/* * 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. * 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 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 (dest) dest[size] = '\n'; size++; } } return size; } static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest) { return xdl_recs_copy_0(0, xe, i, count, add_nl, dest); } static int xdl_orig_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest) { return xdl_recs_copy_0(1, xe, i, count, add_nl, dest); } 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); if (marker_size <= 0) marker_size = DEFAULT_CONFLICT_MARKER_SIZE; /* Before conflicting part */ size += xdl_recs_copy(xe1, i, m->i1 - i, 0, dest ? dest + size : NULL); if (!dest) { size += marker_size + 1 + 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; } dest[size++] = '\n'; } /* Postimage from side #1 */ size += xdl_recs_copy(xe1, m->i1, m->chg1, 1, dest ? dest + size : NULL); if (style == XDL_MERGE_DIFF3) { /* Shared preimage */ if (!dest) { size += marker_size + 1 + 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; } dest[size++] = '\n'; } size += xdl_orig_copy(xe1, m->i0, m->chg0, 1, dest ? dest + size : NULL); } if (!dest) { size += marker_size + 1; } else { memset(dest + size, '=', marker_size); size += marker_size; dest[size++] = '\n'; } /* Postimage from side #2 */ size += xdl_recs_copy(xe2, m->i2, m->chg2, 1, dest ? dest + size : NULL); if (!dest) { size += marker_size + 1 + 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; } 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, dest ? dest + size : NULL); /* Postimage from side #1 */ if (m->mode & 1) size += xdl_recs_copy(xe1, m->i1, m->chg1, 1, dest ? dest + size : NULL); /* Postimage from side #2 */ if (m->mode & 2) size += xdl_recs_copy(xe2, m->i2, m->chg2, 1, dest ? dest + size : NULL); } else continue; i = m->i1 + m->chg1; } size += xdl_recs_copy(xe1, i, xe1->xdf2.nrec - i, 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, 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 || 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) { 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; }