1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10// REQUIRES: linux
11
12// TODO: Figure out why this fails with Memory Sanitizer.
13// XFAIL: msan
14
15// Basic test for _Unwind_ForcedUnwind.
16// See libcxxabi/test/forced_unwind* tests too.
17
18#undef NDEBUG
19#include <assert.h>
20#include <signal.h>
21#include <stdint.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <sys/types.h>
26#include <unistd.h>
27#include <unwind.h>
28
29// Using __attribute__((section("main_func"))) is Linux specific, but then
30// this entire test is marked as requiring Linux, so we should be good.
31//
32// We don't use dladdr() because on musl it's a no-op when statically linked.
33extern char __start_main_func;
34extern char __stop_main_func;
35
36void foo();
37_Unwind_Exception ex;
38
39_Unwind_Reason_Code stop(int version, _Unwind_Action actions,
40 _Unwind_Exception_Class exceptionClass,
41 _Unwind_Exception *exceptionObject,
42 struct _Unwind_Context *context,
43 void *stop_parameter) {
44 assert(version == 1);
45 assert((actions & _UA_FORCE_UNWIND) != 0);
46 (void)exceptionClass;
47 assert(exceptionObject == &ex);
48 assert(stop_parameter == &foo);
49
50 // Unwind until the main is reached, above frames depend on the platform and
51 // architecture.
52 uintptr_t ip = _Unwind_GetIP(context);
53 if (ip >= (uintptr_t)&__start_main_func &&
54 ip < (uintptr_t)&__stop_main_func) {
55 _Exit(status: 0);
56 }
57
58 return _URC_NO_REASON;
59}
60
61__attribute__((noinline)) void foo() {
62
63 // Arm EHABI defines struct _Unwind_Control_Block as exception
64 // object. Ensure struct _Unwind_Exception* work there too,
65 // because _Unwind_Exception in this case is just an alias.
66 struct _Unwind_Exception *e = &ex;
67#if defined(_LIBUNWIND_ARM_EHABI)
68 // Create a mock exception object.
69 memset(e, '\0', sizeof(*e));
70 memcpy(&e->exception_class, "CLNGUNW", sizeof(e->exception_class));
71#endif
72 _Unwind_ForcedUnwind(e, stop, (void *)&foo);
73}
74
75__attribute__((section("main_func"))) int main() {
76 foo();
77 return -2;
78}
79

source code of libunwind/test/forceunwind.pass.cpp