Code

a6c143251c8cd7da84400b960cb153b6f24c2ae6
[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "delta.h"
9 #include "xdiff-interface.h"
10 #include "color.h"
11 #include "attr.h"
12 #include "run-command.h"
13 #include "utf8.h"
15 #ifdef NO_FAST_WORKING_DIRECTORY
16 #define FAST_WORKING_DIRECTORY 0
17 #else
18 #define FAST_WORKING_DIRECTORY 1
19 #endif
21 static int diff_detect_rename_default;
22 static int diff_rename_limit_default = 200;
23 int diff_use_color_default = -1;
24 static const char *external_diff_cmd_cfg;
25 int diff_auto_refresh_index = 1;
27 static char diff_colors[][COLOR_MAXLEN] = {
28         "\033[m",       /* reset */
29         "",             /* PLAIN (normal) */
30         "\033[1m",      /* METAINFO (bold) */
31         "\033[36m",     /* FRAGINFO (cyan) */
32         "\033[31m",     /* OLD (red) */
33         "\033[32m",     /* NEW (green) */
34         "\033[33m",     /* COMMIT (yellow) */
35         "\033[41m",     /* WHITESPACE (red background) */
36 };
38 static int parse_diff_color_slot(const char *var, int ofs)
39 {
40         if (!strcasecmp(var+ofs, "plain"))
41                 return DIFF_PLAIN;
42         if (!strcasecmp(var+ofs, "meta"))
43                 return DIFF_METAINFO;
44         if (!strcasecmp(var+ofs, "frag"))
45                 return DIFF_FRAGINFO;
46         if (!strcasecmp(var+ofs, "old"))
47                 return DIFF_FILE_OLD;
48         if (!strcasecmp(var+ofs, "new"))
49                 return DIFF_FILE_NEW;
50         if (!strcasecmp(var+ofs, "commit"))
51                 return DIFF_COMMIT;
52         if (!strcasecmp(var+ofs, "whitespace"))
53                 return DIFF_WHITESPACE;
54         die("bad config variable '%s'", var);
55 }
57 static struct ll_diff_driver {
58         const char *name;
59         struct ll_diff_driver *next;
60         const char *cmd;
61 } *user_diff, **user_diff_tail;
63 /*
64  * Currently there is only "diff.<drivername>.command" variable;
65  * because there are "diff.color.<slot>" variables, we are parsing
66  * this in a bit convoluted way to allow low level diff driver
67  * called "color".
68  */
69 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
70 {
71         const char *name;
72         int namelen;
73         struct ll_diff_driver *drv;
75         name = var + 5;
76         namelen = ep - name;
77         for (drv = user_diff; drv; drv = drv->next)
78                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
79                         break;
80         if (!drv) {
81                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
82                 drv->name = xmemdupz(name, namelen);
83                 if (!user_diff_tail)
84                         user_diff_tail = &user_diff;
85                 *user_diff_tail = drv;
86                 user_diff_tail = &(drv->next);
87         }
89         return git_config_string(&(drv->cmd), var, value);
90 }
92 /*
93  * 'diff.<what>.funcname' attribute can be specified in the configuration
94  * to define a customized regexp to find the beginning of a function to
95  * be used for hunk header lines of "diff -p" style output.
96  */
97 static struct funcname_pattern {
98         char *name;
99         char *pattern;
100         struct funcname_pattern *next;
101 } *funcname_pattern_list;
103 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
105         const char *name;
106         int namelen;
107         struct funcname_pattern *pp;
109         name = var + 5; /* "diff." */
110         namelen = ep - name;
112         for (pp = funcname_pattern_list; pp; pp = pp->next)
113                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
114                         break;
115         if (!pp) {
116                 pp = xcalloc(1, sizeof(*pp));
117                 pp->name = xmemdupz(name, namelen);
118                 pp->next = funcname_pattern_list;
119                 funcname_pattern_list = pp;
120         }
121         free(pp->pattern);
122         pp->pattern = xstrdup(value);
123         return 0;
126 /*
127  * These are to give UI layer defaults.
128  * The core-level commands such as git-diff-files should
129  * never be affected by the setting of diff.renames
130  * the user happens to have in the configuration file.
131  */
132 int git_diff_ui_config(const char *var, const char *value, void *cb)
134         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
135                 diff_use_color_default = git_config_colorbool(var, value, -1);
136                 return 0;
137         }
138         if (!strcmp(var, "diff.renames")) {
139                 if (!value)
140                         diff_detect_rename_default = DIFF_DETECT_RENAME;
141                 else if (!strcasecmp(value, "copies") ||
142                          !strcasecmp(value, "copy"))
143                         diff_detect_rename_default = DIFF_DETECT_COPY;
144                 else if (git_config_bool(var,value))
145                         diff_detect_rename_default = DIFF_DETECT_RENAME;
146                 return 0;
147         }
148         if (!strcmp(var, "diff.autorefreshindex")) {
149                 diff_auto_refresh_index = git_config_bool(var, value);
150                 return 0;
151         }
152         if (!strcmp(var, "diff.external"))
153                 return git_config_string(&external_diff_cmd_cfg, var, value);
154         if (!prefixcmp(var, "diff.")) {
155                 const char *ep = strrchr(var, '.');
157                 if (ep != var + 4 && !strcmp(ep, ".command"))
158                         return parse_lldiff_command(var, ep, value);
159         }
161         return git_diff_basic_config(var, value, cb);
164 int git_diff_basic_config(const char *var, const char *value, void *cb)
166         if (!strcmp(var, "diff.renamelimit")) {
167                 diff_rename_limit_default = git_config_int(var, value);
168                 return 0;
169         }
171         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
172                 int slot = parse_diff_color_slot(var, 11);
173                 if (!value)
174                         return config_error_nonbool(var);
175                 color_parse(value, var, diff_colors[slot]);
176                 return 0;
177         }
179         if (!prefixcmp(var, "diff.")) {
180                 const char *ep = strrchr(var, '.');
181                 if (ep != var + 4) {
182                         if (!strcmp(ep, ".funcname")) {
183                                 if (!value)
184                                         return config_error_nonbool(var);
185                                 return parse_funcname_pattern(var, ep, value);
186                         }
187                 }
188         }
190         return git_color_default_config(var, value, cb);
193 static char *quote_two(const char *one, const char *two)
195         int need_one = quote_c_style(one, NULL, NULL, 1);
196         int need_two = quote_c_style(two, NULL, NULL, 1);
197         struct strbuf res;
199         strbuf_init(&res, 0);
200         if (need_one + need_two) {
201                 strbuf_addch(&res, '"');
202                 quote_c_style(one, &res, NULL, 1);
203                 quote_c_style(two, &res, NULL, 1);
204                 strbuf_addch(&res, '"');
205         } else {
206                 strbuf_addstr(&res, one);
207                 strbuf_addstr(&res, two);
208         }
209         return strbuf_detach(&res, NULL);
212 static const char *external_diff(void)
214         static const char *external_diff_cmd = NULL;
215         static int done_preparing = 0;
217         if (done_preparing)
218                 return external_diff_cmd;
219         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
220         if (!external_diff_cmd)
221                 external_diff_cmd = external_diff_cmd_cfg;
222         done_preparing = 1;
223         return external_diff_cmd;
226 static struct diff_tempfile {
227         const char *name; /* filename external diff should read from */
228         char hex[41];
229         char mode[10];
230         char tmp_path[PATH_MAX];
231 } diff_temp[2];
233 static int count_lines(const char *data, int size)
235         int count, ch, completely_empty = 1, nl_just_seen = 0;
236         count = 0;
237         while (0 < size--) {
238                 ch = *data++;
239                 if (ch == '\n') {
240                         count++;
241                         nl_just_seen = 1;
242                         completely_empty = 0;
243                 }
244                 else {
245                         nl_just_seen = 0;
246                         completely_empty = 0;
247                 }
248         }
249         if (completely_empty)
250                 return 0;
251         if (!nl_just_seen)
252                 count++; /* no trailing newline */
253         return count;
256 static void print_line_count(FILE *file, int count)
258         switch (count) {
259         case 0:
260                 fprintf(file, "0,0");
261                 break;
262         case 1:
263                 fprintf(file, "1");
264                 break;
265         default:
266                 fprintf(file, "1,%d", count);
267                 break;
268         }
271 static void copy_file_with_prefix(FILE *file,
272                                   int prefix, const char *data, int size,
273                                   const char *set, const char *reset)
275         int ch, nl_just_seen = 1;
276         while (0 < size--) {
277                 ch = *data++;
278                 if (nl_just_seen) {
279                         fputs(set, file);
280                         putc(prefix, file);
281                 }
282                 if (ch == '\n') {
283                         nl_just_seen = 1;
284                         fputs(reset, file);
285                 } else
286                         nl_just_seen = 0;
287                 putc(ch, file);
288         }
289         if (!nl_just_seen)
290                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
293 static void emit_rewrite_diff(const char *name_a,
294                               const char *name_b,
295                               struct diff_filespec *one,
296                               struct diff_filespec *two,
297                               struct diff_options *o)
299         int lc_a, lc_b;
300         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
301         const char *name_a_tab, *name_b_tab;
302         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
303         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
304         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
305         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
306         const char *reset = diff_get_color(color_diff, DIFF_RESET);
307         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
309         name_a += (*name_a == '/');
310         name_b += (*name_b == '/');
311         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
312         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
314         strbuf_reset(&a_name);
315         strbuf_reset(&b_name);
316         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
317         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
319         diff_populate_filespec(one, 0);
320         diff_populate_filespec(two, 0);
321         lc_a = count_lines(one->data, one->size);
322         lc_b = count_lines(two->data, two->size);
323         fprintf(o->file,
324                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
325                 metainfo, a_name.buf, name_a_tab, reset,
326                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
327         print_line_count(o->file, lc_a);
328         fprintf(o->file, " +");
329         print_line_count(o->file, lc_b);
330         fprintf(o->file, " @@%s\n", reset);
331         if (lc_a)
332                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
333         if (lc_b)
334                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
337 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
339         if (!DIFF_FILE_VALID(one)) {
340                 mf->ptr = (char *)""; /* does not matter */
341                 mf->size = 0;
342                 return 0;
343         }
344         else if (diff_populate_filespec(one, 0))
345                 return -1;
346         mf->ptr = one->data;
347         mf->size = one->size;
348         return 0;
351 struct diff_words_buffer {
352         mmfile_t text;
353         long alloc;
354         long current; /* output pointer */
355         int suppressed_newline;
356 };
358 static void diff_words_append(char *line, unsigned long len,
359                 struct diff_words_buffer *buffer)
361         if (buffer->text.size + len > buffer->alloc) {
362                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
363                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
364         }
365         line++;
366         len--;
367         memcpy(buffer->text.ptr + buffer->text.size, line, len);
368         buffer->text.size += len;
371 struct diff_words_data {
372         struct diff_words_buffer minus, plus;
373         FILE *file;
374 };
376 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
377                 int suppress_newline)
379         const char *ptr;
380         int eol = 0;
382         if (len == 0)
383                 return;
385         ptr  = buffer->text.ptr + buffer->current;
386         buffer->current += len;
388         if (ptr[len - 1] == '\n') {
389                 eol = 1;
390                 len--;
391         }
393         fputs(diff_get_color(1, color), file);
394         fwrite(ptr, len, 1, file);
395         fputs(diff_get_color(1, DIFF_RESET), file);
397         if (eol) {
398                 if (suppress_newline)
399                         buffer->suppressed_newline = 1;
400                 else
401                         putc('\n', file);
402         }
405 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
407         struct diff_words_data *diff_words = priv;
409         if (diff_words->minus.suppressed_newline) {
410                 if (line[0] != '+')
411                         putc('\n', diff_words->file);
412                 diff_words->minus.suppressed_newline = 0;
413         }
415         len--;
416         switch (line[0]) {
417                 case '-':
418                         print_word(diff_words->file,
419                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
420                         break;
421                 case '+':
422                         print_word(diff_words->file,
423                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
424                         break;
425                 case ' ':
426                         print_word(diff_words->file,
427                                    &diff_words->plus, len, DIFF_PLAIN, 0);
428                         diff_words->minus.current += len;
429                         break;
430         }
433 /* this executes the word diff on the accumulated buffers */
434 static void diff_words_show(struct diff_words_data *diff_words)
436         xpparam_t xpp;
437         xdemitconf_t xecfg;
438         xdemitcb_t ecb;
439         mmfile_t minus, plus;
440         int i;
442         memset(&xecfg, 0, sizeof(xecfg));
443         minus.size = diff_words->minus.text.size;
444         minus.ptr = xmalloc(minus.size);
445         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
446         for (i = 0; i < minus.size; i++)
447                 if (isspace(minus.ptr[i]))
448                         minus.ptr[i] = '\n';
449         diff_words->minus.current = 0;
451         plus.size = diff_words->plus.text.size;
452         plus.ptr = xmalloc(plus.size);
453         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
454         for (i = 0; i < plus.size; i++)
455                 if (isspace(plus.ptr[i]))
456                         plus.ptr[i] = '\n';
457         diff_words->plus.current = 0;
459         xpp.flags = XDF_NEED_MINIMAL;
460         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
461         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
462                       &xpp, &xecfg, &ecb);
463         free(minus.ptr);
464         free(plus.ptr);
465         diff_words->minus.text.size = diff_words->plus.text.size = 0;
467         if (diff_words->minus.suppressed_newline) {
468                 putc('\n', diff_words->file);
469                 diff_words->minus.suppressed_newline = 0;
470         }
473 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
475 struct emit_callback {
476         int nparents, color_diff;
477         unsigned ws_rule;
478         sane_truncate_fn truncate;
479         const char **label_path;
480         struct diff_words_data *diff_words;
481         int *found_changesp;
482         FILE *file;
483 };
485 static void free_diff_words_data(struct emit_callback *ecbdata)
487         if (ecbdata->diff_words) {
488                 /* flush buffers */
489                 if (ecbdata->diff_words->minus.text.size ||
490                                 ecbdata->diff_words->plus.text.size)
491                         diff_words_show(ecbdata->diff_words);
493                 free (ecbdata->diff_words->minus.text.ptr);
494                 free (ecbdata->diff_words->plus.text.ptr);
495                 free(ecbdata->diff_words);
496                 ecbdata->diff_words = NULL;
497         }
500 const char *diff_get_color(int diff_use_color, enum color_diff ix)
502         if (diff_use_color)
503                 return diff_colors[ix];
504         return "";
507 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
509         int has_trailing_newline = (len > 0 && line[len-1] == '\n');
510         if (has_trailing_newline)
511                 len--;
513         fputs(set, file);
514         fwrite(line, len, 1, file);
515         fputs(reset, file);
516         if (has_trailing_newline)
517                 fputc('\n', file);
520 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
522         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
523         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
525         if (!*ws)
526                 emit_line(ecbdata->file, set, reset, line, len);
527         else {
528                 /* Emit just the prefix, then the rest. */
529                 emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
530                 ws_check_emit(line + ecbdata->nparents,
531                               len - ecbdata->nparents, ecbdata->ws_rule,
532                               ecbdata->file, set, reset, ws);
533         }
536 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
538         const char *cp;
539         unsigned long allot;
540         size_t l = len;
542         if (ecb->truncate)
543                 return ecb->truncate(line, len);
544         cp = line;
545         allot = l;
546         while (0 < l) {
547                 (void) utf8_width(&cp, &l);
548                 if (!cp)
549                         break; /* truncated in the middle? */
550         }
551         return allot - l;
554 static void fn_out_consume(void *priv, char *line, unsigned long len)
556         int i;
557         int color;
558         struct emit_callback *ecbdata = priv;
559         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
560         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
561         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
563         *(ecbdata->found_changesp) = 1;
565         if (ecbdata->label_path[0]) {
566                 const char *name_a_tab, *name_b_tab;
568                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
569                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
571                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
572                         meta, ecbdata->label_path[0], reset, name_a_tab);
573                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
574                         meta, ecbdata->label_path[1], reset, name_b_tab);
575                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
576         }
578         /* This is not really necessary for now because
579          * this codepath only deals with two-way diffs.
