Code

diff --stat: use a maximum of 5/8 for the filename part
[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, graph_width, number_width = 4, 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         count = options->stat_count ? options->stat_count : data->nr;
1348         reset = diff_get_color_opt(options, DIFF_RESET);
1349         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1350         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1352         /*
1353          * Find the longest filename and max number of changes
1354          */
1355         for (i = 0; (i < count) && (i < data->nr); i++) {
1356                 struct diffstat_file *file = data->files[i];
1357                 uintmax_t change = file->added + file->deleted;
1358                 if (!data->files[i]->is_renamed &&
1359                          (change == 0)) {
1360                         count++; /* not shown == room for one more */
1361                         continue;
1362                 }
1363                 fill_print_name(file);
1364                 len = strlen(file->print_name);
1365                 if (max_len < len)
1366                         max_len = len;
1368                 if (file->is_binary || file->is_unmerged)
1369                         continue;
1370                 if (max_change < change)
1371                         max_change = change;
1372         }
1373         count = i; /* min(count, data->nr) */
1375         /*
1376          * We have width = stat_width or term_columns() columns total.
1377          * We want a maximum of min(max_len, stat_name_width) for the name part.
1378          * We also need 1 for " " and 4 + decimal_width(max_change)
1379          * for " | NNNN " and one the empty column at the end, altogether
1380          * 6 + decimal_width(max_change).
1381          *
1382          * If there's not enough space, we will use the smaller of
1383          * stat_name_width (if set) and 5/8*width for the filename,
1384          * and the rest for constant elements + graph part.
1385          * (5/8 gives 50 for filename and 30 for the constant parts + graph
1386          * for the standard terminal size).
1387          *
1388          * In other words: stat_width limits the maximum width, and
1389          * stat_name_width fixes the maximum width of the filename,
1390          * and is also used to divide available columns if there
1391          * aren't enough.
1392          */
1394         if (options->stat_width == -1)
1395                 width = term_columns();
1396         else
1397                 width = options->stat_width ? options->stat_width : 80;
1399         /*
1400          * Guarantee 3/8*16==6 for the graph part
1401          * and 5/8*16==10 for the filename part
1402          */
1403         if (width < 16 + 6 + number_width)
1404                 width = 16 + 6 + number_width;
1406         /*
1407          * First assign sizes that are wanted, ignoring available width.
1408          */
1409         graph_width = max_change;
1410         name_width = (options->stat_name_width > 0 &&
1411                       options->stat_name_width < max_len) ?
1412                 options->stat_name_width : max_len;
1414         /*
1415          * Adjust adjustable widths not to exceed maximum width
1416          */
1417         if (name_width + number_width + 6 + graph_width > width) {
1418                 if (graph_width > width * 3/8 - number_width - 6)
1419                         graph_width = width * 3/8 - number_width - 6;
1420                 if (name_width > width - number_width - 6 - graph_width)
1421                         name_width = width - number_width - 6 - graph_width;
1422                 else
1423                         graph_width = width - number_width - 6 - name_width;
1424         }
1426         /*
1427          * From here name_width is the width of the name area,
1428          * and graph_width is the width of the graph area.
1429          * max_change is used to scale graph properly.
1430          */
1431         for (i = 0; i < count; i++) {
1432                 const char *prefix = "";
1433                 char *name = data->files[i]->print_name;
1434                 uintmax_t added = data->files[i]->added;
1435                 uintmax_t deleted = data->files[i]->deleted;
1436                 int name_len;
1438                 if (!data->files[i]->is_renamed &&
1439                          (added + deleted == 0)) {
1440                         total_files--;
1441                         continue;
1442                 }
1443                 /*
1444                  * "scale" the filename
1445                  */
1446                 len = name_width;
1447                 name_len = strlen(name);
1448                 if (name_width < name_len) {
1449                         char *slash;
1450                         prefix = "...";
1451                         len -= 3;
1452                         name += name_len - len;
1453                         slash = strchr(name, '/');
1454                         if (slash)
1455                                 name = slash;
1456                 }
1458                 if (data->files[i]->is_binary) {
1459                         fprintf(options->file, "%s", line_prefix);
1460                         show_name(options->file, prefix, name, len);
1461                         fprintf(options->file, "  Bin ");
1462                         fprintf(options->file, "%s%"PRIuMAX"%s",
1463                                 del_c, deleted, reset);
1464                         fprintf(options->file, " -> ");
1465                         fprintf(options->file, "%s%"PRIuMAX"%s",
1466                                 add_c, added, reset);
1467                         fprintf(options->file, " bytes");
1468                         fprintf(options->file, "\n");
1469                         continue;
1470                 }
1471                 else if (data->files[i]->is_unmerged) {
1472                         fprintf(options->file, "%s", line_prefix);
1473                         show_name(options->file, prefix, name, len);
1474                         fprintf(options->file, "  Unmerged\n");
1475                         continue;
1476                 }
1478                 /*
1479                  * scale the add/delete
1480                  */
1481                 add = added;
1482                 del = deleted;
1483                 adds += add;
1484                 dels += del;
1486                 if (graph_width <= max_change) {
1487                         int total = add + del;
1489                         total = scale_linear(add + del, graph_width, max_change);
1490                         if (total < 2 && add && del)
1491                                 /* width >= 2 due to the sanity check */
1492                                 total = 2;
1493                         if (add < del) {
1494                                 add = scale_linear(add, graph_width, max_change);
1495                                 del = total - add;
1496                         } else {
1497                                 del = scale_linear(del, graph_width, max_change);
1498                                 add = total - del;
1499                         }
1500                 }
1501                 fprintf(options->file, "%s", line_prefix);
1502                 show_name(options->file, prefix, name, len);
1503                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1504                                 added + deleted ? " " : "");
1505                 show_graph(options->file, '+', add, add_c, reset);
1506                 show_graph(options->file, '-', del, del_c, reset);
1507                 fprintf(options->file, "\n");
1508         }
1509         for (i = count; i < data->nr; i++) {
1510                 uintmax_t added = data->files[i]->added;
1511                 uintmax_t deleted = data->files[i]->deleted;
1512                 if (!data->files[i]->is_renamed &&
1513                          (added + deleted == 0)) {
1514                         total_files--;
1515                         continue;
1516                 }
1517                 adds += added;
1518                 dels += deleted;
1519                 if (!extra_shown)
1520                         fprintf(options->file, "%s ...\n", line_prefix);
1521                 extra_shown = 1;
1522         }
1523         fprintf(options->file, "%s", line_prefix);
1524         fprintf(options->file,
1525                " %d files changed, %d insertions(+), %d deletions(-)\n",
1526                total_files, adds, dels);
1529 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1531         int i, adds = 0, dels = 0, total_files = data->nr;
1533         if (data->nr == 0)
1534                 return;
1536         for (i = 0; i < data->nr; i++) {
1537                 if (!data->files[i]->is_binary &&
1538                     !data->files[i]->is_unmerged) {
1539                         int added = data->files[i]->added;
1540                         int deleted= data->files[i]->deleted;
1541                         if (!data->files[i]->is_renamed &&
1542                             (added + deleted == 0)) {
1543                                 total_files--;
1544                         } else {
1545                                 adds += added;
1546                                 dels += deleted;
1547                         }
1548                 }
1549         }
1550         if (options->output_prefix) {
1551                 struct strbuf *msg = NULL;
1552                 msg = options->output_prefix(options,
1553                                 options->output_prefix_data);
1554                 fprintf(options->file, "%s", msg->buf);
1555         }
1556         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1557                total_files, adds, dels);
1560 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1562         int i;
1564         if (data->nr == 0)
1565                 return;
1567         for (i = 0; i < data->nr; i++) {
1568                 struct diffstat_file *file = data->files[i];
1570                 if (options->output_prefix) {
1571                         struct strbuf *msg = NULL;
1572                         msg = options->output_prefix(options,
1573                                         options->output_prefix_data);
1574                         fprintf(options->file, "%s", msg->buf);
1575                 }
1577                 if (file->is_binary)
1578                         fprintf(options->file, "-\t-\t");
1579                 else
1580                         fprintf(options->file,
1581                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1582                                 file->added, file->deleted);
1583                 if (options->line_termination) {
1584                         fill_print_name(file);
1585                         if (!file->is_renamed)
1586                                 write_name_quoted(file->name, options->file,
1587                                                   options->line_termination);
1588                         else {
1589                                 fputs(file->print_name, options->file);
1590                                 putc(options->line_termination, options->file);
1591                         }
1592                 } else {
1593                         if (file->is_renamed) {
1594                                 putc('\0', options->file);
1595                                 write_name_quoted(file->from_name, options->file, '\0');
1596                         }
1597                         write_name_quoted(file->name, options->file, '\0');
1598                 }
1599         }
1602 struct dirstat_file {
1603         const char *name;
1604         unsigned long changed;
1605 };
1607 struct dirstat_dir {
1608         struct dirstat_file *files;
1609         int alloc, nr, permille, cumulative;
1610 };
1612 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1613                 unsigned long changed, const char *base, int baselen)
1615         unsigned long this_dir = 0;
1616         unsigned int sources = 0;
1617         const char *line_prefix = "";
1618         struct strbuf *msg = NULL;
1620         if (opt->output_prefix) {
1621                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1622                 line_prefix = msg->buf;
1623         }
1625         while (dir->nr) {
1626                 struct dirstat_file *f = dir->files;
1627                 int namelen = strlen(f->name);
1628                 unsigned long this;
1629                 char *slash;
1631                 if (namelen < baselen)
1632                         break;
1633                 if (memcmp(f->name, base, baselen))
1634                         break;
1635                 slash = strchr(f->name + baselen, '/');
1636                 if (slash) {
1637                         int newbaselen = slash + 1 - f->name;
1638                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1639                         sources++;
1640                 } else {
1641                         this = f->changed;
1642                         dir->files++;
1643                         dir->nr--;
1644                         sources += 2;
1645                 }
1646                 this_dir += this;
1647         }
1649         /*
1650          * We don't report dirstat's for
1651          *  - the top level
1652          *  - or cases where everything came from a single directory
1653          *    under this directory (sources == 1).
1654          */
1655         if (baselen && sources != 1) {
1656                 if (this_dir) {
1657                         int permille = this_dir * 1000 / changed;
1658                         if (permille >= dir->permille) {
1659                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1660                                         permille / 10, permille % 10, baselen, base);
1661                                 if (!dir->cumulative)
1662                                         return 0;
1663                         }
1664                 }
1665         }
1666         return this_dir;
1669 static int dirstat_compare(const void *_a, const void *_b)
1671         const struct dirstat_file *a = _a;
1672         const struct dirstat_file *b = _b;
1673         return strcmp(a->name, b->name);
1676 static void show_dirstat(struct diff_options *options)
1678         int i;
1679         unsigned long changed;
1680         struct dirstat_dir dir;
1681         struct diff_queue_struct *q = &diff_queued_diff;
1683         dir.files = NULL;
1684         dir.alloc = 0;
1685         dir.nr = 0;
1686         dir.permille = options->dirstat_permille;
1687         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1689         changed = 0;
1690         for (i = 0; i < q->nr; i++) {
1691                 struct diff_filepair *p = q->queue[i];
1692                 const char *name;
1693                 unsigned long copied, added, damage;
1694                 int content_changed;
1696                 name = p->two->path ? p->two->path : p->one->path;
1698                 if (p->one->sha1_valid && p->two->sha1_valid)
1699                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1700                 else
1701                         content_changed = 1;
1703                 if (!content_changed) {
1704                         /*
1705                          * The SHA1 has not changed, so pre-/post-content is
1706                          * identical. We can therefore skip looking at the
1707                          * file contents altogether.
1708                          */
1709                         damage = 0;
1710                         goto found_damage;
1711                 }
1713                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1714                         /*
1715                          * In --dirstat-by-file mode, we don't really need to
1716                          * look at the actual file contents at all.
1717                          * The fact that the SHA1 changed is enough for us to
1718                          * add this file to the list of results
1719                          * (with each file contributing equal damage).
1720                          */
1721                         damage = 1;
1722                         goto found_damage;
1723                 }
1725                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1726                         diff_populate_filespec(p->one, 0);
1727                         diff_populate_filespec(p->two, 0);
1728                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1729                                                &copied, &added);
1730                         diff_free_filespec_data(p->one);
1731                         diff_free_filespec_data(p->two);
1732                 } else if (DIFF_FILE_VALID(p->one)) {
1733                         diff_populate_filespec(p->one, 1);
1734                         copied = added = 0;
1735                         diff_free_filespec_data(p->one);
1736                 } else if (DIFF_FILE_VALID(p->two)) {
1737                         diff_populate_filespec(p->two, 1);
1738                         copied = 0;
1739                         added = p->two->size;
1740                         diff_free_filespec_data(p->two);
1741                 } else
1742                         continue;
1744                 /*
1745                  * Original minus copied is the removed material,
1746                  * added is the new material.  They are both damages
1747                  * made to the preimage.
1748                  * If the resulting damage is zero, we know that
1749                  * diffcore_count_changes() considers the two entries to
1750                  * be identical, but since content_changed is true, we
1751                  * know that there must have been _some_ kind of change,
1752                  * so we force all entries to have damage > 0.
