Code

diff --whitespace: fix blank lines at end
[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "delta.h"
9 #include "xdiff-interface.h"
10 #include "color.h"
11 #include "attr.h"
12 #include "run-command.h"
13 #include "utf8.h"
15 #ifdef NO_FAST_WORKING_DIRECTORY
16 #define FAST_WORKING_DIRECTORY 0
17 #else
18 #define FAST_WORKING_DIRECTORY 1
19 #endif
21 static int diff_detect_rename_default;
22 static int diff_rename_limit_default = 200;
23 int diff_use_color_default = -1;
24 static const char *external_diff_cmd_cfg;
25 int diff_auto_refresh_index = 1;
27 static char diff_colors[][COLOR_MAXLEN] = {
28         "\033[m",       /* reset */
29         "",             /* PLAIN (normal) */
30         "\033[1m",      /* METAINFO (bold) */
31         "\033[36m",     /* FRAGINFO (cyan) */
32         "\033[31m",     /* OLD (red) */
33         "\033[32m",     /* NEW (green) */
34         "\033[33m",     /* COMMIT (yellow) */
35         "\033[41m",     /* WHITESPACE (red background) */
36 };
38 static int parse_diff_color_slot(const char *var, int ofs)
39 {
40         if (!strcasecmp(var+ofs, "plain"))
41                 return DIFF_PLAIN;
42         if (!strcasecmp(var+ofs, "meta"))
43                 return DIFF_METAINFO;
44         if (!strcasecmp(var+ofs, "frag"))
45                 return DIFF_FRAGINFO;
46         if (!strcasecmp(var+ofs, "old"))
47                 return DIFF_FILE_OLD;
48         if (!strcasecmp(var+ofs, "new"))
49                 return DIFF_FILE_NEW;
50         if (!strcasecmp(var+ofs, "commit"))
51                 return DIFF_COMMIT;
52         if (!strcasecmp(var+ofs, "whitespace"))
53                 return DIFF_WHITESPACE;
54         die("bad config variable '%s'", var);
55 }
57 static struct ll_diff_driver {
58         const char *name;
59         struct ll_diff_driver *next;
60         const char *cmd;
61 } *user_diff, **user_diff_tail;
63 /*
64  * Currently there is only "diff.<drivername>.command" variable;
65  * because there are "diff.color.<slot>" variables, we are parsing
66  * this in a bit convoluted way to allow low level diff driver
67  * called "color".
68  */
69 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
70 {
71         const char *name;
72         int namelen;
73         struct ll_diff_driver *drv;
75         name = var + 5;
76         namelen = ep - name;
77         for (drv = user_diff; drv; drv = drv->next)
78                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
79                         break;
80         if (!drv) {
81                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
82                 drv->name = xmemdupz(name, namelen);
83                 if (!user_diff_tail)
84                         user_diff_tail = &user_diff;
85                 *user_diff_tail = drv;
86                 user_diff_tail = &(drv->next);
87         }
89         return git_config_string(&(drv->cmd), var, value);
90 }
92 /*
93  * 'diff.<what>.funcname' attribute can be specified in the configuration
94  * to define a customized regexp to find the beginning of a function to
95  * be used for hunk header lines of "diff -p" style output.
96  */
97 struct funcname_pattern_entry {
98         char *name;
99         char *pattern;
100         int cflags;
101 };
102 static struct funcname_pattern_list {
103         struct funcname_pattern_list *next;
104         struct funcname_pattern_entry e;
105 } *funcname_pattern_list;
107 static int parse_funcname_pattern(const char *var, const char *ep, const char *value, int cflags)
109         const char *name;
110         int namelen;
111         struct funcname_pattern_list *pp;
113         name = var + 5; /* "diff." */
114         namelen = ep - name;
116         for (pp = funcname_pattern_list; pp; pp = pp->next)
117                 if (!strncmp(pp->e.name, name, namelen) && !pp->e.name[namelen])
118                         break;
119         if (!pp) {
120                 pp = xcalloc(1, sizeof(*pp));
121                 pp->e.name = xmemdupz(name, namelen);
122                 pp->next = funcname_pattern_list;
123                 funcname_pattern_list = pp;
124         }
125         free(pp->e.pattern);
126         pp->e.pattern = xstrdup(value);
127         pp->e.cflags = cflags;
128         return 0;
131 /*
132  * These are to give UI layer defaults.
133  * The core-level commands such as git-diff-files should
134  * never be affected by the setting of diff.renames
135  * the user happens to have in the configuration file.
136  */
137 int git_diff_ui_config(const char *var, const char *value, void *cb)
139         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
140                 diff_use_color_default = git_config_colorbool(var, value, -1);
141                 return 0;
142         }
143         if (!strcmp(var, "diff.renames")) {
144                 if (!value)
145                         diff_detect_rename_default = DIFF_DETECT_RENAME;
146                 else if (!strcasecmp(value, "copies") ||
147                          !strcasecmp(value, "copy"))
148                         diff_detect_rename_default = DIFF_DETECT_COPY;
149                 else if (git_config_bool(var,value))
150                         diff_detect_rename_default = DIFF_DETECT_RENAME;
151                 return 0;
152         }
153         if (!strcmp(var, "diff.autorefreshindex")) {
154                 diff_auto_refresh_index = git_config_bool(var, value);
155                 return 0;
156         }
157         if (!strcmp(var, "diff.external"))
158                 return git_config_string(&external_diff_cmd_cfg, var, value);
159         if (!prefixcmp(var, "diff.")) {
160                 const char *ep = strrchr(var, '.');
162                 if (ep != var + 4 && !strcmp(ep, ".command"))
163                         return parse_lldiff_command(var, ep, value);
164         }
166         return git_diff_basic_config(var, value, cb);
169 int git_diff_basic_config(const char *var, const char *value, void *cb)
171         if (!strcmp(var, "diff.renamelimit")) {
172                 diff_rename_limit_default = git_config_int(var, value);
173                 return 0;
174         }
176         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
177                 int slot = parse_diff_color_slot(var, 11);
178                 if (!value)
179                         return config_error_nonbool(var);
180                 color_parse(value, var, diff_colors[slot]);
181                 return 0;
182         }
184         if (!prefixcmp(var, "diff.")) {
185                 const char *ep = strrchr(var, '.');
186                 if (ep != var + 4) {
187                         if (!strcmp(ep, ".funcname")) {
188                                 if (!value)
189                                         return config_error_nonbool(var);
190                                 return parse_funcname_pattern(var, ep, value,
191                                         0);
192                         } else if (!strcmp(ep, ".xfuncname")) {
193                                 if (!value)
194                                         return config_error_nonbool(var);
195                                 return parse_funcname_pattern(var, ep, value,
196                                         REG_EXTENDED);
197                         }
198                 }
199         }
201         return git_color_default_config(var, value, cb);
204 static char *quote_two(const char *one, const char *two)
206         int need_one = quote_c_style(one, NULL, NULL, 1);
207         int need_two = quote_c_style(two, NULL, NULL, 1);
208         struct strbuf res;
210         strbuf_init(&res, 0);
211         if (need_one + need_two) {
212                 strbuf_addch(&res, '"');
213                 quote_c_style(one, &res, NULL, 1);
214                 quote_c_style(two, &res, NULL, 1);
215                 strbuf_addch(&res, '"');
216         } else {
217                 strbuf_addstr(&res, one);
218                 strbuf_addstr(&res, two);
219         }
220         return strbuf_detach(&res, NULL);
223 static const char *external_diff(void)
225         static const char *external_diff_cmd = NULL;
226         static int done_preparing = 0;
228         if (done_preparing)
229                 return external_diff_cmd;
230         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
231         if (!external_diff_cmd)
232                 external_diff_cmd = external_diff_cmd_cfg;
233         done_preparing = 1;
234         return external_diff_cmd;
237 static struct diff_tempfile {
238         const char *name; /* filename external diff should read from */
239         char hex[41];
240         char mode[10];
241         char tmp_path[PATH_MAX];
242 } diff_temp[2];
244 static int count_lines(const char *data, int size)
246         int count, ch, completely_empty = 1, nl_just_seen = 0;
247         count = 0;
248         while (0 < size--) {
249                 ch = *data++;
250                 if (ch == '\n') {
251                         count++;
252                         nl_just_seen = 1;
253                         completely_empty = 0;
254                 }
255                 else {
256                         nl_just_seen = 0;
257                         completely_empty = 0;
258                 }
259         }
260         if (completely_empty)
261                 return 0;
262         if (!nl_just_seen)
263                 count++; /* no trailing newline */
264         return count;
267 static void print_line_count(FILE *file, int count)
269         switch (count) {
270         case 0:
271                 fprintf(file, "0,0");
272                 break;
273         case 1:
274                 fprintf(file, "1");
275                 break;
276         default:
277                 fprintf(file, "1,%d", count);
278                 break;
279         }
282 static void copy_file_with_prefix(FILE *file,
283                                   int prefix, const char *data, int size,
284                                   const char *set, const char *reset)
286         int ch, nl_just_seen = 1;
287         while (0 < size--) {
288                 ch = *data++;
289                 if (nl_just_seen) {
290                         fputs(set, file);
291                         putc(prefix, file);
292                 }
293                 if (ch == '\n') {
294                         nl_just_seen = 1;
295                         fputs(reset, file);
296                 } else
297                         nl_just_seen = 0;
298                 putc(ch, file);
299         }
300         if (!nl_just_seen)
301                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
304 static void emit_rewrite_diff(const char *name_a,
305                               const char *name_b,
306                               struct diff_filespec *one,
307                               struct diff_filespec *two,
308                               struct diff_options *o)
310         int lc_a, lc_b;
311         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
312         const char *name_a_tab, *name_b_tab;
313         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
314         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
315         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
316         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
317         const char *reset = diff_get_color(color_diff, DIFF_RESET);
318         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
320         name_a += (*name_a == '/');
321         name_b += (*name_b == '/');
322         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
323         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
325         strbuf_reset(&a_name);
326         strbuf_reset(&b_name);
327         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
328         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
330         diff_populate_filespec(one, 0);
331         diff_populate_filespec(two, 0);
332         lc_a = count_lines(one->data, one->size);
333         lc_b = count_lines(two->data, two->size);
334         fprintf(o->file,
335                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
336                 metainfo, a_name.buf, name_a_tab, reset,
337                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
338         print_line_count(o->file, lc_a);
339         fprintf(o->file, " +");
340         print_line_count(o->file, lc_b);
341         fprintf(o->file, " @@%s\n", reset);
342         if (lc_a)
343                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
344         if (lc_b)
345                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
348 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
350         if (!DIFF_FILE_VALID(one)) {
351                 mf->ptr = (char *)""; /* does not matter */
352                 mf->size = 0;
353                 return 0;
354         }
355         else if (diff_populate_filespec(one, 0))
356                 return -1;
357         mf->ptr = one->data;
358         mf->size = one->size;
359         return 0;
362 struct diff_words_buffer {
363         mmfile_t text;
364         long alloc;
365         long current; /* output pointer */
366         int suppressed_newline;
367 };
369 static void diff_words_append(char *line, unsigned long len,
370                 struct diff_words_buffer *buffer)
372         if (buffer->text.size + len > buffer->alloc) {
373                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
374                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
375         }
376         line++;
377         len--;
378         memcpy(buffer->text.ptr + buffer->text.size, line, len);
379         buffer->text.size += len;
382 struct diff_words_data {
383         struct xdiff_emit_state xm;
384         struct diff_words_buffer minus, plus;
385         FILE *file;
386 };
388 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
389                 int suppress_newline)
391         const char *ptr;
392         int eol = 0;
394         if (len == 0)
395                 return;
397         ptr  = buffer->text.ptr + buffer->current;
398         buffer->current += len;
400         if (ptr[len - 1] == '\n') {
401                 eol = 1;
402                 len--;
403         }
405         fputs(diff_get_color(1, color), file);
406         fwrite(ptr, len, 1, file);
407         fputs(diff_get_color(1, DIFF_RESET), file);
409         if (eol) {
410                 if (suppress_newline)
411                         buffer->suppressed_newline = 1;
412                 else
413                         putc('\n', file);
414         }
417 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
419         struct diff_words_data *diff_words = priv;
421         if (diff_words->minus.suppressed_newline) {
422                 if (line[0] != '+')
423                         putc('\n', diff_words->file);
424                 diff_words->minus.suppressed_newline = 0;
425         }
427         len--;
428         switch (line[0]) {
429                 case '-':
430                         print_word(diff_words->file,
431                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
432                         break;
433                 case '+':
434                         print_word(diff_words->file,
435                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
436                         break;
437                 case ' ':
438                         print_word(diff_words->file,
439                                    &diff_words->plus, len, DIFF_PLAIN, 0);
440                         diff_words->minus.current += len;
441                         break;
442         }
445 /* this executes the word diff on the accumulated buffers */
446 static void diff_words_show(struct diff_words_data *diff_words)
448         xpparam_t xpp;
449         xdemitconf_t xecfg;
450         xdemitcb_t ecb;
451         mmfile_t minus, plus;
452         int i;
454         memset(&xecfg, 0, sizeof(xecfg));
455         minus.size = diff_words->minus.text.size;
