Code

Don't dereference NULL upon lookup failure.
[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);
304         name_a += (*name_a == '/');
305         name_b += (*name_b == '/');
306         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
307         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
309         diff_populate_filespec(one, 0);
310         diff_populate_filespec(two, 0);
311         lc_a = count_lines(one->data, one->size);
312         lc_b = count_lines(two->data, two->size);
313         printf("%s--- %s%s%s%s\n%s+++ %s%s%s%s\n%s@@ -",
314                metainfo, o->a_prefix, name_a, name_a_tab, reset,
315                metainfo, o->b_prefix, name_b, name_b_tab, reset, fraginfo);
316         print_line_count(lc_a);
317         printf(" +");
318         print_line_count(lc_b);
319         printf(" @@%s\n", reset);
320         if (lc_a)
321                 copy_file('-', one->data, one->size, old, reset);
322         if (lc_b)
323                 copy_file('+', two->data, two->size, new, reset);
326 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
328         if (!DIFF_FILE_VALID(one)) {
329                 mf->ptr = (char *)""; /* does not matter */
330                 mf->size = 0;
331                 return 0;
332         }
333         else if (diff_populate_filespec(one, 0))
334                 return -1;
335         mf->ptr = one->data;
336         mf->size = one->size;
337         return 0;
340 struct diff_words_buffer {
341         mmfile_t text;
342         long alloc;
343         long current; /* output pointer */
344         int suppressed_newline;
345 };
347 static void diff_words_append(char *line, unsigned long len,
348                 struct diff_words_buffer *buffer)
350         if (buffer->text.size + len > buffer->alloc) {
351                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
352                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
353         }
354         line++;
355         len--;
356         memcpy(buffer->text.ptr + buffer->text.size, line, len);
357         buffer->text.size += len;
360 struct diff_words_data {
361         struct xdiff_emit_state xm;
362         struct diff_words_buffer minus, plus;
363 };
365 static void print_word(struct diff_words_buffer *buffer, int len, int color,
366                 int suppress_newline)
368         const char *ptr;
369         int eol = 0;
371         if (len == 0)
372                 return;
374         ptr  = buffer->text.ptr + buffer->current;
375         buffer->current += len;
377         if (ptr[len - 1] == '\n') {
378                 eol = 1;
379                 len--;
380         }
382         fputs(diff_get_color(1, color), stdout);
383         fwrite(ptr, len, 1, stdout);
384         fputs(diff_get_color(1, DIFF_RESET), stdout);
386         if (eol) {
387                 if (suppress_newline)
388                         buffer->suppressed_newline = 1;
389                 else
390                         putchar('\n');
391         }
394 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
396         struct diff_words_data *diff_words = priv;
398         if (diff_words->minus.suppressed_newline) {
399                 if (line[0] != '+')
400                         putchar('\n');
401                 diff_words->minus.suppressed_newline = 0;
402         }
404         len--;
405         switch (line[0]) {
406                 case '-':
407                         print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
408                         break;
409                 case '+':
410                         print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
411                         break;
412                 case ' ':
413                         print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
414                         diff_words->minus.current += len;
415                         break;
416         }
419 /* this executes the word diff on the accumulated buffers */
420 static void diff_words_show(struct diff_words_data *diff_words)
422         xpparam_t xpp;
423         xdemitconf_t xecfg;
424         xdemitcb_t ecb;
425         mmfile_t minus, plus;
426         int i;
428         memset(&xecfg, 0, sizeof(xecfg));
429         minus.size = diff_words->minus.text.size;
430         minus.ptr = xmalloc(minus.size);
431         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
432         for (i = 0; i < minus.size; i++)
433                 if (isspace(minus.ptr[i]))
434                         minus.ptr[i] = '\n';
435         diff_words->minus.current = 0;
437         plus.size = diff_words->plus.text.size;
438         plus.ptr = xmalloc(plus.size);
439         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
440         for (i = 0; i < plus.size; i++)
441                 if (isspace(plus.ptr[i]))
442                         plus.ptr[i] = '\n';
443         diff_words->plus.current = 0;
445         xpp.flags = XDF_NEED_MINIMAL;
446         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
447         ecb.outf = xdiff_outf;
448         ecb.priv = diff_words;
449         diff_words->xm.consume = fn_out_diff_words_aux;
450         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
452         free(minus.ptr);
453         free(plus.ptr);
454         diff_words->minus.text.size = diff_words->plus.text.size = 0;
456         if (diff_words->minus.suppressed_newline) {
457                 putchar('\n');
458                 diff_words->minus.suppressed_newline = 0;
459         }
462 struct emit_callback {
463         struct xdiff_emit_state xm;
464         int nparents, color_diff;
465         unsigned ws_rule;
466         const char **label_path;
467         struct diff_words_data *diff_words;
468         int *found_changesp;
469 };
471 static void free_diff_words_data(struct emit_callback *ecbdata)
473         if (ecbdata->diff_words) {
474                 /* flush buffers */
475                 if (ecbdata->diff_words->minus.text.size ||
476                                 ecbdata->diff_words->plus.text.size)
477                         diff_words_show(ecbdata->diff_words);
479                 if (ecbdata->diff_words->minus.text.ptr)
480                         free (ecbdata->diff_words->minus.text.ptr);
481                 if (ecbdata->diff_words->plus.text.ptr)
482                         free (ecbdata->diff_words->plus.text.ptr);
483                 free(ecbdata->diff_words);
484                 ecbdata->diff_words = NULL;
485         }
488 const char *diff_get_color(int diff_use_color, enum color_diff ix)
490         if (diff_use_color)
491                 return diff_colors[ix];
492         return "";
495 static void emit_line(const char *set, const char *reset, const char *line, int len)
497         fputs(set, stdout);
498         fwrite(line, len, 1, stdout);
499         fputs(reset, stdout);
502 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
504         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
505         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
507         if (!*ws)
508                 emit_line(set, reset, line, len);
509         else {
510                 /* Emit just the prefix, then the rest. */
511                 emit_line(set, reset, line, ecbdata->nparents);
512                 (void)check_and_emit_line(line + ecbdata->nparents,
513                     len - ecbdata->nparents, ecbdata->ws_rule,
514                     stdout, set, reset, ws);
515         }
518 static void fn_out_consume(void *priv, char *line, unsigned long len)
520         int i;
521         int color;
522         struct emit_callback *ecbdata = priv;
523         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
524         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
526         *(ecbdata->found_changesp) = 1;
528         if (ecbdata->label_path[0]) {
529                 const char *name_a_tab, *name_b_tab;
531                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
532                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
534                 printf("%s--- %s%s%s\n",
535                        set, ecbdata->label_path[0], reset, name_a_tab);
536                 printf("%s+++ %s%s%s\n",
537                        set, ecbdata->label_path[1], reset, name_b_tab);
538                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
539         }
541         /* This is not really necessary for now because
542          * this codepath only deals with two-way diffs.
543          */
544         for (i = 0; i < len && line[i] == '@'; i++)
545                 ;
546         if (2 <= i && i < len && line[i] == ' ') {
547                 ecbdata->nparents = i - 1;
548                 emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
549                           reset, line, len);
550                 return;
551         }
553         if (len < ecbdata->nparents) {
554                 set = reset;
555                 emit_line(reset, reset, line, len);
556                 return;
557         }
559         color = DIFF_PLAIN;
560         if (ecbdata->diff_words && ecbdata->nparents != 1)
561                 /* fall back to normal diff */
562                 free_diff_words_data(ecbdata);
563         if (ecbdata->diff_words) {
564                 if (line[0] == '-') {
565                         diff_words_append(line, len,
566                                           &ecbdata->diff_words->minus);
567                         return;
568                 } else if (line[0] == '+') {
569                         diff_words_append(line, len,
570                                           &ecbdata->diff_words->plus);
571                         return;
572                 }
573                 if (ecbdata->diff_words->minus.text.size ||
574                     ecbdata->diff_words->plus.text.size)
575                         diff_words_show(ecbdata->diff_words);
576                 line++;
577                 len--;
578                 emit_line(set, reset, line, len);
579                 return;
580         }
581         for (i = 0; i < ecbdata->nparents && len; i++) {
582                 if (line[i] == '-')
583                         color = DIFF_FILE_OLD;
584                 else if (line[i] == '+')
585                         color = DIFF_FILE_NEW;
586         }
588         if (color != DIFF_FILE_NEW) {
589                 emit_line(diff_get_color(ecbdata->color_diff, color),
590                           reset, line, len);
591                 return;
592         }
593         emit_add_line(reset, ecbdata, line, len);
596 static char *pprint_rename(const char *a, const char *b)
598         const char *old = a;
599         const char *new = b;
600         struct strbuf name;
601         int pfx_length, sfx_length;
602         int len_a = strlen(a);
603         int len_b = strlen(b);
604         int a_midlen, b_midlen;
605         int qlen_a = quote_c_style(a, NULL, NULL, 0);
606         int qlen_b = quote_c_style(b, NULL, NULL, 0);
608         strbuf_init(&name, 0);
609         if (qlen_a || qlen_b) {
610                 quote_c_style(a, &name, NULL, 0);
611                 strbuf_addstr(&name, " => ");
612                 quote_c_style(b, &name, NULL, 0);
613                 return strbuf_detach(&name, NULL);
614         }
616         /* Find common prefix */
617         pfx_length = 0;
618         while (*old && *new && *old == *new) {
619                 if (*old == '/')
620                         pfx_length = old - a + 1;
621                 old++;
622                 new++;
623         }
625         /* Find common suffix */
626         old = a + len_a;
627         new = b + len_b;
628         sfx_length = 0;
629         while (a <= old && b <= new && *old == *new) {
630                 if (*old == '/')
631                         sfx_length = len_a - (old - a);
632                 old--;
633                 new--;
634         }
636         /*
637          * pfx{mid-a => mid-b}sfx
638          * {pfx-a => pfx-b}sfx
639          * pfx{sfx-a => sfx-b}
640          * name-a => name-b
641          */
642         a_midlen = len_a - pfx_length - sfx_length;
643         b_midlen = len_b - pfx_length - sfx_length;
644         if (a_midlen < 0)
645                 a_midlen = 0;
646         if (b_midlen < 0)
647                 b_midlen = 0;
649         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
650         if (pfx_length + sfx_length) {
651                 strbuf_add(&name, a, pfx_length);
652                 strbuf_addch(&name, '{');
653         }
654         strbuf_add(&name, a + pfx_length, a_midlen);
655         strbuf_addstr(&name, " => ");
656         strbuf_add(&name, b + pfx_length, b_midlen);
657         if (pfx_length + sfx_length) {
658                 strbuf_addch(&name, '}');
659                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
660         }
661         return strbuf_detach(&name, NULL);
664 struct diffstat_t {
665         struct xdiff_emit_state xm;
667         int nr;
668         int alloc;
669         struct diffstat_file {
670                 char *from_name;
671                 char *name;
672                 char *print_name;
673                 unsigned is_unmerged:1;
674                 unsigned is_binary:1;
675                 unsigned is_renamed:1;
676                 unsigned int added, deleted;
677         } **files;
678 };
680 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
681                                           const char *name_a,
682                                           const char *name_b)
684         struct diffstat_file *x;
685         x = xcalloc(sizeof (*x), 1);
686         if (diffstat->nr == diffstat->alloc) {
687                 diffstat->alloc = alloc_nr(diffstat->alloc);
688                 diffstat->files = xrealloc(diffstat->files,
689                                 diffstat->alloc * sizeof(x));
690         }
691         diffstat->files[diffstat->nr++] = x;
692         if (name_b) {
693                 x->from_name = xstrdup(name_a);
694                 x->name = xstrdup(name_b);
695                 x->is_renamed = 1;
696         }
697         else {
698                 x->from_name = NULL;
699                 x->name = xstrdup(name_a);
700         }
701         return x;
704 static void diffstat_consume(void *priv, char *line, unsigned long len)
706         struct diffstat_t *diffstat = priv;
707         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
709         if (line[0] == '+')
710                 x->added++;
711         else if (line[0] == '-')
712                 x->deleted++;
715 const char mime_boundary_leader[] = "------------";
717 static int scale_linear(int it, int width, int max_change)
719         /*
720          * make sure that at least one '-' is printed if there were deletions,
721          * and likewise for '+'.
