Code

diff.c: omit hidden entries from namelen calculation with --stat
[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                 if (!data->files[i]->is_renamed &&
1282                          (change == 0)) {
1283                         continue;
1284                 }
1285                 fill_print_name(file);
1286                 len = strlen(file->print_name);
1287                 if (max_len < len)
1288                         max_len = len;
1290                 if (file->is_binary || file->is_unmerged)
1291                         continue;
1292                 if (max_change < change)
1293                         max_change = change;
1294         }
1296         /* Compute the width of the graph part;
1297          * 10 is for one blank at the beginning of the line plus
1298          * " | count " between the name and the graph.
1299          *
1300          * From here on, name_width is the width of the name area,
1301          * and width is the width of the graph area.
1302          */
1303         name_width = (name_width < max_len) ? name_width : max_len;
1304         if (width < (name_width + 10) + max_change)
1305                 width = width - (name_width + 10);
1306         else
1307                 width = max_change;
1309         for (i = 0; i < data->nr; i++) {
1310                 const char *prefix = "";
1311                 char *name = data->files[i]->print_name;
1312                 uintmax_t added = data->files[i]->added;
1313                 uintmax_t deleted = data->files[i]->deleted;
1314                 int name_len;
1316                 if (!data->files[i]->is_renamed &&
1317                          (added + deleted == 0)) {
1318                         total_files--;
1319                         continue;
1320                 }
1321                 /*
1322                  * "scale" the filename
1323                  */
1324                 len = name_width;
1325                 name_len = strlen(name);
1326                 if (name_width < name_len) {
1327                         char *slash;
1328                         prefix = "...";
1329                         len -= 3;
1330                         name += name_len - len;
1331                         slash = strchr(name, '/');
1332                         if (slash)
1333                                 name = slash;
1334                 }
1336                 if (data->files[i]->is_binary) {
1337                         fprintf(options->file, "%s", line_prefix);
1338                         show_name(options->file, prefix, name, len);
1339                         fprintf(options->file, "  Bin ");
1340                         fprintf(options->file, "%s%"PRIuMAX"%s",
1341                                 del_c, deleted, reset);
1342                         fprintf(options->file, " -> ");
1343                         fprintf(options->file, "%s%"PRIuMAX"%s",
1344                                 add_c, added, reset);
1345                         fprintf(options->file, " bytes");
1346                         fprintf(options->file, "\n");
1347                         continue;
1348                 }
1349                 else if (data->files[i]->is_unmerged) {
1350                         fprintf(options->file, "%s", line_prefix);
1351                         show_name(options->file, prefix, name, len);
1352                         fprintf(options->file, "  Unmerged\n");
1353                         continue;
1354                 }
1356                 /*
1357                  * scale the add/delete
1358                  */
1359                 add = added;
1360                 del = deleted;
1361                 adds += add;
1362                 dels += del;
1364                 if (width <= max_change) {
1365                         add = scale_linear(add, width, max_change);
1366                         del = scale_linear(del, width, max_change);
1367                 }
1368                 fprintf(options->file, "%s", line_prefix);
1369                 show_name(options->file, prefix, name, len);
1370                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1371                                 added + deleted ? " " : "");
1372                 show_graph(options->file, '+', add, add_c, reset);
1373                 show_graph(options->file, '-', del, del_c, reset);
1374                 fprintf(options->file, "\n");
1375         }
1376         fprintf(options->file, "%s", line_prefix);
1377         fprintf(options->file,
1378                " %d files changed, %d insertions(+), %d deletions(-)\n",
1379                total_files, adds, dels);
1382 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1384         int i, adds = 0, dels = 0, total_files = data->nr;
1386         if (data->nr == 0)
1387                 return;
1389         for (i = 0; i < data->nr; i++) {
1390                 if (!data->files[i]->is_binary &&
1391                     !data->files[i]->is_unmerged) {
1392                         int added = data->files[i]->added;
1393                         int deleted= data->files[i]->deleted;
1394                         if (!data->files[i]->is_renamed &&
1395                             (added + deleted == 0)) {
1396                                 total_files--;
1397                         } else {
1398                                 adds += added;
1399                                 dels += deleted;
1400                         }
1401                 }
1402         }
1403         if (options->output_prefix) {
1404                 struct strbuf *msg = NULL;
1405                 msg = options->output_prefix(options,
1406                                 options->output_prefix_data);
1407                 fprintf(options->file, "%s", msg->buf);
1408         }
1409         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1410                total_files, adds, dels);
1413 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1415         int i;
1417         if (data->nr == 0)
1418                 return;
1420         for (i = 0; i < data->nr; i++) {
1421                 struct diffstat_file *file = data->files[i];
1423                 if (options->output_prefix) {
1424                         struct strbuf *msg = NULL;
1425                         msg = options->output_prefix(options,
1426                                         options->output_prefix_data);
1427                         fprintf(options->file, "%s", msg->buf);
1428                 }
1430                 if (file->is_binary)
1431                         fprintf(options->file, "-\t-\t");
1432                 else
1433                         fprintf(options->file,
1434                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1435                                 file->added, file->deleted);
1436                 if (options->line_termination) {
1437                         fill_print_name(file);
1438                         if (!file->is_renamed)
1439                                 write_name_quoted(file->name, options->file,
1440                                                   options->line_termination);
1441                         else {
1442                                 fputs(file->print_name, options->file);
1443                                 putc(options->line_termination, options->file);
1444                         }
1445                 } else {
1446                         if (file->is_renamed) {
1447                                 putc('\0', options->file);
1448                                 write_name_quoted(file->from_name, options->file, '\0');
1449                         }
1450                         write_name_quoted(file->name, options->file, '\0');
1451                 }
1452         }
1455 struct dirstat_file {
1456         const char *name;
1457         unsigned long changed;
1458 };
1460 struct dirstat_dir {
1461         struct dirstat_file *files;
1462         int alloc, nr, percent, cumulative;
1463 };
1465 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1466                 unsigned long changed, const char *base, int baselen)
1468         unsigned long this_dir = 0;
1469         unsigned int sources = 0;
1470         const char *line_prefix = "";
1471         struct strbuf *msg = NULL;
1473         if (opt->output_prefix) {
1474                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1475                 line_prefix = msg->buf;
1476         }
1478         while (dir->nr) {
1479                 struct dirstat_file *f = dir->files;
1480                 int namelen = strlen(f->name);
1481                 unsigned long this;
1482                 char *slash;
1484                 if (namelen < baselen)
1485                         break;
1486                 if (memcmp(f->name, base, baselen))
1487                         break;
1488                 slash = strchr(f->name + baselen, '/');
1489                 if (slash) {
1490                         int newbaselen = slash + 1 - f->name;
1491                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1492                         sources++;
1493                 } else {
1494                         this = f->changed;
1495                         dir->files++;
1496                         dir->nr--;
1497                         sources += 2;
1498                 }
1499                 this_dir += this;
1500         }
1502         /*
1503          * We don't report dirstat's for
1504          *  - the top level
1505          *  - or cases where everything came from a single directory
1506          *    under this directory (sources == 1).
1507          */
1508         if (baselen && sources != 1) {
1509                 int permille = this_dir * 1000 / changed;
1510                 if (permille) {
1511                         int percent = permille / 10;
1512                         if (percent >= dir->percent) {
1513                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1514                                         percent, permille % 10, baselen, base);
1515                                 if (!dir->cumulative)
1516                                         return 0;
1517                         }
1518                 }
1519         }
1520         return this_dir;
1523 static int dirstat_compare(const void *_a, const void *_b)
1525         const struct dirstat_file *a = _a;
1526         const struct dirstat_file *b = _b;
1527         return strcmp(a->name, b->name);
1530 static void show_dirstat(struct diff_options *options)
1532         int i;
1533         unsigned long changed;
1534         struct dirstat_dir dir;
1535         struct diff_queue_struct *q = &diff_queued_diff;
1537         dir.files = NULL;
1538         dir.alloc = 0;
1539         dir.nr = 0;
1540         dir.percent = options->dirstat_percent;
1541         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1543         changed = 0;
1544         for (i = 0; i < q->nr; i++) {
1545                 struct diff_filepair *p = q->queue[i];
1546                 const char *name;
1547                 unsigned long copied, added, damage;
1548                 int content_changed;
1550                 name = p->two->path ? p->two->path : p->one->path;
1552                 if (p->one->sha1_valid && p->two->sha1_valid)
1553                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1554                 else
1555                         content_changed = 1;
1557                 if (!content_changed) {
1558                         /*
1559                          * The SHA1 has not changed, so pre-/post-content is
1560                          * identical. We can therefore skip looking at the
1561                          * file contents altogether.
1562                          */
1563                         damage = 0;
1564                         goto found_damage;
1565                 }
1567                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1568                         /*
1569                          * In --dirstat-by-file mode, we don't really need to
1570                          * look at the actual file contents at all.
1571                          * The fact that the SHA1 changed is enough for us to
1572                          * add this file to the list of results
1573                          * (with each file contributing equal damage).
1574                          */
1575                         damage = 1;
1576                         goto found_damage;
1577                 }
1579                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1580                         diff_populate_filespec(p->one, 0);
1581                         diff_populate_filespec(p->two, 0);
1582                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1583                                                &copied, &added);
1584                         diff_free_filespec_data(p->one);
1585                         diff_free_filespec_data(p->two);
1586                 } else if (DIFF_FILE_VALID(p->one)) {
1587                         diff_populate_filespec(p->one, 1);
1588                         copied = added = 0;
1589                         diff_free_filespec_data(p->one);
1590                 } else if (DIFF_FILE_VALID(p->two)) {
1591                         diff_populate_filespec(p->two, 1);
1592                         copied = 0;
1593                         added = p->two->size;
1594                         diff_free_filespec_data(p->two);
1595                 } else
1596                         continue;
1598                 /*
1599                  * Original minus copied is the removed material,
1600                  * added is the new material.  They are both damages
1601                  * made to the preimage.
1602                  * If the resulting damage is zero, we know that
1603                  * diffcore_count_changes() considers the two entries to
1604                  * be identical, but since content_changed is true, we
1605                  * know that there must have been _some_ kind of change,
1606                  * so we force all entries to have damage > 0.
1607                  */
1608                 damage = (p->one->size - copied) + added;
1609                 if (!damage)
1610                         damage = 1;
1612 found_damage:
1613                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1614                 dir.files[dir.nr].name = name;
1615                 dir.files[dir.nr].changed = damage;
1616                 changed += damage;
1617                 dir.nr++;
1618         }
1620         /* This can happen even with many files, if everything was renames */
1621         if (!changed)
1622                 return;
1624         /* Show all directories with more than x% of the changes */
1625         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1626         gather_dirstat(options, &dir, changed, "", 0);
1629 static void free_diffstat_info(struct diffstat_t *diffstat)
1631         int i;
1632         for (i = 0; i < diffstat->nr; i++) {
1633                 struct diffstat_file *f = diffstat->files[i];
1634                 if (f->name != f->print_name)
1635                         free(f->print_name);
1636                 free(f->name);
1637                 free(f->from_name);
1638                 free(f);
1639         }
1640         free(diffstat->files);
1643 struct checkdiff_t {
1644         const char *filename;
1645         int lineno;
1646         int conflict_marker_size;
1647         struct diff_options *o;
1648         unsigned ws_rule;
1649         unsigned status;
1650 };
1652 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1654         char firstchar;
1655         int cnt;
1657         if (len < marker_size + 1)
1658                 return 0;
1659         firstchar = line[0];
1660         switch (firstchar) {
1661         case '=': case '>': case '<': case '|':
1662                 break;
1663         default:
1664                 return 0;
1665         }
1666         for (cnt = 1; cnt < marker_size; cnt++)
1667                 if (line[cnt] != firstchar)
1668                         return 0;
1669         /* line[1] thru line[marker_size-1] are same as firstchar */
1670         if (len < marker_size + 1 || !isspace(line[marker_size]))
1671                 return 0;
1672         return 1;
1675 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1677         struct checkdiff_t *data = priv;
1678         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1679         int marker_size = data->conflict_marker_size;
1680         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1681         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1682         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1683         char *err;
1684         char *line_prefix = "";
1685         struct strbuf *msgbuf;
1687         assert(data->o);
1688         if (data->o->output_prefix) {
1689                 msgbuf = data->o->output_prefix(data->o,
1690                         data->o->output_prefix_data);
1691                 line_prefix = msgbuf->buf;
1692         }
1694         if (line[0] == '+') {
1695                 unsigned bad;
1696                 data->lineno++;
1697                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1698                         data->status |= 1;
1699                         fprintf(data->o->file,
1700                                 "%s%s:%d: leftover conflict marker\n",
1701                                 line_prefix, data->filename, data->lineno);
1702                 }
1703                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1704                 if (!bad)
1705                         return;
1706                 data->status |= bad;
1707                 err = whitespace_error_string(bad);
1708                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1709                         line_prefix, data->filename, data->lineno, err);
1710                 free(err);
1711                 emit_line(data->o, set, reset, line, 1);
1712                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1713                               data->o->file, set, reset, ws);
1714         } else if (line[0] == ' ') {
1715                 data->lineno++;
1716         } else if (line[0] == '@') {
1717                 char *plus = strchr(line, '+');
1718                 if (plus)
1719                         data->lineno = strtol(plus, NULL, 10) - 1;
1720                 else
1721                         die("invalid diff");
1722         }
1725 static unsigned char *deflate_it(char *data,
1726                                  unsigned long size,
1727                                  unsigned long *result_size)
1729         int bound;
1730         unsigned char *deflated;
1731         z_stream stream;
1733         memset(&stream, 0, sizeof(stream));
1734         deflateInit(&stream, zlib_compression_level);
1735         bound = deflateBound(&stream, size);
1736         deflated = xmalloc(bound);
1737         stream.next_out = deflated;
1738         stream.avail_out = bound;
1740         stream.next_in = (unsigned char *)data;
1741         stream.avail_in = size;
1742         while (deflate(&stream, Z_FINISH) == Z_OK)
1743                 ; /* nothing */
1744         deflateEnd(&stream);
1745         *result_size = stream.total_out;
1746         return deflated;
1749 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1751         void *cp;
1752         void *delta;
1753         void *deflated;
1754         void *data;
1755         unsigned long orig_size;
1756         unsigned long delta_size;
1757         unsigned long deflate_size;
1758         unsigned long data_size;
1760         /* We could do deflated delta, or we could do just deflated two,
1761          * whichever is smaller.
