Code

i18n: git-am die messages
[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 = 400;
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 /* like fill_mmfile, but only for size, so we can avoid retrieving blob */
249 static unsigned long diff_filespec_size(struct diff_filespec *one)
251         if (!DIFF_FILE_VALID(one))
252                 return 0;
253         diff_populate_filespec(one, 1);
254         return one->size;
257 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
259         char *ptr = mf->ptr;
260         long size = mf->size;
261         int cnt = 0;
263         if (!size)
264                 return cnt;
265         ptr += size - 1; /* pointing at the very end */
266         if (*ptr != '\n')
267                 ; /* incomplete line */
268         else
269                 ptr--; /* skip the last LF */
270         while (mf->ptr < ptr) {
271                 char *prev_eol;
272                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
273                         if (*prev_eol == '\n')
274                                 break;
275                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
276                         break;
277                 cnt++;
278                 ptr = prev_eol - 1;
279         }
280         return cnt;
283 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
284                                struct emit_callback *ecbdata)
286         int l1, l2, at;
287         unsigned ws_rule = ecbdata->ws_rule;
288         l1 = count_trailing_blank(mf1, ws_rule);
289         l2 = count_trailing_blank(mf2, ws_rule);
290         if (l2 <= l1) {
291                 ecbdata->blank_at_eof_in_preimage = 0;
292                 ecbdata->blank_at_eof_in_postimage = 0;
293                 return;
294         }
295         at = count_lines(mf1->ptr, mf1->size);
296         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
298         at = count_lines(mf2->ptr, mf2->size);
299         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
302 static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
303                         int first, const char *line, int len)
305         int has_trailing_newline, has_trailing_carriage_return;
306         int nofirst;
307         FILE *file = o->file;
309         if (o->output_prefix) {
310                 struct strbuf *msg = NULL;
311                 msg = o->output_prefix(o, o->output_prefix_data);
312                 assert(msg);
313                 fwrite(msg->buf, msg->len, 1, file);
314         }
316         if (len == 0) {
317                 has_trailing_newline = (first == '\n');
318                 has_trailing_carriage_return = (!has_trailing_newline &&
319                                                 (first == '\r'));
320                 nofirst = has_trailing_newline || has_trailing_carriage_return;
321         } else {
322                 has_trailing_newline = (len > 0 && line[len-1] == '\n');
323                 if (has_trailing_newline)
324                         len--;
325                 has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
326                 if (has_trailing_carriage_return)
327                         len--;
328                 nofirst = 0;
329         }
331         if (len || !nofirst) {
332                 fputs(set, file);
333                 if (!nofirst)
334                         fputc(first, file);
335                 fwrite(line, len, 1, file);
336                 fputs(reset, file);
337         }
338         if (has_trailing_carriage_return)
339                 fputc('\r', file);
340         if (has_trailing_newline)
341                 fputc('\n', file);
344 static void emit_line(struct diff_options *o, const char *set, const char *reset,
345                       const char *line, int len)
347         emit_line_0(o, set, reset, line[0], line+1, len-1);
350 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
352         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
353               ecbdata->blank_at_eof_in_preimage &&
354               ecbdata->blank_at_eof_in_postimage &&
355               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
356               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
357                 return 0;
358         return ws_blank_line(line, len, ecbdata->ws_rule);
361 static void emit_add_line(const char *reset,
362                           struct emit_callback *ecbdata,
363                           const char *line, int len)
365         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
366         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
368         if (!*ws)
369                 emit_line_0(ecbdata->opt, set, reset, '+', line, len);
370         else if (new_blank_line_at_eof(ecbdata, line, len))
371                 /* Blank line at EOF - paint '+' as well */
372                 emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
373         else {
374                 /* Emit just the prefix, then the rest. */
375                 emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
376                 ws_check_emit(line, len, ecbdata->ws_rule,
377                               ecbdata->opt->file, set, reset, ws);
378         }
381 static void emit_hunk_header(struct emit_callback *ecbdata,
382                              const char *line, int len)
384         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
385         const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
386         const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
387         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
388         static const char atat[2] = { '@', '@' };
389         const char *cp, *ep;
390         struct strbuf msgbuf = STRBUF_INIT;
391         int org_len = len;
392         int i = 1;
394         /*
395          * As a hunk header must begin with "@@ -<old>, +<new> @@",
396          * it always is at least 10 bytes long.
397          */
398         if (len < 10 ||
399             memcmp(line, atat, 2) ||
400             !(ep = memmem(line + 2, len - 2, atat, 2))) {
401                 emit_line(ecbdata->opt, plain, reset, line, len);
402                 return;
403         }
404         ep += 2; /* skip over @@ */
406         /* The hunk header in fraginfo color */
407         strbuf_add(&msgbuf, frag, strlen(frag));
408         strbuf_add(&msgbuf, line, ep - line);
409         strbuf_add(&msgbuf, reset, strlen(reset));
411         /*
412          * trailing "\r\n"
413          */
414         for ( ; i < 3; i++)
415                 if (line[len - i] == '\r' || line[len - i] == '\n')
416                         len--;
418         /* blank before the func header */
419         for (cp = ep; ep - line < len; ep++)
420                 if (*ep != ' ' && *ep != '\t')
421                         break;
422         if (ep != cp) {
423                 strbuf_add(&msgbuf, plain, strlen(plain));
424                 strbuf_add(&msgbuf, cp, ep - cp);
425                 strbuf_add(&msgbuf, reset, strlen(reset));
426         }
428         if (ep < line + len) {
429                 strbuf_add(&msgbuf, func, strlen(func));
430                 strbuf_add(&msgbuf, ep, line + len - ep);
431                 strbuf_add(&msgbuf, reset, strlen(reset));
432         }
434         strbuf_add(&msgbuf, line + len, org_len - len);
435         emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
436         strbuf_release(&msgbuf);
439 static struct diff_tempfile *claim_diff_tempfile(void) {
440         int i;
441         for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
442                 if (!diff_temp[i].name)
443                         return diff_temp + i;
444         die("BUG: diff is failing to clean up its tempfiles");
447 static int remove_tempfile_installed;
449 static void remove_tempfile(void)
451         int i;
452         for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
453                 if (diff_temp[i].name == diff_temp[i].tmp_path)
454                         unlink_or_warn(diff_temp[i].name);
455                 diff_temp[i].name = NULL;
456         }
459 static void remove_tempfile_on_signal(int signo)
461         remove_tempfile();
462         sigchain_pop(signo);
463         raise(signo);
466 static void print_line_count(FILE *file, int count)
468         switch (count) {
469         case 0:
470                 fprintf(file, "0,0");
471                 break;
472         case 1:
473                 fprintf(file, "1");
474                 break;
475         default:
476                 fprintf(file, "1,%d", count);
477                 break;
478         }
481 static void emit_rewrite_lines(struct emit_callback *ecb,
482                                int prefix, const char *data, int size)
484         const char *endp = NULL;
485         static const char *nneof = " No newline at end of file\n";
486         const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
487         const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
489         while (0 < size) {
490                 int len;
492                 endp = memchr(data, '\n', size);
493                 len = endp ? (endp - data + 1) : size;
494                 if (prefix != '+') {
495                         ecb->lno_in_preimage++;
496                         emit_line_0(ecb->opt, old, reset, '-',
497                                     data, len);
498                 } else {
499                         ecb->lno_in_postimage++;
500                         emit_add_line(reset, ecb, data, len);
501                 }
502                 size -= len;
503                 data += len;
504         }
505         if (!endp) {
506                 const char *plain = diff_get_color(ecb->color_diff,
507                                                    DIFF_PLAIN);
508                 emit_line_0(ecb->opt, plain, reset, '\\',
509                             nneof, strlen(nneof));
510         }
513 static void emit_rewrite_diff(const char *name_a,
514                               const char *name_b,
515                               struct diff_filespec *one,
516                               struct diff_filespec *two,
517                               struct userdiff_driver *textconv_one,
518                               struct userdiff_driver *textconv_two,
519                               struct diff_options *o)
521         int lc_a, lc_b;
522         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
523         const char *name_a_tab, *name_b_tab;
524         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
525         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
526         const char *reset = diff_get_color(color_diff, DIFF_RESET);
527         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
528         const char *a_prefix, *b_prefix;
529         char *data_one, *data_two;
530         size_t size_one, size_two;
531         struct emit_callback ecbdata;
532         char *line_prefix = "";
533         struct strbuf *msgbuf;
535         if (o && o->output_prefix) {
536                 msgbuf = o->output_prefix(o, o->output_prefix_data);
537                 line_prefix = msgbuf->buf;
538         }
540         if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
541                 a_prefix = o->b_prefix;
542                 b_prefix = o->a_prefix;
543         } else {
544                 a_prefix = o->a_prefix;
545                 b_prefix = o->b_prefix;
546         }
548         name_a += (*name_a == '/');
549         name_b += (*name_b == '/');
550         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
551         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
553         strbuf_reset(&a_name);
554         strbuf_reset(&b_name);
555         quote_two_c_style(&a_name, a_prefix, name_a, 0);
556         quote_two_c_style(&b_name, b_prefix, name_b, 0);
558         size_one = fill_textconv(textconv_one, one, &data_one);
559         size_two = fill_textconv(textconv_two, two, &data_two);
561         memset(&ecbdata, 0, sizeof(ecbdata));
562         ecbdata.color_diff = color_diff;
563         ecbdata.found_changesp = &o->found_changes;
564         ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
565         ecbdata.opt = o;
566         if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
567                 mmfile_t mf1, mf2;
568                 mf1.ptr = (char *)data_one;
569                 mf2.ptr = (char *)data_two;
570                 mf1.size = size_one;
571                 mf2.size = size_two;
572                 check_blank_at_eof(&mf1, &mf2, &ecbdata);
573         }
574         ecbdata.lno_in_preimage = 1;
575         ecbdata.lno_in_postimage = 1;
577         lc_a = count_lines(data_one, size_one);
578         lc_b = count_lines(data_two, size_two);
579         fprintf(o->file,
580                 "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
581                 line_prefix, metainfo, a_name.buf, name_a_tab, reset,
582                 line_prefix, metainfo, b_name.buf, name_b_tab, reset,
583                 line_prefix, fraginfo);
584         if (!o->irreversible_delete)
585                 print_line_count(o->file, lc_a);
586         else
587                 fprintf(o->file, "?,?");
588         fprintf(o->file, " +");
589         print_line_count(o->file, lc_b);
590         fprintf(o->file, " @@%s\n", reset);
591         if (lc_a && !o->irreversible_delete)
592                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
593         if (lc_b)
594                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
595         if (textconv_one)
596                 free((char *)data_one);
597         if (textconv_two)
598                 free((char *)data_two);
601 struct diff_words_buffer {
602         mmfile_t text;
603         long alloc;
604         struct diff_words_orig {
605                 const char *begin, *end;
606         } *orig;
607         int orig_nr, orig_alloc;
608 };
610 static void diff_words_append(char *line, unsigned long len,
611                 struct diff_words_buffer *buffer)
613         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
614         line++;
615         len--;
616         memcpy(buffer->text.ptr + buffer->text.size, line, len);
617         buffer->text.size += len;
618         buffer->text.ptr[buffer->text.size] = '\0';
621 struct diff_words_style_elem {
622         const char *prefix;
623         const char *suffix;
624         const char *color; /* NULL; filled in by the setup code if
625                             * color is enabled */
626 };
628 struct diff_words_style {
629         enum diff_words_type type;
630         struct diff_words_style_elem new, old, ctx;
631         const char *newline;
632 };
634 static struct diff_words_style diff_words_styles[] = {
635         { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
636         { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
637         { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
638 };
640 struct diff_words_data {
641         struct diff_words_buffer minus, plus;
642         const char *current_plus;
643         int last_minus;
644         struct diff_options *opt;
645         regex_t *word_regex;
646         enum diff_words_type type;
647         struct diff_words_style *style;
648 };
650 static int fn_out_diff_words_write_helper(FILE *fp,
651                                           struct diff_words_style_elem *st_el,
652                                           const char *newline,
653                                           size_t count, const char *buf,
654                                           const char *line_prefix)
656         int print = 0;
658         while (count) {
659                 char *p = memchr(buf, '\n', count);
660                 if (print)
661                         fputs(line_prefix, fp);
662                 if (p != buf) {
663                         if (st_el->color && fputs(st_el->color, fp) < 0)
664                                 return -1;
665                         if (fputs(st_el->prefix, fp) < 0 ||
666                             fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
667                             fputs(st_el->suffix, fp) < 0)
668                                 return -1;
669                         if (st_el->color && *st_el->color
670                             && fputs(GIT_COLOR_RESET, fp) < 0)
671                                 return -1;
672                 }
673                 if (!p)
674                         return 0;
675                 if (fputs(newline, fp) < 0)
676                         return -1;
677                 count -= p + 1 - buf;
678                 buf = p + 1;
679                 print = 1;
680         }
681         return 0;
684 /*
685  * '--color-words' algorithm can be described as:
686  *
687  *   1. collect a the minus/plus lines of a diff hunk, divided into
688  *      minus-lines and plus-lines;
689  *
690  *   2. break both minus-lines and plus-lines into words and
691  *      place them into two mmfile_t with one word for each line;
692  *
693  *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
694  *
695  * And for the common parts of the both file, we output the plus side text.
696  * diff_words->current_plus is used to trace the current position of the plus file
697  * which printed. diff_words->last_minus is used to trace the last minus word
698  * printed.
699  *
700  * For '--graph' to work with '--color-words', we need to output the graph prefix
701  * on each line of color words output. Generally, there are two conditions on
702  * which we should output the prefix.
703  *
704  *   1. diff_words->last_minus == 0 &&
705  *      diff_words->current_plus == diff_words->plus.text.ptr
706  *
707  *      that is: the plus text must start as a new line, and if there is no minus
708  *      word printed, a graph prefix must be printed.
709  *
710  *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
711  *      *(diff_words->current_plus - 1) == '\n'
712  *
713  *      that is: a graph prefix must be printed following a '\n'
714  */
715 static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
717         if ((diff_words->last_minus == 0 &&
718                 diff_words->current_plus == diff_words->plus.text.ptr) ||
719                 (diff_words->current_plus > diff_words->plus.text.ptr &&
720                 *(diff_words->current_plus - 1) == '\n')) {
721                 return 1;
722         } else {
723                 return 0;
724         }
727 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
729         struct diff_words_data *diff_words = priv;
730         struct diff_words_style *style = diff_words->style;
731         int minus_first, minus_len, plus_first, plus_len;
732         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
733         struct diff_options *opt = diff_words->opt;
734         struct strbuf *msgbuf;
735         char *line_prefix = "";
737         if (line[0] != '@' || parse_hunk_header(line, len,
738                         &minus_first, &minus_len, &plus_first, &plus_len))
739                 return;
741         assert(opt);
742         if (opt->output_prefix) {
743                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
744                 line_prefix = msgbuf->buf;
745         }
747         /* POSIX requires that first be decremented by one if len == 0... */
748         if (minus_len) {
749                 minus_begin = diff_words->minus.orig[minus_first].begin;
750                 minus_end =
751                         diff_words->minus.orig[minus_first + minus_len - 1].end;
752         } else
753                 minus_begin = minus_end =
754                         diff_words->minus.orig[minus_first].end;
756         if (plus_len) {
757                 plus_begin = diff_words->plus.orig[plus_first].begin;
758                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
759         } else
760                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
762         if (color_words_output_graph_prefix(diff_words)) {
763                 fputs(line_prefix, diff_words->opt->file);
764         }
765         if (diff_words->current_plus != plus_begin) {
766                 fn_out_diff_words_write_helper(diff_words->opt->file,
767                                 &style->ctx, style->newline,
768                                 plus_begin - diff_words->current_plus,
769                                 diff_words->current_plus, line_prefix);
770                 if (*(plus_begin - 1) == '\n')
771                         fputs(line_prefix, diff_words->opt->file);
772         }
773         if (minus_begin != minus_end) {
774                 fn_out_diff_words_write_helper(diff_words->opt->file,
775                                 &style->old, style->newline,
776                                 minus_end - minus_begin, minus_begin,
777                                 line_prefix);
778         }
779         if (plus_begin != plus_end) {
780                 fn_out_diff_words_write_helper(diff_words->opt->file,
781                                 &style->new, style->newline,
782                                 plus_end - plus_begin, plus_begin,
783                                 line_prefix);
784         }
786         diff_words->current_plus = plus_end;
787         diff_words->last_minus = minus_first;
790 /* This function starts looking at *begin, and returns 0 iff a word was found. */
791 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
792                 int *begin, int *end)
794         if (word_regex && *begin < buffer->size) {
795                 regmatch_t match[1];
796                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
797                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
798                                         '\n', match[0].rm_eo - match[0].rm_so);
799                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
800                         *begin += match[0].rm_so;
801                         return *begin >= *end;
802                 }
803                 return -1;
804         }
806         /* find the next word */
807         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
808                 (*begin)++;
809         if (*begin >= buffer->size)
810                 return -1;
812         /* find the end of the word */
813         *end = *begin + 1;
814         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
815                 (*end)++;
817         return 0;
820 /*
821  * This function splits the words in buffer->text, stores the list with
822  * newline separator into out, and saves the offsets of the original words
823  * in buffer->orig.