1753                  */
1754                 damage = (p->one->size - copied) + added;
1755                 if (!damage)
1756                         damage = 1;
1758 found_damage:
1759                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1760                 dir.files[dir.nr].name = name;
1761                 dir.files[dir.nr].changed = damage;
1762                 changed += damage;
1763                 dir.nr++;
1764         }
1766         /* This can happen even with many files, if everything was renames */
1767         if (!changed)
1768                 return;
1770         /* Show all directories with more than x% of the changes */
1771         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1772         gather_dirstat(options, &dir, changed, "", 0);
1775 static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1777         int i;
1778         unsigned long changed;
1779         struct dirstat_dir dir;
1781         if (data->nr == 0)
1782                 return;
1784         dir.files = NULL;
1785         dir.alloc = 0;
1786         dir.nr = 0;
1787         dir.permille = options->dirstat_permille;
1788         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1790         changed = 0;
1791         for (i = 0; i < data->nr; i++) {
1792                 struct diffstat_file *file = data->files[i];
1793                 unsigned long damage = file->added + file->deleted;
1794                 if (file->is_binary)
1795                         /*
1796                          * binary files counts bytes, not lines. Must find some
1797                          * way to normalize binary bytes vs. textual lines.
1798                          * The following heuristic assumes that there are 64
1799                          * bytes per "line".
1800                          * This is stupid and ugly, but very cheap...
1801                          */
1802                         damage = (damage + 63) / 64;
1803                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1804                 dir.files[dir.nr].name = file->name;
1805                 dir.files[dir.nr].changed = damage;
1806                 changed += damage;
1807                 dir.nr++;
1808         }
1810         /* This can happen even with many files, if everything was renames */
1811         if (!changed)
1812                 return;
1814         /* Show all directories with more than x% of the changes */
1815         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1816         gather_dirstat(options, &dir, changed, "", 0);
1819 static void free_diffstat_info(struct diffstat_t *diffstat)
1821         int i;
1822         for (i = 0; i < diffstat->nr; i++) {
1823                 struct diffstat_file *f = diffstat->files[i];
1824                 if (f->name != f->print_name)
1825                         free(f->print_name);
1826                 free(f->name);
1827                 free(f->from_name);
1828                 free(f);
1829         }
1830         free(diffstat->files);
1833 struct checkdiff_t {
1834         const char *filename;
1835         int lineno;
1836         int conflict_marker_size;
1837         struct diff_options *o;
1838         unsigned ws_rule;
1839         unsigned status;
1840 };
1842 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1844         char firstchar;
1845         int cnt;
1847         if (len < marker_size + 1)
1848                 return 0;
1849         firstchar = line[0];
1850         switch (firstchar) {
1851         case '=': case '>': case '<': case '|':
1852                 break;
1853         default:
1854                 return 0;
1855         }
1856         for (cnt = 1; cnt < marker_size; cnt++)
1857                 if (line[cnt] != firstchar)
1858                         return 0;
1859         /* line[1] thru line[marker_size-1] are same as firstchar */
1860         if (len < marker_size + 1 || !isspace(line[marker_size]))
1861                 return 0;
1862         return 1;
1865 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1867         struct checkdiff_t *data = priv;
1868         int marker_size = data->conflict_marker_size;
1869         const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1870         const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1871         const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1872         char *err;
1873         char *line_prefix = "";
1874         struct strbuf *msgbuf;
1876         assert(data->o);
1877         if (data->o->output_prefix) {
1878                 msgbuf = data->o->output_prefix(data->o,
1879                         data->o->output_prefix_data);
1880                 line_prefix = msgbuf->buf;
1881         }
1883         if (line[0] == '+') {
1884                 unsigned bad;
1885                 data->lineno++;
1886                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1887                         data->status |= 1;
1888                         fprintf(data->o->file,
1889                                 "%s%s:%d: leftover conflict marker\n",
1890                                 line_prefix, data->filename, data->lineno);
1891                 }
1892                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1893                 if (!bad)
1894                         return;
1895                 data->status |= bad;
1896                 err = whitespace_error_string(bad);
1897                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1898                         line_prefix, data->filename, data->lineno, err);
1899                 free(err);
1900                 emit_line(data->o, set, reset, line, 1);
1901                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1902                               data->o->file, set, reset, ws);
1903         } else if (line[0] == ' ') {
1904                 data->lineno++;
1905         } else if (line[0] == '@') {
1906                 char *plus = strchr(line, '+');
1907                 if (plus)
1908                         data->lineno = strtol(plus, NULL, 10) - 1;
1909                 else
1910                         die("invalid diff");
1911         }
1914 static unsigned char *deflate_it(char *data,
1915                                  unsigned long size,
1916                                  unsigned long *result_size)
1918         int bound;
1919         unsigned char *deflated;
1920         git_zstream stream;
1922         memset(&stream, 0, sizeof(stream));
1923         git_deflate_init(&stream, zlib_compression_level);
1924         bound = git_deflate_bound(&stream, size);
1925         deflated = xmalloc(bound);
1926         stream.next_out = deflated;
1927         stream.avail_out = bound;
1929         stream.next_in = (unsigned char *)data;
1930         stream.avail_in = size;
1931         while (git_deflate(&stream, Z_FINISH) == Z_OK)
1932                 ; /* nothing */
1933         git_deflate_end(&stream);
1934         *result_size = stream.total_out;
1935         return deflated;
1938 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1940         void *cp;
1941         void *delta;
1942         void *deflated;
1943         void *data;
1944         unsigned long orig_size;
1945         unsigned long delta_size;
1946         unsigned long deflate_size;
1947         unsigned long data_size;
1949         /* We could do deflated delta, or we could do just deflated two,
1950          * whichever is smaller.
1951          */
1952         delta = NULL;
1953         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1954         if (one->size && two->size) {
1955                 delta = diff_delta(one->ptr, one->size,
1956                                    two->ptr, two->size,
1957                                    &delta_size, deflate_size);
1958                 if (delta) {
1959                         void *to_free = delta;
1960                         orig_size = delta_size;
1961                         delta = deflate_it(delta, delta_size, &delta_size);
1962                         free(to_free);
1963                 }
1964         }
1966         if (delta && delta_size < deflate_size) {
1967                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1968                 free(deflated);
1969                 data = delta;
1970                 data_size = delta_size;
1971         }
1972         else {
1973                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1974                 free(delta);
1975                 data = deflated;
1976                 data_size = deflate_size;
1977         }
1979         /* emit data encoded in base85 */
1980         cp = data;
1981         while (data_size) {
1982                 int bytes = (52 < data_size) ? 52 : data_size;
1983                 char line[70];
1984                 data_size -= bytes;
1985                 if (bytes <= 26)
1986                         line[0] = bytes + 'A' - 1;
1987                 else
1988                         line[0] = bytes - 26 + 'a' - 1;
1989                 encode_85(line + 1, cp, bytes);
1990                 cp = (char *) cp + bytes;
1991                 fprintf(file, "%s", prefix);
1992                 fputs(line, file);
1993                 fputc('\n', file);
1994         }
1995         fprintf(file, "%s\n", prefix);
1996         free(data);
1999 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2001         fprintf(file, "%sGIT binary patch\n", prefix);
2002         emit_binary_diff_body(file, one, two, prefix);
2003         emit_binary_diff_body(file, two, one, prefix);
2006 static void diff_filespec_load_driver(struct diff_filespec *one)
2008         /* Use already-loaded driver */
2009         if (one->driver)
2010                 return;
2012         if (S_ISREG(one->mode))
2013                 one->driver = userdiff_find_by_path(one->path);
2015         /* Fallback to default settings */
2016         if (!one->driver)
2017                 one->driver = userdiff_find_by_name("default");
2020 int diff_filespec_is_binary(struct diff_filespec *one)
2022         if (one->is_binary == -1) {
2023                 diff_filespec_load_driver(one);
2024                 if (one->driver->binary != -1)
2025                         one->is_binary = one->driver->binary;
2026                 else {
2027                         if (!one->data && DIFF_FILE_VALID(one))
2028                                 diff_populate_filespec(one, 0);
2029                         if (one->data)
2030                                 one->is_binary = buffer_is_binary(one->data,
2031                                                 one->size);
2032                         if (one->is_binary == -1)
2033                                 one->is_binary = 0;
2034                 }
2035         }
2036         return one->is_binary;
2039 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2041         diff_filespec_load_driver(one);
2042         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2045 static const char *userdiff_word_regex(struct diff_filespec *one)
2047         diff_filespec_load_driver(one);
2048         return one->driver->word_regex;
2051 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2053         if (!options->a_prefix)
2054                 options->a_prefix = a;
2055         if (!options->b_prefix)
2056                 options->b_prefix = b;
2059 struct userdiff_driver *get_textconv(struct diff_filespec *one)
2061         if (!DIFF_FILE_VALID(one))
2062                 return NULL;
2064         diff_filespec_load_driver(one);
2065         return userdiff_get_textconv(one->driver);
2068 static void builtin_diff(const char *name_a,
2069                          const char *name_b,
2070                          struct diff_filespec *one,
2071                          struct diff_filespec *two,
2072                          const char *xfrm_msg,
2073                          int must_show_header,
2074                          struct diff_options *o,
2075                          int complete_rewrite)
2077         mmfile_t mf1, mf2;
2078         const char *lbl[2];
2079         char *a_one, *b_two;
2080         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2081         const char *reset = diff_get_color_opt(o, DIFF_RESET);
2082         const char *a_prefix, *b_prefix;
2083         struct userdiff_driver *textconv_one = NULL;
2084         struct userdiff_driver *textconv_two = NULL;
2085         struct strbuf header = STRBUF_INIT;
2086         struct strbuf *msgbuf;
2087         char *line_prefix = "";
2089         if (o->output_prefix) {
2090                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2091                 line_prefix = msgbuf->buf;
2092         }
2094         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2095                         (!one->mode || S_ISGITLINK(one->mode)) &&
2096                         (!two->mode || S_ISGITLINK(two->mode))) {
2097                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2098                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2099                 show_submodule_summary(o->file, one ? one->path : two->path,
2100                                 one->sha1, two->sha1, two->dirty_submodule,
2101                                 del, add, reset);
2102                 return;
2103         }
2105         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2106                 textconv_one = get_textconv(one);
2107                 textconv_two = get_textconv(two);
2108         }
2110         diff_set_mnemonic_prefix(o, "a/", "b/");
2111         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2112                 a_prefix = o->b_prefix;
2113                 b_prefix = o->a_prefix;
2114         } else {
2115                 a_prefix = o->a_prefix;
2116                 b_prefix = o->b_prefix;
2117         }
2119         /* Never use a non-valid filename anywhere if at all possible */
2120         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2121         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2123         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2124         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2125         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2126         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2127         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2128         if (lbl[0][0] == '/') {
2129                 /* /dev/null */
2130                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2131                 if (xfrm_msg)
2132                         strbuf_addstr(&header, xfrm_msg);
2133                 must_show_header = 1;
2134         }
2135         else if (lbl[1][0] == '/') {
2136                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2137                 if (xfrm_msg)
2138                         strbuf_addstr(&header, xfrm_msg);
2139                 must_show_header = 1;
2140         }
2141         else {
2142                 if (one->mode != two->mode) {
2143                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2144                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2145                         must_show_header = 1;
2146                 }
2147                 if (xfrm_msg)
2148                         strbuf_addstr(&header, xfrm_msg);
2150                 /*
2151                  * we do not run diff between different kind
2152                  * of objects.
