https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/218411
We can't call `Pointer::getNumElems()` on pointers to unknown size arrays. >From c7c99f4d815366f8f49b6bc23832989c9a914ae9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timm=20B=C3=A4der?= <[email protected]> Date: Mon, 24 Aug 2026 15:36:20 +0200 Subject: [PATCH] [clang][bytecode] Protect evaluateString() from invalid pointers We can't call `Pointer::getNumElems()` on pointers to unknown size arrays. --- clang/lib/AST/ByteCode/Context.cpp | 3 +++ clang/test/AST/ByteCode/invalid.cpp | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/clang/lib/AST/ByteCode/Context.cpp b/clang/lib/AST/ByteCode/Context.cpp index 0678b07d0bbf2..9dc0654d6f5cf 100644 --- a/clang/lib/AST/ByteCode/Context.cpp +++ b/clang/lib/AST/ByteCode/Context.cpp @@ -284,6 +284,9 @@ bool Context::evaluateString(State &Parent, const Expr *E, if (!Ptr.isConst()) return false; + if (Ptr.isDummy() || Ptr.isUnknownSizeArray() || Ptr.isPastEnd()) + return false; + unsigned N = Ptr.getNumElems(); if (Ptr.elemSize() == 1 /* bytes */) { diff --git a/clang/test/AST/ByteCode/invalid.cpp b/clang/test/AST/ByteCode/invalid.cpp index 247c8ad732708..67c82cb352d90 100644 --- a/clang/test/AST/ByteCode/invalid.cpp +++ b/clang/test/AST/ByteCode/invalid.cpp @@ -247,3 +247,12 @@ namespace InvalidStaticInvoker { constexpr int (*baz)(int) = foo; int i = baz(42); } + +namespace UnknownSizeArrayInEvaluateString { + void foo() { + constexpr char K[] = {'\0'; // both-error {{expected '}'}} \ + // both-note {{to match this}} + __builtin_verbose_trap("bar", K); // both-error {{argument to __builtin_verbose_trap must be a pointer to a constant string}} + } + } +} // both-error {{extraneous closing brace}} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
