Code

fe43407b78150fd7fffe0d1fdff3456346ea27a6
[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 static int diff_suppress_blank_empty;
24 int diff_use_color_default = -1;
25 static const char *external_diff_cmd_cfg;
26 int diff_auto_refresh_index = 1;
28 static char diff_colors[][COLOR_MAXLEN] = {
29         "\033[m",       /* reset */
30         "",             /* PLAIN (normal) */
31         "\033[1m",      /* METAINFO (bold) */
32         "\033[36m",     /* FRAGINFO (cyan) */
33         "\033[31m",     /* OLD (red) */
34         "\033[32m",     /* NEW (green) */
35         "\033[33m",     /* COMMIT (yellow) */
36         "\033[41m",     /* WHITESPACE (red background) */
37 };
39 static int parse_diff_color_slot(const char *var, int ofs)
40 {
41         if (!strcasecmp(var+ofs, "plain"))
42                 return DIFF_PLAIN;
43         if (!strcasecmp(var+ofs, "meta"))
44                 return DIFF_METAINFO;
45         if (!strcasecmp(var+ofs, "frag"))
46                 return DIFF_FRAGINFO;
47         if (!strcasecmp(var+ofs, "old"))
48                 return DIFF_FILE_OLD;
49         if (!strcasecmp(var+ofs, "new"))
50                 return DIFF_FILE_NEW;
51         if (!strcasecmp(var+ofs, "commit"))
52                 return DIFF_COMMIT;
53         if (!strcasecmp(var+ofs, "whitespace"))
54                 return DIFF_WHITESPACE;
55         die("bad config variable '%s'", var);
56 }
58 static struct ll_diff_driver {
59         const char *name;
60         struct ll_diff_driver *next;
61         const char *cmd;
62 } *user_diff, **user_diff_tail;
64 /*
65  * Currently there is only "diff.<drivername>.command" variable;
66  * because there are "diff.color.<slot>" variables, we are parsing
67  * this in a bit convoluted way to allow low level diff driver
68  * called "color".
69  */
70 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
71 {
72         const char *name;
73         int namelen;
74         struct ll_diff_driver *drv;
76         name = var + 5;
77         namelen = ep - name;
78         for (drv = user_diff; drv; drv = drv->next)
79                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
80                         break;
81         if (!drv) {
82                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
83                 drv->name = xmemdupz(name, namelen);
84                 if (!user_diff_tail)
85                         user_diff_tail = &user_diff;
86                 *user_diff_tail = drv;
87                 user_diff_tail = &(drv->next);
88         }
90         return git_config_string(&(drv->cmd), var, value);
91 }
93 /*
94  * 'diff.<what>.funcname' attribute can be specified in the configuration
95  * to define a customized regexp to find the beginning of a function to
96  * be used for hunk header lines of "diff -p" style output.
97  */
98 static struct funcname_pattern {
99         char *name;
100         char *pattern;
101         struct funcname_pattern *next;
102 } *funcname_pattern_list;
104 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
106         const char *name;
107         int namelen;
108         struct funcname_pattern *pp;
110         name = var + 5; /* "diff." */
111         namelen = ep - name;
113         for (pp = funcname_pattern_list; pp; pp = pp->next)
114                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
115                         break;
116         if (!pp) {
117                 pp = xcalloc(1, sizeof(*pp));
118                 pp->name = xmemdupz(name, namelen);
119                 pp->next = funcname_pattern_list;
120                 funcname_pattern_list = pp;
121         }
122         free(pp->pattern);
123         pp->pattern = xstrdup(value);
124         return 0;
127 /*
128  * These are to give UI layer defaults.
129  * The core-level commands such as git-diff-files should
130  * never be affected by the setting of diff.renames
131  * the user happens to have in the configuration file.
132  */
133 int git_diff_ui_config(const char *var, const char *value, void *cb)
135         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
136                 diff_use_color_default = git_config_colorbool(var, value, -1);
137                 return 0;
138         }
139         if (!strcmp(var, "diff.renames")) {
140                 if (!value)
141                         diff_detect_rename_default = DIFF_DETECT_RENAME;
142                 else if (!strcasecmp(value, "copies") ||
143                          !strcasecmp(value, "copy"))
144                         diff_detect_rename_default = DIFF_DETECT_COPY;
145                 else if (git_config_bool(var,value))
146                         diff_detect_rename_default = DIFF_DETECT_RENAME;
147                 return 0;
148         }
149         if (!strcmp(var, "diff.autorefreshindex")) {
150                 diff_auto_refresh_index = git_config_bool(var, value);
151                 return 0;
152         }
153         if (!strcmp(var, "diff.external"))
154                 return git_config_string(&external_diff_cmd_cfg, var, value);
155         if (!prefixcmp(var, "diff.")) {
156                 const char *ep = strrchr(var, '.');
158                 if (ep != var + 4 && !strcmp(ep, ".command"))
159                         return parse_lldiff_command(var, ep, value);
160         }
162         return git_diff_basic_config(var, value, cb);
165 int git_diff_basic_config(const char *var, const char *value, void *cb)
167         if (!strcmp(var, "diff.renamelimit")) {
168                 diff_rename_limit_default = git_config_int(var, value);
169                 return 0;
170         }
172         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
173                 int slot = parse_diff_color_slot(var, 11);
174                 if (!value)
175                         return config_error_nonbool(var);
176                 color_parse(value, var, diff_colors[slot]);
177                 return 0;
178         }
180         /* like GNU diff's --suppress-blank-empty option  */
181         if (!strcmp(var, "diff.suppress-blank-empty")) {
182                 diff_suppress_blank_empty = git_config_bool(var, value);
183                 return 0;
184         }
186         if (!prefixcmp(var, "diff.")) {
187                 const char *ep = strrchr(var, '.');
188                 if (ep != var + 4) {
189                         if (!strcmp(ep, ".funcname")) {
190                                 if (!value)
191                                         return config_error_nonbool(var);
192                                 return parse_funcname_pattern(var, ep, value);
193                         }
194                 }
195         }
197         return git_color_default_config(var, value, cb);
200 static char *quote_two(const char *one, const char *two)
202         int need_one = quote_c_style(one, NULL, NULL, 1);
203         int need_two = quote_c_style(two, NULL, NULL, 1);
204         struct strbuf res;
206         strbuf_init(&res, 0);
207         if (need_one + need_two) {
208                 strbuf_addch(&res, '"');
209                 quote_c_style(one, &res, NULL, 1);
210                 quote_c_style(two, &res, NULL, 1);
211                 strbuf_addch(&res, '"');
212         } else {
213                 strbuf_addstr(&res, one);
214                 strbuf_addstr(&res, two);
215         }
216         return strbuf_detach(&res, NULL);
219 static const char *external_diff(void)
221         static const char *external_diff_cmd = NULL;
222         static int done_preparing = 0;
224         if (done_preparing)
225                 return external_diff_cmd;
226         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
227         if (!external_diff_cmd)
228                 external_diff_cmd = external_diff_cmd_cfg;
229         done_preparing = 1;
230         return external_diff_cmd;
233 static struct diff_tempfile {
234         const char *name; /* filename external diff should read from */
235         char hex[41];
236         char mode[10];
237         char tmp_path[PATH_MAX];
238 } diff_temp[2];
240 static int count_lines(const char *data, int size)
242         int count, ch, completely_empty = 1, nl_just_seen = 0;
243         count = 0;
244         while (0 < size--) {
245                 ch = *data++;
246                 if (ch == '\n') {
247                         count++;
248                         nl_just_seen = 1;
249                         completely_empty = 0;
250                 }
251                 else {
252                         nl_just_seen = 0;
253                         completely_empty = 0;
254                 }
255         }
256         if (completely_empty)
257                 return 0;
258         if (!nl_just_seen)
259                 count++; /* no trailing newline */
260         return count;
263 static void print_line_count(FILE *file, int count)
265         switch (count) {
266         case 0:
267                 fprintf(file, "0,0");
268                 break;
269         case 1:
270                 fprintf(file, "1");
271                 break;
272         default:
273                 fprintf(file, "1,%d", count);
274                 break;
275         }
278 static void copy_file_with_prefix(FILE *file,
279                                   int prefix, const char *data, int size,
280                                   const char *set, const char *reset)
282         int ch, nl_just_seen = 1;
283         while (0 < size--) {
284                 ch = *data++;
285                 if (nl_just_seen) {
286                         fputs(set, file);
287                         putc(prefix, file);
288                 }
289                 if (ch == '\n') {
290                         nl_just_seen = 1;
291                         fputs(reset, file);
292                 } else
293                         nl_just_seen = 0;
294                 putc(ch, file);
295         }
296         if (!nl_just_seen)
297                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
300 static void emit_rewrite_diff(const char *name_a,
301                               const char *name_b,
302                               struct diff_filespec *one,
303                               struct diff_filespec *two,
304                               struct diff_options *o)
306         int lc_a, lc_b;
307         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
308         const char *name_a_tab, *name_b_tab;
309         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
310         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
311         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
312         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
313         const char *reset = diff_get_color(color_diff, DIFF_RESET);
314         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
316         name_a += (*name_a == '/');
317         name_b += (*name_b == '/');
318         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
319         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
321         strbuf_reset(&a_name);
322         strbuf_reset(&b_name);
323         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
324         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
326         diff_populate_filespec(one, 0);
327         diff_populate_filespec(two, 0);
328         lc_a = count_lines(one->data, one->size);
329         lc_b = count_lines(two->data, two->size);
330         fprintf(o->file,
331                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
332                 metainfo, a_name.buf, name_a_tab, reset,
333                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
334         print_line_count(o->file, lc_a);
335         fprintf(o->file, " +");
336         print_line_count(o->file, lc_b);
337         fprintf(o->file, " @@%s\n", reset);
338         if (lc_a)
339                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
340         if (lc_b)
341                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
344 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
346         if (!DIFF_FILE_VALID(one)) {
347                 mf->ptr = (char *)""; /* does not matter */
348                 mf->size = 0;
349                 return 0;
350         }
351         else if (diff_populate_filespec(one, 0))
352                 return -1;
353         mf->ptr = one->data;
354         mf->size = one->size;
355         return 0;
358 struct diff_words_buffer {
359         mmfile_t text;
360         long alloc;
361         long current; /* output pointer */
362         int suppressed_newline;
363 };
365 static void diff_words_append(char *line, unsigned long len,
366                 struct diff_words_buffer *buffer)
368         if (buffer->text.size + len > buffer->alloc) {
369                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
370                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
371         }
372         line++;
373         len--;
374         memcpy(buffer->text.ptr + buffer->text.size, line, len);
375         buffer->text.size += len;
378 struct diff_words_data {
379         struct xdiff_emit_state xm;
380         struct diff_words_buffer minus, plus;
381         FILE *file;
382 };
384 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
385                 int suppress_newline)
387         const char *ptr;
388         int eol = 0;
390         if (len == 0)
391                 return;
393         ptr  = buffer->text.ptr + buffer->current;
394         buffer->current += len;
396         if (ptr[len - 1] == '\n') {
397                 eol = 1;
398                 len--;
399         }
401         fputs(diff_get_color(1, color), file);
402         fwrite(ptr, len, 1, file);
403         fputs(diff_get_color(1, DIFF_RESET), file);
405         if (eol) {
406                 if (suppress_newline)
407                         buffer->suppressed_newline = 1;
408                 else
409                         putc('\n', file);
410         }
413 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
415         struct diff_words_data *diff_words = priv;
417         if (diff_words->minus.suppressed_newline) {
418                 if (line[0] != '+')
419                         putc('\n', diff_words->file);
420                 diff_words->minus.suppressed_newline = 0;
421         }
423         len--;
424         switch (line[0]) {
425                 case '-':
426                         print_word(diff_words->file,
427                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
428                         break;
429                 case '+':
430                         print_word(diff_words->file,
431                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
432                         break;
433                 case ' ':
434                         print_word(diff_words->file,
435                                    &diff_words->plus, len, DIFF_PLAIN, 0);
436                         diff_words->minus.current += len;
437                         break;
438         }
441 /* this executes the word diff on the accumulated buffers */
442 static void diff_words_show(struct diff_words_data *diff_words)
444         xpparam_t xpp;
445         xdemitconf_t xecfg;
446         xdemitcb_t ecb;
447         mmfile_t minus, plus;
448         int i;
450         memset(&xecfg, 0, sizeof(xecfg));
451         minus.size = diff_words->minus.text.size;
452         minus.ptr = xmalloc(minus.size);
453         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
454         for (i = 0; i < minus.size; i++)
455                 if (isspace(minus.ptr[i]))
456                         minus.ptr[i] = '\n';
457         diff_words->minus.current = 0;
459         plus.size = diff_words->plus.text.size;
460         plus.ptr = xmalloc(plus.size);
461         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
462         for (i = 0; i < plus.size; i++)
463                 if (isspace(plus.ptr[i]))
464                         plus.ptr[i] = '\n';
465         diff_words->plus.current = 0;
467         xpp.flags = XDF_NEED_MINIMAL;
468         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
469         ecb.outf = xdiff_outf;
470         ecb.priv = diff_words;
471         diff_words->xm.consume = fn_out_diff_words_aux;
472         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
474         free(minus.ptr);
475         free(plus.ptr);
476         diff_words->minus.text.size = diff_words->plus.text.size = 0;
478         if (diff_words->minus.suppressed_newline) {
479                 putc('\n', diff_words->file);
480                 diff_words->minus.suppressed_newline = 0;
481         }
484 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
486 struct emit_callback {
487         struct xdiff_emit_state xm;
488         int nparents, color_diff;
489         unsigned ws_rule;
490         sane_truncate_fn truncate;
491         const char **label_path;
492         struct diff_words_data *diff_words;
493         int *found_changesp;
494         FILE *file;
495 };
497 static void free_diff_words_data(struct emit_callback *ecbdata)
499         if (ecbdata->diff_words) {
500                 /* flush buffers */
501                 if (ecbdata->diff_words->minus.text.size ||
502                                 ecbdata->diff_words->plus.text.size)
503                         diff_words_show(ecbdata->diff_words);
505                 free (ecbdata->diff_words->minus.text.ptr);
506                 free (ecbdata->diff_words->plus.text.ptr);
507                 free(ecbdata->diff_words);
508                 ecbdata->diff_words = NULL;
509         }
512 const char *diff_get_color(int diff_use_color, enum color_diff ix)
514         if (diff_use_color)
515                 return diff_colors[ix];
516         return "";
519 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
521         int has_trailing_newline = (len > 0 && line[len-1] == '\n');
522         if (has_trailing_newline)
523                 len--;
525         fputs(set, file);
526         fwrite(line, len, 1, file);
527         fputs(reset, file);
528         if (has_trailing_newline)
529                 fputc('\n', file);
532 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
534         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
535         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
537         if (!*ws)
538                 emit_line(ecbdata->file, set, reset, line, len);
539         else {
540                 /* Emit just the prefix, then the rest. */
541                 emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
542                 ws_check_emit(line + ecbdata->nparents,
543                               len - ecbdata->nparents, ecbdata->ws_rule,
544                               ecbdata->file, set, reset, ws);
545         }
548 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
550         const char *cp;
551         unsigned long allot;
552         size_t l = len;
554         if (ecb->truncate)
555                 return ecb->truncate(line, len);
556         cp = line;
557         allot = l;
558         while (0 < l) {
559                 (void) utf8_width(&cp, &l);
560                 if (!cp)
561                         break; /* truncated in the middle? */
562         }
563         return allot - l;
566 static void fn_out_consume(void *priv, char *line, unsigned long len)
568         int i;
569         int color;
570         struct emit_callback *ecbdata = priv;
571         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
572         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
573         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
575         *(ecbdata->found_changesp) = 1;
577         if (ecbdata->label_path[0]) {
578                 const char *name_a_tab, *name_b_tab;
580                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
581                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
583                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
584                         meta, ecbdata->label_path[0], reset, name_a_tab);
585                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
586                         meta, ecbdata->label_path[1], reset, name_b_tab);
587                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
588         }
590         if (diff_suppress_blank_empty
591             && len == 2 && line[0] == ' ' && line[1] == '\n') {
592                 line[0] = '\n';
593                 len = 1;
594         }
596         /* This is not really necessary for now because
597          * this codepath only deals with two-way diffs.