580          */
581         for (i = 0; i < len && line[i] == '@'; i++)
582                 ;
583         if (2 <= i && i < len && line[i] == ' ') {
584                 ecbdata->nparents = i - 1;
585                 len = sane_truncate_line(ecbdata, line, len);
586                 emit_line(ecbdata->file,
587                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
588                           reset, line, len);
589                 if (line[len-1] != '\n')
590                         putc('\n', ecbdata->file);
591                 return;
592         }
594         if (len < ecbdata->nparents) {
595                 emit_line(ecbdata->file, reset, reset, line, len);
596                 return;
597         }
599         color = DIFF_PLAIN;
600         if (ecbdata->diff_words && ecbdata->nparents != 1)
601                 /* fall back to normal diff */
602                 free_diff_words_data(ecbdata);
603         if (ecbdata->diff_words) {
604                 if (line[0] == '-') {
605                         diff_words_append(line, len,
606                                           &ecbdata->diff_words->minus);
607                         return;
608                 } else if (line[0] == '+') {
609                         diff_words_append(line, len,
610                                           &ecbdata->diff_words->plus);
611                         return;
612                 }
613                 if (ecbdata->diff_words->minus.text.size ||
614                     ecbdata->diff_words->plus.text.size)
615                         diff_words_show(ecbdata->diff_words);
616                 line++;
617                 len--;
618                 emit_line(ecbdata->file, plain, reset, line, len);
619                 return;
620         }
621         for (i = 0; i < ecbdata->nparents && len; i++) {
622                 if (line[i] == '-')
623                         color = DIFF_FILE_OLD;
624                 else if (line[i] == '+')
625                         color = DIFF_FILE_NEW;
626         }
628         if (color != DIFF_FILE_NEW) {
629                 emit_line(ecbdata->file,
630                           diff_get_color(ecbdata->color_diff, color),
631                           reset, line, len);
632                 return;
633         }
634         emit_add_line(reset, ecbdata, line, len);
637 static char *pprint_rename(const char *a, const char *b)
639         const char *old = a;
640         const char *new = b;
641         struct strbuf name;
642         int pfx_length, sfx_length;
643         int len_a = strlen(a);
644         int len_b = strlen(b);
645         int a_midlen, b_midlen;
646         int qlen_a = quote_c_style(a, NULL, NULL, 0);
647         int qlen_b = quote_c_style(b, NULL, NULL, 0);
649         strbuf_init(&name, 0);
650         if (qlen_a || qlen_b) {
651                 quote_c_style(a, &name, NULL, 0);
652                 strbuf_addstr(&name, " => ");
653                 quote_c_style(b, &name, NULL, 0);
654                 return strbuf_detach(&name, NULL);
655         }
657         /* Find common prefix */
658         pfx_length = 0;
659         while (*old && *new && *old == *new) {
660                 if (*old == '/')
661                         pfx_length = old - a + 1;
662                 old++;
663                 new++;
664         }
666         /* Find common suffix */
667         old = a + len_a;
668         new = b + len_b;
669         sfx_length = 0;
670         while (a <= old && b <= new && *old == *new) {
671                 if (*old == '/')
672                         sfx_length = len_a - (old - a);
673                 old--;
674                 new--;
675         }
677         /*
678          * pfx{mid-a => mid-b}sfx
679          * {pfx-a => pfx-b}sfx
680          * pfx{sfx-a => sfx-b}
681          * name-a => name-b
682          */
683         a_midlen = len_a - pfx_length - sfx_length;
684         b_midlen = len_b - pfx_length - sfx_length;
685         if (a_midlen < 0)
686                 a_midlen = 0;
687         if (b_midlen < 0)
688                 b_midlen = 0;
690         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
691         if (pfx_length + sfx_length) {
692                 strbuf_add(&name, a, pfx_length);
693                 strbuf_addch(&name, '{');
694         }
695         strbuf_add(&name, a + pfx_length, a_midlen);
696         strbuf_addstr(&name, " => ");
697         strbuf_add(&name, b + pfx_length, b_midlen);
698         if (pfx_length + sfx_length) {
699                 strbuf_addch(&name, '}');
700                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
701         }
702         return strbuf_detach(&name, NULL);
705 struct diffstat_t {
706         int nr;
707         int alloc;
708         struct diffstat_file {
709                 char *from_name;
710                 char *name;
711                 char *print_name;
712                 unsigned is_unmerged:1;
713                 unsigned is_binary:1;
714                 unsigned is_renamed:1;
715                 unsigned int added, deleted;
716         } **files;
717 };
719 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
720                                           const char *name_a,
721                                           const char *name_b)
723         struct diffstat_file *x;
724         x = xcalloc(sizeof (*x), 1);
725         if (diffstat->nr == diffstat->alloc) {
726                 diffstat->alloc = alloc_nr(diffstat->alloc);
727                 diffstat->files = xrealloc(diffstat->files,
728                                 diffstat->alloc * sizeof(x));
729         }
730         diffstat->files[diffstat->nr++] = x;
731         if (name_b) {
732                 x->from_name = xstrdup(name_a);
733                 x->name = xstrdup(name_b);
734                 x->is_renamed = 1;
735         }
736         else {
737                 x->from_name = NULL;
738                 x->name = xstrdup(name_a);
739         }
740         return x;
743 static void diffstat_consume(void *priv, char *line, unsigned long len)
745         struct diffstat_t *diffstat = priv;
746         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
748         if (line[0] == '+')
749                 x->added++;
750         else if (line[0] == '-')
751                 x->deleted++;
754 const char mime_boundary_leader[] = "------------";
756 static int scale_linear(int it, int width, int max_change)
758         /*
759          * make sure that at least one '-' is printed if there were deletions,
760          * and likewise for '+'.
761          */
762         if (max_change < 2)
763                 return it;
764         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
767 static void show_name(FILE *file,
768                       const char *prefix, const char *name, int len,
769                       const char *reset, const char *set)
771         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
774 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
776         if (cnt <= 0)
777                 return;
778         fprintf(file, "%s", set);
779         while (cnt--)
780                 putc(ch, file);
781         fprintf(file, "%s", reset);
784 static void fill_print_name(struct diffstat_file *file)
786         char *pname;
788         if (file->print_name)
789                 return;
791         if (!file->is_renamed) {
792                 struct strbuf buf;
793                 strbuf_init(&buf, 0);
794                 if (quote_c_style(file->name, &buf, NULL, 0)) {
795                         pname = strbuf_detach(&buf, NULL);
796                 } else {
797                         pname = file->name;
798                         strbuf_release(&buf);
799                 }
800         } else {
801                 pname = pprint_rename(file->from_name, file->name);
802         }
803         file->print_name = pname;
806 static void show_stats(struct diffstat_t* data, struct diff_options *options)
808         int i, len, add, del, total, adds = 0, dels = 0;
809         int max_change = 0, max_len = 0;
810         int total_files = data->nr;
811         int width, name_width;
812         const char *reset, *set, *add_c, *del_c;
814         if (data->nr == 0)
815                 return;
817         width = options->stat_width ? options->stat_width : 80;
818         name_width = options->stat_name_width ? options->stat_name_width : 50;
820         /* Sanity: give at least 5 columns to the graph,
821          * but leave at least 10 columns for the name.
822          */
823         if (width < 25)
824                 width = 25;
825         if (name_width < 10)
826                 name_width = 10;
827         else if (width < name_width + 15)
828                 name_width = width - 15;
830         /* Find the longest filename and max number of changes */
831         reset = diff_get_color_opt(options, DIFF_RESET);
832         set   = diff_get_color_opt(options, DIFF_PLAIN);
833         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
834         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
836         for (i = 0; i < data->nr; i++) {
837                 struct diffstat_file *file = data->files[i];
838                 int change = file->added + file->deleted;
839                 fill_print_name(file);
840                 len = strlen(file->print_name);
841                 if (max_len < len)
842                         max_len = len;
844                 if (file->is_binary || file->is_unmerged)
845                         continue;
846                 if (max_change < change)
847                         max_change = change;
848         }
850         /* Compute the width of the graph part;
851          * 10 is for one blank at the beginning of the line plus
852          * " | count " between the name and the graph.
853          *
854          * From here on, name_width is the width of the name area,
855          * and width is the width of the graph area.