1762          */
1763         delta = NULL;
1764         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1765         if (one->size && two->size) {
1766                 delta = diff_delta(one->ptr, one->size,
1767                                    two->ptr, two->size,
1768                                    &delta_size, deflate_size);
1769                 if (delta) {
1770                         void *to_free = delta;
1771                         orig_size = delta_size;
1772                         delta = deflate_it(delta, delta_size, &delta_size);
1773                         free(to_free);
1774                 }
1775         }
1777         if (delta && delta_size < deflate_size) {
1778                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1779                 free(deflated);
1780                 data = delta;
1781                 data_size = delta_size;
1782         }
1783         else {
1784                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1785                 free(delta);
1786                 data = deflated;
1787                 data_size = deflate_size;
1788         }
1790         /* emit data encoded in base85 */
1791         cp = data;
1792         while (data_size) {
1793                 int bytes = (52 < data_size) ? 52 : data_size;
1794                 char line[70];
1795                 data_size -= bytes;
1796                 if (bytes <= 26)
1797                         line[0] = bytes + 'A' - 1;
1798                 else
1799                         line[0] = bytes - 26 + 'a' - 1;
1800                 encode_85(line + 1, cp, bytes);
1801                 cp = (char *) cp + bytes;
1802                 fprintf(file, "%s", prefix);
1803                 fputs(line, file);
1804                 fputc('\n', file);
1805         }
1806         fprintf(file, "%s\n", prefix);
1807         free(data);
1810 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1812         fprintf(file, "%sGIT binary patch\n", prefix);
1813         emit_binary_diff_body(file, one, two, prefix);
1814         emit_binary_diff_body(file, two, one, prefix);
1817 static void diff_filespec_load_driver(struct diff_filespec *one)
1819         /* Use already-loaded driver */
1820         if (one->driver)
1821                 return;
1823         if (S_ISREG(one->mode))
1824                 one->driver = userdiff_find_by_path(one->path);
1826         /* Fallback to default settings */
1827         if (!one->driver)
1828                 one->driver = userdiff_find_by_name("default");
1831 int diff_filespec_is_binary(struct diff_filespec *one)
1833         if (one->is_binary == -1) {
1834                 diff_filespec_load_driver(one);
1835                 if (one->driver->binary != -1)
1836                         one->is_binary = one->driver->binary;
1837                 else {
1838                         if (!one->data && DIFF_FILE_VALID(one))
1839                                 diff_populate_filespec(one, 0);
1840                         if (one->data)
1841                                 one->is_binary = buffer_is_binary(one->data,
1842                                                 one->size);
1843                         if (one->is_binary == -1)
1844                                 one->is_binary = 0;
1845                 }
1846         }
1847         return one->is_binary;
1850 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1852         diff_filespec_load_driver(one);
1853         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1856 static const char *userdiff_word_regex(struct diff_filespec *one)
1858         diff_filespec_load_driver(one);
1859         return one->driver->word_regex;
1862 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1864         if (!options->a_prefix)
1865                 options->a_prefix = a;
1866         if (!options->b_prefix)
1867                 options->b_prefix = b;
1870 struct userdiff_driver *get_textconv(struct diff_filespec *one)
1872         if (!DIFF_FILE_VALID(one))
1873                 return NULL;
1875         diff_filespec_load_driver(one);
1876         if (!one->driver->textconv)
1877                 return NULL;
1879         if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1880                 struct notes_cache *c = xmalloc(sizeof(*c));
1881                 struct strbuf name = STRBUF_INIT;
1883                 strbuf_addf(&name, "textconv/%s", one->driver->name);
1884                 notes_cache_init(c, name.buf, one->driver->textconv);
1885                 one->driver->textconv_cache = c;
1886         }
1888         return one->driver;
1891 static void builtin_diff(const char *name_a,
1892                          const char *name_b,
1893                          struct diff_filespec *one,
1894                          struct diff_filespec *two,
1895                          const char *xfrm_msg,
1896                          int must_show_header,
1897                          struct diff_options *o,
1898                          int complete_rewrite)
1900         mmfile_t mf1, mf2;
1901         const char *lbl[2];
1902         char *a_one, *b_two;
1903         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1904         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1905         const char *a_prefix, *b_prefix;
1906         struct userdiff_driver *textconv_one = NULL;
1907         struct userdiff_driver *textconv_two = NULL;
1908         struct strbuf header = STRBUF_INIT;
1909         struct strbuf *msgbuf;
1910         char *line_prefix = "";
1912         if (o->output_prefix) {
1913                 msgbuf = o->output_prefix(o, o->output_prefix_data);
1914                 line_prefix = msgbuf->buf;
1915         }
1917         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1918                         (!one->mode || S_ISGITLINK(one->mode)) &&
1919                         (!two->mode || S_ISGITLINK(two->mode))) {
1920                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1921                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1922                 show_submodule_summary(o->file, one ? one->path : two->path,
1923                                 one->sha1, two->sha1, two->dirty_submodule,
1924                                 del, add, reset);
1925                 return;
1926         }
1928         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1929                 textconv_one = get_textconv(one);
1930                 textconv_two = get_textconv(two);
1931         }
1933         diff_set_mnemonic_prefix(o, "a/", "b/");
1934         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1935                 a_prefix = o->b_prefix;
1936                 b_prefix = o->a_prefix;
1937         } else {
1938                 a_prefix = o->a_prefix;
1939                 b_prefix = o->b_prefix;
1940         }
1942         /* Never use a non-valid filename anywhere if at all possible */
1943         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1944         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1946         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1947         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1948         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1949         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1950         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1951         if (lbl[0][0] == '/') {
1952                 /* /dev/null */
1953                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1954                 if (xfrm_msg)
1955                         strbuf_addstr(&header, xfrm_msg);
1956                 must_show_header = 1;
1957         }
1958         else if (lbl[1][0] == '/') {
1959                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1960                 if (xfrm_msg)
1961                         strbuf_addstr(&header, xfrm_msg);
1962                 must_show_header = 1;
1963         }
1964         else {
1965                 if (one->mode != two->mode) {
1966                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1967                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1968                         must_show_header = 1;
1969                 }
1970                 if (xfrm_msg)
1971                         strbuf_addstr(&header, xfrm_msg);
1973                 /*
1974                  * we do not run diff between different kind
1975                  * of objects.
1976                  */
1977                 if ((one->mode ^ two->mode) & S_IFMT)
1978                         goto free_ab_and_return;
1979                 if (complete_rewrite &&
1980                     (textconv_one || !diff_filespec_is_binary(one)) &&
1981                     (textconv_two || !diff_filespec_is_binary(two))) {
1982                         fprintf(o->file, "%s", header.buf);
1983                         strbuf_reset(&header);
1984                         emit_rewrite_diff(name_a, name_b, one, two,
1985                                                 textconv_one, textconv_two, o);
1986                         o->found_changes = 1;
1987                         goto free_ab_and_return;
1988                 }
1989         }
1991         if (o->irreversible_delete && lbl[1][0] == '/') {
1992                 fprintf(o->file, "%s", header.buf);
1993                 strbuf_reset(&header);
1994                 goto free_ab_and_return;
1995         } else if (!DIFF_OPT_TST(o, TEXT) &&
1996             ( (!textconv_one && diff_filespec_is_binary(one)) ||
1997               (!textconv_two && diff_filespec_is_binary(two)) )) {
1998                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1999                         die("unable to read files to diff");
2000                 /* Quite common confusing case */
2001                 if (mf1.size == mf2.size &&
2002                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2003                         if (must_show_header)
2004                                 fprintf(o->file, "%s", header.buf);
2005                         goto free_ab_and_return;
2006                 }
2007                 fprintf(o->file, "%s", header.buf);
2008                 strbuf_reset(&header);
2009                 if (DIFF_OPT_TST(o, BINARY))
2010                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2011                 else
2012                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2013                                 line_prefix, lbl[0], lbl[1]);
2014                 o->found_changes = 1;
2015         } else {
2016                 /* Crazy xdl interfaces.. */
2017                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2018                 xpparam_t xpp;
2019                 xdemitconf_t xecfg;
2020                 struct emit_callback ecbdata;
2021                 const struct userdiff_funcname *pe;
2023                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2024                         fprintf(o->file, "%s", header.buf);
2025                         strbuf_reset(&header);
2026                 }
2028                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2029                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2031                 pe = diff_funcname_pattern(one);
2032                 if (!pe)
2033                         pe = diff_funcname_pattern(two);
2035                 memset(&xpp, 0, sizeof(xpp));
2036                 memset(&xecfg, 0, sizeof(xecfg));
2037                 memset(&ecbdata, 0, sizeof(ecbdata));
2038                 ecbdata.label_path = lbl;
2039                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2040                 ecbdata.found_changesp = &o->found_changes;
2041                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2042                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2043                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2044                 ecbdata.opt = o;
2045                 ecbdata.header = header.len ? &header : NULL;
2046                 xpp.flags = o->xdl_opts;
2047                 xecfg.ctxlen = o->context;
2048                 xecfg.interhunkctxlen = o->interhunkcontext;
2049                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2050                 if (pe)
2051                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2052                 if (!diffopts)
2053                         ;
2054                 else if (!prefixcmp(diffopts, "--unified="))
2055                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2056                 else if (!prefixcmp(diffopts, "-u"))
2057                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2058                 if (o->word_diff) {
2059                         int i;
2061                         ecbdata.diff_words =
2062                                 xcalloc(1, sizeof(struct diff_words_data));
2063                         ecbdata.diff_words->type = o->word_diff;
2064                         ecbdata.diff_words->opt = o;
2065                         if (!o->word_regex)
2066                                 o->word_regex = userdiff_word_regex(one);
2067                         if (!o->word_regex)
2068                                 o->word_regex = userdiff_word_regex(two);
2069                         if (!o->word_regex)
2070                                 o->word_regex = diff_word_regex_cfg;
2071                         if (o->word_regex) {
2072                                 ecbdata.diff_words->word_regex = (regex_t *)
2073                                         xmalloc(sizeof(regex_t));
2074                                 if (regcomp(ecbdata.diff_words->word_regex,
2075                                                 o->word_regex,
2076                                                 REG_EXTENDED | REG_NEWLINE))
2077                                         die ("Invalid regular expression: %s",
2078                                                         o->word_regex);
2079                         }
2080                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2081                                 if (o->word_diff == diff_words_styles[i].type) {
2082                                         ecbdata.diff_words->style =
2083                                                 &diff_words_styles[i];
2084                                         break;
2085                                 }
2086                         }
2087                         if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2088                                 struct diff_words_style *st = ecbdata.diff_words->style;
2089                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2090                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2091                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2092                         }
2093                 }
2094                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2095                               &xpp, &xecfg);
2096                 if (o->word_diff)
2097                         free_diff_words_data(&ecbdata);
2098                 if (textconv_one)
2099                         free(mf1.ptr);
2100                 if (textconv_two)
2101                         free(mf2.ptr);
2102                 xdiff_clear_find_func(&xecfg);
2103         }
2105  free_ab_and_return:
2106         strbuf_release(&header);
2107         diff_free_filespec_data(one);
2108         diff_free_filespec_data(two);
2109         free(a_one);
2110         free(b_two);
2111         return;
2114 static void builtin_diffstat(const char *name_a, const char *name_b,
2115                              struct diff_filespec *one,
2116                              struct diff_filespec *two,
2117                              struct diffstat_t *diffstat,
2118                              struct diff_options *o,
2119                              int complete_rewrite)
2121         mmfile_t mf1, mf2;
2122         struct diffstat_file *data;
2124         data = diffstat_add(diffstat, name_a, name_b);
2126         if (!one || !two) {
2127                 data->is_unmerged = 1;
2128                 return;
2129         }
2131         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2132                 data->is_binary = 1;
2133                 data->added = diff_filespec_size(two);
2134                 data->deleted = diff_filespec_size(one);
2135         }
2137         else if (complete_rewrite) {
2138                 diff_populate_filespec(one, 0);
2139                 diff_populate_filespec(two, 0);
2140                 data->deleted = count_lines(one->data, one->size);
2141                 data->added = count_lines(two->data, two->size);
2142         }
2144         else {
2145                 /* Crazy xdl interfaces.. */
2146                 xpparam_t xpp;
2147                 xdemitconf_t xecfg;
2149                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2150                         die("unable to read files to diff");
2152                 memset(&xpp, 0, sizeof(xpp));
2153                 memset(&xecfg, 0, sizeof(xecfg));
2154                 xpp.flags = o->xdl_opts;
2155                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2156                               &xpp, &xecfg);
2157         }
2159         diff_free_filespec_data(one);
2160         diff_free_filespec_data(two);
2163 static void builtin_checkdiff(const char *name_a, const char *name_b,
2164                               const char *attr_path,
2165                               struct diff_filespec *one,
2166                               struct diff_filespec *two,
2167                               struct diff_options *o)
2169         mmfile_t mf1, mf2;
2170         struct checkdiff_t data;
2172         if (!two)
2173                 return;
2175         memset(&data, 0, sizeof(data));
2176         data.filename = name_b ? name_b : name_a;
2177         data.lineno = 0;
2178         data.o = o;
2179         data.ws_rule = whitespace_rule(attr_path);
2180         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2182         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2183                 die("unable to read files to diff");
2185         /*
2186          * All the other codepaths check both sides, but not checking
2187          * the "old" side here is deliberate.  We are checking the newly
2188          * introduced changes, and as long as the "new" side is text, we
2189          * can and should check what it introduces.
