Code

Fix a warning (on cygwin) to allow -Werror
[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "delta.h"
9 #include "xdiff-interface.h"
10 #include "color.h"
11 #include "attr.h"
12 #include "run-command.h"
13 #include "utf8.h"
15 #ifdef NO_FAST_WORKING_DIRECTORY
16 #define FAST_WORKING_DIRECTORY 0
17 #else
18 #define FAST_WORKING_DIRECTORY 1
19 #endif
21 static int diff_detect_rename_default;
22 static int diff_rename_limit_default = 200;
23 int diff_use_color_default = -1;
24 static const char *external_diff_cmd_cfg;
25 int diff_auto_refresh_index = 1;
27 static char diff_colors[][COLOR_MAXLEN] = {
28         "\033[m",       /* reset */
29         "",             /* PLAIN (normal) */
30         "\033[1m",      /* METAINFO (bold) */
31         "\033[36m",     /* FRAGINFO (cyan) */
32         "\033[31m",     /* OLD (red) */
33         "\033[32m",     /* NEW (green) */
34         "\033[33m",     /* COMMIT (yellow) */
35         "\033[41m",     /* WHITESPACE (red background) */
36 };
38 static int parse_diff_color_slot(const char *var, int ofs)
39 {
40         if (!strcasecmp(var+ofs, "plain"))
41                 return DIFF_PLAIN;
42         if (!strcasecmp(var+ofs, "meta"))
43                 return DIFF_METAINFO;
44         if (!strcasecmp(var+ofs, "frag"))
45                 return DIFF_FRAGINFO;
46         if (!strcasecmp(var+ofs, "old"))
47                 return DIFF_FILE_OLD;
48         if (!strcasecmp(var+ofs, "new"))
49                 return DIFF_FILE_NEW;
50         if (!strcasecmp(var+ofs, "commit"))
51                 return DIFF_COMMIT;
52         if (!strcasecmp(var+ofs, "whitespace"))
53                 return DIFF_WHITESPACE;
54         die("bad config variable '%s'", var);
55 }
57 static struct ll_diff_driver {
58         const char *name;
59         struct ll_diff_driver *next;
60         const char *cmd;
61 } *user_diff, **user_diff_tail;
63 /*
64  * Currently there is only "diff.<drivername>.command" variable;
65  * because there are "diff.color.<slot>" variables, we are parsing
66  * this in a bit convoluted way to allow low level diff driver
67  * called "color".
68  */
69 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
70 {
71         const char *name;
72         int namelen;
73         struct ll_diff_driver *drv;
75         name = var + 5;
76         namelen = ep - name;
77         for (drv = user_diff; drv; drv = drv->next)
78                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
79                         break;
80         if (!drv) {
81                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
82                 drv->name = xmemdupz(name, namelen);
83                 if (!user_diff_tail)
84                         user_diff_tail = &user_diff;
85                 *user_diff_tail = drv;
86                 user_diff_tail = &(drv->next);
87         }
89         return git_config_string(&(drv->cmd), var, value);
90 }
92 /*
93  * 'diff.<what>.funcname' attribute can be specified in the configuration
94  * to define a customized regexp to find the beginning of a function to
95  * be used for hunk header lines of "diff -p" style output.
96  */
97 static struct funcname_pattern {
98         char *name;
99         char *pattern;
100         struct funcname_pattern *next;
101 } *funcname_pattern_list;
103 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
105         const char *name;
106         int namelen;
107         struct funcname_pattern *pp;
109         name = var + 5; /* "diff." */
110         namelen = ep - name;
112         for (pp = funcname_pattern_list; pp; pp = pp->next)
113                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
114                         break;
115         if (!pp) {
116                 pp = xcalloc(1, sizeof(*pp));
117                 pp->name = xmemdupz(name, namelen);
118                 pp->next = funcname_pattern_list;
119                 funcname_pattern_list = pp;
120         }
121         free(pp->pattern);
122         pp->pattern = xstrdup(value);
123         return 0;
126 /*
127  * These are to give UI layer defaults.
128  * The core-level commands such as git-diff-files should
129  * never be affected by the setting of diff.renames
130  * the user happens to have in the configuration file.
131  */
132 int git_diff_ui_config(const char *var, const char *value, void *cb)
134         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
135                 diff_use_color_default = git_config_colorbool(var, value, -1);
136                 return 0;
137         }
138         if (!strcmp(var, "diff.renames")) {
139                 if (!value)
140                         diff_detect_rename_default = DIFF_DETECT_RENAME;
141                 else if (!strcasecmp(value, "copies") ||
142                          !strcasecmp(value, "copy"))
143                         diff_detect_rename_default = DIFF_DETECT_COPY;
144                 else if (git_config_bool(var,value))
145                         diff_detect_rename_default = DIFF_DETECT_RENAME;
146                 return 0;
147         }
148         if (!strcmp(var, "diff.autorefreshindex")) {
149                 diff_auto_refresh_index = git_config_bool(var, value);
150                 return 0;
151         }
152         if (!strcmp(var, "diff.external"))
153                 return git_config_string(&external_diff_cmd_cfg, var, value);
154         if (!prefixcmp(var, "diff.")) {
155                 const char *ep = strrchr(var, '.');
157                 if (ep != var + 4 && !strcmp(ep, ".command"))
158                         return parse_lldiff_command(var, ep, value);
159         }
161         return git_diff_basic_config(var, value, cb);
164 int git_diff_basic_config(const char *var, const char *value, void *cb)
166         if (!strcmp(var, "diff.renamelimit")) {
167                 diff_rename_limit_default = git_config_int(var, value);
168                 return 0;
169         }
171         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
172                 int slot = parse_diff_color_slot(var, 11);
173                 if (!value)
174                         return config_error_nonbool(var);
175                 color_parse(value, var, diff_colors[slot]);
176                 return 0;
177         }
179         if (!prefixcmp(var, "diff.")) {
180                 const char *ep = strrchr(var, '.');
181                 if (ep != var + 4) {
182                         if (!strcmp(ep, ".funcname")) {
183                                 if (!value)
184                                         return config_error_nonbool(var);
185                                 return parse_funcname_pattern(var, ep, value);
186                         }
187                 }
188         }
190         return git_color_default_config(var, value, cb);
193 static char *quote_two(const char *one, const char *two)
195         int need_one = quote_c_style(one, NULL, NULL, 1);
196         int need_two = quote_c_style(two, NULL, NULL, 1);
197         struct strbuf res;
199         strbuf_init(&res, 0);
200         if (need_one + need_two) {
201                 strbuf_addch(&res, '"');
202                 quote_c_style(one, &res, NULL, 1);
203                 quote_c_style(two, &res, NULL, 1);
204                 strbuf_addch(&res, '"');
205         } else {
206                 strbuf_addstr(&res, one);
207                 strbuf_addstr(&res, two);
208         }
209         return strbuf_detach(&res, NULL);
212 static const char *external_diff(void)
214         static const char *external_diff_cmd = NULL;
215         static int done_preparing = 0;
217         if (done_preparing)
218                 return external_diff_cmd;
219         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
220         if (!external_diff_cmd)
221                 external_diff_cmd = external_diff_cmd_cfg;
222         done_preparing = 1;
223         return external_diff_cmd;
226 static struct diff_tempfile {
227         const char *name; /* filename external diff should read from */
228         char hex[41];
229         char mode[10];
230         char tmp_path[PATH_MAX];
231 } diff_temp[2];
233 static int count_lines(const char *data, int size)
235         int count, ch, completely_empty = 1, nl_just_seen = 0;
236         count = 0;
237         while (0 < size--) {
238                 ch = *data++;
239                 if (ch == '\n') {
240                         count++;
241                         nl_just_seen = 1;
242                         completely_empty = 0;
243                 }
244                 else {
245                         nl_just_seen = 0;
246                         completely_empty = 0;
247                 }
248         }
249         if (completely_empty)
250                 return 0;
251         if (!nl_just_seen)
252                 count++; /* no trailing newline */
253         return count;
256 static void print_line_count(FILE *file, int count)
258         switch (count) {
259         case 0:
260                 fprintf(file, "0,0");
261                 break;
262         case 1:
263                 fprintf(file, "1");
264                 break;
265         default:
266                 fprintf(file, "1,%d", count);
267                 break;
268         }
271 static void copy_file_with_prefix(FILE *file,
272                                   int prefix, const char *data, int size,
273                                   const char *set, const char *reset)
275         int ch, nl_just_seen = 1;
276         while (0 < size--) {
277                 ch = *data++;
278                 if (nl_just_seen) {
279                         fputs(set, file);
280                         putc(prefix, file);
281                 }
282                 if (ch == '\n') {
283                         nl_just_seen = 1;
284                         fputs(reset, file);
285                 } else
286                         nl_just_seen = 0;
287                 putc(ch, file);
288         }
289         if (!nl_just_seen)
290                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
293 static void emit_rewrite_diff(const char *name_a,
294                               const char *name_b,
295                               struct diff_filespec *one,
296                               struct diff_filespec *two,
297                               struct diff_options *o)
299         int lc_a, lc_b;
300         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
301         const char *name_a_tab, *name_b_tab;
302         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
303         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
304         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
305         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
306         const char *reset = diff_get_color(color_diff, DIFF_RESET);
307         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
309         name_a += (*name_a == '/');
310         name_b += (*name_b == '/');
311         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
312         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
314         strbuf_reset(&a_name);
315         strbuf_reset(&b_name);
316         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
317         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
319         diff_populate_filespec(one, 0);
320         diff_populate_filespec(two, 0);
321         lc_a = count_lines(one->data, one->size);
322         lc_b = count_lines(two->data, two->size);
323         fprintf(o->file,
324                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
325                 metainfo, a_name.buf, name_a_tab, reset,
326                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
327         print_line_count(o->file, lc_a);
328         fprintf(o->file, " +");
329         print_line_count(o->file, lc_b);
330         fprintf(o->file, " @@%s\n", reset);
331         if (lc_a)
332                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
333         if (lc_b)
334                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
337 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
339         if (!DIFF_FILE_VALID(one)) {
340                 mf->ptr = (char *)""; /* does not matter */
341                 mf->size = 0;
342                 return 0;
343         }
344         else if (diff_populate_filespec(one, 0))
345                 return -1;
346         mf->ptr = one->data;
347         mf->size = one->size;
348         return 0;
351 struct diff_words_buffer {
352         mmfile_t text;
353         long alloc;
354         long current; /* output pointer */
355         int suppressed_newline;
356 };
358 static void diff_words_append(char *line, unsigned long len,
359                 struct diff_words_buffer *buffer)
361         if (buffer->text.size + len > buffer->alloc) {
362                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
363                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
364         }
365         line++;
366         len--;
367         memcpy(buffer->text.ptr + buffer->text.size, line, len);
368         buffer->text.size += len;
371 struct diff_words_data {
372         struct xdiff_emit_state xm;
373         struct diff_words_buffer minus, plus;
374         FILE *file;
375 };
377 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
378                 int suppress_newline)
380         const char *ptr;
381         int eol = 0;
383         if (len == 0)
384                 return;
386         ptr  = buffer->text.ptr + buffer->current;
387         buffer->current += len;
389         if (ptr[len - 1] == '\n') {
390                 eol = 1;
391                 len--;
392         }
394         fputs(diff_get_color(1, color), file);
395         fwrite(ptr, len, 1, file);
396         fputs(diff_get_color(1, DIFF_RESET), file);
398         if (eol) {
399                 if (suppress_newline)
400                         buffer->suppressed_newline = 1;
401                 else
402                         putc('\n', file);
403         }
406 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
408         struct diff_words_data *diff_words = priv;
410         if (diff_words->minus.suppressed_newline) {
411                 if (line[0] != '+')
412                         putc('\n', diff_words->file);
413                 diff_words->minus.suppressed_newline = 0;
414         }
416         len--;
417         switch (line[0]) {
418                 case '-':
419                         print_word(diff_words->file,
420                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
421                         break;
422                 case '+':
423                         print_word(diff_words->file,
424                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
425                         break;
426                 case ' ':
427                         print_word(diff_words->file,
428                                    &diff_words->plus, len, DIFF_PLAIN, 0);
429                         diff_words->minus.current += len;
430                         break;
431         }
434 /* this executes the word diff on the accumulated buffers */
435 static void diff_words_show(struct diff_words_data *diff_words)
437         xpparam_t xpp;
438         xdemitconf_t xecfg;
439         xdemitcb_t ecb;
440         mmfile_t minus, plus;
441         int i;
443         memset(&xecfg, 0, sizeof(xecfg));
444         minus.size = diff_words->minus.text.size;
445         minus.ptr = xmalloc(minus.size);
446         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
447         for (i = 0; i < minus.size; i++)
448                 if (isspace(minus.ptr[i]))
449                         minus.ptr[i] = '\n';
450         diff_words->minus.current = 0;
452         plus.size = diff_words->plus.text.size;
453         plus.ptr = xmalloc(plus.size);
454         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
455         for (i = 0; i < plus.size; i++)
456                 if (isspace(plus.ptr[i]))
457                         plus.ptr[i] = '\n';
458         diff_words->plus.current = 0;
460         xpp.flags = XDF_NEED_MINIMAL;
461         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
462         ecb.outf = xdiff_outf;
463         ecb.priv = diff_words;
464         diff_words->xm.consume = fn_out_diff_words_aux;
465         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
467         free(minus.ptr);
468         free(plus.ptr);
469         diff_words->minus.text.size = diff_words->plus.text.size = 0;
471         if (diff_words->minus.suppressed_newline) {
472                 putc('\n', diff_words->file);
473                 diff_words->minus.suppressed_newline = 0;
474         }
477 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
479 struct emit_callback {
480         struct xdiff_emit_state xm;
481         int nparents, color_diff;
482         unsigned ws_rule;
483         sane_truncate_fn truncate;
484         const char **label_path;
485         struct diff_words_data *diff_words;
486         int *found_changesp;
487         FILE *file;
488 };
490 static void free_diff_words_data(struct emit_callback *ecbdata)
492         if (ecbdata->diff_words) {
493                 /* flush buffers */
494                 if (ecbdata->diff_words->minus.text.size ||
495                                 ecbdata->diff_words->plus.text.size)
496                         diff_words_show(ecbdata->diff_words);
498                 free (ecbdata->diff_words->minus.text.ptr);
499                 free (ecbdata->diff_words->plus.text.ptr);
500                 free(ecbdata->diff_words);
501                 ecbdata->diff_words = NULL;
502         }
505 const char *diff_get_color(int diff_use_color, enum color_diff ix)
507         if (diff_use_color)
508                 return diff_colors[ix];
509         return "";
512 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
514         int has_trailing_newline = (len > 0 && line[len-1] == '\n');
515         if (has_trailing_newline)
516                 len--;
518         fputs(set, file);
519         fwrite(line, len, 1, file);
520         fputs(reset, file);
521         if (has_trailing_newline)
522                 fputc('\n', file);
525 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
527         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
528         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
530         if (!*ws)
531                 emit_line(ecbdata->file, set, reset, line, len);
532         else {
533                 /* Emit just the prefix, then the rest. */
534                 emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
535                 ws_check_emit(line + ecbdata->nparents,
536                               len - ecbdata->nparents, ecbdata->ws_rule,
537                               ecbdata->file, set, reset, ws);
538         }
541 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
543         const char *cp;
544         unsigned long allot;
545         size_t l = len;
547         if (ecb->truncate)
548                 return ecb->truncate(line, len);
549         cp = line;
550         allot = l;
551         while (0 < l) {
552                 (void) utf8_width(&cp, &l);
553                 if (!cp)
554                         break; /* truncated in the middle? */
555         }
556         return allot - l;
559 static void fn_out_consume(void *priv, char *line, unsigned long len)
561         int i;
562         int color;
563         struct emit_callback *ecbdata = priv;
564         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
565         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
566         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
568         *(ecbdata->found_changesp) = 1;
570         if (ecbdata->label_path[0]) {
571                 const char *name_a_tab, *name_b_tab;
573                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
574                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
576                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
577                         meta, ecbdata->label_path[0], reset, name_a_tab);
578                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
579                         meta, ecbdata->label_path[1], reset, name_b_tab);
580                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
581         }
583         /* This is not really necessary for now because
584          * this codepath only deals with two-way diffs.
