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.
33 extern char __start_main_func;
34 extern char __stop_main_func;
35
36 void foo();
37 _Unwind_Exception ex;
38
stop(int version,_Unwind_Action actions,_Unwind_Exception_Class exceptionClass,_Unwind_Exception * exceptionObject,struct _Unwind_Context * context,void * stop_parameter)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(0);
56 }
57
58 return _URC_NO_REASON;
59 }
60
foo()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
main()75 __attribute__((section("main_func"))) int main() {
76 foo();
77 return -2;
78 }
79