Code

b4a830f88fa7a7367fab505f707237ef11e67114
[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 int parse_diff_color_slot(const char *var, int ofs)
47 {
48         if (!strcasecmp(var+ofs, "plain"))
49                 return DIFF_PLAIN;
50         if (!strcasecmp(var+ofs, "meta"))
51                 return DIFF_METAINFO;
52         if (!strcasecmp(var+ofs, "frag"))
53                 return DIFF_FRAGINFO;
54         if (!strcasecmp(var+ofs, "old"))
55                 return DIFF_FILE_OLD;
56         if (!strcasecmp(var+ofs, "new"))
57                 return DIFF_FILE_NEW;
58         if (!strcasecmp(var+ofs, "commit"))
59                 return DIFF_COMMIT;
60         if (!strcasecmp(var+ofs, "whitespace"))
61                 return DIFF_WHITESPACE;
62         if (!strcasecmp(var+ofs, "func"))
63                 return DIFF_FUNCINFO;
64         return -1;
65 }
67 static int git_config_rename(const char *var, const char *value)
68 {
69         if (!value)
70                 return DIFF_DETECT_RENAME;
71         if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
72                 return  DIFF_DETECT_COPY;
73         return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
74 }
76 /*
77  * These are to give UI layer defaults.
78  * The core-level commands such as git-diff-files should
79  * never be affected by the setting of diff.renames
80  * the user happens to have in the configuration file.
81  */
82 int git_diff_ui_config(const char *var, const char *value, void *cb)
83 {
84         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
85                 diff_use_color_default = git_config_colorbool(var, value, -1);
86                 return 0;
87         }
88         if (!strcmp(var, "diff.renames")) {
89                 diff_detect_rename_default = git_config_rename(var, value);
90                 return 0;
91         }
92         if (!strcmp(var, "diff.autorefreshindex")) {
93                 diff_auto_refresh_index = git_config_bool(var, value);
94                 return 0;
95         }
96         if (!strcmp(var, "diff.mnemonicprefix")) {
97                 diff_mnemonic_prefix = git_config_bool(var, value);
98                 return 0;
99         }
100         if (!strcmp(var, "diff.external"))
101                 return git_config_string(&external_diff_cmd_cfg, var, value);
102         if (!strcmp(var, "diff.wordregex"))
103                 return git_config_string(&diff_word_regex_cfg, var, value);
105         return git_diff_basic_config(var, value, cb);
108 int git_diff_basic_config(const char *var, const char *value, void *cb)
110         if (!strcmp(var, "diff.renamelimit")) {
111                 diff_rename_limit_default = git_config_int(var, value);
112                 return 0;
113         }
115         switch (userdiff_config(var, value)) {
116                 case 0: break;
117                 case -1: return -1;
118                 default: return 0;
119         }
121         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
122                 int slot = parse_diff_color_slot(var, 11);
123                 if (slot < 0)
124                         return 0;
125                 if (!value)
126                         return config_error_nonbool(var);
127                 color_parse(value, var, diff_colors[slot]);
128                 return 0;
129         }
131         /* like GNU diff's --suppress-blank-empty option  */
132         if (!strcmp(var, "diff.suppressblankempty") ||
133                         /* for backwards compatibility */
134                         !strcmp(var, "diff.suppress-blank-empty")) {
135                 diff_suppress_blank_empty = git_config_bool(var, value);
136                 return 0;
137         }
139         return git_color_default_config(var, value, cb);
142 static char *quote_two(const char *one, const char *two)
144         int need_one = quote_c_style(one, NULL, NULL, 1);
145         int need_two = quote_c_style(two, NULL, NULL, 1);
146         struct strbuf res = STRBUF_INIT;
148         if (need_one + need_two) {
149                 strbuf_addch(&res, '"');
150                 quote_c_style(one, &res, NULL, 1);
151                 quote_c_style(two, &res, NULL, 1);
152                 strbuf_addch(&res, '"');
153         } else {
154                 strbuf_addstr(&res, one);
155                 strbuf_addstr(&res, two);
156         }
157         return strbuf_detach(&res, NULL);
160 static const char *external_diff(void)
162         static const char *external_diff_cmd = NULL;
163         static int done_preparing = 0;
165         if (done_preparing)
166                 return external_diff_cmd;
167         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
168         if (!external_diff_cmd)
169                 external_diff_cmd = external_diff_cmd_cfg;
170         done_preparing = 1;
171         return external_diff_cmd;
174 static struct diff_tempfile {
175         const char *name; /* filename external diff should read from */
176         char hex[41];
177         char mode[10];
178         char tmp_path[PATH_MAX];
179 } diff_temp[2];
181 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
183 struct emit_callback {
184         int color_diff;
185         unsigned ws_rule;
186         int blank_at_eof_in_preimage;
187         int blank_at_eof_in_postimage;
188         int lno_in_preimage;
189         int lno_in_postimage;
190         sane_truncate_fn truncate;
191         const char **label_path;
192         struct diff_words_data *diff_words;
193         int *found_changesp;
194         FILE *file;
195         struct strbuf *header;
196 };
198 static int count_lines(const char *data, int size)
200         int count, ch, completely_empty = 1, nl_just_seen = 0;
201         count = 0;
202         while (0 < size--) {
203                 ch = *data++;
204                 if (ch == '\n') {
205                         count++;
206                         nl_just_seen = 1;
207                         completely_empty = 0;
208                 }
209                 else {
210                         nl_just_seen = 0;
211                         completely_empty = 0;
212                 }
213         }
214         if (completely_empty)
215                 return 0;
216         if (!nl_just_seen)
217                 count++; /* no trailing newline */
218         return count;
221 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
223         if (!DIFF_FILE_VALID(one)) {
224                 mf->ptr = (char *)""; /* does not matter */
225                 mf->size = 0;
226                 return 0;
227         }
228         else if (diff_populate_filespec(one, 0))
229                 return -1;
231         mf->ptr = one->data;
232         mf->size = one->size;
233         return 0;
236 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
238         char *ptr = mf->ptr;
239         long size = mf->size;
240         int cnt = 0;
242         if (!size)
243                 return cnt;
244         ptr += size - 1; /* pointing at the very end */
245         if (*ptr != '\n')
246                 ; /* incomplete line */
247         else
248                 ptr--; /* skip the last LF */
249         while (mf->ptr < ptr) {
250                 char *prev_eol;
251                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
252                         if (*prev_eol == '\n')
253                                 break;
254                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
255                         break;
256                 cnt++;
257                 ptr = prev_eol - 1;
258         }
259         return cnt;
262 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
263                                struct emit_callback *ecbdata)
265         int l1, l2, at;
266         unsigned ws_rule = ecbdata->ws_rule;
267         l1 = count_trailing_blank(mf1, ws_rule);
268         l2 = count_trailing_blank(mf2, ws_rule);
269         if (l2 <= l1) {
270                 ecbdata->blank_at_eof_in_preimage = 0;
271                 ecbdata->blank_at_eof_in_postimage = 0;
272                 return;
273         }
274         at = count_lines(mf1->ptr, mf1->size);
275         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
277         at = count_lines(mf2->ptr, mf2->size);
278         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
281 static void emit_line_0(FILE *file, const char *set, const char *reset,
282                         int first, const char *line, int len)
284         int has_trailing_newline, has_trailing_carriage_return;
285         int nofirst;
287         if (len == 0) {
288                 has_trailing_newline = (first == '\n');
289                 has_trailing_carriage_return = (!has_trailing_newline &&
290                                                 (first == '\r'));
291                 nofirst = has_trailing_newline || has_trailing_carriage_return;
292         } else {
293                 has_trailing_newline = (len > 0 && line[len-1] == '\n');
294                 if (has_trailing_newline)
295                         len--;
296                 has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
297                 if (has_trailing_carriage_return)
298                         len--;
299                 nofirst = 0;
300         }
302         if (len || !nofirst) {
303                 fputs(set, file);
304                 if (!nofirst)
305                         fputc(first, file);
306                 fwrite(line, len, 1, file);
307                 fputs(reset, file);
308         }
309         if (has_trailing_carriage_return)
310                 fputc('\r', file);
311         if (has_trailing_newline)
312                 fputc('\n', file);
315 static void emit_line(FILE *file, const char *set, const char *reset,
316                       const char *line, int len)
318         emit_line_0(file, set, reset, line[0], line+1, len-1);
321 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
323         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
324               ecbdata->blank_at_eof_in_preimage &&
325               ecbdata->blank_at_eof_in_postimage &&
326               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
327               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
328                 return 0;
329         return ws_blank_line(line, len, ecbdata->ws_rule);
332 static void emit_add_line(const char *reset,
333                           struct emit_callback *ecbdata,
334                           const char *line, int len)
336         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
337         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
339         if (!*ws)
340                 emit_line_0(ecbdata->file, set, reset, '+', line, len);
341         else if (new_blank_line_at_eof(ecbdata, line, len))
342                 /* Blank line at EOF - paint '+' as well */
343                 emit_line_0(ecbdata->file, ws, reset, '+', line, len);
344         else {
345                 /* Emit just the prefix, then the rest. */
346                 emit_line_0(ecbdata->file, set, reset, '+', "", 0);
347                 ws_check_emit(line, len, ecbdata->ws_rule,
348                               ecbdata->file, set, reset, ws);
349         }
352 static void emit_hunk_header(struct emit_callback *ecbdata,
353                              const char *line, int len)
355         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
356         const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
357         const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
358         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
359         static const char atat[2] = { '@', '@' };
360         const char *cp, *ep;
362         /*
363          * As a hunk header must begin with "@@ -<old>, +<new> @@",
364          * it always is at least 10 bytes long.
365          */
366         if (len < 10 ||
367             memcmp(line, atat, 2) ||
368             !(ep = memmem(line + 2, len - 2, atat, 2))) {
369                 emit_line(ecbdata->file, plain, reset, line, len);
370                 return;
371         }
372         ep += 2; /* skip over @@ */
374         /* The hunk header in fraginfo color */
375         emit_line(ecbdata->file, frag, reset, line, ep - line);
377         /* blank before the func header */
378         for (cp = ep; ep - line < len; ep++)
379                 if (*ep != ' ' && *ep != '\t')
380                         break;
381         if (ep != cp)
382                 emit_line(ecbdata->file, plain, reset, cp, ep - cp);
384         if (ep < line + len)
385                 emit_line(ecbdata->file, func, reset, ep, line + len - ep);
388 static struct diff_tempfile *claim_diff_tempfile(void) {
389         int i;
390         for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
391                 if (!diff_temp[i].name)
392                         return diff_temp + i;
393         die("BUG: diff is failing to clean up its tempfiles");
396 static int remove_tempfile_installed;
398 static void remove_tempfile(void)
400         int i;
401         for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
402                 if (diff_temp[i].name == diff_temp[i].tmp_path)
403                         unlink_or_warn(diff_temp[i].name);
404                 diff_temp[i].name = NULL;
405         }
408 static void remove_tempfile_on_signal(int signo)
410         remove_tempfile();
411         sigchain_pop(signo);
412         raise(signo);
415 static void print_line_count(FILE *file, int count)
417         switch (count) {
418         case 0:
419                 fprintf(file, "0,0");
420                 break;
421         case 1:
422                 fprintf(file, "1");
423                 break;
424         default:
425                 fprintf(file, "1,%d", count);
426                 break;
427         }
430 static void emit_rewrite_lines(struct emit_callback *ecb,
431                                int prefix, const char *data, int size)
433         const char *endp = NULL;
434         static const char *nneof = " No newline at end of file\n";
435         const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
436         const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
438         while (0 < size) {
439                 int len;
441                 endp = memchr(data, '\n', size);
442                 len = endp ? (endp - data + 1) : size;
443                 if (prefix != '+') {
444                         ecb->lno_in_preimage++;
445                         emit_line_0(ecb->file, old, reset, '-',
446                                     data, len);
447                 } else {
448                         ecb->lno_in_postimage++;
449                         emit_add_line(reset, ecb, data, len);
450                 }
451                 size -= len;
452                 data += len;
453         }
454         if (!endp) {
455                 const char *plain = diff_get_color(ecb->color_diff,
456                                                    DIFF_PLAIN);
457                 emit_line_0(ecb->file, plain, reset, '\\',
458                             nneof, strlen(nneof));
459         }
462 static void emit_rewrite_diff(const char *name_a,
463                               const char *name_b,
464                               struct diff_filespec *one,
465                               struct diff_filespec *two,
466                               struct userdiff_driver *textconv_one,
467                               struct userdiff_driver *textconv_two,
468                               struct diff_options *o)
470         int lc_a, lc_b;
471         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
472         const char *name_a_tab, *name_b_tab;
473         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
474         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
475         const char *reset = diff_get_color(color_diff, DIFF_RESET);
476         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
477         const char *a_prefix, *b_prefix;
478         char *data_one, *data_two;
479         size_t size_one, size_two;
480         struct emit_callback ecbdata;
482         if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
483                 a_prefix = o->b_prefix;
484                 b_prefix = o->a_prefix;
485         } else {
486                 a_prefix = o->a_prefix;
487                 b_prefix = o->b_prefix;
488         }
490         name_a += (*name_a == '/');
491         name_b += (*name_b == '/');
492         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
493         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
495         strbuf_reset(&a_name);
496         strbuf_reset(&b_name);
497         quote_two_c_style(&a_name, a_prefix, name_a, 0);
498         quote_two_c_style(&b_name, b_prefix, name_b, 0);
500         size_one = fill_textconv(textconv_one, one, &data_one);
501         size_two = fill_textconv(textconv_two, two, &data_two);
503         memset(&ecbdata, 0, sizeof(ecbdata));
504         ecbdata.color_diff = color_diff;
505         ecbdata.found_changesp = &o->found_changes;
506         ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
507         ecbdata.file = o->file;
508         if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
509                 mmfile_t mf1, mf2;
510                 mf1.ptr = (char *)data_one;
511                 mf2.ptr = (char *)data_two;
512                 mf1.size = size_one;
513                 mf2.size = size_two;
514                 check_blank_at_eof(&mf1, &mf2, &ecbdata);
515         }
516         ecbdata.lno_in_preimage = 1;
517         ecbdata.lno_in_postimage = 1;
519         lc_a = count_lines(data_one, size_one);
520         lc_b = count_lines(data_two, size_two);
521         fprintf(o->file,
522                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
523                 metainfo, a_name.buf, name_a_tab, reset,
524                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
525         print_line_count(o->file, lc_a);
526         fprintf(o->file, " +");
527         print_line_count(o->file, lc_b);
528         fprintf(o->file, " @@%s\n", reset);
529         if (lc_a)
530                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
531         if (lc_b)
532                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
533         if (textconv_one)
534                 free((char *)data_one);
535         if (textconv_two)
536                 free((char *)data_two);
539 struct diff_words_buffer {
540         mmfile_t text;
541         long alloc;
542         struct diff_words_orig {
543                 const char *begin, *end;
544         } *orig;
545         int orig_nr, orig_alloc;
546 };
548 static void diff_words_append(char *line, unsigned long len,
549                 struct diff_words_buffer *buffer)
551         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
552         line++;
553         len--;
554         memcpy(buffer->text.ptr + buffer->text.size, line, len);
555         buffer->text.size += len;
556         buffer->text.ptr[buffer->text.size] = '\0';
559 struct diff_words_style_elem
561         const char *prefix;
562         const char *suffix;
563         const char *color; /* NULL; filled in by the setup code if
564                             * color is enabled */
565 };
567 struct diff_words_style
569         enum diff_words_type type;
570         struct diff_words_style_elem new, old, ctx;
571         const char *newline;
572 };
574 struct diff_words_style diff_words_styles[] = {
575         { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
576         { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
577         { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
578 };
580 struct diff_words_data {
581         struct diff_words_buffer minus, plus;
582         const char *current_plus;
583         FILE *file;
584         regex_t *word_regex;
585         enum diff_words_type type;
586         struct diff_words_style *style;
587 };
589 static int fn_out_diff_words_write_helper(FILE *fp,
590                                           struct diff_words_style_elem *st_el,
591                                           const char *newline,
592                                           size_t count, const char *buf)
594         while (count) {
595                 char *p = memchr(buf, '\n', count);
596                 if (p != buf) {
597                         if (st_el->color && fputs(st_el->color, fp) < 0)
598                                 return -1;
599                         if (fputs(st_el->prefix, fp) < 0 ||
600                             fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
601                             fputs(st_el->suffix, fp) < 0)
602                                 return -1;
603                         if (st_el->color && *st_el->color
604                             && fputs(GIT_COLOR_RESET, fp) < 0)
605                                 return -1;
606                 }
607                 if (!p)
608                         return 0;
609                 if (fputs(newline, fp) < 0)
610                         return -1;
611                 count -= p + 1 - buf;
612                 buf = p + 1;
613         }
614         return 0;
617 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
619         struct diff_words_data *diff_words = priv;
620         struct diff_words_style *style = diff_words->style;
621         int minus_first, minus_len, plus_first, plus_len;
622         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
624         if (line[0] != '@' || parse_hunk_header(line, len,
625                         &minus_first, &minus_len, &plus_first, &plus_len))
626                 return;
628         /* POSIX requires that first be decremented by one if len == 0... */
629         if (minus_len) {
630                 minus_begin = diff_words->minus.orig[minus_first].begin;
631                 minus_end =
632                         diff_words->minus.orig[minus_first + minus_len - 1].end;
633         } else
634                 minus_begin = minus_end =
635                         diff_words->minus.orig[minus_first].end;
637         if (plus_len) {
638                 plus_begin = diff_words->plus.orig[plus_first].begin;
639                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
640         } else
641                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
643         if (diff_words->current_plus != plus_begin)
644                 fn_out_diff_words_write_helper(diff_words->file,
645                                 &style->ctx, style->newline,
646                                 plus_begin - diff_words->current_plus,
647                                 diff_words->current_plus);
648         if (minus_begin != minus_end)
649                 fn_out_diff_words_write_helper(diff_words->file,
650                                 &style->old, style->newline,
651                                 minus_end - minus_begin, minus_begin);
652         if (plus_begin != plus_end)
653                 fn_out_diff_words_write_helper(diff_words->file,
654                                 &style->new, style->newline,
655                                 plus_end - plus_begin, plus_begin);
657         diff_words->current_plus = plus_end;
660 /* This function starts looking at *begin, and returns 0 iff a word was found. */
661 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
662                 int *begin, int *end)
664         if (word_regex && *begin < buffer->size) {
665                 regmatch_t match[1];
666                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
667                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
668                                         '\n', match[0].rm_eo - match[0].rm_so);
669                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
670                         *begin += match[0].rm_so;
671                         return *begin >= *end;
672                 }
673                 return -1;
674         }
676         /* find the next word */
677         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
678                 (*begin)++;
679         if (*begin >= buffer->size)
680                 return -1;
682         /* find the end of the word */
683         *end = *begin + 1;
684         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
685                 (*end)++;
687         return 0;
690 /*
691  * This function splits the words in buffer->text, stores the list with
692  * newline separator into out, and saves the offsets of the original words
693  * in buffer->orig.
