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"
  18 #include "string-list.h"
  19
  20 #ifdef NO_FAST_WORKING_DIRECTORY
  21 #define FAST_WORKING_DIRECTORY 0
  22 #else
  23 #define FAST_WORKING_DIRECTORY 1
  24 #endif
  25
  26 static int diff_detect_rename_default;
  27 static int diff_rename_limit_default = 400;
  28 static int diff_suppress_blank_empty;
  29 static int diff_use_color_default = -1;
  30 static int diff_context_default = 3;
  31 static const char *diff_word_regex_cfg;
  32 static const char *external_diff_cmd_cfg;
  33 int diff_auto_refresh_index = 1;
  34 static int diff_mnemonic_prefix;
  35 static int diff_no_prefix;
  36 static int diff_stat_graph_width;
  37 static int diff_dirstat_permille_default = 30;
  38 static struct diff_options default_diff_options;
  39
  40 static char diff_colors[][COLOR_MAXLEN] = {
  41         GIT_COLOR_RESET,
  42         GIT_COLOR_NORMAL,       /* PLAIN */
  43         GIT_COLOR_BOLD,         /* METAINFO */
  44         GIT_COLOR_CYAN,         /* FRAGINFO */
  45         GIT_COLOR_RED,          /* OLD */
  46         GIT_COLOR_GREEN,        /* NEW */
  47         GIT_COLOR_YELLOW,       /* COMMIT */
  48         GIT_COLOR_BG_RED,       /* WHITESPACE */
  49         GIT_COLOR_NORMAL,       /* FUNCINFO */
  50 };
  51
  52 static int parse_diff_color_slot(const char *var, int ofs)
  53 {
  54         if (!strcasecmp(var+ofs, "plain"))
  55                 return DIFF_PLAIN;
  56         if (!strcasecmp(var+ofs, "meta"))
  57                 return DIFF_METAINFO;
  58         if (!strcasecmp(var+ofs, "frag"))
  59                 return DIFF_FRAGINFO;
  60         if (!strcasecmp(var+ofs, "old"))
  61                 return DIFF_FILE_OLD;
  62         if (!strcasecmp(var+ofs, "new"))
  63                 return DIFF_FILE_NEW;
  64         if (!strcasecmp(var+ofs, "commit"))
  65                 return DIFF_COMMIT;
  66         if (!strcasecmp(var+ofs, "whitespace"))
  67                 return DIFF_WHITESPACE;
  68         if (!strcasecmp(var+ofs, "func"))
  69                 return DIFF_FUNCINFO;
  70         return -1;
  71 }
  72
  73 static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  74                                 struct strbuf *errmsg)
  75 {
  76         char *params_copy = xstrdup(params_string);
  77         struct string_list params = STRING_LIST_INIT_NODUP;
  78         int ret = 0;
  79         int i;
  80
  81         if (*params_copy)
  82                 string_list_split_in_place(&params, params_copy, ',', -1);
  83         for (i = 0; i < params.nr; i++) {
  84                 const char *p = params.items[i].string;
  85                 if (!strcmp(p, "changes")) {
  86                         DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                         DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  88                 } else if (!strcmp(p, "lines")) {
  89                         DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  90                         DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  91                 } else if (!strcmp(p, "files")) {
  92                         DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  93                         DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  94                 } else if (!strcmp(p, "noncumulative")) {
  95                         DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  96                 } else if (!strcmp(p, "cumulative")) {
  97                         DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  98                 } else if (isdigit(*p)) {
  99                         char *end;
 100                         int permille = strtoul(p, &end, 10) * 10;
 101                         if (*end == '.' && isdigit(*++end)) {
 102                                 /* only use first digit */
 103                                 permille += *end - '0';
 104                                 /* .. and ignore any further digits */
 105                                 while (isdigit(*++end))
 106                                         ; /* nothing */
 107                         }
 108                         if (!*end)
 109                                 options->dirstat_permille = permille;
 110                         else {
 111                                 strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 112                                             p);
 113                                 ret++;
 114                         }
 115                 } else {
 116                         strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 117                         ret++;
 118                 }
 119
 120         }
 121         string_list_clear(&params, 0);
 122         free(params_copy);
 123         return ret;
 124 }
 125
 126 static int git_config_rename(const char *var, const char *value)
 127 {
 128         if (!value)
 129                 return DIFF_DETECT_RENAME;
 130         if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 131                 return  DIFF_DETECT_COPY;
 132         return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 133 }
 134
 135 /*
 136  * These are to give UI layer defaults.
 137  * The core-level commands such as git-diff-files should
 138  * never be affected by the setting of diff.renames
 139  * the user happens to have in the configuration file.
 140  */
 141 int git_diff_ui_config(const char *var, const char *value, void *cb)
 142 {
 143         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 144                 diff_use_color_default = git_config_colorbool(var, value);
 145                 return 0;
 146         }
 147         if (!strcmp(var, "diff.context")) {
 148                 diff_context_default = git_config_int(var, value);
 149                 if (diff_context_default < 0)
 150                         return -1;
 151                 return 0;
 152         }
 153         if (!strcmp(var, "diff.renames")) {
 154                 diff_detect_rename_default = git_config_rename(var, value);
 155                 return 0;
 156         }
 157         if (!strcmp(var, "diff.autorefreshindex")) {
 158                 diff_auto_refresh_index = git_config_bool(var, value);
 159                 return 0;
 160         }
 161         if (!strcmp(var, "diff.mnemonicprefix")) {
 162                 diff_mnemonic_prefix = git_config_bool(var, value);
 163                 return 0;
 164         }
 165         if (!strcmp(var, "diff.noprefix")) {
 166                 diff_no_prefix = git_config_bool(var, value);
 167                 return 0;
 168         }
 169         if (!strcmp(var, "diff.statgraphwidth")) {
 170                 diff_stat_graph_width = git_config_int(var, value);
 171                 return 0;
 172         }
 173         if (!strcmp(var, "diff.external"))
 174                 return git_config_string(&external_diff_cmd_cfg, var, value);
 175         if (!strcmp(var, "diff.wordregex"))
 176                 return git_config_string(&diff_word_regex_cfg, var, value);
 177
 178         if (!strcmp(var, "diff.ignoresubmodules"))
 179                 handle_ignore_submodules_arg(&default_diff_options, value);
 180
 181         if (git_color_config(var, value, cb) < 0)
 182                 return -1;
 183
 184         return git_diff_basic_config(var, value, cb);
 185 }
 186
 187 int git_diff_basic_config(const char *var, const char *value, void *cb)
 188 {
 189         if (!strcmp(var, "diff.renamelimit")) {
 190                 diff_rename_limit_default = git_config_int(var, value);
 191                 return 0;
 192         }
 193
 194         if (userdiff_config(var, value) < 0)
 195                 return -1;
 196
 197         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 198                 int slot = parse_diff_color_slot(var, 11);
 199                 if (slot < 0)
 200                         return 0;
 201                 if (!value)
 202                         return config_error_nonbool(var);
 203                 color_parse(value, var, diff_colors[slot]);
 204                 return 0;
 205         }
 206
 207         /* like GNU diff's --suppress-blank-empty option  */
 208         if (!strcmp(var, "diff.suppressblankempty") ||
 209                         /* for backwards compatibility */
 210                         !strcmp(var, "diff.suppress-blank-empty")) {
 211                 diff_suppress_blank_empty = git_config_bool(var, value);
 212                 return 0;
 213         }
 214
 215         if (!strcmp(var, "diff.dirstat")) {
 216                 struct strbuf errmsg = STRBUF_INIT;
 217                 default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 218                 if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 219                         warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 220                                 errmsg.buf);
 221                 strbuf_release(&errmsg);
 222                 diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 223                 return 0;
 224         }
 225
 226         if (!prefixcmp(var, "submodule."))
 227                 return parse_submodule_config_option(var, value);
 228
 229         return git_default_config(var, value, cb);
 230 }
 231
 232 static char *quote_two(const char *one, const char *two)
 233 {
 234         int need_one = quote_c_style(one, NULL, NULL, 1);
 235         int need_two = quote_c_style(two, NULL, NULL, 1);
 236         struct strbuf res = STRBUF_INIT;
 237
 238         if (need_one + need_two) {
 239                 strbuf_addch(&res, '"');
 240                 quote_c_style(one, &res, NULL, 1);
 241                 quote_c_style(two, &res, NULL, 1);
 242                 strbuf_addch(&res, '"');
 243         } else {
 244                 strbuf_addstr(&res, one);
 245                 strbuf_addstr(&res, two);
 246         }
 247         return strbuf_detach(&res, NULL);
 248 }
 249
 250 static const char *external_diff(void)
 251 {
 252         static const char *external_diff_cmd = NULL;
 253         static int done_preparing = 0;
 254
 255         if (done_preparing)
 256                 return external_diff_cmd;
 257         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 258         if (!external_diff_cmd)
 259                 external_diff_cmd = external_diff_cmd_cfg;
 260         done_preparing = 1;
 261         return external_diff_cmd;
 262 }
 263
 264 static struct diff_tempfile {
 265         const char *name; /* filename external diff should read from */
 266         char hex[41];
 267         char mode[10];
 268         char tmp_path[PATH_MAX];
 269 } diff_temp[2];
 270
 271 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 272
 273 struct emit_callback {
 274         int color_diff;
 275         unsigned ws_rule;
 276         int blank_at_eof_in_preimage;
 277         int blank_at_eof_in_postimage;
 278         int lno_in_preimage;
 279         int lno_in_postimage;
 280         sane_truncate_fn truncate;
 281         const char **label_path;
 282         struct diff_words_data *diff_words;
 283         struct diff_options *opt;
 284         int *found_changesp;
 285         struct strbuf *header;
 286 };
 287
 288 static int count_lines(const char *data, int size)
 289 {
 290         int count, ch, completely_empty = 1, nl_just_seen = 0;
 291         count = 0;
 292         while (0 < size--) {
 293                 ch = *data++;
 294                 if (ch == '\n') {
 295                         count++;
 296                         nl_just_seen = 1;
 297                         completely_empty = 0;
 298                 }
 299                 else {
 300                         nl_just_seen = 0;
 301                         completely_empty = 0;
 302                 }
 303         }
 304         if (completely_empty)
 305                 return 0;
 306         if (!nl_just_seen)
 307                 count++; /* no trailing newline */
 308         return count;
 309 }
 310
 311 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 312 {
 313         if (!DIFF_FILE_VALID(one)) {
 314                 mf->ptr = (char *)""; /* does not matter */
 315                 mf->size = 0;
 316                 return 0;
 317         }
 318         else if (diff_populate_filespec(one, 0))
 319                 return -1;
 320
 321         mf->ptr = one->data;
 322         mf->size = one->size;
 323         return 0;
 324 }
 325
 326 /* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 327 static unsigned long diff_filespec_size(struct diff_filespec *one)
 328 {
 329         if (!DIFF_FILE_VALID(one))
 330                 return 0;
 331         diff_populate_filespec(one, 1);
 332         return one->size;
 333 }
 334
 335 static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 336 {
 337         char *ptr = mf->ptr;
 338         long size = mf->size;
 339         int cnt = 0;
 340
 341         if (!size)
 342                 return cnt;
 343         ptr += size - 1; /* pointing at the very end */
 344         if (*ptr != '\n')
 345                 ; /* incomplete line */
 346         else
 347                 ptr--; /* skip the last LF */
 348         while (mf->ptr < ptr) {
 349                 char *prev_eol;
 350                 for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 351                         if (*prev_eol == '\n')
 352                                 break;
 353                 if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 354                         break;
 355                 cnt++;
 356                 ptr = prev_eol - 1;
 357         }
 358         return cnt;
 359 }
 360
 361 static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 362                                struct emit_callback *ecbdata)
 363 {
 364         int l1, l2, at;
 365         unsigned ws_rule = ecbdata->ws_rule;
 366         l1 = count_trailing_blank(mf1, ws_rule);
 367         l2 = count_trailing_blank(mf2, ws_rule);
 368         if (l2 <= l1) {
 369                 ecbdata->blank_at_eof_in_preimage = 0;
 370                 ecbdata->blank_at_eof_in_postimage = 0;
 371                 return;
 372         }
 373         at = count_lines(mf1->ptr, mf1->size);
 374         ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 375
 376         at = count_lines(mf2->ptr, mf2->size);
 377         ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 378 }
 379
 380 static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 381                         int first, const char *line, int len)
 382 {
 383         int has_trailing_newline, has_trailing_carriage_return;
 384         int nofirst;
 385         FILE *file = o->file;
 386
 387         if (o->output_prefix) {
 388                 struct strbuf *msg = NULL;
 389                 msg = o->output_prefix(o, o->output_prefix_data);
 390                 assert(msg);
 391                 fwrite(msg->buf, msg->len, 1, file);
 392         }
 393
 394         if (len == 0) {
 395                 has_trailing_newline = (first == '\n');
 396                 has_trailing_carriage_return = (!has_trailing_newline &&
 397                                                 (first == '\r'));
 398                 nofirst = has_trailing_newline || has_trailing_carriage_return;
 399         } else {
 400                 has_trailing_newline = (len > 0 && line[len-1] == '\n');
 401                 if (has_trailing_newline)
 402                         len--;
 403                 has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 404                 if (has_trailing_carriage_return)
 405                         len--;
 406                 nofirst = 0;
 407         }
 408
 409         if (len || !nofirst) {
 410                 fputs(set, file);
 411                 if (!nofirst)
 412                         fputc(first, file);
 413                 fwrite(line, len, 1, file);
 414                 fputs(reset, file);
 415         }
 416         if (has_trailing_carriage_return)
 417                 fputc('\r', file);
 418         if (has_trailing_newline)
 419                 fputc('\n', file);
 420 }
 421
 422 static void emit_line(struct diff_options *o, const char *set, const char *reset,
 423                       const char *line, int len)
 424 {
 425         emit_line_0(o, set, reset, line[0], line+1, len-1);
 426 }
 427
 428 static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 429 {
 430         if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 431               ecbdata->blank_at_eof_in_preimage &&
 432               ecbdata->blank_at_eof_in_postimage &&
 433               ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 434               ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 435                 return 0;
 436         return ws_blank_line(line, len, ecbdata->ws_rule);
 437 }
 438
 439 static void emit_add_line(const char *reset,
 440                           struct emit_callback *ecbdata,
 441                           const char *line, int len)
 442 {
 443         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 444         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 445
 446         if (!*ws)
 447                 emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 448         else if (new_blank_line_at_eof(ecbdata, line, len))
 449                 /* Blank line at EOF - paint '+' as well */
 450                 emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 451         else {
 452                 /* Emit just the prefix, then the rest. */
 453                 emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 454                 ws_check_emit(line, len, ecbdata->ws_rule,
 455                               ecbdata->opt->file, set, reset, ws);
 456         }
 457 }
 458
 459 static void emit_hunk_header(struct emit_callback *ecbdata,
 460                              const char *line, int len)
 461 {
 462         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 463         const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 464         const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 465         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 466         static const char atat[2] = { '@', '@' };
 467         const char *cp, *ep;
 468         struct strbuf msgbuf = STRBUF_INIT;
 469         int org_len = len;
 470         int i = 1;
 471
 472         /*
 473          * As a hunk header must begin with "@@ -<old>, +<new> @@",
 474          * it always is at least 10 bytes long.
