Code

Merge branch 'jc/rename-degrade-cc-to-c' into maint
[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "delta.h"
9 #include "xdiff-interface.h"
10 #include "color.h"
11 #include "attr.h"
12 #include "run-command.h"
13 #include "utf8.h"
14 #include "userdiff.h"
15 #include "sigchain.h"
16 #include "submodule.h"
17 #include "ll-merge.h"
19 #ifdef NO_FAST_WORKING_DIRECTORY
20 #define FAST_WORKING_DIRECTORY 0
21 #else
22 #define FAST_WORKING_DIRECTORY 1
23 #endif
25 static int diff_detect_rename_default;
26 static int diff_rename_limit_default = 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         print_line_count(o->file, lc_a);
585         fprintf(o->file, " +");
586         print_line_count(o->file, lc_b);
587         fprintf(o->file, " @@%s\n", reset);
588         if (lc_a)
589                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
590         if (lc_b)
591                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
592         if (textconv_one)
593                 free((char *)data_one);
594         if (textconv_two)
595                 free((char *)data_two);
598 struct diff_words_buffer {
599         mmfile_t text;
600         long alloc;
601         struct diff_words_orig {
602                 const char *begin, *end;
603         } *orig;
604         int orig_nr, orig_alloc;
605 };
607 static void diff_words_append(char *line, unsigned long len,
608                 struct diff_words_buffer *buffer)
610         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
611         line++;
612         len--;
613         memcpy(buffer->text.ptr + buffer->text.size, line, len);
614         buffer->text.size += len;
615         buffer->text.ptr[buffer->text.size] = '\0';
618 struct diff_words_style_elem {
619         const char *prefix;
620         const char *suffix;
621         const char *color; /* NULL; filled in by the setup code if
622                             * color is enabled */
623 };
625 struct diff_words_style {
626         enum diff_words_type type;
627         struct diff_words_style_elem new, old, ctx;
628         const char *newline;
629 };
631 static struct diff_words_style diff_words_styles[] = {
632         { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
633         { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
634         { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
635 };
637 struct diff_words_data {
638         struct diff_words_buffer minus, plus;
639         const char *current_plus;
640         int last_minus;
641         struct diff_options *opt;
642         regex_t *word_regex;
643         enum diff_words_type type;
644         struct diff_words_style *style;
645 };
647 static int fn_out_diff_words_write_helper(FILE *fp,
648                                           struct diff_words_style_elem *st_el,
649                                           const char *newline,
650                                           size_t count, const char *buf,
651                                           const char *line_prefix)
653         int print = 0;
655         while (count) {
656                 char *p = memchr(buf, '\n', count);
657                 if (print)
658                         fputs(line_prefix, fp);
659                 if (p != buf) {
660                         if (st_el->color && fputs(st_el->color, fp) < 0)
661                                 return -1;
662                         if (fputs(st_el->prefix, fp) < 0 ||
663                             fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
664                             fputs(st_el->suffix, fp) < 0)
665                                 return -1;
666                         if (st_el->color && *st_el->color
667                             && fputs(GIT_COLOR_RESET, fp) < 0)
668                                 return -1;
669                 }
670                 if (!p)
671                         return 0;
672                 if (fputs(newline, fp) < 0)
673                         return -1;
674                 count -= p + 1 - buf;
675                 buf = p + 1;
676                 print = 1;
677         }
678         return 0;
681 /*
682  * '--color-words' algorithm can be described as:
683  *
684  *   1. collect a the minus/plus lines of a diff hunk, divided into
685  *      minus-lines and plus-lines;
686  *
687  *   2. break both minus-lines and plus-lines into words and
688  *      place them into two mmfile_t with one word for each line;
689  *
690  *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
691  *
692  * And for the common parts of the both file, we output the plus side text.
693  * diff_words->current_plus is used to trace the current position of the plus file
694  * which printed. diff_words->last_minus is used to trace the last minus word
695  * printed.
696  *
697  * For '--graph' to work with '--color-words', we need to output the graph prefix
698  * on each line of color words output. Generally, there are two conditions on
699  * which we should output the prefix.
700  *
701  *   1. diff_words->last_minus == 0 &&
702  *      diff_words->current_plus == diff_words->plus.text.ptr
703  *
704  *      that is: the plus text must start as a new line, and if there is no minus
705  *      word printed, a graph prefix must be printed.
706  *
707  *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
708  *      *(diff_words->current_plus - 1) == '\n'
709  *
710  *      that is: a graph prefix must be printed following a '\n'
711  */
712 static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
714         if ((diff_words->last_minus == 0 &&
715                 diff_words->current_plus == diff_words->plus.text.ptr) ||
716                 (diff_words->current_plus > diff_words->plus.text.ptr &&
717                 *(diff_words->current_plus - 1) == '\n')) {
718                 return 1;
719         } else {
720                 return 0;
721         }
724 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
726         struct diff_words_data *diff_words = priv;
727         struct diff_words_style *style = diff_words->style;
728         int minus_first, minus_len, plus_first, plus_len;
729         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
730         struct diff_options *opt = diff_words->opt;
731         struct strbuf *msgbuf;
732         char *line_prefix = "";
734         if (line[0] != '@' || parse_hunk_header(line, len,
735                         &minus_first, &minus_len, &plus_first, &plus_len))
736                 return;
738         assert(opt);
739         if (opt->output_prefix) {
740                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
741                 line_prefix = msgbuf->buf;
742         }
744         /* POSIX requires that first be decremented by one if len == 0... */
745         if (minus_len) {
746                 minus_begin = diff_words->minus.orig[minus_first].begin;
747                 minus_end =
748                         diff_words->minus.orig[minus_first + minus_len - 1].end;
749         } else
750                 minus_begin = minus_end =
751                         diff_words->minus.orig[minus_first].end;
753         if (plus_len) {
754                 plus_begin = diff_words->plus.orig[plus_first].begin;
755                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
756         } else
757                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
759         if (color_words_output_graph_prefix(diff_words)) {
760                 fputs(line_prefix, diff_words->opt->file);
761         }
762         if (diff_words->current_plus != plus_begin) {
763                 fn_out_diff_words_write_helper(diff_words->opt->file,
764                                 &style->ctx, style->newline,
765                                 plus_begin - diff_words->current_plus,
766                                 diff_words->current_plus, line_prefix);
767                 if (*(plus_begin - 1) == '\n')
768                         fputs(line_prefix, diff_words->opt->file);
769         }
770         if (minus_begin != minus_end) {
771                 fn_out_diff_words_write_helper(diff_words->opt->file,
772                                 &style->old, style->newline,
773                                 minus_end - minus_begin, minus_begin,
774                                 line_prefix);
775         }
776         if (plus_begin != plus_end) {
777                 fn_out_diff_words_write_helper(diff_words->opt->file,
778                                 &style->new, style->newline,
779                                 plus_end - plus_begin, plus_begin,
780                                 line_prefix);
781         }
783         diff_words->current_plus = plus_end;
784         diff_words->last_minus = minus_first;
787 /* This function starts looking at *begin, and returns 0 iff a word was found. */
788 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
789                 int *begin, int *end)
791         if (word_regex && *begin < buffer->size) {
792                 regmatch_t match[1];
793                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
794                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
795                                         '\n', match[0].rm_eo - match[0].rm_so);
796                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
797                         *begin += match[0].rm_so;
798                         return *begin >= *end;
799                 }
800                 return -1;
801         }
803         /* find the next word */
804         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
805                 (*begin)++;
806         if (*begin >= buffer->size)
807                 return -1;
809         /* find the end of the word */
810         *end = *begin + 1;
811         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
812                 (*end)++;
814         return 0;
817 /*
818  * This function splits the words in buffer->text, stores the list with
819  * newline separator into out, and saves the offsets of the original words
820  * in buffer->orig.
821  */
822 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
823                 regex_t *word_regex)
825         int i, j;
826         long alloc = 0;
828         out->size = 0;
829         out->ptr = NULL;
831         /* fake an empty "0th" word */
832         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
833         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
834         buffer->orig_nr = 1;
836         for (i = 0; i < buffer->text.size; i++) {
837                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
838                         return;
840                 /* store original boundaries */
841                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
842                                 buffer->orig_alloc);
843                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
844                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
845                 buffer->orig_nr++;
847                 /* store one word */
848                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
849                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
850                 out->ptr[out->size + j - i] = '\n';
851                 out->size += j - i + 1;
853                 i = j - 1;
854         }
857 /* this executes the word diff on the accumulated buffers */
858 static void diff_words_show(struct diff_words_data *diff_words)
860         xpparam_t xpp;
861         xdemitconf_t xecfg;
862         mmfile_t minus, plus;
863         struct diff_words_style *style = diff_words->style;
865         struct diff_options *opt = diff_words->opt;
866         struct strbuf *msgbuf;
867         char *line_prefix = "";
869         assert(opt);
870         if (opt->output_prefix) {
871                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
872                 line_prefix = msgbuf->buf;
873         }
875         /* special case: only removal */
876         if (!diff_words->plus.text.size) {
877                 fputs(line_prefix, diff_words->opt->file);
878                 fn_out_diff_words_write_helper(diff_words->opt->file,
879                         &style->old, style->newline,
880                         diff_words->minus.text.size,
881                         diff_words->minus.text.ptr, line_prefix);
882                 diff_words->minus.text.size = 0;
883                 return;
884         }
886         diff_words->current_plus = diff_words->plus.text.ptr;
887         diff_words->last_minus = 0;
889         memset(&xpp, 0, sizeof(xpp));
890         memset(&xecfg, 0, sizeof(xecfg));
891         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
892         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
893         xpp.flags = 0;
894         /* as only the hunk header will be parsed, we need a 0-context */
895         xecfg.ctxlen = 0;
896         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
897                       &xpp, &xecfg);
898         free(minus.ptr);
899         free(plus.ptr);
900         if (diff_words->current_plus != diff_words->plus.text.ptr +
901                         diff_words->plus.text.size) {
902                 if (color_words_output_graph_prefix(diff_words))
903                         fputs(line_prefix, diff_words->opt->file);
904                 fn_out_diff_words_write_helper(diff_words->opt->file,
905                         &style->ctx, style->newline,
906                         diff_words->plus.text.ptr + diff_words->plus.text.size
907                         - diff_words->current_plus, diff_words->current_plus,
908                         line_prefix);
909         }
910         diff_words->minus.text.size = diff_words->plus.text.size = 0;
913 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
914 static void diff_words_flush(struct emit_callback *ecbdata)
916         if (ecbdata->diff_words->minus.text.size ||
917             ecbdata->diff_words->plus.text.size)
918                 diff_words_show(ecbdata->diff_words);
921 static void free_diff_words_data(struct emit_callback *ecbdata)
923         if (ecbdata->diff_words) {
924                 diff_words_flush(ecbdata);
925                 free (ecbdata->diff_words->minus.text.ptr);
926                 free (ecbdata->diff_words->minus.orig);
927                 free (ecbdata->diff_words->plus.text.ptr);
928                 free (ecbdata->diff_words->plus.orig);
929                 if (ecbdata->diff_words->word_regex) {
930                         regfree(ecbdata->diff_words->word_regex);
931                         free(ecbdata->diff_words->word_regex);
932                 }
933                 free(ecbdata->diff_words);
934                 ecbdata->diff_words = NULL;
935         }
938 const char *diff_get_color(int diff_use_color, enum color_diff ix)
940         if (diff_use_color)
941                 return diff_colors[ix];
942         return "";
945 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
947         const char *cp;
948         unsigned long allot;
949         size_t l = len;
951         if (ecb->truncate)
952                 return ecb->truncate(line, len);
953         cp = line;
954         allot = l;
955         while (0 < l) {
956                 (void) utf8_width(&cp, &l);
957                 if (!cp)
958                         break; /* truncated in the middle? */
959         }
960         return allot - l;
963 static void find_lno(const char *line, struct emit_callback *ecbdata)
965         const char *p;
966         ecbdata->lno_in_preimage = 0;
967         ecbdata->lno_in_postimage = 0;
968         p = strchr(line, '-');
969         if (!p)
970                 return; /* cannot happen */
971         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
972         p = strchr(p, '+');
973         if (!p)
974                 return; /* cannot happen */
975         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
978 static void fn_out_consume(void *priv, char *line, unsigned long len)
980         struct emit_callback *ecbdata = priv;
981         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
982         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
983         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
984         struct diff_options *o = ecbdata->opt;
985         char *line_prefix = "";
986         struct strbuf *msgbuf;
988         if (o && o->output_prefix) {
989                 msgbuf = o->output_prefix(o, o->output_prefix_data);
990                 line_prefix = msgbuf->buf;
991         }
993         if (ecbdata->header) {
994                 fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
995                 strbuf_reset(ecbdata->header);
996                 ecbdata->header = NULL;
997         }
998         *(ecbdata->found_changesp) = 1;
1000         if (ecbdata->label_path[0]) {
1001                 const char *name_a_tab, *name_b_tab;
1003                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1004                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1006                 fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1007                         line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1008                 fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1009                         line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1010                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1011         }
1013         if (diff_suppress_blank_empty
1014             && len == 2 && line[0] == ' ' && line[1] == '\n') {
1015                 line[0] = '\n';
1016                 len = 1;
1017         }
1019         if (line[0] == '@') {
1020                 if (ecbdata->diff_words)
1021                         diff_words_flush(ecbdata);
1022                 len = sane_truncate_line(ecbdata, line, len);
1023                 find_lno(line, ecbdata);
1024                 emit_hunk_header(ecbdata, line, len);
1025                 if (line[len-1] != '\n')
1026                         putc('\n', ecbdata->opt->file);
1027                 return;
1028         }
1030         if (len < 1) {
1031                 emit_line(ecbdata->opt, reset, reset, line, len);
1032                 if (ecbdata->diff_words
1033                     && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1034                         fputs("~\n", ecbdata->opt->file);
1035                 return;
1036         }
1038         if (ecbdata->diff_words) {
1039                 if (line[0] == '-') {
1040                         diff_words_append(line, len,
1041                                           &ecbdata->diff_words->minus);
1042                         return;
1043                 } else if (line[0] == '+') {
1044                         diff_words_append(line, len,
1045                                           &ecbdata->diff_words->plus);
1046                         return;
1047                 }
1048                 diff_words_flush(ecbdata);
1049                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1050                         emit_line(ecbdata->opt, plain, reset, line, len);
1051                         fputs("~\n", ecbdata->opt->file);
1052                 } else {
1053                         /*
1054                          * Skip the prefix character, if any.  With
1055                          * diff_suppress_blank_empty, there may be
1056                          * none.
