Code

diff --stat: show bars of same length for paths with same amount of changes
[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                 }
1117                 diff_words_flush(ecbdata);
1118                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1119                         emit_line(ecbdata->opt, plain, reset, line, len);
1120                         fputs("~\n", ecbdata->opt->file);
1121                 } else {
1122                         /*
1123                          * Skip the prefix character, if any.  With
1124                          * diff_suppress_blank_empty, there may be
1125                          * none.
1126                          */
1127                         if (line[0] != '\n') {
1128                               line++;
1129                               len--;
1130                         }
1131                         emit_line(ecbdata->opt, plain, reset, line, len);
1132                 }
1133                 return;
1134         }
1136         if (line[0] != '+') {
1137                 const char *color =
1138                         diff_get_color(ecbdata->color_diff,
1139                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1140                 ecbdata->lno_in_preimage++;
1141                 if (line[0] == ' ')
1142                         ecbdata->lno_in_postimage++;
1143                 emit_line(ecbdata->opt, color, reset, line, len);
1144         } else {
1145                 ecbdata->lno_in_postimage++;
1146                 emit_add_line(reset, ecbdata, line + 1, len - 1);
1147         }
1150 static char *pprint_rename(const char *a, const char *b)
1152         const char *old = a;
1153         const char *new = b;
1154         struct strbuf name = STRBUF_INIT;
1155         int pfx_length, sfx_length;
1156         int len_a = strlen(a);
1157         int len_b = strlen(b);
1158         int a_midlen, b_midlen;
1159         int qlen_a = quote_c_style(a, NULL, NULL, 0);
1160         int qlen_b = quote_c_style(b, NULL, NULL, 0);
1162         if (qlen_a || qlen_b) {
1163                 quote_c_style(a, &name, NULL, 0);
1164                 strbuf_addstr(&name, " => ");
1165                 quote_c_style(b, &name, NULL, 0);
1166                 return strbuf_detach(&name, NULL);
1167         }
1169         /* Find common prefix */
1170         pfx_length = 0;
1171         while (*old && *new && *old == *new) {
1172                 if (*old == '/')
1173                         pfx_length = old - a + 1;
1174                 old++;
1175                 new++;
1176         }
1178         /* Find common suffix */
1179         old = a + len_a;
1180         new = b + len_b;
1181         sfx_length = 0;
1182         while (a <= old && b <= new && *old == *new) {
1183                 if (*old == '/')
1184                         sfx_length = len_a - (old - a);
1185                 old--;
1186                 new--;
1187         }
1189         /*
1190          * pfx{mid-a => mid-b}sfx
1191          * {pfx-a => pfx-b}sfx
1192          * pfx{sfx-a => sfx-b}
1193          * name-a => name-b
1194          */
1195         a_midlen = len_a - pfx_length - sfx_length;
1196         b_midlen = len_b - pfx_length - sfx_length;
1197         if (a_midlen < 0)
1198                 a_midlen = 0;
1199         if (b_midlen < 0)
1200                 b_midlen = 0;
1202         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1203         if (pfx_length + sfx_length) {
1204                 strbuf_add(&name, a, pfx_length);
1205                 strbuf_addch(&name, '{');
1206         }
1207         strbuf_add(&name, a + pfx_length, a_midlen);
1208         strbuf_addstr(&name, " => ");
1209         strbuf_add(&name, b + pfx_length, b_midlen);
1210         if (pfx_length + sfx_length) {
1211                 strbuf_addch(&name, '}');
1212                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1213         }
1214         return strbuf_detach(&name, NULL);
1217 struct diffstat_t {
1218         int nr;
1219         int alloc;
1220         struct diffstat_file {
1221                 char *from_name;
1222                 char *name;
1223                 char *print_name;
1224                 unsigned is_unmerged:1;
1225                 unsigned is_binary:1;
1226                 unsigned is_renamed:1;
1227                 uintmax_t added, deleted;
1228         } **files;
1229 };
1231 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1232                                           const char *name_a,
1233                                           const char *name_b)
1235         struct diffstat_file *x;
1236         x = xcalloc(sizeof (*x), 1);
1237         if (diffstat->nr == diffstat->alloc) {
1238                 diffstat->alloc = alloc_nr(diffstat->alloc);
1239                 diffstat->files = xrealloc(diffstat->files,
1240                                 diffstat->alloc * sizeof(x));
1241         }
1242         diffstat->files[diffstat->nr++] = x;
1243         if (name_b) {
1244                 x->from_name = xstrdup(name_a);
1245                 x->name = xstrdup(name_b);
1246                 x->is_renamed = 1;
1247         }
1248         else {
1249                 x->from_name = NULL;
1250                 x->name = xstrdup(name_a);
1251         }
1252         return x;
1255 static void diffstat_consume(void *priv, char *line, unsigned long len)
1257         struct diffstat_t *diffstat = priv;
1258         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1260         if (line[0] == '+')
1261                 x->added++;
1262         else if (line[0] == '-')
1263                 x->deleted++;
1266 const char mime_boundary_leader[] = "------------";
1268 static int scale_linear(int it, int width, int max_change)
1270         if (!it)
1271                 return 0;
1272         /*
1273          * make sure that at least one '-' or '+' is printed if
1274          * there is any change to this path. The easiest way is to
1275          * scale linearly as if the alloted width is one column shorter
1276          * than it is, and then add 1 to the result.
1277          */
1278         return 1 + (it * (width - 1) / max_change);
1281 static void show_name(FILE *file,
1282                       const char *prefix, const char *name, int len)
1284         fprintf(file, " %s%-*s |", prefix, len, name);
1287 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1289         if (cnt <= 0)
1290                 return;
1291         fprintf(file, "%s", set);
1292         while (cnt--)
1293                 putc(ch, file);
1294         fprintf(file, "%s", reset);
1297 static void fill_print_name(struct diffstat_file *file)
1299         char *pname;
1301         if (file->print_name)
1302                 return;
1304         if (!file->is_renamed) {
1305                 struct strbuf buf = STRBUF_INIT;
1306                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1307                         pname = strbuf_detach(&buf, NULL);
1308                 } else {
1309                         pname = file->name;
1310                         strbuf_release(&buf);
1311                 }
1312         } else {
1313                 pname = pprint_rename(file->from_name, file->name);
1314         }
1315         file->print_name = pname;
1318 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1320         int i, len, add, del, adds = 0, dels = 0;
1321         uintmax_t max_change = 0, max_len = 0;
1322         int total_files = data->nr;
1323         int width, name_width, count;
1324         const char *reset, *add_c, *del_c;
1325         const char *line_prefix = "";
1326         int extra_shown = 0;
1327         struct strbuf *msg = NULL;
1329         if (data->nr == 0)
1330                 return;
1332         if (options->output_prefix) {
1333                 msg = options->output_prefix(options, options->output_prefix_data);
1334                 line_prefix = msg->buf;
1335         }
1337         width = options->stat_width ? options->stat_width : 80;
1338         name_width = options->stat_name_width ? options->stat_name_width : 50;
1339         count = options->stat_count ? options->stat_count : data->nr;
1341         /* Sanity: give at least 5 columns to the graph,
1342          * but leave at least 10 columns for the name.
1343          */
1344         if (width < 25)
1345                 width = 25;
1346         if (name_width < 10)
1347                 name_width = 10;
1348         else if (width < name_width + 15)
1349                 name_width = width - 15;
1351         /* Find the longest filename and max number of changes */
1352         reset = diff_get_color_opt(options, DIFF_RESET);
1353         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1354         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1356         for (i = 0; (i < count) && (i < data->nr); i++) {
1357                 struct diffstat_file *file = data->files[i];
1358                 uintmax_t change = file->added + file->deleted;
1359                 if (!data->files[i]->is_renamed &&
1360                          (change == 0)) {
1361                         count++; /* not shown == room for one more */
1362                         continue;
1363                 }
1364                 fill_print_name(file);
1365                 len = strlen(file->print_name);
1366                 if (max_len < len)
1367                         max_len = len;
1369                 if (file->is_binary || file->is_unmerged)
1370                         continue;
1371                 if (max_change < change)
1372                         max_change = change;
1373         }
1374         count = i; /* min(count, data->nr) */
1376         /* Compute the width of the graph part;
1377          * 10 is for one blank at the beginning of the line plus
1378          * " | count " between the name and the graph.
1379          *
1380          * From here on, name_width is the width of the name area,
1381          * and width is the width of the graph area.
1382          */
1383         name_width = (name_width < max_len) ? name_width : max_len;
1384         if (width < (name_width + 10) + max_change)
1385                 width = width - (name_width + 10);
1386         else
1387                 width = max_change;
1389         for (i = 0; i < count; i++) {
1390                 const char *prefix = "";
1391                 char *name = data->files[i]->print_name;
1392                 uintmax_t added = data->files[i]->added;
1393                 uintmax_t deleted = data->files[i]->deleted;
1394                 int name_len;
1396                 if (!data->files[i]->is_renamed &&
1397                          (added + deleted == 0)) {
1398                         total_files--;
1399                         continue;
1400                 }
1401                 /*
1402                  * "scale" the filename
1403                  */
1404                 len = name_width;
1405                 name_len = strlen(name);
1406                 if (name_width < name_len) {
1407                         char *slash;
1408                         prefix = "...";
1409                         len -= 3;
1410                         name += name_len - len;
1411                         slash = strchr(name, '/');
1412                         if (slash)
1413                                 name = slash;
1414                 }
1416                 if (data->files[i]->is_binary) {
1417                         fprintf(options->file, "%s", line_prefix);
1418                         show_name(options->file, prefix, name, len);
1419                         fprintf(options->file, "  Bin ");
1420                         fprintf(options->file, "%s%"PRIuMAX"%s",
1421                                 del_c, deleted, reset);
1422                         fprintf(options->file, " -> ");
1423                         fprintf(options->file, "%s%"PRIuMAX"%s",
1424                                 add_c, added, reset);
1425                         fprintf(options->file, " bytes");
1426                         fprintf(options->file, "\n");
1427                         continue;
1428                 }
1429                 else if (data->files[i]->is_unmerged) {
1430                         fprintf(options->file, "%s", line_prefix);
1431                         show_name(options->file, prefix, name, len);
1432                         fprintf(options->file, "  Unmerged\n");
1433                         continue;
1434                 }
1436                 /*
1437                  * scale the add/delete
1438                  */
1439                 add = added;
1440                 del = deleted;
1441                 adds += add;
1442                 dels += del;
1444                 if (width <= max_change) {
1445                         int total = add + del;
1447                         total = scale_linear(add + del, width, max_change);
1448                         if (total < 2 && add && del)
1449                                 /* width >= 2 due to the sanity check */
1450                                 total = 2;
1451                         if (add < del) {
1452                                 add = scale_linear(add, width, max_change);
1453                                 del = total - add;
1454                         } else {
1455                                 del = scale_linear(del, width, max_change);
1456                                 add = total - del;
1457                         }
1458                 }
1459                 fprintf(options->file, "%s", line_prefix);
1460                 show_name(options->file, prefix, name, len);
1461                 fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1462                                 added + deleted ? " " : "");
1463                 show_graph(options->file, '+', add, add_c, reset);
1464                 show_graph(options->file, '-', del, del_c, reset);
1465                 fprintf(options->file, "\n");
1466         }
1467         for (i = count; i < data->nr; i++) {
1468                 uintmax_t added = data->files[i]->added;
1469                 uintmax_t deleted = data->files[i]->deleted;
1470                 if (!data->files[i]->is_renamed &&
1471                          (added + deleted == 0)) {
1472                         total_files--;
1473                         continue;
1474                 }
1475                 adds += added;
1476                 dels += deleted;
1477                 if (!extra_shown)
1478                         fprintf(options->file, "%s ...\n", line_prefix);
1479                 extra_shown = 1;
1480         }
1481         fprintf(options->file, "%s", line_prefix);
1482         fprintf(options->file,
1483                " %d files changed, %d insertions(+), %d deletions(-)\n",
1484                total_files, adds, dels);
1487 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1489         int i, adds = 0, dels = 0, total_files = data->nr;
1491         if (data->nr == 0)
1492                 return;
1494         for (i = 0; i < data->nr; i++) {
1495                 if (!data->files[i]->is_binary &&
1496                     !data->files[i]->is_unmerged) {
1497                         int added = data->files[i]->added;
1498                         int deleted= data->files[i]->deleted;
1499                         if (!data->files[i]->is_renamed &&
1500                             (added + deleted == 0)) {
1501                                 total_files--;
1502                         } else {
1503                                 adds += added;
1504                                 dels += deleted;
1505                         }
1506                 }
1507         }
1508         if (options->output_prefix) {
1509                 struct strbuf *msg = NULL;
1510                 msg = options->output_prefix(options,
1511                                 options->output_prefix_data);
1512                 fprintf(options->file, "%s", msg->buf);
1513         }
1514         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1515                total_files, adds, dels);
1518 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1520         int i;
1522         if (data->nr == 0)
1523                 return;
1525         for (i = 0; i < data->nr; i++) {
1526                 struct diffstat_file *file = data->files[i];
1528                 if (options->output_prefix) {
1529                         struct strbuf *msg = NULL;
1530                         msg = options->output_prefix(options,
1531                                         options->output_prefix_data);
1532                         fprintf(options->file, "%s", msg->buf);
1533                 }
1535                 if (file->is_binary)
1536                         fprintf(options->file, "-\t-\t");
1537                 else
1538                         fprintf(options->file,
1539                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1540                                 file->added, file->deleted);
1541                 if (options->line_termination) {
1542                         fill_print_name(file);
1543                         if (!file->is_renamed)
1544                                 write_name_quoted(file->name, options->file,
1545                                                   options->line_termination);
1546                         else {
1547                                 fputs(file->print_name, options->file);
1548                                 putc(options->line_termination, options->file);
1549                         }
1550                 } else {
1551                         if (file->is_renamed) {
1552                                 putc('\0', options->file);
1553                                 write_name_quoted(file->from_name, options->file, '\0');
1554                         }
1555                         write_name_quoted(file->name, options->file, '\0');
1556                 }
1557         }
1560 struct dirstat_file {
1561         const char *name;
1562         unsigned long changed;
1563 };
1565 struct dirstat_dir {
1566         struct dirstat_file *files;
1567         int alloc, nr, permille, cumulative;
1568 };
1570 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1571                 unsigned long changed, const char *base, int baselen)
1573         unsigned long this_dir = 0;
1574         unsigned int sources = 0;
1575         const char *line_prefix = "";
1576         struct strbuf *msg = NULL;
1578         if (opt->output_prefix) {
1579                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1580                 line_prefix = msg->buf;
1581         }
1583         while (dir->nr) {
1584                 struct dirstat_file *f = dir->files;
1585                 int namelen = strlen(f->name);
1586                 unsigned long this;
1587                 char *slash;
1589                 if (namelen < baselen)
1590                         break;
1591                 if (memcmp(f->name, base, baselen))
1592                         break;
1593                 slash = strchr(f->name + baselen, '/');
1594                 if (slash) {
1595                         int newbaselen = slash + 1 - f->name;
1596                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1597                         sources++;
1598                 } else {
1599                         this = f->changed;
1600                         dir->files++;
1601                         dir->nr--;
1602                         sources += 2;
1603                 }
1604                 this_dir += this;
1605         }
1607         /*
1608          * We don't report dirstat's for
1609          *  - the top level
1610          *  - or cases where everything came from a single directory
1611          *    under this directory (sources == 1).
