1 //===------------------------- cxa_default_handlers.cpp -------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //
9 // This file implements the default terminate_handler and unexpected_handler.
10 //===----------------------------------------------------------------------===//
11
12 #include <stdexcept>
13 #include <new>
14 #include <exception>
15 #include <cstdlib>
16 #include "abort_message.h"
17 #include "cxxabi.h"
18 #include "cxa_handlers.hpp"
19 #include "cxa_exception.hpp"
20 #include "private_typeinfo.h"
21
22 #if !defined(LIBCXXABI_SILENT_TERMINATE)
23 static const char* cause = "uncaught";
24
25 __attribute__((noreturn))
demangling_terminate_handler()26 static void demangling_terminate_handler()
27 {
28 // If there might be an uncaught exception
29 using namespace __cxxabiv1;
30 __cxa_eh_globals* globals = __cxa_get_globals_fast();
31 if (globals)
32 {
33 __cxa_exception* exception_header = globals->caughtExceptions;
34 // If there is an uncaught exception
35 if (exception_header)
36 {
37 _Unwind_Exception* unwind_exception =
38 reinterpret_cast<_Unwind_Exception*>(exception_header + 1) - 1;
39 bool native_exception =
40 (unwind_exception->exception_class & get_vendor_and_language) ==
41 (kOurExceptionClass & get_vendor_and_language);
42 if (native_exception)
43 {
44 void* thrown_object =
45 unwind_exception->exception_class == kOurDependentExceptionClass ?
46 ((__cxa_dependent_exception*)exception_header)->primaryException :
47 exception_header + 1;
48 const __shim_type_info* thrown_type =
49 static_cast<const __shim_type_info*>(exception_header->exceptionType);
50 // Try to get demangled name of thrown_type
51 int status;
52 char buf[1024];
53 size_t len = sizeof(buf);
54 const char* name = __cxa_demangle(thrown_type->name(), buf, &len, &status);
55 if (status != 0)
56 name = thrown_type->name();
57 // If the uncaught exception can be caught with std::exception&
58 const __shim_type_info* catch_type =
59 static_cast<const __shim_type_info*>(&typeid(std::exception));
60 if (catch_type->can_catch(thrown_type, thrown_object))
61 {
62 // Include the what() message from the exception
63 const std::exception* e = static_cast<const std::exception*>(thrown_object);
64 abort_message("terminating with %s exception of type %s: %s",
65 cause, name, e->what());
66 }
67 else
68 // Else just note that we're terminating with an exception
69 abort_message("terminating with %s exception of type %s",
70 cause, name);
71 }
72 else
73 // Else we're terminating with a foreign exception
74 abort_message("terminating with %s foreign exception", cause);
75 }
76 }
77 // Else just note that we're terminating
78 abort_message("terminating");
79 }
80
81 __attribute__((noreturn))
demangling_unexpected_handler()82 static void demangling_unexpected_handler()
83 {
84 cause = "unexpected";
85 std::terminate();
86 }
87
88 static std::terminate_handler default_terminate_handler = demangling_terminate_handler;
89 static std::terminate_handler default_unexpected_handler = demangling_unexpected_handler;
90 #else
91 static std::terminate_handler default_terminate_handler = std::abort;
92 static std::terminate_handler default_unexpected_handler = std::terminate;
93 #endif
94
95 //
96 // Global variables that hold the pointers to the current handler
97 //
98 _LIBCXXABI_DATA_VIS
99 std::terminate_handler __cxa_terminate_handler = default_terminate_handler;
100
101 _LIBCXXABI_DATA_VIS
102 std::unexpected_handler __cxa_unexpected_handler = default_unexpected_handler;
103
104 // In the future these will become:
105 // std::atomic<std::terminate_handler> __cxa_terminate_handler(default_terminate_handler);
106 // std::atomic<std::unexpected_handler> __cxa_unexpected_handler(default_unexpected_handler);
107
108 namespace std
109 {
110
111 unexpected_handler
set_unexpected(unexpected_handler func)112 set_unexpected(unexpected_handler func) _NOEXCEPT
113 {
114 if (func == 0)
115 func = default_unexpected_handler;
116 return __atomic_exchange_n(&__cxa_unexpected_handler, func,
117 __ATOMIC_ACQ_REL);
118 // Using of C++11 atomics this should be rewritten
119 // return __cxa_unexpected_handler.exchange(func, memory_order_acq_rel);
120 }
121
122 terminate_handler
set_terminate(terminate_handler func)123 set_terminate(terminate_handler func) _NOEXCEPT
124 {
125 if (func == 0)
126 func = default_terminate_handler;
127 return __atomic_exchange_n(&__cxa_terminate_handler, func,
128 __ATOMIC_ACQ_REL);
129 // Using of C++11 atomics this should be rewritten
130 // return __cxa_terminate_handler.exchange(func, memory_order_acq_rel);
131 }
132
133 }
134