Code

do not overwrite files marked "assume unchanged"
[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "delta.h"
9 #include "xdiff-interface.h"
10 #include "color.h"
11 #include "attr.h"
12 #include "run-command.h"
13 #include "utf8.h"
14 #include "userdiff.h"
15 #include "sigchain.h"
16 #include "submodule.h"
17 #include "ll-merge.h"
19 #ifdef NO_FAST_WORKING_DIRECTORY
20 #define FAST_WORKING_DIRECTORY 0
21 #else
22 #define FAST_WORKING_DIRECTORY 1
23 #endif
25 static int diff_detect_rename_default;
26 static int diff_rename_limit_default = 200;
27 static int diff_suppress_blank_empty;
28 int diff_use_color_default = -1;
29 static const char *diff_word_regex_cfg;
30 static const char *external_diff_cmd_cfg;
31 int diff_auto_refresh_index = 1;
32 static int diff_mnemonic_prefix;
34 static char diff_colors[][COLOR_MAXLEN] = {
35         GIT_COLOR_RESET,
36         GIT_COLOR_NORMAL,       /* PLAIN */
37         GIT_COLOR_BOLD,         /* METAINFO */
38         GIT_COLOR_CYAN,         /* FRAGINFO */
39         GIT_COLOR_RED,          /* OLD */
40         GIT_COLOR_GREEN,        /* NEW */
41         GIT_COLOR_YELLOW,       /* COMMIT */
42         GIT_COLOR_BG_RED,       /* WHITESPACE */
43         GIT_COLOR_NORMAL,       /* FUNCINFO */
44 };
46 static void diff_filespec_load_driver(struct diff_filespec *one);
47 static char *run_textconv(const char *, struct diff_filespec *, size_t *);
49 static int parse_diff_color_slot(const char *var, int ofs)
50 {
51         if (!strcasecmp(var+ofs, "plain"))
52                 return DIFF_PLAIN;
53         if (!strcasecmp(var+ofs, "meta"))
54                 return DIFF_METAINFO;
55         if (!strcasecmp(var+ofs, "frag"))
56                 return DIFF_FRAGINFO;
57         if (!strcasecmp(var+ofs, "old"))
58                 return DIFF_FILE_OLD;
59         if (!strcasecmp(var+ofs, "new"))
60                 return DIFF_FILE_NEW;
61         if (!strcasecmp(var+ofs, "commit"))
62                 return DIFF_COMMIT;
63         if (!strcasecmp(var+ofs, "whitespace"))
64                 return DIFF_WHITESPACE;
65         if (!strcasecmp(var+ofs, "func"))
66                 return DIFF_FUNCINFO;
67         return -1;
68 }
70 static int git_config_rename(const char *var, const char *value)
71 {
72         if (!value)
73                 return DIFF_DETECT_RENAME;
74         if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
75                 return  DIFF_DETECT_COPY;
76         return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
77 }
79 /*
80  * These are to give UI layer defaults.
81  * The core-level commands such as git-diff-files should
82  * never be affected by the setting of diff.renames
83  * the user happens to have in the configuration file.
84  */
85 int git_diff_ui_config(const char *var, const char *value, void *cb)
86 {
87         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
88                 diff_use_color_default = git_config_colorbool(var, value, -1);
89                 return 0;
90         }
91         if (!strcmp(var, "diff.renames")) {
92                 diff_detect_rename_default = git_config_rename(var, value);
93                 return 0;
94         }
95         if (!strcmp(var, "diff.autorefreshindex")) {
96                 diff_auto_refresh_index = git_config_bool(var, value);
97                 return 0;
98         }
99         if (!strcmp(var, "diff.mnemonicprefix")) {
100                 diff_mnemonic_prefix = git_config_bool(var, value);
101                 return 0;
102         }
103         if (!strcmp(var, "diff.external"))
104                 return git_config_string(&external_diff_cmd_cfg, var, value);
105         if (!strcmp(var, "diff.wordregex"))
106                 return git_config_string(&diff_word_regex_cfg, var, value);
108         return git_diff_basic_config(var, value, cb);
111 int git_diff_basic_config(const char *var, const char *value, void *cb)
113         if (!strcmp(var, "diff.renamelimit")) {
114                 diff_rename_limit_default = git_config_int(var, value);
115                 return 0;
116         }
118         switch (userdiff_config(var, value)) {
119                 case 0: break;
120                 case -1: return -1;
121                 default: return 0;
122         }
124         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
125                 int slot = parse_diff_color_slot(var, 11);
126                 if (slot < 0)
127                         return 0;
128                 if (!value)
129                         return config_error_nonbool(var);
130                 color_parse(value, var, diff_colors[slot]);
131                 return 0;
132         }
134         /* like GNU diff's --suppress-blank-empty option  */
135         if (!strcmp(var, "diff.suppressblankempty") ||
136                         /* for backwards compatibility */
137                         !strcmp(var, "diff.suppress-blank-empty")) {
138                 diff_suppress_blank_empty = git_config_bool(var, value);
139                 return 0;
140         }
142         return git_color_default_config(var, value, cb);
145 static char *quote_two(const char *one, const char *two)
147         int need_one = quote_c_style(one, NULL, NULL, 1);
148         int need_two = quote_c_style(two, NULL, NULL, 1);
149         struct strbuf res = STRBUF_INIT;
151         if (need_one + need_two) {
152                 strbuf_addch(&res, '"');
153                 quote_c_style(one, &res, NULL, 1);
154                 quote_c_style(two, &res, NULL, 1);
155                 strbuf_addch(&res, '"');
156         } else {
157                 strbuf_addstr(&res, one);
158                 strbuf_addstr(&res, two);
159         }
160         return strbuf_detach(&res, NULL);
163 static const char *external_diff(void)
165         static const char *external_diff_cmd = NULL;
166         static int done_preparing = 0;
168         if (done_preparing)
169                 return external_diff_cmd;
170         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
171         if (!external_diff_cmd)
172                 external_diff_cmd = external_diff_cmd_cfg;
173         done_preparing = 1;
174         return external_diff_cmd;
177 static struct diff_tempfile {
178         const char *name; /* filename external diff should read from */
179         char hex[41];
180         char mode[10];
181         char tmp_path[PATH_MAX];
182 } diff_temp[2];
184 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
186 struct emit_callback {
187         int color_diff;
188         unsigned ws_rule;
189         int blank_at_eof_in_preimage;
190         int blank_at_eof_in_postimage;
191         int lno_in_preimage;
192         int lno_in_postimage;
193         sane_truncate_fn truncate;
194         const char **label_path;
195         struct diff_words_data *diff_words;
196         int *found_changesp;
197         FILE *file;
198         struct strbuf *header;
199 };
201 static int count_lines(const char *data, int size)
203         int count, ch, completely_empty = 1, nl_just_seen = 0;
204         count = 0;
205         while (0 < size--) {
206                 ch = *data++;
207                 if (ch == '\n') {
208                         count++;
209                         nl_just_seen = 1;
210                         completely_empty = 0;
211                 }
212                 else {
213                         nl_just_seen = 0;
214                         completely_empty = 0;
215                 }
216         }
217         if (completely_empty)
218                 return 0;
219         if (!nl_just_seen)
220                 count++; /* no trailing newline */
221         return count;
224 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
226         if (!DIFF_FILE_VALID(one)) {
227                 mf->ptr = (char *)""; /* does not matter */
228                 mf->size = 0;
229                 return 0;
230         }
231         else if (diff_populate_filespec(one, 0))
232                 return -1;
234         mf->ptr = one->data;
235         mf->size = one->size;
236         return 0;
239 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
241         char *ptr = mf->ptr;
242         long size = mf->size;
243         int cnt = 0;
245         if (!size)
246                 return cnt;
247         ptr += size - 1; /* pointing at the very end */
248         if (*ptr != '\n')
249                 ; /* incomplete line */
250         else
251                 ptr--; /* skip the last LF */
252         while (mf->ptr < ptr) {
253                 char *prev_eol;
254                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
255                         if (*prev_eol == '\n')
256                                 break;
257                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
258                         break;
259                 cnt++;
260                 ptr = prev_eol - 1;
261         }
262         return cnt;
265 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
266                                struct emit_callback *ecbdata)
268         int l1, l2, at;
269         unsigned ws_rule = ecbdata->ws_rule;
270         l1 = count_trailing_blank(mf1, ws_rule);
271         l2 = count_trailing_blank(mf2, ws_rule);
272         if (l2 <= l1) {
273                 ecbdata->blank_at_eof_in_preimage = 0;
274                 ecbdata->blank_at_eof_in_postimage = 0;
275                 return;
276         }
277         at = count_lines(mf1->ptr, mf1->size);
278         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
280         at = count_lines(mf2->ptr, mf2->size);
281         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
284 static void emit_line_0(FILE *file, const char *set, const char *reset,
285                         int first, const char *line, int len)
287         int has_trailing_newline, has_trailing_carriage_return;
288         int nofirst;
290         if (len == 0) {
291                 has_trailing_newline = (first == '\n');
292                 has_trailing_carriage_return = (!has_trailing_newline &&
293                                                 (first == '\r'));
294                 nofirst = has_trailing_newline || has_trailing_carriage_return;
295         } else {
296                 has_trailing_newline = (len > 0 && line[len-1] == '\n');
297                 if (has_trailing_newline)
298                         len--;
299                 has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
300                 if (has_trailing_carriage_return)
301                         len--;
302                 nofirst = 0;
303         }
305         if (len || !nofirst) {
306                 fputs(set, file);
307                 if (!nofirst)
308                         fputc(first, file);
309                 fwrite(line, len, 1, file);
310                 fputs(reset, file);
311         }
312         if (has_trailing_carriage_return)
313                 fputc('\r', file);
314         if (has_trailing_newline)
315                 fputc('\n', file);
318 static void emit_line(FILE *file, const char *set, const char *reset,
319                       const char *line, int len)
321         emit_line_0(file, set, reset, line[0], line+1, len-1);
324 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
326         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
327               ecbdata->blank_at_eof_in_preimage &&
328               ecbdata->blank_at_eof_in_postimage &&
329               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
330               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
331                 return 0;
332         return ws_blank_line(line, len, ecbdata->ws_rule);
335 static void emit_add_line(const char *reset,
336                           struct emit_callback *ecbdata,
337                           const char *line, int len)
339         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
340         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
342         if (!*ws)
343                 emit_line_0(ecbdata->file, set, reset, '+', line, len);
344         else if (new_blank_line_at_eof(ecbdata, line, len))
345                 /* Blank line at EOF - paint '+' as well */
346                 emit_line_0(ecbdata->file, ws, reset, '+', line, len);
347         else {
348                 /* Emit just the prefix, then the rest. */
349                 emit_line_0(ecbdata->file, set, reset, '+', "", 0);
350                 ws_check_emit(line, len, ecbdata->ws_rule,
351                               ecbdata->file, set, reset, ws);
352         }
355 static void emit_hunk_header(struct emit_callback *ecbdata,
356                              const char *line, int len)
358         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
359         const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
360         const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
361         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
362         static const char atat[2] = { '@', '@' };
363         const char *cp, *ep;
365         /*
366          * As a hunk header must begin with "@@ -<old>, +<new> @@",
367          * it always is at least 10 bytes long.