1057                          */
1058                         if (line[0] != '\n') {
1059                               line++;
1060                               len--;
1061                         }
1062                         emit_line(ecbdata->opt, plain, reset, line, len);
1063                 }
1064                 return;
1065         }
1067         if (line[0] != '+') {
1068                 const char *color =
1069                         diff_get_color(ecbdata->color_diff,
1070                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1071                 ecbdata->lno_in_preimage++;
1072                 if (line[0] == ' ')
1073                         ecbdata->lno_in_postimage++;
1074                 emit_line(ecbdata->opt, color, reset, line, len);
1075         } else {
1076                 ecbdata->lno_in_postimage++;
1077                 emit_add_line(reset, ecbdata, line + 1, len - 1);
1078         }
1081 static char *pprint_rename(const char *a, const char *b)
1083         const char *old = a;
1084         const char *new = b;
1085         struct strbuf name = STRBUF_INIT;
1086         int pfx_length, sfx_length;
1087         int len_a = strlen(a);
1088         int len_b = strlen(b);
1089         int a_midlen, b_midlen;
1090         int qlen_a = quote_c_style(a, NULL, NULL, 0);
1091         int qlen_b = quote_c_style(b, NULL, NULL, 0);
1093         if (qlen_a || qlen_b) {
1094                 quote_c_style(a, &name, NULL, 0);
1095                 strbuf_addstr(&name, " => ");
1096                 quote_c_style(b, &name, NULL, 0);
1097                 return strbuf_detach(&name, NULL);
1098         }
1100         /* Find common prefix */
1101         pfx_length = 0;
1102         while (*old && *new && *old == *new) {
1103                 if (*old == '/')
1104                         pfx_length = old - a + 1;
1105                 old++;
1106                 new++;
1107         }
1109         /* Find common suffix */
1110         old = a + len_a;
1111         new = b + len_b;
1112         sfx_length = 0;
1113         while (a <= old && b <= new && *old == *new) {
1114                 if (*old == '/')
1115                         sfx_length = len_a - (old - a);
1116                 old--;
1117                 new--;
1118         }
1120         /*
1121          * pfx{mid-a => mid-b}sfx
1122          * {pfx-a => pfx-b}sfx
1123          * pfx{sfx-a => sfx-b}
1124          * name-a => name-b
1125          */
1126         a_midlen = len_a - pfx_length - sfx_length;
1127         b_midlen = len_b - pfx_length - sfx_length;
1128         if (a_midlen < 0)
1129                 a_midlen = 0;
1130         if (b_midlen < 0)
1131                 b_midlen = 0;
1133         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1134         if (pfx_length + sfx_length) {
1135                 strbuf_add(&name, a, pfx_length);
1136                 strbuf_addch(&name, '{');
1137         }
1138         strbuf_add(&name, a + pfx_length, a_midlen);
1139         strbuf_addstr(&name, " => ");
1140         strbuf_add(&name, b + pfx_length, b_midlen);
1141         if (pfx_length + sfx_length) {
1142                 strbuf_addch(&name, '}');
1143                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1144         }
1145         return strbuf_detach(&name, NULL);
1148 struct diffstat_t {
1149         int nr;
1150         int alloc;
1151         struct diffstat_file {
1152                 char *from_name;
1153                 char *name;
1154                 char *print_name;
1155                 unsigned is_unmerged:1;
1156                 unsigned is_binary:1;
1157                 unsigned is_renamed:1;
1158                 uintmax_t added, deleted;
1159         } **files;
1160 };
1162 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1163                                           const char *name_a,
1164                                           const char *name_b)
1166         struct diffstat_file *x;
1167         x = xcalloc(sizeof (*x), 1);
1168         if (diffstat->nr == diffstat->alloc) {
1169                 diffstat->alloc = alloc_nr(diffstat->alloc);
1170                 diffstat->files = xrealloc(diffstat->files,
1171                                 diffstat->alloc * sizeof(x));
1172         }
1173         diffstat->files[diffstat->nr++] = x;
1174         if (name_b) {
1175                 x->from_name = xstrdup(name_a);
1176                 x->name = xstrdup(name_b);
1177                 x->is_renamed = 1;
1178         }
1179         else {
1180                 x->from_name = NULL;
1181                 x->name = xstrdup(name_a);
1182         }
1183         return x;
1186 static void diffstat_consume(void *priv, char *line, unsigned long len)
1188         struct diffstat_t *diffstat = priv;
1189         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1191         if (line[0] == '+')
1192                 x->added++;
1193         else if (line[0] == '-')
1194                 x->deleted++;
1197 const char mime_boundary_leader[] = "------------";
1199 static int scale_linear(int it, int width, int max_change)
1201         /*
1202          * make sure that at least one '-' is printed if there were deletions,
1203          * and likewise for '+'.
1204          */
1205         if (max_change < 2)
1206                 return it;
1207         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1210 static void show_name(FILE *file,
1211                       const char *prefix, const char *name, int len)
1213         fprintf(file, " %s%-*s |", prefix, len, name);
1216 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1218         if (cnt <= 0)
1219                 return;
1220         fprintf(file, "%s", set);
1221         while (cnt--)
1222                 putc(ch, file);
1223         fprintf(file, "%s", reset);
1226 static void fill_print_name(struct diffstat_file *file)
1228         char *pname;
1230         if (file->print_name)
1231                 return;
1233         if (!file->is_renamed) {
1234                 struct strbuf buf = STRBUF_INIT;
1235                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1236                         pname = strbuf_detach(&buf, NULL);
1237                 } else {
1238                         pname = file->name;
1239                         strbuf_release(&buf);
1240                 }
1241         } else {
1242                 pname = pprint_rename(file->from_name, file->name);
1243         }
1244         file->print_name = pname;
1247 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1249         int i, len, add, del, adds = 0, dels = 0;
1250         uintmax_t max_change = 0, max_len = 0;
1251         int total_files = data->nr;
1252         int width, name_width;
1253         const char *reset, *add_c, *del_c;
1254         const char *line_prefix = "";
1255         struct strbuf *msg = NULL;
1257         if (data->nr == 0)
1258                 return;
1260         if (options->output_prefix) {
1261                 msg = options->output_prefix(options, options->output_prefix_data);
1262                 line_prefix = msg->buf;
1263         }
1265         width = options->stat_width ? options->stat_width : 80;
1266         name_width = options->stat_name_width ? options->stat_name_width : 50;
1268         /* Sanity: give at least 5 columns to the graph,
1269          * but leave at least 10 columns for the name.
1270          */
1271         if (width < 25)
1272                 width = 25;
1273         if (name_width < 10)
1274                 name_width = 10;
1275         else if (width < name_width + 15)
1276                 name_width = width - 15;
1278         /* Find the longest filename and max number of changes */
1279         reset = diff_get_color_opt(options, DIFF_RESET);
1280         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1281         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1283         for (i = 0; i < data->nr; i++) {
1284                 struct diffstat_file *file = data->files[i];
1285                 uintmax_t change = file->added + file->deleted;
1286                 fill_print_name(file);
1287                 len = strlen(file->print_name);
1288                 if (max_len < len)
1289                         max_len = len;
1291                 if (file->is_binary || file->is_unmerged)
1292                         continue;
1293                 if (max_change < change)
1294                         max_change = change;
1295         }
1297         /* Compute the width of the graph part;
1298          * 10 is for one blank at the beginning of the line plus
1299          * " | count " between the name and the graph.
1300          *
1301          * From here on, name_width is the width of the name area,
1302          * and width is the width of the graph area.
1303          */
1304         name_width = (name_width < max_len) ? name_width : max_len;
1305         if (width < (name_width + 10) + max_change)
1306                 width = width - (name_width + 10);
1307         else
1308                 width = max_change;
1310         for (i = 0; i < data->nr; i++) {
1311                 const char *prefix = "";
1312                 char *name = data->files[i]->print_name;
1313                 uintmax_t added = data->files[i]->added;
1314                 uintmax_t deleted = data->files[i]->deleted;
1315                 int name_len;
1317                 /*
1318                  * "scale" the filename
1319                  */
1320                 len = name_width;
1321                 name_len = strlen(name);
1322                 if (name_width < name_len) {
1323                         char *slash;
1324                         prefix = "...";
1325                         len -= 3;
1326                         name += name_len - len;
1327                         slash = strchr(name, '/');
1328                         if (slash)
1329                                 name = slash;
1330                 }
1332                 if (data->files[i]->is_binary) {
1333                         fprintf(options->file, "%s", line_prefix);
1334                         show_name(options->file, prefix, name, len);
1335                         fprintf(options->file, "  Bin ");
1336                         fprintf(options->file, "%s%"PRIuMAX"%s",
1337                                 del_c, deleted, reset);
1338                         fprintf(options->file, " -> ");
1339                         fprintf(options->file, "%s%"PRIuMAX"%s",
1340                                 add_c, added, reset);
1341                         fprintf(options->file, " bytes");
1342                         fprintf(options->file, "\n");
1343                         continue;
1344                 }
1345                 else if (data->files[i]->is_unmerged) {
1346                         fprintf(options->file, "%s", line_prefix);
1347                         show_name(options->file, prefix, name, len);
1348                         fprintf(options->file, "  Unmerged\n");
1349                         continue;
1350                 }
1351                 else if (!data->files[i]->is_renamed &&
1352                          (added + deleted == 0)) {
1353                         total_files--;
1354                         continue;
1355                 }
1357                 /*
1358                  * scale the add/delete
1359                  */
1360                 add = added;
1361                 del = deleted;
1362                 adds += add;
1363                 dels += del;
1365                 if (width <= max_change) {
1366                         add = scale_linear(add, width, max_change);
1367                         del = scale_linear(del, width, max_change);
1368                 }
1369                 fprintf(options->file, "%s", line_prefix);
1370                 show_name(options->file, prefix, name, len);
1371                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1372                                 added + deleted ? " " : "");
1373                 show_graph(options->file, '+', add, add_c, reset);
1374                 show_graph(options->file, '-', del, del_c, reset);
1375                 fprintf(options->file, "\n");
1376         }
1377         fprintf(options->file, "%s", line_prefix);
1378         fprintf(options->file,
1379                " %d files changed, %d insertions(+), %d deletions(-)\n",
1380                total_files, adds, dels);
1383 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1385         int i, adds = 0, dels = 0, total_files = data->nr;
1387         if (data->nr == 0)
1388                 return;
1390         for (i = 0; i < data->nr; i++) {
1391                 if (!data->files[i]->is_binary &&
1392                     !data->files[i]->is_unmerged) {
1393                         int added = data->files[i]->added;
1394                         int deleted= data->files[i]->deleted;
1395                         if (!data->files[i]->is_renamed &&
1396                             (added + deleted == 0)) {
1397                                 total_files--;
1398                         } else {
1399                                 adds += added;
1400                                 dels += deleted;
1401                         }
1402                 }
1403         }
1404         if (options->output_prefix) {
1405                 struct strbuf *msg = NULL;
1406                 msg = options->output_prefix(options,
1407                                 options->output_prefix_data);
1408                 fprintf(options->file, "%s", msg->buf);
1409         }
1410         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1411                total_files, adds, dels);
1414 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1416         int i;
1418         if (data->nr == 0)
1419                 return;
1421         for (i = 0; i < data->nr; i++) {
1422                 struct diffstat_file *file = data->files[i];
1424                 if (options->output_prefix) {
1425                         struct strbuf *msg = NULL;
1426                         msg = options->output_prefix(options,
1427                                         options->output_prefix_data);
1428                         fprintf(options->file, "%s", msg->buf);
1429                 }
1431                 if (file->is_binary)
1432                         fprintf(options->file, "-\t-\t");
1433                 else
1434                         fprintf(options->file,
1435                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1436                                 file->added, file->deleted);
1437                 if (options->line_termination) {
1438                         fill_print_name(file);
1439                         if (!file->is_renamed)
1440                                 write_name_quoted(file->name, options->file,
1441                                                   options->line_termination);
1442                         else {
1443                                 fputs(file->print_name, options->file);
1444                                 putc(options->line_termination, options->file);
1445                         }
1446                 } else {
1447                         if (file->is_renamed) {
1448                                 putc('\0', options->file);
1449                                 write_name_quoted(file->from_name, options->file, '\0');
1450                         }
1451                         write_name_quoted(file->name, options->file, '\0');
1452                 }
1453         }
1456 struct dirstat_file {
1457         const char *name;
1458         unsigned long changed;
1459 };
1461 struct dirstat_dir {
1462         struct dirstat_file *files;
1463         int alloc, nr, percent, cumulative;
1464 };
1466 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1467                 unsigned long changed, const char *base, int baselen)
1469         unsigned long this_dir = 0;
1470         unsigned int sources = 0;
1471         const char *line_prefix = "";
1472         struct strbuf *msg = NULL;
1474         if (opt->output_prefix) {
1475                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1476                 line_prefix = msg->buf;
1477         }
1479         while (dir->nr) {
1480                 struct dirstat_file *f = dir->files;
1481                 int namelen = strlen(f->name);
1482                 unsigned long this;
1483                 char *slash;
1485                 if (namelen < baselen)
1486                         break;
1487                 if (memcmp(f->name, base, baselen))
1488                         break;
1489                 slash = strchr(f->name + baselen, '/');
1490                 if (slash) {
1491                         int newbaselen = slash + 1 - f->name;
1492                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1493                         sources++;
1494                 } else {
1495                         this = f->changed;
1496                         dir->files++;
1497                         dir->nr--;
1498                         sources += 2;
1499                 }
1500                 this_dir += this;
1501         }
1503         /*
1504          * We don't report dirstat's for
1505          *  - the top level
1506          *  - or cases where everything came from a single directory
1507          *    under this directory (sources == 1).
1508          */
1509         if (baselen && sources != 1) {
1510                 int permille = this_dir * 1000 / changed;
1511                 if (permille) {
1512                         int percent = permille / 10;
1513                         if (percent >= dir->percent) {
1514                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1515                                         percent, permille % 10, baselen, base);
1516                                 if (!dir->cumulative)
1517                                         return 0;
1518                         }
1519                 }
1520         }
1521         return this_dir;
1524 static int dirstat_compare(const void *_a, const void *_b)
1526         const struct dirstat_file *a = _a;
1527         const struct dirstat_file *b = _b;
1528         return strcmp(a->name, b->name);
1531 static void show_dirstat(struct diff_options *options)
1533         int i;
1534         unsigned long changed;
1535         struct dirstat_dir dir;
1536         struct diff_queue_struct *q = &diff_queued_diff;
1538         dir.files = NULL;
1539         dir.alloc = 0;
1540         dir.nr = 0;
1541         dir.percent = options->dirstat_percent;
1542         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1544         changed = 0;
1545         for (i = 0; i < q->nr; i++) {
1546                 struct diff_filepair *p = q->queue[i];
1547                 const char *name;
1548                 unsigned long copied, added, damage;
1549                 int content_changed;
1551                 name = p->two->path ? p->two->path : p->one->path;
1553                 if (p->one->sha1_valid && p->two->sha1_valid)
1554                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1555                 else
1556                         content_changed = 1;
1558                 if (!content_changed) {
1559                         /*
1560                          * The SHA1 has not changed, so pre-/post-content is
1561                          * identical. We can therefore skip looking at the
1562                          * file contents altogether.
1563                          */
1564                         damage = 0;
1565                         goto found_damage;
1566                 }
1568                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1569                         /*
1570                          * In --dirstat-by-file mode, we don't really need to
1571                          * look at the actual file contents at all.
1572                          * The fact that the SHA1 changed is enough for us to
1573                          * add this file to the list of results
1574                          * (with each file contributing equal damage).
