[clang] [clang][bytecode] Check overflow ops for block pointers (PR #165221)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

We can't save the result in a non-block pointer.

Fixes https://github.com/llvm/llvm-project/issues/165076

---
Full diff: https://github.com/llvm/llvm-project/pull/165221.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/InterpBuiltin.cpp (+1-1) 
- (modified) clang/test/AST/ByteCode/builtin-functions.cpp (+5) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index d0b97a18e1815..aec150a9f0781 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -749,7 +749,7 @@ static bool interp__builtin_overflowop(InterpState &S, CodePtr OpPC,
                                        const CallExpr *Call,
                                        unsigned BuiltinOp) {
   const Pointer &ResultPtr = S.Stk.pop<Pointer>();
-  if (ResultPtr.isDummy())
+  if (ResultPtr.isDummy() || !ResultPtr.isBlockPointer())
     return false;
 
   PrimType RHST = *S.getContext().classify(Call->getArg(1)->getType());
diff --git a/clang/test/AST/ByteCode/builtin-functions.cpp b/clang/test/AST/ByteCode/builtin-functions.cpp
index 0b7d51be8d824..2c47e2971f4a1 100644
--- a/clang/test/AST/ByteCode/builtin-functions.cpp
+++ b/clang/test/AST/ByteCode/builtin-functions.cpp
@@ -1853,3 +1853,8 @@ namespace InitParam {
 }
 
 #endif
+
+namespace SAddOverflowInt {
+  int a;
+  void foo(void) { a *= __builtin_sadd_overflow(1, 2, 0); }
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/165221