722          */
723         if (max_change < 2)
724                 return it;
725         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
728 static void show_name(const char *prefix, const char *name, int len,
729                       const char *reset, const char *set)
731         printf(" %s%s%-*s%s |", set, prefix, len, name, reset);
734 static void show_graph(char ch, int cnt, const char *set, const char *reset)
736         if (cnt <= 0)
737                 return;
738         printf("%s", set);
739         while (cnt--)
740                 putchar(ch);
741         printf("%s", reset);
744 static void fill_print_name(struct diffstat_file *file)
746         char *pname;
748         if (file->print_name)
749                 return;
751         if (!file->is_renamed) {
752                 struct strbuf buf;
753                 strbuf_init(&buf, 0);
754                 if (quote_c_style(file->name, &buf, NULL, 0)) {
755                         pname = strbuf_detach(&buf, NULL);
756                 } else {
757                         pname = file->name;
758                         strbuf_release(&buf);
759                 }
760         } else {
761                 pname = pprint_rename(file->from_name, file->name);
762         }
763         file->print_name = pname;
766 static void show_stats(struct diffstat_t* data, struct diff_options *options)
768         int i, len, add, del, total, adds = 0, dels = 0;
769         int max_change = 0, max_len = 0;
770         int total_files = data->nr;
771         int width, name_width;
772         const char *reset, *set, *add_c, *del_c;
774         if (data->nr == 0)
775                 return;
777         width = options->stat_width ? options->stat_width : 80;
778         name_width = options->stat_name_width ? options->stat_name_width : 50;
780         /* Sanity: give at least 5 columns to the graph,
781          * but leave at least 10 columns for the name.
782          */
783         if (width < name_width + 15) {
784                 if (name_width <= 25)
785                         width = name_width + 15;
786                 else
787                         name_width = width - 15;
788         }
790         /* Find the longest filename and max number of changes */
791         reset = diff_get_color_opt(options, DIFF_RESET);
792         set   = diff_get_color_opt(options, DIFF_PLAIN);
793         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
794         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
796         for (i = 0; i < data->nr; i++) {
797                 struct diffstat_file *file = data->files[i];
798                 int change = file->added + file->deleted;
799                 fill_print_name(file);
800                 len = strlen(file->print_name);
801                 if (max_len < len)
802                         max_len = len;
804                 if (file->is_binary || file->is_unmerged)
805                         continue;
806                 if (max_change < change)
807                         max_change = change;
808         }
810         /* Compute the width of the graph part;
811          * 10 is for one blank at the beginning of the line plus
812          * " | count " between the name and the graph.
813          *
814          * From here on, name_width is the width of the name area,
815          * and width is the width of the graph area.
816          */
817         name_width = (name_width < max_len) ? name_width : max_len;
818         if (width < (name_width + 10) + max_change)
819                 width = width - (name_width + 10);
820         else
821                 width = max_change;
823         for (i = 0; i < data->nr; i++) {
824                 const char *prefix = "";
825                 char *name = data->files[i]->print_name;
826                 int added = data->files[i]->added;
827                 int deleted = data->files[i]->deleted;
828                 int name_len;
830                 /*
831                  * "scale" the filename
832                  */
833                 len = name_width;
834                 name_len = strlen(name);
835                 if (name_width < name_len) {
836                         char *slash;
837                         prefix = "...";
838                         len -= 3;
839                         name += name_len - len;
840                         slash = strchr(name, '/');
841                         if (slash)
842                                 name = slash;
843                 }
845                 if (data->files[i]->is_binary) {
846                         show_name(prefix, name, len, reset, set);
847                         printf("  Bin ");
848                         printf("%s%d%s", del_c, deleted, reset);
849                         printf(" -> ");
850                         printf("%s%d%s", add_c, added, reset);
851                         printf(" bytes");
852                         printf("\n");
853                         continue;
854                 }
855                 else if (data->files[i]->is_unmerged) {
856                         show_name(prefix, name, len, reset, set);
857                         printf("  Unmerged\n");
858                         continue;
859                 }
860                 else if (!data->files[i]->is_renamed &&
861                          (added + deleted == 0)) {
862                         total_files--;
863                         continue;
864                 }
866                 /*
867                  * scale the add/delete
868                  */
869                 add = added;
870                 del = deleted;
871                 total = add + del;
872                 adds += add;
873                 dels += del;
875                 if (width <= max_change) {
876                         add = scale_linear(add, width, max_change);
877                         del = scale_linear(del, width, max_change);
878                         total = add + del;
879                 }
880                 show_name(prefix, name, len, reset, set);
881                 printf("%5d ", added + deleted);
882                 show_graph('+', add, add_c, reset);
883                 show_graph('-', del, del_c, reset);
884                 putchar('\n');
885         }
886         printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
887                set, total_files, adds, dels, reset);
890 static void show_shortstats(struct diffstat_t* data)
892         int i, adds = 0, dels = 0, total_files = data->nr;
894         if (data->nr == 0)
895                 return;
897         for (i = 0; i < data->nr; i++) {
898                 if (!data->files[i]->is_binary &&
899                     !data->files[i]->is_unmerged) {
900                         int added = data->files[i]->added;
901                         int deleted= data->files[i]->deleted;
902                         if (!data->files[i]->is_renamed &&
903                             (added + deleted == 0)) {
904                                 total_files--;
905                         } else {
906                                 adds += added;
907                                 dels += deleted;
908                         }
909                 }
910         }
911         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
912                total_files, adds, dels);
915 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
917         int i;
919         if (data->nr == 0)
920                 return;
922         for (i = 0; i < data->nr; i++) {
923                 struct diffstat_file *file = data->files[i];
925                 if (file->is_binary)
926                         printf("-\t-\t");
927                 else
928                         printf("%d\t%d\t", file->added, file->deleted);
929                 if (options->line_termination) {
930                         fill_print_name(file);
931                         if (!file->is_renamed)
932                                 write_name_quoted(file->name, stdout,
933                                                   options->line_termination);
934                         else {
935                                 fputs(file->print_name, stdout);
936                                 putchar(options->line_termination);
937                         }
938                 } else {
939                         if (file->is_renamed) {
940                                 putchar('\0');
941                                 write_name_quoted(file->from_name, stdout, '\0');
942                         }
943                         write_name_quoted(file->name, stdout, '\0');
944                 }
945         }
948 static void free_diffstat_info(struct diffstat_t *diffstat)
950         int i;
951         for (i = 0; i < diffstat->nr; i++) {
952                 struct diffstat_file *f = diffstat->files[i];
953                 if (f->name != f->print_name)
954                         free(f->print_name);
955                 free(f->name);
956                 free(f->from_name);
957                 free(f);
958         }
959         free(diffstat->files);
962 struct checkdiff_t {
963         struct xdiff_emit_state xm;
964         const char *filename;
965         int lineno, color_diff;
966         unsigned ws_rule;
967         unsigned status;
968 };
970 static void checkdiff_consume(void *priv, char *line, unsigned long len)
972         struct checkdiff_t *data = priv;
973         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
974         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
975         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
976         char *err;
978         if (line[0] == '+') {
979                 data->status = check_and_emit_line(line + 1, len - 1,
980                     data->ws_rule, NULL, NULL, NULL, NULL);
981                 if (!data->status)
982                         return;
983                 err = whitespace_error_string(data->status);
984                 printf("%s:%d: %s.\n", data->filename, data->lineno, err);
985                 free(err);
986                 emit_line(set, reset, line, 1);
987                 (void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
988                     stdout, set, reset, ws);
989                 data->lineno++;
990         } else if (line[0] == ' ')
991                 data->lineno++;
992         else if (line[0] == '@') {
993                 char *plus = strchr(line, '+');
994                 if (plus)
995                         data->lineno = strtol(plus, NULL, 10);
996                 else
997                         die("invalid diff");
998         }
1001 static unsigned char *deflate_it(char *data,
1002                                  unsigned long size,
1003                                  unsigned long *result_size)
1005         int bound;
1006         unsigned char *deflated;
1007         z_stream stream;
1009         memset(&stream, 0, sizeof(stream));
1010         deflateInit(&stream, zlib_compression_level);
1011         bound = deflateBound(&stream, size);
1012         deflated = xmalloc(bound);
1013         stream.next_out = deflated;
1014         stream.avail_out = bound;
1016         stream.next_in = (unsigned char *)data;
1017         stream.avail_in = size;
1018         while (deflate(&stream, Z_FINISH) == Z_OK)
1019                 ; /* nothing */
1020         deflateEnd(&stream);
1021         *result_size = stream.total_out;
1022         return deflated;
1025 static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
1027         void *cp;
1028         void *delta;
1029         void *deflated;
1030         void *data;
1031         unsigned long orig_size;
1032         unsigned long delta_size;
1033         unsigned long deflate_size;
1034         unsigned long data_size;
1036         /* We could do deflated delta, or we could do just deflated two,
1037          * whichever is smaller.
