Code

"diff --check" should affect exit status
[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 int diff_auto_refresh_index = 1;
25 static char diff_colors[][COLOR_MAXLEN] = {
26         "\033[m",       /* reset */
27         "",             /* PLAIN (normal) */
28         "\033[1m",      /* METAINFO (bold) */
29         "\033[36m",     /* FRAGINFO (cyan) */
30         "\033[31m",     /* OLD (red) */
31         "\033[32m",     /* NEW (green) */
32         "\033[33m",     /* COMMIT (yellow) */
33         "\033[41m",     /* WHITESPACE (red background) */
34 };
36 static int parse_diff_color_slot(const char *var, int ofs)
37 {
38         if (!strcasecmp(var+ofs, "plain"))
39                 return DIFF_PLAIN;
40         if (!strcasecmp(var+ofs, "meta"))
41                 return DIFF_METAINFO;
42         if (!strcasecmp(var+ofs, "frag"))
43                 return DIFF_FRAGINFO;
44         if (!strcasecmp(var+ofs, "old"))
45                 return DIFF_FILE_OLD;
46         if (!strcasecmp(var+ofs, "new"))
47                 return DIFF_FILE_NEW;
48         if (!strcasecmp(var+ofs, "commit"))
49                 return DIFF_COMMIT;
50         if (!strcasecmp(var+ofs, "whitespace"))
51                 return DIFF_WHITESPACE;
52         die("bad config variable '%s'", var);
53 }
55 static struct ll_diff_driver {
56         const char *name;
57         struct ll_diff_driver *next;
58         char *cmd;
59 } *user_diff, **user_diff_tail;
61 static void read_config_if_needed(void)
62 {
63         if (!user_diff_tail) {
64                 user_diff_tail = &user_diff;
65                 git_config(git_diff_ui_config);
66         }
67 }
69 /*
70  * Currently there is only "diff.<drivername>.command" variable;
71  * because there are "diff.color.<slot>" variables, we are parsing
72  * this in a bit convoluted way to allow low level diff driver
73  * called "color".
74  */
75 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
76 {
77         const char *name;
78         int namelen;
79         struct ll_diff_driver *drv;
81         name = var + 5;
82         namelen = ep - name;
83         for (drv = user_diff; drv; drv = drv->next)
84                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
85                         break;
86         if (!drv) {
87                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
88                 drv->name = xmemdupz(name, namelen);
89                 if (!user_diff_tail)
90                         user_diff_tail = &user_diff;
91                 *user_diff_tail = drv;
92                 user_diff_tail = &(drv->next);
93         }
95         if (!value)
96                 return error("%s: lacks value", var);
97         drv->cmd = strdup(value);
98         return 0;
99 }
101 /*
102  * 'diff.<what>.funcname' attribute can be specified in the configuration
103  * to define a customized regexp to find the beginning of a function to
104  * be used for hunk header lines of "diff -p" style output.
105  */
106 static struct funcname_pattern {
107         char *name;
108         char *pattern;
109         struct funcname_pattern *next;
110 } *funcname_pattern_list;
112 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
114         const char *name;
115         int namelen;
116         struct funcname_pattern *pp;
118         name = var + 5; /* "diff." */
119         namelen = ep - name;
121         for (pp = funcname_pattern_list; pp; pp = pp->next)
122                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
123                         break;
124         if (!pp) {
125                 pp = xcalloc(1, sizeof(*pp));
126                 pp->name = xmemdupz(name, namelen);
127                 pp->next = funcname_pattern_list;
128                 funcname_pattern_list = pp;
129         }
130         if (pp->pattern)
131                 free(pp->pattern);
132         pp->pattern = xstrdup(value);
133         return 0;
136 /*
137  * These are to give UI layer defaults.
138  * The core-level commands such as git-diff-files should
139  * never be affected by the setting of diff.renames
140  * the user happens to have in the configuration file.
141  */
142 int git_diff_ui_config(const char *var, const char *value)
144         if (!strcmp(var, "diff.renamelimit")) {
145                 diff_rename_limit_default = git_config_int(var, value);
146                 return 0;
147         }
148         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
149                 diff_use_color_default = git_config_colorbool(var, value, -1);
150                 return 0;
151         }
152         if (!strcmp(var, "diff.renames")) {
153                 if (!value)
154                         diff_detect_rename_default = DIFF_DETECT_RENAME;
155                 else if (!strcasecmp(value, "copies") ||
156                          !strcasecmp(value, "copy"))
157                         diff_detect_rename_default = DIFF_DETECT_COPY;
158                 else if (git_config_bool(var,value))
159                         diff_detect_rename_default = DIFF_DETECT_RENAME;
160                 return 0;
161         }
162         if (!strcmp(var, "diff.autorefreshindex")) {
163                 diff_auto_refresh_index = git_config_bool(var, value);
164                 return 0;
165         }
166         if (!prefixcmp(var, "diff.")) {
167                 const char *ep = strrchr(var, '.');
169                 if (ep != var + 4) {
170                         if (!strcmp(ep, ".command"))
171                                 return parse_lldiff_command(var, ep, value);
172                         if (!strcmp(ep, ".funcname"))
173                                 return parse_funcname_pattern(var, ep, value);
174                 }
175         }
176         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
177                 int slot = parse_diff_color_slot(var, 11);
178                 color_parse(value, var, diff_colors[slot]);
179                 return 0;
180         }
182         return git_default_config(var, value);
185 static char *quote_two(const char *one, const char *two)
187         int need_one = quote_c_style(one, NULL, NULL, 1);
188         int need_two = quote_c_style(two, NULL, NULL, 1);
189         struct strbuf res;
191         strbuf_init(&res, 0);
192         if (need_one + need_two) {
193                 strbuf_addch(&res, '"');
194                 quote_c_style(one, &res, NULL, 1);
195                 quote_c_style(two, &res, NULL, 1);
196                 strbuf_addch(&res, '"');
197         } else {
198                 strbuf_addstr(&res, one);
199                 strbuf_addstr(&res, two);
200         }
201         return strbuf_detach(&res, NULL);
204 static const char *external_diff(void)
206         static const char *external_diff_cmd = NULL;
207         static int done_preparing = 0;
209         if (done_preparing)
210                 return external_diff_cmd;
211         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
212         done_preparing = 1;
213         return external_diff_cmd;
216 static struct diff_tempfile {
217         const char *name; /* filename external diff should read from */
218         char hex[41];
219         char mode[10];
220         char tmp_path[PATH_MAX];
221 } diff_temp[2];
223 static int count_lines(const char *data, int size)
225         int count, ch, completely_empty = 1, nl_just_seen = 0;
226         count = 0;
227         while (0 < size--) {
228                 ch = *data++;
229                 if (ch == '\n') {
230                         count++;
231                         nl_just_seen = 1;
232                         completely_empty = 0;
233                 }
234                 else {
235                         nl_just_seen = 0;
236                         completely_empty = 0;
237                 }
238         }
239         if (completely_empty)
240                 return 0;
241         if (!nl_just_seen)
242                 count++; /* no trailing newline */
243         return count;
246 static void print_line_count(int count)
248         switch (count) {
249         case 0:
250                 printf("0,0");
251                 break;
252         case 1:
253                 printf("1");
254                 break;
255         default:
256                 printf("1,%d", count);
257                 break;
258         }
261 static void copy_file(int prefix, const char *data, int size,
262                 const char *set, const char *reset)
264         int ch, nl_just_seen = 1;
265         while (0 < size--) {
266                 ch = *data++;
267                 if (nl_just_seen) {
268                         fputs(set, stdout);
269                         putchar(prefix);
270                 }
271                 if (ch == '\n') {
272                         nl_just_seen = 1;
273                         fputs(reset, stdout);
274                 } else
275                         nl_just_seen = 0;
276                 putchar(ch);
277         }
278         if (!nl_just_seen)
279                 printf("%s\n\\ No newline at end of file\n", reset);
282 static void emit_rewrite_diff(const char *name_a,
283                               const char *name_b,
284                               struct diff_filespec *one,
285                               struct diff_filespec *two,
286                               int color_diff)
288         int lc_a, lc_b;
289         const char *name_a_tab, *name_b_tab;
290         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
291         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
292         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
293         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
294         const char *reset = diff_get_color(color_diff, DIFF_RESET);
296         name_a += (*name_a == '/');
297         name_b += (*name_b == '/');
298         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
299         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
301         diff_populate_filespec(one, 0);
302         diff_populate_filespec(two, 0);
303         lc_a = count_lines(one->data, one->size);
304         lc_b = count_lines(two->data, two->size);
305         printf("%s--- a/%s%s%s\n%s+++ b/%s%s%s\n%s@@ -",
306                metainfo, name_a, name_a_tab, reset,
307                metainfo, name_b, name_b_tab, reset, fraginfo);
308         print_line_count(lc_a);
309         printf(" +");
310         print_line_count(lc_b);
311         printf(" @@%s\n", reset);
312         if (lc_a)
313                 copy_file('-', one->data, one->size, old, reset);
314         if (lc_b)
315                 copy_file('+', two->data, two->size, new, reset);
318 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
320         if (!DIFF_FILE_VALID(one)) {
321                 mf->ptr = (char *)""; /* does not matter */
322                 mf->size = 0;
323                 return 0;
324         }
325         else if (diff_populate_filespec(one, 0))
326                 return -1;
327         mf->ptr = one->data;
328         mf->size = one->size;
329         return 0;
332 struct diff_words_buffer {
333         mmfile_t text;
334         long alloc;
335         long current; /* output pointer */
336         int suppressed_newline;
337 };
339 static void diff_words_append(char *line, unsigned long len,
340                 struct diff_words_buffer *buffer)
342         if (buffer->text.size + len > buffer->alloc) {
343                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
344                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
345         }
346         line++;
347         len--;
348         memcpy(buffer->text.ptr + buffer->text.size, line, len);
349         buffer->text.size += len;
352 struct diff_words_data {
353         struct xdiff_emit_state xm;
354         struct diff_words_buffer minus, plus;
355 };
357 static void print_word(struct diff_words_buffer *buffer, int len, int color,
358                 int suppress_newline)
360         const char *ptr;
361         int eol = 0;
363         if (len == 0)
364                 return;
366         ptr  = buffer->text.ptr + buffer->current;
367         buffer->current += len;
369         if (ptr[len - 1] == '\n') {
370                 eol = 1;
371                 len--;
372         }
374         fputs(diff_get_color(1, color), stdout);
375         fwrite(ptr, len, 1, stdout);
376         fputs(diff_get_color(1, DIFF_RESET), stdout);
378         if (eol) {
379                 if (suppress_newline)
380                         buffer->suppressed_newline = 1;
381                 else
382                         putchar('\n');
383         }
386 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
388         struct diff_words_data *diff_words = priv;
390         if (diff_words->minus.suppressed_newline) {
391                 if (line[0] != '+')
392                         putchar('\n');
393                 diff_words->minus.suppressed_newline = 0;
394         }
396         len--;
397         switch (line[0]) {
398                 case '-':
399                         print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
400                         break;
401                 case '+':
402                         print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
403                         break;
404                 case ' ':
405                         print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
406                         diff_words->minus.current += len;
407                         break;
408         }
411 /* this executes the word diff on the accumulated buffers */
412 static void diff_words_show(struct diff_words_data *diff_words)
414         xpparam_t xpp;
415         xdemitconf_t xecfg;
416         xdemitcb_t ecb;
417         mmfile_t minus, plus;
418         int i;
420         memset(&xecfg, 0, sizeof(xecfg));
421         minus.size = diff_words->minus.text.size;
422         minus.ptr = xmalloc(minus.size);
423         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
424         for (i = 0; i < minus.size; i++)
425                 if (isspace(minus.ptr[i]))
426                         minus.ptr[i] = '\n';
427         diff_words->minus.current = 0;
429         plus.size = diff_words->plus.text.size;
430         plus.ptr = xmalloc(plus.size);
431         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
432         for (i = 0; i < plus.size; i++)
433                 if (isspace(plus.ptr[i]))
434                         plus.ptr[i] = '\n';
435         diff_words->plus.current = 0;
437         xpp.flags = XDF_NEED_MINIMAL;
438         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
439         ecb.outf = xdiff_outf;
440         ecb.priv = diff_words;
441         diff_words->xm.consume = fn_out_diff_words_aux;
442         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
444         free(minus.ptr);
445         free(plus.ptr);
446         diff_words->minus.text.size = diff_words->plus.text.size = 0;
448         if (diff_words->minus.suppressed_newline) {
449                 putchar('\n');
450                 diff_words->minus.suppressed_newline = 0;
451         }
454 struct emit_callback {
455         struct xdiff_emit_state xm;
456         int nparents, color_diff;
457         unsigned ws_rule;
458         const char **label_path;
459         struct diff_words_data *diff_words;
460         int *found_changesp;
461 };
463 static void free_diff_words_data(struct emit_callback *ecbdata)
465         if (ecbdata->diff_words) {
466                 /* flush buffers */
467                 if (ecbdata->diff_words->minus.text.size ||
468                                 ecbdata->diff_words->plus.text.size)
469                         diff_words_show(ecbdata->diff_words);
471                 if (ecbdata->diff_words->minus.text.ptr)
472                         free (ecbdata->diff_words->minus.text.ptr);
473                 if (ecbdata->diff_words->plus.text.ptr)
474                         free (ecbdata->diff_words->plus.text.ptr);
475                 free(ecbdata->diff_words);
476                 ecbdata->diff_words = NULL;
477         }
480 const char *diff_get_color(int diff_use_color, enum color_diff ix)
482         if (diff_use_color)
483                 return diff_colors[ix];
484         return "";
487 static void emit_line(const char *set, const char *reset, const char *line, int len)
489         if (len > 0 && line[len-1] == '\n')
490                 len--;
491         fputs(set, stdout);
492         fwrite(line, len, 1, stdout);
493         puts(reset);
496 static void emit_line_with_ws(int nparents,
497                               const char *set, const char *reset, const char *ws,
498                               const char *line, int len, unsigned ws_rule)
500         int col0 = nparents;
501         int last_tab_in_indent = -1;
502         int last_space_in_indent = -1;
503         int i;
504         int tail = len;
505         int need_highlight_leading_space = 0;
506         /*
507          * The line is a newly added line.  Does it have funny leading
508          * whitespaces?  In indent, SP should never precede a TAB.  In
509          * addition, under "indent with non tab" rule, there should not
510          * be more than 8 consecutive spaces.
