[clang] [clang][bytecode] Always return false for invalid bcp results (PR #121467)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/121467.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/InterpBuiltin.cpp (+2-1) 
- (modified) clang/test/AST/ByteCode/builtin-constant-p.cpp (+6) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index b5849553d0bf53..731c9290993f12 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -1544,9 +1544,10 @@ static bool interp__builtin_constant_p(InterpState &S, CodePtr OpPC,
     if (Res.isInvalid()) {
       C.cleanup();
       Stk.clear();
+      return returnInt(false);
     }
 
-    if (!Res.isInvalid() && !Res.empty()) {
+    if (!Res.empty()) {
       const APValue &LV = Res.toAPValue();
       if (LV.isLValue()) {
         APValue::LValueBase Base = LV.getLValueBase();
diff --git a/clang/test/AST/ByteCode/builtin-constant-p.cpp b/clang/test/AST/ByteCode/builtin-constant-p.cpp
index 0d222d1c962778..62899b60064c28 100644
--- a/clang/test/AST/ByteCode/builtin-constant-p.cpp
+++ b/clang/test/AST/ByteCode/builtin-constant-p.cpp
@@ -12,3 +12,9 @@ static_assert(__builtin_constant_p(I + 10.0), "");
 static_assert(__builtin_constant_p(nullptr), "");
 static_assert(__builtin_constant_p(&I), ""); // both-error {{failed due to requirement}}
 static_assert(__builtin_constant_p((void)I), ""); // both-error {{failed due to requirement}}
+
+extern int z;
+constexpr int foo(int &a) {
+  return __builtin_constant_p(a);
+}
+static_assert(!foo(z));

``````````

</details>


https://github.com/llvm/llvm-project/pull/121467