856          */
857         name_width = (name_width < max_len) ? name_width : max_len;
858         if (width < (name_width + 10) + max_change)
859                 width = width - (name_width + 10);
860         else
861                 width = max_change;
863         for (i = 0; i < data->nr; i++) {
864                 const char *prefix = "";
865                 char *name = data->files[i]->print_name;
866                 int added = data->files[i]->added;
867                 int deleted = data->files[i]->deleted;
868                 int name_len;
870                 /*
871                  * "scale" the filename
872                  */
873                 len = name_width;
874                 name_len = strlen(name);
875                 if (name_width < name_len) {
876                         char *slash;
877                         prefix = "...";
878                         len -= 3;
879                         name += name_len - len;
880                         slash = strchr(name, '/');
881                         if (slash)
882                                 name = slash;
883                 }
885                 if (data->files[i]->is_binary) {
886                         show_name(options->file, prefix, name, len, reset, set);
887                         fprintf(options->file, "  Bin ");
888                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
889                         fprintf(options->file, " -> ");
890                         fprintf(options->file, "%s%d%s", add_c, added, reset);
891                         fprintf(options->file, " bytes");
892                         fprintf(options->file, "\n");
893                         continue;
894                 }
895                 else if (data->files[i]->is_unmerged) {
896                         show_name(options->file, prefix, name, len, reset, set);
897                         fprintf(options->file, "  Unmerged\n");
898                         continue;
899                 }
900                 else if (!data->files[i]->is_renamed &&
901                          (added + deleted == 0)) {
902                         total_files--;
903                         continue;
904                 }
906                 /*
907                  * scale the add/delete
908                  */
909                 add = added;
910                 del = deleted;
911                 total = add + del;
912                 adds += add;
913                 dels += del;
915                 if (width <= max_change) {
916                         add = scale_linear(add, width, max_change);
917                         del = scale_linear(del, width, max_change);
918                         total = add + del;
919                 }
920                 show_name(options->file, prefix, name, len, reset, set);
921                 fprintf(options->file, "%5d%s", added + deleted,
922                                 added + deleted ? " " : "");
923                 show_graph(options->file, '+', add, add_c, reset);
924                 show_graph(options->file, '-', del, del_c, reset);
925                 fprintf(options->file, "\n");
926         }
927         fprintf(options->file,
928                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
929                set, total_files, adds, dels, reset);
932 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
934         int i, adds = 0, dels = 0, total_files = data->nr;
936         if (data->nr == 0)
937                 return;
939         for (i = 0; i < data->nr; i++) {
940                 if (!data->files[i]->is_binary &&
941                     !data->files[i]->is_unmerged) {
942                         int added = data->files[i]->added;
943                         int deleted= data->files[i]->deleted;
944                         if (!data->files[i]->is_renamed &&
945                             (added + deleted == 0)) {
946                                 total_files--;
947                         } else {
948                                 adds += added;
949                                 dels += deleted;
950                         }
951                 }
952         }
953         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
954                total_files, adds, dels);
957 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
959         int i;
961         if (data->nr == 0)
962                 return;
964         for (i = 0; i < data->nr; i++) {
965                 struct diffstat_file *file = data->files[i];
967                 if (file->is_binary)
968                         fprintf(options->file, "-\t-\t");
969                 else
970                         fprintf(options->file,
971                                 "%d\t%d\t", file->added, file->deleted);
972                 if (options->line_termination) {
973                         fill_print_name(file);
974                         if (!file->is_renamed)
975                                 write_name_quoted(file->name, options->file,
976                                                   options->line_termination);
977                         else {
978                                 fputs(file->print_name, options->file);
979                                 putc(options->line_termination, options->file);
980                         }
981                 } else {
982                         if (file->is_renamed) {
983                                 putc('\0', options->file);
984                                 write_name_quoted(file->from_name, options->file, '\0');
985                         }
986                         write_name_quoted(file->name, options->file, '\0');
987                 }
988         }
991 struct dirstat_file {
992         const char *name;
993         unsigned long changed;
994 };
996 struct dirstat_dir {
997         struct dirstat_file *files;
998         int alloc, nr, percent, cumulative;
999 };
1001 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1003         unsigned long this_dir = 0;
1004         unsigned int sources = 0;
1006         while (dir->nr) {
1007                 struct dirstat_file *f = dir->files;
1008                 int namelen = strlen(f->name);
1009                 unsigned long this;
1010                 char *slash;
1012                 if (namelen < baselen)
1013                         break;
1014                 if (memcmp(f->name, base, baselen))
1015                         break;
1016                 slash = strchr(f->name + baselen, '/');
1017                 if (slash) {
1018                         int newbaselen = slash + 1 - f->name;
1019                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1020                         sources++;
1021                 } else {
1022                         this = f->changed;
1023                         dir->files++;
1024                         dir->nr--;
1025                         sources += 2;
1026                 }
1027                 this_dir += this;
1028         }
1030         /*
1031          * We don't report dirstat's for
1032          *  - the top level
1033          *  - or cases where everything came from a single directory
1034          *    under this directory (sources == 1).
1035          */
1036         if (baselen && sources != 1) {
1037                 int permille = this_dir * 1000 / changed;
1038                 if (permille) {
1039                         int percent = permille / 10;
1040                         if (percent >= dir->percent) {
1041                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1042                                 if (!dir->cumulative)
1043                                         return 0;
1044                         }
1045                 }
1046         }
1047         return this_dir;
1050 static void show_dirstat(struct diff_options *options)
1052         int i;
1053         unsigned long changed;
1054         struct dirstat_dir dir;
1055         struct diff_queue_struct *q = &diff_queued_diff;
1057         dir.files = NULL;
1058         dir.alloc = 0;
1059         dir.nr = 0;
1060         dir.percent = options->dirstat_percent;
1061         dir.cumulative = options->output_format & DIFF_FORMAT_CUMULATIVE;
1063         changed = 0;
1064         for (i = 0; i < q->nr; i++) {
1065                 struct diff_filepair *p = q->queue[i];
1066                 const char *name;
1067                 unsigned long copied, added, damage;
1069                 name = p->one->path ? p->one->path : p->two->path;
1071                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1072                         diff_populate_filespec(p->one, 0);
1073                         diff_populate_filespec(p->two, 0);
1074                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1075                                                &copied, &added);
1076                         diff_free_filespec_data(p->one);
1077                         diff_free_filespec_data(p->two);
1078                 } else if (DIFF_FILE_VALID(p->one)) {
1079                         diff_populate_filespec(p->one, 1);
1080                         copied = added = 0;
1081                         diff_free_filespec_data(p->one);
1082                 } else if (DIFF_FILE_VALID(p->two)) {
1083                         diff_populate_filespec(p->two, 1);
1084                         copied = 0;
1085                         added = p->two->size;
1086                         diff_free_filespec_data(p->two);
1087                 } else
1088                         continue;
1090                 /*
1091                  * Original minus copied is the removed material,
1092                  * added is the new material.  They are both damages
1093                  * made to the preimage.
1094                  */
1095                 damage = (p->one->size - copied) + added;
1097                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1098                 dir.files[dir.nr].name = name;
1099                 dir.files[dir.nr].changed = damage;
1100                 changed += damage;
1101                 dir.nr++;
1102         }
1104         /* This can happen even with many files, if everything was renames */
1105         if (!changed)
1106                 return;
1108         /* Show all directories with more than x% of the changes */
1109         gather_dirstat(options->file, &dir, changed, "", 0);
1112 static void free_diffstat_info(struct diffstat_t *diffstat)
1114         int i;
1115         for (i = 0; i < diffstat->nr; i++) {
1116                 struct diffstat_file *f = diffstat->files[i];
1117                 if (f->name != f->print_name)
1118                         free(f->print_name);
1119                 free(f->name);
1120                 free(f->from_name);
1121                 free(f);
1122         }
1123         free(diffstat->files);
1126 struct checkdiff_t {
1127         const char *filename;
1128         int lineno;
1129         struct diff_options *o;
1130         unsigned ws_rule;
1131         unsigned status;
1132         int trailing_blanks_start;
1133 };
1135 static int is_conflict_marker(const char *line, unsigned long len)
1137         char firstchar;
1138         int cnt;
1140         if (len < 8)
1141                 return 0;
1142         firstchar = line[0];
1143         switch (firstchar) {
1144         case '=': case '>': case '<':
1145                 break;
1146         default:
1147                 return 0;
1148         }
1149         for (cnt = 1; cnt < 7; cnt++)
1150                 if (line[cnt] != firstchar)
1151                         return 0;
1152         /* line[0] thru line[6] are same as firstchar */
1153         if (firstchar == '=') {
1154                 /* divider between ours and theirs? */
1155                 if (len != 8 || line[7] != '\n')
1156                         return 0;
1157         } else if (len < 8 || !isspace(line[7])) {
1158                 /* not divider before ours nor after theirs */
1159                 return 0;
1160         }
1161         return 1;
1164 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1166         struct checkdiff_t *data = priv;
1167         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1168         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1169         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1170         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1171         char *err;
1173         if (line[0] == '+') {
1174                 unsigned bad;
1175                 data->lineno++;
1176                 if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1177                         data->trailing_blanks_start = 0;
1178                 else if (!data->trailing_blanks_start)
1179                         data->trailing_blanks_start = data->lineno;
1180                 if (is_conflict_marker(line + 1, len - 1)) {
1181                         data->status |= 1;
1182                         fprintf(data->o->file,
1183                                 "%s:%d: leftover conflict marker\n",
1184                                 data->filename, data->lineno);
1185                 }
1186                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1187                 if (!bad)
1188                         return;
1189                 data->status |= bad;
1190                 err = whitespace_error_string(bad);
1191                 fprintf(data->o->file, "%s:%d: %s.\n",
1192                         data->filename, data->lineno, err);
1193                 free(err);
1194                 emit_line(data->o->file, set, reset, line, 1);
1195                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1196                               data->o->file, set, reset, ws);
1197         } else if (line[0] == ' ') {
1198                 data->lineno++;
1199                 data->trailing_blanks_start = 0;
1200         } else if (line[0] == '@') {
1201                 char *plus = strchr(line, '+');
1202                 if (plus)
1203                         data->lineno = strtol(plus, NULL, 10) - 1;
1204                 else
1205                         die("invalid diff");
1206                 data->trailing_blanks_start = 0;
1207         }
1210 static unsigned char *deflate_it(char *data,
1211                                  unsigned long size,
1212                                  unsigned long *result_size)
1214         int bound;
1215         unsigned char *deflated;
1216         z_stream stream;
1218         memset(&stream, 0, sizeof(stream));
1219         deflateInit(&stream, zlib_compression_level);
1220         bound = deflateBound(&stream, size);
1221         deflated = xmalloc(bound);
1222         stream.next_out = deflated;
1223         stream.avail_out = bound;
1225         stream.next_in = (unsigned char *)data;
1226         stream.avail_in = size;
1227         while (deflate(&stream, Z_FINISH) == Z_OK)
1228                 ; /* nothing */
1229         deflateEnd(&stream);
1230         *result_size = stream.total_out;
1231         return deflated;
1234 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1236         void *cp;
1237         void *delta;
1238         void *deflated;
1239         void *data;
1240         unsigned long orig_size;
1241         unsigned long delta_size;
1242         unsigned long deflate_size;
1243         unsigned long data_size;
1245         /* We could do deflated delta, or we could do just deflated two,
1246          * whichever is smaller.
1247          */
1248         delta = NULL;
1249         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1250         if (one->size && two->size) {
1251                 delta = diff_delta(one->ptr, one->size,
1252                                    two->ptr, two->size,
1253                                    &delta_size, deflate_size);
1254                 if (delta) {
1255                         void *to_free = delta;
1256                         orig_size = delta_size;
1257                         delta = deflate_it(delta, delta_size, &delta_size);
1258                         free(to_free);
1259                 }
1260         }
1262         if (delta && delta_size < deflate_size) {
1263                 fprintf(file, "delta %lu\n", orig_size);
1264                 free(deflated);
1265                 data = delta;
1266                 data_size = delta_size;
1267         }
1268         else {
1269                 fprintf(file, "literal %lu\n", two->size);
1270                 free(delta);
1271                 data = deflated;
1272                 data_size = deflate_size;
1273         }
1275         /* emit data encoded in base85 */
1276         cp = data;
1277         while (data_size) {
1278                 int bytes = (52 < data_size) ? 52 : data_size;
1279                 char line[70];
1280                 data_size -= bytes;
1281                 if (bytes <= 26)
1282                         line[0] = bytes + 'A' - 1;
1283                 else
1284                         line[0] = bytes - 26 + 'a' - 1;
1285                 encode_85(line + 1, cp, bytes);
1286                 cp = (char *) cp + bytes;
1287                 fputs(line, file);
1288                 fputc('\n', file);
1289         }
1290         fprintf(file, "\n");
1291         free(data);
1294 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1296         fprintf(file, "GIT binary patch\n");
1297         emit_binary_diff_body(file, one, two);
1298         emit_binary_diff_body(file, two, one);
1301 static void setup_diff_attr_check(struct git_attr_check *check)
1303         static struct git_attr *attr_diff;
1305         if (!attr_diff) {
1306                 attr_diff = git_attr("diff", 4);
1307         }
1308         check[0].attr = attr_diff;
1311 static void diff_filespec_check_attr(struct diff_filespec *one)
1313         struct git_attr_check attr_diff_check;
1314         int check_from_data = 0;
1316         if (one->checked_attr)
1317                 return;
1319         setup_diff_attr_check(&attr_diff_check);
1320         one->is_binary = 0;
1321         one->funcname_pattern_ident = NULL;
1323         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1324                 const char *value;
1326                 /* binaryness */
1327                 value = attr_diff_check.value;
1328                 if (ATTR_TRUE(value))
1329                         ;
1330                 else if (ATTR_FALSE(value))
1331                         one->is_binary = 1;
1332                 else
1333                         check_from_data = 1;
1335                 /* funcname pattern ident */
1336                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1337                         ;
1338                 else
1339                         one->funcname_pattern_ident = value;
1340         }
1342         if (check_from_data) {
1343                 if (!one->data && DIFF_FILE_VALID(one))
1344                         diff_populate_filespec(one, 0);
1346                 if (one->data)
1347                         one->is_binary = buffer_is_binary(one->data, one->size);
1348         }
1351 int diff_filespec_is_binary(struct diff_filespec *one)
1353         diff_filespec_check_attr(one);
1354         return one->is_binary;
1357 static const char *funcname_pattern(const char *ident)
1359         struct funcname_pattern *pp;
1361         for (pp = funcname_pattern_list; pp; pp = pp->next)
1362                 if (!strcmp(ident, pp->name))
1363                         return pp->pattern;
1364         return NULL;
1367 static struct builtin_funcname_pattern {
1368         const char *name;
1369         const char *pattern;
1370 } builtin_funcname_pattern[] = {
1371         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1372                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1373                         "^[     ]*\\(\\([       ]*"
1374                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1375                         "[      ]*([^;]*\\)$" },
1376         { "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
1377                         "destructor\\|interface\\|implementation\\|"
1378                         "initialization\\|finalization\\)[ \t]*.*\\)$"
1379                         "\\|"
1380                         "^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
1381                         },
1382         { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
1383         { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
1384         { "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
1385 };
1387 static const char *diff_funcname_pattern(struct diff_filespec *one)
1389         const char *ident, *pattern;
1390         int i;
1392         diff_filespec_check_attr(one);
1393         ident = one->funcname_pattern_ident;
1395         if (!ident)
1396                 /*
1397                  * If the config file has "funcname.default" defined, that
1398                  * regexp is used; otherwise NULL is returned and xemit uses
1399                  * the built-in default.