456         minus.ptr = xmalloc(minus.size);
457         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
458         for (i = 0; i < minus.size; i++)
459                 if (isspace(minus.ptr[i]))
460                         minus.ptr[i] = '\n';
461         diff_words->minus.current = 0;
463         plus.size = diff_words->plus.text.size;
464         plus.ptr = xmalloc(plus.size);
465         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
466         for (i = 0; i < plus.size; i++)
467                 if (isspace(plus.ptr[i]))
468                         plus.ptr[i] = '\n';
469         diff_words->plus.current = 0;
471         xpp.flags = XDF_NEED_MINIMAL;
472         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
473         ecb.outf = xdiff_outf;
474         ecb.priv = diff_words;
475         diff_words->xm.consume = fn_out_diff_words_aux;
476         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
478         free(minus.ptr);
479         free(plus.ptr);
480         diff_words->minus.text.size = diff_words->plus.text.size = 0;
482         if (diff_words->minus.suppressed_newline) {
483                 putc('\n', diff_words->file);
484                 diff_words->minus.suppressed_newline = 0;
485         }
488 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
490 struct emit_callback {
491         struct xdiff_emit_state xm;
492         int color_diff;
493         unsigned ws_rule;
494         int blank_at_eof_in_preimage;
495         int blank_at_eof_in_postimage;
496         int lno_in_preimage;
497         int lno_in_postimage;
498         sane_truncate_fn truncate;
499         const char **label_path;
500         struct diff_words_data *diff_words;
501         int *found_changesp;
502         FILE *file;
503 };
505 static void free_diff_words_data(struct emit_callback *ecbdata)
507         if (ecbdata->diff_words) {
508                 /* flush buffers */
509                 if (ecbdata->diff_words->minus.text.size ||
510                                 ecbdata->diff_words->plus.text.size)
511                         diff_words_show(ecbdata->diff_words);
513                 free (ecbdata->diff_words->minus.text.ptr);
514                 free (ecbdata->diff_words->plus.text.ptr);
515                 free(ecbdata->diff_words);
516                 ecbdata->diff_words = NULL;
517         }
520 const char *diff_get_color(int diff_use_color, enum color_diff ix)
522         if (diff_use_color)
523                 return diff_colors[ix];
524         return "";
527 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
529         int has_trailing_newline, has_trailing_carriage_return;
531         has_trailing_newline = (len > 0 && line[len-1] == '\n');
532         if (has_trailing_newline)
533                 len--;
534         has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
535         if (has_trailing_carriage_return)
536                 len--;
538         fputs(set, file);
539         fwrite(line, len, 1, file);
540         fputs(reset, file);
541         if (has_trailing_carriage_return)
542                 fputc('\r', file);
543         if (has_trailing_newline)
544                 fputc('\n', file);
547 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
549         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
550               ecbdata->blank_at_eof_in_preimage &&
551               ecbdata->blank_at_eof_in_postimage &&
552               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
553               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
554                 return 0;
555         return ws_blank_line(line + 1, len - 1, ecbdata->ws_rule);
558 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
560         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
561         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
563         if (!*ws)
564                 emit_line(ecbdata->file, set, reset, line, len);
565         else if (new_blank_line_at_eof(ecbdata, line, len))
566                 /* Blank line at EOF - paint '+' as well */
567                 emit_line(ecbdata->file, ws, reset, line, len);
568         else {
569                 /* Emit just the prefix, then the rest. */
570                 emit_line(ecbdata->file, set, reset, line, 1);
571                 ws_check_emit(line + 1, len - 1, ecbdata->ws_rule,
572                               ecbdata->file, set, reset, ws);
573         }
576 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
578         const char *cp;
579         unsigned long allot;
580         size_t l = len;
582         if (ecb->truncate)
583                 return ecb->truncate(line, len);
584         cp = line;
585         allot = l;
586         while (0 < l) {
587                 (void) utf8_width(&cp, &l);
588                 if (!cp)
589                         break; /* truncated in the middle? */
590         }
591         return allot - l;
594 static void find_lno(const char *line, struct emit_callback *ecbdata)
596         const char *p;
597         ecbdata->lno_in_preimage = 0;
598         ecbdata->lno_in_postimage = 0;
599         p = strchr(line, '-');
600         if (!p)
601                 return; /* cannot happen */
602         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
603         p = strchr(p, '+');
604         if (!p)
605                 return; /* cannot happen */
606         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
609 static void fn_out_consume(void *priv, char *line, unsigned long len)
611         struct emit_callback *ecbdata = priv;
612         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
613         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
614         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
616         *(ecbdata->found_changesp) = 1;
618         if (ecbdata->label_path[0]) {
619                 const char *name_a_tab, *name_b_tab;
621                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
622                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
624                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
625                         meta, ecbdata->label_path[0], reset, name_a_tab);
626                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
627                         meta, ecbdata->label_path[1], reset, name_b_tab);
628                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
629         }
631         if (line[0] == '@') {
632                 len = sane_truncate_line(ecbdata, line, len);
633                 find_lno(line, ecbdata);
634                 emit_line(ecbdata->file,
635                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
636                           reset, line, len);
637                 if (line[len-1] != '\n')
638                         putc('\n', ecbdata->file);
639                 return;
640         }
642         if (len < 1) {
643                 emit_line(ecbdata->file, reset, reset, line, len);
644                 return;
645         }
647         if (ecbdata->diff_words) {
648                 if (line[0] == '-') {
649                         diff_words_append(line, len,
650                                           &ecbdata->diff_words->minus);
651                         return;
652                 } else if (line[0] == '+') {
653                         diff_words_append(line, len,
654                                           &ecbdata->diff_words->plus);
655                         return;
656                 }
657                 if (ecbdata->diff_words->minus.text.size ||
658                     ecbdata->diff_words->plus.text.size)
659                         diff_words_show(ecbdata->diff_words);
660                 line++;
661                 len--;
662                 emit_line(ecbdata->file, plain, reset, line, len);
663                 return;
664         }
666         if (line[0] != '+') {
667                 const char *color =
668                         diff_get_color(ecbdata->color_diff,
669                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
670                 ecbdata->lno_in_preimage++;
671                 if (line[0] == ' ')
672                         ecbdata->lno_in_postimage++;
673                 emit_line(ecbdata->file, color, reset, line, len);
674         } else {
675                 ecbdata->lno_in_postimage++;
676                 emit_add_line(reset, ecbdata, line, len);
677         }
680 static char *pprint_rename(const char *a, const char *b)
682         const char *old = a;
683         const char *new = b;
684         struct strbuf name;
685         int pfx_length, sfx_length;
686         int len_a = strlen(a);
687         int len_b = strlen(b);
688         int a_midlen, b_midlen;
689         int qlen_a = quote_c_style(a, NULL, NULL, 0);
690         int qlen_b = quote_c_style(b, NULL, NULL, 0);
692         strbuf_init(&name, 0);
693         if (qlen_a || qlen_b) {
694                 quote_c_style(a, &name, NULL, 0);
695                 strbuf_addstr(&name, " => ");
696                 quote_c_style(b, &name, NULL, 0);
697                 return strbuf_detach(&name, NULL);
698         }
700         /* Find common prefix */
701         pfx_length = 0;
702         while (*old && *new && *old == *new) {
703                 if (*old == '/')
704                         pfx_length = old - a + 1;
705                 old++;
706                 new++;
707         }
709         /* Find common suffix */
710         old = a + len_a;
711         new = b + len_b;
712         sfx_length = 0;
713         while (a <= old && b <= new && *old == *new) {
714                 if (*old == '/')
715                         sfx_length = len_a - (old - a);
716                 old--;
717                 new--;
718         }
720         /*
721          * pfx{mid-a => mid-b}sfx
722          * {pfx-a => pfx-b}sfx
723          * pfx{sfx-a => sfx-b}
724          * name-a => name-b
725          */
726         a_midlen = len_a - pfx_length - sfx_length;
727         b_midlen = len_b - pfx_length - sfx_length;
728         if (a_midlen < 0)
729                 a_midlen = 0;
730         if (b_midlen < 0)
731                 b_midlen = 0;
733         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
734         if (pfx_length + sfx_length) {
735                 strbuf_add(&name, a, pfx_length);
736                 strbuf_addch(&name, '{');
737         }
738         strbuf_add(&name, a + pfx_length, a_midlen);
739         strbuf_addstr(&name, " => ");
740         strbuf_add(&name, b + pfx_length, b_midlen);
741         if (pfx_length + sfx_length) {
742                 strbuf_addch(&name, '}');
743                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
744         }
745         return strbuf_detach(&name, NULL);
748 struct diffstat_t {
749         struct xdiff_emit_state xm;
751         int nr;
752         int alloc;
753         struct diffstat_file {
754                 char *from_name;
755                 char *name;
756                 char *print_name;
757                 unsigned is_unmerged:1;
758                 unsigned is_binary:1;
759                 unsigned is_renamed:1;
760                 unsigned int added, deleted;
761         } **files;
762 };
764 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
765                                           const char *name_a,
766                                           const char *name_b)
768         struct diffstat_file *x;
769         x = xcalloc(sizeof (*x), 1);
770         if (diffstat->nr == diffstat->alloc) {
771                 diffstat->alloc = alloc_nr(diffstat->alloc);
772                 diffstat->files = xrealloc(diffstat->files,
773                                 diffstat->alloc * sizeof(x));
774         }
775         diffstat->files[diffstat->nr++] = x;
776         if (name_b) {
777                 x->from_name = xstrdup(name_a);
778                 x->name = xstrdup(name_b);
779                 x->is_renamed = 1;
780         }
781         else {
782                 x->from_name = NULL;
783                 x->name = xstrdup(name_a);
784         }
785         return x;
788 static void diffstat_consume(void *priv, char *line, unsigned long len)
790         struct diffstat_t *diffstat = priv;
791         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
793         if (line[0] == '+')
794                 x->added++;
795         else if (line[0] == '-')
796                 x->deleted++;
799 const char mime_boundary_leader[] = "------------";
801 static int scale_linear(int it, int width, int max_change)
803         /*
804          * make sure that at least one '-' is printed if there were deletions,
805          * and likewise for '+'.
806          */
807         if (max_change < 2)
808                 return it;
809         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
812 static void show_name(FILE *file,
813                       const char *prefix, const char *name, int len,
814                       const char *reset, const char *set)
816         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
819 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
821         if (cnt <= 0)
822                 return;
823         fprintf(file, "%s", set);
824         while (cnt--)
825                 putc(ch, file);
826         fprintf(file, "%s", reset);
829 static void fill_print_name(struct diffstat_file *file)
831         char *pname;
833         if (file->print_name)
834                 return;
836         if (!file->is_renamed) {
837                 struct strbuf buf;
838                 strbuf_init(&buf, 0);
839                 if (quote_c_style(file->name, &buf, NULL, 0)) {
840                         pname = strbuf_detach(&buf, NULL);
841                 } else {
842                         pname = file->name;
843                         strbuf_release(&buf);
844                 }
845         } else {
846                 pname = pprint_rename(file->from_name, file->name);
847         }
848         file->print_name = pname;
851 static void show_stats(struct diffstat_t* data, struct diff_options *options)
853         int i, len, add, del, total, adds = 0, dels = 0;
854         int max_change = 0, max_len = 0;
855         int total_files = data->nr;
856         int width, name_width;
857         const char *reset, *set, *add_c, *del_c;
859         if (data->nr == 0)
860                 return;
862         width = options->stat_width ? options->stat_width : 80;
863         name_width = options->stat_name_width ? options->stat_name_width : 50;
865         /* Sanity: give at least 5 columns to the graph,
866          * but leave at least 10 columns for the name.
867          */
868         if (width < 25)
869                 width = 25;
870         if (name_width < 10)
871                 name_width = 10;
872         else if (width < name_width + 15)
873                 name_width = width - 15;
875         /* Find the longest filename and max number of changes */
876         reset = diff_get_color_opt(options, DIFF_RESET);
877         set   = diff_get_color_opt(options, DIFF_PLAIN);
878         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
879         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
881         for (i = 0; i < data->nr; i++) {
882                 struct diffstat_file *file = data->files[i];
883                 int change = file->added + file->deleted;
884                 fill_print_name(file);
885                 len = strlen(file->print_name);
886                 if (max_len < len)
887                         max_len = len;
889                 if (file->is_binary || file->is_unmerged)
890                         continue;
891                 if (max_change < change)
892                         max_change = change;
893         }
895         /* Compute the width of the graph part;
896          * 10 is for one blank at the beginning of the line plus
897          * " | count " between the name and the graph.
898          *
899          * From here on, name_width is the width of the name area,
900          * and width is the width of the graph area.