598          */
599         for (i = 0; i < len && line[i] == '@'; i++)
600                 ;
601         if (2 <= i && i < len && line[i] == ' ') {
602                 ecbdata->nparents = i - 1;
603                 len = sane_truncate_line(ecbdata, line, len);
604                 emit_line(ecbdata->file,
605                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
606                           reset, line, len);
607                 if (line[len-1] != '\n')
608                         putc('\n', ecbdata->file);
609                 return;
610         }
612         if (len < ecbdata->nparents) {
613                 emit_line(ecbdata->file, reset, reset, line, len);
614                 return;
615         }
617         color = DIFF_PLAIN;
618         if (ecbdata->diff_words && ecbdata->nparents != 1)
619                 /* fall back to normal diff */
620                 free_diff_words_data(ecbdata);
621         if (ecbdata->diff_words) {
622                 if (line[0] == '-') {
623                         diff_words_append(line, len,
624                                           &ecbdata->diff_words->minus);
625                         return;
626                 } else if (line[0] == '+') {
627                         diff_words_append(line, len,
628                                           &ecbdata->diff_words->plus);
629                         return;
630                 }
631                 if (ecbdata->diff_words->minus.text.size ||
632                     ecbdata->diff_words->plus.text.size)
633                         diff_words_show(ecbdata->diff_words);
634                 line++;
635                 len--;
636                 emit_line(ecbdata->file, plain, reset, line, len);
637                 return;
638         }
639         for (i = 0; i < ecbdata->nparents && len; i++) {
640                 if (line[i] == '-')
641                         color = DIFF_FILE_OLD;
642                 else if (line[i] == '+')
643                         color = DIFF_FILE_NEW;
644         }
646         if (color != DIFF_FILE_NEW) {
647                 emit_line(ecbdata->file,
648                           diff_get_color(ecbdata->color_diff, color),
649                           reset, line, len);
650                 return;
651         }
652         emit_add_line(reset, ecbdata, line, len);
655 static char *pprint_rename(const char *a, const char *b)
657         const char *old = a;
658         const char *new = b;
659         struct strbuf name;
660         int pfx_length, sfx_length;
661         int len_a = strlen(a);
662         int len_b = strlen(b);
663         int a_midlen, b_midlen;
664         int qlen_a = quote_c_style(a, NULL, NULL, 0);
665         int qlen_b = quote_c_style(b, NULL, NULL, 0);
667         strbuf_init(&name, 0);
668         if (qlen_a || qlen_b) {
669                 quote_c_style(a, &name, NULL, 0);
670                 strbuf_addstr(&name, " => ");
671                 quote_c_style(b, &name, NULL, 0);
672                 return strbuf_detach(&name, NULL);
673         }
675         /* Find common prefix */
676         pfx_length = 0;
677         while (*old && *new && *old == *new) {
678                 if (*old == '/')
679                         pfx_length = old - a + 1;
680                 old++;
681                 new++;
682         }
684         /* Find common suffix */
685         old = a + len_a;
686         new = b + len_b;
687         sfx_length = 0;
688         while (a <= old && b <= new && *old == *new) {
689                 if (*old == '/')
690                         sfx_length = len_a - (old - a);
691                 old--;
692                 new--;
693         }
695         /*
696          * pfx{mid-a => mid-b}sfx
697          * {pfx-a => pfx-b}sfx
698          * pfx{sfx-a => sfx-b}
699          * name-a => name-b
700          */
701         a_midlen = len_a - pfx_length - sfx_length;
702         b_midlen = len_b - pfx_length - sfx_length;
703         if (a_midlen < 0)
704                 a_midlen = 0;
705         if (b_midlen < 0)
706                 b_midlen = 0;
708         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
709         if (pfx_length + sfx_length) {
710                 strbuf_add(&name, a, pfx_length);
711                 strbuf_addch(&name, '{');
712         }
713         strbuf_add(&name, a + pfx_length, a_midlen);
714         strbuf_addstr(&name, " => ");
715         strbuf_add(&name, b + pfx_length, b_midlen);
716         if (pfx_length + sfx_length) {
717                 strbuf_addch(&name, '}');
718                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
719         }
720         return strbuf_detach(&name, NULL);
723 struct diffstat_t {
724         struct xdiff_emit_state xm;
726         int nr;
727         int alloc;
728         struct diffstat_file {
729                 char *from_name;
730                 char *name;
731                 char *print_name;
732                 unsigned is_unmerged:1;
733                 unsigned is_binary:1;
734                 unsigned is_renamed:1;
735                 unsigned int added, deleted;
736         } **files;
737 };
739 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
740                                           const char *name_a,
741                                           const char *name_b)
743         struct diffstat_file *x;
744         x = xcalloc(sizeof (*x), 1);
745         if (diffstat->nr == diffstat->alloc) {
746                 diffstat->alloc = alloc_nr(diffstat->alloc);
747                 diffstat->files = xrealloc(diffstat->files,
748                                 diffstat->alloc * sizeof(x));
749         }
750         diffstat->files[diffstat->nr++] = x;
751         if (name_b) {
752                 x->from_name = xstrdup(name_a);
753                 x->name = xstrdup(name_b);
754                 x->is_renamed = 1;
755         }
756         else {
757                 x->from_name = NULL;
758                 x->name = xstrdup(name_a);
759         }
760         return x;
763 static void diffstat_consume(void *priv, char *line, unsigned long len)
765         struct diffstat_t *diffstat = priv;
766         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
768         if (line[0] == '+')
769                 x->added++;
770         else if (line[0] == '-')
771                 x->deleted++;
774 const char mime_boundary_leader[] = "------------";
776 static int scale_linear(int it, int width, int max_change)
778         /*
779          * make sure that at least one '-' is printed if there were deletions,
780          * and likewise for '+'.
781          */
782         if (max_change < 2)
783                 return it;
784         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
787 static void show_name(FILE *file,
788                       const char *prefix, const char *name, int len,
789                       const char *reset, const char *set)
791         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
794 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
796         if (cnt <= 0)
797                 return;
798         fprintf(file, "%s", set);
799         while (cnt--)
800                 putc(ch, file);
801         fprintf(file, "%s", reset);
804 static void fill_print_name(struct diffstat_file *file)
806         char *pname;
808         if (file->print_name)
809                 return;
811         if (!file->is_renamed) {
812                 struct strbuf buf;
813                 strbuf_init(&buf, 0);
814                 if (quote_c_style(file->name, &buf, NULL, 0)) {
815                         pname = strbuf_detach(&buf, NULL);
816                 } else {
817                         pname = file->name;
818                         strbuf_release(&buf);
819                 }
820         } else {
821                 pname = pprint_rename(file->from_name, file->name);
822         }
823         file->print_name = pname;
826 static void show_stats(struct diffstat_t* data, struct diff_options *options)
828         int i, len, add, del, total, adds = 0, dels = 0;
829         int max_change = 0, max_len = 0;
830         int total_files = data->nr;
831         int width, name_width;
832         const char *reset, *set, *add_c, *del_c;
834         if (data->nr == 0)
835                 return;
837         width = options->stat_width ? options->stat_width : 80;
838         name_width = options->stat_name_width ? options->stat_name_width : 50;
840         /* Sanity: give at least 5 columns to the graph,
841          * but leave at least 10 columns for the name.
842          */
843         if (width < 25)
844                 width = 25;
845         if (name_width < 10)
846                 name_width = 10;
847         else if (width < name_width + 15)
848                 name_width = width - 15;
850         /* Find the longest filename and max number of changes */
851         reset = diff_get_color_opt(options, DIFF_RESET);
852         set   = diff_get_color_opt(options, DIFF_PLAIN);
853         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
854         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
856         for (i = 0; i < data->nr; i++) {
857                 struct diffstat_file *file = data->files[i];
858                 int change = file->added + file->deleted;
859                 fill_print_name(file);
860                 len = strlen(file->print_name);
861                 if (max_len < len)
862                         max_len = len;
864                 if (file->is_binary || file->is_unmerged)
865                         continue;
866                 if (max_change < change)
867                         max_change = change;
868         }
870         /* Compute the width of the graph part;
871          * 10 is for one blank at the beginning of the line plus
872          * " | count " between the name and the graph.
873          *
874          * From here on, name_width is the width of the name area,
875          * and width is the width of the graph area.