1400                  */
1401                 return funcname_pattern("default");
1403         /* Look up custom "funcname.$ident" regexp from config. */
1404         pattern = funcname_pattern(ident);
1405         if (pattern)
1406                 return pattern;
1408         /*
1409          * And define built-in fallback patterns here.  Note that
1410          * these can be overridden by the user's config settings.
1411          */
1412         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1413                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1414                         return builtin_funcname_pattern[i].pattern;
1416         return NULL;
1419 static void builtin_diff(const char *name_a,
1420                          const char *name_b,
1421                          struct diff_filespec *one,
1422                          struct diff_filespec *two,
1423                          const char *xfrm_msg,
1424                          struct diff_options *o,
1425                          int complete_rewrite)
1427         mmfile_t mf1, mf2;
1428         const char *lbl[2];
1429         char *a_one, *b_two;
1430         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1431         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1433         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1434         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1435         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1436         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1437         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1438         if (lbl[0][0] == '/') {
1439                 /* /dev/null */
1440                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1441                 if (xfrm_msg && xfrm_msg[0])
1442                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1443         }
1444         else if (lbl[1][0] == '/') {
1445                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1446                 if (xfrm_msg && xfrm_msg[0])
1447                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1448         }
1449         else {
1450                 if (one->mode != two->mode) {
1451                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1452                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1453                 }
1454                 if (xfrm_msg && xfrm_msg[0])
1455                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1456                 /*
1457                  * we do not run diff between different kind
1458                  * of objects.
1459                  */
1460                 if ((one->mode ^ two->mode) & S_IFMT)
1461                         goto free_ab_and_return;
1462                 if (complete_rewrite) {
1463                         emit_rewrite_diff(name_a, name_b, one, two, o);
1464                         o->found_changes = 1;
1465                         goto free_ab_and_return;
1466                 }
1467         }
1469         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1470                 die("unable to read files to diff");
1472         if (!DIFF_OPT_TST(o, TEXT) &&
1473             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1474                 /* Quite common confusing case */
1475                 if (mf1.size == mf2.size &&
1476                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1477                         goto free_ab_and_return;
1478                 if (DIFF_OPT_TST(o, BINARY))
1479                         emit_binary_diff(o->file, &mf1, &mf2);
1480                 else
1481                         fprintf(o->file, "Binary files %s and %s differ\n",
1482                                 lbl[0], lbl[1]);
1483                 o->found_changes = 1;
1484         }
1485         else {
1486                 /* Crazy xdl interfaces.. */
1487                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1488                 xpparam_t xpp;
1489                 xdemitconf_t xecfg;
1490                 xdemitcb_t ecb;
1491                 struct emit_callback ecbdata;
1492                 const char *funcname_pattern;
1494                 funcname_pattern = diff_funcname_pattern(one);
1495                 if (!funcname_pattern)
1496                         funcname_pattern = diff_funcname_pattern(two);
1498                 memset(&xecfg, 0, sizeof(xecfg));
1499                 memset(&ecbdata, 0, sizeof(ecbdata));
1500                 ecbdata.label_path = lbl;
1501                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1502                 ecbdata.found_changesp = &o->found_changes;
1503                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1504                 ecbdata.file = o->file;
1505                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1506                 xecfg.ctxlen = o->context;
1507                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1508                 if (funcname_pattern)
1509                         xdiff_set_find_func(&xecfg, funcname_pattern);
1510                 if (!diffopts)
1511                         ;
1512                 else if (!prefixcmp(diffopts, "--unified="))
1513                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1514                 else if (!prefixcmp(diffopts, "-u"))
1515                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1516                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1517                         ecbdata.diff_words =
1518                                 xcalloc(1, sizeof(struct diff_words_data));
1519                         ecbdata.diff_words->file = o->file;
1520                 }
1521                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1522                               &xpp, &xecfg, &ecb);
1523                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1524                         free_diff_words_data(&ecbdata);
1525         }
1527  free_ab_and_return:
1528         diff_free_filespec_data(one);
1529         diff_free_filespec_data(two);
1530         free(a_one);
1531         free(b_two);
1532         return;
1535 static void builtin_diffstat(const char *name_a, const char *name_b,
1536                              struct diff_filespec *one,
1537                              struct diff_filespec *two,
1538                              struct diffstat_t *diffstat,
1539                              struct diff_options *o,
1540                              int complete_rewrite)
1542         mmfile_t mf1, mf2;
1543         struct diffstat_file *data;
1545         data = diffstat_add(diffstat, name_a, name_b);
1547         if (!one || !two) {
1548                 data->is_unmerged = 1;
1549                 return;
1550         }
1551         if (complete_rewrite) {
1552                 diff_populate_filespec(one, 0);
1553                 diff_populate_filespec(two, 0);
1554                 data->deleted = count_lines(one->data, one->size);
1555                 data->added = count_lines(two->data, two->size);
1556                 goto free_and_return;
1557         }
1558         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1559                 die("unable to read files to diff");
1561         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1562                 data->is_binary = 1;
1563                 data->added = mf2.size;
1564                 data->deleted = mf1.size;
1565         } else {
1566                 /* Crazy xdl interfaces.. */
1567                 xpparam_t xpp;
1568                 xdemitconf_t xecfg;
1569                 xdemitcb_t ecb;
1571                 memset(&xecfg, 0, sizeof(xecfg));
1572                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1573                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1574                               &xpp, &xecfg, &ecb);
1575         }
1577  free_and_return:
1578         diff_free_filespec_data(one);
1579         diff_free_filespec_data(two);
1582 static void builtin_checkdiff(const char *name_a, const char *name_b,
1583                               const char *attr_path,
1584                               struct diff_filespec *one,
1585                               struct diff_filespec *two,
1586                               struct diff_options *o)
1588         mmfile_t mf1, mf2;
1589         struct checkdiff_t data;
1591         if (!two)
1592                 return;
1594         memset(&data, 0, sizeof(data));
1595         data.filename = name_b ? name_b : name_a;
1596         data.lineno = 0;
1597         data.o = o;
1598         data.ws_rule = whitespace_rule(attr_path);
1600         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1601                 die("unable to read files to diff");
1603         /*
1604          * All the other codepaths check both sides, but not checking
1605          * the "old" side here is deliberate.  We are checking the newly
1606          * introduced changes, and as long as the "new" side is text, we
1607          * can and should check what it introduces.
1608          */
1609         if (diff_filespec_is_binary(two))
1610                 goto free_and_return;
1611         else {
1612                 /* Crazy xdl interfaces.. */
1613                 xpparam_t xpp;
1614                 xdemitconf_t xecfg;
1615                 xdemitcb_t ecb;
1617                 memset(&xecfg, 0, sizeof(xecfg));
1618                 xpp.flags = XDF_NEED_MINIMAL;
1619                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1620                               &xpp, &xecfg, &ecb);
1622                 if ((data.ws_rule & WS_TRAILING_SPACE) &&
1623                     data.trailing_blanks_start) {
1624                         fprintf(o->file, "%s:%d: ends with blank lines.\n",
1625                                 data.filename, data.trailing_blanks_start);
1626                         data.status = 1; /* report errors */
1627                 }
1628         }
1629  free_and_return:
1630         diff_free_filespec_data(one);
1631         diff_free_filespec_data(two);
1632         if (data.status)
1633                 DIFF_OPT_SET(o, CHECK_FAILED);
1636 struct diff_filespec *alloc_filespec(const char *path)
1638         int namelen = strlen(path);
1639         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1641         memset(spec, 0, sizeof(*spec));
1642         spec->path = (char *)(spec + 1);
1643         memcpy(spec->path, path, namelen+1);
1644         spec->count = 1;
1645         return spec;
1648 void free_filespec(struct diff_filespec *spec)
1650         if (!--spec->count) {
1651                 diff_free_filespec_data(spec);
1652                 free(spec);
1653         }
1656 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1657                    unsigned short mode)
1659         if (mode) {
1660                 spec->mode = canon_mode(mode);
1661                 hashcpy(spec->sha1, sha1);
1662                 spec->sha1_valid = !is_null_sha1(sha1);
1663         }
1666 /*
1667  * Given a name and sha1 pair, if the index tells us the file in
1668  * the work tree has that object contents, return true, so that
1669  * prepare_temp_file() does not have to inflate and extract.
1670  */
1671 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1673         struct cache_entry *ce;
1674         struct stat st;
1675         int pos, len;
1677         /* We do not read the cache ourselves here, because the
1678          * benchmark with my previous version that always reads cache
1679          * shows that it makes things worse for diff-tree comparing
1680          * two linux-2.6 kernel trees in an already checked out work
1681          * tree.  This is because most diff-tree comparisons deal with
1682          * only a small number of files, while reading the cache is
1683          * expensive for a large project, and its cost outweighs the
1684          * savings we get by not inflating the object to a temporary
1685          * file.  Practically, this code only helps when we are used
1686          * by diff-cache --cached, which does read the cache before
1687          * calling us.
1688          */
1689         if (!active_cache)
1690                 return 0;
1692         /* We want to avoid the working directory if our caller
1693          * doesn't need the data in a normal file, this system
1694          * is rather slow with its stat/open/mmap/close syscalls,
1695          * and the object is contained in a pack file.  The pack
1696          * is probably already open and will be faster to obtain
1697          * the data through than the working directory.  Loose
1698          * objects however would tend to be slower as they need
1699          * to be individually opened and inflated.
1700          */
1701         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1702                 return 0;
1704         len = strlen(name);
1705         pos = cache_name_pos(name, len);
1706         if (pos < 0)
1707                 return 0;
1708         ce = active_cache[pos];
1710         /*
1711          * This is not the sha1 we are looking for, or
1712          * unreusable because it is not a regular file.
1713          */
1714         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1715                 return 0;
1717         /*
1718          * If ce matches the file in the work tree, we can reuse it.
1719          */
1720         if (ce_uptodate(ce) ||
1721             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1722                 return 1;
1724         return 0;
1727 static int populate_from_stdin(struct diff_filespec *s)
1729         struct strbuf buf;
1730         size_t size = 0;
1732         strbuf_init(&buf, 0);
1733         if (strbuf_read(&buf, 0, 0) < 0)
1734                 return error("error while reading from stdin %s",
1735                                      strerror(errno));
1737         s->should_munmap = 0;
1738         s->data = strbuf_detach(&buf, &size);
1739         s->size = size;
1740         s->should_free = 1;
1741         return 0;
1744 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1746         int len;
1747         char *data = xmalloc(100);
1748         len = snprintf(data, 100,
1749                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1750         s->data = data;
1751         s->size = len;
1752         s->should_free = 1;
1753         if (size_only) {
1754                 s->data = NULL;
1755                 free(data);
1756         }
1757         return 0;
1760 /*
1761  * While doing rename detection and pickaxe operation, we may need to
1762  * grab the data for the blob (or file) for our own in-core comparison.
1763  * diff_filespec has data and size fields for this purpose.
