Code

Make git-mv a builtin
[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_detect_rename_default = 0;
17 static int diff_rename_limit_default = -1;
18 static int diff_use_color_default = 0;
20 /* "\033[1;38;5;2xx;48;5;2xxm\0" is 23 bytes */
21 static char diff_colors[][24] = {
22         "\033[m",       /* reset */
23         "",             /* normal */
24         "\033[1m",      /* bold */
25         "\033[36m",     /* cyan */
26         "\033[31m",     /* red */
27         "\033[32m",     /* green */
28         "\033[33m"      /* yellow */
29 };
31 static int parse_diff_color_slot(const char *var, int ofs)
32 {
33         if (!strcasecmp(var+ofs, "plain"))
34                 return DIFF_PLAIN;
35         if (!strcasecmp(var+ofs, "meta"))
36                 return DIFF_METAINFO;
37         if (!strcasecmp(var+ofs, "frag"))
38                 return DIFF_FRAGINFO;
39         if (!strcasecmp(var+ofs, "old"))
40                 return DIFF_FILE_OLD;
41         if (!strcasecmp(var+ofs, "new"))
42                 return DIFF_FILE_NEW;
43         if (!strcasecmp(var+ofs, "commit"))
44                 return DIFF_COMMIT;
45         die("bad config variable '%s'", var);
46 }
48 static int parse_color(const char *name, int len)
49 {
50         static const char * const color_names[] = {
51                 "normal", "black", "red", "green", "yellow",
52                 "blue", "magenta", "cyan", "white"
53         };
54         char *end;
55         int i;
56         for (i = 0; i < ARRAY_SIZE(color_names); i++) {
57                 const char *str = color_names[i];
58                 if (!strncasecmp(name, str, len) && !str[len])
59                         return i - 1;
60         }
61         i = strtol(name, &end, 10);
62         if (*name && !*end && i >= -1 && i <= 255)
63                 return i;
64         return -2;
65 }
67 static int parse_attr(const char *name, int len)
68 {
69         static const int attr_values[] = { 1, 2, 4, 5, 7 };
70         static const char * const attr_names[] = {
71                 "bold", "dim", "ul", "blink", "reverse"
72         };
73         int i;
74         for (i = 0; i < ARRAY_SIZE(attr_names); i++) {
75                 const char *str = attr_names[i];
76                 if (!strncasecmp(name, str, len) && !str[len])
77                         return attr_values[i];
78         }
79         return -1;
80 }
82 static void parse_diff_color_value(const char *value, const char *var, char *dst)
83 {
84         const char *ptr = value;
85         int attr = -1;
86         int fg = -2;
87         int bg = -2;
89         if (!strcasecmp(value, "reset")) {
90                 strcpy(dst, "\033[m");
91                 return;
92         }
94         /* [fg [bg]] [attr] */
95         while (*ptr) {
96                 const char *word = ptr;
97                 int val, len = 0;
99                 while (word[len] && !isspace(word[len]))
100                         len++;
102                 ptr = word + len;
103                 while (*ptr && isspace(*ptr))
104                         ptr++;
106                 val = parse_color(word, len);
107                 if (val >= -1) {
108                         if (fg == -2) {
109                                 fg = val;
110                                 continue;
111                         }
112                         if (bg == -2) {
113                                 bg = val;
114                                 continue;
115                         }
116                         goto bad;
117                 }
118                 val = parse_attr(word, len);
119                 if (val < 0 || attr != -1)
120                         goto bad;
121                 attr = val;
122         }
124         if (attr >= 0 || fg >= 0 || bg >= 0) {
125                 int sep = 0;
127                 *dst++ = '\033';
128                 *dst++ = '[';
129                 if (attr >= 0) {
130                         *dst++ = '0' + attr;
131                         sep++;
132                 }
133                 if (fg >= 0) {
134                         if (sep++)
135                                 *dst++ = ';';
136                         if (fg < 8) {
137                                 *dst++ = '3';
138                                 *dst++ = '0' + fg;
139                         } else {
140                                 dst += sprintf(dst, "38;5;%d", fg);
141                         }
142                 }
143                 if (bg >= 0) {
144                         if (sep++)
145                                 *dst++ = ';';
146                         if (bg < 8) {
147                                 *dst++ = '4';
148                                 *dst++ = '0' + bg;
149                         } else {
150                                 dst += sprintf(dst, "48;5;%d", bg);
151                         }
152                 }
153                 *dst++ = 'm';
154         }
155         *dst = 0;
156         return;
157 bad:
158         die("bad config value '%s' for variable '%s'", value, var);
161 /*
162  * These are to give UI layer defaults.
163  * The core-level commands such as git-diff-files should
164  * never be affected by the setting of diff.renames
165  * the user happens to have in the configuration file.
166  */
167 int git_diff_ui_config(const char *var, const char *value)
169         if (!strcmp(var, "diff.renamelimit")) {
170                 diff_rename_limit_default = git_config_int(var, value);
171                 return 0;
172         }
173         if (!strcmp(var, "diff.color")) {
174                 if (!value)
175                         diff_use_color_default = 1; /* bool */
176                 else if (!strcasecmp(value, "auto")) {
177                         diff_use_color_default = 0;
178                         if (isatty(1) || pager_in_use) {
179                                 char *term = getenv("TERM");
180                                 if (term && strcmp(term, "dumb"))
181                                         diff_use_color_default = 1;
182                         }
183                 }
184                 else if (!strcasecmp(value, "never"))
185                         diff_use_color_default = 0;
186                 else if (!strcasecmp(value, "always"))
187                         diff_use_color_default = 1;
188                 else
189                         diff_use_color_default = git_config_bool(var, value);
190                 return 0;
191         }
192         if (!strcmp(var, "diff.renames")) {
193                 if (!value)
194                         diff_detect_rename_default = DIFF_DETECT_RENAME;
195                 else if (!strcasecmp(value, "copies") ||
196                          !strcasecmp(value, "copy"))
197                         diff_detect_rename_default = DIFF_DETECT_COPY;
198                 else if (git_config_bool(var,value))
199                         diff_detect_rename_default = DIFF_DETECT_RENAME;
200                 return 0;
201         }
202         if (!strncmp(var, "diff.color.", 11)) {
203                 int slot = parse_diff_color_slot(var, 11);
204                 parse_diff_color_value(value, var, diff_colors[slot]);
205                 return 0;
206         }
207         return git_default_config(var, value);
210 static char *quote_one(const char *str)
212         int needlen;
213         char *xp;
215         if (!str)
216                 return NULL;
217         needlen = quote_c_style(str, NULL, NULL, 0);
218         if (!needlen)
219                 return strdup(str);
220         xp = xmalloc(needlen + 1);
221         quote_c_style(str, xp, NULL, 0);
222         return xp;
225 static char *quote_two(const char *one, const char *two)
227         int need_one = quote_c_style(one, NULL, NULL, 1);
228         int need_two = quote_c_style(two, NULL, NULL, 1);
229         char *xp;
231         if (need_one + need_two) {
232                 if (!need_one) need_one = strlen(one);
233                 if (!need_two) need_one = strlen(two);
235                 xp = xmalloc(need_one + need_two + 3);
236                 xp[0] = '"';
237                 quote_c_style(one, xp + 1, NULL, 1);
238                 quote_c_style(two, xp + need_one + 1, NULL, 1);
239                 strcpy(xp + need_one + need_two + 1, "\"");
240                 return xp;
241         }
242         need_one = strlen(one);
243         need_two = strlen(two);
244         xp = xmalloc(need_one + need_two + 1);
245         strcpy(xp, one);
246         strcpy(xp + need_one, two);
247         return xp;
250 static const char *external_diff(void)
252         static const char *external_diff_cmd = NULL;
253         static int done_preparing = 0;
255         if (done_preparing)
256                 return external_diff_cmd;
257         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
258         done_preparing = 1;
259         return external_diff_cmd;
262 #define TEMPFILE_PATH_LEN               50
264 static struct diff_tempfile {
265         const char *name; /* filename external diff should read from */
266         char hex[41];
267         char mode[10];
268         char tmp_path[TEMPFILE_PATH_LEN];
269 } diff_temp[2];
271 static int count_lines(const char *data, int size)
273         int count, ch, completely_empty = 1, nl_just_seen = 0;
274         count = 0;
275         while (0 < size--) {
276                 ch = *data++;
277                 if (ch == '\n') {
278                         count++;
279                         nl_just_seen = 1;
280                         completely_empty = 0;
281                 }
282                 else {
283                         nl_just_seen = 0;
284                         completely_empty = 0;
285                 }
286         }
287         if (completely_empty)
288                 return 0;
289         if (!nl_just_seen)
290                 count++; /* no trailing newline */
291         return count;
294 static void print_line_count(int count)
296         switch (count) {
297         case 0:
298                 printf("0,0");
299                 break;
300         case 1:
301                 printf("1");
302                 break;
303         default:
304                 printf("1,%d", count);
305                 break;
306         }
309 static void copy_file(int prefix, const char *data, int size)
311         int ch, nl_just_seen = 1;
312         while (0 < size--) {
313                 ch = *data++;
314                 if (nl_just_seen)
315                         putchar(prefix);
316                 putchar(ch);
317                 if (ch == '\n')
318                         nl_just_seen = 1;
319                 else
320                         nl_just_seen = 0;
321         }
322         if (!nl_just_seen)
323                 printf("\n\\ No newline at end of file\n");
326 static void emit_rewrite_diff(const char *name_a,
327                               const char *name_b,
328                               struct diff_filespec *one,
329                               struct diff_filespec *two)
331         int lc_a, lc_b;
332         diff_populate_filespec(one, 0);
333         diff_populate_filespec(two, 0);
334         lc_a = count_lines(one->data, one->size);
335         lc_b = count_lines(two->data, two->size);
336         printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
337         print_line_count(lc_a);
338         printf(" +");
339         print_line_count(lc_b);
340         printf(" @@\n");
341         if (lc_a)
342                 copy_file('-', one->data, one->size);
343         if (lc_b)
344                 copy_file('+', two->data, two->size);
347 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
349         if (!DIFF_FILE_VALID(one)) {
350                 mf->ptr = (char *)""; /* does not matter */
351                 mf->size = 0;
352                 return 0;
353         }
354         else if (diff_populate_filespec(one, 0))
355                 return -1;
356         mf->ptr = one->data;
357         mf->size = one->size;
358         return 0;
361 struct emit_callback {
362         struct xdiff_emit_state xm;
363         int nparents, color_diff;
364         const char **label_path;
365 };
367 const char *diff_get_color(int diff_use_color, enum color_diff ix)
369         if (diff_use_color)
370                 return diff_colors[ix];
371         return "";
374 static void fn_out_consume(void *priv, char *line, unsigned long len)
376         int i;
377         struct emit_callback *ecbdata = priv;
378         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
379         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
381         if (ecbdata->label_path[0]) {
382                 printf("%s--- %s%s\n", set, ecbdata->label_path[0], reset);
383                 printf("%s+++ %s%s\n", set, ecbdata->label_path[1], reset);
384                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
385         }
387         /* This is not really necessary for now because
388          * this codepath only deals with two-way diffs.
