Code

Merge branches zj/decimal-width, zj/term-columns and jc/diff-stat-scaler
[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 int diff_dirstat_permille_default = 30;
35 static struct diff_options default_diff_options;
37 static char diff_colors[][COLOR_MAXLEN] = {
38         GIT_COLOR_RESET,
39         GIT_COLOR_NORMAL,       /* PLAIN */
40         GIT_COLOR_BOLD,         /* METAINFO */
41         GIT_COLOR_CYAN,         /* FRAGINFO */
42         GIT_COLOR_RED,          /* OLD */
43         GIT_COLOR_GREEN,        /* NEW */
44         GIT_COLOR_YELLOW,       /* COMMIT */
45         GIT_COLOR_BG_RED,       /* WHITESPACE */
46         GIT_COLOR_NORMAL,       /* FUNCINFO */
47 };
49 static int parse_diff_color_slot(const char *var, int ofs)
50 {
51         if (!strcasecmp(var+ofs, "plain"))
52                 return DIFF_PLAIN;
53         if (!strcasecmp(var+ofs, "meta"))
54                 return DIFF_METAINFO;
55         if (!strcasecmp(var+ofs, "frag"))
56                 return DIFF_FRAGINFO;
57         if (!strcasecmp(var+ofs, "old"))
58                 return DIFF_FILE_OLD;
59         if (!strcasecmp(var+ofs, "new"))
60                 return DIFF_FILE_NEW;
61         if (!strcasecmp(var+ofs, "commit"))
62                 return DIFF_COMMIT;
63         if (!strcasecmp(var+ofs, "whitespace"))
64                 return DIFF_WHITESPACE;
65         if (!strcasecmp(var+ofs, "func"))
66                 return DIFF_FUNCINFO;
67         return -1;
68 }
70 static int parse_dirstat_params(struct diff_options *options, const char *params,
71                                 struct strbuf *errmsg)
72 {
73         const char *p = params;
74         int p_len, ret = 0;
76         while (*p) {
77                 p_len = strchrnul(p, ',') - p;
78                 if (!memcmp(p, "changes", p_len)) {
79                         DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
80                         DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
81                 } else if (!memcmp(p, "lines", p_len)) {
82                         DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
83                         DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
84                 } else if (!memcmp(p, "files", p_len)) {
85                         DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
86                         DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
87                 } else if (!memcmp(p, "noncumulative", p_len)) {
88                         DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
89                 } else if (!memcmp(p, "cumulative", p_len)) {
90                         DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
91                 } else if (isdigit(*p)) {
92                         char *end;
93                         int permille = strtoul(p, &end, 10) * 10;
94                         if (*end == '.' && isdigit(*++end)) {
95                                 /* only use first digit */
96                                 permille += *end - '0';
97                                 /* .. and ignore any further digits */
98                                 while (isdigit(*++end))
99                                         ; /* nothing */
100                         }
101                         if (end - p == p_len)
102                                 options->dirstat_permille = permille;
103                         else {
104                                 strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
105                                             p_len, p);
106                                 ret++;
107                         }
108                 } else {
109                         strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
110                                     p_len, p);
111                         ret++;
112                 }
114                 p += p_len;
116                 if (*p)
117                         p++; /* more parameters, swallow separator */
118         }
119         return ret;
122 static int git_config_rename(const char *var, const char *value)
124         if (!value)
125                 return DIFF_DETECT_RENAME;
126         if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
127                 return  DIFF_DETECT_COPY;
128         return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
131 /*
132  * These are to give UI layer defaults.
133  * The core-level commands such as git-diff-files should
134  * never be affected by the setting of diff.renames
135  * the user happens to have in the configuration file.
136  */
137 int git_diff_ui_config(const char *var, const char *value, void *cb)
139         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
140                 diff_use_color_default = git_config_colorbool(var, value);
141                 return 0;
142         }
143         if (!strcmp(var, "diff.renames")) {
144                 diff_detect_rename_default = git_config_rename(var, value);
145                 return 0;
146         }
147         if (!strcmp(var, "diff.autorefreshindex")) {
148                 diff_auto_refresh_index = git_config_bool(var, value);
149                 return 0;
150         }
151         if (!strcmp(var, "diff.mnemonicprefix")) {
152                 diff_mnemonic_prefix = git_config_bool(var, value);
153                 return 0;
154         }
155         if (!strcmp(var, "diff.noprefix")) {
156                 diff_no_prefix = git_config_bool(var, value);
157                 return 0;
158         }
159         if (!strcmp(var, "diff.external"))
160                 return git_config_string(&external_diff_cmd_cfg, var, value);
161         if (!strcmp(var, "diff.wordregex"))
162                 return git_config_string(&diff_word_regex_cfg, var, value);
164         if (!strcmp(var, "diff.ignoresubmodules"))
165                 handle_ignore_submodules_arg(&default_diff_options, value);
167         if (git_color_config(var, value, cb) < 0)
168                 return -1;
170         return git_diff_basic_config(var, value, cb);
173 int git_diff_basic_config(const char *var, const char *value, void *cb)
175         if (!strcmp(var, "diff.renamelimit")) {
176                 diff_rename_limit_default = git_config_int(var, value);
177                 return 0;
178         }
180         switch (userdiff_config(var, value)) {
181                 case 0: break;
182                 case -1: return -1;
183                 default: return 0;
184         }
186         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
187                 int slot = parse_diff_color_slot(var, 11);
188                 if (slot < 0)
189                         return 0;
190                 if (!value)
191                         return config_error_nonbool(var);
192                 color_parse(value, var, diff_colors[slot]);
193                 return 0;
194         }
196         /* like GNU diff's --suppress-blank-empty option  */
197         if (!strcmp(var, "diff.suppressblankempty") ||
198                         /* for backwards compatibility */
199                         !strcmp(var, "diff.suppress-blank-empty")) {
200                 diff_suppress_blank_empty = git_config_bool(var, value);
201                 return 0;
202         }
204         if (!strcmp(var, "diff.dirstat")) {
205                 struct strbuf errmsg = STRBUF_INIT;
206                 default_diff_options.dirstat_permille = diff_dirstat_permille_default;
207                 if (parse_dirstat_params(&default_diff_options, value, &errmsg))
208                         warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
209                                 errmsg.buf);
210                 strbuf_release(&errmsg);
211                 diff_dirstat_permille_default = default_diff_options.dirstat_permille;
212                 return 0;
213         }
215         if (!prefixcmp(var, "submodule."))
216                 return parse_submodule_config_option(var, value);
218         return git_default_config(var, value, cb);
221 static char *quote_two(const char *one, const char *two)
223         int need_one = quote_c_style(one, NULL, NULL, 1);
224         int need_two = quote_c_style(two, NULL, NULL, 1);
225         struct strbuf res = STRBUF_INIT;
227         if (need_one + need_two) {
228                 strbuf_addch(&res, '"');
229                 quote_c_style(one, &res, NULL, 1);
230                 quote_c_style(two, &res, NULL, 1);
231                 strbuf_addch(&res, '"');
232         } else {
233                 strbuf_addstr(&res, one);
234                 strbuf_addstr(&res, two);
235         }
236         return strbuf_detach(&res, NULL);
239 static const char *external_diff(void)
241         static const char *external_diff_cmd = NULL;
242         static int done_preparing = 0;
244         if (done_preparing)
245                 return external_diff_cmd;
246         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
247         if (!external_diff_cmd)
248                 external_diff_cmd = external_diff_cmd_cfg;
249         done_preparing = 1;
250         return external_diff_cmd;
253 static struct diff_tempfile {
254         const char *name; /* filename external diff should read from */
255         char hex[41];
256         char mode[10];
257         char tmp_path[PATH_MAX];
258 } diff_temp[2];
260 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
262 struct emit_callback {
263         int color_diff;
264         unsigned ws_rule;
265         int blank_at_eof_in_preimage;
266         int blank_at_eof_in_postimage;
267         int lno_in_preimage;
268         int lno_in_postimage;
269         sane_truncate_fn truncate;
270         const char **label_path;
271         struct diff_words_data *diff_words;
272         struct diff_options *opt;
273         int *found_changesp;
274         struct strbuf *header;
275 };
277 static int count_lines(const char *data, int size)
279         int count, ch, completely_empty = 1, nl_just_seen = 0;
280         count = 0;
281         while (0 < size--) {
282                 ch = *data++;
283                 if (ch == '\n') {
284                         count++;
285                         nl_just_seen = 1;
286                         completely_empty = 0;
287                 }
288                 else {
289                         nl_just_seen = 0;
290                         completely_empty = 0;
291                 }
292         }
293         if (completely_empty)
294                 return 0;
295         if (!nl_just_seen)
296                 count++; /* no trailing newline */
297         return count;
300 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
302         if (!DIFF_FILE_VALID(one)) {
303                 mf->ptr = (char *)""; /* does not matter */
304                 mf->size = 0;
305                 return 0;
306         }
307         else if (diff_populate_filespec(one, 0))
308                 return -1;
310         mf->ptr = one->data;
311         mf->size = one->size;
312         return 0;
315 /* like fill_mmfile, but only for size, so we can avoid retrieving blob */
316 static unsigned long diff_filespec_size(struct diff_filespec *one)
318         if (!DIFF_FILE_VALID(one))
319                 return 0;
320         diff_populate_filespec(one, 1);
321         return one->size;
324 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
326         char *ptr = mf->ptr;
327         long size = mf->size;
328         int cnt = 0;
330         if (!size)
331                 return cnt;
332         ptr += size - 1; /* pointing at the very end */
333         if (*ptr != '\n')
334                 ; /* incomplete line */
335         else
336                 ptr--; /* skip the last LF */
337         while (mf->ptr < ptr) {
338                 char *prev_eol;
339                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
340                         if (*prev_eol == '\n')
341                                 break;
342                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
343                         break;
344                 cnt++;
345                 ptr = prev_eol - 1;
346         }
347         return cnt;
350 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
351                                struct emit_callback *ecbdata)
353         int l1, l2, at;
354         unsigned ws_rule = ecbdata->ws_rule;
355         l1 = count_trailing_blank(mf1, ws_rule);
356         l2 = count_trailing_blank(mf2, ws_rule);
357         if (l2 <= l1) {
358                 ecbdata->blank_at_eof_in_preimage = 0;
359                 ecbdata->blank_at_eof_in_postimage = 0;
360                 return;
361         }
362         at = count_lines(mf1->ptr, mf1->size);
363         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
365         at = count_lines(mf2->ptr, mf2->size);
366         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
369 static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
370                         int first, const char *line, int len)
372         int has_trailing_newline, has_trailing_carriage_return;
373         int nofirst;
374         FILE *file = o->file;
376         if (o->output_prefix) {
377                 struct strbuf *msg = NULL;
378                 msg = o->output_prefix(o, o->output_prefix_data);
379                 assert(msg);
380                 fwrite(msg->buf, msg->len, 1, file);
381         }
383         if (len == 0) {
384                 has_trailing_newline = (first == '\n');
385                 has_trailing_carriage_return = (!has_trailing_newline &&
386                                                 (first == '\r'));
387                 nofirst = has_trailing_newline || has_trailing_carriage_return;
388         } else {
389                 has_trailing_newline = (len > 0 && line[len-1] == '\n');
390                 if (has_trailing_newline)
391                         len--;
392                 has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
393                 if (has_trailing_carriage_return)
394                         len--;
395                 nofirst = 0;
396         }
398         if (len || !nofirst) {
399                 fputs(set, file);
400                 if (!nofirst)
401                         fputc(first, file);
402                 fwrite(line, len, 1, file);
403                 fputs(reset, file);
404         }
405         if (has_trailing_carriage_return)
406                 fputc('\r', file);
407         if (has_trailing_newline)
408                 fputc('\n', file);
411 static void emit_line(struct diff_options *o, const char *set, const char *reset,
412                       const char *line, int len)
414         emit_line_0(o, set, reset, line[0], line+1, len-1);
417 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
419         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
420               ecbdata->blank_at_eof_in_preimage &&
421               ecbdata->blank_at_eof_in_postimage &&
422               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
423               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
424                 return 0;
425         return ws_blank_line(line, len, ecbdata->ws_rule);
428 static void emit_add_line(const char *reset,
429                           struct emit_callback *ecbdata,
430                           const char *line, int len)
432         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
433         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
435         if (!*ws)
436                 emit_line_0(ecbdata->opt, set, reset, '+', line, len);
437         else if (new_blank_line_at_eof(ecbdata, line, len))
438                 /* Blank line at EOF - paint '+' as well */
439                 emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
440         else {
441                 /* Emit just the prefix, then the rest. */
442                 emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
443                 ws_check_emit(line, len, ecbdata->ws_rule,
444                               ecbdata->opt->file, set, reset, ws);
445         }
448 static void emit_hunk_header(struct emit_callback *ecbdata,
449                              const char *line, int len)
451         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
452         const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
453         const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
454         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
455         static const char atat[2] = { '@', '@' };
456         const char *cp, *ep;
457         struct strbuf msgbuf = STRBUF_INIT;
458         int org_len = len;
459         int i = 1;
461         /*
462          * As a hunk header must begin with "@@ -<old>, +<new> @@",
463          * it always is at least 10 bytes long.
464          */
465         if (len < 10 ||
466             memcmp(line, atat, 2) ||
467             !(ep = memmem(line + 2, len - 2, atat, 2))) {
468                 emit_line(ecbdata->opt, plain, reset, line, len);
469                 return;
470         }
471         ep += 2; /* skip over @@ */
473         /* The hunk header in fraginfo color */
474         strbuf_add(&msgbuf, frag, strlen(frag));
475         strbuf_add(&msgbuf, line, ep - line);
476         strbuf_add(&msgbuf, reset, strlen(reset));
478         /*
479          * trailing "\r\n"
480          */
481         for ( ; i < 3; i++)
482                 if (line[len - i] == '\r' || line[len - i] == '\n')
483                         len--;
485         /* blank before the func header */
486         for (cp = ep; ep - line < len; ep++)
487                 if (*ep != ' ' && *ep != '\t')
488                         break;
489         if (ep != cp) {
490                 strbuf_add(&msgbuf, plain, strlen(plain));
491                 strbuf_add(&msgbuf, cp, ep - cp);
492                 strbuf_add(&msgbuf, reset, strlen(reset));
493         }
495         if (ep < line + len) {
496                 strbuf_add(&msgbuf, func, strlen(func));
497                 strbuf_add(&msgbuf, ep, line + len - ep);
498                 strbuf_add(&msgbuf, reset, strlen(reset));
499         }
501         strbuf_add(&msgbuf, line + len, org_len - len);
502         emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
503         strbuf_release(&msgbuf);
506 static struct diff_tempfile *claim_diff_tempfile(void) {
507         int i;
508         for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
509                 if (!diff_temp[i].name)
510                         return diff_temp + i;
511         die("BUG: diff is failing to clean up its tempfiles");
514 static int remove_tempfile_installed;
516 static void remove_tempfile(void)
518         int i;
519         for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
520                 if (diff_temp[i].name == diff_temp[i].tmp_path)
521                         unlink_or_warn(diff_temp[i].name);
522                 diff_temp[i].name = NULL;
523         }
526 static void remove_tempfile_on_signal(int signo)
528         remove_tempfile();
529         sigchain_pop(signo);
530         raise(signo);
533 static void print_line_count(FILE *file, int count)
535         switch (count) {
536         case 0:
537                 fprintf(file, "0,0");
538                 break;
539         case 1:
540                 fprintf(file, "1");
541                 break;
542         default:
543                 fprintf(file, "1,%d", count);
544                 break;
545         }
548 static void emit_rewrite_lines(struct emit_callback *ecb,
549                                int prefix, const char *data, int size)
551         const char *endp = NULL;
552         static const char *nneof = " No newline at end of file\n";
553         const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
554         const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
556         while (0 < size) {
557                 int len;
559                 endp = memchr(data, '\n', size);
560                 len = endp ? (endp - data + 1) : size;
561                 if (prefix != '+') {
562                         ecb->lno_in_preimage++;
563                         emit_line_0(ecb->opt, old, reset, '-',
564                                     data, len);
565                 } else {
566                         ecb->lno_in_postimage++;
567                         emit_add_line(reset, ecb, data, len);
568                 }
569                 size -= len;
570                 data += len;
571         }
572         if (!endp) {
573                 const char *plain = diff_get_color(ecb->color_diff,
574                                                    DIFF_PLAIN);
575                 emit_line_0(ecb->opt, plain, reset, '\\',
576                             nneof, strlen(nneof));
577         }
580 static void emit_rewrite_diff(const char *name_a,
581                               const char *name_b,
582                               struct diff_filespec *one,
583                               struct diff_filespec *two,
584                               struct userdiff_driver *textconv_one,
585                               struct userdiff_driver *textconv_two,
586                               struct diff_options *o)
588         int lc_a, lc_b;
589         const char *name_a_tab, *name_b_tab;
590         const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
591         const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
592         const char *reset = diff_get_color(o->use_color, DIFF_RESET);
593         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
594         const char *a_prefix, *b_prefix;
595         char *data_one, *data_two;
596         size_t size_one, size_two;
597         struct emit_callback ecbdata;
598         char *line_prefix = "";
599         struct strbuf *msgbuf;
601         if (o && o->output_prefix) {
602                 msgbuf = o->output_prefix(o, o->output_prefix_data);
603                 line_prefix = msgbuf->buf;
604         }
606         if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
607                 a_prefix = o->b_prefix;
608                 b_prefix = o->a_prefix;
609         } else {
610                 a_prefix = o->a_prefix;
611                 b_prefix = o->b_prefix;
612         }
614         name_a += (*name_a == '/');
615         name_b += (*name_b == '/');
616         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
617         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
619         strbuf_reset(&a_name);
620         strbuf_reset(&b_name);
621         quote_two_c_style(&a_name, a_prefix, name_a, 0);
622         quote_two_c_style(&b_name, b_prefix, name_b, 0);
624         size_one = fill_textconv(textconv_one, one, &data_one);
625         size_two = fill_textconv(textconv_two, two, &data_two);
627         memset(&ecbdata, 0, sizeof(ecbdata));
628         ecbdata.color_diff = want_color(o->use_color);
629         ecbdata.found_changesp = &o->found_changes;
630         ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
631         ecbdata.opt = o;
632         if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
633                 mmfile_t mf1, mf2;
634                 mf1.ptr = (char *)data_one;
635                 mf2.ptr = (char *)data_two;
636                 mf1.size = size_one;
637                 mf2.size = size_two;
638                 check_blank_at_eof(&mf1, &mf2, &ecbdata);
639         }
640         ecbdata.lno_in_preimage = 1;
641         ecbdata.lno_in_postimage = 1;
643         lc_a = count_lines(data_one, size_one);
644         lc_b = count_lines(data_two, size_two);
645         fprintf(o->file,
646                 "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
647                 line_prefix, metainfo, a_name.buf, name_a_tab, reset,
648                 line_prefix, metainfo, b_name.buf, name_b_tab, reset,
649                 line_prefix, fraginfo);
650         if (!o->irreversible_delete)
651                 print_line_count(o->file, lc_a);
652         else
653                 fprintf(o->file, "?,?");
654         fprintf(o->file, " +");
655         print_line_count(o->file, lc_b);
656         fprintf(o->file, " @@%s\n", reset);
657         if (lc_a && !o->irreversible_delete)
658                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
659         if (lc_b)
660                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
661         if (textconv_one)
662                 free((char *)data_one);
663         if (textconv_two)
664                 free((char *)data_two);
667 struct diff_words_buffer {
668         mmfile_t text;
669         long alloc;
670         struct diff_words_orig {
671                 const char *begin, *end;
672         } *orig;
673         int orig_nr, orig_alloc;
674 };
676 static void diff_words_append(char *line, unsigned long len,
677                 struct diff_words_buffer *buffer)
679         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
680         line++;
681         len--;
682         memcpy(buffer->text.ptr + buffer->text.size, line, len);
683         buffer->text.size += len;
684         buffer->text.ptr[buffer->text.size] = '\0';
687 struct diff_words_style_elem {
688         const char *prefix;
689         const char *suffix;
690         const char *color; /* NULL; filled in by the setup code if
691                             * color is enabled */
692 };
694 struct diff_words_style {
695         enum diff_words_type type;
696         struct diff_words_style_elem new, old, ctx;
697         const char *newline;
698 };
700 static struct diff_words_style diff_words_styles[] = {
701         { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
702         { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
703         { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
704 };
706 struct diff_words_data {
707         struct diff_words_buffer minus, plus;
708         const char *current_plus;
709         int last_minus;
710         struct diff_options *opt;
711         regex_t *word_regex;
712         enum diff_words_type type;
713         struct diff_words_style *style;
714 };
716 static int fn_out_diff_words_write_helper(FILE *fp,
717                                           struct diff_words_style_elem *st_el,
718                                           const char *newline,
719                                           size_t count, const char *buf,
720                                           const char *line_prefix)
722         int print = 0;
724         while (count) {
725                 char *p = memchr(buf, '\n', count);
726                 if (print)
727                         fputs(line_prefix, fp);
728                 if (p != buf) {
729                         if (st_el->color && fputs(st_el->color, fp) < 0)
730                                 return -1;
731                         if (fputs(st_el->prefix, fp) < 0 ||
732                             fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
733                             fputs(st_el->suffix, fp) < 0)
734                                 return -1;
735                         if (st_el->color && *st_el->color
736                             && fputs(GIT_COLOR_RESET, fp) < 0)
737                                 return -1;
738                 }
739                 if (!p)
740                         return 0;
741                 if (fputs(newline, fp) < 0)
742                         return -1;
743                 count -= p + 1 - buf;
744                 buf = p + 1;
745                 print = 1;
746         }
747         return 0;
750 /*
751  * '--color-words' algorithm can be described as:
752  *
753  *   1. collect a the minus/plus lines of a diff hunk, divided into
754  *      minus-lines and plus-lines;
755  *
756  *   2. break both minus-lines and plus-lines into words and
757  *      place them into two mmfile_t with one word for each line;
758  *
759  *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
760  *
761  * And for the common parts of the both file, we output the plus side text.
