-note {{to match this '{'}}
+    auto a = [](void)__attribute__((b(({ // expected-note {{to match this '('}}
+    return 0;
+} // expected-error 3 {{expected ')'}} \
+  // expected-error {{expected ';' at end of declaration}}
+// expected-error at +2 {{expected ')'}}
+// expected-error at +1 {{expected body of lambda expression}}
+// expected-error {{expected '}'}}