876          */
877         name_width = (name_width < max_len) ? name_width : max_len;
878         if (width < (name_width + 10) + max_change)
879                 width = width - (name_width + 10);
880         else
881                 width = max_change;
883         for (i = 0; i < data->nr; i++) {
884                 const char *prefix = "";
885                 char *name = data->files[i]->print_name;
886                 int added = data->files[i]->added;
887                 int deleted = data->files[i]->deleted;
888                 int name_len;
890                 /*
891                  * "scale" the filename
892                  */
893                 len = name_width;
894                 name_len = strlen(name);
895                 if (name_width < name_len) {
896                         char *slash;
897                         prefix = "...";
898                         len -= 3;
899                         name += name_len - len;
900                         slash = strchr(name, '/');
901                         if (slash)
902                                 name = slash;
903                 }
905                 if (data->files[i]->is_binary) {
906                         show_name(options->file, prefix, name, len, reset, set);
907                         fprintf(options->file, "  Bin ");
908                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
909                         fprintf(options->file, " -> ");
910                         fprintf(options->file, "%s%d%s", add_c, added, reset);
911                         fprintf(options->file, " bytes");
912                         fprintf(options->file, "\n");
913                         continue;
914                 }
915                 else if (data->files[i]->is_unmerged) {
916                         show_name(options->file, prefix, name, len, reset, set);
917                         fprintf(options->file, "  Unmerged\n");
918                         continue;
919                 }
920                 else if (!data->files[i]->is_renamed &&
921                          (added + deleted == 0)) {
922                         total_files--;
923                         continue;
924                 }
926                 /*
927                  * scale the add/delete
928                  */
929                 add = added;
930                 del = deleted;
931                 total = add + del;
932                 adds += add;
933                 dels += del;
935                 if (width <= max_change) {
936                         add = scale_linear(add, width, max_change);
937                         del = scale_linear(del, width, max_change);
938                         total = add + del;
939                 }
940                 show_name(options->file, prefix, name, len, reset, set);
941                 fprintf(options->file, "%5d%s", added + deleted,
942                                 added + deleted ? " " : "");
943                 show_graph(options->file, '+', add, add_c, reset);
944                 show_graph(options->file, '-', del, del_c, reset);
945                 fprintf(options->file, "\n");
946         }
947         fprintf(options->file,
948                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
949                set, total_files, adds, dels, reset);
952 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
954         int i, adds = 0, dels = 0, total_files = data->nr;
956         if (data->nr == 0)
957                 return;
959         for (i = 0; i < data->nr; i++) {
960                 if (!data->files[i]->is_binary &&
961                     !data->files[i]->is_unmerged) {
962                         int added = data->files[i]->added;
963                         int deleted= data->files[i]->deleted;
964                         if (!data->files[i]->is_renamed &&
965                             (added + deleted == 0)) {
966                                 total_files--;
967                         } else {
968                                 adds += added;
969                                 dels += deleted;
970                         }
971                 }
972         }
973         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
974                total_files, adds, dels);
977 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
979         int i;
981         if (data->nr == 0)
982                 return;
984         for (i = 0; i < data->nr; i++) {
985                 struct diffstat_file *file = data->files[i];
987                 if (file->is_binary)
988                         fprintf(options->file, "-\t-\t");
989                 else
990                         fprintf(options->file,
991                                 "%d\t%d\t", file->added, file->deleted);
992                 if (options->line_termination) {
993                         fill_print_name(file);
994                         if (!file->is_renamed)
995                                 write_name_quoted(file->name, options->file,
996                                                   options->line_termination);
997                         else {
998                                 fputs(file->print_name, options->file);
999                                 putc(options->line_termination, options->file);
1000                         }
1001                 } else {
1002                         if (file->is_renamed) {
1003                                 putc('\0', options->file);
1004                                 write_name_quoted(file->from_name, options->file, '\0');
1005                         }
1006                         write_name_quoted(file->name, options->file, '\0');
1007                 }
1008         }
1011 struct dirstat_file {
1012         const char *name;
1013         unsigned long changed;
1014 };
1016 struct dirstat_dir {
1017         struct dirstat_file *files;
1018         int alloc, nr, percent, cumulative;
1019 };
1021 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1023         unsigned long this_dir = 0;
1024         unsigned int sources = 0;
1026         while (dir->nr) {
1027                 struct dirstat_file *f = dir->files;
1028                 int namelen = strlen(f->name);
1029                 unsigned long this;
1030                 char *slash;
1032                 if (namelen < baselen)
1033                         break;
1034                 if (memcmp(f->name, base, baselen))
1035                         break;
1036                 slash = strchr(f->name + baselen, '/');
1037                 if (slash) {
1038                         int newbaselen = slash + 1 - f->name;
1039                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1040                         sources++;
1041                 } else {
1042                         this = f->changed;
1043                         dir->files++;
1044                         dir->nr--;
1045                         sources += 2;
1046                 }
1047                 this_dir += this;
1048         }
1050         /*
1051          * We don't report dirstat's for
1052          *  - the top level
1053          *  - or cases where everything came from a single directory
1054          *    under this directory (sources == 1).
1055          */
1056         if (baselen && sources != 1) {
1057                 int permille = this_dir * 1000 / changed;
1058                 if (permille) {
1059                         int percent = permille / 10;
1060                         if (percent >= dir->percent) {
1061                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1062                                 if (!dir->cumulative)
1063                                         return 0;
1064                         }
1065                 }
1066         }
1067         return this_dir;
1070 static void show_dirstat(struct diff_options *options)
1072         int i;
1073         unsigned long changed;
1074         struct dirstat_dir dir;
1075         struct diff_queue_struct *q = &diff_queued_diff;
1077         dir.files = NULL;
1078         dir.alloc = 0;
1079         dir.nr = 0;
1080         dir.percent = options->dirstat_percent;
1081         dir.cumulative = options->output_format & DIFF_FORMAT_CUMULATIVE;
1083         changed = 0;
1084         for (i = 0; i < q->nr; i++) {
1085                 struct diff_filepair *p = q->queue[i];
1086                 const char *name;
1087                 unsigned long copied, added, damage;
1089                 name = p->one->path ? p->one->path : p->two->path;
1091                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1092                         diff_populate_filespec(p->one, 0);
1093                         diff_populate_filespec(p->two, 0);
1094                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1095                                                &copied, &added);
1096                         diff_free_filespec_data(p->one);
1097                         diff_free_filespec_data(p->two);
1098                 } else if (DIFF_FILE_VALID(p->one)) {
1099                         diff_populate_filespec(p->one, 1);
1100                         copied = added = 0;
1101                         diff_free_filespec_data(p->one);
1102                 } else if (DIFF_FILE_VALID(p->two)) {
1103                         diff_populate_filespec(p->two, 1);
1104                         copied = 0;
1105                         added = p->two->size;
1106                         diff_free_filespec_data(p->two);
1107                 } else
1108                         continue;
1110                 /*
1111                  * Original minus copied is the removed material,
1112                  * added is the new material.  They are both damages
1113                  * made to the preimage.
1114                  */
1115                 damage = (p->one->size - copied) + added;
1117                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1118                 dir.files[dir.nr].name = name;
1119                 dir.files[dir.nr].changed = damage;
1120                 changed += damage;
1121                 dir.nr++;
1122         }
1124         /* This can happen even with many files, if everything was renames */
1125         if (!changed)
1126                 return;
1128         /* Show all directories with more than x% of the changes */
1129         gather_dirstat(options->file, &dir, changed, "", 0);
1132 static void free_diffstat_info(struct diffstat_t *diffstat)
1134         int i;
1135         for (i = 0; i < diffstat->nr; i++) {
1136                 struct diffstat_file *f = diffstat->files[i];
1137                 if (f->name != f->print_name)
1138                         free(f->print_name);
1139                 free(f->name);
1140                 free(f->from_name);
1141                 free(f);
1142         }
1143         free(diffstat->files);
1146 struct checkdiff_t {
1147         struct xdiff_emit_state xm;
1148         const char *filename;
1149         int lineno;
1150         struct diff_options *o;
1151         unsigned ws_rule;
1152         unsigned status;
1153         int trailing_blanks_start;
1154 };
1156 static int is_conflict_marker(const char *line, unsigned long len)
1158         char firstchar;
1159         int cnt;
1161         if (len < 8)
1162                 return 0;
1163         firstchar = line[0];
1164         switch (firstchar) {
1165         case '=': case '>': case '<':
1166                 break;
1167         default:
1168                 return 0;
1169         }
1170         for (cnt = 1; cnt < 7; cnt++)
1171                 if (line[cnt] != firstchar)
1172                         return 0;
1173         /* line[0] thru line[6] are same as firstchar */
1174         if (firstchar == '=') {
1175                 /* divider between ours and theirs? */
1176                 if (len != 8 || line[7] != '\n')
1177                         return 0;
1178         } else if (len < 8 || !isspace(line[7])) {
1179                 /* not divider before ours nor after theirs */
1180                 return 0;
1181         }
1182         return 1;
1185 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1187         struct checkdiff_t *data = priv;
1188         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1189         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1190         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1191         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1192         char *err;
1194         if (line[0] == '+') {
1195                 unsigned bad;
1196                 data->lineno++;
1197                 if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1198                         data->trailing_blanks_start = 0;
1199                 else if (!data->trailing_blanks_start)
1200                         data->trailing_blanks_start = data->lineno;
1201                 if (is_conflict_marker(line + 1, len - 1)) {
1202                         data->status |= 1;
1203                         fprintf(data->o->file,
1204                                 "%s:%d: leftover conflict marker\n",
1205                                 data->filename, data->lineno);
1206                 }
1207                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1208                 if (!bad)
1209                         return;
1210                 data->status |= bad;
1211                 err = whitespace_error_string(bad);
1212                 fprintf(data->o->file, "%s:%d: %s.\n",
1213                         data->filename, data->lineno, err);
1214                 free(err);
1215                 emit_line(data->o->file, set, reset, line, 1);
1216                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1217                               data->o->file, set, reset, ws);
1218         } else if (line[0] == ' ') {
1219                 data->lineno++;
1220                 data->trailing_blanks_start = 0;
1221         } else if (line[0] == '@') {
1222                 char *plus = strchr(line, '+');
1223                 if (plus)
1224                         data->lineno = strtol(plus, NULL, 10) - 1;
1225                 else
1226                         die("invalid diff");
1227                 data->trailing_blanks_start = 0;
1228         }
1231 static unsigned char *deflate_it(char *data,
1232                                  unsigned long size,
1233                                  unsigned long *result_size)
1235         int bound;
1236         unsigned char *deflated;
1237         z_stream stream;
1239         memset(&stream, 0, sizeof(stream));
1240         deflateInit(&stream, zlib_compression_level);
1241         bound = deflateBound(&stream, size);
1242         deflated = xmalloc(bound);
1243         stream.next_out = deflated;
1244         stream.avail_out = bound;
1246         stream.next_in = (unsigned char *)data;
1247         stream.avail_in = size;
1248         while (deflate(&stream, Z_FINISH) == Z_OK)
1249                 ; /* nothing */
1250         deflateEnd(&stream);
1251         *result_size = stream.total_out;
1252         return deflated;
1255 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1257         void *cp;
1258         void *delta;
1259         void *deflated;
1260         void *data;
1261         unsigned long orig_size;
1262         unsigned long delta_size;
1263         unsigned long deflate_size;
1264         unsigned long data_size;
1266         /* We could do deflated delta, or we could do just deflated two,
1267          * whichever is smaller.
1268          */
1269         delta = NULL;
1270         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1271         if (one->size && two->size) {
1272                 delta = diff_delta(one->ptr, one->size,
1273                                    two->ptr, two->size,
1274                                    &delta_size, deflate_size);
1275                 if (delta) {
1276                         void *to_free = delta;
1277                         orig_size = delta_size;
1278                         delta = deflate_it(delta, delta_size, &delta_size);
1279                         free(to_free);
1280                 }
1281         }
1283         if (delta && delta_size < deflate_size) {
1284                 fprintf(file, "delta %lu\n", orig_size);
1285                 free(deflated);
1286                 data = delta;
1287                 data_size = delta_size;
1288         }
1289         else {
1290                 fprintf(file, "literal %lu\n", two->size);
1291                 free(delta);
1292                 data = deflated;
1293                 data_size = deflate_size;
1294         }
1296         /* emit data encoded in base85 */
1297         cp = data;
1298         while (data_size) {
1299                 int bytes = (52 < data_size) ? 52 : data_size;
1300                 char line[70];
1301                 data_size -= bytes;
1302                 if (bytes <= 26)
1303                         line[0] = bytes + 'A' - 1;
1304                 else
1305                         line[0] = bytes - 26 + 'a' - 1;
1306                 encode_85(line + 1, cp, bytes);
1307                 cp = (char *) cp + bytes;
1308                 fputs(line, file);
1309                 fputc('\n', file);
1310         }
1311         fprintf(file, "\n");
1312         free(data);
1315 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1317         fprintf(file, "GIT binary patch\n");
1318         emit_binary_diff_body(file, one, two);
1319         emit_binary_diff_body(file, two, one);
1322 static void setup_diff_attr_check(struct git_attr_check *check)
1324         static struct git_attr *attr_diff;
1326         if (!attr_diff) {
1327                 attr_diff = git_attr("diff", 4);
1328         }
1329         check[0].attr = attr_diff;
1332 static void diff_filespec_check_attr(struct diff_filespec *one)
1334         struct git_attr_check attr_diff_check;
1335         int check_from_data = 0;
1337         if (one->checked_attr)
1338                 return;
1340         setup_diff_attr_check(&attr_diff_check);
1341         one->is_binary = 0;
1342         one->funcname_pattern_ident = NULL;
1344         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1345                 const char *value;
1347                 /* binaryness */
1348                 value = attr_diff_check.value;
1349                 if (ATTR_TRUE(value))
1350                         ;
1351                 else if (ATTR_FALSE(value))
1352                         one->is_binary = 1;
1353                 else
1354                         check_from_data = 1;
1356                 /* funcname pattern ident */
1357                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1358                         ;
1359                 else
1360                         one->funcname_pattern_ident = value;
1361         }
1363         if (check_from_data) {
1364                 if (!one->data && DIFF_FILE_VALID(one))
1365                         diff_populate_filespec(one, 0);
1367                 if (one->data)
1368                         one->is_binary = buffer_is_binary(one->data, one->size);
1369         }
1372 int diff_filespec_is_binary(struct diff_filespec *one)
1374         diff_filespec_check_attr(one);
1375         return one->is_binary;
1378 static const char *funcname_pattern(const char *ident)
1380         struct funcname_pattern *pp;
1382         for (pp = funcname_pattern_list; pp; pp = pp->next)
1383                 if (!strcmp(ident, pp->name))
1384                         return pp->pattern;
1385         return NULL;
1388 static struct builtin_funcname_pattern {
1389         const char *name;
1390         const char *pattern;
1391 } builtin_funcname_pattern[] = {
1392         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1393                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1394                         "^[     ]*\\(\\([       ]*"
1395                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1396                         "[      ]*([^;]*\\)$" },
1397         { "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
1398                         "destructor\\|interface\\|implementation\\|"
1399                         "initialization\\|finalization\\)[ \t]*.*\\)$"
1400                         "\\|"
1401                         "^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
1402                         },
1403         { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
1404         { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
1405         { "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
1406 };
1408 static const char *diff_funcname_pattern(struct diff_filespec *one)
1410         const char *ident, *pattern;
1411         int i;
1413         diff_filespec_check_attr(one);
1414         ident = one->funcname_pattern_ident;
1416         if (!ident)
1417                 /*
1418                  * If the config file has "funcname.default" defined, that
1419                  * regexp is used; otherwise NULL is returned and xemit uses
1420                  * the built-in default.