1612          */
1613         if (baselen && sources != 1) {
1614                 if (this_dir) {
1615                         int permille = this_dir * 1000 / changed;
1616                         if (permille >= dir->permille) {
1617                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1618                                         permille / 10, permille % 10, baselen, base);
1619                                 if (!dir->cumulative)
1620                                         return 0;
1621                         }
1622                 }
1623         }
1624         return this_dir;
1627 static int dirstat_compare(const void *_a, const void *_b)
1629         const struct dirstat_file *a = _a;
1630         const struct dirstat_file *b = _b;
1631         return strcmp(a->name, b->name);
1634 static void show_dirstat(struct diff_options *options)
1636         int i;
1637         unsigned long changed;
1638         struct dirstat_dir dir;
1639         struct diff_queue_struct *q = &diff_queued_diff;
1641         dir.files = NULL;
1642         dir.alloc = 0;
1643         dir.nr = 0;
1644         dir.permille = options->dirstat_permille;
1645         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1647         changed = 0;
1648         for (i = 0; i < q->nr; i++) {
1649                 struct diff_filepair *p = q->queue[i];
1650                 const char *name;
1651                 unsigned long copied, added, damage;
1652                 int content_changed;
1654                 name = p->two->path ? p->two->path : p->one->path;
1656                 if (p->one->sha1_valid && p->two->sha1_valid)
1657                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1658                 else
1659                         content_changed = 1;
1661                 if (!content_changed) {
1662                         /*
1663                          * The SHA1 has not changed, so pre-/post-content is
1664                          * identical. We can therefore skip looking at the
1665                          * file contents altogether.
1666                          */
1667                         damage = 0;
1668                         goto found_damage;
1669                 }
1671                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1672                         /*
1673                          * In --dirstat-by-file mode, we don't really need to
1674                          * look at the actual file contents at all.
1675                          * The fact that the SHA1 changed is enough for us to
1676                          * add this file to the list of results
1677                          * (with each file contributing equal damage).
1678                          */
1679                         damage = 1;
1680                         goto found_damage;
1681                 }
1683                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1684                         diff_populate_filespec(p->one, 0);
1685                         diff_populate_filespec(p->two, 0);
1686                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1687                                                &copied, &added);
1688                         diff_free_filespec_data(p->one);
1689                         diff_free_filespec_data(p->two);
1690                 } else if (DIFF_FILE_VALID(p->one)) {
1691                         diff_populate_filespec(p->one, 1);
1692                         copied = added = 0;
1693                         diff_free_filespec_data(p->one);
1694                 } else if (DIFF_FILE_VALID(p->two)) {
1695                         diff_populate_filespec(p->two, 1);
1696                         copied = 0;
1697                         added = p->two->size;
1698                         diff_free_filespec_data(p->two);
1699                 } else
1700                         continue;
1702                 /*
1703                  * Original minus copied is the removed material,
1704                  * added is the new material.  They are both damages
1705                  * made to the preimage.
1706                  * If the resulting damage is zero, we know that
1707                  * diffcore_count_changes() considers the two entries to
1708                  * be identical, but since content_changed is true, we
1709                  * know that there must have been _some_ kind of change,
1710                  * so we force all entries to have damage > 0.
1711                  */
1712                 damage = (p->one->size - copied) + added;
1713                 if (!damage)
1714                         damage = 1;
1716 found_damage:
1717                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1718                 dir.files[dir.nr].name = name;
1719                 dir.files[dir.nr].changed = damage;
1720                 changed += damage;
1721                 dir.nr++;
1722         }
1724         /* This can happen even with many files, if everything was renames */
1725         if (!changed)
1726                 return;
1728         /* Show all directories with more than x% of the changes */
1729         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1730         gather_dirstat(options, &dir, changed, "", 0);
1733 static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1735         int i;
1736         unsigned long changed;
1737         struct dirstat_dir dir;
1739         if (data->nr == 0)
1740                 return;
1742         dir.files = NULL;
1743         dir.alloc = 0;
1744         dir.nr = 0;
1745         dir.permille = options->dirstat_permille;
1746         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1748         changed = 0;
1749         for (i = 0; i < data->nr; i++) {
1750                 struct diffstat_file *file = data->files[i];
1751                 unsigned long damage = file->added + file->deleted;
1752                 if (file->is_binary)
1753                         /*
1754                          * binary files counts bytes, not lines. Must find some
1755                          * way to normalize binary bytes vs. textual lines.
1756                          * The following heuristic assumes that there are 64
1757                          * bytes per "line".
1758                          * This is stupid and ugly, but very cheap...
1759                          */
1760                         damage = (damage + 63) / 64;
1761                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1762                 dir.files[dir.nr].name = file->name;
1763                 dir.files[dir.nr].changed = damage;
1764                 changed += damage;
1765                 dir.nr++;
1766         }
1768         /* This can happen even with many files, if everything was renames */
1769         if (!changed)
1770                 return;
1772         /* Show all directories with more than x% of the changes */
1773         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1774         gather_dirstat(options, &dir, changed, "", 0);
1777 static void free_diffstat_info(struct diffstat_t *diffstat)
1779         int i;
1780         for (i = 0; i < diffstat->nr; i++) {
1781                 struct diffstat_file *f = diffstat->files[i];
1782                 if (f->name != f->print_name)
1783                         free(f->print_name);
1784                 free(f->name);
1785                 free(f->from_name);
1786                 free(f);
1787         }
1788         free(diffstat->files);
1791 struct checkdiff_t {
1792         const char *filename;
1793         int lineno;
1794         int conflict_marker_size;
1795         struct diff_options *o;
1796         unsigned ws_rule;
1797         unsigned status;
1798 };
1800 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1802         char firstchar;
1803         int cnt;
1805         if (len < marker_size + 1)
1806                 return 0;
1807         firstchar = line[0];
1808         switch (firstchar) {
1809         case '=': case '>': case '<': case '|':
1810                 break;
1811         default:
1812                 return 0;
1813         }
1814         for (cnt = 1; cnt < marker_size; cnt++)
1815                 if (line[cnt] != firstchar)
1816                         return 0;
1817         /* line[1] thru line[marker_size-1] are same as firstchar */
1818         if (len < marker_size + 1 || !isspace(line[marker_size]))
1819                 return 0;
1820         return 1;
1823 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1825         struct checkdiff_t *data = priv;
1826         int marker_size = data->conflict_marker_size;
1827         const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1828         const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1829         const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1830         char *err;
1831         char *line_prefix = "";
1832         struct strbuf *msgbuf;
1834         assert(data->o);
1835         if (data->o->output_prefix) {
1836                 msgbuf = data->o->output_prefix(data->o,
1837                         data->o->output_prefix_data);
1838                 line_prefix = msgbuf->buf;
1839         }
1841         if (line[0] == '+') {
1842                 unsigned bad;
1843                 data->lineno++;
1844                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1845                         data->status |= 1;
1846                         fprintf(data->o->file,
1847                                 "%s%s:%d: leftover conflict marker\n",
1848                                 line_prefix, data->filename, data->lineno);
1849                 }
1850                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1851                 if (!bad)
1852                         return;
1853                 data->status |= bad;
1854                 err = whitespace_error_string(bad);
1855                 fprintf(data->o->file, "%s%s:%d: %s.\n",
1856                         line_prefix, data->filename, data->lineno, err);
1857                 free(err);
1858                 emit_line(data->o, set, reset, line, 1);
1859                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1860                               data->o->file, set, reset, ws);
1861         } else if (line[0] == ' ') {
1862                 data->lineno++;
1863         } else if (line[0] == '@') {
1864                 char *plus = strchr(line, '+');
1865                 if (plus)
1866                         data->lineno = strtol(plus, NULL, 10) - 1;
1867                 else
1868                         die("invalid diff");
1869         }
1872 static unsigned char *deflate_it(char *data,
1873                                  unsigned long size,
1874                                  unsigned long *result_size)
1876         int bound;
1877         unsigned char *deflated;
1878         git_zstream stream;
1880         memset(&stream, 0, sizeof(stream));
1881         git_deflate_init(&stream, zlib_compression_level);
1882         bound = git_deflate_bound(&stream, size);
1883         deflated = xmalloc(bound);
1884         stream.next_out = deflated;
1885         stream.avail_out = bound;
1887         stream.next_in = (unsigned char *)data;
1888         stream.avail_in = size;
1889         while (git_deflate(&stream, Z_FINISH) == Z_OK)
1890                 ; /* nothing */
1891         git_deflate_end(&stream);
1892         *result_size = stream.total_out;
1893         return deflated;
1896 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1898         void *cp;
1899         void *delta;
1900         void *deflated;
1901         void *data;
1902         unsigned long orig_size;
1903         unsigned long delta_size;
1904         unsigned long deflate_size;
1905         unsigned long data_size;
1907         /* We could do deflated delta, or we could do just deflated two,
1908          * whichever is smaller.
1909          */
1910         delta = NULL;
1911         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1912         if (one->size && two->size) {
1913                 delta = diff_delta(one->ptr, one->size,
1914                                    two->ptr, two->size,
1915                                    &delta_size, deflate_size);
1916                 if (delta) {
1917                         void *to_free = delta;
1918                         orig_size = delta_size;
1919                         delta = deflate_it(delta, delta_size, &delta_size);
1920                         free(to_free);
1921                 }
1922         }
1924         if (delta && delta_size < deflate_size) {
1925                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1926                 free(deflated);
1927                 data = delta;
1928                 data_size = delta_size;
1929         }
1930         else {
1931                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
1932                 free(delta);
1933                 data = deflated;
1934                 data_size = deflate_size;
1935         }
1937         /* emit data encoded in base85 */
1938         cp = data;
1939         while (data_size) {
1940                 int bytes = (52 < data_size) ? 52 : data_size;
1941                 char line[70];
1942                 data_size -= bytes;
1943                 if (bytes <= 26)
1944                         line[0] = bytes + 'A' - 1;
1945                 else
1946                         line[0] = bytes - 26 + 'a' - 1;
1947                 encode_85(line + 1, cp, bytes);
1948                 cp = (char *) cp + bytes;
1949                 fprintf(file, "%s", prefix);
1950                 fputs(line, file);
1951                 fputc('\n', file);
1952         }
1953         fprintf(file, "%s\n", prefix);
1954         free(data);
1957 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1959         fprintf(file, "%sGIT binary patch\n", prefix);
1960         emit_binary_diff_body(file, one, two, prefix);
1961         emit_binary_diff_body(file, two, one, prefix);
1964 static void diff_filespec_load_driver(struct diff_filespec *one)
1966         /* Use already-loaded driver */
1967         if (one->driver)
1968                 return;
1970         if (S_ISREG(one->mode))
1971                 one->driver = userdiff_find_by_path(one->path);
1973         /* Fallback to default settings */
1974         if (!one->driver)
1975                 one->driver = userdiff_find_by_name("default");
1978 int diff_filespec_is_binary(struct diff_filespec *one)
1980         if (one->is_binary == -1) {
1981                 diff_filespec_load_driver(one);
1982                 if (one->driver->binary != -1)
1983                         one->is_binary = one->driver->binary;
1984                 else {
1985                         if (!one->data && DIFF_FILE_VALID(one))
1986                                 diff_populate_filespec(one, 0);
1987                         if (one->data)
1988                                 one->is_binary = buffer_is_binary(one->data,
1989                                                 one->size);
1990                         if (one->is_binary == -1)
1991                                 one->is_binary = 0;
1992                 }
1993         }
1994         return one->is_binary;
1997 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1999         diff_filespec_load_driver(one);
2000         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2003 static const char *userdiff_word_regex(struct diff_filespec *one)
2005         diff_filespec_load_driver(one);
2006         return one->driver->word_regex;
2009 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2011         if (!options->a_prefix)
2012                 options->a_prefix = a;
2013         if (!options->b_prefix)
2014                 options->b_prefix = b;
2017 struct userdiff_driver *get_textconv(struct diff_filespec *one)
2019         if (!DIFF_FILE_VALID(one))
2020                 return NULL;
2022         diff_filespec_load_driver(one);
2023         return userdiff_get_textconv(one->driver);
2026 static void builtin_diff(const char *name_a,
2027                          const char *name_b,
2028                          struct diff_filespec *one,
2029                          struct diff_filespec *two,
2030                          const char *xfrm_msg,
2031                          int must_show_header,
2032                          struct diff_options *o,
2033                          int complete_rewrite)
2035         mmfile_t mf1, mf2;
2036         const char *lbl[2];
2037         char *a_one, *b_two;
2038         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2039         const char *reset = diff_get_color_opt(o, DIFF_RESET);
2040         const char *a_prefix, *b_prefix;
2041         struct userdiff_driver *textconv_one = NULL;
2042         struct userdiff_driver *textconv_two = NULL;
2043         struct strbuf header = STRBUF_INIT;
2044         struct strbuf *msgbuf;
2045         char *line_prefix = "";
2047         if (o->output_prefix) {
2048                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2049                 line_prefix = msgbuf->buf;
2050         }
2052         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2053                         (!one->mode || S_ISGITLINK(one->mode)) &&
2054                         (!two->mode || S_ISGITLINK(two->mode))) {
2055                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2056                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2057                 show_submodule_summary(o->file, one ? one->path : two->path,
2058                                 one->sha1, two->sha1, two->dirty_submodule,
2059                                 del, add, reset);
2060                 return;
2061         }
2063         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2064                 textconv_one = get_textconv(one);
2065                 textconv_two = get_textconv(two);
2066         }
2068         diff_set_mnemonic_prefix(o, "a/", "b/");
2069         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2070                 a_prefix = o->b_prefix;
2071                 b_prefix = o->a_prefix;
2072         } else {
2073                 a_prefix = o->a_prefix;
2074                 b_prefix = o->b_prefix;
2075         }
2077         /* Never use a non-valid filename anywhere if at all possible */
2078         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2079         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2081         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2082         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2083         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2084         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2085         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2086         if (lbl[0][0] == '/') {
2087                 /* /dev/null */
2088                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2089                 if (xfrm_msg)
2090                         strbuf_addstr(&header, xfrm_msg);
2091                 must_show_header = 1;
2092         }
2093         else if (lbl[1][0] == '/') {
2094                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2095                 if (xfrm_msg)
2096                         strbuf_addstr(&header, xfrm_msg);
2097                 must_show_header = 1;
2098         }
2099         else {
2100                 if (one->mode != two->mode) {
2101                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2102                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2103                         must_show_header = 1;
2104                 }
2105                 if (xfrm_msg)
2106                         strbuf_addstr(&header, xfrm_msg);
2108                 /*
2109                  * we do not run diff between different kind
2110                  * of objects.