762  * diff_words->current_plus is used to trace the current position of the plus file
763  * which printed. diff_words->last_minus is used to trace the last minus word
764  * printed.
765  *
766  * For '--graph' to work with '--color-words', we need to output the graph prefix
767  * on each line of color words output. Generally, there are two conditions on
768  * which we should output the prefix.
769  *
770  *   1. diff_words->last_minus == 0 &&
771  *      diff_words->current_plus == diff_words->plus.text.ptr
772  *
773  *      that is: the plus text must start as a new line, and if there is no minus
774  *      word printed, a graph prefix must be printed.
775  *
776  *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
777  *      *(diff_words->current_plus - 1) == '\n'
778  *
779  *      that is: a graph prefix must be printed following a '\n'
780  */
781 static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
783         if ((diff_words->last_minus == 0 &&
784                 diff_words->current_plus == diff_words->plus.text.ptr) ||
785                 (diff_words->current_plus > diff_words->plus.text.ptr &&
786                 *(diff_words->current_plus - 1) == '\n')) {
787                 return 1;
788         } else {
789                 return 0;
790         }
793 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
795         struct diff_words_data *diff_words = priv;
796         struct diff_words_style *style = diff_words->style;
797         int minus_first, minus_len, plus_first, plus_len;
798         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
799         struct diff_options *opt = diff_words->opt;
800         struct strbuf *msgbuf;
801         char *line_prefix = "";
803         if (line[0] != '@' || parse_hunk_header(line, len,
804                         &minus_first, &minus_len, &plus_first, &plus_len))
805                 return;
807         assert(opt);
808         if (opt->output_prefix) {
809                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
810                 line_prefix = msgbuf->buf;
811         }
813         /* POSIX requires that first be decremented by one if len == 0... */
814         if (minus_len) {
815                 minus_begin = diff_words->minus.orig[minus_first].begin;
816                 minus_end =
817                         diff_words->minus.orig[minus_first + minus_len - 1].end;
818         } else
819                 minus_begin = minus_end =
820                         diff_words->minus.orig[minus_first].end;
822         if (plus_len) {
823                 plus_begin = diff_words->plus.orig[plus_first].begin;
824                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
825         } else
826                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
828         if (color_words_output_graph_prefix(diff_words)) {
829                 fputs(line_prefix, diff_words->opt->file);
830         }
831         if (diff_words->current_plus != plus_begin) {
832                 fn_out_diff_words_write_helper(diff_words->opt->file,
833                                 &style->ctx, style->newline,
834                                 plus_begin - diff_words->current_plus,
835                                 diff_words->current_plus, line_prefix);
836                 if (*(plus_begin - 1) == '\n')
837                         fputs(line_prefix, diff_words->opt->file);
838         }
839         if (minus_begin != minus_end) {
840                 fn_out_diff_words_write_helper(diff_words->opt->file,
841                                 &style->old, style->newline,
842                                 minus_end - minus_begin, minus_begin,
843                                 line_prefix);
844         }
845         if (plus_begin != plus_end) {
846                 fn_out_diff_words_write_helper(diff_words->opt->file,
847                                 &style->new, style->newline,
848                                 plus_end - plus_begin, plus_begin,
849                                 line_prefix);
850         }
852         diff_words->current_plus = plus_end;
853         diff_words->last_minus = minus_first;
856 /* This function starts looking at *begin, and returns 0 iff a word was found. */
857 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
858                 int *begin, int *end)
860         if (word_regex && *begin < buffer->size) {
861                 regmatch_t match[1];
862                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
863                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
864                                         '\n', match[0].rm_eo - match[0].rm_so);
865                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
866                         *begin += match[0].rm_so;
867                         return *begin >= *end;
868                 }
869                 return -1;
870         }
872         /* find the next word */
873         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
874                 (*begin)++;
875         if (*begin >= buffer->size)
876                 return -1;
878         /* find the end of the word */
879         *end = *begin + 1;
880         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
881                 (*end)++;
883         return 0;
886 /*
887  * This function splits the words in buffer->text, stores the list with
888  * newline separator into out, and saves the offsets of the original words
889  * in buffer->orig.
890  */
891 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
892                 regex_t *word_regex)
894         int i, j;
895         long alloc = 0;
897         out->size = 0;
898         out->ptr = NULL;
900         /* fake an empty "0th" word */
901         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
902         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
903         buffer->orig_nr = 1;
905         for (i = 0; i < buffer->text.size; i++) {
906                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
907                         return;
909                 /* store original boundaries */
910                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
911                                 buffer->orig_alloc);
912                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
913                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
914                 buffer->orig_nr++;
916                 /* store one word */
917                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
918                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
919                 out->ptr[out->size + j - i] = '\n';
920                 out->size += j - i + 1;
922                 i = j - 1;
923         }
926 /* this executes the word diff on the accumulated buffers */
927 static void diff_words_show(struct diff_words_data *diff_words)
929         xpparam_t xpp;
930         xdemitconf_t xecfg;
931         mmfile_t minus, plus;
932         struct diff_words_style *style = diff_words->style;
934         struct diff_options *opt = diff_words->opt;
935         struct strbuf *msgbuf;
936         char *line_prefix = "";
938         assert(opt);
939         if (opt->output_prefix) {
940                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
941                 line_prefix = msgbuf->buf;
942         }
944         /* special case: only removal */
945         if (!diff_words->plus.text.size) {
946                 fputs(line_prefix, diff_words->opt->file);
947                 fn_out_diff_words_write_helper(diff_words->opt->file,
948                         &style->old, style->newline,
949                         diff_words->minus.text.size,
950                         diff_words->minus.text.ptr, line_prefix);
951                 diff_words->minus.text.size = 0;
952                 return;
953         }
955         diff_words->current_plus = diff_words->plus.text.ptr;
956         diff_words->last_minus = 0;
958         memset(&xpp, 0, sizeof(xpp));
959         memset(&xecfg, 0, sizeof(xecfg));
960         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
961         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
962         xpp.flags = 0;
963         /* as only the hunk header will be parsed, we need a 0-context */
964         xecfg.ctxlen = 0;
965         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
966                       &xpp, &xecfg);
967         free(minus.ptr);
968         free(plus.ptr);
969         if (diff_words->current_plus != diff_words->plus.text.ptr +
970                         diff_words->plus.text.size) {
971                 if (color_words_output_graph_prefix(diff_words))
972                         fputs(line_prefix, diff_words->opt->file);
973                 fn_out_diff_words_write_helper(diff_words->opt->file,
974                         &style->ctx, style->newline,
975                         diff_words->plus.text.ptr + diff_words->plus.text.size
976                         - diff_words->current_plus, diff_words->current_plus,
977                         line_prefix);
978         }
979         diff_words->minus.text.size = diff_words->plus.text.size = 0;
982 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
983 static void diff_words_flush(struct emit_callback *ecbdata)
985         if (ecbdata->diff_words->minus.text.size ||
986             ecbdata->diff_words->plus.text.size)
987                 diff_words_show(ecbdata->diff_words);
990 static void free_diff_words_data(struct emit_callback *ecbdata)
992         if (ecbdata->diff_words) {
993                 diff_words_flush(ecbdata);
994                 free (ecbdata->diff_words->minus.text.ptr);
995                 free (ecbdata->diff_words->minus.orig);
996                 free (ecbdata->diff_words->plus.text.ptr);
997                 free (ecbdata->diff_words->plus.orig);
998                 if (ecbdata->diff_words->word_regex) {
999                         regfree(ecbdata->diff_words->word_regex);
1000                         free(ecbdata->diff_words->word_regex);
1001                 }
1002                 free(ecbdata->diff_words);
1003                 ecbdata->diff_words = NULL;
1004         }
1007 const char *diff_get_color(int diff_use_color, enum color_diff ix)
1009         if (want_color(diff_use_color))
1010                 return diff_colors[ix];
1011         return "";
1014 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1016         const char *cp;
1017         unsigned long allot;
1018         size_t l = len;
1020         if (ecb->truncate)
1021                 return ecb->truncate(line, len);
1022         cp = line;
1023         allot = l;
1024         while (0 < l) {
1025                 (void) utf8_width(&cp, &l);
1026                 if (!cp)
1027                         break; /* truncated in the middle? */
1028         }
1029         return allot - l;
1032 static void find_lno(const char *line, struct emit_callback *ecbdata)
1034         const char *p;
1035         ecbdata->lno_in_preimage = 0;
1036         ecbdata->lno_in_postimage = 0;
1037         p = strchr(line, '-');
1038         if (!p)
1039                 return; /* cannot happen */
1040         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1041         p = strchr(p, '+');
1042         if (!p)
1043                 return; /* cannot happen */
1044         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1047 static void fn_out_consume(void *priv, char *line, unsigned long len)
1049         struct emit_callback *ecbdata = priv;
1050         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1051         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1052         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1053         struct diff_options *o = ecbdata->opt;
1054         char *line_prefix = "";
1055         struct strbuf *msgbuf;
1057         if (o && o->output_prefix) {
1058                 msgbuf = o->output_prefix(o, o->output_prefix_data);
1059                 line_prefix = msgbuf->buf;
1060         }
1062         if (ecbdata->header) {
1063                 fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1064                 strbuf_reset(ecbdata->header);
1065                 ecbdata->header = NULL;
1066         }
1067         *(ecbdata->found_changesp) = 1;
1069         if (ecbdata->label_path[0]) {
1070                 const char *name_a_tab, *name_b_tab;
1072                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1073                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1075                 fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1076                         line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1077                 fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1078                         line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1079                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1080         }
1082         if (diff_suppress_blank_empty
1083             && len == 2 && line[0] == ' ' && line[1] == '\n') {
1084                 line[0] = '\n';
1085                 len = 1;
1086         }
1088         if (line[0] == '@') {
1089                 if (ecbdata->diff_words)
1090                         diff_words_flush(ecbdata);
1091                 len = sane_truncate_line(ecbdata, line, len);
1092                 find_lno(line, ecbdata);
1093                 emit_hunk_header(ecbdata, line, len);
1094                 if (line[len-1] != '\n')
1095                         putc('\n', ecbdata->opt->file);
1096                 return;
1097         }
1099         if (len < 1) {
1100                 emit_line(ecbdata->opt, reset, reset, line, len);
1101                 if (ecbdata->diff_words
1102                     && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1103                         fputs("~\n", ecbdata->opt->file);
1104                 return;
1105         }
1107         if (ecbdata->diff_words) {
1108                 if (line[0] == '-') {
1109                         diff_words_append(line, len,
1110                                           &ecbdata->diff_words->minus);
1111                         return;
1112                 } else if (line[0] == '+') {
1113                         diff_words_append(line, len,
1114                                           &ecbdata->diff_words->plus);
1115                         return;
1116                 } else if (!prefixcmp(line, "\\ ")) {
1117                         /*
1118                          * Eat the "no newline at eof" marker as if we
1119                          * saw a "+" or "-" line with nothing on it,
1120                          * and return without diff_words_flush() to
1121                          * defer processing. If this is the end of
1122                          * preimage, more "+" lines may come after it.
1123                          */
1124                         return;
1125                 }
1126                 diff_words_flush(ecbdata);
1127                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1128                         emit_line(ecbdata->opt, plain, reset, line, len);
1129                         fputs("~\n", ecbdata->opt->file);
1130                 } else {
1131                         /*
1132                          * Skip the prefix character, if any.  With
1133                          * diff_suppress_blank_empty, there may be
1134                          * none.
1135                          */
1136                         if (line[0] != '\n') {
1137                               line++;
1138                               len--;
1139                         }
1140                         emit_line(ecbdata->opt, plain, reset, line, len);
1141                 }
1142                 return;
1143         }
1145         if (line[0] != '+') {
1146                 const char *color =
1147                         diff_get_color(ecbdata->color_diff,
1148                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1149                 ecbdata->lno_in_preimage++;
1150                 if (line[0] == ' ')
1151                         ecbdata->lno_in_postimage++;
1152                 emit_line(ecbdata->opt, color, reset, line, len);
1153         } else {
1154                 ecbdata->lno_in_postimage++;
1155                 emit_add_line(reset, ecbdata, line + 1, len - 1);
1156         }
1159 static char *pprint_rename(const char *a, const char *b)
1161         const char *old = a;
1162         const char *new = b;
1163         struct strbuf name = STRBUF_INIT;
1164         int pfx_length, sfx_length;
1165         int len_a = strlen(a);
1166         int len_b = strlen(b);
1167         int a_midlen, b_midlen;
1168         int qlen_a = quote_c_style(a, NULL, NULL, 0);
1169         int qlen_b = quote_c_style(b, NULL, NULL, 0);
1171         if (qlen_a || qlen_b) {
1172                 quote_c_style(a, &name, NULL, 0);
1173                 strbuf_addstr(&name, " => ");
1174                 quote_c_style(b, &name, NULL, 0);
1175                 return strbuf_detach(&name, NULL);
1176         }
1178         /* Find common prefix */
1179         pfx_length = 0;
1180         while (*old && *new && *old == *new) {
1181                 if (*old == '/')
1182                         pfx_length = old - a + 1;
1183                 old++;
1184                 new++;
1185         }
1187         /* Find common suffix */
1188         old = a + len_a;
1189         new = b + len_b;
1190         sfx_length = 0;
1191         while (a <= old && b <= new && *old == *new) {
1192                 if (*old == '/')
1193                         sfx_length = len_a - (old - a);
1194                 old--;
1195                 new--;
1196         }
1198         /*
1199          * pfx{mid-a => mid-b}sfx
1200          * {pfx-a => pfx-b}sfx
1201          * pfx{sfx-a => sfx-b}
1202          * name-a => name-b
1203          */
1204         a_midlen = len_a - pfx_length - sfx_length;
1205         b_midlen = len_b - pfx_length - sfx_length;
1206         if (a_midlen < 0)
1207                 a_midlen = 0;
1208         if (b_midlen < 0)
1209                 b_midlen = 0;
1211         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1212         if (pfx_length + sfx_length) {
1213                 strbuf_add(&name, a, pfx_length);
1214                 strbuf_addch(&name, '{');
1215         }
1216         strbuf_add(&name, a + pfx_length, a_midlen);
1217         strbuf_addstr(&name, " => ");
1218         strbuf_add(&name, b + pfx_length, b_midlen);
1219         if (pfx_length + sfx_length) {
1220                 strbuf_addch(&name, '}');
1221                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1222         }
1223         return strbuf_detach(&name, NULL);
1226 struct diffstat_t {
1227         int nr;
1228         int alloc;
1229         struct diffstat_file {
1230                 char *from_name;
1231                 char *name;
1232                 char *print_name;
1233                 unsigned is_unmerged:1;
1234                 unsigned is_binary:1;
1235                 unsigned is_renamed:1;
1236                 uintmax_t added, deleted;
1237         } **files;
1238 };
1240 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1241                                           const char *name_a,
1242                                           const char *name_b)
1244         struct diffstat_file *x;
1245         x = xcalloc(sizeof (*x), 1);
1246         if (diffstat->nr == diffstat->alloc) {
1247                 diffstat->alloc = alloc_nr(diffstat->alloc);
1248                 diffstat->files = xrealloc(diffstat->files,
1249                                 diffstat->alloc * sizeof(x));
1250         }
1251         diffstat->files[diffstat->nr++] = x;
1252         if (name_b) {
1253                 x->from_name = xstrdup(name_a);
1254                 x->name = xstrdup(name_b);
1255                 x->is_renamed = 1;
1256         }
1257         else {
1258                 x->from_name = NULL;
1259                 x->name = xstrdup(name_a);
1260         }
1261         return x;
1264 static void diffstat_consume(void *priv, char *line, unsigned long len)
1266         struct diffstat_t *diffstat = priv;
1267         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1269         if (line[0] == '+')
1270                 x->added++;
1271         else if (line[0] == '-')
1272                 x->deleted++;
1275 const char mime_boundary_leader[] = "------------";
1277 static int scale_linear(int it, int width, int max_change)
1279         if (!it)
1280                 return 0;
1281         /*
1282          * make sure that at least one '-' or '+' is printed if
1283          * there is any change to this path. The easiest way is to
1284          * scale linearly as if the alloted width is one column shorter
1285          * than it is, and then add 1 to the result.
