[clang] [clang][bytecode] Fix `__extension__` handling for vector operators (PR #118482)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

Don't reject them, but delegate to the subexpression.

---
Full diff: https://github.com/llvm/llvm-project/pull/118482.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/Compiler.cpp (+3) 
- (modified) clang/test/AST/ByteCode/vectors.cpp (+1) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index a95353fd2943c9..f6e0b54a81e368 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -5911,6 +5911,9 @@ bool Compiler<Emitter>::VisitVectorUnaryOperator(const UnaryOperator *E) {
     return this->discard(SubExpr);
 
   auto UnaryOp = E->getOpcode();
+  if (UnaryOp == UO_Extension)
+    return this->delegate(SubExpr);
+
   if (UnaryOp != UO_Plus && UnaryOp != UO_Minus && UnaryOp != UO_LNot &&
       UnaryOp != UO_Not && UnaryOp != UO_AddrOf)
     return this->emitInvalid(E);
diff --git a/clang/test/AST/ByteCode/vectors.cpp b/clang/test/AST/ByteCode/vectors.cpp
index 08e2ca2adbf5cd..a04b678a623a1e 100644
--- a/clang/test/AST/ByteCode/vectors.cpp
+++ b/clang/test/AST/ByteCode/vectors.cpp
@@ -37,6 +37,7 @@ static_assert(arr4[1][0] == 0, "");
 static_assert(arr4[1][0] == 0, "");
 static_assert(arr4[1][0] == 0, "");
 
+constexpr VI4 B = __extension__(A);
 
 /// From constant-expression-cxx11.cpp
 namespace Vector {

``````````

</details>


https://github.com/llvm/llvm-project/pull/118482