1038          */
1039         delta = NULL;
1040         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1041         if (one->size && two->size) {
1042                 delta = diff_delta(one->ptr, one->size,
1043                                    two->ptr, two->size,
1044                                    &delta_size, deflate_size);
1045                 if (delta) {
1046                         void *to_free = delta;
1047                         orig_size = delta_size;
1048                         delta = deflate_it(delta, delta_size, &delta_size);
1049                         free(to_free);
1050                 }
1051         }
1053         if (delta && delta_size < deflate_size) {
1054                 printf("delta %lu\n", orig_size);
1055                 free(deflated);
1056                 data = delta;
1057                 data_size = delta_size;
1058         }
1059         else {
1060                 printf("literal %lu\n", two->size);
1061                 free(delta);
1062                 data = deflated;
1063                 data_size = deflate_size;
1064         }
1066         /* emit data encoded in base85 */
1067         cp = data;
1068         while (data_size) {
1069                 int bytes = (52 < data_size) ? 52 : data_size;
1070                 char line[70];
1071                 data_size -= bytes;
1072                 if (bytes <= 26)
1073                         line[0] = bytes + 'A' - 1;
1074                 else
1075                         line[0] = bytes - 26 + 'a' - 1;
1076                 encode_85(line + 1, cp, bytes);
1077                 cp = (char *) cp + bytes;
1078                 puts(line);
1079         }
1080         printf("\n");
1081         free(data);
1084 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
1086         printf("GIT binary patch\n");
1087         emit_binary_diff_body(one, two);
1088         emit_binary_diff_body(two, one);
1091 static void setup_diff_attr_check(struct git_attr_check *check)
1093         static struct git_attr *attr_diff;
1095         if (!attr_diff) {
1096                 attr_diff = git_attr("diff", 4);
1097         }
1098         check[0].attr = attr_diff;
1101 static void diff_filespec_check_attr(struct diff_filespec *one)
1103         struct git_attr_check attr_diff_check;
1104         int check_from_data = 0;
1106         if (one->checked_attr)
1107                 return;
1109         setup_diff_attr_check(&attr_diff_check);
1110         one->is_binary = 0;
1111         one->funcname_pattern_ident = NULL;
1113         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1114                 const char *value;
1116                 /* binaryness */
1117                 value = attr_diff_check.value;
1118                 if (ATTR_TRUE(value))
1119                         ;
1120                 else if (ATTR_FALSE(value))
1121                         one->is_binary = 1;
1122                 else
1123                         check_from_data = 1;
1125                 /* funcname pattern ident */
1126                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1127                         ;
1128                 else
1129                         one->funcname_pattern_ident = value;
1130         }
1132         if (check_from_data) {
1133                 if (!one->data && DIFF_FILE_VALID(one))
1134                         diff_populate_filespec(one, 0);
1136                 if (one->data)
1137                         one->is_binary = buffer_is_binary(one->data, one->size);
1138         }
1141 int diff_filespec_is_binary(struct diff_filespec *one)
1143         diff_filespec_check_attr(one);
1144         return one->is_binary;
1147 static const char *funcname_pattern(const char *ident)
1149         struct funcname_pattern *pp;
1151         read_config_if_needed();
1152         for (pp = funcname_pattern_list; pp; pp = pp->next)
1153                 if (!strcmp(ident, pp->name))
1154                         return pp->pattern;
1155         return NULL;
1158 static struct builtin_funcname_pattern {
1159         const char *name;
1160         const char *pattern;
1161 } builtin_funcname_pattern[] = {
1162         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1163                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1164                         "^[     ]*\\(\\([       ]*"
1165                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1166                         "[      ]*([^;]*$\\)" },
1167         { "tex", "^\\(\\\\\\(sub\\)*section{.*\\)$" },
1168 };
1170 static const char *diff_funcname_pattern(struct diff_filespec *one)
1172         const char *ident, *pattern;
1173         int i;
1175         diff_filespec_check_attr(one);
1176         ident = one->funcname_pattern_ident;
1178         if (!ident)
1179                 /*
1180                  * If the config file has "funcname.default" defined, that
1181                  * regexp is used; otherwise NULL is returned and xemit uses
1182                  * the built-in default.
1183                  */
1184                 return funcname_pattern("default");
1186         /* Look up custom "funcname.$ident" regexp from config. */
1187         pattern = funcname_pattern(ident);
1188         if (pattern)
1189                 return pattern;
1191         /*
1192          * And define built-in fallback patterns here.  Note that
1193          * these can be overriden by the user's config settings.
1194          */
1195         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1196                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1197                         return builtin_funcname_pattern[i].pattern;
1199         return NULL;
1202 static void builtin_diff(const char *name_a,
1203                          const char *name_b,
1204                          struct diff_filespec *one,
1205                          struct diff_filespec *two,
1206                          const char *xfrm_msg,
1207                          struct diff_options *o,
1208                          int complete_rewrite)
1210         mmfile_t mf1, mf2;
1211         const char *lbl[2];
1212         char *a_one, *b_two;
1213         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1214         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1216         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1217         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1218         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1219         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1220         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1221         if (lbl[0][0] == '/') {
1222                 /* /dev/null */
1223                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
1224                 if (xfrm_msg && xfrm_msg[0])
1225                         printf("%s%s%s\n", set, xfrm_msg, reset);
1226         }
1227         else if (lbl[1][0] == '/') {
1228                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
1229                 if (xfrm_msg && xfrm_msg[0])
1230                         printf("%s%s%s\n", set, xfrm_msg, reset);
1231         }
1232         else {
1233                 if (one->mode != two->mode) {
1234                         printf("%sold mode %06o%s\n", set, one->mode, reset);
1235                         printf("%snew mode %06o%s\n", set, two->mode, reset);
1236                 }
1237                 if (xfrm_msg && xfrm_msg[0])
1238                         printf("%s%s%s\n", set, xfrm_msg, reset);
1239                 /*
1240                  * we do not run diff between different kind
1241                  * of objects.
1242                  */
1243                 if ((one->mode ^ two->mode) & S_IFMT)
1244                         goto free_ab_and_return;
1245                 if (complete_rewrite) {
1246                         emit_rewrite_diff(name_a, name_b, one, two, o);
1247                         o->found_changes = 1;
1248                         goto free_ab_and_return;
1249                 }
1250         }
1252         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1253                 die("unable to read files to diff");
1255         if (!DIFF_OPT_TST(o, TEXT) &&
1256             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1257                 /* Quite common confusing case */
1258                 if (mf1.size == mf2.size &&
1259                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1260                         goto free_ab_and_return;
1261                 if (DIFF_OPT_TST(o, BINARY))
1262                         emit_binary_diff(&mf1, &mf2);
1263                 else
1264                         printf("Binary files %s and %s differ\n",
1265                                lbl[0], lbl[1]);
1266                 o->found_changes = 1;
1267         }
1268         else {
1269                 /* Crazy xdl interfaces.. */
1270                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1271                 xpparam_t xpp;
1272                 xdemitconf_t xecfg;
1273                 xdemitcb_t ecb;
1274                 struct emit_callback ecbdata;
1275                 const char *funcname_pattern;
1277                 funcname_pattern = diff_funcname_pattern(one);
1278                 if (!funcname_pattern)
1279                         funcname_pattern = diff_funcname_pattern(two);
1281                 memset(&xecfg, 0, sizeof(xecfg));
1282                 memset(&ecbdata, 0, sizeof(ecbdata));
1283                 ecbdata.label_path = lbl;
1284                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1285                 ecbdata.found_changesp = &o->found_changes;
1286                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1287                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1288                 xecfg.ctxlen = o->context;
1289                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1290                 if (funcname_pattern)
1291                         xdiff_set_find_func(&xecfg, funcname_pattern);
1292                 if (!diffopts)
1293                         ;
1294                 else if (!prefixcmp(diffopts, "--unified="))
1295                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1296                 else if (!prefixcmp(diffopts, "-u"))
1297                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1298                 ecb.outf = xdiff_outf;
1299                 ecb.priv = &ecbdata;
1300                 ecbdata.xm.consume = fn_out_consume;
1301                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1302                         ecbdata.diff_words =
1303                                 xcalloc(1, sizeof(struct diff_words_data));
1304                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1305                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1306                         free_diff_words_data(&ecbdata);
1307         }
1309  free_ab_and_return:
1310         diff_free_filespec_data(one);
1311         diff_free_filespec_data(two);
1312         free(a_one);
1313         free(b_two);
1314         return;
1317 static void builtin_diffstat(const char *name_a, const char *name_b,
1318                              struct diff_filespec *one,
1319                              struct diff_filespec *two,
1320                              struct diffstat_t *diffstat,
1321                              struct diff_options *o,
1322                              int complete_rewrite)
1324         mmfile_t mf1, mf2;
1325         struct diffstat_file *data;
1327         data = diffstat_add(diffstat, name_a, name_b);
1329         if (!one || !two) {
1330                 data->is_unmerged = 1;
1331                 return;
1332         }
1333         if (complete_rewrite) {
1334                 diff_populate_filespec(one, 0);
1335                 diff_populate_filespec(two, 0);
1336                 data->deleted = count_lines(one->data, one->size);
1337                 data->added = count_lines(two->data, two->size);
1338                 goto free_and_return;
1339         }
1340         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1341                 die("unable to read files to diff");
1343         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1344                 data->is_binary = 1;
1345                 data->added = mf2.size;
1346                 data->deleted = mf1.size;
1347         } else {
1348                 /* Crazy xdl interfaces.. */
1349                 xpparam_t xpp;
1350                 xdemitconf_t xecfg;
1351                 xdemitcb_t ecb;
1353                 memset(&xecfg, 0, sizeof(xecfg));
1354                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1355                 ecb.outf = xdiff_outf;
1356                 ecb.priv = diffstat;
1357                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1358         }
1360  free_and_return:
1361         diff_free_filespec_data(one);
1362         diff_free_filespec_data(two);
1365 static void builtin_checkdiff(const char *name_a, const char *name_b,
1366                              struct diff_filespec *one,
1367                              struct diff_filespec *two, struct diff_options *o)
1369         mmfile_t mf1, mf2;
1370         struct checkdiff_t data;
1372         if (!two)
1373                 return;
1375         memset(&data, 0, sizeof(data));
1376         data.xm.consume = checkdiff_consume;
1377         data.filename = name_b ? name_b : name_a;
1378         data.lineno = 0;
1379         data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1380         data.ws_rule = whitespace_rule(data.filename);
1382         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1383                 die("unable to read files to diff");
1385         if (diff_filespec_is_binary(two))
1386                 goto free_and_return;
1387         else {
1388                 /* Crazy xdl interfaces.. */
1389                 xpparam_t xpp;
1390                 xdemitconf_t xecfg;
1391                 xdemitcb_t ecb;
1393                 memset(&xecfg, 0, sizeof(xecfg));
1394                 xpp.flags = XDF_NEED_MINIMAL;
1395                 ecb.outf = xdiff_outf;
1396                 ecb.priv = &data;
1397                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1398         }
1399  free_and_return:
1400         diff_free_filespec_data(one);
1401         diff_free_filespec_data(two);
1402         if (data.status)
1403                 DIFF_OPT_SET(o, CHECK_FAILED);
1406 struct diff_filespec *alloc_filespec(const char *path)
1408         int namelen = strlen(path);
1409         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1411         memset(spec, 0, sizeof(*spec));
1412         spec->path = (char *)(spec + 1);
1413         memcpy(spec->path, path, namelen+1);
1414         spec->count = 1;
1415         return spec;
1418 void free_filespec(struct diff_filespec *spec)
1420         if (!--spec->count) {
1421                 diff_free_filespec_data(spec);
1422                 free(spec);
1423         }
1426 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1427                    unsigned short mode)
1429         if (mode) {
1430                 spec->mode = canon_mode(mode);
1431                 hashcpy(spec->sha1, sha1);
1432                 spec->sha1_valid = !is_null_sha1(sha1);
1433         }
1436 /*
1437  * Given a name and sha1 pair, if the index tells us the file in
1438  * the work tree has that object contents, return true, so that
1439  * prepare_temp_file() does not have to inflate and extract.