2190          */
2191         if (diff_filespec_is_binary(two))
2192                 goto free_and_return;
2193         else {
2194                 /* Crazy xdl interfaces.. */
2195                 xpparam_t xpp;
2196                 xdemitconf_t xecfg;
2198                 memset(&xpp, 0, sizeof(xpp));
2199                 memset(&xecfg, 0, sizeof(xecfg));
2200                 xecfg.ctxlen = 1; /* at least one context line */
2201                 xpp.flags = 0;
2202                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2203                               &xpp, &xecfg);
2205                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2206                         struct emit_callback ecbdata;
2207                         int blank_at_eof;
2209                         ecbdata.ws_rule = data.ws_rule;
2210                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2211                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2213                         if (blank_at_eof) {
2214                                 static char *err;
2215                                 if (!err)
2216                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2217                                 fprintf(o->file, "%s:%d: %s.\n",
2218                                         data.filename, blank_at_eof, err);
2219                                 data.status = 1; /* report errors */
2220                         }
2221                 }
2222         }
2223  free_and_return:
2224         diff_free_filespec_data(one);
2225         diff_free_filespec_data(two);
2226         if (data.status)
2227                 DIFF_OPT_SET(o, CHECK_FAILED);
2230 struct diff_filespec *alloc_filespec(const char *path)
2232         int namelen = strlen(path);
2233         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2235         memset(spec, 0, sizeof(*spec));
2236         spec->path = (char *)(spec + 1);
2237         memcpy(spec->path, path, namelen+1);
2238         spec->count = 1;
2239         spec->is_binary = -1;
2240         return spec;
2243 void free_filespec(struct diff_filespec *spec)
2245         if (!--spec->count) {
2246                 diff_free_filespec_data(spec);
2247                 free(spec);
2248         }
2251 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2252                    unsigned short mode)
2254         if (mode) {
2255                 spec->mode = canon_mode(mode);
2256                 hashcpy(spec->sha1, sha1);
2257                 spec->sha1_valid = !is_null_sha1(sha1);
2258         }
2261 /*
2262  * Given a name and sha1 pair, if the index tells us the file in
2263  * the work tree has that object contents, return true, so that
2264  * prepare_temp_file() does not have to inflate and extract.
2265  */
2266 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2268         struct cache_entry *ce;
2269         struct stat st;
2270         int pos, len;
2272         /*
2273          * We do not read the cache ourselves here, because the
2274          * benchmark with my previous version that always reads cache
2275          * shows that it makes things worse for diff-tree comparing
2276          * two linux-2.6 kernel trees in an already checked out work
2277          * tree.  This is because most diff-tree comparisons deal with
2278          * only a small number of files, while reading the cache is
2279          * expensive for a large project, and its cost outweighs the
2280          * savings we get by not inflating the object to a temporary
2281          * file.  Practically, this code only helps when we are used
2282          * by diff-cache --cached, which does read the cache before
2283          * calling us.
2284          */
2285         if (!active_cache)
2286                 return 0;
2288         /* We want to avoid the working directory if our caller
2289          * doesn't need the data in a normal file, this system
2290          * is rather slow with its stat/open/mmap/close syscalls,
2291          * and the object is contained in a pack file.  The pack
2292          * is probably already open and will be faster to obtain
2293          * the data through than the working directory.  Loose
2294          * objects however would tend to be slower as they need
2295          * to be individually opened and inflated.
2296          */
2297         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2298                 return 0;
2300         len = strlen(name);
2301         pos = cache_name_pos(name, len);
2302         if (pos < 0)
2303                 return 0;
2304         ce = active_cache[pos];
2306         /*
2307          * This is not the sha1 we are looking for, or
2308          * unreusable because it is not a regular file.
2309          */
2310         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2311                 return 0;
2313         /*
2314          * If ce is marked as "assume unchanged", there is no
2315          * guarantee that work tree matches what we are looking for.
2316          */
2317         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2318                 return 0;
2320         /*
2321          * If ce matches the file in the work tree, we can reuse it.
2322          */
2323         if (ce_uptodate(ce) ||
2324             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2325                 return 1;
2327         return 0;
2330 static int populate_from_stdin(struct diff_filespec *s)
2332         struct strbuf buf = STRBUF_INIT;
2333         size_t size = 0;
2335         if (strbuf_read(&buf, 0, 0) < 0)
2336                 return error("error while reading from stdin %s",
2337                                      strerror(errno));
2339         s->should_munmap = 0;
2340         s->data = strbuf_detach(&buf, &size);
2341         s->size = size;
2342         s->should_free = 1;
2343         return 0;
2346 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2348         int len;
2349         char *data = xmalloc(100), *dirty = "";
2351         /* Are we looking at the work tree? */
2352         if (s->dirty_submodule)
2353                 dirty = "-dirty";
2355         len = snprintf(data, 100,
2356                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2357         s->data = data;
2358         s->size = len;
2359         s->should_free = 1;
2360         if (size_only) {
2361                 s->data = NULL;
2362                 free(data);
2363         }
2364         return 0;
2367 /*
2368  * While doing rename detection and pickaxe operation, we may need to
2369  * grab the data for the blob (or file) for our own in-core comparison.
2370  * diff_filespec has data and size fields for this purpose.
2371  */
2372 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2374         int err = 0;
2375         if (!DIFF_FILE_VALID(s))
2376                 die("internal error: asking to populate invalid file.");
2377         if (S_ISDIR(s->mode))
2378                 return -1;
2380         if (s->data)
2381                 return 0;
2383         if (size_only && 0 < s->size)
2384                 return 0;
2386         if (S_ISGITLINK(s->mode))
2387                 return diff_populate_gitlink(s, size_only);
2389         if (!s->sha1_valid ||
2390             reuse_worktree_file(s->path, s->sha1, 0)) {
2391                 struct strbuf buf = STRBUF_INIT;
2392                 struct stat st;
2393                 int fd;
2395                 if (!strcmp(s->path, "-"))
2396                         return populate_from_stdin(s);
2398                 if (lstat(s->path, &st) < 0) {
2399                         if (errno == ENOENT) {
2400                         err_empty:
2401                                 err = -1;
2402                         empty:
2403                                 s->data = (char *)"";
2404                                 s->size = 0;
2405                                 return err;
2406                         }
2407                 }
2408                 s->size = xsize_t(st.st_size);
2409                 if (!s->size)
2410                         goto empty;
2411                 if (S_ISLNK(st.st_mode)) {
2412                         struct strbuf sb = STRBUF_INIT;
2414                         if (strbuf_readlink(&sb, s->path, s->size))
2415                                 goto err_empty;
2416                         s->size = sb.len;
2417                         s->data = strbuf_detach(&sb, NULL);
2418                         s->should_free = 1;
2419                         return 0;
2420                 }
2421                 if (size_only)
2422                         return 0;
2423                 fd = open(s->path, O_RDONLY);
2424                 if (fd < 0)
2425                         goto err_empty;
2426                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2427                 close(fd);
2428                 s->should_munmap = 1;
2430                 /*
2431                  * Convert from working tree format to canonical git format
2432                  */
2433                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2434                         size_t size = 0;
2435                         munmap(s->data, s->size);
2436                         s->should_munmap = 0;
2437                         s->data = strbuf_detach(&buf, &size);
2438                         s->size = size;
2439                         s->should_free = 1;
2440                 }
2441         }
2442         else {
2443                 enum object_type type;
2444                 if (size_only) {
2445                         type = sha1_object_info(s->sha1, &s->size);
2446                         if (type < 0)
2447                                 die("unable to read %s", sha1_to_hex(s->sha1));
2448                 } else {
2449                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2450                         if (!s->data)
2451                                 die("unable to read %s", sha1_to_hex(s->sha1));
2452                         s->should_free = 1;
2453                 }
2454         }
2455         return 0;
2458 void diff_free_filespec_blob(struct diff_filespec *s)
2460         if (s->should_free)
2461                 free(s->data);
2462         else if (s->should_munmap)
2463                 munmap(s->data, s->size);
2465         if (s->should_free || s->should_munmap) {
2466                 s->should_free = s->should_munmap = 0;
2467                 s->data = NULL;
2468         }
2471 void diff_free_filespec_data(struct diff_filespec *s)
2473         diff_free_filespec_blob(s);
2474         free(s->cnt_data);
2475         s->cnt_data = NULL;
2478 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2479                            void *blob,
2480                            unsigned long size,
2481                            const unsigned char *sha1,
2482                            int mode)
2484         int fd;
2485         struct strbuf buf = STRBUF_INIT;
2486         struct strbuf template = STRBUF_INIT;
2487         char *path_dup = xstrdup(path);
2488         const char *base = basename(path_dup);
2490         /* Generate "XXXXXX_basename.ext" */
2491         strbuf_addstr(&template, "XXXXXX_");
2492         strbuf_addstr(&template, base);
2494         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2495                         strlen(base) + 1);
2496         if (fd < 0)
2497                 die_errno("unable to create temp-file");
2498         if (convert_to_working_tree(path,
2499                         (const char *)blob, (size_t)size, &buf)) {
2500                 blob = buf.buf;
2501                 size = buf.len;
2502         }
2503         if (write_in_full(fd, blob, size) != size)
2504                 die_errno("unable to write temp-file");
2505         close(fd);
2506         temp->name = temp->tmp_path;
2507         strcpy(temp->hex, sha1_to_hex(sha1));
2508         temp->hex[40] = 0;
2509         sprintf(temp->mode, "%06o", mode);
2510         strbuf_release(&buf);
2511         strbuf_release(&template);
2512         free(path_dup);
2515 static struct diff_tempfile *prepare_temp_file(const char *name,
2516                 struct diff_filespec *one)
2518         struct diff_tempfile *temp = claim_diff_tempfile();
2520         if (!DIFF_FILE_VALID(one)) {
2521         not_a_valid_file:
2522                 /* A '-' entry produces this for file-2, and
2523                  * a '+' entry produces this for file-1.