901          */
902         name_width = (name_width < max_len) ? name_width : max_len;
903         if (width < (name_width + 10) + max_change)
904                 width = width - (name_width + 10);
905         else
906                 width = max_change;
908         for (i = 0; i < data->nr; i++) {
909                 const char *prefix = "";
910                 char *name = data->files[i]->print_name;
911                 int added = data->files[i]->added;
912                 int deleted = data->files[i]->deleted;
913                 int name_len;
915                 /*
916                  * "scale" the filename
917                  */
918                 len = name_width;
919                 name_len = strlen(name);
920                 if (name_width < name_len) {
921                         char *slash;
922                         prefix = "...";
923                         len -= 3;
924                         name += name_len - len;
925                         slash = strchr(name, '/');
926                         if (slash)
927                                 name = slash;
928                 }
930                 if (data->files[i]->is_binary) {
931                         show_name(options->file, prefix, name, len, reset, set);
932                         fprintf(options->file, "  Bin ");
933                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
934                         fprintf(options->file, " -> ");
935                         fprintf(options->file, "%s%d%s", add_c, added, reset);
936                         fprintf(options->file, " bytes");
937                         fprintf(options->file, "\n");
938                         continue;
939                 }
940                 else if (data->files[i]->is_unmerged) {
941                         show_name(options->file, prefix, name, len, reset, set);
942                         fprintf(options->file, "  Unmerged\n");
943                         continue;
944                 }
945                 else if (!data->files[i]->is_renamed &&
946                          (added + deleted == 0)) {
947                         total_files--;
948                         continue;
949                 }
951                 /*
952                  * scale the add/delete
953                  */
954                 add = added;
955                 del = deleted;
956                 total = add + del;
957                 adds += add;
958                 dels += del;
960                 if (width <= max_change) {
961                         add = scale_linear(add, width, max_change);
962                         del = scale_linear(del, width, max_change);
963                         total = add + del;
964                 }
965                 show_name(options->file, prefix, name, len, reset, set);
966                 fprintf(options->file, "%5d%s", added + deleted,
967                                 added + deleted ? " " : "");
968                 show_graph(options->file, '+', add, add_c, reset);
969                 show_graph(options->file, '-', del, del_c, reset);
970                 fprintf(options->file, "\n");
971         }
972         fprintf(options->file,
973                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
974                set, total_files, adds, dels, reset);
977 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
979         int i, adds = 0, dels = 0, total_files = data->nr;
981         if (data->nr == 0)
982                 return;
984         for (i = 0; i < data->nr; i++) {
985                 if (!data->files[i]->is_binary &&
986                     !data->files[i]->is_unmerged) {
987                         int added = data->files[i]->added;
988                         int deleted= data->files[i]->deleted;
989                         if (!data->files[i]->is_renamed &&
990                             (added + deleted == 0)) {
991                                 total_files--;
992                         } else {
993                                 adds += added;
994                                 dels += deleted;
995                         }
996                 }
997         }
998         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
999                total_files, adds, dels);
1002 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
1004         int i;
1006         if (data->nr == 0)
1007                 return;
1009         for (i = 0; i < data->nr; i++) {
1010                 struct diffstat_file *file = data->files[i];
1012                 if (file->is_binary)
1013                         fprintf(options->file, "-\t-\t");
1014                 else
1015                         fprintf(options->file,
1016                                 "%d\t%d\t", file->added, file->deleted);
1017                 if (options->line_termination) {
1018                         fill_print_name(file);
1019                         if (!file->is_renamed)
1020                                 write_name_quoted(file->name, options->file,
1021                                                   options->line_termination);
1022                         else {
1023                                 fputs(file->print_name, options->file);
1024                                 putc(options->line_termination, options->file);
1025                         }
1026                 } else {
1027                         if (file->is_renamed) {
1028                                 putc('\0', options->file);
1029                                 write_name_quoted(file->from_name, options->file, '\0');
1030                         }
1031                         write_name_quoted(file->name, options->file, '\0');
1032                 }
1033         }
1036 struct dirstat_file {
1037         const char *name;
1038         unsigned long changed;
1039 };
1041 struct dirstat_dir {
1042         struct dirstat_file *files;
1043         int alloc, nr, percent, cumulative;
1044 };
1046 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1048         unsigned long this_dir = 0;
1049         unsigned int sources = 0;
1051         while (dir->nr) {
1052                 struct dirstat_file *f = dir->files;
1053                 int namelen = strlen(f->name);
1054                 unsigned long this;
1055                 char *slash;
1057                 if (namelen < baselen)
1058                         break;
1059                 if (memcmp(f->name, base, baselen))
1060                         break;
1061                 slash = strchr(f->name + baselen, '/');
1062                 if (slash) {
1063                         int newbaselen = slash + 1 - f->name;
1064                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1065                         sources++;
1066                 } else {
1067                         this = f->changed;
1068                         dir->files++;
1069                         dir->nr--;
1070                         sources += 2;
1071                 }
1072                 this_dir += this;
1073         }
1075         /*
1076          * We don't report dirstat's for
1077          *  - the top level
1078          *  - or cases where everything came from a single directory
1079          *    under this directory (sources == 1).
1080          */
1081         if (baselen && sources != 1) {
1082                 int permille = this_dir * 1000 / changed;
1083                 if (permille) {
1084                         int percent = permille / 10;
1085                         if (percent >= dir->percent) {
1086                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1087                                 if (!dir->cumulative)
1088                                         return 0;
1089                         }
1090                 }
1091         }
1092         return this_dir;
1095 static int dirstat_compare(const void *_a, const void *_b)
1097         const struct dirstat_file *a = _a;
1098         const struct dirstat_file *b = _b;
1099         return strcmp(a->name, b->name);
1102 static void show_dirstat(struct diff_options *options)
1104         int i;
1105         unsigned long changed;
1106         struct dirstat_dir dir;
1107         struct diff_queue_struct *q = &diff_queued_diff;
1109         dir.files = NULL;
1110         dir.alloc = 0;
1111         dir.nr = 0;
1112         dir.percent = options->dirstat_percent;
1113         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1115         changed = 0;
1116         for (i = 0; i < q->nr; i++) {
1117                 struct diff_filepair *p = q->queue[i];
1118                 const char *name;
1119                 unsigned long copied, added, damage;
1121                 name = p->one->path ? p->one->path : p->two->path;
1123                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1124                         diff_populate_filespec(p->one, 0);
1125                         diff_populate_filespec(p->two, 0);
1126                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1127                                                &copied, &added);
1128                         diff_free_filespec_data(p->one);
1129                         diff_free_filespec_data(p->two);
1130                 } else if (DIFF_FILE_VALID(p->one)) {
1131                         diff_populate_filespec(p->one, 1);
1132                         copied = added = 0;
1133                         diff_free_filespec_data(p->one);
1134                 } else if (DIFF_FILE_VALID(p->two)) {
1135                         diff_populate_filespec(p->two, 1);
1136                         copied = 0;
1137                         added = p->two->size;
1138                         diff_free_filespec_data(p->two);
1139                 } else
1140                         continue;
1142                 /*
1143                  * Original minus copied is the removed material,
1144                  * added is the new material.  They are both damages
1145                  * made to the preimage.
1146                  */
1147                 damage = (p->one->size - copied) + added;
1149                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1150                 dir.files[dir.nr].name = name;
1151                 dir.files[dir.nr].changed = damage;
1152                 changed += damage;
1153                 dir.nr++;
1154         }
1156         /* This can happen even with many files, if everything was renames */
1157         if (!changed)
1158                 return;
1160         /* Show all directories with more than x% of the changes */
1161         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1162         gather_dirstat(options->file, &dir, changed, "", 0);
1165 static void free_diffstat_info(struct diffstat_t *diffstat)
1167         int i;
1168         for (i = 0; i < diffstat->nr; i++) {
1169                 struct diffstat_file *f = diffstat->files[i];
1170                 if (f->name != f->print_name)
1171                         free(f->print_name);
1172                 free(f->name);
1173                 free(f->from_name);
1174                 free(f);
1175         }
1176         free(diffstat->files);
1179 struct checkdiff_t {
1180         struct xdiff_emit_state xm;
1181         const char *filename;
1182         int lineno;
1183         struct diff_options *o;
1184         unsigned ws_rule;
1185         unsigned status;
1186 };
1188 static int is_conflict_marker(const char *line, unsigned long len)
1190         char firstchar;
1191         int cnt;
1193         if (len < 8)
1194                 return 0;
1195         firstchar = line[0];
1196         switch (firstchar) {
1197         case '=': case '>': case '<':
1198                 break;
1199         default:
1200                 return 0;
1201         }
1202         for (cnt = 1; cnt < 7; cnt++)
1203                 if (line[cnt] != firstchar)
1204                         return 0;
1205         /* line[0] thru line[6] are same as firstchar */
1206         if (firstchar == '=') {
1207                 /* divider between ours and theirs? */
1208                 if (len != 8 || line[7] != '\n')
1209                         return 0;
1210         } else if (len < 8 || !isspace(line[7])) {
1211                 /* not divider before ours nor after theirs */
1212                 return 0;
1213         }
1214         return 1;
1217 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1219         struct checkdiff_t *data = priv;
1220         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1221         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1222         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1223         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1224         char *err;
1226         if (line[0] == '+') {
1227                 unsigned bad;
1228                 data->lineno++;
1229                 if (is_conflict_marker(line + 1, len - 1)) {
1230                         data->status |= 1;
1231                         fprintf(data->o->file,
1232                                 "%s:%d: leftover conflict marker\n",
1233                                 data->filename, data->lineno);
1234                 }
1235                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1236                 if (!bad)
1237                         return;
1238                 data->status |= bad;
1239                 err = whitespace_error_string(bad);
1240                 fprintf(data->o->file, "%s:%d: %s.\n",
1241                         data->filename, data->lineno, err);
1242                 free(err);
1243                 emit_line(data->o->file, set, reset, line, 1);
1244                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1245                               data->o->file, set, reset, ws);
1246         } else if (line[0] == ' ') {
1247                 data->lineno++;
1248         } else if (line[0] == '@') {
1249                 char *plus = strchr(line, '+');
1250                 if (plus)
1251                         data->lineno = strtol(plus, NULL, 10) - 1;
1252                 else
1253                         die("invalid diff");
1254         }
1257 static unsigned char *deflate_it(char *data,
1258                                  unsigned long size,
1259                                  unsigned long *result_size)
1261         int bound;
1262         unsigned char *deflated;
1263         z_stream stream;
1265         memset(&stream, 0, sizeof(stream));
1266         deflateInit(&stream, zlib_compression_level);
1267         bound = deflateBound(&stream, size);
1268         deflated = xmalloc(bound);
1269         stream.next_out = deflated;
1270         stream.avail_out = bound;
1272         stream.next_in = (unsigned char *)data;
1273         stream.avail_in = size;
1274         while (deflate(&stream, Z_FINISH) == Z_OK)
1275                 ; /* nothing */
1276         deflateEnd(&stream);
1277         *result_size = stream.total_out;
1278         return deflated;
1281 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1283         void *cp;
1284         void *delta;
1285         void *deflated;
1286         void *data;
1287         unsigned long orig_size;
1288         unsigned long delta_size;
1289         unsigned long deflate_size;
1290         unsigned long data_size;
1292         /* We could do deflated delta, or we could do just deflated two,
1293          * whichever is smaller.
1294          */
1295         delta = NULL;
1296         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1297         if (one->size && two->size) {
1298                 delta = diff_delta(one->ptr, one->size,
1299                                    two->ptr, two->size,
1300                                    &delta_size, deflate_size);
1301                 if (delta) {
1302                         void *to_free = delta;
1303                         orig_size = delta_size;
1304                         delta = deflate_it(delta, delta_size, &delta_size);
1305                         free(to_free);
1306                 }
1307         }
1309         if (delta && delta_size < deflate_size) {
1310                 fprintf(file, "delta %lu\n", orig_size);
1311                 free(deflated);
1312                 data = delta;
1313                 data_size = delta_size;
1314         }
1315         else {
1316                 fprintf(file, "literal %lu\n", two->size);
1317                 free(delta);
1318                 data = deflated;
1319                 data_size = deflate_size;
1320         }
1322         /* emit data encoded in base85 */
1323         cp = data;
1324         while (data_size) {
1325                 int bytes = (52 < data_size) ? 52 : data_size;
1326                 char line[70];
1327                 data_size -= bytes;
1328                 if (bytes <= 26)
1329                         line[0] = bytes + 'A' - 1;
1330                 else
1331                         line[0] = bytes - 26 + 'a' - 1;
1332                 encode_85(line + 1, cp, bytes);
1333                 cp = (char *) cp + bytes;
1334                 fputs(line, file);
1335                 fputc('\n', file);
1336         }
1337         fprintf(file, "\n");
1338         free(data);
1341 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1343         fprintf(file, "GIT binary patch\n");
1344         emit_binary_diff_body(file, one, two);
1345         emit_binary_diff_body(file, two, one);
1348 static void setup_diff_attr_check(struct git_attr_check *check)
1350         static struct git_attr *attr_diff;
1352         if (!attr_diff) {
1353                 attr_diff = git_attr("diff", 4);
1354         }
1355         check[0].attr = attr_diff;
1358 static void diff_filespec_check_attr(struct diff_filespec *one)
1360         struct git_attr_check attr_diff_check;
1361         int check_from_data = 0;
1363         if (one->checked_attr)
1364                 return;
1366         setup_diff_attr_check(&attr_diff_check);
1367         one->is_binary = 0;
1368         one->funcname_pattern_ident = NULL;
1370         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1371                 const char *value;
1373                 /* binaryness */
1374                 value = attr_diff_check.value;
1375                 if (ATTR_TRUE(value))
1376                         ;
1377                 else if (ATTR_FALSE(value))
1378                         one->is_binary = 1;
1379                 else
1380                         check_from_data = 1;
1382                 /* funcname pattern ident */
1383                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1384                         ;
1385                 else
1386                         one->funcname_pattern_ident = value;
1387         }
1389         if (check_from_data) {
1390                 if (!one->data && DIFF_FILE_VALID(one))
1391                         diff_populate_filespec(one, 0);
1393                 if (one->data)
1394                         one->is_binary = buffer_is_binary(one->data, one->size);
1395         }
1398 int diff_filespec_is_binary(struct diff_filespec *one)
1400         diff_filespec_check_attr(one);
1401         return one->is_binary;
1404 static const struct funcname_pattern_entry *funcname_pattern(const char *ident)
1406         struct funcname_pattern_list *pp;
1408         for (pp = funcname_pattern_list; pp; pp = pp->next)
1409                 if (!strcmp(ident, pp->e.name))
1410                         return &pp->e;
1411         return NULL;
1414 static const struct funcname_pattern_entry builtin_funcname_pattern[] = {
1415         { "java",
1416           "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
1417           "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$",
1418           REG_EXTENDED },
1419         { "pascal",
1420           "^((procedure|function|constructor|destructor|interface|"
1421                 "implementation|initialization|finalization)[ \t]*.*)$"
1422           "|"
1423           "^(.*=[ \t]*(class|record).*)$",
1424           REG_EXTENDED },
1425         { "bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
1426           REG_EXTENDED },
1427         { "tex",
1428           "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
1429           REG_EXTENDED },
1430         { "ruby", "^[ \t]*((class|module|def)[ \t].*)$",
1431           REG_EXTENDED },
1432 };
1434 static const struct funcname_pattern_entry *diff_funcname_pattern(struct diff_filespec *one)
1436         const char *ident;
1437         const struct funcname_pattern_entry *pe;
1438         int i;
1440         diff_filespec_check_attr(one);
1441         ident = one->funcname_pattern_ident;
1443         if (!ident)
1444                 /*
1445                  * If the config file has "funcname.default" defined, that
1446                  * regexp is used; otherwise NULL is returned and xemit uses
1447                  * the built-in default.