1764  */
1765 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1767         int err = 0;
1768         if (!DIFF_FILE_VALID(s))
1769                 die("internal error: asking to populate invalid file.");
1770         if (S_ISDIR(s->mode))
1771                 return -1;
1773         if (s->data)
1774                 return 0;
1776         if (size_only && 0 < s->size)
1777                 return 0;
1779         if (S_ISGITLINK(s->mode))
1780                 return diff_populate_gitlink(s, size_only);
1782         if (!s->sha1_valid ||
1783             reuse_worktree_file(s->path, s->sha1, 0)) {
1784                 struct strbuf buf;
1785                 struct stat st;
1786                 int fd;
1788                 if (!strcmp(s->path, "-"))
1789                         return populate_from_stdin(s);
1791                 if (lstat(s->path, &st) < 0) {
1792                         if (errno == ENOENT) {
1793                         err_empty:
1794                                 err = -1;
1795                         empty:
1796                                 s->data = (char *)"";
1797                                 s->size = 0;
1798                                 return err;
1799                         }
1800                 }
1801                 s->size = xsize_t(st.st_size);
1802                 if (!s->size)
1803                         goto empty;
1804                 if (size_only)
1805                         return 0;
1806                 if (S_ISLNK(st.st_mode)) {
1807                         int ret;
1808                         s->data = xmalloc(s->size);
1809                         s->should_free = 1;
1810                         ret = readlink(s->path, s->data, s->size);
1811                         if (ret < 0) {
1812                                 free(s->data);
1813                                 goto err_empty;
1814                         }
1815                         return 0;
1816                 }
1817                 fd = open(s->path, O_RDONLY);
1818                 if (fd < 0)
1819                         goto err_empty;
1820                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1821                 close(fd);
1822                 s->should_munmap = 1;
1824                 /*
1825                  * Convert from working tree format to canonical git format
1826                  */
1827                 strbuf_init(&buf, 0);
1828                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1829                         size_t size = 0;
1830                         munmap(s->data, s->size);
1831                         s->should_munmap = 0;
1832                         s->data = strbuf_detach(&buf, &size);
1833                         s->size = size;
1834                         s->should_free = 1;
1835                 }
1836         }
1837         else {
1838                 enum object_type type;
1839                 if (size_only)
1840                         type = sha1_object_info(s->sha1, &s->size);
1841                 else {
1842                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1843                         s->should_free = 1;
1844                 }
1845         }
1846         return 0;
1849 void diff_free_filespec_blob(struct diff_filespec *s)
1851         if (s->should_free)
1852                 free(s->data);
1853         else if (s->should_munmap)
1854                 munmap(s->data, s->size);
1856         if (s->should_free || s->should_munmap) {
1857                 s->should_free = s->should_munmap = 0;
1858                 s->data = NULL;
1859         }
1862 void diff_free_filespec_data(struct diff_filespec *s)
1864         diff_free_filespec_blob(s);
1865         free(s->cnt_data);
1866         s->cnt_data = NULL;
1869 static void prep_temp_blob(struct diff_tempfile *temp,
1870                            void *blob,
1871                            unsigned long size,
1872                            const unsigned char *sha1,
1873                            int mode)
1875         int fd;
1877         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1878         if (fd < 0)
1879                 die("unable to create temp-file: %s", strerror(errno));
1880         if (write_in_full(fd, blob, size) != size)
1881                 die("unable to write temp-file");
1882         close(fd);
1883         temp->name = temp->tmp_path;
1884         strcpy(temp->hex, sha1_to_hex(sha1));
1885         temp->hex[40] = 0;
1886         sprintf(temp->mode, "%06o", mode);
1889 static void prepare_temp_file(const char *name,
1890                               struct diff_tempfile *temp,
1891                               struct diff_filespec *one)
1893         if (!DIFF_FILE_VALID(one)) {
1894         not_a_valid_file:
1895                 /* A '-' entry produces this for file-2, and
1896                  * a '+' entry produces this for file-1.
1897                  */
1898                 temp->name = "/dev/null";
1899                 strcpy(temp->hex, ".");
1900                 strcpy(temp->mode, ".");
1901                 return;
1902         }
1904         if (!one->sha1_valid ||
1905             reuse_worktree_file(name, one->sha1, 1)) {
1906                 struct stat st;
1907                 if (lstat(name, &st) < 0) {
1908                         if (errno == ENOENT)
1909                                 goto not_a_valid_file;
1910                         die("stat(%s): %s", name, strerror(errno));
1911                 }
1912                 if (S_ISLNK(st.st_mode)) {
1913                         int ret;
1914                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1915                         size_t sz = xsize_t(st.st_size);
1916                         if (sizeof(buf) <= st.st_size)
1917                                 die("symlink too long: %s", name);
1918                         ret = readlink(name, buf, sz);
1919                         if (ret < 0)
1920                                 die("readlink(%s)", name);
1921                         prep_temp_blob(temp, buf, sz,
1922                                        (one->sha1_valid ?
1923                                         one->sha1 : null_sha1),
1924                                        (one->sha1_valid ?
1925                                         one->mode : S_IFLNK));
1926                 }
1927                 else {
1928                         /* we can borrow from the file in the work tree */
1929                         temp->name = name;
1930                         if (!one->sha1_valid)
1931                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1932                         else
1933                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1934                         /* Even though we may sometimes borrow the
1935                          * contents from the work tree, we always want
1936                          * one->mode.  mode is trustworthy even when
1937                          * !(one->sha1_valid), as long as
1938                          * DIFF_FILE_VALID(one).
1939                          */
1940                         sprintf(temp->mode, "%06o", one->mode);
1941                 }
1942                 return;
1943         }
1944         else {
1945                 if (diff_populate_filespec(one, 0))
1946                         die("cannot read data blob for %s", one->path);
1947                 prep_temp_blob(temp, one->data, one->size,
1948                                one->sha1, one->mode);
1949         }
1952 static void remove_tempfile(void)
1954         int i;
1956         for (i = 0; i < 2; i++)
1957                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1958                         unlink(diff_temp[i].name);
1959                         diff_temp[i].name = NULL;
1960                 }
1963 static void remove_tempfile_on_signal(int signo)
1965         remove_tempfile();
1966         signal(SIGINT, SIG_DFL);
1967         raise(signo);
1970 /* An external diff command takes:
1971  *
1972  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1973  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1974  *
1975  */
1976 static void run_external_diff(const char *pgm,
1977                               const char *name,
1978                               const char *other,
1979                               struct diff_filespec *one,
1980                               struct diff_filespec *two,
1981                               const char *xfrm_msg,
1982                               int complete_rewrite)
1984         const char *spawn_arg[10];
1985         struct diff_tempfile *temp = diff_temp;
1986         int retval;
1987         static int atexit_asked = 0;
1988         const char *othername;
1989         const char **arg = &spawn_arg[0];
1991         othername = (other? other : name);
1992         if (one && two) {
1993                 prepare_temp_file(name, &temp[0], one);
1994                 prepare_temp_file(othername, &temp[1], two);
1995                 if (! atexit_asked &&
1996                     (temp[0].name == temp[0].tmp_path ||
1997                      temp[1].name == temp[1].tmp_path)) {
1998                         atexit_asked = 1;
1999                         atexit(remove_tempfile);
2000                 }
2001                 signal(SIGINT, remove_tempfile_on_signal);
2002         }
2004         if (one && two) {
2005                 *arg++ = pgm;
2006                 *arg++ = name;
2007                 *arg++ = temp[0].name;
2008                 *arg++ = temp[0].hex;
2009                 *arg++ = temp[0].mode;
2010                 *arg++ = temp[1].name;
2011                 *arg++ = temp[1].hex;
2012                 *arg++ = temp[1].mode;
2013                 if (other) {
2014                         *arg++ = other;
2015                         *arg++ = xfrm_msg;
2016                 }
2017         } else {
2018                 *arg++ = pgm;
2019                 *arg++ = name;
2020         }
2021         *arg = NULL;
2022         fflush(NULL);
2023         retval = run_command_v_opt(spawn_arg, 0);
2024         remove_tempfile();
2025         if (retval) {
2026                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2027                 exit(1);
2028         }
2031 static const char *external_diff_attr(const char *name)
2033         struct git_attr_check attr_diff_check;
2035         if (!name)
2036                 return NULL;
2038         setup_diff_attr_check(&attr_diff_check);
2039         if (!git_checkattr(name, 1, &attr_diff_check)) {
2040                 const char *value = attr_diff_check.value;
2041                 if (!ATTR_TRUE(value) &&
2042                     !ATTR_FALSE(value) &&
2043                     !ATTR_UNSET(value)) {
2044                         struct ll_diff_driver *drv;
2046                         for (drv = user_diff; drv; drv = drv->next)
2047                                 if (!strcmp(drv->name, value))
2048                                         return drv->cmd;
2049                 }
2050         }
2051         return NULL;
2054 static void run_diff_cmd(const char *pgm,
2055                          const char *name,
2056                          const char *other,
2057                          const char *attr_path,
2058                          struct diff_filespec *one,
2059                          struct diff_filespec *two,
2060                          const char *xfrm_msg,
2061                          struct diff_options *o,
2062                          int complete_rewrite)
2064         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2065                 pgm = NULL;
2066         else {
2067                 const char *cmd = external_diff_attr(attr_path);
2068                 if (cmd)
2069                         pgm = cmd;
2070         }
2072         if (pgm) {
2073                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2074                                   complete_rewrite);
2075                 return;
2076         }
2077         if (one && two)
2078                 builtin_diff(name, other ? other : name,
2079                              one, two, xfrm_msg, o, complete_rewrite);
2080         else
2081                 fprintf(o->file, "* Unmerged path %s\n", name);
2084 static void diff_fill_sha1_info(struct diff_filespec *one)
2086         if (DIFF_FILE_VALID(one)) {
2087                 if (!one->sha1_valid) {
2088                         struct stat st;
2089                         if (!strcmp(one->path, "-")) {
2090                                 hashcpy(one->sha1, null_sha1);
2091                                 return;
2092                         }
2093                         if (lstat(one->path, &st) < 0)
2094                                 die("stat %s", one->path);
2095                         if (index_path(one->sha1, one->path, &st, 0))
2096                                 die("cannot hash %s\n", one->path);
2097                 }
2098         }
2099         else
2100                 hashclr(one->sha1);
2103 static int similarity_index(struct diff_filepair *p)
2105         return p->score * 100 / MAX_SCORE;
2108 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2110         /* Strip the prefix but do not molest /dev/null and absolute paths */
2111         if (*namep && **namep != '/')
2112                 *namep += prefix_length;
2113         if (*otherp && **otherp != '/')
2114                 *otherp += prefix_length;
2117 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2119         const char *pgm = external_diff();
2120         struct strbuf msg;
2121         char *xfrm_msg;
2122         struct diff_filespec *one = p->one;
2123         struct diff_filespec *two = p->two;
2124         const char *name;
2125         const char *other;
2126         const char *attr_path;
2127         int complete_rewrite = 0;
2129         name  = p->one->path;
2130         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2131         attr_path = name;
2132         if (o->prefix_length)
2133                 strip_prefix(o->prefix_length, &name, &other);
2135         if (DIFF_PAIR_UNMERGED(p)) {
2136                 run_diff_cmd(pgm, name, NULL, attr_path,
2137                              NULL, NULL, NULL, o, 0);
2138                 return;
2139         }
2141         diff_fill_sha1_info(one);
2142         diff_fill_sha1_info(two);
2144         strbuf_init(&msg, PATH_MAX * 2 + 300);
2145         switch (p->status) {
2146         case DIFF_STATUS_COPIED:
2147                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2148                 strbuf_addstr(&msg, "\ncopy from ");
2149                 quote_c_style(name, &msg, NULL, 0);
2150                 strbuf_addstr(&msg, "\ncopy to ");
2151                 quote_c_style(other, &msg, NULL, 0);
2152                 strbuf_addch(&msg, '\n');
2153                 break;
2154         case DIFF_STATUS_RENAMED:
2155                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2156                 strbuf_addstr(&msg, "\nrename from ");
2157                 quote_c_style(name, &msg, NULL, 0);
2158                 strbuf_addstr(&msg, "\nrename to ");
2159                 quote_c_style(other, &msg, NULL, 0);
2160                 strbuf_addch(&msg, '\n');
2161                 break;
2162         case DIFF_STATUS_MODIFIED:
2163                 if (p->score) {
2164                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2165                                         similarity_index(p));
2166                         complete_rewrite = 1;
2167                         break;
2168                 }
2169                 /* fallthru */
2170         default:
2171                 /* nothing */
2172                 ;
2173         }
2175         if (hashcmp(one->sha1, two->sha1)) {
2176                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2178                 if (DIFF_OPT_TST(o, BINARY)) {
2179                         mmfile_t mf;
2180                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2181                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2182                                 abbrev = 40;
2183                 }
2184                 strbuf_addf(&msg, "index %.*s..%.*s",
2185                                 abbrev, sha1_to_hex(one->sha1),
2186                                 abbrev, sha1_to_hex(two->sha1));
2187                 if (one->mode == two->mode)
2188                         strbuf_addf(&msg, " %06o", one->mode);
2189                 strbuf_addch(&msg, '\n');
2190         }
2192         if (msg.len)
2193                 strbuf_setlen(&msg, msg.len - 1);
2194         xfrm_msg = msg.len ? msg.buf : NULL;
2196         if (!pgm &&
2197             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2198             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2199                 /* a filepair that changes between file and symlink
2200                  * needs to be split into deletion and creation.