2111                  */
2112                 if ((one->mode ^ two->mode) & S_IFMT)
2113                         goto free_ab_and_return;
2114                 if (complete_rewrite &&
2115                     (textconv_one || !diff_filespec_is_binary(one)) &&
2116                     (textconv_two || !diff_filespec_is_binary(two))) {
2117                         fprintf(o->file, "%s", header.buf);
2118                         strbuf_reset(&header);
2119                         emit_rewrite_diff(name_a, name_b, one, two,
2120                                                 textconv_one, textconv_two, o);
2121                         o->found_changes = 1;
2122                         goto free_ab_and_return;
2123                 }
2124         }
2126         if (o->irreversible_delete && lbl[1][0] == '/') {
2127                 fprintf(o->file, "%s", header.buf);
2128                 strbuf_reset(&header);
2129                 goto free_ab_and_return;
2130         } else if (!DIFF_OPT_TST(o, TEXT) &&
2131             ( (!textconv_one && diff_filespec_is_binary(one)) ||
2132               (!textconv_two && diff_filespec_is_binary(two)) )) {
2133                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2134                         die("unable to read files to diff");
2135                 /* Quite common confusing case */
2136                 if (mf1.size == mf2.size &&
2137                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2138                         if (must_show_header)
2139                                 fprintf(o->file, "%s", header.buf);
2140                         goto free_ab_and_return;
2141                 }
2142                 fprintf(o->file, "%s", header.buf);
2143                 strbuf_reset(&header);
2144                 if (DIFF_OPT_TST(o, BINARY))
2145                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2146                 else
2147                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2148                                 line_prefix, lbl[0], lbl[1]);
2149                 o->found_changes = 1;
2150         } else {
2151                 /* Crazy xdl interfaces.. */
2152                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2153                 xpparam_t xpp;
2154                 xdemitconf_t xecfg;
2155                 struct emit_callback ecbdata;
2156                 const struct userdiff_funcname *pe;
2158                 if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2159                         fprintf(o->file, "%s", header.buf);
2160                         strbuf_reset(&header);
2161                 }
2163                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2164                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2166                 pe = diff_funcname_pattern(one);
2167                 if (!pe)
2168                         pe = diff_funcname_pattern(two);
2170                 memset(&xpp, 0, sizeof(xpp));
2171                 memset(&xecfg, 0, sizeof(xecfg));
2172                 memset(&ecbdata, 0, sizeof(ecbdata));
2173                 ecbdata.label_path = lbl;
2174                 ecbdata.color_diff = want_color(o->use_color);
2175                 ecbdata.found_changesp = &o->found_changes;
2176                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2177                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2178                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2179                 ecbdata.opt = o;
2180                 ecbdata.header = header.len ? &header : NULL;
2181                 xpp.flags = o->xdl_opts;
2182                 xecfg.ctxlen = o->context;
2183                 xecfg.interhunkctxlen = o->interhunkcontext;
2184                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2185                 if (DIFF_OPT_TST(o, FUNCCONTEXT))
2186                         xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2187                 if (pe)
2188                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2189                 if (!diffopts)
2190                         ;
2191                 else if (!prefixcmp(diffopts, "--unified="))
2192                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2193                 else if (!prefixcmp(diffopts, "-u"))
2194                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2195                 if (o->word_diff) {
2196                         int i;
2198                         ecbdata.diff_words =
2199                                 xcalloc(1, sizeof(struct diff_words_data));
2200                         ecbdata.diff_words->type = o->word_diff;
2201                         ecbdata.diff_words->opt = o;
2202                         if (!o->word_regex)
2203                                 o->word_regex = userdiff_word_regex(one);
2204                         if (!o->word_regex)
2205                                 o->word_regex = userdiff_word_regex(two);
2206                         if (!o->word_regex)
2207                                 o->word_regex = diff_word_regex_cfg;
2208                         if (o->word_regex) {
2209                                 ecbdata.diff_words->word_regex = (regex_t *)
2210                                         xmalloc(sizeof(regex_t));
2211                                 if (regcomp(ecbdata.diff_words->word_regex,
2212                                                 o->word_regex,
2213                                                 REG_EXTENDED | REG_NEWLINE))
2214                                         die ("Invalid regular expression: %s",
2215                                                         o->word_regex);
2216                         }
2217                         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2218                                 if (o->word_diff == diff_words_styles[i].type) {
2219                                         ecbdata.diff_words->style =
2220                                                 &diff_words_styles[i];
2221                                         break;
2222                                 }
2223                         }
2224                         if (want_color(o->use_color)) {
2225                                 struct diff_words_style *st = ecbdata.diff_words->style;
2226                                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2227                                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2228                                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2229                         }
2230                 }
2231                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2232                               &xpp, &xecfg);
2233                 if (o->word_diff)
2234                         free_diff_words_data(&ecbdata);
2235                 if (textconv_one)
2236                         free(mf1.ptr);
2237                 if (textconv_two)
2238                         free(mf2.ptr);
2239                 xdiff_clear_find_func(&xecfg);
2240         }
2242  free_ab_and_return:
2243         strbuf_release(&header);
2244         diff_free_filespec_data(one);
2245         diff_free_filespec_data(two);
2246         free(a_one);
2247         free(b_two);
2248         return;
2251 static void builtin_diffstat(const char *name_a, const char *name_b,
2252                              struct diff_filespec *one,
2253                              struct diff_filespec *two,
2254                              struct diffstat_t *diffstat,
2255                              struct diff_options *o,
2256                              int complete_rewrite)
2258         mmfile_t mf1, mf2;
2259         struct diffstat_file *data;
2261         data = diffstat_add(diffstat, name_a, name_b);
2263         if (!one || !two) {
2264                 data->is_unmerged = 1;
2265                 return;
2266         }
2268         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2269                 data->is_binary = 1;
2270                 data->added = diff_filespec_size(two);
2271                 data->deleted = diff_filespec_size(one);
2272         }
2274         else if (complete_rewrite) {
2275                 diff_populate_filespec(one, 0);
2276                 diff_populate_filespec(two, 0);
2277                 data->deleted = count_lines(one->data, one->size);
2278                 data->added = count_lines(two->data, two->size);
2279         }
2281         else {
2282                 /* Crazy xdl interfaces.. */
2283                 xpparam_t xpp;
2284                 xdemitconf_t xecfg;
2286                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2287                         die("unable to read files to diff");
2289                 memset(&xpp, 0, sizeof(xpp));
2290                 memset(&xecfg, 0, sizeof(xecfg));
2291                 xpp.flags = o->xdl_opts;
2292                 xecfg.ctxlen = o->context;
2293                 xecfg.interhunkctxlen = o->interhunkcontext;
2294                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2295                               &xpp, &xecfg);
2296         }
2298         diff_free_filespec_data(one);
2299         diff_free_filespec_data(two);
2302 static void builtin_checkdiff(const char *name_a, const char *name_b,
2303                               const char *attr_path,
2304                               struct diff_filespec *one,
2305                               struct diff_filespec *two,
2306                               struct diff_options *o)
2308         mmfile_t mf1, mf2;
2309         struct checkdiff_t data;
2311         if (!two)
2312                 return;
2314         memset(&data, 0, sizeof(data));
2315         data.filename = name_b ? name_b : name_a;
2316         data.lineno = 0;
2317         data.o = o;
2318         data.ws_rule = whitespace_rule(attr_path);
2319         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2321         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2322                 die("unable to read files to diff");
2324         /*
2325          * All the other codepaths check both sides, but not checking
2326          * the "old" side here is deliberate.  We are checking the newly
2327          * introduced changes, and as long as the "new" side is text, we
2328          * can and should check what it introduces.
2329          */
2330         if (diff_filespec_is_binary(two))
2331                 goto free_and_return;
2332         else {
2333                 /* Crazy xdl interfaces.. */
2334                 xpparam_t xpp;
2335                 xdemitconf_t xecfg;
2337                 memset(&xpp, 0, sizeof(xpp));
2338                 memset(&xecfg, 0, sizeof(xecfg));
2339                 xecfg.ctxlen = 1; /* at least one context line */
2340                 xpp.flags = 0;
2341                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2342                               &xpp, &xecfg);
2344                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2345                         struct emit_callback ecbdata;
2346                         int blank_at_eof;
2348                         ecbdata.ws_rule = data.ws_rule;
2349                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2350                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2352                         if (blank_at_eof) {
2353                                 static char *err;
2354                                 if (!err)
2355                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2356                                 fprintf(o->file, "%s:%d: %s.\n",
2357                                         data.filename, blank_at_eof, err);
2358                                 data.status = 1; /* report errors */
2359                         }
2360                 }
2361         }
2362  free_and_return:
2363         diff_free_filespec_data(one);
2364         diff_free_filespec_data(two);
2365         if (data.status)
2366                 DIFF_OPT_SET(o, CHECK_FAILED);
2369 struct diff_filespec *alloc_filespec(const char *path)
2371         int namelen = strlen(path);
2372         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2374         memset(spec, 0, sizeof(*spec));
2375         spec->path = (char *)(spec + 1);
2376         memcpy(spec->path, path, namelen+1);
2377         spec->count = 1;
2378         spec->is_binary = -1;
2379         return spec;
2382 void free_filespec(struct diff_filespec *spec)
2384         if (!--spec->count) {
2385                 diff_free_filespec_data(spec);
2386                 free(spec);
2387         }
2390 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2391                    unsigned short mode)
2393         if (mode) {
2394                 spec->mode = canon_mode(mode);
2395                 hashcpy(spec->sha1, sha1);
2396                 spec->sha1_valid = !is_null_sha1(sha1);
2397         }
2400 /*
2401  * Given a name and sha1 pair, if the index tells us the file in
2402  * the work tree has that object contents, return true, so that
2403  * prepare_temp_file() does not have to inflate and extract.
2404  */
2405 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2407         struct cache_entry *ce;
2408         struct stat st;
2409         int pos, len;
2411         /*
2412          * We do not read the cache ourselves here, because the
2413          * benchmark with my previous version that always reads cache
2414          * shows that it makes things worse for diff-tree comparing
2415          * two linux-2.6 kernel trees in an already checked out work
2416          * tree.  This is because most diff-tree comparisons deal with
2417          * only a small number of files, while reading the cache is
2418          * expensive for a large project, and its cost outweighs the
2419          * savings we get by not inflating the object to a temporary
2420          * file.  Practically, this code only helps when we are used
2421          * by diff-cache --cached, which does read the cache before
2422          * calling us.
2423          */
2424         if (!active_cache)
2425                 return 0;
2427         /* We want to avoid the working directory if our caller
2428          * doesn't need the data in a normal file, this system
2429          * is rather slow with its stat/open/mmap/close syscalls,
2430          * and the object is contained in a pack file.  The pack
2431          * is probably already open and will be faster to obtain
2432          * the data through than the working directory.  Loose
2433          * objects however would tend to be slower as they need
2434          * to be individually opened and inflated.
2435          */
2436         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2437                 return 0;
2439         len = strlen(name);
2440         pos = cache_name_pos(name, len);
2441         if (pos < 0)
2442                 return 0;
2443         ce = active_cache[pos];
2445         /*
2446          * This is not the sha1 we are looking for, or
2447          * unreusable because it is not a regular file.
2448          */
2449         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2450                 return 0;
2452         /*
2453          * If ce is marked as "assume unchanged", there is no
2454          * guarantee that work tree matches what we are looking for.
2455          */
2456         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2457                 return 0;
2459         /*
2460          * If ce matches the file in the work tree, we can reuse it.
2461          */
2462         if (ce_uptodate(ce) ||
2463             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2464                 return 1;
2466         return 0;
2469 static int populate_from_stdin(struct diff_filespec *s)
2471         struct strbuf buf = STRBUF_INIT;
2472         size_t size = 0;
2474         if (strbuf_read(&buf, 0, 0) < 0)
2475                 return error("error while reading from stdin %s",
2476                                      strerror(errno));
2478         s->should_munmap = 0;
2479         s->data = strbuf_detach(&buf, &size);
2480         s->size = size;
2481         s->should_free = 1;
2482         return 0;
2485 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2487         int len;
2488         char *data = xmalloc(100), *dirty = "";
2490         /* Are we looking at the work tree? */
2491         if (s->dirty_submodule)
2492                 dirty = "-dirty";
2494         len = snprintf(data, 100,
2495                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2496         s->data = data;
2497         s->size = len;
2498         s->should_free = 1;
2499         if (size_only) {
2500                 s->data = NULL;
2501                 free(data);
2502         }
2503         return 0;
2506 /*
2507  * While doing rename detection and pickaxe operation, we may need to
2508  * grab the data for the blob (or file) for our own in-core comparison.