694  */
695 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
696                 regex_t *word_regex)
698         int i, j;
699         long alloc = 0;
701         out->size = 0;
702         out->ptr = NULL;
704         /* fake an empty "0th" word */
705         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
706         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
707         buffer->orig_nr = 1;
709         for (i = 0; i < buffer->text.size; i++) {
710                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
711                         return;
713                 /* store original boundaries */
714                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
715                                 buffer->orig_alloc);
716                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
717                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
718                 buffer->orig_nr++;
720                 /* store one word */
721                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
722                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
723                 out->ptr[out->size + j - i] = '\n';
724                 out->size += j - i + 1;
726                 i = j - 1;
727         }
730 /* this executes the word diff on the accumulated buffers */
731 static void diff_words_show(struct diff_words_data *diff_words)
733         xpparam_t xpp;
734         xdemitconf_t xecfg;
735         mmfile_t minus, plus;
736         struct diff_words_style *style = diff_words->style;
738         /* special case: only removal */
739         if (!diff_words->plus.text.size) {
740                 fn_out_diff_words_write_helper(diff_words->file,
741                         &style->old, style->newline,
742                         diff_words->minus.text.size, diff_words->minus.text.ptr);
743                 diff_words->minus.text.size = 0;
744                 return;
745         }
747         diff_words->current_plus = diff_words->plus.text.ptr;
749         memset(&xpp, 0, sizeof(xpp));
750         memset(&xecfg, 0, sizeof(xecfg));
751         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
752         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
753         xpp.flags = XDF_NEED_MINIMAL;
754         /* as only the hunk header will be parsed, we need a 0-context */
755         xecfg.ctxlen = 0;
756         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
757                       &xpp, &xecfg);
758         free(minus.ptr);
759         free(plus.ptr);
760         if (diff_words->current_plus != diff_words->plus.text.ptr +
761                         diff_words->plus.text.size)
762                 fn_out_diff_words_write_helper(diff_words->file,
763                         &style->ctx, style->newline,
764                         diff_words->plus.text.ptr + diff_words->plus.text.size
765                         - diff_words->current_plus, diff_words->current_plus);
766         diff_words->minus.text.size = diff_words->plus.text.size = 0;
769 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
770 static void diff_words_flush(struct emit_callback *ecbdata)
772         if (ecbdata->diff_words->minus.text.size ||
773             ecbdata->diff_words->plus.text.size)
774                 diff_words_show(ecbdata->diff_words);
777 static void free_diff_words_data(struct emit_callback *ecbdata)
779         if (ecbdata->diff_words) {
780                 diff_words_flush(ecbdata);
781                 free (ecbdata->diff_words->minus.text.ptr);
782                 free (ecbdata->diff_words->minus.orig);
783                 free (ecbdata->diff_words->plus.text.ptr);
784                 free (ecbdata->diff_words->plus.orig);
785                 free(ecbdata->diff_words->word_regex);
786                 free(ecbdata->diff_words);
787                 ecbdata->diff_words = NULL;
788         }
791 const char *diff_get_color(int diff_use_color, enum color_diff ix)
793         if (diff_use_color)
794                 return diff_colors[ix];
795         return "";
798 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
800         const char *cp;
801         unsigned long allot;
802         size_t l = len;
804         if (ecb->truncate)
805                 return ecb->truncate(line, len);
806         cp = line;
807         allot = l;
808         while (0 < l) {
809                 (void) utf8_width(&cp, &l);
810                 if (!cp)
811                         break; /* truncated in the middle? */
812         }
813         return allot - l;
816 static void find_lno(const char *line, struct emit_callback *ecbdata)
818         const char *p;
819         ecbdata->lno_in_preimage = 0;
820         ecbdata->lno_in_postimage = 0;
821         p = strchr(line, '-');
822         if (!p)
823                 return; /* cannot happen */
824         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
825         p = strchr(p, '+');
826         if (!p)
827                 return; /* cannot happen */
828         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
831 static void fn_out_consume(void *priv, char *line, unsigned long len)
833         struct emit_callback *ecbdata = priv;
834         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
835         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
836         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
838         if (ecbdata->header) {
839                 fprintf(ecbdata->file, "%s", ecbdata->header->buf);
840                 strbuf_reset(ecbdata->header);
841                 ecbdata->header = NULL;
842         }
843         *(ecbdata->found_changesp) = 1;
845         if (ecbdata->label_path[0]) {
846                 const char *name_a_tab, *name_b_tab;
848                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
849                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
851                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
852                         meta, ecbdata->label_path[0], reset, name_a_tab);
853                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
854                         meta, ecbdata->label_path[1], reset, name_b_tab);
855                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
856         }
858         if (diff_suppress_blank_empty
859             && len == 2 && line[0] == ' ' && line[1] == '\n') {
860                 line[0] = '\n';
861                 len = 1;
862         }
864         if (line[0] == '@') {
865                 if (ecbdata->diff_words)
866                         diff_words_flush(ecbdata);
867                 len = sane_truncate_line(ecbdata, line, len);
868                 find_lno(line, ecbdata);
869                 emit_hunk_header(ecbdata, line, len);
870                 if (line[len-1] != '\n')
871                         putc('\n', ecbdata->file);
872                 return;
873         }
875         if (len < 1) {
876                 emit_line(ecbdata->file, reset, reset, line, len);
877                 if (ecbdata->diff_words
878                     && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
879                         fputs("~\n", ecbdata->file);
880                 return;
881         }
883         if (ecbdata->diff_words) {
884                 if (line[0] == '-') {
885                         diff_words_append(line, len,
886                                           &ecbdata->diff_words->minus);
887                         return;
888                 } else if (line[0] == '+') {
889                         diff_words_append(line, len,
890                                           &ecbdata->diff_words->plus);
891                         return;
892                 }
893                 diff_words_flush(ecbdata);
894                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
895                         emit_line(ecbdata->file, plain, reset, line, len);
896                         fputs("~\n", ecbdata->file);
897                 } else {
898                         /* don't print the prefix character */
899                         emit_line(ecbdata->file, plain, reset, line+1, len-1);
900                 }
901                 return;
902         }
904         if (line[0] != '+') {
905                 const char *color =
906                         diff_get_color(ecbdata->color_diff,
907                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
908                 ecbdata->lno_in_preimage++;
909                 if (line[0] == ' ')
910                         ecbdata->lno_in_postimage++;
911                 emit_line(ecbdata->file, color, reset, line, len);
912         } else {
913                 ecbdata->lno_in_postimage++;
914                 emit_add_line(reset, ecbdata, line + 1, len - 1);
915         }
918 static char *pprint_rename(const char *a, const char *b)
920         const char *old = a;
921         const char *new = b;
922         struct strbuf name = STRBUF_INIT;
923         int pfx_length, sfx_length;
924         int len_a = strlen(a);
925         int len_b = strlen(b);
926         int a_midlen, b_midlen;
927         int qlen_a = quote_c_style(a, NULL, NULL, 0);
928         int qlen_b = quote_c_style(b, NULL, NULL, 0);
930         if (qlen_a || qlen_b) {
931                 quote_c_style(a, &name, NULL, 0);
932                 strbuf_addstr(&name, " => ");
933                 quote_c_style(b, &name, NULL, 0);
934                 return strbuf_detach(&name, NULL);
935         }
937         /* Find common prefix */
938         pfx_length = 0;
939         while (*old && *new && *old == *new) {
940                 if (*old == '/')
941                         pfx_length = old - a + 1;
942                 old++;
943                 new++;
944         }
946         /* Find common suffix */
947         old = a + len_a;
948         new = b + len_b;
949         sfx_length = 0;
950         while (a <= old && b <= new && *old == *new) {
951                 if (*old == '/')
952                         sfx_length = len_a - (old - a);
953                 old--;
954                 new--;
955         }
957         /*
958          * pfx{mid-a => mid-b}sfx
959          * {pfx-a => pfx-b}sfx
960          * pfx{sfx-a => sfx-b}
961          * name-a => name-b
962          */
963         a_midlen = len_a - pfx_length - sfx_length;
964         b_midlen = len_b - pfx_length - sfx_length;
965         if (a_midlen < 0)
966                 a_midlen = 0;
967         if (b_midlen < 0)
968                 b_midlen = 0;
970         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
971         if (pfx_length + sfx_length) {
972                 strbuf_add(&name, a, pfx_length);
973                 strbuf_addch(&name, '{');
974         }
975         strbuf_add(&name, a + pfx_length, a_midlen);
976         strbuf_addstr(&name, " => ");
977         strbuf_add(&name, b + pfx_length, b_midlen);
978         if (pfx_length + sfx_length) {
979                 strbuf_addch(&name, '}');
980                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
981         }
982         return strbuf_detach(&name, NULL);
985 struct diffstat_t {
986         int nr;
987         int alloc;
988         struct diffstat_file {
989                 char *from_name;
990                 char *name;
991                 char *print_name;
992                 unsigned is_unmerged:1;
993                 unsigned is_binary:1;
994                 unsigned is_renamed:1;
995                 uintmax_t added, deleted;
996         } **files;
997 };
999 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1000                                           const char *name_a,
1001                                           const char *name_b)
1003         struct diffstat_file *x;
1004         x = xcalloc(sizeof (*x), 1);
1005         if (diffstat->nr == diffstat->alloc) {
1006                 diffstat->alloc = alloc_nr(diffstat->alloc);
1007                 diffstat->files = xrealloc(diffstat->files,
1008                                 diffstat->alloc * sizeof(x));
1009         }
1010         diffstat->files[diffstat->nr++] = x;
1011         if (name_b) {
1012                 x->from_name = xstrdup(name_a);
1013                 x->name = xstrdup(name_b);
1014                 x->is_renamed = 1;
1015         }
1016         else {
1017                 x->from_name = NULL;
1018                 x->name = xstrdup(name_a);
1019         }
1020         return x;
1023 static void diffstat_consume(void *priv, char *line, unsigned long len)
1025         struct diffstat_t *diffstat = priv;
1026         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1028         if (line[0] == '+')
1029                 x->added++;
1030         else if (line[0] == '-')
1031                 x->deleted++;
1034 const char mime_boundary_leader[] = "------------";
1036 static int scale_linear(int it, int width, int max_change)
1038         /*
1039          * make sure that at least one '-' is printed if there were deletions,
1040          * and likewise for '+'.
1041          */
1042         if (max_change < 2)
1043                 return it;
1044         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1047 static void show_name(FILE *file,
1048                       const char *prefix, const char *name, int len)
1050         fprintf(file, " %s%-*s |", prefix, len, name);
1053 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1055         if (cnt <= 0)
1056                 return;
1057         fprintf(file, "%s", set);
1058         while (cnt--)
1059                 putc(ch, file);
1060         fprintf(file, "%s", reset);
1063 static void fill_print_name(struct diffstat_file *file)
1065         char *pname;
1067         if (file->print_name)
1068                 return;
1070         if (!file->is_renamed) {
1071                 struct strbuf buf = STRBUF_INIT;
1072                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1073                         pname = strbuf_detach(&buf, NULL);
1074                 } else {
1075                         pname = file->name;
1076                         strbuf_release(&buf);
1077                 }
1078         } else {
1079                 pname = pprint_rename(file->from_name, file->name);
1080         }
1081         file->print_name = pname;
1084 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1086         int i, len, add, del, adds = 0, dels = 0;
1087         uintmax_t max_change = 0, max_len = 0;
1088         int total_files = data->nr;
1089         int width, name_width;
1090         const char *reset, *set, *add_c, *del_c;
1092         if (data->nr == 0)
1093                 return;
1095         width = options->stat_width ? options->stat_width : 80;
1096         name_width = options->stat_name_width ? options->stat_name_width : 50;
1098         /* Sanity: give at least 5 columns to the graph,
1099          * but leave at least 10 columns for the name.
