--- a/mercurial/thirdparty/xdiff/xmerge.c Tue Mar 06 18:41:08 2018 -0800
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,686 +0,0 @@
-/*
- * 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, see
- * <http://www.gnu.org/licenses/>.
- *
- * 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.
- * 3 = no conflict, take both.
- */
- int mode;
- /*
- * These point at the respective postimages. E.g. <i1,chg1> is
- * how side #1 wants to change the common ancestor; if there is no
- * overlap, lines before i1 in the postimage of side #1 appear
- * in the merge result as a region touched by neither side.
- */
- long i1, i2;
- long chg1, chg2;
- /*
- * These point at the preimage; of course there is just one
- * preimage, that is from the shared common ancestor.
- */
- long i0;
- long chg0;
-} xdmerge_t;
-
-static int xdl_append_merge(xdmerge_t **merge, int mode,
- long i0, long chg0,
- 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->chg0 = i0 + chg0 - m->i0;
- 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->i0 = i0;
- m->chg0 = chg0;
- 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_0(int use_orig, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
-{
- xrecord_t **recs;
- int size = 0;
-
- recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;
-
- 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 (needs_cr) {
- if (dest)
- dest[size] = '\r';
- size++;
- }
-
- if (dest)
- dest[size] = '\n';
- size++;
- }
- }
- return size;
-}
-
-static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
-{
- return xdl_recs_copy_0(0, xe, i, count, needs_cr, add_nl, dest);
-}
-
-static int xdl_orig_copy(xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
-{
- return xdl_recs_copy_0(1, xe, i, count, needs_cr, add_nl, dest);
-}
-
-/*
- * Returns 1 if the i'th line ends in CR/LF (if it is the last line and
- * has no eol, the preceding line, if any), 0 if it ends in LF-only, and
- * -1 if the line ending cannot be determined.
- */
-static int is_eol_crlf(xdfile_t *file, int i)
-{
- long size;
-
- if (i < file->nrec - 1)
- /* All lines before the last *must* end in LF */
- return (size = file->recs[i]->size) > 1 &&
- file->recs[i]->ptr[size - 2] == '\r';
- if (!file->nrec)
- /* Cannot determine eol style from empty file */
- return -1;
- if ((size = file->recs[i]->size) &&
- file->recs[i]->ptr[size - 1] == '\n')
- /* Last line; ends in LF; Is it CR/LF? */
- return size > 1 &&
- file->recs[i]->ptr[size - 2] == '\r';
- if (!i)
- /* The only line has no eol */
- return -1;
- /* Determine eol from second-to-last line */
- return (size = file->recs[i - 1]->size) > 1 &&
- file->recs[i - 1]->ptr[size - 2] == '\r';
-}
-
-static int is_cr_needed(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m)
-{
- int needs_cr;
-
- /* Match post-images' preceding, or first, lines' end-of-line style */
- needs_cr = is_eol_crlf(&xe1->xdf2, m->i1 ? m->i1 - 1 : 0);
- if (needs_cr)
- needs_cr = is_eol_crlf(&xe2->xdf2, m->i2 ? m->i2 - 1 : 0);
- /* Look at pre-image's first line, unless we already settled on LF */
- if (needs_cr)
- needs_cr = is_eol_crlf(&xe1->xdf1, 0);
- /* If still undecided, use LF-only */
- return needs_cr < 0 ? 0 : needs_cr;
-}
-
-static int fill_conflict_hunk(xdfenv_t *xe1, const char *name1,
- xdfenv_t *xe2, const char *name2,
- const char *name3,
- int size, int i, int style,
- xdmerge_t *m, char *dest, int marker_size)
-{
- int marker1_size = (name1 ? strlen(name1) + 1 : 0);
- int marker2_size = (name2 ? strlen(name2) + 1 : 0);
