freebsd-dev/contrib/libcxxrt/cxxabi.h

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/*
* Copyright 2012 David Chisnall. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef __CXXABI_H_
#define __CXXABI_H_
#include <stddef.h>
#include <stdint.h>
#include "unwind.h"
namespace std
{
class type_info;
}
/*
* The cxxabi.h header provides a set of public definitions for types and
* functions defined by the Itanium C++ ABI specification. For reference, see
* the ABI specification here:
*
* http://sourcery.mentor.com/public/cxx-abi/abi.html
*
* All deviations from this specification, unless otherwise noted, are
* accidental.
*/
#ifdef __cplusplus
namespace __cxxabiv1 {
extern "C" {
#endif
/**
* Function type to call when an unexpected exception is encountered.
*/
typedef void (*unexpected_handler)();
/**
* Function type to call when an unrecoverable condition is encountered.
*/
typedef void (*terminate_handler)();
/**
* Structure used as a header on thrown exceptions. This is the same layout as
* defined by the Itanium ABI spec, so should be interoperable with any other
* implementation of this spec, such as GNU libsupc++.
*
* This structure is allocated when an exception is thrown. Unwinding happens
* in two phases, the first looks for a handler and the second installs the
* context. This structure stores a cache of the handler location between
* phase 1 and phase 2. Unfortunately, cleanup information is not cached, so
* must be looked up in both phases. This happens for two reasons. The first
* is that we don't know how many frames containing cleanups there will be, and
* we should avoid dynamic allocation during unwinding (the exception may be
* reporting that we've run out of memory). The second is that finding
* cleanups is much cheaper than finding handlers, because we don't have to
* look at the type table at all.
*
* Note: Several fields of this structure have not-very-informative names.
* These are taken from the ABI spec and have not been changed to make it
* easier for people referring to to the spec while reading this code.
*/
struct __cxa_exception
{
#if __LP64__
/**
* Reference count. Used to support the C++11 exception_ptr class. This
* is prepended to the structure in 64-bit mode and squeezed in to the
* padding left before the 64-bit aligned _Unwind_Exception at the end in
* 32-bit mode.
*
* Note that it is safe to extend this structure at the beginning, rather
* than the end, because the public API for creating it returns the address
* of the end (where the exception object can be stored).
*/
uintptr_t referenceCount;
#endif
/** Type info for the thrown object. */
std::type_info *exceptionType;
/** Destructor for the object, if one exists. */
void (*exceptionDestructor) (void *);
/** Handler called when an exception specification is violated. */
unexpected_handler unexpectedHandler;
/** Hander called to terminate. */
terminate_handler terminateHandler;
/**
* Next exception in the list. If an exception is thrown inside a catch
* block and caught in a nested catch, this points to the exception that
* will be handled after the inner catch block completes.
*/
__cxa_exception *nextException;
/**
* The number of handlers that currently have references to this
* exception. The top (non-sign) bit of this is used as a flag to indicate
* that the exception is being rethrown, so should not be deleted when its
* handler count reaches 0 (which it doesn't with the top bit set).
*/
int handlerCount;
#if defined(__arm__) && !defined(__ARM_DWARF_EH__)
/**
* The ARM EH ABI requires the unwind library to keep track of exceptions
* during cleanups. These support nesting, so we need to keep a list of
* them.
*/
_Unwind_Exception *nextCleanup;
/**
* The number of cleanups that are currently being run on this exception.
*/
int cleanupCount;
#endif
/**
* The selector value to be returned when installing the catch handler.
* Used at the call site to determine which catch() block should execute.
* This is found in phase 1 of unwinding then installed in phase 2.
*/
int handlerSwitchValue;
/**
* The action record for the catch. This is cached during phase 1
* unwinding.
*/
const char *actionRecord;
/**
* Pointer to the language-specific data area (LSDA) for the handler
* frame. This is unused in this implementation, but set for ABI
* compatibility in case we want to mix code in very weird ways.
*/
const char *languageSpecificData;
/** The cached landing pad for the catch handler.*/
void *catchTemp;
/**
* The pointer that will be returned as the pointer to the object. When
* throwing a class and catching a virtual superclass (for example), we
* need to adjust the thrown pointer to make it all work correctly.
*/
void *adjustedPtr;
#if !__LP64__
/**
* Reference count. Used to support the C++11 exception_ptr class. This
* is prepended to the structure in 64-bit mode and squeezed in to the
* padding left before the 64-bit aligned _Unwind_Exception at the end in
* 32-bit mode.
*
* Note that it is safe to extend this structure at the beginning, rather
* than the end, because the public API for creating it returns the address
* of the end (where the exception object can be stored)
*/
uintptr_t referenceCount;
#endif
/** The language-agnostic part of the exception header. */
_Unwind_Exception unwindHeader;
};
/**
* ABI-specified globals structure. Returned by the __cxa_get_globals()
* function and its fast variant. This is a per-thread structure - every
* thread will have one lazily allocated.
*
* This structure is defined by the ABI, so may be used outside of this
* library.
*/
struct __cxa_eh_globals
{
/**
* A linked list of exceptions that are currently caught. There may be
* several of these in nested catch() blocks.
*/
__cxa_exception *caughtExceptions;
/**
* The number of uncaught exceptions.
*/
unsigned int uncaughtExceptions;
};
/**
* ABI function returning the __cxa_eh_globals structure.
*/
__cxa_eh_globals *__cxa_get_globals(void);
/**
* Version of __cxa_get_globals() assuming that __cxa_get_globals() has already
* been called at least once by this thread.
*/
__cxa_eh_globals *__cxa_get_globals_fast(void);
std::type_info * __cxa_current_exception_type();
/**
* Throws an exception returned by __cxa_current_primary_exception(). This
* exception may have been caught in another thread.
*/
void __cxa_rethrow_primary_exception(void* thrown_exception);
/**
* Returns the current exception in a form that can be stored in an
* exception_ptr object and then rethrown by a call to
* __cxa_rethrow_primary_exception().
*/
void *__cxa_current_primary_exception(void);
/**
* Increments the reference count of an exception. Called when an
* exception_ptr is copied.
*/
void __cxa_increment_exception_refcount(void* thrown_exception);
/**
* Decrements the reference count of an exception. Called when an
* exception_ptr is deleted.
*/
void __cxa_decrement_exception_refcount(void* thrown_exception);
/**
* Demangles a C++ symbol or type name. The buffer, if non-NULL, must be
* allocated with malloc() and must be *n bytes or more long. This function
* may call realloc() on the value pointed to by buf, and will return the
* length of the string via *n.
*
* The value pointed to by status is set to one of the following:
*
* 0: success
* -1: memory allocation failure
* -2: invalid mangled name
* -3: invalid arguments
*/
char* __cxa_demangle(const char* mangled_name,
char* buf,
size_t* n,
int* status);
#ifdef __cplusplus
} // extern "C"
} // namespace
namespace abi = __cxxabiv1;
#endif /* __cplusplus */
#endif /* __CXXABI_H_ */