824  */
825 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
826                 regex_t *word_regex)
828         int i, j;
829         long alloc = 0;
831         out->size = 0;
832         out->ptr = NULL;
834         /* fake an empty "0th" word */
835         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
836         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
837         buffer->orig_nr = 1;
839         for (i = 0; i < buffer->text.size; i++) {
840                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
841                         return;
843                 /* store original boundaries */
844                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
845                                 buffer->orig_alloc);
846                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
847                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
848                 buffer->orig_nr++;
850                 /* store one word */
851                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
852                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
853                 out->ptr[out->size + j - i] = '\n';
854                 out->size += j - i + 1;
856                 i = j - 1;
857         }
860 /* this executes the word diff on the accumulated buffers */
861 static void diff_words_show(struct diff_words_data *diff_words)
863         xpparam_t xpp;
864         xdemitconf_t xecfg;
865         mmfile_t minus, plus;
866         struct diff_words_style *style = diff_words->style;
868         struct diff_options *opt = diff_words->opt;
869         struct strbuf *msgbuf;
870         char *line_prefix = "";
872         assert(opt);
873         if (opt->output_prefix) {
874                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
875                 line_prefix = msgbuf->buf;
876         }
878         /* special case: only removal */
879         if (!diff_words->plus.text.size) {
880                 fputs(line_prefix, diff_words->opt->file);
881                 fn_out_diff_words_write_helper(diff_words->opt->file,
882                         &style->old, style->newline,
883                         diff_words->minus.text.size,
884                         diff_words->minus.text.ptr, line_prefix);
885                 diff_words->minus.text.size = 0;
886                 return;
887         }
889         diff_words->current_plus = diff_words->plus.text.ptr;
890         diff_words->last_minus = 0;
892         memset(&xpp, 0, sizeof(xpp));
893         memset(&xecfg, 0, sizeof(xecfg));
894         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
895         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
896         xpp.flags = 0;
897         /* as only the hunk header will be parsed, we need a 0-context */
898         xecfg.ctxlen = 0;
899         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
900                       &xpp, &xecfg);
901         free(minus.ptr);
902         free(plus.ptr);
903         if (diff_words->current_plus != diff_words->plus.text.ptr +
904                         diff_words->plus.text.size) {
905                 if (color_words_output_graph_prefix(diff_words))
906                         fputs(line_prefix, diff_words->opt->file);
907                 fn_out_diff_words_write_helper(diff_words->opt->file,
908                         &style->ctx, style->newline,
909                         diff_words->plus.text.ptr + diff_words->plus.text.size
910                         - diff_words->current_plus, diff_words->current_plus,
911                         line_prefix);
912         }
913         diff_words->minus.text.size = diff_words->plus.text.size = 0;
916 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
917 static void diff_words_flush(struct emit_callback *ecbdata)
919         if (ecbdata->diff_words->minus.text.size ||
920             ecbdata->diff_words->plus.text.size)
921                 diff_words_show(ecbdata->diff_words);
924 static void free_diff_words_data(struct emit_callback *ecbdata)
926         if (ecbdata->diff_words) {
927                 diff_words_flush(ecbdata);
928                 free (ecbdata->diff_words->minus.text.ptr);
929                 free (ecbdata->diff_words->minus.orig);
930                 free (ecbdata->diff_words->plus.text.ptr);
931                 free (ecbdata->diff_words->plus.orig);
932                 if (ecbdata->diff_words->word_regex) {
933                         regfree(ecbdata->diff_words->word_regex);
934                         free(ecbdata->diff_words->word_regex);
935                 }
936                 free(ecbdata->diff_words);
937                 ecbdata->diff_words = NULL;
938         }
941 const char *diff_get_color(int diff_use_color, enum color_diff ix)
943         if (diff_use_color)
944                 return diff_colors[ix];
945         return "";
948 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
950         const char *cp;
951         unsigned long allot;
952         size_t l = len;
954         if (ecb->truncate)
955                 return ecb->truncate(line, len);
956         cp = line;
957         allot = l;
958         while (0 < l) {
959                 (void) utf8_width(&cp, &l);
960                 if (!cp)
961                         break; /* truncated in the middle? */
962         }
963         return allot - l;
966 static void find_lno(const char *line, struct emit_callback *ecbdata)
968         const char *p;
969         ecbdata->lno_in_preimage = 0;
970         ecbdata->lno_in_postimage = 0;
971         p = strchr(line, '-');
972         if (!p)
973                 return; /* cannot happen */
974         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
975         p = strchr(p, '+');
976         if (!p)
977                 return; /* cannot happen */
978         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
981 static void fn_out_consume(void *priv, char *line, unsigned long len)
983         struct emit_callback *ecbdata = priv;
984         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
985         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
986         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
987         struct diff_options *o = ecbdata->opt;
988         char *line_prefix = "";
989         struct strbuf *msgbuf;
991         if (o && o->output_prefix) {
992                 msgbuf = o->output_prefix(o, o->output_prefix_data);
993                 line_prefix = msgbuf->buf;
994         }
996         if (ecbdata->header) {
997                 fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
998                 strbuf_reset(ecbdata->header);
999                 ecbdata->header = NULL;
1000         }
1001         *(ecbdata->found_changesp) = 1;
1003         if (ecbdata->label_path[0]) {
1004                 const char *name_a_tab, *name_b_tab;
1006                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1007                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1009                 fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1010                         line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1011                 fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1012                         line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1013                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1014         }
1016         if (diff_suppress_blank_empty
1017             && len == 2 && line[0] == ' ' && line[1] == '\n') {
1018                 line[0] = '\n';
1019                 len = 1;
1020         }
1022         if (line[0] == '@') {
1023                 if (ecbdata->diff_words)
1024                         diff_words_flush(ecbdata);
1025                 len = sane_truncate_line(ecbdata, line, len);
1026                 find_lno(line, ecbdata);
1027                 emit_hunk_header(ecbdata, line, len);
1028                 if (line[len-1] != '\n')
1029                         putc('\n', ecbdata->opt->file);
1030                 return;
1031         }
1033         if (len < 1) {
1034                 emit_line(ecbdata->opt, reset, reset, line, len);
1035                 if (ecbdata->diff_words
1036                     && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1037                         fputs("~\n", ecbdata->opt->file);
1038                 return;
1039         }
1041         if (ecbdata->diff_words) {
1042                 if (line[0] == '-') {
1043                         diff_words_append(line, len,
1044                                           &ecbdata->diff_words->minus);
1045                         return;
1046                 } else if (line[0] == '+') {
1047                         diff_words_append(line, len,
1048                                           &ecbdata->diff_words->plus);
1049                         return;
1050                 }
1051                 diff_words_flush(ecbdata);
1052                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1053                         emit_line(ecbdata->opt, plain, reset, line, len);
1054                         fputs("~\n", ecbdata->opt->file);
1055                 } else {
1056                         /* don't print the prefix character */
1057                         emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1058                 }
1059                 return;
1060         }
1062         if (line[0] != '+') {
1063                 const char *color =
1064                         diff_get_color(ecbdata->color_diff,
1065                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1066                 ecbdata->lno_in_preimage++;
1067                 if (line[0] == ' ')
1068                         ecbdata->lno_in_postimage++;
1069                 emit_line(ecbdata->opt, color, reset, line, len);
1070         } else {
1071                 ecbdata->lno_in_postimage++;
1072                 emit_add_line(reset, ecbdata, line + 1, len - 1);
1073         }
1076 static char *pprint_rename(const char *a, const char *b)
1078         const char *old = a;
1079         const char *new = b;
1080         struct strbuf name = STRBUF_INIT;
1081         int pfx_length, sfx_length;
1082         int len_a = strlen(a);
1083         int len_b = strlen(b);
1084         int a_midlen, b_midlen;
1085         int qlen_a = quote_c_style(a, NULL, NULL, 0);
1086         int qlen_b = quote_c_style(b, NULL, NULL, 0);
1088         if (qlen_a || qlen_b) {
1089                 quote_c_style(a, &name, NULL, 0);
1090                 strbuf_addstr(&name, " => ");
1091                 quote_c_style(b, &name, NULL, 0);
1092                 return strbuf_detach(&name, NULL);
1093         }
1095         /* Find common prefix */
1096         pfx_length = 0;
1097         while (*old && *new && *old == *new) {
1098                 if (*old == '/')
1099                         pfx_length = old - a + 1;
1100                 old++;
1101                 new++;
1102         }
1104         /* Find common suffix */
1105         old = a + len_a;
1106         new = b + len_b;
1107         sfx_length = 0;
1108         while (a <= old && b <= new && *old == *new) {
1109                 if (*old == '/')
1110                         sfx_length = len_a - (old - a);
1111                 old--;
1112                 new--;
1113         }
1115         /*
1116          * pfx{mid-a => mid-b}sfx
1117          * {pfx-a => pfx-b}sfx
1118          * pfx{sfx-a => sfx-b}
1119          * name-a => name-b
1120          */
1121         a_midlen = len_a - pfx_length - sfx_length;
1122         b_midlen = len_b - pfx_length - sfx_length;
1123         if (a_midlen < 0)
1124                 a_midlen = 0;
1125         if (b_midlen < 0)
1126                 b_midlen = 0;
1128         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1129         if (pfx_length + sfx_length) {
1130                 strbuf_add(&name, a, pfx_length);
1131                 strbuf_addch(&name, '{');
1132         }
1133         strbuf_add(&name, a + pfx_length, a_midlen);
1134         strbuf_addstr(&name, " => ");
1135         strbuf_add(&name, b + pfx_length, b_midlen);
1136         if (pfx_length + sfx_length) {
1137                 strbuf_addch(&name, '}');
1138                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1139         }
1140         return strbuf_detach(&name, NULL);
1143 struct diffstat_t {
1144         int nr;
1145         int alloc;
1146         struct diffstat_file {
1147                 char *from_name;
1148                 char *name;
1149                 char *print_name;
1150                 unsigned is_unmerged:1;
1151                 unsigned is_binary:1;
1152                 unsigned is_renamed:1;
1153                 uintmax_t added, deleted;
1154         } **files;
1155 };
1157 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1158                                           const char *name_a,
1159                                           const char *name_b)
1161         struct diffstat_file *x;
1162         x = xcalloc(sizeof (*x), 1);
1163         if (diffstat->nr == diffstat->alloc) {
1164                 diffstat->alloc = alloc_nr(diffstat->alloc);
1165                 diffstat->files = xrealloc(diffstat->files,
1166                                 diffstat->alloc * sizeof(x));
1167         }
1168         diffstat->files[diffstat->nr++] = x;
1169         if (name_b) {
1170                 x->from_name = xstrdup(name_a);
1171                 x->name = xstrdup(name_b);
1172                 x->is_renamed = 1;
1173         }
1174         else {
1175                 x->from_name = NULL;
1176                 x->name = xstrdup(name_a);
1177         }
1178         return x;
1181 static void diffstat_consume(void *priv, char *line, unsigned long len)
1183         struct diffstat_t *diffstat = priv;
1184         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1186         if (line[0] == '+')
1187                 x->added++;
1188         else if (line[0] == '-')
1189                 x->deleted++;
1192 const char mime_boundary_leader[] = "------------";
1194 static int scale_linear(int it, int width, int max_change)
1196         /*
1197          * make sure that at least one '-' is printed if there were deletions,
1198          * and likewise for '+'.
1199          */
1200         if (max_change < 2)
1201                 return it;
1202         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1205 static void show_name(FILE *file,
1206                       const char *prefix, const char *name, int len)
1208         fprintf(file, " %s%-*s |", prefix, len, name);
1211 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1213         if (cnt <= 0)
1214                 return;
1215         fprintf(file, "%s", set);
1216         while (cnt--)
1217                 putc(ch, file);
1218         fprintf(file, "%s", reset);
1221 static void fill_print_name(struct diffstat_file *file)
1223         char *pname;
1225         if (file->print_name)
1226                 return;
1228         if (!file->is_renamed) {
1229                 struct strbuf buf = STRBUF_INIT;
1230                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1231                         pname = strbuf_detach(&buf, NULL);
1232                 } else {
1233                         pname = file->name;
1234                         strbuf_release(&buf);
1235                 }
1236         } else {
1237                 pname = pprint_rename(file->from_name, file->name);
1238         }
1239         file->print_name = pname;
1242 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1244         int i, len, add, del, adds = 0, dels = 0;
1245         uintmax_t max_change = 0, max_len = 0;
1246         int total_files = data->nr;
1247         int width, name_width;
1248         const char *reset, *add_c, *del_c;
1249         const char *line_prefix = "";
1250         struct strbuf *msg = NULL;
1252         if (data->nr == 0)
1253                 return;
1255         if (options->output_prefix) {
1256                 msg = options->output_prefix(options, options->output_prefix_data);
1257                 line_prefix = msg->buf;
1258         }
1260         width = options->stat_width ? options->stat_width : 80;
1261         name_width = options->stat_name_width ? options->stat_name_width : 50;
1263         /* Sanity: give at least 5 columns to the graph,
1264          * but leave at least 10 columns for the name.
1265          */
1266         if (width < 25)
1267                 width = 25;
1268         if (name_width < 10)
1269                 name_width = 10;
1270         else if (width < name_width + 15)
1271                 name_width = width - 15;
1273         /* Find the longest filename and max number of changes */
1274         reset = diff_get_color_opt(options, DIFF_RESET);
1275         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1276         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1278         for (i = 0; i < data->nr; i++) {
1279                 struct diffstat_file *file = data->files[i];
1280                 uintmax_t change = file->added + file->deleted;
1281                 fill_print_name(file);
1282                 len = strlen(file->print_name);
1283                 if (max_len < len)
1284                         max_len = len;
1286                 if (file->is_binary || file->is_unmerged)
1287                         continue;
1288                 if (max_change < change)
1289                         max_change = change;
1290         }
1292         /* Compute the width of the graph part;
1293          * 10 is for one blank at the beginning of the line plus
1294          * " | count " between the name and the graph.
1295          *
1296          * From here on, name_width is the width of the name area,
1297          * and width is the width of the graph area.