2524                  */
2525                 temp->name = "/dev/null";
2526                 strcpy(temp->hex, ".");
2527                 strcpy(temp->mode, ".");
2528                 return temp;
2529         }
2531         if (!remove_tempfile_installed) {
2532                 atexit(remove_tempfile);
2533                 sigchain_push_common(remove_tempfile_on_signal);
2534                 remove_tempfile_installed = 1;
2535         }
2537         if (!one->sha1_valid ||
2538             reuse_worktree_file(name, one->sha1, 1)) {
2539                 struct stat st;
2540                 if (lstat(name, &st) < 0) {
2541                         if (errno == ENOENT)
2542                                 goto not_a_valid_file;
2543                         die_errno("stat(%s)", name);
2544                 }
2545                 if (S_ISLNK(st.st_mode)) {
2546                         struct strbuf sb = STRBUF_INIT;
2547                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2548                                 die_errno("readlink(%s)", name);
2549                         prep_temp_blob(name, temp, sb.buf, sb.len,
2550                                        (one->sha1_valid ?
2551                                         one->sha1 : null_sha1),
2552                                        (one->sha1_valid ?
2553                                         one->mode : S_IFLNK));
2554                         strbuf_release(&sb);
2555                 }
2556                 else {
2557                         /* we can borrow from the file in the work tree */
2558                         temp->name = name;
2559                         if (!one->sha1_valid)
2560                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2561                         else
2562                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2563                         /* Even though we may sometimes borrow the
2564                          * contents from the work tree, we always want
2565                          * one->mode.  mode is trustworthy even when
2566                          * !(one->sha1_valid), as long as
2567                          * DIFF_FILE_VALID(one).
2568                          */
2569                         sprintf(temp->mode, "%06o", one->mode);
2570                 }
2571                 return temp;
2572         }
2573         else {
2574                 if (diff_populate_filespec(one, 0))
2575                         die("cannot read data blob for %s", one->path);
2576                 prep_temp_blob(name, temp, one->data, one->size,
2577                                one->sha1, one->mode);
2578         }
2579         return temp;
2582 /* An external diff command takes:
2583  *
2584  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2585  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2586  *
2587  */
2588 static void run_external_diff(const char *pgm,
2589                               const char *name,
2590                               const char *other,
2591                               struct diff_filespec *one,
2592                               struct diff_filespec *two,
2593                               const char *xfrm_msg,
2594                               int complete_rewrite)
2596         const char *spawn_arg[10];
2597         int retval;
2598         const char **arg = &spawn_arg[0];
2600         if (one && two) {
2601                 struct diff_tempfile *temp_one, *temp_two;
2602                 const char *othername = (other ? other : name);
2603                 temp_one = prepare_temp_file(name, one);
2604                 temp_two = prepare_temp_file(othername, two);
2605                 *arg++ = pgm;
2606                 *arg++ = name;
2607                 *arg++ = temp_one->name;
2608                 *arg++ = temp_one->hex;
2609                 *arg++ = temp_one->mode;
2610                 *arg++ = temp_two->name;
2611                 *arg++ = temp_two->hex;
2612                 *arg++ = temp_two->mode;
2613                 if (other) {
2614                         *arg++ = other;
2615                         *arg++ = xfrm_msg;
2616                 }
2617         } else {
2618                 *arg++ = pgm;
2619                 *arg++ = name;
2620         }
2621         *arg = NULL;
2622         fflush(NULL);
2623         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2624         remove_tempfile();
2625         if (retval) {
2626                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2627                 exit(1);
2628         }
2631 static int similarity_index(struct diff_filepair *p)
2633         return p->score * 100 / MAX_SCORE;
2636 static void fill_metainfo(struct strbuf *msg,
2637                           const char *name,
2638                           const char *other,
2639                           struct diff_filespec *one,
2640                           struct diff_filespec *two,
2641                           struct diff_options *o,
2642                           struct diff_filepair *p,
2643                           int *must_show_header,
2644                           int use_color)
2646         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2647         const char *reset = diff_get_color(use_color, DIFF_RESET);
2648         struct strbuf *msgbuf;
2649         char *line_prefix = "";
2651         *must_show_header = 1;
2652         if (o->output_prefix) {
2653                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2654                 line_prefix = msgbuf->buf;
2655         }
2656         strbuf_init(msg, PATH_MAX * 2 + 300);
2657         switch (p->status) {
2658         case DIFF_STATUS_COPIED:
2659                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2660                             line_prefix, set, similarity_index(p));
2661                 strbuf_addf(msg, "%s\n%s%scopy from ",
2662                             reset,  line_prefix, set);
2663                 quote_c_style(name, msg, NULL, 0);
2664                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2665                 quote_c_style(other, msg, NULL, 0);
2666                 strbuf_addf(msg, "%s\n", reset);
2667                 break;
2668         case DIFF_STATUS_RENAMED:
2669                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2670                             line_prefix, set, similarity_index(p));
2671                 strbuf_addf(msg, "%s\n%s%srename from ",
2672                             reset, line_prefix, set);
2673                 quote_c_style(name, msg, NULL, 0);
2674                 strbuf_addf(msg, "%s\n%s%srename to ",
2675                             reset, line_prefix, set);
2676                 quote_c_style(other, msg, NULL, 0);
2677                 strbuf_addf(msg, "%s\n", reset);
2678                 break;
2679         case DIFF_STATUS_MODIFIED:
2680                 if (p->score) {
2681                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2682                                     line_prefix,
2683                                     set, similarity_index(p), reset);
2684                         break;
2685                 }
2686                 /* fallthru */
2687         default:
2688                 *must_show_header = 0;
2689         }
2690         if (one && two && hashcmp(one->sha1, two->sha1)) {
2691                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2693                 if (DIFF_OPT_TST(o, BINARY)) {
2694                         mmfile_t mf;
2695                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2696                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2697                                 abbrev = 40;
2698                 }
2699                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2700                             find_unique_abbrev(one->sha1, abbrev));
2701                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2702                 if (one->mode == two->mode)
2703                         strbuf_addf(msg, " %06o", one->mode);
2704                 strbuf_addf(msg, "%s\n", reset);
2705         }
2708 static void run_diff_cmd(const char *pgm,
2709                          const char *name,
2710                          const char *other,
2711                          const char *attr_path,
2712                          struct diff_filespec *one,
2713                          struct diff_filespec *two,
2714                          struct strbuf *msg,
2715                          struct diff_options *o,
2716                          struct diff_filepair *p)
2718         const char *xfrm_msg = NULL;
2719         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2720         int must_show_header = 0;
2722         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2723                 pgm = NULL;
2724         else {
2725                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2726                 if (drv && drv->external)
2727                         pgm = drv->external;
2728         }
2730         if (msg) {
2731                 /*
2732                  * don't use colors when the header is intended for an
2733                  * external diff driver
2734                  */
2735                 fill_metainfo(msg, name, other, one, two, o, p,
2736                               &must_show_header,
2737                               DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2738                 xfrm_msg = msg->len ? msg->buf : NULL;
2739         }
2741         if (pgm) {
2742                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2743                                   complete_rewrite);
2744                 return;
2745         }
2746         if (one && two)
2747                 builtin_diff(name, other ? other : name,
2748                              one, two, xfrm_msg, must_show_header,
2749                              o, complete_rewrite);
2750         else
2751                 fprintf(o->file, "* Unmerged path %s\n", name);
2754 static void diff_fill_sha1_info(struct diff_filespec *one)
2756         if (DIFF_FILE_VALID(one)) {
2757                 if (!one->sha1_valid) {
2758                         struct stat st;
2759                         if (!strcmp(one->path, "-")) {
2760                                 hashcpy(one->sha1, null_sha1);
2761                                 return;
2762                         }
2763                         if (lstat(one->path, &st) < 0)
2764                                 die_errno("stat '%s'", one->path);
2765                         if (index_path(one->sha1, one->path, &st, 0))
2766                                 die("cannot hash %s", one->path);
2767                 }
2768         }
2769         else
2770                 hashclr(one->sha1);
2773 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2775         /* Strip the prefix but do not molest /dev/null and absolute paths */
2776         if (*namep && **namep != '/') {
2777                 *namep += prefix_length;
2778                 if (**namep == '/')
2779                         ++*namep;
2780         }
2781         if (*otherp && **otherp != '/') {
2782                 *otherp += prefix_length;
2783                 if (**otherp == '/')
2784                         ++*otherp;
2785         }
2788 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2790         const char *pgm = external_diff();
2791         struct strbuf msg;
2792         struct diff_filespec *one = p->one;
2793         struct diff_filespec *two = p->two;
2794         const char *name;
2795         const char *other;
2796         const char *attr_path;
2798         name  = p->one->path;
2799         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2800         attr_path = name;
2801         if (o->prefix_length)
2802                 strip_prefix(o->prefix_length, &name, &other);
2804         if (DIFF_PAIR_UNMERGED(p)) {
2805                 run_diff_cmd(pgm, name, NULL, attr_path,
2806                              NULL, NULL, NULL, o, p);
2807                 return;
2808         }
2810         diff_fill_sha1_info(one);
2811         diff_fill_sha1_info(two);
2813         if (!pgm &&
2814             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2815             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2816                 /*
2817                  * a filepair that changes between file and symlink
2818                  * needs to be split into deletion and creation.
2819                  */
2820                 struct diff_filespec *null = alloc_filespec(two->path);
2821                 run_diff_cmd(NULL, name, other, attr_path,
2822                              one, null, &msg, o, p);
2823                 free(null);
2824                 strbuf_release(&msg);
2826                 null = alloc_filespec(one->path);
2827                 run_diff_cmd(NULL, name, other, attr_path,
2828                              null, two, &msg, o, p);
2829                 free(null);
2830         }
2831         else
2832                 run_diff_cmd(pgm, name, other, attr_path,
2833                              one, two, &msg, o, p);
2835         strbuf_release(&msg);
2838 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2839                          struct diffstat_t *diffstat)
2841         const char *name;
2842         const char *other;
2843         int complete_rewrite = 0;
2845         if (DIFF_PAIR_UNMERGED(p)) {
2846                 /* unmerged */
2847                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2848                 return;
2849         }
2851         name = p->one->path;
2852         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2854         if (o->prefix_length)
2855                 strip_prefix(o->prefix_length, &name, &other);
2857         diff_fill_sha1_info(p->one);
2858         diff_fill_sha1_info(p->two);
2860         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2861                 complete_rewrite = 1;
2862         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2865 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2867         const char *name;
2868         const char *other;
2869         const char *attr_path;
2871         if (DIFF_PAIR_UNMERGED(p)) {
2872                 /* unmerged */
2873                 return;
2874         }
2876         name = p->one->path;
2877         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2878         attr_path = other ? other : name;
2880         if (o->prefix_length)
2881                 strip_prefix(o->prefix_length, &name, &other);
2883         diff_fill_sha1_info(p->one);
2884         diff_fill_sha1_info(p->two);
2886         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2889 void diff_setup(struct diff_options *options)
2891         memcpy(options, &default_diff_options, sizeof(*options));
2893         options->file = stdout;
2895         options->line_termination = '\n';
2896         options->break_opt = -1;
2897         options->rename_limit = -1;
2898         options->dirstat_percent = 3;
2899         options->context = 3;
2901         options->change = diff_change;
2902         options->add_remove = diff_addremove;
2903         if (diff_use_color_default > 0)
2904                 DIFF_OPT_SET(options, COLOR_DIFF);
2905         options->detect_rename = diff_detect_rename_default;
2907         if (diff_no_prefix) {
2908                 options->a_prefix = options->b_prefix = "";
2909         } else if (!diff_mnemonic_prefix) {
2910                 options->a_prefix = "a/";
2911                 options->b_prefix = "b/";
2912         }
2915 int diff_setup_done(struct diff_options *options)
2917         int count = 0;
2919         if (options->output_format & DIFF_FORMAT_NAME)
2920                 count++;
2921         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2922                 count++;
2923         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2924                 count++;
2925         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2926                 count++;
2927         if (count > 1)
2928                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2930         /*
2931          * Most of the time we can say "there are changes"
2932          * only by checking if there are changed paths, but
2933          * --ignore-whitespace* options force us to look
2934          * inside contents.