1448                  */
1449                 return funcname_pattern("default");
1451         /* Look up custom "funcname.$ident" regexp from config. */
1452         pe = funcname_pattern(ident);
1453         if (pe)
1454                 return pe;
1456         /*
1457          * And define built-in fallback patterns here.  Note that
1458          * these can be overridden by the user's config settings.
1459          */
1460         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1461                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1462                         return &builtin_funcname_pattern[i];
1464         return NULL;
1467 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
1469         char *ptr = mf->ptr;
1470         long size = mf->size;
1471         int cnt = 0;
1473         if (!size)
1474                 return cnt;
1475         ptr += size - 1; /* pointing at the very end */
1476         if (*ptr != '\n')
1477                 ; /* incomplete line */
1478         else
1479                 ptr--; /* skip the last LF */
1480         while (mf->ptr < ptr) {
1481                 char *prev_eol;
1482                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
1483                         if (*prev_eol == '\n')
1484                                 break;
1485                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
1486                         break;
1487                 cnt++;
1488                 ptr = prev_eol - 1;
1489         }
1490         return cnt;
1493 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
1494                                struct emit_callback *ecbdata)
1496         int l1, l2, at;
1497         unsigned ws_rule = ecbdata->ws_rule;
1498         l1 = count_trailing_blank(mf1, ws_rule);
1499         l2 = count_trailing_blank(mf2, ws_rule);
1500         if (l2 <= l1) {
1501                 ecbdata->blank_at_eof_in_preimage = 0;
1502                 ecbdata->blank_at_eof_in_postimage = 0;
1503                 return;
1504         }
1505         at = count_lines(mf1->ptr, mf1->size);
1506         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
1508         at = count_lines(mf2->ptr, mf2->size);
1509         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
1512 static void builtin_diff(const char *name_a,
1513                          const char *name_b,
1514                          struct diff_filespec *one,
1515                          struct diff_filespec *two,
1516                          const char *xfrm_msg,
1517                          struct diff_options *o,
1518                          int complete_rewrite)
1520         mmfile_t mf1, mf2;
1521         const char *lbl[2];
1522         char *a_one, *b_two;
1523         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1524         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1526         /* Never use a non-valid filename anywhere if at all possible */
1527         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1528         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1530         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1531         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1532         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1533         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1534         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1535         if (lbl[0][0] == '/') {
1536                 /* /dev/null */
1537                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1538                 if (xfrm_msg && xfrm_msg[0])
1539                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1540         }
1541         else if (lbl[1][0] == '/') {
1542                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1543                 if (xfrm_msg && xfrm_msg[0])
1544                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1545         }
1546         else {
1547                 if (one->mode != two->mode) {
1548                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1549                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1550                 }
1551                 if (xfrm_msg && xfrm_msg[0])
1552                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1553                 /*
1554                  * we do not run diff between different kind
1555                  * of objects.
1556                  */
1557                 if ((one->mode ^ two->mode) & S_IFMT)
1558                         goto free_ab_and_return;
1559                 if (complete_rewrite) {
1560                         emit_rewrite_diff(name_a, name_b, one, two, o);
1561                         o->found_changes = 1;
1562                         goto free_ab_and_return;
1563                 }
1564         }
1566         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1567                 die("unable to read files to diff");
1569         if (!DIFF_OPT_TST(o, TEXT) &&
1570             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1571                 /* Quite common confusing case */
1572                 if (mf1.size == mf2.size &&
1573                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1574                         goto free_ab_and_return;
1575                 if (DIFF_OPT_TST(o, BINARY))
1576                         emit_binary_diff(o->file, &mf1, &mf2);
1577                 else
1578                         fprintf(o->file, "Binary files %s and %s differ\n",
1579                                 lbl[0], lbl[1]);
1580                 o->found_changes = 1;
1581         }
1582         else {
1583                 /* Crazy xdl interfaces.. */
1584                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1585                 xpparam_t xpp;
1586                 xdemitconf_t xecfg;
1587                 xdemitcb_t ecb;
1588                 struct emit_callback ecbdata;
1589                 const struct funcname_pattern_entry *pe;
1591                 pe = diff_funcname_pattern(one);
1592                 if (!pe)
1593                         pe = diff_funcname_pattern(two);
1595                 memset(&xecfg, 0, sizeof(xecfg));
1596                 memset(&ecbdata, 0, sizeof(ecbdata));
1597                 ecbdata.label_path = lbl;
1598                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1599                 ecbdata.found_changesp = &o->found_changes;
1600                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1601                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1602                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1603                 ecbdata.file = o->file;
1604                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1605                 xecfg.ctxlen = o->context;
1606                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1607                 if (pe)
1608                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1609                 if (!diffopts)
1610                         ;
1611                 else if (!prefixcmp(diffopts, "--unified="))
1612                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1613                 else if (!prefixcmp(diffopts, "-u"))
1614                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1615                 ecb.outf = xdiff_outf;
1616                 ecb.priv = &ecbdata;
1617                 ecbdata.xm.consume = fn_out_consume;
1618                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1619                         ecbdata.diff_words =
1620                                 xcalloc(1, sizeof(struct diff_words_data));
1621                         ecbdata.diff_words->file = o->file;
1622                 }
1623                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1624                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1625                         free_diff_words_data(&ecbdata);
1626         }
1628  free_ab_and_return:
1629         diff_free_filespec_data(one);
1630         diff_free_filespec_data(two);
1631         free(a_one);
1632         free(b_two);
1633         return;
1636 static void builtin_diffstat(const char *name_a, const char *name_b,
1637                              struct diff_filespec *one,
1638                              struct diff_filespec *two,
1639                              struct diffstat_t *diffstat,
1640                              struct diff_options *o,
1641                              int complete_rewrite)
1643         mmfile_t mf1, mf2;
1644         struct diffstat_file *data;
1646         data = diffstat_add(diffstat, name_a, name_b);
1648         if (!one || !two) {
1649                 data->is_unmerged = 1;
1650                 return;
1651         }
1652         if (complete_rewrite) {
1653                 diff_populate_filespec(one, 0);
1654                 diff_populate_filespec(two, 0);
1655                 data->deleted = count_lines(one->data, one->size);
1656                 data->added = count_lines(two->data, two->size);
1657                 goto free_and_return;
1658         }
1659         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1660                 die("unable to read files to diff");
1662         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1663                 data->is_binary = 1;
1664                 data->added = mf2.size;
1665                 data->deleted = mf1.size;
1666         } else {
1667                 /* Crazy xdl interfaces.. */
1668                 xpparam_t xpp;
1669                 xdemitconf_t xecfg;
1670                 xdemitcb_t ecb;
1672                 memset(&xecfg, 0, sizeof(xecfg));
1673                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1674                 ecb.outf = xdiff_outf;
1675                 ecb.priv = diffstat;
1676                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1677         }
1679  free_and_return:
1680         diff_free_filespec_data(one);
1681         diff_free_filespec_data(two);
1684 static void builtin_checkdiff(const char *name_a, const char *name_b,
1685                               const char *attr_path,
1686                               struct diff_filespec *one,
1687                               struct diff_filespec *two,
1688                               struct diff_options *o)
1690         mmfile_t mf1, mf2;
1691         struct checkdiff_t data;
1693         if (!two)
1694                 return;
1696         memset(&data, 0, sizeof(data));
1697         data.xm.consume = checkdiff_consume;
1698         data.filename = name_b ? name_b : name_a;
1699         data.lineno = 0;
1700         data.o = o;
1701         data.ws_rule = whitespace_rule(attr_path);
1703         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1704                 die("unable to read files to diff");
1706         /*
1707          * All the other codepaths check both sides, but not checking
1708          * the "old" side here is deliberate.  We are checking the newly
1709          * introduced changes, and as long as the "new" side is text, we
1710          * can and should check what it introduces.
1711          */
1712         if (diff_filespec_is_binary(two))
1713                 goto free_and_return;
1714         else {
1715                 /* Crazy xdl interfaces.. */
1716                 xpparam_t xpp;
1717                 xdemitconf_t xecfg;
1718                 xdemitcb_t ecb;
1720                 memset(&xecfg, 0, sizeof(xecfg));
1721                 xecfg.ctxlen = 1; /* at least one context line */
1722                 xpp.flags = XDF_NEED_MINIMAL;
1723                 ecb.outf = xdiff_outf;
1724                 ecb.priv = &data;
1725                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1727                 if (data.ws_rule & WS_BLANK_AT_EOF) {
1728                         struct emit_callback ecbdata;
1729                         int blank_at_eof;
1731                         ecbdata.ws_rule = data.ws_rule;
1732                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1733                         blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1735                         if (blank_at_eof) {
1736                                 static char *err;
1737                                 if (!err)
1738                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
1739                                 fprintf(o->file, "%s:%d: %s.\n",
1740                                         data.filename, blank_at_eof, err);
1741                                 data.status = 1; /* report errors */
1742                         }
1743                 }
1744         }
1745  free_and_return:
1746         diff_free_filespec_data(one);
1747         diff_free_filespec_data(two);
1748         if (data.status)
1749                 DIFF_OPT_SET(o, CHECK_FAILED);
1752 struct diff_filespec *alloc_filespec(const char *path)
1754         int namelen = strlen(path);
1755         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1757         memset(spec, 0, sizeof(*spec));
1758         spec->path = (char *)(spec + 1);
1759         memcpy(spec->path, path, namelen+1);
1760         spec->count = 1;
1761         return spec;
1764 void free_filespec(struct diff_filespec *spec)
1766         if (!--spec->count) {
1767                 diff_free_filespec_data(spec);
1768                 free(spec);
1769         }
1772 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1773                    unsigned short mode)
1775         if (mode) {
1776                 spec->mode = canon_mode(mode);
1777                 hashcpy(spec->sha1, sha1);
1778                 spec->sha1_valid = !is_null_sha1(sha1);
1779         }
1782 /*
1783  * Given a name and sha1 pair, if the index tells us the file in
1784  * the work tree has that object contents, return true, so that
1785  * prepare_temp_file() does not have to inflate and extract.
1786  */
1787 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1789         struct cache_entry *ce;
1790         struct stat st;
1791         int pos, len;
1793         /* We do not read the cache ourselves here, because the
1794          * benchmark with my previous version that always reads cache
1795          * shows that it makes things worse for diff-tree comparing
1796          * two linux-2.6 kernel trees in an already checked out work
1797          * tree.  This is because most diff-tree comparisons deal with
1798          * only a small number of files, while reading the cache is
1799          * expensive for a large project, and its cost outweighs the
1800          * savings we get by not inflating the object to a temporary
1801          * file.  Practically, this code only helps when we are used
1802          * by diff-cache --cached, which does read the cache before
1803          * calling us.
1804          */
1805         if (!active_cache)
1806                 return 0;
1808         /* We want to avoid the working directory if our caller
1809          * doesn't need the data in a normal file, this system
1810          * is rather slow with its stat/open/mmap/close syscalls,
1811          * and the object is contained in a pack file.  The pack
1812          * is probably already open and will be faster to obtain
1813          * the data through than the working directory.  Loose
1814          * objects however would tend to be slower as they need
1815          * to be individually opened and inflated.
1816          */
1817         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1818                 return 0;
1820         len = strlen(name);
1821         pos = cache_name_pos(name, len);
1822         if (pos < 0)
1823                 return 0;
1824         ce = active_cache[pos];
1826         /*
1827          * This is not the sha1 we are looking for, or
1828          * unreusable because it is not a regular file.
1829          */
1830         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1831                 return 0;
1833         /*
1834          * If ce matches the file in the work tree, we can reuse it.
1835          */
1836         if (ce_uptodate(ce) ||
1837             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1838                 return 1;
1840         return 0;
1843 static int populate_from_stdin(struct diff_filespec *s)
1845         struct strbuf buf;
1846         size_t size = 0;
1848         strbuf_init(&buf, 0);
1849         if (strbuf_read(&buf, 0, 0) < 0)
1850                 return error("error while reading from stdin %s",
1851                                      strerror(errno));
1853         s->should_munmap = 0;
1854         s->data = strbuf_detach(&buf, &size);
1855         s->size = size;
1856         s->should_free = 1;
1857         return 0;
1860 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1862         int len;
1863         char *data = xmalloc(100);
1864         len = snprintf(data, 100,
1865                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1866         s->data = data;
1867         s->size = len;
1868         s->should_free = 1;
1869         if (size_only) {
1870                 s->data = NULL;
1871                 free(data);
1872         }
1873         return 0;
1876 /*
1877  * While doing rename detection and pickaxe operation, we may need to
1878  * grab the data for the blob (or file) for our own in-core comparison.