2509  * diff_filespec has data and size fields for this purpose.
2510  */
2511 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2513         int err = 0;
2514         if (!DIFF_FILE_VALID(s))
2515                 die("internal error: asking to populate invalid file.");
2516         if (S_ISDIR(s->mode))
2517                 return -1;
2519         if (s->data)
2520                 return 0;
2522         if (size_only && 0 < s->size)
2523                 return 0;
2525         if (S_ISGITLINK(s->mode))
2526                 return diff_populate_gitlink(s, size_only);
2528         if (!s->sha1_valid ||
2529             reuse_worktree_file(s->path, s->sha1, 0)) {
2530                 struct strbuf buf = STRBUF_INIT;
2531                 struct stat st;
2532                 int fd;
2534                 if (!strcmp(s->path, "-"))
2535                         return populate_from_stdin(s);
2537                 if (lstat(s->path, &st) < 0) {
2538                         if (errno == ENOENT) {
2539                         err_empty:
2540                                 err = -1;
2541                         empty:
2542                                 s->data = (char *)"";
2543                                 s->size = 0;
2544                                 return err;
2545                         }
2546                 }
2547                 s->size = xsize_t(st.st_size);
2548                 if (!s->size)
2549                         goto empty;
2550                 if (S_ISLNK(st.st_mode)) {
2551                         struct strbuf sb = STRBUF_INIT;
2553                         if (strbuf_readlink(&sb, s->path, s->size))
2554                                 goto err_empty;
2555                         s->size = sb.len;
2556                         s->data = strbuf_detach(&sb, NULL);
2557                         s->should_free = 1;
2558                         return 0;
2559                 }
2560                 if (size_only)
2561                         return 0;
2562                 fd = open(s->path, O_RDONLY);
2563                 if (fd < 0)
2564                         goto err_empty;
2565                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2566                 close(fd);
2567                 s->should_munmap = 1;
2569                 /*
2570                  * Convert from working tree format to canonical git format
2571                  */
2572                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2573                         size_t size = 0;
2574                         munmap(s->data, s->size);
2575                         s->should_munmap = 0;
2576                         s->data = strbuf_detach(&buf, &size);
2577                         s->size = size;
2578                         s->should_free = 1;
2579                 }
2580         }
2581         else {
2582                 enum object_type type;
2583                 if (size_only) {
2584                         type = sha1_object_info(s->sha1, &s->size);
2585                         if (type < 0)
2586                                 die("unable to read %s", sha1_to_hex(s->sha1));
2587                 } else {
2588                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2589                         if (!s->data)
2590                                 die("unable to read %s", sha1_to_hex(s->sha1));
2591                         s->should_free = 1;
2592                 }
2593         }
2594         return 0;
2597 void diff_free_filespec_blob(struct diff_filespec *s)
2599         if (s->should_free)
2600                 free(s->data);
2601         else if (s->should_munmap)
2602                 munmap(s->data, s->size);
2604         if (s->should_free || s->should_munmap) {
2605                 s->should_free = s->should_munmap = 0;
2606                 s->data = NULL;
2607         }
2610 void diff_free_filespec_data(struct diff_filespec *s)
2612         diff_free_filespec_blob(s);
2613         free(s->cnt_data);
2614         s->cnt_data = NULL;
2617 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2618                            void *blob,
2619                            unsigned long size,
2620                            const unsigned char *sha1,
2621                            int mode)
2623         int fd;
2624         struct strbuf buf = STRBUF_INIT;
2625         struct strbuf template = STRBUF_INIT;
2626         char *path_dup = xstrdup(path);
2627         const char *base = basename(path_dup);
2629         /* Generate "XXXXXX_basename.ext" */
2630         strbuf_addstr(&template, "XXXXXX_");
2631         strbuf_addstr(&template, base);
2633         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2634                         strlen(base) + 1);
2635         if (fd < 0)
2636                 die_errno("unable to create temp-file");
2637         if (convert_to_working_tree(path,
2638                         (const char *)blob, (size_t)size, &buf)) {
2639                 blob = buf.buf;
2640                 size = buf.len;
2641         }
2642         if (write_in_full(fd, blob, size) != size)
2643                 die_errno("unable to write temp-file");
2644         close(fd);
2645         temp->name = temp->tmp_path;
2646         strcpy(temp->hex, sha1_to_hex(sha1));
2647         temp->hex[40] = 0;
2648         sprintf(temp->mode, "%06o", mode);
2649         strbuf_release(&buf);
2650         strbuf_release(&template);
2651         free(path_dup);
2654 static struct diff_tempfile *prepare_temp_file(const char *name,
2655                 struct diff_filespec *one)
2657         struct diff_tempfile *temp = claim_diff_tempfile();
2659         if (!DIFF_FILE_VALID(one)) {
2660         not_a_valid_file:
2661                 /* A '-' entry produces this for file-2, and
2662                  * a '+' entry produces this for file-1.
2663                  */
2664                 temp->name = "/dev/null";
2665                 strcpy(temp->hex, ".");
2666                 strcpy(temp->mode, ".");
2667                 return temp;
2668         }
2670         if (!remove_tempfile_installed) {
2671                 atexit(remove_tempfile);
2672                 sigchain_push_common(remove_tempfile_on_signal);
2673                 remove_tempfile_installed = 1;
2674         }
2676         if (!one->sha1_valid ||
2677             reuse_worktree_file(name, one->sha1, 1)) {
2678                 struct stat st;
2679                 if (lstat(name, &st) < 0) {
2680                         if (errno == ENOENT)
2681                                 goto not_a_valid_file;
2682                         die_errno("stat(%s)", name);
2683                 }
2684                 if (S_ISLNK(st.st_mode)) {
2685                         struct strbuf sb = STRBUF_INIT;
2686                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2687                                 die_errno("readlink(%s)", name);
2688                         prep_temp_blob(name, temp, sb.buf, sb.len,
2689                                        (one->sha1_valid ?
2690                                         one->sha1 : null_sha1),
2691                                        (one->sha1_valid ?
2692                                         one->mode : S_IFLNK));
2693                         strbuf_release(&sb);
2694                 }
2695                 else {
2696                         /* we can borrow from the file in the work tree */
2697                         temp->name = name;
2698                         if (!one->sha1_valid)
2699                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2700                         else
2701                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2702                         /* Even though we may sometimes borrow the
2703                          * contents from the work tree, we always want
2704                          * one->mode.  mode is trustworthy even when
2705                          * !(one->sha1_valid), as long as
2706                          * DIFF_FILE_VALID(one).
2707                          */
2708                         sprintf(temp->mode, "%06o", one->mode);
2709                 }
2710                 return temp;
2711         }
2712         else {
2713                 if (diff_populate_filespec(one, 0))
2714                         die("cannot read data blob for %s", one->path);
2715                 prep_temp_blob(name, temp, one->data, one->size,
2716                                one->sha1, one->mode);
2717         }
2718         return temp;
2721 /* An external diff command takes:
2722  *
2723  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2724  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2725  *
2726  */
2727 static void run_external_diff(const char *pgm,
2728                               const char *name,
2729                               const char *other,
2730                               struct diff_filespec *one,
2731                               struct diff_filespec *two,
2732                               const char *xfrm_msg,
2733                               int complete_rewrite)
2735         const char *spawn_arg[10];
2736         int retval;
2737         const char **arg = &spawn_arg[0];
2739         if (one && two) {
2740                 struct diff_tempfile *temp_one, *temp_two;
2741                 const char *othername = (other ? other : name);
2742                 temp_one = prepare_temp_file(name, one);
2743                 temp_two = prepare_temp_file(othername, two);
2744                 *arg++ = pgm;
2745                 *arg++ = name;
2746                 *arg++ = temp_one->name;
2747                 *arg++ = temp_one->hex;
2748                 *arg++ = temp_one->mode;
2749                 *arg++ = temp_two->name;
2750                 *arg++ = temp_two->hex;
2751                 *arg++ = temp_two->mode;
2752                 if (other) {
2753                         *arg++ = other;
2754                         *arg++ = xfrm_msg;
2755                 }
2756         } else {
2757                 *arg++ = pgm;
2758                 *arg++ = name;
2759         }
2760         *arg = NULL;
2761         fflush(NULL);
2762         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2763         remove_tempfile();
2764         if (retval) {
2765                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2766                 exit(1);
2767         }
2770 static int similarity_index(struct diff_filepair *p)
2772         return p->score * 100 / MAX_SCORE;
2775 static void fill_metainfo(struct strbuf *msg,
2776                           const char *name,
2777                           const char *other,
2778                           struct diff_filespec *one,
2779                           struct diff_filespec *two,
2780                           struct diff_options *o,
2781                           struct diff_filepair *p,
2782                           int *must_show_header,
2783                           int use_color)
2785         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2786         const char *reset = diff_get_color(use_color, DIFF_RESET);
2787         struct strbuf *msgbuf;
2788         char *line_prefix = "";
2790         *must_show_header = 1;
2791         if (o->output_prefix) {
2792                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2793                 line_prefix = msgbuf->buf;
2794         }
2795         strbuf_init(msg, PATH_MAX * 2 + 300);
2796         switch (p->status) {
2797         case DIFF_STATUS_COPIED:
2798                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2799                             line_prefix, set, similarity_index(p));
2800                 strbuf_addf(msg, "%s\n%s%scopy from ",
2801                             reset,  line_prefix, set);
2802                 quote_c_style(name, msg, NULL, 0);
2803                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2804                 quote_c_style(other, msg, NULL, 0);
2805                 strbuf_addf(msg, "%s\n", reset);
2806                 break;
2807         case DIFF_STATUS_RENAMED:
2808                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2809                             line_prefix, set, similarity_index(p));
2810                 strbuf_addf(msg, "%s\n%s%srename from ",
2811                             reset, line_prefix, set);
2812                 quote_c_style(name, msg, NULL, 0);
2813                 strbuf_addf(msg, "%s\n%s%srename to ",
2814                             reset, line_prefix, set);
2815                 quote_c_style(other, msg, NULL, 0);
2816                 strbuf_addf(msg, "%s\n", reset);
2817                 break;
2818         case DIFF_STATUS_MODIFIED:
2819                 if (p->score) {
2820                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2821                                     line_prefix,
2822                                     set, similarity_index(p), reset);
2823                         break;
2824                 }
2825                 /* fallthru */
2826         default:
2827                 *must_show_header = 0;
2828         }
2829         if (one && two && hashcmp(one->sha1, two->sha1)) {
2830                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2832                 if (DIFF_OPT_TST(o, BINARY)) {
2833                         mmfile_t mf;
2834                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2835                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2836                                 abbrev = 40;
2837                 }
2838                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2839                             find_unique_abbrev(one->sha1, abbrev));
2840                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2841                 if (one->mode == two->mode)
2842                         strbuf_addf(msg, " %06o", one->mode);
2843                 strbuf_addf(msg, "%s\n", reset);
2844         }
2847 static void run_diff_cmd(const char *pgm,
2848                          const char *name,
2849                          const char *other,
2850                          const char *attr_path,
2851                          struct diff_filespec *one,
2852                          struct diff_filespec *two,
2853                          struct strbuf *msg,
2854                          struct diff_options *o,
2855                          struct diff_filepair *p)
2857         const char *xfrm_msg = NULL;
2858         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2859         int must_show_header = 0;
2861         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2862                 pgm = NULL;
2863         else {
2864                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2865                 if (drv && drv->external)
2866                         pgm = drv->external;
2867         }
2869         if (msg) {
2870                 /*
2871                  * don't use colors when the header is intended for an
2872                  * external diff driver
2873                  */
2874                 fill_metainfo(msg, name, other, one, two, o, p,
2875                               &must_show_header,
2876                               want_color(o->use_color) && !pgm);
2877                 xfrm_msg = msg->len ? msg->buf : NULL;
2878         }
2880         if (pgm) {
2881                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2882                                   complete_rewrite);
2883                 return;
2884         }
2885         if (one && two)
2886                 builtin_diff(name, other ? other : name,
2887                              one, two, xfrm_msg, must_show_header,
2888                              o, complete_rewrite);
2889         else
2890                 fprintf(o->file, "* Unmerged path %s\n", name);
2893 static void diff_fill_sha1_info(struct diff_filespec *one)
2895         if (DIFF_FILE_VALID(one)) {
2896                 if (!one->sha1_valid) {
2897                         struct stat st;
2898                         if (!strcmp(one->path, "-")) {
2899                                 hashcpy(one->sha1, null_sha1);
2900                                 return;
2901                         }
2902                         if (lstat(one->path, &st) < 0)
2903                                 die_errno("stat '%s'", one->path);
2904                         if (index_path(one->sha1, one->path, &st, 0))
2905                                 die("cannot hash %s", one->path);
2906                 }
2907         }
2908         else
2909                 hashclr(one->sha1);
2912 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2914         /* Strip the prefix but do not molest /dev/null and absolute paths */
2915         if (*namep && **namep != '/') {
2916                 *namep += prefix_length;
2917                 if (**namep == '/')
2918                         ++*namep;
2919         }
2920         if (*otherp && **otherp != '/') {
2921                 *otherp += prefix_length;
2922                 if (**otherp == '/')
2923                         ++*otherp;
2924         }
2927 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2929         const char *pgm = external_diff();
2930         struct strbuf msg;
2931         struct diff_filespec *one = p->one;
2932         struct diff_filespec *two = p->two;
2933         const char *name;
2934         const char *other;
2935         const char *attr_path;
2937         name  = p->one->path;
2938         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2939         attr_path = name;
2940         if (o->prefix_length)
2941                 strip_prefix(o->prefix_length, &name, &other);
2943         if (DIFF_PAIR_UNMERGED(p)) {
2944                 run_diff_cmd(pgm, name, NULL, attr_path,
2945                              NULL, NULL, NULL, o, p);
2946                 return;
2947         }
2949         diff_fill_sha1_info(one);
2950         diff_fill_sha1_info(two);
2952         if (!pgm &&
2953             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2954             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2955                 /*
2956                  * a filepair that changes between file and symlink
2957                  * needs to be split into deletion and creation.