2201                  */
2202                 struct diff_filespec *null = alloc_filespec(two->path);
2203                 run_diff_cmd(NULL, name, other, attr_path,
2204                              one, null, xfrm_msg, o, 0);
2205                 free(null);
2206                 null = alloc_filespec(one->path);
2207                 run_diff_cmd(NULL, name, other, attr_path,
2208                              null, two, xfrm_msg, o, 0);
2209                 free(null);
2210         }
2211         else
2212                 run_diff_cmd(pgm, name, other, attr_path,
2213                              one, two, xfrm_msg, o, complete_rewrite);
2215         strbuf_release(&msg);
2218 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2219                          struct diffstat_t *diffstat)
2221         const char *name;
2222         const char *other;
2223         int complete_rewrite = 0;
2225         if (DIFF_PAIR_UNMERGED(p)) {
2226                 /* unmerged */
2227                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2228                 return;
2229         }
2231         name = p->one->path;
2232         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2234         if (o->prefix_length)
2235                 strip_prefix(o->prefix_length, &name, &other);
2237         diff_fill_sha1_info(p->one);
2238         diff_fill_sha1_info(p->two);
2240         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2241                 complete_rewrite = 1;
2242         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2245 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2247         const char *name;
2248         const char *other;
2249         const char *attr_path;
2251         if (DIFF_PAIR_UNMERGED(p)) {
2252                 /* unmerged */
2253                 return;
2254         }
2256         name = p->one->path;
2257         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2258         attr_path = other ? other : name;
2260         if (o->prefix_length)
2261                 strip_prefix(o->prefix_length, &name, &other);
2263         diff_fill_sha1_info(p->one);
2264         diff_fill_sha1_info(p->two);
2266         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2269 void diff_setup(struct diff_options *options)
2271         memset(options, 0, sizeof(*options));
2273         options->file = stdout;
2275         options->line_termination = '\n';
2276         options->break_opt = -1;
2277         options->rename_limit = -1;
2278         options->dirstat_percent = 3;
2279         options->context = 3;
2281         options->change = diff_change;
2282         options->add_remove = diff_addremove;
2283         if (diff_use_color_default > 0)
2284                 DIFF_OPT_SET(options, COLOR_DIFF);
2285         else
2286                 DIFF_OPT_CLR(options, COLOR_DIFF);
2287         options->detect_rename = diff_detect_rename_default;
2289         options->a_prefix = "a/";
2290         options->b_prefix = "b/";
2293 int diff_setup_done(struct diff_options *options)
2295         int count = 0;
2297         if (options->output_format & DIFF_FORMAT_NAME)
2298                 count++;
2299         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2300                 count++;
2301         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2302                 count++;
2303         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2304                 count++;
2305         if (count > 1)
2306                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2308         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2309                 options->detect_rename = DIFF_DETECT_COPY;
2311         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2312                 options->prefix = NULL;
2313         if (options->prefix)
2314                 options->prefix_length = strlen(options->prefix);
2315         else
2316                 options->prefix_length = 0;
2318         if (options->output_format & (DIFF_FORMAT_NAME |
2319                                       DIFF_FORMAT_NAME_STATUS |
2320                                       DIFF_FORMAT_CHECKDIFF |
2321                                       DIFF_FORMAT_NO_OUTPUT))
2322                 options->output_format &= ~(DIFF_FORMAT_RAW |
2323                                             DIFF_FORMAT_NUMSTAT |
2324                                             DIFF_FORMAT_DIFFSTAT |
2325                                             DIFF_FORMAT_SHORTSTAT |
2326                                             DIFF_FORMAT_DIRSTAT |
2327                                             DIFF_FORMAT_SUMMARY |
2328                                             DIFF_FORMAT_PATCH);
2330         /*
2331          * These cases always need recursive; we do not drop caller-supplied
2332          * recursive bits for other formats here.
2333          */
2334         if (options->output_format & (DIFF_FORMAT_PATCH |
2335                                       DIFF_FORMAT_NUMSTAT |
2336                                       DIFF_FORMAT_DIFFSTAT |
2337                                       DIFF_FORMAT_SHORTSTAT |
2338                                       DIFF_FORMAT_DIRSTAT |
2339                                       DIFF_FORMAT_SUMMARY |
2340                                       DIFF_FORMAT_CHECKDIFF))
2341                 DIFF_OPT_SET(options, RECURSIVE);
2342         /*
2343          * Also pickaxe would not work very well if you do not say recursive
2344          */
2345         if (options->pickaxe)
2346                 DIFF_OPT_SET(options, RECURSIVE);
2348         if (options->detect_rename && options->rename_limit < 0)
2349                 options->rename_limit = diff_rename_limit_default;
2350         if (options->setup & DIFF_SETUP_USE_CACHE) {
2351                 if (!active_cache)
2352                         /* read-cache does not die even when it fails
2353                          * so it is safe for us to do this here.  Also
2354                          * it does not smudge active_cache or active_nr
2355                          * when it fails, so we do not have to worry about
2356                          * cleaning it up ourselves either.
2357                          */
2358                         read_cache();
2359         }
2360         if (options->abbrev <= 0 || 40 < options->abbrev)
2361                 options->abbrev = 40; /* full */
2363         /*
2364          * It does not make sense to show the first hit we happened
2365          * to have found.  It does not make sense not to return with
2366          * exit code in such a case either.
2367          */
2368         if (DIFF_OPT_TST(options, QUIET)) {
2369                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2370                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2371         }
2373         /*
2374          * If we postprocess in diffcore, we cannot simply return
2375          * upon the first hit.  We need to run diff as usual.
2376          */
2377         if (options->pickaxe || options->filter)
2378                 DIFF_OPT_CLR(options, QUIET);
2380         return 0;
2383 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2385         char c, *eq;
2386         int len;
2388         if (*arg != '-')
2389                 return 0;
2390         c = *++arg;
2391         if (!c)
2392                 return 0;
2393         if (c == arg_short) {
2394                 c = *++arg;
2395                 if (!c)
2396                         return 1;
2397                 if (val && isdigit(c)) {
2398                         char *end;
2399                         int n = strtoul(arg, &end, 10);
2400                         if (*end)
2401                                 return 0;
2402                         *val = n;
2403                         return 1;
2404                 }
2405                 return 0;
2406         }
2407         if (c != '-')
2408                 return 0;
2409         arg++;
2410         eq = strchr(arg, '=');
2411         if (eq)
2412                 len = eq - arg;
2413         else
2414                 len = strlen(arg);
2415         if (!len || strncmp(arg, arg_long, len))
2416                 return 0;
2417         if (eq) {
2418                 int n;
2419                 char *end;
2420                 if (!isdigit(*++eq))
2421                         return 0;
2422                 n = strtoul(eq, &end, 10);
2423                 if (*end)
2424                         return 0;
2425                 *val = n;
2426         }
2427         return 1;
2430 static int diff_scoreopt_parse(const char *opt);
2432 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2434         const char *arg = av[0];
2436         /* Output format options */
2437         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2438                 options->output_format |= DIFF_FORMAT_PATCH;
2439         else if (opt_arg(arg, 'U', "unified", &options->context))
2440                 options->output_format |= DIFF_FORMAT_PATCH;
2441         else if (!strcmp(arg, "--raw"))
2442                 options->output_format |= DIFF_FORMAT_RAW;
2443         else if (!strcmp(arg, "--patch-with-raw"))
2444                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2445         else if (!strcmp(arg, "--numstat"))
2446                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2447         else if (!strcmp(arg, "--shortstat"))
2448                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2449         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2450                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2451         else if (!strcmp(arg, "--cumulative"))
2452                 options->output_format |= DIFF_FORMAT_CUMULATIVE;
2453         else if (!strcmp(arg, "--check"))
2454                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2455         else if (!strcmp(arg, "--summary"))
2456                 options->output_format |= DIFF_FORMAT_SUMMARY;
2457         else if (!strcmp(arg, "--patch-with-stat"))
2458                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2459         else if (!strcmp(arg, "--name-only"))
2460                 options->output_format |= DIFF_FORMAT_NAME;
2461         else if (!strcmp(arg, "--name-status"))
2462                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2463         else if (!strcmp(arg, "-s"))
2464                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2465         else if (!prefixcmp(arg, "--stat")) {
2466                 char *end;
2467                 int width = options->stat_width;
2468                 int name_width = options->stat_name_width;
2469                 arg += 6;
2470                 end = (char *)arg;
2472                 switch (*arg) {
2473                 case '-':
2474                         if (!prefixcmp(arg, "-width="))
2475                                 width = strtoul(arg + 7, &end, 10);
2476                         else if (!prefixcmp(arg, "-name-width="))
2477                                 name_width = strtoul(arg + 12, &end, 10);
2478                         break;
2479                 case '=':
2480                         width = strtoul(arg+1, &end, 10);
2481                         if (*end == ',')
2482                                 name_width = strtoul(end+1, &end, 10);
2483                 }
2485                 /* Important! This checks all the error cases! */
2486                 if (*end)
2487                         return 0;
2488                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2489                 options->stat_name_width = name_width;
2490                 options->stat_width = width;
2491         }
2493         /* renames options */
2494         else if (!prefixcmp(arg, "-B")) {
2495                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2496                         return -1;
2497         }
2498         else if (!prefixcmp(arg, "-M")) {
2499                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2500                         return -1;
2501                 options->detect_rename = DIFF_DETECT_RENAME;
2502         }
2503         else if (!prefixcmp(arg, "-C")) {
2504                 if (options->detect_rename == DIFF_DETECT_COPY)
2505                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2506                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2507                         return -1;
2508                 options->detect_rename = DIFF_DETECT_COPY;
2509         }
2510         else if (!strcmp(arg, "--no-renames"))
2511                 options->detect_rename = 0;
2512         else if (!strcmp(arg, "--relative"))
2513                 DIFF_OPT_SET(options, RELATIVE_NAME);
2514         else if (!prefixcmp(arg, "--relative=")) {
2515                 DIFF_OPT_SET(options, RELATIVE_NAME);
2516                 options->prefix = arg + 11;
2517         }
2519         /* xdiff options */
2520         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2521                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2522         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2523                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2524         else if (!strcmp(arg, "--ignore-space-at-eol"))
2525                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2527         /* flags options */
2528         else if (!strcmp(arg, "--binary")) {
2529                 options->output_format |= DIFF_FORMAT_PATCH;
2530                 DIFF_OPT_SET(options, BINARY);
2531         }
2532         else if (!strcmp(arg, "--full-index"))
2533                 DIFF_OPT_SET(options, FULL_INDEX);
2534         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2535                 DIFF_OPT_SET(options, TEXT);
2536         else if (!strcmp(arg, "-R"))
2537                 DIFF_OPT_SET(options, REVERSE_DIFF);
2538         else if (!strcmp(arg, "--find-copies-harder"))
2539                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2540         else if (!strcmp(arg, "--follow"))
2541                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2542         else if (!strcmp(arg, "--color"))
2543                 DIFF_OPT_SET(options, COLOR_DIFF);
2544         else if (!strcmp(arg, "--no-color"))
2545                 DIFF_OPT_CLR(options, COLOR_DIFF);
2546         else if (!strcmp(arg, "--color-words"))
2547                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2548         else if (!strcmp(arg, "--exit-code"))
2549                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2550         else if (!strcmp(arg, "--quiet"))
2551                 DIFF_OPT_SET(options, QUIET);
2552         else if (!strcmp(arg, "--ext-diff"))
2553                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2554         else if (!strcmp(arg, "--no-ext-diff"))
2555                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2556         else if (!strcmp(arg, "--ignore-submodules"))
2557                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2559         /* misc options */
2560         else if (!strcmp(arg, "-z"))
2561                 options->line_termination = 0;
2562         else if (!prefixcmp(arg, "-l"))
2563                 options->rename_limit = strtoul(arg+2, NULL, 10);
2564         else if (!prefixcmp(arg, "-S"))
2565                 options->pickaxe = arg + 2;
2566         else if (!strcmp(arg, "--pickaxe-all"))
2567                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2568         else if (!strcmp(arg, "--pickaxe-regex"))
2569                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2570         else if (!prefixcmp(arg, "-O"))
2571                 options->orderfile = arg + 2;
2572         else if (!prefixcmp(arg, "--diff-filter="))
2573                 options->filter = arg + 14;
2574         else if (!strcmp(arg, "--abbrev"))
2575                 options->abbrev = DEFAULT_ABBREV;
2576         else if (!prefixcmp(arg, "--abbrev=")) {
2577                 options->abbrev = strtoul(arg + 9, NULL, 10);
2578                 if (options->abbrev < MINIMUM_ABBREV)
2579                         options->abbrev = MINIMUM_ABBREV;
2580                 else if (40 < options->abbrev)
2581                         options->abbrev = 40;
2582         }
2583         else if (!prefixcmp(arg, "--src-prefix="))
2584                 options->a_prefix = arg + 13;
2585         else if (!prefixcmp(arg, "--dst-prefix="))
2586                 options->b_prefix = arg + 13;
2587         else if (!strcmp(arg, "--no-prefix"))
2588                 options->a_prefix = options->b_prefix = "";
2589         else if (!prefixcmp(arg, "--output=")) {
2590                 options->file = fopen(arg + strlen("--output="), "w");
2591                 options->close_file = 1;
2592         } else
2593                 return 0;
2594         return 1;
2597 static int parse_num(const char **cp_p)
2599         unsigned long num, scale;
2600         int ch, dot;
2601         const char *cp = *cp_p;
2603         num = 0;
2604         scale = 1;
2605         dot = 0;
2606         for(;;) {
2607                 ch = *cp;
2608                 if ( !dot && ch == '.' ) {
2609                         scale = 1;
2610                         dot = 1;
2611                 } else if ( ch == '%' ) {
2612                         scale = dot ? scale*100 : 100;
2613                         cp++;   /* % is always at the end */
2614                         break;
2615                 } else if ( ch >= '0' && ch <= '9' ) {
2616                         if ( scale < 100000 ) {
2617                                 scale *= 10;
2618                                 num = (num*10) + (ch-'0');
2619                         }
2620                 } else {
2621                         break;
2622                 }
2623                 cp++;
2624         }
2625         *cp_p = cp;
2627         /* user says num divided by scale and we say internally that
2628          * is MAX_SCORE * num / scale.