1298          */
1299         name_width = (name_width < max_len) ? name_width : max_len;
1300         if (width < (name_width + 10) + max_change)
1301                 width = width - (name_width + 10);
1302         else
1303                 width = max_change;
1305         for (i = 0; i < data->nr; i++) {
1306                 const char *prefix = "";
1307                 char *name = data->files[i]->print_name;
1308                 uintmax_t added = data->files[i]->added;
1309                 uintmax_t deleted = data->files[i]->deleted;
1310                 int name_len;
1312                 /*
1313                  * "scale" the filename
1314                  */
1315                 len = name_width;
1316                 name_len = strlen(name);
1317                 if (name_width < name_len) {
1318                         char *slash;
1319                         prefix = "...";
1320                         len -= 3;
1321                         name += name_len - len;
1322                         slash = strchr(name, '/');
1323                         if (slash)
1324                                 name = slash;
1325                 }
1327                 if (data->files[i]->is_binary) {
1328                         fprintf(options->file, "%s", line_prefix);
1329                         show_name(options->file, prefix, name, len);
1330                         fprintf(options->file, "  Bin ");
1331                         fprintf(options->file, "%s%"PRIuMAX"%s",
1332                                 del_c, deleted, reset);
1333                         fprintf(options->file, " -> ");
1334                         fprintf(options->file, "%s%"PRIuMAX"%s",
1335                                 add_c, added, reset);
1336                         fprintf(options->file, " bytes");
1337                         fprintf(options->file, "\n");
1338                         continue;
1339                 }
1340                 else if (data->files[i]->is_unmerged) {
1341                         fprintf(options->file, "%s", line_prefix);
1342                         show_name(options->file, prefix, name, len);
1343                         fprintf(options->file, "  Unmerged\n");
1344                         continue;
1345                 }
1346                 else if (!data->files[i]->is_renamed &&
1347                          (added + deleted == 0)) {
1348                         total_files--;
1349                         continue;
1350                 }
1352                 /*
1353                  * scale the add/delete
1354                  */
1355                 add = added;
1356                 del = deleted;
1357                 adds += add;
1358                 dels += del;
1360                 if (width <= max_change) {
1361                         add = scale_linear(add, width, max_change);
1362                         del = scale_linear(del, width, max_change);
1363                 }
1364                 fprintf(options->file, "%s", line_prefix);
1365                 show_name(options->file, prefix, name, len);
1366                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1367                                 added + deleted ? " " : "");
1368                 show_graph(options->file, '+', add, add_c, reset);
1369                 show_graph(options->file, '-', del, del_c, reset);
1370                 fprintf(options->file, "\n");
1371         }
1372         fprintf(options->file, "%s", line_prefix);
1373         fprintf(options->file,
1374                " %d files changed, %d insertions(+), %d deletions(-)\n",
1375                total_files, adds, dels);
1378 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1380         int i, adds = 0, dels = 0, total_files = data->nr;
1382         if (data->nr == 0)
1383                 return;
1385         for (i = 0; i < data->nr; i++) {
1386                 if (!data->files[i]->is_binary &&
1387                     !data->files[i]->is_unmerged) {
1388                         int added = data->files[i]->added;
1389                         int deleted= data->files[i]->deleted;
1390                         if (!data->files[i]->is_renamed &&
1391                             (added + deleted == 0)) {
1392                                 total_files--;
1393                         } else {
1394                                 adds += added;
1395                                 dels += deleted;
1396                         }
1397                 }
1398         }
1399         if (options->output_prefix) {
1400                 struct strbuf *msg = NULL;
1401                 msg = options->output_prefix(options,
1402                                 options->output_prefix_data);
1403                 fprintf(options->file, "%s", msg->buf);
1404         }
1405         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1406                total_files, adds, dels);
1409 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1411         int i;
1413         if (data->nr == 0)
1414                 return;
1416         for (i = 0; i < data->nr; i++) {
1417                 struct diffstat_file *file = data->files[i];
1419                 if (options->output_prefix) {
1420                         struct strbuf *msg = NULL;
1421                         msg = options->output_prefix(options,
1422                                         options->output_prefix_data);
1423                         fprintf(options->file, "%s", msg->buf);
1424                 }
1426                 if (file->is_binary)
1427                         fprintf(options->file, "-\t-\t");
1428                 else
1429                         fprintf(options->file,
1430                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1431                                 file->added, file->deleted);
1432                 if (options->line_termination) {
1433                         fill_print_name(file);
1434                         if (!file->is_renamed)
1435                                 write_name_quoted(file->name, options->file,
1436                                                   options->line_termination);
1437                         else {
1438                                 fputs(file->print_name, options->file);
1439                                 putc(options->line_termination, options->file);
1440                         }
1441                 } else {
1442                         if (file->is_renamed) {
1443                                 putc('\0', options->file);
1444                                 write_name_quoted(file->from_name, options->file, '\0');
1445                         }
1446                         write_name_quoted(file->name, options->file, '\0');
1447                 }
1448         }
1451 struct dirstat_file {
1452         const char *name;
1453         unsigned long changed;
1454 };
1456 struct dirstat_dir {
1457         struct dirstat_file *files;
1458         int alloc, nr, percent, cumulative;
1459 };
1461 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1462                 unsigned long changed, const char *base, int baselen)
1464         unsigned long this_dir = 0;
1465         unsigned int sources = 0;
1466         const char *line_prefix = "";
1467         struct strbuf *msg = NULL;
1469         if (opt->output_prefix) {
1470                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1471                 line_prefix = msg->buf;
1472         }
1474         while (dir->nr) {
1475                 struct dirstat_file *f = dir->files;
1476                 int namelen = strlen(f->name);
1477                 unsigned long this;
1478                 char *slash;
1480                 if (namelen < baselen)
1481                         break;
1482                 if (memcmp(f->name, base, baselen))
1483                         break;
1484                 slash = strchr(f->name + baselen, '/');
1485                 if (slash) {
1486                         int newbaselen = slash + 1 - f->name;
1487                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1488                         sources++;
1489                 } else {
1490                         this = f->changed;
1491                         dir->files++;
1492                         dir->nr--;
1493                         sources += 2;
1494                 }
1495                 this_dir += this;
1496         }
1498         /*
1499          * We don't report dirstat's for
1500          *  - the top level
1501          *  - or cases where everything came from a single directory
1502          *    under this directory (sources == 1).
1503          */
1504         if (baselen && sources != 1) {
1505                 int permille = this_dir * 1000 / changed;
1506                 if (permille) {
1507                         int percent = permille / 10;
1508                         if (percent >= dir->percent) {
1509                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1510                                         percent, permille % 10, baselen, base);
1511                                 if (!dir->cumulative)
1512                                         return 0;
1513                         }
1514                 }
1515         }
1516         return this_dir;
1519 static int dirstat_compare(const void *_a, const void *_b)
1521         const struct dirstat_file *a = _a;
1522         const struct dirstat_file *b = _b;
1523         return strcmp(a->name, b->name);
1526 static void show_dirstat(struct diff_options *options)
1528         int i;
1529         unsigned long changed;
1530         struct dirstat_dir dir;
1531         struct diff_queue_struct *q = &diff_queued_diff;
1533         dir.files = NULL;
1534         dir.alloc = 0;
1535         dir.nr = 0;
1536         dir.percent = options->dirstat_percent;
1537         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1539         changed = 0;
1540         for (i = 0; i < q->nr; i++) {
1541                 struct diff_filepair *p = q->queue[i];
1542                 const char *name;
1543                 unsigned long copied, added, damage;
1544                 int content_changed;
1546                 name = p->two->path ? p->two->path : p->one->path;
1548                 if (p->one->sha1_valid && p->two->sha1_valid)
1549                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1550                 else
1551                         content_changed = 1;
1553                 if (!content_changed) {
1554                         /*
1555                          * The SHA1 has not changed, so pre-/post-content is
1556                          * identical. We can therefore skip looking at the
1557                          * file contents altogether.
1558                          */
1559                         damage = 0;
1560                         goto found_damage;
1561                 }
1563                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1564                         /*
1565                          * In --dirstat-by-file mode, we don't really need to
1566                          * look at the actual file contents at all.
1567                          * The fact that the SHA1 changed is enough for us to
1568                          * add this file to the list of results
1569                          * (with each file contributing equal damage).
1570                          */
1571                         damage = 1;
1572                         goto found_damage;
1573                 }
1575                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1576                         diff_populate_filespec(p->one, 0);
1577                         diff_populate_filespec(p->two, 0);
1578                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1579                                                &copied, &added);
1580                         diff_free_filespec_data(p->one);
1581                         diff_free_filespec_data(p->two);
1582                 } else if (DIFF_FILE_VALID(p->one)) {
1583                         diff_populate_filespec(p->one, 1);
1584                         copied = added = 0;
1585                         diff_free_filespec_data(p->one);
1586                 } else if (DIFF_FILE_VALID(p->two)) {
1587                         diff_populate_filespec(p->two, 1);
1588                         copied = 0;
1589                         added = p->two->size;
1590                         diff_free_filespec_data(p->two);
1591                 } else
1592                         continue;
1594                 /*
1595                  * Original minus copied is the removed material,
1596                  * added is the new material.  They are both damages
1597                  * made to the preimage.
1598                  * If the resulting damage is zero, we know that
1599                  * diffcore_count_changes() considers the two entries to
1600                  * be identical, but since content_changed is true, we
1601                  * know that there must have been _some_ kind of change,
1602                  * so we force all entries to have damage > 0.
1603                  */
1604                 damage = (p->one->size - copied) + added;
1605                 if (!damage)
1606                         damage = 1;
1608 found_damage:
1609                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1610                 dir.files[dir.nr].name = name;
1611                 dir.files[dir.nr].changed = damage;
1612                 changed += damage;
1613                 dir.nr++;
1614         }
1616         /* This can happen even with many files, if everything was renames */
1617         if (!changed)
1618                 return;
1620         /* Show all directories with more than x% of the changes */
1621         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1622         gather_dirstat(options, &dir, changed, "", 0);
1625 static void free_diffstat_info(struct diffstat_t *diffstat)
1627         int i;
1628         for (i = 0; i < diffstat->nr; i++) {
1629                 struct diffstat_file *f = diffstat->files[i];
1630                 if (f->name != f->print_name)
1631                         free(f->print_name);
1632                 free(f->name);
1633                 free(f->from_name);
1634                 free(f);
1635         }
1636         free(diffstat->files);
1639 struct checkdiff_t {
1640         const char *filename;
1641         int lineno;
1642         int conflict_marker_size;
1643         struct diff_options *o;
1644         unsigned ws_rule;
1645         unsigned status;
1646 };
1648 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1650         char firstchar;
1651         int cnt;
1653         if (len < marker_size + 1)
1654                 return 0;
1655         firstchar = line[0];
1656         switch (firstchar) {
1657         case '=': case '>': case '<': case '|':
1658                 break;
1659         default:
1660                 return 0;
1661         }
1662         for (cnt = 1; cnt < marker_size; cnt++)
1663                 if (line[cnt] != firstchar)
1664                         return 0;
1665         /* line[1] thru line[marker_size-1] are same as firstchar */
1666         if (len < marker_size + 1 || !isspace(line[marker_size]))
1667                 return 0;
1668         return 1;
1671 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1673         struct checkdiff_t *data = priv;
1674         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1675         int marker_size = data->conflict_marker_size;
1676         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1677         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1678         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1679         char *err;
1680         char *line_prefix = "";
1681         struct strbuf *msgbuf;
1683         assert(data->o);
1684         if (data->o->output_prefix) {
1685                 msgbuf = data->o->output_prefix(data->o,
1686                         data->o->output_prefix_data);
1687                 line_prefix = msgbuf->buf;
1688         }
1690         if (line[0] == '+') {
1691                 unsigned bad;
1692                 data->lineno++;
1693                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1694                         data->status |= 1;
1695                         fprintf(data->o->file,
1696                                 "%s%s:%d: leftover conflict marker\n",
1697                                 line_prefix, data->filename, data->lineno);
1698                 }
1699                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1700                 if (!bad)
1701                         return;
1702                 data->status |= bad;
1703                 err = whitespace_error_string(bad);
1704                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1705                         line_prefix, data->filename, data->lineno, err);
1706                 free(err);
1707                 emit_line(data->o, set, reset, line, 1);
1708                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1709                               data->o->file, set, reset, ws);
1710         } else if (line[0] == ' ') {
1711                 data->lineno++;
1712         } else if (line[0] == '@') {
1713                 char *plus = strchr(line, '+');
1714                 if (plus)
1715                         data->lineno = strtol(plus, NULL, 10) - 1;
1716                 else
1717                         die("invalid diff");
1718         }
1721 static unsigned char *deflate_it(char *data,
1722                                  unsigned long size,
1723                                  unsigned long *result_size)
1725         int bound;
1726         unsigned char *deflated;
1727         z_stream stream;
1729         memset(&stream, 0, sizeof(stream));
1730         deflateInit(&stream, zlib_compression_level);
1731         bound = deflateBound(&stream, size);
1732         deflated = xmalloc(bound);
1733         stream.next_out = deflated;
1734         stream.avail_out = bound;
1736         stream.next_in = (unsigned char *)data;
1737         stream.avail_in = size;
1738         while (deflate(&stream, Z_FINISH) == Z_OK)
1739                 ; /* nothing */
1740         deflateEnd(&stream);
1741         *result_size = stream.total_out;
1742         return deflated;
1745 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1747         void *cp;
1748         void *delta;
1749         void *deflated;
1750         void *data;
1751         unsigned long orig_size;
1752         unsigned long delta_size;
1753         unsigned long deflate_size;
1754         unsigned long data_size;
1756         /* We could do deflated delta, or we could do just deflated two,
1757          * whichever is smaller.
1758          */
1759         delta = NULL;
1760         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1761         if (one->size && two->size) {
1762                 delta = diff_delta(one->ptr, one->size,
1763                                    two->ptr, two->size,
1764                                    &delta_size, deflate_size);
1765                 if (delta) {
1766                         void *to_free = delta;
1767                         orig_size = delta_size;
1768                         delta = deflate_it(delta, delta_size, &delta_size);
1769                         free(to_free);
1770                 }
1771         }
1773         if (delta && delta_size < deflate_size) {
1774                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1775                 free(deflated);
1776                 data = delta;
1777                 data_size = delta_size;
1778         }
1779         else {
1780                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1781                 free(delta);
1782                 data = deflated;
1783                 data_size = deflate_size;
1784         }
1786         /* emit data encoded in base85 */
1787         cp = data;
1788         while (data_size) {
1789                 int bytes = (52 < data_size) ? 52 : data_size;
1790                 char line[70];
1791                 data_size -= bytes;
1792                 if (bytes <= 26)
1793                         line[0] = bytes + 'A' - 1;
1794                 else
1795                         line[0] = bytes - 26 + 'a' - 1;
1796                 encode_85(line + 1, cp, bytes);
1797                 cp = (char *) cp + bytes;
1798                 fprintf(file, "%s", prefix);
1799                 fputs(line, file);
1800                 fputc('\n', file);
1801         }
1802         fprintf(file, "%s\n", prefix);
1803         free(data);
1806 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1808         fprintf(file, "%sGIT binary patch\n", prefix);
1809         emit_binary_diff_body(file, one, two, prefix);
1810         emit_binary_diff_body(file, two, one, prefix);
1813 static void diff_filespec_load_driver(struct diff_filespec *one)
1815         /* Use already-loaded driver */
1816         if (one->driver)
1817                 return;
1819         if (S_ISREG(one->mode))
1820                 one->driver = userdiff_find_by_path(one->path);
1822         /* Fallback to default settings */
1823         if (!one->driver)
1824                 one->driver = userdiff_find_by_name("default");
1827 int diff_filespec_is_binary(struct diff_filespec *one)
1829         if (one->is_binary == -1) {
1830                 diff_filespec_load_driver(one);
1831                 if (one->driver->binary != -1)
1832                         one->is_binary = one->driver->binary;
1833                 else {
1834                         if (!one->data && DIFF_FILE_VALID(one))
1835                                 diff_populate_filespec(one, 0);
1836                         if (one->data)
1837                                 one->is_binary = buffer_is_binary(one->data,
1838                                                 one->size);
1839                         if (one->is_binary == -1)
1840                                 one->is_binary = 0;
1841                 }
1842         }
1843         return one->is_binary;
1846 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1848         diff_filespec_load_driver(one);
1849         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1852 static const char *userdiff_word_regex(struct diff_filespec *one)
1854         diff_filespec_load_driver(one);
1855         return one->driver->word_regex;
1858 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1860         if (!options->a_prefix)
1861                 options->a_prefix = a;
1862         if (!options->b_prefix)
1863                 options->b_prefix = b;
1866 struct userdiff_driver *get_textconv(struct diff_filespec *one)
1868         if (!DIFF_FILE_VALID(one))
1869                 return NULL;
1871         diff_filespec_load_driver(one);
1872         if (!one->driver->textconv)
1873                 return NULL;
1875         if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1876                 struct notes_cache *c = xmalloc(sizeof(*c));
1877                 struct strbuf name = STRBUF_INIT;
1879                 strbuf_addf(&name, "textconv/%s", one->driver->name);
1880                 notes_cache_init(c, name.buf, one->driver->textconv);
1881                 one->driver->textconv_cache = c;
1882         }
1884         return one->driver;
1887 static void builtin_diff(const char *name_a,
1888                          const char *name_b,
1889                          struct diff_filespec *one,
1890                          struct diff_filespec *two,
1891                          const char *xfrm_msg,
1892                          int must_show_header,
1893                          struct diff_options *o,
1894                          int complete_rewrite)
1896         mmfile_t mf1, mf2;
1897         const char *lbl[2];
1898         char *a_one, *b_two;
1899         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1900         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1901         const char *a_prefix, *b_prefix;
1902         struct userdiff_driver *textconv_one = NULL;
1903         struct userdiff_driver *textconv_two = NULL;
1904         struct strbuf header = STRBUF_INIT;
1905         struct strbuf *msgbuf;
1906         char *line_prefix = "";
1908         if (o->output_prefix) {
1909                 msgbuf = o->output_prefix(o, o->output_prefix_data);
1910                 line_prefix = msgbuf->buf;
1911         }
1913         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1914                         (!one->mode || S_ISGITLINK(one->mode)) &&
1915                         (!two->mode || S_ISGITLINK(two->mode))) {
1916                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1917                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1918                 show_submodule_summary(o->file, one ? one->path : two->path,
1919                                 one->sha1, two->sha1, two->dirty_submodule,
1920                                 del, add, reset);
1921                 return;
1922         }
1924         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1925                 textconv_one = get_textconv(one);
1926                 textconv_two = get_textconv(two);
1927         }
1929         diff_set_mnemonic_prefix(o, "a/", "b/");
1930         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1931                 a_prefix = o->b_prefix;
1932                 b_prefix = o->a_prefix;
1933         } else {
1934                 a_prefix = o->a_prefix;
1935                 b_prefix = o->b_prefix;
1936         }
1938         /* Never use a non-valid filename anywhere if at all possible */
1939         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1940         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1942         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1943         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1944         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1945         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1946         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1947         if (lbl[0][0] == '/') {
1948                 /* /dev/null */
1949                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1950                 if (xfrm_msg)
1951                         strbuf_addstr(&header, xfrm_msg);
1952                 must_show_header = 1;
1953         }
1954         else if (lbl[1][0] == '/') {
1955                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1956                 if (xfrm_msg)
1957                         strbuf_addstr(&header, xfrm_msg);
1958                 must_show_header = 1;
1959         }
1960         else {
1961                 if (one->mode != two->mode) {
1962                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1963                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1964                         must_show_header = 1;
1965                 }
1966                 if (xfrm_msg)
1967                         strbuf_addstr(&header, xfrm_msg);
1969                 /*
1970                  * we do not run diff between different kind
1971                  * of objects.