- int marker3_size = (name3 ? strlen(name3) + 1 : 0);
- int needs_cr = is_cr_needed(xe1, xe2, m);
-
- if (marker_size <= 0)
- marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
-
- /* Before conflicting part */
- size += xdl_recs_copy(xe1, i, m->i1 - i, 0, 0,
- dest ? dest + size : NULL);
-
- if (!dest) {
- size += marker_size + 1 + needs_cr + marker1_size;
- } else {
- memset(dest + size, '<', marker_size);
- size += marker_size;
- if (marker1_size) {
- dest[size] = ' ';
- memcpy(dest + size + 1, name1, marker1_size - 1);
- size += marker1_size;
- }
- if (needs_cr)
- dest[size++] = '\r';
- dest[size++] = '\n';
- }
-
- /* Postimage from side #1 */
- size += xdl_recs_copy(xe1, m->i1, m->chg1, needs_cr, 1,
- dest ? dest + size : NULL);
-
- if (style == XDL_MERGE_DIFF3) {
- /* Shared preimage */
- if (!dest) {
- size += marker_size + 1 + needs_cr + marker3_size;
- } else {
- memset(dest + size, '|', marker_size);
- size += marker_size;
- if (marker3_size) {
- dest[size] = ' ';
- memcpy(dest + size + 1, name3, marker3_size - 1);
- size += marker3_size;
- }
- if (needs_cr)
- dest[size++] = '\r';
- dest[size++] = '\n';
- }
- size += xdl_orig_copy(xe1, m->i0, m->chg0, needs_cr, 1,
- dest ? dest + size : NULL);
- }
-
- if (!dest) {
- size += marker_size + 1 + needs_cr;
- } else {
- memset(dest + size, '=', marker_size);
- size += marker_size;
- if (needs_cr)
- dest[size++] = '\r';
- dest[size++] = '\n';
- }
-
- /* Postimage from side #2 */
- size += xdl_recs_copy(xe2, m->i2, m->chg2, needs_cr, 1,
- dest ? dest + size : NULL);
- if (!dest) {
- size += marker_size + 1 + needs_cr + marker2_size;
- } else {
- memset(dest + size, '>', marker_size);
- size += marker_size;
- if (marker2_size) {
- dest[size] = ' ';
- memcpy(dest + size + 1, name2, marker2_size - 1);
- size += marker2_size;
- }
- if (needs_cr)
- dest[size++] = '\r';
- dest[size++] = '\n';
- }
- return size;
-}
-
-static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
- xdfenv_t *xe2, const char *name2,
- const char *ancestor_name,
- int favor,
- xdmerge_t *m, char *dest, int style,
- int marker_size)
-{
- int size, i;
-
- for (size = i = 0; m; m = m->next) {
- if (favor && !m->mode)
- m->mode = favor;
-
- if (m->mode == 0)
- size = fill_conflict_hunk(xe1, name1, xe2, name2,
- ancestor_name,
- size, i, style, m, dest,
- marker_size);
- else if (m->mode & 3) {
- /* Before conflicting part */
- size += xdl_recs_copy(xe1, i, m->i1 - i, 0, 0,
- dest ? dest + size : NULL);
- /* Postimage from side #1 */
- if (m->mode & 1) {
- int needs_cr = is_cr_needed(xe1, xe2, m);
-
- size += xdl_recs_copy(xe1, m->i1, m->chg1, needs_cr, (m->mode & 2),
- dest ? dest + size : NULL);
- }
- /* Postimage from side #2 */
- if (m->mode & 2)
- size += xdl_recs_copy(xe2, m->i2, m->chg2, 0, 0,
- dest ? dest + size : NULL);
- } else
- continue;
- i = m->i1 + m->chg1;
- }
- size += xdl_recs_copy(xe1, i, xe1->xdf2.nrec - i, 0, 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((unsigned char)*(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,
- xdfenv_t *xe2, xdchange_t *xscr2,
- xmparam_t const *xmp, mmbuffer_t *result)
-{
- xdmerge_t *changes, *c;
- xpparam_t const *xpp = &xmp->xpp;
- const char *const ancestor_name = xmp->ancestor;
- const char *const name1 = xmp->file1;
- const char *const name2 = xmp->file2;
- int i0, i1, i2, chg0, chg1, chg2;
- int level = xmp->level;
- int style = xmp->style;
- int favor = xmp->favor;
-
- if (style == XDL_MERGE_DIFF3) {
- /*
- * "diff3 -m" output does not make sense for anything
- * more aggressive than XDL_MERGE_EAGER.