 475          */
 476         if (len < 10 ||
 477             memcmp(line, atat, 2) ||
 478             !(ep = memmem(line + 2, len - 2, atat, 2))) {
 479                 emit_line(ecbdata->opt, plain, reset, line, len);
 480                 return;
 481         }
 482         ep += 2; /* skip over @@ */
 483
 484         /* The hunk header in fraginfo color */
 485         strbuf_add(&msgbuf, frag, strlen(frag));
 486         strbuf_add(&msgbuf, line, ep - line);
 487         strbuf_add(&msgbuf, reset, strlen(reset));
 488
 489         /*
 490          * trailing "\r\n"
 491          */
 492         for ( ; i < 3; i++)
 493                 if (line[len - i] == '\r' || line[len - i] == '\n')
 494                         len--;
 495
 496         /* blank before the func header */
 497         for (cp = ep; ep - line < len; ep++)
 498                 if (*ep != ' ' && *ep != '\t')
 499                         break;
 500         if (ep != cp) {
 501                 strbuf_add(&msgbuf, plain, strlen(plain));
 502                 strbuf_add(&msgbuf, cp, ep - cp);
 503                 strbuf_add(&msgbuf, reset, strlen(reset));
 504         }
 505
 506         if (ep < line + len) {
 507                 strbuf_add(&msgbuf, func, strlen(func));
 508                 strbuf_add(&msgbuf, ep, line + len - ep);
 509                 strbuf_add(&msgbuf, reset, strlen(reset));
 510         }
 511
 512         strbuf_add(&msgbuf, line + len, org_len - len);
 513         emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 514         strbuf_release(&msgbuf);
 515 }
 516
 517 static struct diff_tempfile *claim_diff_tempfile(void) {
 518         int i;
 519         for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 520                 if (!diff_temp[i].name)
 521                         return diff_temp + i;
 522         die("BUG: diff is failing to clean up its tempfiles");
 523 }
 524
 525 static int remove_tempfile_installed;
 526
 527 static void remove_tempfile(void)
 528 {
 529         int i;
 530         for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 531                 if (diff_temp[i].name == diff_temp[i].tmp_path)
 532                         unlink_or_warn(diff_temp[i].name);
 533                 diff_temp[i].name = NULL;
 534         }
 535 }
 536
 537 static void remove_tempfile_on_signal(int signo)
 538 {
 539         remove_tempfile();
 540         sigchain_pop(signo);
 541         raise(signo);
 542 }
 543
 544 static void print_line_count(FILE *file, int count)
 545 {
 546         switch (count) {
 547         case 0:
 548                 fprintf(file, "0,0");
 549                 break;
 550         case 1:
 551                 fprintf(file, "1");
 552                 break;
 553         default:
 554                 fprintf(file, "1,%d", count);
 555                 break;
 556         }
 557 }
 558
 559 static void emit_rewrite_lines(struct emit_callback *ecb,
 560                                int prefix, const char *data, int size)
 561 {
 562         const char *endp = NULL;
 563         static const char *nneof = " No newline at end of file\n";
 564         const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 565         const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 566
 567         while (0 < size) {
 568                 int len;
 569
 570                 endp = memchr(data, '\n', size);
 571                 len = endp ? (endp - data + 1) : size;
 572                 if (prefix != '+') {
 573                         ecb->lno_in_preimage++;
 574                         emit_line_0(ecb->opt, old, reset, '-',
 575                                     data, len);
 576                 } else {
 577                         ecb->lno_in_postimage++;
 578                         emit_add_line(reset, ecb, data, len);
 579                 }
 580                 size -= len;
 581                 data += len;
 582         }
 583         if (!endp) {
 584                 const char *plain = diff_get_color(ecb->color_diff,
 585                                                    DIFF_PLAIN);
 586                 putc('\n', ecb->opt->file);
 587                 emit_line_0(ecb->opt, plain, reset, '\\',
 588                             nneof, strlen(nneof));
 589         }
 590 }
 591
 592 static void emit_rewrite_diff(const char *name_a,
 593                               const char *name_b,
 594                               struct diff_filespec *one,
 595                               struct diff_filespec *two,
 596                               struct userdiff_driver *textconv_one,
 597                               struct userdiff_driver *textconv_two,
 598                               struct diff_options *o)
 599 {
 600         int lc_a, lc_b;
 601         const char *name_a_tab, *name_b_tab;
 602         const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 603         const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 604         const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 605         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 606         const char *a_prefix, *b_prefix;
 607         char *data_one, *data_two;
 608         size_t size_one, size_two;
 609         struct emit_callback ecbdata;
 610         char *line_prefix = "";
 611         struct strbuf *msgbuf;
 612
 613         if (o && o->output_prefix) {
 614                 msgbuf = o->output_prefix(o, o->output_prefix_data);
 615                 line_prefix = msgbuf->buf;
 616         }
 617
 618         if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 619                 a_prefix = o->b_prefix;
 620                 b_prefix = o->a_prefix;
 621         } else {
 622                 a_prefix = o->a_prefix;
 623                 b_prefix = o->b_prefix;
 624         }
 625
 626         name_a += (*name_a == '/');
 627         name_b += (*name_b == '/');
 628         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 629         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 630
 631         strbuf_reset(&a_name);
 632         strbuf_reset(&b_name);
 633         quote_two_c_style(&a_name, a_prefix, name_a, 0);
 634         quote_two_c_style(&b_name, b_prefix, name_b, 0);
 635
 636         size_one = fill_textconv(textconv_one, one, &data_one);
 637         size_two = fill_textconv(textconv_two, two, &data_two);
 638
 639         memset(&ecbdata, 0, sizeof(ecbdata));
 640         ecbdata.color_diff = want_color(o->use_color);
 641         ecbdata.found_changesp = &o->found_changes;
 642         ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 643         ecbdata.opt = o;
 644         if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 645                 mmfile_t mf1, mf2;
 646                 mf1.ptr = (char *)data_one;
 647                 mf2.ptr = (char *)data_two;
 648                 mf1.size = size_one;
 649                 mf2.size = size_two;
 650                 check_blank_at_eof(&mf1, &mf2, &ecbdata);
 651         }
 652         ecbdata.lno_in_preimage = 1;
 653         ecbdata.lno_in_postimage = 1;
 654
 655         lc_a = count_lines(data_one, size_one);
 656         lc_b = count_lines(data_two, size_two);
 657         fprintf(o->file,
 658                 "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 659                 line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 660                 line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 661                 line_prefix, fraginfo);
 662         if (!o->irreversible_delete)
 663                 print_line_count(o->file, lc_a);
 664         else
 665                 fprintf(o->file, "?,?");
 666         fprintf(o->file, " +");
 667         print_line_count(o->file, lc_b);
 668         fprintf(o->file, " @@%s\n", reset);
 669         if (lc_a && !o->irreversible_delete)
 670                 emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 671         if (lc_b)
 672                 emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 673         if (textconv_one)
 674                 free((char *)data_one);
 675         if (textconv_two)
 676                 free((char *)data_two);
 677 }
 678
 679 struct diff_words_buffer {
 680         mmfile_t text;
 681         long alloc;
 682         struct diff_words_orig {
 683                 const char *begin, *end;
 684         } *orig;
 685         int orig_nr, orig_alloc;
 686 };
 687
 688 static void diff_words_append(char *line, unsigned long len,
 689                 struct diff_words_buffer *buffer)
 690 {
 691         ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 692         line++;
 693         len--;
 694         memcpy(buffer->text.ptr + buffer->text.size, line, len);
 695         buffer->text.size += len;
 696         buffer->text.ptr[buffer->text.size] = '\0';
 697 }
 698
 699 struct diff_words_style_elem {
 700         const char *prefix;
 701         const char *suffix;
 702         const char *color; /* NULL; filled in by the setup code if
 703                             * color is enabled */
 704 };
 705
 706 struct diff_words_style {
 707         enum diff_words_type type;
 708         struct diff_words_style_elem new, old, ctx;
 709         const char *newline;
 710 };
 711
 712 static struct diff_words_style diff_words_styles[] = {
 713         { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 714         { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 715         { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 716 };
 717
 718 struct diff_words_data {
 719         struct diff_words_buffer minus, plus;
 720         const char *current_plus;
 721         int last_minus;
 722         struct diff_options *opt;
 723         regex_t *word_regex;
 724         enum diff_words_type type;
 725         struct diff_words_style *style;
 726 };
 727
 728 static int fn_out_diff_words_write_helper(FILE *fp,
 729                                           struct diff_words_style_elem *st_el,
 730                                           const char *newline,
 731                                           size_t count, const char *buf,
 732                                           const char *line_prefix)
 733 {
 734         int print = 0;
 735
 736         while (count) {
 737                 char *p = memchr(buf, '\n', count);
 738                 if (print)
 739                         fputs(line_prefix, fp);
 740                 if (p != buf) {
 741                         if (st_el->color && fputs(st_el->color, fp) < 0)
 742                                 return -1;
 743                         if (fputs(st_el->prefix, fp) < 0 ||
 744                             fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 745                             fputs(st_el->suffix, fp) < 0)
 746                                 return -1;
 747                         if (st_el->color && *st_el->color
 748                             && fputs(GIT_COLOR_RESET, fp) < 0)
 749                                 return -1;
 750                 }
 751                 if (!p)
 752                         return 0;
 753                 if (fputs(newline, fp) < 0)
 754                         return -1;
 755                 count -= p + 1 - buf;
 756                 buf = p + 1;
 757                 print = 1;
 758         }
 759         return 0;
 760 }
 761
 762 /*
 763  * '--color-words' algorithm can be described as:
 764  *
 765  *   1. collect a the minus/plus lines of a diff hunk, divided into
 766  *      minus-lines and plus-lines;
 767  *
 768  *   2. break both minus-lines and plus-lines into words and
 769  *      place them into two mmfile_t with one word for each line;
 770  *
 771  *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 772  *
 773  * And for the common parts of the both file, we output the plus side text.
 774  * diff_words->current_plus is used to trace the current position of the plus file
 775  * which printed. diff_words->last_minus is used to trace the last minus word
 776  * printed.
 777  *
 778  * For '--graph' to work with '--color-words', we need to output the graph prefix
 779  * on each line of color words output. Generally, there are two conditions on
 780  * which we should output the prefix.
 781  *
 782  *   1. diff_words->last_minus == 0 &&
 783  *      diff_words->current_plus == diff_words->plus.text.ptr
 784  *
 785  *      that is: the plus text must start as a new line, and if there is no minus
 786  *      word printed, a graph prefix must be printed.
 787  *
 788  *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 789  *      *(diff_words->current_plus - 1) == '\n'
 790  *
 791  *      that is: a graph prefix must be printed following a '\n'
 792  */
 793 static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 794 {
 795         if ((diff_words->last_minus == 0 &&
 796                 diff_words->current_plus == diff_words->plus.text.ptr) ||
 797                 (diff_words->current_plus > diff_words->plus.text.ptr &&
 798                 *(diff_words->current_plus - 1) == '\n')) {
 799                 return 1;
 800         } else {
 801                 return 0;
 802         }
 803 }
 804
 805 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 806 {
 807         struct diff_words_data *diff_words = priv;
 808         struct diff_words_style *style = diff_words->style;
 809         int minus_first, minus_len, plus_first, plus_len;
 810         const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 811         struct diff_options *opt = diff_words->opt;
 812         struct strbuf *msgbuf;
 813         char *line_prefix = "";
 814
 815         if (line[0] != '@' || parse_hunk_header(line, len,
 816                         &minus_first, &minus_len, &plus_first, &plus_len))
 817                 return;
 818
 819         assert(opt);
 820         if (opt->output_prefix) {
 821                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 822                 line_prefix = msgbuf->buf;
 823         }
 824
 825         /* POSIX requires that first be decremented by one if len == 0... */
 826         if (minus_len) {
 827                 minus_begin = diff_words->minus.orig[minus_first].begin;
 828                 minus_end =
 829                         diff_words->minus.orig[minus_first + minus_len - 1].end;
 830         } else
 831                 minus_begin = minus_end =
 832                         diff_words->minus.orig[minus_first].end;
 833
 834         if (plus_len) {
 835                 plus_begin = diff_words->plus.orig[plus_first].begin;
 836                 plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 837         } else
 838                 plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 839
 840         if (color_words_output_graph_prefix(diff_words)) {
 841                 fputs(line_prefix, diff_words->opt->file);
 842         }
 843         if (diff_words->current_plus != plus_begin) {
 844                 fn_out_diff_words_write_helper(diff_words->opt->file,
 845                                 &style->ctx, style->newline,
 846                                 plus_begin - diff_words->current_plus,
 847                                 diff_words->current_plus, line_prefix);
 848                 if (*(plus_begin - 1) == '\n')
 849                         fputs(line_prefix, diff_words->opt->file);
 850         }
 851         if (minus_begin != minus_end) {
 852                 fn_out_diff_words_write_helper(diff_words->opt->file,
 853                                 &style->old, style->newline,
 854                                 minus_end - minus_begin, minus_begin,
 855                                 line_prefix);
 856         }
 857         if (plus_begin != plus_end) {
 858                 fn_out_diff_words_write_helper(diff_words->opt->file,
 859                                 &style->new, style->newline,
 860                                 plus_end - plus_begin, plus_begin,
 861                                 line_prefix);
 862         }
 863
 864         diff_words->current_plus = plus_end;
 865         diff_words->last_minus = minus_first;
 866 }
 867
 868 /* This function starts looking at *begin, and returns 0 iff a word was found. */
 869 static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 870                 int *begin, int *end)
 871 {
 872         if (word_regex && *begin < buffer->size) {
 873                 regmatch_t match[1];
 874                 if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 875                         char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 876                                         '\n', match[0].rm_eo - match[0].rm_so);
 877                         *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 878                         *begin += match[0].rm_so;
 879                         return *begin >= *end;
 880                 }
 881                 return -1;
 882         }
 883
 884         /* find the next word */
 885         while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 886                 (*begin)++;
 887         if (*begin >= buffer->size)
 888                 return -1;
 889
 890         /* find the end of the word */
 891         *end = *begin + 1;
 892         while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 893                 (*end)++;
 894
 895         return 0;
 896 }
 897
 898 /*
 899  * This function splits the words in buffer->text, stores the list with
 900  * newline separator into out, and saves the offsets of the original words
 901  * in buffer->orig.
