Code

Merge branch 'mg/maint-difftool-vim-readonly' into maint
[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;
33 static int diff_no_prefix;
34 static struct diff_options default_diff_options;
36 static char diff_colors[][COLOR_MAXLEN] = {
37         GIT_COLOR_RESET,
38         GIT_COLOR_NORMAL,       /* PLAIN */
39         GIT_COLOR_BOLD,         /* METAINFO */
40         GIT_COLOR_CYAN,         /* FRAGINFO */
41         GIT_COLOR_RED,          /* OLD */
42         GIT_COLOR_GREEN,        /* NEW */
43         GIT_COLOR_YELLOW,       /* COMMIT */
44         GIT_COLOR_BG_RED,       /* WHITESPACE */
45         GIT_COLOR_NORMAL,       /* FUNCINFO */
46 };
48 static int parse_diff_color_slot(const char *var, int ofs)
49 {
50         if (!strcasecmp(var+ofs, "plain"))
51                 return DIFF_PLAIN;
52         if (!strcasecmp(var+ofs, "meta"))
53                 return DIFF_METAINFO;
54         if (!strcasecmp(var+ofs, "frag"))
55                 return DIFF_FRAGINFO;
56         if (!strcasecmp(var+ofs, "old"))
57                 return DIFF_FILE_OLD;
58         if (!strcasecmp(var+ofs, "new"))
59                 return DIFF_FILE_NEW;
60         if (!strcasecmp(var+ofs, "commit"))
61                 return DIFF_COMMIT;
62         if (!strcasecmp(var+ofs, "whitespace"))
63                 return DIFF_WHITESPACE;
64         if (!strcasecmp(var+ofs, "func"))
65                 return DIFF_FUNCINFO;
66         return -1;
67 }
69 static int git_config_rename(const char *var, const char *value)
70 {
71         if (!value)
72                 return DIFF_DETECT_RENAME;
73         if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
74                 return  DIFF_DETECT_COPY;
75         return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
76 }
78 /*
79  * These are to give UI layer defaults.
80  * The core-level commands such as git-diff-files should
81  * never be affected by the setting of diff.renames
82  * the user happens to have in the configuration file.
83  */
84 int git_diff_ui_config(const char *var, const char *value, void *cb)
85 {
86         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
87                 diff_use_color_default = git_config_colorbool(var, value, -1);
88                 return 0;
89         }
90         if (!strcmp(var, "diff.renames")) {
91                 diff_detect_rename_default = git_config_rename(var, value);
92                 return 0;
93         }
94         if (!strcmp(var, "diff.autorefreshindex")) {
95                 diff_auto_refresh_index = git_config_bool(var, value);
96                 return 0;
97         }
98         if (!strcmp(var, "diff.mnemonicprefix")) {
99                 diff_mnemonic_prefix = git_config_bool(var, value);
100                 return 0;
101         }
102         if (!strcmp(var, "diff.noprefix")) {
103                 diff_no_prefix = git_config_bool(var, value);
104                 return 0;
105         }
106         if (!strcmp(var, "diff.external"))
107                 return git_config_string(&external_diff_cmd_cfg, var, value);
108         if (!strcmp(var, "diff.wordregex"))
109                 return git_config_string(&diff_word_regex_cfg, var, value);
111         if (!strcmp(var, "diff.ignoresubmodules"))
112                 handle_ignore_submodules_arg(&default_diff_options, value);
114         return git_diff_basic_config(var, value, cb);
117 int git_diff_basic_config(const char *var, const char *value, void *cb)
119         if (!strcmp(var, "diff.renamelimit")) {
120                 diff_rename_limit_default = git_config_int(var, value);
121                 return 0;
122         }
124         switch (userdiff_config(var, value)) {
125                 case 0: break;
126                 case -1: return -1;
127                 default: return 0;
128         }
130         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
131                 int slot = parse_diff_color_slot(var, 11);
132                 if (slot < 0)
133                         return 0;
134                 if (!value)
135                         return config_error_nonbool(var);
136                 color_parse(value, var, diff_colors[slot]);
137                 return 0;
138         }
140         /* like GNU diff's --suppress-blank-empty option  */
141         if (!strcmp(var, "diff.suppressblankempty") ||
142                         /* for backwards compatibility */
143                         !strcmp(var, "diff.suppress-blank-empty")) {
144                 diff_suppress_blank_empty = git_config_bool(var, value);
145                 return 0;
146         }
148         if (!prefixcmp(var, "submodule."))
149                 return parse_submodule_config_option(var, value);
151         return git_color_default_config(var, value, cb);
154 static char *quote_two(const char *one, const char *two)
156         int need_one = quote_c_style(one, NULL, NULL, 1);
157         int need_two = quote_c_style(two, NULL, NULL, 1);
158         struct strbuf res = STRBUF_INIT;
160         if (need_one + need_two) {
161                 strbuf_addch(&res, '"');
162                 quote_c_style(one, &res, NULL, 1);
163                 quote_c_style(two, &res, NULL, 1);
164                 strbuf_addch(&res, '"');
165         } else {
166                 strbuf_addstr(&res, one);
167                 strbuf_addstr(&res, two);
168         }
169         return strbuf_detach(&res, NULL);
172 static const char *external_diff(void)
174         static const char *external_diff_cmd = NULL;
175         static int done_preparing = 0;
177         if (done_preparing)
178                 return external_diff_cmd;
179         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
180         if (!external_diff_cmd)
181                 external_diff_cmd = external_diff_cmd_cfg;
182         done_preparing = 1;
183         return external_diff_cmd;
186 static struct diff_tempfile {
187         const char *name; /* filename external diff should read from */
188         char hex[41];
189         char mode[10];
190         char tmp_path[PATH_MAX];
191 } diff_temp[2];
193 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
195 struct emit_callback {
196         int color_diff;
197         unsigned ws_rule;
198         int blank_at_eof_in_preimage;
199         int blank_at_eof_in_postimage;
200         int lno_in_preimage;
201         int lno_in_postimage;
202         sane_truncate_fn truncate;
203         const char **label_path;
204         struct diff_words_data *diff_words;
205         struct diff_options *opt;
206         int *found_changesp;
207         struct strbuf *header;
208 };
210 static int count_lines(const char *data, int size)
212         int count, ch, completely_empty = 1, nl_just_seen = 0;
213         count = 0;
214         while (0 < size--) {
215                 ch = *data++;
216                 if (ch == '\n') {
217                         count++;
218                         nl_just_seen = 1;
219                         completely_empty = 0;
220                 }
221                 else {
222                         nl_just_seen = 0;
223                         completely_empty = 0;
224                 }
225         }
226         if (completely_empty)
227                 return 0;
228         if (!nl_just_seen)
229                 count++; /* no trailing newline */
230         return count;
233 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
235         if (!DIFF_FILE_VALID(one)) {
236                 mf->ptr = (char *)""; /* does not matter */
237                 mf->size = 0;
238                 return 0;
239         }
240         else if (diff_populate_filespec(one, 0))
241                 return -1;
243         mf->ptr = one->data;
244         mf->size = one->size;
245         return 0;
248 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
250         char *ptr = mf->ptr;
251         long size = mf->size;
252         int cnt = 0;
254         if (!size)
255                 return cnt;
256         ptr += size - 1; /* pointing at the very end */
257         if (*ptr != '\n')
258                 ; /* incomplete line */
259         else
260                 ptr--; /* skip the last LF */
261         while (mf->ptr < ptr) {
262                 char *prev_eol;
263                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
264                         if (*prev_eol == '\n')
265                                 break;
266                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
267                         break;
268                 cnt++;
269                 ptr = prev_eol - 1;
270         }
271         return cnt;
274 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
275                                struct emit_callback *ecbdata)
277         int l1, l2, at;
278         unsigned ws_rule = ecbdata->ws_rule;
279         l1 = count_trailing_blank(mf1, ws_rule);
280         l2 = count_trailing_blank(mf2, ws_rule);
281         if (l2 <= l1) {
282                 ecbdata->blank_at_eof_in_preimage = 0;
283                 ecbdata->blank_at_eof_in_postimage = 0;
284                 return;
285         }
286         at = count_lines(mf1->ptr, mf1->size);
287         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
289         at = count_lines(mf2->ptr, mf2->size);
290         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
293 static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
294                         int first, const char *line, int len)
296         int has_trailing_newline, has_trailing_carriage_return;
297         int nofirst;
298         FILE *file = o->file;
300         if (o->output_prefix) {
301                 struct strbuf *msg = NULL;
302                 msg = o->output_prefix(o, o->output_prefix_data);
303                 assert(msg);
304                 fwrite(msg->buf, msg->len, 1, file);
305         }
307         if (len == 0) {
308                 has_trailing_newline = (first == '\n');
309                 has_trailing_carriage_return = (!has_trailing_newline &&
310                                                 (first == '\r'));
311                 nofirst = has_trailing_newline || has_trailing_carriage_return;
312         } else {
313                 has_trailing_newline = (len > 0 && line[len-1] == '\n');
314                 if (has_trailing_newline)
315                         len--;
316                 has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
317                 if (has_trailing_carriage_return)
318                         len--;
319                 nofirst = 0;
320         }
322         if (len || !nofirst) {
323                 fputs(set, file);
324                 if (!nofirst)
325                         fputc(first, file);
326                 fwrite(line, len, 1, file);
327                 fputs(reset, file);
328         }
329         if (has_trailing_carriage_return)
330                 fputc('\r', file);
331         if (has_trailing_newline)
332                 fputc('\n', file);
335 static void emit_line(struct diff_options *o, const char *set, const char *reset,
336                       const char *line, int len)
338         emit_line_0(o, set, reset, line[0], line+1, len-1);
341 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
343         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
344               ecbdata->blank_at_eof_in_preimage &&
345               ecbdata->blank_at_eof_in_postimage &&
346               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
347               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
348                 return 0;
349         return ws_blank_line(line, len, ecbdata->ws_rule);
352 static void emit_add_line(const char *reset,
353                           struct emit_callback *ecbdata,
354                           const char *line, int len)
356         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
357         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
359         if (!*ws)
360                 emit_line_0(ecbdata->opt, set, reset, '+', line, len);
361         else if (new_blank_line_at_eof(ecbdata, line, len))
362                 /* Blank line at EOF - paint '+' as well */
363                 emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
364         else {
365                 /* Emit just the prefix, then the rest. */
366                 emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
367                 ws_check_emit(line, len, ecbdata->ws_rule,
368                               ecbdata->opt->file, set, reset, ws);
369         }
372 static void emit_hunk_header(struct emit_callback *ecbdata,
373                              const char *line, int len)
375         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
376         const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
377         const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
378         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
379         static const char atat[2] = { '@', '@' };
380         const char *cp, *ep;
381         struct strbuf msgbuf = STRBUF_INIT;
382         int org_len = len;
383         int i = 1;
385         /*
386          * As a hunk header must begin with "@@ -<old>, +<new> @@",
387          * it always is at least 10 bytes long.
388          */
389         if (len < 10 ||
390             memcmp(line, atat, 2) ||
391             !(ep = memmem(line + 2, len - 2, atat, 2))) {
392                 emit_line(ecbdata->opt, plain, reset, line, len);
393                 return;
394         }
395         ep += 2; /* skip over @@ */
397         /* The hunk header in fraginfo color */
398         strbuf_add(&msgbuf, frag, strlen(frag));
399         strbuf_add(&msgbuf, line, ep - line);
400         strbuf_add(&msgbuf, reset, strlen(reset));
402         /*
403          * trailing "\r\n"
404          */
405         for ( ; i < 3; i++)
406                 if (line[len - i] == '\r' || line[len - i] == '\n')
407                         len--;
409         /* blank before the func header */
410         for (cp = ep; ep - line < len; ep++)
411                 if (*ep != ' ' && *ep != '\t')
412                         break;
413         if (ep != cp) {
414                 strbuf_add(&msgbuf, plain, strlen(plain));
415                 strbuf_add(&msgbuf, cp, ep - cp);
416                 strbuf_add(&msgbuf, reset, strlen(reset));
417         }
419         if (ep < line + len) {
420                 strbuf_add(&msgbuf, func, strlen(func));
421                 strbuf_add(&msgbuf, ep, line + len - ep);
422                 strbuf_add(&msgbuf, reset, strlen(reset));
423         }
425         strbuf_add(&msgbuf, line + len, org_len - len);
426         emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
427         strbuf_release(&msgbuf);
430 static struct diff_tempfile *claim_diff_tempfile(void) {
431         int i;
432         for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
433                 if (!diff_temp[i].name)
434                         return diff_temp + i;
435         die("BUG: diff is failing to clean up its tempfiles");
438 static int remove_tempfile_installed;
440 static void remove_tempfile(void)
442         int i;
443         for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
444                 if (diff_temp[i].name == diff_temp[i].tmp_path)
445                         unlink_or_warn(diff_temp[i].name);
446                 diff_temp[i].name = NULL;
447         }
450 static void remove_tempfile_on_signal(int signo)
452         remove_tempfile();
453         sigchain_pop(signo);
454         raise(signo);
457 static void print_line_count(FILE *file, int count)
459         switch (count) {
460         case 0:
461                 fprintf(file, "0,0");
462                 break;
463         case 1:
464                 fprintf(file, "1");
465                 break;
466         default:
467                 fprintf(file, "1,%d", count);
468                 break;
469         }
472 static void emit_rewrite_lines(struct emit_callback *ecb,
473                                int prefix, const char *data, int size)
475         const char *endp = NULL;
476         static const char *nneof = " No newline at end of file\n";
477         const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
478         const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
480         while (0 < size) {
481                 int len;
483                 endp = memchr(data, '\n', size);
484                 len = endp ? (endp - data + 1) : size;
485                 if (prefix != '+') {
486                         ecb->lno_in_preimage++;
487                         emit_line_0(ecb->opt, old, reset, '-',
488                                     data, len);
489                 } else {
490                         ecb->lno_in_postimage++;
491                         emit_add_line(reset, ecb, data, len);
492                 }
493                 size -= len;
494                 data += len;
495         }
496         if (!endp) {
497                 const char *plain = diff_get_color(ecb->color_diff,
498                                                    DIFF_PLAIN);
499                 emit_line_0(ecb->opt, plain, reset, '\\',
500                             nneof, strlen(nneof));
501         }
504 static void emit_rewrite_diff(const char *name_a,
505                               const char *name_b,
506                               struct diff_filespec *one,
507                               struct diff_filespec *two,
508                               struct userdiff_driver *textconv_one,
509                               struct userdiff_driver *textconv_two,
510                               struct diff_options *o)
512         int lc_a, lc_b;
513         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
514         const char *name_a_tab, *name_b_tab;
515         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
516         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
517         const char *reset = diff_get_color(color_diff, DIFF_RESET);
518         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
519         const char *a_prefix, *b_prefix;
520         char *data_one, *data_two;
521         size_t size_one, size_two;
522         struct emit_callback ecbdata;
523         char *line_prefix = "";
524         struct strbuf *msgbuf;
526         if (o && o->output_prefix) {
527                 msgbuf = o->output_prefix(o, o->output_prefix_data);
528                 line_prefix = msgbuf->buf;
529         }
531         if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
532                 a_prefix = o->b_prefix;
533                 b_prefix = o->a_prefix;
534         } else {
535                 a_prefix = o->a_prefix;
536                 b_prefix = o->b_prefix;
537         }
539         name_a += (*name_a == '/');
540         name_b += (*name_b == '/');
541         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
542         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
544         strbuf_reset(&a_name);
545         strbuf_reset(&b_name);
546         quote_two_c_style(&a_name, a_prefix, name_a, 0);
547         quote_two_c_style(&b_name, b_prefix, name_b, 0);
549         size_one = fill_textconv(textconv_one, one, &data_one);
550         size_two = fill_textconv(textconv_two, two, &data_two);
552         memset(&ecbdata, 0, sizeof(ecbdata));
553         ecbdata.color_diff = color_diff;
554         ecbdata.found_changesp = &o->found_changes;
555         ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
556         ecbdata.opt = o;
557         if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
558                 mmfile_t mf1, mf2;
559                 mf1.ptr = (char *)data_one;
560                 mf2.ptr = (char *)data_two;
561                 mf1.size = size_one;
562                 mf2.size = size_two;
563                 check_blank_at_eof(&mf1, &mf2, &ecbdata);
564         }
565         ecbdata.lno_in_preimage = 1;
566         ecbdata.lno_in_postimage = 1;
568         lc_a = count_lines(data_one, size_one);
569         lc_b = count_lines(data_two, size_two);
570         fprintf(o->file,
571                 "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
572                 line_prefix, metainfo, a_name.buf, name_a_tab, reset,
573                 line_prefix, metainfo, b_name.buf, name_b_tab, reset,
574                 line_prefix, fraginfo);
575         print_line_count(o->file, lc_a);
576         fprintf(o->file, " +");
577         print_line_count(o->file, lc_b);
578         fprintf(o->file, " @@%s\n", reset);
579         if (lc_a)
580                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
581         if (lc_b)
582                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
583         if (textconv_one)
584                 free((char *)data_one);
585         if (textconv_two)
586                 free((char *)data_two);
589 struct diff_words_buffer {
590         mmfile_t text;
591         long alloc;
592         struct diff_words_orig {
593                 const char *begin, *end;
594         } *orig;
595         int orig_nr, orig_alloc;
596 };
598 static void diff_words_append(char *line, unsigned long len,
599                 struct diff_words_buffer *buffer)
601         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
602         line++;
603         len--;
604         memcpy(buffer->text.ptr + buffer->text.size, line, len);
605         buffer->text.size += len;
606         buffer->text.ptr[buffer->text.size] = '\0';
609 struct diff_words_style_elem {
610         const char *prefix;
611         const char *suffix;
612         const char *color; /* NULL; filled in by the setup code if
613                             * color is enabled */
614 };
616 struct diff_words_style {
617         enum diff_words_type type;
618         struct diff_words_style_elem new, old, ctx;
619         const char *newline;
620 };
622 struct diff_words_style diff_words_styles[] = {
623         { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
624         { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
625         { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
626 };
628 struct diff_words_data {
629         struct diff_words_buffer minus, plus;
630         const char *current_plus;
631         int last_minus;
632         struct diff_options *opt;
633         regex_t *word_regex;
634         enum diff_words_type type;
635         struct diff_words_style *style;
636 };
638 static int fn_out_diff_words_write_helper(FILE *fp,
639                                           struct diff_words_style_elem *st_el,
640                                           const char *newline,
641                                           size_t count, const char *buf,
642                                           const char *line_prefix)
644         int print = 0;
646         while (count) {
647                 char *p = memchr(buf, '\n', count);
648                 if (print)
649                         fputs(line_prefix, fp);
650                 if (p != buf) {
651                         if (st_el->color && fputs(st_el->color, fp) < 0)
652                                 return -1;
653                         if (fputs(st_el->prefix, fp) < 0 ||
654                             fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
655                             fputs(st_el->suffix, fp) < 0)
656                                 return -1;
657                         if (st_el->color && *st_el->color
658                             && fputs(GIT_COLOR_RESET, fp) < 0)
659                                 return -1;
660                 }
661                 if (!p)
662                         return 0;
663                 if (fputs(newline, fp) < 0)
664                         return -1;
665                 count -= p + 1 - buf;
666                 buf = p + 1;
667                 print = 1;
668         }
669         return 0;
672 /*
673  * '--color-words' algorithm can be described as:
674  *
675  *   1. collect a the minus/plus lines of a diff hunk, divided into
676  *      minus-lines and plus-lines;
677  *
678  *   2. break both minus-lines and plus-lines into words and
679  *      place them into two mmfile_t with one word for each line;
680  *
681  *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
682  *
683  * And for the common parts of the both file, we output the plus side text.