511          */
512         for (i = col0; i < len; i++) {
513                 if (line[i] == '\t') {
514                         last_tab_in_indent = i;
515                         if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
516                             0 <= last_space_in_indent)
517                                 need_highlight_leading_space = 1;
518                 }
519                 else if (line[i] == ' ')
520                         last_space_in_indent = i;
521                 else
522                         break;
523         }
524         if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
525             0 <= last_space_in_indent &&
526             last_tab_in_indent < 0 &&
527             8 <= (i - col0)) {
528                 last_tab_in_indent = i;
529                 need_highlight_leading_space = 1;
530         }
531         fputs(set, stdout);
532         fwrite(line, col0, 1, stdout);
533         fputs(reset, stdout);
534         if (((i == len) || line[i] == '\n') && i != col0) {
535                 /* The whole line was indent */
536                 emit_line(ws, reset, line + col0, len - col0);
537                 return;
538         }
539         i = col0;
540         if (need_highlight_leading_space) {
541                 while (i < last_tab_in_indent) {
542                         if (line[i] == ' ') {
543                                 fputs(ws, stdout);
544                                 putchar(' ');
545                                 fputs(reset, stdout);
546                         }
547                         else
548                                 putchar(line[i]);
549                         i++;
550                 }
551         }
552         tail = len - 1;
553         if (line[tail] == '\n' && i < tail)
554                 tail--;
555         if (ws_rule & WS_TRAILING_SPACE) {
556                 while (i < tail) {
557                         if (!isspace(line[tail]))
558                                 break;
559                         tail--;
560                 }
561         }
562         if ((i < tail && line[tail + 1] != '\n')) {
563                 /* This has whitespace between tail+1..len */
564                 fputs(set, stdout);
565                 fwrite(line + i, tail - i + 1, 1, stdout);
566                 fputs(reset, stdout);
567                 emit_line(ws, reset, line + tail + 1, len - tail - 1);
568         }
569         else
570                 emit_line(set, reset, line + i, len - i);
573 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
575         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
576         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
578         if (!*ws)
579                 emit_line(set, reset, line, len);
580         else
581                 emit_line_with_ws(ecbdata->nparents, set, reset, ws,
582                                   line, len, ecbdata->ws_rule);
585 static void fn_out_consume(void *priv, char *line, unsigned long len)
587         int i;
588         int color;
589         struct emit_callback *ecbdata = priv;
590         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
591         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
593         *(ecbdata->found_changesp) = 1;
595         if (ecbdata->label_path[0]) {
596                 const char *name_a_tab, *name_b_tab;
598                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
599                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
601                 printf("%s--- %s%s%s\n",
602                        set, ecbdata->label_path[0], reset, name_a_tab);
603                 printf("%s+++ %s%s%s\n",
604                        set, ecbdata->label_path[1], reset, name_b_tab);
605                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
606         }
608         /* This is not really necessary for now because
609          * this codepath only deals with two-way diffs.
610          */
611         for (i = 0; i < len && line[i] == '@'; i++)
612                 ;
613         if (2 <= i && i < len && line[i] == ' ') {
614                 ecbdata->nparents = i - 1;
615                 emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
616                           reset, line, len);
617                 return;
618         }
620         if (len < ecbdata->nparents) {
621                 set = reset;
622                 emit_line(reset, reset, line, len);
623                 return;
624         }
626         color = DIFF_PLAIN;
627         if (ecbdata->diff_words && ecbdata->nparents != 1)
628                 /* fall back to normal diff */
629                 free_diff_words_data(ecbdata);
630         if (ecbdata->diff_words) {
631                 if (line[0] == '-') {
632                         diff_words_append(line, len,
633                                           &ecbdata->diff_words->minus);
634                         return;
635                 } else if (line[0] == '+') {
636                         diff_words_append(line, len,
637                                           &ecbdata->diff_words->plus);
638                         return;
639                 }
640                 if (ecbdata->diff_words->minus.text.size ||
641                     ecbdata->diff_words->plus.text.size)
642                         diff_words_show(ecbdata->diff_words);
643                 line++;
644                 len--;
645                 emit_line(set, reset, line, len);
646                 return;
647         }
648         for (i = 0; i < ecbdata->nparents && len; i++) {
649                 if (line[i] == '-')
650                         color = DIFF_FILE_OLD;
651                 else if (line[i] == '+')
652                         color = DIFF_FILE_NEW;
653         }
655         if (color != DIFF_FILE_NEW) {
656                 emit_line(diff_get_color(ecbdata->color_diff, color),
657                           reset, line, len);
658                 return;
659         }
660         emit_add_line(reset, ecbdata, line, len);
663 static char *pprint_rename(const char *a, const char *b)
665         const char *old = a;
666         const char *new = b;
667         struct strbuf name;
668         int pfx_length, sfx_length;
669         int len_a = strlen(a);
670         int len_b = strlen(b);
671         int a_midlen, b_midlen;
672         int qlen_a = quote_c_style(a, NULL, NULL, 0);
673         int qlen_b = quote_c_style(b, NULL, NULL, 0);
675         strbuf_init(&name, 0);
676         if (qlen_a || qlen_b) {
677                 quote_c_style(a, &name, NULL, 0);
678                 strbuf_addstr(&name, " => ");
679                 quote_c_style(b, &name, NULL, 0);
680                 return strbuf_detach(&name, NULL);
681         }
683         /* Find common prefix */
684         pfx_length = 0;
685         while (*old && *new && *old == *new) {
686                 if (*old == '/')
687                         pfx_length = old - a + 1;
688                 old++;
689                 new++;
690         }
692         /* Find common suffix */
693         old = a + len_a;
694         new = b + len_b;
695         sfx_length = 0;
696         while (a <= old && b <= new && *old == *new) {
697                 if (*old == '/')
698                         sfx_length = len_a - (old - a);
699                 old--;
700                 new--;
701         }
703         /*
704          * pfx{mid-a => mid-b}sfx
705          * {pfx-a => pfx-b}sfx
706          * pfx{sfx-a => sfx-b}
707          * name-a => name-b
708          */
709         a_midlen = len_a - pfx_length - sfx_length;
710         b_midlen = len_b - pfx_length - sfx_length;
711         if (a_midlen < 0)
712                 a_midlen = 0;
713         if (b_midlen < 0)
714                 b_midlen = 0;
716         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
717         if (pfx_length + sfx_length) {
718                 strbuf_add(&name, a, pfx_length);
719                 strbuf_addch(&name, '{');
720         }
721         strbuf_add(&name, a + pfx_length, a_midlen);
722         strbuf_addstr(&name, " => ");
723         strbuf_add(&name, b + pfx_length, b_midlen);
724         if (pfx_length + sfx_length) {
725                 strbuf_addch(&name, '}');
726                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
727         }
728         return strbuf_detach(&name, NULL);
731 struct diffstat_t {
732         struct xdiff_emit_state xm;
734         int nr;
735         int alloc;
736         struct diffstat_file {
737                 char *from_name;
738                 char *name;
739                 char *print_name;
740                 unsigned is_unmerged:1;
741                 unsigned is_binary:1;
742                 unsigned is_renamed:1;
743                 unsigned int added, deleted;
744         } **files;
745 };
747 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
748                                           const char *name_a,
749                                           const char *name_b)
751         struct diffstat_file *x;
752         x = xcalloc(sizeof (*x), 1);
753         if (diffstat->nr == diffstat->alloc) {
754                 diffstat->alloc = alloc_nr(diffstat->alloc);
755                 diffstat->files = xrealloc(diffstat->files,
756                                 diffstat->alloc * sizeof(x));
757         }
758         diffstat->files[diffstat->nr++] = x;
759         if (name_b) {
760                 x->from_name = xstrdup(name_a);
761                 x->name = xstrdup(name_b);
762                 x->is_renamed = 1;
763         }
764         else {
765                 x->from_name = NULL;
766                 x->name = xstrdup(name_a);
767         }
768         return x;
771 static void diffstat_consume(void *priv, char *line, unsigned long len)
773         struct diffstat_t *diffstat = priv;
774         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
776         if (line[0] == '+')
777                 x->added++;
778         else if (line[0] == '-')
779                 x->deleted++;
782 const char mime_boundary_leader[] = "------------";
784 static int scale_linear(int it, int width, int max_change)
786         /*
787          * make sure that at least one '-' is printed if there were deletions,
788          * and likewise for '+'.
789          */
790         if (max_change < 2)
791                 return it;
792         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
795 static void show_name(const char *prefix, const char *name, int len,
796                       const char *reset, const char *set)
798         printf(" %s%s%-*s%s |", set, prefix, len, name, reset);
801 static void show_graph(char ch, int cnt, const char *set, const char *reset)
803         if (cnt <= 0)
804                 return;
805         printf("%s", set);
806         while (cnt--)
807                 putchar(ch);
808         printf("%s", reset);
811 static void fill_print_name(struct diffstat_file *file)
813         char *pname;
815         if (file->print_name)
816                 return;
818         if (!file->is_renamed) {
819                 struct strbuf buf;
820                 strbuf_init(&buf, 0);
821                 if (quote_c_style(file->name, &buf, NULL, 0)) {
822                         pname = strbuf_detach(&buf, NULL);
823                 } else {
824                         pname = file->name;
825                         strbuf_release(&buf);
826                 }
827         } else {
828                 pname = pprint_rename(file->from_name, file->name);
829         }
830         file->print_name = pname;
833 static void show_stats(struct diffstat_t* data, struct diff_options *options)
835         int i, len, add, del, total, adds = 0, dels = 0;
836         int max_change = 0, max_len = 0;
837         int total_files = data->nr;
838         int width, name_width;
839         const char *reset, *set, *add_c, *del_c;
841         if (data->nr == 0)
842                 return;
844         width = options->stat_width ? options->stat_width : 80;
845         name_width = options->stat_name_width ? options->stat_name_width : 50;
847         /* Sanity: give at least 5 columns to the graph,
848          * but leave at least 10 columns for the name.