389          */
390         for (i = 0; i < len && line[i] == '@'; i++)
391                 ;
392         if (2 <= i && i < len && line[i] == ' ') {
393                 ecbdata->nparents = i - 1;
394                 set = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
395         }
396         else if (len < ecbdata->nparents)
397                 set = reset;
398         else {
399                 int nparents = ecbdata->nparents;
400                 int color = DIFF_PLAIN;
401                 for (i = 0; i < nparents && len; i++) {
402                         if (line[i] == '-')
403                                 color = DIFF_FILE_OLD;
404                         else if (line[i] == '+')
405                                 color = DIFF_FILE_NEW;
406                 }
407                 set = diff_get_color(ecbdata->color_diff, color);
408         }
409         if (len > 0 && line[len-1] == '\n')
410                 len--;
411         fputs (set, stdout);
412         fwrite (line, len, 1, stdout);
413         puts (reset);
416 static char *pprint_rename(const char *a, const char *b)
418         const char *old = a;
419         const char *new = b;
420         char *name = NULL;
421         int pfx_length, sfx_length;
422         int len_a = strlen(a);
423         int len_b = strlen(b);
425         /* Find common prefix */
426         pfx_length = 0;
427         while (*old && *new && *old == *new) {
428                 if (*old == '/')
429                         pfx_length = old - a + 1;
430                 old++;
431                 new++;
432         }
434         /* Find common suffix */
435         old = a + len_a;
436         new = b + len_b;
437         sfx_length = 0;
438         while (a <= old && b <= new && *old == *new) {
439                 if (*old == '/')
440                         sfx_length = len_a - (old - a);
441                 old--;
442                 new--;
443         }
445         /*
446          * pfx{mid-a => mid-b}sfx
447          * {pfx-a => pfx-b}sfx
448          * pfx{sfx-a => sfx-b}
449          * name-a => name-b
450          */
451         if (pfx_length + sfx_length) {
452                 int a_midlen = len_a - pfx_length - sfx_length;
453                 int b_midlen = len_b - pfx_length - sfx_length;
454                 if (a_midlen < 0) a_midlen = 0;
455                 if (b_midlen < 0) b_midlen = 0;
457                 name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
458                 sprintf(name, "%.*s{%.*s => %.*s}%s",
459                         pfx_length, a,
460                         a_midlen, a + pfx_length,
461                         b_midlen, b + pfx_length,
462                         a + len_a - sfx_length);
463         }
464         else {
465                 name = xmalloc(len_a + len_b + 5);
466                 sprintf(name, "%s => %s", a, b);
467         }
468         return name;
471 struct diffstat_t {
472         struct xdiff_emit_state xm;
474         int nr;
475         int alloc;
476         struct diffstat_file {
477                 char *name;
478                 unsigned is_unmerged:1;
479                 unsigned is_binary:1;
480                 unsigned is_renamed:1;
481                 unsigned int added, deleted;
482         } **files;
483 };
485 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
486                                           const char *name_a,
487                                           const char *name_b)
489         struct diffstat_file *x;
490         x = xcalloc(sizeof (*x), 1);
491         if (diffstat->nr == diffstat->alloc) {
492                 diffstat->alloc = alloc_nr(diffstat->alloc);
493                 diffstat->files = xrealloc(diffstat->files,
494                                 diffstat->alloc * sizeof(x));
495         }
496         diffstat->files[diffstat->nr++] = x;
497         if (name_b) {
498                 x->name = pprint_rename(name_a, name_b);
499                 x->is_renamed = 1;
500         }
501         else
502                 x->name = strdup(name_a);
503         return x;
506 static void diffstat_consume(void *priv, char *line, unsigned long len)
508         struct diffstat_t *diffstat = priv;
509         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
511         if (line[0] == '+')
512                 x->added++;
513         else if (line[0] == '-')
514                 x->deleted++;
517 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
518 static const char minuses[]= "----------------------------------------------------------------------";
519 const char mime_boundary_leader[] = "------------";
521 static void show_stats(struct diffstat_t* data)
523         int i, len, add, del, total, adds = 0, dels = 0;
524         int max, max_change = 0, max_len = 0;
525         int total_files = data->nr;
527         if (data->nr == 0)
528                 return;
530         for (i = 0; i < data->nr; i++) {
531                 struct diffstat_file *file = data->files[i];
533                 len = strlen(file->name);
534                 if (max_len < len)
535                         max_len = len;
537                 if (file->is_binary || file->is_unmerged)
538                         continue;
539                 if (max_change < file->added + file->deleted)
540                         max_change = file->added + file->deleted;
541         }
543         for (i = 0; i < data->nr; i++) {
544                 const char *prefix = "";
545                 char *name = data->files[i]->name;
546                 int added = data->files[i]->added;
547                 int deleted = data->files[i]->deleted;
549                 if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
550                         char *qname = xmalloc(len + 1);
551                         quote_c_style(name, qname, NULL, 0);
552                         free(name);
553                         data->files[i]->name = name = qname;
554                 }
556                 /*
557                  * "scale" the filename
558                  */
559                 len = strlen(name);
560                 max = max_len;
561                 if (max > 50)
562                         max = 50;
563                 if (len > max) {
564                         char *slash;
565                         prefix = "...";
566                         max -= 3;
567                         name += len - max;
568                         slash = strchr(name, '/');
569                         if (slash)
570                                 name = slash;
571                 }
572                 len = max;
574                 /*
575                  * scale the add/delete
576                  */
577                 max = max_change;
578                 if (max + len > 70)
579                         max = 70 - len;
581                 if (data->files[i]->is_binary) {
582                         printf(" %s%-*s |  Bin\n", prefix, len, name);
583                         goto free_diffstat_file;
584                 }
585                 else if (data->files[i]->is_unmerged) {
586                         printf(" %s%-*s |  Unmerged\n", prefix, len, name);
587                         goto free_diffstat_file;
588                 }
589                 else if (!data->files[i]->is_renamed &&
590                          (added + deleted == 0)) {
591                         total_files--;
592                         goto free_diffstat_file;
593                 }
595                 add = added;
596                 del = deleted;
597                 total = add + del;
598                 adds += add;
599                 dels += del;
601                 if (max_change > 0) {
602                         total = (total * max + max_change / 2) / max_change;
603                         add = (add * max + max_change / 2) / max_change;
604                         del = total - add;
605                 }
606                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
607                                 len, name, added + deleted,
608                                 add, pluses, del, minuses);
609         free_diffstat_file:
610                 free(data->files[i]->name);
611                 free(data->files[i]);
612         }
613         free(data->files);
614         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
615                         total_files, adds, dels);
618 struct checkdiff_t {
619         struct xdiff_emit_state xm;
620         const char *filename;
621         int lineno;
622 };
624 static void checkdiff_consume(void *priv, char *line, unsigned long len)
626         struct checkdiff_t *data = priv;
628         if (line[0] == '+') {
629                 int i, spaces = 0;
631                 data->lineno++;
633                 /* check space before tab */
634                 for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
635                         if (line[i] == ' ')
636                                 spaces++;
637                 if (line[i - 1] == '\t' && spaces)
638                         printf("%s:%d: space before tab:%.*s\n",
639                                 data->filename, data->lineno, (int)len, line);
641                 /* check white space at line end */
642                 if (line[len - 1] == '\n')
643                         len--;
644                 if (isspace(line[len - 1]))
645                         printf("%s:%d: white space at end: %.*s\n",
646                                 data->filename, data->lineno, (int)len, line);
647         } else if (line[0] == ' ')
648                 data->lineno++;
649         else if (line[0] == '@') {
650                 char *plus = strchr(line, '+');
651                 if (plus)
652                         data->lineno = strtol(plus, NULL, 10);
653                 else
654                         die("invalid diff");
655         }
658 static unsigned char *deflate_it(char *data,
659                                  unsigned long size,
660                                  unsigned long *result_size)
662         int bound;
663         unsigned char *deflated;
664         z_stream stream;
666         memset(&stream, 0, sizeof(stream));
667         deflateInit(&stream, zlib_compression_level);
668         bound = deflateBound(&stream, size);
669         deflated = xmalloc(bound);
670         stream.next_out = deflated;
671         stream.avail_out = bound;
673         stream.next_in = (unsigned char *)data;
674         stream.avail_in = size;
675         while (deflate(&stream, Z_FINISH) == Z_OK)
676                 ; /* nothing */
677         deflateEnd(&stream);
678         *result_size = stream.total_out;
679         return deflated;
682 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
684         void *cp;
685         void *delta;
686         void *deflated;
687         void *data;
688         unsigned long orig_size;
689         unsigned long delta_size;
690         unsigned long deflate_size;
691         unsigned long data_size;
693         printf("GIT binary patch\n");
694         /* We could do deflated delta, or we could do just deflated two,
695          * whichever is smaller.
