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[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include <sys/types.h>
5 #include <sys/wait.h>
6 #include <signal.h>
7 #include "cache.h"
8 #include "quote.h"
9 #include "diff.h"
10 #include "diffcore.h"
11 #include "delta.h"
12 #include "xdiff-interface.h"
14 static int use_size_cache;
16 static int diff_rename_limit_default = -1;
17 static int diff_use_color_default = 0;
19 enum color_diff {
20         DIFF_RESET = 0,
21         DIFF_PLAIN = 1,
22         DIFF_METAINFO = 2,
23         DIFF_FRAGINFO = 3,
24         DIFF_FILE_OLD = 4,
25         DIFF_FILE_NEW = 5,
26 };
28 #define COLOR_NORMAL  ""
29 #define COLOR_BOLD    "\033[1m"
30 #define COLOR_DIM     "\033[2m"
31 #define COLOR_UL      "\033[4m"
32 #define COLOR_BLINK   "\033[5m"
33 #define COLOR_REVERSE "\033[7m"
34 #define COLOR_RESET   "\033[m"
36 #define COLOR_BLACK   "\033[30m"
37 #define COLOR_RED     "\033[31m"
38 #define COLOR_GREEN   "\033[32m"
39 #define COLOR_YELLOW  "\033[33m"
40 #define COLOR_BLUE    "\033[34m"
41 #define COLOR_MAGENTA "\033[35m"
42 #define COLOR_CYAN    "\033[36m"
43 #define COLOR_WHITE   "\033[37m"
45 static const char *diff_colors[] = {
46         [DIFF_RESET]    = COLOR_RESET,
47         [DIFF_PLAIN]    = COLOR_NORMAL,
48         [DIFF_METAINFO] = COLOR_BOLD,
49         [DIFF_FRAGINFO] = COLOR_CYAN,
50         [DIFF_FILE_OLD] = COLOR_RED,
51         [DIFF_FILE_NEW] = COLOR_GREEN,
52 };
54 static int parse_diff_color_slot(const char *var, int ofs)
55 {
56         if (!strcasecmp(var+ofs, "plain"))
57                 return DIFF_PLAIN;
58         if (!strcasecmp(var+ofs, "meta"))
59                 return DIFF_METAINFO;
60         if (!strcasecmp(var+ofs, "frag"))
61                 return DIFF_FRAGINFO;
62         if (!strcasecmp(var+ofs, "old"))
63                 return DIFF_FILE_OLD;
64         if (!strcasecmp(var+ofs, "new"))
65                 return DIFF_FILE_NEW;
66         die("bad config variable '%s'", var);
67 }
69 static const char *parse_diff_color_value(const char *value, const char *var)
70 {
71         if (!strcasecmp(value, "normal"))
72                 return COLOR_NORMAL;
73         if (!strcasecmp(value, "bold"))
74                 return COLOR_BOLD;
75         if (!strcasecmp(value, "dim"))
76                 return COLOR_DIM;
77         if (!strcasecmp(value, "ul"))
78                 return COLOR_UL;
79         if (!strcasecmp(value, "blink"))
80                 return COLOR_BLINK;
81         if (!strcasecmp(value, "reverse"))
82                 return COLOR_REVERSE;
83         if (!strcasecmp(value, "reset"))
84                 return COLOR_RESET;
85         if (!strcasecmp(value, "black"))
86                 return COLOR_BLACK;
87         if (!strcasecmp(value, "red"))
88                 return COLOR_RED;
89         if (!strcasecmp(value, "green"))
90                 return COLOR_GREEN;
91         if (!strcasecmp(value, "yellow"))
92                 return COLOR_YELLOW;
93         if (!strcasecmp(value, "blue"))
94                 return COLOR_BLUE;
95         if (!strcasecmp(value, "magenta"))
96                 return COLOR_MAGENTA;
97         if (!strcasecmp(value, "cyan"))
98                 return COLOR_CYAN;
99         if (!strcasecmp(value, "white"))
100                 return COLOR_WHITE;
101         die("bad config value '%s' for variable '%s'", value, var);
104 int git_diff_config(const char *var, const char *value)
106         if (!strcmp(var, "diff.renamelimit")) {
107                 diff_rename_limit_default = git_config_int(var, value);
108                 return 0;
109         }
110         if (!strcmp(var, "diff.color")) {
111                 if (!value)
112                         diff_use_color_default = 1; /* bool */
113                 else if (!strcasecmp(value, "auto")) {
114                         diff_use_color_default = 0;
115                         if (isatty(1) || pager_in_use) {
116                                 char *term = getenv("TERM");
117                                 if (term && strcmp(term, "dumb"))
118                                         diff_use_color_default = 1;
119                         }
120                 }
121                 else if (!strcasecmp(value, "never"))
122                         diff_use_color_default = 0;
123                 else if (!strcasecmp(value, "always"))
124                         diff_use_color_default = 1;
125                 else
126                         diff_use_color_default = git_config_bool(var, value);
127                 return 0;
128         }
129         if (!strncmp(var, "diff.color.", 11)) {
130                 int slot = parse_diff_color_slot(var, 11);
131                 diff_colors[slot] = parse_diff_color_value(value, var);
132                 return 0;
133         }
134         return git_default_config(var, value);
137 static char *quote_one(const char *str)
139         int needlen;
140         char *xp;
142         if (!str)
143                 return NULL;
144         needlen = quote_c_style(str, NULL, NULL, 0);
145         if (!needlen)
146                 return strdup(str);
147         xp = xmalloc(needlen + 1);
148         quote_c_style(str, xp, NULL, 0);
149         return xp;
152 static char *quote_two(const char *one, const char *two)
154         int need_one = quote_c_style(one, NULL, NULL, 1);
155         int need_two = quote_c_style(two, NULL, NULL, 1);
156         char *xp;
158         if (need_one + need_two) {
159                 if (!need_one) need_one = strlen(one);
160                 if (!need_two) need_one = strlen(two);
162                 xp = xmalloc(need_one + need_two + 3);
163                 xp[0] = '"';
164                 quote_c_style(one, xp + 1, NULL, 1);
165                 quote_c_style(two, xp + need_one + 1, NULL, 1);
166                 strcpy(xp + need_one + need_two + 1, "\"");
167                 return xp;
168         }
169         need_one = strlen(one);
170         need_two = strlen(two);
171         xp = xmalloc(need_one + need_two + 1);
172         strcpy(xp, one);
173         strcpy(xp + need_one, two);
174         return xp;
177 static const char *external_diff(void)
179         static const char *external_diff_cmd = NULL;
180         static int done_preparing = 0;
182         if (done_preparing)
183                 return external_diff_cmd;
184         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
185         done_preparing = 1;
186         return external_diff_cmd;
189 #define TEMPFILE_PATH_LEN               50
191 static struct diff_tempfile {
192         const char *name; /* filename external diff should read from */
193         char hex[41];
194         char mode[10];
195         char tmp_path[TEMPFILE_PATH_LEN];
196 } diff_temp[2];
198 static int count_lines(const char *data, int size)
200         int count, ch, completely_empty = 1, nl_just_seen = 0;
201         count = 0;
202         while (0 < size--) {
203                 ch = *data++;
204                 if (ch == '\n') {
205                         count++;
206                         nl_just_seen = 1;
207                         completely_empty = 0;
208                 }
209                 else {
210                         nl_just_seen = 0;
211                         completely_empty = 0;
212                 }
213         }
214         if (completely_empty)
215                 return 0;
216         if (!nl_just_seen)
217                 count++; /* no trailing newline */
218         return count;
221 static void print_line_count(int count)
223         switch (count) {
224         case 0:
225                 printf("0,0");
226                 break;
227         case 1:
228                 printf("1");
229                 break;
230         default:
231                 printf("1,%d", count);
232                 break;
233         }
236 static void copy_file(int prefix, const char *data, int size)
238         int ch, nl_just_seen = 1;
239         while (0 < size--) {
240                 ch = *data++;
241                 if (nl_just_seen)
242                         putchar(prefix);
243                 putchar(ch);
244                 if (ch == '\n')
245                         nl_just_seen = 1;
246                 else
247                         nl_just_seen = 0;
248         }
249         if (!nl_just_seen)
250                 printf("\n\\ No newline at end of file\n");
253 static void emit_rewrite_diff(const char *name_a,
254                               const char *name_b,
255                               struct diff_filespec *one,
256                               struct diff_filespec *two)
258         int lc_a, lc_b;
259         diff_populate_filespec(one, 0);
260         diff_populate_filespec(two, 0);
261         lc_a = count_lines(one->data, one->size);
262         lc_b = count_lines(two->data, two->size);
263         printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
264         print_line_count(lc_a);
265         printf(" +");
266         print_line_count(lc_b);
267         printf(" @@\n");
268         if (lc_a)
269                 copy_file('-', one->data, one->size);
270         if (lc_b)
271                 copy_file('+', two->data, two->size);
274 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
276         if (!DIFF_FILE_VALID(one)) {
277                 mf->ptr = (char *)""; /* does not matter */
278                 mf->size = 0;
279                 return 0;
280         }
281         else if (diff_populate_filespec(one, 0))
282                 return -1;
283         mf->ptr = one->data;
284         mf->size = one->size;
285         return 0;
288 struct emit_callback {
289         struct xdiff_emit_state xm;
290         int nparents, color_diff;
291         const char **label_path;
292 };
294 static inline const char *get_color(int diff_use_color, enum color_diff ix)
296         if (diff_use_color)
297                 return diff_colors[ix];
298         return "";
301 static void fn_out_consume(void *priv, char *line, unsigned long len)
303         int i;
304         struct emit_callback *ecbdata = priv;
305         const char *set = get_color(ecbdata->color_diff, DIFF_METAINFO);
306         const char *reset = get_color(ecbdata->color_diff, DIFF_RESET);
308         if (ecbdata->label_path[0]) {
309                 printf("%s--- %s%s\n", set, ecbdata->label_path[0], reset);
310                 printf("%s+++ %s%s\n", set, ecbdata->label_path[1], reset);
311                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
312         }
314         /* This is not really necessary for now because
315          * this codepath only deals with two-way diffs.
