git/xdiff/xdiff.h
Jeff King 36c8319724 xdiff: use xmalloc/xrealloc
Most of xdiff uses a bare malloc() to allocate memory, and returns an
error when we get NULL. However, there are a few spots which don't check
the return value and may segfault, including at least xdl_merge() and
xpatience.c's find_longest_common_sequence().

Let's use xmalloc() everywhere instead, so that we get a graceful die()
for these cases, without having to do further auditing. This does mean
the existing cases which check errors will now die() instead of
returning an error up the stack. But:

  - that's how the rest of Git behaves already for malloc errors

  - all of the callers of xdi_diff(), etc, die upon seeing an error

So while we might one day want to fully lib-ify the diff code and make
it possible to use as part of a long-running process, we're not close to
that now. And because we're just tweaking the xdl_malloc() macro here,
we're not really moving ourselves any further away from that. We
could, for example, simplify some of the functions which handle malloc()
errors which can no longer occur. But that would probably be taking us
in the wrong direction.

This also makes our malloc handling more consistent with the rest of
Git, including enforcing GIT_ALLOC_LIMIT and trying to reclaim pack
memory when needed.

Reported-by: 王健强 <jianqiang.wang@securitygossip.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-12 13:34:17 +09:00

147 lines
3.7 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(XDIFF_H)
#define XDIFF_H
#ifdef __cplusplus
extern "C" {
#endif /* #ifdef __cplusplus */
/* xpparm_t.flags */
#define XDF_NEED_MINIMAL (1 << 0)
#define XDF_IGNORE_WHITESPACE (1 << 1)
#define XDF_IGNORE_WHITESPACE_CHANGE (1 << 2)
#define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 3)
#define XDF_IGNORE_CR_AT_EOL (1 << 4)
#define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | \
XDF_IGNORE_WHITESPACE_CHANGE | \
XDF_IGNORE_WHITESPACE_AT_EOL | \
XDF_IGNORE_CR_AT_EOL)
#define XDF_IGNORE_BLANK_LINES (1 << 7)
#define XDF_PATIENCE_DIFF (1 << 14)
#define XDF_HISTOGRAM_DIFF (1 << 15)
#define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF)
#define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK)
#define XDF_INDENT_HEURISTIC (1 << 23)
/* xdemitconf_t.flags */
#define XDL_EMIT_FUNCNAMES (1 << 0)
#define XDL_EMIT_FUNCCONTEXT (1 << 2)
/* merge simplification levels */
#define XDL_MERGE_MINIMAL 0
#define XDL_MERGE_EAGER 1
#define XDL_MERGE_ZEALOUS 2
#define XDL_MERGE_ZEALOUS_ALNUM 3
/* merge favor modes */
#define XDL_MERGE_FAVOR_OURS 1
#define XDL_MERGE_FAVOR_THEIRS 2
#define XDL_MERGE_FAVOR_UNION 3
/* merge output styles */
#define XDL_MERGE_DIFF3 1
typedef struct s_mmfile {
char *ptr;
long size;
} mmfile_t;
typedef struct s_mmbuffer {
char *ptr;
long size;
} mmbuffer_t;
typedef struct s_xpparam {
unsigned long flags;
/* See Documentation/diff-options.txt. */
char **anchors;
size_t anchors_nr;
} xpparam_t;
typedef struct s_xdemitcb {
void *priv;
int (*out_hunk)(void *,
long old_begin, long old_nr,
long new_begin, long new_nr,
const char *func, long funclen);
int (*out_line)(void *, mmbuffer_t *, int);
} xdemitcb_t;
typedef long (*find_func_t)(const char *line, long line_len, char *buffer, long buffer_size, void *priv);
typedef int (*xdl_emit_hunk_consume_func_t)(long start_a, long count_a,
long start_b, long count_b,
void *cb_data);
typedef struct s_xdemitconf {
long ctxlen;
long interhunkctxlen;
unsigned long flags;
find_func_t find_func;
void *find_func_priv;
xdl_emit_hunk_consume_func_t hunk_func;
} xdemitconf_t;
typedef struct s_bdiffparam {
long bsize;
} bdiffparam_t;
#define xdl_malloc(x) xmalloc(x)
#define xdl_free(ptr) free(ptr)
#define xdl_realloc(ptr,x) xrealloc(ptr,x)
void *xdl_mmfile_first(mmfile_t *mmf, long *size);
long xdl_mmfile_size(mmfile_t *mmf);
int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
xdemitconf_t const *xecfg, xdemitcb_t *ecb);
typedef struct s_xmparam {
xpparam_t xpp;
int marker_size;
int level;
int favor;
int style;
const char *ancestor; /* label for orig */
const char *file1; /* label for mf1 */
const char *file2; /* label for mf2 */
} xmparam_t;
#define DEFAULT_CONFLICT_MARKER_SIZE 7
int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
xmparam_t const *xmp, mmbuffer_t *result);
#ifdef __cplusplus
}
#endif /* #ifdef __cplusplus */
#endif /* #if !defined(XDIFF_H) */