1286          */
1287         return 1 + (it * (width - 1) / max_change);
1290 static void show_name(FILE *file,
1291                       const char *prefix, const char *name, int len)
1293         fprintf(file, " %s%-*s |", prefix, len, name);
1296 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1298         if (cnt <= 0)
1299                 return;
1300         fprintf(file, "%s", set);
1301         while (cnt--)
1302                 putc(ch, file);
1303         fprintf(file, "%s", reset);
1306 static void fill_print_name(struct diffstat_file *file)
1308         char *pname;
1310         if (file->print_name)
1311                 return;
1313         if (!file->is_renamed) {
1314                 struct strbuf buf = STRBUF_INIT;
1315                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1316                         pname = strbuf_detach(&buf, NULL);
1317                 } else {
1318                         pname = file->name;
1319                         strbuf_release(&buf);
1320                 }
1321         } else {
1322                 pname = pprint_rename(file->from_name, file->name);
1323         }
1324         file->print_name = pname;
1327 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1329         int i, len, add, del, adds = 0, dels = 0;
1330         uintmax_t max_change = 0, max_len = 0;
1331         int total_files = data->nr;
1332         int width, name_width, count;
1333         const char *reset, *add_c, *del_c;
1334         const char *line_prefix = "";
1335         int extra_shown = 0;
1336         struct strbuf *msg = NULL;
1338         if (data->nr == 0)
1339                 return;
1341         if (options->output_prefix) {
1342                 msg = options->output_prefix(options, options->output_prefix_data);
1343                 line_prefix = msg->buf;
1344         }
1346         width = options->stat_width ? options->stat_width : 80;
1347         name_width = options->stat_name_width ? options->stat_name_width : 50;
1348         count = options->stat_count ? options->stat_count : data->nr;
1350         /* Sanity: give at least 5 columns to the graph,
1351          * but leave at least 10 columns for the name.
1352          */
1353         if (width < 25)
1354                 width = 25;
1355         if (name_width < 10)
1356                 name_width = 10;
1357         else if (width < name_width + 15)
1358                 name_width = width - 15;
1360         /* Find the longest filename and max number of changes */
1361         reset = diff_get_color_opt(options, DIFF_RESET);
1362         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1363         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1365         for (i = 0; (i < count) && (i < data->nr); i++) {
1366                 struct diffstat_file *file = data->files[i];
1367                 uintmax_t change = file->added + file->deleted;
1368                 if (!data->files[i]->is_renamed &&
1369                          (change == 0)) {
1370                         count++; /* not shown == room for one more */
1371                         continue;
1372                 }
1373                 fill_print_name(file);
1374                 len = strlen(file->print_name);
1375                 if (max_len < len)
1376                         max_len = len;
1378                 if (file->is_binary || file->is_unmerged)
1379                         continue;
1380                 if (max_change < change)
1381                         max_change = change;
1382         }
1383         count = i; /* min(count, data->nr) */
1385         /* Compute the width of the graph part;
1386          * 10 is for one blank at the beginning of the line plus
1387          * " | count " between the name and the graph.
1388          *
1389          * From here on, name_width is the width of the name area,
1390          * and width is the width of the graph area.
1391          */
1392         name_width = (name_width < max_len) ? name_width : max_len;
1393         if (width < (name_width + 10) + max_change)
1394                 width = width - (name_width + 10);
1395         else
1396                 width = max_change;
1398         for (i = 0; i < count; i++) {
1399                 const char *prefix = "";
1400                 char *name = data->files[i]->print_name;
1401                 uintmax_t added = data->files[i]->added;
1402                 uintmax_t deleted = data->files[i]->deleted;
1403                 int name_len;
1405                 if (!data->files[i]->is_renamed &&
1406                          (added + deleted == 0)) {
1407                         total_files--;
1408                         continue;
1409                 }
1410                 /*
1411                  * "scale" the filename
1412                  */
1413                 len = name_width;
1414                 name_len = strlen(name);
1415                 if (name_width < name_len) {
1416                         char *slash;
1417                         prefix = "...";
1418                         len -= 3;
1419                         name += name_len - len;
1420                         slash = strchr(name, '/');
1421                         if (slash)
1422                                 name = slash;
1423                 }
1425                 if (data->files[i]->is_binary) {
1426                         fprintf(options->file, "%s", line_prefix);
1427                         show_name(options->file, prefix, name, len);
1428                         fprintf(options->file, "  Bin ");
1429                         fprintf(options->file, "%s%"PRIuMAX"%s",
1430                                 del_c, deleted, reset);
1431                         fprintf(options->file, " -> ");
1432                         fprintf(options->file, "%s%"PRIuMAX"%s",
1433                                 add_c, added, reset);
1434                         fprintf(options->file, " bytes");
1435                         fprintf(options->file, "\n");
1436                         continue;
1437                 }
1438                 else if (data->files[i]->is_unmerged) {
1439                         fprintf(options->file, "%s", line_prefix);
1440                         show_name(options->file, prefix, name, len);
1441                         fprintf(options->file, "  Unmerged\n");
1442                         continue;
1443                 }
1445                 /*
1446                  * scale the add/delete
1447                  */
1448                 add = added;
1449                 del = deleted;
1450                 adds += add;
1451                 dels += del;
1453                 if (width <= max_change) {
1454                         int total = add + del;
1456                         total = scale_linear(add + del, width, max_change);
1457                         if (total < 2 && add && del)
1458                                 /* width >= 2 due to the sanity check */
1459                                 total = 2;
1460                         if (add < del) {
1461                                 add = scale_linear(add, width, max_change);
1462                                 del = total - add;
1463                         } else {
1464                                 del = scale_linear(del, width, max_change);
1465                                 add = total - del;
1466                         }
1467                 }
1468                 fprintf(options->file, "%s", line_prefix);
1469                 show_name(options->file, prefix, name, len);
1470                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1471                                 added + deleted ? " " : "");
1472                 show_graph(options->file, '+', add, add_c, reset);
1473                 show_graph(options->file, '-', del, del_c, reset);
1474                 fprintf(options->file, "\n");
1475         }
1476         for (i = count; i < data->nr; i++) {
1477                 uintmax_t added = data->files[i]->added;
1478                 uintmax_t deleted = data->files[i]->deleted;
1479                 if (!data->files[i]->is_renamed &&
1480                          (added + deleted == 0)) {
1481                         total_files--;
1482                         continue;
1483                 }
1484                 adds += added;
1485                 dels += deleted;
1486                 if (!extra_shown)
1487                         fprintf(options->file, "%s ...\n", line_prefix);
1488                 extra_shown = 1;
1489         }
1490         fprintf(options->file, "%s", line_prefix);
1491         fprintf(options->file,
1492                " %d files changed, %d insertions(+), %d deletions(-)\n",
1493                total_files, adds, dels);
1496 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1498         int i, adds = 0, dels = 0, total_files = data->nr;
1500         if (data->nr == 0)
1501                 return;
1503         for (i = 0; i < data->nr; i++) {
1504                 if (!data->files[i]->is_binary &&
1505                     !data->files[i]->is_unmerged) {
1506                         int added = data->files[i]->added;
1507                         int deleted= data->files[i]->deleted;
1508                         if (!data->files[i]->is_renamed &&
1509                             (added + deleted == 0)) {
1510                                 total_files--;
1511                         } else {
1512                                 adds += added;
1513                                 dels += deleted;
1514                         }
1515                 }
1516         }
1517         if (options->output_prefix) {
1518                 struct strbuf *msg = NULL;
1519                 msg = options->output_prefix(options,
1520                                 options->output_prefix_data);
1521                 fprintf(options->file, "%s", msg->buf);
1522         }
1523         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1524                total_files, adds, dels);
1527 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1529         int i;
1531         if (data->nr == 0)
1532                 return;
1534         for (i = 0; i < data->nr; i++) {
1535                 struct diffstat_file *file = data->files[i];
1537                 if (options->output_prefix) {
1538                         struct strbuf *msg = NULL;
1539                         msg = options->output_prefix(options,
1540                                         options->output_prefix_data);
1541                         fprintf(options->file, "%s", msg->buf);
1542                 }
1544                 if (file->is_binary)
1545                         fprintf(options->file, "-\t-\t");
1546                 else
1547                         fprintf(options->file,
1548                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1549                                 file->added, file->deleted);
1550                 if (options->line_termination) {
1551                         fill_print_name(file);
1552                         if (!file->is_renamed)
1553                                 write_name_quoted(file->name, options->file,
1554                                                   options->line_termination);
1555                         else {
1556                                 fputs(file->print_name, options->file);
1557                                 putc(options->line_termination, options->file);
1558                         }
1559                 } else {
1560                         if (file->is_renamed) {
1561                                 putc('\0', options->file);
1562                                 write_name_quoted(file->from_name, options->file, '\0');
1563                         }
1564                         write_name_quoted(file->name, options->file, '\0');
1565                 }
1566         }
1569 struct dirstat_file {
1570         const char *name;
1571         unsigned long changed;
1572 };
1574 struct dirstat_dir {
1575         struct dirstat_file *files;
1576         int alloc, nr, permille, cumulative;
1577 };
1579 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1580                 unsigned long changed, const char *base, int baselen)
1582         unsigned long this_dir = 0;
1583         unsigned int sources = 0;
1584         const char *line_prefix = "";
1585         struct strbuf *msg = NULL;
1587         if (opt->output_prefix) {
1588                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1589                 line_prefix = msg->buf;
1590         }
1592         while (dir->nr) {
1593                 struct dirstat_file *f = dir->files;
1594                 int namelen = strlen(f->name);
1595                 unsigned long this;
1596                 char *slash;
1598                 if (namelen < baselen)
1599                         break;
1600                 if (memcmp(f->name, base, baselen))
1601                         break;
1602                 slash = strchr(f->name + baselen, '/');
1603                 if (slash) {
1604                         int newbaselen = slash + 1 - f->name;
1605                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1606                         sources++;
1607                 } else {
1608                         this = f->changed;
1609                         dir->files++;
1610                         dir->nr--;
1611                         sources += 2;
1612                 }
1613                 this_dir += this;
1614         }
1616         /*
1617          * We don't report dirstat's for
1618          *  - the top level
1619          *  - or cases where everything came from a single directory
1620          *    under this directory (sources == 1).
1621          */
1622         if (baselen && sources != 1) {
1623                 if (this_dir) {
1624                         int permille = this_dir * 1000 / changed;
1625                         if (permille >= dir->permille) {
1626                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1627                                         permille / 10, permille % 10, baselen, base);
1628                                 if (!dir->cumulative)
1629                                         return 0;
1630                         }
1631                 }
1632         }
1633         return this_dir;
1636 static int dirstat_compare(const void *_a, const void *_b)
1638         const struct dirstat_file *a = _a;
1639         const struct dirstat_file *b = _b;
1640         return strcmp(a->name, b->name);
1643 static void show_dirstat(struct diff_options *options)
1645         int i;
1646         unsigned long changed;
1647         struct dirstat_dir dir;
1648         struct diff_queue_struct *q = &diff_queued_diff;
1650         dir.files = NULL;
1651         dir.alloc = 0;
1652         dir.nr = 0;
1653         dir.permille = options->dirstat_permille;
1654         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1656         changed = 0;
1657         for (i = 0; i < q->nr; i++) {
1658                 struct diff_filepair *p = q->queue[i];
1659                 const char *name;
1660                 unsigned long copied, added, damage;
1661                 int content_changed;
1663                 name = p->two->path ? p->two->path : p->one->path;
1665                 if (p->one->sha1_valid && p->two->sha1_valid)
1666                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1667                 else
1668                         content_changed = 1;
1670                 if (!content_changed) {
1671                         /*
1672                          * The SHA1 has not changed, so pre-/post-content is
1673                          * identical. We can therefore skip looking at the
1674                          * file contents altogether.
1675                          */
1676                         damage = 0;
1677                         goto found_damage;
1678                 }
1680                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1681                         /*
1682                          * In --dirstat-by-file mode, we don't really need to
1683                          * look at the actual file contents at all.
1684                          * The fact that the SHA1 changed is enough for us to
1685                          * add this file to the list of results
1686                          * (with each file contributing equal damage).
1687                          */
1688                         damage = 1;
1689                         goto found_damage;
1690                 }
1692                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1693                         diff_populate_filespec(p->one, 0);
1694                         diff_populate_filespec(p->two, 0);
1695                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1696                                                &copied, &added);
1697                         diff_free_filespec_data(p->one);
1698                         diff_free_filespec_data(p->two);
1699                 } else if (DIFF_FILE_VALID(p->one)) {
1700                         diff_populate_filespec(p->one, 1);
1701                         copied = added = 0;
1702                         diff_free_filespec_data(p->one);
1703                 } else if (DIFF_FILE_VALID(p->two)) {
1704                         diff_populate_filespec(p->two, 1);
1705                         copied = 0;
1706                         added = p->two->size;
1707                         diff_free_filespec_data(p->two);
1708                 } else
1709                         continue;
1711                 /*
1712                  * Original minus copied is the removed material,
1713                  * added is the new material.  They are both damages
1714                  * made to the preimage.
1715                  * If the resulting damage is zero, we know that
1716                  * diffcore_count_changes() considers the two entries to
1717                  * be identical, but since content_changed is true, we
1718                  * know that there must have been _some_ kind of change,
1719                  * so we force all entries to have damage > 0.
1720                  */
1721                 damage = (p->one->size - copied) + added;
1722                 if (!damage)
1723                         damage = 1;
1725 found_damage:
1726                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1727                 dir.files[dir.nr].name = name;
1728                 dir.files[dir.nr].changed = damage;
1729                 changed += damage;
1730                 dir.nr++;
1731         }
1733         /* This can happen even with many files, if everything was renames */
1734         if (!changed)
1735                 return;
1737         /* Show all directories with more than x% of the changes */
1738         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1739         gather_dirstat(options, &dir, changed, "", 0);
1742 static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1744         int i;
1745         unsigned long changed;
1746         struct dirstat_dir dir;
1748         if (data->nr == 0)
1749                 return;
1751         dir.files = NULL;
1752         dir.alloc = 0;
1753         dir.nr = 0;
1754         dir.permille = options->dirstat_permille;
1755         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1757         changed = 0;
1758         for (i = 0; i < data->nr; i++) {
1759                 struct diffstat_file *file = data->files[i];
1760                 unsigned long damage = file->added + file->deleted;
1761                 if (file->is_binary)
1762                         /*
1763                          * binary files counts bytes, not lines. Must find some
1764                          * way to normalize binary bytes vs. textual lines.
1765                          * The following heuristic assumes that there are 64
1766                          * bytes per "line".
1767                          * This is stupid and ugly, but very cheap...