368          */
369         if (len < 10 ||
370             memcmp(line, atat, 2) ||
371             !(ep = memmem(line + 2, len - 2, atat, 2))) {
372                 emit_line(ecbdata->file, plain, reset, line, len);
373                 return;
374         }
375         ep += 2; /* skip over @@ */
377         /* The hunk header in fraginfo color */
378         emit_line(ecbdata->file, frag, reset, line, ep - line);
380         /* blank before the func header */
381         for (cp = ep; ep - line < len; ep++)
382                 if (*ep != ' ' && *ep != '\t')
383                         break;
384         if (ep != cp)
385                 emit_line(ecbdata->file, plain, reset, cp, ep - cp);
387         if (ep < line + len)
388                 emit_line(ecbdata->file, func, reset, ep, line + len - ep);
391 static struct diff_tempfile *claim_diff_tempfile(void) {
392         int i;
393         for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
394                 if (!diff_temp[i].name)
395                         return diff_temp + i;
396         die("BUG: diff is failing to clean up its tempfiles");
399 static int remove_tempfile_installed;
401 static void remove_tempfile(void)
403         int i;
404         for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
405                 if (diff_temp[i].name == diff_temp[i].tmp_path)
406                         unlink_or_warn(diff_temp[i].name);
407                 diff_temp[i].name = NULL;
408         }
411 static void remove_tempfile_on_signal(int signo)
413         remove_tempfile();
414         sigchain_pop(signo);
415         raise(signo);
418 static void print_line_count(FILE *file, int count)
420         switch (count) {
421         case 0:
422                 fprintf(file, "0,0");
423                 break;
424         case 1:
425                 fprintf(file, "1");
426                 break;
427         default:
428                 fprintf(file, "1,%d", count);
429                 break;
430         }
433 static void emit_rewrite_lines(struct emit_callback *ecb,
434                                int prefix, const char *data, int size)
436         const char *endp = NULL;
437         static const char *nneof = " No newline at end of file\n";
438         const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
439         const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
441         while (0 < size) {
442                 int len;
444                 endp = memchr(data, '\n', size);
445                 len = endp ? (endp - data + 1) : size;
446                 if (prefix != '+') {
447                         ecb->lno_in_preimage++;
448                         emit_line_0(ecb->file, old, reset, '-',
449                                     data, len);
450                 } else {
451                         ecb->lno_in_postimage++;
452                         emit_add_line(reset, ecb, data, len);
453                 }
454                 size -= len;
455                 data += len;
456         }
457         if (!endp) {
458                 const char *plain = diff_get_color(ecb->color_diff,
459                                                    DIFF_PLAIN);
460                 emit_line_0(ecb->file, plain, reset, '\\',
461                             nneof, strlen(nneof));
462         }
465 static void emit_rewrite_diff(const char *name_a,
466                               const char *name_b,
467                               struct diff_filespec *one,
468                               struct diff_filespec *two,
469                               const char *textconv_one,
470                               const char *textconv_two,
471                               struct diff_options *o)
473         int lc_a, lc_b;
474         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
475         const char *name_a_tab, *name_b_tab;
476         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
477         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
478         const char *reset = diff_get_color(color_diff, DIFF_RESET);
479         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
480         const char *a_prefix, *b_prefix;
481         const char *data_one, *data_two;
482         size_t size_one, size_two;
483         struct emit_callback ecbdata;
485         if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
486                 a_prefix = o->b_prefix;
487                 b_prefix = o->a_prefix;
488         } else {
489                 a_prefix = o->a_prefix;
490                 b_prefix = o->b_prefix;
491         }
493         name_a += (*name_a == '/');
494         name_b += (*name_b == '/');
495         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
496         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
498         strbuf_reset(&a_name);
499         strbuf_reset(&b_name);
500         quote_two_c_style(&a_name, a_prefix, name_a, 0);
501         quote_two_c_style(&b_name, b_prefix, name_b, 0);
503         diff_populate_filespec(one, 0);
504         diff_populate_filespec(two, 0);
505         if (textconv_one) {
506                 data_one = run_textconv(textconv_one, one, &size_one);
507                 if (!data_one)
508                         die("unable to read files to diff");
509         }
510         else {
511                 data_one = one->data;
512                 size_one = one->size;
513         }
514         if (textconv_two) {
515                 data_two = run_textconv(textconv_two, two, &size_two);
516                 if (!data_two)
517                         die("unable to read files to diff");
518         }
519         else {
520                 data_two = two->data;
521                 size_two = two->size;
522         }
524         memset(&ecbdata, 0, sizeof(ecbdata));
525         ecbdata.color_diff = color_diff;
526         ecbdata.found_changesp = &o->found_changes;
527         ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
528         ecbdata.file = o->file;
529         if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
530                 mmfile_t mf1, mf2;
531                 mf1.ptr = (char *)data_one;
532                 mf2.ptr = (char *)data_two;
533                 mf1.size = size_one;
534                 mf2.size = size_two;
535                 check_blank_at_eof(&mf1, &mf2, &ecbdata);
536         }
537         ecbdata.lno_in_preimage = 1;
538         ecbdata.lno_in_postimage = 1;
540         lc_a = count_lines(data_one, size_one);
541         lc_b = count_lines(data_two, size_two);
542         fprintf(o->file,
543                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
544                 metainfo, a_name.buf, name_a_tab, reset,
545                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
546         print_line_count(o->file, lc_a);
547         fprintf(o->file, " +");
548         print_line_count(o->file, lc_b);
549         fprintf(o->file, " @@%s\n", reset);
550         if (lc_a)
551                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
552         if (lc_b)
553                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
556 struct diff_words_buffer {
557         mmfile_t text;
558         long alloc;
559         struct diff_words_orig {
560                 const char *begin, *end;
561         } *orig;
562         int orig_nr, orig_alloc;
563 };
565 static void diff_words_append(char *line, unsigned long len,
566                 struct diff_words_buffer *buffer)
568         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
569         line++;
570         len--;
571         memcpy(buffer->text.ptr + buffer->text.size, line, len);
572         buffer->text.size += len;
573         buffer->text.ptr[buffer->text.size] = '\0';
576 struct diff_words_data {
577         struct diff_words_buffer minus, plus;
578         const char *current_plus;
579         FILE *file;
580         regex_t *word_regex;
581 };
583 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
585         struct diff_words_data *diff_words = priv;
586         int minus_first, minus_len, plus_first, plus_len;
587         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
589         if (line[0] != '@' || parse_hunk_header(line, len,
590                         &minus_first, &minus_len, &plus_first, &plus_len))
591                 return;
593         /* POSIX requires that first be decremented by one if len == 0... */
594         if (minus_len) {
595                 minus_begin = diff_words->minus.orig[minus_first].begin;
596                 minus_end =
597                         diff_words->minus.orig[minus_first + minus_len - 1].end;
598         } else
599                 minus_begin = minus_end =
600                         diff_words->minus.orig[minus_first].end;
602         if (plus_len) {
603                 plus_begin = diff_words->plus.orig[plus_first].begin;
604                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
605         } else
606                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
608         if (diff_words->current_plus != plus_begin)
609                 fwrite(diff_words->current_plus,
610                                 plus_begin - diff_words->current_plus, 1,
611                                 diff_words->file);
612         if (minus_begin != minus_end)
613                 color_fwrite_lines(diff_words->file,
614                                 diff_get_color(1, DIFF_FILE_OLD),
615                                 minus_end - minus_begin, minus_begin);
616         if (plus_begin != plus_end)
617                 color_fwrite_lines(diff_words->file,
618                                 diff_get_color(1, DIFF_FILE_NEW),
619                                 plus_end - plus_begin, plus_begin);
621         diff_words->current_plus = plus_end;
624 /* This function starts looking at *begin, and returns 0 iff a word was found. */
625 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
626                 int *begin, int *end)
628         if (word_regex && *begin < buffer->size) {
629                 regmatch_t match[1];
630                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
631                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
632                                         '\n', match[0].rm_eo - match[0].rm_so);
633                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
634                         *begin += match[0].rm_so;
635                         return *begin >= *end;
636                 }
637                 return -1;
638         }
640         /* find the next word */
641         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
642                 (*begin)++;
643         if (*begin >= buffer->size)
644                 return -1;
646         /* find the end of the word */
647         *end = *begin + 1;
648         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
649                 (*end)++;
651         return 0;
654 /*
655  * This function splits the words in buffer->text, stores the list with
656  * newline separator into out, and saves the offsets of the original words
657  * in buffer->orig.
658  */
659 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
660                 regex_t *word_regex)
662         int i, j;
663         long alloc = 0;
665         out->size = 0;
666         out->ptr = NULL;
668         /* fake an empty "0th" word */
669         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
670         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
671         buffer->orig_nr = 1;
673         for (i = 0; i < buffer->text.size; i++) {
674                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
675                         return;
677                 /* store original boundaries */
678                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
679                                 buffer->orig_alloc);
680                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
681                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
682                 buffer->orig_nr++;
684                 /* store one word */
685                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
686                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
687                 out->ptr[out->size + j - i] = '\n';
688                 out->size += j - i + 1;
690                 i = j - 1;
691         }
694 /* this executes the word diff on the accumulated buffers */
695 static void diff_words_show(struct diff_words_data *diff_words)
697         xpparam_t xpp;
698         xdemitconf_t xecfg;
699         xdemitcb_t ecb;
700         mmfile_t minus, plus;
702         /* special case: only removal */
703         if (!diff_words->plus.text.size) {
704                 color_fwrite_lines(diff_words->file,
705                         diff_get_color(1, DIFF_FILE_OLD),
706                         diff_words->minus.text.size, diff_words->minus.text.ptr);
707                 diff_words->minus.text.size = 0;
708                 return;
709         }
711         diff_words->current_plus = diff_words->plus.text.ptr;
713         memset(&xpp, 0, sizeof(xpp));
714         memset(&xecfg, 0, sizeof(xecfg));
715         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
716         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
717         xpp.flags = XDF_NEED_MINIMAL;
718         /* as only the hunk header will be parsed, we need a 0-context */
719         xecfg.ctxlen = 0;
720         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
721                       &xpp, &xecfg, &ecb);
722         free(minus.ptr);
723         free(plus.ptr);
724         if (diff_words->current_plus != diff_words->plus.text.ptr +
725                         diff_words->plus.text.size)
726                 fwrite(diff_words->current_plus,
727                         diff_words->plus.text.ptr + diff_words->plus.text.size
728                         - diff_words->current_plus, 1,
729                         diff_words->file);
730         diff_words->minus.text.size = diff_words->plus.text.size = 0;
733 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
734 static void diff_words_flush(struct emit_callback *ecbdata)
736         if (ecbdata->diff_words->minus.text.size ||
737             ecbdata->diff_words->plus.text.size)
738                 diff_words_show(ecbdata->diff_words);
741 static void free_diff_words_data(struct emit_callback *ecbdata)
743         if (ecbdata->diff_words) {
744                 diff_words_flush(ecbdata);
745                 free (ecbdata->diff_words->minus.text.ptr);
746                 free (ecbdata->diff_words->minus.orig);
747                 free (ecbdata->diff_words->plus.text.ptr);
748                 free (ecbdata->diff_words->plus.orig);
749                 free(ecbdata->diff_words->word_regex);
750                 free(ecbdata->diff_words);
751                 ecbdata->diff_words = NULL;
752         }
755 const char *diff_get_color(int diff_use_color, enum color_diff ix)
757         if (diff_use_color)
758                 return diff_colors[ix];
759         return "";
762 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
764         const char *cp;
765         unsigned long allot;
766         size_t l = len;
768         if (ecb->truncate)
769                 return ecb->truncate(line, len);
770         cp = line;
771         allot = l;
772         while (0 < l) {
773                 (void) utf8_width(&cp, &l);
774                 if (!cp)
775                         break; /* truncated in the middle? */
776         }
777         return allot - l;
780 static void find_lno(const char *line, struct emit_callback *ecbdata)
782         const char *p;
783         ecbdata->lno_in_preimage = 0;
784         ecbdata->lno_in_postimage = 0;
785         p = strchr(line, '-');
786         if (!p)
787                 return; /* cannot happen */
788         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
789         p = strchr(p, '+');
790         if (!p)
791                 return; /* cannot happen */
792         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
795 static void fn_out_consume(void *priv, char *line, unsigned long len)
797         struct emit_callback *ecbdata = priv;
798         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
799         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
800         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
802         if (ecbdata->header) {
803                 fprintf(ecbdata->file, "%s", ecbdata->header->buf);
804                 strbuf_reset(ecbdata->header);
805                 ecbdata->header = NULL;
806         }
807         *(ecbdata->found_changesp) = 1;
809         if (ecbdata->label_path[0]) {
810                 const char *name_a_tab, *name_b_tab;
812                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
813                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
815                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
816                         meta, ecbdata->label_path[0], reset, name_a_tab);
817                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
818                         meta, ecbdata->label_path[1], reset, name_b_tab);
819                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
820         }
822         if (diff_suppress_blank_empty
823             && len == 2 && line[0] == ' ' && line[1] == '\n') {
824                 line[0] = '\n';
825                 len = 1;
826         }
828         if (line[0] == '@') {
829                 if (ecbdata->diff_words)
830                         diff_words_flush(ecbdata);
831                 len = sane_truncate_line(ecbdata, line, len);
832                 find_lno(line, ecbdata);
833                 emit_hunk_header(ecbdata, line, len);
834                 if (line[len-1] != '\n')
835                         putc('\n', ecbdata->file);
836                 return;
837         }
839         if (len < 1) {
840                 emit_line(ecbdata->file, reset, reset, line, len);
841                 return;
842         }
844         if (ecbdata->diff_words) {
845                 if (line[0] == '-') {
846                         diff_words_append(line, len,
847                                           &ecbdata->diff_words->minus);
848                         return;
849                 } else if (line[0] == '+') {
850                         diff_words_append(line, len,
851                                           &ecbdata->diff_words->plus);
852                         return;
853                 }
854                 diff_words_flush(ecbdata);
855                 line++;
856                 len--;
857                 emit_line(ecbdata->file, plain, reset, line, len);
858                 return;
859         }
861         if (line[0] != '+') {
862                 const char *color =
863                         diff_get_color(ecbdata->color_diff,
864                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
865                 ecbdata->lno_in_preimage++;
866                 if (line[0] == ' ')
867                         ecbdata->lno_in_postimage++;
868                 emit_line(ecbdata->file, color, reset, line, len);
869         } else {
870                 ecbdata->lno_in_postimage++;
871                 emit_add_line(reset, ecbdata, line + 1, len - 1);
872         }
875 static char *pprint_rename(const char *a, const char *b)
877         const char *old = a;
878         const char *new = b;
879         struct strbuf name = STRBUF_INIT;
880         int pfx_length, sfx_length;
881         int len_a = strlen(a);
882         int len_b = strlen(b);
883         int a_midlen, b_midlen;
884         int qlen_a = quote_c_style(a, NULL, NULL, 0);
885         int qlen_b = quote_c_style(b, NULL, NULL, 0);
887         if (qlen_a || qlen_b) {
888                 quote_c_style(a, &name, NULL, 0);
889                 strbuf_addstr(&name, " => ");
890                 quote_c_style(b, &name, NULL, 0);
891                 return strbuf_detach(&name, NULL);
892         }
894         /* Find common prefix */
895         pfx_length = 0;
896         while (*old && *new && *old == *new) {
897                 if (*old == '/')
898                         pfx_length = old - a + 1;
899                 old++;
900                 new++;
901         }
903         /* Find common suffix */
904         old = a + len_a;
905         new = b + len_b;
906         sfx_length = 0;
907         while (a <= old && b <= new && *old == *new) {
908                 if (*old == '/')
909                         sfx_length = len_a - (old - a);
910                 old--;
911                 new--;
912         }
914         /*
915          * pfx{mid-a => mid-b}sfx
916          * {pfx-a => pfx-b}sfx
917          * pfx{sfx-a => sfx-b}
918          * name-a => name-b
919          */
920         a_midlen = len_a - pfx_length - sfx_length;
921         b_midlen = len_b - pfx_length - sfx_length;
922         if (a_midlen < 0)
923                 a_midlen = 0;
924         if (b_midlen < 0)
925                 b_midlen = 0;
927         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
928         if (pfx_length + sfx_length) {
929                 strbuf_add(&name, a, pfx_length);
930                 strbuf_addch(&name, '{');
931         }
932         strbuf_add(&name, a + pfx_length, a_midlen);
933         strbuf_addstr(&name, " => ");
934         strbuf_add(&name, b + pfx_length, b_midlen);
935         if (pfx_length + sfx_length) {
936                 strbuf_addch(&name, '}');
937                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
938         }
939         return strbuf_detach(&name, NULL);
942 struct diffstat_t {
943         int nr;
944         int alloc;
945         struct diffstat_file {
946                 char *from_name;
947                 char *name;
948                 char *print_name;
949                 unsigned is_unmerged:1;
950                 unsigned is_binary:1;
951                 unsigned is_renamed:1;
952                 uintmax_t added, deleted;
953         } **files;
954 };
956 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
957                                           const char *name_a,
958                                           const char *name_b)
960         struct diffstat_file *x;
961         x = xcalloc(sizeof (*x), 1);
962         if (diffstat->nr == diffstat->alloc) {
963                 diffstat->alloc = alloc_nr(diffstat->alloc);
964                 diffstat->files = xrealloc(diffstat->files,
965                                 diffstat->alloc * sizeof(x));
966         }
967         diffstat->files[diffstat->nr++] = x;
968         if (name_b) {
969                 x->from_name = xstrdup(name_a);
970                 x->name = xstrdup(name_b);
971                 x->is_renamed = 1;
972         }
973         else {
974                 x->from_name = NULL;
975                 x->name = xstrdup(name_a);
976         }
977         return x;
980 static void diffstat_consume(void *priv, char *line, unsigned long len)
982         struct diffstat_t *diffstat = priv;
983         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
985         if (line[0] == '+')
986                 x->added++;
987         else if (line[0] == '-')
988                 x->deleted++;
991 const char mime_boundary_leader[] = "------------";
993 static int scale_linear(int it, int width, int max_change)
995         /*
996          * make sure that at least one '-' is printed if there were deletions,
997          * and likewise for '+'.