1972                  */
1973                 if ((one->mode ^ two->mode) & S_IFMT)
1974                         goto free_ab_and_return;
1975                 if (complete_rewrite &&
1976                     (textconv_one || !diff_filespec_is_binary(one)) &&
1977                     (textconv_two || !diff_filespec_is_binary(two))) {
1978                         fprintf(o->file, "%s", header.buf);
1979                         strbuf_reset(&header);
1980                         emit_rewrite_diff(name_a, name_b, one, two,
1981                                                 textconv_one, textconv_two, o);
1982                         o->found_changes = 1;
1983                         goto free_ab_and_return;
1984                 }
1985         }
1987         if (o->irreversible_delete && lbl[1][0] == '/') {
1988                 fprintf(o->file, "%s", header.buf);
1989                 strbuf_reset(&header);
1990                 goto free_ab_and_return;
1991         } else if (!DIFF_OPT_TST(o, TEXT) &&
1992             ( (!textconv_one && diff_filespec_is_binary(one)) ||
1993               (!textconv_two && diff_filespec_is_binary(two)) )) {
1994                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1995                         die("unable to read files to diff");
1996                 /* Quite common confusing case */
1997                 if (mf1.size == mf2.size &&
1998                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1999                         if (must_show_header)
2000                                 fprintf(o->file, "%s", header.buf);
2001                         goto free_ab_and_return;
2002                 }
2003                 fprintf(o->file, "%s", header.buf);
2004                 strbuf_reset(&header);
2005                 if (DIFF_OPT_TST(o, BINARY))
2006                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2007                 else
2008                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2009                                 line_prefix, lbl[0], lbl[1]);
2010                 o->found_changes = 1;
2011         } else {
2012                 /* Crazy xdl interfaces.. */
2013                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2014                 xpparam_t xpp;
2015                 xdemitconf_t xecfg;
2016                 struct emit_callback ecbdata;
2017                 const struct userdiff_funcname *pe;
2019                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2020                         fprintf(o->file, "%s", header.buf);
2021                         strbuf_reset(&header);
2022                 }
2024                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2025                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2027                 pe = diff_funcname_pattern(one);
2028                 if (!pe)
2029                         pe = diff_funcname_pattern(two);
2031                 memset(&xpp, 0, sizeof(xpp));
2032                 memset(&xecfg, 0, sizeof(xecfg));
2033                 memset(&ecbdata, 0, sizeof(ecbdata));
2034                 ecbdata.label_path = lbl;
2035                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2036                 ecbdata.found_changesp = &o->found_changes;
2037                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2038                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2039                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2040                 ecbdata.opt = o;
2041                 ecbdata.header = header.len ? &header : NULL;
2042                 xpp.flags = o->xdl_opts;
2043                 xecfg.ctxlen = o->context;
2044                 xecfg.interhunkctxlen = o->interhunkcontext;
2045                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2046                 if (pe)
2047                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2048                 if (!diffopts)
2049                         ;
2050                 else if (!prefixcmp(diffopts, "--unified="))
2051                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2052                 else if (!prefixcmp(diffopts, "-u"))
2053                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2054                 if (o->word_diff) {
2055                         int i;
2057                         ecbdata.diff_words =
2058                                 xcalloc(1, sizeof(struct diff_words_data));
2059                         ecbdata.diff_words->type = o->word_diff;
2060                         ecbdata.diff_words->opt = o;
2061                         if (!o->word_regex)
2062                                 o->word_regex = userdiff_word_regex(one);
2063                         if (!o->word_regex)
2064                                 o->word_regex = userdiff_word_regex(two);
2065                         if (!o->word_regex)
2066                                 o->word_regex = diff_word_regex_cfg;
2067                         if (o->word_regex) {
2068                                 ecbdata.diff_words->word_regex = (regex_t *)
2069                                         xmalloc(sizeof(regex_t));
2070                                 if (regcomp(ecbdata.diff_words->word_regex,
2071                                                 o->word_regex,
2072                                                 REG_EXTENDED | REG_NEWLINE))
2073                                         die ("Invalid regular expression: %s",
2074                                                         o->word_regex);
2075                         }
2076                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2077                                 if (o->word_diff == diff_words_styles[i].type) {
2078                                         ecbdata.diff_words->style =
2079                                                 &diff_words_styles[i];
2080                                         break;
2081                                 }
2082                         }
2083                         if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2084                                 struct diff_words_style *st = ecbdata.diff_words->style;
2085                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2086                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2087                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2088                         }
2089                 }
2090                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2091                               &xpp, &xecfg);
2092                 if (o->word_diff)
2093                         free_diff_words_data(&ecbdata);
2094                 if (textconv_one)
2095                         free(mf1.ptr);
2096                 if (textconv_two)
2097                         free(mf2.ptr);
2098                 xdiff_clear_find_func(&xecfg);
2099         }
2101  free_ab_and_return:
2102         strbuf_release(&header);
2103         diff_free_filespec_data(one);
2104         diff_free_filespec_data(two);
2105         free(a_one);
2106         free(b_two);
2107         return;
2110 static void builtin_diffstat(const char *name_a, const char *name_b,
2111                              struct diff_filespec *one,
2112                              struct diff_filespec *two,
2113                              struct diffstat_t *diffstat,
2114                              struct diff_options *o,
2115                              int complete_rewrite)
2117         mmfile_t mf1, mf2;
2118         struct diffstat_file *data;
2120         data = diffstat_add(diffstat, name_a, name_b);
2122         if (!one || !two) {
2123                 data->is_unmerged = 1;
2124                 return;
2125         }
2127         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2128                 data->is_binary = 1;
2129                 data->added = diff_filespec_size(two);
2130                 data->deleted = diff_filespec_size(one);
2131         }
2133         else if (complete_rewrite) {
2134                 diff_populate_filespec(one, 0);
2135                 diff_populate_filespec(two, 0);
2136                 data->deleted = count_lines(one->data, one->size);
2137                 data->added = count_lines(two->data, two->size);
2138         }
2140         else {
2141                 /* Crazy xdl interfaces.. */
2142                 xpparam_t xpp;
2143                 xdemitconf_t xecfg;
2145                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2146                         die("unable to read files to diff");
2148                 memset(&xpp, 0, sizeof(xpp));
2149                 memset(&xecfg, 0, sizeof(xecfg));
2150                 xpp.flags = o->xdl_opts;
2151                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2152                               &xpp, &xecfg);
2153         }
2155         diff_free_filespec_data(one);
2156         diff_free_filespec_data(two);
2159 static void builtin_checkdiff(const char *name_a, const char *name_b,
2160                               const char *attr_path,
2161                               struct diff_filespec *one,
2162                               struct diff_filespec *two,
2163                               struct diff_options *o)
2165         mmfile_t mf1, mf2;
2166         struct checkdiff_t data;
2168         if (!two)
2169                 return;
2171         memset(&data, 0, sizeof(data));
2172         data.filename = name_b ? name_b : name_a;
2173         data.lineno = 0;
2174         data.o = o;
2175         data.ws_rule = whitespace_rule(attr_path);
2176         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2178         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2179                 die("unable to read files to diff");
2181         /*
2182          * All the other codepaths check both sides, but not checking
2183          * the "old" side here is deliberate.  We are checking the newly
2184          * introduced changes, and as long as the "new" side is text, we
2185          * can and should check what it introduces.
2186          */
2187         if (diff_filespec_is_binary(two))
2188                 goto free_and_return;
2189         else {
2190                 /* Crazy xdl interfaces.. */
2191                 xpparam_t xpp;
2192                 xdemitconf_t xecfg;
2194                 memset(&xpp, 0, sizeof(xpp));
2195                 memset(&xecfg, 0, sizeof(xecfg));
2196                 xecfg.ctxlen = 1; /* at least one context line */
2197                 xpp.flags = 0;
2198                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2199                               &xpp, &xecfg);
2201                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2202                         struct emit_callback ecbdata;
2203                         int blank_at_eof;
2205                         ecbdata.ws_rule = data.ws_rule;
2206                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2207                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2209                         if (blank_at_eof) {
2210                                 static char *err;
2211                                 if (!err)
2212                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2213                                 fprintf(o->file, "%s:%d: %s.\n",
2214                                         data.filename, blank_at_eof, err);
2215                                 data.status = 1; /* report errors */
2216                         }
2217                 }
2218         }
2219  free_and_return:
2220         diff_free_filespec_data(one);
2221         diff_free_filespec_data(two);
2222         if (data.status)
2223                 DIFF_OPT_SET(o, CHECK_FAILED);
2226 struct diff_filespec *alloc_filespec(const char *path)
2228         int namelen = strlen(path);
2229         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2231         memset(spec, 0, sizeof(*spec));
2232         spec->path = (char *)(spec + 1);
2233         memcpy(spec->path, path, namelen+1);
2234         spec->count = 1;
2235         spec->is_binary = -1;
2236         return spec;
2239 void free_filespec(struct diff_filespec *spec)
2241         if (!--spec->count) {
2242                 diff_free_filespec_data(spec);
2243                 free(spec);
2244         }
2247 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2248                    unsigned short mode)
2250         if (mode) {
2251                 spec->mode = canon_mode(mode);
2252                 hashcpy(spec->sha1, sha1);
2253                 spec->sha1_valid = !is_null_sha1(sha1);
2254         }
2257 /*
2258  * Given a name and sha1 pair, if the index tells us the file in
2259  * the work tree has that object contents, return true, so that
2260  * prepare_temp_file() does not have to inflate and extract.
2261  */
2262 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2264         struct cache_entry *ce;
2265         struct stat st;
2266         int pos, len;
2268         /*
2269          * We do not read the cache ourselves here, because the
2270          * benchmark with my previous version that always reads cache
2271          * shows that it makes things worse for diff-tree comparing
2272          * two linux-2.6 kernel trees in an already checked out work
2273          * tree.  This is because most diff-tree comparisons deal with
2274          * only a small number of files, while reading the cache is
2275          * expensive for a large project, and its cost outweighs the
2276          * savings we get by not inflating the object to a temporary
2277          * file.  Practically, this code only helps when we are used
2278          * by diff-cache --cached, which does read the cache before
2279          * calling us.
2280          */
2281         if (!active_cache)
2282                 return 0;
2284         /* We want to avoid the working directory if our caller
2285          * doesn't need the data in a normal file, this system
2286          * is rather slow with its stat/open/mmap/close syscalls,
2287          * and the object is contained in a pack file.  The pack
2288          * is probably already open and will be faster to obtain
2289          * the data through than the working directory.  Loose
2290          * objects however would tend to be slower as they need
2291          * to be individually opened and inflated.
2292          */
2293         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2294                 return 0;
2296         len = strlen(name);
2297         pos = cache_name_pos(name, len);
2298         if (pos < 0)
2299                 return 0;
2300         ce = active_cache[pos];
2302         /*
2303          * This is not the sha1 we are looking for, or
2304          * unreusable because it is not a regular file.
2305          */
2306         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2307                 return 0;
2309         /*
2310          * If ce is marked as "assume unchanged", there is no
2311          * guarantee that work tree matches what we are looking for.
2312          */
2313         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2314                 return 0;
2316         /*
2317          * If ce matches the file in the work tree, we can reuse it.
2318          */
2319         if (ce_uptodate(ce) ||
2320             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2321                 return 1;
2323         return 0;
2326 static int populate_from_stdin(struct diff_filespec *s)
2328         struct strbuf buf = STRBUF_INIT;
2329         size_t size = 0;
2331         if (strbuf_read(&buf, 0, 0) < 0)
2332                 return error("error while reading from stdin %s",
2333                                      strerror(errno));
2335         s->should_munmap = 0;
2336         s->data = strbuf_detach(&buf, &size);
2337         s->size = size;
2338         s->should_free = 1;
2339         return 0;
2342 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2344         int len;
2345         char *data = xmalloc(100), *dirty = "";
2347         /* Are we looking at the work tree? */
2348         if (s->dirty_submodule)
2349                 dirty = "-dirty";
2351         len = snprintf(data, 100,
2352                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2353         s->data = data;
2354         s->size = len;
2355         s->should_free = 1;
2356         if (size_only) {
2357                 s->data = NULL;
2358                 free(data);
2359         }
2360         return 0;
2363 /*
2364  * While doing rename detection and pickaxe operation, we may need to
2365  * grab the data for the blob (or file) for our own in-core comparison.
2366  * diff_filespec has data and size fields for this purpose.