1100          */
1101         if (width < 25)
1102                 width = 25;
1103         if (name_width < 10)
1104                 name_width = 10;
1105         else if (width < name_width + 15)
1106                 name_width = width - 15;
1108         /* Find the longest filename and max number of changes */
1109         reset = diff_get_color_opt(options, DIFF_RESET);
1110         set   = diff_get_color_opt(options, DIFF_PLAIN);
1111         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1112         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1114         for (i = 0; i < data->nr; i++) {
1115                 struct diffstat_file *file = data->files[i];
1116                 uintmax_t change = file->added + file->deleted;
1117                 fill_print_name(file);
1118                 len = strlen(file->print_name);
1119                 if (max_len < len)
1120                         max_len = len;
1122                 if (file->is_binary || file->is_unmerged)
1123                         continue;
1124                 if (max_change < change)
1125                         max_change = change;
1126         }
1128         /* Compute the width of the graph part;
1129          * 10 is for one blank at the beginning of the line plus
1130          * " | count " between the name and the graph.
1131          *
1132          * From here on, name_width is the width of the name area,
1133          * and width is the width of the graph area.
1134          */
1135         name_width = (name_width < max_len) ? name_width : max_len;
1136         if (width < (name_width + 10) + max_change)
1137                 width = width - (name_width + 10);
1138         else
1139                 width = max_change;
1141         for (i = 0; i < data->nr; i++) {
1142                 const char *prefix = "";
1143                 char *name = data->files[i]->print_name;
1144                 uintmax_t added = data->files[i]->added;
1145                 uintmax_t deleted = data->files[i]->deleted;
1146                 int name_len;
1148                 /*
1149                  * "scale" the filename
1150                  */
1151                 len = name_width;
1152                 name_len = strlen(name);
1153                 if (name_width < name_len) {
1154                         char *slash;
1155                         prefix = "...";
1156                         len -= 3;
1157                         name += name_len - len;
1158                         slash = strchr(name, '/');
1159                         if (slash)
1160                                 name = slash;
1161                 }
1163                 if (data->files[i]->is_binary) {
1164                         show_name(options->file, prefix, name, len);
1165                         fprintf(options->file, "  Bin ");
1166                         fprintf(options->file, "%s%"PRIuMAX"%s",
1167                                 del_c, deleted, reset);
1168                         fprintf(options->file, " -> ");
1169                         fprintf(options->file, "%s%"PRIuMAX"%s",
1170                                 add_c, added, reset);
1171                         fprintf(options->file, " bytes");
1172                         fprintf(options->file, "\n");
1173                         continue;
1174                 }
1175                 else if (data->files[i]->is_unmerged) {
1176                         show_name(options->file, prefix, name, len);
1177                         fprintf(options->file, "  Unmerged\n");
1178                         continue;
1179                 }
1180                 else if (!data->files[i]->is_renamed &&
1181                          (added + deleted == 0)) {
1182                         total_files--;
1183                         continue;
1184                 }
1186                 /*
1187                  * scale the add/delete
1188                  */
1189                 add = added;
1190                 del = deleted;
1191                 adds += add;
1192                 dels += del;
1194                 if (width <= max_change) {
1195                         add = scale_linear(add, width, max_change);
1196                         del = scale_linear(del, width, max_change);
1197                 }
1198                 show_name(options->file, prefix, name, len);
1199                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1200                                 added + deleted ? " " : "");
1201                 show_graph(options->file, '+', add, add_c, reset);
1202                 show_graph(options->file, '-', del, del_c, reset);
1203                 fprintf(options->file, "\n");
1204         }
1205         fprintf(options->file,
1206                " %d files changed, %d insertions(+), %d deletions(-)\n",
1207                total_files, adds, dels);
1210 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1212         int i, adds = 0, dels = 0, total_files = data->nr;
1214         if (data->nr == 0)
1215                 return;
1217         for (i = 0; i < data->nr; i++) {
1218                 if (!data->files[i]->is_binary &&
1219                     !data->files[i]->is_unmerged) {
1220                         int added = data->files[i]->added;
1221                         int deleted= data->files[i]->deleted;
1222                         if (!data->files[i]->is_renamed &&
1223                             (added + deleted == 0)) {
1224                                 total_files--;
1225                         } else {
1226                                 adds += added;
1227                                 dels += deleted;
1228                         }
1229                 }
1230         }
1231         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1232                total_files, adds, dels);
1235 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1237         int i;
1239         if (data->nr == 0)
1240                 return;
1242         for (i = 0; i < data->nr; i++) {
1243                 struct diffstat_file *file = data->files[i];
1245                 if (file->is_binary)
1246                         fprintf(options->file, "-\t-\t");
1247                 else
1248                         fprintf(options->file,
1249                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1250                                 file->added, file->deleted);
1251                 if (options->line_termination) {
1252                         fill_print_name(file);
1253                         if (!file->is_renamed)
1254                                 write_name_quoted(file->name, options->file,
1255                                                   options->line_termination);
1256                         else {
1257                                 fputs(file->print_name, options->file);
1258                                 putc(options->line_termination, options->file);
1259                         }
1260                 } else {
1261                         if (file->is_renamed) {
1262                                 putc('\0', options->file);
1263                                 write_name_quoted(file->from_name, options->file, '\0');
1264                         }
1265                         write_name_quoted(file->name, options->file, '\0');
1266                 }
1267         }
1270 struct dirstat_file {
1271         const char *name;
1272         unsigned long changed;
1273 };
1275 struct dirstat_dir {
1276         struct dirstat_file *files;
1277         int alloc, nr, percent, cumulative;
1278 };
1280 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1282         unsigned long this_dir = 0;
1283         unsigned int sources = 0;
1285         while (dir->nr) {
1286                 struct dirstat_file *f = dir->files;
1287                 int namelen = strlen(f->name);
1288                 unsigned long this;
1289                 char *slash;
1291                 if (namelen < baselen)
1292                         break;
1293                 if (memcmp(f->name, base, baselen))
1294                         break;
1295                 slash = strchr(f->name + baselen, '/');
1296                 if (slash) {
1297                         int newbaselen = slash + 1 - f->name;
1298                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1299                         sources++;
1300                 } else {
1301                         this = f->changed;
1302                         dir->files++;
1303                         dir->nr--;
1304                         sources += 2;
1305                 }
1306                 this_dir += this;
1307         }
1309         /*
1310          * We don't report dirstat's for
1311          *  - the top level
1312          *  - or cases where everything came from a single directory
1313          *    under this directory (sources == 1).
1314          */
1315         if (baselen && sources != 1) {
1316                 int permille = this_dir * 1000 / changed;
1317                 if (permille) {
1318                         int percent = permille / 10;
1319                         if (percent >= dir->percent) {
1320                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1321                                 if (!dir->cumulative)
1322                                         return 0;
1323                         }
1324                 }
1325         }
1326         return this_dir;
1329 static int dirstat_compare(const void *_a, const void *_b)
1331         const struct dirstat_file *a = _a;
1332         const struct dirstat_file *b = _b;
1333         return strcmp(a->name, b->name);
1336 static void show_dirstat(struct diff_options *options)
1338         int i;
1339         unsigned long changed;
1340         struct dirstat_dir dir;
1341         struct diff_queue_struct *q = &diff_queued_diff;
1343         dir.files = NULL;
1344         dir.alloc = 0;
1345         dir.nr = 0;
1346         dir.percent = options->dirstat_percent;
1347         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1349         changed = 0;
1350         for (i = 0; i < q->nr; i++) {
1351                 struct diff_filepair *p = q->queue[i];
1352                 const char *name;
1353                 unsigned long copied, added, damage;
1355                 name = p->one->path ? p->one->path : p->two->path;
1357                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1358                         diff_populate_filespec(p->one, 0);
1359                         diff_populate_filespec(p->two, 0);
1360                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1361                                                &copied, &added);
1362                         diff_free_filespec_data(p->one);
1363                         diff_free_filespec_data(p->two);
1364                 } else if (DIFF_FILE_VALID(p->one)) {
1365                         diff_populate_filespec(p->one, 1);
1366                         copied = added = 0;
1367                         diff_free_filespec_data(p->one);
1368                 } else if (DIFF_FILE_VALID(p->two)) {
1369                         diff_populate_filespec(p->two, 1);
1370                         copied = 0;
1371                         added = p->two->size;
1372                         diff_free_filespec_data(p->two);
1373                 } else
1374                         continue;
1376                 /*
1377                  * Original minus copied is the removed material,
1378                  * added is the new material.  They are both damages
1379                  * made to the preimage. In --dirstat-by-file mode, count
1380                  * damaged files, not damaged lines. This is done by
1381                  * counting only a single damaged line per file.
1382                  */
1383                 damage = (p->one->size - copied) + added;
1384                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1385                         damage = 1;
1387                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1388                 dir.files[dir.nr].name = name;
1389                 dir.files[dir.nr].changed = damage;
1390                 changed += damage;
1391                 dir.nr++;
1392         }
1394         /* This can happen even with many files, if everything was renames */
1395         if (!changed)
1396                 return;
1398         /* Show all directories with more than x% of the changes */
1399         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1400         gather_dirstat(options->file, &dir, changed, "", 0);
1403 static void free_diffstat_info(struct diffstat_t *diffstat)
1405         int i;
1406         for (i = 0; i < diffstat->nr; i++) {
1407                 struct diffstat_file *f = diffstat->files[i];
1408                 if (f->name != f->print_name)
1409                         free(f->print_name);
1410                 free(f->name);
1411                 free(f->from_name);
1412                 free(f);
1413         }
1414         free(diffstat->files);
1417 struct checkdiff_t {
1418         const char *filename;
1419         int lineno;
1420         int conflict_marker_size;
1421         struct diff_options *o;
1422         unsigned ws_rule;
1423         unsigned status;
1424 };
1426 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1428         char firstchar;
1429         int cnt;
1431         if (len < marker_size + 1)
1432                 return 0;
1433         firstchar = line[0];
1434         switch (firstchar) {
1435         case '=': case '>': case '<': case '|':
1436                 break;
1437         default:
1438                 return 0;
1439         }
1440         for (cnt = 1; cnt < marker_size; cnt++)
1441                 if (line[cnt] != firstchar)
1442                         return 0;
1443         /* line[1] thru line[marker_size-1] are same as firstchar */
1444         if (len < marker_size + 1 || !isspace(line[marker_size]))
1445                 return 0;
1446         return 1;
1449 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1451         struct checkdiff_t *data = priv;
1452         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1453         int marker_size = data->conflict_marker_size;
1454         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1455         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1456         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1457         char *err;
1459         if (line[0] == '+') {
1460                 unsigned bad;
1461                 data->lineno++;
1462                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1463                         data->status |= 1;
1464                         fprintf(data->o->file,
1465                                 "%s:%d: leftover conflict marker\n",
1466                                 data->filename, data->lineno);
1467                 }
1468                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1469                 if (!bad)
1470                         return;
1471                 data->status |= bad;
1472                 err = whitespace_error_string(bad);
1473                 fprintf(data->o->file, "%s:%d: %s.\n",
1474                         data->filename, data->lineno, err);
1475                 free(err);
1476                 emit_line(data->o->file, set, reset, line, 1);
1477                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1478                               data->o->file, set, reset, ws);
1479         } else if (line[0] == ' ') {
1480                 data->lineno++;
1481         } else if (line[0] == '@') {
1482                 char *plus = strchr(line, '+');
1483                 if (plus)
1484                         data->lineno = strtol(plus, NULL, 10) - 1;
1485                 else
1486                         die("invalid diff");
1487         }
1490 static unsigned char *deflate_it(char *data,
1491                                  unsigned long size,
1492                                  unsigned long *result_size)
1494         int bound;
1495         unsigned char *deflated;
1496         z_stream stream;
1498         memset(&stream, 0, sizeof(stream));
1499         deflateInit(&stream, zlib_compression_level);
1500         bound = deflateBound(&stream, size);
1501         deflated = xmalloc(bound);
1502         stream.next_out = deflated;
1503         stream.avail_out = bound;
1505         stream.next_in = (unsigned char *)data;
1506         stream.avail_in = size;
1507         while (deflate(&stream, Z_FINISH) == Z_OK)
1508                 ; /* nothing */
1509         deflateEnd(&stream);
1510         *result_size = stream.total_out;
1511         return deflated;
1514 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1516         void *cp;
1517         void *delta;
1518         void *deflated;
1519         void *data;
1520         unsigned long orig_size;
1521         unsigned long delta_size;
1522         unsigned long deflate_size;
1523         unsigned long data_size;
1525         /* We could do deflated delta, or we could do just deflated two,
1526          * whichever is smaller.