998          */
999         if (max_change < 2)
1000                 return it;
1001         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1004 static void show_name(FILE *file,
1005                       const char *prefix, const char *name, int len)
1007         fprintf(file, " %s%-*s |", prefix, len, name);
1010 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1012         if (cnt <= 0)
1013                 return;
1014         fprintf(file, "%s", set);
1015         while (cnt--)
1016                 putc(ch, file);
1017         fprintf(file, "%s", reset);
1020 static void fill_print_name(struct diffstat_file *file)
1022         char *pname;
1024         if (file->print_name)
1025                 return;
1027         if (!file->is_renamed) {
1028                 struct strbuf buf = STRBUF_INIT;
1029                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1030                         pname = strbuf_detach(&buf, NULL);
1031                 } else {
1032                         pname = file->name;
1033                         strbuf_release(&buf);
1034                 }
1035         } else {
1036                 pname = pprint_rename(file->from_name, file->name);
1037         }
1038         file->print_name = pname;
1041 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1043         int i, len, add, del, adds = 0, dels = 0;
1044         uintmax_t max_change = 0, max_len = 0;
1045         int total_files = data->nr;
1046         int width, name_width;
1047         const char *reset, *set, *add_c, *del_c;
1049         if (data->nr == 0)
1050                 return;
1052         width = options->stat_width ? options->stat_width : 80;
1053         name_width = options->stat_name_width ? options->stat_name_width : 50;
1055         /* Sanity: give at least 5 columns to the graph,
1056          * but leave at least 10 columns for the name.
1057          */
1058         if (width < 25)
1059                 width = 25;
1060         if (name_width < 10)
1061                 name_width = 10;
1062         else if (width < name_width + 15)
1063                 name_width = width - 15;
1065         /* Find the longest filename and max number of changes */
1066         reset = diff_get_color_opt(options, DIFF_RESET);
1067         set   = diff_get_color_opt(options, DIFF_PLAIN);
1068         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1069         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1071         for (i = 0; i < data->nr; i++) {
1072                 struct diffstat_file *file = data->files[i];
1073                 uintmax_t change = file->added + file->deleted;
1074                 fill_print_name(file);
1075                 len = strlen(file->print_name);
1076                 if (max_len < len)
1077                         max_len = len;
1079                 if (file->is_binary || file->is_unmerged)
1080                         continue;
1081                 if (max_change < change)
1082                         max_change = change;
1083         }
1085         /* Compute the width of the graph part;
1086          * 10 is for one blank at the beginning of the line plus
1087          * " | count " between the name and the graph.
1088          *
1089          * From here on, name_width is the width of the name area,
1090          * and width is the width of the graph area.
1091          */
1092         name_width = (name_width < max_len) ? name_width : max_len;
1093         if (width < (name_width + 10) + max_change)
1094                 width = width - (name_width + 10);
1095         else
1096                 width = max_change;
1098         for (i = 0; i < data->nr; i++) {
1099                 const char *prefix = "";
1100                 char *name = data->files[i]->print_name;
1101                 uintmax_t added = data->files[i]->added;
1102                 uintmax_t deleted = data->files[i]->deleted;
1103                 int name_len;
1105                 /*
1106                  * "scale" the filename
1107                  */
1108                 len = name_width;
1109                 name_len = strlen(name);
1110                 if (name_width < name_len) {
1111                         char *slash;
1112                         prefix = "...";
1113                         len -= 3;
1114                         name += name_len - len;
1115                         slash = strchr(name, '/');
1116                         if (slash)
1117                                 name = slash;
1118                 }
1120                 if (data->files[i]->is_binary) {
1121                         show_name(options->file, prefix, name, len);
1122                         fprintf(options->file, "  Bin ");
1123                         fprintf(options->file, "%s%"PRIuMAX"%s",
1124                                 del_c, deleted, reset);
1125                         fprintf(options->file, " -> ");
1126                         fprintf(options->file, "%s%"PRIuMAX"%s",
1127                                 add_c, added, reset);
1128                         fprintf(options->file, " bytes");
1129                         fprintf(options->file, "\n");
1130                         continue;
1131                 }
1132                 else if (data->files[i]->is_unmerged) {
1133                         show_name(options->file, prefix, name, len);
1134                         fprintf(options->file, "  Unmerged\n");
1135                         continue;
1136                 }
1137                 else if (!data->files[i]->is_renamed &&
1138                          (added + deleted == 0)) {
1139                         total_files--;
1140                         continue;
1141                 }
1143                 /*
1144                  * scale the add/delete
1145                  */
1146                 add = added;
1147                 del = deleted;
1148                 adds += add;
1149                 dels += del;
1151                 if (width <= max_change) {
1152                         add = scale_linear(add, width, max_change);
1153                         del = scale_linear(del, width, max_change);
1154                 }
1155                 show_name(options->file, prefix, name, len);
1156                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1157                                 added + deleted ? " " : "");
1158                 show_graph(options->file, '+', add, add_c, reset);
1159                 show_graph(options->file, '-', del, del_c, reset);
1160                 fprintf(options->file, "\n");
1161         }
1162         fprintf(options->file,
1163                " %d files changed, %d insertions(+), %d deletions(-)\n",
1164                total_files, adds, dels);
1167 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1169         int i, adds = 0, dels = 0, total_files = data->nr;
1171         if (data->nr == 0)
1172                 return;
1174         for (i = 0; i < data->nr; i++) {
1175                 if (!data->files[i]->is_binary &&
1176                     !data->files[i]->is_unmerged) {
1177                         int added = data->files[i]->added;
1178                         int deleted= data->files[i]->deleted;
1179                         if (!data->files[i]->is_renamed &&
1180                             (added + deleted == 0)) {
1181                                 total_files--;
1182                         } else {
1183                                 adds += added;
1184                                 dels += deleted;
1185                         }
1186                 }
1187         }
1188         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1189                total_files, adds, dels);
1192 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1194         int i;
1196         if (data->nr == 0)
1197                 return;
1199         for (i = 0; i < data->nr; i++) {
1200                 struct diffstat_file *file = data->files[i];
1202                 if (file->is_binary)
1203                         fprintf(options->file, "-\t-\t");
1204                 else
1205                         fprintf(options->file,
1206                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1207                                 file->added, file->deleted);
1208                 if (options->line_termination) {
1209                         fill_print_name(file);
1210                         if (!file->is_renamed)
1211                                 write_name_quoted(file->name, options->file,
1212                                                   options->line_termination);
1213                         else {
1214                                 fputs(file->print_name, options->file);
1215                                 putc(options->line_termination, options->file);
1216                         }
1217                 } else {
1218                         if (file->is_renamed) {
1219                                 putc('\0', options->file);
1220                                 write_name_quoted(file->from_name, options->file, '\0');
1221                         }
1222                         write_name_quoted(file->name, options->file, '\0');
1223                 }
1224         }
1227 struct dirstat_file {
1228         const char *name;
1229         unsigned long changed;
1230 };
1232 struct dirstat_dir {
1233         struct dirstat_file *files;
1234         int alloc, nr, percent, cumulative;
1235 };
1237 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1239         unsigned long this_dir = 0;
1240         unsigned int sources = 0;
1242         while (dir->nr) {
1243                 struct dirstat_file *f = dir->files;
1244                 int namelen = strlen(f->name);
1245                 unsigned long this;
1246                 char *slash;
1248                 if (namelen < baselen)
1249                         break;
1250                 if (memcmp(f->name, base, baselen))
1251                         break;
1252                 slash = strchr(f->name + baselen, '/');
1253                 if (slash) {
1254                         int newbaselen = slash + 1 - f->name;
1255                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1256                         sources++;
1257                 } else {
1258                         this = f->changed;
1259                         dir->files++;
1260                         dir->nr--;
1261                         sources += 2;
1262                 }
1263                 this_dir += this;
1264         }
1266         /*
1267          * We don't report dirstat's for
1268          *  - the top level
1269          *  - or cases where everything came from a single directory
1270          *    under this directory (sources == 1).
1271          */
1272         if (baselen && sources != 1) {
1273                 int permille = this_dir * 1000 / changed;
1274                 if (permille) {
1275                         int percent = permille / 10;
1276                         if (percent >= dir->percent) {
1277                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1278                                 if (!dir->cumulative)
1279                                         return 0;
1280                         }
1281                 }
1282         }
1283         return this_dir;
1286 static int dirstat_compare(const void *_a, const void *_b)
1288         const struct dirstat_file *a = _a;
1289         const struct dirstat_file *b = _b;
1290         return strcmp(a->name, b->name);
1293 static void show_dirstat(struct diff_options *options)
1295         int i;
1296         unsigned long changed;
1297         struct dirstat_dir dir;
1298         struct diff_queue_struct *q = &diff_queued_diff;
1300         dir.files = NULL;
1301         dir.alloc = 0;
1302         dir.nr = 0;
1303         dir.percent = options->dirstat_percent;
1304         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1306         changed = 0;
1307         for (i = 0; i < q->nr; i++) {
1308                 struct diff_filepair *p = q->queue[i];
1309                 const char *name;
1310                 unsigned long copied, added, damage;
1312                 name = p->one->path ? p->one->path : p->two->path;
1314                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1315                         diff_populate_filespec(p->one, 0);
1316                         diff_populate_filespec(p->two, 0);
1317                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1318                                                &copied, &added);
1319                         diff_free_filespec_data(p->one);
1320                         diff_free_filespec_data(p->two);
1321                 } else if (DIFF_FILE_VALID(p->one)) {
1322                         diff_populate_filespec(p->one, 1);
1323                         copied = added = 0;
1324                         diff_free_filespec_data(p->one);
1325                 } else if (DIFF_FILE_VALID(p->two)) {
1326                         diff_populate_filespec(p->two, 1);
1327                         copied = 0;
1328                         added = p->two->size;
1329                         diff_free_filespec_data(p->two);
1330                 } else
1331                         continue;
1333                 /*
1334                  * Original minus copied is the removed material,
1335                  * added is the new material.  They are both damages
1336                  * made to the preimage. In --dirstat-by-file mode, count
1337                  * damaged files, not damaged lines. This is done by
1338                  * counting only a single damaged line per file.
1339                  */
1340                 damage = (p->one->size - copied) + added;
1341                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1342                         damage = 1;
1344                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1345                 dir.files[dir.nr].name = name;
1346                 dir.files[dir.nr].changed = damage;
1347                 changed += damage;
1348                 dir.nr++;
1349         }
1351         /* This can happen even with many files, if everything was renames */
1352         if (!changed)
1353                 return;
1355         /* Show all directories with more than x% of the changes */
1356         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1357         gather_dirstat(options->file, &dir, changed, "", 0);
1360 static void free_diffstat_info(struct diffstat_t *diffstat)
1362         int i;
1363         for (i = 0; i < diffstat->nr; i++) {
1364                 struct diffstat_file *f = diffstat->files[i];
1365                 if (f->name != f->print_name)
1366                         free(f->print_name);
1367                 free(f->name);
1368                 free(f->from_name);
1369                 free(f);
1370         }
1371         free(diffstat->files);
1374 struct checkdiff_t {
1375         const char *filename;
1376         int lineno;
1377         int conflict_marker_size;
1378         struct diff_options *o;
1379         unsigned ws_rule;
1380         unsigned status;
1381 };
1383 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1385         char firstchar;
1386         int cnt;
1388         if (len < marker_size + 1)
1389                 return 0;
1390         firstchar = line[0];
1391         switch (firstchar) {
1392         case '=': case '>': case '<': case '|':
1393                 break;
1394         default:
1395                 return 0;
1396         }
1397         for (cnt = 1; cnt < marker_size; cnt++)
1398                 if (line[cnt] != firstchar)
1399                         return 0;
1400         /* line[1] thru line[marker_size-1] are same as firstchar */
1401         if (len < marker_size + 1 || !isspace(line[marker_size]))
1402                 return 0;
1403         return 1;
1406 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1408         struct checkdiff_t *data = priv;
1409         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1410         int marker_size = data->conflict_marker_size;
1411         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1412         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1413         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1414         char *err;
1416         if (line[0] == '+') {
1417                 unsigned bad;
1418                 data->lineno++;
1419                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1420                         data->status |= 1;
1421                         fprintf(data->o->file,
1422                                 "%s:%d: leftover conflict marker\n",
1423                                 data->filename, data->lineno);
1424                 }
1425                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1426                 if (!bad)
1427                         return;
1428                 data->status |= bad;
1429                 err = whitespace_error_string(bad);
1430                 fprintf(data->o->file, "%s:%d: %s.\n",
1431                         data->filename, data->lineno, err);
1432                 free(err);
1433                 emit_line(data->o->file, set, reset, line, 1);
1434                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1435                               data->o->file, set, reset, ws);
1436         } else if (line[0] == ' ') {
1437                 data->lineno++;
1438         } else if (line[0] == '@') {
1439                 char *plus = strchr(line, '+');
1440                 if (plus)
1441                         data->lineno = strtol(plus, NULL, 10) - 1;
1442                 else
1443                         die("invalid diff");
1444         }
1447 static unsigned char *deflate_it(char *data,
1448                                  unsigned long size,
1449                                  unsigned long *result_size)
1451         int bound;
1452         unsigned char *deflated;
1453         z_stream stream;
1455         memset(&stream, 0, sizeof(stream));
1456         deflateInit(&stream, zlib_compression_level);
1457         bound = deflateBound(&stream, size);
1458         deflated = xmalloc(bound);
1459         stream.next_out = deflated;
1460         stream.avail_out = bound;
1462         stream.next_in = (unsigned char *)data;
1463         stream.avail_in = size;
1464         while (deflate(&stream, Z_FINISH) == Z_OK)
1465                 ; /* nothing */
1466         deflateEnd(&stream);
1467         *result_size = stream.total_out;
1468         return deflated;
1471 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1473         void *cp;
1474         void *delta;
1475         void *deflated;
1476         void *data;
1477         unsigned long orig_size;
1478         unsigned long delta_size;
1479         unsigned long deflate_size;
1480         unsigned long data_size;
1482         /* We could do deflated delta, or we could do just deflated two,
1483          * whichever is smaller.