 902  */
 903 static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 904                 regex_t *word_regex)
 905 {
 906         int i, j;
 907         long alloc = 0;
 908
 909         out->size = 0;
 910         out->ptr = NULL;
 911
 912         /* fake an empty "0th" word */
 913         ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 914         buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 915         buffer->orig_nr = 1;
 916
 917         for (i = 0; i < buffer->text.size; i++) {
 918                 if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 919                         return;
 920
 921                 /* store original boundaries */
 922                 ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 923                                 buffer->orig_alloc);
 924                 buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 925                 buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 926                 buffer->orig_nr++;
 927
 928                 /* store one word */
 929                 ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 930                 memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 931                 out->ptr[out->size + j - i] = '\n';
 932                 out->size += j - i + 1;
 933
 934                 i = j - 1;
 935         }
 936 }
 937
 938 /* this executes the word diff on the accumulated buffers */
 939 static void diff_words_show(struct diff_words_data *diff_words)
 940 {
 941         xpparam_t xpp;
 942         xdemitconf_t xecfg;
 943         mmfile_t minus, plus;
 944         struct diff_words_style *style = diff_words->style;
 945
 946         struct diff_options *opt = diff_words->opt;
 947         struct strbuf *msgbuf;
 948         char *line_prefix = "";
 949
 950         assert(opt);
 951         if (opt->output_prefix) {
 952                 msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 953                 line_prefix = msgbuf->buf;
 954         }
 955
 956         /* special case: only removal */
 957         if (!diff_words->plus.text.size) {
 958                 fputs(line_prefix, diff_words->opt->file);
 959                 fn_out_diff_words_write_helper(diff_words->opt->file,
 960                         &style->old, style->newline,
 961                         diff_words->minus.text.size,
 962                         diff_words->minus.text.ptr, line_prefix);
 963                 diff_words->minus.text.size = 0;
 964                 return;
 965         }
 966
 967         diff_words->current_plus = diff_words->plus.text.ptr;
 968         diff_words->last_minus = 0;
 969
 970         memset(&xpp, 0, sizeof(xpp));
 971         memset(&xecfg, 0, sizeof(xecfg));
 972         diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 973         diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 974         xpp.flags = 0;
 975         /* as only the hunk header will be parsed, we need a 0-context */
 976         xecfg.ctxlen = 0;
 977         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 978                       &xpp, &xecfg);
 979         free(minus.ptr);
 980         free(plus.ptr);
 981         if (diff_words->current_plus != diff_words->plus.text.ptr +
 982                         diff_words->plus.text.size) {
 983                 if (color_words_output_graph_prefix(diff_words))
 984                         fputs(line_prefix, diff_words->opt->file);
 985                 fn_out_diff_words_write_helper(diff_words->opt->file,
 986                         &style->ctx, style->newline,
 987                         diff_words->plus.text.ptr + diff_words->plus.text.size
 988                         - diff_words->current_plus, diff_words->current_plus,
 989                         line_prefix);
 990         }
 991         diff_words->minus.text.size = diff_words->plus.text.size = 0;
 992 }
 993
 994 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
 995 static void diff_words_flush(struct emit_callback *ecbdata)
 996 {
 997         if (ecbdata->diff_words->minus.text.size ||
 998             ecbdata->diff_words->plus.text.size)
 999                 diff_words_show(ecbdata->diff_words);
1000 }
1001
1002 static void diff_filespec_load_driver(struct diff_filespec *one)
1003 {
1004         /* Use already-loaded driver */
1005         if (one->driver)
1006                 return;
1007
1008         if (S_ISREG(one->mode))
1009                 one->driver = userdiff_find_by_path(one->path);
1010
1011         /* Fallback to default settings */
1012         if (!one->driver)
1013                 one->driver = userdiff_find_by_name("default");
1014 }
1015
1016 static const char *userdiff_word_regex(struct diff_filespec *one)
1017 {
1018         diff_filespec_load_driver(one);
1019         return one->driver->word_regex;
1020 }
1021
1022 static void init_diff_words_data(struct emit_callback *ecbdata,
1023                                  struct diff_options *orig_opts,
1024                                  struct diff_filespec *one,
1025                                  struct diff_filespec *two)
1026 {
1027         int i;
1028         struct diff_options *o = xmalloc(sizeof(struct diff_options));
1029         memcpy(o, orig_opts, sizeof(struct diff_options));
1030
1031         ecbdata->diff_words =
1032                 xcalloc(1, sizeof(struct diff_words_data));
1033         ecbdata->diff_words->type = o->word_diff;
1034         ecbdata->diff_words->opt = o;
1035         if (!o->word_regex)
1036                 o->word_regex = userdiff_word_regex(one);
1037         if (!o->word_regex)
1038                 o->word_regex = userdiff_word_regex(two);
1039         if (!o->word_regex)
1040                 o->word_regex = diff_word_regex_cfg;
1041         if (o->word_regex) {
1042                 ecbdata->diff_words->word_regex = (regex_t *)
1043                         xmalloc(sizeof(regex_t));
1044                 if (regcomp(ecbdata->diff_words->word_regex,
1045                             o->word_regex,
1046                             REG_EXTENDED | REG_NEWLINE))
1047                         die ("Invalid regular expression: %s",
1048                              o->word_regex);
1049         }
1050         for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1051                 if (o->word_diff == diff_words_styles[i].type) {
1052                         ecbdata->diff_words->style =
1053                                 &diff_words_styles[i];
1054                         break;
1055                 }
1056         }
1057         if (want_color(o->use_color)) {
1058                 struct diff_words_style *st = ecbdata->diff_words->style;
1059                 st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1060                 st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1061                 st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1062         }
1063 }
1064
1065 static void free_diff_words_data(struct emit_callback *ecbdata)
1066 {
1067         if (ecbdata->diff_words) {
1068                 diff_words_flush(ecbdata);
1069                 free (ecbdata->diff_words->opt);
1070                 free (ecbdata->diff_words->minus.text.ptr);
1071                 free (ecbdata->diff_words->minus.orig);
1072                 free (ecbdata->diff_words->plus.text.ptr);
1073                 free (ecbdata->diff_words->plus.orig);
1074                 if (ecbdata->diff_words->word_regex) {
1075                         regfree(ecbdata->diff_words->word_regex);
1076                         free(ecbdata->diff_words->word_regex);
1077                 }
1078                 free(ecbdata->diff_words);
1079                 ecbdata->diff_words = NULL;
1080         }
1081 }
1082
1083 const char *diff_get_color(int diff_use_color, enum color_diff ix)
1084 {
1085         if (want_color(diff_use_color))
1086                 return diff_colors[ix];
1087         return "";
1088 }
1089
1090 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1091 {
1092         const char *cp;
1093         unsigned long allot;
1094         size_t l = len;
1095
1096         if (ecb->truncate)
1097                 return ecb->truncate(line, len);
1098         cp = line;
1099         allot = l;
1100         while (0 < l) {
1101                 (void) utf8_width(&cp, &l);
1102                 if (!cp)
1103                         break; /* truncated in the middle? */
1104         }
1105         return allot - l;
1106 }
1107
1108 static void find_lno(const char *line, struct emit_callback *ecbdata)
1109 {
1110         const char *p;
1111         ecbdata->lno_in_preimage = 0;
1112         ecbdata->lno_in_postimage = 0;
1113         p = strchr(line, '-');
1114         if (!p)
1115                 return; /* cannot happen */
1116         ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1117         p = strchr(p, '+');
1118         if (!p)
1119                 return; /* cannot happen */
1120         ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1121 }
1122
1123 static void fn_out_consume(void *priv, char *line, unsigned long len)
1124 {
1125         struct emit_callback *ecbdata = priv;
1126         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1127         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1128         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1129         struct diff_options *o = ecbdata->opt;
1130         char *line_prefix = "";
1131         struct strbuf *msgbuf;
1132
1133         if (o && o->output_prefix) {
1134                 msgbuf = o->output_prefix(o, o->output_prefix_data);
1135                 line_prefix = msgbuf->buf;
1136         }
1137
1138         if (ecbdata->header) {
1139                 fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1140                 strbuf_reset(ecbdata->header);
1141                 ecbdata->header = NULL;
1142         }
1143         *(ecbdata->found_changesp) = 1;
1144
1145         if (ecbdata->label_path[0]) {
1146                 const char *name_a_tab, *name_b_tab;
1147
1148                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1149                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1150
1151                 fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1152                         line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1153                 fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1154                         line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1155                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1156         }
1157
1158         if (diff_suppress_blank_empty
1159             && len == 2 && line[0] == ' ' && line[1] == '\n') {
1160                 line[0] = '\n';
1161                 len = 1;
1162         }
1163
1164         if (line[0] == '@') {
1165                 if (ecbdata->diff_words)
1166                         diff_words_flush(ecbdata);
1167                 len = sane_truncate_line(ecbdata, line, len);
1168                 find_lno(line, ecbdata);
1169                 emit_hunk_header(ecbdata, line, len);
1170                 if (line[len-1] != '\n')
1171                         putc('\n', ecbdata->opt->file);
1172                 return;
1173         }
1174
1175         if (len < 1) {
1176                 emit_line(ecbdata->opt, reset, reset, line, len);
1177                 if (ecbdata->diff_words
1178                     && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1179                         fputs("~\n", ecbdata->opt->file);
1180                 return;
1181         }
1182
1183         if (ecbdata->diff_words) {
1184                 if (line[0] == '-') {
1185                         diff_words_append(line, len,
1186                                           &ecbdata->diff_words->minus);
1187                         return;
1188                 } else if (line[0] == '+') {
1189                         diff_words_append(line, len,
1190                                           &ecbdata->diff_words->plus);
1191                         return;
1192                 } else if (!prefixcmp(line, "\\ ")) {
1193                         /*
1194                          * Eat the "no newline at eof" marker as if we
1195                          * saw a "+" or "-" line with nothing on it,
1196                          * and return without diff_words_flush() to
1197                          * defer processing. If this is the end of
1198                          * preimage, more "+" lines may come after it.
1199                          */
1200                         return;
1201                 }
1202                 diff_words_flush(ecbdata);
1203                 if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1204                         emit_line(ecbdata->opt, plain, reset, line, len);
1205                         fputs("~\n", ecbdata->opt->file);
1206                 } else {
1207                         /*
1208                          * Skip the prefix character, if any.  With
1209                          * diff_suppress_blank_empty, there may be
1210                          * none.
1211                          */
1212                         if (line[0] != '\n') {
1213                               line++;
1214                               len--;
1215                         }
1216                         emit_line(ecbdata->opt, plain, reset, line, len);
1217                 }
1218                 return;
1219         }
1220
1221         if (line[0] != '+') {
1222                 const char *color =
1223                         diff_get_color(ecbdata->color_diff,
1224                                        line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1225                 ecbdata->lno_in_preimage++;
1226                 if (line[0] == ' ')
1227                         ecbdata->lno_in_postimage++;
1228                 emit_line(ecbdata->opt, color, reset, line, len);
1229         } else {
1230                 ecbdata->lno_in_postimage++;
1231                 emit_add_line(reset, ecbdata, line + 1, len - 1);
1232         }
1233 }
1234
1235 static char *pprint_rename(const char *a, const char *b)
1236 {
1237         const char *old = a;
1238         const char *new = b;
1239         struct strbuf name = STRBUF_INIT;
1240         int pfx_length, sfx_length;
1241         int len_a = strlen(a);
1242         int len_b = strlen(b);
1243         int a_midlen, b_midlen;
1244         int qlen_a = quote_c_style(a, NULL, NULL, 0);
1245         int qlen_b = quote_c_style(b, NULL, NULL, 0);
1246
1247         if (qlen_a || qlen_b) {
1248                 quote_c_style(a, &name, NULL, 0);
1249                 strbuf_addstr(&name, " => ");
1250                 quote_c_style(b, &name, NULL, 0);
1251                 return strbuf_detach(&name, NULL);
1252         }
1253
1254         /* Find common prefix */
1255         pfx_length = 0;
1256         while (*old && *new && *old == *new) {
1257                 if (*old == '/')
1258                         pfx_length = old - a + 1;
1259                 old++;
1260                 new++;
1261         }
1262
1263         /* Find common suffix */
1264         old = a + len_a;
1265         new = b + len_b;
1266         sfx_length = 0;
1267         while (a <= old && b <= new && *old == *new) {
1268                 if (*old == '/')
1269                         sfx_length = len_a - (old - a);
1270                 old--;
1271                 new--;
1272         }
1273
1274         /*
1275          * pfx{mid-a => mid-b}sfx
1276          * {pfx-a => pfx-b}sfx
1277          * pfx{sfx-a => sfx-b}
1278          * name-a => name-b
1279          */
1280         a_midlen = len_a - pfx_length - sfx_length;
1281         b_midlen = len_b - pfx_length - sfx_length;
1282         if (a_midlen < 0)
1283                 a_midlen = 0;
1284         if (b_midlen < 0)
1285                 b_midlen = 0;
1286
1287         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1288         if (pfx_length + sfx_length) {
1289                 strbuf_add(&name, a, pfx_length);
1290                 strbuf_addch(&name, '{');
1291         }
1292         strbuf_add(&name, a + pfx_length, a_midlen);
1293         strbuf_addstr(&name, " => ");
1294         strbuf_add(&name, b + pfx_length, b_midlen);
1295         if (pfx_length + sfx_length) {
1296                 strbuf_addch(&name, '}');
1297                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1298         }
1299         return strbuf_detach(&name, NULL);
1300 }
1301
1302 struct diffstat_t {
1303         int nr;
1304         int alloc;
1305         struct diffstat_file {
1306                 char *from_name;
1307                 char *name;
1308                 char *print_name;
1309                 unsigned is_unmerged:1;
1310                 unsigned is_binary:1;
1311                 unsigned is_renamed:1;
1312                 uintmax_t added, deleted;
1313         } **files;
1314 };
1315
1316 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1317                                           const char *name_a,
1318                                           const char *name_b)
1319 {
1320         struct diffstat_file *x;
1321         x = xcalloc(sizeof (*x), 1);
1322         if (diffstat->nr == diffstat->alloc) {
1323                 diffstat->alloc = alloc_nr(diffstat->alloc);
1324                 diffstat->files = xrealloc(diffstat->files,
1325                                 diffstat->alloc * sizeof(x));
1326         }
1327         diffstat->files[diffstat->nr++] = x;
1328         if (name_b) {
1329                 x->from_name = xstrdup(name_a);
1330                 x->name = xstrdup(name_b);
1331                 x->is_renamed = 1;
1332         }
1333         else {
1334                 x->from_name = NULL;
1335                 x->name = xstrdup(name_a);
1336         }
1337         return x;
1338 }
1339
1340 static void diffstat_consume(void *priv, char *line, unsigned long len)
1341 {
1342         struct diffstat_t *diffstat = priv;
1343         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1344
1345         if (line[0] == '+')
1346                 x->added++;
1347         else if (line[0] == '-')
1348                 x->deleted++;
1349 }
1350
1351 const char mime_boundary_leader[] = "------------";
1352
1353 static int scale_linear(int it, int width, int max_change)
1354 {
1355         if (!it)
1356                 return 0;
1357         /*
1358          * make sure that at least one '-' or '+' is printed if
1359          * there is any change to this path. The easiest way is to
1360          * scale linearly as if the alloted width is one column shorter
1361          * than it is, and then add 1 to the result.
1362          */
1363         return 1 + (it * (width - 1) / max_change);
1364 }
1365
1366 static void show_name(FILE *file,
1367                       const char *prefix, const char *name, int len)
1368 {
1369         fprintf(file, " %s%-*s |", prefix, len, name);
1370 }
1371
1372 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1373 {
1374         if (cnt <= 0)
1375                 return;
1376         fprintf(file, "%s", set);
1377         while (cnt--)
1378                 putc(ch, file);
1379         fprintf(file, "%s", reset);
1380 }
1381
1382 static void fill_print_name(struct diffstat_file *file)
1383 {
1384         char *pname;
1385
1386         if (file->print_name)
1387                 return;
1388
1389         if (!file->is_renamed) {
1390                 struct strbuf buf = STRBUF_INIT;
1391                 if (quote_c_style(file->name, &buf, NULL, 0)) {
1392                         pname = strbuf_detach(&buf, NULL);
1393                 } else {
1394                         pname = file->name;
1395                         strbuf_release(&buf);
1396                 }
1397         } else {
1398                 pname = pprint_rename(file->from_name, file->name);
1399         }
1400         file->print_name = pname;
1401 }
1402
1403 int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1404 {
1405         struct strbuf sb = STRBUF_INIT;
1406         int ret;
1407
1408         if (!files) {
1409                 assert(insertions == 0 && deletions == 0);
1410                 return fprintf(fp, "%s\n", " 0 files changed");
1411         }
1412
1413         strbuf_addf(&sb,
1414                     (files == 1) ? " %d file changed" : " %d files changed",
1415                     files);
1416
1417         /*
1418          * For binary diff, the caller may want to print "x files
1419          * changed" with insertions == 0 && deletions == 0.
1420          *
1421          * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1422          * is probably less confusing (i.e skip over "2 files changed
1423          * but nothing about added/removed lines? Is this a bug in Git?").
1424          */
1425         if (insertions || deletions == 0) {
1426                 /*
1427                  * TRANSLATORS: "+" in (+) is a line addition marker;
1428                  * do not translate it.
1429                  */
1430                 strbuf_addf(&sb,
1431                             (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1432                             insertions);
1433         }
1434
1435         if (deletions || insertions == 0) {
1436                 /*
1437                  * TRANSLATORS: "-" in (-) is a line removal marker;
1438                  * do not translate it.
1439                  */
1440                 strbuf_addf(&sb,
1441                             (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1442                             deletions);
1443         }
1444         strbuf_addch(&sb, '\n');
1445         ret = fputs(sb.buf, fp);
1446         strbuf_release(&sb);
1447         return ret;
1448 }
1449
1450 static void show_stats(struct diffstat_t *data, struct diff_options *options)
1451 {
1452         int i, len, add, del, adds = 0, dels = 0;
1453         uintmax_t max_change = 0, max_len = 0;
1454         int total_files = data->nr, count;
1455         int width, name_width, graph_width, number_width = 0, bin_width = 0;
1456         const char *reset, *add_c, *del_c;
1457         const char *line_prefix = "";
1458         int extra_shown = 0;
1459         struct strbuf *msg = NULL;
1460
1461         if (data->nr == 0)
1462                 return;
1463
1464         if (options->output_prefix) {
1465                 msg = options->output_prefix(options, options->output_prefix_data);
1466                 line_prefix = msg->buf;
1467         }
1468
1469         count = options->stat_count ? options->stat_count : data->nr;
1470
1471         reset = diff_get_color_opt(options, DIFF_RESET);
1472         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1473         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1474
1475         /*
1476          * Find the longest filename and max number of changes
1477          */
1478         for (i = 0; (i < count) && (i < data->nr); i++) {
1479                 struct diffstat_file *file = data->files[i];
1480                 uintmax_t change = file->added + file->deleted;
1481                 if (!data->files[i]->is_renamed &&
1482                          (change == 0)) {
1483                         count++; /* not shown == room for one more */
1484                         continue;
1485                 }
1486                 fill_print_name(file);
1487                 len = strlen(file->print_name);
1488                 if (max_len < len)
1489                         max_len = len;
1490
1491                 if (file->is_unmerged) {
1492                         /* "Unmerged" is 8 characters */
1493                         bin_width = bin_width < 8 ? 8 : bin_width;
1494                         continue;
1495                 }
1496                 if (file->is_binary) {
1497                         /* "Bin XXX -> YYY bytes" */
1498                         int w = 14 + decimal_width(file->added)
1499                                 + decimal_width(file->deleted);
1500                         bin_width = bin_width < w ? w : bin_width;
1501                         /* Display change counts aligned with "Bin" */
1502                         number_width = 3;
1503                         continue;
1504                 }
1505
1506                 if (max_change < change)
1507                         max_change = change;
1508         }
1509         count = i; /* min(count, data->nr) */
1510
1511         /*
1512          * We have width = stat_width or term_columns() columns total.