585          */
586         for (i = 0; i < len && line[i] == '@'; i++)
587                 ;
588         if (2 <= i && i < len && line[i] == ' ') {
589                 ecbdata->nparents = i - 1;
590                 len = sane_truncate_line(ecbdata, line, len);
591                 emit_line(ecbdata->file,
592                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
593                           reset, line, len);
594                 if (line[len-1] != '\n')
595                         putc('\n', ecbdata->file);
596                 return;
597         }
599         if (len < ecbdata->nparents) {
600                 emit_line(ecbdata->file, reset, reset, line, len);
601                 return;
602         }
604         color = DIFF_PLAIN;
605         if (ecbdata->diff_words && ecbdata->nparents != 1)
606                 /* fall back to normal diff */
607                 free_diff_words_data(ecbdata);
608         if (ecbdata->diff_words) {
609                 if (line[0] == '-') {
610                         diff_words_append(line, len,
611                                           &ecbdata->diff_words->minus);
612                         return;
613                 } else if (line[0] == '+') {
614                         diff_words_append(line, len,
615                                           &ecbdata->diff_words->plus);
616                         return;
617                 }
618                 if (ecbdata->diff_words->minus.text.size ||
619                     ecbdata->diff_words->plus.text.size)
620                         diff_words_show(ecbdata->diff_words);
621                 line++;
622                 len--;
623                 emit_line(ecbdata->file, plain, reset, line, len);
624                 return;
625         }
626         for (i = 0; i < ecbdata->nparents && len; i++) {
627                 if (line[i] == '-')
628                         color = DIFF_FILE_OLD;
629                 else if (line[i] == '+')
630                         color = DIFF_FILE_NEW;
631         }
633         if (color != DIFF_FILE_NEW) {
634                 emit_line(ecbdata->file,
635                           diff_get_color(ecbdata->color_diff, color),
636                           reset, line, len);
637                 return;
638         }
639         emit_add_line(reset, ecbdata, line, len);
642 static char *pprint_rename(const char *a, const char *b)
644         const char *old = a;
645         const char *new = b;
646         struct strbuf name;
647         int pfx_length, sfx_length;
648         int len_a = strlen(a);
649         int len_b = strlen(b);
650         int a_midlen, b_midlen;
651         int qlen_a = quote_c_style(a, NULL, NULL, 0);
652         int qlen_b = quote_c_style(b, NULL, NULL, 0);
654         strbuf_init(&name, 0);
655         if (qlen_a || qlen_b) {
656                 quote_c_style(a, &name, NULL, 0);
657                 strbuf_addstr(&name, " => ");
658                 quote_c_style(b, &name, NULL, 0);
659                 return strbuf_detach(&name, NULL);
660         }
662         /* Find common prefix */
663         pfx_length = 0;
664         while (*old && *new && *old == *new) {
665                 if (*old == '/')
666                         pfx_length = old - a + 1;
667                 old++;
668                 new++;
669         }
671         /* Find common suffix */
672         old = a + len_a;
673         new = b + len_b;
674         sfx_length = 0;
675         while (a <= old && b <= new && *old == *new) {
676                 if (*old == '/')
677                         sfx_length = len_a - (old - a);
678                 old--;
679                 new--;
680         }
682         /*
683          * pfx{mid-a => mid-b}sfx
684          * {pfx-a => pfx-b}sfx
685          * pfx{sfx-a => sfx-b}
686          * name-a => name-b
687          */
688         a_midlen = len_a - pfx_length - sfx_length;
689         b_midlen = len_b - pfx_length - sfx_length;
690         if (a_midlen < 0)
691                 a_midlen = 0;
692         if (b_midlen < 0)
693                 b_midlen = 0;
695         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
696         if (pfx_length + sfx_length) {
697                 strbuf_add(&name, a, pfx_length);
698                 strbuf_addch(&name, '{');
699         }
700         strbuf_add(&name, a + pfx_length, a_midlen);
701         strbuf_addstr(&name, " => ");
702         strbuf_add(&name, b + pfx_length, b_midlen);
703         if (pfx_length + sfx_length) {
704                 strbuf_addch(&name, '}');
705                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
706         }
707         return strbuf_detach(&name, NULL);
710 struct diffstat_t {
711         struct xdiff_emit_state xm;
713         int nr;
714         int alloc;
715         struct diffstat_file {
716                 char *from_name;
717                 char *name;
718                 char *print_name;
719                 unsigned is_unmerged:1;
720                 unsigned is_binary:1;
721                 unsigned is_renamed:1;
722                 unsigned int added, deleted;
723         } **files;
724 };
726 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
727                                           const char *name_a,
728                                           const char *name_b)
730         struct diffstat_file *x;
731         x = xcalloc(sizeof (*x), 1);
732         if (diffstat->nr == diffstat->alloc) {
733                 diffstat->alloc = alloc_nr(diffstat->alloc);
734                 diffstat->files = xrealloc(diffstat->files,
735                                 diffstat->alloc * sizeof(x));
736         }
737         diffstat->files[diffstat->nr++] = x;
738         if (name_b) {
739                 x->from_name = xstrdup(name_a);
740                 x->name = xstrdup(name_b);
741                 x->is_renamed = 1;
742         }
743         else {
744                 x->from_name = NULL;
745                 x->name = xstrdup(name_a);
746         }
747         return x;
750 static void diffstat_consume(void *priv, char *line, unsigned long len)
752         struct diffstat_t *diffstat = priv;
753         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
755         if (line[0] == '+')
756                 x->added++;
757         else if (line[0] == '-')
758                 x->deleted++;
761 const char mime_boundary_leader[] = "------------";
763 static int scale_linear(int it, int width, int max_change)
765         /*
766          * make sure that at least one '-' is printed if there were deletions,
767          * and likewise for '+'.
768          */
769         if (max_change < 2)
770                 return it;
771         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
774 static void show_name(FILE *file,
775                       const char *prefix, const char *name, int len,
776                       const char *reset, const char *set)
778         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
781 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
783         if (cnt <= 0)
784                 return;
785         fprintf(file, "%s", set);
786         while (cnt--)
787                 putc(ch, file);
788         fprintf(file, "%s", reset);
791 static void fill_print_name(struct diffstat_file *file)
793         char *pname;
795         if (file->print_name)
796                 return;
798         if (!file->is_renamed) {
799                 struct strbuf buf;
800                 strbuf_init(&buf, 0);
801                 if (quote_c_style(file->name, &buf, NULL, 0)) {
802                         pname = strbuf_detach(&buf, NULL);
803                 } else {
804                         pname = file->name;
805                         strbuf_release(&buf);
806                 }
807         } else {
808                 pname = pprint_rename(file->from_name, file->name);
809         }
810         file->print_name = pname;
813 static void show_stats(struct diffstat_t* data, struct diff_options *options)
815         int i, len, add, del, total, adds = 0, dels = 0;
816         int max_change = 0, max_len = 0;
817         int total_files = data->nr;
818         int width, name_width;
819         const char *reset, *set, *add_c, *del_c;
821         if (data->nr == 0)
822                 return;
824         width = options->stat_width ? options->stat_width : 80;
825         name_width = options->stat_name_width ? options->stat_name_width : 50;
827         /* Sanity: give at least 5 columns to the graph,
828          * but leave at least 10 columns for the name.
829          */
830         if (width < 25)
831                 width = 25;
832         if (name_width < 10)
833                 name_width = 10;
834         else if (width < name_width + 15)
835                 name_width = width - 15;
837         /* Find the longest filename and max number of changes */
838         reset = diff_get_color_opt(options, DIFF_RESET);
839         set   = diff_get_color_opt(options, DIFF_PLAIN);
840         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
841         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
843         for (i = 0; i < data->nr; i++) {
844                 struct diffstat_file *file = data->files[i];
845                 int change = file->added + file->deleted;
846                 fill_print_name(file);
847                 len = strlen(file->print_name);
848                 if (max_len < len)
849                         max_len = len;
851                 if (file->is_binary || file->is_unmerged)
852                         continue;
853                 if (max_change < change)
854                         max_change = change;
855         }
857         /* Compute the width of the graph part;
858          * 10 is for one blank at the beginning of the line plus
859          * " | count " between the name and the graph.
860          *
861          * From here on, name_width is the width of the name area,
862          * and width is the width of the graph area.
