[llvm-branch-commits] [clang] release/21.x: [clang][ObjC] Fix incorrect return type inference for discarded blocks (#154109) (PR #154210)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport ec4e6aa

Requested by: @<!-- -->ojhunt

---
Full diff: https://github.com/llvm/llvm-project/pull/154210.diff


2 Files Affected:

- (modified) clang/lib/Parse/ParseExpr.cpp (+2-1) 
- (added) clang/test/SemaObjCXX/discarded-block-type-inference.mm (+15) 


``````````diff
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index bc238a9517a37..3515343202de1 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -3342,7 +3342,8 @@ ExprResult Parser::ParseBlockLiteralExpression() {
     Actions.ActOnBlockError(CaretLoc, getCurScope());
     return ExprError();
   }
-
+  EnterExpressionEvaluationContextForFunction PotentiallyEvaluated(
+       Actions, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
   StmtResult Stmt(ParseCompoundStatementBody());
   BlockScope.Exit();
   if (!Stmt.isInvalid())
diff --git a/clang/test/SemaObjCXX/discarded-block-type-inference.mm b/clang/test/SemaObjCXX/discarded-block-type-inference.mm
new file mode 100644
index 0000000000000..8e2587724a7f6
--- /dev/null
+++ b/clang/test/SemaObjCXX/discarded-block-type-inference.mm
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -std=c++23 -fsyntax-only -fobjc-arc -fblocks %s
+
+void  block_receiver(int (^)() );
+
+int f1() {
+  if constexpr (0)
+    (block_receiver)(^{ return 2; });
+  return 1;
+}
+
+int f2() {
+  if constexpr (0)
+    return (^{ return 2; })();
+  return 1;
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/154210