1421                  */
1422                 return funcname_pattern("default");
1424         /* Look up custom "funcname.$ident" regexp from config. */
1425         pattern = funcname_pattern(ident);
1426         if (pattern)
1427                 return pattern;
1429         /*
1430          * And define built-in fallback patterns here.  Note that
1431          * these can be overridden by the user's config settings.
1432          */
1433         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1434                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1435                         return builtin_funcname_pattern[i].pattern;
1437         return NULL;
1440 static void builtin_diff(const char *name_a,
1441                          const char *name_b,
1442                          struct diff_filespec *one,
1443                          struct diff_filespec *two,
1444                          const char *xfrm_msg,
1445                          struct diff_options *o,
1446                          int complete_rewrite)
1448         mmfile_t mf1, mf2;
1449         const char *lbl[2];
1450         char *a_one, *b_two;
1451         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1452         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1454         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1455         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1456         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1457         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1458         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1459         if (lbl[0][0] == '/') {
1460                 /* /dev/null */
1461                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1462                 if (xfrm_msg && xfrm_msg[0])
1463                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1464         }
1465         else if (lbl[1][0] == '/') {
1466                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1467                 if (xfrm_msg && xfrm_msg[0])
1468                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1469         }
1470         else {
1471                 if (one->mode != two->mode) {
1472                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1473                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1474                 }
1475                 if (xfrm_msg && xfrm_msg[0])
1476                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1477                 /*
1478                  * we do not run diff between different kind
1479                  * of objects.
1480                  */
1481                 if ((one->mode ^ two->mode) & S_IFMT)
1482                         goto free_ab_and_return;
1483                 if (complete_rewrite) {
1484                         emit_rewrite_diff(name_a, name_b, one, two, o);
1485                         o->found_changes = 1;
1486                         goto free_ab_and_return;
1487                 }
1488         }
1490         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1491                 die("unable to read files to diff");
1493         if (!DIFF_OPT_TST(o, TEXT) &&
1494             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1495                 /* Quite common confusing case */
1496                 if (mf1.size == mf2.size &&
1497                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1498                         goto free_ab_and_return;
1499                 if (DIFF_OPT_TST(o, BINARY))
1500                         emit_binary_diff(o->file, &mf1, &mf2);
1501                 else
1502                         fprintf(o->file, "Binary files %s and %s differ\n",
1503                                 lbl[0], lbl[1]);
1504                 o->found_changes = 1;
1505         }
1506         else {
1507                 /* Crazy xdl interfaces.. */
1508                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1509                 xpparam_t xpp;
1510                 xdemitconf_t xecfg;
1511                 xdemitcb_t ecb;
1512                 struct emit_callback ecbdata;
1513                 const char *funcname_pattern;
1515                 funcname_pattern = diff_funcname_pattern(one);
1516                 if (!funcname_pattern)
1517                         funcname_pattern = diff_funcname_pattern(two);
1519                 memset(&xecfg, 0, sizeof(xecfg));
1520                 memset(&ecbdata, 0, sizeof(ecbdata));
1521                 ecbdata.label_path = lbl;
1522                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1523                 ecbdata.found_changesp = &o->found_changes;
1524                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1525                 ecbdata.file = o->file;
1526                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1527                 xecfg.ctxlen = o->context;
1528                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1529                 if (funcname_pattern)
1530                         xdiff_set_find_func(&xecfg, funcname_pattern);
1531                 if (!diffopts)
1532                         ;
1533                 else if (!prefixcmp(diffopts, "--unified="))
1534                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1535                 else if (!prefixcmp(diffopts, "-u"))
1536                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1537                 ecb.outf = xdiff_outf;
1538                 ecb.priv = &ecbdata;
1539                 ecbdata.xm.consume = fn_out_consume;
1540                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1541                         ecbdata.diff_words =
1542                                 xcalloc(1, sizeof(struct diff_words_data));
1543                         ecbdata.diff_words->file = o->file;
1544                 }
1545                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1546                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1547                         free_diff_words_data(&ecbdata);
1548         }
1550  free_ab_and_return:
1551         diff_free_filespec_data(one);
1552         diff_free_filespec_data(two);
1553         free(a_one);
1554         free(b_two);
1555         return;
1558 static void builtin_diffstat(const char *name_a, const char *name_b,
1559                              struct diff_filespec *one,
1560                              struct diff_filespec *two,
1561                              struct diffstat_t *diffstat,
1562                              struct diff_options *o,
1563                              int complete_rewrite)
1565         mmfile_t mf1, mf2;
1566         struct diffstat_file *data;
1568         data = diffstat_add(diffstat, name_a, name_b);
1570         if (!one || !two) {
1571                 data->is_unmerged = 1;
1572                 return;
1573         }
1574         if (complete_rewrite) {
1575                 diff_populate_filespec(one, 0);
1576                 diff_populate_filespec(two, 0);
1577                 data->deleted = count_lines(one->data, one->size);
1578                 data->added = count_lines(two->data, two->size);
1579                 goto free_and_return;
1580         }
1581         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1582                 die("unable to read files to diff");
1584         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1585                 data->is_binary = 1;
1586                 data->added = mf2.size;
1587                 data->deleted = mf1.size;
1588         } else {
1589                 /* Crazy xdl interfaces.. */
1590                 xpparam_t xpp;
1591                 xdemitconf_t xecfg;
1592                 xdemitcb_t ecb;
1594                 memset(&xecfg, 0, sizeof(xecfg));
1595                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1596                 ecb.outf = xdiff_outf;
1597                 ecb.priv = diffstat;
1598                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1599         }
1601  free_and_return:
1602         diff_free_filespec_data(one);
1603         diff_free_filespec_data(two);
1606 static void builtin_checkdiff(const char *name_a, const char *name_b,
1607                               const char *attr_path,
1608                               struct diff_filespec *one,
1609                               struct diff_filespec *two,
1610                               struct diff_options *o)
1612         mmfile_t mf1, mf2;
1613         struct checkdiff_t data;
1615         if (!two)
1616                 return;
1618         memset(&data, 0, sizeof(data));
1619         data.xm.consume = checkdiff_consume;
1620         data.filename = name_b ? name_b : name_a;
1621         data.lineno = 0;
1622         data.o = o;
1623         data.ws_rule = whitespace_rule(attr_path);
1625         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1626                 die("unable to read files to diff");
1628         /*
1629          * All the other codepaths check both sides, but not checking
1630          * the "old" side here is deliberate.  We are checking the newly
1631          * introduced changes, and as long as the "new" side is text, we
1632          * can and should check what it introduces.
1633          */
1634         if (diff_filespec_is_binary(two))
1635                 goto free_and_return;
1636         else {
1637                 /* Crazy xdl interfaces.. */
1638                 xpparam_t xpp;
1639                 xdemitconf_t xecfg;
1640                 xdemitcb_t ecb;
1642                 memset(&xecfg, 0, sizeof(xecfg));
1643                 xpp.flags = XDF_NEED_MINIMAL;
1644                 ecb.outf = xdiff_outf;
1645                 ecb.priv = &data;
1646                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1648                 if ((data.ws_rule & WS_TRAILING_SPACE) &&
1649                     data.trailing_blanks_start) {
1650                         fprintf(o->file, "%s:%d: ends with blank lines.\n",
1651                                 data.filename, data.trailing_blanks_start);
1652                         data.status = 1; /* report errors */
1653                 }
1654         }
1655  free_and_return:
1656         diff_free_filespec_data(one);
1657         diff_free_filespec_data(two);
1658         if (data.status)
1659                 DIFF_OPT_SET(o, CHECK_FAILED);
1662 struct diff_filespec *alloc_filespec(const char *path)
1664         int namelen = strlen(path);
1665         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1667         memset(spec, 0, sizeof(*spec));
1668         spec->path = (char *)(spec + 1);
1669         memcpy(spec->path, path, namelen+1);
1670         spec->count = 1;
1671         return spec;
1674 void free_filespec(struct diff_filespec *spec)
1676         if (!--spec->count) {
1677                 diff_free_filespec_data(spec);
1678                 free(spec);
1679         }
1682 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1683                    unsigned short mode)
1685         if (mode) {
1686                 spec->mode = canon_mode(mode);
1687                 hashcpy(spec->sha1, sha1);
1688                 spec->sha1_valid = !is_null_sha1(sha1);
1689         }
1692 /*
1693  * Given a name and sha1 pair, if the index tells us the file in
1694  * the work tree has that object contents, return true, so that
1695  * prepare_temp_file() does not have to inflate and extract.
1696  */
1697 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1699         struct cache_entry *ce;
1700         struct stat st;
1701         int pos, len;
1703         /* We do not read the cache ourselves here, because the
1704          * benchmark with my previous version that always reads cache
1705          * shows that it makes things worse for diff-tree comparing
1706          * two linux-2.6 kernel trees in an already checked out work
1707          * tree.  This is because most diff-tree comparisons deal with
1708          * only a small number of files, while reading the cache is
1709          * expensive for a large project, and its cost outweighs the
1710          * savings we get by not inflating the object to a temporary
1711          * file.  Practically, this code only helps when we are used
1712          * by diff-cache --cached, which does read the cache before
1713          * calling us.
1714          */
1715         if (!active_cache)
1716                 return 0;
1718         /* We want to avoid the working directory if our caller
1719          * doesn't need the data in a normal file, this system
1720          * is rather slow with its stat/open/mmap/close syscalls,
1721          * and the object is contained in a pack file.  The pack
1722          * is probably already open and will be faster to obtain
1723          * the data through than the working directory.  Loose
1724          * objects however would tend to be slower as they need
1725          * to be individually opened and inflated.
1726          */
1727         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1728                 return 0;
1730         len = strlen(name);
1731         pos = cache_name_pos(name, len);
1732         if (pos < 0)
1733                 return 0;
1734         ce = active_cache[pos];
1736         /*
1737          * This is not the sha1 we are looking for, or
1738          * unreusable because it is not a regular file.
1739          */
1740         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1741                 return 0;
1743         /*
1744          * If ce matches the file in the work tree, we can reuse it.
1745          */
1746         if (ce_uptodate(ce) ||
1747             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1748                 return 1;
1750         return 0;
1753 static int populate_from_stdin(struct diff_filespec *s)
1755         struct strbuf buf;
1756         size_t size = 0;
1758         strbuf_init(&buf, 0);
1759         if (strbuf_read(&buf, 0, 0) < 0)
1760                 return error("error while reading from stdin %s",
1761                                      strerror(errno));
1763         s->should_munmap = 0;
1764         s->data = strbuf_detach(&buf, &size);
1765         s->size = size;
1766         s->should_free = 1;
1767         return 0;
1770 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1772         int len;
1773         char *data = xmalloc(100);
1774         len = snprintf(data, 100,
1775                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1776         s->data = data;
1777         s->size = len;
1778         s->should_free = 1;
1779         if (size_only) {
1780                 s->data = NULL;
1781                 free(data);
1782         }
1783         return 0;
1786 /*
1787  * While doing rename detection and pickaxe operation, we may need to
1788  * grab the data for the blob (or file) for our own in-core comparison.
1789  * diff_filespec has data and size fields for this purpose.