1513          * We want a maximum of min(max_len, stat_name_width) for the name part.
1514          * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1515          * We also need 1 for " " and 4 + decimal_width(max_change)
1516          * for " | NNNN " and one the empty column at the end, altogether
1517          * 6 + decimal_width(max_change).
1518          *
1519          * If there's not enough space, we will use the smaller of
1520          * stat_name_width (if set) and 5/8*width for the filename,
1521          * and the rest for constant elements + graph part, but no more
1522          * than stat_graph_width for the graph part.
1523          * (5/8 gives 50 for filename and 30 for the constant parts + graph
1524          * for the standard terminal size).
1525          *
1526          * In other words: stat_width limits the maximum width, and
1527          * stat_name_width fixes the maximum width of the filename,
1528          * and is also used to divide available columns if there
1529          * aren't enough.
1530          *
1531          * Binary files are displayed with "Bin XXX -> YYY bytes"
1532          * instead of the change count and graph. This part is treated
1533          * similarly to the graph part, except that it is not
1534          * "scaled". If total width is too small to accomodate the
1535          * guaranteed minimum width of the filename part and the
1536          * separators and this message, this message will "overflow"
1537          * making the line longer than the maximum width.
1538          */
1539
1540         if (options->stat_width == -1)
1541                 width = term_columns() - options->output_prefix_length;
1542         else
1543                 width = options->stat_width ? options->stat_width : 80;
1544         number_width = decimal_width(max_change) > number_width ?
1545                 decimal_width(max_change) : number_width;
1546
1547         if (options->stat_graph_width == -1)
1548                 options->stat_graph_width = diff_stat_graph_width;
1549
1550         /*
1551          * Guarantee 3/8*16==6 for the graph part
1552          * and 5/8*16==10 for the filename part
1553          */
1554         if (width < 16 + 6 + number_width)
1555                 width = 16 + 6 + number_width;
1556
1557         /*
1558          * First assign sizes that are wanted, ignoring available width.
1559          * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1560          * starting from "XXX" should fit in graph_width.
1561          */
1562         graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1563         if (options->stat_graph_width &&
1564             options->stat_graph_width < graph_width)
1565                 graph_width = options->stat_graph_width;
1566
1567         name_width = (options->stat_name_width > 0 &&
1568                       options->stat_name_width < max_len) ?
1569                 options->stat_name_width : max_len;
1570
1571         /*
1572          * Adjust adjustable widths not to exceed maximum width
1573          */
1574         if (name_width + number_width + 6 + graph_width > width) {
1575                 if (graph_width > width * 3/8 - number_width - 6) {
1576                         graph_width = width * 3/8 - number_width - 6;
1577                         if (graph_width < 6)
1578                                 graph_width = 6;
1579                 }
1580
1581                 if (options->stat_graph_width &&
1582                     graph_width > options->stat_graph_width)
1583                         graph_width = options->stat_graph_width;
1584                 if (name_width > width - number_width - 6 - graph_width)
1585                         name_width = width - number_width - 6 - graph_width;
1586                 else
1587                         graph_width = width - number_width - 6 - name_width;
1588         }
1589
1590         /*
1591          * From here name_width is the width of the name area,
1592          * and graph_width is the width of the graph area.
1593          * max_change is used to scale graph properly.
1594          */
1595         for (i = 0; i < count; i++) {
1596                 const char *prefix = "";
1597                 char *name = data->files[i]->print_name;
1598                 uintmax_t added = data->files[i]->added;
1599                 uintmax_t deleted = data->files[i]->deleted;
1600                 int name_len;
1601
1602                 if (!data->files[i]->is_renamed &&
1603                          (added + deleted == 0)) {
1604                         total_files--;
1605                         continue;
1606                 }
1607                 /*
1608                  * "scale" the filename
1609                  */
1610                 len = name_width;
1611                 name_len = strlen(name);
1612                 if (name_width < name_len) {
1613                         char *slash;
1614                         prefix = "...";
1615                         len -= 3;
1616                         name += name_len - len;
1617                         slash = strchr(name, '/');
1618                         if (slash)
1619                                 name = slash;
1620                 }
1621
1622                 if (data->files[i]->is_binary) {
1623                         fprintf(options->file, "%s", line_prefix);
1624                         show_name(options->file, prefix, name, len);
1625                         fprintf(options->file, " %*s", number_width, "Bin");
1626                         if (!added && !deleted) {
1627                                 putc('\n', options->file);
1628                                 continue;
1629                         }
1630                         fprintf(options->file, " %s%"PRIuMAX"%s",
1631                                 del_c, deleted, reset);
1632                         fprintf(options->file, " -> ");
1633                         fprintf(options->file, "%s%"PRIuMAX"%s",
1634                                 add_c, added, reset);
1635                         fprintf(options->file, " bytes");
1636                         fprintf(options->file, "\n");
1637                         continue;
1638                 }
1639                 else if (data->files[i]->is_unmerged) {
1640                         fprintf(options->file, "%s", line_prefix);
1641                         show_name(options->file, prefix, name, len);
1642                         fprintf(options->file, " Unmerged\n");
1643                         continue;
1644                 }
1645
1646                 /*
1647                  * scale the add/delete
1648                  */
1649                 add = added;
1650                 del = deleted;
1651                 adds += add;
1652                 dels += del;
1653
1654                 if (graph_width <= max_change) {
1655                         int total = add + del;
1656
1657                         total = scale_linear(add + del, graph_width, max_change);
1658                         if (total < 2 && add && del)
1659                                 /* width >= 2 due to the sanity check */
1660                                 total = 2;
1661                         if (add < del) {
1662                                 add = scale_linear(add, graph_width, max_change);
1663                                 del = total - add;
1664                         } else {
1665                                 del = scale_linear(del, graph_width, max_change);
1666                                 add = total - del;
1667                         }
1668                 }
1669                 fprintf(options->file, "%s", line_prefix);
1670                 show_name(options->file, prefix, name, len);
1671                 fprintf(options->file, " %*"PRIuMAX"%s",
1672                         number_width, added + deleted,
1673                         added + deleted ? " " : "");
1674                 show_graph(options->file, '+', add, add_c, reset);
1675                 show_graph(options->file, '-', del, del_c, reset);
1676                 fprintf(options->file, "\n");
1677         }
1678         for (i = count; i < data->nr; i++) {
1679                 uintmax_t added = data->files[i]->added;
1680                 uintmax_t deleted = data->files[i]->deleted;
1681                 if (!data->files[i]->is_renamed &&
1682                          (added + deleted == 0)) {
1683                         total_files--;
1684                         continue;
1685                 }
1686                 adds += added;
1687                 dels += deleted;
1688                 if (!extra_shown)
1689                         fprintf(options->file, "%s ...\n", line_prefix);
1690                 extra_shown = 1;
1691         }
1692         fprintf(options->file, "%s", line_prefix);
1693         print_stat_summary(options->file, total_files, adds, dels);
1694 }
1695
1696 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1697 {
1698         int i, adds = 0, dels = 0, total_files = data->nr;
1699
1700         if (data->nr == 0)
1701                 return;
1702
1703         for (i = 0; i < data->nr; i++) {
1704                 int added = data->files[i]->added;
1705                 int deleted= data->files[i]->deleted;
1706
1707                 if (data->files[i]->is_unmerged)
1708                         continue;
1709                 if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1710                         total_files--;
1711                 } else if (!data->files[i]->is_binary) { /* don't count bytes */
1712                         adds += added;
1713                         dels += deleted;
1714                 }
1715         }
1716         if (options->output_prefix) {
1717                 struct strbuf *msg = NULL;
1718                 msg = options->output_prefix(options,
1719                                 options->output_prefix_data);
1720                 fprintf(options->file, "%s", msg->buf);
1721         }
1722         print_stat_summary(options->file, total_files, adds, dels);
1723 }
1724
1725 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1726 {
1727         int i;
1728
1729         if (data->nr == 0)
1730                 return;
1731
1732         for (i = 0; i < data->nr; i++) {
1733                 struct diffstat_file *file = data->files[i];
1734
1735                 if (options->output_prefix) {
1736                         struct strbuf *msg = NULL;
1737                         msg = options->output_prefix(options,
1738                                         options->output_prefix_data);
1739                         fprintf(options->file, "%s", msg->buf);
1740                 }
1741
1742                 if (file->is_binary)
1743                         fprintf(options->file, "-\t-\t");
1744                 else
1745                         fprintf(options->file,
1746                                 "%"PRIuMAX"\t%"PRIuMAX"\t",
1747                                 file->added, file->deleted);
1748                 if (options->line_termination) {
1749                         fill_print_name(file);
1750                         if (!file->is_renamed)
1751                                 write_name_quoted(file->name, options->file,
1752                                                   options->line_termination);
1753                         else {
1754                                 fputs(file->print_name, options->file);
1755                                 putc(options->line_termination, options->file);
1756                         }
1757                 } else {
1758                         if (file->is_renamed) {
1759                                 putc('\0', options->file);
1760                                 write_name_quoted(file->from_name, options->file, '\0');
1761                         }
1762                         write_name_quoted(file->name, options->file, '\0');
1763                 }
1764         }
1765 }
1766
1767 struct dirstat_file {
1768         const char *name;
1769         unsigned long changed;
1770 };
1771
1772 struct dirstat_dir {
1773         struct dirstat_file *files;
1774         int alloc, nr, permille, cumulative;
1775 };
1776
1777 static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1778                 unsigned long changed, const char *base, int baselen)
1779 {
1780         unsigned long this_dir = 0;
1781         unsigned int sources = 0;
1782         const char *line_prefix = "";
1783         struct strbuf *msg = NULL;
1784
1785         if (opt->output_prefix) {
1786                 msg = opt->output_prefix(opt, opt->output_prefix_data);
1787                 line_prefix = msg->buf;
1788         }
1789
1790         while (dir->nr) {
1791                 struct dirstat_file *f = dir->files;
1792                 int namelen = strlen(f->name);
1793                 unsigned long this;
1794                 char *slash;
1795
1796                 if (namelen < baselen)
1797                         break;
1798                 if (memcmp(f->name, base, baselen))
1799                         break;
1800                 slash = strchr(f->name + baselen, '/');
1801                 if (slash) {
1802                         int newbaselen = slash + 1 - f->name;
1803                         this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1804                         sources++;
1805                 } else {
1806                         this = f->changed;
1807                         dir->files++;
1808                         dir->nr--;
1809                         sources += 2;
1810                 }
1811                 this_dir += this;
1812         }
1813
1814         /*
1815          * We don't report dirstat's for
1816          *  - the top level
1817          *  - or cases where everything came from a single directory
1818          *    under this directory (sources == 1).
1819          */
1820         if (baselen && sources != 1) {
1821                 if (this_dir) {
1822                         int permille = this_dir * 1000 / changed;
1823                         if (permille >= dir->permille) {
1824                                 fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1825                                         permille / 10, permille % 10, baselen, base);
1826                                 if (!dir->cumulative)
1827                                         return 0;
1828                         }
1829                 }
1830         }
1831         return this_dir;
1832 }
1833
1834 static int dirstat_compare(const void *_a, const void *_b)
1835 {
1836         const struct dirstat_file *a = _a;
1837         const struct dirstat_file *b = _b;
1838         return strcmp(a->name, b->name);
1839 }
1840
1841 static void show_dirstat(struct diff_options *options)
1842 {
1843         int i;
1844         unsigned long changed;
1845         struct dirstat_dir dir;
1846         struct diff_queue_struct *q = &diff_queued_diff;
1847
1848         dir.files = NULL;
1849         dir.alloc = 0;
1850         dir.nr = 0;
1851         dir.permille = options->dirstat_permille;
1852         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1853
1854         changed = 0;
1855         for (i = 0; i < q->nr; i++) {
1856                 struct diff_filepair *p = q->queue[i];
1857                 const char *name;
1858                 unsigned long copied, added, damage;
1859                 int content_changed;
1860
1861                 name = p->two->path ? p->two->path : p->one->path;
1862
1863                 if (p->one->sha1_valid && p->two->sha1_valid)
1864                         content_changed = hashcmp(p->one->sha1, p->two->sha1);
1865                 else
1866                         content_changed = 1;
1867
1868                 if (!content_changed) {
1869                         /*
1870                          * The SHA1 has not changed, so pre-/post-content is
1871                          * identical. We can therefore skip looking at the
1872                          * file contents altogether.
1873                          */
1874                         damage = 0;
1875                         goto found_damage;
1876                 }
1877
1878                 if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1879                         /*
1880                          * In --dirstat-by-file mode, we don't really need to
1881                          * look at the actual file contents at all.
1882                          * The fact that the SHA1 changed is enough for us to
1883                          * add this file to the list of results
1884                          * (with each file contributing equal damage).
1885                          */
1886                         damage = 1;
1887                         goto found_damage;
1888                 }
1889
1890                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1891                         diff_populate_filespec(p->one, 0);
1892                         diff_populate_filespec(p->two, 0);
1893                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1894                                                &copied, &added);
1895                         diff_free_filespec_data(p->one);
1896                         diff_free_filespec_data(p->two);
1897                 } else if (DIFF_FILE_VALID(p->one)) {
1898                         diff_populate_filespec(p->one, 1);
1899                         copied = added = 0;
1900                         diff_free_filespec_data(p->one);
1901                 } else if (DIFF_FILE_VALID(p->two)) {
1902                         diff_populate_filespec(p->two, 1);
1903                         copied = 0;
1904                         added = p->two->size;
1905                         diff_free_filespec_data(p->two);
1906                 } else
1907                         continue;
1908
1909                 /*
1910                  * Original minus copied is the removed material,
1911                  * added is the new material.  They are both damages
1912                  * made to the preimage.
1913                  * If the resulting damage is zero, we know that
1914                  * diffcore_count_changes() considers the two entries to
1915                  * be identical, but since content_changed is true, we
1916                  * know that there must have been _some_ kind of change,
1917                  * so we force all entries to have damage > 0.
1918                  */
1919                 damage = (p->one->size - copied) + added;
1920                 if (!damage)
1921                         damage = 1;
1922
1923 found_damage:
1924                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1925                 dir.files[dir.nr].name = name;
1926                 dir.files[dir.nr].changed = damage;
1927                 changed += damage;
1928                 dir.nr++;
1929         }
1930
1931         /* This can happen even with many files, if everything was renames */
1932         if (!changed)
1933                 return;
1934
1935         /* Show all directories with more than x% of the changes */
1936         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1937         gather_dirstat(options, &dir, changed, "", 0);
1938 }
1939
1940 static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1941 {
1942         int i;
1943         unsigned long changed;
1944         struct dirstat_dir dir;
1945
1946         if (data->nr == 0)
1947                 return;
1948
1949         dir.files = NULL;
1950         dir.alloc = 0;
1951         dir.nr = 0;
1952         dir.permille = options->dirstat_permille;
1953         dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1954
1955         changed = 0;
1956         for (i = 0; i < data->nr; i++) {
1957                 struct diffstat_file *file = data->files[i];
1958                 unsigned long damage = file->added + file->deleted;
1959                 if (file->is_binary)
1960                         /*
1961                          * binary files counts bytes, not lines. Must find some
1962                          * way to normalize binary bytes vs. textual lines.
1963                          * The following heuristic assumes that there are 64
1964                          * bytes per "line".
1965                          * This is stupid and ugly, but very cheap...