1440  */
1441 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1443         struct cache_entry *ce;
1444         struct stat st;
1445         int pos, len;
1447         /* We do not read the cache ourselves here, because the
1448          * benchmark with my previous version that always reads cache
1449          * shows that it makes things worse for diff-tree comparing
1450          * two linux-2.6 kernel trees in an already checked out work
1451          * tree.  This is because most diff-tree comparisons deal with
1452          * only a small number of files, while reading the cache is
1453          * expensive for a large project, and its cost outweighs the
1454          * savings we get by not inflating the object to a temporary
1455          * file.  Practically, this code only helps when we are used
1456          * by diff-cache --cached, which does read the cache before
1457          * calling us.
1458          */
1459         if (!active_cache)
1460                 return 0;
1462         /* We want to avoid the working directory if our caller
1463          * doesn't need the data in a normal file, this system
1464          * is rather slow with its stat/open/mmap/close syscalls,
1465          * and the object is contained in a pack file.  The pack
1466          * is probably already open and will be faster to obtain
1467          * the data through than the working directory.  Loose
1468          * objects however would tend to be slower as they need
1469          * to be individually opened and inflated.
1470          */
1471         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1472                 return 0;
1474         len = strlen(name);
1475         pos = cache_name_pos(name, len);
1476         if (pos < 0)
1477                 return 0;
1478         ce = active_cache[pos];
1479         if ((lstat(name, &st) < 0) ||
1480             !S_ISREG(st.st_mode) || /* careful! */
1481             ce_match_stat(ce, &st, 0) ||
1482             hashcmp(sha1, ce->sha1))
1483                 return 0;
1484         /* we return 1 only when we can stat, it is a regular file,
1485          * stat information matches, and sha1 recorded in the cache
1486          * matches.  I.e. we know the file in the work tree really is
1487          * the same as the <name, sha1> pair.
1488          */
1489         return 1;
1492 static int populate_from_stdin(struct diff_filespec *s)
1494         struct strbuf buf;
1495         size_t size = 0;
1497         strbuf_init(&buf, 0);
1498         if (strbuf_read(&buf, 0, 0) < 0)
1499                 return error("error while reading from stdin %s",
1500                                      strerror(errno));
1502         s->should_munmap = 0;
1503         s->data = strbuf_detach(&buf, &size);
1504         s->size = size;
1505         s->should_free = 1;
1506         return 0;
1509 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1511         int len;
1512         char *data = xmalloc(100);
1513         len = snprintf(data, 100,
1514                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1515         s->data = data;
1516         s->size = len;
1517         s->should_free = 1;
1518         if (size_only) {
1519                 s->data = NULL;
1520                 free(data);
1521         }
1522         return 0;
1525 /*
1526  * While doing rename detection and pickaxe operation, we may need to
1527  * grab the data for the blob (or file) for our own in-core comparison.
1528  * diff_filespec has data and size fields for this purpose.
1529  */
1530 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1532         int err = 0;
1533         if (!DIFF_FILE_VALID(s))
1534                 die("internal error: asking to populate invalid file.");
1535         if (S_ISDIR(s->mode))
1536                 return -1;
1538         if (s->data)
1539                 return 0;
1541         if (size_only && 0 < s->size)
1542                 return 0;
1544         if (S_ISGITLINK(s->mode))
1545                 return diff_populate_gitlink(s, size_only);
1547         if (!s->sha1_valid ||
1548             reuse_worktree_file(s->path, s->sha1, 0)) {
1549                 struct strbuf buf;
1550                 struct stat st;
1551                 int fd;
1553                 if (!strcmp(s->path, "-"))
1554                         return populate_from_stdin(s);
1556                 if (lstat(s->path, &st) < 0) {
1557                         if (errno == ENOENT) {
1558                         err_empty:
1559                                 err = -1;
1560                         empty:
1561                                 s->data = (char *)"";
1562                                 s->size = 0;
1563                                 return err;
1564                         }
1565                 }
1566                 s->size = xsize_t(st.st_size);
1567                 if (!s->size)
1568                         goto empty;
1569                 if (size_only)
1570                         return 0;
1571                 if (S_ISLNK(st.st_mode)) {
1572                         int ret;
1573                         s->data = xmalloc(s->size);
1574                         s->should_free = 1;
1575                         ret = readlink(s->path, s->data, s->size);
1576                         if (ret < 0) {
1577                                 free(s->data);
1578                                 goto err_empty;
1579                         }
1580                         return 0;
1581                 }
1582                 fd = open(s->path, O_RDONLY);
1583                 if (fd < 0)
1584                         goto err_empty;
1585                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1586                 close(fd);
1587                 s->should_munmap = 1;
1589                 /*
1590                  * Convert from working tree format to canonical git format
1591                  */
1592                 strbuf_init(&buf, 0);
1593                 if (convert_to_git(s->path, s->data, s->size, &buf)) {
1594                         size_t size = 0;
1595                         munmap(s->data, s->size);
1596                         s->should_munmap = 0;
1597                         s->data = strbuf_detach(&buf, &size);
1598                         s->size = size;
1599                         s->should_free = 1;
1600                 }
1601         }
1602         else {
1603                 enum object_type type;
1604                 if (size_only)
1605                         type = sha1_object_info(s->sha1, &s->size);
1606                 else {
1607                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1608                         s->should_free = 1;
1609                 }
1610         }
1611         return 0;
1614 void diff_free_filespec_blob(struct diff_filespec *s)
1616         if (s->should_free)
1617                 free(s->data);
1618         else if (s->should_munmap)
1619                 munmap(s->data, s->size);
1621         if (s->should_free || s->should_munmap) {
1622                 s->should_free = s->should_munmap = 0;
1623                 s->data = NULL;
1624         }
1627 void diff_free_filespec_data(struct diff_filespec *s)
1629         diff_free_filespec_blob(s);
1630         free(s->cnt_data);
1631         s->cnt_data = NULL;
1634 static void prep_temp_blob(struct diff_tempfile *temp,
1635                            void *blob,
1636                            unsigned long size,
1637                            const unsigned char *sha1,
1638                            int mode)
1640         int fd;
1642         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1643         if (fd < 0)
1644                 die("unable to create temp-file: %s", strerror(errno));
1645         if (write_in_full(fd, blob, size) != size)
1646                 die("unable to write temp-file");
1647         close(fd);
1648         temp->name = temp->tmp_path;
1649         strcpy(temp->hex, sha1_to_hex(sha1));
1650         temp->hex[40] = 0;
1651         sprintf(temp->mode, "%06o", mode);
1654 static void prepare_temp_file(const char *name,
1655                               struct diff_tempfile *temp,
1656                               struct diff_filespec *one)
1658         if (!DIFF_FILE_VALID(one)) {
1659         not_a_valid_file:
1660                 /* A '-' entry produces this for file-2, and
1661                  * a '+' entry produces this for file-1.
1662                  */
1663                 temp->name = "/dev/null";
1664                 strcpy(temp->hex, ".");
1665                 strcpy(temp->mode, ".");
1666                 return;
1667         }
1669         if (!one->sha1_valid ||
1670             reuse_worktree_file(name, one->sha1, 1)) {
1671                 struct stat st;
1672                 if (lstat(name, &st) < 0) {
1673                         if (errno == ENOENT)
1674                                 goto not_a_valid_file;
1675                         die("stat(%s): %s", name, strerror(errno));
1676                 }
1677                 if (S_ISLNK(st.st_mode)) {
1678                         int ret;
1679                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1680                         size_t sz = xsize_t(st.st_size);
1681                         if (sizeof(buf) <= st.st_size)
1682                                 die("symlink too long: %s", name);
1683                         ret = readlink(name, buf, sz);
1684                         if (ret < 0)
1685                                 die("readlink(%s)", name);
1686                         prep_temp_blob(temp, buf, sz,
1687                                        (one->sha1_valid ?
1688                                         one->sha1 : null_sha1),
1689                                        (one->sha1_valid ?
1690                                         one->mode : S_IFLNK));
1691                 }
1692                 else {
1693                         /* we can borrow from the file in the work tree */
1694                         temp->name = name;
1695                         if (!one->sha1_valid)
1696                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1697                         else
1698                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1699                         /* Even though we may sometimes borrow the
1700                          * contents from the work tree, we always want
1701                          * one->mode.  mode is trustworthy even when
1702                          * !(one->sha1_valid), as long as
1703                          * DIFF_FILE_VALID(one).