1790  */
1791 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1793         int err = 0;
1794         if (!DIFF_FILE_VALID(s))
1795                 die("internal error: asking to populate invalid file.");
1796         if (S_ISDIR(s->mode))
1797                 return -1;
1799         if (s->data)
1800                 return 0;
1802         if (size_only && 0 < s->size)
1803                 return 0;
1805         if (S_ISGITLINK(s->mode))
1806                 return diff_populate_gitlink(s, size_only);
1808         if (!s->sha1_valid ||
1809             reuse_worktree_file(s->path, s->sha1, 0)) {
1810                 struct strbuf buf;
1811                 struct stat st;
1812                 int fd;
1814                 if (!strcmp(s->path, "-"))
1815                         return populate_from_stdin(s);
1817                 if (lstat(s->path, &st) < 0) {
1818                         if (errno == ENOENT) {
1819                         err_empty:
1820                                 err = -1;
1821                         empty:
1822                                 s->data = (char *)"";
1823                                 s->size = 0;
1824                                 return err;
1825                         }
1826                 }
1827                 s->size = xsize_t(st.st_size);
1828                 if (!s->size)
1829                         goto empty;
1830                 if (size_only)
1831                         return 0;
1832                 if (S_ISLNK(st.st_mode)) {
1833                         int ret;
1834                         s->data = xmalloc(s->size);
1835                         s->should_free = 1;
1836                         ret = readlink(s->path, s->data, s->size);
1837                         if (ret < 0) {
1838                                 free(s->data);
1839                                 goto err_empty;
1840                         }
1841                         return 0;
1842                 }
1843                 fd = open(s->path, O_RDONLY);
1844                 if (fd < 0)
1845                         goto err_empty;
1846                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1847                 close(fd);
1848                 s->should_munmap = 1;
1850                 /*
1851                  * Convert from working tree format to canonical git format
1852                  */
1853                 strbuf_init(&buf, 0);
1854                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1855                         size_t size = 0;
1856                         munmap(s->data, s->size);
1857                         s->should_munmap = 0;
1858                         s->data = strbuf_detach(&buf, &size);
1859                         s->size = size;
1860                         s->should_free = 1;
1861                 }
1862         }
1863         else {
1864                 enum object_type type;
1865                 if (size_only)
1866                         type = sha1_object_info(s->sha1, &s->size);
1867                 else {
1868                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1869                         s->should_free = 1;
1870                 }
1871         }
1872         return 0;
1875 void diff_free_filespec_blob(struct diff_filespec *s)
1877         if (s->should_free)
1878                 free(s->data);
1879         else if (s->should_munmap)
1880                 munmap(s->data, s->size);
1882         if (s->should_free || s->should_munmap) {
1883                 s->should_free = s->should_munmap = 0;
1884                 s->data = NULL;
1885         }
1888 void diff_free_filespec_data(struct diff_filespec *s)
1890         diff_free_filespec_blob(s);
1891         free(s->cnt_data);
1892         s->cnt_data = NULL;
1895 static void prep_temp_blob(struct diff_tempfile *temp,
1896                            void *blob,
1897                            unsigned long size,
1898                            const unsigned char *sha1,
1899                            int mode)
1901         int fd;
1903         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1904         if (fd < 0)
1905                 die("unable to create temp-file: %s", strerror(errno));
1906         if (write_in_full(fd, blob, size) != size)
1907                 die("unable to write temp-file");
1908         close(fd);
1909         temp->name = temp->tmp_path;
1910         strcpy(temp->hex, sha1_to_hex(sha1));
1911         temp->hex[40] = 0;
1912         sprintf(temp->mode, "%06o", mode);
1915 static void prepare_temp_file(const char *name,
1916                               struct diff_tempfile *temp,
1917                               struct diff_filespec *one)
1919         if (!DIFF_FILE_VALID(one)) {
1920         not_a_valid_file:
1921                 /* A '-' entry produces this for file-2, and
1922                  * a '+' entry produces this for file-1.
1923                  */
1924                 temp->name = "/dev/null";
1925                 strcpy(temp->hex, ".");
1926                 strcpy(temp->mode, ".");
1927                 return;
1928         }
1930         if (!one->sha1_valid ||
1931             reuse_worktree_file(name, one->sha1, 1)) {
1932                 struct stat st;
1933                 if (lstat(name, &st) < 0) {
1934                         if (errno == ENOENT)
1935                                 goto not_a_valid_file;
1936                         die("stat(%s): %s", name, strerror(errno));
1937                 }
1938                 if (S_ISLNK(st.st_mode)) {
1939                         int ret;
1940                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1941                         size_t sz = xsize_t(st.st_size);
1942                         if (sizeof(buf) <= st.st_size)
1943                                 die("symlink too long: %s", name);
1944                         ret = readlink(name, buf, sz);
1945                         if (ret < 0)
1946                                 die("readlink(%s)", name);
1947                         prep_temp_blob(temp, buf, sz,
1948                                        (one->sha1_valid ?
1949                                         one->sha1 : null_sha1),
1950                                        (one->sha1_valid ?
1951                                         one->mode : S_IFLNK));
1952                 }
1953                 else {
1954                         /* we can borrow from the file in the work tree */
1955                         temp->name = name;
1956                         if (!one->sha1_valid)
1957                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1958                         else
1959                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1960                         /* Even though we may sometimes borrow the
1961                          * contents from the work tree, we always want
1962                          * one->mode.  mode is trustworthy even when
1963                          * !(one->sha1_valid), as long as
1964                          * DIFF_FILE_VALID(one).
1965                          */
1966                         sprintf(temp->mode, "%06o", one->mode);
1967                 }
1968                 return;
1969         }
1970         else {
1971                 if (diff_populate_filespec(one, 0))
1972                         die("cannot read data blob for %s", one->path);
1973                 prep_temp_blob(temp, one->data, one->size,
1974                                one->sha1, one->mode);
1975         }
1978 static void remove_tempfile(void)
1980         int i;
1982         for (i = 0; i < 2; i++)
1983                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1984                         unlink(diff_temp[i].name);
1985                         diff_temp[i].name = NULL;
1986                 }
1989 static void remove_tempfile_on_signal(int signo)
1991         remove_tempfile();
1992         signal(SIGINT, SIG_DFL);
1993         raise(signo);
1996 /* An external diff command takes:
1997  *
1998  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1999  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2000  *
2001  */
2002 static void run_external_diff(const char *pgm,
2003                               const char *name,
2004                               const char *other,
2005                               struct diff_filespec *one,
2006                               struct diff_filespec *two,
2007                               const char *xfrm_msg,
2008                               int complete_rewrite)
2010         const char *spawn_arg[10];
2011         struct diff_tempfile *temp = diff_temp;
2012         int retval;
2013         static int atexit_asked = 0;
2014         const char *othername;
2015         const char **arg = &spawn_arg[0];
2017         othername = (other? other : name);
2018         if (one && two) {
2019                 prepare_temp_file(name, &temp[0], one);
2020                 prepare_temp_file(othername, &temp[1], two);
2021                 if (! atexit_asked &&
2022                     (temp[0].name == temp[0].tmp_path ||
2023                      temp[1].name == temp[1].tmp_path)) {
2024                         atexit_asked = 1;
2025                         atexit(remove_tempfile);
2026                 }
2027                 signal(SIGINT, remove_tempfile_on_signal);
2028         }
2030         if (one && two) {
2031                 *arg++ = pgm;
2032                 *arg++ = name;
2033                 *arg++ = temp[0].name;
2034                 *arg++ = temp[0].hex;
2035                 *arg++ = temp[0].mode;
2036                 *arg++ = temp[1].name;
2037                 *arg++ = temp[1].hex;
2038                 *arg++ = temp[1].mode;
2039                 if (other) {
2040                         *arg++ = other;
2041                         *arg++ = xfrm_msg;
2042                 }
2043         } else {
2044                 *arg++ = pgm;
2045                 *arg++ = name;
2046         }
2047         *arg = NULL;
2048         fflush(NULL);
2049         retval = run_command_v_opt(spawn_arg, 0);
2050         remove_tempfile();
2051         if (retval) {
2052                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2053                 exit(1);
2054         }
2057 static const char *external_diff_attr(const char *name)
2059         struct git_attr_check attr_diff_check;
2061         if (!name)
2062                 return NULL;
2064         setup_diff_attr_check(&attr_diff_check);
2065         if (!git_checkattr(name, 1, &attr_diff_check)) {
2066                 const char *value = attr_diff_check.value;
2067                 if (!ATTR_TRUE(value) &&
2068                     !ATTR_FALSE(value) &&
2069                     !ATTR_UNSET(value)) {
2070                         struct ll_diff_driver *drv;
2072                         for (drv = user_diff; drv; drv = drv->next)
2073                                 if (!strcmp(drv->name, value))
2074                                         return drv->cmd;
2075                 }
2076         }
2077         return NULL;
2080 static void run_diff_cmd(const char *pgm,
2081                          const char *name,
2082                          const char *other,
2083                          const char *attr_path,
2084                          struct diff_filespec *one,
2085                          struct diff_filespec *two,
2086                          const char *xfrm_msg,
2087                          struct diff_options *o,
2088                          int complete_rewrite)
2090         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2091                 pgm = NULL;
2092         else {
2093                 const char *cmd = external_diff_attr(attr_path);
2094                 if (cmd)
2095                         pgm = cmd;
2096         }
2098         if (pgm) {
2099                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2100                                   complete_rewrite);
2101                 return;
2102         }
2103         if (one && two)
2104                 builtin_diff(name, other ? other : name,
2105                              one, two, xfrm_msg, o, complete_rewrite);
2106         else
2107                 fprintf(o->file, "* Unmerged path %s\n", name);
2110 static void diff_fill_sha1_info(struct diff_filespec *one)
2112         if (DIFF_FILE_VALID(one)) {
2113                 if (!one->sha1_valid) {
2114                         struct stat st;
2115                         if (!strcmp(one->path, "-")) {
2116                                 hashcpy(one->sha1, null_sha1);
2117                                 return;
2118                         }
2119                         if (lstat(one->path, &st) < 0)
2120                                 die("stat %s", one->path);
2121                         if (index_path(one->sha1, one->path, &st, 0))
2122                                 die("cannot hash %s\n", one->path);
2123                 }
2124         }
2125         else
2126                 hashclr(one->sha1);
2129 static int similarity_index(struct diff_filepair *p)
2131         return p->score * 100 / MAX_SCORE;
2134 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2136         /* Strip the prefix but do not molest /dev/null and absolute paths */
2137         if (*namep && **namep != '/')
2138                 *namep += prefix_length;
2139         if (*otherp && **otherp != '/')
2140                 *otherp += prefix_length;
2143 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2145         const char *pgm = external_diff();
2146         struct strbuf msg;
2147         char *xfrm_msg;
2148         struct diff_filespec *one = p->one;
2149         struct diff_filespec *two = p->two;
2150         const char *name;
2151         const char *other;
2152         const char *attr_path;
2153         int complete_rewrite = 0;
2155         name  = p->one->path;
2156         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2157         attr_path = name;
2158         if (o->prefix_length)
2159                 strip_prefix(o->prefix_length, &name, &other);
2161         if (DIFF_PAIR_UNMERGED(p)) {
2162                 run_diff_cmd(pgm, name, NULL, attr_path,
2163                              NULL, NULL, NULL, o, 0);
2164                 return;
2165         }
2167         diff_fill_sha1_info(one);
2168         diff_fill_sha1_info(two);
2170         strbuf_init(&msg, PATH_MAX * 2 + 300);
2171         switch (p->status) {
2172         case DIFF_STATUS_COPIED:
2173                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2174                 strbuf_addstr(&msg, "\ncopy from ");
2175                 quote_c_style(name, &msg, NULL, 0);
2176                 strbuf_addstr(&msg, "\ncopy to ");
2177                 quote_c_style(other, &msg, NULL, 0);
2178                 strbuf_addch(&msg, '\n');
2179                 break;
2180         case DIFF_STATUS_RENAMED:
2181                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2182                 strbuf_addstr(&msg, "\nrename from ");
2183                 quote_c_style(name, &msg, NULL, 0);
2184                 strbuf_addstr(&msg, "\nrename to ");
2185                 quote_c_style(other, &msg, NULL, 0);
2186                 strbuf_addch(&msg, '\n');
2187                 break;
2188         case DIFF_STATUS_MODIFIED:
2189                 if (p->score) {
2190                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2191                                         similarity_index(p));
2192                         complete_rewrite = 1;
2193                         break;
2194                 }
2195                 /* fallthru */
2196         default:
2197                 /* nothing */
2198                 ;
2199         }
2201         if (hashcmp(one->sha1, two->sha1)) {
2202                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2204                 if (DIFF_OPT_TST(o, BINARY)) {
2205                         mmfile_t mf;
2206                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2207                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2208                                 abbrev = 40;
2209                 }
2210                 strbuf_addf(&msg, "index %.*s..%.*s",
2211                                 abbrev, sha1_to_hex(one->sha1),
2212                                 abbrev, sha1_to_hex(two->sha1));
2213                 if (one->mode == two->mode)
2214                         strbuf_addf(&msg, " %06o", one->mode);
2215                 strbuf_addch(&msg, '\n');
2216         }
2218         if (msg.len)
2219                 strbuf_setlen(&msg, msg.len - 1);
2220         xfrm_msg = msg.len ? msg.buf : NULL;
2222         if (!pgm &&
2223             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2224             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2225                 /* a filepair that changes between file and symlink
2226                  * needs to be split into deletion and creation.