1527          */
1528         delta = NULL;
1529         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1530         if (one->size && two->size) {
1531                 delta = diff_delta(one->ptr, one->size,
1532                                    two->ptr, two->size,
1533                                    &delta_size, deflate_size);
1534                 if (delta) {
1535                         void *to_free = delta;
1536                         orig_size = delta_size;
1537                         delta = deflate_it(delta, delta_size, &delta_size);
1538                         free(to_free);
1539                 }
1540         }
1542         if (delta && delta_size < deflate_size) {
1543                 fprintf(file, "delta %lu\n", orig_size);
1544                 free(deflated);
1545                 data = delta;
1546                 data_size = delta_size;
1547         }
1548         else {
1549                 fprintf(file, "literal %lu\n", two->size);
1550                 free(delta);
1551                 data = deflated;
1552                 data_size = deflate_size;
1553         }
1555         /* emit data encoded in base85 */
1556         cp = data;
1557         while (data_size) {
1558                 int bytes = (52 < data_size) ? 52 : data_size;
1559                 char line[70];
1560                 data_size -= bytes;
1561                 if (bytes <= 26)
1562                         line[0] = bytes + 'A' - 1;
1563                 else
1564                         line[0] = bytes - 26 + 'a' - 1;
1565                 encode_85(line + 1, cp, bytes);
1566                 cp = (char *) cp + bytes;
1567                 fputs(line, file);
1568                 fputc('\n', file);
1569         }
1570         fprintf(file, "\n");
1571         free(data);
1574 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1576         fprintf(file, "GIT binary patch\n");
1577         emit_binary_diff_body(file, one, two);
1578         emit_binary_diff_body(file, two, one);
1581 static void diff_filespec_load_driver(struct diff_filespec *one)
1583         if (!one->driver)
1584                 one->driver = userdiff_find_by_path(one->path);
1585         if (!one->driver)
1586                 one->driver = userdiff_find_by_name("default");
1589 int diff_filespec_is_binary(struct diff_filespec *one)
1591         if (one->is_binary == -1) {
1592                 diff_filespec_load_driver(one);
1593                 if (one->driver->binary != -1)
1594                         one->is_binary = one->driver->binary;
1595                 else {
1596                         if (!one->data && DIFF_FILE_VALID(one))
1597                                 diff_populate_filespec(one, 0);
1598                         if (one->data)
1599                                 one->is_binary = buffer_is_binary(one->data,
1600                                                 one->size);
1601                         if (one->is_binary == -1)
1602                                 one->is_binary = 0;
1603                 }
1604         }
1605         return one->is_binary;
1608 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1610         diff_filespec_load_driver(one);
1611         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1614 static const char *userdiff_word_regex(struct diff_filespec *one)
1616         diff_filespec_load_driver(one);
1617         return one->driver->word_regex;
1620 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1622         if (!options->a_prefix)
1623                 options->a_prefix = a;
1624         if (!options->b_prefix)
1625                 options->b_prefix = b;
1628 struct userdiff_driver *get_textconv(struct diff_filespec *one)
1630         if (!DIFF_FILE_VALID(one))
1631                 return NULL;
1632         if (!S_ISREG(one->mode))
1633                 return NULL;
1634         diff_filespec_load_driver(one);
1635         if (!one->driver->textconv)
1636                 return NULL;
1638         if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1639                 struct notes_cache *c = xmalloc(sizeof(*c));
1640                 struct strbuf name = STRBUF_INIT;
1642                 strbuf_addf(&name, "textconv/%s", one->driver->name);
1643                 notes_cache_init(c, name.buf, one->driver->textconv);
1644                 one->driver->textconv_cache = c;
1645         }
1647         return one->driver;
1650 static void builtin_diff(const char *name_a,
1651                          const char *name_b,
1652                          struct diff_filespec *one,
1653                          struct diff_filespec *two,
1654                          const char *xfrm_msg,
1655                          struct diff_options *o,
1656                          int complete_rewrite)
1658         mmfile_t mf1, mf2;
1659         const char *lbl[2];
1660         char *a_one, *b_two;
1661         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1662         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1663         const char *a_prefix, *b_prefix;
1664         struct userdiff_driver *textconv_one = NULL;
1665         struct userdiff_driver *textconv_two = NULL;
1666         struct strbuf header = STRBUF_INIT;
1668         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1669                         (!one->mode || S_ISGITLINK(one->mode)) &&
1670                         (!two->mode || S_ISGITLINK(two->mode))) {
1671                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1672                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1673                 show_submodule_summary(o->file, one ? one->path : two->path,
1674                                 one->sha1, two->sha1, two->dirty_submodule,
1675                                 del, add, reset);
1676                 return;
1677         }
1679         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1680                 textconv_one = get_textconv(one);
1681                 textconv_two = get_textconv(two);
1682         }
1684         diff_set_mnemonic_prefix(o, "a/", "b/");
1685         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1686                 a_prefix = o->b_prefix;
1687                 b_prefix = o->a_prefix;
1688         } else {
1689                 a_prefix = o->a_prefix;
1690                 b_prefix = o->b_prefix;
1691         }
1693         /* Never use a non-valid filename anywhere if at all possible */
1694         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1695         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1697         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1698         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1699         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1700         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1701         strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1702         if (lbl[0][0] == '/') {
1703                 /* /dev/null */
1704                 strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1705                 if (xfrm_msg && xfrm_msg[0])
1706                         strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1707         }
1708         else if (lbl[1][0] == '/') {
1709                 strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1710                 if (xfrm_msg && xfrm_msg[0])
1711                         strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1712         }
1713         else {
1714                 if (one->mode != two->mode) {
1715                         strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1716                         strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1717                 }
1718                 if (xfrm_msg && xfrm_msg[0])
1719                         strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1721                 /*
1722                  * we do not run diff between different kind
1723                  * of objects.
1724                  */
1725                 if ((one->mode ^ two->mode) & S_IFMT)
1726                         goto free_ab_and_return;
1727                 if (complete_rewrite &&
1728                     (textconv_one || !diff_filespec_is_binary(one)) &&
1729                     (textconv_two || !diff_filespec_is_binary(two))) {
1730                         fprintf(o->file, "%s", header.buf);
1731                         strbuf_reset(&header);
1732                         emit_rewrite_diff(name_a, name_b, one, two,
1733                                                 textconv_one, textconv_two, o);
1734                         o->found_changes = 1;
1735                         goto free_ab_and_return;
1736                 }
1737         }
1739         if (!DIFF_OPT_TST(o, TEXT) &&
1740             ( (!textconv_one && diff_filespec_is_binary(one)) ||
1741               (!textconv_two && diff_filespec_is_binary(two)) )) {
1742                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1743                         die("unable to read files to diff");
1744                 /* Quite common confusing case */
1745                 if (mf1.size == mf2.size &&
1746                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1747                         goto free_ab_and_return;
1748                 fprintf(o->file, "%s", header.buf);
1749                 strbuf_reset(&header);
1750                 if (DIFF_OPT_TST(o, BINARY))
1751                         emit_binary_diff(o->file, &mf1, &mf2);
1752                 else
1753                         fprintf(o->file, "Binary files %s and %s differ\n",
1754                                 lbl[0], lbl[1]);
1755                 o->found_changes = 1;
1756         }
1757         else {
1758                 /* Crazy xdl interfaces.. */
1759                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1760                 xpparam_t xpp;
1761                 xdemitconf_t xecfg;
1762                 struct emit_callback ecbdata;
1763                 const struct userdiff_funcname *pe;
1765                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1766                         fprintf(o->file, "%s", header.buf);
1767                         strbuf_reset(&header);
1768                 }
1770                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1771                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1773                 pe = diff_funcname_pattern(one);
1774                 if (!pe)
1775                         pe = diff_funcname_pattern(two);
1777                 memset(&xpp, 0, sizeof(xpp));
1778                 memset(&xecfg, 0, sizeof(xecfg));
1779                 memset(&ecbdata, 0, sizeof(ecbdata));
1780                 ecbdata.label_path = lbl;
1781                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1782                 ecbdata.found_changesp = &o->found_changes;
1783                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1784                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1785                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1786                 ecbdata.file = o->file;
1787                 ecbdata.header = header.len ? &header : NULL;
1788                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1789                 xecfg.ctxlen = o->context;
1790                 xecfg.interhunkctxlen = o->interhunkcontext;
1791                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1792                 if (pe)
1793                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1794                 if (!diffopts)
1795                         ;
1796                 else if (!prefixcmp(diffopts, "--unified="))
1797                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1798                 else if (!prefixcmp(diffopts, "-u"))
1799                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1800                 if (o->word_diff) {
1801                         int i;
1803                         ecbdata.diff_words =
1804                                 xcalloc(1, sizeof(struct diff_words_data));
1805                         ecbdata.diff_words->file = o->file;
1806                         ecbdata.diff_words->type = o->word_diff;
1807                         if (!o->word_regex)
1808                                 o->word_regex = userdiff_word_regex(one);
1809                         if (!o->word_regex)
1810                                 o->word_regex = userdiff_word_regex(two);
1811                         if (!o->word_regex)
1812                                 o->word_regex = diff_word_regex_cfg;
1813                         if (o->word_regex) {
1814                                 ecbdata.diff_words->word_regex = (regex_t *)
1815                                         xmalloc(sizeof(regex_t));
1816                                 if (regcomp(ecbdata.diff_words->word_regex,
1817                                                 o->word_regex,
1818                                                 REG_EXTENDED | REG_NEWLINE))
1819                                         die ("Invalid regular expression: %s",
1820                                                         o->word_regex);
1821                         }
1822                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1823                                 if (o->word_diff == diff_words_styles[i].type) {
1824                                         ecbdata.diff_words->style =
1825                                                 &diff_words_styles[i];
1826                                         break;
1827                                 }
1828                         }
1829                         if (DIFF_OPT_TST(o, COLOR_DIFF)) {
1830                                 struct diff_words_style *st = ecbdata.diff_words->style;
1831                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1832                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1833                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1834                         }
1835                 }
1836                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1837                               &xpp, &xecfg);
1838                 if (o->word_diff)
1839                         free_diff_words_data(&ecbdata);
1840                 if (textconv_one)
1841                         free(mf1.ptr);
1842                 if (textconv_two)
1843                         free(mf2.ptr);
1844                 xdiff_clear_find_func(&xecfg);
1845         }
1847  free_ab_and_return:
1848         strbuf_release(&header);
1849         diff_free_filespec_data(one);
1850         diff_free_filespec_data(two);
1851         free(a_one);
1852         free(b_two);
1853         return;
1856 static void builtin_diffstat(const char *name_a, const char *name_b,
1857                              struct diff_filespec *one,
1858                              struct diff_filespec *two,
1859                              struct diffstat_t *diffstat,
1860                              struct diff_options *o,
1861                              int complete_rewrite)
1863         mmfile_t mf1, mf2;
1864         struct diffstat_file *data;
1866         data = diffstat_add(diffstat, name_a, name_b);
1868         if (!one || !two) {
1869                 data->is_unmerged = 1;
1870                 return;
1871         }
1872         if (complete_rewrite) {
1873                 diff_populate_filespec(one, 0);
1874                 diff_populate_filespec(two, 0);
1875                 data->deleted = count_lines(one->data, one->size);
1876                 data->added = count_lines(two->data, two->size);
1877                 goto free_and_return;
1878         }
1879         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1880                 die("unable to read files to diff");
1882         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1883                 data->is_binary = 1;
1884                 data->added = mf2.size;
1885                 data->deleted = mf1.size;
1886         } else {
1887                 /* Crazy xdl interfaces.. */
1888                 xpparam_t xpp;
1889                 xdemitconf_t xecfg;
1891                 memset(&xpp, 0, sizeof(xpp));
1892                 memset(&xecfg, 0, sizeof(xecfg));
1893                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1894                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1895                               &xpp, &xecfg);
1896         }
1898  free_and_return:
1899         diff_free_filespec_data(one);
1900         diff_free_filespec_data(two);
1903 static void builtin_checkdiff(const char *name_a, const char *name_b,
1904                               const char *attr_path,
1905                               struct diff_filespec *one,
1906                               struct diff_filespec *two,
1907                               struct diff_options *o)
1909         mmfile_t mf1, mf2;
1910         struct checkdiff_t data;
1912         if (!two)
1913                 return;
1915         memset(&data, 0, sizeof(data));
1916         data.filename = name_b ? name_b : name_a;
1917         data.lineno = 0;
1918         data.o = o;
1919         data.ws_rule = whitespace_rule(attr_path);
1920         data.conflict_marker_size = ll_merge_marker_size(attr_path);
1922         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1923                 die("unable to read files to diff");
1925         /*
1926          * All the other codepaths check both sides, but not checking
1927          * the "old" side here is deliberate.  We are checking the newly
1928          * introduced changes, and as long as the "new" side is text, we
1929          * can and should check what it introduces.
1930          */
1931         if (diff_filespec_is_binary(two))
1932                 goto free_and_return;
1933         else {
1934                 /* Crazy xdl interfaces.. */
1935                 xpparam_t xpp;
1936                 xdemitconf_t xecfg;
1938                 memset(&xpp, 0, sizeof(xpp));
1939                 memset(&xecfg, 0, sizeof(xecfg));
1940                 xecfg.ctxlen = 1; /* at least one context line */
1941                 xpp.flags = XDF_NEED_MINIMAL;
1942                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1943                               &xpp, &xecfg);
1945                 if (data.ws_rule & WS_BLANK_AT_EOF) {
1946                         struct emit_callback ecbdata;
1947                         int blank_at_eof;
1949                         ecbdata.ws_rule = data.ws_rule;
1950                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1951                         blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1953                         if (blank_at_eof) {
1954                                 static char *err;
1955                                 if (!err)
1956                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
1957                                 fprintf(o->file, "%s:%d: %s.\n",
1958                                         data.filename, blank_at_eof, err);
1959                                 data.status = 1; /* report errors */
1960                         }
1961                 }
1962         }
1963  free_and_return:
1964         diff_free_filespec_data(one);
1965         diff_free_filespec_data(two);
1966         if (data.status)
1967                 DIFF_OPT_SET(o, CHECK_FAILED);
1970 struct diff_filespec *alloc_filespec(const char *path)
1972         int namelen = strlen(path);
1973         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1975         memset(spec, 0, sizeof(*spec));
1976         spec->path = (char *)(spec + 1);
1977         memcpy(spec->path, path, namelen+1);
1978         spec->count = 1;
1979         spec->is_binary = -1;
1980         return spec;
1983 void free_filespec(struct diff_filespec *spec)
1985         if (!--spec->count) {
1986                 diff_free_filespec_data(spec);
1987                 free(spec);
1988         }
1991 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1992                    unsigned short mode)
1994         if (mode) {
1995                 spec->mode = canon_mode(mode);
1996                 hashcpy(spec->sha1, sha1);
1997                 spec->sha1_valid = !is_null_sha1(sha1);
1998         }
2001 /*
2002  * Given a name and sha1 pair, if the index tells us the file in
2003  * the work tree has that object contents, return true, so that
2004  * prepare_temp_file() does not have to inflate and extract.
2005  */
2006 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2008         struct cache_entry *ce;
2009         struct stat st;
2010         int pos, len;
2012         /*
2013          * We do not read the cache ourselves here, because the
2014          * benchmark with my previous version that always reads cache
2015          * shows that it makes things worse for diff-tree comparing
2016          * two linux-2.6 kernel trees in an already checked out work
2017          * tree.  This is because most diff-tree comparisons deal with
2018          * only a small number of files, while reading the cache is
2019          * expensive for a large project, and its cost outweighs the
2020          * savings we get by not inflating the object to a temporary
2021          * file.  Practically, this code only helps when we are used
2022          * by diff-cache --cached, which does read the cache before
2023          * calling us.
2024          */
2025         if (!active_cache)
2026                 return 0;
2028         /* We want to avoid the working directory if our caller
2029          * doesn't need the data in a normal file, this system
2030          * is rather slow with its stat/open/mmap/close syscalls,
2031          * and the object is contained in a pack file.  The pack
2032          * is probably already open and will be faster to obtain
2033          * the data through than the working directory.  Loose
2034          * objects however would tend to be slower as they need
2035          * to be individually opened and inflated.
2036          */
2037         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2038                 return 0;
2040         len = strlen(name);
2041         pos = cache_name_pos(name, len);
2042         if (pos < 0)
2043                 return 0;
2044         ce = active_cache[pos];
2046         /*
2047          * This is not the sha1 we are looking for, or
2048          * unreusable because it is not a regular file.
2049          */
2050         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2051                 return 0;
2053         /*
2054          * If ce is marked as "assume unchanged", there is no
2055          * guarantee that work tree matches what we are looking for.
2056          */
2057         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2058                 return 0;
2060         /*
2061          * If ce matches the file in the work tree, we can reuse it.
2062          */
2063         if (ce_uptodate(ce) ||
2064             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2065                 return 1;
2067         return 0;
2070 static int populate_from_stdin(struct diff_filespec *s)
2072         struct strbuf buf = STRBUF_INIT;
2073         size_t size = 0;
2075         if (strbuf_read(&buf, 0, 0) < 0)
2076                 return error("error while reading from stdin %s",
2077                                      strerror(errno));
2079         s->should_munmap = 0;
2080         s->data = strbuf_detach(&buf, &size);
2081         s->size = size;
2082         s->should_free = 1;
2083         return 0;
2086 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2088         int len;
2089         char *data = xmalloc(100), *dirty = "";
2091         /* Are we looking at the work tree? */
2092         if (s->dirty_submodule)
2093                 dirty = "-dirty";
2095         len = snprintf(data, 100,
2096                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2097         s->data = data;
2098         s->size = len;
2099         s->should_free = 1;
2100         if (size_only) {
2101                 s->data = NULL;
2102                 free(data);
2103         }
2104         return 0;
2107 /*
2108  * While doing rename detection and pickaxe operation, we may need to
2109  * grab the data for the blob (or file) for our own in-core comparison.