863          */
864         name_width = (name_width < max_len) ? name_width : max_len;
865         if (width < (name_width + 10) + max_change)
866                 width = width - (name_width + 10);
867         else
868                 width = max_change;
870         for (i = 0; i < data->nr; i++) {
871                 const char *prefix = "";
872                 char *name = data->files[i]->print_name;
873                 int added = data->files[i]->added;
874                 int deleted = data->files[i]->deleted;
875                 int name_len;
877                 /*
878                  * "scale" the filename
879                  */
880                 len = name_width;
881                 name_len = strlen(name);
882                 if (name_width < name_len) {
883                         char *slash;
884                         prefix = "...";
885                         len -= 3;
886                         name += name_len - len;
887                         slash = strchr(name, '/');
888                         if (slash)
889                                 name = slash;
890                 }
892                 if (data->files[i]->is_binary) {
893                         show_name(options->file, prefix, name, len, reset, set);
894                         fprintf(options->file, "  Bin ");
895                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
896                         fprintf(options->file, " -> ");
897                         fprintf(options->file, "%s%d%s", add_c, added, reset);
898                         fprintf(options->file, " bytes");
899                         fprintf(options->file, "\n");
900                         continue;
901                 }
902                 else if (data->files[i]->is_unmerged) {
903                         show_name(options->file, prefix, name, len, reset, set);
904                         fprintf(options->file, "  Unmerged\n");
905                         continue;
906                 }
907                 else if (!data->files[i]->is_renamed &&
908                          (added + deleted == 0)) {
909                         total_files--;
910                         continue;
911                 }
913                 /*
914                  * scale the add/delete
915                  */
916                 add = added;
917                 del = deleted;
918                 total = add + del;
919                 adds += add;
920                 dels += del;
922                 if (width <= max_change) {
923                         add = scale_linear(add, width, max_change);
924                         del = scale_linear(del, width, max_change);
925                         total = add + del;
926                 }
927                 show_name(options->file, prefix, name, len, reset, set);
928                 fprintf(options->file, "%5d%s", added + deleted,
929                                 added + deleted ? " " : "");
930                 show_graph(options->file, '+', add, add_c, reset);
931                 show_graph(options->file, '-', del, del_c, reset);
932                 fprintf(options->file, "\n");
933         }
934         fprintf(options->file,
935                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
936                set, total_files, adds, dels, reset);
939 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
941         int i, adds = 0, dels = 0, total_files = data->nr;
943         if (data->nr == 0)
944                 return;
946         for (i = 0; i < data->nr; i++) {
947                 if (!data->files[i]->is_binary &&
948                     !data->files[i]->is_unmerged) {
949                         int added = data->files[i]->added;
950                         int deleted= data->files[i]->deleted;
951                         if (!data->files[i]->is_renamed &&
952                             (added + deleted == 0)) {
953                                 total_files--;
954                         } else {
955                                 adds += added;
956                                 dels += deleted;
957                         }
958                 }
959         }
960         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
961                total_files, adds, dels);
964 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
966         int i;
968         if (data->nr == 0)
969                 return;
971         for (i = 0; i < data->nr; i++) {
972                 struct diffstat_file *file = data->files[i];
974                 if (file->is_binary)
975                         fprintf(options->file, "-\t-\t");
976                 else
977                         fprintf(options->file,
978                                 "%d\t%d\t", file->added, file->deleted);
979                 if (options->line_termination) {
980                         fill_print_name(file);
981                         if (!file->is_renamed)
982                                 write_name_quoted(file->name, options->file,
983                                                   options->line_termination);
984                         else {
985                                 fputs(file->print_name, options->file);
986                                 putc(options->line_termination, options->file);
987                         }
988                 } else {
989                         if (file->is_renamed) {
990                                 putc('\0', options->file);
991                                 write_name_quoted(file->from_name, options->file, '\0');
992                         }
993                         write_name_quoted(file->name, options->file, '\0');
994                 }
995         }
998 struct dirstat_file {
999         const char *name;
1000         unsigned long changed;
1001 };
1003 struct dirstat_dir {
1004         struct dirstat_file *files;
1005         int alloc, nr, percent, cumulative;
1006 };
1008 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1010         unsigned long this_dir = 0;
1011         unsigned int sources = 0;
1013         while (dir->nr) {
1014                 struct dirstat_file *f = dir->files;
1015                 int namelen = strlen(f->name);
1016                 unsigned long this;
1017                 char *slash;
1019                 if (namelen < baselen)
1020                         break;
1021                 if (memcmp(f->name, base, baselen))
1022                         break;
1023                 slash = strchr(f->name + baselen, '/');
1024                 if (slash) {
1025                         int newbaselen = slash + 1 - f->name;
1026                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1027                         sources++;
1028                 } else {
1029                         this = f->changed;
1030                         dir->files++;
1031                         dir->nr--;
1032                         sources += 2;
1033                 }
1034                 this_dir += this;
1035         }
1037         /*
1038          * We don't report dirstat's for
1039          *  - the top level
1040          *  - or cases where everything came from a single directory
1041          *    under this directory (sources == 1).
1042          */
1043         if (baselen && sources != 1) {
1044                 int permille = this_dir * 1000 / changed;
1045                 if (permille) {
1046                         int percent = permille / 10;
1047                         if (percent >= dir->percent) {
1048                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1049                                 if (!dir->cumulative)
1050                                         return 0;
1051                         }
1052                 }
1053         }
1054         return this_dir;
1057 static void show_dirstat(struct diff_options *options)
1059         int i;
1060         unsigned long changed;
1061         struct dirstat_dir dir;
1062         struct diff_queue_struct *q = &diff_queued_diff;
1064         dir.files = NULL;
1065         dir.alloc = 0;
1066         dir.nr = 0;
1067         dir.percent = options->dirstat_percent;
1068         dir.cumulative = options->output_format & DIFF_FORMAT_CUMULATIVE;
1070         changed = 0;
1071         for (i = 0; i < q->nr; i++) {
1072                 struct diff_filepair *p = q->queue[i];
1073                 const char *name;
1074                 unsigned long copied, added, damage;
1076                 name = p->one->path ? p->one->path : p->two->path;
1078                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1079                         diff_populate_filespec(p->one, 0);
1080                         diff_populate_filespec(p->two, 0);
1081                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1082                                                &copied, &added);
1083                         diff_free_filespec_data(p->one);
1084                         diff_free_filespec_data(p->two);
1085                 } else if (DIFF_FILE_VALID(p->one)) {
1086                         diff_populate_filespec(p->one, 1);
1087                         copied = added = 0;
1088                         diff_free_filespec_data(p->one);
1089                 } else if (DIFF_FILE_VALID(p->two)) {
1090                         diff_populate_filespec(p->two, 1);
1091                         copied = 0;
1092                         added = p->two->size;
1093                         diff_free_filespec_data(p->two);
1094                 } else
1095                         continue;
1097                 /*
1098                  * Original minus copied is the removed material,
1099                  * added is the new material.  They are both damages
1100                  * made to the preimage.
1101                  */
1102                 damage = (p->one->size - copied) + added;
1104                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1105                 dir.files[dir.nr].name = name;
1106                 dir.files[dir.nr].changed = damage;
1107                 changed += damage;
1108                 dir.nr++;
1109         }
1111         /* This can happen even with many files, if everything was renames */
1112         if (!changed)
1113                 return;
1115         /* Show all directories with more than x% of the changes */
1116         gather_dirstat(options->file, &dir, changed, "", 0);
1119 static void free_diffstat_info(struct diffstat_t *diffstat)
1121         int i;
1122         for (i = 0; i < diffstat->nr; i++) {
1123                 struct diffstat_file *f = diffstat->files[i];
1124                 if (f->name != f->print_name)
1125                         free(f->print_name);
1126                 free(f->name);
1127                 free(f->from_name);
1128                 free(f);
1129         }
1130         free(diffstat->files);
1133 struct checkdiff_t {
1134         struct xdiff_emit_state xm;
1135         const char *filename;
1136         int lineno;
1137         struct diff_options *o;
1138         unsigned ws_rule;
1139         unsigned status;
1140         int trailing_blanks_start;
1141 };
1143 static int is_conflict_marker(const char *line, unsigned long len)
1145         char firstchar;
1146         int cnt;
1148         if (len < 8)
1149                 return 0;
1150         firstchar = line[0];
1151         switch (firstchar) {
1152         case '=': case '>': case '<':
1153                 break;
1154         default:
1155                 return 0;
1156         }
1157         for (cnt = 1; cnt < 7; cnt++)
1158                 if (line[cnt] != firstchar)
1159                         return 0;
1160         /* line[0] thru line[6] are same as firstchar */
1161         if (firstchar == '=') {
1162                 /* divider between ours and theirs? */
1163                 if (len != 8 || line[7] != '\n')
1164                         return 0;
1165         } else if (len < 8 || !isspace(line[7])) {
1166                 /* not divider before ours nor after theirs */
1167                 return 0;
1168         }
1169         return 1;
1172 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1174         struct checkdiff_t *data = priv;
1175         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1176         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1177         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1178         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1179         char *err;
1181         if (line[0] == '+') {
1182                 unsigned bad;
1183                 data->lineno++;
1184                 if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1185                         data->trailing_blanks_start = 0;
1186                 else if (!data->trailing_blanks_start)
1187                         data->trailing_blanks_start = data->lineno;
1188                 if (is_conflict_marker(line + 1, len - 1)) {
1189                         data->status |= 1;
1190                         fprintf(data->o->file,
1191                                 "%s:%d: leftover conflict marker\n",
1192                                 data->filename, data->lineno);
1193                 }
1194                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1195                 if (!bad)
1196                         return;
1197                 data->status |= bad;
1198                 err = whitespace_error_string(bad);
1199                 fprintf(data->o->file, "%s:%d: %s.\n",
1200                         data->filename, data->lineno, err);
1201                 free(err);
1202                 emit_line(data->o->file, set, reset, line, 1);
1203                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1204                               data->o->file, set, reset, ws);
1205         } else if (line[0] == ' ') {
1206                 data->lineno++;
1207                 data->trailing_blanks_start = 0;
1208         } else if (line[0] == '@') {
1209                 char *plus = strchr(line, '+');
1210                 if (plus)
1211                         data->lineno = strtol(plus, NULL, 10) - 1;
1212                 else
1213                         die("invalid diff");
1214                 data->trailing_blanks_start = 0;
1215         }
1218 static unsigned char *deflate_it(char *data,
1219                                  unsigned long size,
1220                                  unsigned long *result_size)
1222         int bound;
1223         unsigned char *deflated;
1224         z_stream stream;
1226         memset(&stream, 0, sizeof(stream));
1227         deflateInit(&stream, zlib_compression_level);
1228         bound = deflateBound(&stream, size);
1229         deflated = xmalloc(bound);
1230         stream.next_out = deflated;
1231         stream.avail_out = bound;
1233         stream.next_in = (unsigned char *)data;
1234         stream.avail_in = size;
1235         while (deflate(&stream, Z_FINISH) == Z_OK)
1236                 ; /* nothing */
1237         deflateEnd(&stream);
1238         *result_size = stream.total_out;
1239         return deflated;
1242 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1244         void *cp;
1245         void *delta;
1246         void *deflated;
1247         void *data;
1248         unsigned long orig_size;
1249         unsigned long delta_size;
1250         unsigned long deflate_size;
1251         unsigned long data_size;
1253         /* We could do deflated delta, or we could do just deflated two,
1254          * whichever is smaller.
1255          */
1256         delta = NULL;
1257         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1258         if (one->size && two->size) {
1259                 delta = diff_delta(one->ptr, one->size,
1260                                    two->ptr, two->size,
1261                                    &delta_size, deflate_size);
1262                 if (delta) {
1263                         void *to_free = delta;
1264                         orig_size = delta_size;
1265                         delta = deflate_it(delta, delta_size, &delta_size);
1266                         free(to_free);
1267                 }
1268         }
1270         if (delta && delta_size < deflate_size) {
1271                 fprintf(file, "delta %lu\n", orig_size);
1272                 free(deflated);
1273                 data = delta;
1274                 data_size = delta_size;
1275         }
1276         else {
1277                 fprintf(file, "literal %lu\n", two->size);
1278                 free(delta);
1279                 data = deflated;
1280                 data_size = deflate_size;
1281         }
1283         /* emit data encoded in base85 */
1284         cp = data;
1285         while (data_size) {
1286                 int bytes = (52 < data_size) ? 52 : data_size;
1287                 char line[70];
1288                 data_size -= bytes;
1289                 if (bytes <= 26)
1290                         line[0] = bytes + 'A' - 1;
1291                 else
1292                         line[0] = bytes - 26 + 'a' - 1;
1293                 encode_85(line + 1, cp, bytes);
1294                 cp = (char *) cp + bytes;
1295                 fputs(line, file);
1296                 fputc('\n', file);
1297         }
1298         fprintf(file, "\n");
1299         free(data);
1302 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1304         fprintf(file, "GIT binary patch\n");
1305         emit_binary_diff_body(file, one, two);
1306         emit_binary_diff_body(file, two, one);
1309 static void setup_diff_attr_check(struct git_attr_check *check)
1311         static struct git_attr *attr_diff;
1313         if (!attr_diff) {
1314                 attr_diff = git_attr("diff", 4);
1315         }
1316         check[0].attr = attr_diff;
1319 static void diff_filespec_check_attr(struct diff_filespec *one)
1321         struct git_attr_check attr_diff_check;
1322         int check_from_data = 0;
1324         if (one->checked_attr)
1325                 return;
1327         setup_diff_attr_check(&attr_diff_check);
1328         one->is_binary = 0;
1329         one->funcname_pattern_ident = NULL;
1331         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1332                 const char *value;
1334                 /* binaryness */
1335                 value = attr_diff_check.value;
1336                 if (ATTR_TRUE(value))
1337                         ;
1338                 else if (ATTR_FALSE(value))
1339                         one->is_binary = 1;
1340                 else
1341                         check_from_data = 1;
1343                 /* funcname pattern ident */
1344                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1345                         ;
1346                 else
1347                         one->funcname_pattern_ident = value;
1348         }
1350         if (check_from_data) {
1351                 if (!one->data && DIFF_FILE_VALID(one))
1352                         diff_populate_filespec(one, 0);
1354                 if (one->data)
1355                         one->is_binary = buffer_is_binary(one->data, one->size);
1356         }
1359 int diff_filespec_is_binary(struct diff_filespec *one)
1361         diff_filespec_check_attr(one);
1362         return one->is_binary;
1365 static const char *funcname_pattern(const char *ident)
1367         struct funcname_pattern *pp;
1369         for (pp = funcname_pattern_list; pp; pp = pp->next)
1370                 if (!strcmp(ident, pp->name))
1371                         return pp->pattern;
1372         return NULL;
1375 static struct builtin_funcname_pattern {
1376         const char *name;
1377         const char *pattern;
1378 } builtin_funcname_pattern[] = {
1379         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1380                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1381                         "^[     ]*\\(\\([       ]*"
1382                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1383                         "[      ]*([^;]*\\)$" },
1384         { "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
1385                         "destructor\\|interface\\|implementation\\|"
1386                         "initialization\\|finalization\\)[ \t]*.*\\)$"
1387                         "\\|"
1388                         "^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
1389                         },
1390         { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
1391         { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
1392         { "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
1393 };
1395 static const char *diff_funcname_pattern(struct diff_filespec *one)
1397         const char *ident, *pattern;
1398         int i;
1400         diff_filespec_check_attr(one);
1401         ident = one->funcname_pattern_ident;
1403         if (!ident)
1404                 /*
1405                  * If the config file has "funcname.default" defined, that
1406                  * regexp is used; otherwise NULL is returned and xemit uses
1407                  * the built-in default.