316          */
317         for (i = 0; i < len && line[i] == '@'; i++)
318                 ;
319         if (2 <= i && i < len && line[i] == ' ') {
320                 ecbdata->nparents = i - 1;
321                 set = get_color(ecbdata->color_diff, DIFF_FRAGINFO);
322         }
323         else if (len < ecbdata->nparents)
324                 set = reset;
325         else {
326                 int nparents = ecbdata->nparents;
327                 int color = DIFF_PLAIN;
328                 for (i = 0; i < nparents && len; i++) {
329                         if (line[i] == '-')
330                                 color = DIFF_FILE_OLD;
331                         else if (line[i] == '+')
332                                 color = DIFF_FILE_NEW;
333                 }
334                 set = get_color(ecbdata->color_diff, color);
335         }
336         if (len > 0 && line[len-1] == '\n')
337                 len--;
338         fputs (set, stdout);
339         fwrite (line, len, 1, stdout);
340         puts (reset);
343 static char *pprint_rename(const char *a, const char *b)
345         const char *old = a;
346         const char *new = b;
347         char *name = NULL;
348         int pfx_length, sfx_length;
349         int len_a = strlen(a);
350         int len_b = strlen(b);
352         /* Find common prefix */
353         pfx_length = 0;
354         while (*old && *new && *old == *new) {
355                 if (*old == '/')
356                         pfx_length = old - a + 1;
357                 old++;
358                 new++;
359         }
361         /* Find common suffix */
362         old = a + len_a;
363         new = b + len_b;
364         sfx_length = 0;
365         while (a <= old && b <= new && *old == *new) {
366                 if (*old == '/')
367                         sfx_length = len_a - (old - a);
368                 old--;
369                 new--;
370         }
372         /*
373          * pfx{mid-a => mid-b}sfx
374          * {pfx-a => pfx-b}sfx
375          * pfx{sfx-a => sfx-b}
376          * name-a => name-b
377          */
378         if (pfx_length + sfx_length) {
379                 int a_midlen = len_a - pfx_length - sfx_length;
380                 int b_midlen = len_b - pfx_length - sfx_length;
381                 if (a_midlen < 0) a_midlen = 0;
382                 if (b_midlen < 0) b_midlen = 0;
384                 name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
385                 sprintf(name, "%.*s{%.*s => %.*s}%s",
386                         pfx_length, a,
387                         a_midlen, a + pfx_length,
388                         b_midlen, b + pfx_length,
389                         a + len_a - sfx_length);
390         }
391         else {
392                 name = xmalloc(len_a + len_b + 5);
393                 sprintf(name, "%s => %s", a, b);
394         }
395         return name;
398 struct diffstat_t {
399         struct xdiff_emit_state xm;
401         int nr;
402         int alloc;
403         struct diffstat_file {
404                 char *name;
405                 unsigned is_unmerged:1;
406                 unsigned is_binary:1;
407                 unsigned is_renamed:1;
408                 unsigned int added, deleted;
409         } **files;
410 };
412 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
413                                           const char *name_a,
414                                           const char *name_b)
416         struct diffstat_file *x;
417         x = xcalloc(sizeof (*x), 1);
418         if (diffstat->nr == diffstat->alloc) {
419                 diffstat->alloc = alloc_nr(diffstat->alloc);
420                 diffstat->files = xrealloc(diffstat->files,
421                                 diffstat->alloc * sizeof(x));
422         }
423         diffstat->files[diffstat->nr++] = x;
424         if (name_b) {
425                 x->name = pprint_rename(name_a, name_b);
426                 x->is_renamed = 1;
427         }
428         else
429                 x->name = strdup(name_a);
430         return x;
433 static void diffstat_consume(void *priv, char *line, unsigned long len)
435         struct diffstat_t *diffstat = priv;
436         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
438         if (line[0] == '+')
439                 x->added++;
440         else if (line[0] == '-')
441                 x->deleted++;
444 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
445 static const char minuses[]= "----------------------------------------------------------------------";
446 const char mime_boundary_leader[] = "------------";
448 static void show_stats(struct diffstat_t* data)
450         int i, len, add, del, total, adds = 0, dels = 0;
451         int max, max_change = 0, max_len = 0;
452         int total_files = data->nr;
454         if (data->nr == 0)
455                 return;
457         for (i = 0; i < data->nr; i++) {
458                 struct diffstat_file *file = data->files[i];
460                 len = strlen(file->name);
461                 if (max_len < len)
462                         max_len = len;
464                 if (file->is_binary || file->is_unmerged)
465                         continue;
466                 if (max_change < file->added + file->deleted)
467                         max_change = file->added + file->deleted;
468         }
470         for (i = 0; i < data->nr; i++) {
471                 const char *prefix = "";
472                 char *name = data->files[i]->name;
473                 int added = data->files[i]->added;
474                 int deleted = data->files[i]->deleted;
476                 if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
477                         char *qname = xmalloc(len + 1);
478                         quote_c_style(name, qname, NULL, 0);
479                         free(name);
480                         data->files[i]->name = name = qname;
481                 }
483                 /*
484                  * "scale" the filename
485                  */
486                 len = strlen(name);
487                 max = max_len;
488                 if (max > 50)
489                         max = 50;
490                 if (len > max) {
491                         char *slash;
492                         prefix = "...";
493                         max -= 3;
494                         name += len - max;
495                         slash = strchr(name, '/');
496                         if (slash)
497                                 name = slash;
498                 }
499                 len = max;
501                 /*
502                  * scale the add/delete
503                  */
504                 max = max_change;
505                 if (max + len > 70)
506                         max = 70 - len;
508                 if (data->files[i]->is_binary) {
509                         printf(" %s%-*s |  Bin\n", prefix, len, name);
510                         goto free_diffstat_file;
511                 }
512                 else if (data->files[i]->is_unmerged) {
513                         printf(" %s%-*s |  Unmerged\n", prefix, len, name);
514                         goto free_diffstat_file;
515                 }
516                 else if (!data->files[i]->is_renamed &&
517                          (added + deleted == 0)) {
518                         total_files--;
519                         goto free_diffstat_file;
520                 }
522                 add = added;
523                 del = deleted;
524                 total = add + del;
525                 adds += add;
526                 dels += del;
528                 if (max_change > 0) {
529                         total = (total * max + max_change / 2) / max_change;
530                         add = (add * max + max_change / 2) / max_change;
531                         del = total - add;
532                 }
533                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
534                                 len, name, added + deleted,
535                                 add, pluses, del, minuses);
536         free_diffstat_file:
537                 free(data->files[i]->name);
538                 free(data->files[i]);
539         }
540         free(data->files);
541         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
542                         total_files, adds, dels);
545 struct checkdiff_t {
546         struct xdiff_emit_state xm;
547         const char *filename;
548         int lineno;
549 };
551 static void checkdiff_consume(void *priv, char *line, unsigned long len)
553         struct checkdiff_t *data = priv;
555         if (line[0] == '+') {
556                 int i, spaces = 0;
558                 data->lineno++;
560                 /* check space before tab */
561                 for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
562                         if (line[i] == ' ')
563                                 spaces++;
564                 if (line[i - 1] == '\t' && spaces)
565                         printf("%s:%d: space before tab:%.*s\n",
566                                 data->filename, data->lineno, (int)len, line);
568                 /* check white space at line end */
569                 if (line[len - 1] == '\n')
570                         len--;
571                 if (isspace(line[len - 1]))
572                         printf("%s:%d: white space at end: %.*s\n",
573                                 data->filename, data->lineno, (int)len, line);
574         } else if (line[0] == ' ')
575                 data->lineno++;
576         else if (line[0] == '@') {
577                 char *plus = strchr(line, '+');
578                 if (plus)
579                         data->lineno = strtol(plus, NULL, 10);
580                 else
581                         die("invalid diff");
582         }
585 static unsigned char *deflate_it(char *data,
586                                  unsigned long size,
587                                  unsigned long *result_size)
589         int bound;
590         unsigned char *deflated;
591         z_stream stream;
593         memset(&stream, 0, sizeof(stream));
594         deflateInit(&stream, zlib_compression_level);
595         bound = deflateBound(&stream, size);
596         deflated = xmalloc(bound);
597         stream.next_out = deflated;
598         stream.avail_out = bound;
600         stream.next_in = (unsigned char *)data;
601         stream.avail_in = size;
602         while (deflate(&stream, Z_FINISH) == Z_OK)
603                 ; /* nothing */
604         deflateEnd(&stream);
605         *result_size = stream.total_out;
606         return deflated;
609 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
611         void *cp;
612         void *delta;
613         void *deflated;
614         void *data;
615         unsigned long orig_size;
616         unsigned long delta_size;
617         unsigned long deflate_size;
618         unsigned long data_size;
620         printf("GIT binary patch\n");
621         /* We could do deflated delta, or we could do just deflated two,
622          * whichever is smaller.