1484          */
1485         delta = NULL;
1486         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1487         if (one->size && two->size) {
1488                 delta = diff_delta(one->ptr, one->size,
1489                                    two->ptr, two->size,
1490                                    &delta_size, deflate_size);
1491                 if (delta) {
1492                         void *to_free = delta;
1493                         orig_size = delta_size;
1494                         delta = deflate_it(delta, delta_size, &delta_size);
1495                         free(to_free);
1496                 }
1497         }
1499         if (delta && delta_size < deflate_size) {
1500                 fprintf(file, "delta %lu\n", orig_size);
1501                 free(deflated);
1502                 data = delta;
1503                 data_size = delta_size;
1504         }
1505         else {
1506                 fprintf(file, "literal %lu\n", two->size);
1507                 free(delta);
1508                 data = deflated;
1509                 data_size = deflate_size;
1510         }
1512         /* emit data encoded in base85 */
1513         cp = data;
1514         while (data_size) {
1515                 int bytes = (52 < data_size) ? 52 : data_size;
1516                 char line[70];
1517                 data_size -= bytes;
1518                 if (bytes <= 26)
1519                         line[0] = bytes + 'A' - 1;
1520                 else
1521                         line[0] = bytes - 26 + 'a' - 1;
1522                 encode_85(line + 1, cp, bytes);
1523                 cp = (char *) cp + bytes;
1524                 fputs(line, file);
1525                 fputc('\n', file);
1526         }
1527         fprintf(file, "\n");
1528         free(data);
1531 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1533         fprintf(file, "GIT binary patch\n");
1534         emit_binary_diff_body(file, one, two);
1535         emit_binary_diff_body(file, two, one);
1538 static void diff_filespec_load_driver(struct diff_filespec *one)
1540         if (!one->driver)
1541                 one->driver = userdiff_find_by_path(one->path);
1542         if (!one->driver)
1543                 one->driver = userdiff_find_by_name("default");
1546 int diff_filespec_is_binary(struct diff_filespec *one)
1548         if (one->is_binary == -1) {
1549                 diff_filespec_load_driver(one);
1550                 if (one->driver->binary != -1)
1551                         one->is_binary = one->driver->binary;
1552                 else {
1553                         if (!one->data && DIFF_FILE_VALID(one))
1554                                 diff_populate_filespec(one, 0);
1555                         if (one->data)
1556                                 one->is_binary = buffer_is_binary(one->data,
1557                                                 one->size);
1558                         if (one->is_binary == -1)
1559                                 one->is_binary = 0;
1560                 }
1561         }
1562         return one->is_binary;
1565 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1567         diff_filespec_load_driver(one);
1568         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1571 static const char *userdiff_word_regex(struct diff_filespec *one)
1573         diff_filespec_load_driver(one);
1574         return one->driver->word_regex;
1577 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1579         if (!options->a_prefix)
1580                 options->a_prefix = a;
1581         if (!options->b_prefix)
1582                 options->b_prefix = b;
1585 static const char *get_textconv(struct diff_filespec *one)
1587         if (!DIFF_FILE_VALID(one))
1588                 return NULL;
1589         if (!S_ISREG(one->mode))
1590                 return NULL;
1591         diff_filespec_load_driver(one);
1592         return one->driver->textconv;
1595 static void builtin_diff(const char *name_a,
1596                          const char *name_b,
1597                          struct diff_filespec *one,
1598                          struct diff_filespec *two,
1599                          const char *xfrm_msg,
1600                          struct diff_options *o,
1601                          int complete_rewrite)
1603         mmfile_t mf1, mf2;
1604         const char *lbl[2];
1605         char *a_one, *b_two;
1606         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1607         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1608         const char *a_prefix, *b_prefix;
1609         const char *textconv_one = NULL, *textconv_two = NULL;
1610         struct strbuf header = STRBUF_INIT;
1612         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1613                         (!one->mode || S_ISGITLINK(one->mode)) &&
1614                         (!two->mode || S_ISGITLINK(two->mode))) {
1615                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1616                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1617                 show_submodule_summary(o->file, one ? one->path : two->path,
1618                                 one->sha1, two->sha1, two->dirty_submodule,
1619                                 del, add, reset);
1620                 return;
1621         }
1623         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1624                 textconv_one = get_textconv(one);
1625                 textconv_two = get_textconv(two);
1626         }
1628         diff_set_mnemonic_prefix(o, "a/", "b/");
1629         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1630                 a_prefix = o->b_prefix;
1631                 b_prefix = o->a_prefix;
1632         } else {
1633                 a_prefix = o->a_prefix;
1634                 b_prefix = o->b_prefix;
1635         }
1637         /* Never use a non-valid filename anywhere if at all possible */
1638         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1639         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1641         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1642         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1643         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1644         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1645         strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1646         if (lbl[0][0] == '/') {
1647                 /* /dev/null */
1648                 strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1649                 if (xfrm_msg && xfrm_msg[0])
1650                         strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1651         }
1652         else if (lbl[1][0] == '/') {
1653                 strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1654                 if (xfrm_msg && xfrm_msg[0])
1655                         strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1656         }
1657         else {
1658                 if (one->mode != two->mode) {
1659                         strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1660                         strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1661                 }
1662                 if (xfrm_msg && xfrm_msg[0])
1663                         strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1665                 /*
1666                  * we do not run diff between different kind
1667                  * of objects.
1668                  */
1669                 if ((one->mode ^ two->mode) & S_IFMT)
1670                         goto free_ab_and_return;
1671                 if (complete_rewrite &&
1672                     (textconv_one || !diff_filespec_is_binary(one)) &&
1673                     (textconv_two || !diff_filespec_is_binary(two))) {
1674                         fprintf(o->file, "%s", header.buf);
1675                         strbuf_reset(&header);
1676                         emit_rewrite_diff(name_a, name_b, one, two,
1677                                                 textconv_one, textconv_two, o);
1678                         o->found_changes = 1;
1679                         goto free_ab_and_return;
1680                 }
1681         }
1683         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1684                 die("unable to read files to diff");
1686         if (!DIFF_OPT_TST(o, TEXT) &&
1687             ( (diff_filespec_is_binary(one) && !textconv_one) ||
1688               (diff_filespec_is_binary(two) && !textconv_two) )) {
1689                 /* Quite common confusing case */
1690                 if (mf1.size == mf2.size &&
1691                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1692                         goto free_ab_and_return;
1693                 fprintf(o->file, "%s", header.buf);
1694                 strbuf_reset(&header);
1695                 if (DIFF_OPT_TST(o, BINARY))
1696                         emit_binary_diff(o->file, &mf1, &mf2);
1697                 else
1698                         fprintf(o->file, "Binary files %s and %s differ\n",
1699                                 lbl[0], lbl[1]);
1700                 o->found_changes = 1;
1701         }
1702         else {
1703                 /* Crazy xdl interfaces.. */
1704                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1705                 xpparam_t xpp;
1706                 xdemitconf_t xecfg;
1707                 xdemitcb_t ecb;
1708                 struct emit_callback ecbdata;
1709                 const struct userdiff_funcname *pe;
1711                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1712                         fprintf(o->file, "%s", header.buf);
1713                         strbuf_reset(&header);
1714                 }
1716                 if (textconv_one) {
1717                         size_t size;
1718                         mf1.ptr = run_textconv(textconv_one, one, &size);
1719                         if (!mf1.ptr)
1720                                 die("unable to read files to diff");
1721                         mf1.size = size;
1722                 }
1723                 if (textconv_two) {
1724                         size_t size;
1725                         mf2.ptr = run_textconv(textconv_two, two, &size);
1726                         if (!mf2.ptr)
1727                                 die("unable to read files to diff");
1728                         mf2.size = size;
1729                 }
1731                 pe = diff_funcname_pattern(one);
1732                 if (!pe)
1733                         pe = diff_funcname_pattern(two);
1735                 memset(&xpp, 0, sizeof(xpp));
1736                 memset(&xecfg, 0, sizeof(xecfg));
1737                 memset(&ecbdata, 0, sizeof(ecbdata));
1738                 ecbdata.label_path = lbl;
1739                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1740                 ecbdata.found_changesp = &o->found_changes;
1741                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1742                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1743                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1744                 ecbdata.file = o->file;
1745                 ecbdata.header = header.len ? &header : NULL;
1746                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1747                 xecfg.ctxlen = o->context;
1748                 xecfg.interhunkctxlen = o->interhunkcontext;
1749                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1750                 if (pe)
1751                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1752                 if (!diffopts)
1753                         ;
1754                 else if (!prefixcmp(diffopts, "--unified="))
1755                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1756                 else if (!prefixcmp(diffopts, "-u"))
1757                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1758                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1759                         ecbdata.diff_words =
1760                                 xcalloc(1, sizeof(struct diff_words_data));
1761                         ecbdata.diff_words->file = o->file;
1762                         if (!o->word_regex)
1763                                 o->word_regex = userdiff_word_regex(one);
1764                         if (!o->word_regex)
1765                                 o->word_regex = userdiff_word_regex(two);
1766                         if (!o->word_regex)
1767                                 o->word_regex = diff_word_regex_cfg;
1768                         if (o->word_regex) {
1769                                 ecbdata.diff_words->word_regex = (regex_t *)
1770                                         xmalloc(sizeof(regex_t));
1771                                 if (regcomp(ecbdata.diff_words->word_regex,
1772                                                 o->word_regex,
1773                                                 REG_EXTENDED | REG_NEWLINE))
1774                                         die ("Invalid regular expression: %s",
1775                                                         o->word_regex);
1776                         }
1777                 }
1778                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1779                               &xpp, &xecfg, &ecb);
1780                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1781                         free_diff_words_data(&ecbdata);
1782                 if (textconv_one)
1783                         free(mf1.ptr);
1784                 if (textconv_two)
1785                         free(mf2.ptr);
1786                 xdiff_clear_find_func(&xecfg);
1787         }
1789  free_ab_and_return:
1790         strbuf_release(&header);
1791         diff_free_filespec_data(one);
1792         diff_free_filespec_data(two);
1793         free(a_one);
1794         free(b_two);
1795         return;
1798 static void builtin_diffstat(const char *name_a, const char *name_b,
1799                              struct diff_filespec *one,
1800                              struct diff_filespec *two,
1801                              struct diffstat_t *diffstat,
1802                              struct diff_options *o,
1803                              int complete_rewrite)
1805         mmfile_t mf1, mf2;
1806         struct diffstat_file *data;
1808         data = diffstat_add(diffstat, name_a, name_b);
1810         if (!one || !two) {
1811                 data->is_unmerged = 1;
1812                 return;
1813         }
1814         if (complete_rewrite) {
1815                 diff_populate_filespec(one, 0);
1816                 diff_populate_filespec(two, 0);
1817                 data->deleted = count_lines(one->data, one->size);
1818                 data->added = count_lines(two->data, two->size);
1819                 goto free_and_return;
1820         }
1821         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1822                 die("unable to read files to diff");
1824         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1825                 data->is_binary = 1;
1826                 data->added = mf2.size;
1827                 data->deleted = mf1.size;
1828         } else {
1829                 /* Crazy xdl interfaces.. */
1830                 xpparam_t xpp;
1831                 xdemitconf_t xecfg;
1832                 xdemitcb_t ecb;
1834                 memset(&xpp, 0, sizeof(xpp));
1835                 memset(&xecfg, 0, sizeof(xecfg));
1836                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1837                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1838                               &xpp, &xecfg, &ecb);
1839         }
1841  free_and_return:
1842         diff_free_filespec_data(one);
1843         diff_free_filespec_data(two);
1846 static void builtin_checkdiff(const char *name_a, const char *name_b,
1847                               const char *attr_path,
1848                               struct diff_filespec *one,
1849                               struct diff_filespec *two,
1850                               struct diff_options *o)
1852         mmfile_t mf1, mf2;
1853         struct checkdiff_t data;
1855         if (!two)
1856                 return;
1858         memset(&data, 0, sizeof(data));
1859         data.filename = name_b ? name_b : name_a;
1860         data.lineno = 0;
1861         data.o = o;
1862         data.ws_rule = whitespace_rule(attr_path);
1863         data.conflict_marker_size = ll_merge_marker_size(attr_path);
1865         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1866                 die("unable to read files to diff");
1868         /*
1869          * All the other codepaths check both sides, but not checking
1870          * the "old" side here is deliberate.  We are checking the newly
1871          * introduced changes, and as long as the "new" side is text, we
1872          * can and should check what it introduces.
1873          */
1874         if (diff_filespec_is_binary(two))
1875                 goto free_and_return;
1876         else {
1877                 /* Crazy xdl interfaces.. */
1878                 xpparam_t xpp;
1879                 xdemitconf_t xecfg;
1880                 xdemitcb_t ecb;
1882                 memset(&xpp, 0, sizeof(xpp));
1883                 memset(&xecfg, 0, sizeof(xecfg));
1884                 xecfg.ctxlen = 1; /* at least one context line */
1885                 xpp.flags = XDF_NEED_MINIMAL;
1886                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1887                               &xpp, &xecfg, &ecb);
1889                 if (data.ws_rule & WS_BLANK_AT_EOF) {
1890                         struct emit_callback ecbdata;
1891                         int blank_at_eof;
1893                         ecbdata.ws_rule = data.ws_rule;
1894                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1895                         blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1897                         if (blank_at_eof) {
1898                                 static char *err;
1899                                 if (!err)
1900                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
1901                                 fprintf(o->file, "%s:%d: %s.\n",
1902                                         data.filename, blank_at_eof, err);
1903                                 data.status = 1; /* report errors */
1904                         }
1905                 }
1906         }
1907  free_and_return:
1908         diff_free_filespec_data(one);
1909         diff_free_filespec_data(two);
1910         if (data.status)
1911                 DIFF_OPT_SET(o, CHECK_FAILED);
1914 struct diff_filespec *alloc_filespec(const char *path)
1916         int namelen = strlen(path);
1917         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1919         memset(spec, 0, sizeof(*spec));
1920         spec->path = (char *)(spec + 1);
1921         memcpy(spec->path, path, namelen+1);
1922         spec->count = 1;
1923         spec->is_binary = -1;
1924         return spec;
1927 void free_filespec(struct diff_filespec *spec)
1929         if (!--spec->count) {
1930                 diff_free_filespec_data(spec);
1931                 free(spec);
1932         }
1935 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1936                    unsigned short mode)
1938         if (mode) {
1939                 spec->mode = canon_mode(mode);
1940                 hashcpy(spec->sha1, sha1);
1941                 spec->sha1_valid = !is_null_sha1(sha1);
1942         }
1945 /*
1946  * Given a name and sha1 pair, if the index tells us the file in
1947  * the work tree has that object contents, return true, so that
1948  * prepare_temp_file() does not have to inflate and extract.
1949  */
1950 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1952         struct cache_entry *ce;
1953         struct stat st;
1954         int pos, len;
1956         /*
1957          * We do not read the cache ourselves here, because the
1958          * benchmark with my previous version that always reads cache
1959          * shows that it makes things worse for diff-tree comparing
1960          * two linux-2.6 kernel trees in an already checked out work
1961          * tree.  This is because most diff-tree comparisons deal with
1962          * only a small number of files, while reading the cache is
1963          * expensive for a large project, and its cost outweighs the
1964          * savings we get by not inflating the object to a temporary
1965          * file.  Practically, this code only helps when we are used
1966          * by diff-cache --cached, which does read the cache before
1967          * calling us.
1968          */
1969         if (!active_cache)
1970                 return 0;
1972         /* We want to avoid the working directory if our caller
1973          * doesn't need the data in a normal file, this system
1974          * is rather slow with its stat/open/mmap/close syscalls,
1975          * and the object is contained in a pack file.  The pack
1976          * is probably already open and will be faster to obtain
1977          * the data through than the working directory.  Loose
1978          * objects however would tend to be slower as they need
1979          * to be individually opened and inflated.