1879  * diff_filespec has data and size fields for this purpose.
1880  */
1881 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1883         int err = 0;
1884         if (!DIFF_FILE_VALID(s))
1885                 die("internal error: asking to populate invalid file.");
1886         if (S_ISDIR(s->mode))
1887                 return -1;
1889         if (s->data)
1890                 return 0;
1892         if (size_only && 0 < s->size)
1893                 return 0;
1895         if (S_ISGITLINK(s->mode))
1896                 return diff_populate_gitlink(s, size_only);
1898         if (!s->sha1_valid ||
1899             reuse_worktree_file(s->path, s->sha1, 0)) {
1900                 struct strbuf buf;
1901                 struct stat st;
1902                 int fd;
1904                 if (!strcmp(s->path, "-"))
1905                         return populate_from_stdin(s);
1907                 if (lstat(s->path, &st) < 0) {
1908                         if (errno == ENOENT) {
1909                         err_empty:
1910                                 err = -1;
1911                         empty:
1912                                 s->data = (char *)"";
1913                                 s->size = 0;
1914                                 return err;
1915                         }
1916                 }
1917                 s->size = xsize_t(st.st_size);
1918                 if (!s->size)
1919                         goto empty;
1920                 if (size_only)
1921                         return 0;
1922                 if (S_ISLNK(st.st_mode)) {
1923                         int ret;
1924                         s->data = xmalloc(s->size);
1925                         s->should_free = 1;
1926                         ret = readlink(s->path, s->data, s->size);
1927                         if (ret < 0) {
1928                                 free(s->data);
1929                                 goto err_empty;
1930                         }
1931                         return 0;
1932                 }
1933                 fd = open(s->path, O_RDONLY);
1934                 if (fd < 0)
1935                         goto err_empty;
1936                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1937                 close(fd);
1938                 s->should_munmap = 1;
1940                 /*
1941                  * Convert from working tree format to canonical git format
1942                  */
1943                 strbuf_init(&buf, 0);
1944                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1945                         size_t size = 0;
1946                         munmap(s->data, s->size);
1947                         s->should_munmap = 0;
1948                         s->data = strbuf_detach(&buf, &size);
1949                         s->size = size;
1950                         s->should_free = 1;
1951                 }
1952         }
1953         else {
1954                 enum object_type type;
1955                 if (size_only)
1956                         type = sha1_object_info(s->sha1, &s->size);
1957                 else {
1958                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1959                         s->should_free = 1;
1960                 }
1961         }
1962         return 0;
1965 void diff_free_filespec_blob(struct diff_filespec *s)
1967         if (s->should_free)
1968                 free(s->data);
1969         else if (s->should_munmap)
1970                 munmap(s->data, s->size);
1972         if (s->should_free || s->should_munmap) {
1973                 s->should_free = s->should_munmap = 0;
1974                 s->data = NULL;
1975         }
1978 void diff_free_filespec_data(struct diff_filespec *s)
1980         diff_free_filespec_blob(s);
1981         free(s->cnt_data);
1982         s->cnt_data = NULL;
1985 static void prep_temp_blob(struct diff_tempfile *temp,
1986                            void *blob,
1987                            unsigned long size,
1988                            const unsigned char *sha1,
1989                            int mode)
1991         int fd;
1993         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1994         if (fd < 0)
1995                 die("unable to create temp-file: %s", strerror(errno));
1996         if (write_in_full(fd, blob, size) != size)
1997                 die("unable to write temp-file");
1998         close(fd);
1999         temp->name = temp->tmp_path;
2000         strcpy(temp->hex, sha1_to_hex(sha1));
2001         temp->hex[40] = 0;
2002         sprintf(temp->mode, "%06o", mode);
2005 static void prepare_temp_file(const char *name,
2006                               struct diff_tempfile *temp,
2007                               struct diff_filespec *one)
2009         if (!DIFF_FILE_VALID(one)) {
2010         not_a_valid_file:
2011                 /* A '-' entry produces this for file-2, and
2012                  * a '+' entry produces this for file-1.
2013                  */
2014                 temp->name = "/dev/null";
2015                 strcpy(temp->hex, ".");
2016                 strcpy(temp->mode, ".");
2017                 return;
2018         }
2020         if (!one->sha1_valid ||
2021             reuse_worktree_file(name, one->sha1, 1)) {
2022                 struct stat st;
2023                 if (lstat(name, &st) < 0) {
2024                         if (errno == ENOENT)
2025                                 goto not_a_valid_file;
2026                         die("stat(%s): %s", name, strerror(errno));
2027                 }
2028                 if (S_ISLNK(st.st_mode)) {
2029                         int ret;
2030                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
2031                         size_t sz = xsize_t(st.st_size);
2032                         if (sizeof(buf) <= st.st_size)
2033                                 die("symlink too long: %s", name);
2034                         ret = readlink(name, buf, sz);
2035                         if (ret < 0)
2036                                 die("readlink(%s)", name);
2037                         prep_temp_blob(temp, buf, sz,
2038                                        (one->sha1_valid ?
2039                                         one->sha1 : null_sha1),
2040                                        (one->sha1_valid ?
2041                                         one->mode : S_IFLNK));
2042                 }
2043                 else {
2044                         /* we can borrow from the file in the work tree */
2045                         temp->name = name;
2046                         if (!one->sha1_valid)
2047                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2048                         else
2049                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2050                         /* Even though we may sometimes borrow the
2051                          * contents from the work tree, we always want
2052                          * one->mode.  mode is trustworthy even when
2053                          * !(one->sha1_valid), as long as
2054                          * DIFF_FILE_VALID(one).
2055                          */
2056                         sprintf(temp->mode, "%06o", one->mode);
2057                 }
2058                 return;
2059         }
2060         else {
2061                 if (diff_populate_filespec(one, 0))
2062                         die("cannot read data blob for %s", one->path);
2063                 prep_temp_blob(temp, one->data, one->size,
2064                                one->sha1, one->mode);
2065         }
2068 static void remove_tempfile(void)
2070         int i;
2072         for (i = 0; i < 2; i++)
2073                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
2074                         unlink(diff_temp[i].name);
2075                         diff_temp[i].name = NULL;
2076                 }
2079 static void remove_tempfile_on_signal(int signo)
2081         remove_tempfile();
2082         signal(SIGINT, SIG_DFL);
2083         raise(signo);
2086 /* An external diff command takes:
2087  *
2088  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2089  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2090  *
2091  */
2092 static void run_external_diff(const char *pgm,
2093                               const char *name,
2094                               const char *other,
2095                               struct diff_filespec *one,
2096                               struct diff_filespec *two,
2097                               const char *xfrm_msg,
2098                               int complete_rewrite)
2100         const char *spawn_arg[10];
2101         struct diff_tempfile *temp = diff_temp;
2102         int retval;
2103         static int atexit_asked = 0;
2104         const char *othername;
2105         const char **arg = &spawn_arg[0];
2107         othername = (other? other : name);
2108         if (one && two) {
2109                 prepare_temp_file(name, &temp[0], one);
2110                 prepare_temp_file(othername, &temp[1], two);
2111                 if (! atexit_asked &&
2112                     (temp[0].name == temp[0].tmp_path ||
2113                      temp[1].name == temp[1].tmp_path)) {
2114                         atexit_asked = 1;
2115                         atexit(remove_tempfile);
2116                 }
2117                 signal(SIGINT, remove_tempfile_on_signal);
2118         }
2120         if (one && two) {
2121                 *arg++ = pgm;
2122                 *arg++ = name;
2123                 *arg++ = temp[0].name;
2124                 *arg++ = temp[0].hex;
2125                 *arg++ = temp[0].mode;
2126                 *arg++ = temp[1].name;
2127                 *arg++ = temp[1].hex;
2128                 *arg++ = temp[1].mode;
2129                 if (other) {
2130                         *arg++ = other;
2131                         *arg++ = xfrm_msg;
2132                 }
2133         } else {
2134                 *arg++ = pgm;
2135                 *arg++ = name;
2136         }
2137         *arg = NULL;
2138         fflush(NULL);
2139         retval = run_command_v_opt(spawn_arg, 0);
2140         remove_tempfile();
2141         if (retval) {
2142                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2143                 exit(1);
2144         }
2147 static const char *external_diff_attr(const char *name)
2149         struct git_attr_check attr_diff_check;
2151         if (!name)
2152                 return NULL;
2154         setup_diff_attr_check(&attr_diff_check);
2155         if (!git_checkattr(name, 1, &attr_diff_check)) {
2156                 const char *value = attr_diff_check.value;
2157                 if (!ATTR_TRUE(value) &&
2158                     !ATTR_FALSE(value) &&
2159                     !ATTR_UNSET(value)) {
2160                         struct ll_diff_driver *drv;
2162                         for (drv = user_diff; drv; drv = drv->next)
2163                                 if (!strcmp(drv->name, value))
2164                                         return drv->cmd;
2165                 }
2166         }
2167         return NULL;
2170 static int similarity_index(struct diff_filepair *p)
2172         return p->score * 100 / MAX_SCORE;
2175 static void fill_metainfo(struct strbuf *msg,
2176                           const char *name,
2177                           const char *other,
2178                           struct diff_filespec *one,
2179                           struct diff_filespec *two,
2180                           struct diff_options *o,
2181                           struct diff_filepair *p)
2183         strbuf_init(msg, PATH_MAX * 2 + 300);
2184         switch (p->status) {
2185         case DIFF_STATUS_COPIED:
2186                 strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2187                 strbuf_addstr(msg, "\ncopy from ");
2188                 quote_c_style(name, msg, NULL, 0);
2189                 strbuf_addstr(msg, "\ncopy to ");
2190                 quote_c_style(other, msg, NULL, 0);
2191                 strbuf_addch(msg, '\n');
2192                 break;
2193         case DIFF_STATUS_RENAMED:
2194                 strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2195                 strbuf_addstr(msg, "\nrename from ");
2196                 quote_c_style(name, msg, NULL, 0);
2197                 strbuf_addstr(msg, "\nrename to ");
2198                 quote_c_style(other, msg, NULL, 0);
2199                 strbuf_addch(msg, '\n');
2200                 break;
2201         case DIFF_STATUS_MODIFIED:
2202                 if (p->score) {
2203                         strbuf_addf(msg, "dissimilarity index %d%%\n",
2204                                     similarity_index(p));
2205                         break;
2206                 }
2207                 /* fallthru */
2208         default:
2209                 /* nothing */
2210                 ;
2211         }
2212         if (one && two && hashcmp(one->sha1, two->sha1)) {
2213                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2215                 if (DIFF_OPT_TST(o, BINARY)) {
2216                         mmfile_t mf;
2217                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2218                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2219                                 abbrev = 40;
2220                 }
2221                 strbuf_addf(msg, "index %.*s..%.*s",
2222                             abbrev, sha1_to_hex(one->sha1),
2223                             abbrev, sha1_to_hex(two->sha1));
2224                 if (one->mode == two->mode)
2225                         strbuf_addf(msg, " %06o", one->mode);
2226                 strbuf_addch(msg, '\n');
2227         }
2228         if (msg->len)
2229                 strbuf_setlen(msg, msg->len - 1);
2232 static void run_diff_cmd(const char *pgm,
2233                          const char *name,
2234                          const char *other,
2235                          const char *attr_path,
2236                          struct diff_filespec *one,
2237                          struct diff_filespec *two,
2238                          struct strbuf *msg,
2239                          struct diff_options *o,
2240                          struct diff_filepair *p)
2242         const char *xfrm_msg = NULL;
2243         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2245         if (msg) {
2246                 fill_metainfo(msg, name, other, one, two, o, p);
2247                 xfrm_msg = msg->len ? msg->buf : NULL;
2248         }
2250         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2251                 pgm = NULL;
2252         else {
2253                 const char *cmd = external_diff_attr(attr_path);
2254                 if (cmd)
2255                         pgm = cmd;
2256         }
2258         if (pgm) {
2259                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2260                                   complete_rewrite);
2261                 return;
2262         }
2263         if (one && two)
2264                 builtin_diff(name, other ? other : name,
2265                              one, two, xfrm_msg, o, complete_rewrite);
2266         else
2267                 fprintf(o->file, "* Unmerged path %s\n", name);
2270 static void diff_fill_sha1_info(struct diff_filespec *one)
2272         if (DIFF_FILE_VALID(one)) {
2273                 if (!one->sha1_valid) {
2274                         struct stat st;
2275                         if (!strcmp(one->path, "-")) {
2276                                 hashcpy(one->sha1, null_sha1);
2277                                 return;
2278                         }
2279                         if (lstat(one->path, &st) < 0)
2280                                 die("stat %s", one->path);
2281                         if (index_path(one->sha1, one->path, &st, 0))
2282                                 die("cannot hash %s\n", one->path);
2283                 }
2284         }
2285         else
2286                 hashclr(one->sha1);
2289 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2291         /* Strip the prefix but do not molest /dev/null and absolute paths */
2292         if (*namep && **namep != '/')
2293                 *namep += prefix_length;
2294         if (*otherp && **otherp != '/')
2295                 *otherp += prefix_length;
2298 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2300         const char *pgm = external_diff();
2301         struct strbuf msg;
2302         struct diff_filespec *one = p->one;
2303         struct diff_filespec *two = p->two;
2304         const char *name;
2305         const char *other;
2306         const char *attr_path;
2308         name  = p->one->path;
2309         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2310         attr_path = name;
2311         if (o->prefix_length)
2312                 strip_prefix(o->prefix_length, &name, &other);
2314         if (DIFF_PAIR_UNMERGED(p)) {
2315                 run_diff_cmd(pgm, name, NULL, attr_path,
2316                              NULL, NULL, NULL, o, p);
2317                 return;
2318         }
2320         diff_fill_sha1_info(one);
2321         diff_fill_sha1_info(two);
2323         if (!pgm &&
2324             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2325             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2326                 /*
2327                  * a filepair that changes between file and symlink
2328                  * needs to be split into deletion and creation.
