Code

Don't access line[-1] for a zero-length "line" from fgets.
[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"
14 #ifdef NO_FAST_WORKING_DIRECTORY
15 #define FAST_WORKING_DIRECTORY 0
16 #else
17 #define FAST_WORKING_DIRECTORY 1
18 #endif
20 static int diff_detect_rename_default;
21 static int diff_rename_limit_default = 100;
22 static int diff_use_color_default;
23 static const char *external_diff_cmd_cfg;
24 int diff_auto_refresh_index = 1;
26 static char diff_colors[][COLOR_MAXLEN] = {
27         "\033[m",       /* reset */
28         "",             /* PLAIN (normal) */
29         "\033[1m",      /* METAINFO (bold) */
30         "\033[36m",     /* FRAGINFO (cyan) */
31         "\033[31m",     /* OLD (red) */
32         "\033[32m",     /* NEW (green) */
33         "\033[33m",     /* COMMIT (yellow) */
34         "\033[41m",     /* WHITESPACE (red background) */
35 };
37 static int parse_diff_color_slot(const char *var, int ofs)
38 {
39         if (!strcasecmp(var+ofs, "plain"))
40                 return DIFF_PLAIN;
41         if (!strcasecmp(var+ofs, "meta"))
42                 return DIFF_METAINFO;
43         if (!strcasecmp(var+ofs, "frag"))
44                 return DIFF_FRAGINFO;
45         if (!strcasecmp(var+ofs, "old"))
46                 return DIFF_FILE_OLD;
47         if (!strcasecmp(var+ofs, "new"))
48                 return DIFF_FILE_NEW;
49         if (!strcasecmp(var+ofs, "commit"))
50                 return DIFF_COMMIT;
51         if (!strcasecmp(var+ofs, "whitespace"))
52                 return DIFF_WHITESPACE;
53         die("bad config variable '%s'", var);
54 }
56 static struct ll_diff_driver {
57         const char *name;
58         struct ll_diff_driver *next;
59         char *cmd;
60 } *user_diff, **user_diff_tail;
62 static void read_config_if_needed(void)
63 {
64         if (!user_diff_tail) {
65                 user_diff_tail = &user_diff;
66                 git_config(git_diff_ui_config);
67         }
68 }
70 /*
71  * Currently there is only "diff.<drivername>.command" variable;
72  * because there are "diff.color.<slot>" variables, we are parsing
73  * this in a bit convoluted way to allow low level diff driver
74  * called "color".
75  */
76 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
77 {
78         const char *name;
79         int namelen;
80         struct ll_diff_driver *drv;
82         name = var + 5;
83         namelen = ep - name;
84         for (drv = user_diff; drv; drv = drv->next)
85                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
86                         break;
87         if (!drv) {
88                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
89                 drv->name = xmemdupz(name, namelen);
90                 if (!user_diff_tail)
91                         user_diff_tail = &user_diff;
92                 *user_diff_tail = drv;
93                 user_diff_tail = &(drv->next);
94         }
96         if (!value)
97                 return error("%s: lacks value", var);
98         drv->cmd = strdup(value);
99         return 0;
102 /*
103  * 'diff.<what>.funcname' attribute can be specified in the configuration
104  * to define a customized regexp to find the beginning of a function to
105  * be used for hunk header lines of "diff -p" style output.
106  */
107 static struct funcname_pattern {
108         char *name;
109         char *pattern;
110         struct funcname_pattern *next;
111 } *funcname_pattern_list;
113 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
115         const char *name;
116         int namelen;
117         struct funcname_pattern *pp;
119         name = var + 5; /* "diff." */
120         namelen = ep - name;
122         for (pp = funcname_pattern_list; pp; pp = pp->next)
123                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
124                         break;
125         if (!pp) {
126                 pp = xcalloc(1, sizeof(*pp));
127                 pp->name = xmemdupz(name, namelen);
128                 pp->next = funcname_pattern_list;
129                 funcname_pattern_list = pp;
130         }
131         if (pp->pattern)
132                 free(pp->pattern);
133         pp->pattern = xstrdup(value);
134         return 0;
137 /*
138  * These are to give UI layer defaults.
139  * The core-level commands such as git-diff-files should
140  * never be affected by the setting of diff.renames
141  * the user happens to have in the configuration file.
142  */
143 int git_diff_ui_config(const char *var, const char *value)
145         if (!strcmp(var, "diff.renamelimit")) {
146                 diff_rename_limit_default = git_config_int(var, value);
147                 return 0;
148         }
149         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
150                 diff_use_color_default = git_config_colorbool(var, value, -1);
151                 return 0;
152         }
153         if (!strcmp(var, "diff.renames")) {
154                 if (!value)
155                         diff_detect_rename_default = DIFF_DETECT_RENAME;
156                 else if (!strcasecmp(value, "copies") ||
157                          !strcasecmp(value, "copy"))
158                         diff_detect_rename_default = DIFF_DETECT_COPY;
159                 else if (git_config_bool(var,value))
160                         diff_detect_rename_default = DIFF_DETECT_RENAME;
161                 return 0;
162         }
163         if (!strcmp(var, "diff.autorefreshindex")) {
164                 diff_auto_refresh_index = git_config_bool(var, value);
165                 return 0;
166         }
167         if (!strcmp(var, "diff.external")) {
168                 external_diff_cmd_cfg = xstrdup(value);
169                 return 0;
170         }
171         if (!prefixcmp(var, "diff.")) {
172                 const char *ep = strrchr(var, '.');
174                 if (ep != var + 4) {
175                         if (!strcmp(ep, ".command"))
176                                 return parse_lldiff_command(var, ep, value);
177                         if (!strcmp(ep, ".funcname"))
178                                 return parse_funcname_pattern(var, ep, value);
179                 }
180         }
181         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
182                 int slot = parse_diff_color_slot(var, 11);
183                 color_parse(value, var, diff_colors[slot]);
184                 return 0;
185         }
187         return git_default_config(var, value);
190 static char *quote_two(const char *one, const char *two)
192         int need_one = quote_c_style(one, NULL, NULL, 1);
193         int need_two = quote_c_style(two, NULL, NULL, 1);
194         struct strbuf res;
196         strbuf_init(&res, 0);
197         if (need_one + need_two) {
198                 strbuf_addch(&res, '"');
199                 quote_c_style(one, &res, NULL, 1);
200                 quote_c_style(two, &res, NULL, 1);
201                 strbuf_addch(&res, '"');
202         } else {
203                 strbuf_addstr(&res, one);
204                 strbuf_addstr(&res, two);
205         }
206         return strbuf_detach(&res, NULL);
209 static const char *external_diff(void)
211         static const char *external_diff_cmd = NULL;
212         static int done_preparing = 0;
214         if (done_preparing)
215                 return external_diff_cmd;
216         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
217         if (!external_diff_cmd)
218                 external_diff_cmd = external_diff_cmd_cfg;
219         done_preparing = 1;
220         return external_diff_cmd;
223 static struct diff_tempfile {
224         const char *name; /* filename external diff should read from */
225         char hex[41];
226         char mode[10];
227         char tmp_path[PATH_MAX];
228 } diff_temp[2];
230 static int count_lines(const char *data, int size)
232         int count, ch, completely_empty = 1, nl_just_seen = 0;
233         count = 0;
234         while (0 < size--) {
235                 ch = *data++;
236                 if (ch == '\n') {
237                         count++;
238                         nl_just_seen = 1;
239                         completely_empty = 0;
240                 }
241                 else {
242                         nl_just_seen = 0;
243                         completely_empty = 0;
244                 }
245         }
246         if (completely_empty)
247                 return 0;
248         if (!nl_just_seen)
249                 count++; /* no trailing newline */
250         return count;
253 static void print_line_count(int count)
255         switch (count) {
256         case 0:
257                 printf("0,0");
258                 break;
259         case 1:
260                 printf("1");
261                 break;
262         default:
263                 printf("1,%d", count);
264                 break;
265         }
268 static void copy_file(int prefix, const char *data, int size,
269                 const char *set, const char *reset)
271         int ch, nl_just_seen = 1;
272         while (0 < size--) {
273                 ch = *data++;
274                 if (nl_just_seen) {
275                         fputs(set, stdout);
276                         putchar(prefix);
277                 }
278                 if (ch == '\n') {
279                         nl_just_seen = 1;
280                         fputs(reset, stdout);
281                 } else
282                         nl_just_seen = 0;
283                 putchar(ch);
284         }
285         if (!nl_just_seen)
286                 printf("%s\n\\ No newline at end of file\n", reset);
289 static void emit_rewrite_diff(const char *name_a,
290                               const char *name_b,
291                               struct diff_filespec *one,
292                               struct diff_filespec *two,
293                               struct diff_options *o)
295         int lc_a, lc_b;
296         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
297         const char *name_a_tab, *name_b_tab;
298         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
299         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
300         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
301         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
302         const char *reset = diff_get_color(color_diff, DIFF_RESET);
303         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
305         name_a += (*name_a == '/');
306         name_b += (*name_b == '/');
307         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
308         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
310         strbuf_reset(&a_name);
311         strbuf_reset(&b_name);
312         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
313         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
315         diff_populate_filespec(one, 0);
316         diff_populate_filespec(two, 0);
317         lc_a = count_lines(one->data, one->size);
318         lc_b = count_lines(two->data, two->size);
319         printf("%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
320                metainfo, a_name.buf, name_a_tab, reset,
321                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
322         print_line_count(lc_a);
323         printf(" +");
324         print_line_count(lc_b);
325         printf(" @@%s\n", reset);
326         if (lc_a)
327                 copy_file('-', one->data, one->size, old, reset);
328         if (lc_b)
329                 copy_file('+', two->data, two->size, new, reset);
332 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
334         if (!DIFF_FILE_VALID(one)) {
335                 mf->ptr = (char *)""; /* does not matter */
336                 mf->size = 0;
337                 return 0;
338         }
339         else if (diff_populate_filespec(one, 0))
340                 return -1;
341         mf->ptr = one->data;
342         mf->size = one->size;
343         return 0;
346 struct diff_words_buffer {
347         mmfile_t text;
348         long alloc;
349         long current; /* output pointer */
350         int suppressed_newline;
351 };
353 static void diff_words_append(char *line, unsigned long len,
354                 struct diff_words_buffer *buffer)
356         if (buffer->text.size + len > buffer->alloc) {
357                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
358                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
359         }
360         line++;
361         len--;
362         memcpy(buffer->text.ptr + buffer->text.size, line, len);
363         buffer->text.size += len;
366 struct diff_words_data {
367         struct xdiff_emit_state xm;
368         struct diff_words_buffer minus, plus;
369 };
371 static void print_word(struct diff_words_buffer *buffer, int len, int color,
372                 int suppress_newline)
374         const char *ptr;
375         int eol = 0;
377         if (len == 0)
378                 return;
380         ptr  = buffer->text.ptr + buffer->current;
381         buffer->current += len;
383         if (ptr[len - 1] == '\n') {
384                 eol = 1;
385                 len--;
386         }
388         fputs(diff_get_color(1, color), stdout);
389         fwrite(ptr, len, 1, stdout);
390         fputs(diff_get_color(1, DIFF_RESET), stdout);
392         if (eol) {
393                 if (suppress_newline)
394                         buffer->suppressed_newline = 1;
395                 else
396                         putchar('\n');
397         }
400 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
402         struct diff_words_data *diff_words = priv;
404         if (diff_words->minus.suppressed_newline) {
405                 if (line[0] != '+')
406                         putchar('\n');
407                 diff_words->minus.suppressed_newline = 0;
408         }
410         len--;
411         switch (line[0]) {
412                 case '-':
413                         print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
414                         break;
415                 case '+':
416                         print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
417                         break;
418                 case ' ':
419                         print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
420                         diff_words->minus.current += len;
421                         break;
422         }
425 /* this executes the word diff on the accumulated buffers */
426 static void diff_words_show(struct diff_words_data *diff_words)
428         xpparam_t xpp;
429         xdemitconf_t xecfg;
430         xdemitcb_t ecb;
431         mmfile_t minus, plus;
432         int i;
434         memset(&xecfg, 0, sizeof(xecfg));
435         minus.size = diff_words->minus.text.size;
436         minus.ptr = xmalloc(minus.size);
437         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
438         for (i = 0; i < minus.size; i++)
439                 if (isspace(minus.ptr[i]))
440                         minus.ptr[i] = '\n';
441         diff_words->minus.current = 0;
443         plus.size = diff_words->plus.text.size;
444         plus.ptr = xmalloc(plus.size);
445         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
446         for (i = 0; i < plus.size; i++)
447                 if (isspace(plus.ptr[i]))
448                         plus.ptr[i] = '\n';
449         diff_words->plus.current = 0;
451         xpp.flags = XDF_NEED_MINIMAL;
452         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
453         ecb.outf = xdiff_outf;
454         ecb.priv = diff_words;
455         diff_words->xm.consume = fn_out_diff_words_aux;
456         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
458         free(minus.ptr);
459         free(plus.ptr);
460         diff_words->minus.text.size = diff_words->plus.text.size = 0;
462         if (diff_words->minus.suppressed_newline) {
463                 putchar('\n');
464                 diff_words->minus.suppressed_newline = 0;
465         }
468 struct emit_callback {
469         struct xdiff_emit_state xm;
470         int nparents, color_diff;
471         unsigned ws_rule;
472         const char **label_path;
473         struct diff_words_data *diff_words;
474         int *found_changesp;
475 };
477 static void free_diff_words_data(struct emit_callback *ecbdata)
479         if (ecbdata->diff_words) {
480                 /* flush buffers */
481                 if (ecbdata->diff_words->minus.text.size ||
482                                 ecbdata->diff_words->plus.text.size)
483                         diff_words_show(ecbdata->diff_words);
485                 if (ecbdata->diff_words->minus.text.ptr)
486                         free (ecbdata->diff_words->minus.text.ptr);
487                 if (ecbdata->diff_words->plus.text.ptr)
488                         free (ecbdata->diff_words->plus.text.ptr);
489                 free(ecbdata->diff_words);
490                 ecbdata->diff_words = NULL;
491         }
494 const char *diff_get_color(int diff_use_color, enum color_diff ix)
496         if (diff_use_color)
497                 return diff_colors[ix];
498         return "";
501 static void emit_line(const char *set, const char *reset, const char *line, int len)
503         fputs(set, stdout);
504         fwrite(line, len, 1, stdout);
505         fputs(reset, stdout);
508 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
510         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
511         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
513         if (!*ws)
514                 emit_line(set, reset, line, len);
515         else {
516                 /* Emit just the prefix, then the rest. */
517                 emit_line(set, reset, line, ecbdata->nparents);
518                 (void)check_and_emit_line(line + ecbdata->nparents,
519                     len - ecbdata->nparents, ecbdata->ws_rule,
520                     stdout, set, reset, ws);
521         }
524 static void fn_out_consume(void *priv, char *line, unsigned long len)
526         int i;
527         int color;
528         struct emit_callback *ecbdata = priv;
529         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
530         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
532         *(ecbdata->found_changesp) = 1;
534         if (ecbdata->label_path[0]) {
535                 const char *name_a_tab, *name_b_tab;
537                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
538                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
540                 printf("%s--- %s%s%s\n",
541                        set, ecbdata->label_path[0], reset, name_a_tab);
542                 printf("%s+++ %s%s%s\n",
543                        set, ecbdata->label_path[1], reset, name_b_tab);
544                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
545         }
547         /* This is not really necessary for now because
548          * this codepath only deals with two-way diffs.