849          */
850         if (width < name_width + 15) {
851                 if (name_width <= 25)
852                         width = name_width + 15;
853                 else
854                         name_width = width - 15;
855         }
857         /* Find the longest filename and max number of changes */
858         reset = diff_get_color_opt(options, DIFF_RESET);
859         set   = diff_get_color_opt(options, DIFF_PLAIN);
860         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
861         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
863         for (i = 0; i < data->nr; i++) {
864                 struct diffstat_file *file = data->files[i];
865                 int change = file->added + file->deleted;
866                 fill_print_name(file);
867                 len = strlen(file->print_name);
868                 if (max_len < len)
869                         max_len = len;
871                 if (file->is_binary || file->is_unmerged)
872                         continue;
873                 if (max_change < change)
874                         max_change = change;
875         }
877         /* Compute the width of the graph part;
878          * 10 is for one blank at the beginning of the line plus
879          * " | count " between the name and the graph.
880          *
881          * From here on, name_width is the width of the name area,
882          * and width is the width of the graph area.
883          */
884         name_width = (name_width < max_len) ? name_width : max_len;
885         if (width < (name_width + 10) + max_change)
886                 width = width - (name_width + 10);
887         else
888                 width = max_change;
890         for (i = 0; i < data->nr; i++) {
891                 const char *prefix = "";
892                 char *name = data->files[i]->print_name;
893                 int added = data->files[i]->added;
894                 int deleted = data->files[i]->deleted;
895                 int name_len;
897                 /*
898                  * "scale" the filename
899                  */
900                 len = name_width;
901                 name_len = strlen(name);
902                 if (name_width < name_len) {
903                         char *slash;
904                         prefix = "...";
905                         len -= 3;
906                         name += name_len - len;
907                         slash = strchr(name, '/');
908                         if (slash)
909                                 name = slash;
910                 }
912                 if (data->files[i]->is_binary) {
913                         show_name(prefix, name, len, reset, set);
914                         printf("  Bin ");
915                         printf("%s%d%s", del_c, deleted, reset);
916                         printf(" -> ");
917                         printf("%s%d%s", add_c, added, reset);
918                         printf(" bytes");
919                         printf("\n");
920                         continue;
921                 }
922                 else if (data->files[i]->is_unmerged) {
923                         show_name(prefix, name, len, reset, set);
924                         printf("  Unmerged\n");
925                         continue;
926                 }
927                 else if (!data->files[i]->is_renamed &&
928                          (added + deleted == 0)) {
929                         total_files--;
930                         continue;
931                 }
933                 /*
934                  * scale the add/delete
935                  */
936                 add = added;
937                 del = deleted;
938                 total = add + del;
939                 adds += add;
940                 dels += del;
942                 if (width <= max_change) {
943                         add = scale_linear(add, width, max_change);
944                         del = scale_linear(del, width, max_change);
945                         total = add + del;
946                 }
947                 show_name(prefix, name, len, reset, set);
948                 printf("%5d ", added + deleted);
949                 show_graph('+', add, add_c, reset);
950                 show_graph('-', del, del_c, reset);
951                 putchar('\n');
952         }
953         printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
954                set, total_files, adds, dels, reset);
957 static void show_shortstats(struct diffstat_t* data)
959         int i, adds = 0, dels = 0, total_files = data->nr;
961         if (data->nr == 0)
962                 return;
964         for (i = 0; i < data->nr; i++) {
965                 if (!data->files[i]->is_binary &&
966                     !data->files[i]->is_unmerged) {
967                         int added = data->files[i]->added;
968                         int deleted= data->files[i]->deleted;
969                         if (!data->files[i]->is_renamed &&
970                             (added + deleted == 0)) {
971                                 total_files--;
972                         } else {
973                                 adds += added;
974                                 dels += deleted;
975                         }
976                 }
977         }
978         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
979                total_files, adds, dels);
982 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
984         int i;
986         if (data->nr == 0)
987                 return;
989         for (i = 0; i < data->nr; i++) {
990                 struct diffstat_file *file = data->files[i];
992                 if (file->is_binary)
993                         printf("-\t-\t");
994                 else
995                         printf("%d\t%d\t", file->added, file->deleted);
996                 if (options->line_termination) {
997                         fill_print_name(file);
998                         if (!file->is_renamed)
999                                 write_name_quoted(file->name, stdout,
1000                                                   options->line_termination);
1001                         else {
1002                                 fputs(file->print_name, stdout);
1003                                 putchar(options->line_termination);
1004                         }
1005                 } else {
1006                         if (file->is_renamed) {
1007                                 putchar('\0');
1008                                 write_name_quoted(file->from_name, stdout, '\0');
1009                         }
1010                         write_name_quoted(file->name, stdout, '\0');
1011                 }
1012         }
1015 static void free_diffstat_info(struct diffstat_t *diffstat)
1017         int i;
1018         for (i = 0; i < diffstat->nr; i++) {
1019                 struct diffstat_file *f = diffstat->files[i];
1020                 if (f->name != f->print_name)
1021                         free(f->print_name);
1022                 free(f->name);
1023                 free(f->from_name);
1024                 free(f);
1025         }
1026         free(diffstat->files);
1029 struct checkdiff_t {
1030         struct xdiff_emit_state xm;
1031         const char *filename;
1032         int lineno, color_diff;
1033         unsigned ws_rule;
1034         unsigned status;
1035 };
1037 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1039         struct checkdiff_t *data = priv;
1040         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
1041         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
1042         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
1044         if (line[0] == '+') {
1045                 int i, spaces = 0, space_before_tab = 0, white_space_at_end = 0;
1047                 /* check space before tab */
1048                 for (i = 1; i < len; i++) {
1049                         if (line[i] == ' ')
1050                                 spaces++;
1051                         else if (line[i] == '\t') {
1052                                 if (spaces) {
1053                                         space_before_tab = 1;
1054                                         break;
1055                                 }
1056                         }
1057                         else
1058                                 break;
1059                 }
1061                 /* check whitespace at line end */
1062                 if (line[len - 1] == '\n')
1063                         len--;
1064                 if (isspace(line[len - 1]))
1065                         white_space_at_end = 1;
1067                 if (space_before_tab || white_space_at_end) {
1068                         data->status = 1;
1069                         printf("%s:%d: %s", data->filename, data->lineno, ws);
1070                         if (space_before_tab) {
1071                                 printf("space before tab");
1072                                 if (white_space_at_end)
1073                                         putchar(',');
1074                         }
1075                         if (white_space_at_end)
1076                                 printf("whitespace at end");
1077                         printf(":%s ", reset);
1078                         emit_line_with_ws(1, set, reset, ws, line, len,
1079                                           data->ws_rule);
1080                 }
1082                 data->lineno++;
1083         } else if (line[0] == ' ')
1084                 data->lineno++;
1085         else if (line[0] == '@') {
1086                 char *plus = strchr(line, '+');
1087                 if (plus)
1088                         data->lineno = strtol(plus, NULL, 10);
1089                 else
1090                         die("invalid diff");
1091         }
1094 static unsigned char *deflate_it(char *data,
1095                                  unsigned long size,
1096                                  unsigned long *result_size)
1098         int bound;
1099         unsigned char *deflated;
1100         z_stream stream;
1102         memset(&stream, 0, sizeof(stream));
1103         deflateInit(&stream, zlib_compression_level);
1104         bound = deflateBound(&stream, size);
1105         deflated = xmalloc(bound);
1106         stream.next_out = deflated;
1107         stream.avail_out = bound;
1109         stream.next_in = (unsigned char *)data;
1110         stream.avail_in = size;
1111         while (deflate(&stream, Z_FINISH) == Z_OK)
1112                 ; /* nothing */
1113         deflateEnd(&stream);
1114         *result_size = stream.total_out;
1115         return deflated;
1118 static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
1120         void *cp;
1121         void *delta;
1122         void *deflated;
1123         void *data;
1124         unsigned long orig_size;
1125         unsigned long delta_size;
1126         unsigned long deflate_size;
1127         unsigned long data_size;
1129         /* We could do deflated delta, or we could do just deflated two,
1130          * whichever is smaller.
1131          */
1132         delta = NULL;
1133         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1134         if (one->size && two->size) {
1135                 delta = diff_delta(one->ptr, one->size,
1136                                    two->ptr, two->size,
1137                                    &delta_size, deflate_size);
1138                 if (delta) {
1139                         void *to_free = delta;
1140                         orig_size = delta_size;
1141                         delta = deflate_it(delta, delta_size, &delta_size);
1142                         free(to_free);
1143                 }
1144         }
1146         if (delta && delta_size < deflate_size) {
1147                 printf("delta %lu\n", orig_size);
1148                 free(deflated);
1149                 data = delta;
1150                 data_size = delta_size;
1151         }
1152         else {
1153                 printf("literal %lu\n", two->size);
1154                 free(delta);
1155                 data = deflated;
1156                 data_size = deflate_size;
1157         }
1159         /* emit data encoded in base85 */
1160         cp = data;
1161         while (data_size) {
1162                 int bytes = (52 < data_size) ? 52 : data_size;
1163                 char line[70];
1164                 data_size -= bytes;
1165                 if (bytes <= 26)
1166                         line[0] = bytes + 'A' - 1;
1167                 else
1168                         line[0] = bytes - 26 + 'a' - 1;
1169                 encode_85(line + 1, cp, bytes);
1170                 cp = (char *) cp + bytes;
1171                 puts(line);
1172         }
1173         printf("\n");
1174         free(data);
1177 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
1179         printf("GIT binary patch\n");
1180         emit_binary_diff_body(one, two);
1181         emit_binary_diff_body(two, one);
1184 static void setup_diff_attr_check(struct git_attr_check *check)
1186         static struct git_attr *attr_diff;
1188         if (!attr_diff) {
1189                 attr_diff = git_attr("diff", 4);
1190         }
1191         check[0].attr = attr_diff;
1194 static void diff_filespec_check_attr(struct diff_filespec *one)
1196         struct git_attr_check attr_diff_check;
1197         int check_from_data = 0;
1199         if (one->checked_attr)
1200                 return;
1202         setup_diff_attr_check(&attr_diff_check);
1203         one->is_binary = 0;
1204         one->funcname_pattern_ident = NULL;
1206         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1207                 const char *value;
1209                 /* binaryness */
1210                 value = attr_diff_check.value;
1211                 if (ATTR_TRUE(value))
1212                         ;
1213                 else if (ATTR_FALSE(value))
1214                         one->is_binary = 1;
1215                 else
1216                         check_from_data = 1;
1218                 /* funcname pattern ident */
1219                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1220                         ;
1221                 else
1222                         one->funcname_pattern_ident = value;
1223         }
1225         if (check_from_data) {
1226                 if (!one->data && DIFF_FILE_VALID(one))
1227                         diff_populate_filespec(one, 0);
1229                 if (one->data)
1230                         one->is_binary = buffer_is_binary(one->data, one->size);
1231         }
1234 int diff_filespec_is_binary(struct diff_filespec *one)
1236         diff_filespec_check_attr(one);
1237         return one->is_binary;
1240 static const char *funcname_pattern(const char *ident)
1242         struct funcname_pattern *pp;
1244         read_config_if_needed();
1245         for (pp = funcname_pattern_list; pp; pp = pp->next)
1246                 if (!strcmp(ident, pp->name))
1247                         return pp->pattern;
1248         return NULL;
1251 static struct builtin_funcname_pattern {
1252         const char *name;
1253         const char *pattern;
1254 } builtin_funcname_pattern[] = {
1255         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1256                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1257                         "^[     ]*\\(\\([       ]*"
1258                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1259                         "[      ]*([^;]*$\\)" },
1260         { "tex", "^\\(\\\\\\(sub\\)*section{.*\\)$" },
1261 };
1263 static const char *diff_funcname_pattern(struct diff_filespec *one)
1265         const char *ident, *pattern;
1266         int i;
1268         diff_filespec_check_attr(one);
1269         ident = one->funcname_pattern_ident;
1271         if (!ident)
1272                 /*
1273                  * If the config file has "funcname.default" defined, that
1274                  * regexp is used; otherwise NULL is returned and xemit uses
1275                  * the built-in default.
1276                  */
1277                 return funcname_pattern("default");
1279         /* Look up custom "funcname.$ident" regexp from config. */
1280         pattern = funcname_pattern(ident);
1281         if (pattern)
1282                 return pattern;
1284         /*
1285          * And define built-in fallback patterns here.  Note that
1286          * these can be overriden by the user's config settings.
