[clang] [clang][bytecode] Check builtin_memchr for non-block pointers earlier (PR #174192)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/174192

The getType() call might fail. We can't pull the isReadable() check up though because that creates different diagnostic output compared to the current interpreter.

Fixes #172202

>From ce34cb698089977ed3ebfb7b7dd1e99380144b80 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Fri, 2 Jan 2026 10:56:31 +0100
Subject: [PATCH] [clang][bytecode] Check builtin_memchr for non-block pointers
 earlier

The getType() call might fail. We can't pull the isReadable() check up
though because that creates different diagnostic output compared to the
current interpreter.

Fixes #172202
---
 clang/lib/AST/ByteCode/InterpBuiltin.cpp | 3 +++
 clang/test/AST/ByteCode/builtins.c       | 1 +
 2 files changed, 4 insertions(+)

diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 065870c5c0ab5..b4acb786fa90c 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -2078,6 +2078,9 @@ static bool interp__builtin_memchr(InterpState &S, CodePtr OpPC,
     return false;
   }
 
+  if (!Ptr.isBlockPointer())
+    return false;
+
   QualType ElemTy = Ptr.getFieldDesc()->isArray()
                         ? Ptr.getFieldDesc()->getElemQualType()
                         : Ptr.getFieldDesc()->getType();
diff --git a/clang/test/AST/ByteCode/builtins.c b/clang/test/AST/ByteCode/builtins.c
index 5be5455ab8813..684db52296fc2 100644
--- a/clang/test/AST/ByteCode/builtins.c
+++ b/clang/test/AST/ByteCode/builtins.c
@@ -18,3 +18,4 @@ int structStrlen(void) {
 }
 
 void f() { __builtin_memcpy(f, f, 1); }
+void f2()  { __builtin_memchr(f2, 0, 1); }