1408                  */
1409                 return funcname_pattern("default");
1411         /* Look up custom "funcname.$ident" regexp from config. */
1412         pattern = funcname_pattern(ident);
1413         if (pattern)
1414                 return pattern;
1416         /*
1417          * And define built-in fallback patterns here.  Note that
1418          * these can be overridden by the user's config settings.
1419          */
1420         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1421                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1422                         return builtin_funcname_pattern[i].pattern;
1424         return NULL;
1427 static void builtin_diff(const char *name_a,
1428                          const char *name_b,
1429                          struct diff_filespec *one,
1430                          struct diff_filespec *two,
1431                          const char *xfrm_msg,
1432                          struct diff_options *o,
1433                          int complete_rewrite)
1435         mmfile_t mf1, mf2;
1436         const char *lbl[2];
1437         char *a_one, *b_two;
1438         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1439         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1441         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1442         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1443         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1444         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1445         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1446         if (lbl[0][0] == '/') {
1447                 /* /dev/null */
1448                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1449                 if (xfrm_msg && xfrm_msg[0])
1450                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1451         }
1452         else if (lbl[1][0] == '/') {
1453                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1454                 if (xfrm_msg && xfrm_msg[0])
1455                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1456         }
1457         else {
1458                 if (one->mode != two->mode) {
1459                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1460                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1461                 }
1462                 if (xfrm_msg && xfrm_msg[0])
1463                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1464                 /*
1465                  * we do not run diff between different kind
1466                  * of objects.
1467                  */
1468                 if ((one->mode ^ two->mode) & S_IFMT)
1469                         goto free_ab_and_return;
1470                 if (complete_rewrite) {
1471                         emit_rewrite_diff(name_a, name_b, one, two, o);
1472                         o->found_changes = 1;
1473                         goto free_ab_and_return;
1474                 }
1475         }
1477         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1478                 die("unable to read files to diff");
1480         if (!DIFF_OPT_TST(o, TEXT) &&
1481             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1482                 /* Quite common confusing case */
1483                 if (mf1.size == mf2.size &&
1484                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1485                         goto free_ab_and_return;
1486                 if (DIFF_OPT_TST(o, BINARY))
1487                         emit_binary_diff(o->file, &mf1, &mf2);
1488                 else
1489                         fprintf(o->file, "Binary files %s and %s differ\n",
1490                                 lbl[0], lbl[1]);
1491                 o->found_changes = 1;
1492         }
1493         else {
1494                 /* Crazy xdl interfaces.. */
1495                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1496                 xpparam_t xpp;
1497                 xdemitconf_t xecfg;
1498                 xdemitcb_t ecb;
1499                 struct emit_callback ecbdata;
1500                 const char *funcname_pattern;
1502                 funcname_pattern = diff_funcname_pattern(one);
1503                 if (!funcname_pattern)
1504                         funcname_pattern = diff_funcname_pattern(two);
1506                 memset(&xecfg, 0, sizeof(xecfg));
1507                 memset(&ecbdata, 0, sizeof(ecbdata));
1508                 ecbdata.label_path = lbl;
1509                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1510                 ecbdata.found_changesp = &o->found_changes;
1511                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1512                 ecbdata.file = o->file;
1513                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1514                 xecfg.ctxlen = o->context;
1515                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1516                 if (funcname_pattern)
1517                         xdiff_set_find_func(&xecfg, funcname_pattern);
1518                 if (!diffopts)
1519                         ;
1520                 else if (!prefixcmp(diffopts, "--unified="))
1521                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1522                 else if (!prefixcmp(diffopts, "-u"))
1523                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1524                 ecb.outf = xdiff_outf;
1525                 ecb.priv = &ecbdata;
1526                 ecbdata.xm.consume = fn_out_consume;
1527                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1528                         ecbdata.diff_words =
1529                                 xcalloc(1, sizeof(struct diff_words_data));
1530                         ecbdata.diff_words->file = o->file;
1531                 }
1532                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1533                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1534                         free_diff_words_data(&ecbdata);
1535         }
1537  free_ab_and_return:
1538         diff_free_filespec_data(one);
1539         diff_free_filespec_data(two);
1540         free(a_one);
1541         free(b_two);
1542         return;
1545 static void builtin_diffstat(const char *name_a, const char *name_b,
1546                              struct diff_filespec *one,
1547                              struct diff_filespec *two,
1548                              struct diffstat_t *diffstat,
1549                              struct diff_options *o,
1550                              int complete_rewrite)
1552         mmfile_t mf1, mf2;
1553         struct diffstat_file *data;
1555         data = diffstat_add(diffstat, name_a, name_b);
1557         if (!one || !two) {
1558                 data->is_unmerged = 1;
1559                 return;
1560         }
1561         if (complete_rewrite) {
1562                 diff_populate_filespec(one, 0);
1563                 diff_populate_filespec(two, 0);
1564                 data->deleted = count_lines(one->data, one->size);
1565                 data->added = count_lines(two->data, two->size);
1566                 goto free_and_return;
1567         }
1568         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1569                 die("unable to read files to diff");
1571         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1572                 data->is_binary = 1;
1573                 data->added = mf2.size;
1574                 data->deleted = mf1.size;
1575         } else {
1576                 /* Crazy xdl interfaces.. */
1577                 xpparam_t xpp;
1578                 xdemitconf_t xecfg;
1579                 xdemitcb_t ecb;
1581                 memset(&xecfg, 0, sizeof(xecfg));
1582                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1583                 ecb.outf = xdiff_outf;
1584                 ecb.priv = diffstat;
1585                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1586         }
1588  free_and_return:
1589         diff_free_filespec_data(one);
1590         diff_free_filespec_data(two);
1593 static void builtin_checkdiff(const char *name_a, const char *name_b,
1594                               const char *attr_path,
1595                               struct diff_filespec *one,
1596                               struct diff_filespec *two,
1597                               struct diff_options *o)
1599         mmfile_t mf1, mf2;
1600         struct checkdiff_t data;
1602         if (!two)
1603                 return;
1605         memset(&data, 0, sizeof(data));
1606         data.xm.consume = checkdiff_consume;
1607         data.filename = name_b ? name_b : name_a;
1608         data.lineno = 0;
1609         data.o = o;
1610         data.ws_rule = whitespace_rule(attr_path);
1612         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1613                 die("unable to read files to diff");
1615         /*
1616          * All the other codepaths check both sides, but not checking
1617          * the "old" side here is deliberate.  We are checking the newly
1618          * introduced changes, and as long as the "new" side is text, we
1619          * can and should check what it introduces.
1620          */
1621         if (diff_filespec_is_binary(two))
1622                 goto free_and_return;
1623         else {
1624                 /* Crazy xdl interfaces.. */
1625                 xpparam_t xpp;
1626                 xdemitconf_t xecfg;
1627                 xdemitcb_t ecb;
1629                 memset(&xecfg, 0, sizeof(xecfg));
1630                 xecfg.ctxlen = 1; /* at least one context line */
1631                 xpp.flags = XDF_NEED_MINIMAL;
1632                 ecb.outf = xdiff_outf;
1633                 ecb.priv = &data;
1634                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1636                 if ((data.ws_rule & WS_TRAILING_SPACE) &&
1637                     data.trailing_blanks_start) {
1638                         fprintf(o->file, "%s:%d: ends with blank lines.\n",
1639                                 data.filename, data.trailing_blanks_start);
1640                         data.status = 1; /* report errors */
1641                 }
1642         }
1643  free_and_return:
1644         diff_free_filespec_data(one);
1645         diff_free_filespec_data(two);
1646         if (data.status)
1647                 DIFF_OPT_SET(o, CHECK_FAILED);
1650 struct diff_filespec *alloc_filespec(const char *path)
1652         int namelen = strlen(path);
1653         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1655         memset(spec, 0, sizeof(*spec));
1656         spec->path = (char *)(spec + 1);
1657         memcpy(spec->path, path, namelen+1);
1658         spec->count = 1;
1659         return spec;
1662 void free_filespec(struct diff_filespec *spec)
1664         if (!--spec->count) {
1665                 diff_free_filespec_data(spec);
1666                 free(spec);
1667         }
1670 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1671                    unsigned short mode)
1673         if (mode) {
1674                 spec->mode = canon_mode(mode);
1675                 hashcpy(spec->sha1, sha1);
1676                 spec->sha1_valid = !is_null_sha1(sha1);
1677         }
1680 /*
1681  * Given a name and sha1 pair, if the index tells us the file in
1682  * the work tree has that object contents, return true, so that
1683  * prepare_temp_file() does not have to inflate and extract.
1684  */
1685 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1687         struct cache_entry *ce;
1688         struct stat st;
1689         int pos, len;
1691         /* We do not read the cache ourselves here, because the
1692          * benchmark with my previous version that always reads cache
1693          * shows that it makes things worse for diff-tree comparing
1694          * two linux-2.6 kernel trees in an already checked out work
1695          * tree.  This is because most diff-tree comparisons deal with
1696          * only a small number of files, while reading the cache is
1697          * expensive for a large project, and its cost outweighs the
1698          * savings we get by not inflating the object to a temporary
1699          * file.  Practically, this code only helps when we are used
1700          * by diff-cache --cached, which does read the cache before
1701          * calling us.
1702          */
1703         if (!active_cache)
1704                 return 0;
1706         /* We want to avoid the working directory if our caller
1707          * doesn't need the data in a normal file, this system
1708          * is rather slow with its stat/open/mmap/close syscalls,
1709          * and the object is contained in a pack file.  The pack
1710          * is probably already open and will be faster to obtain
1711          * the data through than the working directory.  Loose
1712          * objects however would tend to be slower as they need
1713          * to be individually opened and inflated.
1714          */
1715         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1716                 return 0;
1718         len = strlen(name);
1719         pos = cache_name_pos(name, len);
1720         if (pos < 0)
1721                 return 0;
1722         ce = active_cache[pos];
1724         /*
1725          * This is not the sha1 we are looking for, or
1726          * unreusable because it is not a regular file.
1727          */
1728         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1729                 return 0;
1731         /*
1732          * If ce matches the file in the work tree, we can reuse it.
1733          */
1734         if (ce_uptodate(ce) ||
1735             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1736                 return 1;
1738         return 0;
1741 static int populate_from_stdin(struct diff_filespec *s)
1743         struct strbuf buf;
1744         size_t size = 0;
1746         strbuf_init(&buf, 0);
1747         if (strbuf_read(&buf, 0, 0) < 0)
1748                 return error("error while reading from stdin %s",
1749                                      strerror(errno));
1751         s->should_munmap = 0;
1752         s->data = strbuf_detach(&buf, &size);
1753         s->size = size;
1754         s->should_free = 1;
1755         return 0;
1758 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1760         int len;
1761         char *data = xmalloc(100);
1762         len = snprintf(data, 100,
1763                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1764         s->data = data;
1765         s->size = len;
1766         s->should_free = 1;
1767         if (size_only) {
1768                 s->data = NULL;
1769                 free(data);
1770         }
1771         return 0;
1774 /*
1775  * While doing rename detection and pickaxe operation, we may need to
1776  * grab the data for the blob (or file) for our own in-core comparison.
1777  * diff_filespec has data and size fields for this purpose.