2329                  */
2330                 struct diff_filespec *null = alloc_filespec(two->path);
2331                 run_diff_cmd(NULL, name, other, attr_path,
2332                              one, null, &msg, o, p);
2333                 free(null);
2334                 strbuf_release(&msg);
2336                 null = alloc_filespec(one->path);
2337                 run_diff_cmd(NULL, name, other, attr_path,
2338                              null, two, &msg, o, p);
2339                 free(null);
2340         }
2341         else
2342                 run_diff_cmd(pgm, name, other, attr_path,
2343                              one, two, &msg, o, p);
2345         strbuf_release(&msg);
2348 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2349                          struct diffstat_t *diffstat)
2351         const char *name;
2352         const char *other;
2353         int complete_rewrite = 0;
2355         if (DIFF_PAIR_UNMERGED(p)) {
2356                 /* unmerged */
2357                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2358                 return;
2359         }
2361         name = p->one->path;
2362         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2364         if (o->prefix_length)
2365                 strip_prefix(o->prefix_length, &name, &other);
2367         diff_fill_sha1_info(p->one);
2368         diff_fill_sha1_info(p->two);
2370         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2371                 complete_rewrite = 1;
2372         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2375 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2377         const char *name;
2378         const char *other;
2379         const char *attr_path;
2381         if (DIFF_PAIR_UNMERGED(p)) {
2382                 /* unmerged */
2383                 return;
2384         }
2386         name = p->one->path;
2387         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2388         attr_path = other ? other : name;
2390         if (o->prefix_length)
2391                 strip_prefix(o->prefix_length, &name, &other);
2393         diff_fill_sha1_info(p->one);
2394         diff_fill_sha1_info(p->two);
2396         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2399 void diff_setup(struct diff_options *options)
2401         memset(options, 0, sizeof(*options));
2403         options->file = stdout;
2405         options->line_termination = '\n';
2406         options->break_opt = -1;
2407         options->rename_limit = -1;
2408         options->dirstat_percent = 3;
2409         DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
2410         options->context = 3;
2412         options->change = diff_change;
2413         options->add_remove = diff_addremove;
2414         if (diff_use_color_default > 0)
2415                 DIFF_OPT_SET(options, COLOR_DIFF);
2416         else
2417                 DIFF_OPT_CLR(options, COLOR_DIFF);
2418         options->detect_rename = diff_detect_rename_default;
2420         options->a_prefix = "a/";
2421         options->b_prefix = "b/";
2424 int diff_setup_done(struct diff_options *options)
2426         int count = 0;
2428         if (options->output_format & DIFF_FORMAT_NAME)
2429                 count++;
2430         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2431                 count++;
2432         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2433                 count++;
2434         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2435                 count++;
2436         if (count > 1)
2437                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2439         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2440                 options->detect_rename = DIFF_DETECT_COPY;
2442         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2443                 options->prefix = NULL;
2444         if (options->prefix)
2445                 options->prefix_length = strlen(options->prefix);
2446         else
2447                 options->prefix_length = 0;
2449         if (options->output_format & (DIFF_FORMAT_NAME |
2450                                       DIFF_FORMAT_NAME_STATUS |
2451                                       DIFF_FORMAT_CHECKDIFF |
2452                                       DIFF_FORMAT_NO_OUTPUT))
2453                 options->output_format &= ~(DIFF_FORMAT_RAW |
2454                                             DIFF_FORMAT_NUMSTAT |
2455                                             DIFF_FORMAT_DIFFSTAT |
2456                                             DIFF_FORMAT_SHORTSTAT |
2457                                             DIFF_FORMAT_DIRSTAT |
2458                                             DIFF_FORMAT_SUMMARY |
2459                                             DIFF_FORMAT_PATCH);
2461         /*
2462          * These cases always need recursive; we do not drop caller-supplied
2463          * recursive bits for other formats here.
2464          */
2465         if (options->output_format & (DIFF_FORMAT_PATCH |
2466                                       DIFF_FORMAT_NUMSTAT |
2467                                       DIFF_FORMAT_DIFFSTAT |
2468                                       DIFF_FORMAT_SHORTSTAT |
2469                                       DIFF_FORMAT_DIRSTAT |
2470                                       DIFF_FORMAT_SUMMARY |
2471                                       DIFF_FORMAT_CHECKDIFF))
2472                 DIFF_OPT_SET(options, RECURSIVE);
2473         /*
2474          * Also pickaxe would not work very well if you do not say recursive
2475          */
2476         if (options->pickaxe)
2477                 DIFF_OPT_SET(options, RECURSIVE);
2479         if (options->detect_rename && options->rename_limit < 0)
2480                 options->rename_limit = diff_rename_limit_default;
2481         if (options->setup & DIFF_SETUP_USE_CACHE) {
2482                 if (!active_cache)
2483                         /* read-cache does not die even when it fails
2484                          * so it is safe for us to do this here.  Also
2485                          * it does not smudge active_cache or active_nr
2486                          * when it fails, so we do not have to worry about
2487                          * cleaning it up ourselves either.
2488                          */
2489                         read_cache();
2490         }
2491         if (options->abbrev <= 0 || 40 < options->abbrev)
2492                 options->abbrev = 40; /* full */
2494         /*
2495          * It does not make sense to show the first hit we happened
2496          * to have found.  It does not make sense not to return with
2497          * exit code in such a case either.
2498          */
2499         if (DIFF_OPT_TST(options, QUIET)) {
2500                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2501                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2502         }
2504         return 0;
2507 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2509         char c, *eq;
2510         int len;
2512         if (*arg != '-')
2513                 return 0;
2514         c = *++arg;
2515         if (!c)
2516                 return 0;
2517         if (c == arg_short) {
2518                 c = *++arg;
2519                 if (!c)
2520                         return 1;
2521                 if (val && isdigit(c)) {
2522                         char *end;
2523                         int n = strtoul(arg, &end, 10);
2524                         if (*end)
2525                                 return 0;
2526                         *val = n;
2527                         return 1;
2528                 }
2529                 return 0;
2530         }
2531         if (c != '-')
2532                 return 0;
2533         arg++;
2534         eq = strchr(arg, '=');
2535         if (eq)
2536                 len = eq - arg;
2537         else
2538                 len = strlen(arg);
2539         if (!len || strncmp(arg, arg_long, len))
2540                 return 0;
2541         if (eq) {
2542                 int n;
2543                 char *end;
2544                 if (!isdigit(*++eq))
2545                         return 0;
2546                 n = strtoul(eq, &end, 10);
2547                 if (*end)
2548                         return 0;
2549                 *val = n;
2550         }
2551         return 1;
2554 static int diff_scoreopt_parse(const char *opt);
2556 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2558         const char *arg = av[0];
2560         /* Output format options */
2561         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2562                 options->output_format |= DIFF_FORMAT_PATCH;
2563         else if (opt_arg(arg, 'U', "unified", &options->context))
2564                 options->output_format |= DIFF_FORMAT_PATCH;
2565         else if (!strcmp(arg, "--raw"))
2566                 options->output_format |= DIFF_FORMAT_RAW;
2567         else if (!strcmp(arg, "--patch-with-raw"))
2568                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2569         else if (!strcmp(arg, "--numstat"))
2570                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2571         else if (!strcmp(arg, "--shortstat"))
2572                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2573         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2574                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2575         else if (!strcmp(arg, "--cumulative")) {
2576                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2577                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2578         }
2579         else if (!strcmp(arg, "--check"))
2580                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2581         else if (!strcmp(arg, "--summary"))
2582                 options->output_format |= DIFF_FORMAT_SUMMARY;
2583         else if (!strcmp(arg, "--patch-with-stat"))
2584                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2585         else if (!strcmp(arg, "--name-only"))
2586                 options->output_format |= DIFF_FORMAT_NAME;
2587         else if (!strcmp(arg, "--name-status"))
2588                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2589         else if (!strcmp(arg, "-s"))
2590                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2591         else if (!prefixcmp(arg, "--stat")) {
2592                 char *end;
2593                 int width = options->stat_width;
2594                 int name_width = options->stat_name_width;
2595                 arg += 6;
2596                 end = (char *)arg;
2598                 switch (*arg) {
2599                 case '-':
2600                         if (!prefixcmp(arg, "-width="))
2601                                 width = strtoul(arg + 7, &end, 10);
2602                         else if (!prefixcmp(arg, "-name-width="))
2603                                 name_width = strtoul(arg + 12, &end, 10);
2604                         break;
2605                 case '=':
2606                         width = strtoul(arg+1, &end, 10);
2607                         if (*end == ',')
2608                                 name_width = strtoul(end+1, &end, 10);
2609                 }
2611                 /* Important! This checks all the error cases! */
2612                 if (*end)
2613                         return 0;
2614                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2615                 options->stat_name_width = name_width;
2616                 options->stat_width = width;
2617         }
2619         /* renames options */
2620         else if (!prefixcmp(arg, "-B")) {
2621                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2622                         return -1;
2623         }
2624         else if (!prefixcmp(arg, "-M")) {
2625                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2626                         return -1;
2627                 options->detect_rename = DIFF_DETECT_RENAME;
2628         }
2629         else if (!prefixcmp(arg, "-C")) {
2630                 if (options->detect_rename == DIFF_DETECT_COPY)
2631                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2632                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2633                         return -1;
2634                 options->detect_rename = DIFF_DETECT_COPY;
2635         }
2636         else if (!strcmp(arg, "--no-renames"))
2637                 options->detect_rename = 0;
2638         else if (!strcmp(arg, "--relative"))
2639                 DIFF_OPT_SET(options, RELATIVE_NAME);
2640         else if (!prefixcmp(arg, "--relative=")) {
2641                 DIFF_OPT_SET(options, RELATIVE_NAME);
2642                 options->prefix = arg + 11;
2643         }
2645         /* xdiff options */
2646         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2647                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2648         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2649                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2650         else if (!strcmp(arg, "--ignore-space-at-eol"))
2651                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2653         /* flags options */
2654         else if (!strcmp(arg, "--binary")) {
2655                 options->output_format |= DIFF_FORMAT_PATCH;
2656                 DIFF_OPT_SET(options, BINARY);
2657         }
2658         else if (!strcmp(arg, "--full-index"))
2659                 DIFF_OPT_SET(options, FULL_INDEX);
2660         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2661                 DIFF_OPT_SET(options, TEXT);
2662         else if (!strcmp(arg, "-R"))
2663                 DIFF_OPT_SET(options, REVERSE_DIFF);
2664         else if (!strcmp(arg, "--find-copies-harder"))
2665                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2666         else if (!strcmp(arg, "--follow"))
2667                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2668         else if (!strcmp(arg, "--color"))
2669                 DIFF_OPT_SET(options, COLOR_DIFF);
2670         else if (!strcmp(arg, "--no-color"))
2671                 DIFF_OPT_CLR(options, COLOR_DIFF);
2672         else if (!strcmp(arg, "--color-words"))
2673                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2674         else if (!strcmp(arg, "--exit-code"))
2675                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2676         else if (!strcmp(arg, "--quiet"))
2677                 DIFF_OPT_SET(options, QUIET);
2678         else if (!strcmp(arg, "--ext-diff"))
2679                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2680         else if (!strcmp(arg, "--no-ext-diff"))
2681                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2682         else if (!strcmp(arg, "--ignore-submodules"))
2683                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2685         /* misc options */
2686         else if (!strcmp(arg, "-z"))
2687                 options->line_termination = 0;
2688         else if (!prefixcmp(arg, "-l"))
2689                 options->rename_limit = strtoul(arg+2, NULL, 10);
2690         else if (!prefixcmp(arg, "-S"))
2691                 options->pickaxe = arg + 2;
2692         else if (!strcmp(arg, "--pickaxe-all"))
2693                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2694         else if (!strcmp(arg, "--pickaxe-regex"))
2695                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2696         else if (!prefixcmp(arg, "-O"))
2697                 options->orderfile = arg + 2;
2698         else if (!prefixcmp(arg, "--diff-filter="))
2699                 options->filter = arg + 14;
2700         else if (!strcmp(arg, "--abbrev"))
2701                 options->abbrev = DEFAULT_ABBREV;
2702         else if (!prefixcmp(arg, "--abbrev=")) {
2703                 options->abbrev = strtoul(arg + 9, NULL, 10);
2704                 if (options->abbrev < MINIMUM_ABBREV)
2705                         options->abbrev = MINIMUM_ABBREV;
2706                 else if (40 < options->abbrev)
2707                         options->abbrev = 40;
2708         }
2709         else if (!prefixcmp(arg, "--src-prefix="))
2710                 options->a_prefix = arg + 13;
2711         else if (!prefixcmp(arg, "--dst-prefix="))
2712                 options->b_prefix = arg + 13;
2713         else if (!strcmp(arg, "--no-prefix"))
2714                 options->a_prefix = options->b_prefix = "";
2715         else if (!prefixcmp(arg, "--output=")) {
2716                 options->file = fopen(arg + strlen("--output="), "w");
2717                 options->close_file = 1;
2718         } else
2719                 return 0;
2720         return 1;
2723 static int parse_num(const char **cp_p)
2725         unsigned long num, scale;
2726         int ch, dot;
2727         const char *cp = *cp_p;
2729         num = 0;
2730         scale = 1;
2731         dot = 0;
2732         for(;;) {
2733                 ch = *cp;
2734                 if ( !dot && ch == '.' ) {
2735                         scale = 1;
2736                         dot = 1;
2737                 } else if ( ch == '%' ) {
2738                         scale = dot ? scale*100 : 100;
2739                         cp++;   /* % is always at the end */
2740                         break;
2741                 } else if ( ch >= '0' && ch <= '9' ) {
2742                         if ( scale < 100000 ) {
2743                                 scale *= 10;
2744                                 num = (num*10) + (ch-'0');
2745                         }
2746                 } else {
2747                         break;
2748                 }
2749                 cp++;
2750         }
2751         *cp_p = cp;
2753         /* user says num divided by scale and we say internally that
2754          * is MAX_SCORE * num / scale.