2153                  */
2154                 if ((one->mode ^ two->mode) & S_IFMT)
2155                         goto free_ab_and_return;
2156                 if (complete_rewrite &&
2157                     (textconv_one || !diff_filespec_is_binary(one)) &&
2158                     (textconv_two || !diff_filespec_is_binary(two))) {
2159                         fprintf(o->file, "%s", header.buf);
2160                         strbuf_reset(&header);
2161                         emit_rewrite_diff(name_a, name_b, one, two,
2162                                                 textconv_one, textconv_two, o);
2163                         o->found_changes = 1;
2164                         goto free_ab_and_return;
2165                 }
2166         }
2168         if (o->irreversible_delete && lbl[1][0] == '/') {
2169                 fprintf(o->file, "%s", header.buf);
2170                 strbuf_reset(&header);
2171                 goto free_ab_and_return;
2172         } else if (!DIFF_OPT_TST(o, TEXT) &&
2173             ( (!textconv_one && diff_filespec_is_binary(one)) ||
2174               (!textconv_two && diff_filespec_is_binary(two)) )) {
2175                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2176                         die("unable to read files to diff");
2177                 /* Quite common confusing case */
2178                 if (mf1.size == mf2.size &&
2179                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2180                         if (must_show_header)
2181                                 fprintf(o->file, "%s", header.buf);
2182                         goto free_ab_and_return;
2183                 }
2184                 fprintf(o->file, "%s", header.buf);
2185                 strbuf_reset(&header);
2186                 if (DIFF_OPT_TST(o, BINARY))
2187                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2188                 else
2189                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2190                                 line_prefix, lbl[0], lbl[1]);
2191                 o->found_changes = 1;
2192         } else {
2193                 /* Crazy xdl interfaces.. */
2194                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2195                 xpparam_t xpp;
2196                 xdemitconf_t xecfg;
2197                 struct emit_callback ecbdata;
2198                 const struct userdiff_funcname *pe;
2200                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2201                         fprintf(o->file, "%s", header.buf);
2202                         strbuf_reset(&header);
2203                 }
2205                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2206                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2208                 pe = diff_funcname_pattern(one);
2209                 if (!pe)
2210                         pe = diff_funcname_pattern(two);
2212                 memset(&xpp, 0, sizeof(xpp));
2213                 memset(&xecfg, 0, sizeof(xecfg));
2214                 memset(&ecbdata, 0, sizeof(ecbdata));
2215                 ecbdata.label_path = lbl;
2216                 ecbdata.color_diff = want_color(o->use_color);
2217                 ecbdata.found_changesp = &o->found_changes;
2218                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2219                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2220                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2221                 ecbdata.opt = o;
2222                 ecbdata.header = header.len ? &header : NULL;
2223                 xpp.flags = o->xdl_opts;
2224                 xecfg.ctxlen = o->context;
2225                 xecfg.interhunkctxlen = o->interhunkcontext;
2226                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2227                 if (DIFF_OPT_TST(o, FUNCCONTEXT))
2228                         xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2229                 if (pe)
2230                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2231                 if (!diffopts)
2232                         ;
2233                 else if (!prefixcmp(diffopts, "--unified="))
2234                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2235                 else if (!prefixcmp(diffopts, "-u"))
2236                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2237                 if (o->word_diff) {
2238                         int i;
2240                         ecbdata.diff_words =
2241                                 xcalloc(1, sizeof(struct diff_words_data));
2242                         ecbdata.diff_words->type = o->word_diff;
2243                         ecbdata.diff_words->opt = o;
2244                         if (!o->word_regex)
2245                                 o->word_regex = userdiff_word_regex(one);
2246                         if (!o->word_regex)
2247                                 o->word_regex = userdiff_word_regex(two);
2248                         if (!o->word_regex)
2249                                 o->word_regex = diff_word_regex_cfg;
2250                         if (o->word_regex) {
2251                                 ecbdata.diff_words->word_regex = (regex_t *)
2252                                         xmalloc(sizeof(regex_t));
2253                                 if (regcomp(ecbdata.diff_words->word_regex,
2254                                                 o->word_regex,
2255                                                 REG_EXTENDED | REG_NEWLINE))
2256                                         die ("Invalid regular expression: %s",
2257                                                         o->word_regex);
2258                         }
2259                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2260                                 if (o->word_diff == diff_words_styles[i].type) {
2261                                         ecbdata.diff_words->style =
2262                                                 &diff_words_styles[i];
2263                                         break;
2264                                 }
2265                         }
2266                         if (want_color(o->use_color)) {
2267                                 struct diff_words_style *st = ecbdata.diff_words->style;
2268                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2269                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2270                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2271                         }
2272                 }
2273                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2274                               &xpp, &xecfg);
2275                 if (o->word_diff)
2276                         free_diff_words_data(&ecbdata);
2277                 if (textconv_one)
2278                         free(mf1.ptr);
2279                 if (textconv_two)
2280                         free(mf2.ptr);
2281                 xdiff_clear_find_func(&xecfg);
2282         }
2284  free_ab_and_return:
2285         strbuf_release(&header);
2286         diff_free_filespec_data(one);
2287         diff_free_filespec_data(two);
2288         free(a_one);
2289         free(b_two);
2290         return;
2293 static void builtin_diffstat(const char *name_a, const char *name_b,
2294                              struct diff_filespec *one,
2295                              struct diff_filespec *two,
2296                              struct diffstat_t *diffstat,
2297                              struct diff_options *o,
2298                              int complete_rewrite)
2300         mmfile_t mf1, mf2;
2301         struct diffstat_file *data;
2303         data = diffstat_add(diffstat, name_a, name_b);
2305         if (!one || !two) {
2306                 data->is_unmerged = 1;
2307                 return;
2308         }
2310         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2311                 data->is_binary = 1;
2312                 data->added = diff_filespec_size(two);
2313                 data->deleted = diff_filespec_size(one);
2314         }
2316         else if (complete_rewrite) {
2317                 diff_populate_filespec(one, 0);
2318                 diff_populate_filespec(two, 0);
2319                 data->deleted = count_lines(one->data, one->size);
2320                 data->added = count_lines(two->data, two->size);
2321         }
2323         else {
2324                 /* Crazy xdl interfaces.. */
2325                 xpparam_t xpp;
2326                 xdemitconf_t xecfg;
2328                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2329                         die("unable to read files to diff");
2331                 memset(&xpp, 0, sizeof(xpp));
2332                 memset(&xecfg, 0, sizeof(xecfg));
2333                 xpp.flags = o->xdl_opts;
2334                 xecfg.ctxlen = o->context;
2335                 xecfg.interhunkctxlen = o->interhunkcontext;
2336                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2337                               &xpp, &xecfg);
2338         }
2340         diff_free_filespec_data(one);
2341         diff_free_filespec_data(two);
2344 static void builtin_checkdiff(const char *name_a, const char *name_b,
2345                               const char *attr_path,
2346                               struct diff_filespec *one,
2347                               struct diff_filespec *two,
2348                               struct diff_options *o)
2350         mmfile_t mf1, mf2;
2351         struct checkdiff_t data;
2353         if (!two)
2354                 return;
2356         memset(&data, 0, sizeof(data));
2357         data.filename = name_b ? name_b : name_a;
2358         data.lineno = 0;
2359         data.o = o;
2360         data.ws_rule = whitespace_rule(attr_path);
2361         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2363         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2364                 die("unable to read files to diff");
2366         /*
2367          * All the other codepaths check both sides, but not checking
2368          * the "old" side here is deliberate.  We are checking the newly
2369          * introduced changes, and as long as the "new" side is text, we
2370          * can and should check what it introduces.
2371          */
2372         if (diff_filespec_is_binary(two))
2373                 goto free_and_return;
2374         else {
2375                 /* Crazy xdl interfaces.. */
2376                 xpparam_t xpp;
2377                 xdemitconf_t xecfg;
2379                 memset(&xpp, 0, sizeof(xpp));
2380                 memset(&xecfg, 0, sizeof(xecfg));
2381                 xecfg.ctxlen = 1; /* at least one context line */
2382                 xpp.flags = 0;
2383                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2384                               &xpp, &xecfg);
2386                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2387                         struct emit_callback ecbdata;
2388                         int blank_at_eof;
2390                         ecbdata.ws_rule = data.ws_rule;
2391                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2392                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2394                         if (blank_at_eof) {
2395                                 static char *err;
2396                                 if (!err)
2397                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2398                                 fprintf(o->file, "%s:%d: %s.\n",
2399                                         data.filename, blank_at_eof, err);
2400                                 data.status = 1; /* report errors */
2401                         }
2402                 }
2403         }
2404  free_and_return:
2405         diff_free_filespec_data(one);
2406         diff_free_filespec_data(two);
2407         if (data.status)
2408                 DIFF_OPT_SET(o, CHECK_FAILED);
2411 struct diff_filespec *alloc_filespec(const char *path)
2413         int namelen = strlen(path);
2414         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2416         memset(spec, 0, sizeof(*spec));
2417         spec->path = (char *)(spec + 1);
2418         memcpy(spec->path, path, namelen+1);
2419         spec->count = 1;
2420         spec->is_binary = -1;
2421         return spec;
2424 void free_filespec(struct diff_filespec *spec)
2426         if (!--spec->count) {
2427                 diff_free_filespec_data(spec);
2428                 free(spec);
2429         }
2432 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2433                    unsigned short mode)
2435         if (mode) {
2436                 spec->mode = canon_mode(mode);
2437                 hashcpy(spec->sha1, sha1);
2438                 spec->sha1_valid = !is_null_sha1(sha1);
2439         }
2442 /*
2443  * Given a name and sha1 pair, if the index tells us the file in
2444  * the work tree has that object contents, return true, so that
2445  * prepare_temp_file() does not have to inflate and extract.
2446  */
2447 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2449         struct cache_entry *ce;
2450         struct stat st;
2451         int pos, len;
2453         /*
2454          * We do not read the cache ourselves here, because the
2455          * benchmark with my previous version that always reads cache
2456          * shows that it makes things worse for diff-tree comparing
2457          * two linux-2.6 kernel trees in an already checked out work
2458          * tree.  This is because most diff-tree comparisons deal with
2459          * only a small number of files, while reading the cache is
2460          * expensive for a large project, and its cost outweighs the
2461          * savings we get by not inflating the object to a temporary
2462          * file.  Practically, this code only helps when we are used
2463          * by diff-cache --cached, which does read the cache before
2464          * calling us.
2465          */
2466         if (!active_cache)
2467                 return 0;
2469         /* We want to avoid the working directory if our caller
2470          * doesn't need the data in a normal file, this system
2471          * is rather slow with its stat/open/mmap/close syscalls,
2472          * and the object is contained in a pack file.  The pack
2473          * is probably already open and will be faster to obtain
2474          * the data through than the working directory.  Loose
2475          * objects however would tend to be slower as they need
2476          * to be individually opened and inflated.
2477          */
2478         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2479                 return 0;
2481         len = strlen(name);
2482         pos = cache_name_pos(name, len);
2483         if (pos < 0)
2484                 return 0;
2485         ce = active_cache[pos];
2487         /*
2488          * This is not the sha1 we are looking for, or
2489          * unreusable because it is not a regular file.
2490          */
2491         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2492                 return 0;
2494         /*
2495          * If ce is marked as "assume unchanged", there is no
2496          * guarantee that work tree matches what we are looking for.
2497          */
2498         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2499                 return 0;
2501         /*
2502          * If ce matches the file in the work tree, we can reuse it.
2503          */
2504         if (ce_uptodate(ce) ||
2505             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2506                 return 1;
2508         return 0;
2511 static int populate_from_stdin(struct diff_filespec *s)
2513         struct strbuf buf = STRBUF_INIT;
2514         size_t size = 0;
2516         if (strbuf_read(&buf, 0, 0) < 0)
2517                 return error("error while reading from stdin %s",
2518                                      strerror(errno));
2520         s->should_munmap = 0;
2521         s->data = strbuf_detach(&buf, &size);
2522         s->size = size;
2523         s->should_free = 1;
2524         return 0;
2527 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2529         int len;
2530         char *data = xmalloc(100), *dirty = "";
2532         /* Are we looking at the work tree? */
2533         if (s->dirty_submodule)
2534                 dirty = "-dirty";
2536         len = snprintf(data, 100,
2537                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2538         s->data = data;
2539         s->size = len;
2540         s->should_free = 1;
2541         if (size_only) {
2542                 s->data = NULL;
2543                 free(data);
2544         }
2545         return 0;
2548 /*
2549  * While doing rename detection and pickaxe operation, we may need to
2550  * grab the data for the blob (or file) for our own in-core comparison.
2551  * diff_filespec has data and size fields for this purpose.
2552  */
2553 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2555         int err = 0;
2556         if (!DIFF_FILE_VALID(s))
2557                 die("internal error: asking to populate invalid file.");
2558         if (S_ISDIR(s->mode))
2559                 return -1;
2561         if (s->data)
2562                 return 0;
2564         if (size_only && 0 < s->size)
2565                 return 0;
2567         if (S_ISGITLINK(s->mode))
2568                 return diff_populate_gitlink(s, size_only);
2570         if (!s->sha1_valid ||
2571             reuse_worktree_file(s->path, s->sha1, 0)) {
2572                 struct strbuf buf = STRBUF_INIT;
2573                 struct stat st;
2574                 int fd;
2576                 if (!strcmp(s->path, "-"))
2577                         return populate_from_stdin(s);
2579                 if (lstat(s->path, &st) < 0) {
2580                         if (errno == ENOENT) {
2581                         err_empty:
2582                                 err = -1;
2583                         empty:
2584                                 s->data = (char *)"";
2585                                 s->size = 0;
2586                                 return err;
2587                         }
2588                 }
2589                 s->size = xsize_t(st.st_size);
2590                 if (!s->size)
2591                         goto empty;
2592                 if (S_ISLNK(st.st_mode)) {
2593                         struct strbuf sb = STRBUF_INIT;
2595                         if (strbuf_readlink(&sb, s->path, s->size))
2596                                 goto err_empty;
2597                         s->size = sb.len;
2598                         s->data = strbuf_detach(&sb, NULL);
2599                         s->should_free = 1;
2600                         return 0;
2601                 }
2602                 if (size_only)
2603                         return 0;
2604                 fd = open(s->path, O_RDONLY);
2605                 if (fd < 0)
2606                         goto err_empty;
2607                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2608                 close(fd);
2609                 s->should_munmap = 1;
2611                 /*
2612                  * Convert from working tree format to canonical git format
2613                  */
2614                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2615                         size_t size = 0;
2616                         munmap(s->data, s->size);
2617                         s->should_munmap = 0;
2618                         s->data = strbuf_detach(&buf, &size);
2619                         s->size = size;
2620                         s->should_free = 1;
2621                 }
2622         }
2623         else {
2624                 enum object_type type;
2625                 if (size_only) {
2626                         type = sha1_object_info(s->sha1, &s->size);
2627                         if (type < 0)
2628                                 die("unable to read %s", sha1_to_hex(s->sha1));
2629                 } else {
2630                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2631                         if (!s->data)
2632                                 die("unable to read %s", sha1_to_hex(s->sha1));
2633                         s->should_free = 1;
2634                 }
2635         }
2636         return 0;
2639 void diff_free_filespec_blob(struct diff_filespec *s)
2641         if (s->should_free)
2642                 free(s->data);
2643         else if (s->should_munmap)
2644                 munmap(s->data, s->size);
2646         if (s->should_free || s->should_munmap) {
2647                 s->should_free = s->should_munmap = 0;
2648                 s->data = NULL;
2649         }
2652 void diff_free_filespec_data(struct diff_filespec *s)
2654         diff_free_filespec_blob(s);
2655         free(s->cnt_data);
2656         s->cnt_data = NULL;
2659 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2660                            void *blob,
2661                            unsigned long size,
2662                            const unsigned char *sha1,
2663                            int mode)
2665         int fd;
2666         struct strbuf buf = STRBUF_INIT;
2667         struct strbuf template = STRBUF_INIT;
2668         char *path_dup = xstrdup(path);
2669         const char *base = basename(path_dup);
2671         /* Generate "XXXXXX_basename.ext" */
2672         strbuf_addstr(&template, "XXXXXX_");
2673         strbuf_addstr(&template, base);
2675         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2676                         strlen(base) + 1);
2677         if (fd < 0)
2678                 die_errno("unable to create temp-file");
2679         if (convert_to_working_tree(path,
2680                         (const char *)blob, (size_t)size, &buf)) {
2681                 blob = buf.buf;
2682                 size = buf.len;
2683         }
2684         if (write_in_full(fd, blob, size) != size)
2685                 die_errno("unable to write temp-file");
2686         close(fd);
2687         temp->name = temp->tmp_path;
2688         strcpy(temp->hex, sha1_to_hex(sha1));
2689         temp->hex[40] = 0;
2690         sprintf(temp->mode, "%06o", mode);
2691         strbuf_release(&buf);
2692         strbuf_release(&template);
2693         free(path_dup);
2696 static struct diff_tempfile *prepare_temp_file(const char *name,
2697                 struct diff_filespec *one)
2699         struct diff_tempfile *temp = claim_diff_tempfile();
2701         if (!DIFF_FILE_VALID(one)) {
2702         not_a_valid_file:
2703                 /* A '-' entry produces this for file-2, and
2704                  * a '+' entry produces this for file-1.