2958                  */
2959                 struct diff_filespec *null = alloc_filespec(two->path);
2960                 run_diff_cmd(NULL, name, other, attr_path,
2961                              one, null, &msg, o, p);
2962                 free(null);
2963                 strbuf_release(&msg);
2965                 null = alloc_filespec(one->path);
2966                 run_diff_cmd(NULL, name, other, attr_path,
2967                              null, two, &msg, o, p);
2968                 free(null);
2969         }
2970         else
2971                 run_diff_cmd(pgm, name, other, attr_path,
2972                              one, two, &msg, o, p);
2974         strbuf_release(&msg);
2977 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2978                          struct diffstat_t *diffstat)
2980         const char *name;
2981         const char *other;
2982         int complete_rewrite = 0;
2984         if (DIFF_PAIR_UNMERGED(p)) {
2985                 /* unmerged */
2986                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2987                 return;
2988         }
2990         name = p->one->path;
2991         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2993         if (o->prefix_length)
2994                 strip_prefix(o->prefix_length, &name, &other);
2996         diff_fill_sha1_info(p->one);
2997         diff_fill_sha1_info(p->two);
2999         if (p->status == DIFF_STATUS_MODIFIED && p->score)
3000                 complete_rewrite = 1;
3001         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3004 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3006         const char *name;
3007         const char *other;
3008         const char *attr_path;
3010         if (DIFF_PAIR_UNMERGED(p)) {
3011                 /* unmerged */
3012                 return;
3013         }
3015         name = p->one->path;
3016         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3017         attr_path = other ? other : name;
3019         if (o->prefix_length)
3020                 strip_prefix(o->prefix_length, &name, &other);
3022         diff_fill_sha1_info(p->one);
3023         diff_fill_sha1_info(p->two);
3025         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3028 void diff_setup(struct diff_options *options)
3030         memcpy(options, &default_diff_options, sizeof(*options));
3032         options->file = stdout;
3034         options->line_termination = '\n';
3035         options->break_opt = -1;
3036         options->rename_limit = -1;
3037         options->dirstat_permille = diff_dirstat_permille_default;
3038         options->context = 3;
3040         options->change = diff_change;
3041         options->add_remove = diff_addremove;
3042         options->use_color = diff_use_color_default;
3043         options->detect_rename = diff_detect_rename_default;
3045         if (diff_no_prefix) {
3046                 options->a_prefix = options->b_prefix = "";
3047         } else if (!diff_mnemonic_prefix) {
3048                 options->a_prefix = "a/";
3049                 options->b_prefix = "b/";
3050         }
3053 int diff_setup_done(struct diff_options *options)
3055         int count = 0;
3057         if (options->output_format & DIFF_FORMAT_NAME)
3058                 count++;
3059         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3060                 count++;
3061         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3062                 count++;
3063         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3064                 count++;
3065         if (count > 1)
3066                 die("--name-only, --name-status, --check and -s are mutually exclusive");
3068         /*
3069          * Most of the time we can say "there are changes"
3070          * only by checking if there are changed paths, but
3071          * --ignore-whitespace* options force us to look
3072          * inside contents.
3073          */
3075         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3076             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3077             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3078                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3079         else
3080                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3082         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3083                 options->detect_rename = DIFF_DETECT_COPY;
3085         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3086                 options->prefix = NULL;
3087         if (options->prefix)
3088                 options->prefix_length = strlen(options->prefix);
3089         else
3090                 options->prefix_length = 0;
3092         if (options->output_format & (DIFF_FORMAT_NAME |
3093                                       DIFF_FORMAT_NAME_STATUS |
3094                                       DIFF_FORMAT_CHECKDIFF |
3095                                       DIFF_FORMAT_NO_OUTPUT))
3096                 options->output_format &= ~(DIFF_FORMAT_RAW |
3097                                             DIFF_FORMAT_NUMSTAT |
3098                                             DIFF_FORMAT_DIFFSTAT |
3099                                             DIFF_FORMAT_SHORTSTAT |
3100                                             DIFF_FORMAT_DIRSTAT |
3101                                             DIFF_FORMAT_SUMMARY |
3102                                             DIFF_FORMAT_PATCH);
3104         /*
3105          * These cases always need recursive; we do not drop caller-supplied
3106          * recursive bits for other formats here.
3107          */
3108         if (options->output_format & (DIFF_FORMAT_PATCH |
3109                                       DIFF_FORMAT_NUMSTAT |
3110                                       DIFF_FORMAT_DIFFSTAT |
3111                                       DIFF_FORMAT_SHORTSTAT |
3112                                       DIFF_FORMAT_DIRSTAT |
3113                                       DIFF_FORMAT_SUMMARY |
3114                                       DIFF_FORMAT_CHECKDIFF))
3115                 DIFF_OPT_SET(options, RECURSIVE);
3116         /*
3117          * Also pickaxe would not work very well if you do not say recursive
3118          */
3119         if (options->pickaxe)
3120                 DIFF_OPT_SET(options, RECURSIVE);
3121         /*
3122          * When patches are generated, submodules diffed against the work tree
3123          * must be checked for dirtiness too so it can be shown in the output
3124          */
3125         if (options->output_format & DIFF_FORMAT_PATCH)
3126                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3128         if (options->detect_rename && options->rename_limit < 0)
3129                 options->rename_limit = diff_rename_limit_default;
3130         if (options->setup & DIFF_SETUP_USE_CACHE) {
3131                 if (!active_cache)
3132                         /* read-cache does not die even when it fails
3133                          * so it is safe for us to do this here.  Also
3134                          * it does not smudge active_cache or active_nr
3135                          * when it fails, so we do not have to worry about
3136                          * cleaning it up ourselves either.
3137                          */
3138                         read_cache();
3139         }
3140         if (options->abbrev <= 0 || 40 < options->abbrev)
3141                 options->abbrev = 40; /* full */
3143         /*
3144          * It does not make sense to show the first hit we happened
3145          * to have found.  It does not make sense not to return with
3146          * exit code in such a case either.
3147          */
3148         if (DIFF_OPT_TST(options, QUICK)) {
3149                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3150                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3151         }
3153         return 0;
3156 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3158         char c, *eq;
3159         int len;
3161         if (*arg != '-')
3162                 return 0;
3163         c = *++arg;
3164         if (!c)
3165                 return 0;
3166         if (c == arg_short) {
3167                 c = *++arg;
3168                 if (!c)
3169                         return 1;
3170                 if (val && isdigit(c)) {
3171                         char *end;
3172                         int n = strtoul(arg, &end, 10);
3173                         if (*end)
3174                                 return 0;
3175                         *val = n;
3176                         return 1;
3177                 }
3178                 return 0;
3179         }
3180         if (c != '-')
3181                 return 0;
3182         arg++;
3183         eq = strchr(arg, '=');
3184         if (eq)
3185                 len = eq - arg;
3186         else
3187                 len = strlen(arg);
3188         if (!len || strncmp(arg, arg_long, len))
3189                 return 0;
3190         if (eq) {
3191                 int n;
3192                 char *end;
3193                 if (!isdigit(*++eq))
3194                         return 0;
3195                 n = strtoul(eq, &end, 10);
3196                 if (*end)
3197                         return 0;
3198                 *val = n;
3199         }
3200         return 1;
3203 static int diff_scoreopt_parse(const char *opt);
3205 static inline int short_opt(char opt, const char **argv,
3206                             const char **optarg)
3208         const char *arg = argv[0];
3209         if (arg[0] != '-' || arg[1] != opt)
3210                 return 0;
3211         if (arg[2] != '\0') {
3212                 *optarg = arg + 2;
3213                 return 1;
3214         }
3215         if (!argv[1])
3216                 die("Option '%c' requires a value", opt);
3217         *optarg = argv[1];
3218         return 2;
3221 int parse_long_opt(const char *opt, const char **argv,
3222                    const char **optarg)
3224         const char *arg = argv[0];
3225         if (arg[0] != '-' || arg[1] != '-')
3226                 return 0;
3227         arg += strlen("--");
3228         if (prefixcmp(arg, opt))
3229                 return 0;
3230         arg += strlen(opt);
3231         if (*arg == '=') { /* sticked form: --option=value */
3232                 *optarg = arg + 1;
3233                 return 1;
3234         }
3235         if (*arg != '\0')
3236                 return 0;
3237         /* separate form: --option value */
3238         if (!argv[1])
3239                 die("Option '--%s' requires a value", opt);
3240         *optarg = argv[1];
3241         return 2;
3244 static int stat_opt(struct diff_options *options, const char **av)
3246         const char *arg = av[0];
3247         char *end;
3248         int width = options->stat_width;
3249         int name_width = options->stat_name_width;
3250         int count = options->stat_count;
3251         int argcount = 1;
3253         arg += strlen("--stat");
3254         end = (char *)arg;
3256         switch (*arg) {
3257         case '-':
3258                 if (!prefixcmp(arg, "-width")) {
3259                         arg += strlen("-width");
3260                         if (*arg == '=')
3261                                 width = strtoul(arg + 1, &end, 10);
3262                         else if (!*arg && !av[1])
3263                                 die("Option '--stat-width' requires a value");
3264                         else if (!*arg) {
3265                                 width = strtoul(av[1], &end, 10);
3266                                 argcount = 2;
3267                         }
3268                 } else if (!prefixcmp(arg, "-name-width")) {
3269                         arg += strlen("-name-width");
3270                         if (*arg == '=')
3271                                 name_width = strtoul(arg + 1, &end, 10);
3272                         else if (!*arg && !av[1])
3273                                 die("Option '--stat-name-width' requires a value");
3274                         else if (!*arg) {
3275                                 name_width = strtoul(av[1], &end, 10);
3276                                 argcount = 2;
3277                         }
3278                 } else if (!prefixcmp(arg, "-count")) {
3279                         arg += strlen("-count");
3280                         if (*arg == '=')
3281                                 count = strtoul(arg + 1, &end, 10);
3282                         else if (!*arg && !av[1])
3283                                 die("Option '--stat-count' requires a value");
3284                         else if (!*arg) {
3285                                 count = strtoul(av[1], &end, 10);
3286                                 argcount = 2;
3287                         }
3288                 }
3289                 break;
3290         case '=':
3291                 width = strtoul(arg+1, &end, 10);
3292                 if (*end == ',')
3293                         name_width = strtoul(end+1, &end, 10);
3294                 if (*end == ',')
3295                         count = strtoul(end+1, &end, 10);
3296         }
3298         /* Important! This checks all the error cases! */
3299         if (*end)
3300                 return 0;
3301         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3302         options->stat_name_width = name_width;
3303         options->stat_width = width;
3304         options->stat_count = count;
3305         return argcount;
3308 static int parse_dirstat_opt(struct diff_options *options, const char *params)
3310         struct strbuf errmsg = STRBUF_INIT;
3311         if (parse_dirstat_params(options, params, &errmsg))
3312                 die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3313                     errmsg.buf);
3314         strbuf_release(&errmsg);
3315         /*
3316          * The caller knows a dirstat-related option is given from the command
3317          * line; allow it to say "return this_function();"
3318          */
3319         options->output_format |= DIFF_FORMAT_DIRSTAT;
3320         return 1;
3323 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3325         const char *arg = av[0];
3326         const char *optarg;
3327         int argcount;
3329         /* Output format options */
3330         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3331                 options->output_format |= DIFF_FORMAT_PATCH;
3332         else if (opt_arg(arg, 'U', "unified", &options->context))
3333                 options->output_format |= DIFF_FORMAT_PATCH;
3334         else if (!strcmp(arg, "--raw"))
3335                 options->output_format |= DIFF_FORMAT_RAW;
3336         else if (!strcmp(arg, "--patch-with-raw"))
3337                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3338         else if (!strcmp(arg, "--numstat"))
3339                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3340         else if (!strcmp(arg, "--shortstat"))
3341                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3342         else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3343                 return parse_dirstat_opt(options, "");
3344         else if (!prefixcmp(arg, "-X"))
3345                 return parse_dirstat_opt(options, arg + 2);
3346         else if (!prefixcmp(arg, "--dirstat="))
3347                 return parse_dirstat_opt(options, arg + 10);
3348         else if (!strcmp(arg, "--cumulative"))
3349                 return parse_dirstat_opt(options, "cumulative");
3350         else if (!strcmp(arg, "--dirstat-by-file"))
3351                 return parse_dirstat_opt(options, "files");
3352         else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3353                 parse_dirstat_opt(options, "files");
3354                 return parse_dirstat_opt(options, arg + 18);
3355         }
3356         else if (!strcmp(arg, "--check"))
3357                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3358         else if (!strcmp(arg, "--summary"))
3359                 options->output_format |= DIFF_FORMAT_SUMMARY;
3360         else if (!strcmp(arg, "--patch-with-stat"))
3361                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3362         else if (!strcmp(arg, "--name-only"))
3363                 options->output_format |= DIFF_FORMAT_NAME;
3364         else if (!strcmp(arg, "--name-status"))
3365                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3366         else if (!strcmp(arg, "-s"))
3367                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3368         else if (!prefixcmp(arg, "--stat"))
3369                 /* --stat, --stat-width, --stat-name-width, or --stat-count */
3370                 return stat_opt(options, av);
3372         /* renames options */
3373         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3374                  !strcmp(arg, "--break-rewrites")) {
3375                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3376                         return error("invalid argument to -B: %s", arg+2);
3377         }