1287          */
1288         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1289                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1290                         return builtin_funcname_pattern[i].pattern;
1292         return NULL;
1295 static void builtin_diff(const char *name_a,
1296                          const char *name_b,
1297                          struct diff_filespec *one,
1298                          struct diff_filespec *two,
1299                          const char *xfrm_msg,
1300                          struct diff_options *o,
1301                          int complete_rewrite)
1303         mmfile_t mf1, mf2;
1304         const char *lbl[2];
1305         char *a_one, *b_two;
1306         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1307         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1309         a_one = quote_two("a/", name_a + (*name_a == '/'));
1310         b_two = quote_two("b/", name_b + (*name_b == '/'));
1311         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1312         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1313         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1314         if (lbl[0][0] == '/') {
1315                 /* /dev/null */
1316                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
1317                 if (xfrm_msg && xfrm_msg[0])
1318                         printf("%s%s%s\n", set, xfrm_msg, reset);
1319         }
1320         else if (lbl[1][0] == '/') {
1321                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
1322                 if (xfrm_msg && xfrm_msg[0])
1323                         printf("%s%s%s\n", set, xfrm_msg, reset);
1324         }
1325         else {
1326                 if (one->mode != two->mode) {
1327                         printf("%sold mode %06o%s\n", set, one->mode, reset);
1328                         printf("%snew mode %06o%s\n", set, two->mode, reset);
1329                 }
1330                 if (xfrm_msg && xfrm_msg[0])
1331                         printf("%s%s%s\n", set, xfrm_msg, reset);
1332                 /*
1333                  * we do not run diff between different kind
1334                  * of objects.
1335                  */
1336                 if ((one->mode ^ two->mode) & S_IFMT)
1337                         goto free_ab_and_return;
1338                 if (complete_rewrite) {
1339                         emit_rewrite_diff(name_a, name_b, one, two,
1340                                         DIFF_OPT_TST(o, COLOR_DIFF));
1341                         o->found_changes = 1;
1342                         goto free_ab_and_return;
1343                 }
1344         }
1346         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1347                 die("unable to read files to diff");
1349         if (!DIFF_OPT_TST(o, TEXT) &&
1350             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1351                 /* Quite common confusing case */
1352                 if (mf1.size == mf2.size &&
1353                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1354                         goto free_ab_and_return;
1355                 if (DIFF_OPT_TST(o, BINARY))
1356                         emit_binary_diff(&mf1, &mf2);
1357                 else
1358                         printf("Binary files %s and %s differ\n",
1359                                lbl[0], lbl[1]);
1360                 o->found_changes = 1;
1361         }
1362         else {
1363                 /* Crazy xdl interfaces.. */
1364                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1365                 xpparam_t xpp;
1366                 xdemitconf_t xecfg;
1367                 xdemitcb_t ecb;
1368                 struct emit_callback ecbdata;
1369                 const char *funcname_pattern;
1371                 funcname_pattern = diff_funcname_pattern(one);
1372                 if (!funcname_pattern)
1373                         funcname_pattern = diff_funcname_pattern(two);
1375                 memset(&xecfg, 0, sizeof(xecfg));
1376                 memset(&ecbdata, 0, sizeof(ecbdata));
1377                 ecbdata.label_path = lbl;
1378                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1379                 ecbdata.found_changesp = &o->found_changes;
1380                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1381                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1382                 xecfg.ctxlen = o->context;
1383                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1384                 if (funcname_pattern)
1385                         xdiff_set_find_func(&xecfg, funcname_pattern);
1386                 if (!diffopts)
1387                         ;
1388                 else if (!prefixcmp(diffopts, "--unified="))
1389                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1390                 else if (!prefixcmp(diffopts, "-u"))
1391                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1392                 ecb.outf = xdiff_outf;
1393                 ecb.priv = &ecbdata;
1394                 ecbdata.xm.consume = fn_out_consume;
1395                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1396                         ecbdata.diff_words =
1397                                 xcalloc(1, sizeof(struct diff_words_data));
1398                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1399                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1400                         free_diff_words_data(&ecbdata);
1401         }
1403  free_ab_and_return:
1404         diff_free_filespec_data(one);
1405         diff_free_filespec_data(two);
1406         free(a_one);
1407         free(b_two);
1408         return;
1411 static void builtin_diffstat(const char *name_a, const char *name_b,
1412                              struct diff_filespec *one,
1413                              struct diff_filespec *two,
1414                              struct diffstat_t *diffstat,
1415                              struct diff_options *o,
1416                              int complete_rewrite)
1418         mmfile_t mf1, mf2;
1419         struct diffstat_file *data;
1421         data = diffstat_add(diffstat, name_a, name_b);
1423         if (!one || !two) {
1424                 data->is_unmerged = 1;
1425                 return;
1426         }
1427         if (complete_rewrite) {
1428                 diff_populate_filespec(one, 0);
1429                 diff_populate_filespec(two, 0);
1430                 data->deleted = count_lines(one->data, one->size);
1431                 data->added = count_lines(two->data, two->size);
1432                 goto free_and_return;
1433         }
1434         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1435                 die("unable to read files to diff");
1437         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1438                 data->is_binary = 1;
1439                 data->added = mf2.size;
1440                 data->deleted = mf1.size;
1441         } else {
1442                 /* Crazy xdl interfaces.. */
1443                 xpparam_t xpp;
1444                 xdemitconf_t xecfg;
1445                 xdemitcb_t ecb;
1447                 memset(&xecfg, 0, sizeof(xecfg));
1448                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1449                 ecb.outf = xdiff_outf;
1450                 ecb.priv = diffstat;
1451                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1452         }
1454  free_and_return:
1455         diff_free_filespec_data(one);
1456         diff_free_filespec_data(two);
1459 static void builtin_checkdiff(const char *name_a, const char *name_b,
1460                              struct diff_filespec *one,
1461                              struct diff_filespec *two, struct diff_options *o)
1463         mmfile_t mf1, mf2;
1464         struct checkdiff_t data;
1466         if (!two)
1467                 return;
1469         memset(&data, 0, sizeof(data));
1470         data.xm.consume = checkdiff_consume;
1471         data.filename = name_b ? name_b : name_a;
1472         data.lineno = 0;
1473         data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1474         data.ws_rule = whitespace_rule(data.filename);
1476         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1477                 die("unable to read files to diff");
1479         if (diff_filespec_is_binary(two))
1480                 goto free_and_return;
1481         else {
1482                 /* Crazy xdl interfaces.. */
1483                 xpparam_t xpp;
1484                 xdemitconf_t xecfg;
1485                 xdemitcb_t ecb;
1487                 memset(&xecfg, 0, sizeof(xecfg));
1488                 xpp.flags = XDF_NEED_MINIMAL;
1489                 ecb.outf = xdiff_outf;
1490                 ecb.priv = &data;
1491                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1492         }
1493  free_and_return:
1494         diff_free_filespec_data(one);
1495         diff_free_filespec_data(two);
1496         if (data.status)
1497                 DIFF_OPT_SET(o, CHECK_FAILED);
1500 struct diff_filespec *alloc_filespec(const char *path)
1502         int namelen = strlen(path);
1503         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1505         memset(spec, 0, sizeof(*spec));
1506         spec->path = (char *)(spec + 1);
1507         memcpy(spec->path, path, namelen+1);
1508         spec->count = 1;
1509         return spec;
1512 void free_filespec(struct diff_filespec *spec)
1514         if (!--spec->count) {
1515                 diff_free_filespec_data(spec);
1516                 free(spec);
1517         }
1520 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1521                    unsigned short mode)
1523         if (mode) {
1524                 spec->mode = canon_mode(mode);
1525                 hashcpy(spec->sha1, sha1);
1526                 spec->sha1_valid = !is_null_sha1(sha1);
1527         }
1530 /*
1531  * Given a name and sha1 pair, if the index tells us the file in
1532  * the work tree has that object contents, return true, so that
1533  * prepare_temp_file() does not have to inflate and extract.
1534  */
1535 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1537         struct cache_entry *ce;
1538         struct stat st;
1539         int pos, len;
1541         /* We do not read the cache ourselves here, because the
1542          * benchmark with my previous version that always reads cache
1543          * shows that it makes things worse for diff-tree comparing
1544          * two linux-2.6 kernel trees in an already checked out work
1545          * tree.  This is because most diff-tree comparisons deal with
1546          * only a small number of files, while reading the cache is
1547          * expensive for a large project, and its cost outweighs the
1548          * savings we get by not inflating the object to a temporary
1549          * file.  Practically, this code only helps when we are used
1550          * by diff-cache --cached, which does read the cache before
1551          * calling us.
1552          */
1553         if (!active_cache)
1554                 return 0;
1556         /* We want to avoid the working directory if our caller
1557          * doesn't need the data in a normal file, this system
1558          * is rather slow with its stat/open/mmap/close syscalls,
1559          * and the object is contained in a pack file.  The pack
1560          * is probably already open and will be faster to obtain
1561          * the data through than the working directory.  Loose
1562          * objects however would tend to be slower as they need
1563          * to be individually opened and inflated.
1564          */
1565         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1566                 return 0;
1568         len = strlen(name);
1569         pos = cache_name_pos(name, len);
1570         if (pos < 0)
1571                 return 0;
1572         ce = active_cache[pos];
1573         if ((lstat(name, &st) < 0) ||
1574             !S_ISREG(st.st_mode) || /* careful! */
1575             ce_match_stat(ce, &st, 0) ||
1576             hashcmp(sha1, ce->sha1))
1577                 return 0;
1578         /* we return 1 only when we can stat, it is a regular file,
1579          * stat information matches, and sha1 recorded in the cache
1580          * matches.  I.e. we know the file in the work tree really is
1581          * the same as the <name, sha1> pair.
1582          */
1583         return 1;
1586 static int populate_from_stdin(struct diff_filespec *s)
1588         struct strbuf buf;
1589         size_t size = 0;
1591         strbuf_init(&buf, 0);
1592         if (strbuf_read(&buf, 0, 0) < 0)
1593                 return error("error while reading from stdin %s",
1594                                      strerror(errno));
1596         s->should_munmap = 0;
1597         s->data = strbuf_detach(&buf, &size);
1598         s->size = size;
1599         s->should_free = 1;
1600         return 0;
1603 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1605         int len;
1606         char *data = xmalloc(100);
1607         len = snprintf(data, 100,
1608                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1609         s->data = data;
1610         s->size = len;
1611         s->should_free = 1;
1612         if (size_only) {
1613                 s->data = NULL;
1614                 free(data);
1615         }
1616         return 0;
1619 /*
1620  * While doing rename detection and pickaxe operation, we may need to
1621  * grab the data for the blob (or file) for our own in-core comparison.
1622  * diff_filespec has data and size fields for this purpose.