1704                          */
1705                         sprintf(temp->mode, "%06o", one->mode);
1706                 }
1707                 return;
1708         }
1709         else {
1710                 if (diff_populate_filespec(one, 0))
1711                         die("cannot read data blob for %s", one->path);
1712                 prep_temp_blob(temp, one->data, one->size,
1713                                one->sha1, one->mode);
1714         }
1717 static void remove_tempfile(void)
1719         int i;
1721         for (i = 0; i < 2; i++)
1722                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1723                         unlink(diff_temp[i].name);
1724                         diff_temp[i].name = NULL;
1725                 }
1728 static void remove_tempfile_on_signal(int signo)
1730         remove_tempfile();
1731         signal(SIGINT, SIG_DFL);
1732         raise(signo);
1735 /* An external diff command takes:
1736  *
1737  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1738  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1739  *
1740  */
1741 static void run_external_diff(const char *pgm,
1742                               const char *name,
1743                               const char *other,
1744                               struct diff_filespec *one,
1745                               struct diff_filespec *two,
1746                               const char *xfrm_msg,
1747                               int complete_rewrite)
1749         const char *spawn_arg[10];
1750         struct diff_tempfile *temp = diff_temp;
1751         int retval;
1752         static int atexit_asked = 0;
1753         const char *othername;
1754         const char **arg = &spawn_arg[0];
1756         othername = (other? other : name);
1757         if (one && two) {
1758                 prepare_temp_file(name, &temp[0], one);
1759                 prepare_temp_file(othername, &temp[1], two);
1760                 if (! atexit_asked &&
1761                     (temp[0].name == temp[0].tmp_path ||
1762                      temp[1].name == temp[1].tmp_path)) {
1763                         atexit_asked = 1;
1764                         atexit(remove_tempfile);
1765                 }
1766                 signal(SIGINT, remove_tempfile_on_signal);
1767         }
1769         if (one && two) {
1770                 *arg++ = pgm;
1771                 *arg++ = name;
1772                 *arg++ = temp[0].name;
1773                 *arg++ = temp[0].hex;
1774                 *arg++ = temp[0].mode;
1775                 *arg++ = temp[1].name;
1776                 *arg++ = temp[1].hex;
1777                 *arg++ = temp[1].mode;
1778                 if (other) {
1779                         *arg++ = other;
1780                         *arg++ = xfrm_msg;
1781                 }
1782         } else {
1783                 *arg++ = pgm;
1784                 *arg++ = name;
1785         }
1786         *arg = NULL;
1787         fflush(NULL);
1788         retval = run_command_v_opt(spawn_arg, 0);
1789         remove_tempfile();
1790         if (retval) {
1791                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1792                 exit(1);
1793         }
1796 static const char *external_diff_attr(const char *name)
1798         struct git_attr_check attr_diff_check;
1800         setup_diff_attr_check(&attr_diff_check);
1801         if (!git_checkattr(name, 1, &attr_diff_check)) {
1802                 const char *value = attr_diff_check.value;
1803                 if (!ATTR_TRUE(value) &&
1804                     !ATTR_FALSE(value) &&
1805                     !ATTR_UNSET(value)) {
1806                         struct ll_diff_driver *drv;
1808                         read_config_if_needed();
1809                         for (drv = user_diff; drv; drv = drv->next)
1810                                 if (!strcmp(drv->name, value))
1811                                         return drv->cmd;
1812                 }
1813         }
1814         return NULL;
1817 static void run_diff_cmd(const char *pgm,
1818                          const char *name,
1819                          const char *other,
1820                          struct diff_filespec *one,
1821                          struct diff_filespec *two,
1822                          const char *xfrm_msg,
1823                          struct diff_options *o,
1824                          int complete_rewrite)
1826         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
1827                 pgm = NULL;
1828         else {
1829                 const char *cmd = external_diff_attr(name);
1830                 if (cmd)
1831                         pgm = cmd;
1832         }
1834         if (pgm) {
1835                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1836                                   complete_rewrite);
1837                 return;
1838         }
1839         if (one && two)
1840                 builtin_diff(name, other ? other : name,
1841                              one, two, xfrm_msg, o, complete_rewrite);
1842         else
1843                 printf("* Unmerged path %s\n", name);
1846 static void diff_fill_sha1_info(struct diff_filespec *one)
1848         if (DIFF_FILE_VALID(one)) {
1849                 if (!one->sha1_valid) {
1850                         struct stat st;
1851                         if (!strcmp(one->path, "-")) {
1852                                 hashcpy(one->sha1, null_sha1);
1853                                 return;
1854                         }
1855                         if (lstat(one->path, &st) < 0)
1856                                 die("stat %s", one->path);
1857                         if (index_path(one->sha1, one->path, &st, 0))
1858                                 die("cannot hash %s\n", one->path);
1859                 }
1860         }
1861         else
1862                 hashclr(one->sha1);
1865 static int similarity_index(struct diff_filepair *p)
1867         return p->score * 100 / MAX_SCORE;
1870 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1872         const char *pgm = external_diff();
1873         struct strbuf msg;
1874         char *xfrm_msg;
1875         struct diff_filespec *one = p->one;
1876         struct diff_filespec *two = p->two;
1877         const char *name;
1878         const char *other;
1879         int complete_rewrite = 0;
1882         if (DIFF_PAIR_UNMERGED(p)) {
1883                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1884                 return;
1885         }
1887         name  = p->one->path;
1888         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1889         diff_fill_sha1_info(one);
1890         diff_fill_sha1_info(two);
1892         strbuf_init(&msg, PATH_MAX * 2 + 300);
1893         switch (p->status) {
1894         case DIFF_STATUS_COPIED:
1895                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
1896                 strbuf_addstr(&msg, "\ncopy from ");
1897                 quote_c_style(name, &msg, NULL, 0);
1898                 strbuf_addstr(&msg, "\ncopy to ");
1899                 quote_c_style(other, &msg, NULL, 0);
1900                 strbuf_addch(&msg, '\n');
1901                 break;
1902         case DIFF_STATUS_RENAMED:
1903                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
1904                 strbuf_addstr(&msg, "\nrename from ");
1905                 quote_c_style(name, &msg, NULL, 0);
1906                 strbuf_addstr(&msg, "\nrename to ");
1907                 quote_c_style(other, &msg, NULL, 0);
1908                 strbuf_addch(&msg, '\n');
1909                 break;
1910         case DIFF_STATUS_MODIFIED:
1911                 if (p->score) {
1912                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
1913                                         similarity_index(p));
1914                         complete_rewrite = 1;
1915                         break;
1916                 }
1917                 /* fallthru */
1918         default:
1919                 /* nothing */
1920                 ;
1921         }
1923         if (hashcmp(one->sha1, two->sha1)) {
1924                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
1926                 if (DIFF_OPT_TST(o, BINARY)) {
1927                         mmfile_t mf;
1928                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
1929                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
1930                                 abbrev = 40;
1931                 }
1932                 strbuf_addf(&msg, "index %.*s..%.*s",
1933                                 abbrev, sha1_to_hex(one->sha1),
1934                                 abbrev, sha1_to_hex(two->sha1));
1935                 if (one->mode == two->mode)
1936                         strbuf_addf(&msg, " %06o", one->mode);
1937                 strbuf_addch(&msg, '\n');
1938         }
1940         if (msg.len)
1941                 strbuf_setlen(&msg, msg.len - 1);
1942         xfrm_msg = msg.len ? msg.buf : NULL;
1944         if (!pgm &&
1945             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1946             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1947                 /* a filepair that changes between file and symlink
1948                  * needs to be split into deletion and creation.
1949                  */
1950                 struct diff_filespec *null = alloc_filespec(two->path);
1951                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1952                 free(null);
1953                 null = alloc_filespec(one->path);
1954                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1955                 free(null);
1956         }
1957         else
1958                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1959                              complete_rewrite);
1961         strbuf_release(&msg);
1964 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1965                          struct diffstat_t *diffstat)
1967         const char *name;
1968         const char *other;
1969         int complete_rewrite = 0;
1971         if (DIFF_PAIR_UNMERGED(p)) {
1972                 /* unmerged */
1973                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1974                 return;
1975         }
1977         name = p->one->path;
1978         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1980         diff_fill_sha1_info(p->one);
1981         diff_fill_sha1_info(p->two);
1983         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1984                 complete_rewrite = 1;
1985         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1988 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1990         const char *name;
1991         const char *other;
1993         if (DIFF_PAIR_UNMERGED(p)) {
1994                 /* unmerged */
1995                 return;
1996         }
1998         name = p->one->path;
1999         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2001         diff_fill_sha1_info(p->one);
2002         diff_fill_sha1_info(p->two);
2004         builtin_checkdiff(name, other, p->one, p->two, o);
2007 void diff_setup(struct diff_options *options)
2009         memset(options, 0, sizeof(*options));
2010         options->line_termination = '\n';
2011         options->break_opt = -1;
2012         options->rename_limit = -1;
2013         options->context = 3;
2014         options->msg_sep = "";
2016         options->change = diff_change;
2017         options->add_remove = diff_addremove;
2018         if (diff_use_color_default)
2019                 DIFF_OPT_SET(options, COLOR_DIFF);
2020         else
2021                 DIFF_OPT_CLR(options, COLOR_DIFF);
2022         options->detect_rename = diff_detect_rename_default;
2024         options->a_prefix = "a/";
2025         options->b_prefix = "b/";
2028 int diff_setup_done(struct diff_options *options)
2030         int count = 0;
2032         if (options->output_format & DIFF_FORMAT_NAME)
2033                 count++;
2034         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2035                 count++;
2036         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2037                 count++;
2038         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2039                 count++;
2040         if (count > 1)
2041                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2043         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2044                 options->detect_rename = DIFF_DETECT_COPY;
2046         if (options->output_format & (DIFF_FORMAT_NAME |
2047                                       DIFF_FORMAT_NAME_STATUS |
2048                                       DIFF_FORMAT_CHECKDIFF |
2049                                       DIFF_FORMAT_NO_OUTPUT))
2050                 options->output_format &= ~(DIFF_FORMAT_RAW |
2051                                             DIFF_FORMAT_NUMSTAT |
2052                                             DIFF_FORMAT_DIFFSTAT |
2053                                             DIFF_FORMAT_SHORTSTAT |
2054                                             DIFF_FORMAT_SUMMARY |
2055                                             DIFF_FORMAT_PATCH);
2057         /*
2058          * These cases always need recursive; we do not drop caller-supplied
2059          * recursive bits for other formats here.
2060          */
2061         if (options->output_format & (DIFF_FORMAT_PATCH |
2062                                       DIFF_FORMAT_NUMSTAT |
2063                                       DIFF_FORMAT_DIFFSTAT |
2064                                       DIFF_FORMAT_SHORTSTAT |
2065                                       DIFF_FORMAT_SUMMARY |
2066                                       DIFF_FORMAT_CHECKDIFF))
2067                 DIFF_OPT_SET(options, RECURSIVE);
2068         /*
2069          * Also pickaxe would not work very well if you do not say recursive
2070          */
2071         if (options->pickaxe)
2072                 DIFF_OPT_SET(options, RECURSIVE);
2074         if (options->detect_rename && options->rename_limit < 0)
2075                 options->rename_limit = diff_rename_limit_default;
2076         if (options->setup & DIFF_SETUP_USE_CACHE) {
2077                 if (!active_cache)
2078                         /* read-cache does not die even when it fails
2079                          * so it is safe for us to do this here.  Also
2080                          * it does not smudge active_cache or active_nr
2081                          * when it fails, so we do not have to worry about
2082                          * cleaning it up ourselves either.
2083                          */
2084                         read_cache();
2085         }
2086         if (options->abbrev <= 0 || 40 < options->abbrev)
2087                 options->abbrev = 40; /* full */
2089         /*
2090          * It does not make sense to show the first hit we happened
2091          * to have found.  It does not make sense not to return with
2092          * exit code in such a case either.
2093          */
2094         if (DIFF_OPT_TST(options, QUIET)) {
2095                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2096                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2097         }
2099         /*
2100          * If we postprocess in diffcore, we cannot simply return
2101          * upon the first hit.  We need to run diff as usual.
