mirror of
https://github.com/git/git
synced 2024-10-30 14:03:28 +00:00
ee95ec5d58
When a merge conflicts, there are often common lines that are not really common, such as empty lines or lines containing a single curly bracket. With XDL_MERGE_ZEALOUS_ALNUM, we use the following heuristics: when a hunk does not contain any letters or digits, it is treated as conflicting. In other words, a conflict which used to look like this: <<<<<<< a = 1; ======= output(); >>>>>>> } } } <<<<<<< output(); ======= b = 1; >>>>>>> will look like this with ZEALOUS_ALNUM: <<<<<<< a = 1; } } } output(); ======= output(); } } } b = 1; >>>>>>> To demonstrate this, git-merge-file has been switched from XDL_MERGE_ZEALOUS to XDL_MERGE_ZEALOUS_ALNUM. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
494 lines
12 KiB
C
494 lines
12 KiB
C
/*
|
|
* LibXDiff by Davide Libenzi ( File Differential Library )
|
|
* Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
|
|
*
|
|
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
* Davide Libenzi <davidel@xmailserver.org>
|
|
*
|
|
*/
|
|
|
|
#include "xinclude.h"
|
|
|
|
typedef struct s_xdmerge {
|
|
struct s_xdmerge *next;
|
|
/*
|
|
* 0 = conflict,
|
|
* 1 = no conflict, take first,
|
|
* 2 = no conflict, take second.
|
|
*/
|
|
int mode;
|
|
long i1, i2;
|
|
long chg1, chg2;
|
|
} xdmerge_t;
|
|
|
|
static int xdl_append_merge(xdmerge_t **merge, int mode,
|
|
long i1, long chg1, long i2, long chg2)
|
|
{
|
|
xdmerge_t *m = *merge;
|
|
if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
|
|
if (mode != m->mode)
|
|
m->mode = 0;
|
|
m->chg1 = i1 + chg1 - m->i1;
|
|
m->chg2 = i2 + chg2 - m->i2;
|
|
} else {
|
|
m = xdl_malloc(sizeof(xdmerge_t));
|
|
if (!m)
|
|
return -1;
|
|
m->next = NULL;
|
|
m->mode = mode;
|
|
m->i1 = i1;
|
|
m->chg1 = chg1;
|
|
m->i2 = i2;
|
|
m->chg2 = chg2;
|
|
if (*merge)
|
|
(*merge)->next = m;
|
|
*merge = m;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int xdl_cleanup_merge(xdmerge_t *c)
|
|
{
|
|
int count = 0;
|
|
xdmerge_t *next_c;
|
|
|
|
/* were there conflicts? */
|
|
for (; c; c = next_c) {
|
|
if (c->mode == 0)
|
|
count++;
|
|
next_c = c->next;
|
|
free(c);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
|
|
int line_count, long flags)
|
|
{
|
|
int i;
|
|
xrecord_t **rec1 = xe1->xdf2.recs + i1;
|
|
xrecord_t **rec2 = xe2->xdf2.recs + i2;
|
|
|
|
for (i = 0; i < line_count; i++) {
|
|
int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
|
|
rec2[i]->ptr, rec2[i]->size, flags);
|
|
if (!result)
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
|
|
{
|
|
xrecord_t **recs = xe->xdf2.recs + i;
|
|
int size = 0;
|
|
|
|
if (count < 1)
|
|
return 0;
|
|
|
|
for (i = 0; i < count; size += recs[i++]->size)
|
|
if (dest)
|
|
memcpy(dest + size, recs[i]->ptr, recs[i]->size);
|
|
if (add_nl) {
|
|
i = recs[count - 1]->size;
|
|
if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
|
|
if (dest)
|
|
dest[size] = '\n';
|
|
size++;
|
|
}
|
|
}
|
|
return size;
|
|
}
|
|
|
|
static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
|
|
xdfenv_t *xe2, const char *name2, xdmerge_t *m, char *dest)
|
|
{
|
|
const int marker_size = 7;
|
|
int marker1_size = (name1 ? strlen(name1) + 1 : 0);
|
|
int marker2_size = (name2 ? strlen(name2) + 1 : 0);
|
|
int conflict_marker_size = 3 * (marker_size + 1)
|
|
+ marker1_size + marker2_size;
|
|
int size, i1, j;
|
|
|
|
for (size = i1 = 0; m; m = m->next) {
|
|
if (m->mode == 0) {
|
|
size += xdl_recs_copy(xe1, i1, m->i1 - i1, 0,
|
|
dest ? dest + size : NULL);
|
|
if (dest) {
|
|
for (j = 0; j < marker_size; j++)
|
|
dest[size++] = '<';
|
|
if (marker1_size) {
|