- */
- if (XDL_MERGE_EAGER < level)
- level = XDL_MERGE_EAGER;
- }
-
- c = changes = NULL;
-
- while (xscr1 && xscr2) {
- if (!changes)
- changes = c;
- if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
- i0 = xscr1->i1;
- i1 = xscr1->i2;
- i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
- chg0 = xscr1->chg1;
- chg1 = xscr1->chg2;
- chg2 = xscr1->chg1;
- if (xdl_append_merge(&c, 1,
- i0, chg0, i1, chg1, i2, chg2)) {
- xdl_cleanup_merge(changes);
- return -1;
- }
- xscr1 = xscr1->next;
- continue;
- }
- if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
- i0 = xscr2->i1;
- i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
- i2 = xscr2->i2;
- chg0 = xscr2->chg1;
- chg1 = xscr2->chg1;
- chg2 = xscr2->chg2;
- if (xdl_append_merge(&c, 2,
- i0, chg0, i1, chg1, i2, chg2)) {
- xdl_cleanup_merge(changes);
- return -1;
- }
- xscr2 = xscr2->next;
- continue;
- }
- if (level == XDL_MERGE_MINIMAL || 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;
-
- i0 = xscr1->i1;
- i1 = xscr1->i2;
- i2 = xscr2->i2;
- if (off > 0) {
- i0 -= off;
- i1 -= off;
- }
- else
- i2 += off;
- chg0 = xscr1->i1 + xscr1->chg1 - i0;
- chg1 = xscr1->i2 + xscr1->chg2 - i1;
- chg2 = xscr2->i2 + xscr2->chg2 - i2;
- if (ffo < 0) {
- chg0 -= ffo;
- chg1 -= ffo;
- } else
- chg2 += ffo;
- if (xdl_append_merge(&c, 0,
- i0, chg0, 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;
- i0 = xscr1->i1;
- i1 = xscr1->i2;
- i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
- chg0 = xscr1->chg1;
- chg1 = xscr1->chg2;
- chg2 = xscr1->chg1;
- if (xdl_append_merge(&c, 1,
- i0, chg0, i1, chg1, i2, chg2)) {
- xdl_cleanup_merge(changes);
- return -1;
- }
- xscr1 = xscr1->next;
- }
- while (xscr2) {
- if (!changes)
- changes = c;
- i0 = xscr2->i1;
- i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
- i2 = xscr2->i2;
- chg0 = xscr2->chg1;
- chg1 = xscr2->chg1;
- chg2 = xscr2->chg2;
- if (xdl_append_merge(&c, 2,
- i0, chg0, i1, chg1, i2, chg2)) {
- xdl_cleanup_merge(changes);
- return -1;
- }
- xscr2 = xscr2->next;
- }
- if (!changes)
- changes = c;
- /* refine conflicts */
- if (XDL_MERGE_ZEALOUS <= level &&
- (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
- xdl_simplify_non_conflicts(xe1, changes,
- XDL_MERGE_ZEALOUS < level) < 0)) {
- xdl_cleanup_merge(changes);
- return -1;
- }
- /* output */
- if (result) {
- int marker_size = xmp->marker_size;
- int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
- ancestor_name,
- favor, changes, NULL, style,
- marker_size);
- 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,
- ancestor_name, favor, changes,
- result->ptr, style, marker_size);
- }
- return xdl_cleanup_merge(changes);
-}
-
-int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
- xmparam_t const *xmp, mmbuffer_t *result)
-{
- xdchange_t *xscr1, *xscr2;
- xdfenv_t xe1, xe2;
- int status;
- xpparam_t const *xpp = &xmp->xpp;
-
- result->ptr = NULL;
- result->size = 0;
-
- if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0) {
- return -1;
- }
- if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
- xdl_free_env(&xe1);
- 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_script(xscr1);
- xdl_free_env(&xe1);
- xdl_free_env(&xe2);
- return -1;
- }
- status = 0;
- 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,
- &xe2, xscr2,
- xmp, result);
- }
- xdl_free_script(xscr1);
- xdl_free_script(xscr2);
-
- xdl_free_env(&xe1);
- xdl_free_env(&xe2);
-
- return status;
-}