2102          */
2103         if (options->pickaxe || options->filter)
2104                 DIFF_OPT_CLR(options, QUIET);
2106         return 0;
2109 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2111         char c, *eq;
2112         int len;
2114         if (*arg != '-')
2115                 return 0;
2116         c = *++arg;
2117         if (!c)
2118                 return 0;
2119         if (c == arg_short) {
2120                 c = *++arg;
2121                 if (!c)
2122                         return 1;
2123                 if (val && isdigit(c)) {
2124                         char *end;
2125                         int n = strtoul(arg, &end, 10);
2126                         if (*end)
2127                                 return 0;
2128                         *val = n;
2129                         return 1;
2130                 }
2131                 return 0;
2132         }
2133         if (c != '-')
2134                 return 0;
2135         arg++;
2136         eq = strchr(arg, '=');
2137         if (eq)
2138                 len = eq - arg;
2139         else
2140                 len = strlen(arg);
2141         if (!len || strncmp(arg, arg_long, len))
2142                 return 0;
2143         if (eq) {
2144                 int n;
2145                 char *end;
2146                 if (!isdigit(*++eq))
2147                         return 0;
2148                 n = strtoul(eq, &end, 10);
2149                 if (*end)
2150                         return 0;
2151                 *val = n;
2152         }
2153         return 1;
2156 static int diff_scoreopt_parse(const char *opt);
2158 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2160         const char *arg = av[0];
2162         /* Output format options */
2163         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2164                 options->output_format |= DIFF_FORMAT_PATCH;
2165         else if (opt_arg(arg, 'U', "unified", &options->context))
2166                 options->output_format |= DIFF_FORMAT_PATCH;
2167         else if (!strcmp(arg, "--raw"))
2168                 options->output_format |= DIFF_FORMAT_RAW;
2169         else if (!strcmp(arg, "--patch-with-raw"))
2170                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2171         else if (!strcmp(arg, "--numstat"))
2172                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2173         else if (!strcmp(arg, "--shortstat"))
2174                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2175         else if (!strcmp(arg, "--check"))
2176                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2177         else if (!strcmp(arg, "--summary"))
2178                 options->output_format |= DIFF_FORMAT_SUMMARY;
2179         else if (!strcmp(arg, "--patch-with-stat"))
2180                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2181         else if (!strcmp(arg, "--name-only"))
2182                 options->output_format |= DIFF_FORMAT_NAME;
2183         else if (!strcmp(arg, "--name-status"))
2184                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2185         else if (!strcmp(arg, "-s"))
2186                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2187         else if (!prefixcmp(arg, "--stat")) {
2188                 char *end;
2189                 int width = options->stat_width;
2190                 int name_width = options->stat_name_width;
2191                 arg += 6;
2192                 end = (char *)arg;
2194                 switch (*arg) {
2195                 case '-':
2196                         if (!prefixcmp(arg, "-width="))
2197                                 width = strtoul(arg + 7, &end, 10);
2198                         else if (!prefixcmp(arg, "-name-width="))
2199                                 name_width = strtoul(arg + 12, &end, 10);
2200                         break;
2201                 case '=':
2202                         width = strtoul(arg+1, &end, 10);
2203                         if (*end == ',')
2204                                 name_width = strtoul(end+1, &end, 10);
2205                 }
2207                 /* Important! This checks all the error cases! */
2208                 if (*end)
2209                         return 0;
2210                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2211                 options->stat_name_width = name_width;
2212                 options->stat_width = width;
2213         }
2215         /* renames options */
2216         else if (!prefixcmp(arg, "-B")) {
2217                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2218                         return -1;
2219         }
2220         else if (!prefixcmp(arg, "-M")) {
2221                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2222                         return -1;
2223                 options->detect_rename = DIFF_DETECT_RENAME;
2224         }
2225         else if (!prefixcmp(arg, "-C")) {
2226                 if (options->detect_rename == DIFF_DETECT_COPY)
2227                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2228                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2229                         return -1;
2230                 options->detect_rename = DIFF_DETECT_COPY;
2231         }
2232         else if (!strcmp(arg, "--no-renames"))
2233                 options->detect_rename = 0;
2235         /* xdiff options */
2236         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2237                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2238         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2239                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2240         else if (!strcmp(arg, "--ignore-space-at-eol"))
2241                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2243         /* flags options */
2244         else if (!strcmp(arg, "--binary")) {
2245                 options->output_format |= DIFF_FORMAT_PATCH;
2246                 DIFF_OPT_SET(options, BINARY);
2247         }
2248         else if (!strcmp(arg, "--full-index"))
2249                 DIFF_OPT_SET(options, FULL_INDEX);
2250         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2251                 DIFF_OPT_SET(options, TEXT);
2252         else if (!strcmp(arg, "-R"))
2253                 DIFF_OPT_SET(options, REVERSE_DIFF);
2254         else if (!strcmp(arg, "--find-copies-harder"))
2255                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2256         else if (!strcmp(arg, "--follow"))
2257                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2258         else if (!strcmp(arg, "--color"))
2259                 DIFF_OPT_SET(options, COLOR_DIFF);
2260         else if (!strcmp(arg, "--no-color"))
2261                 DIFF_OPT_CLR(options, COLOR_DIFF);
2262         else if (!strcmp(arg, "--color-words"))
2263                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2264         else if (!strcmp(arg, "--exit-code"))
2265                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2266         else if (!strcmp(arg, "--quiet"))
2267                 DIFF_OPT_SET(options, QUIET);
2268         else if (!strcmp(arg, "--ext-diff"))
2269                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2270         else if (!strcmp(arg, "--no-ext-diff"))
2271                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2273         /* misc options */
2274         else if (!strcmp(arg, "-z"))
2275                 options->line_termination = 0;
2276         else if (!prefixcmp(arg, "-l"))
2277                 options->rename_limit = strtoul(arg+2, NULL, 10);
2278         else if (!prefixcmp(arg, "-S"))
2279                 options->pickaxe = arg + 2;
2280         else if (!strcmp(arg, "--pickaxe-all"))
2281                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2282         else if (!strcmp(arg, "--pickaxe-regex"))
2283                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2284         else if (!prefixcmp(arg, "-O"))
2285                 options->orderfile = arg + 2;
2286         else if (!prefixcmp(arg, "--diff-filter="))
2287                 options->filter = arg + 14;
2288         else if (!strcmp(arg, "--abbrev"))
2289                 options->abbrev = DEFAULT_ABBREV;
2290         else if (!prefixcmp(arg, "--abbrev=")) {
2291                 options->abbrev = strtoul(arg + 9, NULL, 10);
2292                 if (options->abbrev < MINIMUM_ABBREV)
2293                         options->abbrev = MINIMUM_ABBREV;
2294                 else if (40 < options->abbrev)
2295                         options->abbrev = 40;
2296         }
2297         else if (!prefixcmp(arg, "--src-prefix="))
2298                 options->a_prefix = arg + 13;
2299         else if (!prefixcmp(arg, "--dst-prefix="))
2300                 options->b_prefix = arg + 13;
2301         else if (!strcmp(arg, "--no-prefix"))
2302                 options->a_prefix = options->b_prefix = "";
2303         else
2304                 return 0;
2305         return 1;
2308 static int parse_num(const char **cp_p)
2310         unsigned long num, scale;
2311         int ch, dot;
2312         const char *cp = *cp_p;
2314         num = 0;
2315         scale = 1;
2316         dot = 0;
2317         for(;;) {
2318                 ch = *cp;
2319                 if ( !dot && ch == '.' ) {
2320                         scale = 1;
2321                         dot = 1;
2322                 } else if ( ch == '%' ) {
2323                         scale = dot ? scale*100 : 100;
2324                         cp++;   /* % is always at the end */
2325                         break;
2326                 } else if ( ch >= '0' && ch <= '9' ) {
2327                         if ( scale < 100000 ) {
2328                                 scale *= 10;
2329                                 num = (num*10) + (ch-'0');
2330                         }
2331                 } else {
2332                         break;
2333                 }
2334                 cp++;
2335         }
2336         *cp_p = cp;
2338         /* user says num divided by scale and we say internally that
2339          * is MAX_SCORE * num / scale.
2340          */
2341         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2344 static int diff_scoreopt_parse(const char *opt)
2346         int opt1, opt2, cmd;
2348         if (*opt++ != '-')
2349                 return -1;
2350         cmd = *opt++;
2351         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2352                 return -1; /* that is not a -M, -C nor -B option */
2354         opt1 = parse_num(&opt);
2355         if (cmd != 'B')
2356                 opt2 = 0;
2357         else {
2358                 if (*opt == 0)
2359                         opt2 = 0;
2360                 else if (*opt != '/')
2361                         return -1; /* we expect -B80/99 or -B80 */
2362                 else {
2363                         opt++;
2364                         opt2 = parse_num(&opt);
2365                 }
2366         }
2367         if (*opt != 0)
2368                 return -1;
2369         return opt1 | (opt2 << 16);
2372 struct diff_queue_struct diff_queued_diff;
2374 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2376         if (queue->alloc <= queue->nr) {
2377                 queue->alloc = alloc_nr(queue->alloc);
2378                 queue->queue = xrealloc(queue->queue,
2379                                         sizeof(dp) * queue->alloc);
2380         }
2381         queue->queue[queue->nr++] = dp;
2384 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2385                                  struct diff_filespec *one,
2386                                  struct diff_filespec *two)
2388         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2389         dp->one = one;
2390         dp->two = two;
2391         if (queue)
2392                 diff_q(queue, dp);
2393         return dp;
2396 void diff_free_filepair(struct diff_filepair *p)
2398         free_filespec(p->one);
2399         free_filespec(p->two);
2400         free(p);
2403 /* This is different from find_unique_abbrev() in that
2404  * it stuffs the result with dots for alignment.
2405  */
2406 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2408         int abblen;
2409         const char *abbrev;
2410         if (len == 40)
2411                 return sha1_to_hex(sha1);
2413         abbrev = find_unique_abbrev(sha1, len);
2414         if (!abbrev)
2415                 return sha1_to_hex(sha1);
2416         abblen = strlen(abbrev);
2417         if (abblen < 37) {
2418                 static char hex[41];
2419                 if (len < abblen && abblen <= len + 2)
2420                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2421                 else
2422                         sprintf(hex, "%s...", abbrev);
2423                 return hex;
2424         }
2425         return sha1_to_hex(sha1);
2428 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2430         int line_termination = opt->line_termination;
2431         int inter_name_termination = line_termination ? '\t' : '\0';
2433         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2434                 printf(":%06o %06o %s ", p->one->mode, p->two->mode,
2435                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2436                 printf("%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2437         }
2438         if (p->score) {
2439                 printf("%c%03d%c", p->status, similarity_index(p),
2440                            inter_name_termination);
2441         } else {
2442                 printf("%c%c", p->status, inter_name_termination);
2443         }
2445         if (p->status == DIFF_STATUS_COPIED || p->status == DIFF_STATUS_RENAMED) {
2446                 write_name_quoted(p->one->path, stdout, inter_name_termination);
2447                 write_name_quoted(p->two->path, stdout, line_termination);
2448         } else {
2449                 const char *path = p->one->mode ? p->one->path : p->two->path;
2450                 write_name_quoted(path, stdout, line_termination);
2451         }
2454 int diff_unmodified_pair(struct diff_filepair *p)
2456         /* This function is written stricter than necessary to support
2457          * the currently implemented transformers, but the idea is to
2458          * let transformers to produce diff_filepairs any way they want,
2459          * and filter and clean them up here before producing the output.
2460          */
2461         struct diff_filespec *one = p->one, *two = p->two;
2463         if (DIFF_PAIR_UNMERGED(p))
2464                 return 0; /* unmerged is interesting */
2466         /* deletion, addition, mode or type change
2467          * and rename are all interesting.
2468          */
2469         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2470             DIFF_PAIR_MODE_CHANGED(p) ||
2471             strcmp(one->path, two->path))
2472                 return 0;
2474         /* both are valid and point at the same path.  that is, we are
2475          * dealing with a change.
