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// -*- C++ -*- Exception handling and frame unwind runtime interface routines.

// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009

// Free Software Foundation, Inc.

//

// This file is part of GCC.

//

// GCC is free software; you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation; either version 3, or (at your option)

// any later version.

//

// GCC is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

// This is derived from the C++ ABI for IA-64.  Where we diverge

// for cross-architecture compatibility are noted with "@@@".

#ifndef _UNWIND_CXX_H

#define _UNWIND_CXX_H 1

// Level 2: C++ ABI

#include <typeinfo>

#include <exception>

#include <cstddef>

#include "unwind.h"

#include <bits/atomic_word.h>

#pragma GCC visibility push(default)

namespace __cxxabiv1

{

// A primary C++ exception object consists of a header, which is a wrapper

// around an unwind object header with additional C++ specific information,

// followed by the exception object itself.

struct __cxa_exception

{

  // Manage the exception object itself.

  std::type_info *exceptionType;

  void (*exceptionDestructor)(void *);

  // The C++ standard has entertaining rules wrt calling set_terminate

  // and set_unexpected in the middle of the exception cleanup process.

  std::unexpected_handler unexpectedHandler;

  std::terminate_handler terminateHandler;

  // The caught exception stack threads through here.

  __cxa_exception *nextException;

  // How many nested handlers have caught this exception.  A negated

  // value is a signal that this object has been rethrown.

  int handlerCount;

#ifdef __ARM_EABI_UNWINDER__

  // Stack of exceptions in cleanups.

  __cxa_exception* nextPropagatingException;

  // The nuber of active cleanup handlers for this exception.

  int propagationCount;

#else

  // Cache parsed handler data from the personality routine Phase 1

  // for Phase 2 and __cxa_call_unexpected.

  int handlerSwitchValue;

  const unsigned char *actionRecord;

  const unsigned char *languageSpecificData;

  _Unwind_Ptr catchTemp;

  void *adjustedPtr;

#endif

  // The generic exception header.  Must be last.

  _Unwind_Exception unwindHeader;

};

struct __cxa_refcounted_exception

{

  // Manage this header.

  _Atomic_word referenceCount;

  // __cxa_exception must be last, and no padding can be after it.

  __cxa_exception exc;

};

// A dependent C++ exception object consists of a wrapper around an unwind

// object header with additional C++ specific information, containing a pointer

// to a primary exception object.

struct __cxa_dependent_exception

{

  // The primary exception this thing depends on.

  void *primaryException;

  // The C++ standard has entertaining rules wrt calling set_terminate

  // and set_unexpected in the middle of the exception cleanup process.

  std::unexpected_handler unexpectedHandler;

  std::terminate_handler terminateHandler;

  // The caught exception stack threads through here.

  __cxa_exception *nextException;

  // How many nested handlers have caught this exception.  A negated

  // value is a signal that this object has been rethrown.

  int handlerCount;

#ifdef __ARM_EABI_UNWINDER__

  // Stack of exceptions in cleanups.

  __cxa_exception* nextPropagatingException;

  // The nuber of active cleanup handlers for this exception.

  int propagationCount;

#else

  // Cache parsed handler data from the personality routine Phase 1

  // for Phase 2 and __cxa_call_unexpected.

  int handlerSwitchValue;

  const unsigned char *actionRecord;

  const unsigned char *languageSpecificData;

  _Unwind_Ptr catchTemp;

  void *adjustedPtr;

#endif

  // The generic exception header.  Must be last.

  _Unwind_Exception unwindHeader;

};

// Each thread in a C++ program has access to a __cxa_eh_globals object.

struct __cxa_eh_globals

{

  __cxa_exception *caughtExceptions;

  unsigned int uncaughtExceptions;

#ifdef __ARM_EABI_UNWINDER__

  __cxa_exception* propagatingExceptions;

#endif

};

// The __cxa_eh_globals for the current thread can be obtained by using

// either of the following functions.  The "fast" version assumes at least

// one prior call of __cxa_get_globals has been made from the current

// thread, so no initialization is necessary.

extern "C" __cxa_eh_globals *__cxa_get_globals () throw() __attribute__ ((__const__));

extern "C" __cxa_eh_globals *__cxa_get_globals_fast () throw() __attribute__ ((__const__));

// Allocate memory for the primary exception plus the thrown object.

extern "C" void *__cxa_allocate_exception(std::size_t thrown_size) throw();

// Free the space allocated for the primary exception.

extern "C" void __cxa_free_exception(void *thrown_exception) throw();