684  * diff_words->current_plus is used to trace the current position of the plus file
685  * which printed. diff_words->last_minus is used to trace the last minus word
686  * printed.
687  *
688  * For '--graph' to work with '--color-words', we need to output the graph prefix
689  * on each line of color words output. Generally, there are two conditions on
690  * which we should output the prefix.
691  *
692  *   1. diff_words->last_minus == 0 &&
693  *      diff_words->current_plus == diff_words->plus.text.ptr
694  *
695  *      that is: the plus text must start as a new line, and if there is no minus
696  *      word printed, a graph prefix must be printed.
697  *
698  *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
699  *      *(diff_words->current_plus - 1) == '\n'
700  *
701  *      that is: a graph prefix must be printed following a '\n'
702  */
703 static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
705         if ((diff_words->last_minus == 0 &&
706                 diff_words->current_plus == diff_words->plus.text.ptr) ||
707                 (diff_words->current_plus > diff_words->plus.text.ptr &&
708                 *(diff_words->current_plus - 1) == '\n')) {
709                 return 1;
710         } else {
711                 return 0;
712         }
715 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
717         struct diff_words_data *diff_words = priv;
718         struct diff_words_style *style = diff_words->style;
719         int minus_first, minus_len, plus_first, plus_len;
720         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
721         struct diff_options *opt = diff_words->opt;
722         struct strbuf *msgbuf;
723         char *line_prefix = "";
725         if (line[0] != '@' || parse_hunk_header(line, len,
726                         &minus_first, &minus_len, &plus_first, &plus_len))
727                 return;
729         assert(opt);
730         if (opt->output_prefix) {
731                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
732                 line_prefix = msgbuf->buf;
733         }
735         /* POSIX requires that first be decremented by one if len == 0... */
736         if (minus_len) {
737                 minus_begin = diff_words->minus.orig[minus_first].begin;
738                 minus_end =
739                         diff_words->minus.orig[minus_first + minus_len - 1].end;
740         } else
741                 minus_begin = minus_end =
742                         diff_words->minus.orig[minus_first].end;
744         if (plus_len) {
745                 plus_begin = diff_words->plus.orig[plus_first].begin;
746                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
747         } else
748                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
750         if (color_words_output_graph_prefix(diff_words)) {
751                 fputs(line_prefix, diff_words->opt->file);
752         }
753         if (diff_words->current_plus != plus_begin) {
754                 fn_out_diff_words_write_helper(diff_words->opt->file,
755                                 &style->ctx, style->newline,
756                                 plus_begin - diff_words->current_plus,
757                                 diff_words->current_plus, line_prefix);
758                 if (*(plus_begin - 1) == '\n')
759                         fputs(line_prefix, diff_words->opt->file);
760         }
761         if (minus_begin != minus_end) {
762                 fn_out_diff_words_write_helper(diff_words->opt->file,
763                                 &style->old, style->newline,
764                                 minus_end - minus_begin, minus_begin,
765                                 line_prefix);
766         }
767         if (plus_begin != plus_end) {
768                 fn_out_diff_words_write_helper(diff_words->opt->file,
769                                 &style->new, style->newline,
770                                 plus_end - plus_begin, plus_begin,
771                                 line_prefix);
772         }
774         diff_words->current_plus = plus_end;
775         diff_words->last_minus = minus_first;
778 /* This function starts looking at *begin, and returns 0 iff a word was found. */
779 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
780                 int *begin, int *end)
782         if (word_regex && *begin < buffer->size) {
783                 regmatch_t match[1];
784                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
785                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
786                                         '\n', match[0].rm_eo - match[0].rm_so);
787                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
788                         *begin += match[0].rm_so;
789                         return *begin >= *end;
790                 }
791                 return -1;
792         }
794         /* find the next word */
795         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
796                 (*begin)++;
797         if (*begin >= buffer->size)
798                 return -1;
800         /* find the end of the word */
801         *end = *begin + 1;
802         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
803                 (*end)++;
805         return 0;
808 /*
809  * This function splits the words in buffer->text, stores the list with
810  * newline separator into out, and saves the offsets of the original words
811  * in buffer->orig.
812  */
813 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
814                 regex_t *word_regex)
816         int i, j;
817         long alloc = 0;
819         out->size = 0;
820         out->ptr = NULL;
822         /* fake an empty "0th" word */
823         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
824         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
825         buffer->orig_nr = 1;
827         for (i = 0; i < buffer->text.size; i++) {
828                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
829                         return;
831                 /* store original boundaries */
832                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
833                                 buffer->orig_alloc);
834                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
835                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
836                 buffer->orig_nr++;
838                 /* store one word */
839                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
840                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
841                 out->ptr[out->size + j - i] = '\n';
842                 out->size += j - i + 1;
844                 i = j - 1;
845         }
848 /* this executes the word diff on the accumulated buffers */
849 static void diff_words_show(struct diff_words_data *diff_words)
851         xpparam_t xpp;
852         xdemitconf_t xecfg;
853         mmfile_t minus, plus;
854         struct diff_words_style *style = diff_words->style;
856         struct diff_options *opt = diff_words->opt;
857         struct strbuf *msgbuf;
858         char *line_prefix = "";
860         assert(opt);
861         if (opt->output_prefix) {
862                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
863                 line_prefix = msgbuf->buf;
864         }
866         /* special case: only removal */
867         if (!diff_words->plus.text.size) {
868                 fputs(line_prefix, diff_words->opt->file);
869                 fn_out_diff_words_write_helper(diff_words->opt->file,
870                         &style->old, style->newline,
871                         diff_words->minus.text.size,
872                         diff_words->minus.text.ptr, line_prefix);
873                 diff_words->minus.text.size = 0;
874                 return;
875         }
877         diff_words->current_plus = diff_words->plus.text.ptr;
878         diff_words->last_minus = 0;
880         memset(&xpp, 0, sizeof(xpp));
881         memset(&xecfg, 0, sizeof(xecfg));
882         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
883         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
884         xpp.flags = 0;
885         /* as only the hunk header will be parsed, we need a 0-context */
886         xecfg.ctxlen = 0;
887         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
888                       &xpp, &xecfg);
889         free(minus.ptr);
890         free(plus.ptr);
891         if (diff_words->current_plus != diff_words->plus.text.ptr +
892                         diff_words->plus.text.size) {
893                 if (color_words_output_graph_prefix(diff_words))
894                         fputs(line_prefix, diff_words->opt->file);
895                 fn_out_diff_words_write_helper(diff_words->opt->file,
896                         &style->ctx, style->newline,
897                         diff_words->plus.text.ptr + diff_words->plus.text.size
898                         - diff_words->current_plus, diff_words->current_plus,
899                         line_prefix);
900         }
901         diff_words->minus.text.size = diff_words->plus.text.size = 0;
904 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
905 static void diff_words_flush(struct emit_callback *ecbdata)
907         if (ecbdata->diff_words->minus.text.size ||
908             ecbdata->diff_words->plus.text.size)
909                 diff_words_show(ecbdata->diff_words);
912 static void free_diff_words_data(struct emit_callback *ecbdata)
914         if (ecbdata->diff_words) {
915                 diff_words_flush(ecbdata);
916                 free (ecbdata->diff_words->minus.text.ptr);
917                 free (ecbdata->diff_words->minus.orig);
918                 free (ecbdata->diff_words->plus.text.ptr);
919                 free (ecbdata->diff_words->plus.orig);
920                 if (ecbdata->diff_words->word_regex) {
921                         regfree(ecbdata->diff_words->word_regex);
922                         free(ecbdata->diff_words->word_regex);
923                 }
924                 free(ecbdata->diff_words);
925                 ecbdata->diff_words = NULL;
926         }
929 const char *diff_get_color(int diff_use_color, enum color_diff ix)
931         if (diff_use_color)
932                 return diff_colors[ix];
933         return "";
936 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
938         const char *cp;
939         unsigned long allot;
940         size_t l = len;
942         if (ecb->truncate)
943                 return ecb->truncate(line, len);
944         cp = line;
945         allot = l;
946         while (0 < l) {
947                 (void) utf8_width(&cp, &l);
948                 if (!cp)
949                         break; /* truncated in the middle? */
950         }
951         return allot - l;
954 static void find_lno(const char *line, struct emit_callback *ecbdata)
956         const char *p;
957         ecbdata->lno_in_preimage = 0;
958         ecbdata->lno_in_postimage = 0;
959         p = strchr(line, '-');
960         if (!p)
961                 return; /* cannot happen */
962         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
963         p = strchr(p, '+');
964         if (!p)
965                 return; /* cannot happen */
966         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
969 static void fn_out_consume(void *priv, char *line, unsigned long len)
971         struct emit_callback *ecbdata = priv;
972         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
973         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
974         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
975         struct diff_options *o = ecbdata->opt;
976         char *line_prefix = "";
977         struct strbuf *msgbuf;
979         if (o && o->output_prefix) {
980                 msgbuf = o->output_prefix(o, o->output_prefix_data);
981                 line_prefix = msgbuf->buf;
982         }
984         if (ecbdata->header) {
985                 fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
986                 strbuf_reset(ecbdata->header);
987                 ecbdata->header = NULL;
988         }
989         *(ecbdata->found_changesp) = 1;
991         if (ecbdata->label_path[0]) {
992                 const char *name_a_tab, *name_b_tab;
994                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
995                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
997                 fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
998                         line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
999                 fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1000                         line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1001                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1002         }
1004         if (diff_suppress_blank_empty
1005             && len == 2 && line[0] == ' ' && line[1] == '\n') {
1006                 line[0] = '\n';
1007                 len = 1;
1008         }
1010         if (line[0] == '@') {
1011                 if (ecbdata->diff_words)
1012                         diff_words_flush(ecbdata);
1013                 len = sane_truncate_line(ecbdata, line, len);
1014                 find_lno(line, ecbdata);
1015                 emit_hunk_header(ecbdata, line, len);
1016                 if (line[len-1] != '\n')
1017                         putc('\n', ecbdata->opt->file);
1018                 return;
1019         }
1021         if (len < 1) {
1022                 emit_line(ecbdata->opt, reset, reset, line, len);
1023                 if (ecbdata->diff_words
1024                     && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1025                         fputs("~\n", ecbdata->opt->file);
1026                 return;
1027         }
1029         if (ecbdata->diff_words) {
1030                 if (line[0] == '-') {
1031                         diff_words_append(line, len,
1032                                           &ecbdata->diff_words->minus);
1033                         return;
1034                 } else if (line[0] == '+') {
1035                         diff_words_append(line, len,
1036                                           &ecbdata->diff_words->plus);
1037                         return;
1038                 }
1039                 diff_words_flush(ecbdata);
1040                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1041                         emit_line(ecbdata->opt, plain, reset, line, len);
1042                         fputs("~\n", ecbdata->opt->file);
1043                 } else {
1044                         /* don't print the prefix character */
1045                         emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1046                 }
1047                 return;
1048         }
1050         if (line[0] != '+') {
1051                 const char *color =
1052                         diff_get_color(ecbdata->color_diff,
1053                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1054                 ecbdata->lno_in_preimage++;
1055                 if (line[0] == ' ')
1056                         ecbdata->lno_in_postimage++;
1057                 emit_line(ecbdata->opt, color, reset, line, len);
1058         } else {
1059                 ecbdata->lno_in_postimage++;
1060                 emit_add_line(reset, ecbdata, line + 1, len - 1);
1061         }
1064 static char *pprint_rename(const char *a, const char *b)
1066         const char *old = a;
1067         const char *new = b;
1068         struct strbuf name = STRBUF_INIT;
1069         int pfx_length, sfx_length;
1070         int len_a = strlen(a);
1071         int len_b = strlen(b);
1072         int a_midlen, b_midlen;
1073         int qlen_a = quote_c_style(a, NULL, NULL, 0);
1074         int qlen_b = quote_c_style(b, NULL, NULL, 0);
1076         if (qlen_a || qlen_b) {
1077                 quote_c_style(a, &name, NULL, 0);
1078                 strbuf_addstr(&name, " => ");
1079                 quote_c_style(b, &name, NULL, 0);
1080                 return strbuf_detach(&name, NULL);
1081         }
1083         /* Find common prefix */
1084         pfx_length = 0;
1085         while (*old && *new && *old == *new) {
1086                 if (*old == '/')
1087                         pfx_length = old - a + 1;
1088                 old++;
1089                 new++;
1090         }
1092         /* Find common suffix */
1093         old = a + len_a;
1094         new = b + len_b;
1095         sfx_length = 0;
1096         while (a <= old && b <= new && *old == *new) {
1097                 if (*old == '/')
1098                         sfx_length = len_a - (old - a);
1099                 old--;
1100                 new--;
1101         }
1103         /*
1104          * pfx{mid-a => mid-b}sfx
1105          * {pfx-a => pfx-b}sfx
1106          * pfx{sfx-a => sfx-b}
1107          * name-a => name-b
1108          */
1109         a_midlen = len_a - pfx_length - sfx_length;
1110         b_midlen = len_b - pfx_length - sfx_length;
1111         if (a_midlen < 0)
1112                 a_midlen = 0;
1113         if (b_midlen < 0)
1114                 b_midlen = 0;
1116         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1117         if (pfx_length + sfx_length) {
1118                 strbuf_add(&name, a, pfx_length);
1119                 strbuf_addch(&name, '{');
1120         }
1121         strbuf_add(&name, a + pfx_length, a_midlen);
1122         strbuf_addstr(&name, " => ");
1123         strbuf_add(&name, b + pfx_length, b_midlen);
1124         if (pfx_length + sfx_length) {
1125                 strbuf_addch(&name, '}');
1126                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1127         }
1128         return strbuf_detach(&name, NULL);
1131 struct diffstat_t {
1132         int nr;
1133         int alloc;
1134         struct diffstat_file {
1135                 char *from_name;
1136                 char *name;
1137                 char *print_name;
1138                 unsigned is_unmerged:1;
1139                 unsigned is_binary:1;
1140                 unsigned is_renamed:1;
1141                 uintmax_t added, deleted;
1142         } **files;
1143 };
1145 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1146                                           const char *name_a,
1147                                           const char *name_b)
1149         struct diffstat_file *x;
1150         x = xcalloc(sizeof (*x), 1);
1151         if (diffstat->nr == diffstat->alloc) {
1152                 diffstat->alloc = alloc_nr(diffstat->alloc);
1153                 diffstat->files = xrealloc(diffstat->files,
1154                                 diffstat->alloc * sizeof(x));
1155         }
1156         diffstat->files[diffstat->nr++] = x;
1157         if (name_b) {
1158                 x->from_name = xstrdup(name_a);
1159                 x->name = xstrdup(name_b);
1160                 x->is_renamed = 1;
1161         }
1162         else {
1163                 x->from_name = NULL;
1164                 x->name = xstrdup(name_a);
1165         }
1166         return x;
1169 static void diffstat_consume(void *priv, char *line, unsigned long len)
1171         struct diffstat_t *diffstat = priv;
1172         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1174         if (line[0] == '+')
1175                 x->added++;
1176         else if (line[0] == '-')
1177                 x->deleted++;
1180 const char mime_boundary_leader[] = "------------";
1182 static int scale_linear(int it, int width, int max_change)
1184         /*
1185          * make sure that at least one '-' is printed if there were deletions,
1186          * and likewise for '+'.