2935          */
2937         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2938             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2939             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2940                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2941         else
2942                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2944         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2945                 options->detect_rename = DIFF_DETECT_COPY;
2947         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2948                 options->prefix = NULL;
2949         if (options->prefix)
2950                 options->prefix_length = strlen(options->prefix);
2951         else
2952                 options->prefix_length = 0;
2954         if (options->output_format & (DIFF_FORMAT_NAME |
2955                                       DIFF_FORMAT_NAME_STATUS |
2956                                       DIFF_FORMAT_CHECKDIFF |
2957                                       DIFF_FORMAT_NO_OUTPUT))
2958                 options->output_format &= ~(DIFF_FORMAT_RAW |
2959                                             DIFF_FORMAT_NUMSTAT |
2960                                             DIFF_FORMAT_DIFFSTAT |
2961                                             DIFF_FORMAT_SHORTSTAT |
2962                                             DIFF_FORMAT_DIRSTAT |
2963                                             DIFF_FORMAT_SUMMARY |
2964                                             DIFF_FORMAT_PATCH);
2966         /*
2967          * These cases always need recursive; we do not drop caller-supplied
2968          * recursive bits for other formats here.
2969          */
2970         if (options->output_format & (DIFF_FORMAT_PATCH |
2971                                       DIFF_FORMAT_NUMSTAT |
2972                                       DIFF_FORMAT_DIFFSTAT |
2973                                       DIFF_FORMAT_SHORTSTAT |
2974                                       DIFF_FORMAT_DIRSTAT |
2975                                       DIFF_FORMAT_SUMMARY |
2976                                       DIFF_FORMAT_CHECKDIFF))
2977                 DIFF_OPT_SET(options, RECURSIVE);
2978         /*
2979          * Also pickaxe would not work very well if you do not say recursive
2980          */
2981         if (options->pickaxe)
2982                 DIFF_OPT_SET(options, RECURSIVE);
2983         /*
2984          * When patches are generated, submodules diffed against the work tree
2985          * must be checked for dirtiness too so it can be shown in the output
2986          */
2987         if (options->output_format & DIFF_FORMAT_PATCH)
2988                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2990         if (options->detect_rename && options->rename_limit < 0)
2991                 options->rename_limit = diff_rename_limit_default;
2992         if (options->setup & DIFF_SETUP_USE_CACHE) {
2993                 if (!active_cache)
2994                         /* read-cache does not die even when it fails
2995                          * so it is safe for us to do this here.  Also
2996                          * it does not smudge active_cache or active_nr
2997                          * when it fails, so we do not have to worry about
2998                          * cleaning it up ourselves either.
2999                          */
3000                         read_cache();
3001         }
3002         if (options->abbrev <= 0 || 40 < options->abbrev)
3003                 options->abbrev = 40; /* full */
3005         /*
3006          * It does not make sense to show the first hit we happened
3007          * to have found.  It does not make sense not to return with
3008          * exit code in such a case either.
3009          */
3010         if (DIFF_OPT_TST(options, QUICK)) {
3011                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3012                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3013         }
3015         return 0;
3018 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3020         char c, *eq;
3021         int len;
3023         if (*arg != '-')
3024                 return 0;
3025         c = *++arg;
3026         if (!c)
3027                 return 0;
3028         if (c == arg_short) {
3029                 c = *++arg;
3030                 if (!c)
3031                         return 1;
3032                 if (val && isdigit(c)) {
3033                         char *end;
3034                         int n = strtoul(arg, &end, 10);
3035                         if (*end)
3036                                 return 0;
3037                         *val = n;
3038                         return 1;
3039                 }
3040                 return 0;
3041         }
3042         if (c != '-')
3043                 return 0;
3044         arg++;
3045         eq = strchr(arg, '=');
3046         if (eq)
3047                 len = eq - arg;
3048         else
3049                 len = strlen(arg);
3050         if (!len || strncmp(arg, arg_long, len))
3051                 return 0;
3052         if (eq) {
3053                 int n;
3054                 char *end;
3055                 if (!isdigit(*++eq))
3056                         return 0;
3057                 n = strtoul(eq, &end, 10);
3058                 if (*end)
3059                         return 0;
3060                 *val = n;
3061         }
3062         return 1;
3065 static int diff_scoreopt_parse(const char *opt);
3067 static inline int short_opt(char opt, const char **argv,
3068                             const char **optarg)
3070         const char *arg = argv[0];
3071         if (arg[0] != '-' || arg[1] != opt)
3072                 return 0;
3073         if (arg[2] != '\0') {
3074                 *optarg = arg + 2;
3075                 return 1;
3076         }
3077         if (!argv[1])
3078                 die("Option '%c' requires a value", opt);
3079         *optarg = argv[1];
3080         return 2;
3083 int parse_long_opt(const char *opt, const char **argv,
3084                    const char **optarg)
3086         const char *arg = argv[0];
3087         if (arg[0] != '-' || arg[1] != '-')
3088                 return 0;
3089         arg += strlen("--");
3090         if (prefixcmp(arg, opt))
3091                 return 0;
3092         arg += strlen(opt);
3093         if (*arg == '=') { /* sticked form: --option=value */
3094                 *optarg = arg + 1;
3095                 return 1;
3096         }
3097         if (*arg != '\0')
3098                 return 0;
3099         /* separate form: --option value */
3100         if (!argv[1])
3101                 die("Option '--%s' requires a value", opt);
3102         *optarg = argv[1];
3103         return 2;
3106 static int stat_opt(struct diff_options *options, const char **av)
3108         const char *arg = av[0];
3109         char *end;
3110         int width = options->stat_width;
3111         int name_width = options->stat_name_width;
3112         int argcount = 1;
3114         arg += strlen("--stat");
3115         end = (char *)arg;
3117         switch (*arg) {
3118         case '-':
3119                 if (!prefixcmp(arg, "-width")) {
3120                         arg += strlen("-width");
3121                         if (*arg == '=')
3122                                 width = strtoul(arg + 1, &end, 10);
3123                         else if (!*arg && !av[1])
3124                                 die("Option '--stat-width' requires a value");
3125                         else if (!*arg) {
3126                                 width = strtoul(av[1], &end, 10);
3127                                 argcount = 2;
3128                         }
3129                 } else if (!prefixcmp(arg, "-name-width")) {
3130                         arg += strlen("-name-width");
3131                         if (*arg == '=')
3132                                 name_width = strtoul(arg + 1, &end, 10);
3133                         else if (!*arg && !av[1])
3134                                 die("Option '--stat-name-width' requires a value");
3135                         else if (!*arg) {
3136                                 name_width = strtoul(av[1], &end, 10);
3137                                 argcount = 2;
3138                         }
3139                 }
3140                 break;
3141         case '=':
3142                 width = strtoul(arg+1, &end, 10);
3143                 if (*end == ',')
3144                         name_width = strtoul(end+1, &end, 10);
3145         }
3147         /* Important! This checks all the error cases! */
3148         if (*end)
3149                 return 0;
3150         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3151         options->stat_name_width = name_width;
3152         options->stat_width = width;
3153         return argcount;
3156 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3158         const char *arg = av[0];
3159         const char *optarg;
3160         int argcount;
3162         /* Output format options */
3163         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3164                 options->output_format |= DIFF_FORMAT_PATCH;
3165         else if (opt_arg(arg, 'U', "unified", &options->context))
3166                 options->output_format |= DIFF_FORMAT_PATCH;
3167         else if (!strcmp(arg, "--raw"))
3168                 options->output_format |= DIFF_FORMAT_RAW;
3169         else if (!strcmp(arg, "--patch-with-raw"))
3170                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3171         else if (!strcmp(arg, "--numstat"))
3172                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3173         else if (!strcmp(arg, "--shortstat"))
3174                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3175         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3176                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3177         else if (!strcmp(arg, "--cumulative")) {
3178                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3179                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3180         } else if (opt_arg(arg, 0, "dirstat-by-file",
3181                            &options->dirstat_percent)) {
3182                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3183                 DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3184         }
3185         else if (!strcmp(arg, "--check"))
3186                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3187         else if (!strcmp(arg, "--summary"))
3188                 options->output_format |= DIFF_FORMAT_SUMMARY;
3189         else if (!strcmp(arg, "--patch-with-stat"))
3190                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3191         else if (!strcmp(arg, "--name-only"))
3192                 options->output_format |= DIFF_FORMAT_NAME;
3193         else if (!strcmp(arg, "--name-status"))
3194                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3195         else if (!strcmp(arg, "-s"))
3196                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3197         else if (!prefixcmp(arg, "--stat"))
3198                 /* --stat, --stat-width, or --stat-name-width */
3199                 return stat_opt(options, av);
3201         /* renames options */
3202         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3203                  !strcmp(arg, "--break-rewrites")) {
3204                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3205                         return error("invalid argument to -B: %s", arg+2);
3206         }
3207         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3208                  !strcmp(arg, "--find-renames")) {
3209                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3210                         return error("invalid argument to -M: %s", arg+2);
3211                 options->detect_rename = DIFF_DETECT_RENAME;
3212         }
3213         else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3214                 options->irreversible_delete = 1;
3215         }
3216         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3217                  !strcmp(arg, "--find-copies")) {
3218                 if (options->detect_rename == DIFF_DETECT_COPY)
3219                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3220                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3221                         return error("invalid argument to -C: %s", arg+2);
3222                 options->detect_rename = DIFF_DETECT_COPY;
3223         }
3224         else if (!strcmp(arg, "--no-renames"))
3225                 options->detect_rename = 0;
3226         else if (!strcmp(arg, "--relative"))
3227                 DIFF_OPT_SET(options, RELATIVE_NAME);
3228         else if (!prefixcmp(arg, "--relative=")) {
3229                 DIFF_OPT_SET(options, RELATIVE_NAME);
3230                 options->prefix = arg + 11;
3231         }
3233         /* xdiff options */
3234         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3235                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3236         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3237                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3238         else if (!strcmp(arg, "--ignore-space-at-eol"))
3239                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3240         else if (!strcmp(arg, "--patience"))
3241                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3243         /* flags options */
3244         else if (!strcmp(arg, "--binary")) {
3245                 options->output_format |= DIFF_FORMAT_PATCH;
3246                 DIFF_OPT_SET(options, BINARY);
3247         }
3248         else if (!strcmp(arg, "--full-index"))
3249                 DIFF_OPT_SET(options, FULL_INDEX);
3250         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3251                 DIFF_OPT_SET(options, TEXT);
3252         else if (!strcmp(arg, "-R"))
3253                 DIFF_OPT_SET(options, REVERSE_DIFF);
3254         else if (!strcmp(arg, "--find-copies-harder"))
3255                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3256         else if (!strcmp(arg, "--follow"))
3257                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3258         else if (!strcmp(arg, "--color"))
3259                 DIFF_OPT_SET(options, COLOR_DIFF);
3260         else if (!prefixcmp(arg, "--color=")) {
3261                 int value = git_config_colorbool(NULL, arg+8, -1);
3262                 if (value == 0)
3263                         DIFF_OPT_CLR(options, COLOR_DIFF);
3264                 else if (value > 0)
3265                         DIFF_OPT_SET(options, COLOR_DIFF);
3266                 else
3267                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3268         }
3269         else if (!strcmp(arg, "--no-color"))
3270                 DIFF_OPT_CLR(options, COLOR_DIFF);
3271         else if (!strcmp(arg, "--color-words")) {
3272                 DIFF_OPT_SET(options, COLOR_DIFF);
3273                 options->word_diff = DIFF_WORDS_COLOR;
3274         }
3275         else if (!prefixcmp(arg, "--color-words=")) {
3276                 DIFF_OPT_SET(options, COLOR_DIFF);
3277                 options->word_diff = DIFF_WORDS_COLOR;
3278                 options->word_regex = arg + 14;
3279         }
3280         else if (!strcmp(arg, "--word-diff")) {
3281                 if (options->word_diff == DIFF_WORDS_NONE)
3282                         options->word_diff = DIFF_WORDS_PLAIN;
3283         }
3284         else if (!prefixcmp(arg, "--word-diff=")) {
3285                 const char *type = arg + 12;
3286                 if (!strcmp(type, "plain"))
3287                         options->word_diff = DIFF_WORDS_PLAIN;
3288                 else if (!strcmp(type, "color")) {
3289                         DIFF_OPT_SET(options, COLOR_DIFF);
3290                         options->word_diff = DIFF_WORDS_COLOR;
3291                 }
3292                 else if (!strcmp(type, "porcelain"))
3293                         options->word_diff = DIFF_WORDS_PORCELAIN;
3294                 else if (!strcmp(type, "none"))
3295                         options->word_diff = DIFF_WORDS_NONE;
3296                 else
3297                         die("bad --word-diff argument: %s", type);
3298         }
3299         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3300                 if (options->word_diff == DIFF_WORDS_NONE)