3378         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3379                  !strcmp(arg, "--find-renames")) {
3380                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3381                         return error("invalid argument to -M: %s", arg+2);
3382                 options->detect_rename = DIFF_DETECT_RENAME;
3383         }
3384         else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3385                 options->irreversible_delete = 1;
3386         }
3387         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3388                  !strcmp(arg, "--find-copies")) {
3389                 if (options->detect_rename == DIFF_DETECT_COPY)
3390                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3391                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3392                         return error("invalid argument to -C: %s", arg+2);
3393                 options->detect_rename = DIFF_DETECT_COPY;
3394         }
3395         else if (!strcmp(arg, "--no-renames"))
3396                 options->detect_rename = 0;
3397         else if (!strcmp(arg, "--relative"))
3398                 DIFF_OPT_SET(options, RELATIVE_NAME);
3399         else if (!prefixcmp(arg, "--relative=")) {
3400                 DIFF_OPT_SET(options, RELATIVE_NAME);
3401                 options->prefix = arg + 11;
3402         }
3404         /* xdiff options */
3405         else if (!strcmp(arg, "--minimal"))
3406                 DIFF_XDL_SET(options, NEED_MINIMAL);
3407         else if (!strcmp(arg, "--no-minimal"))
3408                 DIFF_XDL_CLR(options, NEED_MINIMAL);
3409         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3410                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3411         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3412                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3413         else if (!strcmp(arg, "--ignore-space-at-eol"))
3414                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3415         else if (!strcmp(arg, "--patience"))
3416                 DIFF_XDL_SET(options, PATIENCE_DIFF);
3417         else if (!strcmp(arg, "--histogram"))
3418                 DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3420         /* flags options */
3421         else if (!strcmp(arg, "--binary")) {
3422                 options->output_format |= DIFF_FORMAT_PATCH;
3423                 DIFF_OPT_SET(options, BINARY);
3424         }
3425         else if (!strcmp(arg, "--full-index"))
3426                 DIFF_OPT_SET(options, FULL_INDEX);
3427         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3428                 DIFF_OPT_SET(options, TEXT);
3429         else if (!strcmp(arg, "-R"))
3430                 DIFF_OPT_SET(options, REVERSE_DIFF);
3431         else if (!strcmp(arg, "--find-copies-harder"))
3432                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3433         else if (!strcmp(arg, "--follow"))
3434                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3435         else if (!strcmp(arg, "--color"))
3436                 options->use_color = 1;
3437         else if (!prefixcmp(arg, "--color=")) {
3438                 int value = git_config_colorbool(NULL, arg+8);
3439                 if (value < 0)
3440                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3441                 options->use_color = value;
3442         }
3443         else if (!strcmp(arg, "--no-color"))
3444                 options->use_color = 0;
3445         else if (!strcmp(arg, "--color-words")) {
3446                 options->use_color = 1;
3447                 options->word_diff = DIFF_WORDS_COLOR;
3448         }
3449         else if (!prefixcmp(arg, "--color-words=")) {
3450                 options->use_color = 1;
3451                 options->word_diff = DIFF_WORDS_COLOR;
3452                 options->word_regex = arg + 14;
3453         }
3454         else if (!strcmp(arg, "--word-diff")) {
3455                 if (options->word_diff == DIFF_WORDS_NONE)
3456                         options->word_diff = DIFF_WORDS_PLAIN;
3457         }
3458         else if (!prefixcmp(arg, "--word-diff=")) {
3459                 const char *type = arg + 12;
3460                 if (!strcmp(type, "plain"))
3461                         options->word_diff = DIFF_WORDS_PLAIN;
3462                 else if (!strcmp(type, "color")) {
3463                         options->use_color = 1;
3464                         options->word_diff = DIFF_WORDS_COLOR;
3465                 }
3466                 else if (!strcmp(type, "porcelain"))
3467                         options->word_diff = DIFF_WORDS_PORCELAIN;
3468                 else if (!strcmp(type, "none"))
3469                         options->word_diff = DIFF_WORDS_NONE;
3470                 else
3471                         die("bad --word-diff argument: %s", type);
3472         }
3473         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3474                 if (options->word_diff == DIFF_WORDS_NONE)
3475                         options->word_diff = DIFF_WORDS_PLAIN;
3476                 options->word_regex = optarg;
3477                 return argcount;
3478         }
3479         else if (!strcmp(arg, "--exit-code"))
3480                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3481         else if (!strcmp(arg, "--quiet"))
3482                 DIFF_OPT_SET(options, QUICK);
3483         else if (!strcmp(arg, "--ext-diff"))
3484                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3485         else if (!strcmp(arg, "--no-ext-diff"))
3486                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3487         else if (!strcmp(arg, "--textconv"))
3488                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3489         else if (!strcmp(arg, "--no-textconv"))
3490                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3491         else if (!strcmp(arg, "--ignore-submodules")) {
3492                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3493                 handle_ignore_submodules_arg(options, "all");
3494         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3495                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3496                 handle_ignore_submodules_arg(options, arg + 20);
3497         } else if (!strcmp(arg, "--submodule"))
3498                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3499         else if (!prefixcmp(arg, "--submodule=")) {
3500                 if (!strcmp(arg + 12, "log"))
3501                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3502         }
3504         /* misc options */
3505         else if (!strcmp(arg, "-z"))
3506                 options->line_termination = 0;
3507         else if ((argcount = short_opt('l', av, &optarg))) {
3508                 options->rename_limit = strtoul(optarg, NULL, 10);
3509                 return argcount;
3510         }
3511         else if ((argcount = short_opt('S', av, &optarg))) {
3512                 options->pickaxe = optarg;
3513                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3514                 return argcount;
3515         } else if ((argcount = short_opt('G', av, &optarg))) {
3516                 options->pickaxe = optarg;
3517                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3518                 return argcount;
3519         }
3520         else if (!strcmp(arg, "--pickaxe-all"))
3521                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3522         else if (!strcmp(arg, "--pickaxe-regex"))
3523                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3524         else if ((argcount = short_opt('O', av, &optarg))) {
3525                 options->orderfile = optarg;
3526                 return argcount;
3527         }
3528         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3529                 options->filter = optarg;
3530                 return argcount;
3531         }
3532         else if (!strcmp(arg, "--abbrev"))
3533                 options->abbrev = DEFAULT_ABBREV;
3534         else if (!prefixcmp(arg, "--abbrev=")) {
3535                 options->abbrev = strtoul(arg + 9, NULL, 10);
3536                 if (options->abbrev < MINIMUM_ABBREV)
3537                         options->abbrev = MINIMUM_ABBREV;
3538                 else if (40 < options->abbrev)
3539                         options->abbrev = 40;
3540         }
3541         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3542                 options->a_prefix = optarg;
3543                 return argcount;
3544         }
3545         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3546                 options->b_prefix = optarg;
3547                 return argcount;
3548         }
3549         else if (!strcmp(arg, "--no-prefix"))
3550                 options->a_prefix = options->b_prefix = "";
3551         else if (opt_arg(arg, '\0', "inter-hunk-context",
3552                          &options->interhunkcontext))
3553                 ;
3554         else if (!strcmp(arg, "-W"))
3555                 DIFF_OPT_SET(options, FUNCCONTEXT);
3556         else if (!strcmp(arg, "--function-context"))
3557                 DIFF_OPT_SET(options, FUNCCONTEXT);
3558         else if (!strcmp(arg, "--no-function-context"))
3559                 DIFF_OPT_CLR(options, FUNCCONTEXT);
3560         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3561                 options->file = fopen(optarg, "w");
3562                 if (!options->file)
3563                         die_errno("Could not open '%s'", optarg);
3564                 options->close_file = 1;
3565                 return argcount;
3566         } else
3567                 return 0;
3568         return 1;
3571 int parse_rename_score(const char **cp_p)
3573         unsigned long num, scale;
3574         int ch, dot;
3575         const char *cp = *cp_p;
3577         num = 0;
3578         scale = 1;
3579         dot = 0;
3580         for (;;) {
3581                 ch = *cp;
3582                 if ( !dot && ch == '.' ) {
3583                         scale = 1;
3584                         dot = 1;
3585                 } else if ( ch == '%' ) {
3586                         scale = dot ? scale*100 : 100;
3587                         cp++;   /* % is always at the end */
3588                         break;
3589                 } else if ( ch >= '0' && ch <= '9' ) {
3590                         if ( scale < 100000 ) {
3591                                 scale *= 10;
3592                                 num = (num*10) + (ch-'0');
3593                         }
3594                 } else {
3595                         break;
3596                 }
3597                 cp++;
3598         }
3599         *cp_p = cp;
3601         /* user says num divided by scale and we say internally that
3602          * is MAX_SCORE * num / scale.
3603          */
3604         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3607 static int diff_scoreopt_parse(const char *opt)
3609         int opt1, opt2, cmd;
3611         if (*opt++ != '-')
3612                 return -1;
3613         cmd = *opt++;
3614         if (cmd == '-') {
3615                 /* convert the long-form arguments into short-form versions */
3616                 if (!prefixcmp(opt, "break-rewrites")) {
3617                         opt += strlen("break-rewrites");
3618                         if (*opt == 0 || *opt++ == '=')
3619                                 cmd = 'B';
3620                 } else if (!prefixcmp(opt, "find-copies")) {
3621                         opt += strlen("find-copies");
3622                         if (*opt == 0 || *opt++ == '=')
3623                                 cmd = 'C';
3624                 } else if (!prefixcmp(opt, "find-renames")) {
3625                         opt += strlen("find-renames");
3626                         if (*opt == 0 || *opt++ == '=')
3627                                 cmd = 'M';
3628                 }
3629         }
3630         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3631                 return -1; /* that is not a -M, -C nor -B option */
3633         opt1 = parse_rename_score(&opt);
3634         if (cmd != 'B')
3635                 opt2 = 0;
3636         else {
3637                 if (*opt == 0)
3638                         opt2 = 0;
3639                 else if (*opt != '/')
3640                         return -1; /* we expect -B80/99 or -B80 */
3641                 else {
3642                         opt++;
3643                         opt2 = parse_rename_score(&opt);
3644                 }
3645         }
3646         if (*opt != 0)
3647                 return -1;
3648         return opt1 | (opt2 << 16);
3651 struct diff_queue_struct diff_queued_diff;
3653 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3655         if (queue->alloc <= queue->nr) {
3656                 queue->alloc = alloc_nr(queue->alloc);
3657                 queue->queue = xrealloc(queue->queue,
3658                                         sizeof(dp) * queue->alloc);
3659         }
3660         queue->queue[queue->nr++] = dp;
3663 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3664                                  struct diff_filespec *one,
3665                                  struct diff_filespec *two)
3667         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3668         dp->one = one;
3669         dp->two = two;
3670         if (queue)
3671                 diff_q(queue, dp);
3672         return dp;
3675 void diff_free_filepair(struct diff_filepair *p)
3677         free_filespec(p->one);
3678         free_filespec(p->two);
3679         free(p);
3682 /* This is different from find_unique_abbrev() in that
3683  * it stuffs the result with dots for alignment.
3684  */
3685 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3687         int abblen;
3688         const char *abbrev;
3689         if (len == 40)
3690                 return sha1_to_hex(sha1);
3692         abbrev = find_unique_abbrev(sha1, len);
3693         abblen = strlen(abbrev);
3694         if (abblen < 37) {
3695                 static char hex[41];
3696                 if (len < abblen && abblen <= len + 2)
3697                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3698                 else
3699                         sprintf(hex, "%s...", abbrev);
3700                 return hex;
3701         }
3702         return sha1_to_hex(sha1);
3705 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3707         int line_termination = opt->line_termination;
3708         int inter_name_termination = line_termination ? '\t' : '\0';
3709         if (opt->output_prefix) {
3710                 struct strbuf *msg = NULL;
3711                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3712                 fprintf(opt->file, "%s", msg->buf);
3713         }
3715         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3716                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3717                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3718                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3719         }
3720         if (p->score) {
3721                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3722                         inter_name_termination);
3723         } else {
3724                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3725         }
3727         if (p->status == DIFF_STATUS_COPIED ||
3728             p->status == DIFF_STATUS_RENAMED) {
3729                 const char *name_a, *name_b;
3730                 name_a = p->one->path;
3731                 name_b = p->two->path;
3732                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3733                 write_name_quoted(name_a, opt->file, inter_name_termination);
3734                 write_name_quoted(name_b, opt->file, line_termination);
3735         } else {
3736                 const char *name_a, *name_b;
3737                 name_a = p->one->mode ? p->one->path : p->two->path;
3738                 name_b = NULL;
3739                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3740                 write_name_quoted(name_a, opt->file, line_termination);
3741         }
3744 int diff_unmodified_pair(struct diff_filepair *p)
3746         /* This function is written stricter than necessary to support
3747          * the currently implemented transformers, but the idea is to
3748          * let transformers to produce diff_filepairs any way they want,
3749          * and filter and clean them up here before producing the output.
3750          */
3751         struct diff_filespec *one = p->one, *two = p->two;
3753         if (DIFF_PAIR_UNMERGED(p))
3754                 return 0; /* unmerged is interesting */
3756         /* deletion, addition, mode or type change
3757          * and rename are all interesting.
3758          */
3759         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3760             DIFF_PAIR_MODE_CHANGED(p) ||
3761             strcmp(one->path, two->path))
3762                 return 0;
3764         /* both are valid and point at the same path.  that is, we are
3765          * dealing with a change.