2476          */
2477         if (one->sha1_valid && two->sha1_valid &&
2478             !hashcmp(one->sha1, two->sha1))
2479                 return 1; /* no change */
2480         if (!one->sha1_valid && !two->sha1_valid)
2481                 return 1; /* both look at the same file on the filesystem. */
2482         return 0;
2485 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2487         if (diff_unmodified_pair(p))
2488                 return;
2490         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2491             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2492                 return; /* no tree diffs in patch format */
2494         run_diff(p, o);
2497 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2498                             struct diffstat_t *diffstat)
2500         if (diff_unmodified_pair(p))
2501                 return;
2503         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2504             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2505                 return; /* no tree diffs in patch format */
2507         run_diffstat(p, o, diffstat);
2510 static void diff_flush_checkdiff(struct diff_filepair *p,
2511                 struct diff_options *o)
2513         if (diff_unmodified_pair(p))
2514                 return;
2516         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2517             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2518                 return; /* no tree diffs in patch format */
2520         run_checkdiff(p, o);
2523 int diff_queue_is_empty(void)
2525         struct diff_queue_struct *q = &diff_queued_diff;
2526         int i;
2527         for (i = 0; i < q->nr; i++)
2528                 if (!diff_unmodified_pair(q->queue[i]))
2529                         return 0;
2530         return 1;
2533 #if DIFF_DEBUG
2534 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2536         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2537                 x, one ? one : "",
2538                 s->path,
2539                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2540                 s->mode,
2541                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2542         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2543                 x, one ? one : "",
2544                 s->size, s->xfrm_flags);
2547 void diff_debug_filepair(const struct diff_filepair *p, int i)
2549         diff_debug_filespec(p->one, i, "one");
2550         diff_debug_filespec(p->two, i, "two");
2551         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2552                 p->score, p->status ? p->status : '?',
2553                 p->one->rename_used, p->broken_pair);
2556 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2558         int i;
2559         if (msg)
2560                 fprintf(stderr, "%s\n", msg);
2561         fprintf(stderr, "q->nr = %d\n", q->nr);
2562         for (i = 0; i < q->nr; i++) {
2563                 struct diff_filepair *p = q->queue[i];
2564                 diff_debug_filepair(p, i);
2565         }
2567 #endif
2569 static void diff_resolve_rename_copy(void)
2571         int i;
2572         struct diff_filepair *p;
2573         struct diff_queue_struct *q = &diff_queued_diff;
2575         diff_debug_queue("resolve-rename-copy", q);
2577         for (i = 0; i < q->nr; i++) {
2578                 p = q->queue[i];
2579                 p->status = 0; /* undecided */
2580                 if (DIFF_PAIR_UNMERGED(p))
2581                         p->status = DIFF_STATUS_UNMERGED;
2582                 else if (!DIFF_FILE_VALID(p->one))
2583                         p->status = DIFF_STATUS_ADDED;
2584                 else if (!DIFF_FILE_VALID(p->two))
2585                         p->status = DIFF_STATUS_DELETED;
2586                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2587                         p->status = DIFF_STATUS_TYPE_CHANGED;
2589                 /* from this point on, we are dealing with a pair
2590                  * whose both sides are valid and of the same type, i.e.
2591                  * either in-place edit or rename/copy edit.
2592                  */
2593                 else if (DIFF_PAIR_RENAME(p)) {
2594                         /*
2595                          * A rename might have re-connected a broken
2596                          * pair up, causing the pathnames to be the
2597                          * same again. If so, that's not a rename at
2598                          * all, just a modification..
2599                          *
2600                          * Otherwise, see if this source was used for
2601                          * multiple renames, in which case we decrement
2602                          * the count, and call it a copy.
2603                          */
2604                         if (!strcmp(p->one->path, p->two->path))
2605                                 p->status = DIFF_STATUS_MODIFIED;
2606                         else if (--p->one->rename_used > 0)
2607                                 p->status = DIFF_STATUS_COPIED;
2608                         else
2609                                 p->status = DIFF_STATUS_RENAMED;
2610                 }
2611                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2612                          p->one->mode != p->two->mode ||
2613                          is_null_sha1(p->one->sha1))
2614                         p->status = DIFF_STATUS_MODIFIED;
2615                 else {
2616                         /* This is a "no-change" entry and should not
2617                          * happen anymore, but prepare for broken callers.
2618                          */
2619                         error("feeding unmodified %s to diffcore",
2620                               p->one->path);
2621                         p->status = DIFF_STATUS_UNKNOWN;
2622                 }
2623         }
2624         diff_debug_queue("resolve-rename-copy done", q);
2627 static int check_pair_status(struct diff_filepair *p)
2629         switch (p->status) {
2630         case DIFF_STATUS_UNKNOWN:
2631                 return 0;
2632         case 0:
2633                 die("internal error in diff-resolve-rename-copy");
2634         default:
2635                 return 1;
2636         }
2639 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2641         int fmt = opt->output_format;
2643         if (fmt & DIFF_FORMAT_CHECKDIFF)
2644                 diff_flush_checkdiff(p, opt);
2645         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2646                 diff_flush_raw(p, opt);
2647         else if (fmt & DIFF_FORMAT_NAME)
2648                 write_name_quoted(p->two->path, stdout, opt->line_termination);
2651 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2653         if (fs->mode)
2654                 printf(" %s mode %06o ", newdelete, fs->mode);
2655         else
2656                 printf(" %s ", newdelete);
2657         write_name_quoted(fs->path, stdout, '\n');
2661 static void show_mode_change(struct diff_filepair *p, int show_name)
2663         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2664                 printf(" mode change %06o => %06o%c", p->one->mode, p->two->mode,
2665                         show_name ? ' ' : '\n');
2666                 if (show_name) {
2667                         write_name_quoted(p->two->path, stdout, '\n');
2668                 }
2669         }
2672 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2674         char *names = pprint_rename(p->one->path, p->two->path);
2676         printf(" %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2677         free(names);
2678         show_mode_change(p, 0);
2681 static void diff_summary(struct diff_filepair *p)
2683         switch(p->status) {
2684         case DIFF_STATUS_DELETED:
2685                 show_file_mode_name("delete", p->one);
2686                 break;
2687         case DIFF_STATUS_ADDED:
2688                 show_file_mode_name("create", p->two);
2689                 break;
2690         case DIFF_STATUS_COPIED:
2691                 show_rename_copy("copy", p);
2692                 break;
2693         case DIFF_STATUS_RENAMED:
2694                 show_rename_copy("rename", p);
2695                 break;
2696         default:
2697                 if (p->score) {
2698                         fputs(" rewrite ", stdout);
2699                         write_name_quoted(p->two->path, stdout, ' ');
2700                         printf("(%d%%)\n", similarity_index(p));
2701                 }
2702                 show_mode_change(p, !p->score);
2703                 break;
2704         }
2707 struct patch_id_t {
2708         struct xdiff_emit_state xm;
2709         SHA_CTX *ctx;
2710         int patchlen;
2711 };
2713 static int remove_space(char *line, int len)
2715         int i;
2716         char *dst = line;
2717         unsigned char c;
2719         for (i = 0; i < len; i++)
2720                 if (!isspace((c = line[i])))
2721                         *dst++ = c;
2723         return dst - line;
2726 static void patch_id_consume(void *priv, char *line, unsigned long len)
2728         struct patch_id_t *data = priv;
2729         int new_len;
2731         /* Ignore line numbers when computing the SHA1 of the patch */
2732         if (!prefixcmp(line, "@@ -"))
2733                 return;
2735         new_len = remove_space(line, len);
2737         SHA1_Update(data->ctx, line, new_len);
2738         data->patchlen += new_len;
2741 /* returns 0 upon success, and writes result into sha1 */
2742 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2744         struct diff_queue_struct *q = &diff_queued_diff;
2745         int i;
2746         SHA_CTX ctx;
2747         struct patch_id_t data;
2748         char buffer[PATH_MAX * 4 + 20];
2750         SHA1_Init(&ctx);
2751         memset(&data, 0, sizeof(struct patch_id_t));
2752         data.ctx = &ctx;
2753         data.xm.consume = patch_id_consume;
2755         for (i = 0; i < q->nr; i++) {
2756                 xpparam_t xpp;
2757                 xdemitconf_t xecfg;
2758                 xdemitcb_t ecb;
2759                 mmfile_t mf1, mf2;
2760                 struct diff_filepair *p = q->queue[i];
2761                 int len1, len2;
2763                 memset(&xecfg, 0, sizeof(xecfg));
2764                 if (p->status == 0)
2765                         return error("internal diff status error");
2766                 if (p->status == DIFF_STATUS_UNKNOWN)
2767                         continue;
2768                 if (diff_unmodified_pair(p))
2769                         continue;
2770                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2771                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2772                         continue;
2773                 if (DIFF_PAIR_UNMERGED(p))
2774                         continue;
2776                 diff_fill_sha1_info(p->one);
2777                 diff_fill_sha1_info(p->two);
2778                 if (fill_mmfile(&mf1, p->one) < 0 ||
2779                                 fill_mmfile(&mf2, p->two) < 0)
2780                         return error("unable to read files to diff");
2782                 len1 = remove_space(p->one->path, strlen(p->one->path));
2783                 len2 = remove_space(p->two->path, strlen(p->two->path));
2784                 if (p->one->mode == 0)
2785                         len1 = snprintf(buffer, sizeof(buffer),
2786                                         "diff--gita/%.*sb/%.*s"
2787                                         "newfilemode%06o"
2788                                         "---/dev/null"
2789                                         "+++b/%.*s",
2790                                         len1, p->one->path,
2791                                         len2, p->two->path,
2792                                         p->two->mode,
2793                                         len2, p->two->path);
2794                 else if (p->two->mode == 0)
2795                         len1 = snprintf(buffer, sizeof(buffer),
2796                                         "diff--gita/%.*sb/%.*s"
2797                                         "deletedfilemode%06o"
2798                                         "---a/%.*s"
2799                                         "+++/dev/null",
2800                                         len1, p->one->path,
2801                                         len2, p->two->path,
2802                                         p->one->mode,
2803                                         len1, p->one->path);
2804                 else
2805                         len1 = snprintf(buffer, sizeof(buffer),
2806                                         "diff--gita/%.*sb/%.*s"
2807                                         "---a/%.*s"
2808                                         "+++b/%.*s",
2809                                         len1, p->one->path,
2810                                         len2, p->two->path,
2811                                         len1, p->one->path,
2812                                         len2, p->two->path);
2813                 SHA1_Update(&ctx, buffer, len1);
2815                 xpp.flags = XDF_NEED_MINIMAL;
2816                 xecfg.ctxlen = 3;
2817                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2818                 ecb.outf = xdiff_outf;
2819                 ecb.priv = &data;
2820                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2821         }
2823         SHA1_Final(sha1, &ctx);
2824         return 0;
2827 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2829         struct diff_queue_struct *q = &diff_queued_diff;
2830         int i;
2831         int result = diff_get_patch_id(options, sha1);
2833         for (i = 0; i < q->nr; i++)
2834                 diff_free_filepair(q->queue[i]);
2836         free(q->queue);
2837         q->queue = NULL;
2838         q->nr = q->alloc = 0;
2840         return result;
2843 static int is_summary_empty(const struct diff_queue_struct *q)