3301                         options->word_diff = DIFF_WORDS_PLAIN;
3302                 options->word_regex = optarg;
3303                 return argcount;
3304         }
3305         else if (!strcmp(arg, "--exit-code"))
3306                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3307         else if (!strcmp(arg, "--quiet"))
3308                 DIFF_OPT_SET(options, QUICK);
3309         else if (!strcmp(arg, "--ext-diff"))
3310                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3311         else if (!strcmp(arg, "--no-ext-diff"))
3312                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3313         else if (!strcmp(arg, "--textconv"))
3314                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3315         else if (!strcmp(arg, "--no-textconv"))
3316                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3317         else if (!strcmp(arg, "--ignore-submodules")) {
3318                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3319                 handle_ignore_submodules_arg(options, "all");
3320         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3321                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3322                 handle_ignore_submodules_arg(options, arg + 20);
3323         } else if (!strcmp(arg, "--submodule"))
3324                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3325         else if (!prefixcmp(arg, "--submodule=")) {
3326                 if (!strcmp(arg + 12, "log"))
3327                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3328         }
3330         /* misc options */
3331         else if (!strcmp(arg, "-z"))
3332                 options->line_termination = 0;
3333         else if ((argcount = short_opt('l', av, &optarg))) {
3334                 options->rename_limit = strtoul(optarg, NULL, 10);
3335                 return argcount;
3336         }
3337         else if ((argcount = short_opt('S', av, &optarg))) {
3338                 options->pickaxe = optarg;
3339                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3340                 return argcount;
3341         } else if ((argcount = short_opt('G', av, &optarg))) {
3342                 options->pickaxe = optarg;
3343                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3344                 return argcount;
3345         }
3346         else if (!strcmp(arg, "--pickaxe-all"))
3347                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3348         else if (!strcmp(arg, "--pickaxe-regex"))
3349                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3350         else if ((argcount = short_opt('O', av, &optarg))) {
3351                 options->orderfile = optarg;
3352                 return argcount;
3353         }
3354         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3355                 options->filter = optarg;
3356                 return argcount;
3357         }
3358         else if (!strcmp(arg, "--abbrev"))
3359                 options->abbrev = DEFAULT_ABBREV;
3360         else if (!prefixcmp(arg, "--abbrev=")) {
3361                 options->abbrev = strtoul(arg + 9, NULL, 10);
3362                 if (options->abbrev < MINIMUM_ABBREV)
3363                         options->abbrev = MINIMUM_ABBREV;
3364                 else if (40 < options->abbrev)
3365                         options->abbrev = 40;
3366         }
3367         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3368                 options->a_prefix = optarg;
3369                 return argcount;
3370         }
3371         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3372                 options->b_prefix = optarg;
3373                 return argcount;
3374         }
3375         else if (!strcmp(arg, "--no-prefix"))
3376                 options->a_prefix = options->b_prefix = "";
3377         else if (opt_arg(arg, '\0', "inter-hunk-context",
3378                          &options->interhunkcontext))
3379                 ;
3380         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3381                 options->file = fopen(optarg, "w");
3382                 if (!options->file)
3383                         die_errno("Could not open '%s'", optarg);
3384                 options->close_file = 1;
3385                 return argcount;
3386         } else
3387                 return 0;
3388         return 1;
3391 int parse_rename_score(const char **cp_p)
3393         unsigned long num, scale;
3394         int ch, dot;
3395         const char *cp = *cp_p;
3397         num = 0;
3398         scale = 1;
3399         dot = 0;
3400         for (;;) {
3401                 ch = *cp;
3402                 if ( !dot && ch == '.' ) {
3403                         scale = 1;
3404                         dot = 1;
3405                 } else if ( ch == '%' ) {
3406                         scale = dot ? scale*100 : 100;
3407                         cp++;   /* % is always at the end */
3408                         break;
3409                 } else if ( ch >= '0' && ch <= '9' ) {
3410                         if ( scale < 100000 ) {
3411                                 scale *= 10;
3412                                 num = (num*10) + (ch-'0');
3413                         }
3414                 } else {
3415                         break;
3416                 }
3417                 cp++;
3418         }
3419         *cp_p = cp;
3421         /* user says num divided by scale and we say internally that
3422          * is MAX_SCORE * num / scale.
3423          */
3424         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3427 static int diff_scoreopt_parse(const char *opt)
3429         int opt1, opt2, cmd;
3431         if (*opt++ != '-')
3432                 return -1;
3433         cmd = *opt++;
3434         if (cmd == '-') {
3435                 /* convert the long-form arguments into short-form versions */
3436                 if (!prefixcmp(opt, "break-rewrites")) {
3437                         opt += strlen("break-rewrites");
3438                         if (*opt == 0 || *opt++ == '=')
3439                                 cmd = 'B';
3440                 } else if (!prefixcmp(opt, "find-copies")) {
3441                         opt += strlen("find-copies");
3442                         if (*opt == 0 || *opt++ == '=')
3443                                 cmd = 'C';
3444                 } else if (!prefixcmp(opt, "find-renames")) {
3445                         opt += strlen("find-renames");
3446                         if (*opt == 0 || *opt++ == '=')
3447                                 cmd = 'M';
3448                 }
3449         }
3450         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3451                 return -1; /* that is not a -M, -C nor -B option */
3453         opt1 = parse_rename_score(&opt);
3454         if (cmd != 'B')
3455                 opt2 = 0;
3456         else {
3457                 if (*opt == 0)
3458                         opt2 = 0;
3459                 else if (*opt != '/')
3460                         return -1; /* we expect -B80/99 or -B80 */
3461                 else {
3462                         opt++;
3463                         opt2 = parse_rename_score(&opt);
3464                 }
3465         }
3466         if (*opt != 0)
3467                 return -1;
3468         return opt1 | (opt2 << 16);
3471 struct diff_queue_struct diff_queued_diff;
3473 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3475         if (queue->alloc <= queue->nr) {
3476                 queue->alloc = alloc_nr(queue->alloc);
3477                 queue->queue = xrealloc(queue->queue,
3478                                         sizeof(dp) * queue->alloc);
3479         }
3480         queue->queue[queue->nr++] = dp;
3483 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3484                                  struct diff_filespec *one,
3485                                  struct diff_filespec *two)
3487         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3488         dp->one = one;
3489         dp->two = two;
3490         if (queue)
3491                 diff_q(queue, dp);
3492         return dp;
3495 void diff_free_filepair(struct diff_filepair *p)
3497         free_filespec(p->one);
3498         free_filespec(p->two);
3499         free(p);
3502 /* This is different from find_unique_abbrev() in that
3503  * it stuffs the result with dots for alignment.
3504  */
3505 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3507         int abblen;
3508         const char *abbrev;
3509         if (len == 40)
3510                 return sha1_to_hex(sha1);
3512         abbrev = find_unique_abbrev(sha1, len);
3513         abblen = strlen(abbrev);
3514         if (abblen < 37) {
3515                 static char hex[41];
3516                 if (len < abblen && abblen <= len + 2)
3517                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3518                 else
3519                         sprintf(hex, "%s...", abbrev);
3520                 return hex;
3521         }
3522         return sha1_to_hex(sha1);
3525 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3527         int line_termination = opt->line_termination;
3528         int inter_name_termination = line_termination ? '\t' : '\0';
3529         if (opt->output_prefix) {
3530                 struct strbuf *msg = NULL;
3531                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3532                 fprintf(opt->file, "%s", msg->buf);
3533         }
3535         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3536                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3537                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3538                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3539         }
3540         if (p->score) {
3541                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3542                         inter_name_termination);
3543         } else {
3544                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3545         }
3547         if (p->status == DIFF_STATUS_COPIED ||
3548             p->status == DIFF_STATUS_RENAMED) {
3549                 const char *name_a, *name_b;
3550                 name_a = p->one->path;
3551                 name_b = p->two->path;
3552                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3553                 write_name_quoted(name_a, opt->file, inter_name_termination);
3554                 write_name_quoted(name_b, opt->file, line_termination);
3555         } else {
3556                 const char *name_a, *name_b;
3557                 name_a = p->one->mode ? p->one->path : p->two->path;
3558                 name_b = NULL;
3559                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3560                 write_name_quoted(name_a, opt->file, line_termination);
3561         }
3564 int diff_unmodified_pair(struct diff_filepair *p)
3566         /* This function is written stricter than necessary to support
3567          * the currently implemented transformers, but the idea is to
3568          * let transformers to produce diff_filepairs any way they want,
3569          * and filter and clean them up here before producing the output.
3570          */
3571         struct diff_filespec *one = p->one, *two = p->two;
3573         if (DIFF_PAIR_UNMERGED(p))
3574                 return 0; /* unmerged is interesting */
3576         /* deletion, addition, mode or type change
3577          * and rename are all interesting.
3578          */
3579         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3580             DIFF_PAIR_MODE_CHANGED(p) ||
3581             strcmp(one->path, two->path))
3582                 return 0;
3584         /* both are valid and point at the same path.  that is, we are
3585          * dealing with a change.
3586          */
3587         if (one->sha1_valid && two->sha1_valid &&
3588             !hashcmp(one->sha1, two->sha1) &&
3589             !one->dirty_submodule && !two->dirty_submodule)
3590                 return 1; /* no change */
3591         if (!one->sha1_valid && !two->sha1_valid)
3592                 return 1; /* both look at the same file on the filesystem. */
3593         return 0;
3596 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3598         if (diff_unmodified_pair(p))
3599                 return;
3601         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3602             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3603                 return; /* no tree diffs in patch format */
3605         run_diff(p, o);
3608 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3609                             struct diffstat_t *diffstat)
3611         if (diff_unmodified_pair(p))
3612                 return;
3614         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3615             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3616                 return; /* no useful stat for tree diffs */
3618         run_diffstat(p, o, diffstat);
3621 static void diff_flush_checkdiff(struct diff_filepair *p,
3622                 struct diff_options *o)
3624         if (diff_unmodified_pair(p))
3625                 return;
3627         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3628             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3629                 return; /* nothing to check in tree diffs */
3631         run_checkdiff(p, o);
3634 int diff_queue_is_empty(void)
3636         struct diff_queue_struct *q = &diff_queued_diff;
3637         int i;
3638         for (i = 0; i < q->nr; i++)
3639                 if (!diff_unmodified_pair(q->queue[i]))
3640                         return 0;
3641         return 1;
3644 #if DIFF_DEBUG
3645 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3647         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3648                 x, one ? one : "",
3649                 s->path,
3650                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3651                 s->mode,
3652                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3653         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3654                 x, one ? one : "",
3655                 s->size, s->xfrm_flags);
3658 void diff_debug_filepair(const struct diff_filepair *p, int i)
3660         diff_debug_filespec(p->one, i, "one");
3661         diff_debug_filespec(p->two, i, "two");
3662         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3663                 p->score, p->status ? p->status : '?',
3664                 p->one->rename_used, p->broken_pair);
3667 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3669         int i;
3670         if (msg)
3671                 fprintf(stderr, "%s\n", msg);
3672         fprintf(stderr, "q->nr = %d\n", q->nr);
3673         for (i = 0; i < q->nr; i++) {
3674                 struct diff_filepair *p = q->queue[i];
3675                 diff_debug_filepair(p, i);
3676         }
3678 #endif
3680 static void diff_resolve_rename_copy(void)
3682         int i;
3683         struct diff_filepair *p;
3684         struct diff_queue_struct *q = &diff_queued_diff;
3686         diff_debug_queue("resolve-rename-copy", q);
3688         for (i = 0; i < q->nr; i++) {
3689                 p = q->queue[i];
3690                 p->status = 0; /* undecided */
3691                 if (DIFF_PAIR_UNMERGED(p))
3692                         p->status = DIFF_STATUS_UNMERGED;
3693                 else if (!DIFF_FILE_VALID(p->one))
3694                         p->status = DIFF_STATUS_ADDED;
3695                 else if (!DIFF_FILE_VALID(p->two))
3696                         p->status = DIFF_STATUS_DELETED;
3697                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3698                         p->status = DIFF_STATUS_TYPE_CHANGED;
3700                 /* from this point on, we are dealing with a pair
3701                  * whose both sides are valid and of the same type, i.e.
3702                  * either in-place edit or rename/copy edit.
3703                  */
3704                 else if (DIFF_PAIR_RENAME(p)) {
3705                         /*
3706                          * A rename might have re-connected a broken
3707                          * pair up, causing the pathnames to be the
3708                          * same again. If so, that's not a rename at
3709                          * all, just a modification..
