[llvm-branch-commits] [clang] [clang] Remove hasValue() check in `RecordExprEvaluator::VisitCXXConstructExpr()` (#154610) (PR #155218)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Nikolas Klauser (philnik777)

<details>
<summary>Changes</summary>

When initializing an anonymous struct via an `IndirectFieldDecl`, we
create an `APValue` for the struct, but we leave the fields
uninitialized. This would later cause the `CXXConstructExpr` that
initializes the anonymous struct member to not do anything since its
`APValue` already had a value (but the member didn't). Just remove the
check for an `APValue` that already has a value from
`RecordExprEvaluator::VisitCXXConstructExpr()`.

Fixes #<!-- -->154567


---
Full diff: https://github.com/llvm/llvm-project/pull/155218.diff


2 Files Affected:

- (modified) clang/lib/AST/ExprConstant.cpp (-4) 
- (modified) clang/test/SemaCXX/constant-expression-cxx11.cpp (+16) 


``````````diff
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 0733f8e8a33b0..170da16a0cdf8 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -10932,10 +10932,6 @@ bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
 
   bool ZeroInit = E->requiresZeroInitialization();
   if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
-    // If we've already performed zero-initialization, we're already done.
-    if (Result.hasValue())
-      return true;
-
     if (ZeroInit)
       return ZeroInitialization(E, T);
 
diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp
index c390fee1c38d9..935409131e18f 100644
--- a/clang/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp
@@ -2615,3 +2615,19 @@ namespace DoubleCapture {
     };
   }
 }
+
+namespace GH154567 {
+  struct T {
+    int i;
+  };
+
+  struct S {
+    struct { // expected-warning {{GNU extension}}
+      T val;
+    };
+    constexpr S() : val() {}
+  };
+
+  constexpr S s{};
+  static_assert(s.val.i == 0, "");
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/155218