// Allocate memory for a dependent exception.

extern "C" __cxa_dependent_exception*

__cxa_allocate_dependent_exception() throw();

// Free the space allocated for the dependent exception.

extern "C" void

__cxa_free_dependent_exception(__cxa_dependent_exception *ex) throw();

// Throw the exception.

extern "C" void __cxa_throw (void *thrown_exception,

                             std::type_info *tinfo,

                             void (*dest) (void *))

     __attribute__((noreturn));

// Used to implement exception handlers.

extern "C" void *__cxa_get_exception_ptr (void *) throw() __attribute__ ((__pure__));

extern "C" void *__cxa_begin_catch (void *) throw();

extern "C" void __cxa_end_catch ();

extern "C" void __cxa_rethrow () __attribute__((noreturn));

// These facilitate code generation for recurring situations.

extern "C" void __cxa_bad_cast () __attribute__((__noreturn__));

extern "C" void __cxa_bad_typeid () __attribute__((__noreturn__));

// @@@ These are not directly specified by the IA-64 C++ ABI.

// Handles re-checking the exception specification if unexpectedHandler

// throws, and if bad_exception needs to be thrown.  Called from the

// compiler.

extern "C" void __cxa_call_unexpected (void *) __attribute__((noreturn));

extern "C" void __cxa_call_terminate (_Unwind_Exception*) throw () __attribute__((noreturn));

#ifdef __ARM_EABI_UNWINDER__

// Arm EABI specified routines.

typedef enum {

  ctm_failed = 0,

  ctm_succeeded = 1,

  ctm_succeeded_with_ptr_to_base = 2

} __cxa_type_match_result;

extern "C" bool __cxa_type_match(_Unwind_Exception*, const std::type_info*,

                                 bool, void**);

extern "C" void __cxa_begin_cleanup (_Unwind_Exception*);

extern "C" void __cxa_end_cleanup (void);

#endif

// Invokes given handler, dying appropriately if the user handler was

// so inconsiderate as to return.

extern void __terminate(std::terminate_handler) throw () __attribute__((__noreturn__));

extern void __unexpected(std::unexpected_handler) __attribute__((noreturn));

// The current installed user handlers.

extern std::terminate_handler __terminate_handler;

extern std::unexpected_handler __unexpected_handler;

// These are explicitly GNU C++ specific.

// Acquire the C++ exception header from the C++ object.

static inline __cxa_exception *

__get_exception_header_from_obj (void *ptr)

{

  return reinterpret_cast<__cxa_exception *>(ptr) - 1;

}

// Acquire the C++ exception header from the generic exception header.

static inline __cxa_exception *

__get_exception_header_from_ue (_Unwind_Exception *exc)

{

  return reinterpret_cast<__cxa_exception *>(exc + 1) - 1;

}

// Acquire the C++ refcounted exception header from the C++ object.

static inline __cxa_refcounted_exception *

__get_refcounted_exception_header_from_obj (void *ptr)

{

  return reinterpret_cast<__cxa_refcounted_exception *>(ptr) - 1;

}

// Acquire the C++ refcounted exception header from the generic exception

// header.

static inline __cxa_refcounted_exception *

__get_refcounted_exception_header_from_ue (_Unwind_Exception *exc)

{

  return reinterpret_cast<__cxa_refcounted_exception *>(exc + 1) - 1;

}

static inline __cxa_dependent_exception *

__get_dependent_exception_from_ue (_Unwind_Exception *exc)

{

  return reinterpret_cast<__cxa_dependent_exception *>(exc + 1) - 1;

}

#ifdef __ARM_EABI_UNWINDER__

static inline bool

__is_gxx_exception_class(_Unwind_Exception_Class c)

{

  // TODO: Take advantage of the fact that c will always be word aligned.

  return c[0] == 'G'

         && c[1] == 'N'

         && c[2] == 'U'

         && c[3] == 'C'

         && c[4] == 'C'

         && c[5] == '+'

         && c[6] == '+'

         && (c[7] == '\0' || c[7] == '\x01');

}

// Only checks for primary or dependent, but not that it is a C++ exception at

// all.

static inline bool

__is_dependent_exception(_Unwind_Exception_Class c)

{

  return c[7] == '\x01';

}

static inline void

__GXX_INIT_PRIMARY_EXCEPTION_CLASS(_Unwind_Exception_Class c)

{

  c[0] = 'G';

  c[1] = 'N';

  c[2] = 'U';

  c[3] = 'C';

  c[4] = 'C';

  c[5] = '+';

  c[6] = '+';

  c[7] = '\0';