623          */
624         delta = NULL;
625         deflated = deflate_it(two->ptr, two->size, &deflate_size);
626         if (one->size && two->size) {
627                 delta = diff_delta(one->ptr, one->size,
628                                    two->ptr, two->size,
629                                    &delta_size, deflate_size);
630                 if (delta) {
631                         void *to_free = delta;
632                         orig_size = delta_size;
633                         delta = deflate_it(delta, delta_size, &delta_size);
634                         free(to_free);
635                 }
636         }
638         if (delta && delta_size < deflate_size) {
639                 printf("delta %lu\n", orig_size);
640                 free(deflated);
641                 data = delta;
642                 data_size = delta_size;
643         }
644         else {
645                 printf("literal %lu\n", two->size);
646                 free(delta);
647                 data = deflated;
648                 data_size = deflate_size;
649         }
651         /* emit data encoded in base85 */
652         cp = data;
653         while (data_size) {
654                 int bytes = (52 < data_size) ? 52 : data_size;
655                 char line[70];
656                 data_size -= bytes;
657                 if (bytes <= 26)
658                         line[0] = bytes + 'A' - 1;
659                 else
660                         line[0] = bytes - 26 + 'a' - 1;
661                 encode_85(line + 1, cp, bytes);
662                 cp = (char *) cp + bytes;
663                 puts(line);
664         }
665         printf("\n");
666         free(data);
669 #define FIRST_FEW_BYTES 8000
670 static int mmfile_is_binary(mmfile_t *mf)
672         long sz = mf->size;
673         if (FIRST_FEW_BYTES < sz)
674                 sz = FIRST_FEW_BYTES;
675         if (memchr(mf->ptr, 0, sz))
676                 return 1;
677         return 0;
680 static void builtin_diff(const char *name_a,
681                          const char *name_b,
682                          struct diff_filespec *one,
683                          struct diff_filespec *two,
684                          const char *xfrm_msg,
685                          struct diff_options *o,
686                          int complete_rewrite)
688         mmfile_t mf1, mf2;
689         const char *lbl[2];
690         char *a_one, *b_two;
691         const char *set = get_color(o->color_diff, DIFF_METAINFO);
692         const char *reset = get_color(o->color_diff, DIFF_RESET);
694         a_one = quote_two("a/", name_a);
695         b_two = quote_two("b/", name_b);
696         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
697         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
698         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
699         if (lbl[0][0] == '/') {
700                 /* /dev/null */
701                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
702                 if (xfrm_msg && xfrm_msg[0])
703                         printf("%s%s%s\n", set, xfrm_msg, reset);
704         }
705         else if (lbl[1][0] == '/') {
706                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
707                 if (xfrm_msg && xfrm_msg[0])
708                         printf("%s%s%s\n", set, xfrm_msg, reset);
709         }
710         else {
711                 if (one->mode != two->mode) {
712                         printf("%sold mode %06o%s\n", set, one->mode, reset);
713                         printf("%snew mode %06o%s\n", set, two->mode, reset);
714                 }
715                 if (xfrm_msg && xfrm_msg[0])
716                         printf("%s%s%s\n", set, xfrm_msg, reset);
717                 /*
718                  * we do not run diff between different kind
719                  * of objects.
720                  */
721                 if ((one->mode ^ two->mode) & S_IFMT)
722                         goto free_ab_and_return;
723                 if (complete_rewrite) {
724                         emit_rewrite_diff(name_a, name_b, one, two);
725                         goto free_ab_and_return;
726                 }
727         }
729         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
730                 die("unable to read files to diff");
732         if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
733                 /* Quite common confusing case */
734                 if (mf1.size == mf2.size &&
735                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
736                         goto free_ab_and_return;
737                 if (o->binary)
738                         emit_binary_diff(&mf1, &mf2);
739                 else
740                         printf("Binary files %s and %s differ\n",
741                                lbl[0], lbl[1]);
742         }
743         else {
744                 /* Crazy xdl interfaces.. */
745                 const char *diffopts = getenv("GIT_DIFF_OPTS");
746                 xpparam_t xpp;
747                 xdemitconf_t xecfg;
748                 xdemitcb_t ecb;
749                 struct emit_callback ecbdata;
751                 memset(&ecbdata, 0, sizeof(ecbdata));
752                 ecbdata.label_path = lbl;
753                 ecbdata.color_diff = o->color_diff;
754                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
755                 xecfg.ctxlen = o->context;
756                 xecfg.flags = XDL_EMIT_FUNCNAMES;
757                 if (!diffopts)
758                         ;
759                 else if (!strncmp(diffopts, "--unified=", 10))
760                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
761                 else if (!strncmp(diffopts, "-u", 2))
762                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
763                 ecb.outf = xdiff_outf;
764                 ecb.priv = &ecbdata;
765                 ecbdata.xm.consume = fn_out_consume;
766                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
767         }
769  free_ab_and_return:
770         free(a_one);
771         free(b_two);
772         return;
775 static void builtin_diffstat(const char *name_a, const char *name_b,
776                              struct diff_filespec *one,
777                              struct diff_filespec *two,
778                              struct diffstat_t *diffstat,
779                              struct diff_options *o,
780                              int complete_rewrite)
782         mmfile_t mf1, mf2;
783         struct diffstat_file *data;
785         data = diffstat_add(diffstat, name_a, name_b);
787         if (!one || !two) {
788                 data->is_unmerged = 1;
789                 return;
790         }
791         if (complete_rewrite) {
792                 diff_populate_filespec(one, 0);
793                 diff_populate_filespec(two, 0);
794                 data->deleted = count_lines(one->data, one->size);
795                 data->added = count_lines(two->data, two->size);
796                 return;
797         }
798         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
799                 die("unable to read files to diff");
801         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
802                 data->is_binary = 1;
803         else {
804                 /* Crazy xdl interfaces.. */
805                 xpparam_t xpp;
806                 xdemitconf_t xecfg;
807                 xdemitcb_t ecb;
809                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
810                 xecfg.ctxlen = 0;
811                 xecfg.flags = 0;
812                 ecb.outf = xdiff_outf;
813                 ecb.priv = diffstat;
814                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
815         }
818 static void builtin_checkdiff(const char *name_a, const char *name_b,
819                              struct diff_filespec *one,
820                              struct diff_filespec *two)
822         mmfile_t mf1, mf2;
823         struct checkdiff_t data;
825         if (!two)
826                 return;
828         memset(&data, 0, sizeof(data));
829         data.xm.consume = checkdiff_consume;
830         data.filename = name_b ? name_b : name_a;
831         data.lineno = 0;
833         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
834                 die("unable to read files to diff");
836         if (mmfile_is_binary(&mf2))
837                 return;
838         else {
839                 /* Crazy xdl interfaces.. */
840                 xpparam_t xpp;
841                 xdemitconf_t xecfg;
842                 xdemitcb_t ecb;
844                 xpp.flags = XDF_NEED_MINIMAL;
845                 xecfg.ctxlen = 0;
846                 xecfg.flags = 0;
847                 ecb.outf = xdiff_outf;
848                 ecb.priv = &data;
849                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
850         }
853 struct diff_filespec *alloc_filespec(const char *path)
855         int namelen = strlen(path);
856         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
858         memset(spec, 0, sizeof(*spec));
859         spec->path = (char *)(spec + 1);
860         memcpy(spec->path, path, namelen+1);
861         return spec;
864 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
865                    unsigned short mode)
867         if (mode) {
868                 spec->mode = canon_mode(mode);
869                 memcpy(spec->sha1, sha1, 20);
870                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
871         }
874 /*
875  * Given a name and sha1 pair, if the dircache tells us the file in
876  * the work tree has that object contents, return true, so that
877  * prepare_temp_file() does not have to inflate and extract.
878  */
879 static int work_tree_matches(const char *name, const unsigned char *sha1)
881         struct cache_entry *ce;
882         struct stat st;
883         int pos, len;
885         /* We do not read the cache ourselves here, because the
886          * benchmark with my previous version that always reads cache
887          * shows that it makes things worse for diff-tree comparing
888          * two linux-2.6 kernel trees in an already checked out work
889          * tree.  This is because most diff-tree comparisons deal with
890          * only a small number of files, while reading the cache is
891          * expensive for a large project, and its cost outweighs the
892          * savings we get by not inflating the object to a temporary
893          * file.  Practically, this code only helps when we are used
894          * by diff-cache --cached, which does read the cache before
895          * calling us.
896          */
897         if (!active_cache)
898                 return 0;
900         len = strlen(name);
901         pos = cache_name_pos(name, len);
902         if (pos < 0)
903                 return 0;
904         ce = active_cache[pos];
905         if ((lstat(name, &st) < 0) ||
906             !S_ISREG(st.st_mode) || /* careful! */
907             ce_match_stat(ce, &st, 0) ||
908             memcmp(sha1, ce->sha1, 20))
909                 return 0;
910         /* we return 1 only when we can stat, it is a regular file,
911          * stat information matches, and sha1 recorded in the cache
912          * matches.  I.e. we know the file in the work tree really is
913          * the same as the <name, sha1> pair.