1966                          */
1967                         damage = (damage + 63) / 64;
1968                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1969                 dir.files[dir.nr].name = file->name;
1970                 dir.files[dir.nr].changed = damage;
1971                 changed += damage;
1972                 dir.nr++;
1973         }
1974
1975         /* This can happen even with many files, if everything was renames */
1976         if (!changed)
1977                 return;
1978
1979         /* Show all directories with more than x% of the changes */
1980         qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1981         gather_dirstat(options, &dir, changed, "", 0);
1982 }
1983
1984 static void free_diffstat_info(struct diffstat_t *diffstat)
1985 {
1986         int i;
1987         for (i = 0; i < diffstat->nr; i++) {
1988                 struct diffstat_file *f = diffstat->files[i];
1989                 if (f->name != f->print_name)
1990                         free(f->print_name);
1991                 free(f->name);
1992                 free(f->from_name);
1993                 free(f);
1994         }
1995         free(diffstat->files);
1996 }
1997
1998 struct checkdiff_t {
1999         const char *filename;
2000         int lineno;
2001         int conflict_marker_size;
2002         struct diff_options *o;
2003         unsigned ws_rule;
2004         unsigned status;
2005 };
2006
2007 static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2008 {
2009         char firstchar;
2010         int cnt;
2011
2012         if (len < marker_size + 1)
2013                 return 0;
2014         firstchar = line[0];
2015         switch (firstchar) {
2016         case '=': case '>': case '<': case '|':
2017                 break;
2018         default:
2019                 return 0;
2020         }
2021         for (cnt = 1; cnt < marker_size; cnt++)
2022                 if (line[cnt] != firstchar)
2023                         return 0;
2024         /* line[1] thru line[marker_size-1] are same as firstchar */
2025         if (len < marker_size + 1 || !isspace(line[marker_size]))
2026                 return 0;
2027         return 1;
2028 }
2029
2030 static void checkdiff_consume(void *priv, char *line, unsigned long len)
2031 {
2032         struct checkdiff_t *data = priv;
2033         int marker_size = data->conflict_marker_size;
2034         const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2035         const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2036         const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2037         char *err;
2038         char *line_prefix = "";
2039         struct strbuf *msgbuf;
2040
2041         assert(data->o);
2042         if (data->o->output_prefix) {
2043                 msgbuf = data->o->output_prefix(data->o,
2044                         data->o->output_prefix_data);
2045                 line_prefix = msgbuf->buf;
2046         }
2047
2048         if (line[0] == '+') {
2049                 unsigned bad;
2050                 data->lineno++;
2051                 if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2052                         data->status |= 1;
2053                         fprintf(data->o->file,
2054                                 "%s%s:%d: leftover conflict marker\n",
2055                                 line_prefix, data->filename, data->lineno);
2056                 }
2057                 bad = ws_check(line + 1, len - 1, data->ws_rule);
2058                 if (!bad)
2059                         return;
2060                 data->status |= bad;
2061                 err = whitespace_error_string(bad);
2062                 fprintf(data->o->file, "%s%s:%d: %s.\n",
2063                         line_prefix, data->filename, data->lineno, err);
2064                 free(err);
2065                 emit_line(data->o, set, reset, line, 1);
2066                 ws_check_emit(line + 1, len - 1, data->ws_rule,
2067                               data->o->file, set, reset, ws);
2068         } else if (line[0] == ' ') {
2069                 data->lineno++;
2070         } else if (line[0] == '@') {
2071                 char *plus = strchr(line, '+');
2072                 if (plus)
2073                         data->lineno = strtol(plus, NULL, 10) - 1;
2074                 else
2075                         die("invalid diff");
2076         }
2077 }
2078
2079 static unsigned char *deflate_it(char *data,
2080                                  unsigned long size,
2081                                  unsigned long *result_size)
2082 {
2083         int bound;
2084         unsigned char *deflated;
2085         git_zstream stream;
2086
2087         memset(&stream, 0, sizeof(stream));
2088         git_deflate_init(&stream, zlib_compression_level);
2089         bound = git_deflate_bound(&stream, size);
2090         deflated = xmalloc(bound);
2091         stream.next_out = deflated;
2092         stream.avail_out = bound;
2093
2094         stream.next_in = (unsigned char *)data;
2095         stream.avail_in = size;
2096         while (git_deflate(&stream, Z_FINISH) == Z_OK)
2097                 ; /* nothing */
2098         git_deflate_end(&stream);
2099         *result_size = stream.total_out;
2100         return deflated;
2101 }
2102
2103 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2104 {
2105         void *cp;
2106         void *delta;
2107         void *deflated;
2108         void *data;
2109         unsigned long orig_size;
2110         unsigned long delta_size;
2111         unsigned long deflate_size;
2112         unsigned long data_size;
2113
2114         /* We could do deflated delta, or we could do just deflated two,
2115          * whichever is smaller.
2116          */
2117         delta = NULL;
2118         deflated = deflate_it(two->ptr, two->size, &deflate_size);
2119         if (one->size && two->size) {
2120                 delta = diff_delta(one->ptr, one->size,
2121                                    two->ptr, two->size,
2122                                    &delta_size, deflate_size);
2123                 if (delta) {
2124                         void *to_free = delta;
2125                         orig_size = delta_size;
2126                         delta = deflate_it(delta, delta_size, &delta_size);
2127                         free(to_free);
2128                 }
2129         }
2130
2131         if (delta && delta_size < deflate_size) {
2132                 fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2133                 free(deflated);
2134                 data = delta;
2135                 data_size = delta_size;
2136         }
2137         else {
2138                 fprintf(file, "%sliteral %lu\n", prefix, two->size);
2139                 free(delta);
2140                 data = deflated;
2141                 data_size = deflate_size;
2142         }
2143
2144         /* emit data encoded in base85 */
2145         cp = data;
2146         while (data_size) {
2147                 int bytes = (52 < data_size) ? 52 : data_size;
2148                 char line[70];
2149                 data_size -= bytes;
2150                 if (bytes <= 26)
2151                         line[0] = bytes + 'A' - 1;
2152                 else
2153                         line[0] = bytes - 26 + 'a' - 1;
2154                 encode_85(line + 1, cp, bytes);
2155                 cp = (char *) cp + bytes;
2156                 fprintf(file, "%s", prefix);
2157                 fputs(line, file);
2158                 fputc('\n', file);
2159         }
2160         fprintf(file, "%s\n", prefix);
2161         free(data);
2162 }
2163
2164 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2165 {
2166         fprintf(file, "%sGIT binary patch\n", prefix);
2167         emit_binary_diff_body(file, one, two, prefix);
2168         emit_binary_diff_body(file, two, one, prefix);
2169 }
2170
2171 int diff_filespec_is_binary(struct diff_filespec *one)
2172 {
2173         if (one->is_binary == -1) {
2174                 diff_filespec_load_driver(one);
2175                 if (one->driver->binary != -1)
2176                         one->is_binary = one->driver->binary;
2177                 else {
2178                         if (!one->data && DIFF_FILE_VALID(one))
2179                                 diff_populate_filespec(one, 0);
2180                         if (one->data)
2181                                 one->is_binary = buffer_is_binary(one->data,
2182                                                 one->size);
2183                         if (one->is_binary == -1)
2184                                 one->is_binary = 0;
2185                 }
2186         }
2187         return one->is_binary;
2188 }
2189
2190 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2191 {
2192         diff_filespec_load_driver(one);
2193         return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2194 }
2195
2196 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2197 {
2198         if (!options->a_prefix)
2199                 options->a_prefix = a;
2200         if (!options->b_prefix)
2201                 options->b_prefix = b;
2202 }
2203
2204 struct userdiff_driver *get_textconv(struct diff_filespec *one)
2205 {
2206         if (!DIFF_FILE_VALID(one))
2207                 return NULL;
2208
2209         diff_filespec_load_driver(one);
2210         return userdiff_get_textconv(one->driver);
2211 }
2212
2213 static void builtin_diff(const char *name_a,
2214                          const char *name_b,
2215                          struct diff_filespec *one,
2216                          struct diff_filespec *two,
2217                          const char *xfrm_msg,
2218                          int must_show_header,
2219                          struct diff_options *o,
2220                          int complete_rewrite)
2221 {
2222         mmfile_t mf1, mf2;
2223         const char *lbl[2];
2224         char *a_one, *b_two;
2225         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2226         const char *reset = diff_get_color_opt(o, DIFF_RESET);
2227         const char *a_prefix, *b_prefix;
2228         struct userdiff_driver *textconv_one = NULL;
2229         struct userdiff_driver *textconv_two = NULL;
2230         struct strbuf header = STRBUF_INIT;
2231         struct strbuf *msgbuf;
2232         char *line_prefix = "";
2233
2234         if (o->output_prefix) {
2235                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2236                 line_prefix = msgbuf->buf;
2237         }
2238
2239         if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2240                         (!one->mode || S_ISGITLINK(one->mode)) &&
2241                         (!two->mode || S_ISGITLINK(two->mode))) {
2242                 const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2243                 const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2244                 show_submodule_summary(o->file, one ? one->path : two->path,
2245                                 one->sha1, two->sha1, two->dirty_submodule,
2246                                 del, add, reset);
2247                 return;
2248         }
2249
2250         if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2251                 textconv_one = get_textconv(one);
2252                 textconv_two = get_textconv(two);
2253         }
2254
2255         diff_set_mnemonic_prefix(o, "a/", "b/");
2256         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2257                 a_prefix = o->b_prefix;
2258                 b_prefix = o->a_prefix;
2259         } else {
2260                 a_prefix = o->a_prefix;
2261                 b_prefix = o->b_prefix;
2262         }
2263
2264         /* Never use a non-valid filename anywhere if at all possible */
2265         name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2266         name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2267
2268         a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2269         b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2270         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2271         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2272         strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2273         if (lbl[0][0] == '/') {
2274                 /* /dev/null */
2275                 strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2276                 if (xfrm_msg)
2277                         strbuf_addstr(&header, xfrm_msg);
2278                 must_show_header = 1;
2279         }
2280         else if (lbl[1][0] == '/') {
2281                 strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2282                 if (xfrm_msg)
2283                         strbuf_addstr(&header, xfrm_msg);
2284                 must_show_header = 1;
2285         }
2286         else {
2287                 if (one->mode != two->mode) {
2288                         strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2289                         strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2290                         must_show_header = 1;
2291                 }
2292                 if (xfrm_msg)
2293                         strbuf_addstr(&header, xfrm_msg);
2294
2295                 /*
2296                  * we do not run diff between different kind
2297                  * of objects.
2298                  */
2299                 if ((one->mode ^ two->mode) & S_IFMT)
2300                         goto free_ab_and_return;
2301                 if (complete_rewrite &&
2302                     (textconv_one || !diff_filespec_is_binary(one)) &&
2303                     (textconv_two || !diff_filespec_is_binary(two))) {
2304                         fprintf(o->file, "%s", header.buf);
2305                         strbuf_reset(&header);
2306                         emit_rewrite_diff(name_a, name_b, one, two,
2307                                                 textconv_one, textconv_two, o);
2308                         o->found_changes = 1;
2309                         goto free_ab_and_return;
2310                 }
2311         }
2312
2313         if (o->irreversible_delete && lbl[1][0] == '/') {
2314                 fprintf(o->file, "%s", header.buf);
2315                 strbuf_reset(&header);
2316                 goto free_ab_and_return;
2317         } else if (!DIFF_OPT_TST(o, TEXT) &&
2318             ( (!textconv_one && diff_filespec_is_binary(one)) ||
2319               (!textconv_two && diff_filespec_is_binary(two)) )) {
2320                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2321                         die("unable to read files to diff");
2322                 /* Quite common confusing case */
2323                 if (mf1.size == mf2.size &&
2324                     !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2325                         if (must_show_header)
2326                                 fprintf(o->file, "%s", header.buf);
2327                         goto free_ab_and_return;
2328                 }
2329                 fprintf(o->file, "%s", header.buf);
2330                 strbuf_reset(&header);
2331                 if (DIFF_OPT_TST(o, BINARY))
2332                         emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2333                 else
2334                         fprintf(o->file, "%sBinary files %s and %s differ\n",
2335                                 line_prefix, lbl[0], lbl[1]);
2336                 o->found_changes = 1;
2337         } else {
2338                 /* Crazy xdl interfaces.. */
2339                 const char *diffopts = getenv("GIT_DIFF_OPTS");
2340                 xpparam_t xpp;
2341                 xdemitconf_t xecfg;
2342                 struct emit_callback ecbdata;
2343                 const struct userdiff_funcname *pe;
2344
2345                 if (must_show_header) {
2346                         fprintf(o->file, "%s", header.buf);
2347                         strbuf_reset(&header);
2348                 }
2349
2350                 mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2351                 mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2352
2353                 pe = diff_funcname_pattern(one);
2354                 if (!pe)
2355                         pe = diff_funcname_pattern(two);
2356
2357                 memset(&xpp, 0, sizeof(xpp));
2358                 memset(&xecfg, 0, sizeof(xecfg));
2359                 memset(&ecbdata, 0, sizeof(ecbdata));
2360                 ecbdata.label_path = lbl;
2361                 ecbdata.color_diff = want_color(o->use_color);
2362                 ecbdata.found_changesp = &o->found_changes;
2363                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2364                 if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2365                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2366                 ecbdata.opt = o;
2367                 ecbdata.header = header.len ? &header : NULL;
2368                 xpp.flags = o->xdl_opts;
2369                 xecfg.ctxlen = o->context;
2370                 xecfg.interhunkctxlen = o->interhunkcontext;
2371                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2372                 if (DIFF_OPT_TST(o, FUNCCONTEXT))
2373                         xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2374                 if (pe)
2375                         xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2376                 if (!diffopts)
2377                         ;
2378                 else if (!prefixcmp(diffopts, "--unified="))
2379                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2380                 else if (!prefixcmp(diffopts, "-u"))
2381                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2382                 if (o->word_diff)
2383                         init_diff_words_data(&ecbdata, o, one, two);
2384                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2385                               &xpp, &xecfg);
2386                 if (o->word_diff)
2387                         free_diff_words_data(&ecbdata);
2388                 if (textconv_one)
2389                         free(mf1.ptr);
2390                 if (textconv_two)
2391                         free(mf2.ptr);
2392                 xdiff_clear_find_func(&xecfg);
2393         }
2394
2395  free_ab_and_return:
2396         strbuf_release(&header);
2397         diff_free_filespec_data(one);
2398         diff_free_filespec_data(two);
2399         free(a_one);
2400         free(b_two);
2401         return;
2402 }
2403
2404 static void builtin_diffstat(const char *name_a, const char *name_b,
2405                              struct diff_filespec *one,
2406                              struct diff_filespec *two,
2407                              struct diffstat_t *diffstat,
2408                              struct diff_options *o,
2409                              int complete_rewrite)
2410 {
2411         mmfile_t mf1, mf2;
2412         struct diffstat_file *data;
2413         int same_contents;
2414
2415         data = diffstat_add(diffstat, name_a, name_b);
2416
2417         if (!one || !two) {
2418                 data->is_unmerged = 1;
2419                 return;
2420         }
2421
2422         same_contents = !hashcmp(one->sha1, two->sha1);
2423
2424         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2425                 data->is_binary = 1;
2426                 if (same_contents) {
2427                         data->added = 0;
2428                         data->deleted = 0;
2429                 } else {
2430                         data->added = diff_filespec_size(two);
2431                         data->deleted = diff_filespec_size(one);
2432                 }
2433         }
2434
2435         else if (complete_rewrite) {
2436                 diff_populate_filespec(one, 0);
2437                 diff_populate_filespec(two, 0);
2438                 data->deleted = count_lines(one->data, one->size);
2439                 data->added = count_lines(two->data, two->size);
2440         }
2441
2442         else if (!same_contents) {
2443                 /* Crazy xdl interfaces.. */
2444                 xpparam_t xpp;
2445                 xdemitconf_t xecfg;
2446
2447                 if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2448                         die("unable to read files to diff");
2449
2450                 memset(&xpp, 0, sizeof(xpp));
2451                 memset(&xecfg, 0, sizeof(xecfg));
2452                 xpp.flags = o->xdl_opts;
2453                 xecfg.ctxlen = o->context;
2454                 xecfg.interhunkctxlen = o->interhunkcontext;
2455                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2456                               &xpp, &xecfg);
2457         }
2458
2459         diff_free_filespec_data(one);
2460         diff_free_filespec_data(two);
2461 }
2462
2463 static void builtin_checkdiff(const char *name_a, const char *name_b,
2464                               const char *attr_path,
2465                               struct diff_filespec *one,
2466                               struct diff_filespec *two,
2467                               struct diff_options *o)
2468 {
2469         mmfile_t mf1, mf2;
2470         struct checkdiff_t data;
2471
2472         if (!two)
2473                 return;
2474
2475         memset(&data, 0, sizeof(data));
2476         data.filename = name_b ? name_b : name_a;
2477         data.lineno = 0;
2478         data.o = o;
2479         data.ws_rule = whitespace_rule(attr_path);
2480         data.conflict_marker_size = ll_merge_marker_size(attr_path);
2481
2482         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2483                 die("unable to read files to diff");
2484
2485         /*
2486          * All the other codepaths check both sides, but not checking
2487          * the "old" side here is deliberate.  We are checking the newly
2488          * introduced changes, and as long as the "new" side is text, we
2489          * can and should check what it introduces.