1980          */
1981         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1982                 return 0;
1984         len = strlen(name);
1985         pos = cache_name_pos(name, len);
1986         if (pos < 0)
1987                 return 0;
1988         ce = active_cache[pos];
1990         /*
1991          * This is not the sha1 we are looking for, or
1992          * unreusable because it is not a regular file.
1993          */
1994         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1995                 return 0;
1997         /*
1998          * If ce is marked as "assume unchanged", there is no
1999          * guarantee that work tree matches what we are looking for.
2000          */
2001         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2002                 return 0;
2004         /*
2005          * If ce matches the file in the work tree, we can reuse it.
2006          */
2007         if (ce_uptodate(ce) ||
2008             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2009                 return 1;
2011         return 0;
2014 static int populate_from_stdin(struct diff_filespec *s)
2016         struct strbuf buf = STRBUF_INIT;
2017         size_t size = 0;
2019         if (strbuf_read(&buf, 0, 0) < 0)
2020                 return error("error while reading from stdin %s",
2021                                      strerror(errno));
2023         s->should_munmap = 0;
2024         s->data = strbuf_detach(&buf, &size);
2025         s->size = size;
2026         s->should_free = 1;
2027         return 0;
2030 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2032         int len;
2033         char *data = xmalloc(100), *dirty = "";
2035         /* Are we looking at the work tree? */
2036         if (!s->sha1_valid && s->dirty_submodule)
2037                 dirty = "-dirty";
2039         len = snprintf(data, 100,
2040                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2041         s->data = data;
2042         s->size = len;
2043         s->should_free = 1;
2044         if (size_only) {
2045                 s->data = NULL;
2046                 free(data);
2047         }
2048         return 0;
2051 /*
2052  * While doing rename detection and pickaxe operation, we may need to
2053  * grab the data for the blob (or file) for our own in-core comparison.
2054  * diff_filespec has data and size fields for this purpose.
2055  */
2056 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2058         int err = 0;
2059         if (!DIFF_FILE_VALID(s))
2060                 die("internal error: asking to populate invalid file.");
2061         if (S_ISDIR(s->mode))
2062                 return -1;
2064         if (s->data)
2065                 return 0;
2067         if (size_only && 0 < s->size)
2068                 return 0;
2070         if (S_ISGITLINK(s->mode))
2071                 return diff_populate_gitlink(s, size_only);
2073         if (!s->sha1_valid ||
2074             reuse_worktree_file(s->path, s->sha1, 0)) {
2075                 struct strbuf buf = STRBUF_INIT;
2076                 struct stat st;
2077                 int fd;
2079                 if (!strcmp(s->path, "-"))
2080                         return populate_from_stdin(s);
2082                 if (lstat(s->path, &st) < 0) {
2083                         if (errno == ENOENT) {
2084                         err_empty:
2085                                 err = -1;
2086                         empty:
2087                                 s->data = (char *)"";
2088                                 s->size = 0;
2089                                 return err;
2090                         }
2091                 }
2092                 s->size = xsize_t(st.st_size);
2093                 if (!s->size)
2094                         goto empty;
2095                 if (S_ISLNK(st.st_mode)) {
2096                         struct strbuf sb = STRBUF_INIT;
2098                         if (strbuf_readlink(&sb, s->path, s->size))
2099                                 goto err_empty;
2100                         s->size = sb.len;
2101                         s->data = strbuf_detach(&sb, NULL);
2102                         s->should_free = 1;
2103                         return 0;
2104                 }
2105                 if (size_only)
2106                         return 0;
2107                 fd = open(s->path, O_RDONLY);
2108                 if (fd < 0)
2109                         goto err_empty;
2110                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2111                 close(fd);
2112                 s->should_munmap = 1;
2114                 /*
2115                  * Convert from working tree format to canonical git format
2116                  */
2117                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2118                         size_t size = 0;
2119                         munmap(s->data, s->size);
2120                         s->should_munmap = 0;
2121                         s->data = strbuf_detach(&buf, &size);
2122                         s->size = size;
2123                         s->should_free = 1;
2124                 }
2125         }
2126         else {
2127                 enum object_type type;
2128                 if (size_only)
2129                         type = sha1_object_info(s->sha1, &s->size);
2130                 else {
2131                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2132                         s->should_free = 1;
2133                 }
2134         }
2135         return 0;
2138 void diff_free_filespec_blob(struct diff_filespec *s)
2140         if (s->should_free)
2141                 free(s->data);
2142         else if (s->should_munmap)
2143                 munmap(s->data, s->size);
2145         if (s->should_free || s->should_munmap) {
2146                 s->should_free = s->should_munmap = 0;
2147                 s->data = NULL;
2148         }
2151 void diff_free_filespec_data(struct diff_filespec *s)
2153         diff_free_filespec_blob(s);
2154         free(s->cnt_data);
2155         s->cnt_data = NULL;
2158 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2159                            void *blob,
2160                            unsigned long size,
2161                            const unsigned char *sha1,
2162                            int mode)
2164         int fd;
2165         struct strbuf buf = STRBUF_INIT;
2166         struct strbuf template = STRBUF_INIT;
2167         char *path_dup = xstrdup(path);
2168         const char *base = basename(path_dup);
2170         /* Generate "XXXXXX_basename.ext" */
2171         strbuf_addstr(&template, "XXXXXX_");
2172         strbuf_addstr(&template, base);
2174         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2175                         strlen(base) + 1);
2176         if (fd < 0)
2177                 die_errno("unable to create temp-file");
2178         if (convert_to_working_tree(path,
2179                         (const char *)blob, (size_t)size, &buf)) {
2180                 blob = buf.buf;
2181                 size = buf.len;
2182         }
2183         if (write_in_full(fd, blob, size) != size)
2184                 die_errno("unable to write temp-file");
2185         close(fd);
2186         temp->name = temp->tmp_path;
2187         strcpy(temp->hex, sha1_to_hex(sha1));
2188         temp->hex[40] = 0;
2189         sprintf(temp->mode, "%06o", mode);
2190         strbuf_release(&buf);
2191         strbuf_release(&template);
2192         free(path_dup);
2195 static struct diff_tempfile *prepare_temp_file(const char *name,
2196                 struct diff_filespec *one)
2198         struct diff_tempfile *temp = claim_diff_tempfile();
2200         if (!DIFF_FILE_VALID(one)) {
2201         not_a_valid_file:
2202                 /* A '-' entry produces this for file-2, and
2203                  * a '+' entry produces this for file-1.
2204                  */
2205                 temp->name = "/dev/null";
2206                 strcpy(temp->hex, ".");
2207                 strcpy(temp->mode, ".");
2208                 return temp;
2209         }
2211         if (!remove_tempfile_installed) {
2212                 atexit(remove_tempfile);
2213                 sigchain_push_common(remove_tempfile_on_signal);
2214                 remove_tempfile_installed = 1;
2215         }
2217         if (!one->sha1_valid ||
2218             reuse_worktree_file(name, one->sha1, 1)) {
2219                 struct stat st;
2220                 if (lstat(name, &st) < 0) {
2221                         if (errno == ENOENT)
2222                                 goto not_a_valid_file;
2223                         die_errno("stat(%s)", name);
2224                 }
2225                 if (S_ISLNK(st.st_mode)) {
2226                         struct strbuf sb = STRBUF_INIT;
2227                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2228                                 die_errno("readlink(%s)", name);
2229                         prep_temp_blob(name, temp, sb.buf, sb.len,
2230                                        (one->sha1_valid ?
2231                                         one->sha1 : null_sha1),
2232                                        (one->sha1_valid ?
2233                                         one->mode : S_IFLNK));
2234                         strbuf_release(&sb);
2235                 }
2236                 else {
2237                         /* we can borrow from the file in the work tree */
2238                         temp->name = name;
2239                         if (!one->sha1_valid)
2240                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2241                         else
2242                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2243                         /* Even though we may sometimes borrow the
2244                          * contents from the work tree, we always want
2245                          * one->mode.  mode is trustworthy even when
2246                          * !(one->sha1_valid), as long as
2247                          * DIFF_FILE_VALID(one).
2248                          */
2249                         sprintf(temp->mode, "%06o", one->mode);
2250                 }
2251                 return temp;
2252         }
2253         else {
2254                 if (diff_populate_filespec(one, 0))
2255                         die("cannot read data blob for %s", one->path);
2256                 prep_temp_blob(name, temp, one->data, one->size,
2257                                one->sha1, one->mode);
2258         }
2259         return temp;
2262 /* An external diff command takes:
2263  *
2264  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2265  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2266  *
2267  */
2268 static void run_external_diff(const char *pgm,
2269                               const char *name,
2270                               const char *other,
2271                               struct diff_filespec *one,
2272                               struct diff_filespec *two,
2273                               const char *xfrm_msg,
2274                               int complete_rewrite)
2276         const char *spawn_arg[10];
2277         int retval;
2278         const char **arg = &spawn_arg[0];
2280         if (one && two) {
2281                 struct diff_tempfile *temp_one, *temp_two;
2282                 const char *othername = (other ? other : name);
2283                 temp_one = prepare_temp_file(name, one);
2284                 temp_two = prepare_temp_file(othername, two);
2285                 *arg++ = pgm;
2286                 *arg++ = name;
2287                 *arg++ = temp_one->name;
2288                 *arg++ = temp_one->hex;
2289                 *arg++ = temp_one->mode;
2290                 *arg++ = temp_two->name;
2291                 *arg++ = temp_two->hex;
2292                 *arg++ = temp_two->mode;
2293                 if (other) {
2294                         *arg++ = other;
2295                         *arg++ = xfrm_msg;
2296                 }
2297         } else {
2298                 *arg++ = pgm;
2299                 *arg++ = name;
2300         }
2301         *arg = NULL;
2302         fflush(NULL);
2303         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2304         remove_tempfile();
2305         if (retval) {
2306                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2307                 exit(1);
2308         }
2311 static int similarity_index(struct diff_filepair *p)
2313         return p->score * 100 / MAX_SCORE;
2316 static void fill_metainfo(struct strbuf *msg,
2317                           const char *name,
2318                           const char *other,
2319                           struct diff_filespec *one,
2320                           struct diff_filespec *two,
2321                           struct diff_options *o,
2322                           struct diff_filepair *p)
2324         strbuf_init(msg, PATH_MAX * 2 + 300);
2325         switch (p->status) {
2326         case DIFF_STATUS_COPIED:
2327                 strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2328                 strbuf_addstr(msg, "\ncopy from ");
2329                 quote_c_style(name, msg, NULL, 0);
2330                 strbuf_addstr(msg, "\ncopy to ");
2331                 quote_c_style(other, msg, NULL, 0);
2332                 strbuf_addch(msg, '\n');
2333                 break;
2334         case DIFF_STATUS_RENAMED:
2335                 strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2336                 strbuf_addstr(msg, "\nrename from ");
2337                 quote_c_style(name, msg, NULL, 0);
2338                 strbuf_addstr(msg, "\nrename to ");
2339                 quote_c_style(other, msg, NULL, 0);
2340                 strbuf_addch(msg, '\n');
2341                 break;
2342         case DIFF_STATUS_MODIFIED:
2343                 if (p->score) {
2344                         strbuf_addf(msg, "dissimilarity index %d%%\n",
2345                                     similarity_index(p));
2346                         break;
2347                 }
2348                 /* fallthru */
2349         default:
2350                 /* nothing */
2351                 ;
2352         }
2353         if (one && two && hashcmp(one->sha1, two->sha1)) {
2354                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2356                 if (DIFF_OPT_TST(o, BINARY)) {
2357                         mmfile_t mf;
2358                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2359                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2360                                 abbrev = 40;
2361                 }
2362                 strbuf_addf(msg, "index %.*s..%.*s",
2363                             abbrev, sha1_to_hex(one->sha1),
2364                             abbrev, sha1_to_hex(two->sha1));
2365                 if (one->mode == two->mode)
2366                         strbuf_addf(msg, " %06o", one->mode);
2367                 strbuf_addch(msg, '\n');
2368         }
2369         if (msg->len)
2370                 strbuf_setlen(msg, msg->len - 1);
2373 static void run_diff_cmd(const char *pgm,
2374                          const char *name,
2375                          const char *other,
2376                          const char *attr_path,
2377                          struct diff_filespec *one,
2378                          struct diff_filespec *two,
2379                          struct strbuf *msg,
2380                          struct diff_options *o,
2381                          struct diff_filepair *p)
2383         const char *xfrm_msg = NULL;
2384         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2386         if (msg) {
2387                 fill_metainfo(msg, name, other, one, two, o, p);
2388                 xfrm_msg = msg->len ? msg->buf : NULL;
2389         }
2391         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2392                 pgm = NULL;
2393         else {
2394                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2395                 if (drv && drv->external)
2396                         pgm = drv->external;
2397         }
2399         if (pgm) {
2400                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2401                                   complete_rewrite);
2402                 return;
2403         }
2404         if (one && two)
2405                 builtin_diff(name, other ? other : name,
2406                              one, two, xfrm_msg, o, complete_rewrite);
2407         else
2408                 fprintf(o->file, "* Unmerged path %s\n", name);
2411 static void diff_fill_sha1_info(struct diff_filespec *one)
2413         if (DIFF_FILE_VALID(one)) {
2414                 if (!one->sha1_valid) {
2415                         struct stat st;
2416                         if (!strcmp(one->path, "-")) {
2417                                 hashcpy(one->sha1, null_sha1);
2418                                 return;
2419                         }
2420                         if (lstat(one->path, &st) < 0)
2421                                 die_errno("stat '%s'", one->path);
2422                         if (index_path(one->sha1, one->path, &st, 0))
2423                                 die("cannot hash %s", one->path);
2424                 }
2425         }
2426         else
2427                 hashclr(one->sha1);
2430 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2432         /* Strip the prefix but do not molest /dev/null and absolute paths */
2433         if (*namep && **namep != '/')
2434                 *namep += prefix_length;
2435         if (*otherp && **otherp != '/')
2436                 *otherp += prefix_length;
2439 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2441         const char *pgm = external_diff();
2442         struct strbuf msg;
2443         struct diff_filespec *one = p->one;
2444         struct diff_filespec *two = p->two;
2445         const char *name;
2446         const char *other;
2447         const char *attr_path;
2449         name  = p->one->path;
2450         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2451         attr_path = name;
2452         if (o->prefix_length)
2453                 strip_prefix(o->prefix_length, &name, &other);
2455         if (DIFF_PAIR_UNMERGED(p)) {
2456                 run_diff_cmd(pgm, name, NULL, attr_path,
2457                              NULL, NULL, NULL, o, p);
2458                 return;
2459         }
2461         diff_fill_sha1_info(one);
2462         diff_fill_sha1_info(two);
2464         if (!pgm &&
2465             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2466             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2467                 /*
2468                  * a filepair that changes between file and symlink
2469                  * needs to be split into deletion and creation.