696          */
697         delta = NULL;
698         deflated = deflate_it(two->ptr, two->size, &deflate_size);
699         if (one->size && two->size) {
700                 delta = diff_delta(one->ptr, one->size,
701                                    two->ptr, two->size,
702                                    &delta_size, deflate_size);
703                 if (delta) {
704                         void *to_free = delta;
705                         orig_size = delta_size;
706                         delta = deflate_it(delta, delta_size, &delta_size);
707                         free(to_free);
708                 }
709         }
711         if (delta && delta_size < deflate_size) {
712                 printf("delta %lu\n", orig_size);
713                 free(deflated);
714                 data = delta;
715                 data_size = delta_size;
716         }
717         else {
718                 printf("literal %lu\n", two->size);
719                 free(delta);
720                 data = deflated;
721                 data_size = deflate_size;
722         }
724         /* emit data encoded in base85 */
725         cp = data;
726         while (data_size) {
727                 int bytes = (52 < data_size) ? 52 : data_size;
728                 char line[70];
729                 data_size -= bytes;
730                 if (bytes <= 26)
731                         line[0] = bytes + 'A' - 1;
732                 else
733                         line[0] = bytes - 26 + 'a' - 1;
734                 encode_85(line + 1, cp, bytes);
735                 cp = (char *) cp + bytes;
736                 puts(line);
737         }
738         printf("\n");
739         free(data);
742 #define FIRST_FEW_BYTES 8000
743 static int mmfile_is_binary(mmfile_t *mf)
745         long sz = mf->size;
746         if (FIRST_FEW_BYTES < sz)
747                 sz = FIRST_FEW_BYTES;
748         if (memchr(mf->ptr, 0, sz))
749                 return 1;
750         return 0;
753 static void builtin_diff(const char *name_a,
754                          const char *name_b,
755                          struct diff_filespec *one,
756                          struct diff_filespec *two,
757                          const char *xfrm_msg,
758                          struct diff_options *o,
759                          int complete_rewrite)
761         mmfile_t mf1, mf2;
762         const char *lbl[2];
763         char *a_one, *b_two;
764         const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
765         const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
767         a_one = quote_two("a/", name_a);
768         b_two = quote_two("b/", name_b);
769         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
770         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
771         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
772         if (lbl[0][0] == '/') {
773                 /* /dev/null */
774                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
775                 if (xfrm_msg && xfrm_msg[0])
776                         printf("%s%s%s\n", set, xfrm_msg, reset);
777         }
778         else if (lbl[1][0] == '/') {
779                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
780                 if (xfrm_msg && xfrm_msg[0])
781                         printf("%s%s%s\n", set, xfrm_msg, reset);
782         }
783         else {
784                 if (one->mode != two->mode) {
785                         printf("%sold mode %06o%s\n", set, one->mode, reset);
786                         printf("%snew mode %06o%s\n", set, two->mode, reset);
787                 }
788                 if (xfrm_msg && xfrm_msg[0])
789                         printf("%s%s%s\n", set, xfrm_msg, reset);
790                 /*
791                  * we do not run diff between different kind
792                  * of objects.
793                  */
794                 if ((one->mode ^ two->mode) & S_IFMT)
795                         goto free_ab_and_return;
796                 if (complete_rewrite) {
797                         emit_rewrite_diff(name_a, name_b, one, two);
798                         goto free_ab_and_return;
799                 }
800         }
802         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
803                 die("unable to read files to diff");
805         if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
806                 /* Quite common confusing case */
807                 if (mf1.size == mf2.size &&
808                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
809                         goto free_ab_and_return;
810                 if (o->binary)
811                         emit_binary_diff(&mf1, &mf2);
812                 else
813                         printf("Binary files %s and %s differ\n",
814                                lbl[0], lbl[1]);
815         }
816         else {
817                 /* Crazy xdl interfaces.. */
818                 const char *diffopts = getenv("GIT_DIFF_OPTS");
819                 xpparam_t xpp;
820                 xdemitconf_t xecfg;
821                 xdemitcb_t ecb;
822                 struct emit_callback ecbdata;
824                 memset(&ecbdata, 0, sizeof(ecbdata));
825                 ecbdata.label_path = lbl;
826                 ecbdata.color_diff = o->color_diff;
827                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
828                 xecfg.ctxlen = o->context;
829                 xecfg.flags = XDL_EMIT_FUNCNAMES;
830                 if (!diffopts)
831                         ;
832                 else if (!strncmp(diffopts, "--unified=", 10))
833                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
834                 else if (!strncmp(diffopts, "-u", 2))
835                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
836                 ecb.outf = xdiff_outf;
837                 ecb.priv = &ecbdata;
838                 ecbdata.xm.consume = fn_out_consume;
839                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
840         }
842  free_ab_and_return:
843         free(a_one);
844         free(b_two);
845         return;
848 static void builtin_diffstat(const char *name_a, const char *name_b,
849                              struct diff_filespec *one,
850                              struct diff_filespec *two,
851                              struct diffstat_t *diffstat,
852                              struct diff_options *o,
853                              int complete_rewrite)
855         mmfile_t mf1, mf2;
856         struct diffstat_file *data;
858         data = diffstat_add(diffstat, name_a, name_b);
860         if (!one || !two) {
861                 data->is_unmerged = 1;
862                 return;
863         }
864         if (complete_rewrite) {
865                 diff_populate_filespec(one, 0);
866                 diff_populate_filespec(two, 0);
867                 data->deleted = count_lines(one->data, one->size);
868                 data->added = count_lines(two->data, two->size);
869                 return;
870         }
871         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
872                 die("unable to read files to diff");
874         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
875                 data->is_binary = 1;
876         else {
877                 /* Crazy xdl interfaces.. */
878                 xpparam_t xpp;
879                 xdemitconf_t xecfg;
880                 xdemitcb_t ecb;
882                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
883                 xecfg.ctxlen = 0;
884                 xecfg.flags = 0;
885                 ecb.outf = xdiff_outf;
886                 ecb.priv = diffstat;
887                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
888         }
891 static void builtin_checkdiff(const char *name_a, const char *name_b,
892                              struct diff_filespec *one,
893                              struct diff_filespec *two)
895         mmfile_t mf1, mf2;
896         struct checkdiff_t data;
898         if (!two)
899                 return;
901         memset(&data, 0, sizeof(data));
902         data.xm.consume = checkdiff_consume;
903         data.filename = name_b ? name_b : name_a;
904         data.lineno = 0;
906         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
907                 die("unable to read files to diff");
909         if (mmfile_is_binary(&mf2))
910                 return;
911         else {
912                 /* Crazy xdl interfaces.. */
913                 xpparam_t xpp;
914                 xdemitconf_t xecfg;
915                 xdemitcb_t ecb;
917                 xpp.flags = XDF_NEED_MINIMAL;
918                 xecfg.ctxlen = 0;
919                 xecfg.flags = 0;
920                 ecb.outf = xdiff_outf;
921                 ecb.priv = &data;
922                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
923         }
926 struct diff_filespec *alloc_filespec(const char *path)
928         int namelen = strlen(path);
929         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
931         memset(spec, 0, sizeof(*spec));
932         spec->path = (char *)(spec + 1);
933         memcpy(spec->path, path, namelen+1);
934         return spec;
937 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
938                    unsigned short mode)
940         if (mode) {
941                 spec->mode = canon_mode(mode);
942                 memcpy(spec->sha1, sha1, 20);
943                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
944         }
947 /*
948  * Given a name and sha1 pair, if the dircache tells us the file in
949  * the work tree has that object contents, return true, so that
950  * prepare_temp_file() does not have to inflate and extract.
951  */
952 static int work_tree_matches(const char *name, const unsigned char *sha1)
954         struct cache_entry *ce;
955         struct stat st;
956         int pos, len;
958         /* We do not read the cache ourselves here, because the
959          * benchmark with my previous version that always reads cache
960          * shows that it makes things worse for diff-tree comparing
961          * two linux-2.6 kernel trees in an already checked out work
962          * tree.  This is because most diff-tree comparisons deal with
963          * only a small number of files, while reading the cache is
964          * expensive for a large project, and its cost outweighs the
965          * savings we get by not inflating the object to a temporary
966          * file.  Practically, this code only helps when we are used
967          * by diff-cache --cached, which does read the cache before
968          * calling us.
969          */
970         if (!active_cache)
971                 return 0;
973         len = strlen(name);
974         pos = cache_name_pos(name, len);
975         if (pos < 0)
976                 return 0;
977         ce = active_cache[pos];
978         if ((lstat(name, &st) < 0) ||
979             !S_ISREG(st.st_mode) || /* careful! */
980             ce_match_stat(ce, &st, 0) ||
981             memcmp(sha1, ce->sha1, 20))
982                 return 0;
983         /* we return 1 only when we can stat, it is a regular file,
984          * stat information matches, and sha1 recorded in the cache
985          * matches.  I.e. we know the file in the work tree really is
986          * the same as the <name, sha1> pair.