549          */
550         for (i = 0; i < len && line[i] == '@'; i++)
551                 ;
552         if (2 <= i && i < len && line[i] == ' ') {
553                 ecbdata->nparents = i - 1;
554                 emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
555                           reset, line, len);
556                 return;
557         }
559         if (len < ecbdata->nparents) {
560                 set = reset;
561                 emit_line(reset, reset, line, len);
562                 return;
563         }
565         color = DIFF_PLAIN;
566         if (ecbdata->diff_words && ecbdata->nparents != 1)
567                 /* fall back to normal diff */
568                 free_diff_words_data(ecbdata);
569         if (ecbdata->diff_words) {
570                 if (line[0] == '-') {
571                         diff_words_append(line, len,
572                                           &ecbdata->diff_words->minus);
573                         return;
574                 } else if (line[0] == '+') {
575                         diff_words_append(line, len,
576                                           &ecbdata->diff_words->plus);
577                         return;
578                 }
579                 if (ecbdata->diff_words->minus.text.size ||
580                     ecbdata->diff_words->plus.text.size)
581                         diff_words_show(ecbdata->diff_words);
582                 line++;
583                 len--;
584                 emit_line(set, reset, line, len);
585                 return;
586         }
587         for (i = 0; i < ecbdata->nparents && len; i++) {
588                 if (line[i] == '-')
589                         color = DIFF_FILE_OLD;
590                 else if (line[i] == '+')
591                         color = DIFF_FILE_NEW;
592         }
594         if (color != DIFF_FILE_NEW) {
595                 emit_line(diff_get_color(ecbdata->color_diff, color),
596                           reset, line, len);
597                 return;
598         }
599         emit_add_line(reset, ecbdata, line, len);
602 static char *pprint_rename(const char *a, const char *b)
604         const char *old = a;
605         const char *new = b;
606         struct strbuf name;
607         int pfx_length, sfx_length;
608         int len_a = strlen(a);
609         int len_b = strlen(b);
610         int a_midlen, b_midlen;
611         int qlen_a = quote_c_style(a, NULL, NULL, 0);
612         int qlen_b = quote_c_style(b, NULL, NULL, 0);
614         strbuf_init(&name, 0);
615         if (qlen_a || qlen_b) {
616                 quote_c_style(a, &name, NULL, 0);
617                 strbuf_addstr(&name, " => ");
618                 quote_c_style(b, &name, NULL, 0);
619                 return strbuf_detach(&name, NULL);
620         }
622         /* Find common prefix */
623         pfx_length = 0;
624         while (*old && *new && *old == *new) {
625                 if (*old == '/')
626                         pfx_length = old - a + 1;
627                 old++;
628                 new++;
629         }
631         /* Find common suffix */
632         old = a + len_a;
633         new = b + len_b;
634         sfx_length = 0;
635         while (a <= old && b <= new && *old == *new) {
636                 if (*old == '/')
637                         sfx_length = len_a - (old - a);
638                 old--;
639                 new--;
640         }
642         /*
643          * pfx{mid-a => mid-b}sfx
644          * {pfx-a => pfx-b}sfx
645          * pfx{sfx-a => sfx-b}
646          * name-a => name-b
647          */
648         a_midlen = len_a - pfx_length - sfx_length;
649         b_midlen = len_b - pfx_length - sfx_length;
650         if (a_midlen < 0)
651                 a_midlen = 0;
652         if (b_midlen < 0)
653                 b_midlen = 0;
655         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
656         if (pfx_length + sfx_length) {
657                 strbuf_add(&name, a, pfx_length);
658                 strbuf_addch(&name, '{');
659         }
660         strbuf_add(&name, a + pfx_length, a_midlen);
661         strbuf_addstr(&name, " => ");
662         strbuf_add(&name, b + pfx_length, b_midlen);
663         if (pfx_length + sfx_length) {
664                 strbuf_addch(&name, '}');
665                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
666         }
667         return strbuf_detach(&name, NULL);
670 struct diffstat_t {
671         struct xdiff_emit_state xm;
673         int nr;
674         int alloc;
675         struct diffstat_file {
676                 char *from_name;
677                 char *name;
678                 char *print_name;
679                 unsigned is_unmerged:1;
680                 unsigned is_binary:1;
681                 unsigned is_renamed:1;
682                 unsigned int added, deleted;
683         } **files;
684 };
686 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
687                                           const char *name_a,
688                                           const char *name_b)
690         struct diffstat_file *x;
691         x = xcalloc(sizeof (*x), 1);
692         if (diffstat->nr == diffstat->alloc) {
693                 diffstat->alloc = alloc_nr(diffstat->alloc);
694                 diffstat->files = xrealloc(diffstat->files,
695                                 diffstat->alloc * sizeof(x));
696         }
697         diffstat->files[diffstat->nr++] = x;
698         if (name_b) {
699                 x->from_name = xstrdup(name_a);
700                 x->name = xstrdup(name_b);
701                 x->is_renamed = 1;
702         }
703         else {
704                 x->from_name = NULL;
705                 x->name = xstrdup(name_a);
706         }
707         return x;
710 static void diffstat_consume(void *priv, char *line, unsigned long len)
712         struct diffstat_t *diffstat = priv;
713         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
715         if (line[0] == '+')
716                 x->added++;
717         else if (line[0] == '-')
718                 x->deleted++;
721 const char mime_boundary_leader[] = "------------";
723 static int scale_linear(int it, int width, int max_change)
725         /*
726          * make sure that at least one '-' is printed if there were deletions,
727          * and likewise for '+'.
728          */
729         if (max_change < 2)
730                 return it;
731         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
734 static void show_name(const char *prefix, const char *name, int len,
735                       const char *reset, const char *set)
737         printf(" %s%s%-*s%s |", set, prefix, len, name, reset);
740 static void show_graph(char ch, int cnt, const char *set, const char *reset)
742         if (cnt <= 0)
743                 return;
744         printf("%s", set);
745         while (cnt--)
746                 putchar(ch);
747         printf("%s", reset);
750 static void fill_print_name(struct diffstat_file *file)
752         char *pname;
754         if (file->print_name)
755                 return;
757         if (!file->is_renamed) {
758                 struct strbuf buf;
759                 strbuf_init(&buf, 0);
760                 if (quote_c_style(file->name, &buf, NULL, 0)) {
761                         pname = strbuf_detach(&buf, NULL);
762                 } else {
763                         pname = file->name;
764                         strbuf_release(&buf);
765                 }
766         } else {
767                 pname = pprint_rename(file->from_name, file->name);
768         }
769         file->print_name = pname;
772 static void show_stats(struct diffstat_t* data, struct diff_options *options)
774         int i, len, add, del, total, adds = 0, dels = 0;
775         int max_change = 0, max_len = 0;
776         int total_files = data->nr;
777         int width, name_width;
778         const char *reset, *set, *add_c, *del_c;
780         if (data->nr == 0)
781                 return;
783         width = options->stat_width ? options->stat_width : 80;
784         name_width = options->stat_name_width ? options->stat_name_width : 50;
786         /* Sanity: give at least 5 columns to the graph,
787          * but leave at least 10 columns for the name.
788          */
789         if (width < name_width + 15) {
790                 if (name_width <= 25)
791                         width = name_width + 15;
792                 else
793                         name_width = width - 15;
794         }
796         /* Find the longest filename and max number of changes */
797         reset = diff_get_color_opt(options, DIFF_RESET);
798         set   = diff_get_color_opt(options, DIFF_PLAIN);
799         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
800         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
802         for (i = 0; i < data->nr; i++) {
803                 struct diffstat_file *file = data->files[i];
804                 int change = file->added + file->deleted;
805                 fill_print_name(file);
806                 len = strlen(file->print_name);
807                 if (max_len < len)
808                         max_len = len;
810                 if (file->is_binary || file->is_unmerged)
811                         continue;
812                 if (max_change < change)
813                         max_change = change;
814         }
816         /* Compute the width of the graph part;
817          * 10 is for one blank at the beginning of the line plus
818          * " | count " between the name and the graph.
819          *
820          * From here on, name_width is the width of the name area,
821          * and width is the width of the graph area.
