brealloc.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 66 行

/****************************************************************************
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*                            Open Watcom Project
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*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
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*    This file contains Original Code and/or Modifications of Original
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#include "dll.h"        // needs to be first
#include "variety.h"
#include <malloc.h>
#include <string.h>
#include "heap.h"

_WCRTLINK void __based(void) *_brealloc( __segment seg,
                                        void __based(void) *mem,
                                        size_t size )
{
    void __based(void)  *p;
    size_t              old_size;

    if( mem == _NULLOFF )  return( _bmalloc( seg, size ) );
    if( size == 0 ) {
        _bfree( seg, mem );
        return( _NULLOFF );
    }
    old_size = _bmsize( seg, mem );
    p = _bexpand( seg, mem, size );
    if( p == _NULLOFF ) {               /* if it couldn't be expanded */
        p = _bmalloc( seg, size );      /* - allocate new block */
        if( p != _NULLOFF ) {           /* - if we got one */
            _fmemcpy( (void _WCFAR *)(seg :> p),
                      (void _WCFAR *)(seg :> mem),
                      old_size );
            _bfree( seg, mem );
        } else {
            _bexpand( seg, mem, old_size );
        }
    }
    return( p );
}