2367  */
2368 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2370         int err = 0;
2371         if (!DIFF_FILE_VALID(s))
2372                 die("internal error: asking to populate invalid file.");
2373         if (S_ISDIR(s->mode))
2374                 return -1;
2376         if (s->data)
2377                 return 0;
2379         if (size_only && 0 < s->size)
2380                 return 0;
2382         if (S_ISGITLINK(s->mode))
2383                 return diff_populate_gitlink(s, size_only);
2385         if (!s->sha1_valid ||
2386             reuse_worktree_file(s->path, s->sha1, 0)) {
2387                 struct strbuf buf = STRBUF_INIT;
2388                 struct stat st;
2389                 int fd;
2391                 if (!strcmp(s->path, "-"))
2392                         return populate_from_stdin(s);
2394                 if (lstat(s->path, &st) < 0) {
2395                         if (errno == ENOENT) {
2396                         err_empty:
2397                                 err = -1;
2398                         empty:
2399                                 s->data = (char *)"";
2400                                 s->size = 0;
2401                                 return err;
2402                         }
2403                 }
2404                 s->size = xsize_t(st.st_size);
2405                 if (!s->size)
2406                         goto empty;
2407                 if (S_ISLNK(st.st_mode)) {
2408                         struct strbuf sb = STRBUF_INIT;
2410                         if (strbuf_readlink(&sb, s->path, s->size))
2411                                 goto err_empty;
2412                         s->size = sb.len;
2413                         s->data = strbuf_detach(&sb, NULL);
2414                         s->should_free = 1;
2415                         return 0;
2416                 }
2417                 if (size_only)
2418                         return 0;
2419                 fd = open(s->path, O_RDONLY);
2420                 if (fd < 0)
2421                         goto err_empty;
2422                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2423                 close(fd);
2424                 s->should_munmap = 1;
2426                 /*
2427                  * Convert from working tree format to canonical git format
2428                  */
2429                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2430                         size_t size = 0;
2431                         munmap(s->data, s->size);
2432                         s->should_munmap = 0;
2433                         s->data = strbuf_detach(&buf, &size);
2434                         s->size = size;
2435                         s->should_free = 1;
2436                 }
2437         }
2438         else {
2439                 enum object_type type;
2440                 if (size_only) {
2441                         type = sha1_object_info(s->sha1, &s->size);
2442                         if (type < 0)
2443                                 die("unable to read %s", sha1_to_hex(s->sha1));
2444                 } else {
2445                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2446                         if (!s->data)
2447                                 die("unable to read %s", sha1_to_hex(s->sha1));
2448                         s->should_free = 1;
2449                 }
2450         }
2451         return 0;
2454 void diff_free_filespec_blob(struct diff_filespec *s)
2456         if (s->should_free)
2457                 free(s->data);
2458         else if (s->should_munmap)
2459                 munmap(s->data, s->size);
2461         if (s->should_free || s->should_munmap) {
2462                 s->should_free = s->should_munmap = 0;
2463                 s->data = NULL;
2464         }
2467 void diff_free_filespec_data(struct diff_filespec *s)
2469         diff_free_filespec_blob(s);
2470         free(s->cnt_data);
2471         s->cnt_data = NULL;
2474 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2475                            void *blob,
2476                            unsigned long size,
2477                            const unsigned char *sha1,
2478                            int mode)
2480         int fd;
2481         struct strbuf buf = STRBUF_INIT;
2482         struct strbuf template = STRBUF_INIT;
2483         char *path_dup = xstrdup(path);
2484         const char *base = basename(path_dup);
2486         /* Generate "XXXXXX_basename.ext" */
2487         strbuf_addstr(&template, "XXXXXX_");
2488         strbuf_addstr(&template, base);
2490         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2491                         strlen(base) + 1);
2492         if (fd < 0)
2493                 die_errno("unable to create temp-file");
2494         if (convert_to_working_tree(path,
2495                         (const char *)blob, (size_t)size, &buf)) {
2496                 blob = buf.buf;
2497                 size = buf.len;
2498         }
2499         if (write_in_full(fd, blob, size) != size)
2500                 die_errno("unable to write temp-file");
2501         close(fd);
2502         temp->name = temp->tmp_path;
2503         strcpy(temp->hex, sha1_to_hex(sha1));
2504         temp->hex[40] = 0;
2505         sprintf(temp->mode, "%06o", mode);
2506         strbuf_release(&buf);
2507         strbuf_release(&template);
2508         free(path_dup);
2511 static struct diff_tempfile *prepare_temp_file(const char *name,
2512                 struct diff_filespec *one)
2514         struct diff_tempfile *temp = claim_diff_tempfile();
2516         if (!DIFF_FILE_VALID(one)) {
2517         not_a_valid_file:
2518                 /* A '-' entry produces this for file-2, and
2519                  * a '+' entry produces this for file-1.
2520                  */
2521                 temp->name = "/dev/null";
2522                 strcpy(temp->hex, ".");
2523                 strcpy(temp->mode, ".");
2524                 return temp;
2525         }
2527         if (!remove_tempfile_installed) {
2528                 atexit(remove_tempfile);
2529                 sigchain_push_common(remove_tempfile_on_signal);
2530                 remove_tempfile_installed = 1;
2531         }
2533         if (!one->sha1_valid ||
2534             reuse_worktree_file(name, one->sha1, 1)) {
2535                 struct stat st;
2536                 if (lstat(name, &st) < 0) {
2537                         if (errno == ENOENT)
2538                                 goto not_a_valid_file;
2539                         die_errno("stat(%s)", name);
2540                 }
2541                 if (S_ISLNK(st.st_mode)) {
2542                         struct strbuf sb = STRBUF_INIT;
2543                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2544                                 die_errno("readlink(%s)", name);
2545                         prep_temp_blob(name, temp, sb.buf, sb.len,
2546                                        (one->sha1_valid ?
2547                                         one->sha1 : null_sha1),
2548                                        (one->sha1_valid ?
2549                                         one->mode : S_IFLNK));
2550                         strbuf_release(&sb);
2551                 }
2552                 else {
2553                         /* we can borrow from the file in the work tree */
2554                         temp->name = name;
2555                         if (!one->sha1_valid)
2556                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2557                         else
2558                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2559                         /* Even though we may sometimes borrow the
2560                          * contents from the work tree, we always want
2561                          * one->mode.  mode is trustworthy even when
2562                          * !(one->sha1_valid), as long as
2563                          * DIFF_FILE_VALID(one).
2564                          */
2565                         sprintf(temp->mode, "%06o", one->mode);
2566                 }
2567                 return temp;
2568         }
2569         else {
2570                 if (diff_populate_filespec(one, 0))
2571                         die("cannot read data blob for %s", one->path);
2572                 prep_temp_blob(name, temp, one->data, one->size,
2573                                one->sha1, one->mode);
2574         }
2575         return temp;
2578 /* An external diff command takes:
2579  *
2580  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2581  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2582  *
2583  */
2584 static void run_external_diff(const char *pgm,
2585                               const char *name,
2586                               const char *other,
2587                               struct diff_filespec *one,
2588                               struct diff_filespec *two,
2589                               const char *xfrm_msg,
2590                               int complete_rewrite)
2592         const char *spawn_arg[10];
2593         int retval;
2594         const char **arg = &spawn_arg[0];
2596         if (one && two) {
2597                 struct diff_tempfile *temp_one, *temp_two;
2598                 const char *othername = (other ? other : name);
2599                 temp_one = prepare_temp_file(name, one);
2600                 temp_two = prepare_temp_file(othername, two);
2601                 *arg++ = pgm;
2602                 *arg++ = name;
2603                 *arg++ = temp_one->name;
2604                 *arg++ = temp_one->hex;
2605                 *arg++ = temp_one->mode;
2606                 *arg++ = temp_two->name;
2607                 *arg++ = temp_two->hex;
2608                 *arg++ = temp_two->mode;
2609                 if (other) {
2610                         *arg++ = other;
2611                         *arg++ = xfrm_msg;
2612                 }
2613         } else {
2614                 *arg++ = pgm;
2615                 *arg++ = name;
2616         }
2617         *arg = NULL;
2618         fflush(NULL);
2619         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2620         remove_tempfile();
2621         if (retval) {
2622                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2623                 exit(1);
2624         }
2627 static int similarity_index(struct diff_filepair *p)
2629         return p->score * 100 / MAX_SCORE;
2632 static void fill_metainfo(struct strbuf *msg,
2633                           const char *name,
2634                           const char *other,
2635                           struct diff_filespec *one,
2636                           struct diff_filespec *two,
2637                           struct diff_options *o,
2638                           struct diff_filepair *p,
2639                           int *must_show_header,
2640                           int use_color)
2642         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2643         const char *reset = diff_get_color(use_color, DIFF_RESET);
2644         struct strbuf *msgbuf;
2645         char *line_prefix = "";
2647         *must_show_header = 1;
2648         if (o->output_prefix) {
2649                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2650                 line_prefix = msgbuf->buf;
2651         }
2652         strbuf_init(msg, PATH_MAX * 2 + 300);
2653         switch (p->status) {
2654         case DIFF_STATUS_COPIED:
2655                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2656                             line_prefix, set, similarity_index(p));
2657                 strbuf_addf(msg, "%s\n%s%scopy from ",
2658                             reset,  line_prefix, set);
2659                 quote_c_style(name, msg, NULL, 0);
2660                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2661                 quote_c_style(other, msg, NULL, 0);
2662                 strbuf_addf(msg, "%s\n", reset);
2663                 break;
2664         case DIFF_STATUS_RENAMED:
2665                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2666                             line_prefix, set, similarity_index(p));
2667                 strbuf_addf(msg, "%s\n%s%srename from ",
2668                             reset, line_prefix, set);
2669                 quote_c_style(name, msg, NULL, 0);
2670                 strbuf_addf(msg, "%s\n%s%srename to ",
2671                             reset, line_prefix, set);
2672                 quote_c_style(other, msg, NULL, 0);
2673                 strbuf_addf(msg, "%s\n", reset);
2674                 break;
2675         case DIFF_STATUS_MODIFIED:
2676                 if (p->score) {
2677                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2678                                     line_prefix,
2679                                     set, similarity_index(p), reset);
2680                         break;
2681                 }
2682                 /* fallthru */
2683         default:
2684                 *must_show_header = 0;
2685         }
2686         if (one && two && hashcmp(one->sha1, two->sha1)) {
2687                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2689                 if (DIFF_OPT_TST(o, BINARY)) {
2690                         mmfile_t mf;
2691                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2692                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2693                                 abbrev = 40;
2694                 }
2695                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2696                             find_unique_abbrev(one->sha1, abbrev));
2697                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2698                 if (one->mode == two->mode)
2699                         strbuf_addf(msg, " %06o", one->mode);
2700                 strbuf_addf(msg, "%s\n", reset);
2701         }
2704 static void run_diff_cmd(const char *pgm,
2705                          const char *name,
2706                          const char *other,
2707                          const char *attr_path,
2708                          struct diff_filespec *one,
2709                          struct diff_filespec *two,
2710                          struct strbuf *msg,
2711                          struct diff_options *o,
2712                          struct diff_filepair *p)
2714         const char *xfrm_msg = NULL;
2715         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2716         int must_show_header = 0;
2718         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2719                 pgm = NULL;
2720         else {
2721                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2722                 if (drv && drv->external)
2723                         pgm = drv->external;
2724         }
2726         if (msg) {
2727                 /*
2728                  * don't use colors when the header is intended for an
2729                  * external diff driver
2730                  */
2731                 fill_metainfo(msg, name, other, one, two, o, p,
2732                               &must_show_header,
2733                               DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2734                 xfrm_msg = msg->len ? msg->buf : NULL;
2735         }
2737         if (pgm) {
2738                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2739                                   complete_rewrite);
2740                 return;
2741         }
2742         if (one && two)
2743                 builtin_diff(name, other ? other : name,
2744                              one, two, xfrm_msg, must_show_header,
2745                              o, complete_rewrite);
2746         else
2747                 fprintf(o->file, "* Unmerged path %s\n", name);
2750 static void diff_fill_sha1_info(struct diff_filespec *one)
2752         if (DIFF_FILE_VALID(one)) {
2753                 if (!one->sha1_valid) {
2754                         struct stat st;
2755                         if (!strcmp(one->path, "-")) {
2756                                 hashcpy(one->sha1, null_sha1);
2757                                 return;
2758                         }
2759                         if (lstat(one->path, &st) < 0)
2760                                 die_errno("stat '%s'", one->path);
2761                         if (index_path(one->sha1, one->path, &st, 0))
2762                                 die("cannot hash %s", one->path);
2763                 }
2764         }
2765         else
2766                 hashclr(one->sha1);
2769 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2771         /* Strip the prefix but do not molest /dev/null and absolute paths */
2772         if (*namep && **namep != '/') {
2773                 *namep += prefix_length;
2774                 if (**namep == '/')
2775                         ++*namep;
2776         }
2777         if (*otherp && **otherp != '/') {
2778                 *otherp += prefix_length;
2779                 if (**otherp == '/')
2780                         ++*otherp;
2781         }
2784 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2786         const char *pgm = external_diff();
2787         struct strbuf msg;
2788         struct diff_filespec *one = p->one;
2789         struct diff_filespec *two = p->two;
2790         const char *name;
2791         const char *other;
2792         const char *attr_path;
2794         name  = p->one->path;
2795         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2796         attr_path = name;
2797         if (o->prefix_length)
2798                 strip_prefix(o->prefix_length, &name, &other);
2800         if (DIFF_PAIR_UNMERGED(p)) {
2801                 run_diff_cmd(pgm, name, NULL, attr_path,
2802                              NULL, NULL, NULL, o, p);
2803                 return;
2804         }
2806         diff_fill_sha1_info(one);
2807         diff_fill_sha1_info(two);
2809         if (!pgm &&
2810             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2811             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2812                 /*
2813                  * a filepair that changes between file and symlink
2814                  * needs to be split into deletion and creation.
2815                  */
2816                 struct diff_filespec *null = alloc_filespec(two->path);
2817                 run_diff_cmd(NULL, name, other, attr_path,
2818                              one, null, &msg, o, p);
2819                 free(null);
2820                 strbuf_release(&msg);
2822                 null = alloc_filespec(one->path);
2823                 run_diff_cmd(NULL, name, other, attr_path,
2824                              null, two, &msg, o, p);
2825                 free(null);
2826         }
2827         else
2828                 run_diff_cmd(pgm, name, other, attr_path,
2829                              one, two, &msg, o, p);
2831         strbuf_release(&msg);
2834 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2835                          struct diffstat_t *diffstat)
2837         const char *name;
2838         const char *other;
2839         int complete_rewrite = 0;
2841         if (DIFF_PAIR_UNMERGED(p)) {
2842                 /* unmerged */
2843                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2844                 return;
2845         }
2847         name = p->one->path;
2848         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2850         if (o->prefix_length)
2851                 strip_prefix(o->prefix_length, &name, &other);
2853         diff_fill_sha1_info(p->one);
2854         diff_fill_sha1_info(p->two);
2856         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2857                 complete_rewrite = 1;
2858         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2861 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2863         const char *name;
2864         const char *other;
2865         const char *attr_path;
2867         if (DIFF_PAIR_UNMERGED(p)) {
2868                 /* unmerged */
2869                 return;
2870         }
2872         name = p->one->path;
2873         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2874         attr_path = other ? other : name;
2876         if (o->prefix_length)
2877                 strip_prefix(o->prefix_length, &name, &other);
2879         diff_fill_sha1_info(p->one);
2880         diff_fill_sha1_info(p->two);
2882         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2885 void diff_setup(struct diff_options *options)
2887         memcpy(options, &default_diff_options, sizeof(*options));
2889         options->file = stdout;
2891         options->line_termination = '\n';
2892         options->break_opt = -1;
2893         options->rename_limit = -1;
2894         options->dirstat_percent = 3;
2895         options->context = 3;
2897         options->change = diff_change;
2898         options->add_remove = diff_addremove;
2899         if (diff_use_color_default > 0)
2900                 DIFF_OPT_SET(options, COLOR_DIFF);
2901         options->detect_rename = diff_detect_rename_default;
2903         if (diff_no_prefix) {
2904                 options->a_prefix = options->b_prefix = "";
2905         } else if (!diff_mnemonic_prefix) {
2906                 options->a_prefix = "a/";
2907                 options->b_prefix = "b/";
2908         }
2911 int diff_setup_done(struct diff_options *options)
2913         int count = 0;
2915         if (options->output_format & DIFF_FORMAT_NAME)
2916                 count++;
2917         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2918                 count++;
2919         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2920                 count++;
2921         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2922                 count++;
2923         if (count > 1)
2924                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2926         /*
2927          * Most of the time we can say "there are changes"
2928          * only by checking if there are changed paths, but
2929          * --ignore-whitespace* options force us to look
2930          * inside contents.
2931          */
2933         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2934             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2935             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2936                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2937         else
2938                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2940         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2941                 options->detect_rename = DIFF_DETECT_COPY;
2943         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2944                 options->prefix = NULL;
2945         if (options->prefix)
2946                 options->prefix_length = strlen(options->prefix);
2947         else
2948                 options->prefix_length = 0;
2950         if (options->output_format & (DIFF_FORMAT_NAME |
2951                                       DIFF_FORMAT_NAME_STATUS |
2952                                       DIFF_FORMAT_CHECKDIFF |
2953                                       DIFF_FORMAT_NO_OUTPUT))
2954                 options->output_format &= ~(DIFF_FORMAT_RAW |
2955                                             DIFF_FORMAT_NUMSTAT |
2956                                             DIFF_FORMAT_DIFFSTAT |
2957                                             DIFF_FORMAT_SHORTSTAT |
2958                                             DIFF_FORMAT_DIRSTAT |
2959                                             DIFF_FORMAT_SUMMARY |
2960                                             DIFF_FORMAT_PATCH);
2962         /*
2963          * These cases always need recursive; we do not drop caller-supplied
2964          * recursive bits for other formats here.
