Commit 223b9cae authored by Josh Coalson's avatar Josh Coalson

add alloc.h

parent 4c30f1ff
......@@ -5,6 +5,7 @@ AUTOMAKE_OPTIONS = foreign
SUBDIRS = grabbag
EXTRA_DIST = \
alloc.h \
getopt.h \
grabbag.h \
replaygain_analysis.h \
......
/* alloc - Convenience routines for safely allocating memory
* Copyright (C) 2007 Josh Coalson
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef FLAC__SHARE__ALLOC_H
#define FLAC__SHARE__ALLOC_H
/* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
* before #including this file, otherwise SIZE_MAX might not be defined
*/
#include <limits.h> /* for SIZE_MAX */
#if !defined _MSC_VER && !defined __MINGW32__ && !defined __EMX__
#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
#endif
#include <stdlib.h> /* for size_t, malloc(), etc */
/* avoid malloc()ing 0 bytes, see:
* https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
*/
static void *safe_malloc_(size_t size)
{
/* malloc(0) is undefined; FLAC src convention is to always allocate */
if(!size)
size++;
return malloc(size);
}
static void *safe_calloc_(size_t nmemb, size_t size)
{
if(!nmemb || !size)
return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
return calloc(nmemb, size);
}
/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
static void *safe_malloc_add_2op_(size_t size1, size_t size2)
{
size2 += size1;
if(size2 < size1)
return 0;
return safe_malloc_(size2);
}
static void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
return safe_malloc_(size3);
}
static void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
size4 += size3;
if(size4 < size3)
return 0;
return safe_malloc_(size4);
}
static void *safe_malloc_mul_2op_(size_t size1, size_t size2)
#if 0
needs support for cases where sizeof(size_t) != 4
{
/* could be faster #ifdef'ing off SIZEOF_SIZE_T */
if(sizeof(size_t) == 4) {
if ((double)size1 * (double)size2 < 4294967296.0)
return malloc(size1*size2);
}
return 0;
}
#else
/* better? */
{
if(!size1 || !size2)
return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
if(size1 > SIZE_MAX / size2)
return 0;
return malloc(size1*size2);
}
#endif
static void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
{
if(!size1 || !size2 || !size3)
return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
if(size1 > SIZE_MAX / size2)
return 0;
size1 *= size2;
if(size1 > SIZE_MAX / size3)
return 0;
return malloc(size1*size3);
}
/* size1*size2 + size3 */
static void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
{
if(!size1 || !size2)
return safe_malloc_(size3);
if(size1 > SIZE_MAX / size2)
return 0;
return safe_malloc_add_2op_(size1*size2, size3);
}
static void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
{
size2 += size1;
if(size2 < size1)
return 0;
return realloc(ptr, size2);
}
static void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
return realloc(ptr, size3);
}
static void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
size4 += size3;
if(size4 < size3)
return 0;
return realloc(ptr, size4);
}
static void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
{
if(!size1 || !size2)
return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
if(size1 > SIZE_MAX / size2)
return 0;
return realloc(ptr, size1*size2);
}
#endif
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