[clang] [clang][bytecode] Load value of non-lvalue ArraySubscriptExpr (PR #160024)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

As happens in C.

Fixes #<!-- -->158482

---
Full diff: https://github.com/llvm/llvm-project/pull/160024.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/Compiler.cpp (+6-1) 
- (modified) clang/test/AST/ByteCode/c.c (+4) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index fafec47f7de3c..7518cfd2cf94d 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -1787,7 +1787,12 @@ bool Compiler<Emitter>::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
     return false;
   if (DiscardResult)
     return this->emitPopPtr(E);
-  return true;
+
+  if (E->isGLValue())
+    return true;
+
+  OptPrimType T = classifyPrim(E);
+  return this->emitLoadPop(*T, E);
 }
 
 template <class Emitter>
diff --git a/clang/test/AST/ByteCode/c.c b/clang/test/AST/ByteCode/c.c
index 6681a4f427093..657a920e7d02c 100644
--- a/clang/test/AST/ByteCode/c.c
+++ b/clang/test/AST/ByteCode/c.c
@@ -368,3 +368,7 @@ void discardedCmp(void)
 {
     (*_b) = ((&a == &a) , a); // all-warning {{left operand of comma operator has no effect}}
 }
+
+/// ArraySubscriptExpr that's not an lvalue
+typedef unsigned char U __attribute__((vector_size(1)));
+void nonLValueASE(U f) { f[0] = f[((U)(U){0})[0]]; }

``````````

</details>


https://github.com/llvm/llvm-project/pull/160024