2110  * diff_filespec has data and size fields for this purpose.
2111  */
2112 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2114         int err = 0;
2115         if (!DIFF_FILE_VALID(s))
2116                 die("internal error: asking to populate invalid file.");
2117         if (S_ISDIR(s->mode))
2118                 return -1;
2120         if (s->data)
2121                 return 0;
2123         if (size_only && 0 < s->size)
2124                 return 0;
2126         if (S_ISGITLINK(s->mode))
2127                 return diff_populate_gitlink(s, size_only);
2129         if (!s->sha1_valid ||
2130             reuse_worktree_file(s->path, s->sha1, 0)) {
2131                 struct strbuf buf = STRBUF_INIT;
2132                 struct stat st;
2133                 int fd;
2135                 if (!strcmp(s->path, "-"))
2136                         return populate_from_stdin(s);
2138                 if (lstat(s->path, &st) < 0) {
2139                         if (errno == ENOENT) {
2140                         err_empty:
2141                                 err = -1;
2142                         empty:
2143                                 s->data = (char *)"";
2144                                 s->size = 0;
2145                                 return err;
2146                         }
2147                 }
2148                 s->size = xsize_t(st.st_size);
2149                 if (!s->size)
2150                         goto empty;
2151                 if (S_ISLNK(st.st_mode)) {
2152                         struct strbuf sb = STRBUF_INIT;
2154                         if (strbuf_readlink(&sb, s->path, s->size))
2155                                 goto err_empty;
2156                         s->size = sb.len;
2157                         s->data = strbuf_detach(&sb, NULL);
2158                         s->should_free = 1;
2159                         return 0;
2160                 }
2161                 if (size_only)
2162                         return 0;
2163                 fd = open(s->path, O_RDONLY);
2164                 if (fd < 0)
2165                         goto err_empty;
2166                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2167                 close(fd);
2168                 s->should_munmap = 1;
2170                 /*
2171                  * Convert from working tree format to canonical git format
2172                  */
2173                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2174                         size_t size = 0;
2175                         munmap(s->data, s->size);
2176                         s->should_munmap = 0;
2177                         s->data = strbuf_detach(&buf, &size);
2178                         s->size = size;
2179                         s->should_free = 1;
2180                 }
2181         }
2182         else {
2183                 enum object_type type;
2184                 if (size_only)
2185                         type = sha1_object_info(s->sha1, &s->size);
2186                 else {
2187                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2188                         s->should_free = 1;
2189                 }
2190         }
2191         return 0;
2194 void diff_free_filespec_blob(struct diff_filespec *s)
2196         if (s->should_free)
2197                 free(s->data);
2198         else if (s->should_munmap)
2199                 munmap(s->data, s->size);
2201         if (s->should_free || s->should_munmap) {
2202                 s->should_free = s->should_munmap = 0;
2203                 s->data = NULL;
2204         }
2207 void diff_free_filespec_data(struct diff_filespec *s)
2209         diff_free_filespec_blob(s);
2210         free(s->cnt_data);
2211         s->cnt_data = NULL;
2214 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2215                            void *blob,
2216                            unsigned long size,
2217                            const unsigned char *sha1,
2218                            int mode)
2220         int fd;
2221         struct strbuf buf = STRBUF_INIT;
2222         struct strbuf template = STRBUF_INIT;
2223         char *path_dup = xstrdup(path);
2224         const char *base = basename(path_dup);
2226         /* Generate "XXXXXX_basename.ext" */
2227         strbuf_addstr(&template, "XXXXXX_");
2228         strbuf_addstr(&template, base);
2230         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2231                         strlen(base) + 1);
2232         if (fd < 0)
2233                 die_errno("unable to create temp-file");
2234         if (convert_to_working_tree(path,
2235                         (const char *)blob, (size_t)size, &buf)) {
2236                 blob = buf.buf;
2237                 size = buf.len;
2238         }
2239         if (write_in_full(fd, blob, size) != size)
2240                 die_errno("unable to write temp-file");
2241         close(fd);
2242         temp->name = temp->tmp_path;
2243         strcpy(temp->hex, sha1_to_hex(sha1));
2244         temp->hex[40] = 0;
2245         sprintf(temp->mode, "%06o", mode);
2246         strbuf_release(&buf);
2247         strbuf_release(&template);
2248         free(path_dup);
2251 static struct diff_tempfile *prepare_temp_file(const char *name,
2252                 struct diff_filespec *one)
2254         struct diff_tempfile *temp = claim_diff_tempfile();
2256         if (!DIFF_FILE_VALID(one)) {
2257         not_a_valid_file:
2258                 /* A '-' entry produces this for file-2, and
2259                  * a '+' entry produces this for file-1.
2260                  */
2261                 temp->name = "/dev/null";
2262                 strcpy(temp->hex, ".");
2263                 strcpy(temp->mode, ".");
2264                 return temp;
2265         }
2267         if (!remove_tempfile_installed) {
2268                 atexit(remove_tempfile);
2269                 sigchain_push_common(remove_tempfile_on_signal);
2270                 remove_tempfile_installed = 1;
2271         }
2273         if (!one->sha1_valid ||
2274             reuse_worktree_file(name, one->sha1, 1)) {
2275                 struct stat st;
2276                 if (lstat(name, &st) < 0) {
2277                         if (errno == ENOENT)
2278                                 goto not_a_valid_file;
2279                         die_errno("stat(%s)", name);
2280                 }
2281                 if (S_ISLNK(st.st_mode)) {
2282                         struct strbuf sb = STRBUF_INIT;
2283                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2284                                 die_errno("readlink(%s)", name);
2285                         prep_temp_blob(name, temp, sb.buf, sb.len,
2286                                        (one->sha1_valid ?
2287                                         one->sha1 : null_sha1),
2288                                        (one->sha1_valid ?
2289                                         one->mode : S_IFLNK));
2290                         strbuf_release(&sb);
2291                 }
2292                 else {
2293                         /* we can borrow from the file in the work tree */
2294                         temp->name = name;
2295                         if (!one->sha1_valid)
2296                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2297                         else
2298                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2299                         /* Even though we may sometimes borrow the
2300                          * contents from the work tree, we always want
2301                          * one->mode.  mode is trustworthy even when
2302                          * !(one->sha1_valid), as long as
2303                          * DIFF_FILE_VALID(one).
2304                          */
2305                         sprintf(temp->mode, "%06o", one->mode);
2306                 }
2307                 return temp;
2308         }
2309         else {
2310                 if (diff_populate_filespec(one, 0))
2311                         die("cannot read data blob for %s", one->path);
2312                 prep_temp_blob(name, temp, one->data, one->size,
2313                                one->sha1, one->mode);
2314         }
2315         return temp;
2318 /* An external diff command takes:
2319  *
2320  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2321  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2322  *
2323  */
2324 static void run_external_diff(const char *pgm,
2325                               const char *name,
2326                               const char *other,
2327                               struct diff_filespec *one,
2328                               struct diff_filespec *two,
2329                               const char *xfrm_msg,
2330                               int complete_rewrite)
2332         const char *spawn_arg[10];
2333         int retval;
2334         const char **arg = &spawn_arg[0];
2336         if (one && two) {
2337                 struct diff_tempfile *temp_one, *temp_two;
2338                 const char *othername = (other ? other : name);
2339                 temp_one = prepare_temp_file(name, one);
2340                 temp_two = prepare_temp_file(othername, two);
2341                 *arg++ = pgm;
2342                 *arg++ = name;
2343                 *arg++ = temp_one->name;
2344                 *arg++ = temp_one->hex;
2345                 *arg++ = temp_one->mode;
2346                 *arg++ = temp_two->name;
2347                 *arg++ = temp_two->hex;
2348                 *arg++ = temp_two->mode;
2349                 if (other) {
2350                         *arg++ = other;
2351                         *arg++ = xfrm_msg;
2352                 }
2353         } else {
2354                 *arg++ = pgm;
2355                 *arg++ = name;
2356         }
2357         *arg = NULL;
2358         fflush(NULL);
2359         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2360         remove_tempfile();
2361         if (retval) {
2362                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2363                 exit(1);
2364         }
2367 static int similarity_index(struct diff_filepair *p)
2369         return p->score * 100 / MAX_SCORE;
2372 static void fill_metainfo(struct strbuf *msg,
2373                           const char *name,
2374                           const char *other,
2375                           struct diff_filespec *one,
2376                           struct diff_filespec *two,
2377                           struct diff_options *o,
2378                           struct diff_filepair *p)
2380         strbuf_init(msg, PATH_MAX * 2 + 300);
2381         switch (p->status) {
2382         case DIFF_STATUS_COPIED:
2383                 strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2384                 strbuf_addstr(msg, "\ncopy from ");
2385                 quote_c_style(name, msg, NULL, 0);
2386                 strbuf_addstr(msg, "\ncopy to ");
2387                 quote_c_style(other, msg, NULL, 0);
2388                 strbuf_addch(msg, '\n');
2389                 break;
2390         case DIFF_STATUS_RENAMED:
2391                 strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2392                 strbuf_addstr(msg, "\nrename from ");
2393                 quote_c_style(name, msg, NULL, 0);
2394                 strbuf_addstr(msg, "\nrename to ");
2395                 quote_c_style(other, msg, NULL, 0);
2396                 strbuf_addch(msg, '\n');
2397                 break;
2398         case DIFF_STATUS_MODIFIED:
2399                 if (p->score) {
2400                         strbuf_addf(msg, "dissimilarity index %d%%\n",
2401                                     similarity_index(p));
2402                         break;
2403                 }
2404                 /* fallthru */
2405         default:
2406                 /* nothing */
2407                 ;
2408         }
2409         if (one && two && hashcmp(one->sha1, two->sha1)) {
2410                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2412                 if (DIFF_OPT_TST(o, BINARY)) {
2413                         mmfile_t mf;
2414                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2415                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2416                                 abbrev = 40;
2417                 }
2418                 strbuf_addf(msg, "index %.*s..%.*s",
2419                             abbrev, sha1_to_hex(one->sha1),
2420                             abbrev, sha1_to_hex(two->sha1));
2421                 if (one->mode == two->mode)
2422                         strbuf_addf(msg, " %06o", one->mode);
2423                 strbuf_addch(msg, '\n');
2424         }
2425         if (msg->len)
2426                 strbuf_setlen(msg, msg->len - 1);
2429 static void run_diff_cmd(const char *pgm,
2430                          const char *name,
2431                          const char *other,
2432                          const char *attr_path,
2433                          struct diff_filespec *one,
2434                          struct diff_filespec *two,
2435                          struct strbuf *msg,
2436                          struct diff_options *o,
2437                          struct diff_filepair *p)
2439         const char *xfrm_msg = NULL;
2440         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2442         if (msg) {
2443                 fill_metainfo(msg, name, other, one, two, o, p);
2444                 xfrm_msg = msg->len ? msg->buf : NULL;
2445         }
2447         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2448                 pgm = NULL;
2449         else {
2450                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2451                 if (drv && drv->external)
2452                         pgm = drv->external;
2453         }
2455         if (pgm) {
2456                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2457                                   complete_rewrite);
2458                 return;
2459         }
2460         if (one && two)
2461                 builtin_diff(name, other ? other : name,
2462                              one, two, xfrm_msg, o, complete_rewrite);
2463         else
2464                 fprintf(o->file, "* Unmerged path %s\n", name);
2467 static void diff_fill_sha1_info(struct diff_filespec *one)
2469         if (DIFF_FILE_VALID(one)) {
2470                 if (!one->sha1_valid) {
2471                         struct stat st;
2472                         if (!strcmp(one->path, "-")) {
2473                                 hashcpy(one->sha1, null_sha1);
2474                                 return;
2475                         }
2476                         if (lstat(one->path, &st) < 0)
2477                                 die_errno("stat '%s'", one->path);
2478                         if (index_path(one->sha1, one->path, &st, 0))
2479                                 die("cannot hash %s", one->path);
2480                 }
2481         }
2482         else
2483                 hashclr(one->sha1);
2486 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2488         /* Strip the prefix but do not molest /dev/null and absolute paths */
2489         if (*namep && **namep != '/')
2490                 *namep += prefix_length;
2491         if (*otherp && **otherp != '/')
2492                 *otherp += prefix_length;
2495 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2497         const char *pgm = external_diff();
2498         struct strbuf msg;
2499         struct diff_filespec *one = p->one;
2500         struct diff_filespec *two = p->two;
2501         const char *name;
2502         const char *other;
2503         const char *attr_path;
2505         name  = p->one->path;
2506         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2507         attr_path = name;
2508         if (o->prefix_length)
2509                 strip_prefix(o->prefix_length, &name, &other);
2511         if (DIFF_PAIR_UNMERGED(p)) {
2512                 run_diff_cmd(pgm, name, NULL, attr_path,
2513                              NULL, NULL, NULL, o, p);
2514                 return;
2515         }
2517         diff_fill_sha1_info(one);
2518         diff_fill_sha1_info(two);
2520         if (!pgm &&
2521             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2522             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2523                 /*
2524                  * a filepair that changes between file and symlink
2525                  * needs to be split into deletion and creation.
2526                  */
2527                 struct diff_filespec *null = alloc_filespec(two->path);
2528                 run_diff_cmd(NULL, name, other, attr_path,
2529                              one, null, &msg, o, p);
2530                 free(null);
2531                 strbuf_release(&msg);
2533                 null = alloc_filespec(one->path);
2534                 run_diff_cmd(NULL, name, other, attr_path,
2535                              null, two, &msg, o, p);
2536                 free(null);
2537         }
2538         else
2539                 run_diff_cmd(pgm, name, other, attr_path,
2540                              one, two, &msg, o, p);
2542         strbuf_release(&msg);
2545 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2546                          struct diffstat_t *diffstat)
2548         const char *name;
2549         const char *other;
2550         int complete_rewrite = 0;
2552         if (DIFF_PAIR_UNMERGED(p)) {
2553                 /* unmerged */
2554                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2555                 return;
2556         }
2558         name = p->one->path;
2559         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2561         if (o->prefix_length)
2562                 strip_prefix(o->prefix_length, &name, &other);
2564         diff_fill_sha1_info(p->one);
2565         diff_fill_sha1_info(p->two);
2567         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2568                 complete_rewrite = 1;
2569         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2572 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2574         const char *name;
2575         const char *other;
2576         const char *attr_path;
2578         if (DIFF_PAIR_UNMERGED(p)) {
2579                 /* unmerged */
2580                 return;
2581         }
2583         name = p->one->path;
2584         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2585         attr_path = other ? other : name;
2587         if (o->prefix_length)
2588                 strip_prefix(o->prefix_length, &name, &other);
2590         diff_fill_sha1_info(p->one);
2591         diff_fill_sha1_info(p->two);
2593         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2596 void diff_setup(struct diff_options *options)
2598         memset(options, 0, sizeof(*options));
2599         memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2601         options->file = stdout;
2603         options->line_termination = '\n';
2604         options->break_opt = -1;
2605         options->rename_limit = -1;
2606         options->dirstat_percent = 3;
2607         options->context = 3;
2609         options->change = diff_change;
2610         options->add_remove = diff_addremove;
2611         if (diff_use_color_default > 0)
2612                 DIFF_OPT_SET(options, COLOR_DIFF);
2613         options->detect_rename = diff_detect_rename_default;
2615         if (!diff_mnemonic_prefix) {
2616                 options->a_prefix = "a/";
2617                 options->b_prefix = "b/";
2618         }
2621 int diff_setup_done(struct diff_options *options)
2623         int count = 0;
2625         if (options->output_format & DIFF_FORMAT_NAME)
2626                 count++;
2627         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2628                 count++;
2629         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2630                 count++;
2631         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2632                 count++;
2633         if (count > 1)
2634                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2636         /*
2637          * Most of the time we can say "there are changes"
2638          * only by checking if there are changed paths, but
2639          * --ignore-whitespace* options force us to look
2640          * inside contents.