2705                  */
2706                 temp->name = "/dev/null";
2707                 strcpy(temp->hex, ".");
2708                 strcpy(temp->mode, ".");
2709                 return temp;
2710         }
2712         if (!remove_tempfile_installed) {
2713                 atexit(remove_tempfile);
2714                 sigchain_push_common(remove_tempfile_on_signal);
2715                 remove_tempfile_installed = 1;
2716         }
2718         if (!one->sha1_valid ||
2719             reuse_worktree_file(name, one->sha1, 1)) {
2720                 struct stat st;
2721                 if (lstat(name, &st) < 0) {
2722                         if (errno == ENOENT)
2723                                 goto not_a_valid_file;
2724                         die_errno("stat(%s)", name);
2725                 }
2726                 if (S_ISLNK(st.st_mode)) {
2727                         struct strbuf sb = STRBUF_INIT;
2728                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2729                                 die_errno("readlink(%s)", name);
2730                         prep_temp_blob(name, temp, sb.buf, sb.len,
2731                                        (one->sha1_valid ?
2732                                         one->sha1 : null_sha1),
2733                                        (one->sha1_valid ?
2734                                         one->mode : S_IFLNK));
2735                         strbuf_release(&sb);
2736                 }
2737                 else {
2738                         /* we can borrow from the file in the work tree */
2739                         temp->name = name;
2740                         if (!one->sha1_valid)
2741                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2742                         else
2743                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2744                         /* Even though we may sometimes borrow the
2745                          * contents from the work tree, we always want
2746                          * one->mode.  mode is trustworthy even when
2747                          * !(one->sha1_valid), as long as
2748                          * DIFF_FILE_VALID(one).
2749                          */
2750                         sprintf(temp->mode, "%06o", one->mode);
2751                 }
2752                 return temp;
2753         }
2754         else {
2755                 if (diff_populate_filespec(one, 0))
2756                         die("cannot read data blob for %s", one->path);
2757                 prep_temp_blob(name, temp, one->data, one->size,
2758                                one->sha1, one->mode);
2759         }
2760         return temp;
2763 /* An external diff command takes:
2764  *
2765  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2766  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2767  *
2768  */
2769 static void run_external_diff(const char *pgm,
2770                               const char *name,
2771                               const char *other,
2772                               struct diff_filespec *one,
2773                               struct diff_filespec *two,
2774                               const char *xfrm_msg,
2775                               int complete_rewrite)
2777         const char *spawn_arg[10];
2778         int retval;
2779         const char **arg = &spawn_arg[0];
2781         if (one && two) {
2782                 struct diff_tempfile *temp_one, *temp_two;
2783                 const char *othername = (other ? other : name);
2784                 temp_one = prepare_temp_file(name, one);
2785                 temp_two = prepare_temp_file(othername, two);
2786                 *arg++ = pgm;
2787                 *arg++ = name;
2788                 *arg++ = temp_one->name;
2789                 *arg++ = temp_one->hex;
2790                 *arg++ = temp_one->mode;
2791                 *arg++ = temp_two->name;
2792                 *arg++ = temp_two->hex;
2793                 *arg++ = temp_two->mode;
2794                 if (other) {
2795                         *arg++ = other;
2796                         *arg++ = xfrm_msg;
2797                 }
2798         } else {
2799                 *arg++ = pgm;
2800                 *arg++ = name;
2801         }
2802         *arg = NULL;
2803         fflush(NULL);
2804         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2805         remove_tempfile();
2806         if (retval) {
2807                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2808                 exit(1);
2809         }
2812 static int similarity_index(struct diff_filepair *p)
2814         return p->score * 100 / MAX_SCORE;
2817 static void fill_metainfo(struct strbuf *msg,
2818                           const char *name,
2819                           const char *other,
2820                           struct diff_filespec *one,
2821                           struct diff_filespec *two,
2822                           struct diff_options *o,
2823                           struct diff_filepair *p,
2824                           int *must_show_header,
2825                           int use_color)
2827         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2828         const char *reset = diff_get_color(use_color, DIFF_RESET);
2829         struct strbuf *msgbuf;
2830         char *line_prefix = "";
2832         *must_show_header = 1;
2833         if (o->output_prefix) {
2834                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2835                 line_prefix = msgbuf->buf;
2836         }
2837         strbuf_init(msg, PATH_MAX * 2 + 300);
2838         switch (p->status) {
2839         case DIFF_STATUS_COPIED:
2840                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2841                             line_prefix, set, similarity_index(p));
2842                 strbuf_addf(msg, "%s\n%s%scopy from ",
2843                             reset,  line_prefix, set);
2844                 quote_c_style(name, msg, NULL, 0);
2845                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2846                 quote_c_style(other, msg, NULL, 0);
2847                 strbuf_addf(msg, "%s\n", reset);
2848                 break;
2849         case DIFF_STATUS_RENAMED:
2850                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2851                             line_prefix, set, similarity_index(p));
2852                 strbuf_addf(msg, "%s\n%s%srename from ",
2853                             reset, line_prefix, set);
2854                 quote_c_style(name, msg, NULL, 0);
2855                 strbuf_addf(msg, "%s\n%s%srename to ",
2856                             reset, line_prefix, set);
2857                 quote_c_style(other, msg, NULL, 0);
2858                 strbuf_addf(msg, "%s\n", reset);
2859                 break;
2860         case DIFF_STATUS_MODIFIED:
2861                 if (p->score) {
2862                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2863                                     line_prefix,
2864                                     set, similarity_index(p), reset);
2865                         break;
2866                 }
2867                 /* fallthru */
2868         default:
2869                 *must_show_header = 0;
2870         }
2871         if (one && two && hashcmp(one->sha1, two->sha1)) {
2872                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2874                 if (DIFF_OPT_TST(o, BINARY)) {
2875                         mmfile_t mf;
2876                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2877                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2878                                 abbrev = 40;
2879                 }
2880                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2881                             find_unique_abbrev(one->sha1, abbrev));
2882                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2883                 if (one->mode == two->mode)
2884                         strbuf_addf(msg, " %06o", one->mode);
2885                 strbuf_addf(msg, "%s\n", reset);
2886         }
2889 static void run_diff_cmd(const char *pgm,
2890                          const char *name,
2891                          const char *other,
2892                          const char *attr_path,
2893                          struct diff_filespec *one,
2894                          struct diff_filespec *two,
2895                          struct strbuf *msg,
2896                          struct diff_options *o,
2897                          struct diff_filepair *p)
2899         const char *xfrm_msg = NULL;
2900         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2901         int must_show_header = 0;
2903         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2904                 pgm = NULL;
2905         else {
2906                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2907                 if (drv && drv->external)
2908                         pgm = drv->external;
2909         }
2911         if (msg) {
2912                 /*
2913                  * don't use colors when the header is intended for an
2914                  * external diff driver
2915                  */
2916                 fill_metainfo(msg, name, other, one, two, o, p,
2917                               &must_show_header,
2918                               want_color(o->use_color) && !pgm);
2919                 xfrm_msg = msg->len ? msg->buf : NULL;
2920         }
2922         if (pgm) {
2923                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2924                                   complete_rewrite);
2925                 return;
2926         }
2927         if (one && two)
2928                 builtin_diff(name, other ? other : name,
2929                              one, two, xfrm_msg, must_show_header,
2930                              o, complete_rewrite);
2931         else
2932                 fprintf(o->file, "* Unmerged path %s\n", name);
2935 static void diff_fill_sha1_info(struct diff_filespec *one)
2937         if (DIFF_FILE_VALID(one)) {
2938                 if (!one->sha1_valid) {
2939                         struct stat st;
2940                         if (!strcmp(one->path, "-")) {
2941                                 hashcpy(one->sha1, null_sha1);
2942                                 return;
2943                         }
2944                         if (lstat(one->path, &st) < 0)
2945                                 die_errno("stat '%s'", one->path);
2946                         if (index_path(one->sha1, one->path, &st, 0))
2947                                 die("cannot hash %s", one->path);
2948                 }
2949         }
2950         else
2951                 hashclr(one->sha1);
2954 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2956         /* Strip the prefix but do not molest /dev/null and absolute paths */
2957         if (*namep && **namep != '/') {
2958                 *namep += prefix_length;
2959                 if (**namep == '/')
2960                         ++*namep;
2961         }
2962         if (*otherp && **otherp != '/') {
2963                 *otherp += prefix_length;
2964                 if (**otherp == '/')
2965                         ++*otherp;
2966         }
2969 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2971         const char *pgm = external_diff();
2972         struct strbuf msg;
2973         struct diff_filespec *one = p->one;
2974         struct diff_filespec *two = p->two;
2975         const char *name;
2976         const char *other;
2977         const char *attr_path;
2979         name  = p->one->path;
2980         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2981         attr_path = name;
2982         if (o->prefix_length)
2983                 strip_prefix(o->prefix_length, &name, &other);
2985         if (DIFF_PAIR_UNMERGED(p)) {
2986                 run_diff_cmd(pgm, name, NULL, attr_path,
2987                              NULL, NULL, NULL, o, p);
2988                 return;
2989         }
2991         diff_fill_sha1_info(one);
2992         diff_fill_sha1_info(two);
2994         if (!pgm &&
2995             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2996             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2997                 /*
2998                  * a filepair that changes between file and symlink
2999                  * needs to be split into deletion and creation.
3000                  */
3001                 struct diff_filespec *null = alloc_filespec(two->path);
3002                 run_diff_cmd(NULL, name, other, attr_path,
3003                              one, null, &msg, o, p);
3004                 free(null);
3005                 strbuf_release(&msg);
3007                 null = alloc_filespec(one->path);
3008                 run_diff_cmd(NULL, name, other, attr_path,
3009                              null, two, &msg, o, p);
3010                 free(null);
3011         }
3012         else
3013                 run_diff_cmd(pgm, name, other, attr_path,
3014                              one, two, &msg, o, p);
3016         strbuf_release(&msg);
3019 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3020                          struct diffstat_t *diffstat)
3022         const char *name;
3023         const char *other;
3024         int complete_rewrite = 0;
3026         if (DIFF_PAIR_UNMERGED(p)) {
3027                 /* unmerged */
3028                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3029                 return;
3030         }
3032         name = p->one->path;
3033         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3035         if (o->prefix_length)
3036                 strip_prefix(o->prefix_length, &name, &other);
3038         diff_fill_sha1_info(p->one);
3039         diff_fill_sha1_info(p->two);
3041         if (p->status == DIFF_STATUS_MODIFIED && p->score)
3042                 complete_rewrite = 1;
3043         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3046 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3048         const char *name;
3049         const char *other;
3050         const char *attr_path;
3052         if (DIFF_PAIR_UNMERGED(p)) {
3053                 /* unmerged */
3054                 return;
3055         }
3057         name = p->one->path;
3058         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3059         attr_path = other ? other : name;
3061         if (o->prefix_length)
3062                 strip_prefix(o->prefix_length, &name, &other);
3064         diff_fill_sha1_info(p->one);
3065         diff_fill_sha1_info(p->two);
3067         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3070 void diff_setup(struct diff_options *options)
3072         memcpy(options, &default_diff_options, sizeof(*options));
3074         options->file = stdout;
3076         options->line_termination = '\n';
3077         options->break_opt = -1;
3078         options->rename_limit = -1;
3079         options->dirstat_permille = diff_dirstat_permille_default;
3080         options->context = 3;
3082         options->change = diff_change;
3083         options->add_remove = diff_addremove;
3084         options->use_color = diff_use_color_default;
3085         options->detect_rename = diff_detect_rename_default;
3087         if (diff_no_prefix) {
3088                 options->a_prefix = options->b_prefix = "";
3089         } else if (!diff_mnemonic_prefix) {
3090                 options->a_prefix = "a/";
3091                 options->b_prefix = "b/";
3092         }
3095 int diff_setup_done(struct diff_options *options)
3097         int count = 0;
3099         if (options->output_format & DIFF_FORMAT_NAME)
3100                 count++;
3101         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3102                 count++;
3103         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3104                 count++;
3105         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3106                 count++;
3107         if (count > 1)
3108                 die("--name-only, --name-status, --check and -s are mutually exclusive");
3110         /*
3111          * Most of the time we can say "there are changes"
3112          * only by checking if there are changed paths, but
3113          * --ignore-whitespace* options force us to look
3114          * inside contents.