2965          */
2966         if (options->output_format & (DIFF_FORMAT_PATCH |
2967                                       DIFF_FORMAT_NUMSTAT |
2968                                       DIFF_FORMAT_DIFFSTAT |
2969                                       DIFF_FORMAT_SHORTSTAT |
2970                                       DIFF_FORMAT_DIRSTAT |
2971                                       DIFF_FORMAT_SUMMARY |
2972                                       DIFF_FORMAT_CHECKDIFF))
2973                 DIFF_OPT_SET(options, RECURSIVE);
2974         /*
2975          * Also pickaxe would not work very well if you do not say recursive
2976          */
2977         if (options->pickaxe)
2978                 DIFF_OPT_SET(options, RECURSIVE);
2979         /*
2980          * When patches are generated, submodules diffed against the work tree
2981          * must be checked for dirtiness too so it can be shown in the output
2982          */
2983         if (options->output_format & DIFF_FORMAT_PATCH)
2984                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2986         if (options->detect_rename && options->rename_limit < 0)
2987                 options->rename_limit = diff_rename_limit_default;
2988         if (options->setup & DIFF_SETUP_USE_CACHE) {
2989                 if (!active_cache)
2990                         /* read-cache does not die even when it fails
2991                          * so it is safe for us to do this here.  Also
2992                          * it does not smudge active_cache or active_nr
2993                          * when it fails, so we do not have to worry about
2994                          * cleaning it up ourselves either.
2995                          */
2996                         read_cache();
2997         }
2998         if (options->abbrev <= 0 || 40 < options->abbrev)
2999                 options->abbrev = 40; /* full */
3001         /*
3002          * It does not make sense to show the first hit we happened
3003          * to have found.  It does not make sense not to return with
3004          * exit code in such a case either.
3005          */
3006         if (DIFF_OPT_TST(options, QUICK)) {
3007                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3008                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3009         }
3011         return 0;
3014 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3016         char c, *eq;
3017         int len;
3019         if (*arg != '-')
3020                 return 0;
3021         c = *++arg;
3022         if (!c)
3023                 return 0;
3024         if (c == arg_short) {
3025                 c = *++arg;
3026                 if (!c)
3027                         return 1;
3028                 if (val && isdigit(c)) {
3029                         char *end;
3030                         int n = strtoul(arg, &end, 10);
3031                         if (*end)
3032                                 return 0;
3033                         *val = n;
3034                         return 1;
3035                 }
3036                 return 0;
3037         }
3038         if (c != '-')
3039                 return 0;
3040         arg++;
3041         eq = strchr(arg, '=');
3042         if (eq)
3043                 len = eq - arg;
3044         else
3045                 len = strlen(arg);
3046         if (!len || strncmp(arg, arg_long, len))
3047                 return 0;
3048         if (eq) {
3049                 int n;
3050                 char *end;
3051                 if (!isdigit(*++eq))
3052                         return 0;
3053                 n = strtoul(eq, &end, 10);
3054                 if (*end)
3055                         return 0;
3056                 *val = n;
3057         }
3058         return 1;
3061 static int diff_scoreopt_parse(const char *opt);
3063 static inline int short_opt(char opt, const char **argv,
3064                             const char **optarg)
3066         const char *arg = argv[0];
3067         if (arg[0] != '-' || arg[1] != opt)
3068                 return 0;
3069         if (arg[2] != '\0') {
3070                 *optarg = arg + 2;
3071                 return 1;
3072         }
3073         if (!argv[1])
3074                 die("Option '%c' requires a value", opt);
3075         *optarg = argv[1];
3076         return 2;
3079 int parse_long_opt(const char *opt, const char **argv,
3080                    const char **optarg)
3082         const char *arg = argv[0];
3083         if (arg[0] != '-' || arg[1] != '-')
3084                 return 0;
3085         arg += strlen("--");
3086         if (prefixcmp(arg, opt))
3087                 return 0;
3088         arg += strlen(opt);
3089         if (*arg == '=') { /* sticked form: --option=value */
3090                 *optarg = arg + 1;
3091                 return 1;
3092         }
3093         if (*arg != '\0')
3094                 return 0;
3095         /* separate form: --option value */
3096         if (!argv[1])
3097                 die("Option '--%s' requires a value", opt);
3098         *optarg = argv[1];
3099         return 2;
3102 static int stat_opt(struct diff_options *options, const char **av)
3104         const char *arg = av[0];
3105         char *end;
3106         int width = options->stat_width;
3107         int name_width = options->stat_name_width;
3108         int argcount = 1;
3110         arg += strlen("--stat");
3111         end = (char *)arg;
3113         switch (*arg) {
3114         case '-':
3115                 if (!prefixcmp(arg, "-width")) {
3116                         arg += strlen("-width");
3117                         if (*arg == '=')
3118                                 width = strtoul(arg + 1, &end, 10);
3119                         else if (!*arg && !av[1])
3120                                 die("Option '--stat-width' requires a value");
3121                         else if (!*arg) {
3122                                 width = strtoul(av[1], &end, 10);
3123                                 argcount = 2;
3124                         }
3125                 } else if (!prefixcmp(arg, "-name-width")) {
3126                         arg += strlen("-name-width");
3127                         if (*arg == '=')
3128                                 name_width = strtoul(arg + 1, &end, 10);
3129                         else if (!*arg && !av[1])
3130                                 die("Option '--stat-name-width' requires a value");
3131                         else if (!*arg) {
3132                                 name_width = strtoul(av[1], &end, 10);
3133                                 argcount = 2;
3134                         }
3135                 }
3136                 break;
3137         case '=':
3138                 width = strtoul(arg+1, &end, 10);
3139                 if (*end == ',')
3140                         name_width = strtoul(end+1, &end, 10);
3141         }
3143         /* Important! This checks all the error cases! */
3144         if (*end)
3145                 return 0;
3146         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3147         options->stat_name_width = name_width;
3148         options->stat_width = width;
3149         return argcount;
3152 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3154         const char *arg = av[0];
3155         const char *optarg;
3156         int argcount;
3158         /* Output format options */
3159         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3160                 options->output_format |= DIFF_FORMAT_PATCH;
3161         else if (opt_arg(arg, 'U', "unified", &options->context))
3162                 options->output_format |= DIFF_FORMAT_PATCH;
3163         else if (!strcmp(arg, "--raw"))
3164                 options->output_format |= DIFF_FORMAT_RAW;
3165         else if (!strcmp(arg, "--patch-with-raw"))
3166                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3167         else if (!strcmp(arg, "--numstat"))
3168                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3169         else if (!strcmp(arg, "--shortstat"))
3170                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3171         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3172                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3173         else if (!strcmp(arg, "--cumulative")) {
3174                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3175                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3176         } else if (opt_arg(arg, 0, "dirstat-by-file",
3177                            &options->dirstat_percent)) {
3178                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3179                 DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3180         }
3181         else if (!strcmp(arg, "--check"))
3182                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3183         else if (!strcmp(arg, "--summary"))
3184                 options->output_format |= DIFF_FORMAT_SUMMARY;
3185         else if (!strcmp(arg, "--patch-with-stat"))
3186                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3187         else if (!strcmp(arg, "--name-only"))
3188                 options->output_format |= DIFF_FORMAT_NAME;
3189         else if (!strcmp(arg, "--name-status"))
3190                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3191         else if (!strcmp(arg, "-s"))
3192                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3193         else if (!prefixcmp(arg, "--stat"))
3194                 /* --stat, --stat-width, or --stat-name-width */
3195                 return stat_opt(options, av);
3197         /* renames options */
3198         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3199                  !strcmp(arg, "--break-rewrites")) {
3200                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3201                         return error("invalid argument to -B: %s", arg+2);
3202         }
3203         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3204                  !strcmp(arg, "--find-renames")) {
3205                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3206                         return error("invalid argument to -M: %s", arg+2);
3207                 options->detect_rename = DIFF_DETECT_RENAME;
3208         }
3209         else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3210                 options->irreversible_delete = 1;
3211         }
3212         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3213                  !strcmp(arg, "--find-copies")) {
3214                 if (options->detect_rename == DIFF_DETECT_COPY)
3215                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3216                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3217                         return error("invalid argument to -C: %s", arg+2);
3218                 options->detect_rename = DIFF_DETECT_COPY;
3219         }
3220         else if (!strcmp(arg, "--no-renames"))
3221                 options->detect_rename = 0;
3222         else if (!strcmp(arg, "--relative"))
3223                 DIFF_OPT_SET(options, RELATIVE_NAME);
3224         else if (!prefixcmp(arg, "--relative=")) {
3225                 DIFF_OPT_SET(options, RELATIVE_NAME);
3226                 options->prefix = arg + 11;
3227         }
3229         /* xdiff options */
3230         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3231                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3232         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3233                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3234         else if (!strcmp(arg, "--ignore-space-at-eol"))
3235                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3236         else if (!strcmp(arg, "--patience"))
3237                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3239         /* flags options */
3240         else if (!strcmp(arg, "--binary")) {
3241                 options->output_format |= DIFF_FORMAT_PATCH;
3242                 DIFF_OPT_SET(options, BINARY);
3243         }
3244         else if (!strcmp(arg, "--full-index"))
3245                 DIFF_OPT_SET(options, FULL_INDEX);
3246         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3247                 DIFF_OPT_SET(options, TEXT);
3248         else if (!strcmp(arg, "-R"))
3249                 DIFF_OPT_SET(options, REVERSE_DIFF);
3250         else if (!strcmp(arg, "--find-copies-harder"))
3251                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3252         else if (!strcmp(arg, "--follow"))
3253                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3254         else if (!strcmp(arg, "--color"))
3255                 DIFF_OPT_SET(options, COLOR_DIFF);
3256         else if (!prefixcmp(arg, "--color=")) {
3257                 int value = git_config_colorbool(NULL, arg+8, -1);
3258                 if (value == 0)
3259                         DIFF_OPT_CLR(options, COLOR_DIFF);
3260                 else if (value > 0)
3261                         DIFF_OPT_SET(options, COLOR_DIFF);
3262                 else
3263                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3264         }
3265         else if (!strcmp(arg, "--no-color"))
3266                 DIFF_OPT_CLR(options, COLOR_DIFF);
3267         else if (!strcmp(arg, "--color-words")) {
3268                 DIFF_OPT_SET(options, COLOR_DIFF);
3269                 options->word_diff = DIFF_WORDS_COLOR;
3270         }
3271         else if (!prefixcmp(arg, "--color-words=")) {
3272                 DIFF_OPT_SET(options, COLOR_DIFF);
3273                 options->word_diff = DIFF_WORDS_COLOR;
3274                 options->word_regex = arg + 14;
3275         }
3276         else if (!strcmp(arg, "--word-diff")) {
3277                 if (options->word_diff == DIFF_WORDS_NONE)
3278                         options->word_diff = DIFF_WORDS_PLAIN;
3279         }
3280         else if (!prefixcmp(arg, "--word-diff=")) {
3281                 const char *type = arg + 12;
3282                 if (!strcmp(type, "plain"))
3283                         options->word_diff = DIFF_WORDS_PLAIN;
3284                 else if (!strcmp(type, "color")) {
3285                         DIFF_OPT_SET(options, COLOR_DIFF);
3286                         options->word_diff = DIFF_WORDS_COLOR;
3287                 }
3288                 else if (!strcmp(type, "porcelain"))
3289                         options->word_diff = DIFF_WORDS_PORCELAIN;
3290                 else if (!strcmp(type, "none"))
3291                         options->word_diff = DIFF_WORDS_NONE;
3292                 else
3293                         die("bad --word-diff argument: %s", type);
3294         }
3295         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3296                 if (options->word_diff == DIFF_WORDS_NONE)
3297                         options->word_diff = DIFF_WORDS_PLAIN;
3298                 options->word_regex = optarg;
3299                 return argcount;
3300         }
3301         else if (!strcmp(arg, "--exit-code"))
3302                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3303         else if (!strcmp(arg, "--quiet"))
3304                 DIFF_OPT_SET(options, QUICK);
3305         else if (!strcmp(arg, "--ext-diff"))
3306                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3307         else if (!strcmp(arg, "--no-ext-diff"))
3308                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3309         else if (!strcmp(arg, "--textconv"))
3310                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3311         else if (!strcmp(arg, "--no-textconv"))
3312                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3313         else if (!strcmp(arg, "--ignore-submodules")) {
3314                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3315                 handle_ignore_submodules_arg(options, "all");
3316         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3317                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3318                 handle_ignore_submodules_arg(options, arg + 20);
3319         } else if (!strcmp(arg, "--submodule"))
3320                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3321         else if (!prefixcmp(arg, "--submodule=")) {
3322                 if (!strcmp(arg + 12, "log"))
3323                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3324         }
3326         /* misc options */
3327         else if (!strcmp(arg, "-z"))
3328                 options->line_termination = 0;
3329         else if ((argcount = short_opt('l', av, &optarg))) {
3330                 options->rename_limit = strtoul(optarg, NULL, 10);
3331                 return argcount;
3332         }
3333         else if ((argcount = short_opt('S', av, &optarg))) {
3334                 options->pickaxe = optarg;
3335                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3336                 return argcount;
3337         } else if ((argcount = short_opt('G', av, &optarg))) {
3338                 options->pickaxe = optarg;
3339                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3340                 return argcount;
3341         }
3342         else if (!strcmp(arg, "--pickaxe-all"))
3343                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3344         else if (!strcmp(arg, "--pickaxe-regex"))
3345                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3346         else if ((argcount = short_opt('O', av, &optarg))) {
3347                 options->orderfile = optarg;
3348                 return argcount;
3349         }
3350         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3351                 options->filter = optarg;
3352                 return argcount;
3353         }
3354         else if (!strcmp(arg, "--abbrev"))
3355                 options->abbrev = DEFAULT_ABBREV;
3356         else if (!prefixcmp(arg, "--abbrev=")) {
3357                 options->abbrev = strtoul(arg + 9, NULL, 10);
3358                 if (options->abbrev < MINIMUM_ABBREV)
3359                         options->abbrev = MINIMUM_ABBREV;
3360                 else if (40 < options->abbrev)
3361                         options->abbrev = 40;
3362         }
3363         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3364                 options->a_prefix = optarg;
3365                 return argcount;
3366         }
3367         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3368                 options->b_prefix = optarg;
3369                 return argcount;
3370         }
3371         else if (!strcmp(arg, "--no-prefix"))
3372                 options->a_prefix = options->b_prefix = "";
3373         else if (opt_arg(arg, '\0', "inter-hunk-context",
3374                          &options->interhunkcontext))
3375                 ;
3376         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3377                 options->file = fopen(optarg, "w");
3378                 if (!options->file)
3379                         die_errno("Could not open '%s'", optarg);
3380                 options->close_file = 1;
3381                 return argcount;
3382         } else
3383                 return 0;
3384         return 1;
3387 int parse_rename_score(const char **cp_p)
3389         unsigned long num, scale;
3390         int ch, dot;
3391         const char *cp = *cp_p;
3393         num = 0;
3394         scale = 1;
3395         dot = 0;
3396         for (;;) {
3397                 ch = *cp;
3398                 if ( !dot && ch == '.' ) {
3399                         scale = 1;
3400                         dot = 1;
3401                 } else if ( ch == '%' ) {
3402                         scale = dot ? scale*100 : 100;
3403                         cp++;   /* % is always at the end */
3404                         break;
3405                 } else if ( ch >= '0' && ch <= '9' ) {
3406                         if ( scale < 100000 ) {
3407                                 scale *= 10;
3408                                 num = (num*10) + (ch-'0');
3409                         }
3410                 } else {
3411                         break;
3412                 }
3413                 cp++;
3414         }
3415         *cp_p = cp;
3417         /* user says num divided by scale and we say internally that
3418          * is MAX_SCORE * num / scale.