1768                          */
1769                         damage = (damage + 63) / 64;
1770                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1771                 dir.files[dir.nr].name = file->name;
1772                 dir.files[dir.nr].changed = damage;
1773                 changed += damage;
1774                 dir.nr++;
1775         }
1777         /* This can happen even with many files, if everything was renames */
1778         if (!changed)
1779                 return;
1781         /* Show all directories with more than x% of the changes */
1782         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1783         gather_dirstat(options, &dir, changed, "", 0);
1786 static void free_diffstat_info(struct diffstat_t *diffstat)
1788         int i;
1789         for (i = 0; i < diffstat->nr; i++) {
1790                 struct diffstat_file *f = diffstat->files[i];
1791                 if (f->name != f->print_name)
1792                         free(f->print_name);
1793                 free(f->name);
1794                 free(f->from_name);
1795                 free(f);
1796         }
1797         free(diffstat->files);
1800 struct checkdiff_t {
1801         const char *filename;
1802         int lineno;
1803         int conflict_marker_size;
1804         struct diff_options *o;
1805         unsigned ws_rule;
1806         unsigned status;
1807 };
1809 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1811         char firstchar;
1812         int cnt;
1814         if (len < marker_size + 1)
1815                 return 0;
1816         firstchar = line[0];
1817         switch (firstchar) {
1818         case '=': case '>': case '<': case '|':
1819                 break;
1820         default:
1821                 return 0;
1822         }
1823         for (cnt = 1; cnt < marker_size; cnt++)
1824                 if (line[cnt] != firstchar)
1825                         return 0;
1826         /* line[1] thru line[marker_size-1] are same as firstchar */
1827         if (len < marker_size + 1 || !isspace(line[marker_size]))
1828                 return 0;
1829         return 1;
1832 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1834         struct checkdiff_t *data = priv;
1835         int marker_size = data->conflict_marker_size;
1836         const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1837         const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1838         const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1839         char *err;
1840         char *line_prefix = "";
1841         struct strbuf *msgbuf;
1843         assert(data->o);
1844         if (data->o->output_prefix) {
1845                 msgbuf = data->o->output_prefix(data->o,
1846                         data->o->output_prefix_data);
1847                 line_prefix = msgbuf->buf;
1848         }
1850         if (line[0] == '+') {
1851                 unsigned bad;
1852                 data->lineno++;
1853                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1854                         data->status |= 1;
1855                         fprintf(data->o->file,
1856                                 "%s%s:%d: leftover conflict marker\n",
1857                                 line_prefix, data->filename, data->lineno);
1858                 }
1859                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1860                 if (!bad)
1861                         return;
1862                 data->status |= bad;
1863                 err = whitespace_error_string(bad);
1864                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1865                         line_prefix, data->filename, data->lineno, err);
1866                 free(err);
1867                 emit_line(data->o, set, reset, line, 1);
1868                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1869                               data->o->file, set, reset, ws);
1870         } else if (line[0] == ' ') {
1871                 data->lineno++;
1872         } else if (line[0] == '@') {
1873                 char *plus = strchr(line, '+');
1874                 if (plus)
1875                         data->lineno = strtol(plus, NULL, 10) - 1;
1876                 else
1877                         die("invalid diff");
1878         }
1881 static unsigned char *deflate_it(char *data,
1882                                  unsigned long size,
1883                                  unsigned long *result_size)
1885         int bound;
1886         unsigned char *deflated;
1887         git_zstream stream;
1889         memset(&stream, 0, sizeof(stream));
1890         git_deflate_init(&stream, zlib_compression_level);
1891         bound = git_deflate_bound(&stream, size);
1892         deflated = xmalloc(bound);
1893         stream.next_out = deflated;
1894         stream.avail_out = bound;
1896         stream.next_in = (unsigned char *)data;
1897         stream.avail_in = size;
1898         while (git_deflate(&stream, Z_FINISH) == Z_OK)
1899                 ; /* nothing */
1900         git_deflate_end(&stream);
1901         *result_size = stream.total_out;
1902         return deflated;
1905 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1907         void *cp;
1908         void *delta;
1909         void *deflated;
1910         void *data;
1911         unsigned long orig_size;
1912         unsigned long delta_size;
1913         unsigned long deflate_size;
1914         unsigned long data_size;
1916         /* We could do deflated delta, or we could do just deflated two,
1917          * whichever is smaller.
1918          */
1919         delta = NULL;
1920         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1921         if (one->size && two->size) {
1922                 delta = diff_delta(one->ptr, one->size,
1923                                    two->ptr, two->size,
1924                                    &delta_size, deflate_size);
1925                 if (delta) {
1926                         void *to_free = delta;
1927                         orig_size = delta_size;
1928                         delta = deflate_it(delta, delta_size, &delta_size);
1929                         free(to_free);
1930                 }
1931         }
1933         if (delta && delta_size < deflate_size) {
1934                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1935                 free(deflated);
1936                 data = delta;
1937                 data_size = delta_size;
1938         }
1939         else {
1940                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1941                 free(delta);
1942                 data = deflated;
1943                 data_size = deflate_size;
1944         }
1946         /* emit data encoded in base85 */
1947         cp = data;
1948         while (data_size) {
1949                 int bytes = (52 < data_size) ? 52 : data_size;
1950                 char line[70];
1951                 data_size -= bytes;
1952                 if (bytes <= 26)
1953                         line[0] = bytes + 'A' - 1;
1954                 else
1955                         line[0] = bytes - 26 + 'a' - 1;
1956                 encode_85(line + 1, cp, bytes);
1957                 cp = (char *) cp + bytes;
1958                 fprintf(file, "%s", prefix);
1959                 fputs(line, file);
1960                 fputc('\n', file);
1961         }
1962         fprintf(file, "%s\n", prefix);
1963         free(data);
1966 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1968         fprintf(file, "%sGIT binary patch\n", prefix);
1969         emit_binary_diff_body(file, one, two, prefix);
1970         emit_binary_diff_body(file, two, one, prefix);
1973 static void diff_filespec_load_driver(struct diff_filespec *one)
1975         /* Use already-loaded driver */
1976         if (one->driver)
1977                 return;
1979         if (S_ISREG(one->mode))
1980                 one->driver = userdiff_find_by_path(one->path);
1982         /* Fallback to default settings */
1983         if (!one->driver)
1984                 one->driver = userdiff_find_by_name("default");
1987 int diff_filespec_is_binary(struct diff_filespec *one)
1989         if (one->is_binary == -1) {
1990                 diff_filespec_load_driver(one);
1991                 if (one->driver->binary != -1)
1992                         one->is_binary = one->driver->binary;
1993                 else {
1994                         if (!one->data && DIFF_FILE_VALID(one))
1995                                 diff_populate_filespec(one, 0);
1996                         if (one->data)
1997                                 one->is_binary = buffer_is_binary(one->data,
1998                                                 one->size);
1999                         if (one->is_binary == -1)
2000                                 one->is_binary = 0;
2001                 }
2002         }
2003         return one->is_binary;
2006 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2008         diff_filespec_load_driver(one);
2009         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2012 static const char *userdiff_word_regex(struct diff_filespec *one)
2014         diff_filespec_load_driver(one);
2015         return one->driver->word_regex;
2018 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2020         if (!options->a_prefix)
2021                 options->a_prefix = a;
2022         if (!options->b_prefix)
2023                 options->b_prefix = b;
2026 struct userdiff_driver *get_textconv(struct diff_filespec *one)
2028         if (!DIFF_FILE_VALID(one))
2029                 return NULL;
2031         diff_filespec_load_driver(one);
2032         return userdiff_get_textconv(one->driver);
2035 static void builtin_diff(const char *name_a,
2036                          const char *name_b,
2037                          struct diff_filespec *one,
2038                          struct diff_filespec *two,
2039                          const char *xfrm_msg,
2040                          int must_show_header,
2041                          struct diff_options *o,
2042                          int complete_rewrite)
2044         mmfile_t mf1, mf2;
2045         const char *lbl[2];
2046         char *a_one, *b_two;
2047         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2048         const char *reset = diff_get_color_opt(o, DIFF_RESET);
2049         const char *a_prefix, *b_prefix;
2050         struct userdiff_driver *textconv_one = NULL;
2051         struct userdiff_driver *textconv_two = NULL;
2052         struct strbuf header = STRBUF_INIT;
2053         struct strbuf *msgbuf;
2054         char *line_prefix = "";
2056         if (o->output_prefix) {
2057                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2058                 line_prefix = msgbuf->buf;
2059         }
2061         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2062                         (!one->mode || S_ISGITLINK(one->mode)) &&
2063                         (!two->mode || S_ISGITLINK(two->mode))) {
2064                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2065                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2066                 show_submodule_summary(o->file, one ? one->path : two->path,
2067                                 one->sha1, two->sha1, two->dirty_submodule,
2068                                 del, add, reset);
2069                 return;
2070         }
2072         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2073                 textconv_one = get_textconv(one);
2074                 textconv_two = get_textconv(two);
2075         }
2077         diff_set_mnemonic_prefix(o, "a/", "b/");
2078         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2079                 a_prefix = o->b_prefix;
2080                 b_prefix = o->a_prefix;
2081         } else {
2082                 a_prefix = o->a_prefix;
2083                 b_prefix = o->b_prefix;
2084         }
2086         /* Never use a non-valid filename anywhere if at all possible */
2087         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2088         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2090         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2091         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2092         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2093         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2094         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2095         if (lbl[0][0] == '/') {
2096                 /* /dev/null */
2097                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2098                 if (xfrm_msg)
2099                         strbuf_addstr(&header, xfrm_msg);
2100                 must_show_header = 1;
2101         }
2102         else if (lbl[1][0] == '/') {
2103                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2104                 if (xfrm_msg)
2105                         strbuf_addstr(&header, xfrm_msg);
2106                 must_show_header = 1;
2107         }
2108         else {
2109                 if (one->mode != two->mode) {
2110                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2111                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2112                         must_show_header = 1;
2113                 }
2114                 if (xfrm_msg)
2115                         strbuf_addstr(&header, xfrm_msg);
2117                 /*
2118                  * we do not run diff between different kind
2119                  * of objects.
2120                  */
2121                 if ((one->mode ^ two->mode) & S_IFMT)
2122                         goto free_ab_and_return;
2123                 if (complete_rewrite &&
2124                     (textconv_one || !diff_filespec_is_binary(one)) &&
2125                     (textconv_two || !diff_filespec_is_binary(two))) {
2126                         fprintf(o->file, "%s", header.buf);
2127                         strbuf_reset(&header);
2128                         emit_rewrite_diff(name_a, name_b, one, two,
2129                                                 textconv_one, textconv_two, o);
2130                         o->found_changes = 1;
2131                         goto free_ab_and_return;
2132                 }
2133         }
2135         if (o->irreversible_delete && lbl[1][0] == '/') {
2136                 fprintf(o->file, "%s", header.buf);
2137                 strbuf_reset(&header);
2138                 goto free_ab_and_return;
2139         } else if (!DIFF_OPT_TST(o, TEXT) &&
2140             ( (!textconv_one && diff_filespec_is_binary(one)) ||
2141               (!textconv_two && diff_filespec_is_binary(two)) )) {
2142                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2143                         die("unable to read files to diff");
2144                 /* Quite common confusing case */
2145                 if (mf1.size == mf2.size &&
2146                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2147                         if (must_show_header)
2148                                 fprintf(o->file, "%s", header.buf);
2149                         goto free_ab_and_return;
2150                 }
2151                 fprintf(o->file, "%s", header.buf);
2152                 strbuf_reset(&header);
2153                 if (DIFF_OPT_TST(o, BINARY))
2154                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2155                 else
2156                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2157                                 line_prefix, lbl[0], lbl[1]);
2158                 o->found_changes = 1;
2159         } else {
2160                 /* Crazy xdl interfaces.. */
2161                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2162                 xpparam_t xpp;
2163                 xdemitconf_t xecfg;
2164                 struct emit_callback ecbdata;
2165                 const struct userdiff_funcname *pe;
2167                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2168                         fprintf(o->file, "%s", header.buf);
2169                         strbuf_reset(&header);
2170                 }
2172                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2173                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2175                 pe = diff_funcname_pattern(one);
2176                 if (!pe)
2177                         pe = diff_funcname_pattern(two);
2179                 memset(&xpp, 0, sizeof(xpp));
2180                 memset(&xecfg, 0, sizeof(xecfg));
2181                 memset(&ecbdata, 0, sizeof(ecbdata));
2182                 ecbdata.label_path = lbl;
2183                 ecbdata.color_diff = want_color(o->use_color);
2184                 ecbdata.found_changesp = &o->found_changes;
2185                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2186                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2187                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2188                 ecbdata.opt = o;
2189                 ecbdata.header = header.len ? &header : NULL;
2190                 xpp.flags = o->xdl_opts;
2191                 xecfg.ctxlen = o->context;
2192                 xecfg.interhunkctxlen = o->interhunkcontext;
2193                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2194                 if (DIFF_OPT_TST(o, FUNCCONTEXT))
2195                         xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2196                 if (pe)
2197                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2198                 if (!diffopts)
2199                         ;
2200                 else if (!prefixcmp(diffopts, "--unified="))
2201                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2202                 else if (!prefixcmp(diffopts, "-u"))
2203                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2204                 if (o->word_diff) {
2205                         int i;
2207                         ecbdata.diff_words =
2208                                 xcalloc(1, sizeof(struct diff_words_data));
2209                         ecbdata.diff_words->type = o->word_diff;
2210                         ecbdata.diff_words->opt = o;
2211                         if (!o->word_regex)
2212                                 o->word_regex = userdiff_word_regex(one);
2213                         if (!o->word_regex)
2214                                 o->word_regex = userdiff_word_regex(two);
2215                         if (!o->word_regex)
2216                                 o->word_regex = diff_word_regex_cfg;
2217                         if (o->word_regex) {
2218                                 ecbdata.diff_words->word_regex = (regex_t *)
2219                                         xmalloc(sizeof(regex_t));
2220                                 if (regcomp(ecbdata.diff_words->word_regex,
2221                                                 o->word_regex,
2222                                                 REG_EXTENDED | REG_NEWLINE))
2223                                         die ("Invalid regular expression: %s",
2224                                                         o->word_regex);
2225                         }
2226                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2227                                 if (o->word_diff == diff_words_styles[i].type) {
2228                                         ecbdata.diff_words->style =
2229                                                 &diff_words_styles[i];
2230                                         break;
2231                                 }
2232                         }
2233                         if (want_color(o->use_color)) {
2234                                 struct diff_words_style *st = ecbdata.diff_words->style;
2235                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2236                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2237                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2238                         }
2239                 }
2240                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2241                               &xpp, &xecfg);
2242                 if (o->word_diff)
2243                         free_diff_words_data(&ecbdata);
2244                 if (textconv_one)
2245                         free(mf1.ptr);
2246                 if (textconv_two)
2247                         free(mf2.ptr);
2248                 xdiff_clear_find_func(&xecfg);
2249         }
2251  free_ab_and_return:
2252         strbuf_release(&header);
2253         diff_free_filespec_data(one);
2254         diff_free_filespec_data(two);
2255         free(a_one);
2256         free(b_two);
2257         return;
2260 static void builtin_diffstat(const char *name_a, const char *name_b,
2261                              struct diff_filespec *one,
2262                              struct diff_filespec *two,
2263                              struct diffstat_t *diffstat,
2264                              struct diff_options *o,
2265                              int complete_rewrite)
2267         mmfile_t mf1, mf2;
2268         struct diffstat_file *data;
2270         data = diffstat_add(diffstat, name_a, name_b);
2272         if (!one || !two) {
2273                 data->is_unmerged = 1;
2274                 return;
2275         }
2277         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2278                 data->is_binary = 1;
2279                 data->added = diff_filespec_size(two);
2280                 data->deleted = diff_filespec_size(one);
2281         }
2283         else if (complete_rewrite) {
2284                 diff_populate_filespec(one, 0);
2285                 diff_populate_filespec(two, 0);
2286                 data->deleted = count_lines(one->data, one->size);
2287                 data->added = count_lines(two->data, two->size);
2288         }
2290         else {
2291                 /* Crazy xdl interfaces.. */
2292                 xpparam_t xpp;
2293                 xdemitconf_t xecfg;
2295                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2296                         die("unable to read files to diff");
2298                 memset(&xpp, 0, sizeof(xpp));
2299                 memset(&xecfg, 0, sizeof(xecfg));
2300                 xpp.flags = o->xdl_opts;
2301                 xecfg.ctxlen = o->context;
2302                 xecfg.interhunkctxlen = o->interhunkcontext;
2303                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2304                               &xpp, &xecfg);
2305         }
2307         diff_free_filespec_data(one);
2308         diff_free_filespec_data(two);
2311 static void builtin_checkdiff(const char *name_a, const char *name_b,
2312                               const char *attr_path,
2313                               struct diff_filespec *one,
2314                               struct diff_filespec *two,
2315                               struct diff_options *o)
2317         mmfile_t mf1, mf2;
2318         struct checkdiff_t data;
2320         if (!two)
2321                 return;
2323         memset(&data, 0, sizeof(data));
2324         data.filename = name_b ? name_b : name_a;
2325         data.lineno = 0;
2326         data.o = o;
2327         data.ws_rule = whitespace_rule(attr_path);
2328         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2330         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2331                 die("unable to read files to diff");
2333         /*
2334          * All the other codepaths check both sides, but not checking
2335          * the "old" side here is deliberate.  We are checking the newly
2336          * introduced changes, and as long as the "new" side is text, we
2337          * can and should check what it introduces.
2338          */
2339         if (diff_filespec_is_binary(two))
2340                 goto free_and_return;
2341         else {
2342                 /* Crazy xdl interfaces.. */
2343                 xpparam_t xpp;
2344                 xdemitconf_t xecfg;
2346                 memset(&xpp, 0, sizeof(xpp));
2347                 memset(&xecfg, 0, sizeof(xecfg));
2348                 xecfg.ctxlen = 1; /* at least one context line */
2349                 xpp.flags = 0;
2350                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2351                               &xpp, &xecfg);
2353                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2354                         struct emit_callback ecbdata;
2355                         int blank_at_eof;
2357                         ecbdata.ws_rule = data.ws_rule;
2358                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2359                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2361                         if (blank_at_eof) {
2362                                 static char *err;
2363                                 if (!err)
2364                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2365                                 fprintf(o->file, "%s:%d: %s.\n",
2366                                         data.filename, blank_at_eof, err);
2367                                 data.status = 1; /* report errors */
2368                         }
2369                 }
2370         }
2371  free_and_return:
2372         diff_free_filespec_data(one);
2373         diff_free_filespec_data(two);
2374         if (data.status)
2375                 DIFF_OPT_SET(o, CHECK_FAILED);
2378 struct diff_filespec *alloc_filespec(const char *path)
2380         int namelen = strlen(path);
2381         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2383         memset(spec, 0, sizeof(*spec));
2384         spec->path = (char *)(spec + 1);
2385         memcpy(spec->path, path, namelen+1);
2386         spec->count = 1;
2387         spec->is_binary = -1;
2388         return spec;
2391 void free_filespec(struct diff_filespec *spec)
2393         if (!--spec->count) {
2394                 diff_free_filespec_data(spec);
2395                 free(spec);
2396         }
2399 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2400                    unsigned short mode)
2402         if (mode) {
2403                 spec->mode = canon_mode(mode);
2404                 hashcpy(spec->sha1, sha1);
2405                 spec->sha1_valid = !is_null_sha1(sha1);
2406         }
2409 /*
2410  * Given a name and sha1 pair, if the index tells us the file in
2411  * the work tree has that object contents, return true, so that
2412  * prepare_temp_file() does not have to inflate and extract.