3115          */
3117         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3118             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3119             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3120                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3121         else
3122                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3124         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3125                 options->detect_rename = DIFF_DETECT_COPY;
3127         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3128                 options->prefix = NULL;
3129         if (options->prefix)
3130                 options->prefix_length = strlen(options->prefix);
3131         else
3132                 options->prefix_length = 0;
3134         if (options->output_format & (DIFF_FORMAT_NAME |
3135                                       DIFF_FORMAT_NAME_STATUS |
3136                                       DIFF_FORMAT_CHECKDIFF |
3137                                       DIFF_FORMAT_NO_OUTPUT))
3138                 options->output_format &= ~(DIFF_FORMAT_RAW |
3139                                             DIFF_FORMAT_NUMSTAT |
3140                                             DIFF_FORMAT_DIFFSTAT |
3141                                             DIFF_FORMAT_SHORTSTAT |
3142                                             DIFF_FORMAT_DIRSTAT |
3143                                             DIFF_FORMAT_SUMMARY |
3144                                             DIFF_FORMAT_PATCH);
3146         /*
3147          * These cases always need recursive; we do not drop caller-supplied
3148          * recursive bits for other formats here.
3149          */
3150         if (options->output_format & (DIFF_FORMAT_PATCH |
3151                                       DIFF_FORMAT_NUMSTAT |
3152                                       DIFF_FORMAT_DIFFSTAT |
3153                                       DIFF_FORMAT_SHORTSTAT |
3154                                       DIFF_FORMAT_DIRSTAT |
3155                                       DIFF_FORMAT_SUMMARY |
3156                                       DIFF_FORMAT_CHECKDIFF))
3157                 DIFF_OPT_SET(options, RECURSIVE);
3158         /*
3159          * Also pickaxe would not work very well if you do not say recursive
3160          */
3161         if (options->pickaxe)
3162                 DIFF_OPT_SET(options, RECURSIVE);
3163         /*
3164          * When patches are generated, submodules diffed against the work tree
3165          * must be checked for dirtiness too so it can be shown in the output
3166          */
3167         if (options->output_format & DIFF_FORMAT_PATCH)
3168                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3170         if (options->detect_rename && options->rename_limit < 0)
3171                 options->rename_limit = diff_rename_limit_default;
3172         if (options->setup & DIFF_SETUP_USE_CACHE) {
3173                 if (!active_cache)
3174                         /* read-cache does not die even when it fails
3175                          * so it is safe for us to do this here.  Also
3176                          * it does not smudge active_cache or active_nr
3177                          * when it fails, so we do not have to worry about
3178                          * cleaning it up ourselves either.
3179                          */
3180                         read_cache();
3181         }
3182         if (options->abbrev <= 0 || 40 < options->abbrev)
3183                 options->abbrev = 40; /* full */
3185         /*
3186          * It does not make sense to show the first hit we happened
3187          * to have found.  It does not make sense not to return with
3188          * exit code in such a case either.
3189          */
3190         if (DIFF_OPT_TST(options, QUICK)) {
3191                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3192                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3193         }
3195         return 0;
3198 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3200         char c, *eq;
3201         int len;
3203         if (*arg != '-')
3204                 return 0;
3205         c = *++arg;
3206         if (!c)
3207                 return 0;
3208         if (c == arg_short) {
3209                 c = *++arg;
3210                 if (!c)
3211                         return 1;
3212                 if (val && isdigit(c)) {
3213                         char *end;
3214                         int n = strtoul(arg, &end, 10);
3215                         if (*end)
3216                                 return 0;
3217                         *val = n;
3218                         return 1;
3219                 }
3220                 return 0;
3221         }
3222         if (c != '-')
3223                 return 0;
3224         arg++;
3225         eq = strchr(arg, '=');
3226         if (eq)
3227                 len = eq - arg;
3228         else
3229                 len = strlen(arg);
3230         if (!len || strncmp(arg, arg_long, len))
3231                 return 0;
3232         if (eq) {
3233                 int n;
3234                 char *end;
3235                 if (!isdigit(*++eq))
3236                         return 0;
3237                 n = strtoul(eq, &end, 10);
3238                 if (*end)
3239                         return 0;
3240                 *val = n;
3241         }
3242         return 1;
3245 static int diff_scoreopt_parse(const char *opt);
3247 static inline int short_opt(char opt, const char **argv,
3248                             const char **optarg)
3250         const char *arg = argv[0];
3251         if (arg[0] != '-' || arg[1] != opt)
3252                 return 0;
3253         if (arg[2] != '\0') {
3254                 *optarg = arg + 2;
3255                 return 1;
3256         }
3257         if (!argv[1])
3258                 die("Option '%c' requires a value", opt);
3259         *optarg = argv[1];
3260         return 2;
3263 int parse_long_opt(const char *opt, const char **argv,
3264                    const char **optarg)
3266         const char *arg = argv[0];
3267         if (arg[0] != '-' || arg[1] != '-')
3268                 return 0;
3269         arg += strlen("--");
3270         if (prefixcmp(arg, opt))
3271                 return 0;
3272         arg += strlen(opt);
3273         if (*arg == '=') { /* sticked form: --option=value */
3274                 *optarg = arg + 1;
3275                 return 1;
3276         }
3277         if (*arg != '\0')
3278                 return 0;
3279         /* separate form: --option value */
3280         if (!argv[1])
3281                 die("Option '--%s' requires a value", opt);
3282         *optarg = argv[1];
3283         return 2;
3286 static int stat_opt(struct diff_options *options, const char **av)
3288         const char *arg = av[0];
3289         char *end;
3290         int width = options->stat_width;
3291         int name_width = options->stat_name_width;
3292         int count = options->stat_count;
3293         int argcount = 1;
3295         arg += strlen("--stat");
3296         end = (char *)arg;
3298         switch (*arg) {
3299         case '-':
3300                 if (!prefixcmp(arg, "-width")) {
3301                         arg += strlen("-width");
3302                         if (*arg == '=')
3303                                 width = strtoul(arg + 1, &end, 10);
3304                         else if (!*arg && !av[1])
3305                                 die("Option '--stat-width' requires a value");
3306                         else if (!*arg) {
3307                                 width = strtoul(av[1], &end, 10);
3308                                 argcount = 2;
3309                         }
3310                 } else if (!prefixcmp(arg, "-name-width")) {
3311                         arg += strlen("-name-width");
3312                         if (*arg == '=')
3313                                 name_width = strtoul(arg + 1, &end, 10);
3314                         else if (!*arg && !av[1])
3315                                 die("Option '--stat-name-width' requires a value");
3316                         else if (!*arg) {
3317                                 name_width = strtoul(av[1], &end, 10);
3318                                 argcount = 2;
3319                         }
3320                 } else if (!prefixcmp(arg, "-count")) {
3321                         arg += strlen("-count");
3322                         if (*arg == '=')
3323                                 count = strtoul(arg + 1, &end, 10);
3324                         else if (!*arg && !av[1])
3325                                 die("Option '--stat-count' requires a value");
3326                         else if (!*arg) {
3327                                 count = strtoul(av[1], &end, 10);
3328                                 argcount = 2;
3329                         }
3330                 }
3331                 break;
3332         case '=':
3333                 width = strtoul(arg+1, &end, 10);
3334                 if (*end == ',')
3335                         name_width = strtoul(end+1, &end, 10);
3336                 if (*end == ',')
3337                         count = strtoul(end+1, &end, 10);
3338         }
3340         /* Important! This checks all the error cases! */
3341         if (*end)
3342                 return 0;
3343         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3344         options->stat_name_width = name_width;
3345         options->stat_width = width;
3346         options->stat_count = count;
3347         return argcount;
3350 static int parse_dirstat_opt(struct diff_options *options, const char *params)
3352         struct strbuf errmsg = STRBUF_INIT;
3353         if (parse_dirstat_params(options, params, &errmsg))
3354                 die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3355                     errmsg.buf);
3356         strbuf_release(&errmsg);
3357         /*
3358          * The caller knows a dirstat-related option is given from the command
3359          * line; allow it to say "return this_function();"
3360          */
3361         options->output_format |= DIFF_FORMAT_DIRSTAT;
3362         return 1;
3365 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3367         const char *arg = av[0];
3368         const char *optarg;
3369         int argcount;
3371         /* Output format options */
3372         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3373                 options->output_format |= DIFF_FORMAT_PATCH;
3374         else if (opt_arg(arg, 'U', "unified", &options->context))
3375                 options->output_format |= DIFF_FORMAT_PATCH;
3376         else if (!strcmp(arg, "--raw"))
3377                 options->output_format |= DIFF_FORMAT_RAW;
3378         else if (!strcmp(arg, "--patch-with-raw"))
3379                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3380         else if (!strcmp(arg, "--numstat"))
3381                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3382         else if (!strcmp(arg, "--shortstat"))
3383                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3384         else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3385                 return parse_dirstat_opt(options, "");
3386         else if (!prefixcmp(arg, "-X"))
3387                 return parse_dirstat_opt(options, arg + 2);
3388         else if (!prefixcmp(arg, "--dirstat="))
3389                 return parse_dirstat_opt(options, arg + 10);
3390         else if (!strcmp(arg, "--cumulative"))
3391                 return parse_dirstat_opt(options, "cumulative");
3392         else if (!strcmp(arg, "--dirstat-by-file"))
3393                 return parse_dirstat_opt(options, "files");
3394         else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3395                 parse_dirstat_opt(options, "files");
3396                 return parse_dirstat_opt(options, arg + 18);
3397         }
3398         else if (!strcmp(arg, "--check"))
3399                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3400         else if (!strcmp(arg, "--summary"))
3401                 options->output_format |= DIFF_FORMAT_SUMMARY;
3402         else if (!strcmp(arg, "--patch-with-stat"))
3403                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3404         else if (!strcmp(arg, "--name-only"))
3405                 options->output_format |= DIFF_FORMAT_NAME;
3406         else if (!strcmp(arg, "--name-status"))
3407                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3408         else if (!strcmp(arg, "-s"))
3409                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3410         else if (!prefixcmp(arg, "--stat"))
3411                 /* --stat, --stat-width, --stat-name-width, or --stat-count */
3412                 return stat_opt(options, av);
3414         /* renames options */
3415         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3416                  !strcmp(arg, "--break-rewrites")) {
3417                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3418                         return error("invalid argument to -B: %s", arg+2);
3419         }
3420         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3421                  !strcmp(arg, "--find-renames")) {
3422                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3423                         return error("invalid argument to -M: %s", arg+2);
3424                 options->detect_rename = DIFF_DETECT_RENAME;
3425         }
3426         else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3427                 options->irreversible_delete = 1;
3428         }
3429         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3430                  !strcmp(arg, "--find-copies")) {
3431                 if (options->detect_rename == DIFF_DETECT_COPY)
3432                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3433                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3434                         return error("invalid argument to -C: %s", arg+2);
3435                 options->detect_rename = DIFF_DETECT_COPY;
3436         }
3437         else if (!strcmp(arg, "--no-renames"))
3438                 options->detect_rename = 0;
3439         else if (!strcmp(arg, "--relative"))
3440                 DIFF_OPT_SET(options, RELATIVE_NAME);
3441         else if (!prefixcmp(arg, "--relative=")) {
3442                 DIFF_OPT_SET(options, RELATIVE_NAME);
3443                 options->prefix = arg + 11;
3444         }
3446         /* xdiff options */
3447         else if (!strcmp(arg, "--minimal"))
3448                 DIFF_XDL_SET(options, NEED_MINIMAL);
3449         else if (!strcmp(arg, "--no-minimal"))
3450                 DIFF_XDL_CLR(options, NEED_MINIMAL);
3451         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3452                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3453         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3454                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3455         else if (!strcmp(arg, "--ignore-space-at-eol"))
3456                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3457         else if (!strcmp(arg, "--patience"))
3458                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3459         else if (!strcmp(arg, "--histogram"))
3460                 DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3462         /* flags options */
3463         else if (!strcmp(arg, "--binary")) {
3464                 options->output_format |= DIFF_FORMAT_PATCH;
3465                 DIFF_OPT_SET(options, BINARY);
3466         }
3467         else if (!strcmp(arg, "--full-index"))
3468                 DIFF_OPT_SET(options, FULL_INDEX);
3469         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3470                 DIFF_OPT_SET(options, TEXT);
3471         else if (!strcmp(arg, "-R"))
3472                 DIFF_OPT_SET(options, REVERSE_DIFF);
3473         else if (!strcmp(arg, "--find-copies-harder"))
3474                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3475         else if (!strcmp(arg, "--follow"))
3476                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3477         else if (!strcmp(arg, "--color"))
3478                 options->use_color = 1;
3479         else if (!prefixcmp(arg, "--color=")) {
3480                 int value = git_config_colorbool(NULL, arg+8);
3481                 if (value < 0)
3482                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3483                 options->use_color = value;
3484         }
3485         else if (!strcmp(arg, "--no-color"))
3486                 options->use_color = 0;
3487         else if (!strcmp(arg, "--color-words")) {
3488                 options->use_color = 1;
3489                 options->word_diff = DIFF_WORDS_COLOR;
3490         }
3491         else if (!prefixcmp(arg, "--color-words=")) {
3492                 options->use_color = 1;
3493                 options->word_diff = DIFF_WORDS_COLOR;
3494                 options->word_regex = arg + 14;
3495         }
3496         else if (!strcmp(arg, "--word-diff")) {
3497                 if (options->word_diff == DIFF_WORDS_NONE)