822          */
823         name_width = (name_width < max_len) ? name_width : max_len;
824         if (width < (name_width + 10) + max_change)
825                 width = width - (name_width + 10);
826         else
827                 width = max_change;
829         for (i = 0; i < data->nr; i++) {
830                 const char *prefix = "";
831                 char *name = data->files[i]->print_name;
832                 int added = data->files[i]->added;
833                 int deleted = data->files[i]->deleted;
834                 int name_len;
836                 /*
837                  * "scale" the filename
838                  */
839                 len = name_width;
840                 name_len = strlen(name);
841                 if (name_width < name_len) {
842                         char *slash;
843                         prefix = "...";
844                         len -= 3;
845                         name += name_len - len;
846                         slash = strchr(name, '/');
847                         if (slash)
848                                 name = slash;
849                 }
851                 if (data->files[i]->is_binary) {
852                         show_name(prefix, name, len, reset, set);
853                         printf("  Bin ");
854                         printf("%s%d%s", del_c, deleted, reset);
855                         printf(" -> ");
856                         printf("%s%d%s", add_c, added, reset);
857                         printf(" bytes");
858                         printf("\n");
859                         continue;
860                 }
861                 else if (data->files[i]->is_unmerged) {
862                         show_name(prefix, name, len, reset, set);
863                         printf("  Unmerged\n");
864                         continue;
865                 }
866                 else if (!data->files[i]->is_renamed &&
867                          (added + deleted == 0)) {
868                         total_files--;
869                         continue;
870                 }
872                 /*
873                  * scale the add/delete
874                  */
875                 add = added;
876                 del = deleted;
877                 total = add + del;
878                 adds += add;
879                 dels += del;
881                 if (width <= max_change) {
882                         add = scale_linear(add, width, max_change);
883                         del = scale_linear(del, width, max_change);
884                         total = add + del;
885                 }
886                 show_name(prefix, name, len, reset, set);
887                 printf("%5d ", added + deleted);
888                 show_graph('+', add, add_c, reset);
889                 show_graph('-', del, del_c, reset);
890                 putchar('\n');
891         }
892         printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
893                set, total_files, adds, dels, reset);
896 static void show_shortstats(struct diffstat_t* data)
898         int i, adds = 0, dels = 0, total_files = data->nr;
900         if (data->nr == 0)
901                 return;
903         for (i = 0; i < data->nr; i++) {
904                 if (!data->files[i]->is_binary &&
905                     !data->files[i]->is_unmerged) {
906                         int added = data->files[i]->added;
907                         int deleted= data->files[i]->deleted;
908                         if (!data->files[i]->is_renamed &&
909                             (added + deleted == 0)) {
910                                 total_files--;
911                         } else {
912                                 adds += added;
913                                 dels += deleted;
914                         }
915                 }
916         }
917         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
918                total_files, adds, dels);
921 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
923         int i;
925         if (data->nr == 0)
926                 return;
928         for (i = 0; i < data->nr; i++) {
929                 struct diffstat_file *file = data->files[i];
931                 if (file->is_binary)
932                         printf("-\t-\t");
933                 else
934                         printf("%d\t%d\t", file->added, file->deleted);
935                 if (options->line_termination) {
936                         fill_print_name(file);
937                         if (!file->is_renamed)
938                                 write_name_quoted(file->name, stdout,
939                                                   options->line_termination);
940                         else {
941                                 fputs(file->print_name, stdout);
942                                 putchar(options->line_termination);
943                         }
944                 } else {
945                         if (file->is_renamed) {
946                                 putchar('\0');
947                                 write_name_quoted(file->from_name, stdout, '\0');
948                         }
949                         write_name_quoted(file->name, stdout, '\0');
950                 }
951         }
954 static void free_diffstat_info(struct diffstat_t *diffstat)
956         int i;
957         for (i = 0; i < diffstat->nr; i++) {
958                 struct diffstat_file *f = diffstat->files[i];
959                 if (f->name != f->print_name)
960                         free(f->print_name);
961                 free(f->name);
962                 free(f->from_name);
963                 free(f);
964         }
965         free(diffstat->files);
968 struct checkdiff_t {
969         struct xdiff_emit_state xm;
970         const char *filename;
971         int lineno, color_diff;
972         unsigned ws_rule;
973         unsigned status;
974 };
976 static void checkdiff_consume(void *priv, char *line, unsigned long len)
978         struct checkdiff_t *data = priv;
979         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
980         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
981         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
982         char *err;
984         if (line[0] == '+') {
985                 data->status = check_and_emit_line(line + 1, len - 1,
986                     data->ws_rule, NULL, NULL, NULL, NULL);
987                 if (!data->status)
988                         return;
989                 err = whitespace_error_string(data->status);
990                 printf("%s:%d: %s.\n", data->filename, data->lineno, err);
991                 free(err);
992                 emit_line(set, reset, line, 1);
993                 (void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
994                     stdout, set, reset, ws);
995                 data->lineno++;
996         } else if (line[0] == ' ')
997                 data->lineno++;
998         else if (line[0] == '@') {
999                 char *plus = strchr(line, '+');
1000                 if (plus)
1001                         data->lineno = strtol(plus, NULL, 10);
1002                 else
1003                         die("invalid diff");
1004         }
1007 static unsigned char *deflate_it(char *data,
1008                                  unsigned long size,
1009                                  unsigned long *result_size)
1011         int bound;
1012         unsigned char *deflated;
1013         z_stream stream;
1015         memset(&stream, 0, sizeof(stream));
1016         deflateInit(&stream, zlib_compression_level);
1017         bound = deflateBound(&stream, size);
1018         deflated = xmalloc(bound);
1019         stream.next_out = deflated;
1020         stream.avail_out = bound;
1022         stream.next_in = (unsigned char *)data;
1023         stream.avail_in = size;
1024         while (deflate(&stream, Z_FINISH) == Z_OK)
1025                 ; /* nothing */
1026         deflateEnd(&stream);
1027         *result_size = stream.total_out;
1028         return deflated;
1031 static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
1033         void *cp;
1034         void *delta;
1035         void *deflated;
1036         void *data;
1037         unsigned long orig_size;
1038         unsigned long delta_size;
1039         unsigned long deflate_size;
1040         unsigned long data_size;
1042         /* We could do deflated delta, or we could do just deflated two,
1043          * whichever is smaller.
1044          */
1045         delta = NULL;
1046         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1047         if (one->size && two->size) {
1048                 delta = diff_delta(one->ptr, one->size,
1049                                    two->ptr, two->size,
1050                                    &delta_size, deflate_size);
1051                 if (delta) {
1052                         void *to_free = delta;
1053                         orig_size = delta_size;
1054                         delta = deflate_it(delta, delta_size, &delta_size);
1055                         free(to_free);
1056                 }
1057         }
1059         if (delta && delta_size < deflate_size) {
1060                 printf("delta %lu\n", orig_size);
1061                 free(deflated);
1062                 data = delta;
1063                 data_size = delta_size;
1064         }
1065         else {
1066                 printf("literal %lu\n", two->size);
1067                 free(delta);
1068                 data = deflated;
1069                 data_size = deflate_size;
1070         }
1072         /* emit data encoded in base85 */
1073         cp = data;
1074         while (data_size) {
1075                 int bytes = (52 < data_size) ? 52 : data_size;
1076                 char line[70];
1077                 data_size -= bytes;
1078                 if (bytes <= 26)
1079                         line[0] = bytes + 'A' - 1;
1080                 else
1081                         line[0] = bytes - 26 + 'a' - 1;
1082                 encode_85(line + 1, cp, bytes);
1083                 cp = (char *) cp + bytes;
1084                 puts(line);
1085         }
1086         printf("\n");
1087         free(data);
1090 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
1092         printf("GIT binary patch\n");
1093         emit_binary_diff_body(one, two);
1094         emit_binary_diff_body(two, one);
1097 static void setup_diff_attr_check(struct git_attr_check *check)
1099         static struct git_attr *attr_diff;
1101         if (!attr_diff) {
1102                 attr_diff = git_attr("diff", 4);
1103         }
1104         check[0].attr = attr_diff;
1107 static void diff_filespec_check_attr(struct diff_filespec *one)
1109         struct git_attr_check attr_diff_check;
1110         int check_from_data = 0;
1112         if (one->checked_attr)
1113                 return;
1115         setup_diff_attr_check(&attr_diff_check);
1116         one->is_binary = 0;
1117         one->funcname_pattern_ident = NULL;
1119         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1120                 const char *value;
1122                 /* binaryness */
1123                 value = attr_diff_check.value;
1124                 if (ATTR_TRUE(value))
1125                         ;
1126                 else if (ATTR_FALSE(value))
1127                         one->is_binary = 1;
1128                 else
1129                         check_from_data = 1;
1131                 /* funcname pattern ident */
1132                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1133                         ;
1134                 else
1135                         one->funcname_pattern_ident = value;
1136         }
1138         if (check_from_data) {
1139                 if (!one->data && DIFF_FILE_VALID(one))
1140                         diff_populate_filespec(one, 0);
1142                 if (one->data)
1143                         one->is_binary = buffer_is_binary(one->data, one->size);
1144         }
1147 int diff_filespec_is_binary(struct diff_filespec *one)
1149         diff_filespec_check_attr(one);
1150         return one->is_binary;
1153 static const char *funcname_pattern(const char *ident)
1155         struct funcname_pattern *pp;
1157         read_config_if_needed();
1158         for (pp = funcname_pattern_list; pp; pp = pp->next)
1159                 if (!strcmp(ident, pp->name))
1160                         return pp->pattern;
1161         return NULL;
1164 static struct builtin_funcname_pattern {
1165         const char *name;
1166         const char *pattern;
1167 } builtin_funcname_pattern[] = {
1168         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1169                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1170                         "^[     ]*\\(\\([       ]*"
1171                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1172                         "[      ]*([^;]*$\\)" },
1173         { "tex", "^\\(\\\\\\(sub\\)*section{.*\\)$" },
1174 };
1176 static const char *diff_funcname_pattern(struct diff_filespec *one)
1178         const char *ident, *pattern;
1179         int i;
1181         diff_filespec_check_attr(one);
1182         ident = one->funcname_pattern_ident;
1184         if (!ident)
1185                 /*
1186                  * If the config file has "funcname.default" defined, that
1187                  * regexp is used; otherwise NULL is returned and xemit uses
1188                  * the built-in default.
1189                  */
1190                 return funcname_pattern("default");
1192         /* Look up custom "funcname.$ident" regexp from config. */
1193         pattern = funcname_pattern(ident);
1194         if (pattern)
1195                 return pattern;
1197         /*
1198          * And define built-in fallback patterns here.  Note that
1199          * these can be overriden by the user's config settings.
1200          */
1201         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1202                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1203                         return builtin_funcname_pattern[i].pattern;
1205         return NULL;
1208 static void builtin_diff(const char *name_a,
1209                          const char *name_b,
1210                          struct diff_filespec *one,
1211                          struct diff_filespec *two,
1212                          const char *xfrm_msg,
1213                          struct diff_options *o,
1214                          int complete_rewrite)
1216         mmfile_t mf1, mf2;
1217         const char *lbl[2];
1218         char *a_one, *b_two;
1219         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1220         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1222         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1223         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1224         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1225         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1226         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1227         if (lbl[0][0] == '/') {
1228                 /* /dev/null */
1229                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
1230                 if (xfrm_msg && xfrm_msg[0])
1231                         printf("%s%s%s\n", set, xfrm_msg, reset);
1232         }
1233         else if (lbl[1][0] == '/') {
1234                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
1235                 if (xfrm_msg && xfrm_msg[0])
1236                         printf("%s%s%s\n", set, xfrm_msg, reset);
1237         }
1238         else {
1239                 if (one->mode != two->mode) {
1240                         printf("%sold mode %06o%s\n", set, one->mode, reset);
1241                         printf("%snew mode %06o%s\n", set, two->mode, reset);
1242                 }
1243                 if (xfrm_msg && xfrm_msg[0])
1244                         printf("%s%s%s\n", set, xfrm_msg, reset);
1245                 /*
1246                  * we do not run diff between different kind
1247                  * of objects.