1187          */
1188         if (max_change < 2)
1189                 return it;
1190         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1193 static void show_name(FILE *file,
1194                       const char *prefix, const char *name, int len)
1196         fprintf(file, " %s%-*s |", prefix, len, name);
1199 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1201         if (cnt <= 0)
1202                 return;
1203         fprintf(file, "%s", set);
1204         while (cnt--)
1205                 putc(ch, file);
1206         fprintf(file, "%s", reset);
1209 static void fill_print_name(struct diffstat_file *file)
1211         char *pname;
1213         if (file->print_name)
1214                 return;
1216         if (!file->is_renamed) {
1217                 struct strbuf buf = STRBUF_INIT;
1218                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1219                         pname = strbuf_detach(&buf, NULL);
1220                 } else {
1221                         pname = file->name;
1222                         strbuf_release(&buf);
1223                 }
1224         } else {
1225                 pname = pprint_rename(file->from_name, file->name);
1226         }
1227         file->print_name = pname;
1230 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1232         int i, len, add, del, adds = 0, dels = 0;
1233         uintmax_t max_change = 0, max_len = 0;
1234         int total_files = data->nr;
1235         int width, name_width;
1236         const char *reset, *set, *add_c, *del_c;
1237         const char *line_prefix = "";
1238         struct strbuf *msg = NULL;
1240         if (data->nr == 0)
1241                 return;
1243         if (options->output_prefix) {
1244                 msg = options->output_prefix(options, options->output_prefix_data);
1245                 line_prefix = msg->buf;
1246         }
1248         width = options->stat_width ? options->stat_width : 80;
1249         name_width = options->stat_name_width ? options->stat_name_width : 50;
1251         /* Sanity: give at least 5 columns to the graph,
1252          * but leave at least 10 columns for the name.
1253          */
1254         if (width < 25)
1255                 width = 25;
1256         if (name_width < 10)
1257                 name_width = 10;
1258         else if (width < name_width + 15)
1259                 name_width = width - 15;
1261         /* Find the longest filename and max number of changes */
1262         reset = diff_get_color_opt(options, DIFF_RESET);
1263         set   = diff_get_color_opt(options, DIFF_PLAIN);
1264         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1265         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1267         for (i = 0; i < data->nr; i++) {
1268                 struct diffstat_file *file = data->files[i];
1269                 uintmax_t change = file->added + file->deleted;
1270                 fill_print_name(file);
1271                 len = strlen(file->print_name);
1272                 if (max_len < len)
1273                         max_len = len;
1275                 if (file->is_binary || file->is_unmerged)
1276                         continue;
1277                 if (max_change < change)
1278                         max_change = change;
1279         }
1281         /* Compute the width of the graph part;
1282          * 10 is for one blank at the beginning of the line plus
1283          * " | count " between the name and the graph.
1284          *
1285          * From here on, name_width is the width of the name area,
1286          * and width is the width of the graph area.
1287          */
1288         name_width = (name_width < max_len) ? name_width : max_len;
1289         if (width < (name_width + 10) + max_change)
1290                 width = width - (name_width + 10);
1291         else
1292                 width = max_change;
1294         for (i = 0; i < data->nr; i++) {
1295                 const char *prefix = "";
1296                 char *name = data->files[i]->print_name;
1297                 uintmax_t added = data->files[i]->added;
1298                 uintmax_t deleted = data->files[i]->deleted;
1299                 int name_len;
1301                 /*
1302                  * "scale" the filename
1303                  */
1304                 len = name_width;
1305                 name_len = strlen(name);
1306                 if (name_width < name_len) {
1307                         char *slash;
1308                         prefix = "...";
1309                         len -= 3;
1310                         name += name_len - len;
1311                         slash = strchr(name, '/');
1312                         if (slash)
1313                                 name = slash;
1314                 }
1316                 if (data->files[i]->is_binary) {
1317                         fprintf(options->file, "%s", line_prefix);
1318                         show_name(options->file, prefix, name, len);
1319                         fprintf(options->file, "  Bin ");
1320                         fprintf(options->file, "%s%"PRIuMAX"%s",
1321                                 del_c, deleted, reset);
1322                         fprintf(options->file, " -> ");
1323                         fprintf(options->file, "%s%"PRIuMAX"%s",
1324                                 add_c, added, reset);
1325                         fprintf(options->file, " bytes");
1326                         fprintf(options->file, "\n");
1327                         continue;
1328                 }
1329                 else if (data->files[i]->is_unmerged) {
1330                         fprintf(options->file, "%s", line_prefix);
1331                         show_name(options->file, prefix, name, len);
1332                         fprintf(options->file, "  Unmerged\n");
1333                         continue;
1334                 }
1335                 else if (!data->files[i]->is_renamed &&
1336                          (added + deleted == 0)) {
1337                         total_files--;
1338                         continue;
1339                 }
1341                 /*
1342                  * scale the add/delete
1343                  */
1344                 add = added;
1345                 del = deleted;
1346                 adds += add;
1347                 dels += del;
1349                 if (width <= max_change) {
1350                         add = scale_linear(add, width, max_change);
1351                         del = scale_linear(del, width, max_change);
1352                 }
1353                 fprintf(options->file, "%s", line_prefix);
1354                 show_name(options->file, prefix, name, len);
1355                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1356                                 added + deleted ? " " : "");
1357                 show_graph(options->file, '+', add, add_c, reset);
1358                 show_graph(options->file, '-', del, del_c, reset);
1359                 fprintf(options->file, "\n");
1360         }
1361         fprintf(options->file, "%s", line_prefix);
1362         fprintf(options->file,
1363                " %d files changed, %d insertions(+), %d deletions(-)\n",
1364                total_files, adds, dels);
1367 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1369         int i, adds = 0, dels = 0, total_files = data->nr;
1371         if (data->nr == 0)
1372                 return;
1374         for (i = 0; i < data->nr; i++) {
1375                 if (!data->files[i]->is_binary &&
1376                     !data->files[i]->is_unmerged) {
1377                         int added = data->files[i]->added;
1378                         int deleted= data->files[i]->deleted;
1379                         if (!data->files[i]->is_renamed &&
1380                             (added + deleted == 0)) {
1381                                 total_files--;
1382                         } else {
1383                                 adds += added;
1384                                 dels += deleted;
1385                         }
1386                 }
1387         }
1388         if (options->output_prefix) {
1389                 struct strbuf *msg = NULL;
1390                 msg = options->output_prefix(options,
1391                                 options->output_prefix_data);
1392                 fprintf(options->file, "%s", msg->buf);
1393         }
1394         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1395                total_files, adds, dels);
1398 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1400         int i;
1402         if (data->nr == 0)
1403                 return;
1405         for (i = 0; i < data->nr; i++) {
1406                 struct diffstat_file *file = data->files[i];
1408                 if (options->output_prefix) {
1409                         struct strbuf *msg = NULL;
1410                         msg = options->output_prefix(options,
1411                                         options->output_prefix_data);
1412                         fprintf(options->file, "%s", msg->buf);
1413                 }
1415                 if (file->is_binary)
1416                         fprintf(options->file, "-\t-\t");
1417                 else
1418                         fprintf(options->file,
1419                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1420                                 file->added, file->deleted);
1421                 if (options->line_termination) {
1422                         fill_print_name(file);
1423                         if (!file->is_renamed)
1424                                 write_name_quoted(file->name, options->file,
1425                                                   options->line_termination);
1426                         else {
1427                                 fputs(file->print_name, options->file);
1428                                 putc(options->line_termination, options->file);
1429                         }
1430                 } else {
1431                         if (file->is_renamed) {
1432                                 putc('\0', options->file);
1433                                 write_name_quoted(file->from_name, options->file, '\0');
1434                         }
1435                         write_name_quoted(file->name, options->file, '\0');
1436                 }
1437         }
1440 struct dirstat_file {
1441         const char *name;
1442         unsigned long changed;
1443 };
1445 struct dirstat_dir {
1446         struct dirstat_file *files;
1447         int alloc, nr, percent, cumulative;
1448 };
1450 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1451                 unsigned long changed, const char *base, int baselen)
1453         unsigned long this_dir = 0;
1454         unsigned int sources = 0;
1455         const char *line_prefix = "";
1456         struct strbuf *msg = NULL;
1458         if (opt->output_prefix) {
1459                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1460                 line_prefix = msg->buf;
1461         }
1463         while (dir->nr) {
1464                 struct dirstat_file *f = dir->files;
1465                 int namelen = strlen(f->name);
1466                 unsigned long this;
1467                 char *slash;
1469                 if (namelen < baselen)
1470                         break;
1471                 if (memcmp(f->name, base, baselen))
1472                         break;
1473                 slash = strchr(f->name + baselen, '/');
1474                 if (slash) {
1475                         int newbaselen = slash + 1 - f->name;
1476                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1477                         sources++;
1478                 } else {
1479                         this = f->changed;
1480                         dir->files++;
1481                         dir->nr--;
1482                         sources += 2;
1483                 }
1484                 this_dir += this;
1485         }
1487         /*
1488          * We don't report dirstat's for
1489          *  - the top level
1490          *  - or cases where everything came from a single directory
1491          *    under this directory (sources == 1).
1492          */
1493         if (baselen && sources != 1) {
1494                 int permille = this_dir * 1000 / changed;
1495                 if (permille) {
1496                         int percent = permille / 10;
1497                         if (percent >= dir->percent) {
1498                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1499                                         percent, permille % 10, baselen, base);
1500                                 if (!dir->cumulative)
1501                                         return 0;
1502                         }
1503                 }
1504         }
1505         return this_dir;
1508 static int dirstat_compare(const void *_a, const void *_b)
1510         const struct dirstat_file *a = _a;
1511         const struct dirstat_file *b = _b;
1512         return strcmp(a->name, b->name);
1515 static void show_dirstat(struct diff_options *options)
1517         int i;
1518         unsigned long changed;
1519         struct dirstat_dir dir;
1520         struct diff_queue_struct *q = &diff_queued_diff;
1522         dir.files = NULL;
1523         dir.alloc = 0;
1524         dir.nr = 0;
1525         dir.percent = options->dirstat_percent;
1526         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1528         changed = 0;
1529         for (i = 0; i < q->nr; i++) {
1530                 struct diff_filepair *p = q->queue[i];
1531                 const char *name;
1532                 unsigned long copied, added, damage;
1534                 name = p->one->path ? p->one->path : p->two->path;
1536                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1537                         diff_populate_filespec(p->one, 0);
1538                         diff_populate_filespec(p->two, 0);
1539                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1540                                                &copied, &added);
1541                         diff_free_filespec_data(p->one);
1542                         diff_free_filespec_data(p->two);
1543                 } else if (DIFF_FILE_VALID(p->one)) {
1544                         diff_populate_filespec(p->one, 1);
1545                         copied = added = 0;
1546                         diff_free_filespec_data(p->one);
1547                 } else if (DIFF_FILE_VALID(p->two)) {
1548                         diff_populate_filespec(p->two, 1);
1549                         copied = 0;
1550                         added = p->two->size;
1551                         diff_free_filespec_data(p->two);
1552                 } else
1553                         continue;
1555                 /*
1556                  * Original minus copied is the removed material,
1557                  * added is the new material.  They are both damages
1558                  * made to the preimage. In --dirstat-by-file mode, count
1559                  * damaged files, not damaged lines. This is done by
1560                  * counting only a single damaged line per file.
1561                  */
1562                 damage = (p->one->size - copied) + added;
1563                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1564                         damage = 1;
1566                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1567                 dir.files[dir.nr].name = name;
1568                 dir.files[dir.nr].changed = damage;
1569                 changed += damage;
1570                 dir.nr++;
1571         }
1573         /* This can happen even with many files, if everything was renames */
1574         if (!changed)
1575                 return;
1577         /* Show all directories with more than x% of the changes */
1578         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1579         gather_dirstat(options, &dir, changed, "", 0);
1582 static void free_diffstat_info(struct diffstat_t *diffstat)
1584         int i;
1585         for (i = 0; i < diffstat->nr; i++) {
1586                 struct diffstat_file *f = diffstat->files[i];
1587                 if (f->name != f->print_name)
1588                         free(f->print_name);
1589                 free(f->name);
1590                 free(f->from_name);
1591                 free(f);
1592         }
1593         free(diffstat->files);
1596 struct checkdiff_t {
1597         const char *filename;
1598         int lineno;
1599         int conflict_marker_size;
1600         struct diff_options *o;
1601         unsigned ws_rule;
1602         unsigned status;
1603 };
1605 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1607         char firstchar;
1608         int cnt;
1610         if (len < marker_size + 1)
1611                 return 0;
1612         firstchar = line[0];
1613         switch (firstchar) {
1614         case '=': case '>': case '<': case '|':
1615                 break;
1616         default:
1617                 return 0;
1618         }
1619         for (cnt = 1; cnt < marker_size; cnt++)
1620                 if (line[cnt] != firstchar)
1621                         return 0;
1622         /* line[1] thru line[marker_size-1] are same as firstchar */
1623         if (len < marker_size + 1 || !isspace(line[marker_size]))
1624                 return 0;
1625         return 1;
1628 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1630         struct checkdiff_t *data = priv;
1631         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1632         int marker_size = data->conflict_marker_size;
1633         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1634         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1635         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1636         char *err;
1637         char *line_prefix = "";
1638         struct strbuf *msgbuf;
1640         assert(data->o);
1641         if (data->o->output_prefix) {
1642                 msgbuf = data->o->output_prefix(data->o,
1643                         data->o->output_prefix_data);
1644                 line_prefix = msgbuf->buf;
1645         }
1647         if (line[0] == '+') {
1648                 unsigned bad;
1649                 data->lineno++;
1650                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1651                         data->status |= 1;
1652                         fprintf(data->o->file,
1653                                 "%s%s:%d: leftover conflict marker\n",
1654                                 line_prefix, data->filename, data->lineno);
1655                 }
1656                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1657                 if (!bad)
1658                         return;
1659                 data->status |= bad;
1660                 err = whitespace_error_string(bad);
1661                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1662                         line_prefix, data->filename, data->lineno, err);
1663                 free(err);
1664                 emit_line(data->o, set, reset, line, 1);
1665                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1666                               data->o->file, set, reset, ws);
1667         } else if (line[0] == ' ') {
1668                 data->lineno++;
1669         } else if (line[0] == '@') {
1670                 char *plus = strchr(line, '+');
1671                 if (plus)
1672                         data->lineno = strtol(plus, NULL, 10) - 1;
1673                 else
1674                         die("invalid diff");
1675         }
1678 static unsigned char *deflate_it(char *data,
1679                                  unsigned long size,
1680                                  unsigned long *result_size)
1682         int bound;
1683         unsigned char *deflated;
1684         z_stream stream;
1686         memset(&stream, 0, sizeof(stream));
1687         deflateInit(&stream, zlib_compression_level);
1688         bound = deflateBound(&stream, size);
1689         deflated = xmalloc(bound);
1690         stream.next_out = deflated;
1691         stream.avail_out = bound;
1693         stream.next_in = (unsigned char *)data;
1694         stream.avail_in = size;
1695         while (deflate(&stream, Z_FINISH) == Z_OK)
1696                 ; /* nothing */
1697         deflateEnd(&stream);
1698         *result_size = stream.total_out;
1699         return deflated;
1702 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1704         void *cp;
1705         void *delta;
1706         void *deflated;
1707         void *data;
1708         unsigned long orig_size;
1709         unsigned long delta_size;
1710         unsigned long deflate_size;
1711         unsigned long data_size;
1713         /* We could do deflated delta, or we could do just deflated two,
1714          * whichever is smaller.