1575                          */
1576                         damage = 1;
1577                         goto found_damage;
1578                 }
1580                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1581                         diff_populate_filespec(p->one, 0);
1582                         diff_populate_filespec(p->two, 0);
1583                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1584                                                &copied, &added);
1585                         diff_free_filespec_data(p->one);
1586                         diff_free_filespec_data(p->two);
1587                 } else if (DIFF_FILE_VALID(p->one)) {
1588                         diff_populate_filespec(p->one, 1);
1589                         copied = added = 0;
1590                         diff_free_filespec_data(p->one);
1591                 } else if (DIFF_FILE_VALID(p->two)) {
1592                         diff_populate_filespec(p->two, 1);
1593                         copied = 0;
1594                         added = p->two->size;
1595                         diff_free_filespec_data(p->two);
1596                 } else
1597                         continue;
1599                 /*
1600                  * Original minus copied is the removed material,
1601                  * added is the new material.  They are both damages
1602                  * made to the preimage.
1603                  * If the resulting damage is zero, we know that
1604                  * diffcore_count_changes() considers the two entries to
1605                  * be identical, but since content_changed is true, we
1606                  * know that there must have been _some_ kind of change,
1607                  * so we force all entries to have damage > 0.
1608                  */
1609                 damage = (p->one->size - copied) + added;
1610                 if (!damage)
1611                         damage = 1;
1613 found_damage:
1614                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1615                 dir.files[dir.nr].name = name;
1616                 dir.files[dir.nr].changed = damage;
1617                 changed += damage;
1618                 dir.nr++;
1619         }
1621         /* This can happen even with many files, if everything was renames */
1622         if (!changed)
1623                 return;
1625         /* Show all directories with more than x% of the changes */
1626         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1627         gather_dirstat(options, &dir, changed, "", 0);
1630 static void free_diffstat_info(struct diffstat_t *diffstat)
1632         int i;
1633         for (i = 0; i < diffstat->nr; i++) {
1634                 struct diffstat_file *f = diffstat->files[i];
1635                 if (f->name != f->print_name)
1636                         free(f->print_name);
1637                 free(f->name);
1638                 free(f->from_name);
1639                 free(f);
1640         }
1641         free(diffstat->files);
1644 struct checkdiff_t {
1645         const char *filename;
1646         int lineno;
1647         int conflict_marker_size;
1648         struct diff_options *o;
1649         unsigned ws_rule;
1650         unsigned status;
1651 };
1653 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1655         char firstchar;
1656         int cnt;
1658         if (len < marker_size + 1)
1659                 return 0;
1660         firstchar = line[0];
1661         switch (firstchar) {
1662         case '=': case '>': case '<': case '|':
1663                 break;
1664         default:
1665                 return 0;
1666         }
1667         for (cnt = 1; cnt < marker_size; cnt++)
1668                 if (line[cnt] != firstchar)
1669                         return 0;
1670         /* line[1] thru line[marker_size-1] are same as firstchar */
1671         if (len < marker_size + 1 || !isspace(line[marker_size]))
1672                 return 0;
1673         return 1;
1676 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1678         struct checkdiff_t *data = priv;
1679         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1680         int marker_size = data->conflict_marker_size;
1681         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1682         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1683         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1684         char *err;
1685         char *line_prefix = "";
1686         struct strbuf *msgbuf;
1688         assert(data->o);
1689         if (data->o->output_prefix) {
1690                 msgbuf = data->o->output_prefix(data->o,
1691                         data->o->output_prefix_data);
1692                 line_prefix = msgbuf->buf;
1693         }
1695         if (line[0] == '+') {
1696                 unsigned bad;
1697                 data->lineno++;
1698                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1699                         data->status |= 1;
1700                         fprintf(data->o->file,
1701                                 "%s%s:%d: leftover conflict marker\n",
1702                                 line_prefix, data->filename, data->lineno);
1703                 }
1704                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1705                 if (!bad)
1706                         return;
1707                 data->status |= bad;
1708                 err = whitespace_error_string(bad);
1709                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1710                         line_prefix, data->filename, data->lineno, err);
1711                 free(err);
1712                 emit_line(data->o, set, reset, line, 1);
1713                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1714                               data->o->file, set, reset, ws);
1715         } else if (line[0] == ' ') {
1716                 data->lineno++;
1717         } else if (line[0] == '@') {
1718                 char *plus = strchr(line, '+');
1719                 if (plus)
1720                         data->lineno = strtol(plus, NULL, 10) - 1;
1721                 else
1722                         die("invalid diff");
1723         }
1726 static unsigned char *deflate_it(char *data,
1727                                  unsigned long size,
1728                                  unsigned long *result_size)
1730         int bound;
1731         unsigned char *deflated;
1732         z_stream stream;
1734         memset(&stream, 0, sizeof(stream));
1735         deflateInit(&stream, zlib_compression_level);
1736         bound = deflateBound(&stream, size);
1737         deflated = xmalloc(bound);
1738         stream.next_out = deflated;
1739         stream.avail_out = bound;
1741         stream.next_in = (unsigned char *)data;
1742         stream.avail_in = size;
1743         while (deflate(&stream, Z_FINISH) == Z_OK)
1744                 ; /* nothing */
1745         deflateEnd(&stream);
1746         *result_size = stream.total_out;
1747         return deflated;
1750 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1752         void *cp;
1753         void *delta;
1754         void *deflated;
1755         void *data;
1756         unsigned long orig_size;
1757         unsigned long delta_size;
1758         unsigned long deflate_size;
1759         unsigned long data_size;
1761         /* We could do deflated delta, or we could do just deflated two,
1762          * whichever is smaller.
1763          */
1764         delta = NULL;
1765         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1766         if (one->size && two->size) {
1767                 delta = diff_delta(one->ptr, one->size,
1768                                    two->ptr, two->size,
1769                                    &delta_size, deflate_size);
1770                 if (delta) {
1771                         void *to_free = delta;
1772                         orig_size = delta_size;
1773                         delta = deflate_it(delta, delta_size, &delta_size);
1774                         free(to_free);
1775                 }
1776         }
1778         if (delta && delta_size < deflate_size) {
1779                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1780                 free(deflated);
1781                 data = delta;
1782                 data_size = delta_size;
1783         }
1784         else {
1785                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1786                 free(delta);
1787                 data = deflated;
1788                 data_size = deflate_size;
1789         }
1791         /* emit data encoded in base85 */
1792         cp = data;
1793         while (data_size) {
1794                 int bytes = (52 < data_size) ? 52 : data_size;
1795                 char line[70];
1796                 data_size -= bytes;
1797                 if (bytes <= 26)
1798                         line[0] = bytes + 'A' - 1;
1799                 else
1800                         line[0] = bytes - 26 + 'a' - 1;
1801                 encode_85(line + 1, cp, bytes);
1802                 cp = (char *) cp + bytes;
1803                 fprintf(file, "%s", prefix);
1804                 fputs(line, file);
1805                 fputc('\n', file);
1806         }
1807         fprintf(file, "%s\n", prefix);
1808         free(data);
1811 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1813         fprintf(file, "%sGIT binary patch\n", prefix);
1814         emit_binary_diff_body(file, one, two, prefix);
1815         emit_binary_diff_body(file, two, one, prefix);
1818 static void diff_filespec_load_driver(struct diff_filespec *one)
1820         /* Use already-loaded driver */
1821         if (one->driver)
1822                 return;
1824         if (S_ISREG(one->mode))
1825                 one->driver = userdiff_find_by_path(one->path);
1827         /* Fallback to default settings */
1828         if (!one->driver)
1829                 one->driver = userdiff_find_by_name("default");
1832 int diff_filespec_is_binary(struct diff_filespec *one)
1834         if (one->is_binary == -1) {
1835                 diff_filespec_load_driver(one);
1836                 if (one->driver->binary != -1)
1837                         one->is_binary = one->driver->binary;
1838                 else {
1839                         if (!one->data && DIFF_FILE_VALID(one))
1840                                 diff_populate_filespec(one, 0);
1841                         if (one->data)
1842                                 one->is_binary = buffer_is_binary(one->data,
1843                                                 one->size);
1844                         if (one->is_binary == -1)
1845                                 one->is_binary = 0;
1846                 }
1847         }
1848         return one->is_binary;
1851 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1853         diff_filespec_load_driver(one);
1854         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1857 static const char *userdiff_word_regex(struct diff_filespec *one)
1859         diff_filespec_load_driver(one);
1860         return one->driver->word_regex;
1863 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1865         if (!options->a_prefix)
1866                 options->a_prefix = a;
1867         if (!options->b_prefix)
1868                 options->b_prefix = b;
1871 struct userdiff_driver *get_textconv(struct diff_filespec *one)
1873         if (!DIFF_FILE_VALID(one))
1874                 return NULL;
1876         diff_filespec_load_driver(one);
1877         if (!one->driver->textconv)
1878                 return NULL;
1880         if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1881                 struct notes_cache *c = xmalloc(sizeof(*c));
1882                 struct strbuf name = STRBUF_INIT;
1884                 strbuf_addf(&name, "textconv/%s", one->driver->name);
1885                 notes_cache_init(c, name.buf, one->driver->textconv);
1886                 one->driver->textconv_cache = c;
1887         }
1889         return one->driver;
1892 static void builtin_diff(const char *name_a,
1893                          const char *name_b,
1894                          struct diff_filespec *one,
1895                          struct diff_filespec *two,
1896                          const char *xfrm_msg,
1897                          int must_show_header,
1898                          struct diff_options *o,
1899                          int complete_rewrite)
1901         mmfile_t mf1, mf2;
1902         const char *lbl[2];
1903         char *a_one, *b_two;
1904         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1905         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1906         const char *a_prefix, *b_prefix;
1907         struct userdiff_driver *textconv_one = NULL;
1908         struct userdiff_driver *textconv_two = NULL;
1909         struct strbuf header = STRBUF_INIT;
1910         struct strbuf *msgbuf;
1911         char *line_prefix = "";
1913         if (o->output_prefix) {
1914                 msgbuf = o->output_prefix(o, o->output_prefix_data);
1915                 line_prefix = msgbuf->buf;
1916         }
1918         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1919                         (!one->mode || S_ISGITLINK(one->mode)) &&
1920                         (!two->mode || S_ISGITLINK(two->mode))) {
1921                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1922                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1923                 show_submodule_summary(o->file, one ? one->path : two->path,
1924                                 one->sha1, two->sha1, two->dirty_submodule,
1925                                 del, add, reset);
1926                 return;
1927         }
1929         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1930                 textconv_one = get_textconv(one);
1931                 textconv_two = get_textconv(two);
1932         }
1934         diff_set_mnemonic_prefix(o, "a/", "b/");
1935         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1936                 a_prefix = o->b_prefix;
1937                 b_prefix = o->a_prefix;
1938         } else {
1939                 a_prefix = o->a_prefix;
1940                 b_prefix = o->b_prefix;
1941         }
1943         /* Never use a non-valid filename anywhere if at all possible */
1944         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1945         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1947         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1948         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1949         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1950         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1951         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1952         if (lbl[0][0] == '/') {
1953                 /* /dev/null */
1954                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1955                 if (xfrm_msg)
1956                         strbuf_addstr(&header, xfrm_msg);
1957                 must_show_header = 1;
1958         }
1959         else if (lbl[1][0] == '/') {
1960                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1961                 if (xfrm_msg)
1962                         strbuf_addstr(&header, xfrm_msg);
1963                 must_show_header = 1;
1964         }
1965         else {
1966                 if (one->mode != two->mode) {
1967                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1968                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1969                         must_show_header = 1;
1970                 }
1971                 if (xfrm_msg)
1972                         strbuf_addstr(&header, xfrm_msg);
1974                 /*
1975                  * we do not run diff between different kind
1976                  * of objects.