914          */
915         return 1;
918 static struct sha1_size_cache {
919         unsigned char sha1[20];
920         unsigned long size;
921 } **sha1_size_cache;
922 static int sha1_size_cache_nr, sha1_size_cache_alloc;
924 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
925                                                  int find_only,
926                                                  unsigned long size)
928         int first, last;
929         struct sha1_size_cache *e;
931         first = 0;
932         last = sha1_size_cache_nr;
933         while (last > first) {
934                 int cmp, next = (last + first) >> 1;
935                 e = sha1_size_cache[next];
936                 cmp = memcmp(e->sha1, sha1, 20);
937                 if (!cmp)
938                         return e;
939                 if (cmp < 0) {
940                         last = next;
941                         continue;
942                 }
943                 first = next+1;
944         }
945         /* not found */
946         if (find_only)
947                 return NULL;
948         /* insert to make it at "first" */
949         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
950                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
951                 sha1_size_cache = xrealloc(sha1_size_cache,
952                                            sha1_size_cache_alloc *
953                                            sizeof(*sha1_size_cache));
954         }
955         sha1_size_cache_nr++;
956         if (first < sha1_size_cache_nr)
957                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
958                         (sha1_size_cache_nr - first - 1) *
959                         sizeof(*sha1_size_cache));
960         e = xmalloc(sizeof(struct sha1_size_cache));
961         sha1_size_cache[first] = e;
962         memcpy(e->sha1, sha1, 20);
963         e->size = size;
964         return e;
967 /*
968  * While doing rename detection and pickaxe operation, we may need to
969  * grab the data for the blob (or file) for our own in-core comparison.
970  * diff_filespec has data and size fields for this purpose.
971  */
972 int diff_populate_filespec(struct diff_filespec *s, int size_only)
974         int err = 0;
975         if (!DIFF_FILE_VALID(s))
976                 die("internal error: asking to populate invalid file.");
977         if (S_ISDIR(s->mode))
978                 return -1;
980         if (!use_size_cache)
981                 size_only = 0;
983         if (s->data)
984                 return err;
985         if (!s->sha1_valid ||
986             work_tree_matches(s->path, s->sha1)) {
987                 struct stat st;
988                 int fd;
989                 if (lstat(s->path, &st) < 0) {
990                         if (errno == ENOENT) {
991                         err_empty:
992                                 err = -1;
993                         empty:
994                                 s->data = (char *)"";
995                                 s->size = 0;
996                                 return err;
997                         }
998                 }
999                 s->size = st.st_size;
1000                 if (!s->size)
1001                         goto empty;
1002                 if (size_only)
1003                         return 0;
1004                 if (S_ISLNK(st.st_mode)) {
1005                         int ret;
1006                         s->data = xmalloc(s->size);
1007                         s->should_free = 1;
1008                         ret = readlink(s->path, s->data, s->size);
1009                         if (ret < 0) {
1010                                 free(s->data);
1011                                 goto err_empty;
1012                         }
1013                         return 0;
1014                 }
1015                 fd = open(s->path, O_RDONLY);
1016                 if (fd < 0)
1017                         goto err_empty;
1018                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1019                 close(fd);
1020                 if (s->data == MAP_FAILED)
1021                         goto err_empty;
1022                 s->should_munmap = 1;
1023         }
1024         else {
1025                 char type[20];
1026                 struct sha1_size_cache *e;
1028                 if (size_only) {
1029                         e = locate_size_cache(s->sha1, 1, 0);
1030                         if (e) {
1031                                 s->size = e->size;
1032                                 return 0;
1033                         }
1034                         if (!sha1_object_info(s->sha1, type, &s->size))
1035                                 locate_size_cache(s->sha1, 0, s->size);
1036                 }
1037                 else {
1038                         s->data = read_sha1_file(s->sha1, type, &s->size);
1039                         s->should_free = 1;
1040                 }
1041         }
1042         return 0;
1045 void diff_free_filespec_data(struct diff_filespec *s)
1047         if (s->should_free)
1048                 free(s->data);
1049         else if (s->should_munmap)
1050                 munmap(s->data, s->size);
1051         s->should_free = s->should_munmap = 0;
1052         s->data = NULL;
1053         free(s->cnt_data);
1054         s->cnt_data = NULL;
1057 static void prep_temp_blob(struct diff_tempfile *temp,
1058                            void *blob,
1059                            unsigned long size,
1060                            const unsigned char *sha1,
1061                            int mode)
1063         int fd;
1065         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1066         if (fd < 0)
1067                 die("unable to create temp-file");
1068         if (write(fd, blob, size) != size)
1069                 die("unable to write temp-file");
1070         close(fd);
1071         temp->name = temp->tmp_path;
1072         strcpy(temp->hex, sha1_to_hex(sha1));
1073         temp->hex[40] = 0;
1074         sprintf(temp->mode, "%06o", mode);
1077 static void prepare_temp_file(const char *name,
1078                               struct diff_tempfile *temp,
1079                               struct diff_filespec *one)
1081         if (!DIFF_FILE_VALID(one)) {
1082         not_a_valid_file:
1083                 /* A '-' entry produces this for file-2, and
1084                  * a '+' entry produces this for file-1.
1085                  */
1086                 temp->name = "/dev/null";
1087                 strcpy(temp->hex, ".");
1088                 strcpy(temp->mode, ".");
1089                 return;
1090         }
1092         if (!one->sha1_valid ||
1093             work_tree_matches(name, one->sha1)) {
1094                 struct stat st;
1095                 if (lstat(name, &st) < 0) {
1096                         if (errno == ENOENT)
1097                                 goto not_a_valid_file;
1098                         die("stat(%s): %s", name, strerror(errno));
1099                 }
1100                 if (S_ISLNK(st.st_mode)) {
1101                         int ret;
1102                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1103                         if (sizeof(buf) <= st.st_size)
1104                                 die("symlink too long: %s", name);
1105                         ret = readlink(name, buf, st.st_size);
1106                         if (ret < 0)
1107                                 die("readlink(%s)", name);
1108                         prep_temp_blob(temp, buf, st.st_size,
1109                                        (one->sha1_valid ?
1110                                         one->sha1 : null_sha1),
1111                                        (one->sha1_valid ?
1112                                         one->mode : S_IFLNK));
1113                 }
1114                 else {
1115                         /* we can borrow from the file in the work tree */
1116                         temp->name = name;
1117                         if (!one->sha1_valid)
1118                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1119                         else
1120                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1121                         /* Even though we may sometimes borrow the
1122                          * contents from the work tree, we always want
1123                          * one->mode.  mode is trustworthy even when
1124                          * !(one->sha1_valid), as long as
1125                          * DIFF_FILE_VALID(one).
1126                          */
1127                         sprintf(temp->mode, "%06o", one->mode);
1128                 }
1129                 return;
1130         }
1131         else {
1132                 if (diff_populate_filespec(one, 0))
1133                         die("cannot read data blob for %s", one->path);
1134                 prep_temp_blob(temp, one->data, one->size,
1135                                one->sha1, one->mode);
1136         }
1139 static void remove_tempfile(void)
1141         int i;
1143         for (i = 0; i < 2; i++)
1144                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1145                         unlink(diff_temp[i].name);
1146                         diff_temp[i].name = NULL;
1147                 }
1150 static void remove_tempfile_on_signal(int signo)
1152         remove_tempfile();
1153         signal(SIGINT, SIG_DFL);
1154         raise(signo);
1157 static int spawn_prog(const char *pgm, const char **arg)
1159         pid_t pid;
1160         int status;
1162         fflush(NULL);
1163         pid = fork();
1164         if (pid < 0)
1165                 die("unable to fork");
1166         if (!pid) {
1167                 execvp(pgm, (char *const*) arg);
1168                 exit(255);
1169         }
1171         while (waitpid(pid, &status, 0) < 0) {
1172                 if (errno == EINTR)
1173                         continue;
1174                 return -1;
1175         }
1177         /* Earlier we did not check the exit status because
1178          * diff exits non-zero if files are different, and
1179          * we are not interested in knowing that.  It was a
1180          * mistake which made it harder to quit a diff-*
1181          * session that uses the git-apply-patch-script as
1182          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1183          * should also exit non-zero only when it wants to
1184          * abort the entire diff-* session.