1248                  */
1249                 if ((one->mode ^ two->mode) & S_IFMT)
1250                         goto free_ab_and_return;
1251                 if (complete_rewrite) {
1252                         emit_rewrite_diff(name_a, name_b, one, two, o);
1253                         o->found_changes = 1;
1254                         goto free_ab_and_return;
1255                 }
1256         }
1258         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1259                 die("unable to read files to diff");
1261         if (!DIFF_OPT_TST(o, TEXT) &&
1262             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1263                 /* Quite common confusing case */
1264                 if (mf1.size == mf2.size &&
1265                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1266                         goto free_ab_and_return;
1267                 if (DIFF_OPT_TST(o, BINARY))
1268                         emit_binary_diff(&mf1, &mf2);
1269                 else
1270                         printf("Binary files %s and %s differ\n",
1271                                lbl[0], lbl[1]);
1272                 o->found_changes = 1;
1273         }
1274         else {
1275                 /* Crazy xdl interfaces.. */
1276                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1277                 xpparam_t xpp;
1278                 xdemitconf_t xecfg;
1279                 xdemitcb_t ecb;
1280                 struct emit_callback ecbdata;
1281                 const char *funcname_pattern;
1283                 funcname_pattern = diff_funcname_pattern(one);
1284                 if (!funcname_pattern)
1285                         funcname_pattern = diff_funcname_pattern(two);
1287                 memset(&xecfg, 0, sizeof(xecfg));
1288                 memset(&ecbdata, 0, sizeof(ecbdata));
1289                 ecbdata.label_path = lbl;
1290                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1291                 ecbdata.found_changesp = &o->found_changes;
1292                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1293                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1294                 xecfg.ctxlen = o->context;
1295                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1296                 if (funcname_pattern)
1297                         xdiff_set_find_func(&xecfg, funcname_pattern);
1298                 if (!diffopts)
1299                         ;
1300                 else if (!prefixcmp(diffopts, "--unified="))
1301                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1302                 else if (!prefixcmp(diffopts, "-u"))
1303                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1304                 ecb.outf = xdiff_outf;
1305                 ecb.priv = &ecbdata;
1306                 ecbdata.xm.consume = fn_out_consume;
1307                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1308                         ecbdata.diff_words =
1309                                 xcalloc(1, sizeof(struct diff_words_data));
1310                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1311                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1312                         free_diff_words_data(&ecbdata);
1313         }
1315  free_ab_and_return:
1316         diff_free_filespec_data(one);
1317         diff_free_filespec_data(two);
1318         free(a_one);
1319         free(b_two);
1320         return;
1323 static void builtin_diffstat(const char *name_a, const char *name_b,
1324                              struct diff_filespec *one,
1325                              struct diff_filespec *two,
1326                              struct diffstat_t *diffstat,
1327                              struct diff_options *o,
1328                              int complete_rewrite)
1330         mmfile_t mf1, mf2;
1331         struct diffstat_file *data;
1333         data = diffstat_add(diffstat, name_a, name_b);
1335         if (!one || !two) {
1336                 data->is_unmerged = 1;
1337                 return;
1338         }
1339         if (complete_rewrite) {
1340                 diff_populate_filespec(one, 0);
1341                 diff_populate_filespec(two, 0);
1342                 data->deleted = count_lines(one->data, one->size);
1343                 data->added = count_lines(two->data, two->size);
1344                 goto free_and_return;
1345         }
1346         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1347                 die("unable to read files to diff");
1349         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1350                 data->is_binary = 1;
1351                 data->added = mf2.size;
1352                 data->deleted = mf1.size;
1353         } else {
1354                 /* Crazy xdl interfaces.. */
1355                 xpparam_t xpp;
1356                 xdemitconf_t xecfg;
1357                 xdemitcb_t ecb;
1359                 memset(&xecfg, 0, sizeof(xecfg));
1360                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1361                 ecb.outf = xdiff_outf;
1362                 ecb.priv = diffstat;
1363                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1364         }
1366  free_and_return:
1367         diff_free_filespec_data(one);
1368         diff_free_filespec_data(two);
1371 static void builtin_checkdiff(const char *name_a, const char *name_b,
1372                              struct diff_filespec *one,
1373                              struct diff_filespec *two, struct diff_options *o)
1375         mmfile_t mf1, mf2;
1376         struct checkdiff_t data;
1378         if (!two)
1379                 return;
1381         memset(&data, 0, sizeof(data));
1382         data.xm.consume = checkdiff_consume;
1383         data.filename = name_b ? name_b : name_a;
1384         data.lineno = 0;
1385         data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1386         data.ws_rule = whitespace_rule(data.filename);
1388         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1389                 die("unable to read files to diff");
1391         if (diff_filespec_is_binary(two))
1392                 goto free_and_return;
1393         else {
1394                 /* Crazy xdl interfaces.. */
1395                 xpparam_t xpp;
1396                 xdemitconf_t xecfg;
1397                 xdemitcb_t ecb;
1399                 memset(&xecfg, 0, sizeof(xecfg));
1400                 xpp.flags = XDF_NEED_MINIMAL;
1401                 ecb.outf = xdiff_outf;
1402                 ecb.priv = &data;
1403                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1404         }
1405  free_and_return:
1406         diff_free_filespec_data(one);
1407         diff_free_filespec_data(two);
1408         if (data.status)
1409                 DIFF_OPT_SET(o, CHECK_FAILED);
1412 struct diff_filespec *alloc_filespec(const char *path)
1414         int namelen = strlen(path);
1415         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1417         memset(spec, 0, sizeof(*spec));
1418         spec->path = (char *)(spec + 1);
1419         memcpy(spec->path, path, namelen+1);
1420         spec->count = 1;
1421         return spec;
1424 void free_filespec(struct diff_filespec *spec)
1426         if (!--spec->count) {
1427                 diff_free_filespec_data(spec);
1428                 free(spec);
1429         }
1432 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1433                    unsigned short mode)
1435         if (mode) {
1436                 spec->mode = canon_mode(mode);
1437                 hashcpy(spec->sha1, sha1);
1438                 spec->sha1_valid = !is_null_sha1(sha1);
1439         }
1442 /*
1443  * Given a name and sha1 pair, if the index tells us the file in
1444  * the work tree has that object contents, return true, so that
1445  * prepare_temp_file() does not have to inflate and extract.
1446  */
1447 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1449         struct cache_entry *ce;
1450         struct stat st;
1451         int pos, len;
1453         /* We do not read the cache ourselves here, because the
1454          * benchmark with my previous version that always reads cache
1455          * shows that it makes things worse for diff-tree comparing
1456          * two linux-2.6 kernel trees in an already checked out work
1457          * tree.  This is because most diff-tree comparisons deal with
1458          * only a small number of files, while reading the cache is
1459          * expensive for a large project, and its cost outweighs the
1460          * savings we get by not inflating the object to a temporary
1461          * file.  Practically, this code only helps when we are used
1462          * by diff-cache --cached, which does read the cache before
1463          * calling us.
1464          */
1465         if (!active_cache)
1466                 return 0;
1468         /* We want to avoid the working directory if our caller
1469          * doesn't need the data in a normal file, this system
1470          * is rather slow with its stat/open/mmap/close syscalls,
1471          * and the object is contained in a pack file.  The pack
1472          * is probably already open and will be faster to obtain
1473          * the data through than the working directory.  Loose
1474          * objects however would tend to be slower as they need
1475          * to be individually opened and inflated.
1476          */
1477         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1478                 return 0;
1480         len = strlen(name);
1481         pos = cache_name_pos(name, len);
1482         if (pos < 0)
1483                 return 0;
1484         ce = active_cache[pos];
1485         if ((lstat(name, &st) < 0) ||
1486             !S_ISREG(st.st_mode) || /* careful! */
1487             ce_match_stat(ce, &st, 0) ||
1488             hashcmp(sha1, ce->sha1))
1489                 return 0;
1490         /* we return 1 only when we can stat, it is a regular file,
1491          * stat information matches, and sha1 recorded in the cache
1492          * matches.  I.e. we know the file in the work tree really is
1493          * the same as the <name, sha1> pair.
1494          */
1495         return 1;
1498 static int populate_from_stdin(struct diff_filespec *s)
1500         struct strbuf buf;
1501         size_t size = 0;
1503         strbuf_init(&buf, 0);
1504         if (strbuf_read(&buf, 0, 0) < 0)
1505                 return error("error while reading from stdin %s",
1506                                      strerror(errno));
1508         s->should_munmap = 0;
1509         s->data = strbuf_detach(&buf, &size);
1510         s->size = size;
1511         s->should_free = 1;
1512         return 0;
1515 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1517         int len;
1518         char *data = xmalloc(100);
1519         len = snprintf(data, 100,
1520                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1521         s->data = data;
1522         s->size = len;
1523         s->should_free = 1;
1524         if (size_only) {
1525                 s->data = NULL;
1526                 free(data);
1527         }
1528         return 0;
1531 /*
1532  * While doing rename detection and pickaxe operation, we may need to
1533  * grab the data for the blob (or file) for our own in-core comparison.
1534  * diff_filespec has data and size fields for this purpose.
1535  */
1536 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1538         int err = 0;
1539         if (!DIFF_FILE_VALID(s))
1540                 die("internal error: asking to populate invalid file.");
1541         if (S_ISDIR(s->mode))
1542                 return -1;
1544         if (s->data)
1545                 return 0;
1547         if (size_only && 0 < s->size)
1548                 return 0;
1550         if (S_ISGITLINK(s->mode))
1551                 return diff_populate_gitlink(s, size_only);
1553         if (!s->sha1_valid ||
1554             reuse_worktree_file(s->path, s->sha1, 0)) {
1555                 struct strbuf buf;
1556                 struct stat st;
1557                 int fd;
1559                 if (!strcmp(s->path, "-"))
1560                         return populate_from_stdin(s);
1562                 if (lstat(s->path, &st) < 0) {
1563                         if (errno == ENOENT) {
1564                         err_empty:
1565                                 err = -1;
1566                         empty:
1567                                 s->data = (char *)"";
1568                                 s->size = 0;
1569                                 return err;
1570                         }
1571                 }
1572                 s->size = xsize_t(st.st_size);
1573                 if (!s->size)
1574                         goto empty;
1575                 if (size_only)
1576                         return 0;
1577                 if (S_ISLNK(st.st_mode)) {
1578                         int ret;
1579                         s->data = xmalloc(s->size);
1580                         s->should_free = 1;
1581                         ret = readlink(s->path, s->data, s->size);
1582                         if (ret < 0) {
1583                                 free(s->data);
1584                                 goto err_empty;
1585                         }
1586                         return 0;
1587                 }
1588                 fd = open(s->path, O_RDONLY);
1589                 if (fd < 0)
1590                         goto err_empty;
1591                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1592                 close(fd);
1593                 s->should_munmap = 1;
1595                 /*
1596                  * Convert from working tree format to canonical git format
1597                  */
1598                 strbuf_init(&buf, 0);
1599                 if (convert_to_git(s->path, s->data, s->size, &buf)) {
1600                         size_t size = 0;
1601                         munmap(s->data, s->size);
1602                         s->should_munmap = 0;
1603                         s->data = strbuf_detach(&buf, &size);
1604                         s->size = size;
1605                         s->should_free = 1;
1606                 }
1607         }
1608         else {
1609                 enum object_type type;
1610                 if (size_only)
1611                         type = sha1_object_info(s->sha1, &s->size);
1612                 else {
1613                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1614                         s->should_free = 1;
1615                 }
1616         }
1617         return 0;
1620 void diff_free_filespec_blob(struct diff_filespec *s)
1622         if (s->should_free)
1623                 free(s->data);
1624         else if (s->should_munmap)
1625                 munmap(s->data, s->size);
1627         if (s->should_free || s->should_munmap) {
1628                 s->should_free = s->should_munmap = 0;
1629                 s->data = NULL;
1630         }
1633 void diff_free_filespec_data(struct diff_filespec *s)
1635         diff_free_filespec_blob(s);
1636         free(s->cnt_data);
1637         s->cnt_data = NULL;
1640 static void prep_temp_blob(struct diff_tempfile *temp,
1641                            void *blob,
1642                            unsigned long size,
1643                            const unsigned char *sha1,
1644                            int mode)
1646         int fd;
1648         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1649         if (fd < 0)
1650                 die("unable to create temp-file: %s", strerror(errno));
1651         if (write_in_full(fd, blob, size) != size)
1652                 die("unable to write temp-file");
1653         close(fd);
1654         temp->name = temp->tmp_path;
1655         strcpy(temp->hex, sha1_to_hex(sha1));
1656         temp->hex[40] = 0;
1657         sprintf(temp->mode, "%06o", mode);
1660 static void prepare_temp_file(const char *name,
1661                               struct diff_tempfile *temp,
1662                               struct diff_filespec *one)
1664         if (!DIFF_FILE_VALID(one)) {
1665         not_a_valid_file:
1666                 /* A '-' entry produces this for file-2, and
1667                  * a '+' entry produces this for file-1.