2490          */
2491         if (diff_filespec_is_binary(two))
2492                 goto free_and_return;
2493         else {
2494                 /* Crazy xdl interfaces.. */
2495                 xpparam_t xpp;
2496                 xdemitconf_t xecfg;
2497
2498                 memset(&xpp, 0, sizeof(xpp));
2499                 memset(&xecfg, 0, sizeof(xecfg));
2500                 xecfg.ctxlen = 1; /* at least one context line */
2501                 xpp.flags = 0;
2502                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2503                               &xpp, &xecfg);
2504
2505                 if (data.ws_rule & WS_BLANK_AT_EOF) {
2506                         struct emit_callback ecbdata;
2507                         int blank_at_eof;
2508
2509                         ecbdata.ws_rule = data.ws_rule;
2510                         check_blank_at_eof(&mf1, &mf2, &ecbdata);
2511                         blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2512
2513                         if (blank_at_eof) {
2514                                 static char *err;
2515                                 if (!err)
2516                                         err = whitespace_error_string(WS_BLANK_AT_EOF);
2517                                 fprintf(o->file, "%s:%d: %s.\n",
2518                                         data.filename, blank_at_eof, err);
2519                                 data.status = 1; /* report errors */
2520                         }
2521                 }
2522         }
2523  free_and_return:
2524         diff_free_filespec_data(one);
2525         diff_free_filespec_data(two);
2526         if (data.status)
2527                 DIFF_OPT_SET(o, CHECK_FAILED);
2528 }
2529
2530 struct diff_filespec *alloc_filespec(const char *path)
2531 {
2532         int namelen = strlen(path);
2533         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2534
2535         memset(spec, 0, sizeof(*spec));
2536         spec->path = (char *)(spec + 1);
2537         memcpy(spec->path, path, namelen+1);
2538         spec->count = 1;
2539         spec->is_binary = -1;
2540         return spec;
2541 }
2542
2543 void free_filespec(struct diff_filespec *spec)
2544 {
2545         if (!--spec->count) {
2546                 diff_free_filespec_data(spec);
2547                 free(spec);
2548         }
2549 }
2550
2551 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2552                    int sha1_valid, unsigned short mode)
2553 {
2554         if (mode) {
2555                 spec->mode = canon_mode(mode);
2556                 hashcpy(spec->sha1, sha1);
2557                 spec->sha1_valid = sha1_valid;
2558         }
2559 }
2560
2561 /*
2562  * Given a name and sha1 pair, if the index tells us the file in
2563  * the work tree has that object contents, return true, so that
2564  * prepare_temp_file() does not have to inflate and extract.
2565  */
2566 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2567 {
2568         struct cache_entry *ce;
2569         struct stat st;
2570         int pos, len;
2571
2572         /*
2573          * We do not read the cache ourselves here, because the
2574          * benchmark with my previous version that always reads cache
2575          * shows that it makes things worse for diff-tree comparing
2576          * two linux-2.6 kernel trees in an already checked out work
2577          * tree.  This is because most diff-tree comparisons deal with
2578          * only a small number of files, while reading the cache is
2579          * expensive for a large project, and its cost outweighs the
2580          * savings we get by not inflating the object to a temporary
2581          * file.  Practically, this code only helps when we are used
2582          * by diff-cache --cached, which does read the cache before
2583          * calling us.
2584          */
2585         if (!active_cache)
2586                 return 0;
2587
2588         /* We want to avoid the working directory if our caller
2589          * doesn't need the data in a normal file, this system
2590          * is rather slow with its stat/open/mmap/close syscalls,
2591          * and the object is contained in a pack file.  The pack
2592          * is probably already open and will be faster to obtain
2593          * the data through than the working directory.  Loose
2594          * objects however would tend to be slower as they need
2595          * to be individually opened and inflated.
2596          */
2597         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2598                 return 0;
2599
2600         len = strlen(name);
2601         pos = cache_name_pos(name, len);
2602         if (pos < 0)
2603                 return 0;
2604         ce = active_cache[pos];
2605
2606         /*
2607          * This is not the sha1 we are looking for, or
2608          * unreusable because it is not a regular file.
2609          */
2610         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2611                 return 0;
2612
2613         /*
2614          * If ce is marked as "assume unchanged", there is no
2615          * guarantee that work tree matches what we are looking for.
2616          */
2617         if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2618                 return 0;
2619
2620         /*
2621          * If ce matches the file in the work tree, we can reuse it.
2622          */
2623         if (ce_uptodate(ce) ||
2624             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2625                 return 1;
2626
2627         return 0;
2628 }
2629
2630 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2631 {
2632         int len;
2633         char *data = xmalloc(100), *dirty = "";
2634
2635         /* Are we looking at the work tree? */
2636         if (s->dirty_submodule)
2637                 dirty = "-dirty";
2638
2639         len = snprintf(data, 100,
2640                        "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2641         s->data = data;
2642         s->size = len;
2643         s->should_free = 1;
2644         if (size_only) {
2645                 s->data = NULL;
2646                 free(data);
2647         }
2648         return 0;
2649 }
2650
2651 /*
2652  * While doing rename detection and pickaxe operation, we may need to
2653  * grab the data for the blob (or file) for our own in-core comparison.
2654  * diff_filespec has data and size fields for this purpose.
2655  */
2656 int diff_populate_filespec(struct diff_filespec *s, int size_only)
2657 {
2658         int err = 0;
2659         if (!DIFF_FILE_VALID(s))
2660                 die("internal error: asking to populate invalid file.");
2661         if (S_ISDIR(s->mode))
2662                 return -1;
2663
2664         if (s->data)
2665                 return 0;
2666
2667         if (size_only && 0 < s->size)
2668                 return 0;
2669
2670         if (S_ISGITLINK(s->mode))
2671                 return diff_populate_gitlink(s, size_only);
2672
2673         if (!s->sha1_valid ||
2674             reuse_worktree_file(s->path, s->sha1, 0)) {
2675                 struct strbuf buf = STRBUF_INIT;
2676                 struct stat st;
2677                 int fd;
2678
2679                 if (lstat(s->path, &st) < 0) {
2680                         if (errno == ENOENT) {
2681                         err_empty:
2682                                 err = -1;
2683                         empty:
2684                                 s->data = (char *)"";
2685                                 s->size = 0;
2686                                 return err;
2687                         }
2688                 }
2689                 s->size = xsize_t(st.st_size);
2690                 if (!s->size)
2691                         goto empty;
2692                 if (S_ISLNK(st.st_mode)) {
2693                         struct strbuf sb = STRBUF_INIT;
2694
2695                         if (strbuf_readlink(&sb, s->path, s->size))
2696                                 goto err_empty;
2697                         s->size = sb.len;
2698                         s->data = strbuf_detach(&sb, NULL);
2699                         s->should_free = 1;
2700                         return 0;
2701                 }
2702                 if (size_only)
2703                         return 0;
2704                 fd = open(s->path, O_RDONLY);
2705                 if (fd < 0)
2706                         goto err_empty;
2707                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2708                 close(fd);
2709                 s->should_munmap = 1;
2710
2711                 /*
2712                  * Convert from working tree format to canonical git format
2713                  */
2714                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2715                         size_t size = 0;
2716                         munmap(s->data, s->size);
2717                         s->should_munmap = 0;
2718                         s->data = strbuf_detach(&buf, &size);
2719                         s->size = size;
2720                         s->should_free = 1;
2721                 }
2722         }
2723         else {
2724                 enum object_type type;
2725                 if (size_only) {
2726                         type = sha1_object_info(s->sha1, &s->size);
2727                         if (type < 0)
2728                                 die("unable to read %s", sha1_to_hex(s->sha1));
2729                 } else {
2730                         s->data = read_sha1_file(s->sha1, &type, &s->size);
2731                         if (!s->data)
2732                                 die("unable to read %s", sha1_to_hex(s->sha1));
2733                         s->should_free = 1;
2734                 }
2735         }
2736         return 0;
2737 }
2738
2739 void diff_free_filespec_blob(struct diff_filespec *s)
2740 {
2741         if (s->should_free)
2742                 free(s->data);
2743         else if (s->should_munmap)
2744                 munmap(s->data, s->size);
2745
2746         if (s->should_free || s->should_munmap) {
2747                 s->should_free = s->should_munmap = 0;
2748                 s->data = NULL;
2749         }
2750 }
2751
2752 void diff_free_filespec_data(struct diff_filespec *s)
2753 {
2754         diff_free_filespec_blob(s);
2755         free(s->cnt_data);
2756         s->cnt_data = NULL;
2757 }
2758
2759 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2760                            void *blob,
2761                            unsigned long size,
2762                            const unsigned char *sha1,
2763                            int mode)
2764 {
2765         int fd;
2766         struct strbuf buf = STRBUF_INIT;
2767         struct strbuf template = STRBUF_INIT;
2768         char *path_dup = xstrdup(path);
2769         const char *base = basename(path_dup);
2770
2771         /* Generate "XXXXXX_basename.ext" */
2772         strbuf_addstr(&template, "XXXXXX_");
2773         strbuf_addstr(&template, base);
2774
2775         fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2776                         strlen(base) + 1);
2777         if (fd < 0)
2778                 die_errno("unable to create temp-file");
2779         if (convert_to_working_tree(path,
2780                         (const char *)blob, (size_t)size, &buf)) {
2781                 blob = buf.buf;
2782                 size = buf.len;
2783         }
2784         if (write_in_full(fd, blob, size) != size)
2785                 die_errno("unable to write temp-file");
2786         close(fd);
2787         temp->name = temp->tmp_path;
2788         strcpy(temp->hex, sha1_to_hex(sha1));
2789         temp->hex[40] = 0;
2790         sprintf(temp->mode, "%06o", mode);
2791         strbuf_release(&buf);
2792         strbuf_release(&template);
2793         free(path_dup);
2794 }
2795
2796 static struct diff_tempfile *prepare_temp_file(const char *name,
2797                 struct diff_filespec *one)
2798 {
2799         struct diff_tempfile *temp = claim_diff_tempfile();
2800
2801         if (!DIFF_FILE_VALID(one)) {
2802         not_a_valid_file:
2803                 /* A '-' entry produces this for file-2, and
2804                  * a '+' entry produces this for file-1.
2805                  */
2806                 temp->name = "/dev/null";
2807                 strcpy(temp->hex, ".");
2808                 strcpy(temp->mode, ".");
2809                 return temp;
2810         }
2811
2812         if (!remove_tempfile_installed) {
2813                 atexit(remove_tempfile);
2814                 sigchain_push_common(remove_tempfile_on_signal);
2815                 remove_tempfile_installed = 1;
2816         }
2817
2818         if (!one->sha1_valid ||
2819             reuse_worktree_file(name, one->sha1, 1)) {
2820                 struct stat st;
2821                 if (lstat(name, &st) < 0) {
2822                         if (errno == ENOENT)
2823                                 goto not_a_valid_file;
2824                         die_errno("stat(%s)", name);
2825                 }
2826                 if (S_ISLNK(st.st_mode)) {
2827                         struct strbuf sb = STRBUF_INIT;
2828                         if (strbuf_readlink(&sb, name, st.st_size) < 0)
2829                                 die_errno("readlink(%s)", name);
2830                         prep_temp_blob(name, temp, sb.buf, sb.len,
2831                                        (one->sha1_valid ?
2832                                         one->sha1 : null_sha1),
2833                                        (one->sha1_valid ?
2834                                         one->mode : S_IFLNK));
2835                         strbuf_release(&sb);
2836                 }
2837                 else {
2838                         /* we can borrow from the file in the work tree */
2839                         temp->name = name;
2840                         if (!one->sha1_valid)
2841                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
2842                         else
2843                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
2844                         /* Even though we may sometimes borrow the
2845                          * contents from the work tree, we always want
2846                          * one->mode.  mode is trustworthy even when
2847                          * !(one->sha1_valid), as long as
2848                          * DIFF_FILE_VALID(one).