2413  */
2414 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2416         struct cache_entry *ce;
2417         struct stat st;
2418         int pos, len;
2420         /*
2421          * We do not read the cache ourselves here, because the
2422          * benchmark with my previous version that always reads cache
2423          * shows that it makes things worse for diff-tree comparing
2424          * two linux-2.6 kernel trees in an already checked out work
2425          * tree.  This is because most diff-tree comparisons deal with
2426          * only a small number of files, while reading the cache is
2427          * expensive for a large project, and its cost outweighs the
2428          * savings we get by not inflating the object to a temporary
2429          * file.  Practically, this code only helps when we are used
2430          * by diff-cache --cached, which does read the cache before
2431          * calling us.
2432          */
2433         if (!active_cache)
2434                 return 0;
2436         /* We want to avoid the working directory if our caller
2437          * doesn't need the data in a normal file, this system
2438          * is rather slow with its stat/open/mmap/close syscalls,
2439          * and the object is contained in a pack file.  The pack
2440          * is probably already open and will be faster to obtain
2441          * the data through than the working directory.  Loose
2442          * objects however would tend to be slower as they need
2443          * to be individually opened and inflated.
2444          */
2445         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2446                 return 0;
2448         len = strlen(name);
2449         pos = cache_name_pos(name, len);
2450         if (pos < 0)
2451                 return 0;
2452         ce = active_cache[pos];
2454         /*
2455          * This is not the sha1 we are looking for, or
2456          * unreusable because it is not a regular file.
2457          */
2458         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2459                 return 0;
2461         /*
2462          * If ce is marked as "assume unchanged", there is no
2463          * guarantee that work tree matches what we are looking for.
2464          */
2465         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2466                 return 0;
2468         /*
2469          * If ce matches the file in the work tree, we can reuse it.
2470          */
2471         if (ce_uptodate(ce) ||
2472             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2473                 return 1;
2475         return 0;
2478 static int populate_from_stdin(struct diff_filespec *s)
2480         struct strbuf buf = STRBUF_INIT;
2481         size_t size = 0;
2483         if (strbuf_read(&buf, 0, 0) < 0)
2484                 return error("error while reading from stdin %s",
2485                                      strerror(errno));
2487         s->should_munmap = 0;
2488         s->data = strbuf_detach(&buf, &size);
2489         s->size = size;
2490         s->should_free = 1;
2491         return 0;
2494 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2496         int len;
2497         char *data = xmalloc(100), *dirty = "";
2499         /* Are we looking at the work tree? */
2500         if (s->dirty_submodule)
2501                 dirty = "-dirty";
2503         len = snprintf(data, 100,
2504                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2505         s->data = data;
2506         s->size = len;
2507         s->should_free = 1;
2508         if (size_only) {
2509                 s->data = NULL;
2510                 free(data);
2511         }
2512         return 0;
2515 /*
2516  * While doing rename detection and pickaxe operation, we may need to
2517  * grab the data for the blob (or file) for our own in-core comparison.
2518  * diff_filespec has data and size fields for this purpose.
2519  */
2520 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2522         int err = 0;
2523         if (!DIFF_FILE_VALID(s))
2524                 die("internal error: asking to populate invalid file.");
2525         if (S_ISDIR(s->mode))
2526                 return -1;
2528         if (s->data)
2529                 return 0;
2531         if (size_only && 0 < s->size)
2532                 return 0;
2534         if (S_ISGITLINK(s->mode))
2535                 return diff_populate_gitlink(s, size_only);
2537         if (!s->sha1_valid ||
2538             reuse_worktree_file(s->path, s->sha1, 0)) {
2539                 struct strbuf buf = STRBUF_INIT;
2540                 struct stat st;
2541                 int fd;
2543                 if (!strcmp(s->path, "-"))
2544                         return populate_from_stdin(s);
2546                 if (lstat(s->path, &st) < 0) {
2547                         if (errno == ENOENT) {
2548                         err_empty:
2549                                 err = -1;
2550                         empty:
2551                                 s->data = (char *)"";
2552                                 s->size = 0;
2553                                 return err;
2554                         }
2555                 }
2556                 s->size = xsize_t(st.st_size);
2557                 if (!s->size)
2558                         goto empty;
2559                 if (S_ISLNK(st.st_mode)) {
2560                         struct strbuf sb = STRBUF_INIT;
2562                         if (strbuf_readlink(&sb, s->path, s->size))
2563                                 goto err_empty;
2564                         s->size = sb.len;
2565                         s->data = strbuf_detach(&sb, NULL);
2566                         s->should_free = 1;
2567                         return 0;
2568                 }
2569                 if (size_only)
2570                         return 0;
2571                 fd = open(s->path, O_RDONLY);
2572                 if (fd < 0)
2573                         goto err_empty;
2574                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2575                 close(fd);
2576                 s->should_munmap = 1;
2578                 /*
2579                  * Convert from working tree format to canonical git format
2580                  */
2581                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2582                         size_t size = 0;
2583                         munmap(s->data, s->size);
2584                         s->should_munmap = 0;
2585                         s->data = strbuf_detach(&buf, &size);
2586                         s->size = size;
2587                         s->should_free = 1;
2588                 }
2589         }
2590         else {
2591                 enum object_type type;
2592                 if (size_only) {
2593                         type = sha1_object_info(s->sha1, &s->size);
2594                         if (type < 0)
2595                                 die("unable to read %s", sha1_to_hex(s->sha1));
2596                 } else {
2597                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2598                         if (!s->data)
2599                                 die("unable to read %s", sha1_to_hex(s->sha1));
2600                         s->should_free = 1;
2601                 }
2602         }
2603         return 0;
2606 void diff_free_filespec_blob(struct diff_filespec *s)
2608         if (s->should_free)
2609                 free(s->data);
2610         else if (s->should_munmap)
2611                 munmap(s->data, s->size);
2613         if (s->should_free || s->should_munmap) {
2614                 s->should_free = s->should_munmap = 0;
2615                 s->data = NULL;
2616         }
2619 void diff_free_filespec_data(struct diff_filespec *s)
2621         diff_free_filespec_blob(s);
2622         free(s->cnt_data);
2623         s->cnt_data = NULL;
2626 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2627                            void *blob,
2628                            unsigned long size,
2629                            const unsigned char *sha1,
2630                            int mode)
2632         int fd;
2633         struct strbuf buf = STRBUF_INIT;
2634         struct strbuf template = STRBUF_INIT;
2635         char *path_dup = xstrdup(path);
2636         const char *base = basename(path_dup);
2638         /* Generate "XXXXXX_basename.ext" */
2639         strbuf_addstr(&template, "XXXXXX_");
2640         strbuf_addstr(&template, base);
2642         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2643                         strlen(base) + 1);
2644         if (fd < 0)
2645                 die_errno("unable to create temp-file");
2646         if (convert_to_working_tree(path,
2647                         (const char *)blob, (size_t)size, &buf)) {
2648                 blob = buf.buf;
2649                 size = buf.len;
2650         }
2651         if (write_in_full(fd, blob, size) != size)
2652                 die_errno("unable to write temp-file");
2653         close(fd);
2654         temp->name = temp->tmp_path;
2655         strcpy(temp->hex, sha1_to_hex(sha1));
2656         temp->hex[40] = 0;
2657         sprintf(temp->mode, "%06o", mode);
2658         strbuf_release(&buf);
2659         strbuf_release(&template);
2660         free(path_dup);
2663 static struct diff_tempfile *prepare_temp_file(const char *name,
2664                 struct diff_filespec *one)
2666         struct diff_tempfile *temp = claim_diff_tempfile();
2668         if (!DIFF_FILE_VALID(one)) {
2669         not_a_valid_file:
2670                 /* A '-' entry produces this for file-2, and
2671                  * a '+' entry produces this for file-1.
2672                  */
2673                 temp->name = "/dev/null";
2674                 strcpy(temp->hex, ".");
2675                 strcpy(temp->mode, ".");
2676                 return temp;
2677         }
2679         if (!remove_tempfile_installed) {
2680                 atexit(remove_tempfile);
2681                 sigchain_push_common(remove_tempfile_on_signal);
2682                 remove_tempfile_installed = 1;
2683         }
2685         if (!one->sha1_valid ||
2686             reuse_worktree_file(name, one->sha1, 1)) {
2687                 struct stat st;
2688                 if (lstat(name, &st) < 0) {
2689                         if (errno == ENOENT)
2690                                 goto not_a_valid_file;
2691                         die_errno("stat(%s)", name);
2692                 }
2693                 if (S_ISLNK(st.st_mode)) {
2694                         struct strbuf sb = STRBUF_INIT;
2695                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2696                                 die_errno("readlink(%s)", name);
2697                         prep_temp_blob(name, temp, sb.buf, sb.len,
2698                                        (one->sha1_valid ?
2699                                         one->sha1 : null_sha1),
2700                                        (one->sha1_valid ?
2701                                         one->mode : S_IFLNK));
2702                         strbuf_release(&sb);
2703                 }
2704                 else {
2705                         /* we can borrow from the file in the work tree */
2706                         temp->name = name;
2707                         if (!one->sha1_valid)
2708                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2709                         else
2710                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2711                         /* Even though we may sometimes borrow the
2712                          * contents from the work tree, we always want
2713                          * one->mode.  mode is trustworthy even when
2714                          * !(one->sha1_valid), as long as
2715                          * DIFF_FILE_VALID(one).
2716                          */
2717                         sprintf(temp->mode, "%06o", one->mode);
2718                 }
2719                 return temp;
2720         }
2721         else {
2722                 if (diff_populate_filespec(one, 0))
2723                         die("cannot read data blob for %s", one->path);
2724                 prep_temp_blob(name, temp, one->data, one->size,
2725                                one->sha1, one->mode);
2726         }
2727         return temp;
2730 /* An external diff command takes:
2731  *
2732  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2733  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2734  *
2735  */
2736 static void run_external_diff(const char *pgm,
2737                               const char *name,
2738                               const char *other,
2739                               struct diff_filespec *one,
2740                               struct diff_filespec *two,
2741                               const char *xfrm_msg,
2742                               int complete_rewrite)
2744         const char *spawn_arg[10];
2745         int retval;
2746         const char **arg = &spawn_arg[0];
2748         if (one && two) {
2749                 struct diff_tempfile *temp_one, *temp_two;
2750                 const char *othername = (other ? other : name);
2751                 temp_one = prepare_temp_file(name, one);
2752                 temp_two = prepare_temp_file(othername, two);
2753                 *arg++ = pgm;
2754                 *arg++ = name;
2755                 *arg++ = temp_one->name;
2756                 *arg++ = temp_one->hex;
2757                 *arg++ = temp_one->mode;
2758                 *arg++ = temp_two->name;
2759                 *arg++ = temp_two->hex;
2760                 *arg++ = temp_two->mode;
2761                 if (other) {
2762                         *arg++ = other;
2763                         *arg++ = xfrm_msg;
2764                 }
2765         } else {
2766                 *arg++ = pgm;
2767                 *arg++ = name;
2768         }
2769         *arg = NULL;
2770         fflush(NULL);
2771         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2772         remove_tempfile();
2773         if (retval) {
2774                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2775                 exit(1);
2776         }
2779 static int similarity_index(struct diff_filepair *p)
2781         return p->score * 100 / MAX_SCORE;
2784 static void fill_metainfo(struct strbuf *msg,
2785                           const char *name,
2786                           const char *other,
2787                           struct diff_filespec *one,
2788                           struct diff_filespec *two,
2789                           struct diff_options *o,
2790                           struct diff_filepair *p,
2791                           int *must_show_header,
2792                           int use_color)
2794         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2795         const char *reset = diff_get_color(use_color, DIFF_RESET);
2796         struct strbuf *msgbuf;
2797         char *line_prefix = "";
2799         *must_show_header = 1;
2800         if (o->output_prefix) {
2801                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2802                 line_prefix = msgbuf->buf;
2803         }
2804         strbuf_init(msg, PATH_MAX * 2 + 300);
2805         switch (p->status) {
2806         case DIFF_STATUS_COPIED:
2807                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2808                             line_prefix, set, similarity_index(p));
2809                 strbuf_addf(msg, "%s\n%s%scopy from ",
2810                             reset,  line_prefix, set);
2811                 quote_c_style(name, msg, NULL, 0);
2812                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2813                 quote_c_style(other, msg, NULL, 0);
2814                 strbuf_addf(msg, "%s\n", reset);
2815                 break;
2816         case DIFF_STATUS_RENAMED:
2817                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2818                             line_prefix, set, similarity_index(p));
2819                 strbuf_addf(msg, "%s\n%s%srename from ",
2820                             reset, line_prefix, set);
2821                 quote_c_style(name, msg, NULL, 0);
2822                 strbuf_addf(msg, "%s\n%s%srename to ",
2823                             reset, line_prefix, set);
2824                 quote_c_style(other, msg, NULL, 0);
2825                 strbuf_addf(msg, "%s\n", reset);
2826                 break;
2827         case DIFF_STATUS_MODIFIED:
2828                 if (p->score) {
2829                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2830                                     line_prefix,
2831                                     set, similarity_index(p), reset);
2832                         break;
2833                 }
2834                 /* fallthru */
2835         default:
2836                 *must_show_header = 0;
2837         }
2838         if (one && two && hashcmp(one->sha1, two->sha1)) {
2839                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2841                 if (DIFF_OPT_TST(o, BINARY)) {
2842                         mmfile_t mf;
2843                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2844                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2845                                 abbrev = 40;
2846                 }
2847                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2848                             find_unique_abbrev(one->sha1, abbrev));
2849                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2850                 if (one->mode == two->mode)
2851                         strbuf_addf(msg, " %06o", one->mode);
2852                 strbuf_addf(msg, "%s\n", reset);
2853         }
2856 static void run_diff_cmd(const char *pgm,
2857                          const char *name,
2858                          const char *other,
2859                          const char *attr_path,
2860                          struct diff_filespec *one,
2861                          struct diff_filespec *two,
2862                          struct strbuf *msg,
2863                          struct diff_options *o,
2864                          struct diff_filepair *p)
2866         const char *xfrm_msg = NULL;
2867         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2868         int must_show_header = 0;
2870         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2871                 pgm = NULL;
2872         else {
2873                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2874                 if (drv && drv->external)
2875                         pgm = drv->external;
2876         }
2878         if (msg) {
2879                 /*
2880                  * don't use colors when the header is intended for an
2881                  * external diff driver
2882                  */
2883                 fill_metainfo(msg, name, other, one, two, o, p,
2884                               &must_show_header,
2885                               want_color(o->use_color) && !pgm);
2886                 xfrm_msg = msg->len ? msg->buf : NULL;
2887         }
2889         if (pgm) {
2890                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2891                                   complete_rewrite);
2892                 return;
2893         }
2894         if (one && two)
2895                 builtin_diff(name, other ? other : name,
2896                              one, two, xfrm_msg, must_show_header,
2897                              o, complete_rewrite);
2898         else
2899                 fprintf(o->file, "* Unmerged path %s\n", name);
2902 static void diff_fill_sha1_info(struct diff_filespec *one)
2904         if (DIFF_FILE_VALID(one)) {
2905                 if (!one->sha1_valid) {
2906                         struct stat st;
2907                         if (!strcmp(one->path, "-")) {
2908                                 hashcpy(one->sha1, null_sha1);
2909                                 return;
2910                         }
2911                         if (lstat(one->path, &st) < 0)
2912                                 die_errno("stat '%s'", one->path);
2913                         if (index_path(one->sha1, one->path, &st, 0))
2914                                 die("cannot hash %s", one->path);
2915                 }
2916         }
2917         else
2918                 hashclr(one->sha1);
2921 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2923         /* Strip the prefix but do not molest /dev/null and absolute paths */
2924         if (*namep && **namep != '/') {
2925                 *namep += prefix_length;
2926                 if (**namep == '/')
2927                         ++*namep;
2928         }
2929         if (*otherp && **otherp != '/') {
2930                 *otherp += prefix_length;
2931                 if (**otherp == '/')
2932                         ++*otherp;
2933         }
2936 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2938         const char *pgm = external_diff();
2939         struct strbuf msg;
2940         struct diff_filespec *one = p->one;
2941         struct diff_filespec *two = p->two;
2942         const char *name;
2943         const char *other;
2944         const char *attr_path;
2946         name  = p->one->path;
2947         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2948         attr_path = name;
2949         if (o->prefix_length)
2950                 strip_prefix(o->prefix_length, &name, &other);
2952         if (DIFF_PAIR_UNMERGED(p)) {
2953                 run_diff_cmd(pgm, name, NULL, attr_path,
2954                              NULL, NULL, NULL, o, p);
2955                 return;
2956         }
2958         diff_fill_sha1_info(one);
2959         diff_fill_sha1_info(two);
2961         if (!pgm &&
2962             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2963             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2964                 /*
2965                  * a filepair that changes between file and symlink
2966                  * needs to be split into deletion and creation.
