1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // Let's run ForcedUnwind until it reaches end of the stack, this test simulates
10 // what pthread_cancel does.
11 
12 // UNSUPPORTED: c++03
13 // UNSUPPORTED: libcxxabi-no-threads
14 // UNSUPPORTED: no-exceptions
15 
16 #include <assert.h>
17 #include <exception>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <unwind.h>
21 #include <thread>
22 #include <tuple>
23 #include <__cxxabi_config.h>
24 
25 // TODO: dump version back to 14 once clang is updated on the CI.
26 #if defined(_LIBCXXABI_ARM_EHABI) && defined(__clang__) && __clang_major__ < 15
27 // _Unwind_ForcedUnwind is not available or broken before version 14.
28 int main(int, char**) { return 0; }
29 
30 #else
31 static bool destructorCalled = false;
32 
33 struct myClass {
34   myClass() {}
35   ~myClass() {
36     assert(destructorCalled == false);
37     destructorCalled = true;
38   };
39 };
40 
41 template <typename T>
42 struct Stop;
43 
44 template <typename R, typename... Args>
45 struct Stop<R (*)(Args...)> {
46   // The third argument of _Unwind_Stop_Fn is uint64_t in Itanium C++ ABI/LLVM
47   // libunwind while _Unwind_Exception_Class in libgcc.
48   typedef typename std::tuple_element<2, std::tuple<Args...>>::type type;
49 
50   static _Unwind_Reason_Code stop(int, _Unwind_Action actions, type, struct _Unwind_Exception*, struct _Unwind_Context*,
51                                   void*) {
52     if (actions & _UA_END_OF_STACK) {
53       assert(destructorCalled == true);
54       exit(0);
55     }
56     return _URC_NO_REASON;
57   }
58 };
59 
60 static void forced_unwind() {
61   _Unwind_Exception* exc = new _Unwind_Exception;
62   memset(&exc->exception_class, 0, sizeof(exc->exception_class));
63   exc->exception_cleanup = 0;
64   _Unwind_ForcedUnwind(exc, Stop<_Unwind_Stop_Fn>::stop, 0);
65   abort();
66 }
67 
68 __attribute__((__noinline__)) static void test() {
69   myClass c{};
70   forced_unwind();
71   abort();
72 }
73 
74 int main(int, char**) {
75   std::thread t{test};
76   t.join();
77   return -1;
78 }
79 #endif
80