1977                  */
1978                 if ((one->mode ^ two->mode) & S_IFMT)
1979                         goto free_ab_and_return;
1980                 if (complete_rewrite &&
1981                     (textconv_one || !diff_filespec_is_binary(one)) &&
1982                     (textconv_two || !diff_filespec_is_binary(two))) {
1983                         fprintf(o->file, "%s", header.buf);
1984                         strbuf_reset(&header);
1985                         emit_rewrite_diff(name_a, name_b, one, two,
1986                                                 textconv_one, textconv_two, o);
1987                         o->found_changes = 1;
1988                         goto free_ab_and_return;
1989                 }
1990         }
1992         if (!DIFF_OPT_TST(o, TEXT) &&
1993             ( (!textconv_one && diff_filespec_is_binary(one)) ||
1994               (!textconv_two && diff_filespec_is_binary(two)) )) {
1995                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1996                         die("unable to read files to diff");
1997                 /* Quite common confusing case */
1998                 if (mf1.size == mf2.size &&
1999                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2000                         if (must_show_header)
2001                                 fprintf(o->file, "%s", header.buf);
2002                         goto free_ab_and_return;
2003                 }
2004                 fprintf(o->file, "%s", header.buf);
2005                 strbuf_reset(&header);
2006                 if (DIFF_OPT_TST(o, BINARY))
2007                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2008                 else
2009                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2010                                 line_prefix, lbl[0], lbl[1]);
2011                 o->found_changes = 1;
2012         }
2013         else {
2014                 /* Crazy xdl interfaces.. */
2015                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2016                 xpparam_t xpp;
2017                 xdemitconf_t xecfg;
2018                 struct emit_callback ecbdata;
2019                 const struct userdiff_funcname *pe;
2021                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2022                         fprintf(o->file, "%s", header.buf);
2023                         strbuf_reset(&header);
2024                 }
2026                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2027                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2029                 pe = diff_funcname_pattern(one);
2030                 if (!pe)
2031                         pe = diff_funcname_pattern(two);
2033                 memset(&xpp, 0, sizeof(xpp));
2034                 memset(&xecfg, 0, sizeof(xecfg));
2035                 memset(&ecbdata, 0, sizeof(ecbdata));
2036                 ecbdata.label_path = lbl;
2037                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2038                 ecbdata.found_changesp = &o->found_changes;
2039                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2040                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2041                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2042                 ecbdata.opt = o;
2043                 ecbdata.header = header.len ? &header : NULL;
2044                 xpp.flags = o->xdl_opts;
2045                 xecfg.ctxlen = o->context;
2046                 xecfg.interhunkctxlen = o->interhunkcontext;
2047                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2048                 if (pe)
2049                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2050                 if (!diffopts)
2051                         ;
2052                 else if (!prefixcmp(diffopts, "--unified="))
2053                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2054                 else if (!prefixcmp(diffopts, "-u"))
2055                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2056                 if (o->word_diff) {
2057                         int i;
2059                         ecbdata.diff_words =
2060                                 xcalloc(1, sizeof(struct diff_words_data));
2061                         ecbdata.diff_words->type = o->word_diff;
2062                         ecbdata.diff_words->opt = o;
2063                         if (!o->word_regex)
2064                                 o->word_regex = userdiff_word_regex(one);
2065                         if (!o->word_regex)
2066                                 o->word_regex = userdiff_word_regex(two);
2067                         if (!o->word_regex)
2068                                 o->word_regex = diff_word_regex_cfg;
2069                         if (o->word_regex) {
2070                                 ecbdata.diff_words->word_regex = (regex_t *)
2071                                         xmalloc(sizeof(regex_t));
2072                                 if (regcomp(ecbdata.diff_words->word_regex,
2073                                                 o->word_regex,
2074                                                 REG_EXTENDED | REG_NEWLINE))
2075                                         die ("Invalid regular expression: %s",
2076                                                         o->word_regex);
2077                         }
2078                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2079                                 if (o->word_diff == diff_words_styles[i].type) {
2080                                         ecbdata.diff_words->style =
2081                                                 &diff_words_styles[i];
2082                                         break;
2083                                 }
2084                         }
2085                         if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2086                                 struct diff_words_style *st = ecbdata.diff_words->style;
2087                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2088                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2089                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2090                         }
2091                 }
2092                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2093                               &xpp, &xecfg);
2094                 if (o->word_diff)
2095                         free_diff_words_data(&ecbdata);
2096                 if (textconv_one)
2097                         free(mf1.ptr);
2098                 if (textconv_two)
2099                         free(mf2.ptr);
2100                 xdiff_clear_find_func(&xecfg);
2101         }
2103  free_ab_and_return:
2104         strbuf_release(&header);
2105         diff_free_filespec_data(one);
2106         diff_free_filespec_data(two);
2107         free(a_one);
2108         free(b_two);
2109         return;
2112 static void builtin_diffstat(const char *name_a, const char *name_b,
2113                              struct diff_filespec *one,
2114                              struct diff_filespec *two,
2115                              struct diffstat_t *diffstat,
2116                              struct diff_options *o,
2117                              int complete_rewrite)
2119         mmfile_t mf1, mf2;
2120         struct diffstat_file *data;
2122         data = diffstat_add(diffstat, name_a, name_b);
2124         if (!one || !two) {
2125                 data->is_unmerged = 1;
2126                 return;
2127         }
2129         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2130                 data->is_binary = 1;
2131                 data->added = diff_filespec_size(two);
2132                 data->deleted = diff_filespec_size(one);
2133         }
2135         else if (complete_rewrite) {
2136                 diff_populate_filespec(one, 0);
2137                 diff_populate_filespec(two, 0);
2138                 data->deleted = count_lines(one->data, one->size);
2139                 data->added = count_lines(two->data, two->size);
2140         }
2142         else {
2143                 /* Crazy xdl interfaces.. */
2144                 xpparam_t xpp;
2145                 xdemitconf_t xecfg;
2147                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2148                         die("unable to read files to diff");
2150                 memset(&xpp, 0, sizeof(xpp));
2151                 memset(&xecfg, 0, sizeof(xecfg));
2152                 xpp.flags = o->xdl_opts;
2153                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2154                               &xpp, &xecfg);
2155         }
2157         diff_free_filespec_data(one);
2158         diff_free_filespec_data(two);
2161 static void builtin_checkdiff(const char *name_a, const char *name_b,
2162                               const char *attr_path,
2163                               struct diff_filespec *one,
2164                               struct diff_filespec *two,
2165                               struct diff_options *o)
2167         mmfile_t mf1, mf2;
2168         struct checkdiff_t data;
2170         if (!two)
2171                 return;
2173         memset(&data, 0, sizeof(data));
2174         data.filename = name_b ? name_b : name_a;
2175         data.lineno = 0;
2176         data.o = o;
2177         data.ws_rule = whitespace_rule(attr_path);
2178         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2180         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2181                 die("unable to read files to diff");
2183         /*
2184          * All the other codepaths check both sides, but not checking
2185          * the "old" side here is deliberate.  We are checking the newly
2186          * introduced changes, and as long as the "new" side is text, we
2187          * can and should check what it introduces.
2188          */
2189         if (diff_filespec_is_binary(two))
2190                 goto free_and_return;
2191         else {
2192                 /* Crazy xdl interfaces.. */
2193                 xpparam_t xpp;
2194                 xdemitconf_t xecfg;
2196                 memset(&xpp, 0, sizeof(xpp));
2197                 memset(&xecfg, 0, sizeof(xecfg));
2198                 xecfg.ctxlen = 1; /* at least one context line */
2199                 xpp.flags = 0;
2200                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2201                               &xpp, &xecfg);
2203                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2204                         struct emit_callback ecbdata;
2205                         int blank_at_eof;
2207                         ecbdata.ws_rule = data.ws_rule;
2208                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2209                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2211                         if (blank_at_eof) {
2212                                 static char *err;
2213                                 if (!err)
2214                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2215                                 fprintf(o->file, "%s:%d: %s.\n",
2216                                         data.filename, blank_at_eof, err);
2217                                 data.status = 1; /* report errors */
2218                         }
2219                 }
2220         }
2221  free_and_return:
2222         diff_free_filespec_data(one);
2223         diff_free_filespec_data(two);
2224         if (data.status)
2225                 DIFF_OPT_SET(o, CHECK_FAILED);
2228 struct diff_filespec *alloc_filespec(const char *path)
2230         int namelen = strlen(path);
2231         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2233         memset(spec, 0, sizeof(*spec));
2234         spec->path = (char *)(spec + 1);
2235         memcpy(spec->path, path, namelen+1);
2236         spec->count = 1;
2237         spec->is_binary = -1;
2238         return spec;
2241 void free_filespec(struct diff_filespec *spec)
2243         if (!--spec->count) {
2244                 diff_free_filespec_data(spec);
2245                 free(spec);
2246         }
2249 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2250                    unsigned short mode)
2252         if (mode) {
2253                 spec->mode = canon_mode(mode);
2254                 hashcpy(spec->sha1, sha1);
2255                 spec->sha1_valid = !is_null_sha1(sha1);
2256         }
2259 /*
2260  * Given a name and sha1 pair, if the index tells us the file in
2261  * the work tree has that object contents, return true, so that
2262  * prepare_temp_file() does not have to inflate and extract.
2263  */
2264 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2266         struct cache_entry *ce;
2267         struct stat st;
2268         int pos, len;
2270         /*
2271          * We do not read the cache ourselves here, because the
2272          * benchmark with my previous version that always reads cache
2273          * shows that it makes things worse for diff-tree comparing
2274          * two linux-2.6 kernel trees in an already checked out work
2275          * tree.  This is because most diff-tree comparisons deal with
2276          * only a small number of files, while reading the cache is
2277          * expensive for a large project, and its cost outweighs the
2278          * savings we get by not inflating the object to a temporary
2279          * file.  Practically, this code only helps when we are used
2280          * by diff-cache --cached, which does read the cache before
2281          * calling us.
2282          */
2283         if (!active_cache)
2284                 return 0;
2286         /* We want to avoid the working directory if our caller
2287          * doesn't need the data in a normal file, this system
2288          * is rather slow with its stat/open/mmap/close syscalls,
2289          * and the object is contained in a pack file.  The pack
2290          * is probably already open and will be faster to obtain
2291          * the data through than the working directory.  Loose
2292          * objects however would tend to be slower as they need
2293          * to be individually opened and inflated.
2294          */
2295         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2296                 return 0;
2298         len = strlen(name);
2299         pos = cache_name_pos(name, len);
2300         if (pos < 0)
2301                 return 0;
2302         ce = active_cache[pos];
2304         /*
2305          * This is not the sha1 we are looking for, or
2306          * unreusable because it is not a regular file.
2307          */
2308         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2309                 return 0;
2311         /*
2312          * If ce is marked as "assume unchanged", there is no
2313          * guarantee that work tree matches what we are looking for.
2314          */
2315         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2316                 return 0;
2318         /*
2319          * If ce matches the file in the work tree, we can reuse it.
2320          */
2321         if (ce_uptodate(ce) ||
2322             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2323                 return 1;
2325         return 0;
2328 static int populate_from_stdin(struct diff_filespec *s)
2330         struct strbuf buf = STRBUF_INIT;
2331         size_t size = 0;
2333         if (strbuf_read(&buf, 0, 0) < 0)
2334                 return error("error while reading from stdin %s",
2335                                      strerror(errno));
2337         s->should_munmap = 0;
2338         s->data = strbuf_detach(&buf, &size);
2339         s->size = size;
2340         s->should_free = 1;
2341         return 0;
2344 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2346         int len;
2347         char *data = xmalloc(100), *dirty = "";
2349         /* Are we looking at the work tree? */
2350         if (s->dirty_submodule)
2351                 dirty = "-dirty";
2353         len = snprintf(data, 100,
2354                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2355         s->data = data;
2356         s->size = len;
2357         s->should_free = 1;
2358         if (size_only) {
2359                 s->data = NULL;
2360                 free(data);
2361         }
2362         return 0;
2365 /*
2366  * While doing rename detection and pickaxe operation, we may need to
2367  * grab the data for the blob (or file) for our own in-core comparison.
2368  * diff_filespec has data and size fields for this purpose.
2369  */
2370 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2372         int err = 0;
2373         if (!DIFF_FILE_VALID(s))
2374                 die("internal error: asking to populate invalid file.");
2375         if (S_ISDIR(s->mode))
2376                 return -1;
2378         if (s->data)
2379                 return 0;
2381         if (size_only && 0 < s->size)
2382                 return 0;
2384         if (S_ISGITLINK(s->mode))
2385                 return diff_populate_gitlink(s, size_only);
2387         if (!s->sha1_valid ||
2388             reuse_worktree_file(s->path, s->sha1, 0)) {
2389                 struct strbuf buf = STRBUF_INIT;
2390                 struct stat st;
2391                 int fd;
2393                 if (!strcmp(s->path, "-"))
2394                         return populate_from_stdin(s);
2396                 if (lstat(s->path, &st) < 0) {
2397                         if (errno == ENOENT) {
2398                         err_empty:
2399                                 err = -1;
2400                         empty:
2401                                 s->data = (char *)"";
2402                                 s->size = 0;
2403                                 return err;
2404                         }
2405                 }
2406                 s->size = xsize_t(st.st_size);
2407                 if (!s->size)
2408                         goto empty;
2409                 if (S_ISLNK(st.st_mode)) {
2410                         struct strbuf sb = STRBUF_INIT;
2412                         if (strbuf_readlink(&sb, s->path, s->size))
2413                                 goto err_empty;
2414                         s->size = sb.len;
2415                         s->data = strbuf_detach(&sb, NULL);
2416                         s->should_free = 1;
2417                         return 0;
2418                 }
2419                 if (size_only)
2420                         return 0;
2421                 fd = open(s->path, O_RDONLY);
2422                 if (fd < 0)
2423                         goto err_empty;
2424                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2425                 close(fd);
2426                 s->should_munmap = 1;
2428                 /*
2429                  * Convert from working tree format to canonical git format
2430                  */
2431                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2432                         size_t size = 0;
2433                         munmap(s->data, s->size);
2434                         s->should_munmap = 0;
2435                         s->data = strbuf_detach(&buf, &size);
2436                         s->size = size;
2437                         s->should_free = 1;
2438                 }
2439         }
2440         else {
2441                 enum object_type type;
2442                 if (size_only) {
2443                         type = sha1_object_info(s->sha1, &s->size);
2444                         if (type < 0)
2445                                 die("unable to read %s", sha1_to_hex(s->sha1));
2446                 } else {
2447                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2448                         if (!s->data)
2449                                 die("unable to read %s", sha1_to_hex(s->sha1));
2450                         s->should_free = 1;
2451                 }
2452         }
2453         return 0;
2456 void diff_free_filespec_blob(struct diff_filespec *s)
2458         if (s->should_free)
2459                 free(s->data);
2460         else if (s->should_munmap)
2461                 munmap(s->data, s->size);
2463         if (s->should_free || s->should_munmap) {
2464                 s->should_free = s->should_munmap = 0;
2465                 s->data = NULL;
2466         }
2469 void diff_free_filespec_data(struct diff_filespec *s)
2471         diff_free_filespec_blob(s);
2472         free(s->cnt_data);
2473         s->cnt_data = NULL;
2476 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2477                            void *blob,
2478                            unsigned long size,
2479                            const unsigned char *sha1,
2480                            int mode)
2482         int fd;
2483         struct strbuf buf = STRBUF_INIT;
2484         struct strbuf template = STRBUF_INIT;
2485         char *path_dup = xstrdup(path);
2486         const char *base = basename(path_dup);
2488         /* Generate "XXXXXX_basename.ext" */
2489         strbuf_addstr(&template, "XXXXXX_");
2490         strbuf_addstr(&template, base);
2492         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2493                         strlen(base) + 1);
2494         if (fd < 0)
2495                 die_errno("unable to create temp-file");
2496         if (convert_to_working_tree(path,
2497                         (const char *)blob, (size_t)size, &buf)) {
2498                 blob = buf.buf;
2499                 size = buf.len;
2500         }
2501         if (write_in_full(fd, blob, size) != size)
2502                 die_errno("unable to write temp-file");
2503         close(fd);
2504         temp->name = temp->tmp_path;
2505         strcpy(temp->hex, sha1_to_hex(sha1));
2506         temp->hex[40] = 0;
2507         sprintf(temp->mode, "%06o", mode);
2508         strbuf_release(&buf);
2509         strbuf_release(&template);
2510         free(path_dup);
2513 static struct diff_tempfile *prepare_temp_file(const char *name,
2514                 struct diff_filespec *one)
2516         struct diff_tempfile *temp = claim_diff_tempfile();
2518         if (!DIFF_FILE_VALID(one)) {
2519         not_a_valid_file:
2520                 /* A '-' entry produces this for file-2, and
2521                  * a '+' entry produces this for file-1.
2522                  */
2523                 temp->name = "/dev/null";
2524                 strcpy(temp->hex, ".");
2525                 strcpy(temp->mode, ".");
2526                 return temp;
2527         }
2529         if (!remove_tempfile_installed) {
2530                 atexit(remove_tempfile);
2531                 sigchain_push_common(remove_tempfile_on_signal);
2532                 remove_tempfile_installed = 1;
2533         }
2535         if (!one->sha1_valid ||
2536             reuse_worktree_file(name, one->sha1, 1)) {
2537                 struct stat st;
2538                 if (lstat(name, &st) < 0) {
2539                         if (errno == ENOENT)
2540                                 goto not_a_valid_file;
2541                         die_errno("stat(%s)", name);
2542                 }
2543                 if (S_ISLNK(st.st_mode)) {
2544                         struct strbuf sb = STRBUF_INIT;
2545                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2546                                 die_errno("readlink(%s)", name);
2547                         prep_temp_blob(name, temp, sb.buf, sb.len,
2548                                        (one->sha1_valid ?
2549                                         one->sha1 : null_sha1),
2550                                        (one->sha1_valid ?
2551                                         one->mode : S_IFLNK));
2552                         strbuf_release(&sb);
2553                 }
2554                 else {
2555                         /* we can borrow from the file in the work tree */
2556                         temp->name = name;
2557                         if (!one->sha1_valid)
2558                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2559                         else
2560                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2561                         /* Even though we may sometimes borrow the
2562                          * contents from the work tree, we always want
2563                          * one->mode.  mode is trustworthy even when
2564                          * !(one->sha1_valid), as long as
2565                          * DIFF_FILE_VALID(one).