|
dest[size] = ' ';
|
|
memcpy(dest + size + 1, name1,
|
|
marker1_size - 1);
|
|
size += marker1_size;
|
|
}
|
|
dest[size++] = '\n';
|
|
} else
|
|
size += conflict_marker_size;
|
|
size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
|
|
dest ? dest + size : NULL);
|
|
if (dest) {
|
|
for (j = 0; j < marker_size; j++)
|
|
dest[size++] = '=';
|
|
dest[size++] = '\n';
|
|
}
|
|
size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
|
|
dest ? dest + size : NULL);
|
|
if (dest) {
|
|
for (j = 0; j < marker_size; j++)
|
|
dest[size++] = '>';
|
|
if (marker2_size) {
|
|
dest[size] = ' ';
|
|
memcpy(dest + size + 1, name2,
|
|
marker2_size - 1);
|
|
size += marker2_size;
|
|
}
|
|
dest[size++] = '\n';
|
|
}
|
|
} else if (m->mode == 1)
|
|
size += xdl_recs_copy(xe1, i1, m->i1 + m->chg1 - i1, 0,
|
|
dest ? dest + size : NULL);
|
|
else if (m->mode == 2)
|
|
size += xdl_recs_copy(xe2, m->i2 - m->i1 + i1,
|
|
m->i1 + m->chg2 - i1, 0,
|
|
dest ? dest + size : NULL);
|
|
else
|
|
continue;
|
|
i1 = m->i1 + m->chg1;
|
|
}
|
|
size += xdl_recs_copy(xe1, i1, xe1->xdf2.nrec - i1, 0,
|
|
dest ? dest + size : NULL);
|
|
return size;
|
|
}
|
|
|
|
/*
|
|
* Sometimes, changes are not quite identical, but differ in only a few
|
|
* lines. Try hard to show only these few lines as conflicting.
|
|
*/
|
|
static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
|
|
xpparam_t const *xpp)
|
|
{
|
|
for (; m; m = m->next) {
|
|
mmfile_t t1, t2;
|
|
xdfenv_t xe;
|
|
xdchange_t *xscr, *x;
|
|
int i1 = m->i1, i2 = m->i2;
|
|
|
|
/* let's handle just the conflicts */
|
|
if (m->mode)
|
|
continue;
|
|
|
|
/* no sense refining a conflict when one side is empty */
|
|
if (m->chg1 == 0 || m->chg2 == 0)
|
|
continue;
|
|
|
|
/*
|
|
* This probably does not work outside git, since
|
|
* we have a very simple mmfile structure.
|
|
*/
|
|
t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
|
|
t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
|
|
+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
|
|
t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
|
|
t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
|
|
+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
|
|
if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
|
|
return -1;
|
|
if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
|
|
xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
|
|
xdl_build_script(&xe, &xscr) < 0) {
|
|
xdl_free_env(&xe);
|
|
return -1;
|
|
}
|
|
if (!xscr) {
|
|
/* If this happens, the changes are identical. */
|
|
xdl_free_env(&xe);
|
|
m->mode = 4;
|
|
continue;
|
|
}
|
|
x = xscr;
|
|
m->i1 = xscr->i1 + i1;
|
|
m->chg1 = xscr->chg1;
|
|
m->i2 = xscr->i2 + i2;
|
|
m->chg2 = xscr->chg2;
|
|
while (xscr->next) {
|
|
xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
|
|
if (!m2) {
|
|
xdl_free_env(&xe);
|
|
xdl_free_script(x);
|
|
return -1;
|
|
}
|
|
xscr = xscr->next;
|
|
m2->next = m->next;
|
|
m->next = m2;
|
|
m = m2;
|
|
m->mode = 0;
|
|
m->i1 = xscr->i1 + i1;
|
|
m->chg1 = xscr->chg1;
|
|
m->i2 = xscr->i2 + i2;
|
|
m->chg2 = xscr->chg2;
|
|
}
|
|
xdl_free_env(&xe);
|
|
xdl_free_script(x);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int line_contains_alnum(const char *ptr, long size)
|
|
{
|
|
while (size--)
|
|
if (isalnum(*(ptr++)))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
|
|
{
|
|
for (; chg; chg--, i++)
|
|
if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
|
|
xe->xdf2.recs[i]->size))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This function merges m and m->next, marking everything between those hunks
|
|
* as conflicting, too.