1185          */
1186         if (WIFEXITED(status) && !WEXITSTATUS(status))
1187                 return 0;
1188         return -1;
1191 /* An external diff command takes:
1192  *
1193  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1194  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1195  *
1196  */
1197 static void run_external_diff(const char *pgm,
1198                               const char *name,
1199                               const char *other,
1200                               struct diff_filespec *one,
1201                               struct diff_filespec *two,
1202                               const char *xfrm_msg,
1203                               int complete_rewrite)
1205         const char *spawn_arg[10];
1206         struct diff_tempfile *temp = diff_temp;
1207         int retval;
1208         static int atexit_asked = 0;
1209         const char *othername;
1210         const char **arg = &spawn_arg[0];
1212         othername = (other? other : name);
1213         if (one && two) {
1214                 prepare_temp_file(name, &temp[0], one);
1215                 prepare_temp_file(othername, &temp[1], two);
1216                 if (! atexit_asked &&
1217                     (temp[0].name == temp[0].tmp_path ||
1218                      temp[1].name == temp[1].tmp_path)) {
1219                         atexit_asked = 1;
1220                         atexit(remove_tempfile);
1221                 }
1222                 signal(SIGINT, remove_tempfile_on_signal);
1223         }
1225         if (one && two) {
1226                 *arg++ = pgm;
1227                 *arg++ = name;
1228                 *arg++ = temp[0].name;
1229                 *arg++ = temp[0].hex;
1230                 *arg++ = temp[0].mode;
1231                 *arg++ = temp[1].name;
1232                 *arg++ = temp[1].hex;
1233                 *arg++ = temp[1].mode;
1234                 if (other) {
1235                         *arg++ = other;
1236                         *arg++ = xfrm_msg;
1237                 }
1238         } else {
1239                 *arg++ = pgm;
1240                 *arg++ = name;
1241         }
1242         *arg = NULL;
1243         retval = spawn_prog(pgm, spawn_arg);
1244         remove_tempfile();
1245         if (retval) {
1246                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1247                 exit(1);
1248         }
1251 static void run_diff_cmd(const char *pgm,
1252                          const char *name,
1253                          const char *other,
1254                          struct diff_filespec *one,
1255                          struct diff_filespec *two,
1256                          const char *xfrm_msg,
1257                          struct diff_options *o,
1258                          int complete_rewrite)
1260         if (pgm) {
1261                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1262                                   complete_rewrite);
1263                 return;
1264         }
1265         if (one && two)
1266                 builtin_diff(name, other ? other : name,
1267                              one, two, xfrm_msg, o, complete_rewrite);
1268         else
1269                 printf("* Unmerged path %s\n", name);
1272 static void diff_fill_sha1_info(struct diff_filespec *one)
1274         if (DIFF_FILE_VALID(one)) {
1275                 if (!one->sha1_valid) {
1276                         struct stat st;
1277                         if (lstat(one->path, &st) < 0)
1278                                 die("stat %s", one->path);
1279                         if (index_path(one->sha1, one->path, &st, 0))
1280                                 die("cannot hash %s\n", one->path);
1281                 }
1282         }
1283         else
1284                 memset(one->sha1, 0, 20);
1287 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1289         const char *pgm = external_diff();
1290         char msg[PATH_MAX*2+300], *xfrm_msg;
1291         struct diff_filespec *one;
1292         struct diff_filespec *two;
1293         const char *name;
1294         const char *other;
1295         char *name_munged, *other_munged;
1296         int complete_rewrite = 0;
1297         int len;
1299         if (DIFF_PAIR_UNMERGED(p)) {
1300                 /* unmerged */
1301                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1302                 return;
1303         }
1305         name = p->one->path;
1306         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1307         name_munged = quote_one(name);
1308         other_munged = quote_one(other);
1309         one = p->one; two = p->two;
1311         diff_fill_sha1_info(one);
1312         diff_fill_sha1_info(two);
1314         len = 0;
1315         switch (p->status) {
1316         case DIFF_STATUS_COPIED:
1317                 len += snprintf(msg + len, sizeof(msg) - len,
1318                                 "similarity index %d%%\n"
1319                                 "copy from %s\n"
1320                                 "copy to %s\n",
1321                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1322                                 name_munged, other_munged);
1323                 break;
1324         case DIFF_STATUS_RENAMED:
1325                 len += snprintf(msg + len, sizeof(msg) - len,
1326                                 "similarity index %d%%\n"
1327                                 "rename from %s\n"
1328                                 "rename to %s\n",
1329                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1330                                 name_munged, other_munged);
1331                 break;
1332         case DIFF_STATUS_MODIFIED:
1333                 if (p->score) {
1334                         len += snprintf(msg + len, sizeof(msg) - len,
1335                                         "dissimilarity index %d%%\n",
1336                                         (int)(0.5 + p->score *
1337                                               100.0/MAX_SCORE));
1338                         complete_rewrite = 1;
1339                         break;
1340                 }
1341                 /* fallthru */
1342         default:
1343                 /* nothing */
1344                 ;
1345         }
1347         if (memcmp(one->sha1, two->sha1, 20)) {
1348                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1350                 len += snprintf(msg + len, sizeof(msg) - len,
1351                                 "index %.*s..%.*s",
1352                                 abbrev, sha1_to_hex(one->sha1),
1353                                 abbrev, sha1_to_hex(two->sha1));
1354                 if (one->mode == two->mode)
1355                         len += snprintf(msg + len, sizeof(msg) - len,
1356                                         " %06o", one->mode);
1357                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
1358         }
1360         if (len)
1361                 msg[--len] = 0;
1362         xfrm_msg = len ? msg : NULL;
1364         if (!pgm &&
1365             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1366             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1367                 /* a filepair that changes between file and symlink
1368                  * needs to be split into deletion and creation.
1369                  */
1370                 struct diff_filespec *null = alloc_filespec(two->path);
1371                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1372                 free(null);
1373                 null = alloc_filespec(one->path);
1374                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1375                 free(null);
1376         }
1377         else
1378                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1379                              complete_rewrite);
1381         free(name_munged);
1382         free(other_munged);
1385 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1386                          struct diffstat_t *diffstat)
1388         const char *name;
1389         const char *other;
1390         int complete_rewrite = 0;
1392         if (DIFF_PAIR_UNMERGED(p)) {
1393                 /* unmerged */
1394                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1395                 return;
1396         }
1398         name = p->one->path;
1399         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1401         diff_fill_sha1_info(p->one);
1402         diff_fill_sha1_info(p->two);
1404         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1405                 complete_rewrite = 1;
1406         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1409 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1411         const char *name;
1412         const char *other;
1414         if (DIFF_PAIR_UNMERGED(p)) {
1415                 /* unmerged */
1416                 return;
1417         }
1419         name = p->one->path;
1420         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1422         diff_fill_sha1_info(p->one);
1423         diff_fill_sha1_info(p->two);
1425         builtin_checkdiff(name, other, p->one, p->two);
1428 void diff_setup(struct diff_options *options)
1430         memset(options, 0, sizeof(*options));
1431         options->line_termination = '\n';
1432         options->break_opt = -1;
1433         options->rename_limit = -1;
1434         options->context = 3;
1435         options->msg_sep = "";
1437         options->change = diff_change;
1438         options->add_remove = diff_addremove;
1439         options->color_diff = diff_use_color_default;
1442 int diff_setup_done(struct diff_options *options)
1444         if ((options->find_copies_harder &&
1445              options->detect_rename != DIFF_DETECT_COPY) ||
1446             (0 <= options->rename_limit && !options->detect_rename))
1447                 return -1;
1449         if (options->output_format & (DIFF_FORMAT_NAME |
1450                                       DIFF_FORMAT_NAME_STATUS |
1451                                       DIFF_FORMAT_CHECKDIFF |
1452                                       DIFF_FORMAT_NO_OUTPUT))
1453                 options->output_format &= ~(DIFF_FORMAT_RAW |
1454                                             DIFF_FORMAT_DIFFSTAT |
1455                                             DIFF_FORMAT_SUMMARY |
1456                                             DIFF_FORMAT_PATCH);
1458         /*
1459          * These cases always need recursive; we do not drop caller-supplied
1460          * recursive bits for other formats here.
1461          */
1462         if (options->output_format & (DIFF_FORMAT_PATCH |
1463                                       DIFF_FORMAT_DIFFSTAT |
1464                                       DIFF_FORMAT_CHECKDIFF))
1465                 options->recursive = 1;
1466         /*
1467          * Also pickaxe would not work very well if you do not say recursive
1468          */
1469         if (options->pickaxe)
1470                 options->recursive = 1;
1472         if (options->detect_rename && options->rename_limit < 0)
1473                 options->rename_limit = diff_rename_limit_default;
1474         if (options->setup & DIFF_SETUP_USE_CACHE) {
1475                 if (!active_cache)
1476                         /* read-cache does not die even when it fails
1477                          * so it is safe for us to do this here.  Also
1478                          * it does not smudge active_cache or active_nr
1479                          * when it fails, so we do not have to worry about
1480                          * cleaning it up ourselves either.