2641          */
2643         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2644             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2645             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2646                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2647         else
2648                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2650         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2651                 options->detect_rename = DIFF_DETECT_COPY;
2653         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2654                 options->prefix = NULL;
2655         if (options->prefix)
2656                 options->prefix_length = strlen(options->prefix);
2657         else
2658                 options->prefix_length = 0;
2660         if (options->output_format & (DIFF_FORMAT_NAME |
2661                                       DIFF_FORMAT_NAME_STATUS |
2662                                       DIFF_FORMAT_CHECKDIFF |
2663                                       DIFF_FORMAT_NO_OUTPUT))
2664                 options->output_format &= ~(DIFF_FORMAT_RAW |
2665                                             DIFF_FORMAT_NUMSTAT |
2666                                             DIFF_FORMAT_DIFFSTAT |
2667                                             DIFF_FORMAT_SHORTSTAT |
2668                                             DIFF_FORMAT_DIRSTAT |
2669                                             DIFF_FORMAT_SUMMARY |
2670                                             DIFF_FORMAT_PATCH);
2672         /*
2673          * These cases always need recursive; we do not drop caller-supplied
2674          * recursive bits for other formats here.
2675          */
2676         if (options->output_format & (DIFF_FORMAT_PATCH |
2677                                       DIFF_FORMAT_NUMSTAT |
2678                                       DIFF_FORMAT_DIFFSTAT |
2679                                       DIFF_FORMAT_SHORTSTAT |
2680                                       DIFF_FORMAT_DIRSTAT |
2681                                       DIFF_FORMAT_SUMMARY |
2682                                       DIFF_FORMAT_CHECKDIFF))
2683                 DIFF_OPT_SET(options, RECURSIVE);
2684         /*
2685          * Also pickaxe would not work very well if you do not say recursive
2686          */
2687         if (options->pickaxe)
2688                 DIFF_OPT_SET(options, RECURSIVE);
2689         /*
2690          * When patches are generated, submodules diffed against the work tree
2691          * must be checked for dirtiness too so it can be shown in the output
2692          */
2693         if (options->output_format & DIFF_FORMAT_PATCH)
2694                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2696         if (options->detect_rename && options->rename_limit < 0)
2697                 options->rename_limit = diff_rename_limit_default;
2698         if (options->setup & DIFF_SETUP_USE_CACHE) {
2699                 if (!active_cache)
2700                         /* read-cache does not die even when it fails
2701                          * so it is safe for us to do this here.  Also
2702                          * it does not smudge active_cache or active_nr
2703                          * when it fails, so we do not have to worry about
2704                          * cleaning it up ourselves either.
2705                          */
2706                         read_cache();
2707         }
2708         if (options->abbrev <= 0 || 40 < options->abbrev)
2709                 options->abbrev = 40; /* full */
2711         /*
2712          * It does not make sense to show the first hit we happened
2713          * to have found.  It does not make sense not to return with
2714          * exit code in such a case either.
2715          */
2716         if (DIFF_OPT_TST(options, QUICK)) {
2717                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2718                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2719         }
2721         return 0;
2724 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2726         char c, *eq;
2727         int len;
2729         if (*arg != '-')
2730                 return 0;
2731         c = *++arg;
2732         if (!c)
2733                 return 0;
2734         if (c == arg_short) {
2735                 c = *++arg;
2736                 if (!c)
2737                         return 1;
2738                 if (val && isdigit(c)) {
2739                         char *end;
2740                         int n = strtoul(arg, &end, 10);
2741                         if (*end)
2742                                 return 0;
2743                         *val = n;
2744                         return 1;
2745                 }
2746                 return 0;
2747         }
2748         if (c != '-')
2749                 return 0;
2750         arg++;
2751         eq = strchr(arg, '=');
2752         if (eq)
2753                 len = eq - arg;
2754         else
2755                 len = strlen(arg);
2756         if (!len || strncmp(arg, arg_long, len))
2757                 return 0;
2758         if (eq) {
2759                 int n;
2760                 char *end;
2761                 if (!isdigit(*++eq))
2762                         return 0;
2763                 n = strtoul(eq, &end, 10);
2764                 if (*end)
2765                         return 0;
2766                 *val = n;
2767         }
2768         return 1;
2771 static int diff_scoreopt_parse(const char *opt);
2773 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2775         const char *arg = av[0];
2777         /* Output format options */
2778         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
2779                 options->output_format |= DIFF_FORMAT_PATCH;
2780         else if (opt_arg(arg, 'U', "unified", &options->context))
2781                 options->output_format |= DIFF_FORMAT_PATCH;
2782         else if (!strcmp(arg, "--raw"))
2783                 options->output_format |= DIFF_FORMAT_RAW;
2784         else if (!strcmp(arg, "--patch-with-raw"))
2785                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2786         else if (!strcmp(arg, "--numstat"))
2787                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2788         else if (!strcmp(arg, "--shortstat"))
2789                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2790         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2791                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2792         else if (!strcmp(arg, "--cumulative")) {
2793                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2794                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2795         } else if (opt_arg(arg, 0, "dirstat-by-file",
2796                            &options->dirstat_percent)) {
2797                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2798                 DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2799         }
2800         else if (!strcmp(arg, "--check"))
2801                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2802         else if (!strcmp(arg, "--summary"))
2803                 options->output_format |= DIFF_FORMAT_SUMMARY;
2804         else if (!strcmp(arg, "--patch-with-stat"))
2805                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2806         else if (!strcmp(arg, "--name-only"))
2807                 options->output_format |= DIFF_FORMAT_NAME;
2808         else if (!strcmp(arg, "--name-status"))
2809                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2810         else if (!strcmp(arg, "-s"))
2811                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2812         else if (!prefixcmp(arg, "--stat")) {
2813                 char *end;
2814                 int width = options->stat_width;
2815                 int name_width = options->stat_name_width;
2816                 arg += 6;
2817                 end = (char *)arg;
2819                 switch (*arg) {
2820                 case '-':
2821                         if (!prefixcmp(arg, "-width="))
2822                                 width = strtoul(arg + 7, &end, 10);
2823                         else if (!prefixcmp(arg, "-name-width="))
2824                                 name_width = strtoul(arg + 12, &end, 10);
2825                         break;
2826                 case '=':
2827                         width = strtoul(arg+1, &end, 10);
2828                         if (*end == ',')
2829                                 name_width = strtoul(end+1, &end, 10);
2830                 }
2832                 /* Important! This checks all the error cases! */
2833                 if (*end)
2834                         return 0;
2835                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2836                 options->stat_name_width = name_width;
2837                 options->stat_width = width;
2838         }
2840         /* renames options */
2841         else if (!prefixcmp(arg, "-B")) {
2842                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2843                         return -1;
2844         }
2845         else if (!prefixcmp(arg, "-M")) {
2846                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2847                         return -1;
2848                 options->detect_rename = DIFF_DETECT_RENAME;
2849         }
2850         else if (!prefixcmp(arg, "-C")) {
2851                 if (options->detect_rename == DIFF_DETECT_COPY)
2852                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2853                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2854                         return -1;
2855                 options->detect_rename = DIFF_DETECT_COPY;
2856         }
2857         else if (!strcmp(arg, "--no-renames"))
2858                 options->detect_rename = 0;
2859         else if (!strcmp(arg, "--relative"))
2860                 DIFF_OPT_SET(options, RELATIVE_NAME);
2861         else if (!prefixcmp(arg, "--relative=")) {
2862                 DIFF_OPT_SET(options, RELATIVE_NAME);
2863                 options->prefix = arg + 11;
2864         }
2866         /* xdiff options */
2867         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2868                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2869         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2870                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2871         else if (!strcmp(arg, "--ignore-space-at-eol"))
2872                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2873         else if (!strcmp(arg, "--patience"))
2874                 DIFF_XDL_SET(options, PATIENCE_DIFF);
2876         /* flags options */
2877         else if (!strcmp(arg, "--binary")) {
2878                 options->output_format |= DIFF_FORMAT_PATCH;
2879                 DIFF_OPT_SET(options, BINARY);
2880         }
2881         else if (!strcmp(arg, "--full-index"))
2882                 DIFF_OPT_SET(options, FULL_INDEX);
2883         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2884                 DIFF_OPT_SET(options, TEXT);
2885         else if (!strcmp(arg, "-R"))
2886                 DIFF_OPT_SET(options, REVERSE_DIFF);
2887         else if (!strcmp(arg, "--find-copies-harder"))
2888                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2889         else if (!strcmp(arg, "--follow"))
2890                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2891         else if (!strcmp(arg, "--color"))
2892                 DIFF_OPT_SET(options, COLOR_DIFF);
2893         else if (!prefixcmp(arg, "--color=")) {
2894                 int value = git_config_colorbool(NULL, arg+8, -1);
2895                 if (value == 0)
2896                         DIFF_OPT_CLR(options, COLOR_DIFF);
2897                 else if (value > 0)
2898                         DIFF_OPT_SET(options, COLOR_DIFF);
2899                 else
2900                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
2901         }
2902         else if (!strcmp(arg, "--no-color"))
2903                 DIFF_OPT_CLR(options, COLOR_DIFF);
2904         else if (!strcmp(arg, "--color-words")) {
2905                 DIFF_OPT_SET(options, COLOR_DIFF);
2906                 options->word_diff = DIFF_WORDS_COLOR;
2907         }
2908         else if (!prefixcmp(arg, "--color-words=")) {
2909                 DIFF_OPT_SET(options, COLOR_DIFF);
2910                 options->word_diff = DIFF_WORDS_COLOR;
2911                 options->word_regex = arg + 14;
2912         }
2913         else if (!strcmp(arg, "--word-diff")) {
2914                 if (options->word_diff == DIFF_WORDS_NONE)
2915                         options->word_diff = DIFF_WORDS_PLAIN;
2916         }
2917         else if (!prefixcmp(arg, "--word-diff=")) {
2918                 const char *type = arg + 12;
2919                 if (!strcmp(type, "plain"))
2920                         options->word_diff = DIFF_WORDS_PLAIN;
2921                 else if (!strcmp(type, "color")) {
2922                         DIFF_OPT_SET(options, COLOR_DIFF);
2923                         options->word_diff = DIFF_WORDS_COLOR;
2924                 }
2925                 else if (!strcmp(type, "porcelain"))
2926                         options->word_diff = DIFF_WORDS_PORCELAIN;
2927                 else if (!strcmp(type, "none"))
2928                         options->word_diff = DIFF_WORDS_NONE;
2929                 else
2930                         die("bad --word-diff argument: %s", type);
2931         }
2932         else if (!prefixcmp(arg, "--word-diff-regex=")) {
2933                 if (options->word_diff == DIFF_WORDS_NONE)
2934                         options->word_diff = DIFF_WORDS_PLAIN;
2935                 options->word_regex = arg + 18;
2936         }
2937         else if (!strcmp(arg, "--exit-code"))
2938                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2939         else if (!strcmp(arg, "--quiet"))
2940                 DIFF_OPT_SET(options, QUICK);
2941         else if (!strcmp(arg, "--ext-diff"))
2942                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2943         else if (!strcmp(arg, "--no-ext-diff"))
2944                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2945         else if (!strcmp(arg, "--textconv"))
2946                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2947         else if (!strcmp(arg, "--no-textconv"))
2948                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2949         else if (!strcmp(arg, "--ignore-submodules"))
2950                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2951         else if (!strcmp(arg, "--submodule"))
2952                 DIFF_OPT_SET(options, SUBMODULE_LOG);
2953         else if (!prefixcmp(arg, "--submodule=")) {
2954                 if (!strcmp(arg + 12, "log"))
2955                         DIFF_OPT_SET(options, SUBMODULE_LOG);
2956         }
2958         /* misc options */
2959         else if (!strcmp(arg, "-z"))
2960                 options->line_termination = 0;
2961         else if (!prefixcmp(arg, "-l"))
2962                 options->rename_limit = strtoul(arg+2, NULL, 10);
2963         else if (!prefixcmp(arg, "-S"))
2964                 options->pickaxe = arg + 2;
2965         else if (!strcmp(arg, "--pickaxe-all"))
2966                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2967         else if (!strcmp(arg, "--pickaxe-regex"))
2968                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2969         else if (!prefixcmp(arg, "-O"))
2970                 options->orderfile = arg + 2;
2971         else if (!prefixcmp(arg, "--diff-filter="))
2972                 options->filter = arg + 14;
2973         else if (!strcmp(arg, "--abbrev"))
2974                 options->abbrev = DEFAULT_ABBREV;
2975         else if (!prefixcmp(arg, "--abbrev=")) {
2976                 options->abbrev = strtoul(arg + 9, NULL, 10);
2977                 if (options->abbrev < MINIMUM_ABBREV)
2978                         options->abbrev = MINIMUM_ABBREV;
2979                 else if (40 < options->abbrev)
2980                         options->abbrev = 40;
2981         }
2982         else if (!prefixcmp(arg, "--src-prefix="))
2983                 options->a_prefix = arg + 13;
2984         else if (!prefixcmp(arg, "--dst-prefix="))
2985                 options->b_prefix = arg + 13;
2986         else if (!strcmp(arg, "--no-prefix"))
2987                 options->a_prefix = options->b_prefix = "";
2988         else if (opt_arg(arg, '\0', "inter-hunk-context",
2989                          &options->interhunkcontext))
2990                 ;
2991         else if (!prefixcmp(arg, "--output=")) {
2992                 options->file = fopen(arg + strlen("--output="), "w");
2993                 if (!options->file)
2994                         die_errno("Could not open '%s'", arg + strlen("--output="));
2995                 options->close_file = 1;
2996         } else
2997                 return 0;
2998         return 1;
3001 static int parse_num(const char **cp_p)
3003         unsigned long num, scale;
3004         int ch, dot;
3005         const char *cp = *cp_p;
3007         num = 0;
3008         scale = 1;
3009         dot = 0;
3010         for (;;) {
3011                 ch = *cp;
3012                 if ( !dot && ch == '.' ) {
3013                         scale = 1;
3014                         dot = 1;
3015                 } else if ( ch == '%' ) {
3016                         scale = dot ? scale*100 : 100;
3017                         cp++;   /* % is always at the end */
3018                         break;
3019                 } else if ( ch >= '0' && ch <= '9' ) {
3020                         if ( scale < 100000 ) {
3021                                 scale *= 10;
3022                                 num = (num*10) + (ch-'0');
3023                         }
3024                 } else {
3025                         break;
3026                 }
3027                 cp++;
3028         }
3029         *cp_p = cp;
3031         /* user says num divided by scale and we say internally that
3032          * is MAX_SCORE * num / scale.