|
|
*/
|
|
static void xdl_merge_two_conflicts(xdmerge_t *m)
|
|
{
|
|
xdmerge_t *next_m = m->next;
|
|
m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
|
|
m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
|
|
m->next = next_m->next;
|
|
free(next_m);
|
|
}
|
|
|
|
/*
|
|
* If there are less than 3 non-conflicting lines between conflicts,
|
|
* it appears simpler -- because it takes up less (or as many) lines --
|
|
* if the lines are moved into the conflicts.
|
|
*/
|
|
static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
|
|
int simplify_if_no_alnum)
|
|
{
|
|
int result = 0;
|
|
|
|
if (!m)
|
|
return result;
|
|
for (;;) {
|
|
xdmerge_t *next_m = m->next;
|
|
int begin, end;
|
|
|
|
if (!next_m)
|
|
return result;
|
|
|
|
begin = m->i1 + m->chg1;
|
|
end = next_m->i1;
|
|
|
|
if (m->mode != 0 || next_m->mode != 0 ||
|
|
(end - begin > 3 &&
|
|
(!simplify_if_no_alnum ||
|
|
lines_contain_alnum(xe1, begin, end - begin)))) {
|
|
m = next_m;
|
|
} else {
|
|
result++;
|
|
xdl_merge_two_conflicts(m);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* level == 0: mark all overlapping changes as conflict
|
|
* level == 1: mark overlapping changes as conflict only if not identical
|
|
* level == 2: analyze non-identical changes for minimal conflict set
|
|
* level == 3: analyze non-identical changes for minimal conflict set, but
|
|
* treat hunks not containing any letter or number as conflicting
|
|
*
|
|
* returns < 0 on error, == 0 for no conflicts, else number of conflicts
|
|
*/
|
|
static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
|
|
xdfenv_t *xe2, xdchange_t *xscr2, const char *name2,
|
|
int level, xpparam_t const *xpp, mmbuffer_t *result) {
|
|
xdmerge_t *changes, *c;
|
|
int i1, i2, chg1, chg2;
|
|
|
|
c = changes = NULL;
|
|
|
|
while (xscr1 && xscr2) {
|
|
if (!changes)
|
|
changes = c;
|
|
if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
|
|
i1 = xscr1->i2;
|
|
i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
|
|
chg1 = xscr1->chg2;
|
|
chg2 = xscr1->chg1;
|
|
if (xdl_append_merge(&c, 1, i1, chg1, i2, chg2)) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
xscr1 = xscr1->next;
|
|
continue;
|
|
}
|
|
if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
|
|
i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
|
|
i2 = xscr2->i2;
|
|
chg1 = xscr2->chg1;
|
|
chg2 = xscr2->chg2;
|
|
if (xdl_append_merge(&c, 2, i1, chg1, i2, chg2)) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
xscr2 = xscr2->next;
|
|
continue;
|
|
}
|
|
if (level < 1 || xscr1->i1 != xscr2->i1 ||
|
|
xscr1->chg1 != xscr2->chg1 ||
|
|
xscr1->chg2 != xscr2->chg2 ||
|
|
xdl_merge_cmp_lines(xe1, xscr1->i2,
|
|
xe2, xscr2->i2,
|
|
xscr1->chg2, xpp->flags)) {
|
|
/* conflict */
|
|
int off = xscr1->i1 - xscr2->i1;
|
|
int ffo = off + xscr1->chg1 - xscr2->chg1;
|
|
|
|
i1 = xscr1->i2;
|
|
i2 = xscr2->i2;
|
|
if (off > 0)
|
|
i1 -= off;
|
|
else
|
|
i2 += off;
|
|
chg1 = xscr1->i2 + xscr1->chg2 - i1;
|
|
chg2 = xscr2->i2 + xscr2->chg2 - i2;