}

static inline void

__GXX_INIT_DEPENDENT_EXCEPTION_CLASS(_Unwind_Exception_Class c)

{

  c[0] = 'G';

  c[1] = 'N';

  c[2] = 'U';

  c[3] = 'C';

  c[4] = 'C';

  c[5] = '+';

  c[6] = '+';

  c[7] = '\x01';

}

static inline bool

__is_gxx_forced_unwind_class(_Unwind_Exception_Class c)

{

  return c[0] == 'G'

         && c[1] == 'N'

         && c[2] == 'U'

         && c[3] == 'C'

         && c[4] == 'F'

         && c[5] == 'O'

         && c[6] == 'R'

         && c[7] == '\0';

}

static inline void

__GXX_INIT_FORCED_UNWIND_CLASS(_Unwind_Exception_Class c)

{

  c[0] = 'G';

  c[1] = 'N';

  c[2] = 'U';

  c[3] = 'C';

  c[4] = 'F';

  c[5] = 'O';

  c[6] = 'R';

  c[7] = '\0';

}

static inline void*

__gxx_caught_object(_Unwind_Exception* eo)

{

  return (void*)eo->barrier_cache.bitpattern[0];

}

#else // !__ARM_EABI_UNWINDER__

// This is the primary exception class we report -- "GNUCC++\0".

const _Unwind_Exception_Class __gxx_primary_exception_class

= ((((((((_Unwind_Exception_Class) 'G'

         << 8 | (_Unwind_Exception_Class) 'N')

        << 8 | (_Unwind_Exception_Class) 'U')

       << 8 | (_Unwind_Exception_Class) 'C')

      << 8 | (_Unwind_Exception_Class) 'C')

     << 8 | (_Unwind_Exception_Class) '+')

    << 8 | (_Unwind_Exception_Class) '+')

   << 8 | (_Unwind_Exception_Class) '\0');

// This is the dependent (from std::rethrow_exception) exception class we report

// "GNUCC++\x01"

const _Unwind_Exception_Class __gxx_dependent_exception_class

= ((((((((_Unwind_Exception_Class) 'G'

         << 8 | (_Unwind_Exception_Class) 'N')

        << 8 | (_Unwind_Exception_Class) 'U')

       << 8 | (_Unwind_Exception_Class) 'C')

      << 8 | (_Unwind_Exception_Class) 'C')

     << 8 | (_Unwind_Exception_Class) '+')

    << 8 | (_Unwind_Exception_Class) '+')

   << 8 | (_Unwind_Exception_Class) '\x01');

static inline bool

__is_gxx_exception_class(_Unwind_Exception_Class c)

{

  return c == __gxx_primary_exception_class

      || c == __gxx_dependent_exception_class;

}

// Only checks for primary or dependent, but not that it is a C++ exception at

// all.

static inline bool

__is_dependent_exception(_Unwind_Exception_Class c)

{

  return (c & 1);

}

#define __GXX_INIT_PRIMARY_EXCEPTION_CLASS(c) c = __gxx_primary_exception_class

#define __GXX_INIT_DEPENDENT_EXCEPTION_CLASS(c) \

  c = __gxx_dependent_exception_class

// GNU C++ personality routine, Version 0.

extern "C" _Unwind_Reason_Code __gxx_personality_v0

     (int, _Unwind_Action, _Unwind_Exception_Class,

      struct _Unwind_Exception *, struct _Unwind_Context *);

// GNU C++ sjlj personality routine, Version 0.

extern "C" _Unwind_Reason_Code __gxx_personality_sj0

     (int, _Unwind_Action, _Unwind_Exception_Class,

      struct _Unwind_Exception *, struct _Unwind_Context *);

static inline void*

__gxx_caught_object(_Unwind_Exception* eo)

{

  // Bad as it looks, this actually works for dependent exceptions too.

  __cxa_exception* header = __get_exception_header_from_ue (eo);

  return header->adjustedPtr;

}

#endif // !__ARM_EABI_UNWINDER__

static inline void*

__get_object_from_ue(_Unwind_Exception* eo) throw()

{

  return __is_dependent_exception (eo->exception_class) ?

    __get_dependent_exception_from_ue (eo)->primaryException :

    eo + 1;

}

static inline void *

__get_object_from_ambiguous_exception(__cxa_exception *p_or_d) throw()

{

        return __get_object_from_ue (&p_or_d->unwindHeader);

}

} /* namespace __cxxabiv1 */

#pragma GCC visibility pop

#endif // _UNWIND_CXX_H