987          */
988         return 1;
991 static struct sha1_size_cache {
992         unsigned char sha1[20];
993         unsigned long size;
994 } **sha1_size_cache;
995 static int sha1_size_cache_nr, sha1_size_cache_alloc;
997 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
998                                                  int find_only,
999                                                  unsigned long size)
1001         int first, last;
1002         struct sha1_size_cache *e;
1004         first = 0;
1005         last = sha1_size_cache_nr;
1006         while (last > first) {
1007                 int cmp, next = (last + first) >> 1;
1008                 e = sha1_size_cache[next];
1009                 cmp = memcmp(e->sha1, sha1, 20);
1010                 if (!cmp)
1011                         return e;
1012                 if (cmp < 0) {
1013                         last = next;
1014                         continue;
1015                 }
1016                 first = next+1;
1017         }
1018         /* not found */
1019         if (find_only)
1020                 return NULL;
1021         /* insert to make it at "first" */
1022         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
1023                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
1024                 sha1_size_cache = xrealloc(sha1_size_cache,
1025                                            sha1_size_cache_alloc *
1026                                            sizeof(*sha1_size_cache));
1027         }
1028         sha1_size_cache_nr++;
1029         if (first < sha1_size_cache_nr)
1030                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
1031                         (sha1_size_cache_nr - first - 1) *
1032                         sizeof(*sha1_size_cache));
1033         e = xmalloc(sizeof(struct sha1_size_cache));
1034         sha1_size_cache[first] = e;
1035         memcpy(e->sha1, sha1, 20);
1036         e->size = size;
1037         return e;
1040 /*
1041  * While doing rename detection and pickaxe operation, we may need to
1042  * grab the data for the blob (or file) for our own in-core comparison.
1043  * diff_filespec has data and size fields for this purpose.
1044  */
1045 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1047         int err = 0;
1048         if (!DIFF_FILE_VALID(s))
1049                 die("internal error: asking to populate invalid file.");
1050         if (S_ISDIR(s->mode))
1051                 return -1;
1053         if (!use_size_cache)
1054                 size_only = 0;
1056         if (s->data)
1057                 return err;
1058         if (!s->sha1_valid ||
1059             work_tree_matches(s->path, s->sha1)) {
1060                 struct stat st;
1061                 int fd;
1062                 if (lstat(s->path, &st) < 0) {
1063                         if (errno == ENOENT) {
1064                         err_empty:
1065                                 err = -1;
1066                         empty:
1067                                 s->data = (char *)"";
1068                                 s->size = 0;
1069                                 return err;
1070                         }
1071                 }
1072                 s->size = st.st_size;
1073                 if (!s->size)
1074                         goto empty;
1075                 if (size_only)
1076                         return 0;
1077                 if (S_ISLNK(st.st_mode)) {
1078                         int ret;
1079                         s->data = xmalloc(s->size);
1080                         s->should_free = 1;
1081                         ret = readlink(s->path, s->data, s->size);
1082                         if (ret < 0) {
1083                                 free(s->data);
1084                                 goto err_empty;
1085                         }
1086                         return 0;
1087                 }
1088                 fd = open(s->path, O_RDONLY);
1089                 if (fd < 0)
1090                         goto err_empty;
1091                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1092                 close(fd);
1093                 if (s->data == MAP_FAILED)
1094                         goto err_empty;
1095                 s->should_munmap = 1;
1096         }
1097         else {
1098                 char type[20];
1099                 struct sha1_size_cache *e;
1101                 if (size_only) {
1102                         e = locate_size_cache(s->sha1, 1, 0);
1103                         if (e) {
1104                                 s->size = e->size;
1105                                 return 0;
1106                         }
1107                         if (!sha1_object_info(s->sha1, type, &s->size))
1108                                 locate_size_cache(s->sha1, 0, s->size);
1109                 }
1110                 else {
1111                         s->data = read_sha1_file(s->sha1, type, &s->size);
1112                         s->should_free = 1;
1113                 }
1114         }
1115         return 0;
1118 void diff_free_filespec_data(struct diff_filespec *s)
1120         if (s->should_free)
1121                 free(s->data);
1122         else if (s->should_munmap)
1123                 munmap(s->data, s->size);
1124         s->should_free = s->should_munmap = 0;
1125         s->data = NULL;
1126         free(s->cnt_data);
1127         s->cnt_data = NULL;
1130 static void prep_temp_blob(struct diff_tempfile *temp,
1131                            void *blob,
1132                            unsigned long size,
1133                            const unsigned char *sha1,
1134                            int mode)
1136         int fd;
1138         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1139         if (fd < 0)
1140                 die("unable to create temp-file");
1141         if (write(fd, blob, size) != size)
1142                 die("unable to write temp-file");
1143         close(fd);
1144         temp->name = temp->tmp_path;
1145         strcpy(temp->hex, sha1_to_hex(sha1));
1146         temp->hex[40] = 0;
1147         sprintf(temp->mode, "%06o", mode);
1150 static void prepare_temp_file(const char *name,
1151                               struct diff_tempfile *temp,
1152                               struct diff_filespec *one)
1154         if (!DIFF_FILE_VALID(one)) {
1155         not_a_valid_file:
1156                 /* A '-' entry produces this for file-2, and
1157                  * a '+' entry produces this for file-1.
1158                  */
1159                 temp->name = "/dev/null";
1160                 strcpy(temp->hex, ".");
1161                 strcpy(temp->mode, ".");
1162                 return;
1163         }
1165         if (!one->sha1_valid ||
1166             work_tree_matches(name, one->sha1)) {
1167                 struct stat st;
1168                 if (lstat(name, &st) < 0) {
1169                         if (errno == ENOENT)
1170                                 goto not_a_valid_file;
1171                         die("stat(%s): %s", name, strerror(errno));
1172                 }
1173                 if (S_ISLNK(st.st_mode)) {
1174                         int ret;
1175                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1176                         if (sizeof(buf) <= st.st_size)
1177                                 die("symlink too long: %s", name);
1178                         ret = readlink(name, buf, st.st_size);
1179                         if (ret < 0)
1180                                 die("readlink(%s)", name);
1181                         prep_temp_blob(temp, buf, st.st_size,
1182                                        (one->sha1_valid ?
1183                                         one->sha1 : null_sha1),
1184                                        (one->sha1_valid ?
1185                                         one->mode : S_IFLNK));
1186                 }
1187                 else {
1188                         /* we can borrow from the file in the work tree */
1189                         temp->name = name;
1190                         if (!one->sha1_valid)
1191                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1192                         else
1193                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1194                         /* Even though we may sometimes borrow the
1195                          * contents from the work tree, we always want
1196                          * one->mode.  mode is trustworthy even when
1197                          * !(one->sha1_valid), as long as
1198                          * DIFF_FILE_VALID(one).
1199                          */
1200                         sprintf(temp->mode, "%06o", one->mode);
1201                 }
1202                 return;
1203         }
1204         else {
1205                 if (diff_populate_filespec(one, 0))
1206                         die("cannot read data blob for %s", one->path);
1207                 prep_temp_blob(temp, one->data, one->size,
1208                                one->sha1, one->mode);
1209         }
1212 static void remove_tempfile(void)
1214         int i;
1216         for (i = 0; i < 2; i++)
1217                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1218                         unlink(diff_temp[i].name);
1219                         diff_temp[i].name = NULL;
1220                 }
1223 static void remove_tempfile_on_signal(int signo)
1225         remove_tempfile();
1226         signal(SIGINT, SIG_DFL);
1227         raise(signo);
1230 static int spawn_prog(const char *pgm, const char **arg)
1232         pid_t pid;
1233         int status;
1235         fflush(NULL);
1236         pid = fork();
1237         if (pid < 0)
1238                 die("unable to fork");
1239         if (!pid) {
1240                 execvp(pgm, (char *const*) arg);
1241                 exit(255);
1242         }
1244         while (waitpid(pid, &status, 0) < 0) {
1245                 if (errno == EINTR)
1246                         continue;
1247                 return -1;
1248         }
1250         /* Earlier we did not check the exit status because
1251          * diff exits non-zero if files are different, and
1252          * we are not interested in knowing that.  It was a
1253          * mistake which made it harder to quit a diff-*
1254          * session that uses the git-apply-patch-script as
1255          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1256          * should also exit non-zero only when it wants to
1257          * abort the entire diff-* session.