1715          */
1716         delta = NULL;
1717         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1718         if (one->size && two->size) {
1719                 delta = diff_delta(one->ptr, one->size,
1720                                    two->ptr, two->size,
1721                                    &delta_size, deflate_size);
1722                 if (delta) {
1723                         void *to_free = delta;
1724                         orig_size = delta_size;
1725                         delta = deflate_it(delta, delta_size, &delta_size);
1726                         free(to_free);
1727                 }
1728         }
1730         if (delta && delta_size < deflate_size) {
1731                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1732                 free(deflated);
1733                 data = delta;
1734                 data_size = delta_size;
1735         }
1736         else {
1737                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1738                 free(delta);
1739                 data = deflated;
1740                 data_size = deflate_size;
1741         }
1743         /* emit data encoded in base85 */
1744         cp = data;
1745         while (data_size) {
1746                 int bytes = (52 < data_size) ? 52 : data_size;
1747                 char line[70];
1748                 data_size -= bytes;
1749                 if (bytes <= 26)
1750                         line[0] = bytes + 'A' - 1;
1751                 else
1752                         line[0] = bytes - 26 + 'a' - 1;
1753                 encode_85(line + 1, cp, bytes);
1754                 cp = (char *) cp + bytes;
1755                 fprintf(file, "%s", prefix);
1756                 fputs(line, file);
1757                 fputc('\n', file);
1758         }
1759         fprintf(file, "%s\n", prefix);
1760         free(data);
1763 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1765         fprintf(file, "%sGIT binary patch\n", prefix);
1766         emit_binary_diff_body(file, one, two, prefix);
1767         emit_binary_diff_body(file, two, one, prefix);
1770 static void diff_filespec_load_driver(struct diff_filespec *one)
1772         /* Use already-loaded driver */
1773         if (one->driver)
1774                 return;
1776         if (S_ISREG(one->mode))
1777                 one->driver = userdiff_find_by_path(one->path);
1779         /* Fallback to default settings */
1780         if (!one->driver)
1781                 one->driver = userdiff_find_by_name("default");
1784 int diff_filespec_is_binary(struct diff_filespec *one)
1786         if (one->is_binary == -1) {
1787                 diff_filespec_load_driver(one);
1788                 if (one->driver->binary != -1)
1789                         one->is_binary = one->driver->binary;
1790                 else {
1791                         if (!one->data && DIFF_FILE_VALID(one))
1792                                 diff_populate_filespec(one, 0);
1793                         if (one->data)
1794                                 one->is_binary = buffer_is_binary(one->data,
1795                                                 one->size);
1796                         if (one->is_binary == -1)
1797                                 one->is_binary = 0;
1798                 }
1799         }
1800         return one->is_binary;
1803 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1805         diff_filespec_load_driver(one);
1806         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1809 static const char *userdiff_word_regex(struct diff_filespec *one)
1811         diff_filespec_load_driver(one);
1812         return one->driver->word_regex;
1815 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1817         if (!options->a_prefix)
1818                 options->a_prefix = a;
1819         if (!options->b_prefix)
1820                 options->b_prefix = b;
1823 struct userdiff_driver *get_textconv(struct diff_filespec *one)
1825         if (!DIFF_FILE_VALID(one))
1826                 return NULL;
1828         diff_filespec_load_driver(one);
1829         if (!one->driver->textconv)
1830                 return NULL;
1832         if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1833                 struct notes_cache *c = xmalloc(sizeof(*c));
1834                 struct strbuf name = STRBUF_INIT;
1836                 strbuf_addf(&name, "textconv/%s", one->driver->name);
1837                 notes_cache_init(c, name.buf, one->driver->textconv);
1838                 one->driver->textconv_cache = c;
1839         }
1841         return one->driver;
1844 static void builtin_diff(const char *name_a,
1845                          const char *name_b,
1846                          struct diff_filespec *one,
1847                          struct diff_filespec *two,
1848                          const char *xfrm_msg,
1849                          int must_show_header,
1850                          struct diff_options *o,
1851                          int complete_rewrite)
1853         mmfile_t mf1, mf2;
1854         const char *lbl[2];
1855         char *a_one, *b_two;
1856         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1857         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1858         const char *a_prefix, *b_prefix;
1859         struct userdiff_driver *textconv_one = NULL;
1860         struct userdiff_driver *textconv_two = NULL;
1861         struct strbuf header = STRBUF_INIT;
1862         struct strbuf *msgbuf;
1863         char *line_prefix = "";
1865         if (o->output_prefix) {
1866                 msgbuf = o->output_prefix(o, o->output_prefix_data);
1867                 line_prefix = msgbuf->buf;
1868         }
1870         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1871                         (!one->mode || S_ISGITLINK(one->mode)) &&
1872                         (!two->mode || S_ISGITLINK(two->mode))) {
1873                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1874                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1875                 show_submodule_summary(o->file, one ? one->path : two->path,
1876                                 one->sha1, two->sha1, two->dirty_submodule,
1877                                 del, add, reset);
1878                 return;
1879         }
1881         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1882                 textconv_one = get_textconv(one);
1883                 textconv_two = get_textconv(two);
1884         }
1886         diff_set_mnemonic_prefix(o, "a/", "b/");
1887         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1888                 a_prefix = o->b_prefix;
1889                 b_prefix = o->a_prefix;
1890         } else {
1891                 a_prefix = o->a_prefix;
1892                 b_prefix = o->b_prefix;
1893         }
1895         /* Never use a non-valid filename anywhere if at all possible */
1896         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1897         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1899         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1900         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1901         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1902         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1903         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1904         if (lbl[0][0] == '/') {
1905                 /* /dev/null */
1906                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1907                 if (xfrm_msg)
1908                         strbuf_addstr(&header, xfrm_msg);
1909                 must_show_header = 1;
1910         }
1911         else if (lbl[1][0] == '/') {
1912                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1913                 if (xfrm_msg)
1914                         strbuf_addstr(&header, xfrm_msg);
1915                 must_show_header = 1;
1916         }
1917         else {
1918                 if (one->mode != two->mode) {
1919                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1920                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1921                         must_show_header = 1;
1922                 }
1923                 if (xfrm_msg)
1924                         strbuf_addstr(&header, xfrm_msg);
1926                 /*
1927                  * we do not run diff between different kind
1928                  * of objects.
1929                  */
1930                 if ((one->mode ^ two->mode) & S_IFMT)
1931                         goto free_ab_and_return;
1932                 if (complete_rewrite &&
1933                     (textconv_one || !diff_filespec_is_binary(one)) &&
1934                     (textconv_two || !diff_filespec_is_binary(two))) {
1935                         fprintf(o->file, "%s", header.buf);
1936                         strbuf_reset(&header);
1937                         emit_rewrite_diff(name_a, name_b, one, two,
1938                                                 textconv_one, textconv_two, o);
1939                         o->found_changes = 1;
1940                         goto free_ab_and_return;
1941                 }
1942         }
1944         if (!DIFF_OPT_TST(o, TEXT) &&
1945             ( (!textconv_one && diff_filespec_is_binary(one)) ||
1946               (!textconv_two && diff_filespec_is_binary(two)) )) {
1947                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1948                         die("unable to read files to diff");
1949                 /* Quite common confusing case */
1950                 if (mf1.size == mf2.size &&
1951                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1952                         if (must_show_header)
1953                                 fprintf(o->file, "%s", header.buf);
1954                         goto free_ab_and_return;
1955                 }
1956                 fprintf(o->file, "%s", header.buf);
1957                 strbuf_reset(&header);
1958                 if (DIFF_OPT_TST(o, BINARY))
1959                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1960                 else
1961                         fprintf(o->file, "%sBinary files %s and %s differ\n",
1962                                 line_prefix, lbl[0], lbl[1]);
1963                 o->found_changes = 1;
1964         }
1965         else {
1966                 /* Crazy xdl interfaces.. */
1967                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1968                 xpparam_t xpp;
1969                 xdemitconf_t xecfg;
1970                 struct emit_callback ecbdata;
1971                 const struct userdiff_funcname *pe;
1973                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1974                         fprintf(o->file, "%s", header.buf);
1975                         strbuf_reset(&header);
1976                 }
1978                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1979                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1981                 pe = diff_funcname_pattern(one);
1982                 if (!pe)
1983                         pe = diff_funcname_pattern(two);
1985                 memset(&xpp, 0, sizeof(xpp));
1986                 memset(&xecfg, 0, sizeof(xecfg));
1987                 memset(&ecbdata, 0, sizeof(ecbdata));
1988                 ecbdata.label_path = lbl;
1989                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1990                 ecbdata.found_changesp = &o->found_changes;
1991                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1992                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1993                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
1994                 ecbdata.opt = o;
1995                 ecbdata.header = header.len ? &header : NULL;
1996                 xpp.flags = o->xdl_opts;
1997                 xecfg.ctxlen = o->context;
1998                 xecfg.interhunkctxlen = o->interhunkcontext;
1999                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2000                 if (pe)
2001                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2002                 if (!diffopts)
2003                         ;
2004                 else if (!prefixcmp(diffopts, "--unified="))
2005                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2006                 else if (!prefixcmp(diffopts, "-u"))
2007                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2008                 if (o->word_diff) {
2009                         int i;
2011                         ecbdata.diff_words =
2012                                 xcalloc(1, sizeof(struct diff_words_data));
2013                         ecbdata.diff_words->type = o->word_diff;
2014                         ecbdata.diff_words->opt = o;
2015                         if (!o->word_regex)
2016                                 o->word_regex = userdiff_word_regex(one);
2017                         if (!o->word_regex)
2018                                 o->word_regex = userdiff_word_regex(two);
2019                         if (!o->word_regex)
2020                                 o->word_regex = diff_word_regex_cfg;
2021                         if (o->word_regex) {
2022                                 ecbdata.diff_words->word_regex = (regex_t *)
2023                                         xmalloc(sizeof(regex_t));
2024                                 if (regcomp(ecbdata.diff_words->word_regex,
2025                                                 o->word_regex,
2026                                                 REG_EXTENDED | REG_NEWLINE))
2027                                         die ("Invalid regular expression: %s",
2028                                                         o->word_regex);
2029                         }
2030                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2031                                 if (o->word_diff == diff_words_styles[i].type) {
2032                                         ecbdata.diff_words->style =
2033                                                 &diff_words_styles[i];
2034                                         break;
2035                                 }
2036                         }
2037                         if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2038                                 struct diff_words_style *st = ecbdata.diff_words->style;
2039                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2040                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2041                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2042                         }
2043                 }
2044                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2045                               &xpp, &xecfg);
2046                 if (o->word_diff)
2047                         free_diff_words_data(&ecbdata);
2048                 if (textconv_one)
2049                         free(mf1.ptr);
2050                 if (textconv_two)
2051                         free(mf2.ptr);
2052                 xdiff_clear_find_func(&xecfg);
2053         }
2055  free_ab_and_return:
2056         strbuf_release(&header);
2057         diff_free_filespec_data(one);
2058         diff_free_filespec_data(two);
2059         free(a_one);
2060         free(b_two);
2061         return;
2064 static void builtin_diffstat(const char *name_a, const char *name_b,
2065                              struct diff_filespec *one,
2066                              struct diff_filespec *two,
2067                              struct diffstat_t *diffstat,
2068                              struct diff_options *o,
2069                              int complete_rewrite)
2071         mmfile_t mf1, mf2;
2072         struct diffstat_file *data;
2074         data = diffstat_add(diffstat, name_a, name_b);
2076         if (!one || !two) {
2077                 data->is_unmerged = 1;
2078                 return;
2079         }
2080         if (complete_rewrite) {
2081                 diff_populate_filespec(one, 0);
2082                 diff_populate_filespec(two, 0);
2083                 data->deleted = count_lines(one->data, one->size);
2084                 data->added = count_lines(two->data, two->size);
2085                 goto free_and_return;
2086         }
2087         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2088                 die("unable to read files to diff");
2090         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2091                 data->is_binary = 1;
2092                 data->added = mf2.size;
2093                 data->deleted = mf1.size;
2094         } else {
2095                 /* Crazy xdl interfaces.. */
2096                 xpparam_t xpp;
2097                 xdemitconf_t xecfg;
2099                 memset(&xpp, 0, sizeof(xpp));
2100                 memset(&xecfg, 0, sizeof(xecfg));
2101                 xpp.flags = o->xdl_opts;
2102                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2103                               &xpp, &xecfg);
2104         }
2106  free_and_return:
2107         diff_free_filespec_data(one);
2108         diff_free_filespec_data(two);
2111 static void builtin_checkdiff(const char *name_a, const char *name_b,
2112                               const char *attr_path,
2113                               struct diff_filespec *one,
2114                               struct diff_filespec *two,
2115                               struct diff_options *o)
2117         mmfile_t mf1, mf2;
2118         struct checkdiff_t data;
2120         if (!two)
2121                 return;
2123         memset(&data, 0, sizeof(data));
2124         data.filename = name_b ? name_b : name_a;
2125         data.lineno = 0;
2126         data.o = o;
2127         data.ws_rule = whitespace_rule(attr_path);
2128         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2130         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2131                 die("unable to read files to diff");
2133         /*
2134          * All the other codepaths check both sides, but not checking
2135          * the "old" side here is deliberate.  We are checking the newly
2136          * introduced changes, and as long as the "new" side is text, we
2137          * can and should check what it introduces.
2138          */
2139         if (diff_filespec_is_binary(two))
2140                 goto free_and_return;
2141         else {
2142                 /* Crazy xdl interfaces.. */
2143                 xpparam_t xpp;
2144                 xdemitconf_t xecfg;
2146                 memset(&xpp, 0, sizeof(xpp));
2147                 memset(&xecfg, 0, sizeof(xecfg));
2148                 xecfg.ctxlen = 1; /* at least one context line */
2149                 xpp.flags = 0;
2150                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2151                               &xpp, &xecfg);
2153                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2154                         struct emit_callback ecbdata;
2155                         int blank_at_eof;
2157                         ecbdata.ws_rule = data.ws_rule;
2158                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2159                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2161                         if (blank_at_eof) {
2162                                 static char *err;
2163                                 if (!err)
2164                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2165                                 fprintf(o->file, "%s:%d: %s.\n",
2166                                         data.filename, blank_at_eof, err);
2167                                 data.status = 1; /* report errors */
2168                         }
2169                 }
2170         }
2171  free_and_return:
2172         diff_free_filespec_data(one);
2173         diff_free_filespec_data(two);
2174         if (data.status)
2175                 DIFF_OPT_SET(o, CHECK_FAILED);
2178 struct diff_filespec *alloc_filespec(const char *path)
2180         int namelen = strlen(path);
2181         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2183         memset(spec, 0, sizeof(*spec));
2184         spec->path = (char *)(spec + 1);
2185         memcpy(spec->path, path, namelen+1);
2186         spec->count = 1;
2187         spec->is_binary = -1;
2188         return spec;
2191 void free_filespec(struct diff_filespec *spec)
2193         if (!--spec->count) {
2194                 diff_free_filespec_data(spec);
2195                 free(spec);
2196         }
2199 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2200                    unsigned short mode)
2202         if (mode) {
2203                 spec->mode = canon_mode(mode);
2204                 hashcpy(spec->sha1, sha1);
2205                 spec->sha1_valid = !is_null_sha1(sha1);
2206         }
2209 /*
2210  * Given a name and sha1 pair, if the index tells us the file in
2211  * the work tree has that object contents, return true, so that
2212  * prepare_temp_file() does not have to inflate and extract.
2213  */
2214 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2216         struct cache_entry *ce;
2217         struct stat st;
2218         int pos, len;
2220         /*
2221          * We do not read the cache ourselves here, because the
2222          * benchmark with my previous version that always reads cache
2223          * shows that it makes things worse for diff-tree comparing
2224          * two linux-2.6 kernel trees in an already checked out work
2225          * tree.  This is because most diff-tree comparisons deal with
2226          * only a small number of files, while reading the cache is
2227          * expensive for a large project, and its cost outweighs the
2228          * savings we get by not inflating the object to a temporary
2229          * file.  Practically, this code only helps when we are used
2230          * by diff-cache --cached, which does read the cache before
2231          * calling us.
2232          */
2233         if (!active_cache)
2234                 return 0;
2236         /* We want to avoid the working directory if our caller
2237          * doesn't need the data in a normal file, this system
2238          * is rather slow with its stat/open/mmap/close syscalls,
2239          * and the object is contained in a pack file.  The pack
2240          * is probably already open and will be faster to obtain
2241          * the data through than the working directory.  Loose
2242          * objects however would tend to be slower as they need
2243          * to be individually opened and inflated.
2244          */
2245         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2246                 return 0;
2248         len = strlen(name);
2249         pos = cache_name_pos(name, len);
2250         if (pos < 0)
2251                 return 0;
2252         ce = active_cache[pos];
2254         /*
2255          * This is not the sha1 we are looking for, or
2256          * unreusable because it is not a regular file.
