git/xdiff/xmacros.h
Phillip Wood abf04bdaa8 xdiff: introduce XDL_ALLOC_ARRAY()
Add a helper to allocate an array that automatically calculates the
allocation size. This is analogous to ALLOC_ARRAY() in the rest of the
codebase but returns NULL if the allocation fails to accommodate other
users of libxdiff such as libgit2. The helper will also return NULL if
the multiplication in the allocation calculation overflows.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-08 09:34:30 -07:00

59 lines
2.0 KiB
C

/*
* LibXDiff by Davide Libenzi ( File Differential Library )
* Copyright (C) 2003 Davide Libenzi
*
* 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, see
* <http://www.gnu.org/licenses/>.
*
* Davide Libenzi <davidel@xmailserver.org>
*
*/
#if !defined(XMACROS_H)
#define XMACROS_H
#define XDL_MIN(a, b) ((a) < (b) ? (a): (b))
#define XDL_MAX(a, b) ((a) > (b) ? (a): (b))
#define XDL_ABS(v) ((v) >= 0 ? (v): -(v))
#define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
#define XDL_ISSPACE(c) (isspace((unsigned char)(c)))
#define XDL_ADDBITS(v,b) ((v) + ((v) >> (b)))
#define XDL_MASKBITS(b) ((1UL << (b)) - 1)
#define XDL_HASHLONG(v,b) (XDL_ADDBITS((unsigned long)(v), b) & XDL_MASKBITS(b))
#define XDL_LE32_PUT(p, v) \
do { \
unsigned char *__p = (unsigned char *) (p); \
*__p++ = (unsigned char) (v); \
*__p++ = (unsigned char) ((v) >> 8); \
*__p++ = (unsigned char) ((v) >> 16); \
*__p = (unsigned char) ((v) >> 24); \
} while (0)
#define XDL_LE32_GET(p, v) \
do { \
unsigned char const *__p = (unsigned char const *) (p); \
(v) = (unsigned long) __p[0] | ((unsigned long) __p[1]) << 8 | \
((unsigned long) __p[2]) << 16 | ((unsigned long) __p[3]) << 24; \
} while (0)
/* Allocate an array of nr elements, returns NULL on failure */
#define XDL_ALLOC_ARRAY(p, nr) \
((p) = SIZE_MAX / sizeof(*(p)) >= (size_t)(nr) \
? xdl_malloc((nr) * sizeof(*(p))) \
: NULL)
#endif /* #if !defined(XMACROS_H) */