3498                         options->word_diff = DIFF_WORDS_PLAIN;
3499         }
3500         else if (!prefixcmp(arg, "--word-diff=")) {
3501                 const char *type = arg + 12;
3502                 if (!strcmp(type, "plain"))
3503                         options->word_diff = DIFF_WORDS_PLAIN;
3504                 else if (!strcmp(type, "color")) {
3505                         options->use_color = 1;
3506                         options->word_diff = DIFF_WORDS_COLOR;
3507                 }
3508                 else if (!strcmp(type, "porcelain"))
3509                         options->word_diff = DIFF_WORDS_PORCELAIN;
3510                 else if (!strcmp(type, "none"))
3511                         options->word_diff = DIFF_WORDS_NONE;
3512                 else
3513                         die("bad --word-diff argument: %s", type);
3514         }
3515         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3516                 if (options->word_diff == DIFF_WORDS_NONE)
3517                         options->word_diff = DIFF_WORDS_PLAIN;
3518                 options->word_regex = optarg;
3519                 return argcount;
3520         }
3521         else if (!strcmp(arg, "--exit-code"))
3522                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3523         else if (!strcmp(arg, "--quiet"))
3524                 DIFF_OPT_SET(options, QUICK);
3525         else if (!strcmp(arg, "--ext-diff"))
3526                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3527         else if (!strcmp(arg, "--no-ext-diff"))
3528                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3529         else if (!strcmp(arg, "--textconv"))
3530                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3531         else if (!strcmp(arg, "--no-textconv"))
3532                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3533         else if (!strcmp(arg, "--ignore-submodules")) {
3534                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3535                 handle_ignore_submodules_arg(options, "all");
3536         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3537                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3538                 handle_ignore_submodules_arg(options, arg + 20);
3539         } else if (!strcmp(arg, "--submodule"))
3540                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3541         else if (!prefixcmp(arg, "--submodule=")) {
3542                 if (!strcmp(arg + 12, "log"))
3543                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3544         }
3546         /* misc options */
3547         else if (!strcmp(arg, "-z"))
3548                 options->line_termination = 0;
3549         else if ((argcount = short_opt('l', av, &optarg))) {
3550                 options->rename_limit = strtoul(optarg, NULL, 10);
3551                 return argcount;
3552         }
3553         else if ((argcount = short_opt('S', av, &optarg))) {
3554                 options->pickaxe = optarg;
3555                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3556                 return argcount;
3557         } else if ((argcount = short_opt('G', av, &optarg))) {
3558                 options->pickaxe = optarg;
3559                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3560                 return argcount;
3561         }
3562         else if (!strcmp(arg, "--pickaxe-all"))
3563                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3564         else if (!strcmp(arg, "--pickaxe-regex"))
3565                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3566         else if ((argcount = short_opt('O', av, &optarg))) {
3567                 options->orderfile = optarg;
3568                 return argcount;
3569         }
3570         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3571                 options->filter = optarg;
3572                 return argcount;
3573         }
3574         else if (!strcmp(arg, "--abbrev"))
3575                 options->abbrev = DEFAULT_ABBREV;
3576         else if (!prefixcmp(arg, "--abbrev=")) {
3577                 options->abbrev = strtoul(arg + 9, NULL, 10);
3578                 if (options->abbrev < MINIMUM_ABBREV)
3579                         options->abbrev = MINIMUM_ABBREV;
3580                 else if (40 < options->abbrev)
3581                         options->abbrev = 40;
3582         }
3583         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3584                 options->a_prefix = optarg;
3585                 return argcount;
3586         }
3587         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3588                 options->b_prefix = optarg;
3589                 return argcount;
3590         }
3591         else if (!strcmp(arg, "--no-prefix"))
3592                 options->a_prefix = options->b_prefix = "";
3593         else if (opt_arg(arg, '\0', "inter-hunk-context",
3594                          &options->interhunkcontext))
3595                 ;
3596         else if (!strcmp(arg, "-W"))
3597                 DIFF_OPT_SET(options, FUNCCONTEXT);
3598         else if (!strcmp(arg, "--function-context"))
3599                 DIFF_OPT_SET(options, FUNCCONTEXT);
3600         else if (!strcmp(arg, "--no-function-context"))
3601                 DIFF_OPT_CLR(options, FUNCCONTEXT);
3602         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3603                 options->file = fopen(optarg, "w");
3604                 if (!options->file)
3605                         die_errno("Could not open '%s'", optarg);
3606                 options->close_file = 1;
3607                 return argcount;
3608         } else
3609                 return 0;
3610         return 1;
3613 int parse_rename_score(const char **cp_p)
3615         unsigned long num, scale;
3616         int ch, dot;
3617         const char *cp = *cp_p;
3619         num = 0;
3620         scale = 1;
3621         dot = 0;
3622         for (;;) {
3623                 ch = *cp;
3624                 if ( !dot && ch == '.' ) {
3625                         scale = 1;
3626                         dot = 1;
3627                 } else if ( ch == '%' ) {
3628                         scale = dot ? scale*100 : 100;
3629                         cp++;   /* % is always at the end */
3630                         break;
3631                 } else if ( ch >= '0' && ch <= '9' ) {
3632                         if ( scale < 100000 ) {
3633                                 scale *= 10;
3634                                 num = (num*10) + (ch-'0');
3635                         }
3636                 } else {
3637                         break;
3638                 }
3639                 cp++;
3640         }
3641         *cp_p = cp;
3643         /* user says num divided by scale and we say internally that
3644          * is MAX_SCORE * num / scale.
3645          */
3646         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3649 static int diff_scoreopt_parse(const char *opt)
3651         int opt1, opt2, cmd;
3653         if (*opt++ != '-')
3654                 return -1;
3655         cmd = *opt++;
3656         if (cmd == '-') {
3657                 /* convert the long-form arguments into short-form versions */
3658                 if (!prefixcmp(opt, "break-rewrites")) {
3659                         opt += strlen("break-rewrites");
3660                         if (*opt == 0 || *opt++ == '=')
3661                                 cmd = 'B';
3662                 } else if (!prefixcmp(opt, "find-copies")) {
3663                         opt += strlen("find-copies");
3664                         if (*opt == 0 || *opt++ == '=')
3665                                 cmd = 'C';
3666                 } else if (!prefixcmp(opt, "find-renames")) {
3667                         opt += strlen("find-renames");
3668                         if (*opt == 0 || *opt++ == '=')
3669                                 cmd = 'M';
3670                 }
3671         }
3672         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3673                 return -1; /* that is not a -M, -C nor -B option */
3675         opt1 = parse_rename_score(&opt);
3676         if (cmd != 'B')
3677                 opt2 = 0;
3678         else {
3679                 if (*opt == 0)
3680                         opt2 = 0;
3681                 else if (*opt != '/')
3682                         return -1; /* we expect -B80/99 or -B80 */
3683                 else {
3684                         opt++;
3685                         opt2 = parse_rename_score(&opt);
3686                 }
3687         }
3688         if (*opt != 0)
3689                 return -1;
3690         return opt1 | (opt2 << 16);
3693 struct diff_queue_struct diff_queued_diff;
3695 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3697         if (queue->alloc <= queue->nr) {
3698                 queue->alloc = alloc_nr(queue->alloc);
3699                 queue->queue = xrealloc(queue->queue,
3700                                         sizeof(dp) * queue->alloc);
3701         }
3702         queue->queue[queue->nr++] = dp;
3705 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3706                                  struct diff_filespec *one,
3707                                  struct diff_filespec *two)
3709         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3710         dp->one = one;
3711         dp->two = two;
3712         if (queue)
3713                 diff_q(queue, dp);
3714         return dp;
3717 void diff_free_filepair(struct diff_filepair *p)
3719         free_filespec(p->one);
3720         free_filespec(p->two);
3721         free(p);
3724 /* This is different from find_unique_abbrev() in that
3725  * it stuffs the result with dots for alignment.
3726  */
3727 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3729         int abblen;
3730         const char *abbrev;
3731         if (len == 40)
3732                 return sha1_to_hex(sha1);
3734         abbrev = find_unique_abbrev(sha1, len);
3735         abblen = strlen(abbrev);
3736         if (abblen < 37) {
3737                 static char hex[41];
3738                 if (len < abblen && abblen <= len + 2)
3739                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3740                 else
3741                         sprintf(hex, "%s...", abbrev);
3742                 return hex;
3743         }
3744         return sha1_to_hex(sha1);
3747 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3749         int line_termination = opt->line_termination;
3750         int inter_name_termination = line_termination ? '\t' : '\0';
3751         if (opt->output_prefix) {
3752                 struct strbuf *msg = NULL;
3753                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3754                 fprintf(opt->file, "%s", msg->buf);
3755         }
3757         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3758                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3759                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3760                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3761         }
3762         if (p->score) {
3763                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3764                         inter_name_termination);
3765         } else {
3766                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3767         }
3769         if (p->status == DIFF_STATUS_COPIED ||
3770             p->status == DIFF_STATUS_RENAMED) {
3771                 const char *name_a, *name_b;
3772                 name_a = p->one->path;
3773                 name_b = p->two->path;
3774                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3775                 write_name_quoted(name_a, opt->file, inter_name_termination);
3776                 write_name_quoted(name_b, opt->file, line_termination);
3777         } else {
3778                 const char *name_a, *name_b;
3779                 name_a = p->one->mode ? p->one->path : p->two->path;
3780                 name_b = NULL;
3781                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3782                 write_name_quoted(name_a, opt->file, line_termination);
3783         }
3786 int diff_unmodified_pair(struct diff_filepair *p)
3788         /* This function is written stricter than necessary to support
3789          * the currently implemented transformers, but the idea is to
3790          * let transformers to produce diff_filepairs any way they want,
3791          * and filter and clean them up here before producing the output.
3792          */
3793         struct diff_filespec *one = p->one, *two = p->two;
3795         if (DIFF_PAIR_UNMERGED(p))
3796                 return 0; /* unmerged is interesting */
3798         /* deletion, addition, mode or type change
3799          * and rename are all interesting.
3800          */
3801         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3802             DIFF_PAIR_MODE_CHANGED(p) ||
3803             strcmp(one->path, two->path))
3804                 return 0;
3806         /* both are valid and point at the same path.  that is, we are
3807          * dealing with a change.
3808          */
3809         if (one->sha1_valid && two->sha1_valid &&
3810             !hashcmp(one->sha1, two->sha1) &&
3811             !one->dirty_submodule && !two->dirty_submodule)
3812                 return 1; /* no change */
3813         if (!one->sha1_valid && !two->sha1_valid)
3814                 return 1; /* both look at the same file on the filesystem. */
3815         return 0;
3818 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3820         if (diff_unmodified_pair(p))
3821                 return;
3823         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3824             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3825                 return; /* no tree diffs in patch format */
3827         run_diff(p, o);
3830 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3831                             struct diffstat_t *diffstat)
3833         if (diff_unmodified_pair(p))
3834                 return;
3836         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3837             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3838                 return; /* no useful stat for tree diffs */
3840         run_diffstat(p, o, diffstat);
3843 static void diff_flush_checkdiff(struct diff_filepair *p,
3844                 struct diff_options *o)
3846         if (diff_unmodified_pair(p))
3847                 return;
3849         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3850             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3851                 return; /* nothing to check in tree diffs */
3853         run_checkdiff(p, o);
3856 int diff_queue_is_empty(void)
3858         struct diff_queue_struct *q = &diff_queued_diff;
3859         int i;
3860         for (i = 0; i < q->nr; i++)
3861                 if (!diff_unmodified_pair(q->queue[i]))
3862                         return 0;
3863         return 1;
3866 #if DIFF_DEBUG
3867 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3869         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3870                 x, one ? one : "",
3871                 s->path,
3872                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3873                 s->mode,
3874                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3875         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3876                 x, one ? one : "",
3877                 s->size, s->xfrm_flags);
3880 void diff_debug_filepair(const struct diff_filepair *p, int i)
3882         diff_debug_filespec(p->one, i, "one");
3883         diff_debug_filespec(p->two, i, "two");
3884         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3885                 p->score, p->status ? p->status : '?',
3886                 p->one->rename_used, p->broken_pair);
3889 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3891         int i;
3892         if (msg)
3893                 fprintf(stderr, "%s\n", msg);
3894         fprintf(stderr, "q->nr = %d\n", q->nr);
3895         for (i = 0; i < q->nr; i++) {
3896                 struct diff_filepair *p = q->queue[i];
3897                 diff_debug_filepair(p, i);
3898         }
3900 #endif
3902 static void diff_resolve_rename_copy(void)
3904         int i;
3905         struct diff_filepair *p;
3906         struct diff_queue_struct *q = &diff_queued_diff;
3908         diff_debug_queue("resolve-rename-copy", q);
3910         for (i = 0; i < q->nr; i++) {
3911                 p = q->queue[i];
3912                 p->status = 0; /* undecided */
3913                 if (DIFF_PAIR_UNMERGED(p))
3914                         p->status = DIFF_STATUS_UNMERGED;
3915                 else if (!DIFF_FILE_VALID(p->one))
3916                         p->status = DIFF_STATUS_ADDED;
3917                 else if (!DIFF_FILE_VALID(p->two))
3918                         p->status = DIFF_STATUS_DELETED;
3919                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3920                         p->status = DIFF_STATUS_TYPE_CHANGED;
3922                 /* from this point on, we are dealing with a pair
3923                  * whose both sides are valid and of the same type, i.e.