1258          */
1259         if (WIFEXITED(status) && !WEXITSTATUS(status))
1260                 return 0;
1261         return -1;
1264 /* An external diff command takes:
1265  *
1266  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1267  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1268  *
1269  */
1270 static void run_external_diff(const char *pgm,
1271                               const char *name,
1272                               const char *other,
1273                               struct diff_filespec *one,
1274                               struct diff_filespec *two,
1275                               const char *xfrm_msg,
1276                               int complete_rewrite)
1278         const char *spawn_arg[10];
1279         struct diff_tempfile *temp = diff_temp;
1280         int retval;
1281         static int atexit_asked = 0;
1282         const char *othername;
1283         const char **arg = &spawn_arg[0];
1285         othername = (other? other : name);
1286         if (one && two) {
1287                 prepare_temp_file(name, &temp[0], one);
1288                 prepare_temp_file(othername, &temp[1], two);
1289                 if (! atexit_asked &&
1290                     (temp[0].name == temp[0].tmp_path ||
1291                      temp[1].name == temp[1].tmp_path)) {
1292                         atexit_asked = 1;
1293                         atexit(remove_tempfile);
1294                 }
1295                 signal(SIGINT, remove_tempfile_on_signal);
1296         }
1298         if (one && two) {
1299                 *arg++ = pgm;
1300                 *arg++ = name;
1301                 *arg++ = temp[0].name;
1302                 *arg++ = temp[0].hex;
1303                 *arg++ = temp[0].mode;
1304                 *arg++ = temp[1].name;
1305                 *arg++ = temp[1].hex;
1306                 *arg++ = temp[1].mode;
1307                 if (other) {
1308                         *arg++ = other;
1309                         *arg++ = xfrm_msg;
1310                 }
1311         } else {
1312                 *arg++ = pgm;
1313                 *arg++ = name;
1314         }
1315         *arg = NULL;
1316         retval = spawn_prog(pgm, spawn_arg);
1317         remove_tempfile();
1318         if (retval) {
1319                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1320                 exit(1);
1321         }
1324 static void run_diff_cmd(const char *pgm,
1325                          const char *name,
1326                          const char *other,
1327                          struct diff_filespec *one,
1328                          struct diff_filespec *two,
1329                          const char *xfrm_msg,
1330                          struct diff_options *o,
1331                          int complete_rewrite)
1333         if (pgm) {
1334                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1335                                   complete_rewrite);
1336                 return;
1337         }
1338         if (one && two)
1339                 builtin_diff(name, other ? other : name,
1340                              one, two, xfrm_msg, o, complete_rewrite);
1341         else
1342                 printf("* Unmerged path %s\n", name);
1345 static void diff_fill_sha1_info(struct diff_filespec *one)
1347         if (DIFF_FILE_VALID(one)) {
1348                 if (!one->sha1_valid) {
1349                         struct stat st;
1350                         if (lstat(one->path, &st) < 0)
1351                                 die("stat %s", one->path);
1352                         if (index_path(one->sha1, one->path, &st, 0))
1353                                 die("cannot hash %s\n", one->path);
1354                 }
1355         }
1356         else
1357                 memset(one->sha1, 0, 20);
1360 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1362         const char *pgm = external_diff();
1363         char msg[PATH_MAX*2+300], *xfrm_msg;
1364         struct diff_filespec *one;
1365         struct diff_filespec *two;
1366         const char *name;
1367         const char *other;
1368         char *name_munged, *other_munged;
1369         int complete_rewrite = 0;
1370         int len;
1372         if (DIFF_PAIR_UNMERGED(p)) {
1373                 /* unmerged */
1374                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1375                 return;
1376         }
1378         name = p->one->path;
1379         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1380         name_munged = quote_one(name);
1381         other_munged = quote_one(other);
1382         one = p->one; two = p->two;
1384         diff_fill_sha1_info(one);
1385         diff_fill_sha1_info(two);
1387         len = 0;
1388         switch (p->status) {
1389         case DIFF_STATUS_COPIED:
1390                 len += snprintf(msg + len, sizeof(msg) - len,
1391                                 "similarity index %d%%\n"
1392                                 "copy from %s\n"
1393                                 "copy to %s\n",
1394                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1395                                 name_munged, other_munged);
1396                 break;
1397         case DIFF_STATUS_RENAMED:
1398                 len += snprintf(msg + len, sizeof(msg) - len,
1399                                 "similarity index %d%%\n"
1400                                 "rename from %s\n"
1401                                 "rename to %s\n",
1402                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1403                                 name_munged, other_munged);
1404                 break;
1405         case DIFF_STATUS_MODIFIED:
1406                 if (p->score) {
1407                         len += snprintf(msg + len, sizeof(msg) - len,
1408                                         "dissimilarity index %d%%\n",
1409                                         (int)(0.5 + p->score *
1410                                               100.0/MAX_SCORE));
1411                         complete_rewrite = 1;
1412                         break;
1413                 }
1414                 /* fallthru */
1415         default:
1416                 /* nothing */
1417                 ;
1418         }
1420         if (memcmp(one->sha1, two->sha1, 20)) {
1421                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1423                 len += snprintf(msg + len, sizeof(msg) - len,
1424                                 "index %.*s..%.*s",
1425                                 abbrev, sha1_to_hex(one->sha1),
1426                                 abbrev, sha1_to_hex(two->sha1));
1427                 if (one->mode == two->mode)
1428                         len += snprintf(msg + len, sizeof(msg) - len,
1429                                         " %06o", one->mode);
1430                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
1431         }
1433         if (len)
1434                 msg[--len] = 0;
1435         xfrm_msg = len ? msg : NULL;
1437         if (!pgm &&
1438             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1439             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1440                 /* a filepair that changes between file and symlink
1441                  * needs to be split into deletion and creation.
1442                  */
1443                 struct diff_filespec *null = alloc_filespec(two->path);
1444                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1445                 free(null);
1446                 null = alloc_filespec(one->path);
1447                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1448                 free(null);
1449         }
1450         else
1451                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1452                              complete_rewrite);
1454         free(name_munged);
1455         free(other_munged);
1458 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1459                          struct diffstat_t *diffstat)
1461         const char *name;
1462         const char *other;
1463         int complete_rewrite = 0;
1465         if (DIFF_PAIR_UNMERGED(p)) {
1466                 /* unmerged */
1467                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1468                 return;
1469         }
1471         name = p->one->path;
1472         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1474         diff_fill_sha1_info(p->one);
1475         diff_fill_sha1_info(p->two);
1477         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1478                 complete_rewrite = 1;
1479         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1482 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1484         const char *name;
1485         const char *other;
1487         if (DIFF_PAIR_UNMERGED(p)) {
1488                 /* unmerged */
1489                 return;
1490         }
1492         name = p->one->path;
1493         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1495         diff_fill_sha1_info(p->one);
1496         diff_fill_sha1_info(p->two);
1498         builtin_checkdiff(name, other, p->one, p->two);
1501 void diff_setup(struct diff_options *options)
1503         memset(options, 0, sizeof(*options));
1504         options->line_termination = '\n';
1505         options->break_opt = -1;
1506         options->rename_limit = -1;
1507         options->context = 3;
1508         options->msg_sep = "";
1510         options->change = diff_change;
1511         options->add_remove = diff_addremove;
1512         options->color_diff = diff_use_color_default;
1513         options->detect_rename = diff_detect_rename_default;
1516 int diff_setup_done(struct diff_options *options)
1518         if ((options->find_copies_harder &&
1519              options->detect_rename != DIFF_DETECT_COPY) ||
1520             (0 <= options->rename_limit && !options->detect_rename))
1521                 return -1;
1523         if (options->output_format & (DIFF_FORMAT_NAME |
1524                                       DIFF_FORMAT_NAME_STATUS |
1525                                       DIFF_FORMAT_CHECKDIFF |
1526                                       DIFF_FORMAT_NO_OUTPUT))
1527                 options->output_format &= ~(DIFF_FORMAT_RAW |
1528                                             DIFF_FORMAT_DIFFSTAT |
1529                                             DIFF_FORMAT_SUMMARY |
1530                                             DIFF_FORMAT_PATCH);
1532         /*
1533          * These cases always need recursive; we do not drop caller-supplied
1534          * recursive bits for other formats here.
1535          */
1536         if (options->output_format & (DIFF_FORMAT_PATCH |
1537                                       DIFF_FORMAT_DIFFSTAT |
1538                                       DIFF_FORMAT_CHECKDIFF))
1539                 options->recursive = 1;
1540         /*
1541          * Also pickaxe would not work very well if you do not say recursive
1542          */
1543         if (options->pickaxe)
1544                 options->recursive = 1;
1546         if (options->detect_rename && options->rename_limit < 0)
1547                 options->rename_limit = diff_rename_limit_default;
1548         if (options->setup & DIFF_SETUP_USE_CACHE) {
1549                 if (!active_cache)
1550                         /* read-cache does not die even when it fails
1551                          * so it is safe for us to do this here.  Also
1552                          * it does not smudge active_cache or active_nr
1553                          * when it fails, so we do not have to worry about
1554                          * cleaning it up ourselves either.