2566                          */
2567                         sprintf(temp->mode, "%06o", one->mode);
2568                 }
2569                 return temp;
2570         }
2571         else {
2572                 if (diff_populate_filespec(one, 0))
2573                         die("cannot read data blob for %s", one->path);
2574                 prep_temp_blob(name, temp, one->data, one->size,
2575                                one->sha1, one->mode);
2576         }
2577         return temp;
2580 /* An external diff command takes:
2581  *
2582  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2583  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2584  *
2585  */
2586 static void run_external_diff(const char *pgm,
2587                               const char *name,
2588                               const char *other,
2589                               struct diff_filespec *one,
2590                               struct diff_filespec *two,
2591                               const char *xfrm_msg,
2592                               int complete_rewrite)
2594         const char *spawn_arg[10];
2595         int retval;
2596         const char **arg = &spawn_arg[0];
2598         if (one && two) {
2599                 struct diff_tempfile *temp_one, *temp_two;
2600                 const char *othername = (other ? other : name);
2601                 temp_one = prepare_temp_file(name, one);
2602                 temp_two = prepare_temp_file(othername, two);
2603                 *arg++ = pgm;
2604                 *arg++ = name;
2605                 *arg++ = temp_one->name;
2606                 *arg++ = temp_one->hex;
2607                 *arg++ = temp_one->mode;
2608                 *arg++ = temp_two->name;
2609                 *arg++ = temp_two->hex;
2610                 *arg++ = temp_two->mode;
2611                 if (other) {
2612                         *arg++ = other;
2613                         *arg++ = xfrm_msg;
2614                 }
2615         } else {
2616                 *arg++ = pgm;
2617                 *arg++ = name;
2618         }
2619         *arg = NULL;
2620         fflush(NULL);
2621         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2622         remove_tempfile();
2623         if (retval) {
2624                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2625                 exit(1);
2626         }
2629 static int similarity_index(struct diff_filepair *p)
2631         return p->score * 100 / MAX_SCORE;
2634 static void fill_metainfo(struct strbuf *msg,
2635                           const char *name,
2636                           const char *other,
2637                           struct diff_filespec *one,
2638                           struct diff_filespec *two,
2639                           struct diff_options *o,
2640                           struct diff_filepair *p,
2641                           int *must_show_header,
2642                           int use_color)
2644         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2645         const char *reset = diff_get_color(use_color, DIFF_RESET);
2646         struct strbuf *msgbuf;
2647         char *line_prefix = "";
2649         *must_show_header = 1;
2650         if (o->output_prefix) {
2651                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2652                 line_prefix = msgbuf->buf;
2653         }
2654         strbuf_init(msg, PATH_MAX * 2 + 300);
2655         switch (p->status) {
2656         case DIFF_STATUS_COPIED:
2657                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2658                             line_prefix, set, similarity_index(p));
2659                 strbuf_addf(msg, "%s\n%s%scopy from ",
2660                             reset,  line_prefix, set);
2661                 quote_c_style(name, msg, NULL, 0);
2662                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2663                 quote_c_style(other, msg, NULL, 0);
2664                 strbuf_addf(msg, "%s\n", reset);
2665                 break;
2666         case DIFF_STATUS_RENAMED:
2667                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2668                             line_prefix, set, similarity_index(p));
2669                 strbuf_addf(msg, "%s\n%s%srename from ",
2670                             reset, line_prefix, set);
2671                 quote_c_style(name, msg, NULL, 0);
2672                 strbuf_addf(msg, "%s\n%s%srename to ",
2673                             reset, line_prefix, set);
2674                 quote_c_style(other, msg, NULL, 0);
2675                 strbuf_addf(msg, "%s\n", reset);
2676                 break;
2677         case DIFF_STATUS_MODIFIED:
2678                 if (p->score) {
2679                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2680                                     line_prefix,
2681                                     set, similarity_index(p), reset);
2682                         break;
2683                 }
2684                 /* fallthru */
2685         default:
2686                 *must_show_header = 0;
2687         }
2688         if (one && two && hashcmp(one->sha1, two->sha1)) {
2689                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2691                 if (DIFF_OPT_TST(o, BINARY)) {
2692                         mmfile_t mf;
2693                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2694                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2695                                 abbrev = 40;
2696                 }
2697                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2698                             find_unique_abbrev(one->sha1, abbrev));
2699                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2700                 if (one->mode == two->mode)
2701                         strbuf_addf(msg, " %06o", one->mode);
2702                 strbuf_addf(msg, "%s\n", reset);
2703         }
2706 static void run_diff_cmd(const char *pgm,
2707                          const char *name,
2708                          const char *other,
2709                          const char *attr_path,
2710                          struct diff_filespec *one,
2711                          struct diff_filespec *two,
2712                          struct strbuf *msg,
2713                          struct diff_options *o,
2714                          struct diff_filepair *p)
2716         const char *xfrm_msg = NULL;
2717         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2718         int must_show_header = 0;
2720         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2721                 pgm = NULL;
2722         else {
2723                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2724                 if (drv && drv->external)
2725                         pgm = drv->external;
2726         }
2728         if (msg) {
2729                 /*
2730                  * don't use colors when the header is intended for an
2731                  * external diff driver
2732                  */
2733                 fill_metainfo(msg, name, other, one, two, o, p,
2734                               &must_show_header,
2735                               DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2736                 xfrm_msg = msg->len ? msg->buf : NULL;
2737         }
2739         if (pgm) {
2740                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2741                                   complete_rewrite);
2742                 return;
2743         }
2744         if (one && two)
2745                 builtin_diff(name, other ? other : name,
2746                              one, two, xfrm_msg, must_show_header,
2747                              o, complete_rewrite);
2748         else
2749                 fprintf(o->file, "* Unmerged path %s\n", name);
2752 static void diff_fill_sha1_info(struct diff_filespec *one)
2754         if (DIFF_FILE_VALID(one)) {
2755                 if (!one->sha1_valid) {
2756                         struct stat st;
2757                         if (!strcmp(one->path, "-")) {
2758                                 hashcpy(one->sha1, null_sha1);
2759                                 return;
2760                         }
2761                         if (lstat(one->path, &st) < 0)
2762                                 die_errno("stat '%s'", one->path);
2763                         if (index_path(one->sha1, one->path, &st, 0))
2764                                 die("cannot hash %s", one->path);
2765                 }
2766         }
2767         else
2768                 hashclr(one->sha1);
2771 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2773         /* Strip the prefix but do not molest /dev/null and absolute paths */
2774         if (*namep && **namep != '/') {
2775                 *namep += prefix_length;
2776                 if (**namep == '/')
2777                         ++*namep;
2778         }
2779         if (*otherp && **otherp != '/') {
2780                 *otherp += prefix_length;
2781                 if (**otherp == '/')
2782                         ++*otherp;
2783         }
2786 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2788         const char *pgm = external_diff();
2789         struct strbuf msg;
2790         struct diff_filespec *one = p->one;
2791         struct diff_filespec *two = p->two;
2792         const char *name;
2793         const char *other;
2794         const char *attr_path;
2796         name  = p->one->path;
2797         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2798         attr_path = name;
2799         if (o->prefix_length)
2800                 strip_prefix(o->prefix_length, &name, &other);
2802         if (DIFF_PAIR_UNMERGED(p)) {
2803                 run_diff_cmd(pgm, name, NULL, attr_path,
2804                              NULL, NULL, NULL, o, p);
2805                 return;
2806         }
2808         diff_fill_sha1_info(one);
2809         diff_fill_sha1_info(two);
2811         if (!pgm &&
2812             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2813             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2814                 /*
2815                  * a filepair that changes between file and symlink
2816                  * needs to be split into deletion and creation.
2817                  */
2818                 struct diff_filespec *null = alloc_filespec(two->path);
2819                 run_diff_cmd(NULL, name, other, attr_path,
2820                              one, null, &msg, o, p);
2821                 free(null);
2822                 strbuf_release(&msg);
2824                 null = alloc_filespec(one->path);
2825                 run_diff_cmd(NULL, name, other, attr_path,
2826                              null, two, &msg, o, p);
2827                 free(null);
2828         }
2829         else
2830                 run_diff_cmd(pgm, name, other, attr_path,
2831                              one, two, &msg, o, p);
2833         strbuf_release(&msg);
2836 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2837                          struct diffstat_t *diffstat)
2839         const char *name;
2840         const char *other;
2841         int complete_rewrite = 0;
2843         if (DIFF_PAIR_UNMERGED(p)) {
2844                 /* unmerged */
2845                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2846                 return;
2847         }
2849         name = p->one->path;
2850         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2852         if (o->prefix_length)
2853                 strip_prefix(o->prefix_length, &name, &other);
2855         diff_fill_sha1_info(p->one);
2856         diff_fill_sha1_info(p->two);
2858         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2859                 complete_rewrite = 1;
2860         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2863 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2865         const char *name;
2866         const char *other;
2867         const char *attr_path;
2869         if (DIFF_PAIR_UNMERGED(p)) {
2870                 /* unmerged */
2871                 return;
2872         }
2874         name = p->one->path;
2875         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2876         attr_path = other ? other : name;
2878         if (o->prefix_length)
2879                 strip_prefix(o->prefix_length, &name, &other);
2881         diff_fill_sha1_info(p->one);
2882         diff_fill_sha1_info(p->two);
2884         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2887 void diff_setup(struct diff_options *options)
2889         memcpy(options, &default_diff_options, sizeof(*options));
2891         options->file = stdout;
2893         options->line_termination = '\n';
2894         options->break_opt = -1;
2895         options->rename_limit = -1;
2896         options->dirstat_percent = 3;
2897         options->context = 3;
2899         options->change = diff_change;
2900         options->add_remove = diff_addremove;
2901         if (diff_use_color_default > 0)
2902                 DIFF_OPT_SET(options, COLOR_DIFF);
2903         options->detect_rename = diff_detect_rename_default;
2905         if (diff_no_prefix) {
2906                 options->a_prefix = options->b_prefix = "";
2907         } else if (!diff_mnemonic_prefix) {
2908                 options->a_prefix = "a/";
2909                 options->b_prefix = "b/";
2910         }
2913 int diff_setup_done(struct diff_options *options)
2915         int count = 0;
2917         if (options->output_format & DIFF_FORMAT_NAME)
2918                 count++;
2919         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2920                 count++;
2921         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2922                 count++;
2923         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2924                 count++;
2925         if (count > 1)
2926                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2928         /*
2929          * Most of the time we can say "there are changes"
2930          * only by checking if there are changed paths, but
2931          * --ignore-whitespace* options force us to look
2932          * inside contents.
2933          */
2935         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2936             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2937             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2938                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2939         else
2940                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2942         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2943                 options->detect_rename = DIFF_DETECT_COPY;
2945         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2946                 options->prefix = NULL;
2947         if (options->prefix)
2948                 options->prefix_length = strlen(options->prefix);
2949         else
2950                 options->prefix_length = 0;
2952         if (options->output_format & (DIFF_FORMAT_NAME |
2953                                       DIFF_FORMAT_NAME_STATUS |
2954                                       DIFF_FORMAT_CHECKDIFF |
2955                                       DIFF_FORMAT_NO_OUTPUT))
2956                 options->output_format &= ~(DIFF_FORMAT_RAW |
2957                                             DIFF_FORMAT_NUMSTAT |
2958                                             DIFF_FORMAT_DIFFSTAT |
2959                                             DIFF_FORMAT_SHORTSTAT |
2960                                             DIFF_FORMAT_DIRSTAT |
2961                                             DIFF_FORMAT_SUMMARY |
2962                                             DIFF_FORMAT_PATCH);
2964         /*
2965          * These cases always need recursive; we do not drop caller-supplied
2966          * recursive bits for other formats here.
2967          */
2968         if (options->output_format & (DIFF_FORMAT_PATCH |
2969                                       DIFF_FORMAT_NUMSTAT |
2970                                       DIFF_FORMAT_DIFFSTAT |
2971                                       DIFF_FORMAT_SHORTSTAT |
2972                                       DIFF_FORMAT_DIRSTAT |
2973                                       DIFF_FORMAT_SUMMARY |
2974                                       DIFF_FORMAT_CHECKDIFF))
2975                 DIFF_OPT_SET(options, RECURSIVE);
2976         /*
2977          * Also pickaxe would not work very well if you do not say recursive
2978          */
2979         if (options->pickaxe)
2980                 DIFF_OPT_SET(options, RECURSIVE);
2981         /*
2982          * When patches are generated, submodules diffed against the work tree
2983          * must be checked for dirtiness too so it can be shown in the output
2984          */
2985         if (options->output_format & DIFF_FORMAT_PATCH)
2986                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2988         if (options->detect_rename && options->rename_limit < 0)
2989                 options->rename_limit = diff_rename_limit_default;
2990         if (options->setup & DIFF_SETUP_USE_CACHE) {
2991                 if (!active_cache)
2992                         /* read-cache does not die even when it fails
2993                          * so it is safe for us to do this here.  Also
2994                          * it does not smudge active_cache or active_nr
2995                          * when it fails, so we do not have to worry about
2996                          * cleaning it up ourselves either.
2997                          */
2998                         read_cache();
2999         }
3000         if (options->abbrev <= 0 || 40 < options->abbrev)
3001                 options->abbrev = 40; /* full */
3003         /*
3004          * It does not make sense to show the first hit we happened
3005          * to have found.  It does not make sense not to return with
3006          * exit code in such a case either.