3033          */
3034         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3037 static int diff_scoreopt_parse(const char *opt)
3039         int opt1, opt2, cmd;
3041         if (*opt++ != '-')
3042                 return -1;
3043         cmd = *opt++;
3044         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3045                 return -1; /* that is not a -M, -C nor -B option */
3047         opt1 = parse_num(&opt);
3048         if (cmd != 'B')
3049                 opt2 = 0;
3050         else {
3051                 if (*opt == 0)
3052                         opt2 = 0;
3053                 else if (*opt != '/')
3054                         return -1; /* we expect -B80/99 or -B80 */
3055                 else {
3056                         opt++;
3057                         opt2 = parse_num(&opt);
3058                 }
3059         }
3060         if (*opt != 0)
3061                 return -1;
3062         return opt1 | (opt2 << 16);
3065 struct diff_queue_struct diff_queued_diff;
3067 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3069         if (queue->alloc <= queue->nr) {
3070                 queue->alloc = alloc_nr(queue->alloc);
3071                 queue->queue = xrealloc(queue->queue,
3072                                         sizeof(dp) * queue->alloc);
3073         }
3074         queue->queue[queue->nr++] = dp;
3077 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3078                                  struct diff_filespec *one,
3079                                  struct diff_filespec *two)
3081         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3082         dp->one = one;
3083         dp->two = two;
3084         if (queue)
3085                 diff_q(queue, dp);
3086         return dp;
3089 void diff_free_filepair(struct diff_filepair *p)
3091         free_filespec(p->one);
3092         free_filespec(p->two);
3093         free(p);
3096 /* This is different from find_unique_abbrev() in that
3097  * it stuffs the result with dots for alignment.
3098  */
3099 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3101         int abblen;
3102         const char *abbrev;
3103         if (len == 40)
3104                 return sha1_to_hex(sha1);
3106         abbrev = find_unique_abbrev(sha1, len);
3107         abblen = strlen(abbrev);
3108         if (abblen < 37) {
3109                 static char hex[41];
3110                 if (len < abblen && abblen <= len + 2)
3111                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3112                 else
3113                         sprintf(hex, "%s...", abbrev);
3114                 return hex;
3115         }
3116         return sha1_to_hex(sha1);
3119 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3121         int line_termination = opt->line_termination;
3122         int inter_name_termination = line_termination ? '\t' : '\0';
3124         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3125                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3126                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3127                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3128         }
3129         if (p->score) {
3130                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3131                         inter_name_termination);
3132         } else {
3133                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3134         }
3136         if (p->status == DIFF_STATUS_COPIED ||
3137             p->status == DIFF_STATUS_RENAMED) {
3138                 const char *name_a, *name_b;
3139                 name_a = p->one->path;
3140                 name_b = p->two->path;
3141                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3142                 write_name_quoted(name_a, opt->file, inter_name_termination);
3143                 write_name_quoted(name_b, opt->file, line_termination);
3144         } else {
3145                 const char *name_a, *name_b;
3146                 name_a = p->one->mode ? p->one->path : p->two->path;
3147                 name_b = NULL;
3148                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3149                 write_name_quoted(name_a, opt->file, line_termination);
3150         }
3153 int diff_unmodified_pair(struct diff_filepair *p)
3155         /* This function is written stricter than necessary to support
3156          * the currently implemented transformers, but the idea is to
3157          * let transformers to produce diff_filepairs any way they want,
3158          * and filter and clean them up here before producing the output.
3159          */
3160         struct diff_filespec *one = p->one, *two = p->two;
3162         if (DIFF_PAIR_UNMERGED(p))
3163                 return 0; /* unmerged is interesting */
3165         /* deletion, addition, mode or type change
3166          * and rename are all interesting.
3167          */
3168         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3169             DIFF_PAIR_MODE_CHANGED(p) ||
3170             strcmp(one->path, two->path))
3171                 return 0;
3173         /* both are valid and point at the same path.  that is, we are
3174          * dealing with a change.
3175          */
3176         if (one->sha1_valid && two->sha1_valid &&
3177             !hashcmp(one->sha1, two->sha1) &&
3178             !one->dirty_submodule && !two->dirty_submodule)
3179                 return 1; /* no change */
3180         if (!one->sha1_valid && !two->sha1_valid)
3181                 return 1; /* both look at the same file on the filesystem. */
3182         return 0;
3185 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3187         if (diff_unmodified_pair(p))
3188                 return;
3190         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3191             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3192                 return; /* no tree diffs in patch format */
3194         run_diff(p, o);
3197 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3198                             struct diffstat_t *diffstat)
3200         if (diff_unmodified_pair(p))
3201                 return;
3203         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3204             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3205                 return; /* no tree diffs in patch format */
3207         run_diffstat(p, o, diffstat);
3210 static void diff_flush_checkdiff(struct diff_filepair *p,
3211                 struct diff_options *o)
3213         if (diff_unmodified_pair(p))
3214                 return;
3216         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3217             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3218                 return; /* no tree diffs in patch format */
3220         run_checkdiff(p, o);
3223 int diff_queue_is_empty(void)
3225         struct diff_queue_struct *q = &diff_queued_diff;
3226         int i;
3227         for (i = 0; i < q->nr; i++)
3228                 if (!diff_unmodified_pair(q->queue[i]))
3229                         return 0;
3230         return 1;
3233 #if DIFF_DEBUG
3234 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3236         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3237                 x, one ? one : "",
3238                 s->path,
3239                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3240                 s->mode,
3241                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3242         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3243                 x, one ? one : "",
3244                 s->size, s->xfrm_flags);
3247 void diff_debug_filepair(const struct diff_filepair *p, int i)
3249         diff_debug_filespec(p->one, i, "one");
3250         diff_debug_filespec(p->two, i, "two");
3251         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3252                 p->score, p->status ? p->status : '?',
3253                 p->one->rename_used, p->broken_pair);
3256 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3258         int i;
3259         if (msg)
3260                 fprintf(stderr, "%s\n", msg);
3261         fprintf(stderr, "q->nr = %d\n", q->nr);
3262         for (i = 0; i < q->nr; i++) {
3263                 struct diff_filepair *p = q->queue[i];
3264                 diff_debug_filepair(p, i);
3265         }
3267 #endif
3269 static void diff_resolve_rename_copy(void)
3271         int i;
3272         struct diff_filepair *p;
3273         struct diff_queue_struct *q = &diff_queued_diff;
3275         diff_debug_queue("resolve-rename-copy", q);
3277         for (i = 0; i < q->nr; i++) {
3278                 p = q->queue[i];
3279                 p->status = 0; /* undecided */
3280                 if (DIFF_PAIR_UNMERGED(p))
3281                         p->status = DIFF_STATUS_UNMERGED;
3282                 else if (!DIFF_FILE_VALID(p->one))
3283                         p->status = DIFF_STATUS_ADDED;
3284                 else if (!DIFF_FILE_VALID(p->two))
3285                         p->status = DIFF_STATUS_DELETED;
3286                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3287                         p->status = DIFF_STATUS_TYPE_CHANGED;
3289                 /* from this point on, we are dealing with a pair
3290                  * whose both sides are valid and of the same type, i.e.
3291                  * either in-place edit or rename/copy edit.
3292                  */
3293                 else if (DIFF_PAIR_RENAME(p)) {
3294                         /*
3295                          * A rename might have re-connected a broken
3296                          * pair up, causing the pathnames to be the
3297                          * same again. If so, that's not a rename at
3298                          * all, just a modification..
3299                          *
3300                          * Otherwise, see if this source was used for
3301                          * multiple renames, in which case we decrement
3302                          * the count, and call it a copy.
3303                          */
3304                         if (!strcmp(p->one->path, p->two->path))
3305                                 p->status = DIFF_STATUS_MODIFIED;
3306                         else if (--p->one->rename_used > 0)
3307                                 p->status = DIFF_STATUS_COPIED;
3308                         else
3309                                 p->status = DIFF_STATUS_RENAMED;
3310                 }
3311                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3312                          p->one->mode != p->two->mode ||
3313                          p->one->dirty_submodule ||
3314                          p->two->dirty_submodule ||
3315                          is_null_sha1(p->one->sha1))
3316                         p->status = DIFF_STATUS_MODIFIED;
3317                 else {
3318                         /* This is a "no-change" entry and should not
3319                          * happen anymore, but prepare for broken callers.
3320                          */
3321                         error("feeding unmodified %s to diffcore",
3322                               p->one->path);
3323                         p->status = DIFF_STATUS_UNKNOWN;
3324                 }
3325         }
3326         diff_debug_queue("resolve-rename-copy done", q);
3329 static int check_pair_status(struct diff_filepair *p)
3331         switch (p->status) {
3332         case DIFF_STATUS_UNKNOWN:
3333                 return 0;
3334         case 0:
3335                 die("internal error in diff-resolve-rename-copy");
3336         default:
3337                 return 1;
3338         }
3341 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3343         int fmt = opt->output_format;
3345         if (fmt & DIFF_FORMAT_CHECKDIFF)
3346                 diff_flush_checkdiff(p, opt);
3347         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3348                 diff_flush_raw(p, opt);
3349         else if (fmt & DIFF_FORMAT_NAME) {
3350                 const char *name_a, *name_b;
3351                 name_a = p->two->path;
3352                 name_b = NULL;
3353                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3354                 write_name_quoted(name_a, opt->file, opt->line_termination);
3355         }
3358 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3360         if (fs->mode)
3361                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3362         else
3363                 fprintf(file, " %s ", newdelete);
3364         write_name_quoted(fs->path, file, '\n');
3368 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3370         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3371                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3372                         show_name ? ' ' : '\n');
3373                 if (show_name) {
3374                         write_name_quoted(p->two->path, file, '\n');
3375                 }
3376         }
3379 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3381         char *names = pprint_rename(p->one->path, p->two->path);
3383         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3384         free(names);
3385         show_mode_change(file, p, 0);
3388 static void diff_summary(FILE *file, struct diff_filepair *p)
3390         switch(p->status) {
3391         case DIFF_STATUS_DELETED:
3392                 show_file_mode_name(file, "delete", p->one);
3393                 break;
3394         case DIFF_STATUS_ADDED:
3395                 show_file_mode_name(file, "create", p->two);
3396                 break;
3397         case DIFF_STATUS_COPIED:
3398                 show_rename_copy(file, "copy", p);
3399                 break;
3400         case DIFF_STATUS_RENAMED:
3401                 show_rename_copy(file, "rename", p);
3402                 break;
3403         default:
3404                 if (p->score) {
3405                         fputs(" rewrite ", file);
3406                         write_name_quoted(p->two->path, file, ' ');
3407                         fprintf(file, "(%d%%)\n", similarity_index(p));
3408                 }
3409                 show_mode_change(file, p, !p->score);
3410                 break;
3411         }
3414 struct patch_id_t {
3415         git_SHA_CTX *ctx;
3416         int patchlen;
3417 };
3419 static int remove_space(char *line, int len)
3421         int i;
3422         char *dst = line;
3423         unsigned char c;
3425         for (i = 0; i < len; i++)
3426                 if (!isspace((c = line[i])))
3427                         *dst++ = c;
3429         return dst - line;
3432 static void patch_id_consume(void *priv, char *line, unsigned long len)
3434         struct patch_id_t *data = priv;
3435         int new_len;
3437         /* Ignore line numbers when computing the SHA1 of the patch */
3438         if (!prefixcmp(line, "@@ -"))
3439                 return;
3441         new_len = remove_space(line, len);
3443         git_SHA1_Update(data->ctx, line, new_len);
3444         data->patchlen += new_len;
3447 /* returns 0 upon success, and writes result into sha1 */
3448 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3450         struct diff_queue_struct *q = &diff_queued_diff;
3451         int i;
3452         git_SHA_CTX ctx;
3453         struct patch_id_t data;
3454         char buffer[PATH_MAX * 4 + 20];
3456         git_SHA1_Init(&ctx);
3457         memset(&data, 0, sizeof(struct patch_id_t));
3458         data.ctx = &ctx;
3460         for (i = 0; i < q->nr; i++) {
3461                 xpparam_t xpp;
3462                 xdemitconf_t xecfg;
3463                 mmfile_t mf1, mf2;
3464                 struct diff_filepair *p = q->queue[i];
3465                 int len1, len2;
3467                 memset(&xpp, 0, sizeof(xpp));
3468                 memset(&xecfg, 0, sizeof(xecfg));
3469                 if (p->status == 0)
3470                         return error("internal diff status error");
3471                 if (p->status == DIFF_STATUS_UNKNOWN)
3472                         continue;
3473                 if (diff_unmodified_pair(p))
3474                         continue;
3475                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3476                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3477                         continue;
3478                 if (DIFF_PAIR_UNMERGED(p))
3479                         continue;
3481                 diff_fill_sha1_info(p->one);
3482                 diff_fill_sha1_info(p->two);
3483                 if (fill_mmfile(&mf1, p->one) < 0 ||
3484                                 fill_mmfile(&mf2, p->two) < 0)
3485                         return error("unable to read files to diff");
3487                 len1 = remove_space(p->one->path, strlen(p->one->path));
3488                 len2 = remove_space(p->two->path, strlen(p->two->path));
3489                 if (p->one->mode == 0)
3490                         len1 = snprintf(buffer, sizeof(buffer),
3491                                         "diff--gita/%.*sb/%.*s"
3492                                         "newfilemode%06o"
3493                                         "---/dev/null"
3494                                         "+++b/%.*s",
3495                                         len1, p->one->path,
3496                                         len2, p->two->path,
3497                                         p->two->mode,
3498                                         len2, p->two->path);
3499                 else if (p->two->mode == 0)
3500                         len1 = snprintf(buffer, sizeof(buffer),
3501                                         "diff--gita/%.*sb/%.*s"
3502                                         "deletedfilemode%06o"
3503                                         "---a/%.*s"
3504                                         "+++/dev/null",
3505                                         len1, p->one->path,
3506                                         len2, p->two->path,
3507                                         p->one->mode,
3508                                         len1, p->one->path);
3509                 else
3510                         len1 = snprintf(buffer, sizeof(buffer),
3511                                         "diff--gita/%.*sb/%.*s"
3512                                         "---a/%.*s"
3513                                         "+++b/%.*s",
3514                                         len1, p->one->path,
3515                                         len2, p->two->path,
3516                                         len1, p->one->path,
3517                                         len2, p->two->path);
3518                 git_SHA1_Update(&ctx, buffer, len1);
3520                 xpp.flags = XDF_NEED_MINIMAL;
3521                 xecfg.ctxlen = 3;
3522                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3523                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3524                               &xpp, &xecfg);
3525         }
3527         git_SHA1_Final(sha1, &ctx);
3528         return 0;
3531 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3533         struct diff_queue_struct *q = &diff_queued_diff;
3534         int i;
3535         int result = diff_get_patch_id(options, sha1);
3537         for (i = 0; i < q->nr; i++)
3538                 diff_free_filepair(q->queue[i]);
3540         free(q->queue);
3541         DIFF_QUEUE_CLEAR(q);
3543         return result;
3546 static int is_summary_empty(const struct diff_queue_struct *q)
3548         int i;
3550         for (i = 0; i < q->nr; i++) {
3551                 const struct diff_filepair *p = q->queue[i];
3553                 switch (p->status) {
3554                 case DIFF_STATUS_DELETED:
3555                 case DIFF_STATUS_ADDED:
3556                 case DIFF_STATUS_COPIED:
3557                 case DIFF_STATUS_RENAMED:
3558                         return 0;
3559                 default:
3560                         if (p->score)
3561                                 return 0;
3562                         if (p->one->mode && p->two->mode &&
3563                             p->one->mode != p->two->mode)
3564                                 return 0;
3565                         break;
3566                 }
3567         }
3568         return 1;
3571 void diff_flush(struct diff_options *options)
3573         struct diff_queue_struct *q = &diff_queued_diff;
3574         int i, output_format = options->output_format;
3575         int separator = 0;
3577         /*
3578          * Order: raw, stat, summary, patch
3579          * or:    name/name-status/checkdiff (other bits clear)
3580          */
3581         if (!q->nr)
3582                 goto free_queue;
3584         if (output_format & (DIFF_FORMAT_RAW |
3585                              DIFF_FORMAT_NAME |
3586                              DIFF_FORMAT_NAME_STATUS |
3587                              DIFF_FORMAT_CHECKDIFF)) {
3588                 for (i = 0; i < q->nr; i++) {
3589                         struct diff_filepair *p = q->queue[i];
3590                         if (check_pair_status(p))
3591                                 flush_one_pair(p, options);
3592                 }
3593                 separator++;
3594         }
3596         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3597                 struct diffstat_t diffstat;
3599                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3600                 for (i = 0; i < q->nr; i++) {
3601                         struct diff_filepair *p = q->queue[i];
3602                         if (check_pair_status(p))
3603                                 diff_flush_stat(p, options, &diffstat);
3604                 }
3605                 if (output_format & DIFF_FORMAT_NUMSTAT)
3606                         show_numstat(&diffstat, options);
3607                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3608                         show_stats(&diffstat, options);
3609                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3610                         show_shortstats(&diffstat, options);
3611                 free_diffstat_info(&diffstat);
3612                 separator++;
3613         }
3614         if (output_format & DIFF_FORMAT_DIRSTAT)
3615                 show_dirstat(options);
3617         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3618                 for (i = 0; i < q->nr; i++)
3619                         diff_summary(options->file, q->queue[i]);
3620                 separator++;
3621         }
3623         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3624             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3625             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3626                 /*
3627                  * run diff_flush_patch for the exit status. setting
3628                  * options->file to /dev/null should be safe, becaue we
3629                  * aren't supposed to produce any output anyway.