3419          */
3420         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3423 static int diff_scoreopt_parse(const char *opt)
3425         int opt1, opt2, cmd;
3427         if (*opt++ != '-')
3428                 return -1;
3429         cmd = *opt++;
3430         if (cmd == '-') {
3431                 /* convert the long-form arguments into short-form versions */
3432                 if (!prefixcmp(opt, "break-rewrites")) {
3433                         opt += strlen("break-rewrites");
3434                         if (*opt == 0 || *opt++ == '=')
3435                                 cmd = 'B';
3436                 } else if (!prefixcmp(opt, "find-copies")) {
3437                         opt += strlen("find-copies");
3438                         if (*opt == 0 || *opt++ == '=')
3439                                 cmd = 'C';
3440                 } else if (!prefixcmp(opt, "find-renames")) {
3441                         opt += strlen("find-renames");
3442                         if (*opt == 0 || *opt++ == '=')
3443                                 cmd = 'M';
3444                 }
3445         }
3446         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3447                 return -1; /* that is not a -M, -C nor -B option */
3449         opt1 = parse_rename_score(&opt);
3450         if (cmd != 'B')
3451                 opt2 = 0;
3452         else {
3453                 if (*opt == 0)
3454                         opt2 = 0;
3455                 else if (*opt != '/')
3456                         return -1; /* we expect -B80/99 or -B80 */
3457                 else {
3458                         opt++;
3459                         opt2 = parse_rename_score(&opt);
3460                 }
3461         }
3462         if (*opt != 0)
3463                 return -1;
3464         return opt1 | (opt2 << 16);
3467 struct diff_queue_struct diff_queued_diff;
3469 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3471         if (queue->alloc <= queue->nr) {
3472                 queue->alloc = alloc_nr(queue->alloc);
3473                 queue->queue = xrealloc(queue->queue,
3474                                         sizeof(dp) * queue->alloc);
3475         }
3476         queue->queue[queue->nr++] = dp;
3479 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3480                                  struct diff_filespec *one,
3481                                  struct diff_filespec *two)
3483         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3484         dp->one = one;
3485         dp->two = two;
3486         if (queue)
3487                 diff_q(queue, dp);
3488         return dp;
3491 void diff_free_filepair(struct diff_filepair *p)
3493         free_filespec(p->one);
3494         free_filespec(p->two);
3495         free(p);
3498 /* This is different from find_unique_abbrev() in that
3499  * it stuffs the result with dots for alignment.
3500  */
3501 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3503         int abblen;
3504         const char *abbrev;
3505         if (len == 40)
3506                 return sha1_to_hex(sha1);
3508         abbrev = find_unique_abbrev(sha1, len);
3509         abblen = strlen(abbrev);
3510         if (abblen < 37) {
3511                 static char hex[41];
3512                 if (len < abblen && abblen <= len + 2)
3513                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3514                 else
3515                         sprintf(hex, "%s...", abbrev);
3516                 return hex;
3517         }
3518         return sha1_to_hex(sha1);
3521 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3523         int line_termination = opt->line_termination;
3524         int inter_name_termination = line_termination ? '\t' : '\0';
3525         if (opt->output_prefix) {
3526                 struct strbuf *msg = NULL;
3527                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3528                 fprintf(opt->file, "%s", msg->buf);
3529         }
3531         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3532                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3533                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3534                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3535         }
3536         if (p->score) {
3537                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3538                         inter_name_termination);
3539         } else {
3540                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3541         }
3543         if (p->status == DIFF_STATUS_COPIED ||
3544             p->status == DIFF_STATUS_RENAMED) {
3545                 const char *name_a, *name_b;
3546                 name_a = p->one->path;
3547                 name_b = p->two->path;
3548                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3549                 write_name_quoted(name_a, opt->file, inter_name_termination);
3550                 write_name_quoted(name_b, opt->file, line_termination);
3551         } else {
3552                 const char *name_a, *name_b;
3553                 name_a = p->one->mode ? p->one->path : p->two->path;
3554                 name_b = NULL;
3555                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3556                 write_name_quoted(name_a, opt->file, line_termination);
3557         }
3560 int diff_unmodified_pair(struct diff_filepair *p)
3562         /* This function is written stricter than necessary to support
3563          * the currently implemented transformers, but the idea is to
3564          * let transformers to produce diff_filepairs any way they want,
3565          * and filter and clean them up here before producing the output.
3566          */
3567         struct diff_filespec *one = p->one, *two = p->two;
3569         if (DIFF_PAIR_UNMERGED(p))
3570                 return 0; /* unmerged is interesting */
3572         /* deletion, addition, mode or type change
3573          * and rename are all interesting.
3574          */
3575         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3576             DIFF_PAIR_MODE_CHANGED(p) ||
3577             strcmp(one->path, two->path))
3578                 return 0;
3580         /* both are valid and point at the same path.  that is, we are
3581          * dealing with a change.
3582          */
3583         if (one->sha1_valid && two->sha1_valid &&
3584             !hashcmp(one->sha1, two->sha1) &&
3585             !one->dirty_submodule && !two->dirty_submodule)
3586                 return 1; /* no change */
3587         if (!one->sha1_valid && !two->sha1_valid)
3588                 return 1; /* both look at the same file on the filesystem. */
3589         return 0;
3592 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3594         if (diff_unmodified_pair(p))
3595                 return;
3597         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3598             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3599                 return; /* no tree diffs in patch format */
3601         run_diff(p, o);
3604 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3605                             struct diffstat_t *diffstat)
3607         if (diff_unmodified_pair(p))
3608                 return;
3610         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3611             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3612                 return; /* no useful stat for tree diffs */
3614         run_diffstat(p, o, diffstat);
3617 static void diff_flush_checkdiff(struct diff_filepair *p,
3618                 struct diff_options *o)
3620         if (diff_unmodified_pair(p))
3621                 return;
3623         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3624             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3625                 return; /* nothing to check in tree diffs */
3627         run_checkdiff(p, o);
3630 int diff_queue_is_empty(void)
3632         struct diff_queue_struct *q = &diff_queued_diff;
3633         int i;
3634         for (i = 0; i < q->nr; i++)
3635                 if (!diff_unmodified_pair(q->queue[i]))
3636                         return 0;
3637         return 1;
3640 #if DIFF_DEBUG
3641 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3643         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3644                 x, one ? one : "",
3645                 s->path,
3646                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3647                 s->mode,
3648                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3649         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3650                 x, one ? one : "",
3651                 s->size, s->xfrm_flags);
3654 void diff_debug_filepair(const struct diff_filepair *p, int i)
3656         diff_debug_filespec(p->one, i, "one");
3657         diff_debug_filespec(p->two, i, "two");
3658         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3659                 p->score, p->status ? p->status : '?',
3660                 p->one->rename_used, p->broken_pair);
3663 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3665         int i;
3666         if (msg)
3667                 fprintf(stderr, "%s\n", msg);
3668         fprintf(stderr, "q->nr = %d\n", q->nr);
3669         for (i = 0; i < q->nr; i++) {
3670                 struct diff_filepair *p = q->queue[i];
3671                 diff_debug_filepair(p, i);
3672         }
3674 #endif
3676 static void diff_resolve_rename_copy(void)
3678         int i;
3679         struct diff_filepair *p;
3680         struct diff_queue_struct *q = &diff_queued_diff;
3682         diff_debug_queue("resolve-rename-copy", q);
3684         for (i = 0; i < q->nr; i++) {
3685                 p = q->queue[i];
3686                 p->status = 0; /* undecided */
3687                 if (DIFF_PAIR_UNMERGED(p))
3688                         p->status = DIFF_STATUS_UNMERGED;
3689                 else if (!DIFF_FILE_VALID(p->one))
3690                         p->status = DIFF_STATUS_ADDED;
3691                 else if (!DIFF_FILE_VALID(p->two))
3692                         p->status = DIFF_STATUS_DELETED;
3693                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3694                         p->status = DIFF_STATUS_TYPE_CHANGED;
3696                 /* from this point on, we are dealing with a pair
3697                  * whose both sides are valid and of the same type, i.e.
3698                  * either in-place edit or rename/copy edit.
3699                  */
3700                 else if (DIFF_PAIR_RENAME(p)) {
3701                         /*
3702                          * A rename might have re-connected a broken
3703                          * pair up, causing the pathnames to be the
3704                          * same again. If so, that's not a rename at
3705                          * all, just a modification..
3706                          *
3707                          * Otherwise, see if this source was used for
3708                          * multiple renames, in which case we decrement
3709                          * the count, and call it a copy.
3710                          */
3711                         if (!strcmp(p->one->path, p->two->path))
3712                                 p->status = DIFF_STATUS_MODIFIED;
3713                         else if (--p->one->rename_used > 0)
3714                                 p->status = DIFF_STATUS_COPIED;
3715                         else
3716                                 p->status = DIFF_STATUS_RENAMED;
3717                 }
3718                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3719                          p->one->mode != p->two->mode ||
3720                          p->one->dirty_submodule ||
3721                          p->two->dirty_submodule ||
3722                          is_null_sha1(p->one->sha1))
3723                         p->status = DIFF_STATUS_MODIFIED;
3724                 else {
3725                         /* This is a "no-change" entry and should not
3726                          * happen anymore, but prepare for broken callers.
3727                          */
3728                         error("feeding unmodified %s to diffcore",
3729                               p->one->path);
3730                         p->status = DIFF_STATUS_UNKNOWN;
3731                 }
3732         }
3733         diff_debug_queue("resolve-rename-copy done", q);
3736 static int check_pair_status(struct diff_filepair *p)
3738         switch (p->status) {
3739         case DIFF_STATUS_UNKNOWN:
3740                 return 0;
3741         case 0:
3742                 die("internal error in diff-resolve-rename-copy");
3743         default:
3744                 return 1;
3745         }
3748 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3750         int fmt = opt->output_format;
3752         if (fmt & DIFF_FORMAT_CHECKDIFF)
3753                 diff_flush_checkdiff(p, opt);
3754         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3755                 diff_flush_raw(p, opt);
3756         else if (fmt & DIFF_FORMAT_NAME) {
3757                 const char *name_a, *name_b;
3758                 name_a = p->two->path;
3759                 name_b = NULL;
3760                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3761                 write_name_quoted(name_a, opt->file, opt->line_termination);
3762         }
3765 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3767         if (fs->mode)
3768                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3769         else
3770                 fprintf(file, " %s ", newdelete);
3771         write_name_quoted(fs->path, file, '\n');
3775 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3776                 const char *line_prefix)
3778         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3779                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3780                         p->two->mode, show_name ? ' ' : '\n');
3781                 if (show_name) {
3782                         write_name_quoted(p->two->path, file, '\n');
3783                 }
3784         }
3787 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3788                         const char *line_prefix)
3790         char *names = pprint_rename(p->one->path, p->two->path);
3792         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3793         free(names);
3794         show_mode_change(file, p, 0, line_prefix);
3797 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3799         FILE *file = opt->file;
3800         char *line_prefix = "";
3802         if (opt->output_prefix) {
3803                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3804                 line_prefix = buf->buf;
3805         }
3807         switch(p->status) {
3808         case DIFF_STATUS_DELETED:
3809                 fputs(line_prefix, file);
3810                 show_file_mode_name(file, "delete", p->one);
3811                 break;
3812         case DIFF_STATUS_ADDED:
3813                 fputs(line_prefix, file);
3814                 show_file_mode_name(file, "create", p->two);
3815                 break;
3816         case DIFF_STATUS_COPIED:
3817                 fputs(line_prefix, file);
3818                 show_rename_copy(file, "copy", p, line_prefix);
3819                 break;
3820         case DIFF_STATUS_RENAMED:
3821                 fputs(line_prefix, file);
3822                 show_rename_copy(file, "rename", p, line_prefix);
3823                 break;
3824         default:
3825                 if (p->score) {
3826                         fprintf(file, "%s rewrite ", line_prefix);
3827                         write_name_quoted(p->two->path, file, ' ');
3828                         fprintf(file, "(%d%%)\n", similarity_index(p));
3829                 }
3830                 show_mode_change(file, p, !p->score, line_prefix);
3831                 break;
3832         }
3835 struct patch_id_t {
3836         git_SHA_CTX *ctx;
3837         int patchlen;
3838 };
3840 static int remove_space(char *line, int len)
3842         int i;
3843         char *dst = line;
3844         unsigned char c;
3846         for (i = 0; i < len; i++)
3847                 if (!isspace((c = line[i])))
3848                         *dst++ = c;
3850         return dst - line;
3853 static void patch_id_consume(void *priv, char *line, unsigned long len)
3855         struct patch_id_t *data = priv;
3856         int new_len;
3858         /* Ignore line numbers when computing the SHA1 of the patch */
3859         if (!prefixcmp(line, "@@ -"))
3860                 return;
3862         new_len = remove_space(line, len);
3864         git_SHA1_Update(data->ctx, line, new_len);
3865         data->patchlen += new_len;
3868 /* returns 0 upon success, and writes result into sha1 */
3869 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3871         struct diff_queue_struct *q = &diff_queued_diff;
3872         int i;
3873         git_SHA_CTX ctx;
3874         struct patch_id_t data;
3875         char buffer[PATH_MAX * 4 + 20];
3877         git_SHA1_Init(&ctx);
3878         memset(&data, 0, sizeof(struct patch_id_t));
3879         data.ctx = &ctx;
3881         for (i = 0; i < q->nr; i++) {
3882                 xpparam_t xpp;
3883                 xdemitconf_t xecfg;
3884                 mmfile_t mf1, mf2;
3885                 struct diff_filepair *p = q->queue[i];
3886                 int len1, len2;
3888                 memset(&xpp, 0, sizeof(xpp));
3889                 memset(&xecfg, 0, sizeof(xecfg));
3890                 if (p->status == 0)
3891                         return error("internal diff status error");
3892                 if (p->status == DIFF_STATUS_UNKNOWN)
3893                         continue;
3894                 if (diff_unmodified_pair(p))
3895                         continue;
3896                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3897                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3898                         continue;
3899                 if (DIFF_PAIR_UNMERGED(p))
3900                         continue;
3902                 diff_fill_sha1_info(p->one);
3903                 diff_fill_sha1_info(p->two);
3904                 if (fill_mmfile(&mf1, p->one) < 0 ||
3905                                 fill_mmfile(&mf2, p->two) < 0)
3906                         return error("unable to read files to diff");
3908                 len1 = remove_space(p->one->path, strlen(p->one->path));
3909                 len2 = remove_space(p->two->path, strlen(p->two->path));
3910                 if (p->one->mode == 0)
3911                         len1 = snprintf(buffer, sizeof(buffer),
3912                                         "diff--gita/%.*sb/%.*s"
3913                                         "newfilemode%06o"
3914                                         "---/dev/null"
3915                                         "+++b/%.*s",
3916                                         len1, p->one->path,
3917                                         len2, p->two->path,
3918                                         p->two->mode,
3919                                         len2, p->two->path);
3920                 else if (p->two->mode == 0)
3921                         len1 = snprintf(buffer, sizeof(buffer),
3922                                         "diff--gita/%.*sb/%.*s"
3923                                         "deletedfilemode%06o"
3924                                         "---a/%.*s"
3925                                         "+++/dev/null",
3926                                         len1, p->one->path,
3927                                         len2, p->two->path,
3928                                         p->one->mode,
3929                                         len1, p->one->path);
3930                 else
3931                         len1 = snprintf(buffer, sizeof(buffer),
3932                                         "diff--gita/%.*sb/%.*s"
3933                                         "---a/%.*s"
3934                                         "+++b/%.*s",
3935                                         len1, p->one->path,
3936                                         len2, p->two->path,
3937                                         len1, p->one->path,
3938                                         len2, p->two->path);
3939                 git_SHA1_Update(&ctx, buffer, len1);
3941                 if (diff_filespec_is_binary(p->one) ||
3942                     diff_filespec_is_binary(p->two)) {
3943                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3944                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3945                         continue;
3946                 }
3948                 xpp.flags = 0;
3949                 xecfg.ctxlen = 3;
3950                 xecfg.flags = 0;
3951                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3952                               &xpp, &xecfg);
3953         }
3955         git_SHA1_Final(sha1, &ctx);
3956         return 0;
3959 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3961         struct diff_queue_struct *q = &diff_queued_diff;
3962         int i;
3963         int result = diff_get_patch_id(options, sha1);
3965         for (i = 0; i < q->nr; i++)
3966                 diff_free_filepair(q->queue[i]);
3968         free(q->queue);
3969         DIFF_QUEUE_CLEAR(q);
3971         return result;
3974 static int is_summary_empty(const struct diff_queue_struct *q)
3976         int i;
3978         for (i = 0; i < q->nr; i++) {
3979                 const struct diff_filepair *p = q->queue[i];
3981                 switch (p->status) {
3982                 case DIFF_STATUS_DELETED:
3983                 case DIFF_STATUS_ADDED:
3984                 case DIFF_STATUS_COPIED:
3985                 case DIFF_STATUS_RENAMED:
3986                         return 0;
3987                 default:
3988                         if (p->score)
3989                                 return 0;
3990                         if (p->one->mode && p->two->mode &&
3991                             p->one->mode != p->two->mode)
3992                                 return 0;
3993                         break;
3994                 }
3995         }
3996         return 1;
3999 static const char rename_limit_warning[] =
4000 "inexact rename detection was skipped due to too many files.";
4002 static const char degrade_cc_to_c_warning[] =
4003 "only found copies from modified paths due to too many files.";
4005 static const char rename_limit_advice[] =
4006 "you may want to set your %s variable to at least "
4007 "%d and retry the command.";
4009 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4011         if (degraded_cc)
4012                 warning(degrade_cc_to_c_warning);
4013         else if (needed)
4014                 warning(rename_limit_warning);
4015         else
4016                 return;
4017         if (0 < needed && needed < 32767)
4018                 warning(rename_limit_advice, varname, needed);
4021 void diff_flush(struct diff_options *options)
4023         struct diff_queue_struct *q = &diff_queued_diff;
4024         int i, output_format = options->output_format;
4025         int separator = 0;
4027         /*
4028          * Order: raw, stat, summary, patch
4029          * or:    name/name-status/checkdiff (other bits clear)
4030          */
4031         if (!q->nr)
4032                 goto free_queue;
4034         if (output_format & (DIFF_FORMAT_RAW |
4035                              DIFF_FORMAT_NAME |
4036                              DIFF_FORMAT_NAME_STATUS |
4037                              DIFF_FORMAT_CHECKDIFF)) {
4038                 for (i = 0; i < q->nr; i++) {
4039                         struct diff_filepair *p = q->queue[i];
4040                         if (check_pair_status(p))
4041                                 flush_one_pair(p, options);
4042                 }
4043                 separator++;
4044         }
4046         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4047                 struct diffstat_t diffstat;
4049                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4050                 for (i = 0; i < q->nr; i++) {
4051                         struct diff_filepair *p = q->queue[i];
4052                         if (check_pair_status(p))
4053                                 diff_flush_stat(p, options, &diffstat);
4054                 }
4055                 if (output_format & DIFF_FORMAT_NUMSTAT)
4056                         show_numstat(&diffstat, options);
4057                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4058                         show_stats(&diffstat, options);
4059                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4060                         show_shortstats(&diffstat, options);
4061                 free_diffstat_info(&diffstat);
4062                 separator++;
4063         }
4064         if (output_format & DIFF_FORMAT_DIRSTAT)
4065                 show_dirstat(options);
4067         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4068                 for (i = 0; i < q->nr; i++) {
4069                         diff_summary(options, q->queue[i]);
4070                 }
4071                 separator++;
4072         }
4074         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4075             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4076             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4077                 /*
4078                  * run diff_flush_patch for the exit status. setting
4079                  * options->file to /dev/null should be safe, becaue we
4080                  * aren't supposed to produce any output anyway.