2967                  */
2968                 struct diff_filespec *null = alloc_filespec(two->path);
2969                 run_diff_cmd(NULL, name, other, attr_path,
2970                              one, null, &msg, o, p);
2971                 free(null);
2972                 strbuf_release(&msg);
2974                 null = alloc_filespec(one->path);
2975                 run_diff_cmd(NULL, name, other, attr_path,
2976                              null, two, &msg, o, p);
2977                 free(null);
2978         }
2979         else
2980                 run_diff_cmd(pgm, name, other, attr_path,
2981                              one, two, &msg, o, p);
2983         strbuf_release(&msg);
2986 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2987                          struct diffstat_t *diffstat)
2989         const char *name;
2990         const char *other;
2991         int complete_rewrite = 0;
2993         if (DIFF_PAIR_UNMERGED(p)) {
2994                 /* unmerged */
2995                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2996                 return;
2997         }
2999         name = p->one->path;
3000         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3002         if (o->prefix_length)
3003                 strip_prefix(o->prefix_length, &name, &other);
3005         diff_fill_sha1_info(p->one);
3006         diff_fill_sha1_info(p->two);
3008         if (p->status == DIFF_STATUS_MODIFIED && p->score)
3009                 complete_rewrite = 1;
3010         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3013 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3015         const char *name;
3016         const char *other;
3017         const char *attr_path;
3019         if (DIFF_PAIR_UNMERGED(p)) {
3020                 /* unmerged */
3021                 return;
3022         }
3024         name = p->one->path;
3025         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3026         attr_path = other ? other : name;
3028         if (o->prefix_length)
3029                 strip_prefix(o->prefix_length, &name, &other);
3031         diff_fill_sha1_info(p->one);
3032         diff_fill_sha1_info(p->two);
3034         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3037 void diff_setup(struct diff_options *options)
3039         memcpy(options, &default_diff_options, sizeof(*options));
3041         options->file = stdout;
3043         options->line_termination = '\n';
3044         options->break_opt = -1;
3045         options->rename_limit = -1;
3046         options->dirstat_permille = diff_dirstat_permille_default;
3047         options->context = 3;
3049         options->change = diff_change;
3050         options->add_remove = diff_addremove;
3051         options->use_color = diff_use_color_default;
3052         options->detect_rename = diff_detect_rename_default;
3054         if (diff_no_prefix) {
3055                 options->a_prefix = options->b_prefix = "";
3056         } else if (!diff_mnemonic_prefix) {
3057                 options->a_prefix = "a/";
3058                 options->b_prefix = "b/";
3059         }
3062 int diff_setup_done(struct diff_options *options)
3064         int count = 0;
3066         if (options->output_format & DIFF_FORMAT_NAME)
3067                 count++;
3068         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3069                 count++;
3070         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3071                 count++;
3072         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3073                 count++;
3074         if (count > 1)
3075                 die("--name-only, --name-status, --check and -s are mutually exclusive");
3077         /*
3078          * Most of the time we can say "there are changes"
3079          * only by checking if there are changed paths, but
3080          * --ignore-whitespace* options force us to look
3081          * inside contents.
3082          */
3084         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3085             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3086             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3087                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3088         else
3089                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3091         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3092                 options->detect_rename = DIFF_DETECT_COPY;
3094         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3095                 options->prefix = NULL;
3096         if (options->prefix)
3097                 options->prefix_length = strlen(options->prefix);
3098         else
3099                 options->prefix_length = 0;
3101         if (options->output_format & (DIFF_FORMAT_NAME |
3102                                       DIFF_FORMAT_NAME_STATUS |
3103                                       DIFF_FORMAT_CHECKDIFF |
3104                                       DIFF_FORMAT_NO_OUTPUT))
3105                 options->output_format &= ~(DIFF_FORMAT_RAW |
3106                                             DIFF_FORMAT_NUMSTAT |
3107                                             DIFF_FORMAT_DIFFSTAT |
3108                                             DIFF_FORMAT_SHORTSTAT |
3109                                             DIFF_FORMAT_DIRSTAT |
3110                                             DIFF_FORMAT_SUMMARY |
3111                                             DIFF_FORMAT_PATCH);
3113         /*
3114          * These cases always need recursive; we do not drop caller-supplied
3115          * recursive bits for other formats here.
3116          */
3117         if (options->output_format & (DIFF_FORMAT_PATCH |
3118                                       DIFF_FORMAT_NUMSTAT |
3119                                       DIFF_FORMAT_DIFFSTAT |
3120                                       DIFF_FORMAT_SHORTSTAT |
3121                                       DIFF_FORMAT_DIRSTAT |
3122                                       DIFF_FORMAT_SUMMARY |
3123                                       DIFF_FORMAT_CHECKDIFF))
3124                 DIFF_OPT_SET(options, RECURSIVE);
3125         /*
3126          * Also pickaxe would not work very well if you do not say recursive
3127          */
3128         if (options->pickaxe)
3129                 DIFF_OPT_SET(options, RECURSIVE);
3130         /*
3131          * When patches are generated, submodules diffed against the work tree
3132          * must be checked for dirtiness too so it can be shown in the output
3133          */
3134         if (options->output_format & DIFF_FORMAT_PATCH)
3135                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3137         if (options->detect_rename && options->rename_limit < 0)
3138                 options->rename_limit = diff_rename_limit_default;
3139         if (options->setup & DIFF_SETUP_USE_CACHE) {
3140                 if (!active_cache)
3141                         /* read-cache does not die even when it fails
3142                          * so it is safe for us to do this here.  Also
3143                          * it does not smudge active_cache or active_nr
3144                          * when it fails, so we do not have to worry about
3145                          * cleaning it up ourselves either.
3146                          */
3147                         read_cache();
3148         }
3149         if (options->abbrev <= 0 || 40 < options->abbrev)
3150                 options->abbrev = 40; /* full */
3152         /*
3153          * It does not make sense to show the first hit we happened
3154          * to have found.  It does not make sense not to return with
3155          * exit code in such a case either.
3156          */
3157         if (DIFF_OPT_TST(options, QUICK)) {
3158                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3159                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3160         }
3162         return 0;
3165 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3167         char c, *eq;
3168         int len;
3170         if (*arg != '-')
3171                 return 0;
3172         c = *++arg;
3173         if (!c)
3174                 return 0;
3175         if (c == arg_short) {
3176                 c = *++arg;
3177                 if (!c)
3178                         return 1;
3179                 if (val && isdigit(c)) {
3180                         char *end;
3181                         int n = strtoul(arg, &end, 10);
3182                         if (*end)
3183                                 return 0;
3184                         *val = n;
3185                         return 1;
3186                 }
3187                 return 0;
3188         }
3189         if (c != '-')
3190                 return 0;
3191         arg++;
3192         eq = strchr(arg, '=');
3193         if (eq)
3194                 len = eq - arg;
3195         else
3196                 len = strlen(arg);
3197         if (!len || strncmp(arg, arg_long, len))
3198                 return 0;
3199         if (eq) {
3200                 int n;
3201                 char *end;
3202                 if (!isdigit(*++eq))
3203                         return 0;
3204                 n = strtoul(eq, &end, 10);
3205                 if (*end)
3206                         return 0;
3207                 *val = n;
3208         }
3209         return 1;
3212 static int diff_scoreopt_parse(const char *opt);
3214 static inline int short_opt(char opt, const char **argv,
3215                             const char **optarg)
3217         const char *arg = argv[0];
3218         if (arg[0] != '-' || arg[1] != opt)
3219                 return 0;
3220         if (arg[2] != '\0') {
3221                 *optarg = arg + 2;
3222                 return 1;
3223         }
3224         if (!argv[1])
3225                 die("Option '%c' requires a value", opt);
3226         *optarg = argv[1];
3227         return 2;
3230 int parse_long_opt(const char *opt, const char **argv,
3231                    const char **optarg)
3233         const char *arg = argv[0];
3234         if (arg[0] != '-' || arg[1] != '-')
3235                 return 0;
3236         arg += strlen("--");
3237         if (prefixcmp(arg, opt))
3238                 return 0;
3239         arg += strlen(opt);
3240         if (*arg == '=') { /* sticked form: --option=value */
3241                 *optarg = arg + 1;
3242                 return 1;
3243         }
3244         if (*arg != '\0')
3245                 return 0;
3246         /* separate form: --option value */
3247         if (!argv[1])
3248                 die("Option '--%s' requires a value", opt);
3249         *optarg = argv[1];
3250         return 2;
3253 static int stat_opt(struct diff_options *options, const char **av)
3255         const char *arg = av[0];
3256         char *end;
3257         int width = options->stat_width;
3258         int name_width = options->stat_name_width;
3259         int count = options->stat_count;
3260         int argcount = 1;
3262         arg += strlen("--stat");
3263         end = (char *)arg;
3265         switch (*arg) {
3266         case '-':
3267                 if (!prefixcmp(arg, "-width")) {
3268                         arg += strlen("-width");
3269                         if (*arg == '=')
3270                                 width = strtoul(arg + 1, &end, 10);
3271                         else if (!*arg && !av[1])
3272                                 die("Option '--stat-width' requires a value");
3273                         else if (!*arg) {
3274                                 width = strtoul(av[1], &end, 10);
3275                                 argcount = 2;
3276                         }
3277                 } else if (!prefixcmp(arg, "-name-width")) {
3278                         arg += strlen("-name-width");
3279                         if (*arg == '=')
3280                                 name_width = strtoul(arg + 1, &end, 10);
3281                         else if (!*arg && !av[1])
3282                                 die("Option '--stat-name-width' requires a value");
3283                         else if (!*arg) {
3284                                 name_width = strtoul(av[1], &end, 10);
3285                                 argcount = 2;
3286                         }
3287                 } else if (!prefixcmp(arg, "-count")) {
3288                         arg += strlen("-count");
3289                         if (*arg == '=')
3290                                 count = strtoul(arg + 1, &end, 10);
3291                         else if (!*arg && !av[1])
3292                                 die("Option '--stat-count' requires a value");
3293                         else if (!*arg) {
3294                                 count = strtoul(av[1], &end, 10);
3295                                 argcount = 2;
3296                         }
3297                 }
3298                 break;
3299         case '=':
3300                 width = strtoul(arg+1, &end, 10);
3301                 if (*end == ',')
3302                         name_width = strtoul(end+1, &end, 10);
3303                 if (*end == ',')
3304                         count = strtoul(end+1, &end, 10);
3305         }
3307         /* Important! This checks all the error cases! */
3308         if (*end)
3309                 return 0;
3310         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3311         options->stat_name_width = name_width;
3312         options->stat_width = width;
3313         options->stat_count = count;
3314         return argcount;
3317 static int parse_dirstat_opt(struct diff_options *options, const char *params)
3319         struct strbuf errmsg = STRBUF_INIT;
3320         if (parse_dirstat_params(options, params, &errmsg))
3321                 die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3322                     errmsg.buf);
3323         strbuf_release(&errmsg);
3324         /*
3325          * The caller knows a dirstat-related option is given from the command
3326          * line; allow it to say "return this_function();"
3327          */
3328         options->output_format |= DIFF_FORMAT_DIRSTAT;
3329         return 1;
3332 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3334         const char *arg = av[0];
3335         const char *optarg;
3336         int argcount;
3338         /* Output format options */
3339         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3340                 options->output_format |= DIFF_FORMAT_PATCH;
3341         else if (opt_arg(arg, 'U', "unified", &options->context))
3342                 options->output_format |= DIFF_FORMAT_PATCH;
3343         else if (!strcmp(arg, "--raw"))
3344                 options->output_format |= DIFF_FORMAT_RAW;
3345         else if (!strcmp(arg, "--patch-with-raw"))
3346                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3347         else if (!strcmp(arg, "--numstat"))
3348                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3349         else if (!strcmp(arg, "--shortstat"))
3350                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3351         else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3352                 return parse_dirstat_opt(options, "");
3353         else if (!prefixcmp(arg, "-X"))
3354                 return parse_dirstat_opt(options, arg + 2);
3355         else if (!prefixcmp(arg, "--dirstat="))
3356                 return parse_dirstat_opt(options, arg + 10);
3357         else if (!strcmp(arg, "--cumulative"))
3358                 return parse_dirstat_opt(options, "cumulative");
3359         else if (!strcmp(arg, "--dirstat-by-file"))
3360                 return parse_dirstat_opt(options, "files");
3361         else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3362                 parse_dirstat_opt(options, "files");
3363                 return parse_dirstat_opt(options, arg + 18);
3364         }
3365         else if (!strcmp(arg, "--check"))
3366                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3367         else if (!strcmp(arg, "--summary"))
3368                 options->output_format |= DIFF_FORMAT_SUMMARY;
3369         else if (!strcmp(arg, "--patch-with-stat"))
3370                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3371         else if (!strcmp(arg, "--name-only"))
3372                 options->output_format |= DIFF_FORMAT_NAME;
3373         else if (!strcmp(arg, "--name-status"))
3374                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3375         else if (!strcmp(arg, "-s"))
3376                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3377         else if (!prefixcmp(arg, "--stat"))
3378                 /* --stat, --stat-width, --stat-name-width, or --stat-count */
3379                 return stat_opt(options, av);
3381         /* renames options */
3382         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3383                  !strcmp(arg, "--break-rewrites")) {
3384                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3385                         return error("invalid argument to -B: %s", arg+2);
3386         }
3387         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3388                  !strcmp(arg, "--find-renames")) {
3389                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3390                         return error("invalid argument to -M: %s", arg+2);
3391                 options->detect_rename = DIFF_DETECT_RENAME;
3392         }
3393         else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3394                 options->irreversible_delete = 1;
3395         }
3396         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3397                  !strcmp(arg, "--find-copies")) {
3398                 if (options->detect_rename == DIFF_DETECT_COPY)
3399                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3400                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3401                         return error("invalid argument to -C: %s", arg+2);
3402                 options->detect_rename = DIFF_DETECT_COPY;
3403         }
3404         else if (!strcmp(arg, "--no-renames"))
3405                 options->detect_rename = 0;
3406         else if (!strcmp(arg, "--relative"))
3407                 DIFF_OPT_SET(options, RELATIVE_NAME);
3408         else if (!prefixcmp(arg, "--relative=")) {
3409                 DIFF_OPT_SET(options, RELATIVE_NAME);
3410                 options->prefix = arg + 11;
3411         }
3413         /* xdiff options */
3414         else if (!strcmp(arg, "--minimal"))
3415                 DIFF_XDL_SET(options, NEED_MINIMAL);
3416         else if (!strcmp(arg, "--no-minimal"))
3417                 DIFF_XDL_CLR(options, NEED_MINIMAL);
3418         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3419                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3420         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3421                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3422         else if (!strcmp(arg, "--ignore-space-at-eol"))
3423                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3424         else if (!strcmp(arg, "--patience"))
3425                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3426         else if (!strcmp(arg, "--histogram"))
3427                 DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3429         /* flags options */
3430         else if (!strcmp(arg, "--binary")) {
3431                 options->output_format |= DIFF_FORMAT_PATCH;
3432                 DIFF_OPT_SET(options, BINARY);
3433         }
3434         else if (!strcmp(arg, "--full-index"))
3435                 DIFF_OPT_SET(options, FULL_INDEX);
3436         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3437                 DIFF_OPT_SET(options, TEXT);
3438         else if (!strcmp(arg, "-R"))
3439                 DIFF_OPT_SET(options, REVERSE_DIFF);
3440         else if (!strcmp(arg, "--find-copies-harder"))
3441                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3442         else if (!strcmp(arg, "--follow"))
3443                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3444         else if (!strcmp(arg, "--color"))
3445                 options->use_color = 1;
3446         else if (!prefixcmp(arg, "--color=")) {
3447                 int value = git_config_colorbool(NULL, arg+8);
3448                 if (value < 0)
3449                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3450                 options->use_color = value;
3451         }
3452         else if (!strcmp(arg, "--no-color"))
3453                 options->use_color = 0;
3454         else if (!strcmp(arg, "--color-words")) {
3455                 options->use_color = 1;
3456                 options->word_diff = DIFF_WORDS_COLOR;
3457         }
3458         else if (!prefixcmp(arg, "--color-words=")) {
3459                 options->use_color = 1;
3460                 options->word_diff = DIFF_WORDS_COLOR;
3461                 options->word_regex = arg + 14;
3462         }
3463         else if (!strcmp(arg, "--word-diff")) {
3464                 if (options->word_diff == DIFF_WORDS_NONE)
3465                         options->word_diff = DIFF_WORDS_PLAIN;
3466         }
3467         else if (!prefixcmp(arg, "--word-diff=")) {
3468                 const char *type = arg + 12;
3469                 if (!strcmp(type, "plain"))
3470                         options->word_diff = DIFF_WORDS_PLAIN;
3471                 else if (!strcmp(type, "color")) {
3472                         options->use_color = 1;
3473                         options->word_diff = DIFF_WORDS_COLOR;
3474                 }
3475                 else if (!strcmp(type, "porcelain"))
3476                         options->word_diff = DIFF_WORDS_PORCELAIN;
3477                 else if (!strcmp(type, "none"))
3478                         options->word_diff = DIFF_WORDS_NONE;
3479                 else
3480                         die("bad --word-diff argument: %s", type);
3481         }
3482         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3483                 if (options->word_diff == DIFF_WORDS_NONE)
3484                         options->word_diff = DIFF_WORDS_PLAIN;
3485                 options->word_regex = optarg;
3486                 return argcount;
3487         }
3488         else if (!strcmp(arg, "--exit-code"))
3489                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3490         else if (!strcmp(arg, "--quiet"))
3491                 DIFF_OPT_SET(options, QUICK);
3492         else if (!strcmp(arg, "--ext-diff"))
3493                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3494         else if (!strcmp(arg, "--no-ext-diff"))
3495                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3496         else if (!strcmp(arg, "--textconv"))
3497                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3498         else if (!strcmp(arg, "--no-textconv"))
3499                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3500         else if (!strcmp(arg, "--ignore-submodules")) {
3501                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3502                 handle_ignore_submodules_arg(options, "all");
3503         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3504                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3505                 handle_ignore_submodules_arg(options, arg + 20);
3506         } else if (!strcmp(arg, "--submodule"))
3507                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3508         else if (!prefixcmp(arg, "--submodule=")) {
3509                 if (!strcmp(arg + 12, "log"))
3510                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3511         }
3513         /* misc options */
3514         else if (!strcmp(arg, "-z"))
3515                 options->line_termination = 0;
3516         else if ((argcount = short_opt('l', av, &optarg))) {
3517                 options->rename_limit = strtoul(optarg, NULL, 10);
3518                 return argcount;
3519         }
3520         else if ((argcount = short_opt('S', av, &optarg))) {
3521                 options->pickaxe = optarg;
3522                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3523                 return argcount;
3524         } else if ((argcount = short_opt('G', av, &optarg))) {
3525                 options->pickaxe = optarg;
3526                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3527                 return argcount;
3528         }
3529         else if (!strcmp(arg, "--pickaxe-all"))
3530                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3531         else if (!strcmp(arg, "--pickaxe-regex"))
3532                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3533         else if ((argcount = short_opt('O', av, &optarg))) {
3534                 options->orderfile = optarg;
3535                 return argcount;
3536         }
3537         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3538                 options->filter = optarg;
3539                 return argcount;
3540         }
3541         else if (!strcmp(arg, "--abbrev"))
3542                 options->abbrev = DEFAULT_ABBREV;
3543         else if (!prefixcmp(arg, "--abbrev=")) {
3544                 options->abbrev = strtoul(arg + 9, NULL, 10);
3545                 if (options->abbrev < MINIMUM_ABBREV)
3546                         options->abbrev = MINIMUM_ABBREV;
3547                 else if (40 < options->abbrev)
3548                         options->abbrev = 40;
3549         }
3550         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3551                 options->a_prefix = optarg;
3552                 return argcount;
3553         }
3554         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3555                 options->b_prefix = optarg;
3556                 return argcount;
3557         }
3558         else if (!strcmp(arg, "--no-prefix"))
3559                 options->a_prefix = options->b_prefix = "";
3560         else if (opt_arg(arg, '\0', "inter-hunk-context",
3561                          &options->interhunkcontext))
3562                 ;
3563         else if (!strcmp(arg, "-W"))
3564                 DIFF_OPT_SET(options, FUNCCONTEXT);
3565         else if (!strcmp(arg, "--function-context"))
3566                 DIFF_OPT_SET(options, FUNCCONTEXT);
3567         else if (!strcmp(arg, "--no-function-context"))
3568                 DIFF_OPT_CLR(options, FUNCCONTEXT);
3569         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3570                 options->file = fopen(optarg, "w");
3571                 if (!options->file)
3572                         die_errno("Could not open '%s'", optarg);
3573                 options->close_file = 1;
3574                 return argcount;
3575         } else
3576                 return 0;
3577         return 1;
3580 int parse_rename_score(const char **cp_p)
3582         unsigned long num, scale;
3583         int ch, dot;
3584         const char *cp = *cp_p;
3586         num = 0;
3587         scale = 1;
3588         dot = 0;
3589         for (;;) {
3590                 ch = *cp;
3591                 if ( !dot && ch == '.' ) {
3592                         scale = 1;
3593                         dot = 1;
3594                 } else if ( ch == '%' ) {
3595                         scale = dot ? scale*100 : 100;
3596                         cp++;   /* % is always at the end */
3597                         break;
3598                 } else if ( ch >= '0' && ch <= '9' ) {
3599                         if ( scale < 100000 ) {
3600                                 scale *= 10;
3601                                 num = (num*10) + (ch-'0');
3602                         }
3603                 } else {
3604                         break;
3605                 }
3606                 cp++;
3607         }
3608         *cp_p = cp;
3610         /* user says num divided by scale and we say internally that
3611          * is MAX_SCORE * num / scale.