3630                  */
3631                 if (options->close_file)
3632                         fclose(options->file);
3633                 options->file = fopen("/dev/null", "w");
3634                 if (!options->file)
3635                         die_errno("Could not open /dev/null");
3636                 options->close_file = 1;
3637                 for (i = 0; i < q->nr; i++) {
3638                         struct diff_filepair *p = q->queue[i];
3639                         if (check_pair_status(p))
3640                                 diff_flush_patch(p, options);
3641                         if (options->found_changes)
3642                                 break;
3643                 }
3644         }
3646         if (output_format & DIFF_FORMAT_PATCH) {
3647                 if (separator) {
3648                         putc(options->line_termination, options->file);
3649                         if (options->stat_sep) {
3650                                 /* attach patch instead of inline */
3651                                 fputs(options->stat_sep, options->file);
3652                         }
3653                 }
3655                 for (i = 0; i < q->nr; i++) {
3656                         struct diff_filepair *p = q->queue[i];
3657                         if (check_pair_status(p))
3658                                 diff_flush_patch(p, options);
3659                 }
3660         }
3662         if (output_format & DIFF_FORMAT_CALLBACK)
3663                 options->format_callback(q, options, options->format_callback_data);
3665         for (i = 0; i < q->nr; i++)
3666                 diff_free_filepair(q->queue[i]);
3667 free_queue:
3668         free(q->queue);
3669         DIFF_QUEUE_CLEAR(q);
3670         if (options->close_file)
3671                 fclose(options->file);
3673         /*
3674          * Report the content-level differences with HAS_CHANGES;
3675          * diff_addremove/diff_change does not set the bit when
3676          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3677          */
3678         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3679                 if (options->found_changes)
3680                         DIFF_OPT_SET(options, HAS_CHANGES);
3681                 else
3682                         DIFF_OPT_CLR(options, HAS_CHANGES);
3683         }
3686 static void diffcore_apply_filter(const char *filter)
3688         int i;
3689         struct diff_queue_struct *q = &diff_queued_diff;
3690         struct diff_queue_struct outq;
3691         DIFF_QUEUE_CLEAR(&outq);
3693         if (!filter)
3694                 return;
3696         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3697                 int found;
3698                 for (i = found = 0; !found && i < q->nr; i++) {
3699                         struct diff_filepair *p = q->queue[i];
3700                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3701                              ((p->score &&
3702                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3703                               (!p->score &&
3704                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3705                             ((p->status != DIFF_STATUS_MODIFIED) &&
3706                              strchr(filter, p->status)))
3707                                 found++;
3708                 }
3709                 if (found)
3710                         return;
3712                 /* otherwise we will clear the whole queue
3713                  * by copying the empty outq at the end of this
3714                  * function, but first clear the current entries
3715                  * in the queue.
3716                  */
3717                 for (i = 0; i < q->nr; i++)
3718                         diff_free_filepair(q->queue[i]);
3719         }
3720         else {
3721                 /* Only the matching ones */
3722                 for (i = 0; i < q->nr; i++) {
3723                         struct diff_filepair *p = q->queue[i];
3725                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3726                              ((p->score &&
3727                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3728                               (!p->score &&
3729                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3730                             ((p->status != DIFF_STATUS_MODIFIED) &&
3731                              strchr(filter, p->status)))
3732                                 diff_q(&outq, p);
3733                         else
3734                                 diff_free_filepair(p);
3735                 }
3736         }
3737         free(q->queue);
3738         *q = outq;
3741 /* Check whether two filespecs with the same mode and size are identical */
3742 static int diff_filespec_is_identical(struct diff_filespec *one,
3743                                       struct diff_filespec *two)
3745         if (S_ISGITLINK(one->mode))
3746                 return 0;
3747         if (diff_populate_filespec(one, 0))
3748                 return 0;
3749         if (diff_populate_filespec(two, 0))
3750                 return 0;
3751         return !memcmp(one->data, two->data, one->size);
3754 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3756         int i;
3757         struct diff_queue_struct *q = &diff_queued_diff;
3758         struct diff_queue_struct outq;
3759         DIFF_QUEUE_CLEAR(&outq);
3761         for (i = 0; i < q->nr; i++) {
3762                 struct diff_filepair *p = q->queue[i];
3764                 /*
3765                  * 1. Entries that come from stat info dirtiness
3766                  *    always have both sides (iow, not create/delete),
3767                  *    one side of the object name is unknown, with
3768                  *    the same mode and size.  Keep the ones that
3769                  *    do not match these criteria.  They have real
3770                  *    differences.
3771                  *
3772                  * 2. At this point, the file is known to be modified,
3773                  *    with the same mode and size, and the object
3774                  *    name of one side is unknown.  Need to inspect
3775                  *    the identical contents.
3776                  */
3777                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3778                     !DIFF_FILE_VALID(p->two) ||
3779                     (p->one->sha1_valid && p->two->sha1_valid) ||
3780                     (p->one->mode != p->two->mode) ||
3781                     diff_populate_filespec(p->one, 1) ||
3782                     diff_populate_filespec(p->two, 1) ||
3783                     (p->one->size != p->two->size) ||
3784                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3785                         diff_q(&outq, p);
3786                 else {
3787                         /*
3788                          * The caller can subtract 1 from skip_stat_unmatch
3789                          * to determine how many paths were dirty only
3790                          * due to stat info mismatch.
3791                          */
3792                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3793                                 diffopt->skip_stat_unmatch++;
3794                         diff_free_filepair(p);
3795                 }
3796         }
3797         free(q->queue);
3798         *q = outq;
3801 static int diffnamecmp(const void *a_, const void *b_)
3803         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3804         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3805         const char *name_a, *name_b;
3807         name_a = a->one ? a->one->path : a->two->path;
3808         name_b = b->one ? b->one->path : b->two->path;
3809         return strcmp(name_a, name_b);
3812 void diffcore_fix_diff_index(struct diff_options *options)
3814         struct diff_queue_struct *q = &diff_queued_diff;
3815         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3818 void diffcore_std(struct diff_options *options)
3820         /* We never run this function more than one time, because the
3821          * rename/copy detection logic can only run once.
3822          */
3823         if (diff_queued_diff.run)
3824                 return;
3826         if (options->skip_stat_unmatch)
3827                 diffcore_skip_stat_unmatch(options);
3828         if (options->break_opt != -1)
3829                 diffcore_break(options->break_opt);
3830         if (options->detect_rename)
3831                 diffcore_rename(options);
3832         if (options->break_opt != -1)
3833                 diffcore_merge_broken();
3834         if (options->pickaxe)
3835                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3836         if (options->orderfile)
3837                 diffcore_order(options->orderfile);
3838         diff_resolve_rename_copy();
3839         diffcore_apply_filter(options->filter);
3841         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3842                 DIFF_OPT_SET(options, HAS_CHANGES);
3843         else
3844                 DIFF_OPT_CLR(options, HAS_CHANGES);
3846         diff_queued_diff.run = 1;
3849 int diff_result_code(struct diff_options *opt, int status)
3851         int result = 0;
3852         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3853             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3854                 return status;
3855         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3856             DIFF_OPT_TST(opt, HAS_CHANGES))
3857                 result |= 01;
3858         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3859             DIFF_OPT_TST(opt, CHECK_FAILED))
3860                 result |= 02;
3861         return result;
3864 void diff_addremove(struct diff_options *options,
3865                     int addremove, unsigned mode,
3866                     const unsigned char *sha1,
3867                     const char *concatpath, unsigned dirty_submodule)
3869         struct diff_filespec *one, *two;
3871         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3872                 return;
3874         /* This may look odd, but it is a preparation for
3875          * feeding "there are unchanged files which should
3876          * not produce diffs, but when you are doing copy
3877          * detection you would need them, so here they are"
3878          * entries to the diff-core.  They will be prefixed
3879          * with something like '=' or '*' (I haven't decided
3880          * which but should not make any difference).
3881          * Feeding the same new and old to diff_change()
3882          * also has the same effect.
3883          * Before the final output happens, they are pruned after
3884          * merged into rename/copy pairs as appropriate.
3885          */
3886         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3887                 addremove = (addremove == '+' ? '-' :
3888                              addremove == '-' ? '+' : addremove);
3890         if (options->prefix &&
3891             strncmp(concatpath, options->prefix, options->prefix_length))
3892                 return;
3894         one = alloc_filespec(concatpath);
3895         two = alloc_filespec(concatpath);
3897         if (addremove != '+')
3898                 fill_filespec(one, sha1, mode);
3899         if (addremove != '-') {
3900                 fill_filespec(two, sha1, mode);
3901                 two->dirty_submodule = dirty_submodule;
3902         }
3904         diff_queue(&diff_queued_diff, one, two);
3905         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3906                 DIFF_OPT_SET(options, HAS_CHANGES);
3909 void diff_change(struct diff_options *options,
3910                  unsigned old_mode, unsigned new_mode,
3911                  const unsigned char *old_sha1,
3912                  const unsigned char *new_sha1,
3913                  const char *concatpath,
3914                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3916         struct diff_filespec *one, *two;
3918         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3919                         && S_ISGITLINK(new_mode))
3920                 return;
3922         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3923                 unsigned tmp;
3924                 const unsigned char *tmp_c;
3925                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3926                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3927                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3928                         new_dirty_submodule = tmp;
3929         }
3931         if (options->prefix &&
3932             strncmp(concatpath, options->prefix, options->prefix_length))
3933                 return;
3935         one = alloc_filespec(concatpath);
3936         two = alloc_filespec(concatpath);
3937         fill_filespec(one, old_sha1, old_mode);
3938         fill_filespec(two, new_sha1, new_mode);
3939         one->dirty_submodule = old_dirty_submodule;
3940         two->dirty_submodule = new_dirty_submodule;
3942         diff_queue(&diff_queued_diff, one, two);
3943         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3944                 DIFF_OPT_SET(options, HAS_CHANGES);
3947 void diff_unmerge(struct diff_options *options,
3948                   const char *path,
3949                   unsigned mode, const unsigned char *sha1)
3951         struct diff_filespec *one, *two;
3953         if (options->prefix &&
3954             strncmp(path, options->prefix, options->prefix_length))
3955                 return;
3957         one = alloc_filespec(path);
3958         two = alloc_filespec(path);
3959         fill_filespec(one, sha1, mode);
3960         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3963 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3964                 size_t *outsize)
3966         struct diff_tempfile *temp;
3967         const char *argv[3];
3968         const char **arg = argv;
3969         struct child_process child;
3970         struct strbuf buf = STRBUF_INIT;
3971         int err = 0;
3973         temp = prepare_temp_file(spec->path, spec);
3974         *arg++ = pgm;
3975         *arg++ = temp->name;
3976         *arg = NULL;
3978         memset(&child, 0, sizeof(child));
3979         child.use_shell = 1;
3980         child.argv = argv;
3981         child.out = -1;
3982         if (start_command(&child)) {
3983                 remove_tempfile();
3984                 return NULL;
3985         }
3987         if (strbuf_read(&buf, child.out, 0) < 0)
3988                 err = error("error reading from textconv command '%s'", pgm);
3989         close(child.out);
3991         if (finish_command(&child) || err) {
3992                 strbuf_release(&buf);
3993                 remove_tempfile();
3994                 return NULL;
3995         }
3996         remove_tempfile();
3998         return strbuf_detach(&buf, outsize);
4001 size_t fill_textconv(struct userdiff_driver *driver,
4002                      struct diff_filespec *df,
4003                      char **outbuf)
4005         size_t size;
4007         if (!driver || !driver->textconv) {
4008                 if (!DIFF_FILE_VALID(df)) {
4009                         *outbuf = "";
4010                         return 0;
4011                 }
4012                 if (diff_populate_filespec(df, 0))
4013                         die("unable to read files to diff");
4014                 *outbuf = df->data;
4015                 return df->size;
4016         }
4018         if (driver->textconv_cache) {
4019                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4020                                           &size);
4021                 if (*outbuf)
4022                         return size;
4023         }
4025         *outbuf = run_textconv(driver->textconv, df, &size);
4026         if (!*outbuf)
4027                 die("unable to read files to diff");
4029         if (driver->textconv_cache) {
4030                 /* ignore errors, as we might be in a readonly repository */
4031                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4032                                 size);
4033                 /*
4034                  * we could save up changes and flush them all at the end,
4035                  * but we would need an extra call after all diffing is done.
4036                  * Since generating a cache entry is the slow path anyway,
4037                  * this extra overhead probably isn't a big deal.
4038                  */
4039                 notes_cache_write(driver->textconv_cache);
4040         }
4042         return size;