3007          */
3008         if (DIFF_OPT_TST(options, QUICK)) {
3009                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3010                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3011         }
3013         return 0;
3016 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3018         char c, *eq;
3019         int len;
3021         if (*arg != '-')
3022                 return 0;
3023         c = *++arg;
3024         if (!c)
3025                 return 0;
3026         if (c == arg_short) {
3027                 c = *++arg;
3028                 if (!c)
3029                         return 1;
3030                 if (val && isdigit(c)) {
3031                         char *end;
3032                         int n = strtoul(arg, &end, 10);
3033                         if (*end)
3034                                 return 0;
3035                         *val = n;
3036                         return 1;
3037                 }
3038                 return 0;
3039         }
3040         if (c != '-')
3041                 return 0;
3042         arg++;
3043         eq = strchr(arg, '=');
3044         if (eq)
3045                 len = eq - arg;
3046         else
3047                 len = strlen(arg);
3048         if (!len || strncmp(arg, arg_long, len))
3049                 return 0;
3050         if (eq) {
3051                 int n;
3052                 char *end;
3053                 if (!isdigit(*++eq))
3054                         return 0;
3055                 n = strtoul(eq, &end, 10);
3056                 if (*end)
3057                         return 0;
3058                 *val = n;
3059         }
3060         return 1;
3063 static int diff_scoreopt_parse(const char *opt);
3065 static inline int short_opt(char opt, const char **argv,
3066                             const char **optarg)
3068         const char *arg = argv[0];
3069         if (arg[0] != '-' || arg[1] != opt)
3070                 return 0;
3071         if (arg[2] != '\0') {
3072                 *optarg = arg + 2;
3073                 return 1;
3074         }
3075         if (!argv[1])
3076                 die("Option '%c' requires a value", opt);
3077         *optarg = argv[1];
3078         return 2;
3081 int parse_long_opt(const char *opt, const char **argv,
3082                    const char **optarg)
3084         const char *arg = argv[0];
3085         if (arg[0] != '-' || arg[1] != '-')
3086                 return 0;
3087         arg += strlen("--");
3088         if (prefixcmp(arg, opt))
3089                 return 0;
3090         arg += strlen(opt);
3091         if (*arg == '=') { /* sticked form: --option=value */
3092                 *optarg = arg + 1;
3093                 return 1;
3094         }
3095         if (*arg != '\0')
3096                 return 0;
3097         /* separate form: --option value */
3098         if (!argv[1])
3099                 die("Option '--%s' requires a value", opt);
3100         *optarg = argv[1];
3101         return 2;
3104 static int stat_opt(struct diff_options *options, const char **av)
3106         const char *arg = av[0];
3107         char *end;
3108         int width = options->stat_width;
3109         int name_width = options->stat_name_width;
3110         int argcount = 1;
3112         arg += strlen("--stat");
3113         end = (char *)arg;
3115         switch (*arg) {
3116         case '-':
3117                 if (!prefixcmp(arg, "-width")) {
3118                         arg += strlen("-width");
3119                         if (*arg == '=')
3120                                 width = strtoul(arg + 1, &end, 10);
3121                         else if (!*arg && !av[1])
3122                                 die("Option '--stat-width' requires a value");
3123                         else if (!*arg) {
3124                                 width = strtoul(av[1], &end, 10);
3125                                 argcount = 2;
3126                         }
3127                 } else if (!prefixcmp(arg, "-name-width")) {
3128                         arg += strlen("-name-width");
3129                         if (*arg == '=')
3130                                 name_width = strtoul(arg + 1, &end, 10);
3131                         else if (!*arg && !av[1])
3132                                 die("Option '--stat-name-width' requires a value");
3133                         else if (!*arg) {
3134                                 name_width = strtoul(av[1], &end, 10);
3135                                 argcount = 2;
3136                         }
3137                 }
3138                 break;
3139         case '=':
3140                 width = strtoul(arg+1, &end, 10);
3141                 if (*end == ',')
3142                         name_width = strtoul(end+1, &end, 10);
3143         }
3145         /* Important! This checks all the error cases! */
3146         if (*end)
3147                 return 0;
3148         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3149         options->stat_name_width = name_width;
3150         options->stat_width = width;
3151         return argcount;
3154 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3156         const char *arg = av[0];
3157         const char *optarg;
3158         int argcount;
3160         /* Output format options */
3161         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3162                 options->output_format |= DIFF_FORMAT_PATCH;
3163         else if (opt_arg(arg, 'U', "unified", &options->context))
3164                 options->output_format |= DIFF_FORMAT_PATCH;
3165         else if (!strcmp(arg, "--raw"))
3166                 options->output_format |= DIFF_FORMAT_RAW;
3167         else if (!strcmp(arg, "--patch-with-raw"))
3168                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3169         else if (!strcmp(arg, "--numstat"))
3170                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3171         else if (!strcmp(arg, "--shortstat"))
3172                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3173         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3174                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3175         else if (!strcmp(arg, "--cumulative")) {
3176                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3177                 DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3178         } else if (opt_arg(arg, 0, "dirstat-by-file",
3179                            &options->dirstat_percent)) {
3180                 options->output_format |= DIFF_FORMAT_DIRSTAT;
3181                 DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3182         }
3183         else if (!strcmp(arg, "--check"))
3184                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3185         else if (!strcmp(arg, "--summary"))
3186                 options->output_format |= DIFF_FORMAT_SUMMARY;
3187         else if (!strcmp(arg, "--patch-with-stat"))
3188                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3189         else if (!strcmp(arg, "--name-only"))
3190                 options->output_format |= DIFF_FORMAT_NAME;
3191         else if (!strcmp(arg, "--name-status"))
3192                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3193         else if (!strcmp(arg, "-s"))
3194                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3195         else if (!prefixcmp(arg, "--stat"))
3196                 /* --stat, --stat-width, or --stat-name-width */
3197                 return stat_opt(options, av);
3199         /* renames options */
3200         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3201                  !strcmp(arg, "--break-rewrites")) {
3202                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3203                         return error("invalid argument to -B: %s", arg+2);
3204         }
3205         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3206                  !strcmp(arg, "--find-renames")) {
3207                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3208                         return error("invalid argument to -M: %s", arg+2);
3209                 options->detect_rename = DIFF_DETECT_RENAME;
3210         }
3211         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3212                  !strcmp(arg, "--find-copies")) {
3213                 if (options->detect_rename == DIFF_DETECT_COPY)
3214                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3215                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3216                         return error("invalid argument to -C: %s", arg+2);
3217                 options->detect_rename = DIFF_DETECT_COPY;
3218         }
3219         else if (!strcmp(arg, "--no-renames"))
3220                 options->detect_rename = 0;
3221         else if (!strcmp(arg, "--relative"))
3222                 DIFF_OPT_SET(options, RELATIVE_NAME);
3223         else if (!prefixcmp(arg, "--relative=")) {
3224                 DIFF_OPT_SET(options, RELATIVE_NAME);
3225                 options->prefix = arg + 11;
3226         }
3228         /* xdiff options */
3229         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3230                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3231         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3232                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3233         else if (!strcmp(arg, "--ignore-space-at-eol"))
3234                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3235         else if (!strcmp(arg, "--patience"))
3236                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3238         /* flags options */
3239         else if (!strcmp(arg, "--binary")) {
3240                 options->output_format |= DIFF_FORMAT_PATCH;
3241                 DIFF_OPT_SET(options, BINARY);
3242         }
3243         else if (!strcmp(arg, "--full-index"))
3244                 DIFF_OPT_SET(options, FULL_INDEX);
3245         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3246                 DIFF_OPT_SET(options, TEXT);
3247         else if (!strcmp(arg, "-R"))
3248                 DIFF_OPT_SET(options, REVERSE_DIFF);
3249         else if (!strcmp(arg, "--find-copies-harder"))
3250                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3251         else if (!strcmp(arg, "--follow"))
3252                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3253         else if (!strcmp(arg, "--color"))
3254                 DIFF_OPT_SET(options, COLOR_DIFF);
3255         else if (!prefixcmp(arg, "--color=")) {
3256                 int value = git_config_colorbool(NULL, arg+8, -1);
3257                 if (value == 0)
3258                         DIFF_OPT_CLR(options, COLOR_DIFF);
3259                 else if (value > 0)
3260                         DIFF_OPT_SET(options, COLOR_DIFF);
3261                 else
3262                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3263         }
3264         else if (!strcmp(arg, "--no-color"))
3265                 DIFF_OPT_CLR(options, COLOR_DIFF);
3266         else if (!strcmp(arg, "--color-words")) {
3267                 DIFF_OPT_SET(options, COLOR_DIFF);
3268                 options->word_diff = DIFF_WORDS_COLOR;
3269         }
3270         else if (!prefixcmp(arg, "--color-words=")) {
3271                 DIFF_OPT_SET(options, COLOR_DIFF);
3272                 options->word_diff = DIFF_WORDS_COLOR;
3273                 options->word_regex = arg + 14;
3274         }
3275         else if (!strcmp(arg, "--word-diff")) {
3276                 if (options->word_diff == DIFF_WORDS_NONE)
3277                         options->word_diff = DIFF_WORDS_PLAIN;
3278         }
3279         else if (!prefixcmp(arg, "--word-diff=")) {
3280                 const char *type = arg + 12;
3281                 if (!strcmp(type, "plain"))
3282                         options->word_diff = DIFF_WORDS_PLAIN;
3283                 else if (!strcmp(type, "color")) {
3284                         DIFF_OPT_SET(options, COLOR_DIFF);
3285                         options->word_diff = DIFF_WORDS_COLOR;
3286                 }
3287                 else if (!strcmp(type, "porcelain"))
3288                         options->word_diff = DIFF_WORDS_PORCELAIN;
3289                 else if (!strcmp(type, "none"))
3290                         options->word_diff = DIFF_WORDS_NONE;
3291                 else
3292                         die("bad --word-diff argument: %s", type);
3293         }
3294         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3295                 if (options->word_diff == DIFF_WORDS_NONE)
3296                         options->word_diff = DIFF_WORDS_PLAIN;
3297                 options->word_regex = optarg;
3298                 return argcount;
3299         }
3300         else if (!strcmp(arg, "--exit-code"))
3301                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3302         else if (!strcmp(arg, "--quiet"))
3303                 DIFF_OPT_SET(options, QUICK);
3304         else if (!strcmp(arg, "--ext-diff"))
3305                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3306         else if (!strcmp(arg, "--no-ext-diff"))
3307                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3308         else if (!strcmp(arg, "--textconv"))
3309                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3310         else if (!strcmp(arg, "--no-textconv"))
3311                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3312         else if (!strcmp(arg, "--ignore-submodules")) {
3313                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3314                 handle_ignore_submodules_arg(options, "all");
3315         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3316                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3317                 handle_ignore_submodules_arg(options, arg + 20);
3318         } else if (!strcmp(arg, "--submodule"))
3319                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3320         else if (!prefixcmp(arg, "--submodule=")) {
3321                 if (!strcmp(arg + 12, "log"))
3322                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3323         }
3325         /* misc options */
3326         else if (!strcmp(arg, "-z"))
3327                 options->line_termination = 0;
3328         else if ((argcount = short_opt('l', av, &optarg))) {
3329                 options->rename_limit = strtoul(optarg, NULL, 10);
3330                 return argcount;
3331         }
3332         else if ((argcount = short_opt('S', av, &optarg))) {
3333                 options->pickaxe = optarg;
3334                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3335                 return argcount;
3336         } else if ((argcount = short_opt('G', av, &optarg))) {
3337                 options->pickaxe = optarg;
3338                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3339                 return argcount;
3340         }
3341         else if (!strcmp(arg, "--pickaxe-all"))
3342                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3343         else if (!strcmp(arg, "--pickaxe-regex"))
3344                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3345         else if ((argcount = short_opt('O', av, &optarg))) {
3346                 options->orderfile = optarg;
3347                 return argcount;
3348         }
3349         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3350                 options->filter = optarg;
3351                 return argcount;
3352         }
3353         else if (!strcmp(arg, "--abbrev"))
3354                 options->abbrev = DEFAULT_ABBREV;
3355         else if (!prefixcmp(arg, "--abbrev=")) {
3356                 options->abbrev = strtoul(arg + 9, NULL, 10);
3357                 if (options->abbrev < MINIMUM_ABBREV)
3358                         options->abbrev = MINIMUM_ABBREV;
3359                 else if (40 < options->abbrev)
3360                         options->abbrev = 40;
3361         }
3362         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3363                 options->a_prefix = optarg;
3364                 return argcount;
3365         }
3366         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3367                 options->b_prefix = optarg;
3368                 return argcount;
3369         }
3370         else if (!strcmp(arg, "--no-prefix"))
3371                 options->a_prefix = options->b_prefix = "";
3372         else if (opt_arg(arg, '\0', "inter-hunk-context",
3373                          &options->interhunkcontext))
3374                 ;
3375         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3376                 options->file = fopen(optarg, "w");
3377                 if (!options->file)
3378                         die_errno("Could not open '%s'", optarg);
3379                 options->close_file = 1;
3380                 return argcount;
3381         } else
3382                 return 0;
3383         return 1;
3386 int parse_rename_score(const char **cp_p)
3388         unsigned long num, scale;
3389         int ch, dot;
3390         const char *cp = *cp_p;
3392         num = 0;
3393         scale = 1;
3394         dot = 0;
3395         for (;;) {
3396                 ch = *cp;
3397                 if ( !dot && ch == '.' ) {
3398                         scale = 1;
3399                         dot = 1;
3400                 } else if ( ch == '%' ) {
3401                         scale = dot ? scale*100 : 100;
3402                         cp++;   /* % is always at the end */
3403                         break;
3404                 } else if ( ch >= '0' && ch <= '9' ) {
3405                         if ( scale < 100000 ) {
3406                                 scale *= 10;
3407                                 num = (num*10) + (ch-'0');
3408                         }
3409                 } else {
3410                         break;
3411                 }
3412                 cp++;
3413         }
3414         *cp_p = cp;
3416         /* user says num divided by scale and we say internally that
3417          * is MAX_SCORE * num / scale.
3418          */
3419         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3422 static int diff_scoreopt_parse(const char *opt)
3424         int opt1, opt2, cmd;
3426         if (*opt++ != '-')
3427                 return -1;
3428         cmd = *opt++;
3429         if (cmd == '-') {
3430                 /* convert the long-form arguments into short-form versions */
3431                 if (!prefixcmp(opt, "break-rewrites")) {
3432                         opt += strlen("break-rewrites");
3433                         if (*opt == 0 || *opt++ == '=')
3434                                 cmd = 'B';
3435                 } else if (!prefixcmp(opt, "find-copies")) {
3436                         opt += strlen("find-copies");
3437                         if (*opt == 0 || *opt++ == '=')
3438                                 cmd = 'C';
3439                 } else if (!prefixcmp(opt, "find-renames")) {
3440                         opt += strlen("find-renames");
3441                         if (*opt == 0 || *opt++ == '=')
3442                                 cmd = 'M';
3443                 }
3444         }
3445         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3446                 return -1; /* that is not a -M, -C nor -B option */
3448         opt1 = parse_rename_score(&opt);
3449         if (cmd != 'B')
3450                 opt2 = 0;
3451         else {
3452                 if (*opt == 0)
3453                         opt2 = 0;
3454                 else if (*opt != '/')
3455                         return -1; /* we expect -B80/99 or -B80 */
3456                 else {
3457                         opt++;
3458                         opt2 = parse_rename_score(&opt);
3459                 }
3460         }
3461         if (*opt != 0)
3462                 return -1;
3463         return opt1 | (opt2 << 16);
3466 struct diff_queue_struct diff_queued_diff;
3468 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3470         if (queue->alloc <= queue->nr) {
3471                 queue->alloc = alloc_nr(queue->alloc);
3472                 queue->queue = xrealloc(queue->queue,
3473                                         sizeof(dp) * queue->alloc);
3474         }
3475         queue->queue[queue->nr++] = dp;
3478 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3479                                  struct diff_filespec *one,
3480                                  struct diff_filespec *two)
3482         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3483         dp->one = one;
3484         dp->two = two;
3485         if (queue)
3486                 diff_q(queue, dp);
3487         return dp;
3490 void diff_free_filepair(struct diff_filepair *p)
3492         free_filespec(p->one);
3493         free_filespec(p->two);
3494         free(p);
3497 /* This is different from find_unique_abbrev() in that
3498  * it stuffs the result with dots for alignment.