1668                  */
1669                 temp->name = "/dev/null";
1670                 strcpy(temp->hex, ".");
1671                 strcpy(temp->mode, ".");
1672                 return;
1673         }
1675         if (!one->sha1_valid ||
1676             reuse_worktree_file(name, one->sha1, 1)) {
1677                 struct stat st;
1678                 if (lstat(name, &st) < 0) {
1679                         if (errno == ENOENT)
1680                                 goto not_a_valid_file;
1681                         die("stat(%s): %s", name, strerror(errno));
1682                 }
1683                 if (S_ISLNK(st.st_mode)) {
1684                         int ret;
1685                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1686                         size_t sz = xsize_t(st.st_size);
1687                         if (sizeof(buf) <= st.st_size)
1688                                 die("symlink too long: %s", name);
1689                         ret = readlink(name, buf, sz);
1690                         if (ret < 0)
1691                                 die("readlink(%s)", name);
1692                         prep_temp_blob(temp, buf, sz,
1693                                        (one->sha1_valid ?
1694                                         one->sha1 : null_sha1),
1695                                        (one->sha1_valid ?
1696                                         one->mode : S_IFLNK));
1697                 }
1698                 else {
1699                         /* we can borrow from the file in the work tree */
1700                         temp->name = name;
1701                         if (!one->sha1_valid)
1702                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1703                         else
1704                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1705                         /* Even though we may sometimes borrow the
1706                          * contents from the work tree, we always want
1707                          * one->mode.  mode is trustworthy even when
1708                          * !(one->sha1_valid), as long as
1709                          * DIFF_FILE_VALID(one).
1710                          */
1711                         sprintf(temp->mode, "%06o", one->mode);
1712                 }
1713                 return;
1714         }
1715         else {
1716                 if (diff_populate_filespec(one, 0))
1717                         die("cannot read data blob for %s", one->path);
1718                 prep_temp_blob(temp, one->data, one->size,
1719                                one->sha1, one->mode);
1720         }
1723 static void remove_tempfile(void)
1725         int i;
1727         for (i = 0; i < 2; i++)
1728                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1729                         unlink(diff_temp[i].name);
1730                         diff_temp[i].name = NULL;
1731                 }
1734 static void remove_tempfile_on_signal(int signo)
1736         remove_tempfile();
1737         signal(SIGINT, SIG_DFL);
1738         raise(signo);
1741 /* An external diff command takes:
1742  *
1743  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1744  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1745  *
1746  */
1747 static void run_external_diff(const char *pgm,
1748                               const char *name,
1749                               const char *other,
1750                               struct diff_filespec *one,
1751                               struct diff_filespec *two,
1752                               const char *xfrm_msg,
1753                               int complete_rewrite)
1755         const char *spawn_arg[10];
1756         struct diff_tempfile *temp = diff_temp;
1757         int retval;
1758         static int atexit_asked = 0;
1759         const char *othername;
1760         const char **arg = &spawn_arg[0];
1762         othername = (other? other : name);
1763         if (one && two) {
1764                 prepare_temp_file(name, &temp[0], one);
1765                 prepare_temp_file(othername, &temp[1], two);
1766                 if (! atexit_asked &&
1767                     (temp[0].name == temp[0].tmp_path ||
1768                      temp[1].name == temp[1].tmp_path)) {
1769                         atexit_asked = 1;
1770                         atexit(remove_tempfile);
1771                 }
1772                 signal(SIGINT, remove_tempfile_on_signal);
1773         }
1775         if (one && two) {
1776                 *arg++ = pgm;
1777                 *arg++ = name;
1778                 *arg++ = temp[0].name;
1779                 *arg++ = temp[0].hex;
1780                 *arg++ = temp[0].mode;
1781                 *arg++ = temp[1].name;
1782                 *arg++ = temp[1].hex;
1783                 *arg++ = temp[1].mode;
1784                 if (other) {
1785                         *arg++ = other;
1786                         *arg++ = xfrm_msg;
1787                 }
1788         } else {
1789                 *arg++ = pgm;
1790                 *arg++ = name;
1791         }
1792         *arg = NULL;
1793         fflush(NULL);
1794         retval = run_command_v_opt(spawn_arg, 0);
1795         remove_tempfile();
1796         if (retval) {
1797                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1798                 exit(1);
1799         }
1802 static const char *external_diff_attr(const char *name)
1804         struct git_attr_check attr_diff_check;
1806         setup_diff_attr_check(&attr_diff_check);
1807         if (!git_checkattr(name, 1, &attr_diff_check)) {
1808                 const char *value = attr_diff_check.value;
1809                 if (!ATTR_TRUE(value) &&
1810                     !ATTR_FALSE(value) &&
1811                     !ATTR_UNSET(value)) {
1812                         struct ll_diff_driver *drv;
1814                         read_config_if_needed();
1815                         for (drv = user_diff; drv; drv = drv->next)
1816                                 if (!strcmp(drv->name, value))
1817                                         return drv->cmd;
1818                 }
1819         }
1820         return NULL;
1823 static void run_diff_cmd(const char *pgm,
1824                          const char *name,
1825                          const char *other,
1826                          struct diff_filespec *one,
1827                          struct diff_filespec *two,
1828                          const char *xfrm_msg,
1829                          struct diff_options *o,
1830                          int complete_rewrite)
1832         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
1833                 pgm = NULL;
1834         else {
1835                 const char *cmd = external_diff_attr(name);
1836                 if (cmd)
1837                         pgm = cmd;
1838         }
1840         if (pgm) {
1841                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1842                                   complete_rewrite);
1843                 return;
1844         }
1845         if (one && two)
1846                 builtin_diff(name, other ? other : name,
1847                              one, two, xfrm_msg, o, complete_rewrite);
1848         else
1849                 printf("* Unmerged path %s\n", name);
1852 static void diff_fill_sha1_info(struct diff_filespec *one)
1854         if (DIFF_FILE_VALID(one)) {
1855                 if (!one->sha1_valid) {
1856                         struct stat st;
1857                         if (!strcmp(one->path, "-")) {
1858                                 hashcpy(one->sha1, null_sha1);
1859                                 return;
1860                         }
1861                         if (lstat(one->path, &st) < 0)
1862                                 die("stat %s", one->path);
1863                         if (index_path(one->sha1, one->path, &st, 0))
1864                                 die("cannot hash %s\n", one->path);
1865                 }
1866         }
1867         else
1868                 hashclr(one->sha1);
1871 static int similarity_index(struct diff_filepair *p)
1873         return p->score * 100 / MAX_SCORE;
1876 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1878         const char *pgm = external_diff();
1879         struct strbuf msg;
1880         char *xfrm_msg;
1881         struct diff_filespec *one = p->one;
1882         struct diff_filespec *two = p->two;
1883         const char *name;
1884         const char *other;
1885         int complete_rewrite = 0;
1888         if (DIFF_PAIR_UNMERGED(p)) {
1889                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1890                 return;
1891         }
1893         name  = p->one->path;
1894         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1895         diff_fill_sha1_info(one);
1896         diff_fill_sha1_info(two);
1898         strbuf_init(&msg, PATH_MAX * 2 + 300);
1899         switch (p->status) {
1900         case DIFF_STATUS_COPIED:
1901                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
1902                 strbuf_addstr(&msg, "\ncopy from ");
1903                 quote_c_style(name, &msg, NULL, 0);
1904                 strbuf_addstr(&msg, "\ncopy to ");
1905                 quote_c_style(other, &msg, NULL, 0);
1906                 strbuf_addch(&msg, '\n');
1907                 break;
1908         case DIFF_STATUS_RENAMED:
1909                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
1910                 strbuf_addstr(&msg, "\nrename from ");
1911                 quote_c_style(name, &msg, NULL, 0);
1912                 strbuf_addstr(&msg, "\nrename to ");
1913                 quote_c_style(other, &msg, NULL, 0);
1914                 strbuf_addch(&msg, '\n');
1915                 break;
1916         case DIFF_STATUS_MODIFIED:
1917                 if (p->score) {
1918                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
1919                                         similarity_index(p));
1920                         complete_rewrite = 1;
1921                         break;
1922                 }
1923                 /* fallthru */
1924         default:
1925                 /* nothing */
1926                 ;
1927         }
1929         if (hashcmp(one->sha1, two->sha1)) {
1930                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
1932                 if (DIFF_OPT_TST(o, BINARY)) {
1933                         mmfile_t mf;
1934                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
1935                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
1936                                 abbrev = 40;
1937                 }
1938                 strbuf_addf(&msg, "index %.*s..%.*s",
1939                                 abbrev, sha1_to_hex(one->sha1),
1940                                 abbrev, sha1_to_hex(two->sha1));
1941                 if (one->mode == two->mode)
1942                         strbuf_addf(&msg, " %06o", one->mode);
1943                 strbuf_addch(&msg, '\n');
1944         }
1946         if (msg.len)
1947                 strbuf_setlen(&msg, msg.len - 1);
1948         xfrm_msg = msg.len ? msg.buf : NULL;
1950         if (!pgm &&
1951             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1952             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1953                 /* a filepair that changes between file and symlink
1954                  * needs to be split into deletion and creation.
1955                  */
1956                 struct diff_filespec *null = alloc_filespec(two->path);
1957                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1958                 free(null);
1959                 null = alloc_filespec(one->path);
1960                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1961                 free(null);
1962         }
1963         else
1964                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1965                              complete_rewrite);
1967         strbuf_release(&msg);
1970 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1971                          struct diffstat_t *diffstat)
1973         const char *name;
1974         const char *other;
1975         int complete_rewrite = 0;
1977         if (DIFF_PAIR_UNMERGED(p)) {
1978                 /* unmerged */
1979                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1980                 return;
1981         }
1983         name = p->one->path;
1984         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1986         diff_fill_sha1_info(p->one);
1987         diff_fill_sha1_info(p->two);
1989         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1990                 complete_rewrite = 1;
1991         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1994 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1996         const char *name;
1997         const char *other;
1999         if (DIFF_PAIR_UNMERGED(p)) {
2000                 /* unmerged */
2001                 return;
2002         }
2004         name = p->one->path;
2005         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2007         diff_fill_sha1_info(p->one);
2008         diff_fill_sha1_info(p->two);
2010         builtin_checkdiff(name, other, p->one, p->two, o);
2013 void diff_setup(struct diff_options *options)
2015         memset(options, 0, sizeof(*options));
2016         options->line_termination = '\n';
2017         options->break_opt = -1;
2018         options->rename_limit = -1;
2019         options->context = 3;
2020         options->msg_sep = "";
2022         options->change = diff_change;
2023         options->add_remove = diff_addremove;
2024         if (diff_use_color_default)
2025                 DIFF_OPT_SET(options, COLOR_DIFF);
2026         else
2027                 DIFF_OPT_CLR(options, COLOR_DIFF);
2028         options->detect_rename = diff_detect_rename_default;
2030         options->a_prefix = "a/";
2031         options->b_prefix = "b/";
2034 int diff_setup_done(struct diff_options *options)
2036         int count = 0;
2038         if (options->output_format & DIFF_FORMAT_NAME)
2039                 count++;
2040         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2041                 count++;
2042         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2043                 count++;
2044         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2045                 count++;
2046         if (count > 1)
2047                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2049         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2050                 options->detect_rename = DIFF_DETECT_COPY;
2052         if (options->output_format & (DIFF_FORMAT_NAME |
2053                                       DIFF_FORMAT_NAME_STATUS |
2054                                       DIFF_FORMAT_CHECKDIFF |
2055                                       DIFF_FORMAT_NO_OUTPUT))
2056                 options->output_format &= ~(DIFF_FORMAT_RAW |
2057                                             DIFF_FORMAT_NUMSTAT |
2058                                             DIFF_FORMAT_DIFFSTAT |
2059                                             DIFF_FORMAT_SHORTSTAT |
2060                                             DIFF_FORMAT_SUMMARY |
2061                                             DIFF_FORMAT_PATCH);
2063         /*
2064          * These cases always need recursive; we do not drop caller-supplied
2065          * recursive bits for other formats here.