2849                          */
2850                         sprintf(temp->mode, "%06o", one->mode);
2851                 }
2852                 return temp;
2853         }
2854         else {
2855                 if (diff_populate_filespec(one, 0))
2856                         die("cannot read data blob for %s", one->path);
2857                 prep_temp_blob(name, temp, one->data, one->size,
2858                                one->sha1, one->mode);
2859         }
2860         return temp;
2861 }
2862
2863 /* An external diff command takes:
2864  *
2865  * diff-cmd name infile1 infile1-sha1 infile1-mode \
2866  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2867  *
2868  */
2869 static void run_external_diff(const char *pgm,
2870                               const char *name,
2871                               const char *other,
2872                               struct diff_filespec *one,
2873                               struct diff_filespec *two,
2874                               const char *xfrm_msg,
2875                               int complete_rewrite)
2876 {
2877         const char *spawn_arg[10];
2878         int retval;
2879         const char **arg = &spawn_arg[0];
2880
2881         if (one && two) {
2882                 struct diff_tempfile *temp_one, *temp_two;
2883                 const char *othername = (other ? other : name);
2884                 temp_one = prepare_temp_file(name, one);
2885                 temp_two = prepare_temp_file(othername, two);
2886                 *arg++ = pgm;
2887                 *arg++ = name;
2888                 *arg++ = temp_one->name;
2889                 *arg++ = temp_one->hex;
2890                 *arg++ = temp_one->mode;
2891                 *arg++ = temp_two->name;
2892                 *arg++ = temp_two->hex;
2893                 *arg++ = temp_two->mode;
2894                 if (other) {
2895                         *arg++ = other;
2896                         *arg++ = xfrm_msg;
2897                 }
2898         } else {
2899                 *arg++ = pgm;
2900                 *arg++ = name;
2901         }
2902         *arg = NULL;
2903         fflush(NULL);
2904         retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2905         remove_tempfile();
2906         if (retval) {
2907                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2908                 exit(1);
2909         }
2910 }
2911
2912 static int similarity_index(struct diff_filepair *p)
2913 {
2914         return p->score * 100 / MAX_SCORE;
2915 }
2916
2917 static void fill_metainfo(struct strbuf *msg,
2918                           const char *name,
2919                           const char *other,
2920                           struct diff_filespec *one,
2921                           struct diff_filespec *two,
2922                           struct diff_options *o,
2923                           struct diff_filepair *p,
2924                           int *must_show_header,
2925                           int use_color)
2926 {
2927         const char *set = diff_get_color(use_color, DIFF_METAINFO);
2928         const char *reset = diff_get_color(use_color, DIFF_RESET);
2929         struct strbuf *msgbuf;
2930         char *line_prefix = "";
2931
2932         *must_show_header = 1;
2933         if (o->output_prefix) {
2934                 msgbuf = o->output_prefix(o, o->output_prefix_data);
2935                 line_prefix = msgbuf->buf;
2936         }
2937         strbuf_init(msg, PATH_MAX * 2 + 300);
2938         switch (p->status) {
2939         case DIFF_STATUS_COPIED:
2940                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2941                             line_prefix, set, similarity_index(p));
2942                 strbuf_addf(msg, "%s\n%s%scopy from ",
2943                             reset,  line_prefix, set);
2944                 quote_c_style(name, msg, NULL, 0);
2945                 strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2946                 quote_c_style(other, msg, NULL, 0);
2947                 strbuf_addf(msg, "%s\n", reset);
2948                 break;
2949         case DIFF_STATUS_RENAMED:
2950                 strbuf_addf(msg, "%s%ssimilarity index %d%%",
2951                             line_prefix, set, similarity_index(p));
2952                 strbuf_addf(msg, "%s\n%s%srename from ",
2953                             reset, line_prefix, set);
2954                 quote_c_style(name, msg, NULL, 0);
2955                 strbuf_addf(msg, "%s\n%s%srename to ",
2956                             reset, line_prefix, set);
2957                 quote_c_style(other, msg, NULL, 0);
2958                 strbuf_addf(msg, "%s\n", reset);
2959                 break;
2960         case DIFF_STATUS_MODIFIED:
2961                 if (p->score) {
2962                         strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2963                                     line_prefix,
2964                                     set, similarity_index(p), reset);
2965                         break;
2966                 }
2967                 /* fallthru */
2968         default:
2969                 *must_show_header = 0;
2970         }
2971         if (one && two && hashcmp(one->sha1, two->sha1)) {
2972                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2973
2974                 if (DIFF_OPT_TST(o, BINARY)) {
2975                         mmfile_t mf;
2976                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2977                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2978                                 abbrev = 40;
2979                 }
2980                 strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2981                             find_unique_abbrev(one->sha1, abbrev));
2982                 strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2983                 if (one->mode == two->mode)
2984                         strbuf_addf(msg, " %06o", one->mode);
2985                 strbuf_addf(msg, "%s\n", reset);
2986         }
2987 }
2988
2989 static void run_diff_cmd(const char *pgm,
2990                          const char *name,
2991                          const char *other,
2992                          const char *attr_path,
2993                          struct diff_filespec *one,
2994                          struct diff_filespec *two,
2995                          struct strbuf *msg,
2996                          struct diff_options *o,
2997                          struct diff_filepair *p)
2998 {
2999         const char *xfrm_msg = NULL;
3000         int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3001         int must_show_header = 0;
3002
3003
3004         if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3005                 struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3006                 if (drv && drv->external)
3007                         pgm = drv->external;
3008         }
3009
3010         if (msg) {
3011                 /*
3012                  * don't use colors when the header is intended for an
3013                  * external diff driver
3014                  */
3015                 fill_metainfo(msg, name, other, one, two, o, p,
3016                               &must_show_header,
3017                               want_color(o->use_color) && !pgm);
3018                 xfrm_msg = msg->len ? msg->buf : NULL;
3019         }
3020
3021         if (pgm) {
3022                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
3023                                   complete_rewrite);
3024                 return;
3025         }
3026         if (one && two)
3027                 builtin_diff(name, other ? other : name,
3028                              one, two, xfrm_msg, must_show_header,
3029                              o, complete_rewrite);
3030         else
3031                 fprintf(o->file, "* Unmerged path %s\n", name);
3032 }
3033
3034 static void diff_fill_sha1_info(struct diff_filespec *one)
3035 {
3036         if (DIFF_FILE_VALID(one)) {
3037                 if (!one->sha1_valid) {
3038                         struct stat st;
3039                         if (one->is_stdin) {
3040                                 hashcpy(one->sha1, null_sha1);
3041                                 return;
3042                         }
3043                         if (lstat(one->path, &st) < 0)
3044                                 die_errno("stat '%s'", one->path);
3045                         if (index_path(one->sha1, one->path, &st, 0))
3046                                 die("cannot hash %s", one->path);
3047                 }
3048         }
3049         else
3050                 hashclr(one->sha1);
3051 }
3052
3053 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3054 {
3055         /* Strip the prefix but do not molest /dev/null and absolute paths */
3056         if (*namep && **namep != '/') {
3057                 *namep += prefix_length;
3058                 if (**namep == '/')
3059                         ++*namep;
3060         }
3061         if (*otherp && **otherp != '/') {
3062                 *otherp += prefix_length;
3063                 if (**otherp == '/')
3064                         ++*otherp;
3065         }
3066 }
3067
3068 static void run_diff(struct diff_filepair *p, struct diff_options *o)
3069 {
3070         const char *pgm = external_diff();
3071         struct strbuf msg;
3072         struct diff_filespec *one = p->one;
3073         struct diff_filespec *two = p->two;
3074         const char *name;
3075         const char *other;
3076         const char *attr_path;
3077
3078         name  = p->one->path;
3079         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3080         attr_path = name;
3081         if (o->prefix_length)
3082                 strip_prefix(o->prefix_length, &name, &other);
3083
3084         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3085                 pgm = NULL;
3086
3087         if (DIFF_PAIR_UNMERGED(p)) {
3088                 run_diff_cmd(pgm, name, NULL, attr_path,
3089                              NULL, NULL, NULL, o, p);
3090                 return;
3091         }
3092
3093         diff_fill_sha1_info(one);
3094         diff_fill_sha1_info(two);
3095
3096         if (!pgm &&
3097             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3098             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3099                 /*
3100                  * a filepair that changes between file and symlink
3101                  * needs to be split into deletion and creation.
3102                  */
3103                 struct diff_filespec *null = alloc_filespec(two->path);
3104                 run_diff_cmd(NULL, name, other, attr_path,
3105                              one, null, &msg, o, p);
3106                 free(null);
3107                 strbuf_release(&msg);
3108
3109                 null = alloc_filespec(one->path);
3110                 run_diff_cmd(NULL, name, other, attr_path,
3111                              null, two, &msg, o, p);
3112                 free(null);
3113         }
3114         else
3115                 run_diff_cmd(pgm, name, other, attr_path,
3116                              one, two, &msg, o, p);
3117
3118         strbuf_release(&msg);
3119 }
3120
3121 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3122                          struct diffstat_t *diffstat)
3123 {
3124         const char *name;
3125         const char *other;
3126         int complete_rewrite = 0;
3127
3128         if (DIFF_PAIR_UNMERGED(p)) {
3129                 /* unmerged */
3130                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3131                 return;
3132         }
3133
3134         name = p->one->path;
3135         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3136
3137         if (o->prefix_length)
3138                 strip_prefix(o->prefix_length, &name, &other);
3139
3140         diff_fill_sha1_info(p->one);
3141         diff_fill_sha1_info(p->two);
3142
3143         if (p->status == DIFF_STATUS_MODIFIED && p->score)
3144                 complete_rewrite = 1;
3145         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3146 }
3147
3148 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3149 {
3150         const char *name;
3151         const char *other;
3152         const char *attr_path;
3153
3154         if (DIFF_PAIR_UNMERGED(p)) {
3155                 /* unmerged */
3156                 return;
3157         }
3158
3159         name = p->one->path;
3160         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3161         attr_path = other ? other : name;
3162
3163         if (o->prefix_length)
3164                 strip_prefix(o->prefix_length, &name, &other);
3165
3166         diff_fill_sha1_info(p->one);
3167         diff_fill_sha1_info(p->two);
3168
3169         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3170 }
3171
3172 void diff_setup(struct diff_options *options)
3173 {
3174         memcpy(options, &default_diff_options, sizeof(*options));
3175
3176         options->file = stdout;
3177
3178         options->line_termination = '\n';
3179         options->break_opt = -1;
3180         options->rename_limit = -1;
3181         options->dirstat_permille = diff_dirstat_permille_default;
3182         options->context = diff_context_default;
3183         DIFF_OPT_SET(options, RENAME_EMPTY);
3184
3185         options->change = diff_change;
3186         options->add_remove = diff_addremove;
3187         options->use_color = diff_use_color_default;
3188         options->detect_rename = diff_detect_rename_default;
3189
3190         if (diff_no_prefix) {
3191                 options->a_prefix = options->b_prefix = "";
3192         } else if (!diff_mnemonic_prefix) {
3193                 options->a_prefix = "a/";
3194                 options->b_prefix = "b/";
3195         }
3196 }
3197
3198 void diff_setup_done(struct diff_options *options)
3199 {
3200         int count = 0;
3201
3202         if (options->output_format & DIFF_FORMAT_NAME)
3203                 count++;
3204         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3205                 count++;
3206         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3207                 count++;
3208         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3209                 count++;
3210         if (count > 1)
3211                 die("--name-only, --name-status, --check and -s are mutually exclusive");
3212
3213         /*
3214          * Most of the time we can say "there are changes"
3215          * only by checking if there are changed paths, but
3216          * --ignore-whitespace* options force us to look
3217          * inside contents.
3218          */
3219
3220         if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3221             DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3222             DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3223                 DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3224         else
3225                 DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3226
3227         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3228                 options->detect_rename = DIFF_DETECT_COPY;
3229
3230         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3231                 options->prefix = NULL;
3232         if (options->prefix)
3233                 options->prefix_length = strlen(options->prefix);
3234         else
3235                 options->prefix_length = 0;
3236
3237         if (options->output_format & (DIFF_FORMAT_NAME |
3238                                       DIFF_FORMAT_NAME_STATUS |
3239                                       DIFF_FORMAT_CHECKDIFF |
3240                                       DIFF_FORMAT_NO_OUTPUT))
3241                 options->output_format &= ~(DIFF_FORMAT_RAW |
3242                                             DIFF_FORMAT_NUMSTAT |
3243                                             DIFF_FORMAT_DIFFSTAT |
3244                                             DIFF_FORMAT_SHORTSTAT |
3245                                             DIFF_FORMAT_DIRSTAT |
3246                                             DIFF_FORMAT_SUMMARY |
3247                                             DIFF_FORMAT_PATCH);
3248
3249         /*
3250          * These cases always need recursive; we do not drop caller-supplied
3251          * recursive bits for other formats here.
3252          */
3253         if (options->output_format & (DIFF_FORMAT_PATCH |
3254                                       DIFF_FORMAT_NUMSTAT |
3255                                       DIFF_FORMAT_DIFFSTAT |
3256                                       DIFF_FORMAT_SHORTSTAT |
3257                                       DIFF_FORMAT_DIRSTAT |
3258                                       DIFF_FORMAT_SUMMARY |
3259                                       DIFF_FORMAT_CHECKDIFF))
3260                 DIFF_OPT_SET(options, RECURSIVE);
3261         /*
3262          * Also pickaxe would not work very well if you do not say recursive
3263          */
3264         if (options->pickaxe)
3265                 DIFF_OPT_SET(options, RECURSIVE);
3266         /*
3267          * When patches are generated, submodules diffed against the work tree
3268          * must be checked for dirtiness too so it can be shown in the output
3269          */
3270         if (options->output_format & DIFF_FORMAT_PATCH)
3271                 DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3272
3273         if (options->detect_rename && options->rename_limit < 0)
3274                 options->rename_limit = diff_rename_limit_default;
3275         if (options->setup & DIFF_SETUP_USE_CACHE) {
3276                 if (!active_cache)
3277                         /* read-cache does not die even when it fails
3278                          * so it is safe for us to do this here.  Also
3279                          * it does not smudge active_cache or active_nr
3280                          * when it fails, so we do not have to worry about
3281                          * cleaning it up ourselves either.
3282                          */
3283                         read_cache();
3284         }
3285         if (options->abbrev <= 0 || 40 < options->abbrev)
3286                 options->abbrev = 40; /* full */
3287
3288         /*
3289          * It does not make sense to show the first hit we happened
3290          * to have found.  It does not make sense not to return with
3291          * exit code in such a case either.
3292          */
3293         if (DIFF_OPT_TST(options, QUICK)) {
3294                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
3295                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3296         }
3297 }
3298
3299 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3300 {
3301         char c, *eq;
3302         int len;
3303
3304         if (*arg != '-')
3305                 return 0;
3306         c = *++arg;
3307         if (!c)
3308                 return 0;
3309         if (c == arg_short) {
3310                 c = *++arg;
3311                 if (!c)
3312                         return 1;
3313                 if (val && isdigit(c)) {
3314                         char *end;
3315                         int n = strtoul(arg, &end, 10);
3316                         if (*end)
3317                                 return 0;
3318                         *val = n;
3319                         return 1;
3320                 }
3321                 return 0;
3322         }
3323         if (c != '-')
3324                 return 0;
3325         arg++;
3326         eq = strchr(arg, '=');
3327         if (eq)
3328                 len = eq - arg;
3329         else
3330                 len = strlen(arg);
3331         if (!len || strncmp(arg, arg_long, len))
3332                 return 0;
3333         if (eq) {
3334                 int n;
3335                 char *end;
3336                 if (!isdigit(*++eq))
3337                         return 0;
3338                 n = strtoul(eq, &end, 10);
3339                 if (*end)
3340                         return 0;
3341                 *val = n;
3342         }
3343         return 1;
3344 }
3345
3346 static int diff_scoreopt_parse(const char *opt);
3347
3348 static inline int short_opt(char opt, const char **argv,
3349                             const char **optarg)
3350 {
3351         const char *arg = argv[0];
3352         if (arg[0] != '-' || arg[1] != opt)
3353                 return 0;
3354         if (arg[2] != '\0') {
3355                 *optarg = arg + 2;
3356                 return 1;
3357         }
3358         if (!argv[1])
3359                 die("Option '%c' requires a value", opt);
3360         *optarg = argv[1];
3361         return 2;
3362 }
3363
3364 int parse_long_opt(const char *opt, const char **argv,
3365                    const char **optarg)
3366 {
3367         const char *arg = argv[0];
3368         if (arg[0] != '-' || arg[1] != '-')
3369                 return 0;
3370         arg += strlen("--");
3371         if (prefixcmp(arg, opt))
3372                 return 0;
3373         arg += strlen(opt);
3374         if (*arg == '=') { /* sticked form: --option=value */
3375                 *optarg = arg + 1;
3376                 return 1;
3377         }
3378         if (*arg != '\0')
3379                 return 0;
3380         /* separate form: --option value */
3381         if (!argv[1])
3382                 die("Option '--%s' requires a value", opt);
3383         *optarg = argv[1];
3384         return 2;
3385 }
3386
3387 static int stat_opt(struct diff_options *options, const char **av)
3388 {
3389         const char *arg = av[0];
3390         char *end;
3391         int width = options->stat_width;
3392         int name_width = options->stat_name_width;
3393         int graph_width = options->stat_graph_width;
3394         int count = options->stat_count;
3395         int argcount = 1;
3396
3397         arg += strlen("--stat");
3398         end = (char *)arg;
3399
3400         switch (*arg) {
3401         case '-':
3402                 if (!prefixcmp(arg, "-width")) {
3403                         arg += strlen("-width");
3404                         if (*arg == '=')
3405                                 width = strtoul(arg + 1, &end, 10);
3406                         else if (!*arg && !av[1])
3407                                 die("Option '--stat-width' requires a value");
3408                         else if (!*arg) {
3409                                 width = strtoul(av[1], &end, 10);
3410                                 argcount = 2;
3411                         }
3412                 } else if (!prefixcmp(arg, "-name-width")) {
3413                         arg += strlen("-name-width");
3414                         if (*arg == '=')
3415                                 name_width = strtoul(arg + 1, &end, 10);
3416                         else if (!*arg && !av[1])