2755          */
2756         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2759 static int diff_scoreopt_parse(const char *opt)
2761         int opt1, opt2, cmd;
2763         if (*opt++ != '-')
2764                 return -1;
2765         cmd = *opt++;
2766         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2767                 return -1; /* that is not a -M, -C nor -B option */
2769         opt1 = parse_num(&opt);
2770         if (cmd != 'B')
2771                 opt2 = 0;
2772         else {
2773                 if (*opt == 0)
2774                         opt2 = 0;
2775                 else if (*opt != '/')
2776                         return -1; /* we expect -B80/99 or -B80 */
2777                 else {
2778                         opt++;
2779                         opt2 = parse_num(&opt);
2780                 }
2781         }
2782         if (*opt != 0)
2783                 return -1;
2784         return opt1 | (opt2 << 16);
2787 struct diff_queue_struct diff_queued_diff;
2789 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2791         if (queue->alloc <= queue->nr) {
2792                 queue->alloc = alloc_nr(queue->alloc);
2793                 queue->queue = xrealloc(queue->queue,
2794                                         sizeof(dp) * queue->alloc);
2795         }
2796         queue->queue[queue->nr++] = dp;
2799 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2800                                  struct diff_filespec *one,
2801                                  struct diff_filespec *two)
2803         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2804         dp->one = one;
2805         dp->two = two;
2806         if (queue)
2807                 diff_q(queue, dp);
2808         return dp;
2811 void diff_free_filepair(struct diff_filepair *p)
2813         free_filespec(p->one);
2814         free_filespec(p->two);
2815         free(p);
2818 /* This is different from find_unique_abbrev() in that
2819  * it stuffs the result with dots for alignment.
2820  */
2821 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2823         int abblen;
2824         const char *abbrev;
2825         if (len == 40)
2826                 return sha1_to_hex(sha1);
2828         abbrev = find_unique_abbrev(sha1, len);
2829         abblen = strlen(abbrev);
2830         if (abblen < 37) {
2831                 static char hex[41];
2832                 if (len < abblen && abblen <= len + 2)
2833                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2834                 else
2835                         sprintf(hex, "%s...", abbrev);
2836                 return hex;
2837         }
2838         return sha1_to_hex(sha1);
2841 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2843         int line_termination = opt->line_termination;
2844         int inter_name_termination = line_termination ? '\t' : '\0';
2846         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2847                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2848                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2849                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2850         }
2851         if (p->score) {
2852                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2853                         inter_name_termination);
2854         } else {
2855                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2856         }
2858         if (p->status == DIFF_STATUS_COPIED ||
2859             p->status == DIFF_STATUS_RENAMED) {
2860                 const char *name_a, *name_b;
2861                 name_a = p->one->path;
2862                 name_b = p->two->path;
2863                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2864                 write_name_quoted(name_a, opt->file, inter_name_termination);
2865                 write_name_quoted(name_b, opt->file, line_termination);
2866         } else {
2867                 const char *name_a, *name_b;
2868                 name_a = p->one->mode ? p->one->path : p->two->path;
2869                 name_b = NULL;
2870                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2871                 write_name_quoted(name_a, opt->file, line_termination);
2872         }
2875 int diff_unmodified_pair(struct diff_filepair *p)
2877         /* This function is written stricter than necessary to support
2878          * the currently implemented transformers, but the idea is to
2879          * let transformers to produce diff_filepairs any way they want,
2880          * and filter and clean them up here before producing the output.
2881          */
2882         struct diff_filespec *one = p->one, *two = p->two;
2884         if (DIFF_PAIR_UNMERGED(p))
2885                 return 0; /* unmerged is interesting */
2887         /* deletion, addition, mode or type change
2888          * and rename are all interesting.
2889          */
2890         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2891             DIFF_PAIR_MODE_CHANGED(p) ||
2892             strcmp(one->path, two->path))
2893                 return 0;
2895         /* both are valid and point at the same path.  that is, we are
2896          * dealing with a change.
2897          */
2898         if (one->sha1_valid && two->sha1_valid &&
2899             !hashcmp(one->sha1, two->sha1))
2900                 return 1; /* no change */
2901         if (!one->sha1_valid && !two->sha1_valid)
2902                 return 1; /* both look at the same file on the filesystem. */
2903         return 0;
2906 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2908         if (diff_unmodified_pair(p))
2909                 return;
2911         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2912             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2913                 return; /* no tree diffs in patch format */
2915         run_diff(p, o);
2918 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2919                             struct diffstat_t *diffstat)
2921         if (diff_unmodified_pair(p))
2922                 return;
2924         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2925             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2926                 return; /* no tree diffs in patch format */
2928         run_diffstat(p, o, diffstat);
2931 static void diff_flush_checkdiff(struct diff_filepair *p,
2932                 struct diff_options *o)
2934         if (diff_unmodified_pair(p))
2935                 return;
2937         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2938             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2939                 return; /* no tree diffs in patch format */
2941         run_checkdiff(p, o);
2944 int diff_queue_is_empty(void)
2946         struct diff_queue_struct *q = &diff_queued_diff;
2947         int i;
2948         for (i = 0; i < q->nr; i++)
2949                 if (!diff_unmodified_pair(q->queue[i]))
2950                         return 0;
2951         return 1;
2954 #if DIFF_DEBUG
2955 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2957         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2958                 x, one ? one : "",
2959                 s->path,
2960                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2961                 s->mode,
2962                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2963         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2964                 x, one ? one : "",
2965                 s->size, s->xfrm_flags);
2968 void diff_debug_filepair(const struct diff_filepair *p, int i)
2970         diff_debug_filespec(p->one, i, "one");
2971         diff_debug_filespec(p->two, i, "two");
2972         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2973                 p->score, p->status ? p->status : '?',
2974                 p->one->rename_used, p->broken_pair);
2977 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2979         int i;
2980         if (msg)
2981                 fprintf(stderr, "%s\n", msg);
2982         fprintf(stderr, "q->nr = %d\n", q->nr);
2983         for (i = 0; i < q->nr; i++) {
2984                 struct diff_filepair *p = q->queue[i];
2985                 diff_debug_filepair(p, i);
2986         }
2988 #endif
2990 static void diff_resolve_rename_copy(void)
2992         int i;
2993         struct diff_filepair *p;
2994         struct diff_queue_struct *q = &diff_queued_diff;
2996         diff_debug_queue("resolve-rename-copy", q);
2998         for (i = 0; i < q->nr; i++) {
2999                 p = q->queue[i];
3000                 p->status = 0; /* undecided */
3001                 if (DIFF_PAIR_UNMERGED(p))
3002                         p->status = DIFF_STATUS_UNMERGED;
3003                 else if (!DIFF_FILE_VALID(p->one))
3004                         p->status = DIFF_STATUS_ADDED;
3005                 else if (!DIFF_FILE_VALID(p->two))
3006                         p->status = DIFF_STATUS_DELETED;
3007                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3008                         p->status = DIFF_STATUS_TYPE_CHANGED;
3010                 /* from this point on, we are dealing with a pair
3011                  * whose both sides are valid and of the same type, i.e.
3012                  * either in-place edit or rename/copy edit.
3013                  */
3014                 else if (DIFF_PAIR_RENAME(p)) {
3015                         /*
3016                          * A rename might have re-connected a broken
3017                          * pair up, causing the pathnames to be the
3018                          * same again. If so, that's not a rename at
3019                          * all, just a modification..
3020                          *
3021                          * Otherwise, see if this source was used for
3022                          * multiple renames, in which case we decrement
3023                          * the count, and call it a copy.
3024                          */
3025                         if (!strcmp(p->one->path, p->two->path))
3026                                 p->status = DIFF_STATUS_MODIFIED;
3027                         else if (--p->one->rename_used > 0)
3028                                 p->status = DIFF_STATUS_COPIED;
3029                         else
3030                                 p->status = DIFF_STATUS_RENAMED;
3031                 }
3032                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3033                          p->one->mode != p->two->mode ||
3034                          is_null_sha1(p->one->sha1))
3035                         p->status = DIFF_STATUS_MODIFIED;
3036                 else {
3037                         /* This is a "no-change" entry and should not
3038                          * happen anymore, but prepare for broken callers.
3039                          */
3040                         error("feeding unmodified %s to diffcore",
3041                               p->one->path);
3042                         p->status = DIFF_STATUS_UNKNOWN;
3043                 }
3044         }
3045         diff_debug_queue("resolve-rename-copy done", q);
3048 static int check_pair_status(struct diff_filepair *p)
3050         switch (p->status) {
3051         case DIFF_STATUS_UNKNOWN:
3052                 return 0;
3053         case 0:
3054                 die("internal error in diff-resolve-rename-copy");
3055         default:
3056                 return 1;
3057         }
3060 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3062         int fmt = opt->output_format;
3064         if (fmt & DIFF_FORMAT_CHECKDIFF)
3065                 diff_flush_checkdiff(p, opt);
3066         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3067                 diff_flush_raw(p, opt);
3068         else if (fmt & DIFF_FORMAT_NAME) {
3069                 const char *name_a, *name_b;
3070                 name_a = p->two->path;
3071                 name_b = NULL;
3072                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3073                 write_name_quoted(name_a, opt->file, opt->line_termination);
3074         }
3077 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3079         if (fs->mode)
3080                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3081         else
3082                 fprintf(file, " %s ", newdelete);
3083         write_name_quoted(fs->path, file, '\n');
3087 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3089         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3090                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3091                         show_name ? ' ' : '\n');
3092                 if (show_name) {
3093                         write_name_quoted(p->two->path, file, '\n');
3094                 }
3095         }
3098 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3100         char *names = pprint_rename(p->one->path, p->two->path);
3102         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3103         free(names);
3104         show_mode_change(file, p, 0);
3107 static void diff_summary(FILE *file, struct diff_filepair *p)
3109         switch(p->status) {
3110         case DIFF_STATUS_DELETED:
3111                 show_file_mode_name(file, "delete", p->one);
3112                 break;
3113         case DIFF_STATUS_ADDED:
3114                 show_file_mode_name(file, "create", p->two);
3115                 break;
3116         case DIFF_STATUS_COPIED:
3117                 show_rename_copy(file, "copy", p);
3118                 break;
3119         case DIFF_STATUS_RENAMED:
3120                 show_rename_copy(file, "rename", p);
3121                 break;
3122         default:
3123                 if (p->score) {
3124                         fputs(" rewrite ", file);
3125                         write_name_quoted(p->two->path, file, ' ');
3126                         fprintf(file, "(%d%%)\n", similarity_index(p));
3127                 }
3128                 show_mode_change(file, p, !p->score);
3129                 break;
3130         }
3133 struct patch_id_t {
3134         struct xdiff_emit_state xm;
3135         SHA_CTX *ctx;
3136         int patchlen;
3137 };
3139 static int remove_space(char *line, int len)
3141         int i;
3142         char *dst = line;
3143         unsigned char c;
3145         for (i = 0; i < len; i++)
3146                 if (!isspace((c = line[i])))
3147                         *dst++ = c;
3149         return dst - line;
3152 static void patch_id_consume(void *priv, char *line, unsigned long len)
3154         struct patch_id_t *data = priv;
3155         int new_len;
3157         /* Ignore line numbers when computing the SHA1 of the patch */
3158         if (!prefixcmp(line, "@@ -"))
3159                 return;
3161         new_len = remove_space(line, len);
3163         SHA1_Update(data->ctx, line, new_len);
3164         data->patchlen += new_len;
3167 /* returns 0 upon success, and writes result into sha1 */
3168 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3170         struct diff_queue_struct *q = &diff_queued_diff;
3171         int i;
3172         SHA_CTX ctx;
3173         struct patch_id_t data;
3174         char buffer[PATH_MAX * 4 + 20];
3176         SHA1_Init(&ctx);
3177         memset(&data, 0, sizeof(struct patch_id_t));
3178         data.ctx = &ctx;
3179         data.xm.consume = patch_id_consume;
3181         for (i = 0; i < q->nr; i++) {
3182                 xpparam_t xpp;
3183                 xdemitconf_t xecfg;
3184                 xdemitcb_t ecb;
3185                 mmfile_t mf1, mf2;
3186                 struct diff_filepair *p = q->queue[i];
3187                 int len1, len2;
3189                 memset(&xecfg, 0, sizeof(xecfg));
3190                 if (p->status == 0)
3191                         return error("internal diff status error");
3192                 if (p->status == DIFF_STATUS_UNKNOWN)
3193                         continue;
3194                 if (diff_unmodified_pair(p))
3195                         continue;
3196                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3197                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3198                         continue;
3199                 if (DIFF_PAIR_UNMERGED(p))
3200                         continue;
3202                 diff_fill_sha1_info(p->one);
3203                 diff_fill_sha1_info(p->two);
3204                 if (fill_mmfile(&mf1, p->one) < 0 ||
3205                                 fill_mmfile(&mf2, p->two) < 0)
3206                         return error("unable to read files to diff");
3208                 len1 = remove_space(p->one->path, strlen(p->one->path));
3209                 len2 = remove_space(p->two->path, strlen(p->two->path));
3210                 if (p->one->mode == 0)
3211                         len1 = snprintf(buffer, sizeof(buffer),