1481                          */
1482                         read_cache();
1483         }
1484         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1485                 use_size_cache = 1;
1486         if (options->abbrev <= 0 || 40 < options->abbrev)
1487                 options->abbrev = 40; /* full */
1489         return 0;
1492 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1494         char c, *eq;
1495         int len;
1497         if (*arg != '-')
1498                 return 0;
1499         c = *++arg;
1500         if (!c)
1501                 return 0;
1502         if (c == arg_short) {
1503                 c = *++arg;
1504                 if (!c)
1505                         return 1;
1506                 if (val && isdigit(c)) {
1507                         char *end;
1508                         int n = strtoul(arg, &end, 10);
1509                         if (*end)
1510                                 return 0;
1511                         *val = n;
1512                         return 1;
1513                 }
1514                 return 0;
1515         }
1516         if (c != '-')
1517                 return 0;
1518         arg++;
1519         eq = strchr(arg, '=');
1520         if (eq)
1521                 len = eq - arg;
1522         else
1523                 len = strlen(arg);
1524         if (!len || strncmp(arg, arg_long, len))
1525                 return 0;
1526         if (eq) {
1527                 int n;
1528                 char *end;
1529                 if (!isdigit(*++eq))
1530                         return 0;
1531                 n = strtoul(eq, &end, 10);
1532                 if (*end)
1533                         return 0;
1534                 *val = n;
1535         }
1536         return 1;
1539 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1541         const char *arg = av[0];
1542         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1543                 options->output_format |= DIFF_FORMAT_PATCH;
1544         else if (opt_arg(arg, 'U', "unified", &options->context))
1545                 options->output_format |= DIFF_FORMAT_PATCH;
1546         else if (!strcmp(arg, "--raw"))
1547                 options->output_format |= DIFF_FORMAT_RAW;
1548         else if (!strcmp(arg, "--patch-with-raw")) {
1549                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
1550         }
1551         else if (!strcmp(arg, "--stat"))
1552                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
1553         else if (!strcmp(arg, "--check"))
1554                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
1555         else if (!strcmp(arg, "--summary"))
1556                 options->output_format |= DIFF_FORMAT_SUMMARY;
1557         else if (!strcmp(arg, "--patch-with-stat")) {
1558                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
1559         }
1560         else if (!strcmp(arg, "-z"))
1561                 options->line_termination = 0;
1562         else if (!strncmp(arg, "-l", 2))
1563                 options->rename_limit = strtoul(arg+2, NULL, 10);
1564         else if (!strcmp(arg, "--full-index"))
1565                 options->full_index = 1;
1566         else if (!strcmp(arg, "--binary")) {
1567                 options->output_format |= DIFF_FORMAT_PATCH;
1568                 options->full_index = options->binary = 1;
1569         }
1570         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
1571                 options->text = 1;
1572         }
1573         else if (!strcmp(arg, "--name-only"))
1574                 options->output_format |= DIFF_FORMAT_NAME;
1575         else if (!strcmp(arg, "--name-status"))
1576                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
1577         else if (!strcmp(arg, "-R"))
1578                 options->reverse_diff = 1;
1579         else if (!strncmp(arg, "-S", 2))
1580                 options->pickaxe = arg + 2;
1581         else if (!strcmp(arg, "-s")) {
1582                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
1583         }
1584         else if (!strncmp(arg, "-O", 2))
1585                 options->orderfile = arg + 2;
1586         else if (!strncmp(arg, "--diff-filter=", 14))
1587                 options->filter = arg + 14;
1588         else if (!strcmp(arg, "--pickaxe-all"))
1589                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
1590         else if (!strcmp(arg, "--pickaxe-regex"))
1591                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1592         else if (!strncmp(arg, "-B", 2)) {
1593                 if ((options->break_opt =
1594                      diff_scoreopt_parse(arg)) == -1)
1595                         return -1;
1596         }
1597         else if (!strncmp(arg, "-M", 2)) {
1598                 if ((options->rename_score =
1599                      diff_scoreopt_parse(arg)) == -1)
1600                         return -1;
1601                 options->detect_rename = DIFF_DETECT_RENAME;
1602         }
1603         else if (!strncmp(arg, "-C", 2)) {
1604                 if ((options->rename_score =
1605                      diff_scoreopt_parse(arg)) == -1)
1606                         return -1;
1607                 options->detect_rename = DIFF_DETECT_COPY;
1608         }
1609         else if (!strcmp(arg, "--find-copies-harder"))
1610                 options->find_copies_harder = 1;
1611         else if (!strcmp(arg, "--abbrev"))
1612                 options->abbrev = DEFAULT_ABBREV;
1613         else if (!strncmp(arg, "--abbrev=", 9)) {
1614                 options->abbrev = strtoul(arg + 9, NULL, 10);
1615                 if (options->abbrev < MINIMUM_ABBREV)
1616                         options->abbrev = MINIMUM_ABBREV;
1617                 else if (40 < options->abbrev)
1618                         options->abbrev = 40;
1619         }
1620         else if (!strcmp(arg, "--color"))
1621                 options->color_diff = 1;
1622         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
1623                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
1624         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
1625                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1626         else
1627                 return 0;
1628         return 1;
1631 static int parse_num(const char **cp_p)
1633         unsigned long num, scale;
1634         int ch, dot;
1635         const char *cp = *cp_p;
1637         num = 0;
1638         scale = 1;
1639         dot = 0;
1640         for(;;) {
1641                 ch = *cp;
1642                 if ( !dot && ch == '.' ) {
1643                         scale = 1;
1644                         dot = 1;
1645                 } else if ( ch == '%' ) {
1646                         scale = dot ? scale*100 : 100;
1647                         cp++;   /* % is always at the end */
1648                         break;
1649                 } else if ( ch >= '0' && ch <= '9' ) {
1650                         if ( scale < 100000 ) {
1651                                 scale *= 10;
1652                                 num = (num*10) + (ch-'0');
1653                         }
1654                 } else {
1655                         break;
1656                 }
1657                 cp++;
1658         }
1659         *cp_p = cp;
1661         /* user says num divided by scale and we say internally that
1662          * is MAX_SCORE * num / scale.
1663          */
1664         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1667 int diff_scoreopt_parse(const char *opt)
1669         int opt1, opt2, cmd;
1671         if (*opt++ != '-')
1672                 return -1;
1673         cmd = *opt++;
1674         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1675                 return -1; /* that is not a -M, -C nor -B option */
1677         opt1 = parse_num(&opt);
1678         if (cmd != 'B')
1679                 opt2 = 0;
1680         else {
1681                 if (*opt == 0)
1682                         opt2 = 0;
1683                 else if (*opt != '/')
1684                         return -1; /* we expect -B80/99 or -B80 */
1685                 else {
1686                         opt++;
1687                         opt2 = parse_num(&opt);
1688                 }
1689         }
1690         if (*opt != 0)
1691                 return -1;
1692         return opt1 | (opt2 << 16);
1695 struct diff_queue_struct diff_queued_diff;
1697 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1699         if (queue->alloc <= queue->nr) {
1700                 queue->alloc = alloc_nr(queue->alloc);
1701                 queue->queue = xrealloc(queue->queue,
1702                                         sizeof(dp) * queue->alloc);
1703         }
1704         queue->queue[queue->nr++] = dp;
1707 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1708                                  struct diff_filespec *one,
1709                                  struct diff_filespec *two)
1711         struct diff_filepair *dp = xmalloc(sizeof(*dp));
1712         dp->one = one;
1713         dp->two = two;
1714         dp->score = 0;
1715         dp->status = 0;
1716         dp->source_stays = 0;
1717         dp->broken_pair = 0;
1718         if (queue)
1719                 diff_q(queue, dp);
1720         return dp;
1723 void diff_free_filepair(struct diff_filepair *p)
1725         diff_free_filespec_data(p->one);
1726         diff_free_filespec_data(p->two);
1727         free(p->one);
1728         free(p->two);
1729         free(p);
1732 /* This is different from find_unique_abbrev() in that
1733  * it stuffs the result with dots for alignment.
1734  */
1735 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1737         int abblen;
1738         const char *abbrev;
1739         if (len == 40)
1740                 return sha1_to_hex(sha1);
1742         abbrev = find_unique_abbrev(sha1, len);
1743         if (!abbrev)
1744                 return sha1_to_hex(sha1);
1745         abblen = strlen(abbrev);
1746         if (abblen < 37) {
1747                 static char hex[41];
1748                 if (len < abblen && abblen <= len + 2)
1749                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1750                 else
1751                         sprintf(hex, "%s...", abbrev);
1752                 return hex;
1753         }
1754         return sha1_to_hex(sha1);
1757 static void diff_flush_raw(struct diff_filepair *p,
1758                            struct diff_options *options)
1760         int two_paths;
1761         char status[10];
1762         int abbrev = options->abbrev;
1763         const char *path_one, *path_two;
1764         int inter_name_termination = '\t';
1765         int line_termination = options->line_termination;
1767         if (!line_termination)
1768                 inter_name_termination = 0;
1770         path_one = p->one->path;
1771         path_two = p->two->path;
1772         if (line_termination) {
1773                 path_one = quote_one(path_one);
1774                 path_two = quote_one(path_two);
1775         }
1777         if (p->score)
1778                 sprintf(status, "%c%03d", p->status,
1779                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
1780         else {
1781                 status[0] = p->status;
1782                 status[1] = 0;
1783         }
1784         switch (p->status) {
1785         case DIFF_STATUS_COPIED:
1786         case DIFF_STATUS_RENAMED:
1787                 two_paths = 1;
1788                 break;
1789         case DIFF_STATUS_ADDED:
1790         case DIFF_STATUS_DELETED:
1791                 two_paths = 0;
1792                 break;
1793         default:
1794                 two_paths = 0;
1795                 break;
1796         }
1797         if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
1798                 printf(":%06o %06o %s ",
1799                        p->one->mode, p->two->mode,
1800                        diff_unique_abbrev(p->one->sha1, abbrev));
1801                 printf("%s ",
1802                        diff_unique_abbrev(p->two->sha1, abbrev));
1803         }
1804         printf("%s%c%s", status, inter_name_termination, path_one);
1805         if (two_paths)
1806                 printf("%c%s", inter_name_termination, path_two);
1807         putchar(line_termination);
1808         if (path_one != p->one->path)
1809                 free((void*)path_one);
1810         if (path_two != p->two->path)
1811                 free((void*)path_two);
1814 static void diff_flush_name(struct diff_filepair *p, int line_termination)
1816         char *path = p->two->path;
1818         if (line_termination)
1819                 path = quote_one(p->two->path);
1820         printf("%s%c", path, line_termination);
1821         if (p->two->path != path)
1822                 free(path);
1825 int diff_unmodified_pair(struct diff_filepair *p)
1827         /* This function is written stricter than necessary to support
1828          * the currently implemented transformers, but the idea is to
1829          * let transformers to produce diff_filepairs any way they want,
1830          * and filter and clean them up here before producing the output.
1831          */
1832         struct diff_filespec *one, *two;
1834         if (DIFF_PAIR_UNMERGED(p))
1835                 return 0; /* unmerged is interesting */
1837         one = p->one;
1838         two = p->two;
1840         /* deletion, addition, mode or type change
1841          * and rename are all interesting.
1842          */
1843         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1844             DIFF_PAIR_MODE_CHANGED(p) ||
1845             strcmp(one->path, two->path))
1846                 return 0;
1848         /* both are valid and point at the same path.  that is, we are
1849          * dealing with a change.