1623  */
1624 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1626         int err = 0;
1627         if (!DIFF_FILE_VALID(s))
1628                 die("internal error: asking to populate invalid file.");
1629         if (S_ISDIR(s->mode))
1630                 return -1;
1632         if (s->data)
1633                 return 0;
1635         if (size_only && 0 < s->size)
1636                 return 0;
1638         if (S_ISGITLINK(s->mode))
1639                 return diff_populate_gitlink(s, size_only);
1641         if (!s->sha1_valid ||
1642             reuse_worktree_file(s->path, s->sha1, 0)) {
1643                 struct strbuf buf;
1644                 struct stat st;
1645                 int fd;
1647                 if (!strcmp(s->path, "-"))
1648                         return populate_from_stdin(s);
1650                 if (lstat(s->path, &st) < 0) {
1651                         if (errno == ENOENT) {
1652                         err_empty:
1653                                 err = -1;
1654                         empty:
1655                                 s->data = (char *)"";
1656                                 s->size = 0;
1657                                 return err;
1658                         }
1659                 }
1660                 s->size = xsize_t(st.st_size);
1661                 if (!s->size)
1662                         goto empty;
1663                 if (size_only)
1664                         return 0;
1665                 if (S_ISLNK(st.st_mode)) {
1666                         int ret;
1667                         s->data = xmalloc(s->size);
1668                         s->should_free = 1;
1669                         ret = readlink(s->path, s->data, s->size);
1670                         if (ret < 0) {
1671                                 free(s->data);
1672                                 goto err_empty;
1673                         }
1674                         return 0;
1675                 }
1676                 fd = open(s->path, O_RDONLY);
1677                 if (fd < 0)
1678                         goto err_empty;
1679                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1680                 close(fd);
1681                 s->should_munmap = 1;
1683                 /*
1684                  * Convert from working tree format to canonical git format
1685                  */
1686                 strbuf_init(&buf, 0);
1687                 if (convert_to_git(s->path, s->data, s->size, &buf)) {
1688                         size_t size = 0;
1689                         munmap(s->data, s->size);
1690                         s->should_munmap = 0;
1691                         s->data = strbuf_detach(&buf, &size);
1692                         s->size = size;
1693                         s->should_free = 1;
1694                 }
1695         }
1696         else {
1697                 enum object_type type;
1698                 if (size_only)
1699                         type = sha1_object_info(s->sha1, &s->size);
1700                 else {
1701                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1702                         s->should_free = 1;
1703                 }
1704         }
1705         return 0;
1708 void diff_free_filespec_blob(struct diff_filespec *s)
1710         if (s->should_free)
1711                 free(s->data);
1712         else if (s->should_munmap)
1713                 munmap(s->data, s->size);
1715         if (s->should_free || s->should_munmap) {
1716                 s->should_free = s->should_munmap = 0;
1717                 s->data = NULL;
1718         }
1721 void diff_free_filespec_data(struct diff_filespec *s)
1723         diff_free_filespec_blob(s);
1724         free(s->cnt_data);
1725         s->cnt_data = NULL;
1728 static void prep_temp_blob(struct diff_tempfile *temp,
1729                            void *blob,
1730                            unsigned long size,
1731                            const unsigned char *sha1,
1732                            int mode)
1734         int fd;
1736         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1737         if (fd < 0)
1738                 die("unable to create temp-file: %s", strerror(errno));
1739         if (write_in_full(fd, blob, size) != size)
1740                 die("unable to write temp-file");
1741         close(fd);
1742         temp->name = temp->tmp_path;
1743         strcpy(temp->hex, sha1_to_hex(sha1));
1744         temp->hex[40] = 0;
1745         sprintf(temp->mode, "%06o", mode);
1748 static void prepare_temp_file(const char *name,
1749                               struct diff_tempfile *temp,
1750                               struct diff_filespec *one)
1752         if (!DIFF_FILE_VALID(one)) {
1753         not_a_valid_file:
1754                 /* A '-' entry produces this for file-2, and
1755                  * a '+' entry produces this for file-1.
1756                  */
1757                 temp->name = "/dev/null";
1758                 strcpy(temp->hex, ".");
1759                 strcpy(temp->mode, ".");
1760                 return;
1761         }
1763         if (!one->sha1_valid ||
1764             reuse_worktree_file(name, one->sha1, 1)) {
1765                 struct stat st;
1766                 if (lstat(name, &st) < 0) {
1767                         if (errno == ENOENT)
1768                                 goto not_a_valid_file;
1769                         die("stat(%s): %s", name, strerror(errno));
1770                 }
1771                 if (S_ISLNK(st.st_mode)) {
1772                         int ret;
1773                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1774                         size_t sz = xsize_t(st.st_size);
1775                         if (sizeof(buf) <= st.st_size)
1776                                 die("symlink too long: %s", name);
1777                         ret = readlink(name, buf, sz);
1778                         if (ret < 0)
1779                                 die("readlink(%s)", name);
1780                         prep_temp_blob(temp, buf, sz,
1781                                        (one->sha1_valid ?
1782                                         one->sha1 : null_sha1),
1783                                        (one->sha1_valid ?
1784                                         one->mode : S_IFLNK));
1785                 }
1786                 else {
1787                         /* we can borrow from the file in the work tree */
1788                         temp->name = name;
1789                         if (!one->sha1_valid)
1790                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1791                         else
1792                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1793                         /* Even though we may sometimes borrow the
1794                          * contents from the work tree, we always want
1795                          * one->mode.  mode is trustworthy even when
1796                          * !(one->sha1_valid), as long as
1797                          * DIFF_FILE_VALID(one).
1798                          */
1799                         sprintf(temp->mode, "%06o", one->mode);
1800                 }
1801                 return;
1802         }
1803         else {
1804                 if (diff_populate_filespec(one, 0))
1805                         die("cannot read data blob for %s", one->path);
1806                 prep_temp_blob(temp, one->data, one->size,
1807                                one->sha1, one->mode);
1808         }
1811 static void remove_tempfile(void)
1813         int i;
1815         for (i = 0; i < 2; i++)
1816                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1817                         unlink(diff_temp[i].name);
1818                         diff_temp[i].name = NULL;
1819                 }
1822 static void remove_tempfile_on_signal(int signo)
1824         remove_tempfile();
1825         signal(SIGINT, SIG_DFL);
1826         raise(signo);
1829 /* An external diff command takes:
1830  *
1831  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1832  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1833  *
1834  */
1835 static void run_external_diff(const char *pgm,
1836                               const char *name,
1837                               const char *other,
1838                               struct diff_filespec *one,
1839                               struct diff_filespec *two,
1840                               const char *xfrm_msg,
1841                               int complete_rewrite)
1843         const char *spawn_arg[10];
1844         struct diff_tempfile *temp = diff_temp;
1845         int retval;
1846         static int atexit_asked = 0;
1847         const char *othername;
1848         const char **arg = &spawn_arg[0];
1850         othername = (other? other : name);
1851         if (one && two) {
1852                 prepare_temp_file(name, &temp[0], one);
1853                 prepare_temp_file(othername, &temp[1], two);
1854                 if (! atexit_asked &&
1855                     (temp[0].name == temp[0].tmp_path ||
1856                      temp[1].name == temp[1].tmp_path)) {
1857                         atexit_asked = 1;
1858                         atexit(remove_tempfile);
1859                 }
1860                 signal(SIGINT, remove_tempfile_on_signal);
1861         }
1863         if (one && two) {
1864                 *arg++ = pgm;
1865                 *arg++ = name;
1866                 *arg++ = temp[0].name;
1867                 *arg++ = temp[0].hex;
1868                 *arg++ = temp[0].mode;
1869                 *arg++ = temp[1].name;
1870                 *arg++ = temp[1].hex;
1871                 *arg++ = temp[1].mode;
1872                 if (other) {
1873                         *arg++ = other;
1874                         *arg++ = xfrm_msg;
1875                 }
1876         } else {
1877                 *arg++ = pgm;
1878                 *arg++ = name;
1879         }
1880         *arg = NULL;
1881         fflush(NULL);
1882         retval = run_command_v_opt(spawn_arg, 0);
1883         remove_tempfile();
1884         if (retval) {
1885                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1886                 exit(1);
1887         }
1890 static const char *external_diff_attr(const char *name)
1892         struct git_attr_check attr_diff_check;
1894         setup_diff_attr_check(&attr_diff_check);
1895         if (!git_checkattr(name, 1, &attr_diff_check)) {
1896                 const char *value = attr_diff_check.value;
1897                 if (!ATTR_TRUE(value) &&
1898                     !ATTR_FALSE(value) &&
1899                     !ATTR_UNSET(value)) {
1900                         struct ll_diff_driver *drv;
1902                         read_config_if_needed();
1903                         for (drv = user_diff; drv; drv = drv->next)
1904                                 if (!strcmp(drv->name, value))
1905                                         return drv->cmd;
1906                 }
1907         }
1908         return NULL;
1911 static void run_diff_cmd(const char *pgm,
1912                          const char *name,
1913                          const char *other,
1914                          struct diff_filespec *one,
1915                          struct diff_filespec *two,
1916                          const char *xfrm_msg,
1917                          struct diff_options *o,
1918                          int complete_rewrite)
1920         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
1921                 pgm = NULL;
1922         else {
1923                 const char *cmd = external_diff_attr(name);
1924                 if (cmd)
1925                         pgm = cmd;
1926         }
1928         if (pgm) {
1929                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1930                                   complete_rewrite);
1931                 return;
1932         }
1933         if (one && two)
1934                 builtin_diff(name, other ? other : name,
1935                              one, two, xfrm_msg, o, complete_rewrite);
1936         else
1937                 printf("* Unmerged path %s\n", name);
1940 static void diff_fill_sha1_info(struct diff_filespec *one)
1942         if (DIFF_FILE_VALID(one)) {
1943                 if (!one->sha1_valid) {
1944                         struct stat st;
1945                         if (!strcmp(one->path, "-")) {
1946                                 hashcpy(one->sha1, null_sha1);
1947                                 return;
1948                         }
1949                         if (lstat(one->path, &st) < 0)
1950                                 die("stat %s", one->path);
1951                         if (index_path(one->sha1, one->path, &st, 0))
1952                                 die("cannot hash %s\n", one->path);
1953                 }
1954         }
1955         else
1956                 hashclr(one->sha1);
1959 static int similarity_index(struct diff_filepair *p)
1961         return p->score * 100 / MAX_SCORE;
1964 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1966         const char *pgm = external_diff();
1967         struct strbuf msg;
1968         char *xfrm_msg;
1969         struct diff_filespec *one = p->one;
1970         struct diff_filespec *two = p->two;
1971         const char *name;
1972         const char *other;
1973         int complete_rewrite = 0;
1976         if (DIFF_PAIR_UNMERGED(p)) {
1977                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1978                 return;
1979         }
1981         name  = p->one->path;
1982         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1983         diff_fill_sha1_info(one);
1984         diff_fill_sha1_info(two);
1986         strbuf_init(&msg, PATH_MAX * 2 + 300);
1987         switch (p->status) {
1988         case DIFF_STATUS_COPIED:
1989                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
1990                 strbuf_addstr(&msg, "\ncopy from ");
1991                 quote_c_style(name, &msg, NULL, 0);
1992                 strbuf_addstr(&msg, "\ncopy to ");
1993                 quote_c_style(other, &msg, NULL, 0);
1994                 strbuf_addch(&msg, '\n');
1995                 break;
1996         case DIFF_STATUS_RENAMED:
1997                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
1998                 strbuf_addstr(&msg, "\nrename from ");
1999                 quote_c_style(name, &msg, NULL, 0);
2000                 strbuf_addstr(&msg, "\nrename to ");
2001                 quote_c_style(other, &msg, NULL, 0);
2002                 strbuf_addch(&msg, '\n');
2003                 break;
2004         case DIFF_STATUS_MODIFIED:
2005                 if (p->score) {
2006                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2007                                         similarity_index(p));
2008                         complete_rewrite = 1;
2009                         break;
2010                 }
2011                 /* fallthru */
2012         default:
2013                 /* nothing */
2014                 ;
2015         }
2017         if (hashcmp(one->sha1, two->sha1)) {
2018                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2020                 if (DIFF_OPT_TST(o, BINARY)) {
2021                         mmfile_t mf;
2022                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2023                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2024                                 abbrev = 40;
2025                 }
2026                 strbuf_addf(&msg, "index %.*s..%.*s",
2027                                 abbrev, sha1_to_hex(one->sha1),
2028                                 abbrev, sha1_to_hex(two->sha1));
2029                 if (one->mode == two->mode)
2030                         strbuf_addf(&msg, " %06o", one->mode);
2031                 strbuf_addch(&msg, '\n');
2032         }
2034         if (msg.len)
2035                 strbuf_setlen(&msg, msg.len - 1);
2036         xfrm_msg = msg.len ? msg.buf : NULL;
2038         if (!pgm &&
2039             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2040             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2041                 /* a filepair that changes between file and symlink
2042                  * needs to be split into deletion and creation.