1555                          */
1556                         read_cache();
1557         }
1558         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1559                 use_size_cache = 1;
1560         if (options->abbrev <= 0 || 40 < options->abbrev)
1561                 options->abbrev = 40; /* full */
1563         return 0;
1566 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1568         char c, *eq;
1569         int len;
1571         if (*arg != '-')
1572                 return 0;
1573         c = *++arg;
1574         if (!c)
1575                 return 0;
1576         if (c == arg_short) {
1577                 c = *++arg;
1578                 if (!c)
1579                         return 1;
1580                 if (val && isdigit(c)) {
1581                         char *end;
1582                         int n = strtoul(arg, &end, 10);
1583                         if (*end)
1584                                 return 0;
1585                         *val = n;
1586                         return 1;
1587                 }
1588                 return 0;
1589         }
1590         if (c != '-')
1591                 return 0;
1592         arg++;
1593         eq = strchr(arg, '=');
1594         if (eq)
1595                 len = eq - arg;
1596         else
1597                 len = strlen(arg);
1598         if (!len || strncmp(arg, arg_long, len))
1599                 return 0;
1600         if (eq) {
1601                 int n;
1602                 char *end;
1603                 if (!isdigit(*++eq))
1604                         return 0;
1605                 n = strtoul(eq, &end, 10);
1606                 if (*end)
1607                         return 0;
1608                 *val = n;
1609         }
1610         return 1;
1613 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1615         const char *arg = av[0];
1616         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1617                 options->output_format |= DIFF_FORMAT_PATCH;
1618         else if (opt_arg(arg, 'U', "unified", &options->context))
1619                 options->output_format |= DIFF_FORMAT_PATCH;
1620         else if (!strcmp(arg, "--raw"))
1621                 options->output_format |= DIFF_FORMAT_RAW;
1622         else if (!strcmp(arg, "--patch-with-raw")) {
1623                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
1624         }
1625         else if (!strcmp(arg, "--stat"))
1626                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
1627         else if (!strcmp(arg, "--check"))
1628                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
1629         else if (!strcmp(arg, "--summary"))
1630                 options->output_format |= DIFF_FORMAT_SUMMARY;
1631         else if (!strcmp(arg, "--patch-with-stat")) {
1632                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
1633         }
1634         else if (!strcmp(arg, "-z"))
1635                 options->line_termination = 0;
1636         else if (!strncmp(arg, "-l", 2))
1637                 options->rename_limit = strtoul(arg+2, NULL, 10);
1638         else if (!strcmp(arg, "--full-index"))
1639                 options->full_index = 1;
1640         else if (!strcmp(arg, "--binary")) {
1641                 options->output_format |= DIFF_FORMAT_PATCH;
1642                 options->full_index = options->binary = 1;
1643         }
1644         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
1645                 options->text = 1;
1646         }
1647         else if (!strcmp(arg, "--name-only"))
1648                 options->output_format |= DIFF_FORMAT_NAME;
1649         else if (!strcmp(arg, "--name-status"))
1650                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
1651         else if (!strcmp(arg, "-R"))
1652                 options->reverse_diff = 1;
1653         else if (!strncmp(arg, "-S", 2))
1654                 options->pickaxe = arg + 2;
1655         else if (!strcmp(arg, "-s")) {
1656                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
1657         }
1658         else if (!strncmp(arg, "-O", 2))
1659                 options->orderfile = arg + 2;
1660         else if (!strncmp(arg, "--diff-filter=", 14))
1661                 options->filter = arg + 14;
1662         else if (!strcmp(arg, "--pickaxe-all"))
1663                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
1664         else if (!strcmp(arg, "--pickaxe-regex"))
1665                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1666         else if (!strncmp(arg, "-B", 2)) {
1667                 if ((options->break_opt =
1668                      diff_scoreopt_parse(arg)) == -1)
1669                         return -1;
1670         }
1671         else if (!strncmp(arg, "-M", 2)) {
1672                 if ((options->rename_score =
1673                      diff_scoreopt_parse(arg)) == -1)
1674                         return -1;
1675                 options->detect_rename = DIFF_DETECT_RENAME;
1676         }
1677         else if (!strncmp(arg, "-C", 2)) {
1678                 if ((options->rename_score =
1679                      diff_scoreopt_parse(arg)) == -1)
1680                         return -1;
1681                 options->detect_rename = DIFF_DETECT_COPY;
1682         }
1683         else if (!strcmp(arg, "--find-copies-harder"))
1684                 options->find_copies_harder = 1;
1685         else if (!strcmp(arg, "--abbrev"))
1686                 options->abbrev = DEFAULT_ABBREV;
1687         else if (!strncmp(arg, "--abbrev=", 9)) {
1688                 options->abbrev = strtoul(arg + 9, NULL, 10);
1689                 if (options->abbrev < MINIMUM_ABBREV)
1690                         options->abbrev = MINIMUM_ABBREV;
1691                 else if (40 < options->abbrev)
1692                         options->abbrev = 40;
1693         }
1694         else if (!strcmp(arg, "--color"))
1695                 options->color_diff = 1;
1696         else if (!strcmp(arg, "--no-color"))
1697                 options->color_diff = 0;
1698         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
1699                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
1700         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
1701                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1702         else if (!strcmp(arg, "--no-renames"))
1703                 options->detect_rename = 0;
1704         else
1705                 return 0;
1706         return 1;
1709 static int parse_num(const char **cp_p)
1711         unsigned long num, scale;
1712         int ch, dot;
1713         const char *cp = *cp_p;
1715         num = 0;
1716         scale = 1;
1717         dot = 0;
1718         for(;;) {
1719                 ch = *cp;
1720                 if ( !dot && ch == '.' ) {
1721                         scale = 1;
1722                         dot = 1;
1723                 } else if ( ch == '%' ) {
1724                         scale = dot ? scale*100 : 100;
1725                         cp++;   /* % is always at the end */
1726                         break;
1727                 } else if ( ch >= '0' && ch <= '9' ) {
1728                         if ( scale < 100000 ) {
1729                                 scale *= 10;
1730                                 num = (num*10) + (ch-'0');
1731                         }
1732                 } else {
1733                         break;
1734                 }
1735                 cp++;
1736         }
1737         *cp_p = cp;
1739         /* user says num divided by scale and we say internally that
1740          * is MAX_SCORE * num / scale.
1741          */
1742         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1745 int diff_scoreopt_parse(const char *opt)
1747         int opt1, opt2, cmd;
1749         if (*opt++ != '-')
1750                 return -1;
1751         cmd = *opt++;
1752         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1753                 return -1; /* that is not a -M, -C nor -B option */
1755         opt1 = parse_num(&opt);
1756         if (cmd != 'B')
1757                 opt2 = 0;
1758         else {
1759                 if (*opt == 0)
1760                         opt2 = 0;
1761                 else if (*opt != '/')
1762                         return -1; /* we expect -B80/99 or -B80 */
1763                 else {
1764                         opt++;
1765                         opt2 = parse_num(&opt);
1766                 }
1767         }
1768         if (*opt != 0)
1769                 return -1;
1770         return opt1 | (opt2 << 16);
1773 struct diff_queue_struct diff_queued_diff;
1775 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1777         if (queue->alloc <= queue->nr) {
1778                 queue->alloc = alloc_nr(queue->alloc);
1779                 queue->queue = xrealloc(queue->queue,
1780                                         sizeof(dp) * queue->alloc);
1781         }
1782         queue->queue[queue->nr++] = dp;
1785 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1786                                  struct diff_filespec *one,
1787                                  struct diff_filespec *two)
1789         struct diff_filepair *dp = xmalloc(sizeof(*dp));
1790         dp->one = one;
1791         dp->two = two;
1792         dp->score = 0;
1793         dp->status = 0;
1794         dp->source_stays = 0;
1795         dp->broken_pair = 0;
1796         if (queue)
1797                 diff_q(queue, dp);
1798         return dp;
1801 void diff_free_filepair(struct diff_filepair *p)
1803         diff_free_filespec_data(p->one);
1804         diff_free_filespec_data(p->two);
1805         free(p->one);
1806         free(p->two);
1807         free(p);
1810 /* This is different from find_unique_abbrev() in that
1811  * it stuffs the result with dots for alignment.
1812  */
1813 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1815         int abblen;
1816         const char *abbrev;
1817         if (len == 40)
1818                 return sha1_to_hex(sha1);
1820         abbrev = find_unique_abbrev(sha1, len);
1821         if (!abbrev)
1822                 return sha1_to_hex(sha1);
1823         abblen = strlen(abbrev);
1824         if (abblen < 37) {
1825                 static char hex[41];
1826                 if (len < abblen && abblen <= len + 2)
1827                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1828                 else
1829                         sprintf(hex, "%s...", abbrev);
1830                 return hex;
1831         }
1832         return sha1_to_hex(sha1);
1835 static void diff_flush_raw(struct diff_filepair *p,
1836                            struct diff_options *options)
1838         int two_paths;
1839         char status[10];
1840         int abbrev = options->abbrev;
1841         const char *path_one, *path_two;
1842         int inter_name_termination = '\t';
1843         int line_termination = options->line_termination;
1845         if (!line_termination)
1846                 inter_name_termination = 0;
1848         path_one = p->one->path;
1849         path_two = p->two->path;
1850         if (line_termination) {
1851                 path_one = quote_one(path_one);
1852                 path_two = quote_one(path_two);
1853         }
1855         if (p->score)
1856                 sprintf(status, "%c%03d", p->status,
1857                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
1858         else {
1859                 status[0] = p->status;
1860                 status[1] = 0;
1861         }
1862         switch (p->status) {
1863         case DIFF_STATUS_COPIED:
1864         case DIFF_STATUS_RENAMED:
1865                 two_paths = 1;
1866                 break;
1867         case DIFF_STATUS_ADDED:
1868         case DIFF_STATUS_DELETED:
1869                 two_paths = 0;
1870                 break;
1871         default:
1872                 two_paths = 0;
1873                 break;
1874         }
1875         if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
1876                 printf(":%06o %06o %s ",
1877                        p->one->mode, p->two->mode,
1878                        diff_unique_abbrev(p->one->sha1, abbrev));
1879                 printf("%s ",
1880                        diff_unique_abbrev(p->two->sha1, abbrev));
1881         }
1882         printf("%s%c%s", status, inter_name_termination, path_one);
1883         if (two_paths)
1884                 printf("%c%s", inter_name_termination, path_two);
1885         putchar(line_termination);
1886         if (path_one != p->one->path)
1887                 free((void*)path_one);
1888         if (path_two != p->two->path)
1889                 free((void*)path_two);
1892 static void diff_flush_name(struct diff_filepair *p, int line_termination)
1894         char *path = p->two->path;
1896         if (line_termination)
1897                 path = quote_one(p->two->path);
1898         printf("%s%c", path, line_termination);
1899         if (p->two->path != path)
1900                 free(path);
1903 int diff_unmodified_pair(struct diff_filepair *p)
1905         /* This function is written stricter than necessary to support
1906          * the currently implemented transformers, but the idea is to
1907          * let transformers to produce diff_filepairs any way they want,
1908          * and filter and clean them up here before producing the output.
1909          */
1910         struct diff_filespec *one, *two;
1912         if (DIFF_PAIR_UNMERGED(p))
1913                 return 0; /* unmerged is interesting */
1915         one = p->one;
1916         two = p->two;
1918         /* deletion, addition, mode or type change
1919          * and rename are all interesting.
1920          */
1921         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1922             DIFF_PAIR_MODE_CHANGED(p) ||
1923             strcmp(one->path, two->path))
1924                 return 0;
1926         /* both are valid and point at the same path.  that is, we are
1927          * dealing with a change.