1778  */
1779 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1781         int err = 0;
1782         if (!DIFF_FILE_VALID(s))
1783                 die("internal error: asking to populate invalid file.");
1784         if (S_ISDIR(s->mode))
1785                 return -1;
1787         if (s->data)
1788                 return 0;
1790         if (size_only && 0 < s->size)
1791                 return 0;
1793         if (S_ISGITLINK(s->mode))
1794                 return diff_populate_gitlink(s, size_only);
1796         if (!s->sha1_valid ||
1797             reuse_worktree_file(s->path, s->sha1, 0)) {
1798                 struct strbuf buf;
1799                 struct stat st;
1800                 int fd;
1802                 if (!strcmp(s->path, "-"))
1803                         return populate_from_stdin(s);
1805                 if (lstat(s->path, &st) < 0) {
1806                         if (errno == ENOENT) {
1807                         err_empty:
1808                                 err = -1;
1809                         empty:
1810                                 s->data = (char *)"";
1811                                 s->size = 0;
1812                                 return err;
1813                         }
1814                 }
1815                 s->size = xsize_t(st.st_size);
1816                 if (!s->size)
1817                         goto empty;
1818                 if (size_only)
1819                         return 0;
1820                 if (S_ISLNK(st.st_mode)) {
1821                         int ret;
1822                         s->data = xmalloc(s->size);
1823                         s->should_free = 1;
1824                         ret = readlink(s->path, s->data, s->size);
1825                         if (ret < 0) {
1826                                 free(s->data);
1827                                 goto err_empty;
1828                         }
1829                         return 0;
1830                 }
1831                 fd = open(s->path, O_RDONLY);
1832                 if (fd < 0)
1833                         goto err_empty;
1834                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1835                 close(fd);
1836                 s->should_munmap = 1;
1838                 /*
1839                  * Convert from working tree format to canonical git format
1840                  */
1841                 strbuf_init(&buf, 0);
1842                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1843                         size_t size = 0;
1844                         munmap(s->data, s->size);
1845                         s->should_munmap = 0;
1846                         s->data = strbuf_detach(&buf, &size);
1847                         s->size = size;
1848                         s->should_free = 1;
1849                 }
1850         }
1851         else {
1852                 enum object_type type;
1853                 if (size_only)
1854                         type = sha1_object_info(s->sha1, &s->size);
1855                 else {
1856                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1857                         s->should_free = 1;
1858                 }
1859         }
1860         return 0;
1863 void diff_free_filespec_blob(struct diff_filespec *s)
1865         if (s->should_free)
1866                 free(s->data);
1867         else if (s->should_munmap)
1868                 munmap(s->data, s->size);
1870         if (s->should_free || s->should_munmap) {
1871                 s->should_free = s->should_munmap = 0;
1872                 s->data = NULL;
1873         }
1876 void diff_free_filespec_data(struct diff_filespec *s)
1878         diff_free_filespec_blob(s);
1879         free(s->cnt_data);
1880         s->cnt_data = NULL;
1883 static void prep_temp_blob(struct diff_tempfile *temp,
1884                            void *blob,
1885                            unsigned long size,
1886                            const unsigned char *sha1,
1887                            int mode)
1889         int fd;
1891         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1892         if (fd < 0)
1893                 die("unable to create temp-file: %s", strerror(errno));
1894         if (write_in_full(fd, blob, size) != size)
1895                 die("unable to write temp-file");
1896         close(fd);
1897         temp->name = temp->tmp_path;
1898         strcpy(temp->hex, sha1_to_hex(sha1));
1899         temp->hex[40] = 0;
1900         sprintf(temp->mode, "%06o", mode);
1903 static void prepare_temp_file(const char *name,
1904                               struct diff_tempfile *temp,
1905                               struct diff_filespec *one)
1907         if (!DIFF_FILE_VALID(one)) {
1908         not_a_valid_file:
1909                 /* A '-' entry produces this for file-2, and
1910                  * a '+' entry produces this for file-1.
1911                  */
1912                 temp->name = "/dev/null";
1913                 strcpy(temp->hex, ".");
1914                 strcpy(temp->mode, ".");
1915                 return;
1916         }
1918         if (!one->sha1_valid ||
1919             reuse_worktree_file(name, one->sha1, 1)) {
1920                 struct stat st;
1921                 if (lstat(name, &st) < 0) {
1922                         if (errno == ENOENT)
1923                                 goto not_a_valid_file;
1924                         die("stat(%s): %s", name, strerror(errno));
1925                 }
1926                 if (S_ISLNK(st.st_mode)) {
1927                         int ret;
1928                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1929                         size_t sz = xsize_t(st.st_size);
1930                         if (sizeof(buf) <= st.st_size)
1931                                 die("symlink too long: %s", name);
1932                         ret = readlink(name, buf, sz);
1933                         if (ret < 0)
1934                                 die("readlink(%s)", name);
1935                         prep_temp_blob(temp, buf, sz,
1936                                        (one->sha1_valid ?
1937                                         one->sha1 : null_sha1),
1938                                        (one->sha1_valid ?
1939                                         one->mode : S_IFLNK));
1940                 }
1941                 else {
1942                         /* we can borrow from the file in the work tree */
1943                         temp->name = name;
1944                         if (!one->sha1_valid)
1945                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1946                         else
1947                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1948                         /* Even though we may sometimes borrow the
1949                          * contents from the work tree, we always want
1950                          * one->mode.  mode is trustworthy even when
1951                          * !(one->sha1_valid), as long as
1952                          * DIFF_FILE_VALID(one).
1953                          */
1954                         sprintf(temp->mode, "%06o", one->mode);
1955                 }
1956                 return;
1957         }
1958         else {
1959                 if (diff_populate_filespec(one, 0))
1960                         die("cannot read data blob for %s", one->path);
1961                 prep_temp_blob(temp, one->data, one->size,
1962                                one->sha1, one->mode);
1963         }
1966 static void remove_tempfile(void)
1968         int i;
1970         for (i = 0; i < 2; i++)
1971                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1972                         unlink(diff_temp[i].name);
1973                         diff_temp[i].name = NULL;
1974                 }
1977 static void remove_tempfile_on_signal(int signo)
1979         remove_tempfile();
1980         signal(SIGINT, SIG_DFL);
1981         raise(signo);
1984 /* An external diff command takes:
1985  *
1986  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1987  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1988  *
1989  */
1990 static void run_external_diff(const char *pgm,
1991                               const char *name,
1992                               const char *other,
1993                               struct diff_filespec *one,
1994                               struct diff_filespec *two,
1995                               const char *xfrm_msg,
1996                               int complete_rewrite)
1998         const char *spawn_arg[10];
1999         struct diff_tempfile *temp = diff_temp;
2000         int retval;
2001         static int atexit_asked = 0;
2002         const char *othername;
2003         const char **arg = &spawn_arg[0];
2005         othername = (other? other : name);
2006         if (one && two) {
2007                 prepare_temp_file(name, &temp[0], one);
2008                 prepare_temp_file(othername, &temp[1], two);
2009                 if (! atexit_asked &&
2010                     (temp[0].name == temp[0].tmp_path ||
2011                      temp[1].name == temp[1].tmp_path)) {
2012                         atexit_asked = 1;
2013                         atexit(remove_tempfile);
2014                 }
2015                 signal(SIGINT, remove_tempfile_on_signal);
2016         }
2018         if (one && two) {
2019                 *arg++ = pgm;
2020                 *arg++ = name;
2021                 *arg++ = temp[0].name;
2022                 *arg++ = temp[0].hex;
2023                 *arg++ = temp[0].mode;
2024                 *arg++ = temp[1].name;
2025                 *arg++ = temp[1].hex;
2026                 *arg++ = temp[1].mode;
2027                 if (other) {
2028                         *arg++ = other;
2029                         *arg++ = xfrm_msg;
2030                 }
2031         } else {
2032                 *arg++ = pgm;
2033                 *arg++ = name;
2034         }
2035         *arg = NULL;
2036         fflush(NULL);
2037         retval = run_command_v_opt(spawn_arg, 0);
2038         remove_tempfile();
2039         if (retval) {
2040                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2041                 exit(1);
2042         }
2045 static const char *external_diff_attr(const char *name)
2047         struct git_attr_check attr_diff_check;
2049         if (!name)
2050                 return NULL;
2052         setup_diff_attr_check(&attr_diff_check);
2053         if (!git_checkattr(name, 1, &attr_diff_check)) {
2054                 const char *value = attr_diff_check.value;
2055                 if (!ATTR_TRUE(value) &&
2056                     !ATTR_FALSE(value) &&
2057                     !ATTR_UNSET(value)) {
2058                         struct ll_diff_driver *drv;
2060                         for (drv = user_diff; drv; drv = drv->next)
2061                                 if (!strcmp(drv->name, value))
2062                                         return drv->cmd;
2063                 }
2064         }
2065         return NULL;
2068 static void run_diff_cmd(const char *pgm,
2069                          const char *name,
2070                          const char *other,
2071                          const char *attr_path,
2072                          struct diff_filespec *one,
2073                          struct diff_filespec *two,
2074                          const char *xfrm_msg,
2075                          struct diff_options *o,
2076                          int complete_rewrite)
2078         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2079                 pgm = NULL;
2080         else {
2081                 const char *cmd = external_diff_attr(attr_path);
2082                 if (cmd)
2083                         pgm = cmd;
2084         }
2086         if (pgm) {
2087                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2088                                   complete_rewrite);
2089                 return;
2090         }
2091         if (one && two)
2092                 builtin_diff(name, other ? other : name,
2093                              one, two, xfrm_msg, o, complete_rewrite);
2094         else
2095                 fprintf(o->file, "* Unmerged path %s\n", name);
2098 static void diff_fill_sha1_info(struct diff_filespec *one)
2100         if (DIFF_FILE_VALID(one)) {
2101                 if (!one->sha1_valid) {
2102                         struct stat st;
2103                         if (!strcmp(one->path, "-")) {
2104                                 hashcpy(one->sha1, null_sha1);
2105                                 return;
2106                         }
2107                         if (lstat(one->path, &st) < 0)
2108                                 die("stat %s", one->path);
2109                         if (index_path(one->sha1, one->path, &st, 0))
2110                                 die("cannot hash %s\n", one->path);
2111                 }
2112         }
2113         else
2114                 hashclr(one->sha1);
2117 static int similarity_index(struct diff_filepair *p)
2119         return p->score * 100 / MAX_SCORE;
2122 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2124         /* Strip the prefix but do not molest /dev/null and absolute paths */
2125         if (*namep && **namep != '/')
2126                 *namep += prefix_length;
2127         if (*otherp && **otherp != '/')
2128                 *otherp += prefix_length;
2131 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2133         const char *pgm = external_diff();
2134         struct strbuf msg;
2135         char *xfrm_msg;
2136         struct diff_filespec *one = p->one;
2137         struct diff_filespec *two = p->two;
2138         const char *name;
2139         const char *other;
2140         const char *attr_path;
2141         int complete_rewrite = 0;
2143         name  = p->one->path;
2144         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2145         attr_path = name;
2146         if (o->prefix_length)
2147                 strip_prefix(o->prefix_length, &name, &other);
2149         if (DIFF_PAIR_UNMERGED(p)) {
2150                 run_diff_cmd(pgm, name, NULL, attr_path,
2151                              NULL, NULL, NULL, o, 0);
2152                 return;
2153         }
2155         diff_fill_sha1_info(one);
2156         diff_fill_sha1_info(two);
2158         strbuf_init(&msg, PATH_MAX * 2 + 300);
2159         switch (p->status) {
2160         case DIFF_STATUS_COPIED:
2161                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2162                 strbuf_addstr(&msg, "\ncopy from ");
2163                 quote_c_style(name, &msg, NULL, 0);
2164                 strbuf_addstr(&msg, "\ncopy to ");
2165                 quote_c_style(other, &msg, NULL, 0);
2166                 strbuf_addch(&msg, '\n');
2167                 break;
2168         case DIFF_STATUS_RENAMED:
2169                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2170                 strbuf_addstr(&msg, "\nrename from ");
2171                 quote_c_style(name, &msg, NULL, 0);
2172                 strbuf_addstr(&msg, "\nrename to ");
2173                 quote_c_style(other, &msg, NULL, 0);
2174                 strbuf_addch(&msg, '\n');
2175                 break;
2176         case DIFF_STATUS_MODIFIED:
2177                 if (p->score) {
2178                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2179                                         similarity_index(p));
2180                         complete_rewrite = 1;
2181                         break;
2182                 }
2183                 /* fallthru */
2184         default:
2185                 /* nothing */
2186                 ;
2187         }
2189         if (hashcmp(one->sha1, two->sha1)) {
2190                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2192                 if (DIFF_OPT_TST(o, BINARY)) {
2193                         mmfile_t mf;
2194                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2195                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2196                                 abbrev = 40;
2197                 }
2198                 strbuf_addf(&msg, "index %.*s..%.*s",
2199                                 abbrev, sha1_to_hex(one->sha1),
2200                                 abbrev, sha1_to_hex(two->sha1));
2201                 if (one->mode == two->mode)
2202                         strbuf_addf(&msg, " %06o", one->mode);
2203                 strbuf_addch(&msg, '\n');
2204         }
2206         if (msg.len)
2207                 strbuf_setlen(&msg, msg.len - 1);
2208         xfrm_msg = msg.len ? msg.buf : NULL;
2210         if (!pgm &&
2211             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2212             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2213                 /* a filepair that changes between file and symlink
2214                  * needs to be split into deletion and creation.
