[clang] 242a1e2 - [clang][bytecode] Load value of non-lvalue ArraySubscriptExpr (#160024)

[via cfe-commits]

Author: Timm Baeder
Date: 2025-09-23T09:47:23+02:00
New Revision: 242a1e2fb1b2ddefc8dcde73e22ce3f06f6a8188

URL: https://github.com/llvm/llvm-project/commit/242a1e2fb1b2ddefc8dcde73e22ce3f06f6a8188
DIFF: https://github.com/llvm/llvm-project/commit/242a1e2fb1b2ddefc8dcde73e22ce3f06f6a8188.diff

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

As happens in C.

Fixes #158482

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Compiler.cpp
    clang/test/AST/ByteCode/c.c

Removed: 
    


################################################################################
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]]; }