2227                  */
2228                 struct diff_filespec *null = alloc_filespec(two->path);
2229                 run_diff_cmd(NULL, name, other, attr_path,
2230                              one, null, xfrm_msg, o, 0);
2231                 free(null);
2232                 null = alloc_filespec(one->path);
2233                 run_diff_cmd(NULL, name, other, attr_path,
2234                              null, two, xfrm_msg, o, 0);
2235                 free(null);
2236         }
2237         else
2238                 run_diff_cmd(pgm, name, other, attr_path,
2239                              one, two, xfrm_msg, o, complete_rewrite);
2241         strbuf_release(&msg);
2244 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2245                          struct diffstat_t *diffstat)
2247         const char *name;
2248         const char *other;
2249         int complete_rewrite = 0;
2251         if (DIFF_PAIR_UNMERGED(p)) {
2252                 /* unmerged */
2253                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2254                 return;
2255         }
2257         name = p->one->path;
2258         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
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         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2267                 complete_rewrite = 1;
2268         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2271 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2273         const char *name;
2274         const char *other;
2275         const char *attr_path;
2277         if (DIFF_PAIR_UNMERGED(p)) {
2278                 /* unmerged */
2279                 return;
2280         }
2282         name = p->one->path;
2283         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2284         attr_path = other ? other : name;
2286         if (o->prefix_length)
2287                 strip_prefix(o->prefix_length, &name, &other);
2289         diff_fill_sha1_info(p->one);
2290         diff_fill_sha1_info(p->two);
2292         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2295 void diff_setup(struct diff_options *options)
2297         memset(options, 0, sizeof(*options));
2299         options->file = stdout;
2301         options->line_termination = '\n';
2302         options->break_opt = -1;
2303         options->rename_limit = -1;
2304         options->dirstat_percent = 3;
2305         options->context = 3;
2307         options->change = diff_change;
2308         options->add_remove = diff_addremove;
2309         if (diff_use_color_default > 0)
2310                 DIFF_OPT_SET(options, COLOR_DIFF);
2311         else
2312                 DIFF_OPT_CLR(options, COLOR_DIFF);
2313         options->detect_rename = diff_detect_rename_default;
2315         options->a_prefix = "a/";
2316         options->b_prefix = "b/";
2319 int diff_setup_done(struct diff_options *options)
2321         int count = 0;
2323         if (options->output_format & DIFF_FORMAT_NAME)
2324                 count++;
2325         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2326                 count++;
2327         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2328                 count++;
2329         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2330                 count++;
2331         if (count > 1)
2332                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2334         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2335                 options->detect_rename = DIFF_DETECT_COPY;
2337         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2338                 options->prefix = NULL;
2339         if (options->prefix)
2340                 options->prefix_length = strlen(options->prefix);
2341         else
2342                 options->prefix_length = 0;
2344         if (options->output_format & (DIFF_FORMAT_NAME |
2345                                       DIFF_FORMAT_NAME_STATUS |
2346                                       DIFF_FORMAT_CHECKDIFF |
2347                                       DIFF_FORMAT_NO_OUTPUT))
2348                 options->output_format &= ~(DIFF_FORMAT_RAW |
2349                                             DIFF_FORMAT_NUMSTAT |
2350                                             DIFF_FORMAT_DIFFSTAT |
2351                                             DIFF_FORMAT_SHORTSTAT |
2352                                             DIFF_FORMAT_DIRSTAT |
2353                                             DIFF_FORMAT_SUMMARY |
2354                                             DIFF_FORMAT_PATCH);
2356         /*
2357          * These cases always need recursive; we do not drop caller-supplied
2358          * recursive bits for other formats here.
2359          */
2360         if (options->output_format & (DIFF_FORMAT_PATCH |
2361                                       DIFF_FORMAT_NUMSTAT |
2362                                       DIFF_FORMAT_DIFFSTAT |
2363                                       DIFF_FORMAT_SHORTSTAT |
2364                                       DIFF_FORMAT_DIRSTAT |
2365                                       DIFF_FORMAT_SUMMARY |
2366                                       DIFF_FORMAT_CHECKDIFF))
2367                 DIFF_OPT_SET(options, RECURSIVE);
2368         /*
2369          * Also pickaxe would not work very well if you do not say recursive
2370          */
2371         if (options->pickaxe)
2372                 DIFF_OPT_SET(options, RECURSIVE);
2374         if (options->detect_rename && options->rename_limit < 0)
2375                 options->rename_limit = diff_rename_limit_default;
2376         if (options->setup & DIFF_SETUP_USE_CACHE) {
2377                 if (!active_cache)
2378                         /* read-cache does not die even when it fails
2379                          * so it is safe for us to do this here.  Also
2380                          * it does not smudge active_cache or active_nr
2381                          * when it fails, so we do not have to worry about
2382                          * cleaning it up ourselves either.
2383                          */
2384                         read_cache();
2385         }
2386         if (options->abbrev <= 0 || 40 < options->abbrev)
2387                 options->abbrev = 40; /* full */
2389         /*
2390          * It does not make sense to show the first hit we happened
2391          * to have found.  It does not make sense not to return with
2392          * exit code in such a case either.
2393          */
2394         if (DIFF_OPT_TST(options, QUIET)) {
2395                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2396                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2397         }
2399         /*
2400          * If we postprocess in diffcore, we cannot simply return
2401          * upon the first hit.  We need to run diff as usual.
2402          */
2403         if (options->pickaxe || options->filter)
2404                 DIFF_OPT_CLR(options, QUIET);
2406         return 0;
2409 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2411         char c, *eq;
2412         int len;
2414         if (*arg != '-')
2415                 return 0;
2416         c = *++arg;
2417         if (!c)
2418                 return 0;
2419         if (c == arg_short) {
2420                 c = *++arg;
2421                 if (!c)
2422                         return 1;
2423                 if (val && isdigit(c)) {
2424                         char *end;
2425                         int n = strtoul(arg, &end, 10);
2426                         if (*end)
2427                                 return 0;
2428                         *val = n;
2429                         return 1;
2430                 }
2431                 return 0;
2432         }
2433         if (c != '-')
2434                 return 0;
2435         arg++;
2436         eq = strchr(arg, '=');
2437         if (eq)
2438                 len = eq - arg;
2439         else
2440                 len = strlen(arg);
2441         if (!len || strncmp(arg, arg_long, len))
2442                 return 0;
2443         if (eq) {
2444                 int n;
2445                 char *end;
2446                 if (!isdigit(*++eq))
2447                         return 0;
2448                 n = strtoul(eq, &end, 10);
2449                 if (*end)
2450                         return 0;
2451                 *val = n;
2452         }
2453         return 1;
2456 static int diff_scoreopt_parse(const char *opt);
2458 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2460         const char *arg = av[0];
2462         /* Output format options */
2463         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2464                 options->output_format |= DIFF_FORMAT_PATCH;
2465         else if (opt_arg(arg, 'U', "unified", &options->context))
2466                 options->output_format |= DIFF_FORMAT_PATCH;
2467         else if (!strcmp(arg, "--raw"))
2468                 options->output_format |= DIFF_FORMAT_RAW;
2469         else if (!strcmp(arg, "--patch-with-raw"))
2470                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2471         else if (!strcmp(arg, "--numstat"))
2472                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2473         else if (!strcmp(arg, "--shortstat"))
2474                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2475         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2476                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2477         else if (!strcmp(arg, "--cumulative"))
2478                 options->output_format |= DIFF_FORMAT_CUMULATIVE;
2479         else if (!strcmp(arg, "--check"))
2480                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2481         else if (!strcmp(arg, "--summary"))
2482                 options->output_format |= DIFF_FORMAT_SUMMARY;
2483         else if (!strcmp(arg, "--patch-with-stat"))
2484                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2485         else if (!strcmp(arg, "--name-only"))
2486                 options->output_format |= DIFF_FORMAT_NAME;
2487         else if (!strcmp(arg, "--name-status"))
2488                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2489         else if (!strcmp(arg, "-s"))
2490                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2491         else if (!prefixcmp(arg, "--stat")) {
2492                 char *end;
2493                 int width = options->stat_width;
2494                 int name_width = options->stat_name_width;
2495                 arg += 6;
2496                 end = (char *)arg;
2498                 switch (*arg) {
2499                 case '-':
2500                         if (!prefixcmp(arg, "-width="))
2501                                 width = strtoul(arg + 7, &end, 10);
2502                         else if (!prefixcmp(arg, "-name-width="))
2503                                 name_width = strtoul(arg + 12, &end, 10);
2504                         break;
2505                 case '=':
2506                         width = strtoul(arg+1, &end, 10);
2507                         if (*end == ',')
2508                                 name_width = strtoul(end+1, &end, 10);
2509                 }
2511                 /* Important! This checks all the error cases! */
2512                 if (*end)
2513                         return 0;
2514                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2515                 options->stat_name_width = name_width;
2516                 options->stat_width = width;
2517         }
2519         /* renames options */
2520         else if (!prefixcmp(arg, "-B")) {
2521                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2522                         return -1;
2523         }
2524         else if (!prefixcmp(arg, "-M")) {
2525                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2526                         return -1;
2527                 options->detect_rename = DIFF_DETECT_RENAME;
2528         }
2529         else if (!prefixcmp(arg, "-C")) {
2530                 if (options->detect_rename == DIFF_DETECT_COPY)
2531                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2532                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2533                         return -1;
2534                 options->detect_rename = DIFF_DETECT_COPY;
2535         }
2536         else if (!strcmp(arg, "--no-renames"))
2537                 options->detect_rename = 0;
2538         else if (!strcmp(arg, "--relative"))
2539                 DIFF_OPT_SET(options, RELATIVE_NAME);
2540         else if (!prefixcmp(arg, "--relative=")) {
2541                 DIFF_OPT_SET(options, RELATIVE_NAME);
2542                 options->prefix = arg + 11;
2543         }
2545         /* xdiff options */
2546         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2547                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2548         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2549                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2550         else if (!strcmp(arg, "--ignore-space-at-eol"))
2551                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2553         /* flags options */
2554         else if (!strcmp(arg, "--binary")) {
2555                 options->output_format |= DIFF_FORMAT_PATCH;
2556                 DIFF_OPT_SET(options, BINARY);
2557         }
2558         else if (!strcmp(arg, "--full-index"))
2559                 DIFF_OPT_SET(options, FULL_INDEX);
2560         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2561                 DIFF_OPT_SET(options, TEXT);
2562         else if (!strcmp(arg, "-R"))
2563                 DIFF_OPT_SET(options, REVERSE_DIFF);
2564         else if (!strcmp(arg, "--find-copies-harder"))
2565                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2566         else if (!strcmp(arg, "--follow"))
2567                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2568         else if (!strcmp(arg, "--color"))
2569                 DIFF_OPT_SET(options, COLOR_DIFF);
2570         else if (!strcmp(arg, "--no-color"))
2571                 DIFF_OPT_CLR(options, COLOR_DIFF);
2572         else if (!strcmp(arg, "--color-words"))
2573                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2574         else if (!strcmp(arg, "--exit-code"))
2575                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2576         else if (!strcmp(arg, "--quiet"))
2577                 DIFF_OPT_SET(options, QUIET);
2578         else if (!strcmp(arg, "--ext-diff"))
2579                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2580         else if (!strcmp(arg, "--no-ext-diff"))
2581                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2582         else if (!strcmp(arg, "--ignore-submodules"))
2583                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2585         /* misc options */
2586         else if (!strcmp(arg, "-z"))
2587                 options->line_termination = 0;
2588         else if (!prefixcmp(arg, "-l"))
2589                 options->rename_limit = strtoul(arg+2, NULL, 10);
2590         else if (!prefixcmp(arg, "-S"))
2591                 options->pickaxe = arg + 2;
2592         else if (!strcmp(arg, "--pickaxe-all"))
2593                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2594         else if (!strcmp(arg, "--pickaxe-regex"))
2595                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2596         else if (!prefixcmp(arg, "-O"))
2597                 options->orderfile = arg + 2;
2598         else if (!prefixcmp(arg, "--diff-filter="))
2599                 options->filter = arg + 14;
2600         else if (!strcmp(arg, "--abbrev"))
2601                 options->abbrev = DEFAULT_ABBREV;
2602         else if (!prefixcmp(arg, "--abbrev=")) {
2603                 options->abbrev = strtoul(arg + 9, NULL, 10);
2604                 if (options->abbrev < MINIMUM_ABBREV)
2605                         options->abbrev = MINIMUM_ABBREV;
2606                 else if (40 < options->abbrev)
2607                         options->abbrev = 40;
2608         }
2609         else if (!prefixcmp(arg, "--src-prefix="))
2610                 options->a_prefix = arg + 13;
2611         else if (!prefixcmp(arg, "--dst-prefix="))
2612                 options->b_prefix = arg + 13;
2613         else if (!strcmp(arg, "--no-prefix"))
2614                 options->a_prefix = options->b_prefix = "";
2615         else if (!prefixcmp(arg, "--output=")) {
2616                 options->file = fopen(arg + strlen("--output="), "w");
2617                 options->close_file = 1;
2618         } else
2619                 return 0;
2620         return 1;
2623 static int parse_num(const char **cp_p)
2625         unsigned long num, scale;
2626         int ch, dot;
2627         const char *cp = *cp_p;
2629         num = 0;
2630         scale = 1;
2631         dot = 0;
2632         for(;;) {
2633                 ch = *cp;
2634                 if ( !dot && ch == '.' ) {
2635                         scale = 1;
2636                         dot = 1;
2637                 } else if ( ch == '%' ) {
2638                         scale = dot ? scale*100 : 100;
2639                         cp++;   /* % is always at the end */
2640                         break;
2641                 } else if ( ch >= '0' && ch <= '9' ) {
2642                         if ( scale < 100000 ) {
2643                                 scale *= 10;
2644                                 num = (num*10) + (ch-'0');
2645                         }
2646                 } else {
2647                         break;
2648                 }
2649                 cp++;
2650         }
2651         *cp_p = cp;
2653         /* user says num divided by scale and we say internally that
2654          * is MAX_SCORE * num / scale.