2257          */
2258         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2259                 return 0;
2261         /*
2262          * If ce is marked as "assume unchanged", there is no
2263          * guarantee that work tree matches what we are looking for.
2264          */
2265         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2266                 return 0;
2268         /*
2269          * If ce matches the file in the work tree, we can reuse it.
2270          */
2271         if (ce_uptodate(ce) ||
2272             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2273                 return 1;
2275         return 0;
2278 static int populate_from_stdin(struct diff_filespec *s)
2280         struct strbuf buf = STRBUF_INIT;
2281         size_t size = 0;
2283         if (strbuf_read(&buf, 0, 0) < 0)
2284                 return error("error while reading from stdin %s",
2285                                      strerror(errno));
2287         s->should_munmap = 0;
2288         s->data = strbuf_detach(&buf, &size);
2289         s->size = size;
2290         s->should_free = 1;
2291         return 0;
2294 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2296         int len;
2297         char *data = xmalloc(100), *dirty = "";
2299         /* Are we looking at the work tree? */
2300         if (s->dirty_submodule)
2301                 dirty = "-dirty";
2303         len = snprintf(data, 100,
2304                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2305         s->data = data;
2306         s->size = len;
2307         s->should_free = 1;
2308         if (size_only) {
2309                 s->data = NULL;
2310                 free(data);
2311         }
2312         return 0;
2315 /*
2316  * While doing rename detection and pickaxe operation, we may need to
2317  * grab the data for the blob (or file) for our own in-core comparison.
2318  * diff_filespec has data and size fields for this purpose.
2319  */
2320 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2322         int err = 0;
2323         if (!DIFF_FILE_VALID(s))
2324                 die("internal error: asking to populate invalid file.");
2325         if (S_ISDIR(s->mode))
2326                 return -1;
2328         if (s->data)
2329                 return 0;
2331         if (size_only && 0 < s->size)
2332                 return 0;
2334         if (S_ISGITLINK(s->mode))
2335                 return diff_populate_gitlink(s, size_only);
2337         if (!s->sha1_valid ||
2338             reuse_worktree_file(s->path, s->sha1, 0)) {
2339                 struct strbuf buf = STRBUF_INIT;
2340                 struct stat st;
2341                 int fd;
2343                 if (!strcmp(s->path, "-"))
2344                         return populate_from_stdin(s);
2346                 if (lstat(s->path, &st) < 0) {
2347                         if (errno == ENOENT) {
2348                         err_empty:
2349                                 err = -1;
2350                         empty:
2351                                 s->data = (char *)"";
2352                                 s->size = 0;
2353                                 return err;
2354                         }
2355                 }
2356                 s->size = xsize_t(st.st_size);
2357                 if (!s->size)
2358                         goto empty;
2359                 if (S_ISLNK(st.st_mode)) {
2360                         struct strbuf sb = STRBUF_INIT;
2362                         if (strbuf_readlink(&sb, s->path, s->size))
2363                                 goto err_empty;
2364                         s->size = sb.len;
2365                         s->data = strbuf_detach(&sb, NULL);
2366                         s->should_free = 1;
2367                         return 0;
2368                 }
2369                 if (size_only)
2370                         return 0;
2371                 fd = open(s->path, O_RDONLY);
2372                 if (fd < 0)
2373                         goto err_empty;
2374                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2375                 close(fd);
2376                 s->should_munmap = 1;
2378                 /*
2379                  * Convert from working tree format to canonical git format
2380                  */
2381                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2382                         size_t size = 0;
2383                         munmap(s->data, s->size);
2384                         s->should_munmap = 0;
2385                         s->data = strbuf_detach(&buf, &size);
2386                         s->size = size;
2387                         s->should_free = 1;
2388                 }
2389         }
2390         else {
2391                 enum object_type type;
2392                 if (size_only) {
2393                         type = sha1_object_info(s->sha1, &s->size);
2394                         if (type < 0)
2395                                 die("unable to read %s", sha1_to_hex(s->sha1));
2396                 } else {
2397                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2398                         if (!s->data)
2399                                 die("unable to read %s", sha1_to_hex(s->sha1));
2400                         s->should_free = 1;
2401                 }
2402         }
2403         return 0;
2406 void diff_free_filespec_blob(struct diff_filespec *s)
2408         if (s->should_free)
2409                 free(s->data);
2410         else if (s->should_munmap)
2411                 munmap(s->data, s->size);
2413         if (s->should_free || s->should_munmap) {
2414                 s->should_free = s->should_munmap = 0;
2415                 s->data = NULL;
2416         }
2419 void diff_free_filespec_data(struct diff_filespec *s)
2421         diff_free_filespec_blob(s);
2422         free(s->cnt_data);
2423         s->cnt_data = NULL;
2426 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2427                            void *blob,
2428                            unsigned long size,
2429                            const unsigned char *sha1,
2430                            int mode)
2432         int fd;
2433         struct strbuf buf = STRBUF_INIT;
2434         struct strbuf template = STRBUF_INIT;
2435         char *path_dup = xstrdup(path);
2436         const char *base = basename(path_dup);
2438         /* Generate "XXXXXX_basename.ext" */
2439         strbuf_addstr(&template, "XXXXXX_");
2440         strbuf_addstr(&template, base);
2442         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2443                         strlen(base) + 1);
2444         if (fd < 0)
2445                 die_errno("unable to create temp-file");
2446         if (convert_to_working_tree(path,
2447                         (const char *)blob, (size_t)size, &buf)) {
2448                 blob = buf.buf;
2449                 size = buf.len;
2450         }
2451         if (write_in_full(fd, blob, size) != size)
2452                 die_errno("unable to write temp-file");
2453         close(fd);
2454         temp->name = temp->tmp_path;
2455         strcpy(temp->hex, sha1_to_hex(sha1));
2456         temp->hex[40] = 0;
2457         sprintf(temp->mode, "%06o", mode);
2458         strbuf_release(&buf);
2459         strbuf_release(&template);
2460         free(path_dup);
2463 static struct diff_tempfile *prepare_temp_file(const char *name,
2464                 struct diff_filespec *one)
2466         struct diff_tempfile *temp = claim_diff_tempfile();
2468         if (!DIFF_FILE_VALID(one)) {
2469         not_a_valid_file:
2470                 /* A '-' entry produces this for file-2, and
2471                  * a '+' entry produces this for file-1.
2472                  */
2473                 temp->name = "/dev/null";
2474                 strcpy(temp->hex, ".");
2475                 strcpy(temp->mode, ".");
2476                 return temp;
2477         }
2479         if (!remove_tempfile_installed) {
2480                 atexit(remove_tempfile);
2481                 sigchain_push_common(remove_tempfile_on_signal);
2482                 remove_tempfile_installed = 1;
2483         }
2485         if (!one->sha1_valid ||
2486             reuse_worktree_file(name, one->sha1, 1)) {
2487                 struct stat st;
2488                 if (lstat(name, &st) < 0) {
2489                         if (errno == ENOENT)
2490                                 goto not_a_valid_file;
2491                         die_errno("stat(%s)", name);
2492                 }
2493                 if (S_ISLNK(st.st_mode)) {
2494                         struct strbuf sb = STRBUF_INIT;
2495                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2496                                 die_errno("readlink(%s)", name);
2497                         prep_temp_blob(name, temp, sb.buf, sb.len,
2498                                        (one->sha1_valid ?
2499                                         one->sha1 : null_sha1),
2500                                        (one->sha1_valid ?
2501                                         one->mode : S_IFLNK));
2502                         strbuf_release(&sb);
2503                 }
2504                 else {
2505                         /* we can borrow from the file in the work tree */
2506                         temp->name = name;
2507                         if (!one->sha1_valid)
2508                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2509                         else
2510                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2511                         /* Even though we may sometimes borrow the
2512                          * contents from the work tree, we always want
2513                          * one->mode.  mode is trustworthy even when
2514                          * !(one->sha1_valid), as long as
2515                          * DIFF_FILE_VALID(one).
2516                          */
2517                         sprintf(temp->mode, "%06o", one->mode);
2518                 }
2519                 return temp;
2520         }
2521         else {
2522                 if (diff_populate_filespec(one, 0))
2523                         die("cannot read data blob for %s", one->path);
2524                 prep_temp_blob(name, temp, one->data, one->size,
2525                                one->sha1, one->mode);
2526         }
2527         return temp;
2530 /* An external diff command takes:
2531  *
2532  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2533  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2534  *
2535  */
2536 static void run_external_diff(const char *pgm,
2537                               const char *name,
2538                               const char *other,
2539                               struct diff_filespec *one,
2540                               struct diff_filespec *two,
2541                               const char *xfrm_msg,
2542                               int complete_rewrite)
2544         const char *spawn_arg[10];
2545         int retval;
2546         const char **arg = &spawn_arg[0];
2548         if (one && two) {
2549                 struct diff_tempfile *temp_one, *temp_two;
2550                 const char *othername = (other ? other : name);
2551                 temp_one = prepare_temp_file(name, one);
2552                 temp_two = prepare_temp_file(othername, two);
2553                 *arg++ = pgm;
2554                 *arg++ = name;
2555                 *arg++ = temp_one->name;
2556                 *arg++ = temp_one->hex;
2557                 *arg++ = temp_one->mode;
2558                 *arg++ = temp_two->name;
2559                 *arg++ = temp_two->hex;
2560                 *arg++ = temp_two->mode;
2561                 if (other) {
2562                         *arg++ = other;
2563                         *arg++ = xfrm_msg;
2564                 }
2565         } else {
2566                 *arg++ = pgm;
2567                 *arg++ = name;
2568         }
2569         *arg = NULL;
2570         fflush(NULL);
2571         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2572         remove_tempfile();
2573         if (retval) {
2574                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2575                 exit(1);
2576         }
2579 static int similarity_index(struct diff_filepair *p)
2581         return p->score * 100 / MAX_SCORE;
2584 static void fill_metainfo(struct strbuf *msg,
2585                           const char *name,
2586                           const char *other,
2587                           struct diff_filespec *one,
2588                           struct diff_filespec *two,
2589                           struct diff_options *o,
2590                           struct diff_filepair *p,
2591                           int *must_show_header,
2592                           int use_color)
2594         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2595         const char *reset = diff_get_color(use_color, DIFF_RESET);
2596         struct strbuf *msgbuf;
2597         char *line_prefix = "";
2599         *must_show_header = 1;
2600         if (o->output_prefix) {
2601                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2602                 line_prefix = msgbuf->buf;
2603         }
2604         strbuf_init(msg, PATH_MAX * 2 + 300);
2605         switch (p->status) {
2606         case DIFF_STATUS_COPIED:
2607                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2608                             line_prefix, set, similarity_index(p));
2609                 strbuf_addf(msg, "%s\n%s%scopy from ",
2610                             reset,  line_prefix, set);
2611                 quote_c_style(name, msg, NULL, 0);
2612                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2613                 quote_c_style(other, msg, NULL, 0);
2614                 strbuf_addf(msg, "%s\n", reset);
2615                 break;
2616         case DIFF_STATUS_RENAMED:
2617                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2618                             line_prefix, set, similarity_index(p));
2619                 strbuf_addf(msg, "%s\n%s%srename from ",
2620                             reset, line_prefix, set);
2621                 quote_c_style(name, msg, NULL, 0);
2622                 strbuf_addf(msg, "%s\n%s%srename to ",
2623                             reset, line_prefix, set);
2624                 quote_c_style(other, msg, NULL, 0);
2625                 strbuf_addf(msg, "%s\n", reset);
2626                 break;
2627         case DIFF_STATUS_MODIFIED:
2628                 if (p->score) {
2629                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2630                                     line_prefix,
2631                                     set, similarity_index(p), reset);
2632                         break;
2633                 }
2634                 /* fallthru */
2635         default:
2636                 *must_show_header = 0;
2637         }
2638         if (one && two && hashcmp(one->sha1, two->sha1)) {
2639                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2641                 if (DIFF_OPT_TST(o, BINARY)) {
2642                         mmfile_t mf;
2643                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2644                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2645                                 abbrev = 40;
2646                 }
2647                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2648                             find_unique_abbrev(one->sha1, abbrev));
2649                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2650                 if (one->mode == two->mode)
2651                         strbuf_addf(msg, " %06o", one->mode);
2652                 strbuf_addf(msg, "%s\n", reset);
2653         }
2656 static void run_diff_cmd(const char *pgm,
2657                          const char *name,
2658                          const char *other,
2659                          const char *attr_path,
2660                          struct diff_filespec *one,
2661                          struct diff_filespec *two,
2662                          struct strbuf *msg,
2663                          struct diff_options *o,
2664                          struct diff_filepair *p)
2666         const char *xfrm_msg = NULL;
2667         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2668         int must_show_header = 0;
2670         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2671                 pgm = NULL;
2672         else {
2673                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2674                 if (drv && drv->external)
2675                         pgm = drv->external;
2676         }
2678         if (msg) {
2679                 /*
2680                  * don't use colors when the header is intended for an
2681                  * external diff driver
2682                  */
2683                 fill_metainfo(msg, name, other, one, two, o, p,
2684                               &must_show_header,
2685                               DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2686                 xfrm_msg = msg->len ? msg->buf : NULL;
2687         }
2689         if (pgm) {
2690                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2691                                   complete_rewrite);
2692                 return;
2693         }
2694         if (one && two)
2695                 builtin_diff(name, other ? other : name,
2696                              one, two, xfrm_msg, must_show_header,
2697                              o, complete_rewrite);
2698         else
2699                 fprintf(o->file, "* Unmerged path %s\n", name);
2702 static void diff_fill_sha1_info(struct diff_filespec *one)
2704         if (DIFF_FILE_VALID(one)) {
2705                 if (!one->sha1_valid) {
2706                         struct stat st;
2707                         if (!strcmp(one->path, "-")) {
2708                                 hashcpy(one->sha1, null_sha1);
2709                                 return;
2710                         }
2711                         if (lstat(one->path, &st) < 0)
2712                                 die_errno("stat '%s'", one->path);
2713                         if (index_path(one->sha1, one->path, &st, 0))
2714                                 die("cannot hash %s", one->path);
2715                 }
2716         }
2717         else
2718                 hashclr(one->sha1);
2721 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2723         /* Strip the prefix but do not molest /dev/null and absolute paths */
2724         if (*namep && **namep != '/') {
2725                 *namep += prefix_length;
2726                 if (**namep == '/')
2727                         ++*namep;
2728         }
2729         if (*otherp && **otherp != '/') {
2730                 *otherp += prefix_length;
2731                 if (**otherp == '/')
2732                         ++*otherp;
2733         }
2736 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2738         const char *pgm = external_diff();
2739         struct strbuf msg;
2740         struct diff_filespec *one = p->one;
2741         struct diff_filespec *two = p->two;
2742         const char *name;
2743         const char *other;
2744         const char *attr_path;
2746         name  = p->one->path;
2747         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2748         attr_path = name;
2749         if (o->prefix_length)
2750                 strip_prefix(o->prefix_length, &name, &other);
2752         if (DIFF_PAIR_UNMERGED(p)) {
2753                 run_diff_cmd(pgm, name, NULL, attr_path,
2754                              NULL, NULL, NULL, o, p);
2755                 return;
2756         }
2758         diff_fill_sha1_info(one);
2759         diff_fill_sha1_info(two);
2761         if (!pgm &&
2762             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2763             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2764                 /*
2765                  * a filepair that changes between file and symlink
2766                  * needs to be split into deletion and creation.
2767                  */
2768                 struct diff_filespec *null = alloc_filespec(two->path);
2769                 run_diff_cmd(NULL, name, other, attr_path,
2770                              one, null, &msg, o, p);
2771                 free(null);
2772                 strbuf_release(&msg);
2774                 null = alloc_filespec(one->path);
2775                 run_diff_cmd(NULL, name, other, attr_path,
2776                              null, two, &msg, o, p);
2777                 free(null);
2778         }
2779         else
2780                 run_diff_cmd(pgm, name, other, attr_path,
2781                              one, two, &msg, o, p);
2783         strbuf_release(&msg);
2786 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2787                          struct diffstat_t *diffstat)
2789         const char *name;
2790         const char *other;
2791         int complete_rewrite = 0;
2793         if (DIFF_PAIR_UNMERGED(p)) {
2794                 /* unmerged */
2795                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2796                 return;
2797         }
2799         name = p->one->path;
2800         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2802         if (o->prefix_length)
2803                 strip_prefix(o->prefix_length, &name, &other);
2805         diff_fill_sha1_info(p->one);
2806         diff_fill_sha1_info(p->two);
2808         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2809                 complete_rewrite = 1;
2810         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2813 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2815         const char *name;
2816         const char *other;
2817         const char *attr_path;
2819         if (DIFF_PAIR_UNMERGED(p)) {
2820                 /* unmerged */
2821                 return;
2822         }
2824         name = p->one->path;
2825         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2826         attr_path = other ? other : name;
2828         if (o->prefix_length)
2829                 strip_prefix(o->prefix_length, &name, &other);
2831         diff_fill_sha1_info(p->one);
2832         diff_fill_sha1_info(p->two);
2834         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2837 void diff_setup(struct diff_options *options)
2839         memcpy(options, &default_diff_options, sizeof(*options));
2841         options->file = stdout;
2843         options->line_termination = '\n';
2844         options->break_opt = -1;
2845         options->rename_limit = -1;
2846         options->dirstat_percent = 3;
2847         options->context = 3;
2849         options->change = diff_change;
2850         options->add_remove = diff_addremove;
2851         if (diff_use_color_default > 0)
2852                 DIFF_OPT_SET(options, COLOR_DIFF);
2853         options->detect_rename = diff_detect_rename_default;
2855         if (diff_no_prefix) {
2856                 options->a_prefix = options->b_prefix = "";
2857         } else if (!diff_mnemonic_prefix) {
2858                 options->a_prefix = "a/";
2859                 options->b_prefix = "b/";
2860         }
2863 int diff_setup_done(struct diff_options *options)
2865         int count = 0;
2867         if (options->output_format & DIFF_FORMAT_NAME)
2868                 count++;
2869         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2870                 count++;
2871         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2872                 count++;
2873         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2874                 count++;
2875         if (count > 1)
2876                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2878         /*
2879          * Most of the time we can say "there are changes"
2880          * only by checking if there are changed paths, but
2881          * --ignore-whitespace* options force us to look
2882          * inside contents.
