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//===------------------------- cxa_exception.cpp --------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//
// This file implements the "Exception Handling APIs"
// http://www.codesourcery.com/public/cxx-abi/abi-eh.html
//
//===----------------------------------------------------------------------===//
#include "cxxabi.h"
#include <exception> // for std::terminate
#include <cstdlib> // for malloc, free
#include <string> // for memset
#include <pthread.h>
#include "cxa_exception.hpp"
#include "cxa_exception_storage.hpp"
namespace __cxxabiv1 {
// Utility routines
static __cxa_exception *exception_from_object ( void *p ) {
return ((__cxa_exception *) p ) - 1;
}
void * object_from_exception ( void *p ) {
return (void *) (((__cxa_exception *) p ) + 1 );
}
static size_t object_size_from_exception_size ( size_t size ) {
return size + sizeof (__cxa_exception);
}
#include "fallback_malloc.cpp"
// Allocate some memory from _somewhere_
static void *do_malloc ( size_t size ) throw () {
void *ptr = std::malloc ( size );
if ( NULL == ptr ) // if malloc fails, fall back to emergency stash
ptr = fallback_malloc ( size );
return ptr;
}
// Didn't know you could "return <expression>" from a void function, did you?
// Well, you can, if the type of the expression is "void" also.
static void do_free ( void *ptr ) throw () {
return is_fallback_ptr ( ptr ) ? fallback_free ( ptr ) : std::free ( ptr );
}
// pthread_once_t __globals::flag_ = PTHREAD_ONCE_INIT;
extern "C" {
// Allocate a __cxa_exception object, and zero-fill it.
// Reserve "thrown_size" bytes on the end for the user's exception
// object. Zero-fill the object. If memory can't be allocated, call
// std::terminate. Return a pointer to the memory to be used for the
// user's exception object.
void * __cxa_allocate_exception (size_t thrown_size) throw() {
size_t actual_size = object_size_from_exception_size ( thrown_size );
void *ptr = do_malloc ( actual_size );
if ( NULL == ptr )
std::terminate ();
std::memset ( ptr, 0, actual_size );
return object_from_exception ( ptr );
}
// Free a __cxa_exception object allocated with __cxa_allocate_exception.
void __cxa_free_exception (void * thrown_exception) throw() {
do_free ( exception_from_object ( thrown_exception ));
}
// This function shall allocate a __cxa_dependent_exception and
// return a pointer to it. (Really to the object, not past its' end).
// Otherwise, it will work like __cxa_allocate_exception.
void * __cxa_allocate_dependent_exception () throw() {
size_t actual_size = sizeof ( __cxa_dependent_exception );
void *ptr = do_malloc ( actual_size );
if ( NULL == ptr )
std::terminate ();
std::memset ( ptr, 0, actual_size );
// bookkeeping here ?
return ptr;
}
// This function shall free a dependent_exception.
// It does not affect the reference count of the primary exception.
void __cxa_free_dependent_exception (void * dependent_exception) throw() {
// I'm pretty sure there's no bookkeeping here
do_free ( dependent_exception );
}
} // extern "C"
} // abi
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