2655          */
2656         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2659 static int diff_scoreopt_parse(const char *opt)
2661         int opt1, opt2, cmd;
2663         if (*opt++ != '-')
2664                 return -1;
2665         cmd = *opt++;
2666         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2667                 return -1; /* that is not a -M, -C nor -B option */
2669         opt1 = parse_num(&opt);
2670         if (cmd != 'B')
2671                 opt2 = 0;
2672         else {
2673                 if (*opt == 0)
2674                         opt2 = 0;
2675                 else if (*opt != '/')
2676                         return -1; /* we expect -B80/99 or -B80 */
2677                 else {
2678                         opt++;
2679                         opt2 = parse_num(&opt);
2680                 }
2681         }
2682         if (*opt != 0)
2683                 return -1;
2684         return opt1 | (opt2 << 16);
2687 struct diff_queue_struct diff_queued_diff;
2689 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2691         if (queue->alloc <= queue->nr) {
2692                 queue->alloc = alloc_nr(queue->alloc);
2693                 queue->queue = xrealloc(queue->queue,
2694                                         sizeof(dp) * queue->alloc);
2695         }
2696         queue->queue[queue->nr++] = dp;
2699 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2700                                  struct diff_filespec *one,
2701                                  struct diff_filespec *two)
2703         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2704         dp->one = one;
2705         dp->two = two;
2706         if (queue)
2707                 diff_q(queue, dp);
2708         return dp;
2711 void diff_free_filepair(struct diff_filepair *p)
2713         free_filespec(p->one);
2714         free_filespec(p->two);
2715         free(p);
2718 /* This is different from find_unique_abbrev() in that
2719  * it stuffs the result with dots for alignment.
2720  */
2721 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2723         int abblen;
2724         const char *abbrev;
2725         if (len == 40)
2726                 return sha1_to_hex(sha1);
2728         abbrev = find_unique_abbrev(sha1, len);
2729         abblen = strlen(abbrev);
2730         if (abblen < 37) {
2731                 static char hex[41];
2732                 if (len < abblen && abblen <= len + 2)
2733                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2734                 else
2735                         sprintf(hex, "%s...", abbrev);
2736                 return hex;
2737         }
2738         return sha1_to_hex(sha1);
2741 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2743         int line_termination = opt->line_termination;
2744         int inter_name_termination = line_termination ? '\t' : '\0';
2746         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2747                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2748                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2749                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2750         }
2751         if (p->score) {
2752                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2753                         inter_name_termination);
2754         } else {
2755                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2756         }
2758         if (p->status == DIFF_STATUS_COPIED ||
2759             p->status == DIFF_STATUS_RENAMED) {
2760                 const char *name_a, *name_b;
2761                 name_a = p->one->path;
2762                 name_b = p->two->path;
2763                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2764                 write_name_quoted(name_a, opt->file, inter_name_termination);
2765                 write_name_quoted(name_b, opt->file, line_termination);
2766         } else {
2767                 const char *name_a, *name_b;
2768                 name_a = p->one->mode ? p->one->path : p->two->path;
2769                 name_b = NULL;
2770                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2771                 write_name_quoted(name_a, opt->file, line_termination);
2772         }
2775 int diff_unmodified_pair(struct diff_filepair *p)
2777         /* This function is written stricter than necessary to support
2778          * the currently implemented transformers, but the idea is to
2779          * let transformers to produce diff_filepairs any way they want,
2780          * and filter and clean them up here before producing the output.
2781          */
2782         struct diff_filespec *one = p->one, *two = p->two;
2784         if (DIFF_PAIR_UNMERGED(p))
2785                 return 0; /* unmerged is interesting */
2787         /* deletion, addition, mode or type change
2788          * and rename are all interesting.
2789          */
2790         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2791             DIFF_PAIR_MODE_CHANGED(p) ||
2792             strcmp(one->path, two->path))
2793                 return 0;
2795         /* both are valid and point at the same path.  that is, we are
2796          * dealing with a change.
2797          */
2798         if (one->sha1_valid && two->sha1_valid &&
2799             !hashcmp(one->sha1, two->sha1))
2800                 return 1; /* no change */
2801         if (!one->sha1_valid && !two->sha1_valid)
2802                 return 1; /* both look at the same file on the filesystem. */
2803         return 0;
2806 static void diff_flush_patch(struct diff_filepair *p, 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_diff(p, o);
2818 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2819                             struct diffstat_t *diffstat)
2821         if (diff_unmodified_pair(p))
2822                 return;
2824         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2825             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2826                 return; /* no tree diffs in patch format */
2828         run_diffstat(p, o, diffstat);
2831 static void diff_flush_checkdiff(struct diff_filepair *p,
2832                 struct diff_options *o)
2834         if (diff_unmodified_pair(p))
2835                 return;
2837         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2838             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2839                 return; /* no tree diffs in patch format */
2841         run_checkdiff(p, o);
2844 int diff_queue_is_empty(void)
2846         struct diff_queue_struct *q = &diff_queued_diff;
2847         int i;
2848         for (i = 0; i < q->nr; i++)
2849                 if (!diff_unmodified_pair(q->queue[i]))
2850                         return 0;
2851         return 1;
2854 #if DIFF_DEBUG
2855 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2857         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2858                 x, one ? one : "",
2859                 s->path,
2860                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2861                 s->mode,
2862                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2863         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2864                 x, one ? one : "",
2865                 s->size, s->xfrm_flags);
2868 void diff_debug_filepair(const struct diff_filepair *p, int i)
2870         diff_debug_filespec(p->one, i, "one");
2871         diff_debug_filespec(p->two, i, "two");
2872         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2873                 p->score, p->status ? p->status : '?',
2874                 p->one->rename_used, p->broken_pair);
2877 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2879         int i;
2880         if (msg)
2881                 fprintf(stderr, "%s\n", msg);
2882         fprintf(stderr, "q->nr = %d\n", q->nr);
2883         for (i = 0; i < q->nr; i++) {
2884                 struct diff_filepair *p = q->queue[i];
2885                 diff_debug_filepair(p, i);
2886         }
2888 #endif
2890 static void diff_resolve_rename_copy(void)
2892         int i;
2893         struct diff_filepair *p;
2894         struct diff_queue_struct *q = &diff_queued_diff;
2896         diff_debug_queue("resolve-rename-copy", q);
2898         for (i = 0; i < q->nr; i++) {
2899                 p = q->queue[i];
2900                 p->status = 0; /* undecided */
2901                 if (DIFF_PAIR_UNMERGED(p))
2902                         p->status = DIFF_STATUS_UNMERGED;
2903                 else if (!DIFF_FILE_VALID(p->one))
2904                         p->status = DIFF_STATUS_ADDED;
2905                 else if (!DIFF_FILE_VALID(p->two))
2906                         p->status = DIFF_STATUS_DELETED;
2907                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2908                         p->status = DIFF_STATUS_TYPE_CHANGED;
2910                 /* from this point on, we are dealing with a pair
2911                  * whose both sides are valid and of the same type, i.e.
2912                  * either in-place edit or rename/copy edit.
2913                  */
2914                 else if (DIFF_PAIR_RENAME(p)) {
2915                         /*
2916                          * A rename might have re-connected a broken
2917                          * pair up, causing the pathnames to be the
2918                          * same again. If so, that's not a rename at
2919                          * all, just a modification..
2920                          *
2921                          * Otherwise, see if this source was used for
2922                          * multiple renames, in which case we decrement
2923                          * the count, and call it a copy.
2924                          */
2925                         if (!strcmp(p->one->path, p->two->path))
2926                                 p->status = DIFF_STATUS_MODIFIED;
2927                         else if (--p->one->rename_used > 0)
2928                                 p->status = DIFF_STATUS_COPIED;
2929                         else
2930                                 p->status = DIFF_STATUS_RENAMED;
2931                 }
2932                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2933                          p->one->mode != p->two->mode ||
2934                          is_null_sha1(p->one->sha1))
2935                         p->status = DIFF_STATUS_MODIFIED;
2936                 else {
2937                         /* This is a "no-change" entry and should not
2938                          * happen anymore, but prepare for broken callers.
2939                          */
2940                         error("feeding unmodified %s to diffcore",
2941                               p->one->path);
2942                         p->status = DIFF_STATUS_UNKNOWN;
2943                 }
2944         }
2945         diff_debug_queue("resolve-rename-copy done", q);
2948 static int check_pair_status(struct diff_filepair *p)
2950         switch (p->status) {
2951         case DIFF_STATUS_UNKNOWN:
2952                 return 0;
2953         case 0:
2954                 die("internal error in diff-resolve-rename-copy");
2955         default:
2956                 return 1;
2957         }
2960 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2962         int fmt = opt->output_format;
2964         if (fmt & DIFF_FORMAT_CHECKDIFF)
2965                 diff_flush_checkdiff(p, opt);
2966         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2967                 diff_flush_raw(p, opt);
2968         else if (fmt & DIFF_FORMAT_NAME) {
2969                 const char *name_a, *name_b;
2970                 name_a = p->two->path;
2971                 name_b = NULL;
2972                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2973                 write_name_quoted(name_a, opt->file, opt->line_termination);
2974         }
2977 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2979         if (fs->mode)
2980                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2981         else
2982                 fprintf(file, " %s ", newdelete);
2983         write_name_quoted(fs->path, file, '\n');
2987 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2989         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2990                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2991                         show_name ? ' ' : '\n');
2992                 if (show_name) {
2993                         write_name_quoted(p->two->path, file, '\n');
2994                 }
2995         }
2998 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3000         char *names = pprint_rename(p->one->path, p->two->path);
3002         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3003         free(names);
3004         show_mode_change(file, p, 0);
3007 static void diff_summary(FILE *file, struct diff_filepair *p)
3009         switch(p->status) {
3010         case DIFF_STATUS_DELETED:
3011                 show_file_mode_name(file, "delete", p->one);
3012                 break;
3013         case DIFF_STATUS_ADDED:
3014                 show_file_mode_name(file, "create", p->two);
3015                 break;
3016         case DIFF_STATUS_COPIED:
3017                 show_rename_copy(file, "copy", p);
3018                 break;
3019         case DIFF_STATUS_RENAMED:
3020                 show_rename_copy(file, "rename", p);
3021                 break;
3022         default:
3023                 if (p->score) {
3024                         fputs(" rewrite ", file);
3025                         write_name_quoted(p->two->path, file, ' ');
3026                         fprintf(file, "(%d%%)\n", similarity_index(p));
3027                 }
3028                 show_mode_change(file, p, !p->score);
3029                 break;
3030         }
3033 struct patch_id_t {
3034         struct xdiff_emit_state xm;
3035         SHA_CTX *ctx;
3036         int patchlen;
3037 };
3039 static int remove_space(char *line, int len)
3041         int i;
3042         char *dst = line;
3043         unsigned char c;
3045         for (i = 0; i < len; i++)
3046                 if (!isspace((c = line[i])))
3047                         *dst++ = c;
3049         return dst - line;
3052 static void patch_id_consume(void *priv, char *line, unsigned long len)
3054         struct patch_id_t *data = priv;
3055         int new_len;
3057         /* Ignore line numbers when computing the SHA1 of the patch */
3058         if (!prefixcmp(line, "@@ -"))
3059                 return;
3061         new_len = remove_space(line, len);
3063         SHA1_Update(data->ctx, line, new_len);
3064         data->patchlen += new_len;
3067 /* returns 0 upon success, and writes result into sha1 */
3068 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3070         struct diff_queue_struct *q = &diff_queued_diff;
3071         int i;
3072         SHA_CTX ctx;
3073         struct patch_id_t data;
3074         char buffer[PATH_MAX * 4 + 20];
3076         SHA1_Init(&ctx);
3077         memset(&data, 0, sizeof(struct patch_id_t));
3078         data.ctx = &ctx;
3079         data.xm.consume = patch_id_consume;
3081         for (i = 0; i < q->nr; i++) {
3082                 xpparam_t xpp;
3083                 xdemitconf_t xecfg;
3084                 xdemitcb_t ecb;
3085                 mmfile_t mf1, mf2;
3086                 struct diff_filepair *p = q->queue[i];
3087                 int len1, len2;
3089                 memset(&xecfg, 0, sizeof(xecfg));
3090                 if (p->status == 0)
3091                         return error("internal diff status error");
3092                 if (p->status == DIFF_STATUS_UNKNOWN)
3093                         continue;
3094                 if (diff_unmodified_pair(p))
3095                         continue;
3096                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3097                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3098                         continue;
3099                 if (DIFF_PAIR_UNMERGED(p))
3100                         continue;
3102                 diff_fill_sha1_info(p->one);
3103                 diff_fill_sha1_info(p->two);
3104                 if (fill_mmfile(&mf1, p->one) < 0 ||
3105                                 fill_mmfile(&mf2, p->two) < 0)
3106                         return error("unable to read files to diff");
3108                 len1 = remove_space(p->one->path, strlen(p->one->path));
3109                 len2 = remove_space(p->two->path, strlen(p->two->path));
3110                 if (p->one->mode == 0)
3111                         len1 = snprintf(buffer, sizeof(buffer),
3112                                         "diff--gita/%.*sb/%.*s"
3113                                         "newfilemode%06o"
3114                                         "---/dev/null"