2470                  */
2471                 struct diff_filespec *null = alloc_filespec(two->path);
2472                 run_diff_cmd(NULL, name, other, attr_path,
2473                              one, null, &msg, o, p);
2474                 free(null);
2475                 strbuf_release(&msg);
2477                 null = alloc_filespec(one->path);
2478                 run_diff_cmd(NULL, name, other, attr_path,
2479                              null, two, &msg, o, p);
2480                 free(null);
2481         }
2482         else
2483                 run_diff_cmd(pgm, name, other, attr_path,
2484                              one, two, &msg, o, p);
2486         strbuf_release(&msg);
2489 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2490                          struct diffstat_t *diffstat)
2492         const char *name;
2493         const char *other;
2494         int complete_rewrite = 0;
2496         if (DIFF_PAIR_UNMERGED(p)) {
2497                 /* unmerged */
2498                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2499                 return;
2500         }
2502         name = p->one->path;
2503         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2505         if (o->prefix_length)
2506                 strip_prefix(o->prefix_length, &name, &other);
2508         diff_fill_sha1_info(p->one);
2509         diff_fill_sha1_info(p->two);
2511         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2512                 complete_rewrite = 1;
2513         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2516 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2518         const char *name;
2519         const char *other;
2520         const char *attr_path;
2522         if (DIFF_PAIR_UNMERGED(p)) {
2523                 /* unmerged */
2524                 return;
2525         }
2527         name = p->one->path;
2528         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2529         attr_path = other ? other : name;
2531         if (o->prefix_length)
2532                 strip_prefix(o->prefix_length, &name, &other);
2534         diff_fill_sha1_info(p->one);
2535         diff_fill_sha1_info(p->two);
2537         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2540 void diff_setup(struct diff_options *options)
2542         memset(options, 0, sizeof(*options));
2544         options->file = stdout;
2546         options->line_termination = '\n';
2547         options->break_opt = -1;
2548         options->rename_limit = -1;
2549         options->dirstat_percent = 3;
2550         options->context = 3;
2552         options->change = diff_change;
2553         options->add_remove = diff_addremove;
2554         if (diff_use_color_default > 0)
2555                 DIFF_OPT_SET(options, COLOR_DIFF);
2556         options->detect_rename = diff_detect_rename_default;
2558         if (!diff_mnemonic_prefix) {
2559                 options->a_prefix = "a/";
2560                 options->b_prefix = "b/";
2561         }
2564 int diff_setup_done(struct diff_options *options)
2566         int count = 0;
2568         if (options->output_format & DIFF_FORMAT_NAME)
2569                 count++;
2570         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2571                 count++;
2572         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2573                 count++;
2574         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2575                 count++;
2576         if (count > 1)
2577                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2579         /*
2580          * Most of the time we can say "there are changes"
2581          * only by checking if there are changed paths, but
2582          * --ignore-whitespace* options force us to look
2583          * inside contents.
2584          */
2586         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2587             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2588             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2589                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2590         else
2591                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2593         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2594                 options->detect_rename = DIFF_DETECT_COPY;
2596         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2597                 options->prefix = NULL;
2598         if (options->prefix)
2599                 options->prefix_length = strlen(options->prefix);
2600         else
2601                 options->prefix_length = 0;
2603         if (options->output_format & (DIFF_FORMAT_NAME |
2604                                       DIFF_FORMAT_NAME_STATUS |
2605                                       DIFF_FORMAT_CHECKDIFF |
2606                                       DIFF_FORMAT_NO_OUTPUT))
2607                 options->output_format &= ~(DIFF_FORMAT_RAW |
2608                                             DIFF_FORMAT_NUMSTAT |
2609                                             DIFF_FORMAT_DIFFSTAT |
2610                                             DIFF_FORMAT_SHORTSTAT |
2611                                             DIFF_FORMAT_DIRSTAT |
2612                                             DIFF_FORMAT_SUMMARY |
2613                                             DIFF_FORMAT_PATCH);
2615         /*
2616          * These cases always need recursive; we do not drop caller-supplied
2617          * recursive bits for other formats here.
2618          */
2619         if (options->output_format & (DIFF_FORMAT_PATCH |
2620                                       DIFF_FORMAT_NUMSTAT |
2621                                       DIFF_FORMAT_DIFFSTAT |
2622                                       DIFF_FORMAT_SHORTSTAT |
2623                                       DIFF_FORMAT_DIRSTAT |
2624                                       DIFF_FORMAT_SUMMARY |
2625                                       DIFF_FORMAT_CHECKDIFF))
2626                 DIFF_OPT_SET(options, RECURSIVE);
2627         /*
2628          * Also pickaxe would not work very well if you do not say recursive
2629          */
2630         if (options->pickaxe)
2631                 DIFF_OPT_SET(options, RECURSIVE);
2633         if (options->detect_rename && options->rename_limit < 0)
2634                 options->rename_limit = diff_rename_limit_default;
2635         if (options->setup & DIFF_SETUP_USE_CACHE) {
2636                 if (!active_cache)
2637                         /* read-cache does not die even when it fails
2638                          * so it is safe for us to do this here.  Also
2639                          * it does not smudge active_cache or active_nr
2640                          * when it fails, so we do not have to worry about
2641                          * cleaning it up ourselves either.
2642                          */
2643                         read_cache();
2644         }
2645         if (options->abbrev <= 0 || 40 < options->abbrev)
2646                 options->abbrev = 40; /* full */
2648         /*
2649          * It does not make sense to show the first hit we happened
2650          * to have found.  It does not make sense not to return with
2651          * exit code in such a case either.
2652          */
2653         if (DIFF_OPT_TST(options, QUICK)) {
2654                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2655                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2656         }
2658         return 0;
2661 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2663         char c, *eq;
2664         int len;
2666         if (*arg != '-')
2667                 return 0;
2668         c = *++arg;
2669         if (!c)
2670                 return 0;
2671         if (c == arg_short) {
2672                 c = *++arg;
2673                 if (!c)
2674                         return 1;
2675                 if (val && isdigit(c)) {
2676                         char *end;
2677                         int n = strtoul(arg, &end, 10);
2678                         if (*end)
2679                                 return 0;
2680                         *val = n;
2681                         return 1;
2682                 }
2683                 return 0;
2684         }
2685         if (c != '-')
2686                 return 0;
2687         arg++;
2688         eq = strchr(arg, '=');
2689         if (eq)
2690                 len = eq - arg;
2691         else
2692                 len = strlen(arg);
2693         if (!len || strncmp(arg, arg_long, len))
2694                 return 0;
2695         if (eq) {
2696                 int n;
2697                 char *end;
2698                 if (!isdigit(*++eq))
2699                         return 0;
2700                 n = strtoul(eq, &end, 10);
2701                 if (*end)
2702                         return 0;
2703                 *val = n;
2704         }
2705         return 1;
2708 static int diff_scoreopt_parse(const char *opt);
2710 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2712         const char *arg = av[0];
2714         /* Output format options */
2715         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2716                 options->output_format |= DIFF_FORMAT_PATCH;
2717         else if (opt_arg(arg, 'U', "unified", &options->context))
2718                 options->output_format |= DIFF_FORMAT_PATCH;
2719         else if (!strcmp(arg, "--raw"))
2720                 options->output_format |= DIFF_FORMAT_RAW;
2721         else if (!strcmp(arg, "--patch-with-raw"))
2722                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2723         else if (!strcmp(arg, "--numstat"))
2724                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2725         else if (!strcmp(arg, "--shortstat"))
2726                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2727         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2728                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2729         else if (!strcmp(arg, "--cumulative")) {
2730                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2731                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2732         } else if (opt_arg(arg, 0, "dirstat-by-file",
2733                            &options->dirstat_percent)) {
2734                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2735                 DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2736         }
2737         else if (!strcmp(arg, "--check"))
2738                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2739         else if (!strcmp(arg, "--summary"))
2740                 options->output_format |= DIFF_FORMAT_SUMMARY;
2741         else if (!strcmp(arg, "--patch-with-stat"))
2742                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2743         else if (!strcmp(arg, "--name-only"))
2744                 options->output_format |= DIFF_FORMAT_NAME;
2745         else if (!strcmp(arg, "--name-status"))
2746                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2747         else if (!strcmp(arg, "-s"))
2748                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2749         else if (!prefixcmp(arg, "--stat")) {
2750                 char *end;
2751                 int width = options->stat_width;
2752                 int name_width = options->stat_name_width;
2753                 arg += 6;
2754                 end = (char *)arg;
2756                 switch (*arg) {
2757                 case '-':
2758                         if (!prefixcmp(arg, "-width="))
2759                                 width = strtoul(arg + 7, &end, 10);
2760                         else if (!prefixcmp(arg, "-name-width="))
2761                                 name_width = strtoul(arg + 12, &end, 10);
2762                         break;
2763                 case '=':
2764                         width = strtoul(arg+1, &end, 10);
2765                         if (*end == ',')
2766                                 name_width = strtoul(end+1, &end, 10);
2767                 }
2769                 /* Important! This checks all the error cases! */
2770                 if (*end)
2771                         return 0;
2772                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2773                 options->stat_name_width = name_width;
2774                 options->stat_width = width;
2775         }
2777         /* renames options */
2778         else if (!prefixcmp(arg, "-B")) {
2779                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2780                         return -1;
2781         }
2782         else if (!prefixcmp(arg, "-M")) {
2783                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2784                         return -1;
2785                 options->detect_rename = DIFF_DETECT_RENAME;
2786         }
2787         else if (!prefixcmp(arg, "-C")) {
2788                 if (options->detect_rename == DIFF_DETECT_COPY)
2789                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2790                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2791                         return -1;
2792                 options->detect_rename = DIFF_DETECT_COPY;
2793         }
2794         else if (!strcmp(arg, "--no-renames"))
2795                 options->detect_rename = 0;
2796         else if (!strcmp(arg, "--relative"))
2797                 DIFF_OPT_SET(options, RELATIVE_NAME);
2798         else if (!prefixcmp(arg, "--relative=")) {
2799                 DIFF_OPT_SET(options, RELATIVE_NAME);
2800                 options->prefix = arg + 11;
2801         }
2803         /* xdiff options */
2804         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2805                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2806         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2807                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2808         else if (!strcmp(arg, "--ignore-space-at-eol"))
2809                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2810         else if (!strcmp(arg, "--patience"))
2811                 DIFF_XDL_SET(options, PATIENCE_DIFF);
2813         /* flags options */
2814         else if (!strcmp(arg, "--binary")) {
2815                 options->output_format |= DIFF_FORMAT_PATCH;
2816                 DIFF_OPT_SET(options, BINARY);
2817         }
2818         else if (!strcmp(arg, "--full-index"))
2819                 DIFF_OPT_SET(options, FULL_INDEX);
2820         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2821                 DIFF_OPT_SET(options, TEXT);
2822         else if (!strcmp(arg, "-R"))
2823                 DIFF_OPT_SET(options, REVERSE_DIFF);
2824         else if (!strcmp(arg, "--find-copies-harder"))
2825                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2826         else if (!strcmp(arg, "--follow"))
2827                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2828         else if (!strcmp(arg, "--color"))
2829                 DIFF_OPT_SET(options, COLOR_DIFF);
2830         else if (!strcmp(arg, "--no-color"))
2831                 DIFF_OPT_CLR(options, COLOR_DIFF);
2832         else if (!strcmp(arg, "--color-words")) {
2833                 DIFF_OPT_SET(options, COLOR_DIFF);
2834                 DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2835         }
2836         else if (!prefixcmp(arg, "--color-words=")) {
2837                 DIFF_OPT_SET(options, COLOR_DIFF);
2838                 DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2839                 options->word_regex = arg + 14;
2840         }
2841         else if (!strcmp(arg, "--exit-code"))
2842                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2843         else if (!strcmp(arg, "--quiet"))
2844                 DIFF_OPT_SET(options, QUICK);
2845         else if (!strcmp(arg, "--ext-diff"))
2846                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2847         else if (!strcmp(arg, "--no-ext-diff"))
2848                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2849         else if (!strcmp(arg, "--textconv"))
2850                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2851         else if (!strcmp(arg, "--no-textconv"))
2852                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2853         else if (!strcmp(arg, "--ignore-submodules"))
2854                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2855         else if (!strcmp(arg, "--submodule"))
2856                 DIFF_OPT_SET(options, SUBMODULE_LOG);
2857         else if (!prefixcmp(arg, "--submodule=")) {
2858                 if (!strcmp(arg + 12, "log"))
2859                         DIFF_OPT_SET(options, SUBMODULE_LOG);
2860         }
2862         /* misc options */
2863         else if (!strcmp(arg, "-z"))
2864                 options->line_termination = 0;
2865         else if (!prefixcmp(arg, "-l"))
2866                 options->rename_limit = strtoul(arg+2, NULL, 10);
2867         else if (!prefixcmp(arg, "-S"))
2868                 options->pickaxe = arg + 2;
2869         else if (!strcmp(arg, "--pickaxe-all"))
2870                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2871         else if (!strcmp(arg, "--pickaxe-regex"))
2872                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2873         else if (!prefixcmp(arg, "-O"))
2874                 options->orderfile = arg + 2;
2875         else if (!prefixcmp(arg, "--diff-filter="))
2876                 options->filter = arg + 14;
2877         else if (!strcmp(arg, "--abbrev"))
2878                 options->abbrev = DEFAULT_ABBREV;
2879         else if (!prefixcmp(arg, "--abbrev=")) {
2880                 options->abbrev = strtoul(arg + 9, NULL, 10);
2881                 if (options->abbrev < MINIMUM_ABBREV)
2882                         options->abbrev = MINIMUM_ABBREV;
2883                 else if (40 < options->abbrev)
2884                         options->abbrev = 40;
2885         }
2886         else if (!prefixcmp(arg, "--src-prefix="))
2887                 options->a_prefix = arg + 13;
2888         else if (!prefixcmp(arg, "--dst-prefix="))
2889                 options->b_prefix = arg + 13;
2890         else if (!strcmp(arg, "--no-prefix"))
2891                 options->a_prefix = options->b_prefix = "";
2892         else if (opt_arg(arg, '\0', "inter-hunk-context",
2893                          &options->interhunkcontext))
2894                 ;
2895         else if (!prefixcmp(arg, "--output=")) {
2896                 options->file = fopen(arg + strlen("--output="), "w");
2897                 if (!options->file)
2898                         die_errno("Could not open '%s'", arg + strlen("--output="));
2899                 options->close_file = 1;
2900         } else
2901                 return 0;
2902         return 1;
2905 static int parse_num(const char **cp_p)
2907         unsigned long num, scale;
2908         int ch, dot;
2909         const char *cp = *cp_p;
2911         num = 0;
2912         scale = 1;
2913         dot = 0;
2914         for (;;) {
2915                 ch = *cp;
2916                 if ( !dot && ch == '.' ) {
2917                         scale = 1;
2918                         dot = 1;
2919                 } else if ( ch == '%' ) {
2920                         scale = dot ? scale*100 : 100;
2921                         cp++;   /* % is always at the end */
2922                         break;
2923                 } else if ( ch >= '0' && ch <= '9' ) {
2924                         if ( scale < 100000 ) {
2925                                 scale *= 10;
2926                                 num = (num*10) + (ch-'0');
2927                         }
2928                 } else {
2929                         break;
2930                 }
2931                 cp++;
2932         }
2933         *cp_p = cp;
2935         /* user says num divided by scale and we say internally that
2936          * is MAX_SCORE * num / scale.