3924                  * either in-place edit or rename/copy edit.
3925                  */
3926                 else if (DIFF_PAIR_RENAME(p)) {
3927                         /*
3928                          * A rename might have re-connected a broken
3929                          * pair up, causing the pathnames to be the
3930                          * same again. If so, that's not a rename at
3931                          * all, just a modification..
3932                          *
3933                          * Otherwise, see if this source was used for
3934                          * multiple renames, in which case we decrement
3935                          * the count, and call it a copy.
3936                          */
3937                         if (!strcmp(p->one->path, p->two->path))
3938                                 p->status = DIFF_STATUS_MODIFIED;
3939                         else if (--p->one->rename_used > 0)
3940                                 p->status = DIFF_STATUS_COPIED;
3941                         else
3942                                 p->status = DIFF_STATUS_RENAMED;
3943                 }
3944                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3945                          p->one->mode != p->two->mode ||
3946                          p->one->dirty_submodule ||
3947                          p->two->dirty_submodule ||
3948                          is_null_sha1(p->one->sha1))
3949                         p->status = DIFF_STATUS_MODIFIED;
3950                 else {
3951                         /* This is a "no-change" entry and should not
3952                          * happen anymore, but prepare for broken callers.
3953                          */
3954                         error("feeding unmodified %s to diffcore",
3955                               p->one->path);
3956                         p->status = DIFF_STATUS_UNKNOWN;
3957                 }
3958         }
3959         diff_debug_queue("resolve-rename-copy done", q);
3962 static int check_pair_status(struct diff_filepair *p)
3964         switch (p->status) {
3965         case DIFF_STATUS_UNKNOWN:
3966                 return 0;
3967         case 0:
3968                 die("internal error in diff-resolve-rename-copy");
3969         default:
3970                 return 1;
3971         }
3974 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3976         int fmt = opt->output_format;
3978         if (fmt & DIFF_FORMAT_CHECKDIFF)
3979                 diff_flush_checkdiff(p, opt);
3980         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3981                 diff_flush_raw(p, opt);
3982         else if (fmt & DIFF_FORMAT_NAME) {
3983                 const char *name_a, *name_b;
3984                 name_a = p->two->path;
3985                 name_b = NULL;
3986                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3987                 write_name_quoted(name_a, opt->file, opt->line_termination);
3988         }
3991 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3993         if (fs->mode)
3994                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3995         else
3996                 fprintf(file, " %s ", newdelete);
3997         write_name_quoted(fs->path, file, '\n');
4001 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4002                 const char *line_prefix)
4004         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4005                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4006                         p->two->mode, show_name ? ' ' : '\n');
4007                 if (show_name) {
4008                         write_name_quoted(p->two->path, file, '\n');
4009                 }
4010         }
4013 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4014                         const char *line_prefix)
4016         char *names = pprint_rename(p->one->path, p->two->path);
4018         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4019         free(names);
4020         show_mode_change(file, p, 0, line_prefix);
4023 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4025         FILE *file = opt->file;
4026         char *line_prefix = "";
4028         if (opt->output_prefix) {
4029                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4030                 line_prefix = buf->buf;
4031         }
4033         switch(p->status) {
4034         case DIFF_STATUS_DELETED:
4035                 fputs(line_prefix, file);
4036                 show_file_mode_name(file, "delete", p->one);
4037                 break;
4038         case DIFF_STATUS_ADDED:
4039                 fputs(line_prefix, file);
4040                 show_file_mode_name(file, "create", p->two);
4041                 break;
4042         case DIFF_STATUS_COPIED:
4043                 fputs(line_prefix, file);
4044                 show_rename_copy(file, "copy", p, line_prefix);
4045                 break;
4046         case DIFF_STATUS_RENAMED:
4047                 fputs(line_prefix, file);
4048                 show_rename_copy(file, "rename", p, line_prefix);
4049                 break;
4050         default:
4051                 if (p->score) {
4052                         fprintf(file, "%s rewrite ", line_prefix);
4053                         write_name_quoted(p->two->path, file, ' ');
4054                         fprintf(file, "(%d%%)\n", similarity_index(p));
4055                 }
4056                 show_mode_change(file, p, !p->score, line_prefix);
4057                 break;
4058         }
4061 struct patch_id_t {
4062         git_SHA_CTX *ctx;
4063         int patchlen;
4064 };
4066 static int remove_space(char *line, int len)
4068         int i;
4069         char *dst = line;
4070         unsigned char c;
4072         for (i = 0; i < len; i++)
4073                 if (!isspace((c = line[i])))
4074                         *dst++ = c;
4076         return dst - line;
4079 static void patch_id_consume(void *priv, char *line, unsigned long len)
4081         struct patch_id_t *data = priv;
4082         int new_len;
4084         /* Ignore line numbers when computing the SHA1 of the patch */
4085         if (!prefixcmp(line, "@@ -"))
4086                 return;
4088         new_len = remove_space(line, len);
4090         git_SHA1_Update(data->ctx, line, new_len);
4091         data->patchlen += new_len;
4094 /* returns 0 upon success, and writes result into sha1 */
4095 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4097         struct diff_queue_struct *q = &diff_queued_diff;
4098         int i;
4099         git_SHA_CTX ctx;
4100         struct patch_id_t data;
4101         char buffer[PATH_MAX * 4 + 20];
4103         git_SHA1_Init(&ctx);
4104         memset(&data, 0, sizeof(struct patch_id_t));
4105         data.ctx = &ctx;
4107         for (i = 0; i < q->nr; i++) {
4108                 xpparam_t xpp;
4109                 xdemitconf_t xecfg;
4110                 mmfile_t mf1, mf2;
4111                 struct diff_filepair *p = q->queue[i];
4112                 int len1, len2;
4114                 memset(&xpp, 0, sizeof(xpp));
4115                 memset(&xecfg, 0, sizeof(xecfg));
4116                 if (p->status == 0)
4117                         return error("internal diff status error");
4118                 if (p->status == DIFF_STATUS_UNKNOWN)
4119                         continue;
4120                 if (diff_unmodified_pair(p))
4121                         continue;
4122                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4123                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4124                         continue;
4125                 if (DIFF_PAIR_UNMERGED(p))
4126                         continue;
4128                 diff_fill_sha1_info(p->one);
4129                 diff_fill_sha1_info(p->two);
4130                 if (fill_mmfile(&mf1, p->one) < 0 ||
4131                                 fill_mmfile(&mf2, p->two) < 0)
4132                         return error("unable to read files to diff");
4134                 len1 = remove_space(p->one->path, strlen(p->one->path));
4135                 len2 = remove_space(p->two->path, strlen(p->two->path));
4136                 if (p->one->mode == 0)
4137                         len1 = snprintf(buffer, sizeof(buffer),
4138                                         "diff--gita/%.*sb/%.*s"
4139                                         "newfilemode%06o"
4140                                         "---/dev/null"
4141                                         "+++b/%.*s",
4142                                         len1, p->one->path,
4143                                         len2, p->two->path,
4144                                         p->two->mode,
4145                                         len2, p->two->path);
4146                 else if (p->two->mode == 0)
4147                         len1 = snprintf(buffer, sizeof(buffer),
4148                                         "diff--gita/%.*sb/%.*s"
4149                                         "deletedfilemode%06o"
4150                                         "---a/%.*s"
4151                                         "+++/dev/null",
4152                                         len1, p->one->path,
4153                                         len2, p->two->path,
4154                                         p->one->mode,
4155                                         len1, p->one->path);
4156                 else
4157                         len1 = snprintf(buffer, sizeof(buffer),
4158                                         "diff--gita/%.*sb/%.*s"
4159                                         "---a/%.*s"
4160                                         "+++b/%.*s",
4161                                         len1, p->one->path,
4162                                         len2, p->two->path,
4163                                         len1, p->one->path,
4164                                         len2, p->two->path);
4165                 git_SHA1_Update(&ctx, buffer, len1);
4167                 if (diff_filespec_is_binary(p->one) ||
4168                     diff_filespec_is_binary(p->two)) {
4169                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4170                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4171                         continue;
4172                 }
4174                 xpp.flags = 0;
4175                 xecfg.ctxlen = 3;
4176                 xecfg.flags = 0;
4177                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4178                               &xpp, &xecfg);
4179         }
4181         git_SHA1_Final(sha1, &ctx);
4182         return 0;
4185 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4187         struct diff_queue_struct *q = &diff_queued_diff;
4188         int i;
4189         int result = diff_get_patch_id(options, sha1);
4191         for (i = 0; i < q->nr; i++)
4192                 diff_free_filepair(q->queue[i]);
4194         free(q->queue);
4195         DIFF_QUEUE_CLEAR(q);
4197         return result;
4200 static int is_summary_empty(const struct diff_queue_struct *q)
4202         int i;
4204         for (i = 0; i < q->nr; i++) {
4205                 const struct diff_filepair *p = q->queue[i];
4207                 switch (p->status) {
4208                 case DIFF_STATUS_DELETED:
4209                 case DIFF_STATUS_ADDED:
4210                 case DIFF_STATUS_COPIED:
4211                 case DIFF_STATUS_RENAMED:
4212                         return 0;
4213                 default:
4214                         if (p->score)
4215                                 return 0;
4216                         if (p->one->mode && p->two->mode &&
4217                             p->one->mode != p->two->mode)
4218                                 return 0;
4219                         break;
4220                 }
4221         }
4222         return 1;
4225 static const char rename_limit_warning[] =
4226 "inexact rename detection was skipped due to too many files.";
4228 static const char degrade_cc_to_c_warning[] =
4229 "only found copies from modified paths due to too many files.";
4231 static const char rename_limit_advice[] =
4232 "you may want to set your %s variable to at least "
4233 "%d and retry the command.";
4235 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4237         if (degraded_cc)
4238                 warning(degrade_cc_to_c_warning);
4239         else if (needed)
4240                 warning(rename_limit_warning);
4241         else
4242                 return;
4243         if (0 < needed && needed < 32767)
4244                 warning(rename_limit_advice, varname, needed);
4247 void diff_flush(struct diff_options *options)
4249         struct diff_queue_struct *q = &diff_queued_diff;
4250         int i, output_format = options->output_format;
4251         int separator = 0;
4252         int dirstat_by_line = 0;
4254         /*
4255          * Order: raw, stat, summary, patch
4256          * or:    name/name-status/checkdiff (other bits clear)
4257          */
4258         if (!q->nr)
4259                 goto free_queue;
4261         if (output_format & (DIFF_FORMAT_RAW |
4262                              DIFF_FORMAT_NAME |
4263                              DIFF_FORMAT_NAME_STATUS |
4264                              DIFF_FORMAT_CHECKDIFF)) {
4265                 for (i = 0; i < q->nr; i++) {
4266                         struct diff_filepair *p = q->queue[i];
4267                         if (check_pair_status(p))
4268                                 flush_one_pair(p, options);
4269                 }
4270                 separator++;
4271         }
4273         if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4274                 dirstat_by_line = 1;
4276         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4277             dirstat_by_line) {
4278                 struct diffstat_t diffstat;
4280                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4281                 for (i = 0; i < q->nr; i++) {
4282                         struct diff_filepair *p = q->queue[i];
4283                         if (check_pair_status(p))
4284                                 diff_flush_stat(p, options, &diffstat);
4285                 }
4286                 if (output_format & DIFF_FORMAT_NUMSTAT)
4287                         show_numstat(&diffstat, options);
4288                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4289                         show_stats(&diffstat, options);
4290                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4291                         show_shortstats(&diffstat, options);
4292                 if (output_format & DIFF_FORMAT_DIRSTAT)
4293                         show_dirstat_by_line(&diffstat, options);
4294                 free_diffstat_info(&diffstat);
4295                 separator++;
4296         }
4297         if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4298                 show_dirstat(options);
4300         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4301                 for (i = 0; i < q->nr; i++) {
4302                         diff_summary(options, q->queue[i]);
4303                 }
4304                 separator++;
4305         }
4307         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4308             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4309             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4310                 /*
4311                  * run diff_flush_patch for the exit status. setting
4312                  * options->file to /dev/null should be safe, becaue we
4313                  * aren't supposed to produce any output anyway.