3612          */
3613         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3616 static int diff_scoreopt_parse(const char *opt)
3618         int opt1, opt2, cmd;
3620         if (*opt++ != '-')
3621                 return -1;
3622         cmd = *opt++;
3623         if (cmd == '-') {
3624                 /* convert the long-form arguments into short-form versions */
3625                 if (!prefixcmp(opt, "break-rewrites")) {
3626                         opt += strlen("break-rewrites");
3627                         if (*opt == 0 || *opt++ == '=')
3628                                 cmd = 'B';
3629                 } else if (!prefixcmp(opt, "find-copies")) {
3630                         opt += strlen("find-copies");
3631                         if (*opt == 0 || *opt++ == '=')
3632                                 cmd = 'C';
3633                 } else if (!prefixcmp(opt, "find-renames")) {
3634                         opt += strlen("find-renames");
3635                         if (*opt == 0 || *opt++ == '=')
3636                                 cmd = 'M';
3637                 }
3638         }
3639         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3640                 return -1; /* that is not a -M, -C nor -B option */
3642         opt1 = parse_rename_score(&opt);
3643         if (cmd != 'B')
3644                 opt2 = 0;
3645         else {
3646                 if (*opt == 0)
3647                         opt2 = 0;
3648                 else if (*opt != '/')
3649                         return -1; /* we expect -B80/99 or -B80 */
3650                 else {
3651                         opt++;
3652                         opt2 = parse_rename_score(&opt);
3653                 }
3654         }
3655         if (*opt != 0)
3656                 return -1;
3657         return opt1 | (opt2 << 16);
3660 struct diff_queue_struct diff_queued_diff;
3662 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3664         if (queue->alloc <= queue->nr) {
3665                 queue->alloc = alloc_nr(queue->alloc);
3666                 queue->queue = xrealloc(queue->queue,
3667                                         sizeof(dp) * queue->alloc);
3668         }
3669         queue->queue[queue->nr++] = dp;
3672 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3673                                  struct diff_filespec *one,
3674                                  struct diff_filespec *two)
3676         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3677         dp->one = one;
3678         dp->two = two;
3679         if (queue)
3680                 diff_q(queue, dp);
3681         return dp;
3684 void diff_free_filepair(struct diff_filepair *p)
3686         free_filespec(p->one);
3687         free_filespec(p->two);
3688         free(p);
3691 /* This is different from find_unique_abbrev() in that
3692  * it stuffs the result with dots for alignment.
3693  */
3694 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3696         int abblen;
3697         const char *abbrev;
3698         if (len == 40)
3699                 return sha1_to_hex(sha1);
3701         abbrev = find_unique_abbrev(sha1, len);
3702         abblen = strlen(abbrev);
3703         if (abblen < 37) {
3704                 static char hex[41];
3705                 if (len < abblen && abblen <= len + 2)
3706                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3707                 else
3708                         sprintf(hex, "%s...", abbrev);
3709                 return hex;
3710         }
3711         return sha1_to_hex(sha1);
3714 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3716         int line_termination = opt->line_termination;
3717         int inter_name_termination = line_termination ? '\t' : '\0';
3718         if (opt->output_prefix) {
3719                 struct strbuf *msg = NULL;
3720                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3721                 fprintf(opt->file, "%s", msg->buf);
3722         }
3724         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3725                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3726                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3727                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3728         }
3729         if (p->score) {
3730                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3731                         inter_name_termination);
3732         } else {
3733                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3734         }
3736         if (p->status == DIFF_STATUS_COPIED ||
3737             p->status == DIFF_STATUS_RENAMED) {
3738                 const char *name_a, *name_b;
3739                 name_a = p->one->path;
3740                 name_b = p->two->path;
3741                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3742                 write_name_quoted(name_a, opt->file, inter_name_termination);
3743                 write_name_quoted(name_b, opt->file, line_termination);
3744         } else {
3745                 const char *name_a, *name_b;
3746                 name_a = p->one->mode ? p->one->path : p->two->path;
3747                 name_b = NULL;
3748                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3749                 write_name_quoted(name_a, opt->file, line_termination);
3750         }
3753 int diff_unmodified_pair(struct diff_filepair *p)
3755         /* This function is written stricter than necessary to support
3756          * the currently implemented transformers, but the idea is to
3757          * let transformers to produce diff_filepairs any way they want,
3758          * and filter and clean them up here before producing the output.
3759          */
3760         struct diff_filespec *one = p->one, *two = p->two;
3762         if (DIFF_PAIR_UNMERGED(p))
3763                 return 0; /* unmerged is interesting */
3765         /* deletion, addition, mode or type change
3766          * and rename are all interesting.
3767          */
3768         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3769             DIFF_PAIR_MODE_CHANGED(p) ||
3770             strcmp(one->path, two->path))
3771                 return 0;
3773         /* both are valid and point at the same path.  that is, we are
3774          * dealing with a change.
3775          */
3776         if (one->sha1_valid && two->sha1_valid &&
3777             !hashcmp(one->sha1, two->sha1) &&
3778             !one->dirty_submodule && !two->dirty_submodule)
3779                 return 1; /* no change */
3780         if (!one->sha1_valid && !two->sha1_valid)
3781                 return 1; /* both look at the same file on the filesystem. */
3782         return 0;
3785 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3787         if (diff_unmodified_pair(p))
3788                 return;
3790         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3791             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3792                 return; /* no tree diffs in patch format */
3794         run_diff(p, o);
3797 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3798                             struct diffstat_t *diffstat)
3800         if (diff_unmodified_pair(p))
3801                 return;
3803         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3804             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3805                 return; /* no useful stat for tree diffs */
3807         run_diffstat(p, o, diffstat);
3810 static void diff_flush_checkdiff(struct diff_filepair *p,
3811                 struct diff_options *o)
3813         if (diff_unmodified_pair(p))
3814                 return;
3816         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3817             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3818                 return; /* nothing to check in tree diffs */
3820         run_checkdiff(p, o);
3823 int diff_queue_is_empty(void)
3825         struct diff_queue_struct *q = &diff_queued_diff;
3826         int i;
3827         for (i = 0; i < q->nr; i++)
3828                 if (!diff_unmodified_pair(q->queue[i]))
3829                         return 0;
3830         return 1;
3833 #if DIFF_DEBUG
3834 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3836         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3837                 x, one ? one : "",
3838                 s->path,
3839                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3840                 s->mode,
3841                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3842         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3843                 x, one ? one : "",
3844                 s->size, s->xfrm_flags);
3847 void diff_debug_filepair(const struct diff_filepair *p, int i)
3849         diff_debug_filespec(p->one, i, "one");
3850         diff_debug_filespec(p->two, i, "two");
3851         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3852                 p->score, p->status ? p->status : '?',
3853                 p->one->rename_used, p->broken_pair);
3856 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3858         int i;
3859         if (msg)
3860                 fprintf(stderr, "%s\n", msg);
3861         fprintf(stderr, "q->nr = %d\n", q->nr);
3862         for (i = 0; i < q->nr; i++) {
3863                 struct diff_filepair *p = q->queue[i];
3864                 diff_debug_filepair(p, i);
3865         }
3867 #endif
3869 static void diff_resolve_rename_copy(void)
3871         int i;
3872         struct diff_filepair *p;
3873         struct diff_queue_struct *q = &diff_queued_diff;
3875         diff_debug_queue("resolve-rename-copy", q);
3877         for (i = 0; i < q->nr; i++) {
3878                 p = q->queue[i];
3879                 p->status = 0; /* undecided */
3880                 if (DIFF_PAIR_UNMERGED(p))
3881                         p->status = DIFF_STATUS_UNMERGED;
3882                 else if (!DIFF_FILE_VALID(p->one))
3883                         p->status = DIFF_STATUS_ADDED;
3884                 else if (!DIFF_FILE_VALID(p->two))
3885                         p->status = DIFF_STATUS_DELETED;
3886                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3887                         p->status = DIFF_STATUS_TYPE_CHANGED;
3889                 /* from this point on, we are dealing with a pair
3890                  * whose both sides are valid and of the same type, i.e.
3891                  * either in-place edit or rename/copy edit.
3892                  */
3893                 else if (DIFF_PAIR_RENAME(p)) {
3894                         /*
3895                          * A rename might have re-connected a broken
3896                          * pair up, causing the pathnames to be the
3897                          * same again. If so, that's not a rename at
3898                          * all, just a modification..
3899                          *
3900                          * Otherwise, see if this source was used for
3901                          * multiple renames, in which case we decrement
3902                          * the count, and call it a copy.
3903                          */
3904                         if (!strcmp(p->one->path, p->two->path))
3905                                 p->status = DIFF_STATUS_MODIFIED;
3906                         else if (--p->one->rename_used > 0)
3907                                 p->status = DIFF_STATUS_COPIED;
3908                         else
3909                                 p->status = DIFF_STATUS_RENAMED;
3910                 }
3911                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3912                          p->one->mode != p->two->mode ||
3913                          p->one->dirty_submodule ||
3914                          p->two->dirty_submodule ||
3915                          is_null_sha1(p->one->sha1))
3916                         p->status = DIFF_STATUS_MODIFIED;
3917                 else {
3918                         /* This is a "no-change" entry and should not
3919                          * happen anymore, but prepare for broken callers.
3920                          */
3921                         error("feeding unmodified %s to diffcore",
3922                               p->one->path);
3923                         p->status = DIFF_STATUS_UNKNOWN;
3924                 }
3925         }
3926         diff_debug_queue("resolve-rename-copy done", q);
3929 static int check_pair_status(struct diff_filepair *p)
3931         switch (p->status) {
3932         case DIFF_STATUS_UNKNOWN:
3933                 return 0;
3934         case 0:
3935                 die("internal error in diff-resolve-rename-copy");
3936         default:
3937                 return 1;
3938         }
3941 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3943         int fmt = opt->output_format;
3945         if (fmt & DIFF_FORMAT_CHECKDIFF)
3946                 diff_flush_checkdiff(p, opt);
3947         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3948                 diff_flush_raw(p, opt);
3949         else if (fmt & DIFF_FORMAT_NAME) {
3950                 const char *name_a, *name_b;
3951                 name_a = p->two->path;
3952                 name_b = NULL;
3953                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3954                 write_name_quoted(name_a, opt->file, opt->line_termination);
3955         }
3958 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3960         if (fs->mode)
3961                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3962         else
3963                 fprintf(file, " %s ", newdelete);
3964         write_name_quoted(fs->path, file, '\n');
3968 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3969                 const char *line_prefix)
3971         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3972                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3973                         p->two->mode, show_name ? ' ' : '\n');
3974                 if (show_name) {
3975                         write_name_quoted(p->two->path, file, '\n');
3976                 }
3977         }
3980 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3981                         const char *line_prefix)
3983         char *names = pprint_rename(p->one->path, p->two->path);
3985         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3986         free(names);
3987         show_mode_change(file, p, 0, line_prefix);
3990 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3992         FILE *file = opt->file;
3993         char *line_prefix = "";
3995         if (opt->output_prefix) {
3996                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3997                 line_prefix = buf->buf;
3998         }
4000         switch(p->status) {
4001         case DIFF_STATUS_DELETED:
4002                 fputs(line_prefix, file);
4003                 show_file_mode_name(file, "delete", p->one);
4004                 break;
4005         case DIFF_STATUS_ADDED:
4006                 fputs(line_prefix, file);
4007                 show_file_mode_name(file, "create", p->two);
4008                 break;
4009         case DIFF_STATUS_COPIED:
4010                 fputs(line_prefix, file);
4011                 show_rename_copy(file, "copy", p, line_prefix);
4012                 break;
4013         case DIFF_STATUS_RENAMED:
4014                 fputs(line_prefix, file);
4015                 show_rename_copy(file, "rename", p, line_prefix);
4016                 break;
4017         default:
4018                 if (p->score) {
4019                         fprintf(file, "%s rewrite ", line_prefix);
4020                         write_name_quoted(p->two->path, file, ' ');
4021                         fprintf(file, "(%d%%)\n", similarity_index(p));
4022                 }
4023                 show_mode_change(file, p, !p->score, line_prefix);
4024                 break;
4025         }
4028 struct patch_id_t {
4029         git_SHA_CTX *ctx;
4030         int patchlen;
4031 };
4033 static int remove_space(char *line, int len)
4035         int i;
4036         char *dst = line;
4037         unsigned char c;
4039         for (i = 0; i < len; i++)
4040                 if (!isspace((c = line[i])))
4041                         *dst++ = c;
4043         return dst - line;
4046 static void patch_id_consume(void *priv, char *line, unsigned long len)
4048         struct patch_id_t *data = priv;
4049         int new_len;
4051         /* Ignore line numbers when computing the SHA1 of the patch */
4052         if (!prefixcmp(line, "@@ -"))
4053                 return;
4055         new_len = remove_space(line, len);
4057         git_SHA1_Update(data->ctx, line, new_len);
4058         data->patchlen += new_len;
4061 /* returns 0 upon success, and writes result into sha1 */
4062 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4064         struct diff_queue_struct *q = &diff_queued_diff;
4065         int i;
4066         git_SHA_CTX ctx;
4067         struct patch_id_t data;
4068         char buffer[PATH_MAX * 4 + 20];
4070         git_SHA1_Init(&ctx);
4071         memset(&data, 0, sizeof(struct patch_id_t));
4072         data.ctx = &ctx;
4074         for (i = 0; i < q->nr; i++) {
4075                 xpparam_t xpp;
4076                 xdemitconf_t xecfg;
4077                 mmfile_t mf1, mf2;
4078                 struct diff_filepair *p = q->queue[i];
4079                 int len1, len2;
4081                 memset(&xpp, 0, sizeof(xpp));
4082                 memset(&xecfg, 0, sizeof(xecfg));
4083                 if (p->status == 0)
4084                         return error("internal diff status error");
4085                 if (p->status == DIFF_STATUS_UNKNOWN)
4086                         continue;
4087                 if (diff_unmodified_pair(p))
4088                         continue;
4089                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4090                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4091                         continue;
4092                 if (DIFF_PAIR_UNMERGED(p))
4093                         continue;
4095                 diff_fill_sha1_info(p->one);
4096                 diff_fill_sha1_info(p->two);
4097                 if (fill_mmfile(&mf1, p->one) < 0 ||
4098                                 fill_mmfile(&mf2, p->two) < 0)
4099                         return error("unable to read files to diff");
4101                 len1 = remove_space(p->one->path, strlen(p->one->path));
4102                 len2 = remove_space(p->two->path, strlen(p->two->path));
4103                 if (p->one->mode == 0)
4104                         len1 = snprintf(buffer, sizeof(buffer),
4105                                         "diff--gita/%.*sb/%.*s"
4106                                         "newfilemode%06o"
4107                                         "---/dev/null"
4108                                         "+++b/%.*s",
4109                                         len1, p->one->path,
4110                                         len2, p->two->path,
4111                                         p->two->mode,
4112                                         len2, p->two->path);
4113                 else if (p->two->mode == 0)
4114                         len1 = snprintf(buffer, sizeof(buffer),
4115                                         "diff--gita/%.*sb/%.*s"
4116                                         "deletedfilemode%06o"
4117                                         "---a/%.*s"
4118                                         "+++/dev/null",
4119                                         len1, p->one->path,
4120                                         len2, p->two->path,
4121                                         p->one->mode,
4122                                         len1, p->one->path);
4123                 else
4124                         len1 = snprintf(buffer, sizeof(buffer),
4125                                         "diff--gita/%.*sb/%.*s"
4126                                         "---a/%.*s"
4127                                         "+++b/%.*s",
4128                                         len1, p->one->path,
4129                                         len2, p->two->path,
4130                                         len1, p->one->path,
4131                                         len2, p->two->path);
4132                 git_SHA1_Update(&ctx, buffer, len1);
4134                 if (diff_filespec_is_binary(p->one) ||
4135                     diff_filespec_is_binary(p->two)) {
4136                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4137                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4138                         continue;
4139                 }
4141                 xpp.flags = 0;
4142                 xecfg.ctxlen = 3;
4143                 xecfg.flags = 0;
4144                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4145                               &xpp, &xecfg);
4146         }
4148         git_SHA1_Final(sha1, &ctx);
4149         return 0;
4152 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4154         struct diff_queue_struct *q = &diff_queued_diff;
4155         int i;
4156         int result = diff_get_patch_id(options, sha1);
4158         for (i = 0; i < q->nr; i++)
4159                 diff_free_filepair(q->queue[i]);
4161         free(q->queue);
4162         DIFF_QUEUE_CLEAR(q);
4164         return result;
4167 static int is_summary_empty(const struct diff_queue_struct *q)
4169         int i;
4171         for (i = 0; i < q->nr; i++) {
4172                 const struct diff_filepair *p = q->queue[i];
4174                 switch (p->status) {
4175                 case DIFF_STATUS_DELETED:
4176                 case DIFF_STATUS_ADDED:
4177                 case DIFF_STATUS_COPIED:
4178                 case DIFF_STATUS_RENAMED:
4179                         return 0;
4180                 default:
4181                         if (p->score)
4182                                 return 0;
4183                         if (p->one->mode && p->two->mode &&
4184                             p->one->mode != p->two->mode)
4185                                 return 0;
4186                         break;
4187                 }
4188         }
4189         return 1;
4192 static const char rename_limit_warning[] =
4193 "inexact rename detection was skipped due to too many files.";
4195 static const char degrade_cc_to_c_warning[] =
4196 "only found copies from modified paths due to too many files.";
4198 static const char rename_limit_advice[] =
4199 "you may want to set your %s variable to at least "
4200 "%d and retry the command.";
4202 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4204         if (degraded_cc)
4205                 warning(degrade_cc_to_c_warning);
4206         else if (needed)
4207                 warning(rename_limit_warning);
4208         else
4209                 return;
4210         if (0 < needed && needed < 32767)
4211                 warning(rename_limit_advice, varname, needed);
4214 void diff_flush(struct diff_options *options)
4216         struct diff_queue_struct *q = &diff_queued_diff;
4217         int i, output_format = options->output_format;
4218         int separator = 0;
4219         int dirstat_by_line = 0;
4221         /*
4222          * Order: raw, stat, summary, patch
4223          * or:    name/name-status/checkdiff (other bits clear)
4224          */
4225         if (!q->nr)
4226                 goto free_queue;
4228         if (output_format & (DIFF_FORMAT_RAW |
4229                              DIFF_FORMAT_NAME |
4230                              DIFF_FORMAT_NAME_STATUS |
4231                              DIFF_FORMAT_CHECKDIFF)) {
4232                 for (i = 0; i < q->nr; i++) {
4233                         struct diff_filepair *p = q->queue[i];
4234                         if (check_pair_status(p))
4235                                 flush_one_pair(p, options);
4236                 }
4237                 separator++;
4238         }
4240         if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4241                 dirstat_by_line = 1;
4243         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4244             dirstat_by_line) {
4245                 struct diffstat_t diffstat;
4247                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4248                 for (i = 0; i < q->nr; i++) {
4249                         struct diff_filepair *p = q->queue[i];
4250                         if (check_pair_status(p))
4251                                 diff_flush_stat(p, options, &diffstat);
4252                 }
4253                 if (output_format & DIFF_FORMAT_NUMSTAT)
4254                         show_numstat(&diffstat, options);
4255                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4256                         show_stats(&diffstat, options);
4257                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4258                         show_shortstats(&diffstat, options);
4259                 if (output_format & DIFF_FORMAT_DIRSTAT)
4260                         show_dirstat_by_line(&diffstat, options);
4261                 free_diffstat_info(&diffstat);
4262                 separator++;
4263         }
4264         if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4265                 show_dirstat(options);
4267         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4268                 for (i = 0; i < q->nr; i++) {
4269                         diff_summary(options, q->queue[i]);
4270                 }
4271                 separator++;
4272         }
4274         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4275             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4276             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4277                 /*
4278                  * run diff_flush_patch for the exit status. setting
4279                  * options->file to /dev/null should be safe, becaue we
4280                  * aren't supposed to produce any output anyway.