2629          */
2630         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2633 static int diff_scoreopt_parse(const char *opt)
2635         int opt1, opt2, cmd;
2637         if (*opt++ != '-')
2638                 return -1;
2639         cmd = *opt++;
2640         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2641                 return -1; /* that is not a -M, -C nor -B option */
2643         opt1 = parse_num(&opt);
2644         if (cmd != 'B')
2645                 opt2 = 0;
2646         else {
2647                 if (*opt == 0)
2648                         opt2 = 0;
2649                 else if (*opt != '/')
2650                         return -1; /* we expect -B80/99 or -B80 */
2651                 else {
2652                         opt++;
2653                         opt2 = parse_num(&opt);
2654                 }
2655         }
2656         if (*opt != 0)
2657                 return -1;
2658         return opt1 | (opt2 << 16);
2661 struct diff_queue_struct diff_queued_diff;
2663 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2665         if (queue->alloc <= queue->nr) {
2666                 queue->alloc = alloc_nr(queue->alloc);
2667                 queue->queue = xrealloc(queue->queue,
2668                                         sizeof(dp) * queue->alloc);
2669         }
2670         queue->queue[queue->nr++] = dp;
2673 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2674                                  struct diff_filespec *one,
2675                                  struct diff_filespec *two)
2677         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2678         dp->one = one;
2679         dp->two = two;
2680         if (queue)
2681                 diff_q(queue, dp);
2682         return dp;
2685 void diff_free_filepair(struct diff_filepair *p)
2687         free_filespec(p->one);
2688         free_filespec(p->two);
2689         free(p);
2692 /* This is different from find_unique_abbrev() in that
2693  * it stuffs the result with dots for alignment.
2694  */
2695 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2697         int abblen;
2698         const char *abbrev;
2699         if (len == 40)
2700                 return sha1_to_hex(sha1);
2702         abbrev = find_unique_abbrev(sha1, len);
2703         abblen = strlen(abbrev);
2704         if (abblen < 37) {
2705                 static char hex[41];
2706                 if (len < abblen && abblen <= len + 2)
2707                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2708                 else
2709                         sprintf(hex, "%s...", abbrev);
2710                 return hex;
2711         }
2712         return sha1_to_hex(sha1);
2715 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2717         int line_termination = opt->line_termination;
2718         int inter_name_termination = line_termination ? '\t' : '\0';
2720         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2721                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2722                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2723                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2724         }
2725         if (p->score) {
2726                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2727                         inter_name_termination);
2728         } else {
2729                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2730         }
2732         if (p->status == DIFF_STATUS_COPIED ||
2733             p->status == DIFF_STATUS_RENAMED) {
2734                 const char *name_a, *name_b;
2735                 name_a = p->one->path;
2736                 name_b = p->two->path;
2737                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2738                 write_name_quoted(name_a, opt->file, inter_name_termination);
2739                 write_name_quoted(name_b, opt->file, line_termination);
2740         } else {
2741                 const char *name_a, *name_b;
2742                 name_a = p->one->mode ? p->one->path : p->two->path;
2743                 name_b = NULL;
2744                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2745                 write_name_quoted(name_a, opt->file, line_termination);
2746         }
2749 int diff_unmodified_pair(struct diff_filepair *p)
2751         /* This function is written stricter than necessary to support
2752          * the currently implemented transformers, but the idea is to
2753          * let transformers to produce diff_filepairs any way they want,
2754          * and filter and clean them up here before producing the output.
2755          */
2756         struct diff_filespec *one = p->one, *two = p->two;
2758         if (DIFF_PAIR_UNMERGED(p))
2759                 return 0; /* unmerged is interesting */
2761         /* deletion, addition, mode or type change
2762          * and rename are all interesting.
2763          */
2764         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2765             DIFF_PAIR_MODE_CHANGED(p) ||
2766             strcmp(one->path, two->path))
2767                 return 0;
2769         /* both are valid and point at the same path.  that is, we are
2770          * dealing with a change.
2771          */
2772         if (one->sha1_valid && two->sha1_valid &&
2773             !hashcmp(one->sha1, two->sha1))
2774                 return 1; /* no change */
2775         if (!one->sha1_valid && !two->sha1_valid)
2776                 return 1; /* both look at the same file on the filesystem. */
2777         return 0;
2780 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2782         if (diff_unmodified_pair(p))
2783                 return;
2785         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2786             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2787                 return; /* no tree diffs in patch format */
2789         run_diff(p, o);
2792 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2793                             struct diffstat_t *diffstat)
2795         if (diff_unmodified_pair(p))
2796                 return;
2798         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2799             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2800                 return; /* no tree diffs in patch format */
2802         run_diffstat(p, o, diffstat);
2805 static void diff_flush_checkdiff(struct diff_filepair *p,
2806                 struct diff_options *o)
2808         if (diff_unmodified_pair(p))
2809                 return;
2811         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2812             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2813                 return; /* no tree diffs in patch format */
2815         run_checkdiff(p, o);
2818 int diff_queue_is_empty(void)
2820         struct diff_queue_struct *q = &diff_queued_diff;
2821         int i;
2822         for (i = 0; i < q->nr; i++)
2823                 if (!diff_unmodified_pair(q->queue[i]))
2824                         return 0;
2825         return 1;
2828 #if DIFF_DEBUG
2829 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2831         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2832                 x, one ? one : "",
2833                 s->path,
2834                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2835                 s->mode,
2836                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2837         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2838                 x, one ? one : "",
2839                 s->size, s->xfrm_flags);
2842 void diff_debug_filepair(const struct diff_filepair *p, int i)
2844         diff_debug_filespec(p->one, i, "one");
2845         diff_debug_filespec(p->two, i, "two");
2846         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2847                 p->score, p->status ? p->status : '?',
2848                 p->one->rename_used, p->broken_pair);
2851 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2853         int i;
2854         if (msg)
2855                 fprintf(stderr, "%s\n", msg);
2856         fprintf(stderr, "q->nr = %d\n", q->nr);
2857         for (i = 0; i < q->nr; i++) {
2858                 struct diff_filepair *p = q->queue[i];
2859                 diff_debug_filepair(p, i);
2860         }
2862 #endif
2864 static void diff_resolve_rename_copy(void)
2866         int i;
2867         struct diff_filepair *p;
2868         struct diff_queue_struct *q = &diff_queued_diff;
2870         diff_debug_queue("resolve-rename-copy", q);
2872         for (i = 0; i < q->nr; i++) {
2873                 p = q->queue[i];
2874                 p->status = 0; /* undecided */
2875                 if (DIFF_PAIR_UNMERGED(p))
2876                         p->status = DIFF_STATUS_UNMERGED;
2877                 else if (!DIFF_FILE_VALID(p->one))
2878                         p->status = DIFF_STATUS_ADDED;
2879                 else if (!DIFF_FILE_VALID(p->two))
2880                         p->status = DIFF_STATUS_DELETED;
2881                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2882                         p->status = DIFF_STATUS_TYPE_CHANGED;
2884                 /* from this point on, we are dealing with a pair
2885                  * whose both sides are valid and of the same type, i.e.
2886                  * either in-place edit or rename/copy edit.
2887                  */
2888                 else if (DIFF_PAIR_RENAME(p)) {
2889                         /*
2890                          * A rename might have re-connected a broken
2891                          * pair up, causing the pathnames to be the
2892                          * same again. If so, that's not a rename at
2893                          * all, just a modification..
2894                          *
2895                          * Otherwise, see if this source was used for
2896                          * multiple renames, in which case we decrement
2897                          * the count, and call it a copy.
2898                          */
2899                         if (!strcmp(p->one->path, p->two->path))
2900                                 p->status = DIFF_STATUS_MODIFIED;
2901                         else if (--p->one->rename_used > 0)
2902                                 p->status = DIFF_STATUS_COPIED;
2903                         else
2904                                 p->status = DIFF_STATUS_RENAMED;
2905                 }
2906                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2907                          p->one->mode != p->two->mode ||
2908                          is_null_sha1(p->one->sha1))
2909                         p->status = DIFF_STATUS_MODIFIED;
2910                 else {
2911                         /* This is a "no-change" entry and should not
2912                          * happen anymore, but prepare for broken callers.
2913                          */
2914                         error("feeding unmodified %s to diffcore",
2915                               p->one->path);
2916                         p->status = DIFF_STATUS_UNKNOWN;
2917                 }
2918         }
2919         diff_debug_queue("resolve-rename-copy done", q);
2922 static int check_pair_status(struct diff_filepair *p)
2924         switch (p->status) {
2925         case DIFF_STATUS_UNKNOWN:
2926                 return 0;
2927         case 0:
2928                 die("internal error in diff-resolve-rename-copy");
2929         default:
2930                 return 1;
2931         }
2934 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2936         int fmt = opt->output_format;
2938         if (fmt & DIFF_FORMAT_CHECKDIFF)
2939                 diff_flush_checkdiff(p, opt);
2940         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2941                 diff_flush_raw(p, opt);
2942         else if (fmt & DIFF_FORMAT_NAME) {
2943                 const char *name_a, *name_b;
2944                 name_a = p->two->path;
2945                 name_b = NULL;
2946                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2947                 write_name_quoted(name_a, opt->file, opt->line_termination);
2948         }
2951 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2953         if (fs->mode)
2954                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2955         else
2956                 fprintf(file, " %s ", newdelete);
2957         write_name_quoted(fs->path, file, '\n');
2961 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2963         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2964                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2965                         show_name ? ' ' : '\n');
2966                 if (show_name) {
2967                         write_name_quoted(p->two->path, file, '\n');
2968                 }
2969         }
2972 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2974         char *names = pprint_rename(p->one->path, p->two->path);
2976         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2977         free(names);
2978         show_mode_change(file, p, 0);
2981 static void diff_summary(FILE *file, struct diff_filepair *p)
2983         switch(p->status) {
2984         case DIFF_STATUS_DELETED:
2985                 show_file_mode_name(file, "delete", p->one);
2986                 break;
2987         case DIFF_STATUS_ADDED:
2988                 show_file_mode_name(file, "create", p->two);
2989                 break;
2990         case DIFF_STATUS_COPIED:
2991                 show_rename_copy(file, "copy", p);
2992                 break;
2993         case DIFF_STATUS_RENAMED:
2994                 show_rename_copy(file, "rename", p);
2995                 break;
2996         default:
2997                 if (p->score) {
2998                         fputs(" rewrite ", file);
2999                         write_name_quoted(p->two->path, file, ' ');
3000                         fprintf(file, "(%d%%)\n", similarity_index(p));
3001                 }
3002                 show_mode_change(file, p, !p->score);
3003                 break;
3004         }
3007 struct patch_id_t {
3008         SHA_CTX *ctx;
3009         int patchlen;
3010 };
3012 static int remove_space(char *line, int len)
3014         int i;
3015         char *dst = line;
3016         unsigned char c;
3018         for (i = 0; i < len; i++)
3019                 if (!isspace((c = line[i])))
3020                         *dst++ = c;
3022         return dst - line;
3025 static void patch_id_consume(void *priv, char *line, unsigned long len)
3027         struct patch_id_t *data = priv;
3028         int new_len;
3030         /* Ignore line numbers when computing the SHA1 of the patch */
3031         if (!prefixcmp(line, "@@ -"))
3032                 return;
3034         new_len = remove_space(line, len);
3036         SHA1_Update(data->ctx, line, new_len);
3037         data->patchlen += new_len;
3040 /* returns 0 upon success, and writes result into sha1 */
3041 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3043         struct diff_queue_struct *q = &diff_queued_diff;
3044         int i;
3045         SHA_CTX ctx;
3046         struct patch_id_t data;
3047         char buffer[PATH_MAX * 4 + 20];
3049         SHA1_Init(&ctx);
3050         memset(&data, 0, sizeof(struct patch_id_t));
3051         data.ctx = &ctx;
3053         for (i = 0; i < q->nr; i++) {
3054                 xpparam_t xpp;
3055                 xdemitconf_t xecfg;
3056                 xdemitcb_t ecb;
3057                 mmfile_t mf1, mf2;
3058                 struct diff_filepair *p = q->queue[i];
3059                 int len1, len2;
3061                 memset(&xecfg, 0, sizeof(xecfg));
3062                 if (p->status == 0)
3063                         return error("internal diff status error");
3064                 if (p->status == DIFF_STATUS_UNKNOWN)
3065                         continue;
3066                 if (diff_unmodified_pair(p))
3067                         continue;
3068                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3069                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3070                         continue;
3071                 if (DIFF_PAIR_UNMERGED(p))
3072                         continue;
3074                 diff_fill_sha1_info(p->one);
3075                 diff_fill_sha1_info(p->two);
3076                 if (fill_mmfile(&mf1, p->one) < 0 ||
3077                                 fill_mmfile(&mf2, p->two) < 0)
3078                         return error("unable to read files to diff");
3080                 len1 = remove_space(p->one->path, strlen(p->one->path));
3081                 len2 = remove_space(p->two->path, strlen(p->two->path));
3082                 if (p->one->mode == 0)
3083                         len1 = snprintf(buffer, sizeof(buffer),
3084                                         "diff--gita/%.*sb/%.*s"