1850          */
1851         if (one->sha1_valid && two->sha1_valid &&
1852             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1853                 return 1; /* no change */
1854         if (!one->sha1_valid && !two->sha1_valid)
1855                 return 1; /* both look at the same file on the filesystem. */
1856         return 0;
1859 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1861         if (diff_unmodified_pair(p))
1862                 return;
1864         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1865             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1866                 return; /* no tree diffs in patch format */
1868         run_diff(p, o);
1871 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1872                             struct diffstat_t *diffstat)
1874         if (diff_unmodified_pair(p))
1875                 return;
1877         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1878             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1879                 return; /* no tree diffs in patch format */
1881         run_diffstat(p, o, diffstat);
1884 static void diff_flush_checkdiff(struct diff_filepair *p,
1885                 struct diff_options *o)
1887         if (diff_unmodified_pair(p))
1888                 return;
1890         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1891             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1892                 return; /* no tree diffs in patch format */
1894         run_checkdiff(p, o);
1897 int diff_queue_is_empty(void)
1899         struct diff_queue_struct *q = &diff_queued_diff;
1900         int i;
1901         for (i = 0; i < q->nr; i++)
1902                 if (!diff_unmodified_pair(q->queue[i]))
1903                         return 0;
1904         return 1;
1907 #if DIFF_DEBUG
1908 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1910         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1911                 x, one ? one : "",
1912                 s->path,
1913                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1914                 s->mode,
1915                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1916         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1917                 x, one ? one : "",
1918                 s->size, s->xfrm_flags);
1921 void diff_debug_filepair(const struct diff_filepair *p, int i)
1923         diff_debug_filespec(p->one, i, "one");
1924         diff_debug_filespec(p->two, i, "two");
1925         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1926                 p->score, p->status ? p->status : '?',
1927                 p->source_stays, p->broken_pair);
1930 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1932         int i;
1933         if (msg)
1934                 fprintf(stderr, "%s\n", msg);
1935         fprintf(stderr, "q->nr = %d\n", q->nr);
1936         for (i = 0; i < q->nr; i++) {
1937                 struct diff_filepair *p = q->queue[i];
1938                 diff_debug_filepair(p, i);
1939         }
1941 #endif
1943 static void diff_resolve_rename_copy(void)
1945         int i, j;
1946         struct diff_filepair *p, *pp;
1947         struct diff_queue_struct *q = &diff_queued_diff;
1949         diff_debug_queue("resolve-rename-copy", q);
1951         for (i = 0; i < q->nr; i++) {
1952                 p = q->queue[i];
1953                 p->status = 0; /* undecided */
1954                 if (DIFF_PAIR_UNMERGED(p))
1955                         p->status = DIFF_STATUS_UNMERGED;
1956                 else if (!DIFF_FILE_VALID(p->one))
1957                         p->status = DIFF_STATUS_ADDED;
1958                 else if (!DIFF_FILE_VALID(p->two))
1959                         p->status = DIFF_STATUS_DELETED;
1960                 else if (DIFF_PAIR_TYPE_CHANGED(p))
1961                         p->status = DIFF_STATUS_TYPE_CHANGED;
1963                 /* from this point on, we are dealing with a pair
1964                  * whose both sides are valid and of the same type, i.e.
1965                  * either in-place edit or rename/copy edit.
1966                  */
1967                 else if (DIFF_PAIR_RENAME(p)) {
1968                         if (p->source_stays) {
1969                                 p->status = DIFF_STATUS_COPIED;
1970                                 continue;
1971                         }
1972                         /* See if there is some other filepair that
1973                          * copies from the same source as us.  If so
1974                          * we are a copy.  Otherwise we are either a
1975                          * copy if the path stays, or a rename if it
1976                          * does not, but we already handled "stays" case.
1977                          */
1978                         for (j = i + 1; j < q->nr; j++) {
1979                                 pp = q->queue[j];
1980                                 if (strcmp(pp->one->path, p->one->path))
1981                                         continue; /* not us */
1982                                 if (!DIFF_PAIR_RENAME(pp))
1983                                         continue; /* not a rename/copy */
1984                                 /* pp is a rename/copy from the same source */
1985                                 p->status = DIFF_STATUS_COPIED;
1986                                 break;
1987                         }
1988                         if (!p->status)
1989                                 p->status = DIFF_STATUS_RENAMED;
1990                 }
1991                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1992                          p->one->mode != p->two->mode)
1993                         p->status = DIFF_STATUS_MODIFIED;
1994                 else {
1995                         /* This is a "no-change" entry and should not
1996                          * happen anymore, but prepare for broken callers.
1997                          */
1998                         error("feeding unmodified %s to diffcore",
1999                               p->one->path);
2000                         p->status = DIFF_STATUS_UNKNOWN;
2001                 }
2002         }
2003         diff_debug_queue("resolve-rename-copy done", q);
2006 static int check_pair_status(struct diff_filepair *p)
2008         switch (p->status) {
2009         case DIFF_STATUS_UNKNOWN:
2010                 return 0;
2011         case 0:
2012                 die("internal error in diff-resolve-rename-copy");
2013         default:
2014                 return 1;
2015         }
2018 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2020         int fmt = opt->output_format;
2022         if (fmt & DIFF_FORMAT_CHECKDIFF)
2023                 diff_flush_checkdiff(p, opt);
2024         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2025                 diff_flush_raw(p, opt);
2026         else if (fmt & DIFF_FORMAT_NAME)
2027                 diff_flush_name(p, opt->line_termination);
2030 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2032         if (fs->mode)
2033                 printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
2034         else
2035                 printf(" %s %s\n", newdelete, fs->path);
2039 static void show_mode_change(struct diff_filepair *p, int show_name)
2041         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2042                 if (show_name)
2043                         printf(" mode change %06o => %06o %s\n",
2044                                p->one->mode, p->two->mode, p->two->path);
2045                 else
2046                         printf(" mode change %06o => %06o\n",
2047                                p->one->mode, p->two->mode);
2048         }
2051 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2053         const char *old, *new;
2055         /* Find common prefix */
2056         old = p->one->path;
2057         new = p->two->path;
2058         while (1) {
2059                 const char *slash_old, *slash_new;
2060                 slash_old = strchr(old, '/');
2061                 slash_new = strchr(new, '/');
2062                 if (!slash_old ||
2063                     !slash_new ||
2064                     slash_old - old != slash_new - new ||
2065                     memcmp(old, new, slash_new - new))
2066                         break;
2067                 old = slash_old + 1;
2068                 new = slash_new + 1;
2069         }
2070         /* p->one->path thru old is the common prefix, and old and new
2071          * through the end of names are renames
2072          */
2073         if (old != p->one->path)
2074                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2075                        (int)(old - p->one->path), p->one->path,
2076                        old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
2077         else
2078                 printf(" %s %s => %s (%d%%)\n", renamecopy,
2079                        p->one->path, p->two->path,
2080                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
2081         show_mode_change(p, 0);
2084 static void diff_summary(struct diff_filepair *p)
2086         switch(p->status) {
2087         case DIFF_STATUS_DELETED:
2088                 show_file_mode_name("delete", p->one);
2089                 break;
2090         case DIFF_STATUS_ADDED:
2091                 show_file_mode_name("create", p->two);
2092                 break;
2093         case DIFF_STATUS_COPIED:
2094                 show_rename_copy("copy", p);
2095                 break;
2096         case DIFF_STATUS_RENAMED:
2097                 show_rename_copy("rename", p);
2098                 break;
2099         default:
2100                 if (p->score) {
2101                         printf(" rewrite %s (%d%%)\n", p->two->path,
2102                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
2103                         show_mode_change(p, 0);
2104                 } else  show_mode_change(p, 1);
2105                 break;
2106         }
2109 struct patch_id_t {
2110         struct xdiff_emit_state xm;
2111         SHA_CTX *ctx;
2112         int patchlen;
2113 };
2115 static int remove_space(char *line, int len)
2117         int i;
2118         char *dst = line;
2119         unsigned char c;
2121         for (i = 0; i < len; i++)
2122                 if (!isspace((c = line[i])))
2123                         *dst++ = c;
2125         return dst - line;
2128 static void patch_id_consume(void *priv, char *line, unsigned long len)
2130         struct patch_id_t *data = priv;
2131         int new_len;
2133         /* Ignore line numbers when computing the SHA1 of the patch */
2134         if (!strncmp(line, "@@ -", 4))
2135                 return;
2137         new_len = remove_space(line, len);
2139         SHA1_Update(data->ctx, line, new_len);
2140         data->patchlen += new_len;
2143 /* returns 0 upon success, and writes result into sha1 */
2144 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2146         struct diff_queue_struct *q = &diff_queued_diff;
2147         int i;
2148         SHA_CTX ctx;
2149         struct patch_id_t data;
2150         char buffer[PATH_MAX * 4 + 20];
2152         SHA1_Init(&ctx);
2153         memset(&data, 0, sizeof(struct patch_id_t));
2154         data.ctx = &ctx;
2155         data.xm.consume = patch_id_consume;
2157         for (i = 0; i < q->nr; i++) {
2158                 xpparam_t xpp;
2159                 xdemitconf_t xecfg;
2160                 xdemitcb_t ecb;
2161                 mmfile_t mf1, mf2;
2162                 struct diff_filepair *p = q->queue[i];
2163                 int len1, len2;
2165                 if (p->status == 0)
2166                         return error("internal diff status error");
2167                 if (p->status == DIFF_STATUS_UNKNOWN)
2168                         continue;
2169                 if (diff_unmodified_pair(p))
2170                         continue;
2171                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2172                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2173                         continue;
2174                 if (DIFF_PAIR_UNMERGED(p))
2175                         continue;
2177                 diff_fill_sha1_info(p->one);
2178                 diff_fill_sha1_info(p->two);
2179                 if (fill_mmfile(&mf1, p->one) < 0 ||
2180                                 fill_mmfile(&mf2, p->two) < 0)
2181                         return error("unable to read files to diff");
2183                 /* Maybe hash p->two? into the patch id? */