1928          */
1929         if (one->sha1_valid && two->sha1_valid &&
1930             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1931                 return 1; /* no change */
1932         if (!one->sha1_valid && !two->sha1_valid)
1933                 return 1; /* both look at the same file on the filesystem. */
1934         return 0;
1937 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1939         if (diff_unmodified_pair(p))
1940                 return;
1942         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1943             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1944                 return; /* no tree diffs in patch format */
1946         run_diff(p, o);
1949 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1950                             struct diffstat_t *diffstat)
1952         if (diff_unmodified_pair(p))
1953                 return;
1955         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1956             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1957                 return; /* no tree diffs in patch format */
1959         run_diffstat(p, o, diffstat);
1962 static void diff_flush_checkdiff(struct diff_filepair *p,
1963                 struct diff_options *o)
1965         if (diff_unmodified_pair(p))
1966                 return;
1968         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1969             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1970                 return; /* no tree diffs in patch format */
1972         run_checkdiff(p, o);
1975 int diff_queue_is_empty(void)
1977         struct diff_queue_struct *q = &diff_queued_diff;
1978         int i;
1979         for (i = 0; i < q->nr; i++)
1980                 if (!diff_unmodified_pair(q->queue[i]))
1981                         return 0;
1982         return 1;
1985 #if DIFF_DEBUG
1986 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1988         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1989                 x, one ? one : "",
1990                 s->path,
1991                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1992                 s->mode,
1993                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1994         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1995                 x, one ? one : "",
1996                 s->size, s->xfrm_flags);
1999 void diff_debug_filepair(const struct diff_filepair *p, int i)
2001         diff_debug_filespec(p->one, i, "one");
2002         diff_debug_filespec(p->two, i, "two");
2003         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
2004                 p->score, p->status ? p->status : '?',
2005                 p->source_stays, p->broken_pair);
2008 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2010         int i;
2011         if (msg)
2012                 fprintf(stderr, "%s\n", msg);
2013         fprintf(stderr, "q->nr = %d\n", q->nr);
2014         for (i = 0; i < q->nr; i++) {
2015                 struct diff_filepair *p = q->queue[i];
2016                 diff_debug_filepair(p, i);
2017         }
2019 #endif
2021 static void diff_resolve_rename_copy(void)
2023         int i, j;
2024         struct diff_filepair *p, *pp;
2025         struct diff_queue_struct *q = &diff_queued_diff;
2027         diff_debug_queue("resolve-rename-copy", q);
2029         for (i = 0; i < q->nr; i++) {
2030                 p = q->queue[i];
2031                 p->status = 0; /* undecided */
2032                 if (DIFF_PAIR_UNMERGED(p))
2033                         p->status = DIFF_STATUS_UNMERGED;
2034                 else if (!DIFF_FILE_VALID(p->one))
2035                         p->status = DIFF_STATUS_ADDED;
2036                 else if (!DIFF_FILE_VALID(p->two))
2037                         p->status = DIFF_STATUS_DELETED;
2038                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2039                         p->status = DIFF_STATUS_TYPE_CHANGED;
2041                 /* from this point on, we are dealing with a pair
2042                  * whose both sides are valid and of the same type, i.e.
2043                  * either in-place edit or rename/copy edit.
2044                  */
2045                 else if (DIFF_PAIR_RENAME(p)) {
2046                         if (p->source_stays) {
2047                                 p->status = DIFF_STATUS_COPIED;
2048                                 continue;
2049                         }
2050                         /* See if there is some other filepair that
2051                          * copies from the same source as us.  If so
2052                          * we are a copy.  Otherwise we are either a
2053                          * copy if the path stays, or a rename if it
2054                          * does not, but we already handled "stays" case.
2055                          */
2056                         for (j = i + 1; j < q->nr; j++) {
2057                                 pp = q->queue[j];
2058                                 if (strcmp(pp->one->path, p->one->path))
2059                                         continue; /* not us */
2060                                 if (!DIFF_PAIR_RENAME(pp))
2061                                         continue; /* not a rename/copy */
2062                                 /* pp is a rename/copy from the same source */
2063                                 p->status = DIFF_STATUS_COPIED;
2064                                 break;
2065                         }
2066                         if (!p->status)
2067                                 p->status = DIFF_STATUS_RENAMED;
2068                 }
2069                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
2070                          p->one->mode != p->two->mode)
2071                         p->status = DIFF_STATUS_MODIFIED;
2072                 else {
2073                         /* This is a "no-change" entry and should not
2074                          * happen anymore, but prepare for broken callers.
2075                          */
2076                         error("feeding unmodified %s to diffcore",
2077                               p->one->path);
2078                         p->status = DIFF_STATUS_UNKNOWN;
2079                 }
2080         }
2081         diff_debug_queue("resolve-rename-copy done", q);
2084 static int check_pair_status(struct diff_filepair *p)
2086         switch (p->status) {
2087         case DIFF_STATUS_UNKNOWN:
2088                 return 0;
2089         case 0:
2090                 die("internal error in diff-resolve-rename-copy");
2091         default:
2092                 return 1;
2093         }
2096 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2098         int fmt = opt->output_format;
2100         if (fmt & DIFF_FORMAT_CHECKDIFF)
2101                 diff_flush_checkdiff(p, opt);
2102         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2103                 diff_flush_raw(p, opt);
2104         else if (fmt & DIFF_FORMAT_NAME)
2105                 diff_flush_name(p, opt->line_termination);
2108 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2110         if (fs->mode)
2111                 printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
2112         else
2113                 printf(" %s %s\n", newdelete, fs->path);
2117 static void show_mode_change(struct diff_filepair *p, int show_name)
2119         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2120                 if (show_name)
2121                         printf(" mode change %06o => %06o %s\n",
2122                                p->one->mode, p->two->mode, p->two->path);
2123                 else
2124                         printf(" mode change %06o => %06o\n",
2125                                p->one->mode, p->two->mode);
2126         }
2129 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2131         const char *old, *new;
2133         /* Find common prefix */
2134         old = p->one->path;
2135         new = p->two->path;
2136         while (1) {
2137                 const char *slash_old, *slash_new;
2138                 slash_old = strchr(old, '/');
2139                 slash_new = strchr(new, '/');
2140                 if (!slash_old ||
2141                     !slash_new ||
2142                     slash_old - old != slash_new - new ||
2143                     memcmp(old, new, slash_new - new))
2144                         break;
2145                 old = slash_old + 1;
2146                 new = slash_new + 1;
2147         }
2148         /* p->one->path thru old is the common prefix, and old and new
2149          * through the end of names are renames
2150          */
2151         if (old != p->one->path)
2152                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2153                        (int)(old - p->one->path), p->one->path,
2154                        old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
2155         else
2156                 printf(" %s %s => %s (%d%%)\n", renamecopy,
2157                        p->one->path, p->two->path,
2158                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
2159         show_mode_change(p, 0);
2162 static void diff_summary(struct diff_filepair *p)
2164         switch(p->status) {
2165         case DIFF_STATUS_DELETED:
2166                 show_file_mode_name("delete", p->one);
2167                 break;
2168         case DIFF_STATUS_ADDED:
2169                 show_file_mode_name("create", p->two);
2170                 break;
2171         case DIFF_STATUS_COPIED:
2172                 show_rename_copy("copy", p);
2173                 break;
2174         case DIFF_STATUS_RENAMED:
2175                 show_rename_copy("rename", p);
2176                 break;
2177         default:
2178                 if (p->score) {
2179                         printf(" rewrite %s (%d%%)\n", p->two->path,
2180                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
2181                         show_mode_change(p, 0);
2182                 } else  show_mode_change(p, 1);
2183                 break;
2184         }
2187 struct patch_id_t {
2188         struct xdiff_emit_state xm;
2189         SHA_CTX *ctx;
2190         int patchlen;
2191 };
2193 static int remove_space(char *line, int len)
2195         int i;
2196         char *dst = line;
2197         unsigned char c;
2199         for (i = 0; i < len; i++)
2200                 if (!isspace((c = line[i])))
2201                         *dst++ = c;
2203         return dst - line;
2206 static void patch_id_consume(void *priv, char *line, unsigned long len)
2208         struct patch_id_t *data = priv;
2209         int new_len;
2211         /* Ignore line numbers when computing the SHA1 of the patch */
2212         if (!strncmp(line, "@@ -", 4))
2213                 return;
2215         new_len = remove_space(line, len);
2217         SHA1_Update(data->ctx, line, new_len);
2218         data->patchlen += new_len;
2221 /* returns 0 upon success, and writes result into sha1 */
2222 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2224         struct diff_queue_struct *q = &diff_queued_diff;
2225         int i;
2226         SHA_CTX ctx;
2227         struct patch_id_t data;
2228         char buffer[PATH_MAX * 4 + 20];
2230         SHA1_Init(&ctx);
2231         memset(&data, 0, sizeof(struct patch_id_t));
2232         data.ctx = &ctx;
2233         data.xm.consume = patch_id_consume;
2235         for (i = 0; i < q->nr; i++) {
2236                 xpparam_t xpp;
2237                 xdemitconf_t xecfg;
2238                 xdemitcb_t ecb;
2239                 mmfile_t mf1, mf2;
2240                 struct diff_filepair *p = q->queue[i];
2241                 int len1, len2;
2243                 if (p->status == 0)
2244                         return error("internal diff status error");
2245                 if (p->status == DIFF_STATUS_UNKNOWN)
2246                         continue;
2247                 if (diff_unmodified_pair(p))
2248                         continue;
2249                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2250                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2251                         continue;
2252                 if (DIFF_PAIR_UNMERGED(p))
2253                         continue;
2255                 diff_fill_sha1_info(p->one);
2256                 diff_fill_sha1_info(p->two);
2257                 if (fill_mmfile(&mf1, p->one) < 0 ||
2258                                 fill_mmfile(&mf2, p->two) < 0)
2259                         return error("unable to read files to diff");
2261                 /* Maybe hash p->two? into the patch id? */