2937          */
2938         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2941 static int diff_scoreopt_parse(const char *opt)
2943         int opt1, opt2, cmd;
2945         if (*opt++ != '-')
2946                 return -1;
2947         cmd = *opt++;
2948         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2949                 return -1; /* that is not a -M, -C nor -B option */
2951         opt1 = parse_num(&opt);
2952         if (cmd != 'B')
2953                 opt2 = 0;
2954         else {
2955                 if (*opt == 0)
2956                         opt2 = 0;
2957                 else if (*opt != '/')
2958                         return -1; /* we expect -B80/99 or -B80 */
2959                 else {
2960                         opt++;
2961                         opt2 = parse_num(&opt);
2962                 }
2963         }
2964         if (*opt != 0)
2965                 return -1;
2966         return opt1 | (opt2 << 16);
2969 struct diff_queue_struct diff_queued_diff;
2971 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2973         if (queue->alloc <= queue->nr) {
2974                 queue->alloc = alloc_nr(queue->alloc);
2975                 queue->queue = xrealloc(queue->queue,
2976                                         sizeof(dp) * queue->alloc);
2977         }
2978         queue->queue[queue->nr++] = dp;
2981 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2982                                  struct diff_filespec *one,
2983                                  struct diff_filespec *two)
2985         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2986         dp->one = one;
2987         dp->two = two;
2988         if (queue)
2989                 diff_q(queue, dp);
2990         return dp;
2993 void diff_free_filepair(struct diff_filepair *p)
2995         free_filespec(p->one);
2996         free_filespec(p->two);
2997         free(p);
3000 /* This is different from find_unique_abbrev() in that
3001  * it stuffs the result with dots for alignment.
3002  */
3003 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3005         int abblen;
3006         const char *abbrev;
3007         if (len == 40)
3008                 return sha1_to_hex(sha1);
3010         abbrev = find_unique_abbrev(sha1, len);
3011         abblen = strlen(abbrev);
3012         if (abblen < 37) {
3013                 static char hex[41];
3014                 if (len < abblen && abblen <= len + 2)
3015                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3016                 else
3017                         sprintf(hex, "%s...", abbrev);
3018                 return hex;
3019         }
3020         return sha1_to_hex(sha1);
3023 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3025         int line_termination = opt->line_termination;
3026         int inter_name_termination = line_termination ? '\t' : '\0';
3028         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3029                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3030                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3031                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3032         }
3033         if (p->score) {
3034                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3035                         inter_name_termination);
3036         } else {
3037                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3038         }
3040         if (p->status == DIFF_STATUS_COPIED ||
3041             p->status == DIFF_STATUS_RENAMED) {
3042                 const char *name_a, *name_b;
3043                 name_a = p->one->path;
3044                 name_b = p->two->path;
3045                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3046                 write_name_quoted(name_a, opt->file, inter_name_termination);
3047                 write_name_quoted(name_b, opt->file, line_termination);
3048         } else {
3049                 const char *name_a, *name_b;
3050                 name_a = p->one->mode ? p->one->path : p->two->path;
3051                 name_b = NULL;
3052                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3053                 write_name_quoted(name_a, opt->file, line_termination);
3054         }
3057 int diff_unmodified_pair(struct diff_filepair *p)
3059         /* This function is written stricter than necessary to support
3060          * the currently implemented transformers, but the idea is to
3061          * let transformers to produce diff_filepairs any way they want,
3062          * and filter and clean them up here before producing the output.
3063          */
3064         struct diff_filespec *one = p->one, *two = p->two;
3066         if (DIFF_PAIR_UNMERGED(p))
3067                 return 0; /* unmerged is interesting */
3069         /* deletion, addition, mode or type change
3070          * and rename are all interesting.
3071          */
3072         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3073             DIFF_PAIR_MODE_CHANGED(p) ||
3074             strcmp(one->path, two->path))
3075                 return 0;
3077         /* both are valid and point at the same path.  that is, we are
3078          * dealing with a change.
3079          */
3080         if (one->sha1_valid && two->sha1_valid &&
3081             !hashcmp(one->sha1, two->sha1))
3082                 return 1; /* no change */
3083         if (!one->sha1_valid && !two->sha1_valid)
3084                 return 1; /* both look at the same file on the filesystem. */
3085         return 0;
3088 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3090         if (diff_unmodified_pair(p))
3091                 return;
3093         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3094             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3095                 return; /* no tree diffs in patch format */
3097         run_diff(p, o);
3100 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3101                             struct diffstat_t *diffstat)
3103         if (diff_unmodified_pair(p))
3104                 return;
3106         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3107             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3108                 return; /* no tree diffs in patch format */
3110         run_diffstat(p, o, diffstat);
3113 static void diff_flush_checkdiff(struct diff_filepair *p,
3114                 struct diff_options *o)
3116         if (diff_unmodified_pair(p))
3117                 return;
3119         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3120             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3121                 return; /* no tree diffs in patch format */
3123         run_checkdiff(p, o);
3126 int diff_queue_is_empty(void)
3128         struct diff_queue_struct *q = &diff_queued_diff;
3129         int i;
3130         for (i = 0; i < q->nr; i++)
3131                 if (!diff_unmodified_pair(q->queue[i]))
3132                         return 0;
3133         return 1;
3136 #if DIFF_DEBUG
3137 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3139         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3140                 x, one ? one : "",
3141                 s->path,
3142                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3143                 s->mode,
3144                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3145         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3146                 x, one ? one : "",
3147                 s->size, s->xfrm_flags);
3150 void diff_debug_filepair(const struct diff_filepair *p, int i)
3152         diff_debug_filespec(p->one, i, "one");
3153         diff_debug_filespec(p->two, i, "two");
3154         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3155                 p->score, p->status ? p->status : '?',
3156                 p->one->rename_used, p->broken_pair);
3159 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3161         int i;
3162         if (msg)
3163                 fprintf(stderr, "%s\n", msg);
3164         fprintf(stderr, "q->nr = %d\n", q->nr);
3165         for (i = 0; i < q->nr; i++) {
3166                 struct diff_filepair *p = q->queue[i];
3167                 diff_debug_filepair(p, i);
3168         }
3170 #endif
3172 static void diff_resolve_rename_copy(void)
3174         int i;
3175         struct diff_filepair *p;
3176         struct diff_queue_struct *q = &diff_queued_diff;
3178         diff_debug_queue("resolve-rename-copy", q);
3180         for (i = 0; i < q->nr; i++) {
3181                 p = q->queue[i];
3182                 p->status = 0; /* undecided */
3183                 if (DIFF_PAIR_UNMERGED(p))
3184                         p->status = DIFF_STATUS_UNMERGED;
3185                 else if (!DIFF_FILE_VALID(p->one))
3186                         p->status = DIFF_STATUS_ADDED;
3187                 else if (!DIFF_FILE_VALID(p->two))
3188                         p->status = DIFF_STATUS_DELETED;
3189                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3190                         p->status = DIFF_STATUS_TYPE_CHANGED;
3192                 /* from this point on, we are dealing with a pair
3193                  * whose both sides are valid and of the same type, i.e.
3194                  * either in-place edit or rename/copy edit.
3195                  */
3196                 else if (DIFF_PAIR_RENAME(p)) {
3197                         /*
3198                          * A rename might have re-connected a broken
3199                          * pair up, causing the pathnames to be the
3200                          * same again. If so, that's not a rename at
3201                          * all, just a modification..
3202                          *
3203                          * Otherwise, see if this source was used for
3204                          * multiple renames, in which case we decrement
3205                          * the count, and call it a copy.
3206                          */
3207                         if (!strcmp(p->one->path, p->two->path))
3208                                 p->status = DIFF_STATUS_MODIFIED;
3209                         else if (--p->one->rename_used > 0)
3210                                 p->status = DIFF_STATUS_COPIED;
3211                         else
3212                                 p->status = DIFF_STATUS_RENAMED;
3213                 }
3214                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3215                          p->one->mode != p->two->mode ||
3216                          is_null_sha1(p->one->sha1))
3217                         p->status = DIFF_STATUS_MODIFIED;
3218                 else {
3219                         /* This is a "no-change" entry and should not
3220                          * happen anymore, but prepare for broken callers.
3221                          */
3222                         error("feeding unmodified %s to diffcore",
3223                               p->one->path);
3224                         p->status = DIFF_STATUS_UNKNOWN;
3225                 }
3226         }
3227         diff_debug_queue("resolve-rename-copy done", q);
3230 static int check_pair_status(struct diff_filepair *p)
3232         switch (p->status) {
3233         case DIFF_STATUS_UNKNOWN:
3234                 return 0;
3235         case 0:
3236                 die("internal error in diff-resolve-rename-copy");
3237         default:
3238                 return 1;
3239         }
3242 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3244         int fmt = opt->output_format;
3246         if (fmt & DIFF_FORMAT_CHECKDIFF)
3247                 diff_flush_checkdiff(p, opt);
3248         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3249                 diff_flush_raw(p, opt);
3250         else if (fmt & DIFF_FORMAT_NAME) {
3251                 const char *name_a, *name_b;
3252                 name_a = p->two->path;
3253                 name_b = NULL;
3254                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3255                 write_name_quoted(name_a, opt->file, opt->line_termination);
3256         }
3259 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3261         if (fs->mode)
3262                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3263         else
3264                 fprintf(file, " %s ", newdelete);
3265         write_name_quoted(fs->path, file, '\n');
3269 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3271         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3272                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3273                         show_name ? ' ' : '\n');
3274                 if (show_name) {
3275                         write_name_quoted(p->two->path, file, '\n');
3276                 }
3277         }
3280 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3282         char *names = pprint_rename(p->one->path, p->two->path);
3284         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3285         free(names);
3286         show_mode_change(file, p, 0);
3289 static void diff_summary(FILE *file, struct diff_filepair *p)
3291         switch(p->status) {
3292         case DIFF_STATUS_DELETED:
3293                 show_file_mode_name(file, "delete", p->one);
3294                 break;
3295         case DIFF_STATUS_ADDED:
3296                 show_file_mode_name(file, "create", p->two);
3297                 break;
3298         case DIFF_STATUS_COPIED:
3299                 show_rename_copy(file, "copy", p);
3300                 break;
3301         case DIFF_STATUS_RENAMED:
3302                 show_rename_copy(file, "rename", p);
3303                 break;
3304         default:
3305                 if (p->score) {
3306                         fputs(" rewrite ", file);
3307                         write_name_quoted(p->two->path, file, ' ');
3308                         fprintf(file, "(%d%%)\n", similarity_index(p));
3309                 }
3310                 show_mode_change(file, p, !p->score);
3311                 break;
3312         }
3315 struct patch_id_t {
3316         git_SHA_CTX *ctx;
3317         int patchlen;
3318 };
3320 static int remove_space(char *line, int len)
3322         int i;
3323         char *dst = line;
3324         unsigned char c;
3326         for (i = 0; i < len; i++)
3327                 if (!isspace((c = line[i])))
3328                         *dst++ = c;
3330         return dst - line;
3333 static void patch_id_consume(void *priv, char *line, unsigned long len)
3335         struct patch_id_t *data = priv;
3336         int new_len;
3338         /* Ignore line numbers when computing the SHA1 of the patch */
3339         if (!prefixcmp(line, "@@ -"))
3340                 return;
3342         new_len = remove_space(line, len);
3344         git_SHA1_Update(data->ctx, line, new_len);
3345         data->patchlen += new_len;
3348 /* returns 0 upon success, and writes result into sha1 */
3349 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3351         struct diff_queue_struct *q = &diff_queued_diff;
3352         int i;
3353         git_SHA_CTX ctx;
3354         struct patch_id_t data;
3355         char buffer[PATH_MAX * 4 + 20];
3357         git_SHA1_Init(&ctx);
3358         memset(&data, 0, sizeof(struct patch_id_t));
3359         data.ctx = &ctx;
3361         for (i = 0; i < q->nr; i++) {
3362                 xpparam_t xpp;
3363                 xdemitconf_t xecfg;
3364                 xdemitcb_t ecb;
3365                 mmfile_t mf1, mf2;
3366                 struct diff_filepair *p = q->queue[i];
3367                 int len1, len2;
3369                 memset(&xpp, 0, sizeof(xpp));
3370                 memset(&xecfg, 0, sizeof(xecfg));
3371                 if (p->status == 0)
3372                         return error("internal diff status error");
3373                 if (p->status == DIFF_STATUS_UNKNOWN)
3374                         continue;
3375                 if (diff_unmodified_pair(p))
3376                         continue;
3377                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3378                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3379                         continue;
3380                 if (DIFF_PAIR_UNMERGED(p))
3381                         continue;
3383                 diff_fill_sha1_info(p->one);
3384                 diff_fill_sha1_info(p->two);
3385                 if (fill_mmfile(&mf1, p->one) < 0 ||
3386                                 fill_mmfile(&mf2, p->two) < 0)
3387                         return error("unable to read files to diff");
3389                 len1 = remove_space(p->one->path, strlen(p->one->path));
3390                 len2 = remove_space(p->two->path, strlen(p->two->path));
3391                 if (p->one->mode == 0)
3392                         len1 = snprintf(buffer, sizeof(buffer),
3393                                         "diff--gita/%.*sb/%.*s"
3394                                         "newfilemode%06o"
3395                                         "---/dev/null"
3396                                         "+++b/%.*s",
3397                                         len1, p->one->path,
3398                                         len2, p->two->path,
3399                                         p->two->mode,
3400                                         len2, p->two->path);
3401                 else if (p->two->mode == 0)
3402                         len1 = snprintf(buffer, sizeof(buffer),
3403                                         "diff--gita/%.*sb/%.*s"
3404                                         "deletedfilemode%06o"
3405                                         "---a/%.*s"
3406                                         "+++/dev/null",
3407                                         len1, p->one->path,
3408                                         len2, p->two->path,
3409                                         p->one->mode,
3410                                         len1, p->one->path);
3411                 else
3412                         len1 = snprintf(buffer, sizeof(buffer),
3413                                         "diff--gita/%.*sb/%.*s"
3414                                         "---a/%.*s"
3415                                         "+++b/%.*s",
3416                                         len1, p->one->path,
3417                                         len2, p->two->path,
3418                                         len1, p->one->path,
3419                                         len2, p->two->path);
3420                 git_SHA1_Update(&ctx, buffer, len1);
3422                 xpp.flags = XDF_NEED_MINIMAL;
3423                 xecfg.ctxlen = 3;
3424                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3425                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3426                               &xpp, &xecfg, &ecb);
3427         }
3429         git_SHA1_Final(sha1, &ctx);
3430         return 0;
3433 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3435         struct diff_queue_struct *q = &diff_queued_diff;
3436         int i;
3437         int result = diff_get_patch_id(options, sha1);
3439         for (i = 0; i < q->nr; i++)
3440                 diff_free_filepair(q->queue[i]);
3442         free(q->queue);
3443         q->queue = NULL;
3444         q->nr = q->alloc = 0;
3446         return result;
3449 static int is_summary_empty(const struct diff_queue_struct *q)
3451         int i;
3453         for (i = 0; i < q->nr; i++) {
3454                 const struct diff_filepair *p = q->queue[i];
3456                 switch (p->status) {
3457                 case DIFF_STATUS_DELETED:
3458                 case DIFF_STATUS_ADDED:
3459                 case DIFF_STATUS_COPIED:
3460                 case DIFF_STATUS_RENAMED:
3461                         return 0;
3462                 default:
3463                         if (p->score)
3464                                 return 0;
3465                         if (p->one->mode && p->two->mode &&
3466                             p->one->mode != p->two->mode)
3467                                 return 0;
3468                         break;
3469                 }
3470         }
3471         return 1;
3474 void diff_flush(struct diff_options *options)
3476         struct diff_queue_struct *q = &diff_queued_diff;
3477         int i, output_format = options->output_format;
3478         int separator = 0;
3480         /*
3481          * Order: raw, stat, summary, patch
3482          * or:    name/name-status/checkdiff (other bits clear)
3483          */
3484         if (!q->nr)
3485                 goto free_queue;
3487         if (output_format & (DIFF_FORMAT_RAW |
3488                              DIFF_FORMAT_NAME |
3489                              DIFF_FORMAT_NAME_STATUS |
3490                              DIFF_FORMAT_CHECKDIFF)) {
3491                 for (i = 0; i < q->nr; i++) {
3492                         struct diff_filepair *p = q->queue[i];
3493                         if (check_pair_status(p))
3494                                 flush_one_pair(p, options);
3495                 }
3496                 separator++;
3497         }
3499         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3500                 struct diffstat_t diffstat;
3502                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3503                 for (i = 0; i < q->nr; i++) {
3504                         struct diff_filepair *p = q->queue[i];
3505                         if (check_pair_status(p))
3506                                 diff_flush_stat(p, options, &diffstat);
3507                 }
3508                 if (output_format & DIFF_FORMAT_NUMSTAT)
3509                         show_numstat(&diffstat, options);
3510                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3511                         show_stats(&diffstat, options);
3512                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3513                         show_shortstats(&diffstat, options);
3514                 free_diffstat_info(&diffstat);
3515                 separator++;
3516         }
3517         if (output_format & DIFF_FORMAT_DIRSTAT)
3518                 show_dirstat(options);
3520         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3521                 for (i = 0; i < q->nr; i++)
3522                         diff_summary(options->file, q->queue[i]);
3523                 separator++;
3524         }
3526         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3527             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3528             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3529                 /*
3530                  * run diff_flush_patch for the exit status. setting
3531                  * options->file to /dev/null should be safe, becaue we
3532                  * aren't supposed to produce any output anyway.
