libcxxabi/src/cxa_handlers.cpp

   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 // This file implements the functionality associated with the terminate_handler,
   9 // unexpected_handler, and new_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.h"
  18 #include "cxa_exception.h"
  19 #include "private_typeinfo.h"
  20 #include "include/atomic_support.h" // from libc++
  21
  22 namespace std
  23 {
  24
  25 unexpected_handler
  26 get_unexpected() noexcept
  27 {
  28     return __libcpp_atomic_load(&__cxa_unexpected_handler, _AO_Acquire);
  29 }
  30
  31 void
  32 __unexpected(unexpected_handler func)
  33 {
  34     func();
  35     // unexpected handler should not return
  36     __abort_message("unexpected_handler unexpectedly returned");
  37 }
  38
  39 __attribute__((noreturn))
  40 void
  41 unexpected()
  42 {
  43     __unexpected(get_unexpected());
  44 }
  45
  46 terminate_handler
  47 get_terminate() noexcept
  48 {
  49     return __libcpp_atomic_load(&__cxa_terminate_handler, _AO_Acquire);
  50 }
  51
  52 void
  53 __terminate(terminate_handler func) noexcept
  54 {
  55 #ifndef _LIBCXXABI_NO_EXCEPTIONS
  56     try
  57     {
  58 #endif // _LIBCXXABI_NO_EXCEPTIONS
  59         func();
  60         // handler should not return
  61         __abort_message("terminate_handler unexpectedly returned");
  62 #ifndef _LIBCXXABI_NO_EXCEPTIONS
  63     }
  64     catch (...)
  65     {
  66         // handler should not throw exception
  67         __abort_message("terminate_handler unexpectedly threw an exception");
  68     }
  69 #endif // _LIBCXXABI_NO_EXCEPTIONS
  70 }
  71
  72 __attribute__((noreturn))
  73 void
  74 terminate() noexcept
  75 {
  76 #ifndef _LIBCXXABI_NO_EXCEPTIONS
  77     // If there might be an uncaught exception
  78     using namespace __cxxabiv1;
  79     __cxa_eh_globals* globals = __cxa_get_globals_fast();
  80     if (globals)
  81     {
  82         __cxa_exception* exception_header = globals->caughtExceptions;
  83         if (exception_header)
  84         {
  85             _Unwind_Exception* unwind_exception =
  86                 reinterpret_cast<_Unwind_Exception*>(exception_header + 1) - 1;
  87             if (__isOurExceptionClass(unwind_exception))
  88                 __terminate(exception_header->terminateHandler);
  89         }
  90     }
  91 #endif
  92     __terminate(get_terminate());
  93 }
  94
  95 new_handler
  96 get_new_handler() noexcept
  97 {
  98     return __libcpp_atomic_load(&__cxa_new_handler, _AO_Acquire);
  99 }
 100
 101 }  // std