2066          */
2067         if (options->output_format & (DIFF_FORMAT_PATCH |
2068                                       DIFF_FORMAT_NUMSTAT |
2069                                       DIFF_FORMAT_DIFFSTAT |
2070                                       DIFF_FORMAT_SHORTSTAT |
2071                                       DIFF_FORMAT_SUMMARY |
2072                                       DIFF_FORMAT_CHECKDIFF))
2073                 DIFF_OPT_SET(options, RECURSIVE);
2074         /*
2075          * Also pickaxe would not work very well if you do not say recursive
2076          */
2077         if (options->pickaxe)
2078                 DIFF_OPT_SET(options, RECURSIVE);
2080         if (options->detect_rename && options->rename_limit < 0)
2081                 options->rename_limit = diff_rename_limit_default;
2082         if (options->setup & DIFF_SETUP_USE_CACHE) {
2083                 if (!active_cache)
2084                         /* read-cache does not die even when it fails
2085                          * so it is safe for us to do this here.  Also
2086                          * it does not smudge active_cache or active_nr
2087                          * when it fails, so we do not have to worry about
2088                          * cleaning it up ourselves either.
2089                          */
2090                         read_cache();
2091         }
2092         if (options->abbrev <= 0 || 40 < options->abbrev)
2093                 options->abbrev = 40; /* full */
2095         /*
2096          * It does not make sense to show the first hit we happened
2097          * to have found.  It does not make sense not to return with
2098          * exit code in such a case either.
2099          */
2100         if (DIFF_OPT_TST(options, QUIET)) {
2101                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2102                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2103         }
2105         /*
2106          * If we postprocess in diffcore, we cannot simply return
2107          * upon the first hit.  We need to run diff as usual.
2108          */
2109         if (options->pickaxe || options->filter)
2110                 DIFF_OPT_CLR(options, QUIET);
2112         return 0;
2115 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2117         char c, *eq;
2118         int len;
2120         if (*arg != '-')
2121                 return 0;
2122         c = *++arg;
2123         if (!c)
2124                 return 0;
2125         if (c == arg_short) {
2126                 c = *++arg;
2127                 if (!c)
2128                         return 1;
2129                 if (val && isdigit(c)) {
2130                         char *end;
2131                         int n = strtoul(arg, &end, 10);
2132                         if (*end)
2133                                 return 0;
2134                         *val = n;
2135                         return 1;
2136                 }
2137                 return 0;
2138         }
2139         if (c != '-')
2140                 return 0;
2141         arg++;
2142         eq = strchr(arg, '=');
2143         if (eq)
2144                 len = eq - arg;
2145         else
2146                 len = strlen(arg);
2147         if (!len || strncmp(arg, arg_long, len))
2148                 return 0;
2149         if (eq) {
2150                 int n;
2151                 char *end;
2152                 if (!isdigit(*++eq))
2153                         return 0;
2154                 n = strtoul(eq, &end, 10);
2155                 if (*end)
2156                         return 0;
2157                 *val = n;
2158         }
2159         return 1;
2162 static int diff_scoreopt_parse(const char *opt);
2164 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2166         const char *arg = av[0];
2168         /* Output format options */
2169         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2170                 options->output_format |= DIFF_FORMAT_PATCH;
2171         else if (opt_arg(arg, 'U', "unified", &options->context))
2172                 options->output_format |= DIFF_FORMAT_PATCH;
2173         else if (!strcmp(arg, "--raw"))
2174                 options->output_format |= DIFF_FORMAT_RAW;
2175         else if (!strcmp(arg, "--patch-with-raw"))
2176                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2177         else if (!strcmp(arg, "--numstat"))
2178                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2179         else if (!strcmp(arg, "--shortstat"))
2180                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2181         else if (!strcmp(arg, "--check"))
2182                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2183         else if (!strcmp(arg, "--summary"))
2184                 options->output_format |= DIFF_FORMAT_SUMMARY;
2185         else if (!strcmp(arg, "--patch-with-stat"))
2186                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2187         else if (!strcmp(arg, "--name-only"))
2188                 options->output_format |= DIFF_FORMAT_NAME;
2189         else if (!strcmp(arg, "--name-status"))
2190                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2191         else if (!strcmp(arg, "-s"))
2192                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2193         else if (!prefixcmp(arg, "--stat")) {
2194                 char *end;
2195                 int width = options->stat_width;
2196                 int name_width = options->stat_name_width;
2197                 arg += 6;
2198                 end = (char *)arg;
2200                 switch (*arg) {
2201                 case '-':
2202                         if (!prefixcmp(arg, "-width="))
2203                                 width = strtoul(arg + 7, &end, 10);
2204                         else if (!prefixcmp(arg, "-name-width="))
2205                                 name_width = strtoul(arg + 12, &end, 10);
2206                         break;
2207                 case '=':
2208                         width = strtoul(arg+1, &end, 10);
2209                         if (*end == ',')
2210                                 name_width = strtoul(end+1, &end, 10);
2211                 }
2213                 /* Important! This checks all the error cases! */
2214                 if (*end)
2215                         return 0;
2216                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2217                 options->stat_name_width = name_width;
2218                 options->stat_width = width;
2219         }
2221         /* renames options */
2222         else if (!prefixcmp(arg, "-B")) {
2223                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2224                         return -1;
2225         }
2226         else if (!prefixcmp(arg, "-M")) {
2227                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2228                         return -1;
2229                 options->detect_rename = DIFF_DETECT_RENAME;
2230         }
2231         else if (!prefixcmp(arg, "-C")) {
2232                 if (options->detect_rename == DIFF_DETECT_COPY)
2233                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2234                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2235                         return -1;
2236                 options->detect_rename = DIFF_DETECT_COPY;
2237         }
2238         else if (!strcmp(arg, "--no-renames"))
2239                 options->detect_rename = 0;
2241         /* xdiff options */
2242         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2243                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2244         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2245                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2246         else if (!strcmp(arg, "--ignore-space-at-eol"))
2247                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2249         /* flags options */
2250         else if (!strcmp(arg, "--binary")) {
2251                 options->output_format |= DIFF_FORMAT_PATCH;
2252                 DIFF_OPT_SET(options, BINARY);
2253         }
2254         else if (!strcmp(arg, "--full-index"))
2255                 DIFF_OPT_SET(options, FULL_INDEX);
2256         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2257                 DIFF_OPT_SET(options, TEXT);
2258         else if (!strcmp(arg, "-R"))
2259                 DIFF_OPT_SET(options, REVERSE_DIFF);
2260         else if (!strcmp(arg, "--find-copies-harder"))
2261                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2262         else if (!strcmp(arg, "--follow"))
2263                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2264         else if (!strcmp(arg, "--color"))
2265                 DIFF_OPT_SET(options, COLOR_DIFF);
2266         else if (!strcmp(arg, "--no-color"))
2267                 DIFF_OPT_CLR(options, COLOR_DIFF);
2268         else if (!strcmp(arg, "--color-words"))
2269                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2270         else if (!strcmp(arg, "--exit-code"))
2271                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2272         else if (!strcmp(arg, "--quiet"))
2273                 DIFF_OPT_SET(options, QUIET);
2274         else if (!strcmp(arg, "--ext-diff"))
2275                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2276         else if (!strcmp(arg, "--no-ext-diff"))
2277                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2279         /* misc options */
2280         else if (!strcmp(arg, "-z"))
2281                 options->line_termination = 0;
2282         else if (!prefixcmp(arg, "-l"))
2283                 options->rename_limit = strtoul(arg+2, NULL, 10);
2284         else if (!prefixcmp(arg, "-S"))
2285                 options->pickaxe = arg + 2;
2286         else if (!strcmp(arg, "--pickaxe-all"))
2287                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2288         else if (!strcmp(arg, "--pickaxe-regex"))
2289                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2290         else if (!prefixcmp(arg, "-O"))
2291                 options->orderfile = arg + 2;
2292         else if (!prefixcmp(arg, "--diff-filter="))
2293                 options->filter = arg + 14;
2294         else if (!strcmp(arg, "--abbrev"))
2295                 options->abbrev = DEFAULT_ABBREV;
2296         else if (!prefixcmp(arg, "--abbrev=")) {
2297                 options->abbrev = strtoul(arg + 9, NULL, 10);
2298                 if (options->abbrev < MINIMUM_ABBREV)
2299                         options->abbrev = MINIMUM_ABBREV;
2300                 else if (40 < options->abbrev)
2301                         options->abbrev = 40;
2302         }
2303         else if (!prefixcmp(arg, "--src-prefix="))
2304                 options->a_prefix = arg + 13;
2305         else if (!prefixcmp(arg, "--dst-prefix="))
2306                 options->b_prefix = arg + 13;
2307         else if (!strcmp(arg, "--no-prefix"))
2308                 options->a_prefix = options->b_prefix = "";
2309         else
2310                 return 0;
2311         return 1;
2314 static int parse_num(const char **cp_p)
2316         unsigned long num, scale;
2317         int ch, dot;
2318         const char *cp = *cp_p;
2320         num = 0;
2321         scale = 1;
2322         dot = 0;
2323         for(;;) {
2324                 ch = *cp;
2325                 if ( !dot && ch == '.' ) {
2326                         scale = 1;
2327                         dot = 1;
2328                 } else if ( ch == '%' ) {
2329                         scale = dot ? scale*100 : 100;
2330                         cp++;   /* % is always at the end */
2331                         break;
2332                 } else if ( ch >= '0' && ch <= '9' ) {
2333                         if ( scale < 100000 ) {
2334                                 scale *= 10;
2335                                 num = (num*10) + (ch-'0');
2336                         }
2337                 } else {
2338                         break;
2339                 }
2340                 cp++;
2341         }
2342         *cp_p = cp;
2344         /* user says num divided by scale and we say internally that
2345          * is MAX_SCORE * num / scale.
2346          */
2347         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2350 static int diff_scoreopt_parse(const char *opt)
2352         int opt1, opt2, cmd;
2354         if (*opt++ != '-')
2355                 return -1;
2356         cmd = *opt++;
2357         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2358                 return -1; /* that is not a -M, -C nor -B option */
2360         opt1 = parse_num(&opt);
2361         if (cmd != 'B')
2362                 opt2 = 0;
2363         else {
2364                 if (*opt == 0)
2365                         opt2 = 0;
2366                 else if (*opt != '/')
2367                         return -1; /* we expect -B80/99 or -B80 */
2368                 else {
2369                         opt++;
2370                         opt2 = parse_num(&opt);
2371                 }
2372         }
2373         if (*opt != 0)
2374                 return -1;
2375         return opt1 | (opt2 << 16);
2378 struct diff_queue_struct diff_queued_diff;
2380 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2382         if (queue->alloc <= queue->nr) {
2383                 queue->alloc = alloc_nr(queue->alloc);
2384                 queue->queue = xrealloc(queue->queue,
2385                                         sizeof(dp) * queue->alloc);
2386         }
2387         queue->queue[queue->nr++] = dp;
2390 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2391                                  struct diff_filespec *one,
2392                                  struct diff_filespec *two)
2394         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2395         dp->one = one;
2396         dp->two = two;
2397         if (queue)
2398                 diff_q(queue, dp);
2399         return dp;
2402 void diff_free_filepair(struct diff_filepair *p)
2404         free_filespec(p->one);
2405         free_filespec(p->two);
2406         free(p);
2409 /* This is different from find_unique_abbrev() in that
2410  * it stuffs the result with dots for alignment.
