src/third_party/libc++abi/trunk/src/cxa_default_handlers.cpp

   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 "abort_message.h"
  16 #include "cxxabi.h"
  17 #include "cxa_handlers.hpp"
  18 #include "cxa_exception.hpp"
  19 #include "private_typeinfo.h"
  20
  21 static const char* cause = "uncaught";
  22
  23 __attribute__((noreturn))
  24 static void default_terminate_handler()
  25 {
  26     // If there might be an uncaught exception
  27     using namespace __cxxabiv1;
  28     __cxa_eh_globals* globals = __cxa_get_globals_fast();
  29     if (globals)
  30     {
  31         __cxa_exception* exception_header = globals->caughtExceptions;
  32         // If there is an uncaught exception
  33         if (exception_header)
  34         {
  35             _Unwind_Exception* unwind_exception =
  36                 reinterpret_cast<_Unwind_Exception*>(exception_header + 1) - 1;
  37             bool native_exception =
  38                 (unwind_exception->exception_class   & get_vendor_and_language) ==
  39                                  (kOurExceptionClass & get_vendor_and_language);
  40             if (native_exception)
  41             {
  42                 void* thrown_object =
  43                     unwind_exception->exception_class == kOurDependentExceptionClass ?
  44                         ((__cxa_dependent_exception*)exception_header)->primaryException :
  45                         exception_header + 1;
  46                 const __shim_type_info* thrown_type =
  47                     static_cast<const __shim_type_info*>(exception_header->exceptionType);
  48                 // Try to get demangled name of thrown_type
  49                 int status;
  50                 char buf[1024];
  51                 size_t len = sizeof(buf);
  52                 const char* name = __cxa_demangle(thrown_type->name(), buf, &len, &status);
  53                 if (status != 0)
  54                     name = thrown_type->name();
  55                 // If the uncaught exception can be caught with std::exception&
  56                 const __shim_type_info* catch_type =
  57                                  static_cast<const __shim_type_info*>(&typeid(std::exception));
  58                 if (catch_type->can_catch(thrown_type, thrown_object))
  59                 {
  60                     // Include the what() message from the exception
  61                     const std::exception* e = static_cast<const std::exception*>(thrown_object);
  62                     abort_message("terminating with %s exception of type %s: %s",
  63                                   cause, name, e->what());
  64                 }
  65                 else
  66                     // Else just note that we're terminating with an exception
  67                     abort_message("terminating with %s exception of type %s",
  68                                    cause, name);
  69             }
  70             else
  71                 // Else we're terminating with a foreign exception
  72                 abort_message("terminating with %s foreign exception", cause);
  73         }
  74     }
  75     // Else just note that we're terminating
  76     abort_message("terminating");
  77 }
  78
  79 __attribute__((noreturn))
  80 static void default_unexpected_handler()
  81 {
  82     cause = "unexpected";
  83     std::terminate();
  84 }
  85
  86
  87 //
  88 // Global variables that hold the pointers to the current handler
  89 //
  90 std::terminate_handler  __cxa_terminate_handler = default_terminate_handler;
  91 std::unexpected_handler __cxa_unexpected_handler = default_unexpected_handler;
  92
  93 // In the future these will become:
  94 // std::atomic<std::terminate_handler>  __cxa_terminate_handler(default_terminate_handler);
  95 // std::atomic<std::unexpected_handler> __cxa_unexpected_handler(default_unexpected_handler);
  96
  97 namespace std
  98 {
  99
 100 unexpected_handler
 101 set_unexpected(unexpected_handler func) _NOEXCEPT
 102 {
 103         if (func == 0)
 104                 func = default_unexpected_handler;
 105         return __sync_swap(&__cxa_unexpected_handler, func);
 106 //  Using of C++11 atomics this should be rewritten
 107 //  return __cxa_unexpected_handler.exchange(func, memory_order_acq_rel);
 108 }
 109
 110 terminate_handler
 111 set_terminate(terminate_handler func) _NOEXCEPT
 112 {
 113         if (func == 0)
 114                 func = default_terminate_handler;
 115         return __sync_swap(&__cxa_terminate_handler, func);
 116 //  Using of C++11 atomics this should be rewritten
 117 //  return __cxa_terminate_handler.exchange(func, memory_order_acq_rel);
 118 }
 119
 120 }