3533                  */
3534                 if (options->close_file)
3535                         fclose(options->file);
3536                 options->file = fopen("/dev/null", "w");
3537                 if (!options->file)
3538                         die_errno("Could not open /dev/null");
3539                 options->close_file = 1;
3540                 for (i = 0; i < q->nr; i++) {
3541                         struct diff_filepair *p = q->queue[i];
3542                         if (check_pair_status(p))
3543                                 diff_flush_patch(p, options);
3544                         if (options->found_changes)
3545                                 break;
3546                 }
3547         }
3549         if (output_format & DIFF_FORMAT_PATCH) {
3550                 if (separator) {
3551                         putc(options->line_termination, options->file);
3552                         if (options->stat_sep) {
3553                                 /* attach patch instead of inline */
3554                                 fputs(options->stat_sep, options->file);
3555                         }
3556                 }
3558                 for (i = 0; i < q->nr; i++) {
3559                         struct diff_filepair *p = q->queue[i];
3560                         if (check_pair_status(p))
3561                                 diff_flush_patch(p, options);
3562                 }
3563         }
3565         if (output_format & DIFF_FORMAT_CALLBACK)
3566                 options->format_callback(q, options, options->format_callback_data);
3568         for (i = 0; i < q->nr; i++)
3569                 diff_free_filepair(q->queue[i]);
3570 free_queue:
3571         free(q->queue);
3572         q->queue = NULL;
3573         q->nr = q->alloc = 0;
3574         if (options->close_file)
3575                 fclose(options->file);
3577         /*
3578          * Report the content-level differences with HAS_CHANGES;
3579          * diff_addremove/diff_change does not set the bit when
3580          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3581          */
3582         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3583                 if (options->found_changes)
3584                         DIFF_OPT_SET(options, HAS_CHANGES);
3585                 else
3586                         DIFF_OPT_CLR(options, HAS_CHANGES);
3587         }
3590 static void diffcore_apply_filter(const char *filter)
3592         int i;
3593         struct diff_queue_struct *q = &diff_queued_diff;
3594         struct diff_queue_struct outq;
3595         outq.queue = NULL;
3596         outq.nr = outq.alloc = 0;
3598         if (!filter)
3599                 return;
3601         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3602                 int found;
3603                 for (i = found = 0; !found && i < q->nr; i++) {
3604                         struct diff_filepair *p = q->queue[i];
3605                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3606                              ((p->score &&
3607                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3608                               (!p->score &&
3609                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3610                             ((p->status != DIFF_STATUS_MODIFIED) &&
3611                              strchr(filter, p->status)))
3612                                 found++;
3613                 }
3614                 if (found)
3615                         return;
3617                 /* otherwise we will clear the whole queue
3618                  * by copying the empty outq at the end of this
3619                  * function, but first clear the current entries
3620                  * in the queue.
3621                  */
3622                 for (i = 0; i < q->nr; i++)
3623                         diff_free_filepair(q->queue[i]);
3624         }
3625         else {
3626                 /* Only the matching ones */
3627                 for (i = 0; i < q->nr; i++) {
3628                         struct diff_filepair *p = q->queue[i];
3630                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3631                              ((p->score &&
3632                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3633                               (!p->score &&
3634                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3635                             ((p->status != DIFF_STATUS_MODIFIED) &&
3636                              strchr(filter, p->status)))
3637                                 diff_q(&outq, p);
3638                         else
3639                                 diff_free_filepair(p);
3640                 }
3641         }
3642         free(q->queue);
3643         *q = outq;
3646 /* Check whether two filespecs with the same mode and size are identical */
3647 static int diff_filespec_is_identical(struct diff_filespec *one,
3648                                       struct diff_filespec *two)
3650         if (S_ISGITLINK(one->mode))
3651                 return 0;
3652         if (diff_populate_filespec(one, 0))
3653                 return 0;
3654         if (diff_populate_filespec(two, 0))
3655                 return 0;
3656         return !memcmp(one->data, two->data, one->size);
3659 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3661         int i;
3662         struct diff_queue_struct *q = &diff_queued_diff;
3663         struct diff_queue_struct outq;
3664         outq.queue = NULL;
3665         outq.nr = outq.alloc = 0;
3667         for (i = 0; i < q->nr; i++) {
3668                 struct diff_filepair *p = q->queue[i];
3670                 /*
3671                  * 1. Entries that come from stat info dirtiness
3672                  *    always have both sides (iow, not create/delete),
3673                  *    one side of the object name is unknown, with
3674                  *    the same mode and size.  Keep the ones that
3675                  *    do not match these criteria.  They have real
3676                  *    differences.
3677                  *
3678                  * 2. At this point, the file is known to be modified,
3679                  *    with the same mode and size, and the object
3680                  *    name of one side is unknown.  Need to inspect
3681                  *    the identical contents.
3682                  */
3683                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3684                     !DIFF_FILE_VALID(p->two) ||
3685                     (p->one->sha1_valid && p->two->sha1_valid) ||
3686                     (p->one->mode != p->two->mode) ||
3687                     diff_populate_filespec(p->one, 1) ||
3688                     diff_populate_filespec(p->two, 1) ||
3689                     (p->one->size != p->two->size) ||
3690                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3691                         diff_q(&outq, p);
3692                 else {
3693                         /*
3694                          * The caller can subtract 1 from skip_stat_unmatch
3695                          * to determine how many paths were dirty only
3696                          * due to stat info mismatch.
3697                          */
3698                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3699                                 diffopt->skip_stat_unmatch++;
3700                         diff_free_filepair(p);
3701                 }
3702         }
3703         free(q->queue);
3704         *q = outq;
3707 static int diffnamecmp(const void *a_, const void *b_)
3709         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3710         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3711         const char *name_a, *name_b;
3713         name_a = a->one ? a->one->path : a->two->path;
3714         name_b = b->one ? b->one->path : b->two->path;
3715         return strcmp(name_a, name_b);
3718 void diffcore_fix_diff_index(struct diff_options *options)
3720         struct diff_queue_struct *q = &diff_queued_diff;
3721         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3724 void diffcore_std(struct diff_options *options)
3726         if (options->skip_stat_unmatch)
3727                 diffcore_skip_stat_unmatch(options);
3728         if (options->break_opt != -1)
3729                 diffcore_break(options->break_opt);
3730         if (options->detect_rename)
3731                 diffcore_rename(options);
3732         if (options->break_opt != -1)
3733                 diffcore_merge_broken();
3734         if (options->pickaxe)
3735                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3736         if (options->orderfile)
3737                 diffcore_order(options->orderfile);
3738         diff_resolve_rename_copy();
3739         diffcore_apply_filter(options->filter);
3741         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3742                 DIFF_OPT_SET(options, HAS_CHANGES);
3743         else
3744                 DIFF_OPT_CLR(options, HAS_CHANGES);
3747 int diff_result_code(struct diff_options *opt, int status)
3749         int result = 0;
3750         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3751             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3752                 return status;
3753         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3754             DIFF_OPT_TST(opt, HAS_CHANGES))
3755                 result |= 01;
3756         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3757             DIFF_OPT_TST(opt, CHECK_FAILED))
3758                 result |= 02;
3759         return result;
3762 void diff_addremove(struct diff_options *options,
3763                     int addremove, unsigned mode,
3764                     const unsigned char *sha1,
3765                     const char *concatpath, unsigned dirty_submodule)
3767         struct diff_filespec *one, *two;
3769         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3770                 return;
3772         /* This may look odd, but it is a preparation for
3773          * feeding "there are unchanged files which should
3774          * not produce diffs, but when you are doing copy
3775          * detection you would need them, so here they are"
3776          * entries to the diff-core.  They will be prefixed
3777          * with something like '=' or '*' (I haven't decided
3778          * which but should not make any difference).
3779          * Feeding the same new and old to diff_change()
3780          * also has the same effect.
3781          * Before the final output happens, they are pruned after
3782          * merged into rename/copy pairs as appropriate.
3783          */
3784         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3785                 addremove = (addremove == '+' ? '-' :
3786                              addremove == '-' ? '+' : addremove);
3788         if (options->prefix &&
3789             strncmp(concatpath, options->prefix, options->prefix_length))
3790                 return;
3792         one = alloc_filespec(concatpath);
3793         two = alloc_filespec(concatpath);
3795         if (addremove != '+')
3796                 fill_filespec(one, sha1, mode);
3797         if (addremove != '-') {
3798                 fill_filespec(two, sha1, mode);
3799                 two->dirty_submodule = dirty_submodule;
3800         }
3802         diff_queue(&diff_queued_diff, one, two);
3803         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3804                 DIFF_OPT_SET(options, HAS_CHANGES);
3807 void diff_change(struct diff_options *options,
3808                  unsigned old_mode, unsigned new_mode,
3809                  const unsigned char *old_sha1,
3810                  const unsigned char *new_sha1,
3811                  const char *concatpath,
3812                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3814         struct diff_filespec *one, *two;
3816         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3817                         && S_ISGITLINK(new_mode))
3818                 return;
3820         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3821                 unsigned tmp;
3822                 const unsigned char *tmp_c;
3823                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3824                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3825                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3826                         new_dirty_submodule = tmp;
3827         }
3829         if (options->prefix &&
3830             strncmp(concatpath, options->prefix, options->prefix_length))
3831                 return;
3833         one = alloc_filespec(concatpath);
3834         two = alloc_filespec(concatpath);
3835         fill_filespec(one, old_sha1, old_mode);
3836         fill_filespec(two, new_sha1, new_mode);
3837         one->dirty_submodule = old_dirty_submodule;
3838         two->dirty_submodule = new_dirty_submodule;
3840         diff_queue(&diff_queued_diff, one, two);
3841         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3842                 DIFF_OPT_SET(options, HAS_CHANGES);
3845 void diff_unmerge(struct diff_options *options,
3846                   const char *path,
3847                   unsigned mode, const unsigned char *sha1)
3849         struct diff_filespec *one, *two;
3851         if (options->prefix &&
3852             strncmp(path, options->prefix, options->prefix_length))
3853                 return;
3855         one = alloc_filespec(path);
3856         two = alloc_filespec(path);
3857         fill_filespec(one, sha1, mode);
3858         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3861 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3862                 size_t *outsize)
3864         struct diff_tempfile *temp;
3865         const char *argv[3];
3866         const char **arg = argv;
3867         struct child_process child;
3868         struct strbuf buf = STRBUF_INIT;
3869         int err = 0;
3871         temp = prepare_temp_file(spec->path, spec);
3872         *arg++ = pgm;
3873         *arg++ = temp->name;
3874         *arg = NULL;
3876         memset(&child, 0, sizeof(child));
3877         child.use_shell = 1;
3878         child.argv = argv;
3879         child.out = -1;
3880         if (start_command(&child)) {
3881                 remove_tempfile();
3882                 return NULL;
3883         }
3885         if (strbuf_read(&buf, child.out, 0) < 0)
3886                 err = error("error reading from textconv command '%s'", pgm);
3887         close(child.out);
3889         if (finish_command(&child) || err) {
3890                 strbuf_release(&buf);
3891                 remove_tempfile();
3892                 return NULL;
3893         }
3894         remove_tempfile();
3896         return strbuf_detach(&buf, outsize);