2262                 if (mmfile_is_binary(&mf2))
2263                         continue;
2265                 len1 = remove_space(p->one->path, strlen(p->one->path));
2266                 len2 = remove_space(p->two->path, strlen(p->two->path));
2267                 if (p->one->mode == 0)
2268                         len1 = snprintf(buffer, sizeof(buffer),
2269                                         "diff--gita/%.*sb/%.*s"
2270                                         "newfilemode%06o"
2271                                         "---/dev/null"
2272                                         "+++b/%.*s",
2273                                         len1, p->one->path,
2274                                         len2, p->two->path,
2275                                         p->two->mode,
2276                                         len2, p->two->path);
2277                 else if (p->two->mode == 0)
2278                         len1 = snprintf(buffer, sizeof(buffer),
2279                                         "diff--gita/%.*sb/%.*s"
2280                                         "deletedfilemode%06o"
2281                                         "---a/%.*s"
2282                                         "+++/dev/null",
2283                                         len1, p->one->path,
2284                                         len2, p->two->path,
2285                                         p->one->mode,
2286                                         len1, p->one->path);
2287                 else
2288                         len1 = snprintf(buffer, sizeof(buffer),
2289                                         "diff--gita/%.*sb/%.*s"
2290                                         "---a/%.*s"
2291                                         "+++b/%.*s",
2292                                         len1, p->one->path,
2293                                         len2, p->two->path,
2294                                         len1, p->one->path,
2295                                         len2, p->two->path);
2296                 SHA1_Update(&ctx, buffer, len1);
2298                 xpp.flags = XDF_NEED_MINIMAL;
2299                 xecfg.ctxlen = 3;
2300                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2301                 ecb.outf = xdiff_outf;
2302                 ecb.priv = &data;
2303                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2304         }
2306         SHA1_Final(sha1, &ctx);
2307         return 0;
2310 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2312         struct diff_queue_struct *q = &diff_queued_diff;
2313         int i;
2314         int result = diff_get_patch_id(options, sha1);
2316         for (i = 0; i < q->nr; i++)
2317                 diff_free_filepair(q->queue[i]);
2319         free(q->queue);
2320         q->queue = NULL;
2321         q->nr = q->alloc = 0;
2323         return result;
2326 static int is_summary_empty(const struct diff_queue_struct *q)
2328         int i;
2330         for (i = 0; i < q->nr; i++) {
2331                 const struct diff_filepair *p = q->queue[i];
2333                 switch (p->status) {
2334                 case DIFF_STATUS_DELETED:
2335                 case DIFF_STATUS_ADDED:
2336                 case DIFF_STATUS_COPIED:
2337                 case DIFF_STATUS_RENAMED:
2338                         return 0;
2339                 default:
2340                         if (p->score)
2341                                 return 0;
2342                         if (p->one->mode && p->two->mode &&
2343                             p->one->mode != p->two->mode)
2344                                 return 0;
2345                         break;
2346                 }
2347         }
2348         return 1;
2351 void diff_flush(struct diff_options *options)
2353         struct diff_queue_struct *q = &diff_queued_diff;
2354         int i, output_format = options->output_format;
2355         int separator = 0;
2357         /*
2358          * Order: raw, stat, summary, patch
2359          * or:    name/name-status/checkdiff (other bits clear)
2360          */
2361         if (!q->nr)
2362                 goto free_queue;
2364         if (output_format & (DIFF_FORMAT_RAW |
2365                              DIFF_FORMAT_NAME |
2366                              DIFF_FORMAT_NAME_STATUS |
2367                              DIFF_FORMAT_CHECKDIFF)) {
2368                 for (i = 0; i < q->nr; i++) {
2369                         struct diff_filepair *p = q->queue[i];
2370                         if (check_pair_status(p))
2371                                 flush_one_pair(p, options);
2372                 }
2373                 separator++;
2374         }
2376         if (output_format & DIFF_FORMAT_DIFFSTAT) {
2377                 struct diffstat_t diffstat;
2379                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2380                 diffstat.xm.consume = diffstat_consume;
2381                 for (i = 0; i < q->nr; i++) {
2382                         struct diff_filepair *p = q->queue[i];
2383                         if (check_pair_status(p))
2384                                 diff_flush_stat(p, options, &diffstat);
2385                 }
2386                 show_stats(&diffstat);
2387                 separator++;
2388         }
2390         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2391                 for (i = 0; i < q->nr; i++)
2392                         diff_summary(q->queue[i]);
2393                 separator++;
2394         }
2396         if (output_format & DIFF_FORMAT_PATCH) {
2397                 if (separator) {
2398                         if (options->stat_sep) {
2399                                 /* attach patch instead of inline */
2400                                 fputs(options->stat_sep, stdout);
2401                         } else {
2402                                 putchar(options->line_termination);
2403                         }
2404                 }
2406                 for (i = 0; i < q->nr; i++) {
2407                         struct diff_filepair *p = q->queue[i];
2408                         if (check_pair_status(p))
2409                                 diff_flush_patch(p, options);
2410                 }
2411         }
2413         for (i = 0; i < q->nr; i++)
2414                 diff_free_filepair(q->queue[i]);
2415 free_queue:
2416         free(q->queue);
2417         q->queue = NULL;
2418         q->nr = q->alloc = 0;
2421 static void diffcore_apply_filter(const char *filter)
2423         int i;
2424         struct diff_queue_struct *q = &diff_queued_diff;
2425         struct diff_queue_struct outq;
2426         outq.queue = NULL;
2427         outq.nr = outq.alloc = 0;
2429         if (!filter)
2430                 return;
2432         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2433                 int found;
2434                 for (i = found = 0; !found && i < q->nr; i++) {
2435                         struct diff_filepair *p = q->queue[i];
2436                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2437                              ((p->score &&
2438                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2439                               (!p->score &&
2440                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2441                             ((p->status != DIFF_STATUS_MODIFIED) &&
2442                              strchr(filter, p->status)))
2443                                 found++;
2444                 }
2445                 if (found)
2446                         return;
2448                 /* otherwise we will clear the whole queue
2449                  * by copying the empty outq at the end of this
2450                  * function, but first clear the current entries
2451                  * in the queue.
2452                  */
2453                 for (i = 0; i < q->nr; i++)
2454                         diff_free_filepair(q->queue[i]);
2455         }
2456         else {
2457                 /* Only the matching ones */
2458                 for (i = 0; i < q->nr; i++) {
2459                         struct diff_filepair *p = q->queue[i];
2461                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2462                              ((p->score &&
2463                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2464                               (!p->score &&
2465                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2466                             ((p->status != DIFF_STATUS_MODIFIED) &&
2467                              strchr(filter, p->status)))
2468                                 diff_q(&outq, p);
2469                         else
2470                                 diff_free_filepair(p);
2471                 }
2472         }
2473         free(q->queue);
2474         *q = outq;
2477 void diffcore_std(struct diff_options *options)
2479         if (options->break_opt != -1)
2480                 diffcore_break(options->break_opt);
2481         if (options->detect_rename)
2482                 diffcore_rename(options);
2483         if (options->break_opt != -1)
2484                 diffcore_merge_broken();
2485         if (options->pickaxe)
2486                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2487         if (options->orderfile)
2488                 diffcore_order(options->orderfile);
2489         diff_resolve_rename_copy();
2490         diffcore_apply_filter(options->filter);
2494 void diffcore_std_no_resolve(struct diff_options *options)
2496         if (options->pickaxe)
2497                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2498         if (options->orderfile)
2499                 diffcore_order(options->orderfile);
2500         diffcore_apply_filter(options->filter);
2503 void diff_addremove(struct diff_options *options,
2504                     int addremove, unsigned mode,
2505                     const unsigned char *sha1,
2506                     const char *base, const char *path)
2508         char concatpath[PATH_MAX];
2509         struct diff_filespec *one, *two;
2511         /* This may look odd, but it is a preparation for
2512          * feeding "there are unchanged files which should
2513          * not produce diffs, but when you are doing copy
2514          * detection you would need them, so here they are"
2515          * entries to the diff-core.  They will be prefixed
2516          * with something like '=' or '*' (I haven't decided
2517          * which but should not make any difference).
2518          * Feeding the same new and old to diff_change() 
2519          * also has the same effect.
2520          * Before the final output happens, they are pruned after
2521          * merged into rename/copy pairs as appropriate.
2522          */
2523         if (options->reverse_diff)
2524                 addremove = (addremove == '+' ? '-' :
2525                              addremove == '-' ? '+' : addremove);
2527         if (!path) path = "";
2528         sprintf(concatpath, "%s%s", base, path);
2529         one = alloc_filespec(concatpath);
2530         two = alloc_filespec(concatpath);
2532         if (addremove != '+')
2533                 fill_filespec(one, sha1, mode);
2534         if (addremove != '-')
2535                 fill_filespec(two, sha1, mode);
2537         diff_queue(&diff_queued_diff, one, two);
2540 void diff_change(struct diff_options *options,
2541                  unsigned old_mode, unsigned new_mode,
2542                  const unsigned char *old_sha1,
2543                  const unsigned char *new_sha1,
2544                  const char *base, const char *path) 
2546         char concatpath[PATH_MAX];
2547         struct diff_filespec *one, *two;
2549         if (options->reverse_diff) {
2550                 unsigned tmp;
2551                 const unsigned char *tmp_c;
2552                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2553                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2554         }
2555         if (!path) path = "";
2556         sprintf(concatpath, "%s%s", base, path);
2557         one = alloc_filespec(concatpath);
2558         two = alloc_filespec(concatpath);
2559         fill_filespec(one, old_sha1, old_mode);
2560         fill_filespec(two, new_sha1, new_mode);
2562         diff_queue(&diff_queued_diff, one, two);
2565 void diff_unmerge(struct diff_options *options,
2566                   const char *path)
2568         struct diff_filespec *one, *two;
2569         one = alloc_filespec(path);
2570         two = alloc_filespec(path);
2571         diff_queue(&diff_queued_diff, one, two);