3710                          *
3711                          * Otherwise, see if this source was used for
3712                          * multiple renames, in which case we decrement
3713                          * the count, and call it a copy.
3714                          */
3715                         if (!strcmp(p->one->path, p->two->path))
3716                                 p->status = DIFF_STATUS_MODIFIED;
3717                         else if (--p->one->rename_used > 0)
3718                                 p->status = DIFF_STATUS_COPIED;
3719                         else
3720                                 p->status = DIFF_STATUS_RENAMED;
3721                 }
3722                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3723                          p->one->mode != p->two->mode ||
3724                          p->one->dirty_submodule ||
3725                          p->two->dirty_submodule ||
3726                          is_null_sha1(p->one->sha1))
3727                         p->status = DIFF_STATUS_MODIFIED;
3728                 else {
3729                         /* This is a "no-change" entry and should not
3730                          * happen anymore, but prepare for broken callers.
3731                          */
3732                         error("feeding unmodified %s to diffcore",
3733                               p->one->path);
3734                         p->status = DIFF_STATUS_UNKNOWN;
3735                 }
3736         }
3737         diff_debug_queue("resolve-rename-copy done", q);
3740 static int check_pair_status(struct diff_filepair *p)
3742         switch (p->status) {
3743         case DIFF_STATUS_UNKNOWN:
3744                 return 0;
3745         case 0:
3746                 die("internal error in diff-resolve-rename-copy");
3747         default:
3748                 return 1;
3749         }
3752 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3754         int fmt = opt->output_format;
3756         if (fmt & DIFF_FORMAT_CHECKDIFF)
3757                 diff_flush_checkdiff(p, opt);
3758         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3759                 diff_flush_raw(p, opt);
3760         else if (fmt & DIFF_FORMAT_NAME) {
3761                 const char *name_a, *name_b;
3762                 name_a = p->two->path;
3763                 name_b = NULL;
3764                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3765                 write_name_quoted(name_a, opt->file, opt->line_termination);
3766         }
3769 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3771         if (fs->mode)
3772                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3773         else
3774                 fprintf(file, " %s ", newdelete);
3775         write_name_quoted(fs->path, file, '\n');
3779 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3780                 const char *line_prefix)
3782         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3783                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3784                         p->two->mode, show_name ? ' ' : '\n');
3785                 if (show_name) {
3786                         write_name_quoted(p->two->path, file, '\n');
3787                 }
3788         }
3791 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3792                         const char *line_prefix)
3794         char *names = pprint_rename(p->one->path, p->two->path);
3796         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3797         free(names);
3798         show_mode_change(file, p, 0, line_prefix);
3801 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3803         FILE *file = opt->file;
3804         char *line_prefix = "";
3806         if (opt->output_prefix) {
3807                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3808                 line_prefix = buf->buf;
3809         }
3811         switch(p->status) {
3812         case DIFF_STATUS_DELETED:
3813                 fputs(line_prefix, file);
3814                 show_file_mode_name(file, "delete", p->one);
3815                 break;
3816         case DIFF_STATUS_ADDED:
3817                 fputs(line_prefix, file);
3818                 show_file_mode_name(file, "create", p->two);
3819                 break;
3820         case DIFF_STATUS_COPIED:
3821                 fputs(line_prefix, file);
3822                 show_rename_copy(file, "copy", p, line_prefix);
3823                 break;
3824         case DIFF_STATUS_RENAMED:
3825                 fputs(line_prefix, file);
3826                 show_rename_copy(file, "rename", p, line_prefix);
3827                 break;
3828         default:
3829                 if (p->score) {
3830                         fprintf(file, "%s rewrite ", line_prefix);
3831                         write_name_quoted(p->two->path, file, ' ');
3832                         fprintf(file, "(%d%%)\n", similarity_index(p));
3833                 }
3834                 show_mode_change(file, p, !p->score, line_prefix);
3835                 break;
3836         }
3839 struct patch_id_t {
3840         git_SHA_CTX *ctx;
3841         int patchlen;
3842 };
3844 static int remove_space(char *line, int len)
3846         int i;
3847         char *dst = line;
3848         unsigned char c;
3850         for (i = 0; i < len; i++)
3851                 if (!isspace((c = line[i])))
3852                         *dst++ = c;
3854         return dst - line;
3857 static void patch_id_consume(void *priv, char *line, unsigned long len)
3859         struct patch_id_t *data = priv;
3860         int new_len;
3862         /* Ignore line numbers when computing the SHA1 of the patch */
3863         if (!prefixcmp(line, "@@ -"))
3864                 return;
3866         new_len = remove_space(line, len);
3868         git_SHA1_Update(data->ctx, line, new_len);
3869         data->patchlen += new_len;
3872 /* returns 0 upon success, and writes result into sha1 */
3873 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3875         struct diff_queue_struct *q = &diff_queued_diff;
3876         int i;
3877         git_SHA_CTX ctx;
3878         struct patch_id_t data;
3879         char buffer[PATH_MAX * 4 + 20];
3881         git_SHA1_Init(&ctx);
3882         memset(&data, 0, sizeof(struct patch_id_t));
3883         data.ctx = &ctx;
3885         for (i = 0; i < q->nr; i++) {
3886                 xpparam_t xpp;
3887                 xdemitconf_t xecfg;
3888                 mmfile_t mf1, mf2;
3889                 struct diff_filepair *p = q->queue[i];
3890                 int len1, len2;
3892                 memset(&xpp, 0, sizeof(xpp));
3893                 memset(&xecfg, 0, sizeof(xecfg));
3894                 if (p->status == 0)
3895                         return error("internal diff status error");
3896                 if (p->status == DIFF_STATUS_UNKNOWN)
3897                         continue;
3898                 if (diff_unmodified_pair(p))
3899                         continue;
3900                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3901                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3902                         continue;
3903                 if (DIFF_PAIR_UNMERGED(p))
3904                         continue;
3906                 diff_fill_sha1_info(p->one);
3907                 diff_fill_sha1_info(p->two);
3908                 if (fill_mmfile(&mf1, p->one) < 0 ||
3909                                 fill_mmfile(&mf2, p->two) < 0)
3910                         return error("unable to read files to diff");
3912                 len1 = remove_space(p->one->path, strlen(p->one->path));
3913                 len2 = remove_space(p->two->path, strlen(p->two->path));
3914                 if (p->one->mode == 0)
3915                         len1 = snprintf(buffer, sizeof(buffer),
3916                                         "diff--gita/%.*sb/%.*s"
3917                                         "newfilemode%06o"
3918                                         "---/dev/null"
3919                                         "+++b/%.*s",
3920                                         len1, p->one->path,
3921                                         len2, p->two->path,
3922                                         p->two->mode,
3923                                         len2, p->two->path);
3924                 else if (p->two->mode == 0)
3925                         len1 = snprintf(buffer, sizeof(buffer),
3926                                         "diff--gita/%.*sb/%.*s"
3927                                         "deletedfilemode%06o"
3928                                         "---a/%.*s"
3929                                         "+++/dev/null",
3930                                         len1, p->one->path,
3931                                         len2, p->two->path,
3932                                         p->one->mode,
3933                                         len1, p->one->path);
3934                 else
3935                         len1 = snprintf(buffer, sizeof(buffer),
3936                                         "diff--gita/%.*sb/%.*s"
3937                                         "---a/%.*s"
3938                                         "+++b/%.*s",
3939                                         len1, p->one->path,
3940                                         len2, p->two->path,
3941                                         len1, p->one->path,
3942                                         len2, p->two->path);
3943                 git_SHA1_Update(&ctx, buffer, len1);
3945                 if (diff_filespec_is_binary(p->one) ||
3946                     diff_filespec_is_binary(p->two)) {
3947                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3948                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3949                         continue;
3950                 }
3952                 xpp.flags = 0;
3953                 xecfg.ctxlen = 3;
3954                 xecfg.flags = 0;
3955                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3956                               &xpp, &xecfg);
3957         }
3959         git_SHA1_Final(sha1, &ctx);
3960         return 0;
3963 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3965         struct diff_queue_struct *q = &diff_queued_diff;
3966         int i;
3967         int result = diff_get_patch_id(options, sha1);
3969         for (i = 0; i < q->nr; i++)
3970                 diff_free_filepair(q->queue[i]);
3972         free(q->queue);
3973         DIFF_QUEUE_CLEAR(q);
3975         return result;
3978 static int is_summary_empty(const struct diff_queue_struct *q)
3980         int i;
3982         for (i = 0; i < q->nr; i++) {
3983                 const struct diff_filepair *p = q->queue[i];
3985                 switch (p->status) {
3986                 case DIFF_STATUS_DELETED:
3987                 case DIFF_STATUS_ADDED:
3988                 case DIFF_STATUS_COPIED:
3989                 case DIFF_STATUS_RENAMED:
3990                         return 0;
3991                 default:
3992                         if (p->score)
3993                                 return 0;
3994                         if (p->one->mode && p->two->mode &&
3995                             p->one->mode != p->two->mode)
3996                                 return 0;
3997                         break;
3998                 }
3999         }
4000         return 1;
4003 static const char rename_limit_warning[] =
4004 "inexact rename detection was skipped due to too many files.";
4006 static const char degrade_cc_to_c_warning[] =
4007 "only found copies from modified paths due to too many files.";
4009 static const char rename_limit_advice[] =
4010 "you may want to set your %s variable to at least "
4011 "%d and retry the command.";
4013 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4015         if (degraded_cc)
4016                 warning(degrade_cc_to_c_warning);
4017         else if (needed)
4018                 warning(rename_limit_warning);
4019         else
4020                 return;
4021         if (0 < needed && needed < 32767)
4022                 warning(rename_limit_advice, varname, needed);
4025 void diff_flush(struct diff_options *options)
4027         struct diff_queue_struct *q = &diff_queued_diff;
4028         int i, output_format = options->output_format;
4029         int separator = 0;
4031         /*
4032          * Order: raw, stat, summary, patch
4033          * or:    name/name-status/checkdiff (other bits clear)
4034          */
4035         if (!q->nr)
4036                 goto free_queue;
4038         if (output_format & (DIFF_FORMAT_RAW |
4039                              DIFF_FORMAT_NAME |
4040                              DIFF_FORMAT_NAME_STATUS |
4041                              DIFF_FORMAT_CHECKDIFF)) {
4042                 for (i = 0; i < q->nr; i++) {
4043                         struct diff_filepair *p = q->queue[i];
4044                         if (check_pair_status(p))
4045                                 flush_one_pair(p, options);
4046                 }
4047                 separator++;
4048         }
4050         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4051                 struct diffstat_t diffstat;
4053                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4054                 for (i = 0; i < q->nr; i++) {
4055                         struct diff_filepair *p = q->queue[i];
4056                         if (check_pair_status(p))
4057                                 diff_flush_stat(p, options, &diffstat);
4058                 }
4059                 if (output_format & DIFF_FORMAT_NUMSTAT)
4060                         show_numstat(&diffstat, options);
4061                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4062                         show_stats(&diffstat, options);
4063                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4064                         show_shortstats(&diffstat, options);
4065                 free_diffstat_info(&diffstat);
4066                 separator++;
4067         }
4068         if (output_format & DIFF_FORMAT_DIRSTAT)
4069                 show_dirstat(options);
4071         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4072                 for (i = 0; i < q->nr; i++) {
4073                         diff_summary(options, q->queue[i]);
4074                 }
4075                 separator++;
4076         }
4078         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4079             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4080             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4081                 /*
4082                  * run diff_flush_patch for the exit status. setting
4083                  * options->file to /dev/null should be safe, becaue we
4084                  * aren't supposed to produce any output anyway.