3499  */
3500 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3502         int abblen;
3503         const char *abbrev;
3504         if (len == 40)
3505                 return sha1_to_hex(sha1);
3507         abbrev = find_unique_abbrev(sha1, len);
3508         abblen = strlen(abbrev);
3509         if (abblen < 37) {
3510                 static char hex[41];
3511                 if (len < abblen && abblen <= len + 2)
3512                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3513                 else
3514                         sprintf(hex, "%s...", abbrev);
3515                 return hex;
3516         }
3517         return sha1_to_hex(sha1);
3520 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3522         int line_termination = opt->line_termination;
3523         int inter_name_termination = line_termination ? '\t' : '\0';
3524         if (opt->output_prefix) {
3525                 struct strbuf *msg = NULL;
3526                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3527                 fprintf(opt->file, "%s", msg->buf);
3528         }
3530         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3531                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3532                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3533                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3534         }
3535         if (p->score) {
3536                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3537                         inter_name_termination);
3538         } else {
3539                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3540         }
3542         if (p->status == DIFF_STATUS_COPIED ||
3543             p->status == DIFF_STATUS_RENAMED) {
3544                 const char *name_a, *name_b;
3545                 name_a = p->one->path;
3546                 name_b = p->two->path;
3547                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3548                 write_name_quoted(name_a, opt->file, inter_name_termination);
3549                 write_name_quoted(name_b, opt->file, line_termination);
3550         } else {
3551                 const char *name_a, *name_b;
3552                 name_a = p->one->mode ? p->one->path : p->two->path;
3553                 name_b = NULL;
3554                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3555                 write_name_quoted(name_a, opt->file, line_termination);
3556         }
3559 int diff_unmodified_pair(struct diff_filepair *p)
3561         /* This function is written stricter than necessary to support
3562          * the currently implemented transformers, but the idea is to
3563          * let transformers to produce diff_filepairs any way they want,
3564          * and filter and clean them up here before producing the output.
3565          */
3566         struct diff_filespec *one = p->one, *two = p->two;
3568         if (DIFF_PAIR_UNMERGED(p))
3569                 return 0; /* unmerged is interesting */
3571         /* deletion, addition, mode or type change
3572          * and rename are all interesting.
3573          */
3574         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3575             DIFF_PAIR_MODE_CHANGED(p) ||
3576             strcmp(one->path, two->path))
3577                 return 0;
3579         /* both are valid and point at the same path.  that is, we are
3580          * dealing with a change.
3581          */
3582         if (one->sha1_valid && two->sha1_valid &&
3583             !hashcmp(one->sha1, two->sha1) &&
3584             !one->dirty_submodule && !two->dirty_submodule)
3585                 return 1; /* no change */
3586         if (!one->sha1_valid && !two->sha1_valid)
3587                 return 1; /* both look at the same file on the filesystem. */
3588         return 0;
3591 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3593         if (diff_unmodified_pair(p))
3594                 return;
3596         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3597             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3598                 return; /* no tree diffs in patch format */
3600         run_diff(p, o);
3603 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3604                             struct diffstat_t *diffstat)
3606         if (diff_unmodified_pair(p))
3607                 return;
3609         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3610             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3611                 return; /* no useful stat for tree diffs */
3613         run_diffstat(p, o, diffstat);
3616 static void diff_flush_checkdiff(struct diff_filepair *p,
3617                 struct diff_options *o)
3619         if (diff_unmodified_pair(p))
3620                 return;
3622         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3623             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3624                 return; /* nothing to check in tree diffs */
3626         run_checkdiff(p, o);
3629 int diff_queue_is_empty(void)
3631         struct diff_queue_struct *q = &diff_queued_diff;
3632         int i;
3633         for (i = 0; i < q->nr; i++)
3634                 if (!diff_unmodified_pair(q->queue[i]))
3635                         return 0;
3636         return 1;
3639 #if DIFF_DEBUG
3640 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3642         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3643                 x, one ? one : "",
3644                 s->path,
3645                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3646                 s->mode,
3647                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3648         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3649                 x, one ? one : "",
3650                 s->size, s->xfrm_flags);
3653 void diff_debug_filepair(const struct diff_filepair *p, int i)
3655         diff_debug_filespec(p->one, i, "one");
3656         diff_debug_filespec(p->two, i, "two");
3657         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3658                 p->score, p->status ? p->status : '?',
3659                 p->one->rename_used, p->broken_pair);
3662 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3664         int i;
3665         if (msg)
3666                 fprintf(stderr, "%s\n", msg);
3667         fprintf(stderr, "q->nr = %d\n", q->nr);
3668         for (i = 0; i < q->nr; i++) {
3669                 struct diff_filepair *p = q->queue[i];
3670                 diff_debug_filepair(p, i);
3671         }
3673 #endif
3675 static void diff_resolve_rename_copy(void)
3677         int i;
3678         struct diff_filepair *p;
3679         struct diff_queue_struct *q = &diff_queued_diff;
3681         diff_debug_queue("resolve-rename-copy", q);
3683         for (i = 0; i < q->nr; i++) {
3684                 p = q->queue[i];
3685                 p->status = 0; /* undecided */
3686                 if (DIFF_PAIR_UNMERGED(p))
3687                         p->status = DIFF_STATUS_UNMERGED;
3688                 else if (!DIFF_FILE_VALID(p->one))
3689                         p->status = DIFF_STATUS_ADDED;
3690                 else if (!DIFF_FILE_VALID(p->two))
3691                         p->status = DIFF_STATUS_DELETED;
3692                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3693                         p->status = DIFF_STATUS_TYPE_CHANGED;
3695                 /* from this point on, we are dealing with a pair
3696                  * whose both sides are valid and of the same type, i.e.
3697                  * either in-place edit or rename/copy edit.
3698                  */
3699                 else if (DIFF_PAIR_RENAME(p)) {
3700                         /*
3701                          * A rename might have re-connected a broken
3702                          * pair up, causing the pathnames to be the
3703                          * same again. If so, that's not a rename at
3704                          * all, just a modification..
3705                          *
3706                          * Otherwise, see if this source was used for
3707                          * multiple renames, in which case we decrement
3708                          * the count, and call it a copy.
3709                          */
3710                         if (!strcmp(p->one->path, p->two->path))
3711                                 p->status = DIFF_STATUS_MODIFIED;
3712                         else if (--p->one->rename_used > 0)
3713                                 p->status = DIFF_STATUS_COPIED;
3714                         else
3715                                 p->status = DIFF_STATUS_RENAMED;
3716                 }
3717                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3718                          p->one->mode != p->two->mode ||
3719                          p->one->dirty_submodule ||
3720                          p->two->dirty_submodule ||
3721                          is_null_sha1(p->one->sha1))
3722                         p->status = DIFF_STATUS_MODIFIED;
3723                 else {
3724                         /* This is a "no-change" entry and should not
3725                          * happen anymore, but prepare for broken callers.
3726                          */
3727                         error("feeding unmodified %s to diffcore",
3728                               p->one->path);
3729                         p->status = DIFF_STATUS_UNKNOWN;
3730                 }
3731         }
3732         diff_debug_queue("resolve-rename-copy done", q);
3735 static int check_pair_status(struct diff_filepair *p)
3737         switch (p->status) {
3738         case DIFF_STATUS_UNKNOWN:
3739                 return 0;
3740         case 0:
3741                 die("internal error in diff-resolve-rename-copy");
3742         default:
3743                 return 1;
3744         }
3747 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3749         int fmt = opt->output_format;
3751         if (fmt & DIFF_FORMAT_CHECKDIFF)
3752                 diff_flush_checkdiff(p, opt);
3753         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3754                 diff_flush_raw(p, opt);
3755         else if (fmt & DIFF_FORMAT_NAME) {
3756                 const char *name_a, *name_b;
3757                 name_a = p->two->path;
3758                 name_b = NULL;
3759                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3760                 write_name_quoted(name_a, opt->file, opt->line_termination);
3761         }
3764 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3766         if (fs->mode)
3767                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3768         else
3769                 fprintf(file, " %s ", newdelete);
3770         write_name_quoted(fs->path, file, '\n');
3774 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3775                 const char *line_prefix)
3777         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3778                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3779                         p->two->mode, show_name ? ' ' : '\n');
3780                 if (show_name) {
3781                         write_name_quoted(p->two->path, file, '\n');
3782                 }
3783         }
3786 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3787                         const char *line_prefix)
3789         char *names = pprint_rename(p->one->path, p->two->path);
3791         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3792         free(names);
3793         show_mode_change(file, p, 0, line_prefix);
3796 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3798         FILE *file = opt->file;
3799         char *line_prefix = "";
3801         if (opt->output_prefix) {
3802                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3803                 line_prefix = buf->buf;
3804         }
3806         switch(p->status) {
3807         case DIFF_STATUS_DELETED:
3808                 fputs(line_prefix, file);
3809                 show_file_mode_name(file, "delete", p->one);
3810                 break;
3811         case DIFF_STATUS_ADDED:
3812                 fputs(line_prefix, file);
3813                 show_file_mode_name(file, "create", p->two);
3814                 break;
3815         case DIFF_STATUS_COPIED:
3816                 fputs(line_prefix, file);
3817                 show_rename_copy(file, "copy", p, line_prefix);
3818                 break;
3819         case DIFF_STATUS_RENAMED:
3820                 fputs(line_prefix, file);
3821                 show_rename_copy(file, "rename", p, line_prefix);
3822                 break;
3823         default:
3824                 if (p->score) {
3825                         fprintf(file, "%s rewrite ", line_prefix);
3826                         write_name_quoted(p->two->path, file, ' ');
3827                         fprintf(file, "(%d%%)\n", similarity_index(p));
3828                 }
3829                 show_mode_change(file, p, !p->score, line_prefix);
3830                 break;
3831         }
3834 struct patch_id_t {
3835         git_SHA_CTX *ctx;
3836         int patchlen;
3837 };
3839 static int remove_space(char *line, int len)
3841         int i;
3842         char *dst = line;
3843         unsigned char c;
3845         for (i = 0; i < len; i++)
3846                 if (!isspace((c = line[i])))
3847                         *dst++ = c;
3849         return dst - line;
3852 static void patch_id_consume(void *priv, char *line, unsigned long len)
3854         struct patch_id_t *data = priv;
3855         int new_len;
3857         /* Ignore line numbers when computing the SHA1 of the patch */
3858         if (!prefixcmp(line, "@@ -"))
3859                 return;
3861         new_len = remove_space(line, len);
3863         git_SHA1_Update(data->ctx, line, new_len);
3864         data->patchlen += new_len;
3867 /* returns 0 upon success, and writes result into sha1 */
3868 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3870         struct diff_queue_struct *q = &diff_queued_diff;
3871         int i;
3872         git_SHA_CTX ctx;
3873         struct patch_id_t data;
3874         char buffer[PATH_MAX * 4 + 20];
3876         git_SHA1_Init(&ctx);
3877         memset(&data, 0, sizeof(struct patch_id_t));
3878         data.ctx = &ctx;
3880         for (i = 0; i < q->nr; i++) {
3881                 xpparam_t xpp;
3882                 xdemitconf_t xecfg;
3883                 mmfile_t mf1, mf2;
3884                 struct diff_filepair *p = q->queue[i];
3885                 int len1, len2;
3887                 memset(&xpp, 0, sizeof(xpp));
3888                 memset(&xecfg, 0, sizeof(xecfg));
3889                 if (p->status == 0)
3890                         return error("internal diff status error");
3891                 if (p->status == DIFF_STATUS_UNKNOWN)
3892                         continue;
3893                 if (diff_unmodified_pair(p))
3894                         continue;
3895                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3896                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3897                         continue;
3898                 if (DIFF_PAIR_UNMERGED(p))
3899                         continue;
3901                 diff_fill_sha1_info(p->one);
3902                 diff_fill_sha1_info(p->two);
3903                 if (fill_mmfile(&mf1, p->one) < 0 ||
3904                                 fill_mmfile(&mf2, p->two) < 0)
3905                         return error("unable to read files to diff");
3907                 len1 = remove_space(p->one->path, strlen(p->one->path));
3908                 len2 = remove_space(p->two->path, strlen(p->two->path));
3909                 if (p->one->mode == 0)
3910                         len1 = snprintf(buffer, sizeof(buffer),
3911                                         "diff--gita/%.*sb/%.*s"
3912                                         "newfilemode%06o"
3913                                         "---/dev/null"
3914                                         "+++b/%.*s",
3915                                         len1, p->one->path,
3916                                         len2, p->two->path,
3917                                         p->two->mode,
3918                                         len2, p->two->path);
3919                 else if (p->two->mode == 0)
3920                         len1 = snprintf(buffer, sizeof(buffer),
3921                                         "diff--gita/%.*sb/%.*s"
3922                                         "deletedfilemode%06o"
3923                                         "---a/%.*s"
3924                                         "+++/dev/null",
3925                                         len1, p->one->path,
3926                                         len2, p->two->path,
3927                                         p->one->mode,
3928                                         len1, p->one->path);
3929                 else
3930                         len1 = snprintf(buffer, sizeof(buffer),
3931                                         "diff--gita/%.*sb/%.*s"
3932                                         "---a/%.*s"
3933                                         "+++b/%.*s",
3934                                         len1, p->one->path,
3935                                         len2, p->two->path,
3936                                         len1, p->one->path,
3937                                         len2, p->two->path);
3938                 git_SHA1_Update(&ctx, buffer, len1);
3940                 if (diff_filespec_is_binary(p->one) ||
3941                     diff_filespec_is_binary(p->two)) {
3942                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3943                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3944                         continue;
3945                 }
3947                 xpp.flags = 0;
3948                 xecfg.ctxlen = 3;
3949                 xecfg.flags = 0;
3950                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3951                               &xpp, &xecfg);
3952         }
3954         git_SHA1_Final(sha1, &ctx);
3955         return 0;
3958 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3960         struct diff_queue_struct *q = &diff_queued_diff;
3961         int i;
3962         int result = diff_get_patch_id(options, sha1);
3964         for (i = 0; i < q->nr; i++)
3965                 diff_free_filepair(q->queue[i]);
3967         free(q->queue);
3968         DIFF_QUEUE_CLEAR(q);
3970         return result;
3973 static int is_summary_empty(const struct diff_queue_struct *q)
3975         int i;
3977         for (i = 0; i < q->nr; i++) {
3978                 const struct diff_filepair *p = q->queue[i];
3980                 switch (p->status) {
3981                 case DIFF_STATUS_DELETED:
3982                 case DIFF_STATUS_ADDED:
3983                 case DIFF_STATUS_COPIED:
3984                 case DIFF_STATUS_RENAMED:
3985                         return 0;
3986                 default:
3987                         if (p->score)
3988                                 return 0;
3989                         if (p->one->mode && p->two->mode &&
3990                             p->one->mode != p->two->mode)
3991                                 return 0;
3992                         break;
3993                 }
3994         }
3995         return 1;
3998 static const char rename_limit_warning[] =
3999 "inexact rename detection was skipped due to too many files.";
4001 static const char degrade_cc_to_c_warning[] =
4002 "only found copies from modified paths due to too many files.";
4004 static const char rename_limit_advice[] =
4005 "you may want to set your %s variable to at least "
4006 "%d and retry the command.";
4008 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4010         if (degraded_cc)
4011                 warning(degrade_cc_to_c_warning);
4012         else if (needed)
4013                 warning(rename_limit_warning);
4014         else
4015                 return;
4016         if (0 < needed && needed < 32767)
4017                 warning(rename_limit_advice, varname, needed);
4020 void diff_flush(struct diff_options *options)
4022         struct diff_queue_struct *q = &diff_queued_diff;
4023         int i, output_format = options->output_format;
4024         int separator = 0;
4026         /*
4027          * Order: raw, stat, summary, patch
4028          * or:    name/name-status/checkdiff (other bits clear)
4029          */
4030         if (!q->nr)
4031                 goto free_queue;
4033         if (output_format & (DIFF_FORMAT_RAW |
4034                              DIFF_FORMAT_NAME |
4035                              DIFF_FORMAT_NAME_STATUS |
4036                              DIFF_FORMAT_CHECKDIFF)) {
4037                 for (i = 0; i < q->nr; i++) {
4038                         struct diff_filepair *p = q->queue[i];
4039                         if (check_pair_status(p))
4040                                 flush_one_pair(p, options);
4041                 }
4042                 separator++;
4043         }
4045         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4046                 struct diffstat_t diffstat;
4048                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4049                 for (i = 0; i < q->nr; i++) {
4050                         struct diff_filepair *p = q->queue[i];
4051                         if (check_pair_status(p))
4052                                 diff_flush_stat(p, options, &diffstat);
4053                 }
4054                 if (output_format & DIFF_FORMAT_NUMSTAT)
4055                         show_numstat(&diffstat, options);
4056                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4057                         show_stats(&diffstat, options);
4058                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4059                         show_shortstats(&diffstat, options);
4060                 free_diffstat_info(&diffstat);
4061                 separator++;
4062         }
4063         if (output_format & DIFF_FORMAT_DIRSTAT)
4064                 show_dirstat(options);
4066         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4067                 for (i = 0; i < q->nr; i++) {
4068                         diff_summary(options, q->queue[i]);
4069                 }
4070                 separator++;
4071         }
4073         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4074             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4075             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4076                 /*
4077                  * run diff_flush_patch for the exit status. setting
4078                  * options->file to /dev/null should be safe, becaue we
4079                  * aren't supposed to produce any output anyway.