2043                  */
2044                 struct diff_filespec *null = alloc_filespec(two->path);
2045                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
2046                 free(null);
2047                 null = alloc_filespec(one->path);
2048                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
2049                 free(null);
2050         }
2051         else
2052                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
2053                              complete_rewrite);
2055         strbuf_release(&msg);
2058 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2059                          struct diffstat_t *diffstat)
2061         const char *name;
2062         const char *other;
2063         int complete_rewrite = 0;
2065         if (DIFF_PAIR_UNMERGED(p)) {
2066                 /* unmerged */
2067                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2068                 return;
2069         }
2071         name = p->one->path;
2072         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2074         diff_fill_sha1_info(p->one);
2075         diff_fill_sha1_info(p->two);
2077         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2078                 complete_rewrite = 1;
2079         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2082 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2084         const char *name;
2085         const char *other;
2087         if (DIFF_PAIR_UNMERGED(p)) {
2088                 /* unmerged */
2089                 return;
2090         }
2092         name = p->one->path;
2093         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2095         diff_fill_sha1_info(p->one);
2096         diff_fill_sha1_info(p->two);
2098         builtin_checkdiff(name, other, p->one, p->two, o);
2101 void diff_setup(struct diff_options *options)
2103         memset(options, 0, sizeof(*options));
2104         options->line_termination = '\n';
2105         options->break_opt = -1;
2106         options->rename_limit = -1;
2107         options->context = 3;
2108         options->msg_sep = "";
2110         options->change = diff_change;
2111         options->add_remove = diff_addremove;
2112         if (diff_use_color_default)
2113                 DIFF_OPT_SET(options, COLOR_DIFF);
2114         else
2115                 DIFF_OPT_CLR(options, COLOR_DIFF);
2116         options->detect_rename = diff_detect_rename_default;
2119 int diff_setup_done(struct diff_options *options)
2121         int count = 0;
2123         if (options->output_format & DIFF_FORMAT_NAME)
2124                 count++;
2125         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2126                 count++;
2127         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2128         {
2129                 count++;
2130                 if (DIFF_OPT_TST(options, QUIET) ||
2131                     DIFF_OPT_TST(options, EXIT_WITH_STATUS))
2132                         die("--check may not be used with --quiet or --exit-code");
2133         }
2134         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2135                 count++;
2136         if (count > 1)
2137                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2139         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2140                 options->detect_rename = DIFF_DETECT_COPY;
2142         if (options->output_format & (DIFF_FORMAT_NAME |
2143                                       DIFF_FORMAT_NAME_STATUS |
2144                                       DIFF_FORMAT_CHECKDIFF |
2145                                       DIFF_FORMAT_NO_OUTPUT))
2146                 options->output_format &= ~(DIFF_FORMAT_RAW |
2147                                             DIFF_FORMAT_NUMSTAT |
2148                                             DIFF_FORMAT_DIFFSTAT |
2149                                             DIFF_FORMAT_SHORTSTAT |
2150                                             DIFF_FORMAT_SUMMARY |
2151                                             DIFF_FORMAT_PATCH);
2153         /*
2154          * These cases always need recursive; we do not drop caller-supplied
2155          * recursive bits for other formats here.
2156          */
2157         if (options->output_format & (DIFF_FORMAT_PATCH |
2158                                       DIFF_FORMAT_NUMSTAT |
2159                                       DIFF_FORMAT_DIFFSTAT |
2160                                       DIFF_FORMAT_SHORTSTAT |
2161                                       DIFF_FORMAT_SUMMARY |
2162                                       DIFF_FORMAT_CHECKDIFF))
2163                 DIFF_OPT_SET(options, RECURSIVE);
2164         /*
2165          * Also pickaxe would not work very well if you do not say recursive
2166          */
2167         if (options->pickaxe)
2168                 DIFF_OPT_SET(options, RECURSIVE);
2170         if (options->detect_rename && options->rename_limit < 0)
2171                 options->rename_limit = diff_rename_limit_default;
2172         if (options->setup & DIFF_SETUP_USE_CACHE) {
2173                 if (!active_cache)
2174                         /* read-cache does not die even when it fails
2175                          * so it is safe for us to do this here.  Also
2176                          * it does not smudge active_cache or active_nr
2177                          * when it fails, so we do not have to worry about
2178                          * cleaning it up ourselves either.
2179                          */
2180                         read_cache();
2181         }
2182         if (options->abbrev <= 0 || 40 < options->abbrev)
2183                 options->abbrev = 40; /* full */
2185         /*
2186          * It does not make sense to show the first hit we happened
2187          * to have found.  It does not make sense not to return with
2188          * exit code in such a case either.
2189          */
2190         if (DIFF_OPT_TST(options, QUIET)) {
2191                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2192                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2193         }
2195         /*
2196          * If we postprocess in diffcore, we cannot simply return
2197          * upon the first hit.  We need to run diff as usual.
2198          */
2199         if (options->pickaxe || options->filter)
2200                 DIFF_OPT_CLR(options, QUIET);
2202         return 0;
2205 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2207         char c, *eq;
2208         int len;
2210         if (*arg != '-')
2211                 return 0;
2212         c = *++arg;
2213         if (!c)
2214                 return 0;
2215         if (c == arg_short) {
2216                 c = *++arg;
2217                 if (!c)
2218                         return 1;
2219                 if (val && isdigit(c)) {
2220                         char *end;
2221                         int n = strtoul(arg, &end, 10);
2222                         if (*end)
2223                                 return 0;
2224                         *val = n;
2225                         return 1;
2226                 }
2227                 return 0;
2228         }
2229         if (c != '-')
2230                 return 0;
2231         arg++;
2232         eq = strchr(arg, '=');
2233         if (eq)
2234                 len = eq - arg;
2235         else
2236                 len = strlen(arg);
2237         if (!len || strncmp(arg, arg_long, len))
2238                 return 0;
2239         if (eq) {
2240                 int n;
2241                 char *end;
2242                 if (!isdigit(*++eq))
2243                         return 0;
2244                 n = strtoul(eq, &end, 10);
2245                 if (*end)
2246                         return 0;
2247                 *val = n;
2248         }
2249         return 1;
2252 static int diff_scoreopt_parse(const char *opt);
2254 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2256         const char *arg = av[0];
2258         /* Output format options */
2259         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2260                 options->output_format |= DIFF_FORMAT_PATCH;
2261         else if (opt_arg(arg, 'U', "unified", &options->context))
2262                 options->output_format |= DIFF_FORMAT_PATCH;
2263         else if (!strcmp(arg, "--raw"))
2264                 options->output_format |= DIFF_FORMAT_RAW;
2265         else if (!strcmp(arg, "--patch-with-raw"))
2266                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2267         else if (!strcmp(arg, "--numstat"))
2268                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2269         else if (!strcmp(arg, "--shortstat"))
2270                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2271         else if (!strcmp(arg, "--check"))
2272                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2273         else if (!strcmp(arg, "--summary"))
2274                 options->output_format |= DIFF_FORMAT_SUMMARY;
2275         else if (!strcmp(arg, "--patch-with-stat"))
2276                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2277         else if (!strcmp(arg, "--name-only"))
2278                 options->output_format |= DIFF_FORMAT_NAME;
2279         else if (!strcmp(arg, "--name-status"))
2280                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2281         else if (!strcmp(arg, "-s"))
2282                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2283         else if (!prefixcmp(arg, "--stat")) {
2284                 char *end;
2285                 int width = options->stat_width;
2286                 int name_width = options->stat_name_width;
2287                 arg += 6;
2288                 end = (char *)arg;
2290                 switch (*arg) {
2291                 case '-':
2292                         if (!prefixcmp(arg, "-width="))
2293                                 width = strtoul(arg + 7, &end, 10);
2294                         else if (!prefixcmp(arg, "-name-width="))
2295                                 name_width = strtoul(arg + 12, &end, 10);
2296                         break;
2297                 case '=':
2298                         width = strtoul(arg+1, &end, 10);
2299                         if (*end == ',')
2300                                 name_width = strtoul(end+1, &end, 10);
2301                 }
2303                 /* Important! This checks all the error cases! */
2304                 if (*end)
2305                         return 0;
2306                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2307                 options->stat_name_width = name_width;
2308                 options->stat_width = width;
2309         }
2311         /* renames options */
2312         else if (!prefixcmp(arg, "-B")) {
2313                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2314                         return -1;
2315         }
2316         else if (!prefixcmp(arg, "-M")) {
2317                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2318                         return -1;
2319                 options->detect_rename = DIFF_DETECT_RENAME;
2320         }
2321         else if (!prefixcmp(arg, "-C")) {
2322                 if (options->detect_rename == DIFF_DETECT_COPY)
2323                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2324                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2325                         return -1;
2326                 options->detect_rename = DIFF_DETECT_COPY;
2327         }
2328         else if (!strcmp(arg, "--no-renames"))
2329                 options->detect_rename = 0;
2331         /* xdiff options */
2332         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2333                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2334         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2335                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2336         else if (!strcmp(arg, "--ignore-space-at-eol"))
2337                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2339         /* flags options */
2340         else if (!strcmp(arg, "--binary")) {
2341                 options->output_format |= DIFF_FORMAT_PATCH;
2342                 DIFF_OPT_SET(options, BINARY);
2343         }
2344         else if (!strcmp(arg, "--full-index"))
2345                 DIFF_OPT_SET(options, FULL_INDEX);
2346         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2347                 DIFF_OPT_SET(options, TEXT);
2348         else if (!strcmp(arg, "-R"))
2349                 DIFF_OPT_SET(options, REVERSE_DIFF);
2350         else if (!strcmp(arg, "--find-copies-harder"))
2351                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2352         else if (!strcmp(arg, "--follow"))
2353                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2354         else if (!strcmp(arg, "--color"))
2355                 DIFF_OPT_SET(options, COLOR_DIFF);
2356         else if (!strcmp(arg, "--no-color"))
2357                 DIFF_OPT_CLR(options, COLOR_DIFF);
2358         else if (!strcmp(arg, "--color-words"))
2359                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2360         else if (!strcmp(arg, "--exit-code"))
2361                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2362         else if (!strcmp(arg, "--quiet"))
2363                 DIFF_OPT_SET(options, QUIET);
2364         else if (!strcmp(arg, "--ext-diff"))
2365                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2366         else if (!strcmp(arg, "--no-ext-diff"))
2367                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2369         /* misc options */
2370         else if (!strcmp(arg, "-z"))
2371                 options->line_termination = 0;
2372         else if (!prefixcmp(arg, "-l"))
2373                 options->rename_limit = strtoul(arg+2, NULL, 10);
2374         else if (!prefixcmp(arg, "-S"))
2375                 options->pickaxe = arg + 2;
2376         else if (!strcmp(arg, "--pickaxe-all"))
2377                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2378         else if (!strcmp(arg, "--pickaxe-regex"))
2379                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2380         else if (!prefixcmp(arg, "-O"))
2381                 options->orderfile = arg + 2;
2382         else if (!prefixcmp(arg, "--diff-filter="))
2383                 options->filter = arg + 14;
2384         else if (!strcmp(arg, "--abbrev"))
2385                 options->abbrev = DEFAULT_ABBREV;
2386         else if (!prefixcmp(arg, "--abbrev=")) {
2387                 options->abbrev = strtoul(arg + 9, NULL, 10);
2388                 if (options->abbrev < MINIMUM_ABBREV)
2389                         options->abbrev = MINIMUM_ABBREV;
2390                 else if (40 < options->abbrev)
2391                         options->abbrev = 40;
2392         }
2393         else
2394                 return 0;
2395         return 1;
2398 static int parse_num(const char **cp_p)
2400         unsigned long num, scale;
2401         int ch, dot;
2402         const char *cp = *cp_p;
2404         num = 0;
2405         scale = 1;
2406         dot = 0;
2407         for(;;) {
2408                 ch = *cp;
2409                 if ( !dot && ch == '.' ) {
2410                         scale = 1;
2411                         dot = 1;
2412                 } else if ( ch == '%' ) {
2413                         scale = dot ? scale*100 : 100;
2414                         cp++;   /* % is always at the end */
2415                         break;
2416                 } else if ( ch >= '0' && ch <= '9' ) {
2417                         if ( scale < 100000 ) {
2418                                 scale *= 10;
2419                                 num = (num*10) + (ch-'0');
2420                         }
2421                 } else {
2422                         break;
2423                 }
2424                 cp++;
2425         }
2426         *cp_p = cp;
2428         /* user says num divided by scale and we say internally that
2429          * is MAX_SCORE * num / scale.
2430          */
2431         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2434 static int diff_scoreopt_parse(const char *opt)
2436         int opt1, opt2, cmd;
2438         if (*opt++ != '-')
2439                 return -1;
2440         cmd = *opt++;
2441         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2442                 return -1; /* that is not a -M, -C nor -B option */
2444         opt1 = parse_num(&opt);
2445         if (cmd != 'B')
2446                 opt2 = 0;
2447         else {
2448                 if (*opt == 0)
2449                         opt2 = 0;
2450                 else if (*opt != '/')
2451                         return -1; /* we expect -B80/99 or -B80 */
2452                 else {
2453                         opt++;
2454                         opt2 = parse_num(&opt);
2455                 }
2456         }
2457         if (*opt != 0)
2458                 return -1;
2459         return opt1 | (opt2 << 16);
2462 struct diff_queue_struct diff_queued_diff;
2464 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2466         if (queue->alloc <= queue->nr) {
2467                 queue->alloc = alloc_nr(queue->alloc);
2468                 queue->queue = xrealloc(queue->queue,
2469                                         sizeof(dp) * queue->alloc);
2470         }
2471         queue->queue[queue->nr++] = dp;
2474 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2475                                  struct diff_filespec *one,
2476                                  struct diff_filespec *two)
2478         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2479         dp->one = one;
2480         dp->two = two;
2481         if (queue)
2482                 diff_q(queue, dp);
2483         return dp;
2486 void diff_free_filepair(struct diff_filepair *p)
2488         free_filespec(p->one);
2489         free_filespec(p->two);
2490         free(p);
2493 /* This is different from find_unique_abbrev() in that
2494  * it stuffs the result with dots for alignment.