2883          */
2885         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2886             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2887             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2888                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2889         else
2890                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2892         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2893                 options->detect_rename = DIFF_DETECT_COPY;
2895         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2896                 options->prefix = NULL;
2897         if (options->prefix)
2898                 options->prefix_length = strlen(options->prefix);
2899         else
2900                 options->prefix_length = 0;
2902         if (options->output_format & (DIFF_FORMAT_NAME |
2903                                       DIFF_FORMAT_NAME_STATUS |
2904                                       DIFF_FORMAT_CHECKDIFF |
2905                                       DIFF_FORMAT_NO_OUTPUT))
2906                 options->output_format &= ~(DIFF_FORMAT_RAW |
2907                                             DIFF_FORMAT_NUMSTAT |
2908                                             DIFF_FORMAT_DIFFSTAT |
2909                                             DIFF_FORMAT_SHORTSTAT |
2910                                             DIFF_FORMAT_DIRSTAT |
2911                                             DIFF_FORMAT_SUMMARY |
2912                                             DIFF_FORMAT_PATCH);
2914         /*
2915          * These cases always need recursive; we do not drop caller-supplied
2916          * recursive bits for other formats here.
2917          */
2918         if (options->output_format & (DIFF_FORMAT_PATCH |
2919                                       DIFF_FORMAT_NUMSTAT |
2920                                       DIFF_FORMAT_DIFFSTAT |
2921                                       DIFF_FORMAT_SHORTSTAT |
2922                                       DIFF_FORMAT_DIRSTAT |
2923                                       DIFF_FORMAT_SUMMARY |
2924                                       DIFF_FORMAT_CHECKDIFF))
2925                 DIFF_OPT_SET(options, RECURSIVE);
2926         /*
2927          * Also pickaxe would not work very well if you do not say recursive
2928          */
2929         if (options->pickaxe)
2930                 DIFF_OPT_SET(options, RECURSIVE);
2931         /*
2932          * When patches are generated, submodules diffed against the work tree
2933          * must be checked for dirtiness too so it can be shown in the output
2934          */
2935         if (options->output_format & DIFF_FORMAT_PATCH)
2936                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2938         if (options->detect_rename && options->rename_limit < 0)
2939                 options->rename_limit = diff_rename_limit_default;
2940         if (options->setup & DIFF_SETUP_USE_CACHE) {
2941                 if (!active_cache)
2942                         /* read-cache does not die even when it fails
2943                          * so it is safe for us to do this here.  Also
2944                          * it does not smudge active_cache or active_nr
2945                          * when it fails, so we do not have to worry about
2946                          * cleaning it up ourselves either.
2947                          */
2948                         read_cache();
2949         }
2950         if (options->abbrev <= 0 || 40 < options->abbrev)
2951                 options->abbrev = 40; /* full */
2953         /*
2954          * It does not make sense to show the first hit we happened
2955          * to have found.  It does not make sense not to return with
2956          * exit code in such a case either.
2957          */
2958         if (DIFF_OPT_TST(options, QUICK)) {
2959                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2960                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2961         }
2963         return 0;
2966 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2968         char c, *eq;
2969         int len;
2971         if (*arg != '-')
2972                 return 0;
2973         c = *++arg;
2974         if (!c)
2975                 return 0;
2976         if (c == arg_short) {
2977                 c = *++arg;
2978                 if (!c)
2979                         return 1;
2980                 if (val && isdigit(c)) {
2981                         char *end;
2982                         int n = strtoul(arg, &end, 10);
2983                         if (*end)
2984                                 return 0;
2985                         *val = n;
2986                         return 1;
2987                 }
2988                 return 0;
2989         }
2990         if (c != '-')
2991                 return 0;
2992         arg++;
2993         eq = strchr(arg, '=');
2994         if (eq)
2995                 len = eq - arg;
2996         else
2997                 len = strlen(arg);
2998         if (!len || strncmp(arg, arg_long, len))
2999                 return 0;
3000         if (eq) {
3001                 int n;
3002                 char *end;
3003                 if (!isdigit(*++eq))
3004                         return 0;
3005                 n = strtoul(eq, &end, 10);
3006                 if (*end)
3007                         return 0;
3008                 *val = n;
3009         }
3010         return 1;
3013 static int diff_scoreopt_parse(const char *opt);
3015 static inline int short_opt(char opt, const char **argv,
3016                             const char **optarg)
3018         const char *arg = argv[0];
3019         if (arg[0] != '-' || arg[1] != opt)
3020                 return 0;
3021         if (arg[2] != '\0') {
3022                 *optarg = arg + 2;
3023                 return 1;
3024         }
3025         if (!argv[1])
3026                 die("Option '%c' requires a value", opt);
3027         *optarg = argv[1];
3028         return 2;
3031 int parse_long_opt(const char *opt, const char **argv,
3032                    const char **optarg)
3034         const char *arg = argv[0];
3035         if (arg[0] != '-' || arg[1] != '-')
3036                 return 0;
3037         arg += strlen("--");
3038         if (prefixcmp(arg, opt))
3039                 return 0;
3040         arg += strlen(opt);
3041         if (*arg == '=') { /* sticked form: --option=value */
3042                 *optarg = arg + 1;
3043                 return 1;
3044         }
3045         if (*arg != '\0')
3046                 return 0;
3047         /* separate form: --option value */
3048         if (!argv[1])
3049                 die("Option '--%s' requires a value", opt);
3050         *optarg = argv[1];
3051         return 2;
3054 static int stat_opt(struct diff_options *options, const char **av)
3056         const char *arg = av[0];
3057         char *end;
3058         int width = options->stat_width;
3059         int name_width = options->stat_name_width;
3060         int argcount = 1;
3062         arg += strlen("--stat");
3063         end = (char *)arg;
3065         switch (*arg) {
3066         case '-':
3067                 if (!prefixcmp(arg, "-width")) {
3068                         arg += strlen("-width");
3069                         if (*arg == '=')
3070                                 width = strtoul(arg + 1, &end, 10);
3071                         else if (!*arg && !av[1])
3072                                 die("Option '--stat-width' requires a value");
3073                         else if (!*arg) {
3074                                 width = strtoul(av[1], &end, 10);
3075                                 argcount = 2;
3076                         }
3077                 } else if (!prefixcmp(arg, "-name-width")) {
3078                         arg += strlen("-name-width");
3079                         if (*arg == '=')
3080                                 name_width = strtoul(arg + 1, &end, 10);
3081                         else if (!*arg && !av[1])
3082                                 die("Option '--stat-name-width' requires a value");
3083                         else if (!*arg) {
3084                                 name_width = strtoul(av[1], &end, 10);
3085                                 argcount = 2;
3086                         }
3087                 }
3088                 break;
3089         case '=':
3090                 width = strtoul(arg+1, &end, 10);
3091                 if (*end == ',')
3092                         name_width = strtoul(end+1, &end, 10);
3093         }
3095         /* Important! This checks all the error cases! */
3096         if (*end)
3097                 return 0;
3098         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3099         options->stat_name_width = name_width;
3100         options->stat_width = width;
3101         return argcount;
3104 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3106         const char *arg = av[0];
3107         const char *optarg;
3108         int argcount;
3110         /* Output format options */
3111         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3112                 options->output_format |= DIFF_FORMAT_PATCH;
3113         else if (opt_arg(arg, 'U', "unified", &options->context))
3114                 options->output_format |= DIFF_FORMAT_PATCH;
3115         else if (!strcmp(arg, "--raw"))
3116                 options->output_format |= DIFF_FORMAT_RAW;
3117         else if (!strcmp(arg, "--patch-with-raw"))
3118                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3119         else if (!strcmp(arg, "--numstat"))
3120                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3121         else if (!strcmp(arg, "--shortstat"))
3122                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3123         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3124                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3125         else if (!strcmp(arg, "--cumulative")) {
3126                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3127                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3128         } else if (opt_arg(arg, 0, "dirstat-by-file",
3129                            &options->dirstat_percent)) {
3130                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3131                 DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3132         }
3133         else if (!strcmp(arg, "--check"))
3134                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3135         else if (!strcmp(arg, "--summary"))
3136                 options->output_format |= DIFF_FORMAT_SUMMARY;
3137         else if (!strcmp(arg, "--patch-with-stat"))
3138                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3139         else if (!strcmp(arg, "--name-only"))
3140                 options->output_format |= DIFF_FORMAT_NAME;
3141         else if (!strcmp(arg, "--name-status"))
3142                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3143         else if (!strcmp(arg, "-s"))
3144                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3145         else if (!prefixcmp(arg, "--stat"))
3146                 /* --stat, --stat-width, or --stat-name-width */
3147                 return stat_opt(options, av);
3149         /* renames options */
3150         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3151                  !strcmp(arg, "--break-rewrites")) {
3152                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3153                         return error("invalid argument to -B: %s", arg+2);
3154         }
3155         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3156                  !strcmp(arg, "--find-renames")) {
3157                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3158                         return error("invalid argument to -M: %s", arg+2);
3159                 options->detect_rename = DIFF_DETECT_RENAME;
3160         }
3161         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3162                  !strcmp(arg, "--find-copies")) {
3163                 if (options->detect_rename == DIFF_DETECT_COPY)
3164                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3165                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3166                         return error("invalid argument to -C: %s", arg+2);
3167                 options->detect_rename = DIFF_DETECT_COPY;
3168         }
3169         else if (!strcmp(arg, "--no-renames"))
3170                 options->detect_rename = 0;
3171         else if (!strcmp(arg, "--relative"))
3172                 DIFF_OPT_SET(options, RELATIVE_NAME);
3173         else if (!prefixcmp(arg, "--relative=")) {
3174                 DIFF_OPT_SET(options, RELATIVE_NAME);
3175                 options->prefix = arg + 11;
3176         }
3178         /* xdiff options */
3179         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3180                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3181         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3182                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3183         else if (!strcmp(arg, "--ignore-space-at-eol"))
3184                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3185         else if (!strcmp(arg, "--patience"))
3186                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3188         /* flags options */
3189         else if (!strcmp(arg, "--binary")) {
3190                 options->output_format |= DIFF_FORMAT_PATCH;
3191                 DIFF_OPT_SET(options, BINARY);
3192         }
3193         else if (!strcmp(arg, "--full-index"))
3194                 DIFF_OPT_SET(options, FULL_INDEX);
3195         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3196                 DIFF_OPT_SET(options, TEXT);
3197         else if (!strcmp(arg, "-R"))
3198                 DIFF_OPT_SET(options, REVERSE_DIFF);
3199         else if (!strcmp(arg, "--find-copies-harder"))
3200                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3201         else if (!strcmp(arg, "--follow"))
3202                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3203         else if (!strcmp(arg, "--color"))
3204                 DIFF_OPT_SET(options, COLOR_DIFF);
3205         else if (!prefixcmp(arg, "--color=")) {
3206                 int value = git_config_colorbool(NULL, arg+8, -1);
3207                 if (value == 0)
3208                         DIFF_OPT_CLR(options, COLOR_DIFF);
3209                 else if (value > 0)
3210                         DIFF_OPT_SET(options, COLOR_DIFF);
3211                 else
3212                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3213         }
3214         else if (!strcmp(arg, "--no-color"))
3215                 DIFF_OPT_CLR(options, COLOR_DIFF);
3216         else if (!strcmp(arg, "--color-words")) {
3217                 DIFF_OPT_SET(options, COLOR_DIFF);
3218                 options->word_diff = DIFF_WORDS_COLOR;
3219         }
3220         else if (!prefixcmp(arg, "--color-words=")) {
3221                 DIFF_OPT_SET(options, COLOR_DIFF);
3222                 options->word_diff = DIFF_WORDS_COLOR;
3223                 options->word_regex = arg + 14;
3224         }
3225         else if (!strcmp(arg, "--word-diff")) {
3226                 if (options->word_diff == DIFF_WORDS_NONE)
3227                         options->word_diff = DIFF_WORDS_PLAIN;
3228         }
3229         else if (!prefixcmp(arg, "--word-diff=")) {
3230                 const char *type = arg + 12;
3231                 if (!strcmp(type, "plain"))
3232                         options->word_diff = DIFF_WORDS_PLAIN;
3233                 else if (!strcmp(type, "color")) {
3234                         DIFF_OPT_SET(options, COLOR_DIFF);
3235                         options->word_diff = DIFF_WORDS_COLOR;
3236                 }
3237                 else if (!strcmp(type, "porcelain"))
3238                         options->word_diff = DIFF_WORDS_PORCELAIN;
3239                 else if (!strcmp(type, "none"))
3240                         options->word_diff = DIFF_WORDS_NONE;
3241                 else
3242                         die("bad --word-diff argument: %s", type);
3243         }
3244         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3245                 if (options->word_diff == DIFF_WORDS_NONE)
3246                         options->word_diff = DIFF_WORDS_PLAIN;
3247                 options->word_regex = optarg;
3248                 return argcount;
3249         }
3250         else if (!strcmp(arg, "--exit-code"))
3251                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3252         else if (!strcmp(arg, "--quiet"))
3253                 DIFF_OPT_SET(options, QUICK);
3254         else if (!strcmp(arg, "--ext-diff"))
3255                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3256         else if (!strcmp(arg, "--no-ext-diff"))
3257                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3258         else if (!strcmp(arg, "--textconv"))
3259                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3260         else if (!strcmp(arg, "--no-textconv"))
3261                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3262         else if (!strcmp(arg, "--ignore-submodules")) {
3263                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3264                 handle_ignore_submodules_arg(options, "all");
3265         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3266                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3267                 handle_ignore_submodules_arg(options, arg + 20);
3268         } else if (!strcmp(arg, "--submodule"))
3269                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3270         else if (!prefixcmp(arg, "--submodule=")) {
3271                 if (!strcmp(arg + 12, "log"))
3272                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3273         }
3275         /* misc options */
3276         else if (!strcmp(arg, "-z"))
3277                 options->line_termination = 0;
3278         else if ((argcount = short_opt('l', av, &optarg))) {
3279                 options->rename_limit = strtoul(optarg, NULL, 10);
3280                 return argcount;
3281         }
3282         else if ((argcount = short_opt('S', av, &optarg))) {
3283                 options->pickaxe = optarg;
3284                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3285                 return argcount;
3286         } else if ((argcount = short_opt('G', av, &optarg))) {
3287                 options->pickaxe = optarg;
3288                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3289                 return argcount;
3290         }
3291         else if (!strcmp(arg, "--pickaxe-all"))
3292                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3293         else if (!strcmp(arg, "--pickaxe-regex"))
3294                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3295         else if ((argcount = short_opt('O', av, &optarg))) {
3296                 options->orderfile = optarg;
3297                 return argcount;
3298         }
3299         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3300                 options->filter = optarg;
3301                 return argcount;
3302         }
3303         else if (!strcmp(arg, "--abbrev"))
3304                 options->abbrev = DEFAULT_ABBREV;
3305         else if (!prefixcmp(arg, "--abbrev=")) {
3306                 options->abbrev = strtoul(arg + 9, NULL, 10);
3307                 if (options->abbrev < MINIMUM_ABBREV)
3308                         options->abbrev = MINIMUM_ABBREV;
3309                 else if (40 < options->abbrev)
3310                         options->abbrev = 40;
3311         }
3312         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3313                 options->a_prefix = optarg;
3314                 return argcount;
3315         }
3316         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3317                 options->b_prefix = optarg;
3318                 return argcount;
3319         }
3320         else if (!strcmp(arg, "--no-prefix"))
3321                 options->a_prefix = options->b_prefix = "";
3322         else if (opt_arg(arg, '\0', "inter-hunk-context",
3323                          &options->interhunkcontext))
3324                 ;
3325         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3326                 options->file = fopen(optarg, "w");
3327                 if (!options->file)
3328                         die_errno("Could not open '%s'", optarg);
3329                 options->close_file = 1;
3330                 return argcount;
3331         } else
3332                 return 0;
3333         return 1;
3336 int parse_rename_score(const char **cp_p)
3338         unsigned long num, scale;
3339         int ch, dot;
3340         const char *cp = *cp_p;
3342         num = 0;
3343         scale = 1;
3344         dot = 0;
3345         for (;;) {
3346                 ch = *cp;
3347                 if ( !dot && ch == '.' ) {
3348                         scale = 1;
3349                         dot = 1;
3350                 } else if ( ch == '%' ) {
3351                         scale = dot ? scale*100 : 100;
3352                         cp++;   /* % is always at the end */
3353                         break;
3354                 } else if ( ch >= '0' && ch <= '9' ) {
3355                         if ( scale < 100000 ) {
3356                                 scale *= 10;
3357                                 num = (num*10) + (ch-'0');
3358                         }
3359                 } else {
3360                         break;
3361                 }
3362                 cp++;
3363         }
3364         *cp_p = cp;
3366         /* user says num divided by scale and we say internally that
3367          * is MAX_SCORE * num / scale.