3212                                         "diff--gita/%.*sb/%.*s"
3213                                         "newfilemode%06o"
3214                                         "---/dev/null"
3215                                         "+++b/%.*s",
3216                                         len1, p->one->path,
3217                                         len2, p->two->path,
3218                                         p->two->mode,
3219                                         len2, p->two->path);
3220                 else if (p->two->mode == 0)
3221                         len1 = snprintf(buffer, sizeof(buffer),
3222                                         "diff--gita/%.*sb/%.*s"
3223                                         "deletedfilemode%06o"
3224                                         "---a/%.*s"
3225                                         "+++/dev/null",
3226                                         len1, p->one->path,
3227                                         len2, p->two->path,
3228                                         p->one->mode,
3229                                         len1, p->one->path);
3230                 else
3231                         len1 = snprintf(buffer, sizeof(buffer),
3232                                         "diff--gita/%.*sb/%.*s"
3233                                         "---a/%.*s"
3234                                         "+++b/%.*s",
3235                                         len1, p->one->path,
3236                                         len2, p->two->path,
3237                                         len1, p->one->path,
3238                                         len2, p->two->path);
3239                 SHA1_Update(&ctx, buffer, len1);
3241                 xpp.flags = XDF_NEED_MINIMAL;
3242                 xecfg.ctxlen = 3;
3243                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3244                 ecb.outf = xdiff_outf;
3245                 ecb.priv = &data;
3246                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
3247         }
3249         SHA1_Final(sha1, &ctx);
3250         return 0;
3253 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3255         struct diff_queue_struct *q = &diff_queued_diff;
3256         int i;
3257         int result = diff_get_patch_id(options, sha1);
3259         for (i = 0; i < q->nr; i++)
3260                 diff_free_filepair(q->queue[i]);
3262         free(q->queue);
3263         q->queue = NULL;
3264         q->nr = q->alloc = 0;
3266         return result;
3269 static int is_summary_empty(const struct diff_queue_struct *q)
3271         int i;
3273         for (i = 0; i < q->nr; i++) {
3274                 const struct diff_filepair *p = q->queue[i];
3276                 switch (p->status) {
3277                 case DIFF_STATUS_DELETED:
3278                 case DIFF_STATUS_ADDED:
3279                 case DIFF_STATUS_COPIED:
3280                 case DIFF_STATUS_RENAMED:
3281                         return 0;
3282                 default:
3283                         if (p->score)
3284                                 return 0;
3285                         if (p->one->mode && p->two->mode &&
3286                             p->one->mode != p->two->mode)
3287                                 return 0;
3288                         break;
3289                 }
3290         }
3291         return 1;
3294 void diff_flush(struct diff_options *options)
3296         struct diff_queue_struct *q = &diff_queued_diff;
3297         int i, output_format = options->output_format;
3298         int separator = 0;
3300         /*
3301          * Order: raw, stat, summary, patch
3302          * or:    name/name-status/checkdiff (other bits clear)
3303          */
3304         if (!q->nr)
3305                 goto free_queue;
3307         if (output_format & (DIFF_FORMAT_RAW |
3308                              DIFF_FORMAT_NAME |
3309                              DIFF_FORMAT_NAME_STATUS |
3310                              DIFF_FORMAT_CHECKDIFF)) {
3311                 for (i = 0; i < q->nr; i++) {
3312                         struct diff_filepair *p = q->queue[i];
3313                         if (check_pair_status(p))
3314                                 flush_one_pair(p, options);
3315                 }
3316                 separator++;
3317         }
3319         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3320                 struct diffstat_t diffstat;
3322                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3323                 diffstat.xm.consume = diffstat_consume;
3324                 for (i = 0; i < q->nr; i++) {
3325                         struct diff_filepair *p = q->queue[i];
3326                         if (check_pair_status(p))
3327                                 diff_flush_stat(p, options, &diffstat);
3328                 }
3329                 if (output_format & DIFF_FORMAT_NUMSTAT)
3330                         show_numstat(&diffstat, options);
3331                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3332                         show_stats(&diffstat, options);
3333                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3334                         show_shortstats(&diffstat, options);
3335                 free_diffstat_info(&diffstat);
3336                 separator++;
3337         }
3338         if (output_format & DIFF_FORMAT_DIRSTAT)
3339                 show_dirstat(options);
3341         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3342                 for (i = 0; i < q->nr; i++)
3343                         diff_summary(options->file, q->queue[i]);
3344                 separator++;
3345         }
3347         if (output_format & DIFF_FORMAT_PATCH) {
3348                 if (separator) {
3349                         putc(options->line_termination, options->file);
3350                         if (options->stat_sep) {
3351                                 /* attach patch instead of inline */
3352                                 fputs(options->stat_sep, options->file);
3353                         }
3354                 }
3356                 for (i = 0; i < q->nr; i++) {
3357                         struct diff_filepair *p = q->queue[i];
3358                         if (check_pair_status(p))
3359                                 diff_flush_patch(p, options);
3360                 }
3361         }
3363         if (output_format & DIFF_FORMAT_CALLBACK)
3364                 options->format_callback(q, options, options->format_callback_data);
3366         for (i = 0; i < q->nr; i++)
3367                 diff_free_filepair(q->queue[i]);
3368 free_queue:
3369         free(q->queue);
3370         q->queue = NULL;
3371         q->nr = q->alloc = 0;
3372         if (options->close_file)
3373                 fclose(options->file);
3376 static void diffcore_apply_filter(const char *filter)
3378         int i;
3379         struct diff_queue_struct *q = &diff_queued_diff;
3380         struct diff_queue_struct outq;
3381         outq.queue = NULL;
3382         outq.nr = outq.alloc = 0;
3384         if (!filter)
3385                 return;
3387         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3388                 int found;
3389                 for (i = found = 0; !found && i < q->nr; i++) {
3390                         struct diff_filepair *p = q->queue[i];
3391                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3392                              ((p->score &&
3393                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3394                               (!p->score &&
3395                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3396                             ((p->status != DIFF_STATUS_MODIFIED) &&
3397                              strchr(filter, p->status)))
3398                                 found++;
3399                 }
3400                 if (found)
3401                         return;
3403                 /* otherwise we will clear the whole queue
3404                  * by copying the empty outq at the end of this
3405                  * function, but first clear the current entries
3406                  * in the queue.
3407                  */
3408                 for (i = 0; i < q->nr; i++)
3409                         diff_free_filepair(q->queue[i]);
3410         }
3411         else {
3412                 /* Only the matching ones */
3413                 for (i = 0; i < q->nr; i++) {
3414                         struct diff_filepair *p = q->queue[i];
3416                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3417                              ((p->score &&
3418                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3419                               (!p->score &&
3420                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3421                             ((p->status != DIFF_STATUS_MODIFIED) &&
3422                              strchr(filter, p->status)))
3423                                 diff_q(&outq, p);
3424                         else
3425                                 diff_free_filepair(p);
3426                 }
3427         }
3428         free(q->queue);
3429         *q = outq;
3432 /* Check whether two filespecs with the same mode and size are identical */
3433 static int diff_filespec_is_identical(struct diff_filespec *one,
3434                                       struct diff_filespec *two)
3436         if (S_ISGITLINK(one->mode))
3437                 return 0;
3438         if (diff_populate_filespec(one, 0))
3439                 return 0;
3440         if (diff_populate_filespec(two, 0))
3441                 return 0;
3442         return !memcmp(one->data, two->data, one->size);
3445 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3447         int i;
3448         struct diff_queue_struct *q = &diff_queued_diff;
3449         struct diff_queue_struct outq;
3450         outq.queue = NULL;
3451         outq.nr = outq.alloc = 0;
3453         for (i = 0; i < q->nr; i++) {
3454                 struct diff_filepair *p = q->queue[i];
3456                 /*
3457                  * 1. Entries that come from stat info dirtyness
3458                  *    always have both sides (iow, not create/delete),
3459                  *    one side of the object name is unknown, with
3460                  *    the same mode and size.  Keep the ones that
3461                  *    do not match these criteria.  They have real
3462                  *    differences.
3463                  *
3464                  * 2. At this point, the file is known to be modified,
3465                  *    with the same mode and size, and the object
3466                  *    name of one side is unknown.  Need to inspect
3467                  *    the identical contents.
3468                  */
3469                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3470                     !DIFF_FILE_VALID(p->two) ||
3471                     (p->one->sha1_valid && p->two->sha1_valid) ||
3472                     (p->one->mode != p->two->mode) ||
3473                     diff_populate_filespec(p->one, 1) ||
3474                     diff_populate_filespec(p->two, 1) ||
3475                     (p->one->size != p->two->size) ||
3476                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3477                         diff_q(&outq, p);
3478                 else {
3479                         /*
3480                          * The caller can subtract 1 from skip_stat_unmatch
3481                          * to determine how many paths were dirty only
3482                          * due to stat info mismatch.
3483                          */
3484                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3485                                 diffopt->skip_stat_unmatch++;
3486                         diff_free_filepair(p);
3487                 }
3488         }
3489         free(q->queue);
3490         *q = outq;
3493 void diffcore_std(struct diff_options *options)
3495         if (options->skip_stat_unmatch)
3496                 diffcore_skip_stat_unmatch(options);
3497         if (options->break_opt != -1)
3498                 diffcore_break(options->break_opt);
3499         if (options->detect_rename)
3500                 diffcore_rename(options);
3501         if (options->break_opt != -1)
3502                 diffcore_merge_broken();
3503         if (options->pickaxe)
3504                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3505         if (options->orderfile)
3506                 diffcore_order(options->orderfile);
3507         diff_resolve_rename_copy();
3508         diffcore_apply_filter(options->filter);
3510         if (diff_queued_diff.nr)
3511                 DIFF_OPT_SET(options, HAS_CHANGES);
3512         else
3513                 DIFF_OPT_CLR(options, HAS_CHANGES);
3516 int diff_result_code(struct diff_options *opt, int status)
3518         int result = 0;
3519         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3520             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3521                 return status;
3522         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3523             DIFF_OPT_TST(opt, HAS_CHANGES))
3524                 result |= 01;
3525         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3526             DIFF_OPT_TST(opt, CHECK_FAILED))
3527                 result |= 02;
3528         return result;
3531 void diff_addremove(struct diff_options *options,
3532                     int addremove, unsigned mode,
3533                     const unsigned char *sha1,
3534                     const char *concatpath)
3536         struct diff_filespec *one, *two;
3538         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3539                 return;
3541         /* This may look odd, but it is a preparation for
3542          * feeding "there are unchanged files which should
3543          * not produce diffs, but when you are doing copy
3544          * detection you would need them, so here they are"
3545          * entries to the diff-core.  They will be prefixed
3546          * with something like '=' or '*' (I haven't decided
3547          * which but should not make any difference).
3548          * Feeding the same new and old to diff_change()
3549          * also has the same effect.
3550          * Before the final output happens, they are pruned after
3551          * merged into rename/copy pairs as appropriate.
3552          */
3553         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3554                 addremove = (addremove == '+' ? '-' :
3555                              addremove == '-' ? '+' : addremove);
3557         if (options->prefix &&
3558             strncmp(concatpath, options->prefix, options->prefix_length))
3559                 return;
3561         one = alloc_filespec(concatpath);
3562         two = alloc_filespec(concatpath);
3564         if (addremove != '+')
3565                 fill_filespec(one, sha1, mode);
3566         if (addremove != '-')
3567                 fill_filespec(two, sha1, mode);
3569         diff_queue(&diff_queued_diff, one, two);
3570         DIFF_OPT_SET(options, HAS_CHANGES);
3573 void diff_change(struct diff_options *options,
3574                  unsigned old_mode, unsigned new_mode,
3575                  const unsigned char *old_sha1,
3576                  const unsigned char *new_sha1,
3577                  const char *concatpath)
3579         struct diff_filespec *one, *two;
3581         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3582                         && S_ISGITLINK(new_mode))
3583                 return;
3585         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3586                 unsigned tmp;
3587                 const unsigned char *tmp_c;
3588                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3589                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3590         }
3592         if (options->prefix &&
3593             strncmp(concatpath, options->prefix, options->prefix_length))
3594                 return;
3596         one = alloc_filespec(concatpath);
3597         two = alloc_filespec(concatpath);
3598         fill_filespec(one, old_sha1, old_mode);
3599         fill_filespec(two, new_sha1, new_mode);
3601         diff_queue(&diff_queued_diff, one, two);
3602         DIFF_OPT_SET(options, HAS_CHANGES);
3605 void diff_unmerge(struct diff_options *options,
3606                   const char *path,
3607                   unsigned mode, const unsigned char *sha1)
3609         struct diff_filespec *one, *two;
3611         if (options->prefix &&
3612             strncmp(path, options->prefix, options->prefix_length))
3613                 return;
3615         one = alloc_filespec(path);
3616         two = alloc_filespec(path);
3617         fill_filespec(one, sha1, mode);
3618         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;