2411  */
2412 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2414         int abblen;
2415         const char *abbrev;
2416         if (len == 40)
2417                 return sha1_to_hex(sha1);
2419         abbrev = find_unique_abbrev(sha1, len);
2420         if (!abbrev)
2421                 return sha1_to_hex(sha1);
2422         abblen = strlen(abbrev);
2423         if (abblen < 37) {
2424                 static char hex[41];
2425                 if (len < abblen && abblen <= len + 2)
2426                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2427                 else
2428                         sprintf(hex, "%s...", abbrev);
2429                 return hex;
2430         }
2431         return sha1_to_hex(sha1);
2434 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2436         int line_termination = opt->line_termination;
2437         int inter_name_termination = line_termination ? '\t' : '\0';
2439         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2440                 printf(":%06o %06o %s ", p->one->mode, p->two->mode,
2441                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2442                 printf("%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2443         }
2444         if (p->score) {
2445                 printf("%c%03d%c", p->status, similarity_index(p),
2446                            inter_name_termination);
2447         } else {
2448                 printf("%c%c", p->status, inter_name_termination);
2449         }
2451         if (p->status == DIFF_STATUS_COPIED || p->status == DIFF_STATUS_RENAMED) {
2452                 write_name_quoted(p->one->path, stdout, inter_name_termination);
2453                 write_name_quoted(p->two->path, stdout, line_termination);
2454         } else {
2455                 const char *path = p->one->mode ? p->one->path : p->two->path;
2456                 write_name_quoted(path, stdout, line_termination);
2457         }
2460 int diff_unmodified_pair(struct diff_filepair *p)
2462         /* This function is written stricter than necessary to support
2463          * the currently implemented transformers, but the idea is to
2464          * let transformers to produce diff_filepairs any way they want,
2465          * and filter and clean them up here before producing the output.
2466          */
2467         struct diff_filespec *one = p->one, *two = p->two;
2469         if (DIFF_PAIR_UNMERGED(p))
2470                 return 0; /* unmerged is interesting */
2472         /* deletion, addition, mode or type change
2473          * and rename are all interesting.
2474          */
2475         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2476             DIFF_PAIR_MODE_CHANGED(p) ||
2477             strcmp(one->path, two->path))
2478                 return 0;
2480         /* both are valid and point at the same path.  that is, we are
2481          * dealing with a change.
2482          */
2483         if (one->sha1_valid && two->sha1_valid &&
2484             !hashcmp(one->sha1, two->sha1))
2485                 return 1; /* no change */
2486         if (!one->sha1_valid && !two->sha1_valid)
2487                 return 1; /* both look at the same file on the filesystem. */
2488         return 0;
2491 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2493         if (diff_unmodified_pair(p))
2494                 return;
2496         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2497             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2498                 return; /* no tree diffs in patch format */
2500         run_diff(p, o);
2503 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2504                             struct diffstat_t *diffstat)
2506         if (diff_unmodified_pair(p))
2507                 return;
2509         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2510             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2511                 return; /* no tree diffs in patch format */
2513         run_diffstat(p, o, diffstat);
2516 static void diff_flush_checkdiff(struct diff_filepair *p,
2517                 struct diff_options *o)
2519         if (diff_unmodified_pair(p))
2520                 return;
2522         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2523             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2524                 return; /* no tree diffs in patch format */
2526         run_checkdiff(p, o);
2529 int diff_queue_is_empty(void)
2531         struct diff_queue_struct *q = &diff_queued_diff;
2532         int i;
2533         for (i = 0; i < q->nr; i++)
2534                 if (!diff_unmodified_pair(q->queue[i]))
2535                         return 0;
2536         return 1;
2539 #if DIFF_DEBUG
2540 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2542         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2543                 x, one ? one : "",
2544                 s->path,
2545                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2546                 s->mode,
2547                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2548         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2549                 x, one ? one : "",
2550                 s->size, s->xfrm_flags);
2553 void diff_debug_filepair(const struct diff_filepair *p, int i)
2555         diff_debug_filespec(p->one, i, "one");
2556         diff_debug_filespec(p->two, i, "two");
2557         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2558                 p->score, p->status ? p->status : '?',
2559                 p->one->rename_used, p->broken_pair);
2562 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2564         int i;
2565         if (msg)
2566                 fprintf(stderr, "%s\n", msg);
2567         fprintf(stderr, "q->nr = %d\n", q->nr);
2568         for (i = 0; i < q->nr; i++) {
2569                 struct diff_filepair *p = q->queue[i];
2570                 diff_debug_filepair(p, i);
2571         }
2573 #endif
2575 static void diff_resolve_rename_copy(void)
2577         int i;
2578         struct diff_filepair *p;
2579         struct diff_queue_struct *q = &diff_queued_diff;
2581         diff_debug_queue("resolve-rename-copy", q);
2583         for (i = 0; i < q->nr; i++) {
2584                 p = q->queue[i];
2585                 p->status = 0; /* undecided */
2586                 if (DIFF_PAIR_UNMERGED(p))
2587                         p->status = DIFF_STATUS_UNMERGED;
2588                 else if (!DIFF_FILE_VALID(p->one))
2589                         p->status = DIFF_STATUS_ADDED;
2590                 else if (!DIFF_FILE_VALID(p->two))
2591                         p->status = DIFF_STATUS_DELETED;
2592                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2593                         p->status = DIFF_STATUS_TYPE_CHANGED;
2595                 /* from this point on, we are dealing with a pair
2596                  * whose both sides are valid and of the same type, i.e.
2597                  * either in-place edit or rename/copy edit.
2598                  */
2599                 else if (DIFF_PAIR_RENAME(p)) {
2600                         /*
2601                          * A rename might have re-connected a broken
2602                          * pair up, causing the pathnames to be the
2603                          * same again. If so, that's not a rename at
2604                          * all, just a modification..
2605                          *
2606                          * Otherwise, see if this source was used for
2607                          * multiple renames, in which case we decrement
2608                          * the count, and call it a copy.
2609                          */
2610                         if (!strcmp(p->one->path, p->two->path))
2611                                 p->status = DIFF_STATUS_MODIFIED;
2612                         else if (--p->one->rename_used > 0)
2613                                 p->status = DIFF_STATUS_COPIED;
2614                         else
2615                                 p->status = DIFF_STATUS_RENAMED;
2616                 }
2617                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2618                          p->one->mode != p->two->mode ||
2619                          is_null_sha1(p->one->sha1))
2620                         p->status = DIFF_STATUS_MODIFIED;
2621                 else {
2622                         /* This is a "no-change" entry and should not
2623                          * happen anymore, but prepare for broken callers.
2624                          */
2625                         error("feeding unmodified %s to diffcore",
2626                               p->one->path);
2627                         p->status = DIFF_STATUS_UNKNOWN;
2628                 }
2629         }
2630         diff_debug_queue("resolve-rename-copy done", q);
2633 static int check_pair_status(struct diff_filepair *p)
2635         switch (p->status) {
2636         case DIFF_STATUS_UNKNOWN:
2637                 return 0;
2638         case 0:
2639                 die("internal error in diff-resolve-rename-copy");
2640         default:
2641                 return 1;
2642         }
2645 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2647         int fmt = opt->output_format;
2649         if (fmt & DIFF_FORMAT_CHECKDIFF)
2650                 diff_flush_checkdiff(p, opt);
2651         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2652                 diff_flush_raw(p, opt);
2653         else if (fmt & DIFF_FORMAT_NAME)
2654                 write_name_quoted(p->two->path, stdout, opt->line_termination);
2657 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2659         if (fs->mode)
2660                 printf(" %s mode %06o ", newdelete, fs->mode);
2661         else
2662                 printf(" %s ", newdelete);
2663         write_name_quoted(fs->path, stdout, '\n');
2667 static void show_mode_change(struct diff_filepair *p, int show_name)
2669         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2670                 printf(" mode change %06o => %06o%c", p->one->mode, p->two->mode,
2671                         show_name ? ' ' : '\n');
2672                 if (show_name) {
2673                         write_name_quoted(p->two->path, stdout, '\n');
2674                 }
2675         }
2678 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2680         char *names = pprint_rename(p->one->path, p->two->path);
2682         printf(" %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2683         free(names);
2684         show_mode_change(p, 0);
2687 static void diff_summary(struct diff_filepair *p)
2689         switch(p->status) {
2690         case DIFF_STATUS_DELETED:
2691                 show_file_mode_name("delete", p->one);
2692                 break;
2693         case DIFF_STATUS_ADDED:
2694                 show_file_mode_name("create", p->two);
2695                 break;
2696         case DIFF_STATUS_COPIED:
2697                 show_rename_copy("copy", p);
2698                 break;
2699         case DIFF_STATUS_RENAMED:
2700                 show_rename_copy("rename", p);
2701                 break;
2702         default:
2703                 if (p->score) {
2704                         fputs(" rewrite ", stdout);
2705                         write_name_quoted(p->two->path, stdout, ' ');
2706                         printf("(%d%%)\n", similarity_index(p));
2707                 }
2708                 show_mode_change(p, !p->score);
2709                 break;
2710         }
2713 struct patch_id_t {
2714         struct xdiff_emit_state xm;
2715         SHA_CTX *ctx;
2716         int patchlen;
2717 };
2719 static int remove_space(char *line, int len)
2721         int i;
2722         char *dst = line;
2723         unsigned char c;
2725         for (i = 0; i < len; i++)
2726                 if (!isspace((c = line[i])))
2727                         *dst++ = c;
2729         return dst - line;
2732 static void patch_id_consume(void *priv, char *line, unsigned long len)
2734         struct patch_id_t *data = priv;
2735         int new_len;
2737         /* Ignore line numbers when computing the SHA1 of the patch */
2738         if (!prefixcmp(line, "@@ -"))
2739                 return;
2741         new_len = remove_space(line, len);
2743         SHA1_Update(data->ctx, line, new_len);
2744         data->patchlen += new_len;
2747 /* returns 0 upon success, and writes result into sha1 */
2748 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2750         struct diff_queue_struct *q = &diff_queued_diff;
2751         int i;
2752         SHA_CTX ctx;
2753         struct patch_id_t data;
2754         char buffer[PATH_MAX * 4 + 20];
2756         SHA1_Init(&ctx);
2757         memset(&data, 0, sizeof(struct patch_id_t));
2758         data.ctx = &ctx;
2759         data.xm.consume = patch_id_consume;
2761         for (i = 0; i < q->nr; i++) {
2762                 xpparam_t xpp;
2763                 xdemitconf_t xecfg;
2764                 xdemitcb_t ecb;
2765                 mmfile_t mf1, mf2;
2766                 struct diff_filepair *p = q->queue[i];
2767                 int len1, len2;
2769                 memset(&xecfg, 0, sizeof(xecfg));
2770                 if (p->status == 0)
2771                         return error("internal diff status error");
2772                 if (p->status == DIFF_STATUS_UNKNOWN)
2773                         continue;
2774                 if (diff_unmodified_pair(p))
2775                         continue;
2776                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2777                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2778                         continue;
2779                 if (DIFF_PAIR_UNMERGED(p))
2780                         continue;
2782                 diff_fill_sha1_info(p->one);
2783                 diff_fill_sha1_info(p->two);
2784                 if (fill_mmfile(&mf1, p->one) < 0 ||
2785                                 fill_mmfile(&mf2, p->two) < 0)
2786                         return error("unable to read files to diff");
2788                 len1 = remove_space(p->one->path, strlen(p->one->path));
2789                 len2 = remove_space(p->two->path, strlen(p->two->path));
2790                 if (p->one->mode == 0)
2791                         len1 = snprintf(buffer, sizeof(buffer),
2792                                         "diff--gita/%.*sb/%.*s"
2793                                         "newfilemode%06o"
2794                                         "---/dev/null"
2795                                         "+++b/%.*s",
2796                                         len1, p->one->path,
2797                                         len2, p->two->path,
2798                                         p->two->mode,
2799                                         len2, p->two->path);
2800                 else if (p->two->mode == 0)
2801                         len1 = snprintf(buffer, sizeof(buffer),
2802                                         "diff--gita/%.*sb/%.*s"
2803                                         "deletedfilemode%06o"
2804                                         "---a/%.*s"
2805                                         "+++/dev/null",
2806                                         len1, p->one->path,
2807                                         len2, p->two->path,
2808                                         p->one->mode,
2809                                         len1, p->one->path);