3368          */
3369         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3372 static int diff_scoreopt_parse(const char *opt)
3374         int opt1, opt2, cmd;
3376         if (*opt++ != '-')
3377                 return -1;
3378         cmd = *opt++;
3379         if (cmd == '-') {
3380                 /* convert the long-form arguments into short-form versions */
3381                 if (!prefixcmp(opt, "break-rewrites")) {
3382                         opt += strlen("break-rewrites");
3383                         if (*opt == 0 || *opt++ == '=')
3384                                 cmd = 'B';
3385                 } else if (!prefixcmp(opt, "find-copies")) {
3386                         opt += strlen("find-copies");
3387                         if (*opt == 0 || *opt++ == '=')
3388                                 cmd = 'C';
3389                 } else if (!prefixcmp(opt, "find-renames")) {
3390                         opt += strlen("find-renames");
3391                         if (*opt == 0 || *opt++ == '=')
3392                                 cmd = 'M';
3393                 }
3394         }
3395         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3396                 return -1; /* that is not a -M, -C nor -B option */
3398         opt1 = parse_rename_score(&opt);
3399         if (cmd != 'B')
3400                 opt2 = 0;
3401         else {
3402                 if (*opt == 0)
3403                         opt2 = 0;
3404                 else if (*opt != '/')
3405                         return -1; /* we expect -B80/99 or -B80 */
3406                 else {
3407                         opt++;
3408                         opt2 = parse_rename_score(&opt);
3409                 }
3410         }
3411         if (*opt != 0)
3412                 return -1;
3413         return opt1 | (opt2 << 16);
3416 struct diff_queue_struct diff_queued_diff;
3418 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3420         if (queue->alloc <= queue->nr) {
3421                 queue->alloc = alloc_nr(queue->alloc);
3422                 queue->queue = xrealloc(queue->queue,
3423                                         sizeof(dp) * queue->alloc);
3424         }
3425         queue->queue[queue->nr++] = dp;
3428 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3429                                  struct diff_filespec *one,
3430                                  struct diff_filespec *two)
3432         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3433         dp->one = one;
3434         dp->two = two;
3435         if (queue)
3436                 diff_q(queue, dp);
3437         return dp;
3440 void diff_free_filepair(struct diff_filepair *p)
3442         free_filespec(p->one);
3443         free_filespec(p->two);
3444         free(p);
3447 /* This is different from find_unique_abbrev() in that
3448  * it stuffs the result with dots for alignment.
3449  */
3450 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3452         int abblen;
3453         const char *abbrev;
3454         if (len == 40)
3455                 return sha1_to_hex(sha1);
3457         abbrev = find_unique_abbrev(sha1, len);
3458         abblen = strlen(abbrev);
3459         if (abblen < 37) {
3460                 static char hex[41];
3461                 if (len < abblen && abblen <= len + 2)
3462                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3463                 else
3464                         sprintf(hex, "%s...", abbrev);
3465                 return hex;
3466         }
3467         return sha1_to_hex(sha1);
3470 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3472         int line_termination = opt->line_termination;
3473         int inter_name_termination = line_termination ? '\t' : '\0';
3474         if (opt->output_prefix) {
3475                 struct strbuf *msg = NULL;
3476                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3477                 fprintf(opt->file, "%s", msg->buf);
3478         }
3480         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3481                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3482                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3483                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3484         }
3485         if (p->score) {
3486                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3487                         inter_name_termination);
3488         } else {
3489                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3490         }
3492         if (p->status == DIFF_STATUS_COPIED ||
3493             p->status == DIFF_STATUS_RENAMED) {
3494                 const char *name_a, *name_b;
3495                 name_a = p->one->path;
3496                 name_b = p->two->path;
3497                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3498                 write_name_quoted(name_a, opt->file, inter_name_termination);
3499                 write_name_quoted(name_b, opt->file, line_termination);
3500         } else {
3501                 const char *name_a, *name_b;
3502                 name_a = p->one->mode ? p->one->path : p->two->path;
3503                 name_b = NULL;
3504                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3505                 write_name_quoted(name_a, opt->file, line_termination);
3506         }
3509 int diff_unmodified_pair(struct diff_filepair *p)
3511         /* This function is written stricter than necessary to support
3512          * the currently implemented transformers, but the idea is to
3513          * let transformers to produce diff_filepairs any way they want,
3514          * and filter and clean them up here before producing the output.
3515          */
3516         struct diff_filespec *one = p->one, *two = p->two;
3518         if (DIFF_PAIR_UNMERGED(p))
3519                 return 0; /* unmerged is interesting */
3521         /* deletion, addition, mode or type change
3522          * and rename are all interesting.
3523          */
3524         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3525             DIFF_PAIR_MODE_CHANGED(p) ||
3526             strcmp(one->path, two->path))
3527                 return 0;
3529         /* both are valid and point at the same path.  that is, we are
3530          * dealing with a change.
3531          */
3532         if (one->sha1_valid && two->sha1_valid &&
3533             !hashcmp(one->sha1, two->sha1) &&
3534             !one->dirty_submodule && !two->dirty_submodule)
3535                 return 1; /* no change */
3536         if (!one->sha1_valid && !two->sha1_valid)
3537                 return 1; /* both look at the same file on the filesystem. */
3538         return 0;
3541 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3543         if (diff_unmodified_pair(p))
3544                 return;
3546         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3547             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3548                 return; /* no tree diffs in patch format */
3550         run_diff(p, o);
3553 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3554                             struct diffstat_t *diffstat)
3556         if (diff_unmodified_pair(p))
3557                 return;
3559         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3560             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3561                 return; /* no useful stat for tree diffs */
3563         run_diffstat(p, o, diffstat);
3566 static void diff_flush_checkdiff(struct diff_filepair *p,
3567                 struct diff_options *o)
3569         if (diff_unmodified_pair(p))
3570                 return;
3572         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3573             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3574                 return; /* nothing to check in tree diffs */
3576         run_checkdiff(p, o);
3579 int diff_queue_is_empty(void)
3581         struct diff_queue_struct *q = &diff_queued_diff;
3582         int i;
3583         for (i = 0; i < q->nr; i++)
3584                 if (!diff_unmodified_pair(q->queue[i]))
3585                         return 0;
3586         return 1;
3589 #if DIFF_DEBUG
3590 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3592         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3593                 x, one ? one : "",
3594                 s->path,
3595                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3596                 s->mode,
3597                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3598         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3599                 x, one ? one : "",
3600                 s->size, s->xfrm_flags);
3603 void diff_debug_filepair(const struct diff_filepair *p, int i)
3605         diff_debug_filespec(p->one, i, "one");
3606         diff_debug_filespec(p->two, i, "two");
3607         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3608                 p->score, p->status ? p->status : '?',
3609                 p->one->rename_used, p->broken_pair);
3612 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3614         int i;
3615         if (msg)
3616                 fprintf(stderr, "%s\n", msg);
3617         fprintf(stderr, "q->nr = %d\n", q->nr);
3618         for (i = 0; i < q->nr; i++) {
3619                 struct diff_filepair *p = q->queue[i];
3620                 diff_debug_filepair(p, i);
3621         }
3623 #endif
3625 static void diff_resolve_rename_copy(void)
3627         int i;
3628         struct diff_filepair *p;
3629         struct diff_queue_struct *q = &diff_queued_diff;
3631         diff_debug_queue("resolve-rename-copy", q);
3633         for (i = 0; i < q->nr; i++) {
3634                 p = q->queue[i];
3635                 p->status = 0; /* undecided */
3636                 if (DIFF_PAIR_UNMERGED(p))
3637                         p->status = DIFF_STATUS_UNMERGED;
3638                 else if (!DIFF_FILE_VALID(p->one))
3639                         p->status = DIFF_STATUS_ADDED;
3640                 else if (!DIFF_FILE_VALID(p->two))
3641                         p->status = DIFF_STATUS_DELETED;
3642                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3643                         p->status = DIFF_STATUS_TYPE_CHANGED;
3645                 /* from this point on, we are dealing with a pair
3646                  * whose both sides are valid and of the same type, i.e.
3647                  * either in-place edit or rename/copy edit.
3648                  */
3649                 else if (DIFF_PAIR_RENAME(p)) {
3650                         /*
3651                          * A rename might have re-connected a broken
3652                          * pair up, causing the pathnames to be the
3653                          * same again. If so, that's not a rename at
3654                          * all, just a modification..
3655                          *
3656                          * Otherwise, see if this source was used for
3657                          * multiple renames, in which case we decrement
3658                          * the count, and call it a copy.
3659                          */
3660                         if (!strcmp(p->one->path, p->two->path))
3661                                 p->status = DIFF_STATUS_MODIFIED;
3662                         else if (--p->one->rename_used > 0)
3663                                 p->status = DIFF_STATUS_COPIED;
3664                         else
3665                                 p->status = DIFF_STATUS_RENAMED;
3666                 }
3667                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3668                          p->one->mode != p->two->mode ||
3669                          p->one->dirty_submodule ||
3670                          p->two->dirty_submodule ||
3671                          is_null_sha1(p->one->sha1))
3672                         p->status = DIFF_STATUS_MODIFIED;
3673                 else {
3674                         /* This is a "no-change" entry and should not
3675                          * happen anymore, but prepare for broken callers.
3676                          */
3677                         error("feeding unmodified %s to diffcore",
3678                               p->one->path);
3679                         p->status = DIFF_STATUS_UNKNOWN;
3680                 }
3681         }
3682         diff_debug_queue("resolve-rename-copy done", q);
3685 static int check_pair_status(struct diff_filepair *p)
3687         switch (p->status) {
3688         case DIFF_STATUS_UNKNOWN:
3689                 return 0;
3690         case 0:
3691                 die("internal error in diff-resolve-rename-copy");
3692         default:
3693                 return 1;
3694         }
3697 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3699         int fmt = opt->output_format;
3701         if (fmt & DIFF_FORMAT_CHECKDIFF)
3702                 diff_flush_checkdiff(p, opt);
3703         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3704                 diff_flush_raw(p, opt);
3705         else if (fmt & DIFF_FORMAT_NAME) {
3706                 const char *name_a, *name_b;
3707                 name_a = p->two->path;
3708                 name_b = NULL;
3709                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3710                 write_name_quoted(name_a, opt->file, opt->line_termination);
3711         }
3714 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3716         if (fs->mode)
3717                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3718         else
3719                 fprintf(file, " %s ", newdelete);
3720         write_name_quoted(fs->path, file, '\n');
3724 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3725                 const char *line_prefix)
3727         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3728                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3729                         p->two->mode, show_name ? ' ' : '\n');
3730                 if (show_name) {
3731                         write_name_quoted(p->two->path, file, '\n');
3732                 }
3733         }
3736 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3737                         const char *line_prefix)
3739         char *names = pprint_rename(p->one->path, p->two->path);
3741         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3742         free(names);
3743         show_mode_change(file, p, 0, line_prefix);
3746 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3748         FILE *file = opt->file;
3749         char *line_prefix = "";
3751         if (opt->output_prefix) {
3752                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3753                 line_prefix = buf->buf;
3754         }
3756         switch(p->status) {
3757         case DIFF_STATUS_DELETED:
3758                 fputs(line_prefix, file);
3759                 show_file_mode_name(file, "delete", p->one);
3760                 break;
3761         case DIFF_STATUS_ADDED:
3762                 fputs(line_prefix, file);
3763                 show_file_mode_name(file, "create", p->two);
3764                 break;
3765         case DIFF_STATUS_COPIED:
3766                 fputs(line_prefix, file);
3767                 show_rename_copy(file, "copy", p, line_prefix);
3768                 break;
3769         case DIFF_STATUS_RENAMED:
3770                 fputs(line_prefix, file);
3771                 show_rename_copy(file, "rename", p, line_prefix);
3772                 break;
3773         default:
3774                 if (p->score) {
3775                         fprintf(file, "%s rewrite ", line_prefix);
3776                         write_name_quoted(p->two->path, file, ' ');
3777                         fprintf(file, "(%d%%)\n", similarity_index(p));
3778                 }
3779                 show_mode_change(file, p, !p->score, line_prefix);
3780                 break;
3781         }
3784 struct patch_id_t {
3785         git_SHA_CTX *ctx;
3786         int patchlen;
3787 };
3789 static int remove_space(char *line, int len)
3791         int i;
3792         char *dst = line;
3793         unsigned char c;
3795         for (i = 0; i < len; i++)
3796                 if (!isspace((c = line[i])))
3797                         *dst++ = c;
3799         return dst - line;
3802 static void patch_id_consume(void *priv, char *line, unsigned long len)
3804         struct patch_id_t *data = priv;
3805         int new_len;
3807         /* Ignore line numbers when computing the SHA1 of the patch */
3808         if (!prefixcmp(line, "@@ -"))
3809                 return;
3811         new_len = remove_space(line, len);
3813         git_SHA1_Update(data->ctx, line, new_len);
3814         data->patchlen += new_len;
3817 /* returns 0 upon success, and writes result into sha1 */
3818 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3820         struct diff_queue_struct *q = &diff_queued_diff;
3821         int i;
3822         git_SHA_CTX ctx;
3823         struct patch_id_t data;
3824         char buffer[PATH_MAX * 4 + 20];
3826         git_SHA1_Init(&ctx);
3827         memset(&data, 0, sizeof(struct patch_id_t));
3828         data.ctx = &ctx;
3830         for (i = 0; i < q->nr; i++) {
3831                 xpparam_t xpp;
3832                 xdemitconf_t xecfg;
3833                 mmfile_t mf1, mf2;
3834                 struct diff_filepair *p = q->queue[i];
3835                 int len1, len2;
3837                 memset(&xpp, 0, sizeof(xpp));
3838                 memset(&xecfg, 0, sizeof(xecfg));
3839                 if (p->status == 0)
3840                         return error("internal diff status error");
3841                 if (p->status == DIFF_STATUS_UNKNOWN)
3842                         continue;
3843                 if (diff_unmodified_pair(p))
3844                         continue;
3845                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3846                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3847                         continue;
3848                 if (DIFF_PAIR_UNMERGED(p))
3849                         continue;
3851                 diff_fill_sha1_info(p->one);
3852                 diff_fill_sha1_info(p->two);
3853                 if (fill_mmfile(&mf1, p->one) < 0 ||
3854                                 fill_mmfile(&mf2, p->two) < 0)
3855                         return error("unable to read files to diff");
3857                 len1 = remove_space(p->one->path, strlen(p->one->path));
3858                 len2 = remove_space(p->two->path, strlen(p->two->path));
3859                 if (p->one->mode == 0)
3860                         len1 = snprintf(buffer, sizeof(buffer),
3861                                         "diff--gita/%.*sb/%.*s"
3862                                         "newfilemode%06o"
3863                                         "---/dev/null"
3864                                         "+++b/%.*s",
3865                                         len1, p->one->path,
3866                                         len2, p->two->path,
3867                                         p->two->mode,
3868                                         len2, p->two->path);
3869                 else if (p->two->mode == 0)
3870                         len1 = snprintf(buffer, sizeof(buffer),
3871                                         "diff--gita/%.*sb/%.*s"
3872                                         "deletedfilemode%06o"
3873                                         "---a/%.*s"
3874                                         "+++/dev/null",
3875                                         len1, p->one->path,
3876                                         len2, p->two->path,
3877                                         p->one->mode,
3878                                         len1, p->one->path);
3879                 else
3880                         len1 = snprintf(buffer, sizeof(buffer),
3881                                         "diff--gita/%.*sb/%.*s"
3882                                         "---a/%.*s"
3883                                         "+++b/%.*s",
3884                                         len1, p->one->path,
3885                                         len2, p->two->path,
3886                                         len1, p->one->path,
3887                                         len2, p->two->path);
3888                 git_SHA1_Update(&ctx, buffer, len1);
3890                 if (diff_filespec_is_binary(p->one) ||
3891                     diff_filespec_is_binary(p->two)) {
3892                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3893                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3894                         continue;
3895                 }
3897                 xpp.flags = 0;
3898                 xecfg.ctxlen = 3;
3899                 xecfg.flags = 0;
3900                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3901                               &xpp, &xecfg);
3902         }
3904         git_SHA1_Final(sha1, &ctx);
3905         return 0;
3908 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3910         struct diff_queue_struct *q = &diff_queued_diff;
3911         int i;
3912         int result = diff_get_patch_id(options, sha1);
3914         for (i = 0; i < q->nr; i++)
3915                 diff_free_filepair(q->queue[i]);
3917         free(q->queue);
3918         DIFF_QUEUE_CLEAR(q);
3920         return result;
3923 static int is_summary_empty(const struct diff_queue_struct *q)
3925         int i;
3927         for (i = 0; i < q->nr; i++) {
3928                 const struct diff_filepair *p = q->queue[i];
3930                 switch (p->status) {
3931                 case DIFF_STATUS_DELETED:
3932                 case DIFF_STATUS_ADDED:
3933                 case DIFF_STATUS_COPIED:
3934                 case DIFF_STATUS_RENAMED:
3935                         return 0;
3936                 default:
3937                         if (p->score)
3938                                 return 0;
3939                         if (p->one->mode && p->two->mode &&
3940                             p->one->mode != p->two->mode)
3941                                 return 0;
3942                         break;
3943                 }
3944         }
3945         return 1;
3948 void diff_flush(struct diff_options *options)
3950         struct diff_queue_struct *q = &diff_queued_diff;
3951         int i, output_format = options->output_format;
3952         int separator = 0;
3954         /*
3955          * Order: raw, stat, summary, patch
3956          * or:    name/name-status/checkdiff (other bits clear)
3957          */
3958         if (!q->nr)
3959                 goto free_queue;
3961         if (output_format & (DIFF_FORMAT_RAW |
3962                              DIFF_FORMAT_NAME |
3963                              DIFF_FORMAT_NAME_STATUS |
3964                              DIFF_FORMAT_CHECKDIFF)) {
3965                 for (i = 0; i < q->nr; i++) {
3966                         struct diff_filepair *p = q->queue[i];
3967                         if (check_pair_status(p))
3968                                 flush_one_pair(p, options);
3969                 }
3970                 separator++;
3971         }
3973         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3974                 struct diffstat_t diffstat;
3976                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3977                 for (i = 0; i < q->nr; i++) {
3978                         struct diff_filepair *p = q->queue[i];
3979                         if (check_pair_status(p))
3980                                 diff_flush_stat(p, options, &diffstat);
3981                 }
3982                 if (output_format & DIFF_FORMAT_NUMSTAT)
3983                         show_numstat(&diffstat, options);
3984                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3985                         show_stats(&diffstat, options);
3986                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3987                         show_shortstats(&diffstat, options);
3988                 free_diffstat_info(&diffstat);
3989                 separator++;
3990         }
3991         if (output_format & DIFF_FORMAT_DIRSTAT)
3992                 show_dirstat(options);
3994         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3995                 for (i = 0; i < q->nr; i++) {
3996                         diff_summary(options, q->queue[i]);
3997                 }
3998                 separator++;
3999         }
4001         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4002             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4003             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4004                 /*
4005                  * run diff_flush_patch for the exit status. setting
4006                  * options->file to /dev/null should be safe, becaue we
4007                  * aren't supposed to produce any output anyway.