2495  */
2496 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2498         int abblen;
2499         const char *abbrev;
2500         if (len == 40)
2501                 return sha1_to_hex(sha1);
2503         abbrev = find_unique_abbrev(sha1, len);
2504         if (!abbrev)
2505                 return sha1_to_hex(sha1);
2506         abblen = strlen(abbrev);
2507         if (abblen < 37) {
2508                 static char hex[41];
2509                 if (len < abblen && abblen <= len + 2)
2510                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2511                 else
2512                         sprintf(hex, "%s...", abbrev);
2513                 return hex;
2514         }
2515         return sha1_to_hex(sha1);
2518 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2520         int line_termination = opt->line_termination;
2521         int inter_name_termination = line_termination ? '\t' : '\0';
2523         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2524                 printf(":%06o %06o %s ", p->one->mode, p->two->mode,
2525                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2526                 printf("%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2527         }
2528         if (p->score) {
2529                 printf("%c%03d%c", p->status, similarity_index(p),
2530                            inter_name_termination);
2531         } else {
2532                 printf("%c%c", p->status, inter_name_termination);
2533         }
2535         if (p->status == DIFF_STATUS_COPIED || p->status == DIFF_STATUS_RENAMED) {
2536                 write_name_quoted(p->one->path, stdout, inter_name_termination);
2537                 write_name_quoted(p->two->path, stdout, line_termination);
2538         } else {
2539                 const char *path = p->one->mode ? p->one->path : p->two->path;
2540                 write_name_quoted(path, stdout, line_termination);
2541         }
2544 int diff_unmodified_pair(struct diff_filepair *p)
2546         /* This function is written stricter than necessary to support
2547          * the currently implemented transformers, but the idea is to
2548          * let transformers to produce diff_filepairs any way they want,
2549          * and filter and clean them up here before producing the output.
2550          */
2551         struct diff_filespec *one = p->one, *two = p->two;
2553         if (DIFF_PAIR_UNMERGED(p))
2554                 return 0; /* unmerged is interesting */
2556         /* deletion, addition, mode or type change
2557          * and rename are all interesting.
2558          */
2559         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2560             DIFF_PAIR_MODE_CHANGED(p) ||
2561             strcmp(one->path, two->path))
2562                 return 0;
2564         /* both are valid and point at the same path.  that is, we are
2565          * dealing with a change.
2566          */
2567         if (one->sha1_valid && two->sha1_valid &&
2568             !hashcmp(one->sha1, two->sha1))
2569                 return 1; /* no change */
2570         if (!one->sha1_valid && !two->sha1_valid)
2571                 return 1; /* both look at the same file on the filesystem. */
2572         return 0;
2575 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2577         if (diff_unmodified_pair(p))
2578                 return;
2580         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2581             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2582                 return; /* no tree diffs in patch format */
2584         run_diff(p, o);
2587 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2588                             struct diffstat_t *diffstat)
2590         if (diff_unmodified_pair(p))
2591                 return;
2593         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2594             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2595                 return; /* no tree diffs in patch format */
2597         run_diffstat(p, o, diffstat);
2600 static void diff_flush_checkdiff(struct diff_filepair *p,
2601                 struct diff_options *o)
2603         if (diff_unmodified_pair(p))
2604                 return;
2606         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2607             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2608                 return; /* no tree diffs in patch format */
2610         run_checkdiff(p, o);
2613 int diff_queue_is_empty(void)
2615         struct diff_queue_struct *q = &diff_queued_diff;
2616         int i;
2617         for (i = 0; i < q->nr; i++)
2618                 if (!diff_unmodified_pair(q->queue[i]))
2619                         return 0;
2620         return 1;
2623 #if DIFF_DEBUG
2624 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2626         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2627                 x, one ? one : "",
2628                 s->path,
2629                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2630                 s->mode,
2631                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2632         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2633                 x, one ? one : "",
2634                 s->size, s->xfrm_flags);
2637 void diff_debug_filepair(const struct diff_filepair *p, int i)
2639         diff_debug_filespec(p->one, i, "one");
2640         diff_debug_filespec(p->two, i, "two");
2641         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2642                 p->score, p->status ? p->status : '?',
2643                 p->one->rename_used, p->broken_pair);
2646 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2648         int i;
2649         if (msg)
2650                 fprintf(stderr, "%s\n", msg);
2651         fprintf(stderr, "q->nr = %d\n", q->nr);
2652         for (i = 0; i < q->nr; i++) {
2653                 struct diff_filepair *p = q->queue[i];
2654                 diff_debug_filepair(p, i);
2655         }
2657 #endif
2659 static void diff_resolve_rename_copy(void)
2661         int i;
2662         struct diff_filepair *p;
2663         struct diff_queue_struct *q = &diff_queued_diff;
2665         diff_debug_queue("resolve-rename-copy", q);
2667         for (i = 0; i < q->nr; i++) {
2668                 p = q->queue[i];
2669                 p->status = 0; /* undecided */
2670                 if (DIFF_PAIR_UNMERGED(p))
2671                         p->status = DIFF_STATUS_UNMERGED;
2672                 else if (!DIFF_FILE_VALID(p->one))
2673                         p->status = DIFF_STATUS_ADDED;
2674                 else if (!DIFF_FILE_VALID(p->two))
2675                         p->status = DIFF_STATUS_DELETED;
2676                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2677                         p->status = DIFF_STATUS_TYPE_CHANGED;
2679                 /* from this point on, we are dealing with a pair
2680                  * whose both sides are valid and of the same type, i.e.
2681                  * either in-place edit or rename/copy edit.
2682                  */
2683                 else if (DIFF_PAIR_RENAME(p)) {
2684                         /*
2685                          * A rename might have re-connected a broken
2686                          * pair up, causing the pathnames to be the
2687                          * same again. If so, that's not a rename at
2688                          * all, just a modification..
2689                          *
2690                          * Otherwise, see if this source was used for
2691                          * multiple renames, in which case we decrement
2692                          * the count, and call it a copy.
2693                          */
2694                         if (!strcmp(p->one->path, p->two->path))
2695                                 p->status = DIFF_STATUS_MODIFIED;
2696                         else if (--p->one->rename_used > 0)
2697                                 p->status = DIFF_STATUS_COPIED;
2698                         else
2699                                 p->status = DIFF_STATUS_RENAMED;
2700                 }
2701                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2702                          p->one->mode != p->two->mode ||
2703                          is_null_sha1(p->one->sha1))
2704                         p->status = DIFF_STATUS_MODIFIED;
2705                 else {
2706                         /* This is a "no-change" entry and should not
2707                          * happen anymore, but prepare for broken callers.
2708                          */
2709                         error("feeding unmodified %s to diffcore",
2710                               p->one->path);
2711                         p->status = DIFF_STATUS_UNKNOWN;
2712                 }
2713         }
2714         diff_debug_queue("resolve-rename-copy done", q);
2717 static int check_pair_status(struct diff_filepair *p)
2719         switch (p->status) {
2720         case DIFF_STATUS_UNKNOWN:
2721                 return 0;
2722         case 0:
2723                 die("internal error in diff-resolve-rename-copy");
2724         default:
2725                 return 1;
2726         }
2729 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2731         int fmt = opt->output_format;
2733         if (fmt & DIFF_FORMAT_CHECKDIFF)
2734                 diff_flush_checkdiff(p, opt);
2735         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2736                 diff_flush_raw(p, opt);
2737         else if (fmt & DIFF_FORMAT_NAME)
2738                 write_name_quoted(p->two->path, stdout, opt->line_termination);
2741 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2743         if (fs->mode)
2744                 printf(" %s mode %06o ", newdelete, fs->mode);
2745         else
2746                 printf(" %s ", newdelete);
2747         write_name_quoted(fs->path, stdout, '\n');
2751 static void show_mode_change(struct diff_filepair *p, int show_name)
2753         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2754                 printf(" mode change %06o => %06o%c", p->one->mode, p->two->mode,
2755                         show_name ? ' ' : '\n');
2756                 if (show_name) {
2757                         write_name_quoted(p->two->path, stdout, '\n');
2758                 }
2759         }
2762 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2764         char *names = pprint_rename(p->one->path, p->two->path);
2766         printf(" %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2767         free(names);
2768         show_mode_change(p, 0);
2771 static void diff_summary(struct diff_filepair *p)
2773         switch(p->status) {
2774         case DIFF_STATUS_DELETED:
2775                 show_file_mode_name("delete", p->one);
2776                 break;
2777         case DIFF_STATUS_ADDED:
2778                 show_file_mode_name("create", p->two);
2779                 break;
2780         case DIFF_STATUS_COPIED:
2781                 show_rename_copy("copy", p);
2782                 break;
2783         case DIFF_STATUS_RENAMED:
2784                 show_rename_copy("rename", p);
2785                 break;
2786         default:
2787                 if (p->score) {
2788                         fputs(" rewrite ", stdout);
2789                         write_name_quoted(p->two->path, stdout, ' ');
2790                         printf("(%d%%)\n", similarity_index(p));
2791                 }
2792                 show_mode_change(p, !p->score);
2793                 break;
2794         }
2797 struct patch_id_t {
2798         struct xdiff_emit_state xm;
2799         SHA_CTX *ctx;
2800         int patchlen;
2801 };
2803 static int remove_space(char *line, int len)
2805         int i;
2806         char *dst = line;
2807         unsigned char c;
2809         for (i = 0; i < len; i++)
2810                 if (!isspace((c = line[i])))
2811                         *dst++ = c;
2813         return dst - line;
2816 static void patch_id_consume(void *priv, char *line, unsigned long len)
2818         struct patch_id_t *data = priv;
2819         int new_len;
2821         /* Ignore line numbers when computing the SHA1 of the patch */
2822         if (!prefixcmp(line, "@@ -"))
2823                 return;
2825         new_len = remove_space(line, len);
2827         SHA1_Update(data->ctx, line, new_len);
2828         data->patchlen += new_len;
2831 /* returns 0 upon success, and writes result into sha1 */
2832 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2834         struct diff_queue_struct *q = &diff_queued_diff;
2835         int i;
2836         SHA_CTX ctx;
2837         struct patch_id_t data;
2838         char buffer[PATH_MAX * 4 + 20];
2840         SHA1_Init(&ctx);
2841         memset(&data, 0, sizeof(struct patch_id_t));
2842         data.ctx = &ctx;
2843         data.xm.consume = patch_id_consume;
2845         for (i = 0; i < q->nr; i++) {
2846                 xpparam_t xpp;
2847                 xdemitconf_t xecfg;
2848                 xdemitcb_t ecb;
2849                 mmfile_t mf1, mf2;
2850                 struct diff_filepair *p = q->queue[i];
2851                 int len1, len2;
2853                 memset(&xecfg, 0, sizeof(xecfg));
2854                 if (p->status == 0)
2855                         return error("internal diff status error");
2856                 if (p->status == DIFF_STATUS_UNKNOWN)
2857                         continue;
2858                 if (diff_unmodified_pair(p))
2859                         continue;
2860                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2861                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2862                         continue;
2863                 if (DIFF_PAIR_UNMERGED(p))
2864                         continue;
2866                 diff_fill_sha1_info(p->one);
2867                 diff_fill_sha1_info(p->two);
2868                 if (fill_mmfile(&mf1, p->one) < 0 ||
2869                                 fill_mmfile(&mf2, p->two) < 0)
2870                         return error("unable to read files to diff");
2872                 len1 = remove_space(p->one->path, strlen(p->one->path));
2873                 len2 = remove_space(p->two->path, strlen(p->two->path));
2874                 if (p->one->mode == 0)
2875                         len1 = snprintf(buffer, sizeof(buffer),
2876                                         "diff--gita/%.*sb/%.*s"
2877                                         "newfilemode%06o"
2878                                         "---/dev/null"
2879                                         "+++b/%.*s",
2880                                         len1, p->one->path,
2881                                         len2, p->two->path,
2882                                         p->two->mode,
2883                                         len2, p->two->path);
2884                 else if (p->two->mode == 0)
2885                         len1 = snprintf(buffer, sizeof(buffer),
2886                                         "diff--gita/%.*sb/%.*s"
2887                                         "deletedfilemode%06o"
2888                                         "---a/%.*s"