4080                  */
4081                 if (options->close_file)
4082                         fclose(options->file);
4083                 options->file = fopen("/dev/null", "w");
4084                 if (!options->file)
4085                         die_errno("Could not open /dev/null");
4086                 options->close_file = 1;
4087                 for (i = 0; i < q->nr; i++) {
4088                         struct diff_filepair *p = q->queue[i];
4089                         if (check_pair_status(p))
4090                                 diff_flush_patch(p, options);
4091                         if (options->found_changes)
4092                                 break;
4093                 }
4094         }
4096         if (output_format & DIFF_FORMAT_PATCH) {
4097                 if (separator) {
4098                         putc(options->line_termination, options->file);
4099                         if (options->stat_sep) {
4100                                 /* attach patch instead of inline */
4101                                 fputs(options->stat_sep, options->file);
4102                         }
4103                 }
4105                 for (i = 0; i < q->nr; i++) {
4106                         struct diff_filepair *p = q->queue[i];
4107                         if (check_pair_status(p))
4108                                 diff_flush_patch(p, options);
4109                 }
4110         }
4112         if (output_format & DIFF_FORMAT_CALLBACK)
4113                 options->format_callback(q, options, options->format_callback_data);
4115         for (i = 0; i < q->nr; i++)
4116                 diff_free_filepair(q->queue[i]);
4117 free_queue:
4118         free(q->queue);
4119         DIFF_QUEUE_CLEAR(q);
4120         if (options->close_file)
4121                 fclose(options->file);
4123         /*
4124          * Report the content-level differences with HAS_CHANGES;
4125          * diff_addremove/diff_change does not set the bit when
4126          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4127          */
4128         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4129                 if (options->found_changes)
4130                         DIFF_OPT_SET(options, HAS_CHANGES);
4131                 else
4132                         DIFF_OPT_CLR(options, HAS_CHANGES);
4133         }
4136 static void diffcore_apply_filter(const char *filter)
4138         int i;
4139         struct diff_queue_struct *q = &diff_queued_diff;
4140         struct diff_queue_struct outq;
4141         DIFF_QUEUE_CLEAR(&outq);
4143         if (!filter)
4144                 return;
4146         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4147                 int found;
4148                 for (i = found = 0; !found && i < q->nr; i++) {
4149                         struct diff_filepair *p = q->queue[i];
4150                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4151                              ((p->score &&
4152                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4153                               (!p->score &&
4154                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4155                             ((p->status != DIFF_STATUS_MODIFIED) &&
4156                              strchr(filter, p->status)))
4157                                 found++;
4158                 }
4159                 if (found)
4160                         return;
4162                 /* otherwise we will clear the whole queue
4163                  * by copying the empty outq at the end of this
4164                  * function, but first clear the current entries
4165                  * in the queue.
4166                  */
4167                 for (i = 0; i < q->nr; i++)
4168                         diff_free_filepair(q->queue[i]);
4169         }
4170         else {
4171                 /* Only the matching ones */
4172                 for (i = 0; i < q->nr; i++) {
4173                         struct diff_filepair *p = q->queue[i];
4175                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4176                              ((p->score &&
4177                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4178                               (!p->score &&
4179                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4180                             ((p->status != DIFF_STATUS_MODIFIED) &&
4181                              strchr(filter, p->status)))
4182                                 diff_q(&outq, p);
4183                         else
4184                                 diff_free_filepair(p);
4185                 }
4186         }
4187         free(q->queue);
4188         *q = outq;
4191 /* Check whether two filespecs with the same mode and size are identical */
4192 static int diff_filespec_is_identical(struct diff_filespec *one,
4193                                       struct diff_filespec *two)
4195         if (S_ISGITLINK(one->mode))
4196                 return 0;
4197         if (diff_populate_filespec(one, 0))
4198                 return 0;
4199         if (diff_populate_filespec(two, 0))
4200                 return 0;
4201         return !memcmp(one->data, two->data, one->size);
4204 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4206         int i;
4207         struct diff_queue_struct *q = &diff_queued_diff;
4208         struct diff_queue_struct outq;
4209         DIFF_QUEUE_CLEAR(&outq);
4211         for (i = 0; i < q->nr; i++) {
4212                 struct diff_filepair *p = q->queue[i];
4214                 /*
4215                  * 1. Entries that come from stat info dirtiness
4216                  *    always have both sides (iow, not create/delete),
4217                  *    one side of the object name is unknown, with
4218                  *    the same mode and size.  Keep the ones that
4219                  *    do not match these criteria.  They have real
4220                  *    differences.
4221                  *
4222                  * 2. At this point, the file is known to be modified,
4223                  *    with the same mode and size, and the object
4224                  *    name of one side is unknown.  Need to inspect
4225                  *    the identical contents.
4226                  */
4227                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4228                     !DIFF_FILE_VALID(p->two) ||
4229                     (p->one->sha1_valid && p->two->sha1_valid) ||
4230                     (p->one->mode != p->two->mode) ||
4231                     diff_populate_filespec(p->one, 1) ||
4232                     diff_populate_filespec(p->two, 1) ||
4233                     (p->one->size != p->two->size) ||
4234                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4235                         diff_q(&outq, p);
4236                 else {
4237                         /*
4238                          * The caller can subtract 1 from skip_stat_unmatch
4239                          * to determine how many paths were dirty only
4240                          * due to stat info mismatch.
4241                          */
4242                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4243                                 diffopt->skip_stat_unmatch++;
4244                         diff_free_filepair(p);
4245                 }
4246         }
4247         free(q->queue);
4248         *q = outq;
4251 static int diffnamecmp(const void *a_, const void *b_)
4253         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4254         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4255         const char *name_a, *name_b;
4257         name_a = a->one ? a->one->path : a->two->path;
4258         name_b = b->one ? b->one->path : b->two->path;
4259         return strcmp(name_a, name_b);
4262 void diffcore_fix_diff_index(struct diff_options *options)
4264         struct diff_queue_struct *q = &diff_queued_diff;
4265         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4268 void diffcore_std(struct diff_options *options)
4270         if (options->skip_stat_unmatch)
4271                 diffcore_skip_stat_unmatch(options);
4272         if (!options->found_follow) {
4273                 /* See try_to_follow_renames() in tree-diff.c */
4274                 if (options->break_opt != -1)
4275                         diffcore_break(options->break_opt);
4276                 if (options->detect_rename)
4277                         diffcore_rename(options);
4278                 if (options->break_opt != -1)
4279                         diffcore_merge_broken();
4280         }
4281         if (options->pickaxe)
4282                 diffcore_pickaxe(options);
4283         if (options->orderfile)
4284                 diffcore_order(options->orderfile);
4285         if (!options->found_follow)
4286                 /* See try_to_follow_renames() in tree-diff.c */
4287                 diff_resolve_rename_copy();
4288         diffcore_apply_filter(options->filter);
4290         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4291                 DIFF_OPT_SET(options, HAS_CHANGES);
4292         else
4293                 DIFF_OPT_CLR(options, HAS_CHANGES);
4295         options->found_follow = 0;
4298 int diff_result_code(struct diff_options *opt, int status)
4300         int result = 0;
4302         diff_warn_rename_limit("diff.renamelimit",
4303                                opt->needed_rename_limit,
4304                                opt->degraded_cc_to_c);
4305         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4306             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4307                 return status;
4308         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4309             DIFF_OPT_TST(opt, HAS_CHANGES))
4310                 result |= 01;
4311         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4312             DIFF_OPT_TST(opt, CHECK_FAILED))
4313                 result |= 02;
4314         return result;
4317 /*
4318  * Shall changes to this submodule be ignored?
4319  *
4320  * Submodule changes can be configured to be ignored separately for each path,
4321  * but that configuration can be overridden from the command line.
4322  */
4323 static int is_submodule_ignored(const char *path, struct diff_options *options)
4325         int ignored = 0;
4326         unsigned orig_flags = options->flags;
4327         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4328                 set_diffopt_flags_from_submodule_config(options, path);
4329         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4330                 ignored = 1;
4331         options->flags = orig_flags;
4332         return ignored;
4335 void diff_addremove(struct diff_options *options,
4336                     int addremove, unsigned mode,
4337                     const unsigned char *sha1,
4338                     const char *concatpath, unsigned dirty_submodule)
4340         struct diff_filespec *one, *two;
4342         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4343                 return;
4345         /* This may look odd, but it is a preparation for
4346          * feeding "there are unchanged files which should
4347          * not produce diffs, but when you are doing copy
4348          * detection you would need them, so here they are"
4349          * entries to the diff-core.  They will be prefixed
4350          * with something like '=' or '*' (I haven't decided
4351          * which but should not make any difference).
4352          * Feeding the same new and old to diff_change()
4353          * also has the same effect.
4354          * Before the final output happens, they are pruned after
4355          * merged into rename/copy pairs as appropriate.
4356          */
4357         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4358                 addremove = (addremove == '+' ? '-' :
4359                              addremove == '-' ? '+' : addremove);
4361         if (options->prefix &&
4362             strncmp(concatpath, options->prefix, options->prefix_length))
4363                 return;
4365         one = alloc_filespec(concatpath);
4366         two = alloc_filespec(concatpath);
4368         if (addremove != '+')
4369                 fill_filespec(one, sha1, mode);
4370         if (addremove != '-') {
4371                 fill_filespec(two, sha1, mode);
4372                 two->dirty_submodule = dirty_submodule;
4373         }
4375         diff_queue(&diff_queued_diff, one, two);
4376         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4377                 DIFF_OPT_SET(options, HAS_CHANGES);
4380 void diff_change(struct diff_options *options,
4381                  unsigned old_mode, unsigned new_mode,
4382                  const unsigned char *old_sha1,
4383                  const unsigned char *new_sha1,
4384                  const char *concatpath,
4385                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4387         struct diff_filespec *one, *two;
4389         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4390             is_submodule_ignored(concatpath, options))
4391                 return;
4393         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4394                 unsigned tmp;
4395                 const unsigned char *tmp_c;
4396                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4397                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4398                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4399                         new_dirty_submodule = tmp;
4400         }
4402         if (options->prefix &&
4403             strncmp(concatpath, options->prefix, options->prefix_length))
4404                 return;
4406         one = alloc_filespec(concatpath);
4407         two = alloc_filespec(concatpath);
4408         fill_filespec(one, old_sha1, old_mode);
4409         fill_filespec(two, new_sha1, new_mode);
4410         one->dirty_submodule = old_dirty_submodule;
4411         two->dirty_submodule = new_dirty_submodule;
4413         diff_queue(&diff_queued_diff, one, two);
4414         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4415                 DIFF_OPT_SET(options, HAS_CHANGES);
4418 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4420         struct diff_filepair *pair;
4421         struct diff_filespec *one, *two;
4423         if (options->prefix &&
4424             strncmp(path, options->prefix, options->prefix_length))
4425                 return NULL;
4427         one = alloc_filespec(path);
4428         two = alloc_filespec(path);
4429         pair = diff_queue(&diff_queued_diff, one, two);
4430         pair->is_unmerged = 1;
4431         return pair;
4434 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4435                 size_t *outsize)
4437         struct diff_tempfile *temp;
4438         const char *argv[3];
4439         const char **arg = argv;
4440         struct child_process child;
4441         struct strbuf buf = STRBUF_INIT;
4442         int err = 0;
4444         temp = prepare_temp_file(spec->path, spec);
4445         *arg++ = pgm;
4446         *arg++ = temp->name;
4447         *arg = NULL;
4449         memset(&child, 0, sizeof(child));
4450         child.use_shell = 1;
4451         child.argv = argv;
4452         child.out = -1;
4453         if (start_command(&child)) {
4454                 remove_tempfile();
4455                 return NULL;
4456         }
4458         if (strbuf_read(&buf, child.out, 0) < 0)
4459                 err = error("error reading from textconv command '%s'", pgm);
4460         close(child.out);
4462         if (finish_command(&child) || err) {
4463                 strbuf_release(&buf);
4464                 remove_tempfile();
4465                 return NULL;
4466         }
4467         remove_tempfile();
4469         return strbuf_detach(&buf, outsize);
4472 size_t fill_textconv(struct userdiff_driver *driver,
4473                      struct diff_filespec *df,
4474                      char **outbuf)
4476         size_t size;
4478         if (!driver || !driver->textconv) {
4479                 if (!DIFF_FILE_VALID(df)) {
4480                         *outbuf = "";
4481                         return 0;
4482                 }
4483                 if (diff_populate_filespec(df, 0))
4484                         die("unable to read files to diff");
4485                 *outbuf = df->data;
4486                 return df->size;
4487         }
4489         if (driver->textconv_cache && df->sha1_valid) {
4490                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4491                                           &size);
4492                 if (*outbuf)
4493                         return size;
4494         }
4496         *outbuf = run_textconv(driver->textconv, df, &size);
4497         if (!*outbuf)
4498                 die("unable to read files to diff");
4500         if (driver->textconv_cache && df->sha1_valid) {
4501                 /* ignore errors, as we might be in a readonly repository */
4502                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4503                                 size);
4504                 /*
4505                  * we could save up changes and flush them all at the end,
4506                  * but we would need an extra call after all diffing is done.
4507                  * Since generating a cache entry is the slow path anyway,
4508                  * this extra overhead probably isn't a big deal.
4509                  */
4510                 notes_cache_write(driver->textconv_cache);
4511         }
4513         return size;