3766          */
3767         if (one->sha1_valid && two->sha1_valid &&
3768             !hashcmp(one->sha1, two->sha1) &&
3769             !one->dirty_submodule && !two->dirty_submodule)
3770                 return 1; /* no change */
3771         if (!one->sha1_valid && !two->sha1_valid)
3772                 return 1; /* both look at the same file on the filesystem. */
3773         return 0;
3776 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3778         if (diff_unmodified_pair(p))
3779                 return;
3781         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3782             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3783                 return; /* no tree diffs in patch format */
3785         run_diff(p, o);
3788 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3789                             struct diffstat_t *diffstat)
3791         if (diff_unmodified_pair(p))
3792                 return;
3794         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3795             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3796                 return; /* no useful stat for tree diffs */
3798         run_diffstat(p, o, diffstat);
3801 static void diff_flush_checkdiff(struct diff_filepair *p,
3802                 struct diff_options *o)
3804         if (diff_unmodified_pair(p))
3805                 return;
3807         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3808             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3809                 return; /* nothing to check in tree diffs */
3811         run_checkdiff(p, o);
3814 int diff_queue_is_empty(void)
3816         struct diff_queue_struct *q = &diff_queued_diff;
3817         int i;
3818         for (i = 0; i < q->nr; i++)
3819                 if (!diff_unmodified_pair(q->queue[i]))
3820                         return 0;
3821         return 1;
3824 #if DIFF_DEBUG
3825 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3827         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3828                 x, one ? one : "",
3829                 s->path,
3830                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3831                 s->mode,
3832                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3833         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3834                 x, one ? one : "",
3835                 s->size, s->xfrm_flags);
3838 void diff_debug_filepair(const struct diff_filepair *p, int i)
3840         diff_debug_filespec(p->one, i, "one");
3841         diff_debug_filespec(p->two, i, "two");
3842         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3843                 p->score, p->status ? p->status : '?',
3844                 p->one->rename_used, p->broken_pair);
3847 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3849         int i;
3850         if (msg)
3851                 fprintf(stderr, "%s\n", msg);
3852         fprintf(stderr, "q->nr = %d\n", q->nr);
3853         for (i = 0; i < q->nr; i++) {
3854                 struct diff_filepair *p = q->queue[i];
3855                 diff_debug_filepair(p, i);
3856         }
3858 #endif
3860 static void diff_resolve_rename_copy(void)
3862         int i;
3863         struct diff_filepair *p;
3864         struct diff_queue_struct *q = &diff_queued_diff;
3866         diff_debug_queue("resolve-rename-copy", q);
3868         for (i = 0; i < q->nr; i++) {
3869                 p = q->queue[i];
3870                 p->status = 0; /* undecided */
3871                 if (DIFF_PAIR_UNMERGED(p))
3872                         p->status = DIFF_STATUS_UNMERGED;
3873                 else if (!DIFF_FILE_VALID(p->one))
3874                         p->status = DIFF_STATUS_ADDED;
3875                 else if (!DIFF_FILE_VALID(p->two))
3876                         p->status = DIFF_STATUS_DELETED;
3877                 else if (DIFF_PAIR_TYPE_CHANGED(p))
3878                         p->status = DIFF_STATUS_TYPE_CHANGED;
3880                 /* from this point on, we are dealing with a pair
3881                  * whose both sides are valid and of the same type, i.e.
3882                  * either in-place edit or rename/copy edit.
3883                  */
3884                 else if (DIFF_PAIR_RENAME(p)) {
3885                         /*
3886                          * A rename might have re-connected a broken
3887                          * pair up, causing the pathnames to be the
3888                          * same again. If so, that's not a rename at
3889                          * all, just a modification..
3890                          *
3891                          * Otherwise, see if this source was used for
3892                          * multiple renames, in which case we decrement
3893                          * the count, and call it a copy.
3894                          */
3895                         if (!strcmp(p->one->path, p->two->path))
3896                                 p->status = DIFF_STATUS_MODIFIED;
3897                         else if (--p->one->rename_used > 0)
3898                                 p->status = DIFF_STATUS_COPIED;
3899                         else
3900                                 p->status = DIFF_STATUS_RENAMED;
3901                 }
3902                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
3903                          p->one->mode != p->two->mode ||
3904                          p->one->dirty_submodule ||
3905                          p->two->dirty_submodule ||
3906                          is_null_sha1(p->one->sha1))
3907                         p->status = DIFF_STATUS_MODIFIED;
3908                 else {
3909                         /* This is a "no-change" entry and should not
3910                          * happen anymore, but prepare for broken callers.
3911                          */
3912                         error("feeding unmodified %s to diffcore",
3913                               p->one->path);
3914                         p->status = DIFF_STATUS_UNKNOWN;
3915                 }
3916         }
3917         diff_debug_queue("resolve-rename-copy done", q);
3920 static int check_pair_status(struct diff_filepair *p)
3922         switch (p->status) {
3923         case DIFF_STATUS_UNKNOWN:
3924                 return 0;
3925         case 0:
3926                 die("internal error in diff-resolve-rename-copy");
3927         default:
3928                 return 1;
3929         }
3932 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3934         int fmt = opt->output_format;
3936         if (fmt & DIFF_FORMAT_CHECKDIFF)
3937                 diff_flush_checkdiff(p, opt);
3938         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3939                 diff_flush_raw(p, opt);
3940         else if (fmt & DIFF_FORMAT_NAME) {
3941                 const char *name_a, *name_b;
3942                 name_a = p->two->path;
3943                 name_b = NULL;
3944                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3945                 write_name_quoted(name_a, opt->file, opt->line_termination);
3946         }
3949 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3951         if (fs->mode)
3952                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3953         else
3954                 fprintf(file, " %s ", newdelete);
3955         write_name_quoted(fs->path, file, '\n');
3959 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3960                 const char *line_prefix)
3962         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3963                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3964                         p->two->mode, show_name ? ' ' : '\n');
3965                 if (show_name) {
3966                         write_name_quoted(p->two->path, file, '\n');
3967                 }
3968         }
3971 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3972                         const char *line_prefix)
3974         char *names = pprint_rename(p->one->path, p->two->path);
3976         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3977         free(names);
3978         show_mode_change(file, p, 0, line_prefix);
3981 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3983         FILE *file = opt->file;
3984         char *line_prefix = "";
3986         if (opt->output_prefix) {
3987                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3988                 line_prefix = buf->buf;
3989         }
3991         switch(p->status) {
3992         case DIFF_STATUS_DELETED:
3993                 fputs(line_prefix, file);
3994                 show_file_mode_name(file, "delete", p->one);
3995                 break;
3996         case DIFF_STATUS_ADDED:
3997                 fputs(line_prefix, file);
3998                 show_file_mode_name(file, "create", p->two);
3999                 break;
4000         case DIFF_STATUS_COPIED:
4001                 fputs(line_prefix, file);
4002                 show_rename_copy(file, "copy", p, line_prefix);
4003                 break;
4004         case DIFF_STATUS_RENAMED:
4005                 fputs(line_prefix, file);
4006                 show_rename_copy(file, "rename", p, line_prefix);
4007                 break;
4008         default:
4009                 if (p->score) {
4010                         fprintf(file, "%s rewrite ", line_prefix);
4011                         write_name_quoted(p->two->path, file, ' ');
4012                         fprintf(file, "(%d%%)\n", similarity_index(p));
4013                 }
4014                 show_mode_change(file, p, !p->score, line_prefix);
4015                 break;
4016         }
4019 struct patch_id_t {
4020         git_SHA_CTX *ctx;
4021         int patchlen;
4022 };
4024 static int remove_space(char *line, int len)
4026         int i;
4027         char *dst = line;
4028         unsigned char c;
4030         for (i = 0; i < len; i++)
4031                 if (!isspace((c = line[i])))
4032                         *dst++ = c;
4034         return dst - line;
4037 static void patch_id_consume(void *priv, char *line, unsigned long len)
4039         struct patch_id_t *data = priv;
4040         int new_len;
4042         /* Ignore line numbers when computing the SHA1 of the patch */
4043         if (!prefixcmp(line, "@@ -"))
4044                 return;
4046         new_len = remove_space(line, len);
4048         git_SHA1_Update(data->ctx, line, new_len);
4049         data->patchlen += new_len;
4052 /* returns 0 upon success, and writes result into sha1 */
4053 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4055         struct diff_queue_struct *q = &diff_queued_diff;
4056         int i;
4057         git_SHA_CTX ctx;
4058         struct patch_id_t data;
4059         char buffer[PATH_MAX * 4 + 20];
4061         git_SHA1_Init(&ctx);
4062         memset(&data, 0, sizeof(struct patch_id_t));
4063         data.ctx = &ctx;
4065         for (i = 0; i < q->nr; i++) {
4066                 xpparam_t xpp;
4067                 xdemitconf_t xecfg;
4068                 mmfile_t mf1, mf2;
4069                 struct diff_filepair *p = q->queue[i];
4070                 int len1, len2;
4072                 memset(&xpp, 0, sizeof(xpp));
4073                 memset(&xecfg, 0, sizeof(xecfg));
4074                 if (p->status == 0)
4075                         return error("internal diff status error");
4076                 if (p->status == DIFF_STATUS_UNKNOWN)
4077                         continue;
4078                 if (diff_unmodified_pair(p))
4079                         continue;
4080                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4081                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4082                         continue;
4083                 if (DIFF_PAIR_UNMERGED(p))
4084                         continue;
4086                 diff_fill_sha1_info(p->one);
4087                 diff_fill_sha1_info(p->two);
4088                 if (fill_mmfile(&mf1, p->one) < 0 ||
4089                                 fill_mmfile(&mf2, p->two) < 0)
4090                         return error("unable to read files to diff");
4092                 len1 = remove_space(p->one->path, strlen(p->one->path));
4093                 len2 = remove_space(p->two->path, strlen(p->two->path));
4094                 if (p->one->mode == 0)
4095                         len1 = snprintf(buffer, sizeof(buffer),
4096                                         "diff--gita/%.*sb/%.*s"
4097                                         "newfilemode%06o"
4098                                         "---/dev/null"
4099                                         "+++b/%.*s",
4100                                         len1, p->one->path,
4101                                         len2, p->two->path,
4102                                         p->two->mode,
4103                                         len2, p->two->path);
4104                 else if (p->two->mode == 0)
4105                         len1 = snprintf(buffer, sizeof(buffer),
4106                                         "diff--gita/%.*sb/%.*s"
4107                                         "deletedfilemode%06o"
4108                                         "---a/%.*s"
4109                                         "+++/dev/null",
4110                                         len1, p->one->path,
4111                                         len2, p->two->path,
4112                                         p->one->mode,
4113                                         len1, p->one->path);
4114                 else
4115                         len1 = snprintf(buffer, sizeof(buffer),
4116                                         "diff--gita/%.*sb/%.*s"
4117                                         "---a/%.*s"
4118                                         "+++b/%.*s",
4119                                         len1, p->one->path,
4120                                         len2, p->two->path,
4121                                         len1, p->one->path,
4122                                         len2, p->two->path);
4123                 git_SHA1_Update(&ctx, buffer, len1);
4125                 if (diff_filespec_is_binary(p->one) ||
4126                     diff_filespec_is_binary(p->two)) {
4127                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4128                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4129                         continue;
4130                 }
4132                 xpp.flags = 0;
4133                 xecfg.ctxlen = 3;
4134                 xecfg.flags = 0;
4135                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4136                               &xpp, &xecfg);
4137         }
4139         git_SHA1_Final(sha1, &ctx);
4140         return 0;
4143 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4145         struct diff_queue_struct *q = &diff_queued_diff;
4146         int i;
4147         int result = diff_get_patch_id(options, sha1);
4149         for (i = 0; i < q->nr; i++)
4150                 diff_free_filepair(q->queue[i]);
4152         free(q->queue);
4153         DIFF_QUEUE_CLEAR(q);
4155         return result;
4158 static int is_summary_empty(const struct diff_queue_struct *q)
4160         int i;
4162         for (i = 0; i < q->nr; i++) {
4163                 const struct diff_filepair *p = q->queue[i];
4165                 switch (p->status) {
4166                 case DIFF_STATUS_DELETED:
4167                 case DIFF_STATUS_ADDED:
4168                 case DIFF_STATUS_COPIED:
4169                 case DIFF_STATUS_RENAMED:
4170                         return 0;
4171                 default:
4172                         if (p->score)
4173                                 return 0;
4174                         if (p->one->mode && p->two->mode &&
4175                             p->one->mode != p->two->mode)
4176                                 return 0;
4177                         break;
4178                 }
4179         }
4180         return 1;
4183 static const char rename_limit_warning[] =
4184 "inexact rename detection was skipped due to too many files.";
4186 static const char degrade_cc_to_c_warning[] =
4187 "only found copies from modified paths due to too many files.";
4189 static const char rename_limit_advice[] =
4190 "you may want to set your %s variable to at least "
4191 "%d and retry the command.";
4193 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4195         if (degraded_cc)
4196                 warning(degrade_cc_to_c_warning);
4197         else if (needed)
4198                 warning(rename_limit_warning);
4199         else
4200                 return;
4201         if (0 < needed && needed < 32767)
4202                 warning(rename_limit_advice, varname, needed);
4205 void diff_flush(struct diff_options *options)
4207         struct diff_queue_struct *q = &diff_queued_diff;
4208         int i, output_format = options->output_format;
4209         int separator = 0;
4210         int dirstat_by_line = 0;
4212         /*
4213          * Order: raw, stat, summary, patch
4214          * or:    name/name-status/checkdiff (other bits clear)
4215          */
4216         if (!q->nr)
4217                 goto free_queue;
4219         if (output_format & (DIFF_FORMAT_RAW |
4220                              DIFF_FORMAT_NAME |
4221                              DIFF_FORMAT_NAME_STATUS |
4222                              DIFF_FORMAT_CHECKDIFF)) {
4223                 for (i = 0; i < q->nr; i++) {
4224                         struct diff_filepair *p = q->queue[i];
4225                         if (check_pair_status(p))
4226                                 flush_one_pair(p, options);
4227                 }
4228                 separator++;
4229         }
4231         if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4232                 dirstat_by_line = 1;
4234         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4235             dirstat_by_line) {
4236                 struct diffstat_t diffstat;
4238                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4239                 for (i = 0; i < q->nr; i++) {
4240                         struct diff_filepair *p = q->queue[i];
4241                         if (check_pair_status(p))
4242                                 diff_flush_stat(p, options, &diffstat);
4243                 }
4244                 if (output_format & DIFF_FORMAT_NUMSTAT)
4245                         show_numstat(&diffstat, options);
4246                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4247                         show_stats(&diffstat, options);
4248                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4249                         show_shortstats(&diffstat, options);
4250                 if (output_format & DIFF_FORMAT_DIRSTAT)
4251                         show_dirstat_by_line(&diffstat, options);
4252                 free_diffstat_info(&diffstat);
4253                 separator++;
4254         }
4255         if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4256                 show_dirstat(options);
4258         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4259                 for (i = 0; i < q->nr; i++) {
4260                         diff_summary(options, q->queue[i]);
4261                 }
4262                 separator++;
4263         }
4265         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4266             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4267             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4268                 /*
4269                  * run diff_flush_patch for the exit status. setting
4270                  * options->file to /dev/null should be safe, becaue we
4271                  * aren't supposed to produce any output anyway.