4008                  */
4009                 if (options->close_file)
4010                         fclose(options->file);
4011                 options->file = fopen("/dev/null", "w");
4012                 if (!options->file)
4013                         die_errno("Could not open /dev/null");
4014                 options->close_file = 1;
4015                 for (i = 0; i < q->nr; i++) {
4016                         struct diff_filepair *p = q->queue[i];
4017                         if (check_pair_status(p))
4018                                 diff_flush_patch(p, options);
4019                         if (options->found_changes)
4020                                 break;
4021                 }
4022         }
4024         if (output_format & DIFF_FORMAT_PATCH) {
4025                 if (separator) {
4026                         putc(options->line_termination, options->file);
4027                         if (options->stat_sep) {
4028                                 /* attach patch instead of inline */
4029                                 fputs(options->stat_sep, options->file);
4030                         }
4031                 }
4033                 for (i = 0; i < q->nr; i++) {
4034                         struct diff_filepair *p = q->queue[i];
4035                         if (check_pair_status(p))
4036                                 diff_flush_patch(p, options);
4037                 }
4038         }
4040         if (output_format & DIFF_FORMAT_CALLBACK)
4041                 options->format_callback(q, options, options->format_callback_data);
4043         for (i = 0; i < q->nr; i++)
4044                 diff_free_filepair(q->queue[i]);
4045 free_queue:
4046         free(q->queue);
4047         DIFF_QUEUE_CLEAR(q);
4048         if (options->close_file)
4049                 fclose(options->file);
4051         /*
4052          * Report the content-level differences with HAS_CHANGES;
4053          * diff_addremove/diff_change does not set the bit when
4054          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4055          */
4056         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4057                 if (options->found_changes)
4058                         DIFF_OPT_SET(options, HAS_CHANGES);
4059                 else
4060                         DIFF_OPT_CLR(options, HAS_CHANGES);
4061         }
4064 static void diffcore_apply_filter(const char *filter)
4066         int i;
4067         struct diff_queue_struct *q = &diff_queued_diff;
4068         struct diff_queue_struct outq;
4069         DIFF_QUEUE_CLEAR(&outq);
4071         if (!filter)
4072                 return;
4074         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4075                 int found;
4076                 for (i = found = 0; !found && i < q->nr; i++) {
4077                         struct diff_filepair *p = q->queue[i];
4078                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4079                              ((p->score &&
4080                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4081                               (!p->score &&
4082                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4083                             ((p->status != DIFF_STATUS_MODIFIED) &&
4084                              strchr(filter, p->status)))
4085                                 found++;
4086                 }
4087                 if (found)
4088                         return;
4090                 /* otherwise we will clear the whole queue
4091                  * by copying the empty outq at the end of this
4092                  * function, but first clear the current entries
4093                  * in the queue.
4094                  */
4095                 for (i = 0; i < q->nr; i++)
4096                         diff_free_filepair(q->queue[i]);
4097         }
4098         else {
4099                 /* Only the matching ones */
4100                 for (i = 0; i < q->nr; i++) {
4101                         struct diff_filepair *p = q->queue[i];
4103                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4104                              ((p->score &&
4105                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4106                               (!p->score &&
4107                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4108                             ((p->status != DIFF_STATUS_MODIFIED) &&
4109                              strchr(filter, p->status)))
4110                                 diff_q(&outq, p);
4111                         else
4112                                 diff_free_filepair(p);
4113                 }
4114         }
4115         free(q->queue);
4116         *q = outq;
4119 /* Check whether two filespecs with the same mode and size are identical */
4120 static int diff_filespec_is_identical(struct diff_filespec *one,
4121                                       struct diff_filespec *two)
4123         if (S_ISGITLINK(one->mode))
4124                 return 0;
4125         if (diff_populate_filespec(one, 0))
4126                 return 0;
4127         if (diff_populate_filespec(two, 0))
4128                 return 0;
4129         return !memcmp(one->data, two->data, one->size);
4132 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4134         int i;
4135         struct diff_queue_struct *q = &diff_queued_diff;
4136         struct diff_queue_struct outq;
4137         DIFF_QUEUE_CLEAR(&outq);
4139         for (i = 0; i < q->nr; i++) {
4140                 struct diff_filepair *p = q->queue[i];
4142                 /*
4143                  * 1. Entries that come from stat info dirtiness
4144                  *    always have both sides (iow, not create/delete),
4145                  *    one side of the object name is unknown, with
4146                  *    the same mode and size.  Keep the ones that
4147                  *    do not match these criteria.  They have real
4148                  *    differences.
4149                  *
4150                  * 2. At this point, the file is known to be modified,
4151                  *    with the same mode and size, and the object
4152                  *    name of one side is unknown.  Need to inspect
4153                  *    the identical contents.
4154                  */
4155                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4156                     !DIFF_FILE_VALID(p->two) ||
4157                     (p->one->sha1_valid && p->two->sha1_valid) ||
4158                     (p->one->mode != p->two->mode) ||
4159                     diff_populate_filespec(p->one, 1) ||
4160                     diff_populate_filespec(p->two, 1) ||
4161                     (p->one->size != p->two->size) ||
4162                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4163                         diff_q(&outq, p);
4164                 else {
4165                         /*
4166                          * The caller can subtract 1 from skip_stat_unmatch
4167                          * to determine how many paths were dirty only
4168                          * due to stat info mismatch.
4169                          */
4170                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4171                                 diffopt->skip_stat_unmatch++;
4172                         diff_free_filepair(p);
4173                 }
4174         }
4175         free(q->queue);
4176         *q = outq;
4179 static int diffnamecmp(const void *a_, const void *b_)
4181         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4182         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4183         const char *name_a, *name_b;
4185         name_a = a->one ? a->one->path : a->two->path;
4186         name_b = b->one ? b->one->path : b->two->path;
4187         return strcmp(name_a, name_b);
4190 void diffcore_fix_diff_index(struct diff_options *options)
4192         struct diff_queue_struct *q = &diff_queued_diff;
4193         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4196 void diffcore_std(struct diff_options *options)
4198         if (options->skip_stat_unmatch)
4199                 diffcore_skip_stat_unmatch(options);
4200         if (!options->found_follow) {
4201                 /* See try_to_follow_renames() in tree-diff.c */
4202                 if (options->break_opt != -1)
4203                         diffcore_break(options->break_opt);
4204                 if (options->detect_rename)
4205                         diffcore_rename(options);
4206                 if (options->break_opt != -1)
4207                         diffcore_merge_broken();
4208         }
4209         if (options->pickaxe)
4210                 diffcore_pickaxe(options);
4211         if (options->orderfile)
4212                 diffcore_order(options->orderfile);
4213         if (!options->found_follow)
4214                 /* See try_to_follow_renames() in tree-diff.c */
4215                 diff_resolve_rename_copy();
4216         diffcore_apply_filter(options->filter);
4218         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4219                 DIFF_OPT_SET(options, HAS_CHANGES);
4220         else
4221                 DIFF_OPT_CLR(options, HAS_CHANGES);
4223         options->found_follow = 0;
4226 int diff_result_code(struct diff_options *opt, int status)
4228         int result = 0;
4229         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4230             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4231                 return status;
4232         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4233             DIFF_OPT_TST(opt, HAS_CHANGES))
4234                 result |= 01;
4235         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4236             DIFF_OPT_TST(opt, CHECK_FAILED))
4237                 result |= 02;
4238         return result;
4241 /*
4242  * Shall changes to this submodule be ignored?
4243  *
4244  * Submodule changes can be configured to be ignored separately for each path,
4245  * but that configuration can be overridden from the command line.
4246  */
4247 static int is_submodule_ignored(const char *path, struct diff_options *options)
4249         int ignored = 0;
4250         unsigned orig_flags = options->flags;
4251         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4252                 set_diffopt_flags_from_submodule_config(options, path);
4253         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4254                 ignored = 1;
4255         options->flags = orig_flags;
4256         return ignored;
4259 void diff_addremove(struct diff_options *options,
4260                     int addremove, unsigned mode,
4261                     const unsigned char *sha1,
4262                     const char *concatpath, unsigned dirty_submodule)
4264         struct diff_filespec *one, *two;
4266         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4267                 return;
4269         /* This may look odd, but it is a preparation for
4270          * feeding "there are unchanged files which should
4271          * not produce diffs, but when you are doing copy
4272          * detection you would need them, so here they are"
4273          * entries to the diff-core.  They will be prefixed
4274          * with something like '=' or '*' (I haven't decided
4275          * which but should not make any difference).
4276          * Feeding the same new and old to diff_change()
4277          * also has the same effect.
4278          * Before the final output happens, they are pruned after
4279          * merged into rename/copy pairs as appropriate.
4280          */
4281         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4282                 addremove = (addremove == '+' ? '-' :
4283                              addremove == '-' ? '+' : addremove);
4285         if (options->prefix &&
4286             strncmp(concatpath, options->prefix, options->prefix_length))
4287                 return;
4289         one = alloc_filespec(concatpath);
4290         two = alloc_filespec(concatpath);
4292         if (addremove != '+')
4293                 fill_filespec(one, sha1, mode);
4294         if (addremove != '-') {
4295                 fill_filespec(two, sha1, mode);
4296                 two->dirty_submodule = dirty_submodule;
4297         }
4299         diff_queue(&diff_queued_diff, one, two);
4300         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4301                 DIFF_OPT_SET(options, HAS_CHANGES);
4304 void diff_change(struct diff_options *options,
4305                  unsigned old_mode, unsigned new_mode,
4306                  const unsigned char *old_sha1,
4307                  const unsigned char *new_sha1,
4308                  const char *concatpath,
4309                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4311         struct diff_filespec *one, *two;
4313         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4314             is_submodule_ignored(concatpath, options))
4315                 return;
4317         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4318                 unsigned tmp;
4319                 const unsigned char *tmp_c;
4320                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4321                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4322                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4323                         new_dirty_submodule = tmp;
4324         }
4326         if (options->prefix &&
4327             strncmp(concatpath, options->prefix, options->prefix_length))
4328                 return;
4330         one = alloc_filespec(concatpath);
4331         two = alloc_filespec(concatpath);
4332         fill_filespec(one, old_sha1, old_mode);
4333         fill_filespec(two, new_sha1, new_mode);
4334         one->dirty_submodule = old_dirty_submodule;
4335         two->dirty_submodule = new_dirty_submodule;
4337         diff_queue(&diff_queued_diff, one, two);
4338         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4339                 DIFF_OPT_SET(options, HAS_CHANGES);
4342 void diff_unmerge(struct diff_options *options,
4343                   const char *path,
4344                   unsigned mode, const unsigned char *sha1)
4346         struct diff_filespec *one, *two;
4348         if (options->prefix &&
4349             strncmp(path, options->prefix, options->prefix_length))
4350                 return;
4352         one = alloc_filespec(path);
4353         two = alloc_filespec(path);
4354         fill_filespec(one, sha1, mode);
4355         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4358 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4359                 size_t *outsize)
4361         struct diff_tempfile *temp;
4362         const char *argv[3];
4363         const char **arg = argv;
4364         struct child_process child;
4365         struct strbuf buf = STRBUF_INIT;
4366         int err = 0;
4368         temp = prepare_temp_file(spec->path, spec);
4369         *arg++ = pgm;
4370         *arg++ = temp->name;
4371         *arg = NULL;
4373         memset(&child, 0, sizeof(child));
4374         child.use_shell = 1;
4375         child.argv = argv;
4376         child.out = -1;
4377         if (start_command(&child)) {
4378                 remove_tempfile();
4379                 return NULL;
4380         }
4382         if (strbuf_read(&buf, child.out, 0) < 0)
4383                 err = error("error reading from textconv command '%s'", pgm);
4384         close(child.out);
4386         if (finish_command(&child) || err) {
4387                 strbuf_release(&buf);
4388                 remove_tempfile();
4389                 return NULL;
4390         }
4391         remove_tempfile();
4393         return strbuf_detach(&buf, outsize);
4396 size_t fill_textconv(struct userdiff_driver *driver,
4397                      struct diff_filespec *df,
4398                      char **outbuf)
4400         size_t size;
4402         if (!driver || !driver->textconv) {
4403                 if (!DIFF_FILE_VALID(df)) {
4404                         *outbuf = "";
4405                         return 0;
4406                 }
4407                 if (diff_populate_filespec(df, 0))
4408                         die("unable to read files to diff");
4409                 *outbuf = df->data;
4410                 return df->size;
4411         }
4413         if (driver->textconv_cache && df->sha1_valid) {
4414                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4415                                           &size);
4416                 if (*outbuf)
4417                         return size;
4418         }
4420         *outbuf = run_textconv(driver->textconv, df, &size);
4421         if (!*outbuf)
4422                 die("unable to read files to diff");
4424         if (driver->textconv_cache && df->sha1_valid) {
4425                 /* ignore errors, as we might be in a readonly repository */
4426                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4427                                 size);
4428                 /*
4429                  * we could save up changes and flush them all at the end,
4430                  * but we would need an extra call after all diffing is done.
4431                  * Since generating a cache entry is the slow path anyway,
4432                  * this extra overhead probably isn't a big deal.
4433                  */
4434                 notes_cache_write(driver->textconv_cache);
4435         }
4437         return size;