4314                  */
4315                 if (options->close_file)
4316                         fclose(options->file);
4317                 options->file = fopen("/dev/null", "w");
4318                 if (!options->file)
4319                         die_errno("Could not open /dev/null");
4320                 options->close_file = 1;
4321                 for (i = 0; i < q->nr; i++) {
4322                         struct diff_filepair *p = q->queue[i];
4323                         if (check_pair_status(p))
4324                                 diff_flush_patch(p, options);
4325                         if (options->found_changes)
4326                                 break;
4327                 }
4328         }
4330         if (output_format & DIFF_FORMAT_PATCH) {
4331                 if (separator) {
4332                         putc(options->line_termination, options->file);
4333                         if (options->stat_sep) {
4334                                 /* attach patch instead of inline */
4335                                 fputs(options->stat_sep, options->file);
4336                         }
4337                 }
4339                 for (i = 0; i < q->nr; i++) {
4340                         struct diff_filepair *p = q->queue[i];
4341                         if (check_pair_status(p))
4342                                 diff_flush_patch(p, options);
4343                 }
4344         }
4346         if (output_format & DIFF_FORMAT_CALLBACK)
4347                 options->format_callback(q, options, options->format_callback_data);
4349         for (i = 0; i < q->nr; i++)
4350                 diff_free_filepair(q->queue[i]);
4351 free_queue:
4352         free(q->queue);
4353         DIFF_QUEUE_CLEAR(q);
4354         if (options->close_file)
4355                 fclose(options->file);
4357         /*
4358          * Report the content-level differences with HAS_CHANGES;
4359          * diff_addremove/diff_change does not set the bit when
4360          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4361          */
4362         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4363                 if (options->found_changes)
4364                         DIFF_OPT_SET(options, HAS_CHANGES);
4365                 else
4366                         DIFF_OPT_CLR(options, HAS_CHANGES);
4367         }
4370 static void diffcore_apply_filter(const char *filter)
4372         int i;
4373         struct diff_queue_struct *q = &diff_queued_diff;
4374         struct diff_queue_struct outq;
4375         DIFF_QUEUE_CLEAR(&outq);
4377         if (!filter)
4378                 return;
4380         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4381                 int found;
4382                 for (i = found = 0; !found && i < q->nr; i++) {
4383                         struct diff_filepair *p = q->queue[i];
4384                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4385                              ((p->score &&
4386                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4387                               (!p->score &&
4388                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4389                             ((p->status != DIFF_STATUS_MODIFIED) &&
4390                              strchr(filter, p->status)))
4391                                 found++;
4392                 }
4393                 if (found)
4394                         return;
4396                 /* otherwise we will clear the whole queue
4397                  * by copying the empty outq at the end of this
4398                  * function, but first clear the current entries
4399                  * in the queue.
4400                  */
4401                 for (i = 0; i < q->nr; i++)
4402                         diff_free_filepair(q->queue[i]);
4403         }
4404         else {
4405                 /* Only the matching ones */
4406                 for (i = 0; i < q->nr; i++) {
4407                         struct diff_filepair *p = q->queue[i];
4409                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4410                              ((p->score &&
4411                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4412                               (!p->score &&
4413                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4414                             ((p->status != DIFF_STATUS_MODIFIED) &&
4415                              strchr(filter, p->status)))
4416                                 diff_q(&outq, p);
4417                         else
4418                                 diff_free_filepair(p);
4419                 }
4420         }
4421         free(q->queue);
4422         *q = outq;
4425 /* Check whether two filespecs with the same mode and size are identical */
4426 static int diff_filespec_is_identical(struct diff_filespec *one,
4427                                       struct diff_filespec *two)
4429         if (S_ISGITLINK(one->mode))
4430                 return 0;
4431         if (diff_populate_filespec(one, 0))
4432                 return 0;
4433         if (diff_populate_filespec(two, 0))
4434                 return 0;
4435         return !memcmp(one->data, two->data, one->size);
4438 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4440         int i;
4441         struct diff_queue_struct *q = &diff_queued_diff;
4442         struct diff_queue_struct outq;
4443         DIFF_QUEUE_CLEAR(&outq);
4445         for (i = 0; i < q->nr; i++) {
4446                 struct diff_filepair *p = q->queue[i];
4448                 /*
4449                  * 1. Entries that come from stat info dirtiness
4450                  *    always have both sides (iow, not create/delete),
4451                  *    one side of the object name is unknown, with
4452                  *    the same mode and size.  Keep the ones that
4453                  *    do not match these criteria.  They have real
4454                  *    differences.
4455                  *
4456                  * 2. At this point, the file is known to be modified,
4457                  *    with the same mode and size, and the object
4458                  *    name of one side is unknown.  Need to inspect
4459                  *    the identical contents.
4460                  */
4461                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4462                     !DIFF_FILE_VALID(p->two) ||
4463                     (p->one->sha1_valid && p->two->sha1_valid) ||
4464                     (p->one->mode != p->two->mode) ||
4465                     diff_populate_filespec(p->one, 1) ||
4466                     diff_populate_filespec(p->two, 1) ||
4467                     (p->one->size != p->two->size) ||
4468                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4469                         diff_q(&outq, p);
4470                 else {
4471                         /*
4472                          * The caller can subtract 1 from skip_stat_unmatch
4473                          * to determine how many paths were dirty only
4474                          * due to stat info mismatch.
4475                          */
4476                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4477                                 diffopt->skip_stat_unmatch++;
4478                         diff_free_filepair(p);
4479                 }
4480         }
4481         free(q->queue);
4482         *q = outq;
4485 static int diffnamecmp(const void *a_, const void *b_)
4487         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4488         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4489         const char *name_a, *name_b;
4491         name_a = a->one ? a->one->path : a->two->path;
4492         name_b = b->one ? b->one->path : b->two->path;
4493         return strcmp(name_a, name_b);
4496 void diffcore_fix_diff_index(struct diff_options *options)
4498         struct diff_queue_struct *q = &diff_queued_diff;
4499         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4502 void diffcore_std(struct diff_options *options)
4504         if (options->skip_stat_unmatch)
4505                 diffcore_skip_stat_unmatch(options);
4506         if (!options->found_follow) {
4507                 /* See try_to_follow_renames() in tree-diff.c */
4508                 if (options->break_opt != -1)
4509                         diffcore_break(options->break_opt);
4510                 if (options->detect_rename)
4511                         diffcore_rename(options);
4512                 if (options->break_opt != -1)
4513                         diffcore_merge_broken();
4514         }
4515         if (options->pickaxe)
4516                 diffcore_pickaxe(options);
4517         if (options->orderfile)
4518                 diffcore_order(options->orderfile);
4519         if (!options->found_follow)
4520                 /* See try_to_follow_renames() in tree-diff.c */
4521                 diff_resolve_rename_copy();
4522         diffcore_apply_filter(options->filter);
4524         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4525                 DIFF_OPT_SET(options, HAS_CHANGES);
4526         else
4527                 DIFF_OPT_CLR(options, HAS_CHANGES);
4529         options->found_follow = 0;
4532 int diff_result_code(struct diff_options *opt, int status)
4534         int result = 0;
4536         diff_warn_rename_limit("diff.renamelimit",
4537                                opt->needed_rename_limit,
4538                                opt->degraded_cc_to_c);
4539         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4540             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4541                 return status;
4542         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4543             DIFF_OPT_TST(opt, HAS_CHANGES))
4544                 result |= 01;
4545         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4546             DIFF_OPT_TST(opt, CHECK_FAILED))
4547                 result |= 02;
4548         return result;
4551 int diff_can_quit_early(struct diff_options *opt)
4553         return (DIFF_OPT_TST(opt, QUICK) &&
4554                 !opt->filter &&
4555                 DIFF_OPT_TST(opt, HAS_CHANGES));
4558 /*
4559  * Shall changes to this submodule be ignored?
4560  *
4561  * Submodule changes can be configured to be ignored separately for each path,
4562  * but that configuration can be overridden from the command line.
4563  */
4564 static int is_submodule_ignored(const char *path, struct diff_options *options)
4566         int ignored = 0;
4567         unsigned orig_flags = options->flags;
4568         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4569                 set_diffopt_flags_from_submodule_config(options, path);
4570         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4571                 ignored = 1;
4572         options->flags = orig_flags;
4573         return ignored;
4576 void diff_addremove(struct diff_options *options,
4577                     int addremove, unsigned mode,
4578                     const unsigned char *sha1,
4579                     const char *concatpath, unsigned dirty_submodule)
4581         struct diff_filespec *one, *two;
4583         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4584                 return;
4586         /* This may look odd, but it is a preparation for
4587          * feeding "there are unchanged files which should
4588          * not produce diffs, but when you are doing copy
4589          * detection you would need them, so here they are"
4590          * entries to the diff-core.  They will be prefixed
4591          * with something like '=' or '*' (I haven't decided
4592          * which but should not make any difference).
4593          * Feeding the same new and old to diff_change()
4594          * also has the same effect.
4595          * Before the final output happens, they are pruned after
4596          * merged into rename/copy pairs as appropriate.
4597          */
4598         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4599                 addremove = (addremove == '+' ? '-' :
4600                              addremove == '-' ? '+' : addremove);
4602         if (options->prefix &&
4603             strncmp(concatpath, options->prefix, options->prefix_length))
4604                 return;
4606         one = alloc_filespec(concatpath);
4607         two = alloc_filespec(concatpath);
4609         if (addremove != '+')
4610                 fill_filespec(one, sha1, mode);
4611         if (addremove != '-') {
4612                 fill_filespec(two, sha1, mode);
4613                 two->dirty_submodule = dirty_submodule;
4614         }
4616         diff_queue(&diff_queued_diff, one, two);
4617         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4618                 DIFF_OPT_SET(options, HAS_CHANGES);
4621 void diff_change(struct diff_options *options,
4622                  unsigned old_mode, unsigned new_mode,
4623                  const unsigned char *old_sha1,
4624                  const unsigned char *new_sha1,
4625                  const char *concatpath,
4626                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4628         struct diff_filespec *one, *two;
4630         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4631             is_submodule_ignored(concatpath, options))
4632                 return;
4634         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4635                 unsigned tmp;
4636                 const unsigned char *tmp_c;
4637                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4638                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4639                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4640                         new_dirty_submodule = tmp;
4641         }
4643         if (options->prefix &&
4644             strncmp(concatpath, options->prefix, options->prefix_length))
4645                 return;
4647         one = alloc_filespec(concatpath);
4648         two = alloc_filespec(concatpath);
4649         fill_filespec(one, old_sha1, old_mode);
4650         fill_filespec(two, new_sha1, new_mode);
4651         one->dirty_submodule = old_dirty_submodule;
4652         two->dirty_submodule = new_dirty_submodule;
4654         diff_queue(&diff_queued_diff, one, two);
4655         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4656                 DIFF_OPT_SET(options, HAS_CHANGES);
4659 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4661         struct diff_filepair *pair;
4662         struct diff_filespec *one, *two;
4664         if (options->prefix &&
4665             strncmp(path, options->prefix, options->prefix_length))
4666                 return NULL;
4668         one = alloc_filespec(path);
4669         two = alloc_filespec(path);
4670         pair = diff_queue(&diff_queued_diff, one, two);
4671         pair->is_unmerged = 1;
4672         return pair;
4675 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4676                 size_t *outsize)
4678         struct diff_tempfile *temp;
4679         const char *argv[3];
4680         const char **arg = argv;
4681         struct child_process child;
4682         struct strbuf buf = STRBUF_INIT;
4683         int err = 0;
4685         temp = prepare_temp_file(spec->path, spec);
4686         *arg++ = pgm;
4687         *arg++ = temp->name;
4688         *arg = NULL;
4690         memset(&child, 0, sizeof(child));
4691         child.use_shell = 1;
4692         child.argv = argv;
4693         child.out = -1;
4694         if (start_command(&child)) {
4695                 remove_tempfile();
4696                 return NULL;
4697         }
4699         if (strbuf_read(&buf, child.out, 0) < 0)
4700                 err = error("error reading from textconv command '%s'", pgm);
4701         close(child.out);
4703         if (finish_command(&child) || err) {
4704                 strbuf_release(&buf);
4705                 remove_tempfile();
4706                 return NULL;
4707         }
4708         remove_tempfile();
4710         return strbuf_detach(&buf, outsize);
4713 size_t fill_textconv(struct userdiff_driver *driver,
4714                      struct diff_filespec *df,
4715                      char **outbuf)
4717         size_t size;
4719         if (!driver || !driver->textconv) {
4720                 if (!DIFF_FILE_VALID(df)) {
4721                         *outbuf = "";
4722                         return 0;
4723                 }
4724                 if (diff_populate_filespec(df, 0))
4725                         die("unable to read files to diff");
4726                 *outbuf = df->data;
4727                 return df->size;
4728         }
4730         if (driver->textconv_cache && df->sha1_valid) {
4731                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4732                                           &size);
4733                 if (*outbuf)
4734                         return size;
4735         }
4737         *outbuf = run_textconv(driver->textconv, df, &size);
4738         if (!*outbuf)
4739                 die("unable to read files to diff");
4741         if (driver->textconv_cache && df->sha1_valid) {
4742                 /* ignore errors, as we might be in a readonly repository */
4743                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4744                                 size);
4745                 /*
4746                  * we could save up changes and flush them all at the end,
4747                  * but we would need an extra call after all diffing is done.
4748                  * Since generating a cache entry is the slow path anyway,
4749                  * this extra overhead probably isn't a big deal.
4750                  */
4751                 notes_cache_write(driver->textconv_cache);
4752         }
4754         return size;