3085                                         "newfilemode%06o"
3086                                         "---/dev/null"
3087                                         "+++b/%.*s",
3088                                         len1, p->one->path,
3089                                         len2, p->two->path,
3090                                         p->two->mode,
3091                                         len2, p->two->path);
3092                 else if (p->two->mode == 0)
3093                         len1 = snprintf(buffer, sizeof(buffer),
3094                                         "diff--gita/%.*sb/%.*s"
3095                                         "deletedfilemode%06o"
3096                                         "---a/%.*s"
3097                                         "+++/dev/null",
3098                                         len1, p->one->path,
3099                                         len2, p->two->path,
3100                                         p->one->mode,
3101                                         len1, p->one->path);
3102                 else
3103                         len1 = snprintf(buffer, sizeof(buffer),
3104                                         "diff--gita/%.*sb/%.*s"
3105                                         "---a/%.*s"
3106                                         "+++b/%.*s",
3107                                         len1, p->one->path,
3108                                         len2, p->two->path,
3109                                         len1, p->one->path,
3110                                         len2, p->two->path);
3111                 SHA1_Update(&ctx, buffer, len1);
3113                 xpp.flags = XDF_NEED_MINIMAL;
3114                 xecfg.ctxlen = 3;
3115                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3116                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3117                               &xpp, &xecfg, &ecb);
3118         }
3120         SHA1_Final(sha1, &ctx);
3121         return 0;
3124 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3126         struct diff_queue_struct *q = &diff_queued_diff;
3127         int i;
3128         int result = diff_get_patch_id(options, sha1);
3130         for (i = 0; i < q->nr; i++)
3131                 diff_free_filepair(q->queue[i]);
3133         free(q->queue);
3134         q->queue = NULL;
3135         q->nr = q->alloc = 0;
3137         return result;
3140 static int is_summary_empty(const struct diff_queue_struct *q)
3142         int i;
3144         for (i = 0; i < q->nr; i++) {
3145                 const struct diff_filepair *p = q->queue[i];
3147                 switch (p->status) {
3148                 case DIFF_STATUS_DELETED:
3149                 case DIFF_STATUS_ADDED:
3150                 case DIFF_STATUS_COPIED:
3151                 case DIFF_STATUS_RENAMED:
3152                         return 0;
3153                 default:
3154                         if (p->score)
3155                                 return 0;
3156                         if (p->one->mode && p->two->mode &&
3157                             p->one->mode != p->two->mode)
3158                                 return 0;
3159                         break;
3160                 }
3161         }
3162         return 1;
3165 void diff_flush(struct diff_options *options)
3167         struct diff_queue_struct *q = &diff_queued_diff;
3168         int i, output_format = options->output_format;
3169         int separator = 0;
3171         /*
3172          * Order: raw, stat, summary, patch
3173          * or:    name/name-status/checkdiff (other bits clear)
3174          */
3175         if (!q->nr)
3176                 goto free_queue;
3178         if (output_format & (DIFF_FORMAT_RAW |
3179                              DIFF_FORMAT_NAME |
3180                              DIFF_FORMAT_NAME_STATUS |
3181                              DIFF_FORMAT_CHECKDIFF)) {
3182                 for (i = 0; i < q->nr; i++) {
3183                         struct diff_filepair *p = q->queue[i];
3184                         if (check_pair_status(p))
3185                                 flush_one_pair(p, options);
3186                 }
3187                 separator++;
3188         }
3190         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3191                 struct diffstat_t diffstat;
3193                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3194                 for (i = 0; i < q->nr; i++) {
3195                         struct diff_filepair *p = q->queue[i];
3196                         if (check_pair_status(p))
3197                                 diff_flush_stat(p, options, &diffstat);
3198                 }
3199                 if (output_format & DIFF_FORMAT_NUMSTAT)
3200                         show_numstat(&diffstat, options);
3201                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3202                         show_stats(&diffstat, options);
3203                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3204                         show_shortstats(&diffstat, options);
3205                 free_diffstat_info(&diffstat);
3206                 separator++;
3207         }
3208         if (output_format & DIFF_FORMAT_DIRSTAT)
3209                 show_dirstat(options);
3211         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3212                 for (i = 0; i < q->nr; i++)
3213                         diff_summary(options->file, q->queue[i]);
3214                 separator++;
3215         }
3217         if (output_format & DIFF_FORMAT_PATCH) {
3218                 if (separator) {
3219                         putc(options->line_termination, options->file);
3220                         if (options->stat_sep) {
3221                                 /* attach patch instead of inline */
3222                                 fputs(options->stat_sep, options->file);
3223                         }
3224                 }
3226                 for (i = 0; i < q->nr; i++) {
3227                         struct diff_filepair *p = q->queue[i];
3228                         if (check_pair_status(p))
3229                                 diff_flush_patch(p, options);
3230                 }
3231         }
3233         if (output_format & DIFF_FORMAT_CALLBACK)
3234                 options->format_callback(q, options, options->format_callback_data);
3236         for (i = 0; i < q->nr; i++)
3237                 diff_free_filepair(q->queue[i]);
3238 free_queue:
3239         free(q->queue);
3240         q->queue = NULL;
3241         q->nr = q->alloc = 0;
3242         if (options->close_file)
3243                 fclose(options->file);
3246 static void diffcore_apply_filter(const char *filter)
3248         int i;
3249         struct diff_queue_struct *q = &diff_queued_diff;
3250         struct diff_queue_struct outq;
3251         outq.queue = NULL;
3252         outq.nr = outq.alloc = 0;
3254         if (!filter)
3255                 return;
3257         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3258                 int found;
3259                 for (i = found = 0; !found && i < q->nr; i++) {
3260                         struct diff_filepair *p = q->queue[i];
3261                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3262                              ((p->score &&
3263                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3264                               (!p->score &&
3265                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3266                             ((p->status != DIFF_STATUS_MODIFIED) &&
3267                              strchr(filter, p->status)))
3268                                 found++;
3269                 }
3270                 if (found)
3271                         return;
3273                 /* otherwise we will clear the whole queue
3274                  * by copying the empty outq at the end of this
3275                  * function, but first clear the current entries
3276                  * in the queue.
3277                  */
3278                 for (i = 0; i < q->nr; i++)
3279                         diff_free_filepair(q->queue[i]);
3280         }
3281         else {
3282                 /* Only the matching ones */
3283                 for (i = 0; i < q->nr; i++) {
3284                         struct diff_filepair *p = q->queue[i];
3286                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3287                              ((p->score &&
3288                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3289                               (!p->score &&
3290                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3291                             ((p->status != DIFF_STATUS_MODIFIED) &&
3292                              strchr(filter, p->status)))
3293                                 diff_q(&outq, p);
3294                         else
3295                                 diff_free_filepair(p);
3296                 }
3297         }
3298         free(q->queue);
3299         *q = outq;
3302 /* Check whether two filespecs with the same mode and size are identical */
3303 static int diff_filespec_is_identical(struct diff_filespec *one,
3304                                       struct diff_filespec *two)
3306         if (S_ISGITLINK(one->mode))
3307                 return 0;
3308         if (diff_populate_filespec(one, 0))
3309                 return 0;
3310         if (diff_populate_filespec(two, 0))
3311                 return 0;
3312         return !memcmp(one->data, two->data, one->size);
3315 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3317         int i;
3318         struct diff_queue_struct *q = &diff_queued_diff;
3319         struct diff_queue_struct outq;
3320         outq.queue = NULL;
3321         outq.nr = outq.alloc = 0;
3323         for (i = 0; i < q->nr; i++) {
3324                 struct diff_filepair *p = q->queue[i];
3326                 /*
3327                  * 1. Entries that come from stat info dirtyness
3328                  *    always have both sides (iow, not create/delete),
3329                  *    one side of the object name is unknown, with
3330                  *    the same mode and size.  Keep the ones that
3331                  *    do not match these criteria.  They have real
3332                  *    differences.
3333                  *
3334                  * 2. At this point, the file is known to be modified,
3335                  *    with the same mode and size, and the object
3336                  *    name of one side is unknown.  Need to inspect
3337                  *    the identical contents.
3338                  */
3339                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3340                     !DIFF_FILE_VALID(p->two) ||
3341                     (p->one->sha1_valid && p->two->sha1_valid) ||
3342                     (p->one->mode != p->two->mode) ||
3343                     diff_populate_filespec(p->one, 1) ||
3344                     diff_populate_filespec(p->two, 1) ||
3345                     (p->one->size != p->two->size) ||
3346                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3347                         diff_q(&outq, p);
3348                 else {
3349                         /*
3350                          * The caller can subtract 1 from skip_stat_unmatch
3351                          * to determine how many paths were dirty only
3352                          * due to stat info mismatch.
3353                          */
3354                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3355                                 diffopt->skip_stat_unmatch++;
3356                         diff_free_filepair(p);
3357                 }
3358         }
3359         free(q->queue);
3360         *q = outq;
3363 void diffcore_std(struct diff_options *options)
3365         if (DIFF_OPT_TST(options, QUIET))
3366                 return;
3368         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3369                 diffcore_skip_stat_unmatch(options);
3370         if (options->break_opt != -1)
3371                 diffcore_break(options->break_opt);
3372         if (options->detect_rename)
3373                 diffcore_rename(options);
3374         if (options->break_opt != -1)
3375                 diffcore_merge_broken();
3376         if (options->pickaxe)
3377                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3378         if (options->orderfile)
3379                 diffcore_order(options->orderfile);
3380         diff_resolve_rename_copy();
3381         diffcore_apply_filter(options->filter);
3383         if (diff_queued_diff.nr)
3384                 DIFF_OPT_SET(options, HAS_CHANGES);
3385         else
3386                 DIFF_OPT_CLR(options, HAS_CHANGES);
3389 int diff_result_code(struct diff_options *opt, int status)
3391         int result = 0;
3392         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3393             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3394                 return status;
3395         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3396             DIFF_OPT_TST(opt, HAS_CHANGES))
3397                 result |= 01;
3398         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3399             DIFF_OPT_TST(opt, CHECK_FAILED))
3400                 result |= 02;
3401         return result;
3404 void diff_addremove(struct diff_options *options,
3405                     int addremove, unsigned mode,
3406                     const unsigned char *sha1,
3407                     const char *concatpath)
3409         struct diff_filespec *one, *two;
3411         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3412                 return;
3414         /* This may look odd, but it is a preparation for
3415          * feeding "there are unchanged files which should
3416          * not produce diffs, but when you are doing copy
3417          * detection you would need them, so here they are"
3418          * entries to the diff-core.  They will be prefixed
3419          * with something like '=' or '*' (I haven't decided
3420          * which but should not make any difference).
3421          * Feeding the same new and old to diff_change()
3422          * also has the same effect.
3423          * Before the final output happens, they are pruned after
3424          * merged into rename/copy pairs as appropriate.
3425          */
3426         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3427                 addremove = (addremove == '+' ? '-' :
3428                              addremove == '-' ? '+' : addremove);
3430         if (options->prefix &&
3431             strncmp(concatpath, options->prefix, options->prefix_length))
3432                 return;
3434         one = alloc_filespec(concatpath);
3435         two = alloc_filespec(concatpath);
3437         if (addremove != '+')
3438                 fill_filespec(one, sha1, mode);
3439         if (addremove != '-')
3440                 fill_filespec(two, sha1, mode);
3442         diff_queue(&diff_queued_diff, one, two);
3443         DIFF_OPT_SET(options, HAS_CHANGES);
3446 void diff_change(struct diff_options *options,
3447                  unsigned old_mode, unsigned new_mode,
3448                  const unsigned char *old_sha1,
3449                  const unsigned char *new_sha1,
3450                  const char *concatpath)
3452         struct diff_filespec *one, *two;
3454         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3455                         && S_ISGITLINK(new_mode))
3456                 return;
3458         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3459                 unsigned tmp;
3460                 const unsigned char *tmp_c;
3461                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3462                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3463         }
3465         if (options->prefix &&
3466             strncmp(concatpath, options->prefix, options->prefix_length))
3467                 return;
3469         one = alloc_filespec(concatpath);
3470         two = alloc_filespec(concatpath);
3471         fill_filespec(one, old_sha1, old_mode);
3472         fill_filespec(two, new_sha1, new_mode);
3474         diff_queue(&diff_queued_diff, one, two);
3475         DIFF_OPT_SET(options, HAS_CHANGES);
3478 void diff_unmerge(struct diff_options *options,
3479                   const char *path,
3480                   unsigned mode, const unsigned char *sha1)
3482         struct diff_filespec *one, *two;
3484         if (options->prefix &&
3485             strncmp(path, options->prefix, options->prefix_length))
3486                 return;
3488         one = alloc_filespec(path);
3489         two = alloc_filespec(path);
3490         fill_filespec(one, sha1, mode);
3491         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;