2889                                         "+++/dev/null",
2890                                         len1, p->one->path,
2891                                         len2, p->two->path,
2892                                         p->one->mode,
2893                                         len1, p->one->path);
2894                 else
2895                         len1 = snprintf(buffer, sizeof(buffer),
2896                                         "diff--gita/%.*sb/%.*s"
2897                                         "---a/%.*s"
2898                                         "+++b/%.*s",
2899                                         len1, p->one->path,
2900                                         len2, p->two->path,
2901                                         len1, p->one->path,
2902                                         len2, p->two->path);
2903                 SHA1_Update(&ctx, buffer, len1);
2905                 xpp.flags = XDF_NEED_MINIMAL;
2906                 xecfg.ctxlen = 3;
2907                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2908                 ecb.outf = xdiff_outf;
2909                 ecb.priv = &data;
2910                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2911         }
2913         SHA1_Final(sha1, &ctx);
2914         return 0;
2917 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2919         struct diff_queue_struct *q = &diff_queued_diff;
2920         int i;
2921         int result = diff_get_patch_id(options, sha1);
2923         for (i = 0; i < q->nr; i++)
2924                 diff_free_filepair(q->queue[i]);
2926         free(q->queue);
2927         q->queue = NULL;
2928         q->nr = q->alloc = 0;
2930         return result;
2933 static int is_summary_empty(const struct diff_queue_struct *q)
2935         int i;
2937         for (i = 0; i < q->nr; i++) {
2938                 const struct diff_filepair *p = q->queue[i];
2940                 switch (p->status) {
2941                 case DIFF_STATUS_DELETED:
2942                 case DIFF_STATUS_ADDED:
2943                 case DIFF_STATUS_COPIED:
2944                 case DIFF_STATUS_RENAMED:
2945                         return 0;
2946                 default:
2947                         if (p->score)
2948                                 return 0;
2949                         if (p->one->mode && p->two->mode &&
2950                             p->one->mode != p->two->mode)
2951                                 return 0;
2952                         break;
2953                 }
2954         }
2955         return 1;
2958 void diff_flush(struct diff_options *options)
2960         struct diff_queue_struct *q = &diff_queued_diff;
2961         int i, output_format = options->output_format;
2962         int separator = 0;
2964         /*
2965          * Order: raw, stat, summary, patch
2966          * or:    name/name-status/checkdiff (other bits clear)
2967          */
2968         if (!q->nr)
2969                 goto free_queue;
2971         if (output_format & (DIFF_FORMAT_RAW |
2972                              DIFF_FORMAT_NAME |
2973                              DIFF_FORMAT_NAME_STATUS |
2974                              DIFF_FORMAT_CHECKDIFF)) {
2975                 for (i = 0; i < q->nr; i++) {
2976                         struct diff_filepair *p = q->queue[i];
2977                         if (check_pair_status(p))
2978                                 flush_one_pair(p, options);
2979                 }
2980                 separator++;
2981         }
2983         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
2984                 struct diffstat_t diffstat;
2986                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2987                 diffstat.xm.consume = diffstat_consume;
2988                 for (i = 0; i < q->nr; i++) {
2989                         struct diff_filepair *p = q->queue[i];
2990                         if (check_pair_status(p))
2991                                 diff_flush_stat(p, options, &diffstat);
2992                 }
2993                 if (output_format & DIFF_FORMAT_NUMSTAT)
2994                         show_numstat(&diffstat, options);
2995                 if (output_format & DIFF_FORMAT_DIFFSTAT)
2996                         show_stats(&diffstat, options);
2997                 if (output_format & DIFF_FORMAT_SHORTSTAT)
2998                         show_shortstats(&diffstat);
2999                 free_diffstat_info(&diffstat);
3000                 separator++;
3001         }
3003         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3004                 for (i = 0; i < q->nr; i++)
3005                         diff_summary(q->queue[i]);
3006                 separator++;
3007         }
3009         if (output_format & DIFF_FORMAT_PATCH) {
3010                 if (separator) {
3011                         if (options->stat_sep) {
3012                                 /* attach patch instead of inline */
3013                                 fputs(options->stat_sep, stdout);
3014                         } else {
3015                                 putchar(options->line_termination);
3016                         }
3017                 }
3019                 for (i = 0; i < q->nr; i++) {
3020                         struct diff_filepair *p = q->queue[i];
3021                         if (check_pair_status(p))
3022                                 diff_flush_patch(p, options);
3023                 }
3024         }
3026         if (output_format & DIFF_FORMAT_CALLBACK)
3027                 options->format_callback(q, options, options->format_callback_data);
3029         for (i = 0; i < q->nr; i++)
3030                 diff_free_filepair(q->queue[i]);
3031 free_queue:
3032         free(q->queue);
3033         q->queue = NULL;
3034         q->nr = q->alloc = 0;
3037 static void diffcore_apply_filter(const char *filter)
3039         int i;
3040         struct diff_queue_struct *q = &diff_queued_diff;
3041         struct diff_queue_struct outq;
3042         outq.queue = NULL;
3043         outq.nr = outq.alloc = 0;
3045         if (!filter)
3046                 return;
3048         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3049                 int found;
3050                 for (i = found = 0; !found && i < q->nr; i++) {
3051                         struct diff_filepair *p = q->queue[i];
3052                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3053                              ((p->score &&
3054                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3055                               (!p->score &&
3056                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3057                             ((p->status != DIFF_STATUS_MODIFIED) &&
3058                              strchr(filter, p->status)))
3059                                 found++;
3060                 }
3061                 if (found)
3062                         return;
3064                 /* otherwise we will clear the whole queue
3065                  * by copying the empty outq at the end of this
3066                  * function, but first clear the current entries
3067                  * in the queue.
3068                  */
3069                 for (i = 0; i < q->nr; i++)
3070                         diff_free_filepair(q->queue[i]);
3071         }
3072         else {
3073                 /* Only the matching ones */
3074                 for (i = 0; i < q->nr; i++) {
3075                         struct diff_filepair *p = q->queue[i];
3077                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3078                              ((p->score &&
3079                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3080                               (!p->score &&
3081                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3082                             ((p->status != DIFF_STATUS_MODIFIED) &&
3083                              strchr(filter, p->status)))
3084                                 diff_q(&outq, p);
3085                         else
3086                                 diff_free_filepair(p);
3087                 }
3088         }
3089         free(q->queue);
3090         *q = outq;
3093 /* Check whether two filespecs with the same mode and size are identical */
3094 static int diff_filespec_is_identical(struct diff_filespec *one,
3095                                       struct diff_filespec *two)
3097         if (S_ISGITLINK(one->mode)) {
3098                 diff_fill_sha1_info(one);
3099                 diff_fill_sha1_info(two);
3100                 return !hashcmp(one->sha1, two->sha1);
3101         }
3102         if (diff_populate_filespec(one, 0))
3103                 return 0;
3104         if (diff_populate_filespec(two, 0))
3105                 return 0;
3106         return !memcmp(one->data, two->data, one->size);
3109 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3111         int i;
3112         struct diff_queue_struct *q = &diff_queued_diff;
3113         struct diff_queue_struct outq;
3114         outq.queue = NULL;
3115         outq.nr = outq.alloc = 0;
3117         for (i = 0; i < q->nr; i++) {
3118                 struct diff_filepair *p = q->queue[i];
3120                 /*
3121                  * 1. Entries that come from stat info dirtyness
3122                  *    always have both sides (iow, not create/delete),
3123                  *    one side of the object name is unknown, with
3124                  *    the same mode and size.  Keep the ones that
3125                  *    do not match these criteria.  They have real
3126                  *    differences.
3127                  *
3128                  * 2. At this point, the file is known to be modified,
3129                  *    with the same mode and size, and the object
3130                  *    name of one side is unknown.  Need to inspect
3131                  *    the identical contents.
3132                  */
3133                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3134                     !DIFF_FILE_VALID(p->two) ||
3135                     (p->one->sha1_valid && p->two->sha1_valid) ||
3136                     (p->one->mode != p->two->mode) ||
3137                     diff_populate_filespec(p->one, 1) ||
3138                     diff_populate_filespec(p->two, 1) ||
3139                     (p->one->size != p->two->size) ||
3140                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3141                         diff_q(&outq, p);
3142                 else {
3143                         /*
3144                          * The caller can subtract 1 from skip_stat_unmatch
3145                          * to determine how many paths were dirty only
3146                          * due to stat info mismatch.
3147                          */
3148                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3149                                 diffopt->skip_stat_unmatch++;
3150                         diff_free_filepair(p);
3151                 }
3152         }
3153         free(q->queue);
3154         *q = outq;
3157 void diffcore_std(struct diff_options *options)
3159         if (DIFF_OPT_TST(options, QUIET))
3160                 return;
3162         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3163                 diffcore_skip_stat_unmatch(options);
3164         if (options->break_opt != -1)
3165                 diffcore_break(options->break_opt);
3166         if (options->detect_rename)
3167                 diffcore_rename(options);
3168         if (options->break_opt != -1)
3169                 diffcore_merge_broken();
3170         if (options->pickaxe)
3171                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3172         if (options->orderfile)
3173                 diffcore_order(options->orderfile);
3174         diff_resolve_rename_copy();
3175         diffcore_apply_filter(options->filter);
3177         if (diff_queued_diff.nr)
3178                 DIFF_OPT_SET(options, HAS_CHANGES);
3179         else
3180                 DIFF_OPT_CLR(options, HAS_CHANGES);
3184 void diff_addremove(struct diff_options *options,
3185                     int addremove, unsigned mode,
3186                     const unsigned char *sha1,
3187                     const char *base, const char *path)
3189         char concatpath[PATH_MAX];
3190         struct diff_filespec *one, *two;
3192         /* This may look odd, but it is a preparation for
3193          * feeding "there are unchanged files which should
3194          * not produce diffs, but when you are doing copy
3195          * detection you would need them, so here they are"
3196          * entries to the diff-core.  They will be prefixed
3197          * with something like '=' or '*' (I haven't decided
3198          * which but should not make any difference).
3199          * Feeding the same new and old to diff_change()
3200          * also has the same effect.
3201          * Before the final output happens, they are pruned after
3202          * merged into rename/copy pairs as appropriate.
3203          */
3204         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3205                 addremove = (addremove == '+' ? '-' :
3206                              addremove == '-' ? '+' : addremove);
3208         if (!path) path = "";
3209         sprintf(concatpath, "%s%s", base, path);
3210         one = alloc_filespec(concatpath);
3211         two = alloc_filespec(concatpath);
3213         if (addremove != '+')
3214                 fill_filespec(one, sha1, mode);
3215         if (addremove != '-')
3216                 fill_filespec(two, sha1, mode);
3218         diff_queue(&diff_queued_diff, one, two);
3219         DIFF_OPT_SET(options, HAS_CHANGES);
3222 void diff_change(struct diff_options *options,
3223                  unsigned old_mode, unsigned new_mode,
3224                  const unsigned char *old_sha1,
3225                  const unsigned char *new_sha1,
3226                  const char *base, const char *path)
3228         char concatpath[PATH_MAX];
3229         struct diff_filespec *one, *two;
3231         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3232                 unsigned tmp;
3233                 const unsigned char *tmp_c;
3234                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3235                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3236         }
3237         if (!path) path = "";
3238         sprintf(concatpath, "%s%s", base, path);
3239         one = alloc_filespec(concatpath);
3240         two = alloc_filespec(concatpath);
3241         fill_filespec(one, old_sha1, old_mode);
3242         fill_filespec(two, new_sha1, new_mode);
3244         diff_queue(&diff_queued_diff, one, two);
3245         DIFF_OPT_SET(options, HAS_CHANGES);
3248 void diff_unmerge(struct diff_options *options,
3249                   const char *path,
3250                   unsigned mode, const unsigned char *sha1)
3252         struct diff_filespec *one, *two;
3253         one = alloc_filespec(path);
3254         two = alloc_filespec(path);
3255         fill_filespec(one, sha1, mode);
3256         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;