4081                  */
4082                 if (options->close_file)
4083                         fclose(options->file);
4084                 options->file = fopen("/dev/null", "w");
4085                 if (!options->file)
4086                         die_errno("Could not open /dev/null");
4087                 options->close_file = 1;
4088                 for (i = 0; i < q->nr; i++) {
4089                         struct diff_filepair *p = q->queue[i];
4090                         if (check_pair_status(p))
4091                                 diff_flush_patch(p, options);
4092                         if (options->found_changes)
4093                                 break;
4094                 }
4095         }
4097         if (output_format & DIFF_FORMAT_PATCH) {
4098                 if (separator) {
4099                         putc(options->line_termination, options->file);
4100                         if (options->stat_sep) {
4101                                 /* attach patch instead of inline */
4102                                 fputs(options->stat_sep, options->file);
4103                         }
4104                 }
4106                 for (i = 0; i < q->nr; i++) {
4107                         struct diff_filepair *p = q->queue[i];
4108                         if (check_pair_status(p))
4109                                 diff_flush_patch(p, options);
4110                 }
4111         }
4113         if (output_format & DIFF_FORMAT_CALLBACK)
4114                 options->format_callback(q, options, options->format_callback_data);
4116         for (i = 0; i < q->nr; i++)
4117                 diff_free_filepair(q->queue[i]);
4118 free_queue:
4119         free(q->queue);
4120         DIFF_QUEUE_CLEAR(q);
4121         if (options->close_file)
4122                 fclose(options->file);
4124         /*
4125          * Report the content-level differences with HAS_CHANGES;
4126          * diff_addremove/diff_change does not set the bit when
4127          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4128          */
4129         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4130                 if (options->found_changes)
4131                         DIFF_OPT_SET(options, HAS_CHANGES);
4132                 else
4133                         DIFF_OPT_CLR(options, HAS_CHANGES);
4134         }
4137 static void diffcore_apply_filter(const char *filter)
4139         int i;
4140         struct diff_queue_struct *q = &diff_queued_diff;
4141         struct diff_queue_struct outq;
4142         DIFF_QUEUE_CLEAR(&outq);
4144         if (!filter)
4145                 return;
4147         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4148                 int found;
4149                 for (i = found = 0; !found && i < q->nr; i++) {
4150                         struct diff_filepair *p = q->queue[i];
4151                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4152                              ((p->score &&
4153                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4154                               (!p->score &&
4155                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4156                             ((p->status != DIFF_STATUS_MODIFIED) &&
4157                              strchr(filter, p->status)))
4158                                 found++;
4159                 }
4160                 if (found)
4161                         return;
4163                 /* otherwise we will clear the whole queue
4164                  * by copying the empty outq at the end of this
4165                  * function, but first clear the current entries
4166                  * in the queue.
4167                  */
4168                 for (i = 0; i < q->nr; i++)
4169                         diff_free_filepair(q->queue[i]);
4170         }
4171         else {
4172                 /* Only the matching ones */
4173                 for (i = 0; i < q->nr; i++) {
4174                         struct diff_filepair *p = q->queue[i];
4176                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4177                              ((p->score &&
4178                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4179                               (!p->score &&
4180                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4181                             ((p->status != DIFF_STATUS_MODIFIED) &&
4182                              strchr(filter, p->status)))
4183                                 diff_q(&outq, p);
4184                         else
4185                                 diff_free_filepair(p);
4186                 }
4187         }
4188         free(q->queue);
4189         *q = outq;
4192 /* Check whether two filespecs with the same mode and size are identical */
4193 static int diff_filespec_is_identical(struct diff_filespec *one,
4194                                       struct diff_filespec *two)
4196         if (S_ISGITLINK(one->mode))
4197                 return 0;
4198         if (diff_populate_filespec(one, 0))
4199                 return 0;
4200         if (diff_populate_filespec(two, 0))
4201                 return 0;
4202         return !memcmp(one->data, two->data, one->size);
4205 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4207         int i;
4208         struct diff_queue_struct *q = &diff_queued_diff;
4209         struct diff_queue_struct outq;
4210         DIFF_QUEUE_CLEAR(&outq);
4212         for (i = 0; i < q->nr; i++) {
4213                 struct diff_filepair *p = q->queue[i];
4215                 /*
4216                  * 1. Entries that come from stat info dirtiness
4217                  *    always have both sides (iow, not create/delete),
4218                  *    one side of the object name is unknown, with
4219                  *    the same mode and size.  Keep the ones that
4220                  *    do not match these criteria.  They have real
4221                  *    differences.
4222                  *
4223                  * 2. At this point, the file is known to be modified,
4224                  *    with the same mode and size, and the object
4225                  *    name of one side is unknown.  Need to inspect
4226                  *    the identical contents.
4227                  */
4228                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4229                     !DIFF_FILE_VALID(p->two) ||
4230                     (p->one->sha1_valid && p->two->sha1_valid) ||
4231                     (p->one->mode != p->two->mode) ||
4232                     diff_populate_filespec(p->one, 1) ||
4233                     diff_populate_filespec(p->two, 1) ||
4234                     (p->one->size != p->two->size) ||
4235                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4236                         diff_q(&outq, p);
4237                 else {
4238                         /*
4239                          * The caller can subtract 1 from skip_stat_unmatch
4240                          * to determine how many paths were dirty only
4241                          * due to stat info mismatch.
4242                          */
4243                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4244                                 diffopt->skip_stat_unmatch++;
4245                         diff_free_filepair(p);
4246                 }
4247         }
4248         free(q->queue);
4249         *q = outq;
4252 static int diffnamecmp(const void *a_, const void *b_)
4254         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4255         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4256         const char *name_a, *name_b;
4258         name_a = a->one ? a->one->path : a->two->path;
4259         name_b = b->one ? b->one->path : b->two->path;
4260         return strcmp(name_a, name_b);
4263 void diffcore_fix_diff_index(struct diff_options *options)
4265         struct diff_queue_struct *q = &diff_queued_diff;
4266         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4269 void diffcore_std(struct diff_options *options)
4271         if (options->skip_stat_unmatch)
4272                 diffcore_skip_stat_unmatch(options);
4273         if (!options->found_follow) {
4274                 /* See try_to_follow_renames() in tree-diff.c */
4275                 if (options->break_opt != -1)
4276                         diffcore_break(options->break_opt);
4277                 if (options->detect_rename)
4278                         diffcore_rename(options);
4279                 if (options->break_opt != -1)
4280                         diffcore_merge_broken();
4281         }
4282         if (options->pickaxe)
4283                 diffcore_pickaxe(options);
4284         if (options->orderfile)
4285                 diffcore_order(options->orderfile);
4286         if (!options->found_follow)
4287                 /* See try_to_follow_renames() in tree-diff.c */
4288                 diff_resolve_rename_copy();
4289         diffcore_apply_filter(options->filter);
4291         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4292                 DIFF_OPT_SET(options, HAS_CHANGES);
4293         else
4294                 DIFF_OPT_CLR(options, HAS_CHANGES);
4296         options->found_follow = 0;
4299 int diff_result_code(struct diff_options *opt, int status)
4301         int result = 0;
4303         diff_warn_rename_limit("diff.renamelimit",
4304                                opt->needed_rename_limit,
4305                                opt->degraded_cc_to_c);
4306         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4307             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4308                 return status;
4309         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4310             DIFF_OPT_TST(opt, HAS_CHANGES))
4311                 result |= 01;
4312         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4313             DIFF_OPT_TST(opt, CHECK_FAILED))
4314                 result |= 02;
4315         return result;
4318 /*
4319  * Shall changes to this submodule be ignored?
4320  *
4321  * Submodule changes can be configured to be ignored separately for each path,
4322  * but that configuration can be overridden from the command line.
4323  */
4324 static int is_submodule_ignored(const char *path, struct diff_options *options)
4326         int ignored = 0;
4327         unsigned orig_flags = options->flags;
4328         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4329                 set_diffopt_flags_from_submodule_config(options, path);
4330         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4331                 ignored = 1;
4332         options->flags = orig_flags;
4333         return ignored;
4336 void diff_addremove(struct diff_options *options,
4337                     int addremove, unsigned mode,
4338                     const unsigned char *sha1,
4339                     const char *concatpath, unsigned dirty_submodule)
4341         struct diff_filespec *one, *two;
4343         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4344                 return;
4346         /* This may look odd, but it is a preparation for
4347          * feeding "there are unchanged files which should
4348          * not produce diffs, but when you are doing copy
4349          * detection you would need them, so here they are"
4350          * entries to the diff-core.  They will be prefixed
4351          * with something like '=' or '*' (I haven't decided
4352          * which but should not make any difference).
4353          * Feeding the same new and old to diff_change()
4354          * also has the same effect.
4355          * Before the final output happens, they are pruned after
4356          * merged into rename/copy pairs as appropriate.
4357          */
4358         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4359                 addremove = (addremove == '+' ? '-' :
4360                              addremove == '-' ? '+' : addremove);
4362         if (options->prefix &&
4363             strncmp(concatpath, options->prefix, options->prefix_length))
4364                 return;
4366         one = alloc_filespec(concatpath);
4367         two = alloc_filespec(concatpath);
4369         if (addremove != '+')
4370                 fill_filespec(one, sha1, mode);
4371         if (addremove != '-') {
4372                 fill_filespec(two, sha1, mode);
4373                 two->dirty_submodule = dirty_submodule;
4374         }
4376         diff_queue(&diff_queued_diff, one, two);
4377         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4378                 DIFF_OPT_SET(options, HAS_CHANGES);
4381 void diff_change(struct diff_options *options,
4382                  unsigned old_mode, unsigned new_mode,
4383                  const unsigned char *old_sha1,
4384                  const unsigned char *new_sha1,
4385                  const char *concatpath,
4386                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4388         struct diff_filespec *one, *two;
4390         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4391             is_submodule_ignored(concatpath, options))
4392                 return;
4394         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4395                 unsigned tmp;
4396                 const unsigned char *tmp_c;
4397                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4398                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4399                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4400                         new_dirty_submodule = tmp;
4401         }
4403         if (options->prefix &&
4404             strncmp(concatpath, options->prefix, options->prefix_length))
4405                 return;
4407         one = alloc_filespec(concatpath);
4408         two = alloc_filespec(concatpath);
4409         fill_filespec(one, old_sha1, old_mode);
4410         fill_filespec(two, new_sha1, new_mode);
4411         one->dirty_submodule = old_dirty_submodule;
4412         two->dirty_submodule = new_dirty_submodule;
4414         diff_queue(&diff_queued_diff, one, two);
4415         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4416                 DIFF_OPT_SET(options, HAS_CHANGES);
4419 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4421         struct diff_filepair *pair;
4422         struct diff_filespec *one, *two;
4424         if (options->prefix &&
4425             strncmp(path, options->prefix, options->prefix_length))
4426                 return NULL;
4428         one = alloc_filespec(path);
4429         two = alloc_filespec(path);
4430         pair = diff_queue(&diff_queued_diff, one, two);
4431         pair->is_unmerged = 1;
4432         return pair;
4435 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4436                 size_t *outsize)
4438         struct diff_tempfile *temp;
4439         const char *argv[3];
4440         const char **arg = argv;
4441         struct child_process child;
4442         struct strbuf buf = STRBUF_INIT;
4443         int err = 0;
4445         temp = prepare_temp_file(spec->path, spec);
4446         *arg++ = pgm;
4447         *arg++ = temp->name;
4448         *arg = NULL;
4450         memset(&child, 0, sizeof(child));
4451         child.use_shell = 1;
4452         child.argv = argv;
4453         child.out = -1;
4454         if (start_command(&child)) {
4455                 remove_tempfile();
4456                 return NULL;
4457         }
4459         if (strbuf_read(&buf, child.out, 0) < 0)
4460                 err = error("error reading from textconv command '%s'", pgm);
4461         close(child.out);
4463         if (finish_command(&child) || err) {
4464                 strbuf_release(&buf);
4465                 remove_tempfile();
4466                 return NULL;
4467         }
4468         remove_tempfile();
4470         return strbuf_detach(&buf, outsize);
4473 size_t fill_textconv(struct userdiff_driver *driver,
4474                      struct diff_filespec *df,
4475                      char **outbuf)
4477         size_t size;
4479         if (!driver || !driver->textconv) {
4480                 if (!DIFF_FILE_VALID(df)) {
4481                         *outbuf = "";
4482                         return 0;
4483                 }
4484                 if (diff_populate_filespec(df, 0))
4485                         die("unable to read files to diff");
4486                 *outbuf = df->data;
4487                 return df->size;
4488         }
4490         if (driver->textconv_cache && df->sha1_valid) {
4491                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4492                                           &size);
4493                 if (*outbuf)
4494                         return size;
4495         }
4497         *outbuf = run_textconv(driver->textconv, df, &size);
4498         if (!*outbuf)
4499                 die("unable to read files to diff");
4501         if (driver->textconv_cache && df->sha1_valid) {
4502                 /* ignore errors, as we might be in a readonly repository */
4503                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4504                                 size);
4505                 /*
4506                  * we could save up changes and flush them all at the end,
4507                  * but we would need an extra call after all diffing is done.
4508                  * Since generating a cache entry is the slow path anyway,
4509                  * this extra overhead probably isn't a big deal.
4510                  */
4511                 notes_cache_write(driver->textconv_cache);
4512         }
4514         return size;