4272                  */
4273                 if (options->close_file)
4274                         fclose(options->file);
4275                 options->file = fopen("/dev/null", "w");
4276                 if (!options->file)
4277                         die_errno("Could not open /dev/null");
4278                 options->close_file = 1;
4279                 for (i = 0; i < q->nr; i++) {
4280                         struct diff_filepair *p = q->queue[i];
4281                         if (check_pair_status(p))
4282                                 diff_flush_patch(p, options);
4283                         if (options->found_changes)
4284                                 break;
4285                 }
4286         }
4288         if (output_format & DIFF_FORMAT_PATCH) {
4289                 if (separator) {
4290                         putc(options->line_termination, options->file);
4291                         if (options->stat_sep) {
4292                                 /* attach patch instead of inline */
4293                                 fputs(options->stat_sep, options->file);
4294                         }
4295                 }
4297                 for (i = 0; i < q->nr; i++) {
4298                         struct diff_filepair *p = q->queue[i];
4299                         if (check_pair_status(p))
4300                                 diff_flush_patch(p, options);
4301                 }
4302         }
4304         if (output_format & DIFF_FORMAT_CALLBACK)
4305                 options->format_callback(q, options, options->format_callback_data);
4307         for (i = 0; i < q->nr; i++)
4308                 diff_free_filepair(q->queue[i]);
4309 free_queue:
4310         free(q->queue);
4311         DIFF_QUEUE_CLEAR(q);
4312         if (options->close_file)
4313                 fclose(options->file);
4315         /*
4316          * Report the content-level differences with HAS_CHANGES;
4317          * diff_addremove/diff_change does not set the bit when
4318          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4319          */
4320         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4321                 if (options->found_changes)
4322                         DIFF_OPT_SET(options, HAS_CHANGES);
4323                 else
4324                         DIFF_OPT_CLR(options, HAS_CHANGES);
4325         }
4328 static void diffcore_apply_filter(const char *filter)
4330         int i;
4331         struct diff_queue_struct *q = &diff_queued_diff;
4332         struct diff_queue_struct outq;
4333         DIFF_QUEUE_CLEAR(&outq);
4335         if (!filter)
4336                 return;
4338         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4339                 int found;
4340                 for (i = found = 0; !found && i < q->nr; i++) {
4341                         struct diff_filepair *p = q->queue[i];
4342                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4343                              ((p->score &&
4344                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4345                               (!p->score &&
4346                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4347                             ((p->status != DIFF_STATUS_MODIFIED) &&
4348                              strchr(filter, p->status)))
4349                                 found++;
4350                 }
4351                 if (found)
4352                         return;
4354                 /* otherwise we will clear the whole queue
4355                  * by copying the empty outq at the end of this
4356                  * function, but first clear the current entries
4357                  * in the queue.
4358                  */
4359                 for (i = 0; i < q->nr; i++)
4360                         diff_free_filepair(q->queue[i]);
4361         }
4362         else {
4363                 /* Only the matching ones */
4364                 for (i = 0; i < q->nr; i++) {
4365                         struct diff_filepair *p = q->queue[i];
4367                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4368                              ((p->score &&
4369                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4370                               (!p->score &&
4371                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4372                             ((p->status != DIFF_STATUS_MODIFIED) &&
4373                              strchr(filter, p->status)))
4374                                 diff_q(&outq, p);
4375                         else
4376                                 diff_free_filepair(p);
4377                 }
4378         }
4379         free(q->queue);
4380         *q = outq;
4383 /* Check whether two filespecs with the same mode and size are identical */
4384 static int diff_filespec_is_identical(struct diff_filespec *one,
4385                                       struct diff_filespec *two)
4387         if (S_ISGITLINK(one->mode))
4388                 return 0;
4389         if (diff_populate_filespec(one, 0))
4390                 return 0;
4391         if (diff_populate_filespec(two, 0))
4392                 return 0;
4393         return !memcmp(one->data, two->data, one->size);
4396 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4398         int i;
4399         struct diff_queue_struct *q = &diff_queued_diff;
4400         struct diff_queue_struct outq;
4401         DIFF_QUEUE_CLEAR(&outq);
4403         for (i = 0; i < q->nr; i++) {
4404                 struct diff_filepair *p = q->queue[i];
4406                 /*
4407                  * 1. Entries that come from stat info dirtiness
4408                  *    always have both sides (iow, not create/delete),
4409                  *    one side of the object name is unknown, with
4410                  *    the same mode and size.  Keep the ones that
4411                  *    do not match these criteria.  They have real
4412                  *    differences.
4413                  *
4414                  * 2. At this point, the file is known to be modified,
4415                  *    with the same mode and size, and the object
4416                  *    name of one side is unknown.  Need to inspect
4417                  *    the identical contents.
4418                  */
4419                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4420                     !DIFF_FILE_VALID(p->two) ||
4421                     (p->one->sha1_valid && p->two->sha1_valid) ||
4422                     (p->one->mode != p->two->mode) ||
4423                     diff_populate_filespec(p->one, 1) ||
4424                     diff_populate_filespec(p->two, 1) ||
4425                     (p->one->size != p->two->size) ||
4426                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4427                         diff_q(&outq, p);
4428                 else {
4429                         /*
4430                          * The caller can subtract 1 from skip_stat_unmatch
4431                          * to determine how many paths were dirty only
4432                          * due to stat info mismatch.
4433                          */
4434                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4435                                 diffopt->skip_stat_unmatch++;
4436                         diff_free_filepair(p);
4437                 }
4438         }
4439         free(q->queue);
4440         *q = outq;
4443 static int diffnamecmp(const void *a_, const void *b_)
4445         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4446         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4447         const char *name_a, *name_b;
4449         name_a = a->one ? a->one->path : a->two->path;
4450         name_b = b->one ? b->one->path : b->two->path;
4451         return strcmp(name_a, name_b);
4454 void diffcore_fix_diff_index(struct diff_options *options)
4456         struct diff_queue_struct *q = &diff_queued_diff;
4457         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4460 void diffcore_std(struct diff_options *options)
4462         if (options->skip_stat_unmatch)
4463                 diffcore_skip_stat_unmatch(options);
4464         if (!options->found_follow) {
4465                 /* See try_to_follow_renames() in tree-diff.c */
4466                 if (options->break_opt != -1)
4467                         diffcore_break(options->break_opt);
4468                 if (options->detect_rename)
4469                         diffcore_rename(options);
4470                 if (options->break_opt != -1)
4471                         diffcore_merge_broken();
4472         }
4473         if (options->pickaxe)
4474                 diffcore_pickaxe(options);
4475         if (options->orderfile)
4476                 diffcore_order(options->orderfile);
4477         if (!options->found_follow)
4478                 /* See try_to_follow_renames() in tree-diff.c */
4479                 diff_resolve_rename_copy();
4480         diffcore_apply_filter(options->filter);
4482         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4483                 DIFF_OPT_SET(options, HAS_CHANGES);
4484         else
4485                 DIFF_OPT_CLR(options, HAS_CHANGES);
4487         options->found_follow = 0;
4490 int diff_result_code(struct diff_options *opt, int status)
4492         int result = 0;
4494         diff_warn_rename_limit("diff.renamelimit",
4495                                opt->needed_rename_limit,
4496                                opt->degraded_cc_to_c);
4497         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4498             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4499                 return status;
4500         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4501             DIFF_OPT_TST(opt, HAS_CHANGES))
4502                 result |= 01;
4503         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4504             DIFF_OPT_TST(opt, CHECK_FAILED))
4505                 result |= 02;
4506         return result;
4509 int diff_can_quit_early(struct diff_options *opt)
4511         return (DIFF_OPT_TST(opt, QUICK) &&
4512                 !opt->filter &&
4513                 DIFF_OPT_TST(opt, HAS_CHANGES));
4516 /*
4517  * Shall changes to this submodule be ignored?
4518  *
4519  * Submodule changes can be configured to be ignored separately for each path,
4520  * but that configuration can be overridden from the command line.
4521  */
4522 static int is_submodule_ignored(const char *path, struct diff_options *options)
4524         int ignored = 0;
4525         unsigned orig_flags = options->flags;
4526         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4527                 set_diffopt_flags_from_submodule_config(options, path);
4528         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4529                 ignored = 1;
4530         options->flags = orig_flags;
4531         return ignored;
4534 void diff_addremove(struct diff_options *options,
4535                     int addremove, unsigned mode,
4536                     const unsigned char *sha1,
4537                     const char *concatpath, unsigned dirty_submodule)
4539         struct diff_filespec *one, *two;
4541         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4542                 return;
4544         /* This may look odd, but it is a preparation for
4545          * feeding "there are unchanged files which should
4546          * not produce diffs, but when you are doing copy
4547          * detection you would need them, so here they are"
4548          * entries to the diff-core.  They will be prefixed
4549          * with something like '=' or '*' (I haven't decided
4550          * which but should not make any difference).
4551          * Feeding the same new and old to diff_change()
4552          * also has the same effect.
4553          * Before the final output happens, they are pruned after
4554          * merged into rename/copy pairs as appropriate.
4555          */
4556         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4557                 addremove = (addremove == '+' ? '-' :
4558                              addremove == '-' ? '+' : addremove);
4560         if (options->prefix &&
4561             strncmp(concatpath, options->prefix, options->prefix_length))
4562                 return;
4564         one = alloc_filespec(concatpath);
4565         two = alloc_filespec(concatpath);
4567         if (addremove != '+')
4568                 fill_filespec(one, sha1, mode);
4569         if (addremove != '-') {
4570                 fill_filespec(two, sha1, mode);
4571                 two->dirty_submodule = dirty_submodule;
4572         }
4574         diff_queue(&diff_queued_diff, one, two);
4575         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4576                 DIFF_OPT_SET(options, HAS_CHANGES);
4579 void diff_change(struct diff_options *options,
4580                  unsigned old_mode, unsigned new_mode,
4581                  const unsigned char *old_sha1,
4582                  const unsigned char *new_sha1,
4583                  const char *concatpath,
4584                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4586         struct diff_filespec *one, *two;
4588         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4589             is_submodule_ignored(concatpath, options))
4590                 return;
4592         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4593                 unsigned tmp;
4594                 const unsigned char *tmp_c;
4595                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4596                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4597                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4598                         new_dirty_submodule = tmp;
4599         }
4601         if (options->prefix &&
4602             strncmp(concatpath, options->prefix, options->prefix_length))
4603                 return;
4605         one = alloc_filespec(concatpath);
4606         two = alloc_filespec(concatpath);
4607         fill_filespec(one, old_sha1, old_mode);
4608         fill_filespec(two, new_sha1, new_mode);
4609         one->dirty_submodule = old_dirty_submodule;
4610         two->dirty_submodule = new_dirty_submodule;
4612         diff_queue(&diff_queued_diff, one, two);
4613         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4614                 DIFF_OPT_SET(options, HAS_CHANGES);
4617 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4619         struct diff_filepair *pair;
4620         struct diff_filespec *one, *two;
4622         if (options->prefix &&
4623             strncmp(path, options->prefix, options->prefix_length))
4624                 return NULL;
4626         one = alloc_filespec(path);
4627         two = alloc_filespec(path);
4628         pair = diff_queue(&diff_queued_diff, one, two);
4629         pair->is_unmerged = 1;
4630         return pair;
4633 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4634                 size_t *outsize)
4636         struct diff_tempfile *temp;
4637         const char *argv[3];
4638         const char **arg = argv;
4639         struct child_process child;
4640         struct strbuf buf = STRBUF_INIT;
4641         int err = 0;
4643         temp = prepare_temp_file(spec->path, spec);
4644         *arg++ = pgm;
4645         *arg++ = temp->name;
4646         *arg = NULL;
4648         memset(&child, 0, sizeof(child));
4649         child.use_shell = 1;
4650         child.argv = argv;
4651         child.out = -1;
4652         if (start_command(&child)) {
4653                 remove_tempfile();
4654                 return NULL;
4655         }
4657         if (strbuf_read(&buf, child.out, 0) < 0)
4658                 err = error("error reading from textconv command '%s'", pgm);
4659         close(child.out);
4661         if (finish_command(&child) || err) {
4662                 strbuf_release(&buf);
4663                 remove_tempfile();
4664                 return NULL;
4665         }
4666         remove_tempfile();
4668         return strbuf_detach(&buf, outsize);
4671 size_t fill_textconv(struct userdiff_driver *driver,
4672                      struct diff_filespec *df,
4673                      char **outbuf)
4675         size_t size;
4677         if (!driver || !driver->textconv) {
4678                 if (!DIFF_FILE_VALID(df)) {
4679                         *outbuf = "";
4680                         return 0;
4681                 }
4682                 if (diff_populate_filespec(df, 0))
4683                         die("unable to read files to diff");
4684                 *outbuf = df->data;
4685                 return df->size;
4686         }
4688         if (driver->textconv_cache && df->sha1_valid) {
4689                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4690                                           &size);
4691                 if (*outbuf)
4692                         return size;
4693         }
4695         *outbuf = run_textconv(driver->textconv, df, &size);
4696         if (!*outbuf)
4697                 die("unable to read files to diff");
4699         if (driver->textconv_cache && df->sha1_valid) {
4700                 /* ignore errors, as we might be in a readonly repository */
4701                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4702                                 size);
4703                 /*
4704                  * we could save up changes and flush them all at the end,
4705                  * but we would need an extra call after all diffing is done.
4706                  * Since generating a cache entry is the slow path anyway,
4707                  * this extra overhead probably isn't a big deal.
4708                  */
4709                 notes_cache_write(driver->textconv_cache);
4710         }
4712         return size;