2184                 if (mmfile_is_binary(&mf2))
2185                         continue;
2187                 len1 = remove_space(p->one->path, strlen(p->one->path));
2188                 len2 = remove_space(p->two->path, strlen(p->two->path));
2189                 if (p->one->mode == 0)
2190                         len1 = snprintf(buffer, sizeof(buffer),
2191                                         "diff--gita/%.*sb/%.*s"
2192                                         "newfilemode%06o"
2193                                         "---/dev/null"
2194                                         "+++b/%.*s",
2195                                         len1, p->one->path,
2196                                         len2, p->two->path,
2197                                         p->two->mode,
2198                                         len2, p->two->path);
2199                 else if (p->two->mode == 0)
2200                         len1 = snprintf(buffer, sizeof(buffer),
2201                                         "diff--gita/%.*sb/%.*s"
2202                                         "deletedfilemode%06o"
2203                                         "---a/%.*s"
2204                                         "+++/dev/null",
2205                                         len1, p->one->path,
2206                                         len2, p->two->path,
2207                                         p->one->mode,
2208                                         len1, p->one->path);
2209                 else
2210                         len1 = snprintf(buffer, sizeof(buffer),
2211                                         "diff--gita/%.*sb/%.*s"
2212                                         "---a/%.*s"
2213                                         "+++b/%.*s",
2214                                         len1, p->one->path,
2215                                         len2, p->two->path,
2216                                         len1, p->one->path,
2217                                         len2, p->two->path);
2218                 SHA1_Update(&ctx, buffer, len1);
2220                 xpp.flags = XDF_NEED_MINIMAL;
2221                 xecfg.ctxlen = 3;
2222                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2223                 ecb.outf = xdiff_outf;
2224                 ecb.priv = &data;
2225                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2226         }
2228         SHA1_Final(sha1, &ctx);
2229         return 0;
2232 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2234         struct diff_queue_struct *q = &diff_queued_diff;
2235         int i;
2236         int result = diff_get_patch_id(options, sha1);
2238         for (i = 0; i < q->nr; i++)
2239                 diff_free_filepair(q->queue[i]);
2241         free(q->queue);
2242         q->queue = NULL;
2243         q->nr = q->alloc = 0;
2245         return result;
2248 static int is_summary_empty(const struct diff_queue_struct *q)
2250         int i;
2252         for (i = 0; i < q->nr; i++) {
2253                 const struct diff_filepair *p = q->queue[i];
2255                 switch (p->status) {
2256                 case DIFF_STATUS_DELETED:
2257                 case DIFF_STATUS_ADDED:
2258                 case DIFF_STATUS_COPIED:
2259                 case DIFF_STATUS_RENAMED:
2260                         return 0;
2261                 default:
2262                         if (p->score)
2263                                 return 0;
2264                         if (p->one->mode && p->two->mode &&
2265                             p->one->mode != p->two->mode)
2266                                 return 0;
2267                         break;
2268                 }
2269         }
2270         return 1;
2273 void diff_flush(struct diff_options *options)
2275         struct diff_queue_struct *q = &diff_queued_diff;
2276         int i, output_format = options->output_format;
2277         int separator = 0;
2279         /*
2280          * Order: raw, stat, summary, patch
2281          * or:    name/name-status/checkdiff (other bits clear)
2282          */
2283         if (!q->nr)
2284                 goto free_queue;
2286         if (output_format & (DIFF_FORMAT_RAW |
2287                              DIFF_FORMAT_NAME |
2288                              DIFF_FORMAT_NAME_STATUS |
2289                              DIFF_FORMAT_CHECKDIFF)) {
2290                 for (i = 0; i < q->nr; i++) {
2291                         struct diff_filepair *p = q->queue[i];
2292                         if (check_pair_status(p))
2293                                 flush_one_pair(p, options);
2294                 }
2295                 separator++;
2296         }
2298         if (output_format & DIFF_FORMAT_DIFFSTAT) {
2299                 struct diffstat_t diffstat;
2301                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2302                 diffstat.xm.consume = diffstat_consume;
2303                 for (i = 0; i < q->nr; i++) {
2304                         struct diff_filepair *p = q->queue[i];
2305                         if (check_pair_status(p))
2306                                 diff_flush_stat(p, options, &diffstat);
2307                 }
2308                 show_stats(&diffstat);
2309                 separator++;
2310         }
2312         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2313                 for (i = 0; i < q->nr; i++)
2314                         diff_summary(q->queue[i]);
2315                 separator++;
2316         }
2318         if (output_format & DIFF_FORMAT_PATCH) {
2319                 if (separator) {
2320                         if (options->stat_sep) {
2321                                 /* attach patch instead of inline */
2322                                 fputs(options->stat_sep, stdout);
2323                         } else {
2324                                 putchar(options->line_termination);
2325                         }
2326                 }
2328                 for (i = 0; i < q->nr; i++) {
2329                         struct diff_filepair *p = q->queue[i];
2330                         if (check_pair_status(p))
2331                                 diff_flush_patch(p, options);
2332                 }
2333         }
2335         for (i = 0; i < q->nr; i++)
2336                 diff_free_filepair(q->queue[i]);
2337 free_queue:
2338         free(q->queue);
2339         q->queue = NULL;
2340         q->nr = q->alloc = 0;
2343 static void diffcore_apply_filter(const char *filter)
2345         int i;
2346         struct diff_queue_struct *q = &diff_queued_diff;
2347         struct diff_queue_struct outq;
2348         outq.queue = NULL;
2349         outq.nr = outq.alloc = 0;
2351         if (!filter)
2352                 return;
2354         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2355                 int found;
2356                 for (i = found = 0; !found && i < q->nr; i++) {
2357                         struct diff_filepair *p = q->queue[i];
2358                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2359                              ((p->score &&
2360                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2361                               (!p->score &&
2362                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2363                             ((p->status != DIFF_STATUS_MODIFIED) &&
2364                              strchr(filter, p->status)))
2365                                 found++;
2366                 }
2367                 if (found)
2368                         return;
2370                 /* otherwise we will clear the whole queue
2371                  * by copying the empty outq at the end of this
2372                  * function, but first clear the current entries
2373                  * in the queue.
2374                  */
2375                 for (i = 0; i < q->nr; i++)
2376                         diff_free_filepair(q->queue[i]);
2377         }
2378         else {
2379                 /* Only the matching ones */
2380                 for (i = 0; i < q->nr; i++) {
2381                         struct diff_filepair *p = q->queue[i];
2383                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2384                              ((p->score &&
2385                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2386                               (!p->score &&
2387                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2388                             ((p->status != DIFF_STATUS_MODIFIED) &&
2389                              strchr(filter, p->status)))
2390                                 diff_q(&outq, p);
2391                         else
2392                                 diff_free_filepair(p);
2393                 }
2394         }
2395         free(q->queue);
2396         *q = outq;
2399 void diffcore_std(struct diff_options *options)
2401         if (options->break_opt != -1)
2402                 diffcore_break(options->break_opt);
2403         if (options->detect_rename)
2404                 diffcore_rename(options);
2405         if (options->break_opt != -1)
2406                 diffcore_merge_broken();
2407         if (options->pickaxe)
2408                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2409         if (options->orderfile)
2410                 diffcore_order(options->orderfile);
2411         diff_resolve_rename_copy();
2412         diffcore_apply_filter(options->filter);
2416 void diffcore_std_no_resolve(struct diff_options *options)
2418         if (options->pickaxe)
2419                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2420         if (options->orderfile)
2421                 diffcore_order(options->orderfile);
2422         diffcore_apply_filter(options->filter);
2425 void diff_addremove(struct diff_options *options,
2426                     int addremove, unsigned mode,
2427                     const unsigned char *sha1,
2428                     const char *base, const char *path)
2430         char concatpath[PATH_MAX];
2431         struct diff_filespec *one, *two;
2433         /* This may look odd, but it is a preparation for
2434          * feeding "there are unchanged files which should
2435          * not produce diffs, but when you are doing copy
2436          * detection you would need them, so here they are"
2437          * entries to the diff-core.  They will be prefixed
2438          * with something like '=' or '*' (I haven't decided
2439          * which but should not make any difference).
2440          * Feeding the same new and old to diff_change() 
2441          * also has the same effect.
2442          * Before the final output happens, they are pruned after
2443          * merged into rename/copy pairs as appropriate.
2444          */
2445         if (options->reverse_diff)
2446                 addremove = (addremove == '+' ? '-' :
2447                              addremove == '-' ? '+' : addremove);
2449         if (!path) path = "";
2450         sprintf(concatpath, "%s%s", base, path);
2451         one = alloc_filespec(concatpath);
2452         two = alloc_filespec(concatpath);
2454         if (addremove != '+')
2455                 fill_filespec(one, sha1, mode);
2456         if (addremove != '-')
2457                 fill_filespec(two, sha1, mode);
2459         diff_queue(&diff_queued_diff, one, two);
2462 void diff_change(struct diff_options *options,
2463                  unsigned old_mode, unsigned new_mode,
2464                  const unsigned char *old_sha1,
2465                  const unsigned char *new_sha1,
2466                  const char *base, const char *path) 
2468         char concatpath[PATH_MAX];
2469         struct diff_filespec *one, *two;
2471         if (options->reverse_diff) {
2472                 unsigned tmp;
2473                 const unsigned char *tmp_c;
2474                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2475                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2476         }
2477         if (!path) path = "";
2478         sprintf(concatpath, "%s%s", base, path);
2479         one = alloc_filespec(concatpath);
2480         two = alloc_filespec(concatpath);
2481         fill_filespec(one, old_sha1, old_mode);
2482         fill_filespec(two, new_sha1, new_mode);
2484         diff_queue(&diff_queued_diff, one, two);
2487 void diff_unmerge(struct diff_options *options,
2488                   const char *path)
2490         struct diff_filespec *one, *two;
2491         one = alloc_filespec(path);
2492         two = alloc_filespec(path);
2493         diff_queue(&diff_queued_diff, one, two);