2810                 else
2811                         len1 = snprintf(buffer, sizeof(buffer),
2812                                         "diff--gita/%.*sb/%.*s"
2813                                         "---a/%.*s"
2814                                         "+++b/%.*s",
2815                                         len1, p->one->path,
2816                                         len2, p->two->path,
2817                                         len1, p->one->path,
2818                                         len2, p->two->path);
2819                 SHA1_Update(&ctx, buffer, len1);
2821                 xpp.flags = XDF_NEED_MINIMAL;
2822                 xecfg.ctxlen = 3;
2823                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2824                 ecb.outf = xdiff_outf;
2825                 ecb.priv = &data;
2826                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2827         }
2829         SHA1_Final(sha1, &ctx);
2830         return 0;
2833 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2835         struct diff_queue_struct *q = &diff_queued_diff;
2836         int i;
2837         int result = diff_get_patch_id(options, sha1);
2839         for (i = 0; i < q->nr; i++)
2840                 diff_free_filepair(q->queue[i]);
2842         free(q->queue);
2843         q->queue = NULL;
2844         q->nr = q->alloc = 0;
2846         return result;
2849 static int is_summary_empty(const struct diff_queue_struct *q)
2851         int i;
2853         for (i = 0; i < q->nr; i++) {
2854                 const struct diff_filepair *p = q->queue[i];
2856                 switch (p->status) {
2857                 case DIFF_STATUS_DELETED:
2858                 case DIFF_STATUS_ADDED:
2859                 case DIFF_STATUS_COPIED:
2860                 case DIFF_STATUS_RENAMED:
2861                         return 0;
2862                 default:
2863                         if (p->score)
2864                                 return 0;
2865                         if (p->one->mode && p->two->mode &&
2866                             p->one->mode != p->two->mode)
2867                                 return 0;
2868                         break;
2869                 }
2870         }
2871         return 1;
2874 void diff_flush(struct diff_options *options)
2876         struct diff_queue_struct *q = &diff_queued_diff;
2877         int i, output_format = options->output_format;
2878         int separator = 0;
2880         /*
2881          * Order: raw, stat, summary, patch
2882          * or:    name/name-status/checkdiff (other bits clear)
2883          */
2884         if (!q->nr)
2885                 goto free_queue;
2887         if (output_format & (DIFF_FORMAT_RAW |
2888                              DIFF_FORMAT_NAME |
2889                              DIFF_FORMAT_NAME_STATUS |
2890                              DIFF_FORMAT_CHECKDIFF)) {
2891                 for (i = 0; i < q->nr; i++) {
2892                         struct diff_filepair *p = q->queue[i];
2893                         if (check_pair_status(p))
2894                                 flush_one_pair(p, options);
2895                 }
2896                 separator++;
2897         }
2899         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
2900                 struct diffstat_t diffstat;
2902                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2903                 diffstat.xm.consume = diffstat_consume;
2904                 for (i = 0; i < q->nr; i++) {
2905                         struct diff_filepair *p = q->queue[i];
2906                         if (check_pair_status(p))
2907                                 diff_flush_stat(p, options, &diffstat);
2908                 }
2909                 if (output_format & DIFF_FORMAT_NUMSTAT)
2910                         show_numstat(&diffstat, options);
2911                 if (output_format & DIFF_FORMAT_DIFFSTAT)
2912                         show_stats(&diffstat, options);
2913                 if (output_format & DIFF_FORMAT_SHORTSTAT)
2914                         show_shortstats(&diffstat);
2915                 free_diffstat_info(&diffstat);
2916                 separator++;
2917         }
2919         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2920                 for (i = 0; i < q->nr; i++)
2921                         diff_summary(q->queue[i]);
2922                 separator++;
2923         }
2925         if (output_format & DIFF_FORMAT_PATCH) {
2926                 if (separator) {
2927                         if (options->stat_sep) {
2928                                 /* attach patch instead of inline */
2929                                 fputs(options->stat_sep, stdout);
2930                         } else {
2931                                 putchar(options->line_termination);
2932                         }
2933                 }
2935                 for (i = 0; i < q->nr; i++) {
2936                         struct diff_filepair *p = q->queue[i];
2937                         if (check_pair_status(p))
2938                                 diff_flush_patch(p, options);
2939                 }
2940         }
2942         if (output_format & DIFF_FORMAT_CALLBACK)
2943                 options->format_callback(q, options, options->format_callback_data);
2945         for (i = 0; i < q->nr; i++)
2946                 diff_free_filepair(q->queue[i]);
2947 free_queue:
2948         free(q->queue);
2949         q->queue = NULL;
2950         q->nr = q->alloc = 0;
2953 static void diffcore_apply_filter(const char *filter)
2955         int i;
2956         struct diff_queue_struct *q = &diff_queued_diff;
2957         struct diff_queue_struct outq;
2958         outq.queue = NULL;
2959         outq.nr = outq.alloc = 0;
2961         if (!filter)
2962                 return;
2964         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2965                 int found;
2966                 for (i = found = 0; !found && i < q->nr; i++) {
2967                         struct diff_filepair *p = q->queue[i];
2968                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2969                              ((p->score &&
2970                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2971                               (!p->score &&
2972                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2973                             ((p->status != DIFF_STATUS_MODIFIED) &&
2974                              strchr(filter, p->status)))
2975                                 found++;
2976                 }
2977                 if (found)
2978                         return;
2980                 /* otherwise we will clear the whole queue
2981                  * by copying the empty outq at the end of this
2982                  * function, but first clear the current entries
2983                  * in the queue.
2984                  */
2985                 for (i = 0; i < q->nr; i++)
2986                         diff_free_filepair(q->queue[i]);
2987         }
2988         else {
2989                 /* Only the matching ones */
2990                 for (i = 0; i < q->nr; i++) {
2991                         struct diff_filepair *p = q->queue[i];
2993                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2994                              ((p->score &&
2995                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2996                               (!p->score &&
2997                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2998                             ((p->status != DIFF_STATUS_MODIFIED) &&
2999                              strchr(filter, p->status)))
3000                                 diff_q(&outq, p);
3001                         else
3002                                 diff_free_filepair(p);
3003                 }
3004         }
3005         free(q->queue);
3006         *q = outq;
3009 /* Check whether two filespecs with the same mode and size are identical */
3010 static int diff_filespec_is_identical(struct diff_filespec *one,
3011                                       struct diff_filespec *two)
3013         if (S_ISGITLINK(one->mode)) {
3014                 diff_fill_sha1_info(one);
3015                 diff_fill_sha1_info(two);
3016                 return !hashcmp(one->sha1, two->sha1);
3017         }
3018         if (diff_populate_filespec(one, 0))
3019                 return 0;
3020         if (diff_populate_filespec(two, 0))
3021                 return 0;
3022         return !memcmp(one->data, two->data, one->size);
3025 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3027         int i;
3028         struct diff_queue_struct *q = &diff_queued_diff;
3029         struct diff_queue_struct outq;
3030         outq.queue = NULL;
3031         outq.nr = outq.alloc = 0;
3033         for (i = 0; i < q->nr; i++) {
3034                 struct diff_filepair *p = q->queue[i];
3036                 /*
3037                  * 1. Entries that come from stat info dirtyness
3038                  *    always have both sides (iow, not create/delete),
3039                  *    one side of the object name is unknown, with
3040                  *    the same mode and size.  Keep the ones that
3041                  *    do not match these criteria.  They have real
3042                  *    differences.
3043                  *
3044                  * 2. At this point, the file is known to be modified,
3045                  *    with the same mode and size, and the object
3046                  *    name of one side is unknown.  Need to inspect
3047                  *    the identical contents.
3048                  */
3049                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3050                     !DIFF_FILE_VALID(p->two) ||
3051                     (p->one->sha1_valid && p->two->sha1_valid) ||
3052                     (p->one->mode != p->two->mode) ||
3053                     diff_populate_filespec(p->one, 1) ||
3054                     diff_populate_filespec(p->two, 1) ||
3055                     (p->one->size != p->two->size) ||
3056                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3057                         diff_q(&outq, p);
3058                 else {
3059                         /*
3060                          * The caller can subtract 1 from skip_stat_unmatch
3061                          * to determine how many paths were dirty only
3062                          * due to stat info mismatch.
3063                          */
3064                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3065                                 diffopt->skip_stat_unmatch++;
3066                         diff_free_filepair(p);
3067                 }
3068         }
3069         free(q->queue);
3070         *q = outq;
3073 void diffcore_std(struct diff_options *options)
3075         if (DIFF_OPT_TST(options, QUIET))
3076                 return;
3078         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3079                 diffcore_skip_stat_unmatch(options);
3080         if (options->break_opt != -1)
3081                 diffcore_break(options->break_opt);
3082         if (options->detect_rename)
3083                 diffcore_rename(options);
3084         if (options->break_opt != -1)
3085                 diffcore_merge_broken();
3086         if (options->pickaxe)
3087                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3088         if (options->orderfile)
3089                 diffcore_order(options->orderfile);
3090         diff_resolve_rename_copy();
3091         diffcore_apply_filter(options->filter);
3093         if (diff_queued_diff.nr)
3094                 DIFF_OPT_SET(options, HAS_CHANGES);
3095         else
3096                 DIFF_OPT_CLR(options, HAS_CHANGES);
3099 int diff_result_code(struct diff_options *opt, int status)
3101         int result = 0;
3102         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3103             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3104                 return status;
3105         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3106             DIFF_OPT_TST(opt, HAS_CHANGES))
3107                 result |= 01;
3108         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3109             DIFF_OPT_TST(opt, CHECK_FAILED))
3110                 result |= 02;
3111         return result;
3114 void diff_addremove(struct diff_options *options,
3115                     int addremove, unsigned mode,
3116                     const unsigned char *sha1,
3117                     const char *base, const char *path)
3119         char concatpath[PATH_MAX];
3120         struct diff_filespec *one, *two;
3122         /* This may look odd, but it is a preparation for
3123          * feeding "there are unchanged files which should
3124          * not produce diffs, but when you are doing copy
3125          * detection you would need them, so here they are"
3126          * entries to the diff-core.  They will be prefixed
3127          * with something like '=' or '*' (I haven't decided
3128          * which but should not make any difference).
3129          * Feeding the same new and old to diff_change()
3130          * also has the same effect.
3131          * Before the final output happens, they are pruned after
3132          * merged into rename/copy pairs as appropriate.
3133          */
3134         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3135                 addremove = (addremove == '+' ? '-' :
3136                              addremove == '-' ? '+' : addremove);
3138         if (!path) path = "";
3139         sprintf(concatpath, "%s%s", base, path);
3140         one = alloc_filespec(concatpath);
3141         two = alloc_filespec(concatpath);
3143         if (addremove != '+')
3144                 fill_filespec(one, sha1, mode);
3145         if (addremove != '-')
3146                 fill_filespec(two, sha1, mode);
3148         diff_queue(&diff_queued_diff, one, two);
3149         DIFF_OPT_SET(options, HAS_CHANGES);
3152 void diff_change(struct diff_options *options,
3153                  unsigned old_mode, unsigned new_mode,
3154                  const unsigned char *old_sha1,
3155                  const unsigned char *new_sha1,
3156                  const char *base, const char *path)
3158         char concatpath[PATH_MAX];
3159         struct diff_filespec *one, *two;
3161         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3162                 unsigned tmp;
3163                 const unsigned char *tmp_c;
3164                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3165                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3166         }
3167         if (!path) path = "";
3168         sprintf(concatpath, "%s%s", base, path);
3169         one = alloc_filespec(concatpath);
3170         two = alloc_filespec(concatpath);
3171         fill_filespec(one, old_sha1, old_mode);
3172         fill_filespec(two, new_sha1, new_mode);
3174         diff_queue(&diff_queued_diff, one, two);
3175         DIFF_OPT_SET(options, HAS_CHANGES);
3178 void diff_unmerge(struct diff_options *options,
3179                   const char *path,
3180                   unsigned mode, const unsigned char *sha1)
3182         struct diff_filespec *one, *two;
3183         one = alloc_filespec(path);
3184         two = alloc_filespec(path);
3185         fill_filespec(one, sha1, mode);
3186         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;