4281                  */
4282                 if (options->close_file)
4283                         fclose(options->file);
4284                 options->file = fopen("/dev/null", "w");
4285                 if (!options->file)
4286                         die_errno("Could not open /dev/null");
4287                 options->close_file = 1;
4288                 for (i = 0; i < q->nr; i++) {
4289                         struct diff_filepair *p = q->queue[i];
4290                         if (check_pair_status(p))
4291                                 diff_flush_patch(p, options);
4292                         if (options->found_changes)
4293                                 break;
4294                 }
4295         }
4297         if (output_format & DIFF_FORMAT_PATCH) {
4298                 if (separator) {
4299                         putc(options->line_termination, options->file);
4300                         if (options->stat_sep) {
4301                                 /* attach patch instead of inline */
4302                                 fputs(options->stat_sep, options->file);
4303                         }
4304                 }
4306                 for (i = 0; i < q->nr; i++) {
4307                         struct diff_filepair *p = q->queue[i];
4308                         if (check_pair_status(p))
4309                                 diff_flush_patch(p, options);
4310                 }
4311         }
4313         if (output_format & DIFF_FORMAT_CALLBACK)
4314                 options->format_callback(q, options, options->format_callback_data);
4316         for (i = 0; i < q->nr; i++)
4317                 diff_free_filepair(q->queue[i]);
4318 free_queue:
4319         free(q->queue);
4320         DIFF_QUEUE_CLEAR(q);
4321         if (options->close_file)
4322                 fclose(options->file);
4324         /*
4325          * Report the content-level differences with HAS_CHANGES;
4326          * diff_addremove/diff_change does not set the bit when
4327          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4328          */
4329         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4330                 if (options->found_changes)
4331                         DIFF_OPT_SET(options, HAS_CHANGES);
4332                 else
4333                         DIFF_OPT_CLR(options, HAS_CHANGES);
4334         }
4337 static void diffcore_apply_filter(const char *filter)
4339         int i;
4340         struct diff_queue_struct *q = &diff_queued_diff;
4341         struct diff_queue_struct outq;
4342         DIFF_QUEUE_CLEAR(&outq);
4344         if (!filter)
4345                 return;
4347         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4348                 int found;
4349                 for (i = found = 0; !found && i < q->nr; i++) {
4350                         struct diff_filepair *p = q->queue[i];
4351                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4352                              ((p->score &&
4353                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4354                               (!p->score &&
4355                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4356                             ((p->status != DIFF_STATUS_MODIFIED) &&
4357                              strchr(filter, p->status)))
4358                                 found++;
4359                 }
4360                 if (found)
4361                         return;
4363                 /* otherwise we will clear the whole queue
4364                  * by copying the empty outq at the end of this
4365                  * function, but first clear the current entries
4366                  * in the queue.
4367                  */
4368                 for (i = 0; i < q->nr; i++)
4369                         diff_free_filepair(q->queue[i]);
4370         }
4371         else {
4372                 /* Only the matching ones */
4373                 for (i = 0; i < q->nr; i++) {
4374                         struct diff_filepair *p = q->queue[i];
4376                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4377                              ((p->score &&
4378                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4379                               (!p->score &&
4380                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4381                             ((p->status != DIFF_STATUS_MODIFIED) &&
4382                              strchr(filter, p->status)))
4383                                 diff_q(&outq, p);
4384                         else
4385                                 diff_free_filepair(p);
4386                 }
4387         }
4388         free(q->queue);
4389         *q = outq;
4392 /* Check whether two filespecs with the same mode and size are identical */
4393 static int diff_filespec_is_identical(struct diff_filespec *one,
4394                                       struct diff_filespec *two)
4396         if (S_ISGITLINK(one->mode))
4397                 return 0;
4398         if (diff_populate_filespec(one, 0))
4399                 return 0;
4400         if (diff_populate_filespec(two, 0))
4401                 return 0;
4402         return !memcmp(one->data, two->data, one->size);
4405 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4407         int i;
4408         struct diff_queue_struct *q = &diff_queued_diff;
4409         struct diff_queue_struct outq;
4410         DIFF_QUEUE_CLEAR(&outq);
4412         for (i = 0; i < q->nr; i++) {
4413                 struct diff_filepair *p = q->queue[i];
4415                 /*
4416                  * 1. Entries that come from stat info dirtiness
4417                  *    always have both sides (iow, not create/delete),
4418                  *    one side of the object name is unknown, with
4419                  *    the same mode and size.  Keep the ones that
4420                  *    do not match these criteria.  They have real
4421                  *    differences.
4422                  *
4423                  * 2. At this point, the file is known to be modified,
4424                  *    with the same mode and size, and the object
4425                  *    name of one side is unknown.  Need to inspect
4426                  *    the identical contents.
4427                  */
4428                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4429                     !DIFF_FILE_VALID(p->two) ||
4430                     (p->one->sha1_valid && p->two->sha1_valid) ||
4431                     (p->one->mode != p->two->mode) ||
4432                     diff_populate_filespec(p->one, 1) ||
4433                     diff_populate_filespec(p->two, 1) ||
4434                     (p->one->size != p->two->size) ||
4435                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4436                         diff_q(&outq, p);
4437                 else {
4438                         /*
4439                          * The caller can subtract 1 from skip_stat_unmatch
4440                          * to determine how many paths were dirty only
4441                          * due to stat info mismatch.
4442                          */
4443                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4444                                 diffopt->skip_stat_unmatch++;
4445                         diff_free_filepair(p);
4446                 }
4447         }
4448         free(q->queue);
4449         *q = outq;
4452 static int diffnamecmp(const void *a_, const void *b_)
4454         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4455         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4456         const char *name_a, *name_b;
4458         name_a = a->one ? a->one->path : a->two->path;
4459         name_b = b->one ? b->one->path : b->two->path;
4460         return strcmp(name_a, name_b);
4463 void diffcore_fix_diff_index(struct diff_options *options)
4465         struct diff_queue_struct *q = &diff_queued_diff;
4466         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4469 void diffcore_std(struct diff_options *options)
4471         if (options->skip_stat_unmatch)
4472                 diffcore_skip_stat_unmatch(options);
4473         if (!options->found_follow) {
4474                 /* See try_to_follow_renames() in tree-diff.c */
4475                 if (options->break_opt != -1)
4476                         diffcore_break(options->break_opt);
4477                 if (options->detect_rename)
4478                         diffcore_rename(options);
4479                 if (options->break_opt != -1)
4480                         diffcore_merge_broken();
4481         }
4482         if (options->pickaxe)
4483                 diffcore_pickaxe(options);
4484         if (options->orderfile)
4485                 diffcore_order(options->orderfile);
4486         if (!options->found_follow)
4487                 /* See try_to_follow_renames() in tree-diff.c */
4488                 diff_resolve_rename_copy();
4489         diffcore_apply_filter(options->filter);
4491         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4492                 DIFF_OPT_SET(options, HAS_CHANGES);
4493         else
4494                 DIFF_OPT_CLR(options, HAS_CHANGES);
4496         options->found_follow = 0;
4499 int diff_result_code(struct diff_options *opt, int status)
4501         int result = 0;
4503         diff_warn_rename_limit("diff.renamelimit",
4504                                opt->needed_rename_limit,
4505                                opt->degraded_cc_to_c);
4506         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4507             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4508                 return status;
4509         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4510             DIFF_OPT_TST(opt, HAS_CHANGES))
4511                 result |= 01;
4512         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4513             DIFF_OPT_TST(opt, CHECK_FAILED))
4514                 result |= 02;
4515         return result;
4518 int diff_can_quit_early(struct diff_options *opt)
4520         return (DIFF_OPT_TST(opt, QUICK) &&
4521                 !opt->filter &&
4522                 DIFF_OPT_TST(opt, HAS_CHANGES));
4525 /*
4526  * Shall changes to this submodule be ignored?
4527  *
4528  * Submodule changes can be configured to be ignored separately for each path,
4529  * but that configuration can be overridden from the command line.
4530  */
4531 static int is_submodule_ignored(const char *path, struct diff_options *options)
4533         int ignored = 0;
4534         unsigned orig_flags = options->flags;
4535         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4536                 set_diffopt_flags_from_submodule_config(options, path);
4537         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4538                 ignored = 1;
4539         options->flags = orig_flags;
4540         return ignored;
4543 void diff_addremove(struct diff_options *options,
4544                     int addremove, unsigned mode,
4545                     const unsigned char *sha1,
4546                     const char *concatpath, unsigned dirty_submodule)
4548         struct diff_filespec *one, *two;
4550         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4551                 return;
4553         /* This may look odd, but it is a preparation for
4554          * feeding "there are unchanged files which should
4555          * not produce diffs, but when you are doing copy
4556          * detection you would need them, so here they are"
4557          * entries to the diff-core.  They will be prefixed
4558          * with something like '=' or '*' (I haven't decided
4559          * which but should not make any difference).
4560          * Feeding the same new and old to diff_change()
4561          * also has the same effect.
4562          * Before the final output happens, they are pruned after
4563          * merged into rename/copy pairs as appropriate.
4564          */
4565         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4566                 addremove = (addremove == '+' ? '-' :
4567                              addremove == '-' ? '+' : addremove);
4569         if (options->prefix &&
4570             strncmp(concatpath, options->prefix, options->prefix_length))
4571                 return;
4573         one = alloc_filespec(concatpath);
4574         two = alloc_filespec(concatpath);
4576         if (addremove != '+')
4577                 fill_filespec(one, sha1, mode);
4578         if (addremove != '-') {
4579                 fill_filespec(two, sha1, mode);
4580                 two->dirty_submodule = dirty_submodule;
4581         }
4583         diff_queue(&diff_queued_diff, one, two);
4584         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4585                 DIFF_OPT_SET(options, HAS_CHANGES);
4588 void diff_change(struct diff_options *options,
4589                  unsigned old_mode, unsigned new_mode,
4590                  const unsigned char *old_sha1,
4591                  const unsigned char *new_sha1,
4592                  const char *concatpath,
4593                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4595         struct diff_filespec *one, *two;
4597         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4598             is_submodule_ignored(concatpath, options))
4599                 return;
4601         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4602                 unsigned tmp;
4603                 const unsigned char *tmp_c;
4604                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4605                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4606                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4607                         new_dirty_submodule = tmp;
4608         }
4610         if (options->prefix &&
4611             strncmp(concatpath, options->prefix, options->prefix_length))
4612                 return;
4614         one = alloc_filespec(concatpath);
4615         two = alloc_filespec(concatpath);
4616         fill_filespec(one, old_sha1, old_mode);
4617         fill_filespec(two, new_sha1, new_mode);
4618         one->dirty_submodule = old_dirty_submodule;
4619         two->dirty_submodule = new_dirty_submodule;
4621         diff_queue(&diff_queued_diff, one, two);
4622         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4623                 DIFF_OPT_SET(options, HAS_CHANGES);
4626 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4628         struct diff_filepair *pair;
4629         struct diff_filespec *one, *two;
4631         if (options->prefix &&
4632             strncmp(path, options->prefix, options->prefix_length))
4633                 return NULL;
4635         one = alloc_filespec(path);
4636         two = alloc_filespec(path);
4637         pair = diff_queue(&diff_queued_diff, one, two);
4638         pair->is_unmerged = 1;
4639         return pair;
4642 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4643                 size_t *outsize)
4645         struct diff_tempfile *temp;
4646         const char *argv[3];
4647         const char **arg = argv;
4648         struct child_process child;
4649         struct strbuf buf = STRBUF_INIT;
4650         int err = 0;
4652         temp = prepare_temp_file(spec->path, spec);
4653         *arg++ = pgm;
4654         *arg++ = temp->name;
4655         *arg = NULL;
4657         memset(&child, 0, sizeof(child));
4658         child.use_shell = 1;
4659         child.argv = argv;
4660         child.out = -1;
4661         if (start_command(&child)) {
4662                 remove_tempfile();
4663                 return NULL;
4664         }
4666         if (strbuf_read(&buf, child.out, 0) < 0)
4667                 err = error("error reading from textconv command '%s'", pgm);
4668         close(child.out);
4670         if (finish_command(&child) || err) {
4671                 strbuf_release(&buf);
4672                 remove_tempfile();
4673                 return NULL;
4674         }
4675         remove_tempfile();
4677         return strbuf_detach(&buf, outsize);
4680 size_t fill_textconv(struct userdiff_driver *driver,
4681                      struct diff_filespec *df,
4682                      char **outbuf)
4684         size_t size;
4686         if (!driver || !driver->textconv) {
4687                 if (!DIFF_FILE_VALID(df)) {
4688                         *outbuf = "";
4689                         return 0;
4690                 }
4691                 if (diff_populate_filespec(df, 0))
4692                         die("unable to read files to diff");
4693                 *outbuf = df->data;
4694                 return df->size;
4695         }
4697         if (driver->textconv_cache && df->sha1_valid) {
4698                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4699                                           &size);
4700                 if (*outbuf)
4701                         return size;
4702         }
4704         *outbuf = run_textconv(driver->textconv, df, &size);
4705         if (!*outbuf)
4706                 die("unable to read files to diff");
4708         if (driver->textconv_cache && df->sha1_valid) {
4709                 /* ignore errors, as we might be in a readonly repository */
4710                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4711                                 size);
4712                 /*
4713                  * we could save up changes and flush them all at the end,
4714                  * but we would need an extra call after all diffing is done.
4715                  * Since generating a cache entry is the slow path anyway,
4716                  * this extra overhead probably isn't a big deal.
4717                  */
4718                 notes_cache_write(driver->textconv_cache);
4719         }
4721         return size;