2215                  */
2216                 struct diff_filespec *null = alloc_filespec(two->path);
2217                 run_diff_cmd(NULL, name, other, attr_path,
2218                              one, null, xfrm_msg, o, 0);
2219                 free(null);
2220                 null = alloc_filespec(one->path);
2221                 run_diff_cmd(NULL, name, other, attr_path,
2222                              null, two, xfrm_msg, o, 0);
2223                 free(null);
2224         }
2225         else
2226                 run_diff_cmd(pgm, name, other, attr_path,
2227                              one, two, xfrm_msg, o, complete_rewrite);
2229         strbuf_release(&msg);
2232 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2233                          struct diffstat_t *diffstat)
2235         const char *name;
2236         const char *other;
2237         int complete_rewrite = 0;
2239         if (DIFF_PAIR_UNMERGED(p)) {
2240                 /* unmerged */
2241                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2242                 return;
2243         }
2245         name = p->one->path;
2246         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2248         if (o->prefix_length)
2249                 strip_prefix(o->prefix_length, &name, &other);
2251         diff_fill_sha1_info(p->one);
2252         diff_fill_sha1_info(p->two);
2254         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2255                 complete_rewrite = 1;
2256         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2259 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2261         const char *name;
2262         const char *other;
2263         const char *attr_path;
2265         if (DIFF_PAIR_UNMERGED(p)) {
2266                 /* unmerged */
2267                 return;
2268         }
2270         name = p->one->path;
2271         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2272         attr_path = other ? other : name;
2274         if (o->prefix_length)
2275                 strip_prefix(o->prefix_length, &name, &other);
2277         diff_fill_sha1_info(p->one);
2278         diff_fill_sha1_info(p->two);
2280         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2283 void diff_setup(struct diff_options *options)
2285         memset(options, 0, sizeof(*options));
2287         options->file = stdout;
2289         options->line_termination = '\n';
2290         options->break_opt = -1;
2291         options->rename_limit = -1;
2292         options->dirstat_percent = 3;
2293         options->context = 3;
2295         options->change = diff_change;
2296         options->add_remove = diff_addremove;
2297         if (diff_use_color_default > 0)
2298                 DIFF_OPT_SET(options, COLOR_DIFF);
2299         else
2300                 DIFF_OPT_CLR(options, COLOR_DIFF);
2301         options->detect_rename = diff_detect_rename_default;
2303         options->a_prefix = "a/";
2304         options->b_prefix = "b/";
2307 int diff_setup_done(struct diff_options *options)
2309         int count = 0;
2311         if (options->output_format & DIFF_FORMAT_NAME)
2312                 count++;
2313         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2314                 count++;
2315         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2316                 count++;
2317         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2318                 count++;
2319         if (count > 1)
2320                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2322         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2323                 options->detect_rename = DIFF_DETECT_COPY;
2325         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2326                 options->prefix = NULL;
2327         if (options->prefix)
2328                 options->prefix_length = strlen(options->prefix);
2329         else
2330                 options->prefix_length = 0;
2332         if (options->output_format & (DIFF_FORMAT_NAME |
2333                                       DIFF_FORMAT_NAME_STATUS |
2334                                       DIFF_FORMAT_CHECKDIFF |
2335                                       DIFF_FORMAT_NO_OUTPUT))
2336                 options->output_format &= ~(DIFF_FORMAT_RAW |
2337                                             DIFF_FORMAT_NUMSTAT |
2338                                             DIFF_FORMAT_DIFFSTAT |
2339                                             DIFF_FORMAT_SHORTSTAT |
2340                                             DIFF_FORMAT_DIRSTAT |
2341                                             DIFF_FORMAT_SUMMARY |
2342                                             DIFF_FORMAT_PATCH);
2344         /*
2345          * These cases always need recursive; we do not drop caller-supplied
2346          * recursive bits for other formats here.
2347          */
2348         if (options->output_format & (DIFF_FORMAT_PATCH |
2349                                       DIFF_FORMAT_NUMSTAT |
2350                                       DIFF_FORMAT_DIFFSTAT |
2351                                       DIFF_FORMAT_SHORTSTAT |
2352                                       DIFF_FORMAT_DIRSTAT |
2353                                       DIFF_FORMAT_SUMMARY |
2354                                       DIFF_FORMAT_CHECKDIFF))
2355                 DIFF_OPT_SET(options, RECURSIVE);
2356         /*
2357          * Also pickaxe would not work very well if you do not say recursive
2358          */
2359         if (options->pickaxe)
2360                 DIFF_OPT_SET(options, RECURSIVE);
2362         if (options->detect_rename && options->rename_limit < 0)
2363                 options->rename_limit = diff_rename_limit_default;
2364         if (options->setup & DIFF_SETUP_USE_CACHE) {
2365                 if (!active_cache)
2366                         /* read-cache does not die even when it fails
2367                          * so it is safe for us to do this here.  Also
2368                          * it does not smudge active_cache or active_nr
2369                          * when it fails, so we do not have to worry about
2370                          * cleaning it up ourselves either.
2371                          */
2372                         read_cache();
2373         }
2374         if (options->abbrev <= 0 || 40 < options->abbrev)
2375                 options->abbrev = 40; /* full */
2377         /*
2378          * It does not make sense to show the first hit we happened
2379          * to have found.  It does not make sense not to return with
2380          * exit code in such a case either.
2381          */
2382         if (DIFF_OPT_TST(options, QUIET)) {
2383                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2384                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2385         }
2387         /*
2388          * If we postprocess in diffcore, we cannot simply return
2389          * upon the first hit.  We need to run diff as usual.
2390          */
2391         if (options->pickaxe || options->filter)
2392                 DIFF_OPT_CLR(options, QUIET);
2394         return 0;
2397 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2399         char c, *eq;
2400         int len;
2402         if (*arg != '-')
2403                 return 0;
2404         c = *++arg;
2405         if (!c)
2406                 return 0;
2407         if (c == arg_short) {
2408                 c = *++arg;
2409                 if (!c)
2410                         return 1;
2411                 if (val && isdigit(c)) {
2412                         char *end;
2413                         int n = strtoul(arg, &end, 10);
2414                         if (*end)
2415                                 return 0;
2416                         *val = n;
2417                         return 1;
2418                 }
2419                 return 0;
2420         }
2421         if (c != '-')
2422                 return 0;
2423         arg++;
2424         eq = strchr(arg, '=');
2425         if (eq)
2426                 len = eq - arg;
2427         else
2428                 len = strlen(arg);
2429         if (!len || strncmp(arg, arg_long, len))
2430                 return 0;
2431         if (eq) {
2432                 int n;
2433                 char *end;
2434                 if (!isdigit(*++eq))
2435                         return 0;
2436                 n = strtoul(eq, &end, 10);
2437                 if (*end)
2438                         return 0;
2439                 *val = n;
2440         }
2441         return 1;
2444 static int diff_scoreopt_parse(const char *opt);
2446 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2448         const char *arg = av[0];
2450         /* Output format options */
2451         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2452                 options->output_format |= DIFF_FORMAT_PATCH;
2453         else if (opt_arg(arg, 'U', "unified", &options->context))
2454                 options->output_format |= DIFF_FORMAT_PATCH;
2455         else if (!strcmp(arg, "--raw"))
2456                 options->output_format |= DIFF_FORMAT_RAW;
2457         else if (!strcmp(arg, "--patch-with-raw"))
2458                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2459         else if (!strcmp(arg, "--numstat"))
2460                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2461         else if (!strcmp(arg, "--shortstat"))
2462                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2463         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2464                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2465         else if (!strcmp(arg, "--cumulative"))
2466                 options->output_format |= DIFF_FORMAT_CUMULATIVE;
2467         else if (!strcmp(arg, "--check"))
2468                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2469         else if (!strcmp(arg, "--summary"))
2470                 options->output_format |= DIFF_FORMAT_SUMMARY;
2471         else if (!strcmp(arg, "--patch-with-stat"))
2472                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2473         else if (!strcmp(arg, "--name-only"))
2474                 options->output_format |= DIFF_FORMAT_NAME;
2475         else if (!strcmp(arg, "--name-status"))
2476                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2477         else if (!strcmp(arg, "-s"))
2478                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2479         else if (!prefixcmp(arg, "--stat")) {
2480                 char *end;
2481                 int width = options->stat_width;
2482                 int name_width = options->stat_name_width;
2483                 arg += 6;
2484                 end = (char *)arg;
2486                 switch (*arg) {
2487                 case '-':
2488                         if (!prefixcmp(arg, "-width="))
2489                                 width = strtoul(arg + 7, &end, 10);
2490                         else if (!prefixcmp(arg, "-name-width="))
2491                                 name_width = strtoul(arg + 12, &end, 10);
2492                         break;
2493                 case '=':
2494                         width = strtoul(arg+1, &end, 10);
2495                         if (*end == ',')
2496                                 name_width = strtoul(end+1, &end, 10);
2497                 }
2499                 /* Important! This checks all the error cases! */
2500                 if (*end)
2501                         return 0;
2502                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2503                 options->stat_name_width = name_width;
2504                 options->stat_width = width;
2505         }
2507         /* renames options */
2508         else if (!prefixcmp(arg, "-B")) {
2509                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2510                         return -1;
2511         }
2512         else if (!prefixcmp(arg, "-M")) {
2513                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2514                         return -1;
2515                 options->detect_rename = DIFF_DETECT_RENAME;
2516         }
2517         else if (!prefixcmp(arg, "-C")) {
2518                 if (options->detect_rename == DIFF_DETECT_COPY)
2519                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2520                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2521                         return -1;
2522                 options->detect_rename = DIFF_DETECT_COPY;
2523         }
2524         else if (!strcmp(arg, "--no-renames"))
2525                 options->detect_rename = 0;
2526         else if (!strcmp(arg, "--relative"))
2527                 DIFF_OPT_SET(options, RELATIVE_NAME);
2528         else if (!prefixcmp(arg, "--relative=")) {
2529                 DIFF_OPT_SET(options, RELATIVE_NAME);
2530                 options->prefix = arg + 11;
2531         }
2533         /* xdiff options */
2534         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2535                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2536         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2537                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2538         else if (!strcmp(arg, "--ignore-space-at-eol"))
2539                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2541         /* flags options */
2542         else if (!strcmp(arg, "--binary")) {
2543                 options->output_format |= DIFF_FORMAT_PATCH;
2544                 DIFF_OPT_SET(options, BINARY);
2545         }
2546         else if (!strcmp(arg, "--full-index"))
2547                 DIFF_OPT_SET(options, FULL_INDEX);
2548         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2549                 DIFF_OPT_SET(options, TEXT);
2550         else if (!strcmp(arg, "-R"))
2551                 DIFF_OPT_SET(options, REVERSE_DIFF);
2552         else if (!strcmp(arg, "--find-copies-harder"))
2553                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2554         else if (!strcmp(arg, "--follow"))
2555                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2556         else if (!strcmp(arg, "--color"))
2557                 DIFF_OPT_SET(options, COLOR_DIFF);
2558         else if (!strcmp(arg, "--no-color"))
2559                 DIFF_OPT_CLR(options, COLOR_DIFF);
2560         else if (!strcmp(arg, "--color-words"))
2561                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2562         else if (!strcmp(arg, "--exit-code"))
2563                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2564         else if (!strcmp(arg, "--quiet"))
2565                 DIFF_OPT_SET(options, QUIET);
2566         else if (!strcmp(arg, "--ext-diff"))
2567                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2568         else if (!strcmp(arg, "--no-ext-diff"))
2569                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2570         else if (!strcmp(arg, "--ignore-submodules"))
2571                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2573         /* misc options */
2574         else if (!strcmp(arg, "-z"))
2575                 options->line_termination = 0;
2576         else if (!prefixcmp(arg, "-l"))
2577                 options->rename_limit = strtoul(arg+2, NULL, 10);
2578         else if (!prefixcmp(arg, "-S"))
2579                 options->pickaxe = arg + 2;
2580         else if (!strcmp(arg, "--pickaxe-all"))
2581                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2582         else if (!strcmp(arg, "--pickaxe-regex"))
2583                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2584         else if (!prefixcmp(arg, "-O"))
2585                 options->orderfile = arg + 2;
2586         else if (!prefixcmp(arg, "--diff-filter="))
2587                 options->filter = arg + 14;
2588         else if (!strcmp(arg, "--abbrev"))
2589                 options->abbrev = DEFAULT_ABBREV;
2590         else if (!prefixcmp(arg, "--abbrev=")) {
2591                 options->abbrev = strtoul(arg + 9, NULL, 10);
2592                 if (options->abbrev < MINIMUM_ABBREV)
2593                         options->abbrev = MINIMUM_ABBREV;
2594                 else if (40 < options->abbrev)
2595                         options->abbrev = 40;
2596         }
2597         else if (!prefixcmp(arg, "--src-prefix="))
2598                 options->a_prefix = arg + 13;
2599         else if (!prefixcmp(arg, "--dst-prefix="))
2600                 options->b_prefix = arg + 13;
2601         else if (!strcmp(arg, "--no-prefix"))
2602                 options->a_prefix = options->b_prefix = "";
2603         else if (!prefixcmp(arg, "--output=")) {
2604                 options->file = fopen(arg + strlen("--output="), "w");
2605                 options->close_file = 1;
2606         } else
2607                 return 0;
2608         return 1;
2611 static int parse_num(const char **cp_p)
2613         unsigned long num, scale;
2614         int ch, dot;
2615         const char *cp = *cp_p;
2617         num = 0;
2618         scale = 1;
2619         dot = 0;
2620         for(;;) {
2621                 ch = *cp;
2622                 if ( !dot && ch == '.' ) {
2623                         scale = 1;
2624                         dot = 1;
2625                 } else if ( ch == '%' ) {
2626                         scale = dot ? scale*100 : 100;
2627                         cp++;   /* % is always at the end */
2628                         break;
2629                 } else if ( ch >= '0' && ch <= '9' ) {
2630                         if ( scale < 100000 ) {
2631                                 scale *= 10;
2632                                 num = (num*10) + (ch-'0');
2633                         }
2634                 } else {
2635                         break;
2636                 }
2637                 cp++;
2638         }
2639         *cp_p = cp;
2641         /* user says num divided by scale and we say internally that
2642          * is MAX_SCORE * num / scale.