3115                                         "+++b/%.*s",
3116                                         len1, p->one->path,
3117                                         len2, p->two->path,
3118                                         p->two->mode,
3119                                         len2, p->two->path);
3120                 else if (p->two->mode == 0)
3121                         len1 = snprintf(buffer, sizeof(buffer),
3122                                         "diff--gita/%.*sb/%.*s"
3123                                         "deletedfilemode%06o"
3124                                         "---a/%.*s"
3125                                         "+++/dev/null",
3126                                         len1, p->one->path,
3127                                         len2, p->two->path,
3128                                         p->one->mode,
3129                                         len1, p->one->path);
3130                 else
3131                         len1 = snprintf(buffer, sizeof(buffer),
3132                                         "diff--gita/%.*sb/%.*s"
3133                                         "---a/%.*s"
3134                                         "+++b/%.*s",
3135                                         len1, p->one->path,
3136                                         len2, p->two->path,
3137                                         len1, p->one->path,
3138                                         len2, p->two->path);
3139                 SHA1_Update(&ctx, buffer, len1);
3141                 xpp.flags = XDF_NEED_MINIMAL;
3142                 xecfg.ctxlen = 3;
3143                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3144                 ecb.outf = xdiff_outf;
3145                 ecb.priv = &data;
3146                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
3147         }
3149         SHA1_Final(sha1, &ctx);
3150         return 0;
3153 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3155         struct diff_queue_struct *q = &diff_queued_diff;
3156         int i;
3157         int result = diff_get_patch_id(options, sha1);
3159         for (i = 0; i < q->nr; i++)
3160                 diff_free_filepair(q->queue[i]);
3162         free(q->queue);
3163         q->queue = NULL;
3164         q->nr = q->alloc = 0;
3166         return result;
3169 static int is_summary_empty(const struct diff_queue_struct *q)
3171         int i;
3173         for (i = 0; i < q->nr; i++) {
3174                 const struct diff_filepair *p = q->queue[i];
3176                 switch (p->status) {
3177                 case DIFF_STATUS_DELETED:
3178                 case DIFF_STATUS_ADDED:
3179                 case DIFF_STATUS_COPIED:
3180                 case DIFF_STATUS_RENAMED:
3181                         return 0;
3182                 default:
3183                         if (p->score)
3184                                 return 0;
3185                         if (p->one->mode && p->two->mode &&
3186                             p->one->mode != p->two->mode)
3187                                 return 0;
3188                         break;
3189                 }
3190         }
3191         return 1;
3194 void diff_flush(struct diff_options *options)
3196         struct diff_queue_struct *q = &diff_queued_diff;
3197         int i, output_format = options->output_format;
3198         int separator = 0;
3200         /*
3201          * Order: raw, stat, summary, patch
3202          * or:    name/name-status/checkdiff (other bits clear)
3203          */
3204         if (!q->nr)
3205                 goto free_queue;
3207         if (output_format & (DIFF_FORMAT_RAW |
3208                              DIFF_FORMAT_NAME |
3209                              DIFF_FORMAT_NAME_STATUS |
3210                              DIFF_FORMAT_CHECKDIFF)) {
3211                 for (i = 0; i < q->nr; i++) {
3212                         struct diff_filepair *p = q->queue[i];
3213                         if (check_pair_status(p))
3214                                 flush_one_pair(p, options);
3215                 }
3216                 separator++;
3217         }
3219         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3220                 struct diffstat_t diffstat;
3222                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3223                 diffstat.xm.consume = diffstat_consume;
3224                 for (i = 0; i < q->nr; i++) {
3225                         struct diff_filepair *p = q->queue[i];
3226                         if (check_pair_status(p))
3227                                 diff_flush_stat(p, options, &diffstat);
3228                 }
3229                 if (output_format & DIFF_FORMAT_NUMSTAT)
3230                         show_numstat(&diffstat, options);
3231                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3232                         show_stats(&diffstat, options);
3233                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3234                         show_shortstats(&diffstat, options);
3235                 free_diffstat_info(&diffstat);
3236                 separator++;
3237         }
3238         if (output_format & DIFF_FORMAT_DIRSTAT)
3239                 show_dirstat(options);
3241         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3242                 for (i = 0; i < q->nr; i++)
3243                         diff_summary(options->file, q->queue[i]);
3244                 separator++;
3245         }
3247         if (output_format & DIFF_FORMAT_PATCH) {
3248                 if (separator) {
3249                         putc(options->line_termination, options->file);
3250                         if (options->stat_sep) {
3251                                 /* attach patch instead of inline */
3252                                 fputs(options->stat_sep, options->file);
3253                         }
3254                 }
3256                 for (i = 0; i < q->nr; i++) {
3257                         struct diff_filepair *p = q->queue[i];
3258                         if (check_pair_status(p))
3259                                 diff_flush_patch(p, options);
3260                 }
3261         }
3263         if (output_format & DIFF_FORMAT_CALLBACK)
3264                 options->format_callback(q, options, options->format_callback_data);
3266         for (i = 0; i < q->nr; i++)
3267                 diff_free_filepair(q->queue[i]);
3268 free_queue:
3269         free(q->queue);
3270         q->queue = NULL;
3271         q->nr = q->alloc = 0;
3272         if (options->close_file)
3273                 fclose(options->file);
3276 static void diffcore_apply_filter(const char *filter)
3278         int i;
3279         struct diff_queue_struct *q = &diff_queued_diff;
3280         struct diff_queue_struct outq;
3281         outq.queue = NULL;
3282         outq.nr = outq.alloc = 0;
3284         if (!filter)
3285                 return;
3287         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3288                 int found;
3289                 for (i = found = 0; !found && i < q->nr; i++) {
3290                         struct diff_filepair *p = q->queue[i];
3291                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3292                              ((p->score &&
3293                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3294                               (!p->score &&
3295                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3296                             ((p->status != DIFF_STATUS_MODIFIED) &&
3297                              strchr(filter, p->status)))
3298                                 found++;
3299                 }
3300                 if (found)
3301                         return;
3303                 /* otherwise we will clear the whole queue
3304                  * by copying the empty outq at the end of this
3305                  * function, but first clear the current entries
3306                  * in the queue.
3307                  */
3308                 for (i = 0; i < q->nr; i++)
3309                         diff_free_filepair(q->queue[i]);
3310         }
3311         else {
3312                 /* Only the matching ones */
3313                 for (i = 0; i < q->nr; i++) {
3314                         struct diff_filepair *p = q->queue[i];
3316                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3317                              ((p->score &&
3318                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3319                               (!p->score &&
3320                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3321                             ((p->status != DIFF_STATUS_MODIFIED) &&
3322                              strchr(filter, p->status)))
3323                                 diff_q(&outq, p);
3324                         else
3325                                 diff_free_filepair(p);
3326                 }
3327         }
3328         free(q->queue);
3329         *q = outq;
3332 /* Check whether two filespecs with the same mode and size are identical */
3333 static int diff_filespec_is_identical(struct diff_filespec *one,
3334                                       struct diff_filespec *two)
3336         if (S_ISGITLINK(one->mode))
3337                 return 0;
3338         if (diff_populate_filespec(one, 0))
3339                 return 0;
3340         if (diff_populate_filespec(two, 0))
3341                 return 0;
3342         return !memcmp(one->data, two->data, one->size);
3345 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3347         int i;
3348         struct diff_queue_struct *q = &diff_queued_diff;
3349         struct diff_queue_struct outq;
3350         outq.queue = NULL;
3351         outq.nr = outq.alloc = 0;
3353         for (i = 0; i < q->nr; i++) {
3354                 struct diff_filepair *p = q->queue[i];
3356                 /*
3357                  * 1. Entries that come from stat info dirtyness
3358                  *    always have both sides (iow, not create/delete),
3359                  *    one side of the object name is unknown, with
3360                  *    the same mode and size.  Keep the ones that
3361                  *    do not match these criteria.  They have real
3362                  *    differences.
3363                  *
3364                  * 2. At this point, the file is known to be modified,
3365                  *    with the same mode and size, and the object
3366                  *    name of one side is unknown.  Need to inspect
3367                  *    the identical contents.
3368                  */
3369                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3370                     !DIFF_FILE_VALID(p->two) ||
3371                     (p->one->sha1_valid && p->two->sha1_valid) ||
3372                     (p->one->mode != p->two->mode) ||
3373                     diff_populate_filespec(p->one, 1) ||
3374                     diff_populate_filespec(p->two, 1) ||
3375                     (p->one->size != p->two->size) ||
3376                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3377                         diff_q(&outq, p);
3378                 else {
3379                         /*
3380                          * The caller can subtract 1 from skip_stat_unmatch
3381                          * to determine how many paths were dirty only
3382                          * due to stat info mismatch.
3383                          */
3384                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3385                                 diffopt->skip_stat_unmatch++;
3386                         diff_free_filepair(p);
3387                 }
3388         }
3389         free(q->queue);
3390         *q = outq;
3393 void diffcore_std(struct diff_options *options)
3395         if (DIFF_OPT_TST(options, QUIET))
3396                 return;
3398         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3399                 diffcore_skip_stat_unmatch(options);
3400         if (options->break_opt != -1)
3401                 diffcore_break(options->break_opt);
3402         if (options->detect_rename)
3403                 diffcore_rename(options);
3404         if (options->break_opt != -1)
3405                 diffcore_merge_broken();
3406         if (options->pickaxe)
3407                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3408         if (options->orderfile)
3409                 diffcore_order(options->orderfile);
3410         diff_resolve_rename_copy();
3411         diffcore_apply_filter(options->filter);
3413         if (diff_queued_diff.nr)
3414                 DIFF_OPT_SET(options, HAS_CHANGES);
3415         else
3416                 DIFF_OPT_CLR(options, HAS_CHANGES);
3419 int diff_result_code(struct diff_options *opt, int status)
3421         int result = 0;
3422         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3423             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3424                 return status;
3425         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3426             DIFF_OPT_TST(opt, HAS_CHANGES))
3427                 result |= 01;
3428         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3429             DIFF_OPT_TST(opt, CHECK_FAILED))
3430                 result |= 02;
3431         return result;
3434 void diff_addremove(struct diff_options *options,
3435                     int addremove, unsigned mode,
3436                     const unsigned char *sha1,
3437                     const char *concatpath)
3439         struct diff_filespec *one, *two;
3441         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3442                 return;
3444         /* This may look odd, but it is a preparation for
3445          * feeding "there are unchanged files which should
3446          * not produce diffs, but when you are doing copy
3447          * detection you would need them, so here they are"
3448          * entries to the diff-core.  They will be prefixed
3449          * with something like '=' or '*' (I haven't decided
3450          * which but should not make any difference).
3451          * Feeding the same new and old to diff_change()
3452          * also has the same effect.
3453          * Before the final output happens, they are pruned after
3454          * merged into rename/copy pairs as appropriate.
3455          */
3456         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3457                 addremove = (addremove == '+' ? '-' :
3458                              addremove == '-' ? '+' : addremove);
3460         if (options->prefix &&
3461             strncmp(concatpath, options->prefix, options->prefix_length))
3462                 return;
3464         one = alloc_filespec(concatpath);
3465         two = alloc_filespec(concatpath);
3467         if (addremove != '+')
3468                 fill_filespec(one, sha1, mode);
3469         if (addremove != '-')
3470                 fill_filespec(two, sha1, mode);
3472         diff_queue(&diff_queued_diff, one, two);
3473         DIFF_OPT_SET(options, HAS_CHANGES);
3476 void diff_change(struct diff_options *options,
3477                  unsigned old_mode, unsigned new_mode,
3478                  const unsigned char *old_sha1,
3479                  const unsigned char *new_sha1,
3480                  const char *concatpath)
3482         struct diff_filespec *one, *two;
3484         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3485                         && S_ISGITLINK(new_mode))
3486                 return;
3488         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3489                 unsigned tmp;
3490                 const unsigned char *tmp_c;
3491                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3492                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3493         }
3495         if (options->prefix &&
3496             strncmp(concatpath, options->prefix, options->prefix_length))
3497                 return;
3499         one = alloc_filespec(concatpath);
3500         two = alloc_filespec(concatpath);
3501         fill_filespec(one, old_sha1, old_mode);
3502         fill_filespec(two, new_sha1, new_mode);
3504         diff_queue(&diff_queued_diff, one, two);
3505         DIFF_OPT_SET(options, HAS_CHANGES);
3508 void diff_unmerge(struct diff_options *options,
3509                   const char *path,
3510                   unsigned mode, const unsigned char *sha1)
3512         struct diff_filespec *one, *two;
3514         if (options->prefix &&
3515             strncmp(path, options->prefix, options->prefix_length))
3516                 return;
3518         one = alloc_filespec(path);
3519         two = alloc_filespec(path);
3520         fill_filespec(one, sha1, mode);
3521         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;