4085                  */
4086                 if (options->close_file)
4087                         fclose(options->file);
4088                 options->file = fopen("/dev/null", "w");
4089                 if (!options->file)
4090                         die_errno("Could not open /dev/null");
4091                 options->close_file = 1;
4092                 for (i = 0; i < q->nr; i++) {
4093                         struct diff_filepair *p = q->queue[i];
4094                         if (check_pair_status(p))
4095                                 diff_flush_patch(p, options);
4096                         if (options->found_changes)
4097                                 break;
4098                 }
4099         }
4101         if (output_format & DIFF_FORMAT_PATCH) {
4102                 if (separator) {
4103                         putc(options->line_termination, options->file);
4104                         if (options->stat_sep) {
4105                                 /* attach patch instead of inline */
4106                                 fputs(options->stat_sep, options->file);
4107                         }
4108                 }
4110                 for (i = 0; i < q->nr; i++) {
4111                         struct diff_filepair *p = q->queue[i];
4112                         if (check_pair_status(p))
4113                                 diff_flush_patch(p, options);
4114                 }
4115         }
4117         if (output_format & DIFF_FORMAT_CALLBACK)
4118                 options->format_callback(q, options, options->format_callback_data);
4120         for (i = 0; i < q->nr; i++)
4121                 diff_free_filepair(q->queue[i]);
4122 free_queue:
4123         free(q->queue);
4124         DIFF_QUEUE_CLEAR(q);
4125         if (options->close_file)
4126                 fclose(options->file);
4128         /*
4129          * Report the content-level differences with HAS_CHANGES;
4130          * diff_addremove/diff_change does not set the bit when
4131          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4132          */
4133         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4134                 if (options->found_changes)
4135                         DIFF_OPT_SET(options, HAS_CHANGES);
4136                 else
4137                         DIFF_OPT_CLR(options, HAS_CHANGES);
4138         }
4141 static void diffcore_apply_filter(const char *filter)
4143         int i;
4144         struct diff_queue_struct *q = &diff_queued_diff;
4145         struct diff_queue_struct outq;
4146         DIFF_QUEUE_CLEAR(&outq);
4148         if (!filter)
4149                 return;
4151         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4152                 int found;
4153                 for (i = found = 0; !found && i < q->nr; i++) {
4154                         struct diff_filepair *p = q->queue[i];
4155                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4156                              ((p->score &&
4157                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4158                               (!p->score &&
4159                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4160                             ((p->status != DIFF_STATUS_MODIFIED) &&
4161                              strchr(filter, p->status)))
4162                                 found++;
4163                 }
4164                 if (found)
4165                         return;
4167                 /* otherwise we will clear the whole queue
4168                  * by copying the empty outq at the end of this
4169                  * function, but first clear the current entries
4170                  * in the queue.
4171                  */
4172                 for (i = 0; i < q->nr; i++)
4173                         diff_free_filepair(q->queue[i]);
4174         }
4175         else {
4176                 /* Only the matching ones */
4177                 for (i = 0; i < q->nr; i++) {
4178                         struct diff_filepair *p = q->queue[i];
4180                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4181                              ((p->score &&
4182                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4183                               (!p->score &&
4184                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4185                             ((p->status != DIFF_STATUS_MODIFIED) &&
4186                              strchr(filter, p->status)))
4187                                 diff_q(&outq, p);
4188                         else
4189                                 diff_free_filepair(p);
4190                 }
4191         }
4192         free(q->queue);
4193         *q = outq;
4196 /* Check whether two filespecs with the same mode and size are identical */
4197 static int diff_filespec_is_identical(struct diff_filespec *one,
4198                                       struct diff_filespec *two)
4200         if (S_ISGITLINK(one->mode))
4201                 return 0;
4202         if (diff_populate_filespec(one, 0))
4203                 return 0;
4204         if (diff_populate_filespec(two, 0))
4205                 return 0;
4206         return !memcmp(one->data, two->data, one->size);
4209 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4211         int i;
4212         struct diff_queue_struct *q = &diff_queued_diff;
4213         struct diff_queue_struct outq;
4214         DIFF_QUEUE_CLEAR(&outq);
4216         for (i = 0; i < q->nr; i++) {
4217                 struct diff_filepair *p = q->queue[i];
4219                 /*
4220                  * 1. Entries that come from stat info dirtiness
4221                  *    always have both sides (iow, not create/delete),
4222                  *    one side of the object name is unknown, with
4223                  *    the same mode and size.  Keep the ones that
4224                  *    do not match these criteria.  They have real
4225                  *    differences.
4226                  *
4227                  * 2. At this point, the file is known to be modified,
4228                  *    with the same mode and size, and the object
4229                  *    name of one side is unknown.  Need to inspect
4230                  *    the identical contents.
4231                  */
4232                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4233                     !DIFF_FILE_VALID(p->two) ||
4234                     (p->one->sha1_valid && p->two->sha1_valid) ||
4235                     (p->one->mode != p->two->mode) ||
4236                     diff_populate_filespec(p->one, 1) ||
4237                     diff_populate_filespec(p->two, 1) ||
4238                     (p->one->size != p->two->size) ||
4239                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4240                         diff_q(&outq, p);
4241                 else {
4242                         /*
4243                          * The caller can subtract 1 from skip_stat_unmatch
4244                          * to determine how many paths were dirty only
4245                          * due to stat info mismatch.
4246                          */
4247                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4248                                 diffopt->skip_stat_unmatch++;
4249                         diff_free_filepair(p);
4250                 }
4251         }
4252         free(q->queue);
4253         *q = outq;
4256 static int diffnamecmp(const void *a_, const void *b_)
4258         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4259         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4260         const char *name_a, *name_b;
4262         name_a = a->one ? a->one->path : a->two->path;
4263         name_b = b->one ? b->one->path : b->two->path;
4264         return strcmp(name_a, name_b);
4267 void diffcore_fix_diff_index(struct diff_options *options)
4269         struct diff_queue_struct *q = &diff_queued_diff;
4270         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4273 void diffcore_std(struct diff_options *options)
4275         if (options->skip_stat_unmatch)
4276                 diffcore_skip_stat_unmatch(options);
4277         if (!options->found_follow) {
4278                 /* See try_to_follow_renames() in tree-diff.c */
4279                 if (options->break_opt != -1)
4280                         diffcore_break(options->break_opt);
4281                 if (options->detect_rename)
4282                         diffcore_rename(options);
4283                 if (options->break_opt != -1)
4284                         diffcore_merge_broken();
4285         }
4286         if (options->pickaxe)
4287                 diffcore_pickaxe(options);
4288         if (options->orderfile)
4289                 diffcore_order(options->orderfile);
4290         if (!options->found_follow)
4291                 /* See try_to_follow_renames() in tree-diff.c */
4292                 diff_resolve_rename_copy();
4293         diffcore_apply_filter(options->filter);
4295         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4296                 DIFF_OPT_SET(options, HAS_CHANGES);
4297         else
4298                 DIFF_OPT_CLR(options, HAS_CHANGES);
4300         options->found_follow = 0;
4303 int diff_result_code(struct diff_options *opt, int status)
4305         int result = 0;
4307         diff_warn_rename_limit("diff.renamelimit",
4308                                opt->needed_rename_limit,
4309                                opt->degraded_cc_to_c);
4310         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4311             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4312                 return status;
4313         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4314             DIFF_OPT_TST(opt, HAS_CHANGES))
4315                 result |= 01;
4316         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4317             DIFF_OPT_TST(opt, CHECK_FAILED))
4318                 result |= 02;
4319         return result;
4322 /*
4323  * Shall changes to this submodule be ignored?
4324  *
4325  * Submodule changes can be configured to be ignored separately for each path,
4326  * but that configuration can be overridden from the command line.
4327  */
4328 static int is_submodule_ignored(const char *path, struct diff_options *options)
4330         int ignored = 0;
4331         unsigned orig_flags = options->flags;
4332         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4333                 set_diffopt_flags_from_submodule_config(options, path);
4334         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4335                 ignored = 1;
4336         options->flags = orig_flags;
4337         return ignored;
4340 void diff_addremove(struct diff_options *options,
4341                     int addremove, unsigned mode,
4342                     const unsigned char *sha1,
4343                     const char *concatpath, unsigned dirty_submodule)
4345         struct diff_filespec *one, *two;
4347         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4348                 return;
4350         /* This may look odd, but it is a preparation for
4351          * feeding "there are unchanged files which should
4352          * not produce diffs, but when you are doing copy
4353          * detection you would need them, so here they are"
4354          * entries to the diff-core.  They will be prefixed
4355          * with something like '=' or '*' (I haven't decided
4356          * which but should not make any difference).
4357          * Feeding the same new and old to diff_change()
4358          * also has the same effect.
4359          * Before the final output happens, they are pruned after
4360          * merged into rename/copy pairs as appropriate.
4361          */
4362         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4363                 addremove = (addremove == '+' ? '-' :
4364                              addremove == '-' ? '+' : addremove);
4366         if (options->prefix &&
4367             strncmp(concatpath, options->prefix, options->prefix_length))
4368                 return;
4370         one = alloc_filespec(concatpath);
4371         two = alloc_filespec(concatpath);
4373         if (addremove != '+')
4374                 fill_filespec(one, sha1, mode);
4375         if (addremove != '-') {
4376                 fill_filespec(two, sha1, mode);
4377                 two->dirty_submodule = dirty_submodule;
4378         }
4380         diff_queue(&diff_queued_diff, one, two);
4381         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4382                 DIFF_OPT_SET(options, HAS_CHANGES);
4385 void diff_change(struct diff_options *options,
4386                  unsigned old_mode, unsigned new_mode,
4387                  const unsigned char *old_sha1,
4388                  const unsigned char *new_sha1,
4389                  const char *concatpath,
4390                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4392         struct diff_filespec *one, *two;
4394         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4395             is_submodule_ignored(concatpath, options))
4396                 return;
4398         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4399                 unsigned tmp;
4400                 const unsigned char *tmp_c;
4401                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4402                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4403                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4404                         new_dirty_submodule = tmp;
4405         }
4407         if (options->prefix &&
4408             strncmp(concatpath, options->prefix, options->prefix_length))
4409                 return;
4411         one = alloc_filespec(concatpath);
4412         two = alloc_filespec(concatpath);
4413         fill_filespec(one, old_sha1, old_mode);
4414         fill_filespec(two, new_sha1, new_mode);
4415         one->dirty_submodule = old_dirty_submodule;
4416         two->dirty_submodule = new_dirty_submodule;
4418         diff_queue(&diff_queued_diff, one, two);
4419         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4420                 DIFF_OPT_SET(options, HAS_CHANGES);
4423 void diff_unmerge(struct diff_options *options,
4424                   const char *path,
4425                   unsigned mode, const unsigned char *sha1)
4427         struct diff_filespec *one, *two;
4429         if (options->prefix &&
4430             strncmp(path, options->prefix, options->prefix_length))
4431                 return;
4433         one = alloc_filespec(path);
4434         two = alloc_filespec(path);
4435         fill_filespec(one, sha1, mode);
4436         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4439 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4440                 size_t *outsize)
4442         struct diff_tempfile *temp;
4443         const char *argv[3];
4444         const char **arg = argv;
4445         struct child_process child;
4446         struct strbuf buf = STRBUF_INIT;
4447         int err = 0;
4449         temp = prepare_temp_file(spec->path, spec);
4450         *arg++ = pgm;
4451         *arg++ = temp->name;
4452         *arg = NULL;
4454         memset(&child, 0, sizeof(child));
4455         child.use_shell = 1;
4456         child.argv = argv;
4457         child.out = -1;
4458         if (start_command(&child)) {
4459                 remove_tempfile();
4460                 return NULL;
4461         }
4463         if (strbuf_read(&buf, child.out, 0) < 0)
4464                 err = error("error reading from textconv command '%s'", pgm);
4465         close(child.out);
4467         if (finish_command(&child) || err) {
4468                 strbuf_release(&buf);
4469                 remove_tempfile();
4470                 return NULL;
4471         }
4472         remove_tempfile();
4474         return strbuf_detach(&buf, outsize);
4477 size_t fill_textconv(struct userdiff_driver *driver,
4478                      struct diff_filespec *df,
4479                      char **outbuf)
4481         size_t size;
4483         if (!driver || !driver->textconv) {
4484                 if (!DIFF_FILE_VALID(df)) {
4485                         *outbuf = "";
4486                         return 0;
4487                 }
4488                 if (diff_populate_filespec(df, 0))
4489                         die("unable to read files to diff");
4490                 *outbuf = df->data;
4491                 return df->size;
4492         }
4494         if (driver->textconv_cache && df->sha1_valid) {
4495                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4496                                           &size);
4497                 if (*outbuf)
4498                         return size;
4499         }
4501         *outbuf = run_textconv(driver->textconv, df, &size);
4502         if (!*outbuf)
4503                 die("unable to read files to diff");
4505         if (driver->textconv_cache && df->sha1_valid) {
4506                 /* ignore errors, as we might be in a readonly repository */
4507                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4508                                 size);
4509                 /*
4510                  * we could save up changes and flush them all at the end,
4511                  * but we would need an extra call after all diffing is done.
4512                  * Since generating a cache entry is the slow path anyway,
4513                  * this extra overhead probably isn't a big deal.
4514                  */
4515                 notes_cache_write(driver->textconv_cache);
4516         }
4518         return size;