https://github.com/eleviant created https://github.com/llvm/llvm-project/pull/196550
Patch lowers unreachable to the trap (ud2) when `-fms-kernel` is provided to ensure kernel trap handler is invoked in case something goes wrong, instead of falling through. >From 619a097bf225a6de75ef18411520cec49677864f Mon Sep 17 00:00:00 2001 From: Evgeny Leviant <[email protected]> Date: Wed, 15 Apr 2026 19:51:57 +0200 Subject: [PATCH] [clang][X86] Always emit trap for noreturn functions with -fms-kernel Patch lowers unreachable to the trap (ud2) when `-fms-kernel` is provided to ensure kernel trap handler is invoked in case something goes wrong, instead of falling through. --- clang/lib/CodeGen/BackendUtil.cpp | 3 +++ clang/test/CodeGen/MSKernel/noreturn.c | 13 +++++++++++++ 2 files changed, 16 insertions(+) create mode 100644 clang/test/CodeGen/MSKernel/noreturn.c diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp index a46a25c4492f2..6b2a81f100d7a 100644 --- a/clang/lib/CodeGen/BackendUtil.cpp +++ b/clang/lib/CodeGen/BackendUtil.cpp @@ -477,6 +477,9 @@ static bool initTargetOptions(const CompilerInstance &CI, Options.VecLib = convertDriverVectorLibraryToVectorLibrary(CodeGenOpts.getVecLib()); + if (LangOpts.Kernel) + Options.TrapUnreachable = true; + switch (CodeGenOpts.getSwiftAsyncFramePointer()) { case CodeGenOptions::SwiftAsyncFramePointerKind::Auto: Options.SwiftAsyncFramePointer = diff --git a/clang/test/CodeGen/MSKernel/noreturn.c b/clang/test/CodeGen/MSKernel/noreturn.c new file mode 100644 index 0000000000000..4a5eae3472b48 --- /dev/null +++ b/clang/test/CodeGen/MSKernel/noreturn.c @@ -0,0 +1,13 @@ +// REQUIRES: x86-registered-target +// RUN: %clang_cc1 -fms-kernel -fms-extensions -triple x86_64-windows-msvc -O2 -S %s -o - | FileCheck %s + +// CHECK-LABEL: my_noreturn_func: +// CHECK: movl $0, (%rax) +// CHECK-NEXT: ud2 + +extern long volatile *gtrap; + +__declspec(noreturn) void my_noreturn_func(void) { + *gtrap = 0; +} + _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