2845         int i;
2847         for (i = 0; i < q->nr; i++) {
2848                 const struct diff_filepair *p = q->queue[i];
2850                 switch (p->status) {
2851                 case DIFF_STATUS_DELETED:
2852                 case DIFF_STATUS_ADDED:
2853                 case DIFF_STATUS_COPIED:
2854                 case DIFF_STATUS_RENAMED:
2855                         return 0;
2856                 default:
2857                         if (p->score)
2858                                 return 0;
2859                         if (p->one->mode && p->two->mode &&
2860                             p->one->mode != p->two->mode)
2861                                 return 0;
2862                         break;
2863                 }
2864         }
2865         return 1;
2868 void diff_flush(struct diff_options *options)
2870         struct diff_queue_struct *q = &diff_queued_diff;
2871         int i, output_format = options->output_format;
2872         int separator = 0;
2874         /*
2875          * Order: raw, stat, summary, patch
2876          * or:    name/name-status/checkdiff (other bits clear)
2877          */
2878         if (!q->nr)
2879                 goto free_queue;
2881         if (output_format & (DIFF_FORMAT_RAW |
2882                              DIFF_FORMAT_NAME |
2883                              DIFF_FORMAT_NAME_STATUS |
2884                              DIFF_FORMAT_CHECKDIFF)) {
2885                 for (i = 0; i < q->nr; i++) {
2886                         struct diff_filepair *p = q->queue[i];
2887                         if (check_pair_status(p))
2888                                 flush_one_pair(p, options);
2889                 }
2890                 separator++;
2891         }
2893         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
2894                 struct diffstat_t diffstat;
2896                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2897                 diffstat.xm.consume = diffstat_consume;
2898                 for (i = 0; i < q->nr; i++) {
2899                         struct diff_filepair *p = q->queue[i];
2900                         if (check_pair_status(p))
2901                                 diff_flush_stat(p, options, &diffstat);
2902                 }
2903                 if (output_format & DIFF_FORMAT_NUMSTAT)
2904                         show_numstat(&diffstat, options);
2905                 if (output_format & DIFF_FORMAT_DIFFSTAT)
2906                         show_stats(&diffstat, options);
2907                 if (output_format & DIFF_FORMAT_SHORTSTAT)
2908                         show_shortstats(&diffstat);
2909                 free_diffstat_info(&diffstat);
2910                 separator++;
2911         }
2913         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2914                 for (i = 0; i < q->nr; i++)
2915                         diff_summary(q->queue[i]);
2916                 separator++;
2917         }
2919         if (output_format & DIFF_FORMAT_PATCH) {
2920                 if (separator) {
2921                         if (options->stat_sep) {
2922                                 /* attach patch instead of inline */
2923                                 fputs(options->stat_sep, stdout);
2924                         } else {
2925                                 putchar(options->line_termination);
2926                         }
2927                 }
2929                 for (i = 0; i < q->nr; i++) {
2930                         struct diff_filepair *p = q->queue[i];
2931                         if (check_pair_status(p))
2932                                 diff_flush_patch(p, options);
2933                 }
2934         }
2936         if (output_format & DIFF_FORMAT_CALLBACK)
2937                 options->format_callback(q, options, options->format_callback_data);
2939         for (i = 0; i < q->nr; i++)
2940                 diff_free_filepair(q->queue[i]);
2941 free_queue:
2942         free(q->queue);
2943         q->queue = NULL;
2944         q->nr = q->alloc = 0;
2947 static void diffcore_apply_filter(const char *filter)
2949         int i;
2950         struct diff_queue_struct *q = &diff_queued_diff;
2951         struct diff_queue_struct outq;
2952         outq.queue = NULL;
2953         outq.nr = outq.alloc = 0;
2955         if (!filter)
2956                 return;
2958         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2959                 int found;
2960                 for (i = found = 0; !found && i < q->nr; i++) {
2961                         struct diff_filepair *p = q->queue[i];
2962                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2963                              ((p->score &&
2964                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2965                               (!p->score &&
2966                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2967                             ((p->status != DIFF_STATUS_MODIFIED) &&
2968                              strchr(filter, p->status)))
2969                                 found++;
2970                 }
2971                 if (found)
2972                         return;
2974                 /* otherwise we will clear the whole queue
2975                  * by copying the empty outq at the end of this
2976                  * function, but first clear the current entries
2977                  * in the queue.
2978                  */
2979                 for (i = 0; i < q->nr; i++)
2980                         diff_free_filepair(q->queue[i]);
2981         }
2982         else {
2983                 /* Only the matching ones */
2984                 for (i = 0; i < q->nr; i++) {
2985                         struct diff_filepair *p = q->queue[i];
2987                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2988                              ((p->score &&
2989                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2990                               (!p->score &&
2991                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2992                             ((p->status != DIFF_STATUS_MODIFIED) &&
2993                              strchr(filter, p->status)))
2994                                 diff_q(&outq, p);
2995                         else
2996                                 diff_free_filepair(p);
2997                 }
2998         }
2999         free(q->queue);
3000         *q = outq;
3003 /* Check whether two filespecs with the same mode and size are identical */
3004 static int diff_filespec_is_identical(struct diff_filespec *one,
3005                                       struct diff_filespec *two)
3007         if (S_ISGITLINK(one->mode)) {
3008                 diff_fill_sha1_info(one);
3009                 diff_fill_sha1_info(two);
3010                 return !hashcmp(one->sha1, two->sha1);
3011         }
3012         if (diff_populate_filespec(one, 0))
3013                 return 0;
3014         if (diff_populate_filespec(two, 0))
3015                 return 0;
3016         return !memcmp(one->data, two->data, one->size);
3019 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3021         int i;
3022         struct diff_queue_struct *q = &diff_queued_diff;
3023         struct diff_queue_struct outq;
3024         outq.queue = NULL;
3025         outq.nr = outq.alloc = 0;
3027         for (i = 0; i < q->nr; i++) {
3028                 struct diff_filepair *p = q->queue[i];
3030                 /*
3031                  * 1. Entries that come from stat info dirtyness
3032                  *    always have both sides (iow, not create/delete),
3033                  *    one side of the object name is unknown, with
3034                  *    the same mode and size.  Keep the ones that
3035                  *    do not match these criteria.  They have real
3036                  *    differences.
3037                  *
3038                  * 2. At this point, the file is known to be modified,
3039                  *    with the same mode and size, and the object
3040                  *    name of one side is unknown.  Need to inspect
3041                  *    the identical contents.
3042                  */
3043                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3044                     !DIFF_FILE_VALID(p->two) ||
3045                     (p->one->sha1_valid && p->two->sha1_valid) ||
3046                     (p->one->mode != p->two->mode) ||
3047                     diff_populate_filespec(p->one, 1) ||
3048                     diff_populate_filespec(p->two, 1) ||
3049                     (p->one->size != p->two->size) ||
3050                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3051                         diff_q(&outq, p);
3052                 else {
3053                         /*
3054                          * The caller can subtract 1 from skip_stat_unmatch
3055                          * to determine how many paths were dirty only
3056                          * due to stat info mismatch.
3057                          */
3058                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3059                                 diffopt->skip_stat_unmatch++;
3060                         diff_free_filepair(p);
3061                 }
3062         }
3063         free(q->queue);
3064         *q = outq;
3067 void diffcore_std(struct diff_options *options)
3069         if (DIFF_OPT_TST(options, QUIET))
3070                 return;
3072         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3073                 diffcore_skip_stat_unmatch(options);
3074         if (options->break_opt != -1)
3075                 diffcore_break(options->break_opt);
3076         if (options->detect_rename)
3077                 diffcore_rename(options);
3078         if (options->break_opt != -1)
3079                 diffcore_merge_broken();
3080         if (options->pickaxe)
3081                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3082         if (options->orderfile)
3083                 diffcore_order(options->orderfile);
3084         diff_resolve_rename_copy();
3085         diffcore_apply_filter(options->filter);
3087         if (diff_queued_diff.nr)
3088                 DIFF_OPT_SET(options, HAS_CHANGES);
3089         else
3090                 DIFF_OPT_CLR(options, HAS_CHANGES);
3093 int diff_result_code(struct diff_options *opt, int status)
3095         int result = 0;
3096         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3097             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3098                 return status;
3099         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3100             DIFF_OPT_TST(opt, HAS_CHANGES))
3101                 result |= 01;
3102         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3103             DIFF_OPT_TST(opt, CHECK_FAILED))
3104                 result |= 02;
3105         return result;
3108 void diff_addremove(struct diff_options *options,
3109                     int addremove, unsigned mode,
3110                     const unsigned char *sha1,
3111                     const char *base, const char *path)
3113         char concatpath[PATH_MAX];
3114         struct diff_filespec *one, *two;
3116         /* This may look odd, but it is a preparation for
3117          * feeding "there are unchanged files which should
3118          * not produce diffs, but when you are doing copy
3119          * detection you would need them, so here they are"
3120          * entries to the diff-core.  They will be prefixed
3121          * with something like '=' or '*' (I haven't decided
3122          * which but should not make any difference).
3123          * Feeding the same new and old to diff_change()
3124          * also has the same effect.
3125          * Before the final output happens, they are pruned after
3126          * merged into rename/copy pairs as appropriate.
3127          */
3128         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3129                 addremove = (addremove == '+' ? '-' :
3130                              addremove == '-' ? '+' : addremove);
3132         if (!path) path = "";
3133         sprintf(concatpath, "%s%s", base, path);
3134         one = alloc_filespec(concatpath);
3135         two = alloc_filespec(concatpath);
3137         if (addremove != '+')
3138                 fill_filespec(one, sha1, mode);
3139         if (addremove != '-')
3140                 fill_filespec(two, sha1, mode);
3142         diff_queue(&diff_queued_diff, one, two);
3143         DIFF_OPT_SET(options, HAS_CHANGES);
3146 void diff_change(struct diff_options *options,
3147                  unsigned old_mode, unsigned new_mode,
3148                  const unsigned char *old_sha1,
3149                  const unsigned char *new_sha1,
3150                  const char *base, const char *path)
3152         char concatpath[PATH_MAX];
3153         struct diff_filespec *one, *two;
3155         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3156                 unsigned tmp;
3157                 const unsigned char *tmp_c;
3158                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3159                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3160         }
3161         if (!path) path = "";
3162         sprintf(concatpath, "%s%s", base, path);
3163         one = alloc_filespec(concatpath);
3164         two = alloc_filespec(concatpath);
3165         fill_filespec(one, old_sha1, old_mode);
3166         fill_filespec(two, new_sha1, new_mode);
3168         diff_queue(&diff_queued_diff, one, two);
3169         DIFF_OPT_SET(options, HAS_CHANGES);
3172 void diff_unmerge(struct diff_options *options,
3173                   const char *path,
3174                   unsigned mode, const unsigned char *sha1)
3176         struct diff_filespec *one, *two;
3177         one = alloc_filespec(path);
3178         two = alloc_filespec(path);
3179         fill_filespec(one, sha1, mode);
3180         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;