|
|
if (ffo > 0)
|
|
chg2 += ffo;
|
|
else
|
|
chg1 -= ffo;
|
|
if (xdl_append_merge(&c, 0, i1, chg1, i2, chg2)) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
i1 = xscr1->i1 + xscr1->chg1;
|
|
i2 = xscr2->i1 + xscr2->chg1;
|
|
|
|
if (i1 >= i2)
|
|
xscr2 = xscr2->next;
|
|
if (i2 >= i1)
|
|
xscr1 = xscr1->next;
|
|
}
|
|
while (xscr1) {
|
|
if (!changes)
|
|
changes = c;
|
|
i1 = xscr1->i2;
|
|
i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
|
|
chg1 = xscr1->chg2;
|
|
chg2 = xscr1->chg1;
|
|
if (xdl_append_merge(&c, 1, i1, chg1, i2, chg2)) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
xscr1 = xscr1->next;
|
|
}
|
|
while (xscr2) {
|
|
if (!changes)
|
|
changes = c;
|
|
i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
|
|
i2 = xscr2->i2;
|
|
chg1 = xscr2->chg1;
|
|
chg2 = xscr2->chg2;
|
|
if (xdl_append_merge(&c, 2, i1, chg1, i2, chg2)) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
xscr2 = xscr2->next;
|
|
}
|
|
if (!changes)
|
|
changes = c;
|
|
/* refine conflicts */
|
|
if (level > 1 &&
|
|
(xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
|
|
xdl_simplify_non_conflicts(xe1, changes, level > 2) < 0)) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
/* output */
|
|
if (result) {
|
|
int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
|
|
changes, NULL);
|
|
result->ptr = xdl_malloc(size);
|
|
if (!result->ptr) {
|
|
xdl_cleanup_merge(changes);
|
|
return -1;
|
|
}
|
|
result->size = size;
|
|
xdl_fill_merge_buffer(xe1, name1, xe2, name2, changes,
|
|
result->ptr);
|
|
}
|
|
return xdl_cleanup_merge(changes);
|
|
}
|
|
|
|
int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
|
|
mmfile_t *mf2, const char *name2,
|
|
xpparam_t const *xpp, int level, mmbuffer_t *result) {
|
|
xdchange_t *xscr1, *xscr2;
|
|
xdfenv_t xe1, xe2;
|
|
int status;
|
|
|
|
result->ptr = NULL;
|
|
result->size = 0;
|
|
|
|
if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0 ||
|
|
xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
|
|
return -1;
|
|
}
|
|
if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
|
|
xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
|
|
xdl_build_script(&xe1, &xscr1) < 0) {
|
|
xdl_free_env(&xe1);
|
|
return -1;
|
|
}
|
|
if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
|
|
xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
|
|
xdl_build_script(&xe2, &xscr2) < 0) {
|
|
xdl_free_env(&xe2);
|
|
return -1;
|
|
}
|
|
status = 0;
|
|
if (xscr1 || xscr2) {
|
|
if (!xscr1) {
|
|
result->ptr = xdl_malloc(mf2->size);
|
|
memcpy(result->ptr, mf2->ptr, mf2->size);
|
|
result->size = mf2->size;
|
|
} else if (!xscr2) {
|
|
result->ptr = xdl_malloc(mf1->size);
|
|
memcpy(result->ptr, mf1->ptr, mf1->size);
|
|
result->size = mf1->size;
|
|
} else {
|
|
status = xdl_do_merge(&xe1, xscr1, name1,
|
|
&xe2, xscr2, name2,
|
|
level, xpp, result);
|
|
}
|
|
xdl_free_script(xscr1);
|
|
xdl_free_script(xscr2);
|
|
}
|
|
xdl_free_env(&xe1);
|
|
xdl_free_env(&xe2);
|
|
|
|
return status;
|
|
}
|