2643          */
2644         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2647 static int diff_scoreopt_parse(const char *opt)
2649         int opt1, opt2, cmd;
2651         if (*opt++ != '-')
2652                 return -1;
2653         cmd = *opt++;
2654         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2655                 return -1; /* that is not a -M, -C nor -B option */
2657         opt1 = parse_num(&opt);
2658         if (cmd != 'B')
2659                 opt2 = 0;
2660         else {
2661                 if (*opt == 0)
2662                         opt2 = 0;
2663                 else if (*opt != '/')
2664                         return -1; /* we expect -B80/99 or -B80 */
2665                 else {
2666                         opt++;
2667                         opt2 = parse_num(&opt);
2668                 }
2669         }
2670         if (*opt != 0)
2671                 return -1;
2672         return opt1 | (opt2 << 16);
2675 struct diff_queue_struct diff_queued_diff;
2677 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2679         if (queue->alloc <= queue->nr) {
2680                 queue->alloc = alloc_nr(queue->alloc);
2681                 queue->queue = xrealloc(queue->queue,
2682                                         sizeof(dp) * queue->alloc);
2683         }
2684         queue->queue[queue->nr++] = dp;
2687 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2688                                  struct diff_filespec *one,
2689                                  struct diff_filespec *two)
2691         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2692         dp->one = one;
2693         dp->two = two;
2694         if (queue)
2695                 diff_q(queue, dp);
2696         return dp;
2699 void diff_free_filepair(struct diff_filepair *p)
2701         free_filespec(p->one);
2702         free_filespec(p->two);
2703         free(p);
2706 /* This is different from find_unique_abbrev() in that
2707  * it stuffs the result with dots for alignment.
2708  */
2709 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2711         int abblen;
2712         const char *abbrev;
2713         if (len == 40)
2714                 return sha1_to_hex(sha1);
2716         abbrev = find_unique_abbrev(sha1, len);
2717         abblen = strlen(abbrev);
2718         if (abblen < 37) {
2719                 static char hex[41];
2720                 if (len < abblen && abblen <= len + 2)
2721                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2722                 else
2723                         sprintf(hex, "%s...", abbrev);
2724                 return hex;
2725         }
2726         return sha1_to_hex(sha1);
2729 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2731         int line_termination = opt->line_termination;
2732         int inter_name_termination = line_termination ? '\t' : '\0';
2734         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2735                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2736                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2737                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2738         }
2739         if (p->score) {
2740                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2741                         inter_name_termination);
2742         } else {
2743                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2744         }
2746         if (p->status == DIFF_STATUS_COPIED ||
2747             p->status == DIFF_STATUS_RENAMED) {
2748                 const char *name_a, *name_b;
2749                 name_a = p->one->path;
2750                 name_b = p->two->path;
2751                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2752                 write_name_quoted(name_a, opt->file, inter_name_termination);
2753                 write_name_quoted(name_b, opt->file, line_termination);
2754         } else {
2755                 const char *name_a, *name_b;
2756                 name_a = p->one->mode ? p->one->path : p->two->path;
2757                 name_b = NULL;
2758                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2759                 write_name_quoted(name_a, opt->file, line_termination);
2760         }
2763 int diff_unmodified_pair(struct diff_filepair *p)
2765         /* This function is written stricter than necessary to support
2766          * the currently implemented transformers, but the idea is to
2767          * let transformers to produce diff_filepairs any way they want,
2768          * and filter and clean them up here before producing the output.
2769          */
2770         struct diff_filespec *one = p->one, *two = p->two;
2772         if (DIFF_PAIR_UNMERGED(p))
2773                 return 0; /* unmerged is interesting */
2775         /* deletion, addition, mode or type change
2776          * and rename are all interesting.
2777          */
2778         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2779             DIFF_PAIR_MODE_CHANGED(p) ||
2780             strcmp(one->path, two->path))
2781                 return 0;
2783         /* both are valid and point at the same path.  that is, we are
2784          * dealing with a change.
2785          */
2786         if (one->sha1_valid && two->sha1_valid &&
2787             !hashcmp(one->sha1, two->sha1))
2788                 return 1; /* no change */
2789         if (!one->sha1_valid && !two->sha1_valid)
2790                 return 1; /* both look at the same file on the filesystem. */
2791         return 0;
2794 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2796         if (diff_unmodified_pair(p))
2797                 return;
2799         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2800             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2801                 return; /* no tree diffs in patch format */
2803         run_diff(p, o);
2806 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2807                             struct diffstat_t *diffstat)
2809         if (diff_unmodified_pair(p))
2810                 return;
2812         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2813             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2814                 return; /* no tree diffs in patch format */
2816         run_diffstat(p, o, diffstat);
2819 static void diff_flush_checkdiff(struct diff_filepair *p,
2820                 struct diff_options *o)
2822         if (diff_unmodified_pair(p))
2823                 return;
2825         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2826             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2827                 return; /* no tree diffs in patch format */
2829         run_checkdiff(p, o);
2832 int diff_queue_is_empty(void)
2834         struct diff_queue_struct *q = &diff_queued_diff;
2835         int i;
2836         for (i = 0; i < q->nr; i++)
2837                 if (!diff_unmodified_pair(q->queue[i]))
2838                         return 0;
2839         return 1;
2842 #if DIFF_DEBUG
2843 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2845         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2846                 x, one ? one : "",
2847                 s->path,
2848                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2849                 s->mode,
2850                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2851         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2852                 x, one ? one : "",
2853                 s->size, s->xfrm_flags);
2856 void diff_debug_filepair(const struct diff_filepair *p, int i)
2858         diff_debug_filespec(p->one, i, "one");
2859         diff_debug_filespec(p->two, i, "two");
2860         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2861                 p->score, p->status ? p->status : '?',
2862                 p->one->rename_used, p->broken_pair);
2865 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2867         int i;
2868         if (msg)
2869                 fprintf(stderr, "%s\n", msg);
2870         fprintf(stderr, "q->nr = %d\n", q->nr);
2871         for (i = 0; i < q->nr; i++) {
2872                 struct diff_filepair *p = q->queue[i];
2873                 diff_debug_filepair(p, i);
2874         }
2876 #endif
2878 static void diff_resolve_rename_copy(void)
2880         int i;
2881         struct diff_filepair *p;
2882         struct diff_queue_struct *q = &diff_queued_diff;
2884         diff_debug_queue("resolve-rename-copy", q);
2886         for (i = 0; i < q->nr; i++) {
2887                 p = q->queue[i];
2888                 p->status = 0; /* undecided */
2889                 if (DIFF_PAIR_UNMERGED(p))
2890                         p->status = DIFF_STATUS_UNMERGED;
2891                 else if (!DIFF_FILE_VALID(p->one))
2892                         p->status = DIFF_STATUS_ADDED;
2893                 else if (!DIFF_FILE_VALID(p->two))
2894                         p->status = DIFF_STATUS_DELETED;
2895                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2896                         p->status = DIFF_STATUS_TYPE_CHANGED;
2898                 /* from this point on, we are dealing with a pair
2899                  * whose both sides are valid and of the same type, i.e.
2900                  * either in-place edit or rename/copy edit.
2901                  */
2902                 else if (DIFF_PAIR_RENAME(p)) {
2903                         /*
2904                          * A rename might have re-connected a broken
2905                          * pair up, causing the pathnames to be the
2906                          * same again. If so, that's not a rename at
2907                          * all, just a modification..
2908                          *
2909                          * Otherwise, see if this source was used for
2910                          * multiple renames, in which case we decrement
2911                          * the count, and call it a copy.
2912                          */
2913                         if (!strcmp(p->one->path, p->two->path))
2914                                 p->status = DIFF_STATUS_MODIFIED;
2915                         else if (--p->one->rename_used > 0)
2916                                 p->status = DIFF_STATUS_COPIED;
2917                         else
2918                                 p->status = DIFF_STATUS_RENAMED;
2919                 }
2920                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2921                          p->one->mode != p->two->mode ||
2922                          is_null_sha1(p->one->sha1))
2923                         p->status = DIFF_STATUS_MODIFIED;
2924                 else {
2925                         /* This is a "no-change" entry and should not
2926                          * happen anymore, but prepare for broken callers.
2927                          */
2928                         error("feeding unmodified %s to diffcore",
2929                               p->one->path);
2930                         p->status = DIFF_STATUS_UNKNOWN;
2931                 }
2932         }
2933         diff_debug_queue("resolve-rename-copy done", q);
2936 static int check_pair_status(struct diff_filepair *p)
2938         switch (p->status) {
2939         case DIFF_STATUS_UNKNOWN:
2940                 return 0;
2941         case 0:
2942                 die("internal error in diff-resolve-rename-copy");
2943         default:
2944                 return 1;
2945         }
2948 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2950         int fmt = opt->output_format;
2952         if (fmt & DIFF_FORMAT_CHECKDIFF)
2953                 diff_flush_checkdiff(p, opt);
2954         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2955                 diff_flush_raw(p, opt);
2956         else if (fmt & DIFF_FORMAT_NAME) {
2957                 const char *name_a, *name_b;
2958                 name_a = p->two->path;
2959                 name_b = NULL;
2960                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2961                 write_name_quoted(name_a, opt->file, opt->line_termination);
2962         }
2965 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2967         if (fs->mode)
2968                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2969         else
2970                 fprintf(file, " %s ", newdelete);
2971         write_name_quoted(fs->path, file, '\n');
2975 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2977         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2978                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2979                         show_name ? ' ' : '\n');
2980                 if (show_name) {
2981                         write_name_quoted(p->two->path, file, '\n');
2982                 }
2983         }
2986 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2988         char *names = pprint_rename(p->one->path, p->two->path);
2990         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2991         free(names);
2992         show_mode_change(file, p, 0);
2995 static void diff_summary(FILE *file, struct diff_filepair *p)
2997         switch(p->status) {
2998         case DIFF_STATUS_DELETED:
2999                 show_file_mode_name(file, "delete", p->one);
3000                 break;
3001         case DIFF_STATUS_ADDED:
3002                 show_file_mode_name(file, "create", p->two);
3003                 break;
3004         case DIFF_STATUS_COPIED:
3005                 show_rename_copy(file, "copy", p);
3006                 break;
3007         case DIFF_STATUS_RENAMED:
3008                 show_rename_copy(file, "rename", p);
3009                 break;
3010         default:
3011                 if (p->score) {
3012                         fputs(" rewrite ", file);
3013                         write_name_quoted(p->two->path, file, ' ');
3014                         fprintf(file, "(%d%%)\n", similarity_index(p));
3015                 }
3016                 show_mode_change(file, p, !p->score);
3017                 break;
3018         }
3021 struct patch_id_t {
3022         struct xdiff_emit_state xm;
3023         SHA_CTX *ctx;
3024         int patchlen;
3025 };
3027 static int remove_space(char *line, int len)
3029         int i;
3030         char *dst = line;
3031         unsigned char c;
3033         for (i = 0; i < len; i++)
3034                 if (!isspace((c = line[i])))
3035                         *dst++ = c;
3037         return dst - line;
3040 static void patch_id_consume(void *priv, char *line, unsigned long len)
3042         struct patch_id_t *data = priv;
3043         int new_len;
3045         /* Ignore line numbers when computing the SHA1 of the patch */
3046         if (!prefixcmp(line, "@@ -"))
3047                 return;
3049         new_len = remove_space(line, len);
3051         SHA1_Update(data->ctx, line, new_len);
3052         data->patchlen += new_len;
3055 /* returns 0 upon success, and writes result into sha1 */
3056 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3058         struct diff_queue_struct *q = &diff_queued_diff;
3059         int i;
3060         SHA_CTX ctx;
3061         struct patch_id_t data;
3062         char buffer[PATH_MAX * 4 + 20];
3064         SHA1_Init(&ctx);
3065         memset(&data, 0, sizeof(struct patch_id_t));
3066         data.ctx = &ctx;
3067         data.xm.consume = patch_id_consume;
3069         for (i = 0; i < q->nr; i++) {
3070                 xpparam_t xpp;
3071                 xdemitconf_t xecfg;
3072                 xdemitcb_t ecb;
3073                 mmfile_t mf1, mf2;
3074                 struct diff_filepair *p = q->queue[i];
3075                 int len1, len2;
3077                 memset(&xecfg, 0, sizeof(xecfg));
3078                 if (p->status == 0)
3079                         return error("internal diff status error");
3080                 if (p->status == DIFF_STATUS_UNKNOWN)
3081                         continue;
3082                 if (diff_unmodified_pair(p))
3083                         continue;
3084                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3085                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3086                         continue;
3087                 if (DIFF_PAIR_UNMERGED(p))
3088                         continue;
3090                 diff_fill_sha1_info(p->one);
3091                 diff_fill_sha1_info(p->two);
3092                 if (fill_mmfile(&mf1, p->one) < 0 ||
3093                                 fill_mmfile(&mf2, p->two) < 0)
3094                         return error("unable to read files to diff");
3096                 len1 = remove_space(p->one->path, strlen(p->one->path));
3097                 len2 = remove_space(p->two->path, strlen(p->two->path));
3098                 if (p->one->mode == 0)
3099                         len1 = snprintf(buffer, sizeof(buffer),
3100                                         "diff--gita/%.*sb/%.*s"
3101                                         "newfilemode%06o"
3102                                         "---/dev/null"
3103                                         "+++b/%.*s",
3104                                         len1, p->one->path,
3105                                         len2, p->two->path,
3106                                         p->two->mode,
3107                                         len2, p->two->path);
3108                 else if (p->two->mode == 0)
3109                         len1 = snprintf(buffer, sizeof(buffer),
3110                                         "diff--gita/%.*sb/%.*s"
3111                                         "deletedfilemode%06o"
3112                                         "---a/%.*s"
3113                                         "+++/dev/null",
3114                                         len1, p->one->path,
3115                                         len2, p->two->path,
3116                                         p->one->mode,
3117                                         len1, p->one->path);
3118                 else
3119                         len1 = snprintf(buffer, sizeof(buffer),
3120                                         "diff--gita/%.*sb/%.*s"
3121                                         "---a/%.*s"
3122                                         "+++b/%.*s",
3123                                         len1, p->one->path,
3124                                         len2, p->two->path,
3125                                         len1, p->one->path,
3126                                         len2, p->two->path);
3127                 SHA1_Update(&ctx, buffer, len1);
3129                 xpp.flags = XDF_NEED_MINIMAL;
3130                 xecfg.ctxlen = 3;
3131                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3132                 ecb.outf = xdiff_outf;
3133                 ecb.priv = &data;
3134                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
3135         }
3137         SHA1_Final(sha1, &ctx);
3138         return 0;
3141 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3143         struct diff_queue_struct *q = &diff_queued_diff;
3144         int i;
3145         int result = diff_get_patch_id(options, sha1);
3147         for (i = 0; i < q->nr; i++)
3148                 diff_free_filepair(q->queue[i]);
3150         free(q->queue);
3151         q->queue = NULL;
3152         q->nr = q->alloc = 0;
3154         return result;
3157 static int is_summary_empty(const struct diff_queue_struct *q)
3159         int i;
3161         for (i = 0; i < q->nr; i++) {
3162                 const struct diff_filepair *p = q->queue[i];
3164                 switch (p->status) {
3165                 case DIFF_STATUS_DELETED:
3166                 case DIFF_STATUS_ADDED:
3167                 case DIFF_STATUS_COPIED:
3168                 case DIFF_STATUS_RENAMED:
3169                         return 0;
3170                 default:
3171                         if (p->score)
3172                                 return 0;
3173                         if (p->one->mode && p->two->mode &&
3174                             p->one->mode != p->two->mode)
3175                                 return 0;
3176                         break;
3177                 }
3178         }
3179         return 1;
3182 void diff_flush(struct diff_options *options)
3184         struct diff_queue_struct *q = &diff_queued_diff;
3185         int i, output_format = options->output_format;
3186         int separator = 0;
3188         /*
3189          * Order: raw, stat, summary, patch
3190          * or:    name/name-status/checkdiff (other bits clear)
3191          */
3192         if (!q->nr)
3193                 goto free_queue;
3195         if (output_format & (DIFF_FORMAT_RAW |
3196                              DIFF_FORMAT_NAME |
3197                              DIFF_FORMAT_NAME_STATUS |
3198                              DIFF_FORMAT_CHECKDIFF)) {
3199                 for (i = 0; i < q->nr; i++) {
3200                         struct diff_filepair *p = q->queue[i];
3201                         if (check_pair_status(p))
3202                                 flush_one_pair(p, options);
3203                 }
3204                 separator++;
3205         }
3207         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3208                 struct diffstat_t diffstat;
3210                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3211                 diffstat.xm.consume = diffstat_consume;
3212                 for (i = 0; i < q->nr; i++) {
3213                         struct diff_filepair *p = q->queue[i];
3214                         if (check_pair_status(p))
3215                                 diff_flush_stat(p, options, &diffstat);
3216                 }
3217                 if (output_format & DIFF_FORMAT_NUMSTAT)
3218                         show_numstat(&diffstat, options);
3219                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3220                         show_stats(&diffstat, options);
3221                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3222                         show_shortstats(&diffstat, options);
3223                 free_diffstat_info(&diffstat);
3224                 separator++;
3225         }
3226         if (output_format & DIFF_FORMAT_DIRSTAT)
3227                 show_dirstat(options);
3229         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3230                 for (i = 0; i < q->nr; i++)
3231                         diff_summary(options->file, q->queue[i]);
3232                 separator++;
3233         }
3235         if (output_format & DIFF_FORMAT_PATCH) {
3236                 if (separator) {
3237                         putc(options->line_termination, options->file);
3238                         if (options->stat_sep) {
3239                                 /* attach patch instead of inline */
3240                                 fputs(options->stat_sep, options->file);
3241                         }
3242                 }
3244                 for (i = 0; i < q->nr; i++) {
3245                         struct diff_filepair *p = q->queue[i];
3246                         if (check_pair_status(p))
3247                                 diff_flush_patch(p, options);
3248                 }
3249         }
3251         if (output_format & DIFF_FORMAT_CALLBACK)
3252                 options->format_callback(q, options, options->format_callback_data);
3254         for (i = 0; i < q->nr; i++)
3255                 diff_free_filepair(q->queue[i]);
3256 free_queue:
3257         free(q->queue);
3258         q->queue = NULL;
3259         q->nr = q->alloc = 0;
3260         if (options->close_file)
3261                 fclose(options->file);
3264 static void diffcore_apply_filter(const char *filter)
3266         int i;
3267         struct diff_queue_struct *q = &diff_queued_diff;
3268         struct diff_queue_struct outq;
3269         outq.queue = NULL;
3270         outq.nr = outq.alloc = 0;
3272         if (!filter)
3273                 return;
3275         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3276                 int found;
3277                 for (i = found = 0; !found && i < q->nr; i++) {
3278                         struct diff_filepair *p = q->queue[i];
3279                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3280                              ((p->score &&
3281                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3282                               (!p->score &&
3283                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3284                             ((p->status != DIFF_STATUS_MODIFIED) &&
3285                              strchr(filter, p->status)))
3286                                 found++;
3287                 }
3288                 if (found)
3289                         return;
3291                 /* otherwise we will clear the whole queue
3292                  * by copying the empty outq at the end of this
3293                  * function, but first clear the current entries
3294                  * in the queue.
3295                  */
3296                 for (i = 0; i < q->nr; i++)
3297                         diff_free_filepair(q->queue[i]);
3298         }
3299         else {
3300                 /* Only the matching ones */
3301                 for (i = 0; i < q->nr; i++) {
3302                         struct diff_filepair *p = q->queue[i];
3304                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3305                              ((p->score &&
3306                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3307                               (!p->score &&
3308                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3309                             ((p->status != DIFF_STATUS_MODIFIED) &&
3310                              strchr(filter, p->status)))
3311                                 diff_q(&outq, p);
3312                         else
3313                                 diff_free_filepair(p);
3314                 }
3315         }
3316         free(q->queue);
3317         *q = outq;
3320 /* Check whether two filespecs with the same mode and size are identical */
3321 static int diff_filespec_is_identical(struct diff_filespec *one,
3322                                       struct diff_filespec *two)
3324         if (S_ISGITLINK(one->mode))
3325                 return 0;
3326         if (diff_populate_filespec(one, 0))
3327                 return 0;
3328         if (diff_populate_filespec(two, 0))
3329                 return 0;
3330         return !memcmp(one->data, two->data, one->size);
3333 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3335         int i;
3336         struct diff_queue_struct *q = &diff_queued_diff;
3337         struct diff_queue_struct outq;
3338         outq.queue = NULL;
3339         outq.nr = outq.alloc = 0;
3341         for (i = 0; i < q->nr; i++) {
3342                 struct diff_filepair *p = q->queue[i];
3344                 /*
3345                  * 1. Entries that come from stat info dirtyness
3346                  *    always have both sides (iow, not create/delete),
3347                  *    one side of the object name is unknown, with
3348                  *    the same mode and size.  Keep the ones that
3349                  *    do not match these criteria.  They have real
3350                  *    differences.
3351                  *
3352                  * 2. At this point, the file is known to be modified,
3353                  *    with the same mode and size, and the object
3354                  *    name of one side is unknown.  Need to inspect
3355                  *    the identical contents.
3356                  */
3357                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3358                     !DIFF_FILE_VALID(p->two) ||
3359                     (p->one->sha1_valid && p->two->sha1_valid) ||
3360                     (p->one->mode != p->two->mode) ||
3361                     diff_populate_filespec(p->one, 1) ||
3362                     diff_populate_filespec(p->two, 1) ||
3363                     (p->one->size != p->two->size) ||
3364                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3365                         diff_q(&outq, p);
3366                 else {
3367                         /*
3368                          * The caller can subtract 1 from skip_stat_unmatch
3369                          * to determine how many paths were dirty only
3370                          * due to stat info mismatch.
3371                          */
3372                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3373                                 diffopt->skip_stat_unmatch++;
3374                         diff_free_filepair(p);
3375                 }
3376         }
3377         free(q->queue);
3378         *q = outq;
3381 void diffcore_std(struct diff_options *options)
3383         if (DIFF_OPT_TST(options, QUIET))
3384                 return;
3386         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3387                 diffcore_skip_stat_unmatch(options);
3388         if (options->break_opt != -1)
3389                 diffcore_break(options->break_opt);
3390         if (options->detect_rename)
3391                 diffcore_rename(options);
3392         if (options->break_opt != -1)
3393                 diffcore_merge_broken();
3394         if (options->pickaxe)
3395                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3396         if (options->orderfile)
3397                 diffcore_order(options->orderfile);
3398         diff_resolve_rename_copy();
3399         diffcore_apply_filter(options->filter);
3401         if (diff_queued_diff.nr)
3402                 DIFF_OPT_SET(options, HAS_CHANGES);
3403         else
3404                 DIFF_OPT_CLR(options, HAS_CHANGES);
3407 int diff_result_code(struct diff_options *opt, int status)
3409         int result = 0;
3410         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3411             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3412                 return status;
3413         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3414             DIFF_OPT_TST(opt, HAS_CHANGES))
3415                 result |= 01;
3416         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3417             DIFF_OPT_TST(opt, CHECK_FAILED))
3418                 result |= 02;
3419         return result;
3422 void diff_addremove(struct diff_options *options,
3423                     int addremove, unsigned mode,
3424                     const unsigned char *sha1,
3425                     const char *concatpath)
3427         struct diff_filespec *one, *two;
3429         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3430                 return;
3432         /* This may look odd, but it is a preparation for
3433          * feeding "there are unchanged files which should
3434          * not produce diffs, but when you are doing copy
3435          * detection you would need them, so here they are"
3436          * entries to the diff-core.  They will be prefixed
3437          * with something like '=' or '*' (I haven't decided
3438          * which but should not make any difference).
3439          * Feeding the same new and old to diff_change()
3440          * also has the same effect.
3441          * Before the final output happens, they are pruned after
3442          * merged into rename/copy pairs as appropriate.
3443          */
3444         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3445                 addremove = (addremove == '+' ? '-' :
3446                              addremove == '-' ? '+' : addremove);
3448         if (options->prefix &&
3449             strncmp(concatpath, options->prefix, options->prefix_length))
3450                 return;
3452         one = alloc_filespec(concatpath);
3453         two = alloc_filespec(concatpath);
3455         if (addremove != '+')
3456                 fill_filespec(one, sha1, mode);
3457         if (addremove != '-')
3458                 fill_filespec(two, sha1, mode);
3460         diff_queue(&diff_queued_diff, one, two);
3461         DIFF_OPT_SET(options, HAS_CHANGES);
3464 void diff_change(struct diff_options *options,
3465                  unsigned old_mode, unsigned new_mode,
3466                  const unsigned char *old_sha1,
3467                  const unsigned char *new_sha1,
3468                  const char *concatpath)
3470         struct diff_filespec *one, *two;
3472         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3473                         && S_ISGITLINK(new_mode))
3474                 return;
3476         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3477                 unsigned tmp;
3478                 const unsigned char *tmp_c;
3479                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3480                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3481         }
3483         if (options->prefix &&
3484             strncmp(concatpath, options->prefix, options->prefix_length))
3485                 return;
3487         one = alloc_filespec(concatpath);
3488         two = alloc_filespec(concatpath);
3489         fill_filespec(one, old_sha1, old_mode);
3490         fill_filespec(two, new_sha1, new_mode);
3492         diff_queue(&diff_queued_diff, one, two);
3493         DIFF_OPT_SET(options, HAS_CHANGES);
3496 void diff_unmerge(struct diff_options *options,
3497                   const char *path,
3498                   unsigned mode, const unsigned char *sha1)
3500         struct diff_filespec *one, *two;
3502         if (options->prefix &&
3503             strncmp(path, options->prefix, options->prefix_length))
3504                 return;
3506         one = alloc_filespec(path);
3507         two = alloc_filespec(path);
3508         fill_filespec(one, sha1, mode);
3509         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;