3417                                 die("Option '--stat-name-width' requires a value");
3418                         else if (!*arg) {
3419                                 name_width = strtoul(av[1], &end, 10);
3420                                 argcount = 2;
3421                         }
3422                 } else if (!prefixcmp(arg, "-graph-width")) {
3423                         arg += strlen("-graph-width");
3424                         if (*arg == '=')
3425                                 graph_width = strtoul(arg + 1, &end, 10);
3426                         else if (!*arg && !av[1])
3427                                 die("Option '--stat-graph-width' requires a value");
3428                         else if (!*arg) {
3429                                 graph_width = strtoul(av[1], &end, 10);
3430                                 argcount = 2;
3431                         }
3432                 } else if (!prefixcmp(arg, "-count")) {
3433                         arg += strlen("-count");
3434                         if (*arg == '=')
3435                                 count = strtoul(arg + 1, &end, 10);
3436                         else if (!*arg && !av[1])
3437                                 die("Option '--stat-count' requires a value");
3438                         else if (!*arg) {
3439                                 count = strtoul(av[1], &end, 10);
3440                                 argcount = 2;
3441                         }
3442                 }
3443                 break;
3444         case '=':
3445                 width = strtoul(arg+1, &end, 10);
3446                 if (*end == ',')
3447                         name_width = strtoul(end+1, &end, 10);
3448                 if (*end == ',')
3449                         count = strtoul(end+1, &end, 10);
3450         }
3451
3452         /* Important! This checks all the error cases! */
3453         if (*end)
3454                 return 0;
3455         options->output_format |= DIFF_FORMAT_DIFFSTAT;
3456         options->stat_name_width = name_width;
3457         options->stat_graph_width = graph_width;
3458         options->stat_width = width;
3459         options->stat_count = count;
3460         return argcount;
3461 }
3462
3463 static int parse_dirstat_opt(struct diff_options *options, const char *params)
3464 {
3465         struct strbuf errmsg = STRBUF_INIT;
3466         if (parse_dirstat_params(options, params, &errmsg))
3467                 die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3468                     errmsg.buf);
3469         strbuf_release(&errmsg);
3470         /*
3471          * The caller knows a dirstat-related option is given from the command
3472          * line; allow it to say "return this_function();"
3473          */
3474         options->output_format |= DIFF_FORMAT_DIRSTAT;
3475         return 1;
3476 }
3477
3478 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3479 {
3480         const char *arg = av[0];
3481         const char *optarg;
3482         int argcount;
3483
3484         /* Output format options */
3485         if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3486                 options->output_format |= DIFF_FORMAT_PATCH;
3487         else if (opt_arg(arg, 'U', "unified", &options->context))
3488                 options->output_format |= DIFF_FORMAT_PATCH;
3489         else if (!strcmp(arg, "--raw"))
3490                 options->output_format |= DIFF_FORMAT_RAW;
3491         else if (!strcmp(arg, "--patch-with-raw"))
3492                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3493         else if (!strcmp(arg, "--numstat"))
3494                 options->output_format |= DIFF_FORMAT_NUMSTAT;
3495         else if (!strcmp(arg, "--shortstat"))
3496                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
3497         else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3498                 return parse_dirstat_opt(options, "");
3499         else if (!prefixcmp(arg, "-X"))
3500                 return parse_dirstat_opt(options, arg + 2);
3501         else if (!prefixcmp(arg, "--dirstat="))
3502                 return parse_dirstat_opt(options, arg + 10);
3503         else if (!strcmp(arg, "--cumulative"))
3504                 return parse_dirstat_opt(options, "cumulative");
3505         else if (!strcmp(arg, "--dirstat-by-file"))
3506                 return parse_dirstat_opt(options, "files");
3507         else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3508                 parse_dirstat_opt(options, "files");
3509                 return parse_dirstat_opt(options, arg + 18);
3510         }
3511         else if (!strcmp(arg, "--check"))
3512                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
3513         else if (!strcmp(arg, "--summary"))
3514                 options->output_format |= DIFF_FORMAT_SUMMARY;
3515         else if (!strcmp(arg, "--patch-with-stat"))
3516                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3517         else if (!strcmp(arg, "--name-only"))
3518                 options->output_format |= DIFF_FORMAT_NAME;
3519         else if (!strcmp(arg, "--name-status"))
3520                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
3521         else if (!strcmp(arg, "-s"))
3522                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3523         else if (!prefixcmp(arg, "--stat"))
3524                 /* --stat, --stat-width, --stat-name-width, or --stat-count */
3525                 return stat_opt(options, av);
3526
3527         /* renames options */
3528         else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3529                  !strcmp(arg, "--break-rewrites")) {
3530                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3531                         return error("invalid argument to -B: %s", arg+2);
3532         }
3533         else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3534                  !strcmp(arg, "--find-renames")) {
3535                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3536                         return error("invalid argument to -M: %s", arg+2);
3537                 options->detect_rename = DIFF_DETECT_RENAME;
3538         }
3539         else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3540                 options->irreversible_delete = 1;
3541         }
3542         else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3543                  !strcmp(arg, "--find-copies")) {
3544                 if (options->detect_rename == DIFF_DETECT_COPY)
3545                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3546                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3547                         return error("invalid argument to -C: %s", arg+2);
3548                 options->detect_rename = DIFF_DETECT_COPY;
3549         }
3550         else if (!strcmp(arg, "--no-renames"))
3551                 options->detect_rename = 0;
3552         else if (!strcmp(arg, "--rename-empty"))
3553                 DIFF_OPT_SET(options, RENAME_EMPTY);
3554         else if (!strcmp(arg, "--no-rename-empty"))
3555                 DIFF_OPT_CLR(options, RENAME_EMPTY);
3556         else if (!strcmp(arg, "--relative"))
3557                 DIFF_OPT_SET(options, RELATIVE_NAME);
3558         else if (!prefixcmp(arg, "--relative=")) {
3559                 DIFF_OPT_SET(options, RELATIVE_NAME);
3560                 options->prefix = arg + 11;
3561         }
3562
3563         /* xdiff options */
3564         else if (!strcmp(arg, "--minimal"))
3565                 DIFF_XDL_SET(options, NEED_MINIMAL);
3566         else if (!strcmp(arg, "--no-minimal"))
3567                 DIFF_XDL_CLR(options, NEED_MINIMAL);
3568         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3569                 DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3570         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3571                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3572         else if (!strcmp(arg, "--ignore-space-at-eol"))
3573                 DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3574         else if (!strcmp(arg, "--patience"))
3575                 options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3576         else if (!strcmp(arg, "--histogram"))
3577                 options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3578
3579         /* flags options */
3580         else if (!strcmp(arg, "--binary")) {
3581                 options->output_format |= DIFF_FORMAT_PATCH;
3582                 DIFF_OPT_SET(options, BINARY);
3583         }
3584         else if (!strcmp(arg, "--full-index"))
3585                 DIFF_OPT_SET(options, FULL_INDEX);
3586         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3587                 DIFF_OPT_SET(options, TEXT);
3588         else if (!strcmp(arg, "-R"))
3589                 DIFF_OPT_SET(options, REVERSE_DIFF);
3590         else if (!strcmp(arg, "--find-copies-harder"))
3591                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3592         else if (!strcmp(arg, "--follow"))
3593                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
3594         else if (!strcmp(arg, "--color"))
3595                 options->use_color = 1;
3596         else if (!prefixcmp(arg, "--color=")) {
3597                 int value = git_config_colorbool(NULL, arg+8);
3598                 if (value < 0)
3599                         return error("option `color' expects \"always\", \"auto\", or \"never\"");
3600                 options->use_color = value;
3601         }
3602         else if (!strcmp(arg, "--no-color"))
3603                 options->use_color = 0;
3604         else if (!strcmp(arg, "--color-words")) {
3605                 options->use_color = 1;
3606                 options->word_diff = DIFF_WORDS_COLOR;
3607         }
3608         else if (!prefixcmp(arg, "--color-words=")) {
3609                 options->use_color = 1;
3610                 options->word_diff = DIFF_WORDS_COLOR;
3611                 options->word_regex = arg + 14;
3612         }
3613         else if (!strcmp(arg, "--word-diff")) {
3614                 if (options->word_diff == DIFF_WORDS_NONE)
3615                         options->word_diff = DIFF_WORDS_PLAIN;
3616         }
3617         else if (!prefixcmp(arg, "--word-diff=")) {
3618                 const char *type = arg + 12;
3619                 if (!strcmp(type, "plain"))
3620                         options->word_diff = DIFF_WORDS_PLAIN;
3621                 else if (!strcmp(type, "color")) {
3622                         options->use_color = 1;
3623                         options->word_diff = DIFF_WORDS_COLOR;
3624                 }
3625                 else if (!strcmp(type, "porcelain"))
3626                         options->word_diff = DIFF_WORDS_PORCELAIN;
3627                 else if (!strcmp(type, "none"))
3628                         options->word_diff = DIFF_WORDS_NONE;
3629                 else
3630                         die("bad --word-diff argument: %s", type);
3631         }
3632         else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3633                 if (options->word_diff == DIFF_WORDS_NONE)
3634                         options->word_diff = DIFF_WORDS_PLAIN;
3635                 options->word_regex = optarg;
3636                 return argcount;
3637         }
3638         else if (!strcmp(arg, "--exit-code"))
3639                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3640         else if (!strcmp(arg, "--quiet"))
3641                 DIFF_OPT_SET(options, QUICK);
3642         else if (!strcmp(arg, "--ext-diff"))
3643                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3644         else if (!strcmp(arg, "--no-ext-diff"))
3645                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3646         else if (!strcmp(arg, "--textconv"))
3647                 DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3648         else if (!strcmp(arg, "--no-textconv"))
3649                 DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3650         else if (!strcmp(arg, "--ignore-submodules")) {
3651                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3652                 handle_ignore_submodules_arg(options, "all");
3653         } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3654                 DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3655                 handle_ignore_submodules_arg(options, arg + 20);
3656         } else if (!strcmp(arg, "--submodule"))
3657                 DIFF_OPT_SET(options, SUBMODULE_LOG);
3658         else if (!prefixcmp(arg, "--submodule=")) {
3659                 if (!strcmp(arg + 12, "log"))
3660                         DIFF_OPT_SET(options, SUBMODULE_LOG);
3661         }
3662
3663         /* misc options */
3664         else if (!strcmp(arg, "-z"))
3665                 options->line_termination = 0;
3666         else if ((argcount = short_opt('l', av, &optarg))) {
3667                 options->rename_limit = strtoul(optarg, NULL, 10);
3668                 return argcount;
3669         }
3670         else if ((argcount = short_opt('S', av, &optarg))) {
3671                 options->pickaxe = optarg;
3672                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3673                 return argcount;
3674         } else if ((argcount = short_opt('G', av, &optarg))) {
3675                 options->pickaxe = optarg;
3676                 options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3677                 return argcount;
3678         }
3679         else if (!strcmp(arg, "--pickaxe-all"))
3680                 options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3681         else if (!strcmp(arg, "--pickaxe-regex"))
3682                 options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3683         else if ((argcount = short_opt('O', av, &optarg))) {
3684                 options->orderfile = optarg;
3685                 return argcount;
3686         }
3687         else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3688                 options->filter = optarg;
3689                 return argcount;
3690         }
3691         else if (!strcmp(arg, "--abbrev"))
3692                 options->abbrev = DEFAULT_ABBREV;
3693         else if (!prefixcmp(arg, "--abbrev=")) {
3694                 options->abbrev = strtoul(arg + 9, NULL, 10);
3695                 if (options->abbrev < MINIMUM_ABBREV)
3696                         options->abbrev = MINIMUM_ABBREV;
3697                 else if (40 < options->abbrev)
3698                         options->abbrev = 40;
3699         }
3700         else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3701                 options->a_prefix = optarg;
3702                 return argcount;
3703         }
3704         else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3705                 options->b_prefix = optarg;
3706                 return argcount;
3707         }
3708         else if (!strcmp(arg, "--no-prefix"))
3709                 options->a_prefix = options->b_prefix = "";
3710         else if (opt_arg(arg, '\0', "inter-hunk-context",
3711                          &options->interhunkcontext))
3712                 ;
3713         else if (!strcmp(arg, "-W"))
3714                 DIFF_OPT_SET(options, FUNCCONTEXT);
3715         else if (!strcmp(arg, "--function-context"))
3716                 DIFF_OPT_SET(options, FUNCCONTEXT);
3717         else if (!strcmp(arg, "--no-function-context"))
3718                 DIFF_OPT_CLR(options, FUNCCONTEXT);
3719         else if ((argcount = parse_long_opt("output", av, &optarg))) {
3720                 options->file = fopen(optarg, "w");
3721                 if (!options->file)
3722                         die_errno("Could not open '%s'", optarg);
3723                 options->close_file = 1;
3724                 return argcount;
3725         } else
3726                 return 0;
3727         return 1;
3728 }
3729
3730 int parse_rename_score(const char **cp_p)
3731 {
3732         unsigned long num, scale;
3733         int ch, dot;
3734         const char *cp = *cp_p;
3735
3736         num = 0;
3737         scale = 1;
3738         dot = 0;
3739         for (;;) {
3740                 ch = *cp;
3741                 if ( !dot && ch == '.' ) {
3742                         scale = 1;
3743                         dot = 1;
3744                 } else if ( ch == '%' ) {
3745                         scale = dot ? scale*100 : 100;
3746                         cp++;   /* % is always at the end */
3747                         break;
3748                 } else if ( ch >= '0' && ch <= '9' ) {
3749                         if ( scale < 100000 ) {
3750                                 scale *= 10;
3751                                 num = (num*10) + (ch-'0');
3752                         }
3753                 } else {
3754                         break;
3755                 }
3756                 cp++;
3757         }
3758         *cp_p = cp;
3759
3760         /* user says num divided by scale and we say internally that
3761          * is MAX_SCORE * num / scale.
3762          */
3763         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3764 }
3765
3766 static int diff_scoreopt_parse(const char *opt)
3767 {
3768         int opt1, opt2, cmd;
3769
3770         if (*opt++ != '-')
3771                 return -1;
3772         cmd = *opt++;
3773         if (cmd == '-') {
3774                 /* convert the long-form arguments into short-form versions */
3775                 if (!prefixcmp(opt, "break-rewrites")) {
3776                         opt += strlen("break-rewrites");
3777                         if (*opt == 0 || *opt++ == '=')
3778                                 cmd = 'B';
3779                 } else if (!prefixcmp(opt, "find-copies")) {
3780                         opt += strlen("find-copies");
3781                         if (*opt == 0 || *opt++ == '=')
3782                                 cmd = 'C';
3783                 } else if (!prefixcmp(opt, "find-renames")) {
3784                         opt += strlen("find-renames");
3785                         if (*opt == 0 || *opt++ == '=')
3786                                 cmd = 'M';
3787                 }
3788         }
3789         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3790                 return -1; /* that is not a -M, -C nor -B option */
3791
3792         opt1 = parse_rename_score(&opt);
3793         if (cmd != 'B')
3794                 opt2 = 0;
3795         else {
3796                 if (*opt == 0)
3797                         opt2 = 0;
3798                 else if (*opt != '/')
3799                         return -1; /* we expect -B80/99 or -B80 */
3800                 else {
3801                         opt++;
3802                         opt2 = parse_rename_score(&opt);
3803                 }
3804         }
3805         if (*opt != 0)
3806                 return -1;
3807         return opt1 | (opt2 << 16);
3808 }
3809
3810 struct diff_queue_struct diff_queued_diff;
3811
3812 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3813 {
3814         if (queue->alloc <= queue->nr) {
3815                 queue->alloc = alloc_nr(queue->alloc);
3816                 queue->queue = xrealloc(queue->queue,
3817                                         sizeof(dp) * queue->alloc);
3818         }
3819         queue->queue[queue->nr++] = dp;
3820 }
3821
3822 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3823                                  struct diff_filespec *one,
3824                                  struct diff_filespec *two)
3825 {
3826         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3827         dp->one = one;
3828         dp->two = two;
3829         if (queue)
3830                 diff_q(queue, dp);
3831         return dp;
3832 }
3833
3834 void diff_free_filepair(struct diff_filepair *p)
3835 {
3836         free_filespec(p->one);
3837         free_filespec(p->two);
3838         free(p);
3839 }
3840
3841 /* This is different from find_unique_abbrev() in that
3842  * it stuffs the result with dots for alignment.
3843  */
3844 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3845 {
3846         int abblen;
3847         const char *abbrev;
3848         if (len == 40)
3849                 return sha1_to_hex(sha1);
3850
3851         abbrev = find_unique_abbrev(sha1, len);
3852         abblen = strlen(abbrev);
3853         if (abblen < 37) {
3854                 static char hex[41];
3855                 if (len < abblen && abblen <= len + 2)
3856                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3857                 else
3858                         sprintf(hex, "%s...", abbrev);
3859                 return hex;
3860         }
3861         return sha1_to_hex(sha1);
3862 }
3863
3864 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3865 {
3866         int line_termination = opt->line_termination;
3867         int inter_name_termination = line_termination ? '\t' : '\0';
3868         if (opt->output_prefix) {
3869                 struct strbuf *msg = NULL;
3870                 msg = opt->output_prefix(opt, opt->output_prefix_data);
3871                 fprintf(opt->file, "%s", msg->buf);
3872         }
3873
3874         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3875                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3876                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
3877                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3878         }
3879         if (p->score) {
3880                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3881                         inter_name_termination);
3882         } else {
3883                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3884         }
3885
3886         if (p->status == DIFF_STATUS_COPIED ||
3887             p->status == DIFF_STATUS_RENAMED) {
3888                 const char *name_a, *name_b;
3889                 name_a = p->one->path;
3890                 name_b = p->two->path;
3891                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3892                 write_name_quoted(name_a, opt->file, inter_name_termination);
3893                 write_name_quoted(name_b, opt->file, line_termination);
3894         } else {
3895                 const char *name_a, *name_b;
3896                 name_a = p->one->mode ? p->one->path : p->two->path;
3897                 name_b = NULL;
3898                 strip_prefix(opt->prefix_length, &name_a, &name_b);
3899                 write_name_quoted(name_a, opt->file, line_termination);
3900         }
3901 }
3902
3903 int diff_unmodified_pair(struct diff_filepair *p)
3904 {
3905         /* This function is written stricter than necessary to support
3906          * the currently implemented transformers, but the idea is to
3907          * let transformers to produce diff_filepairs any way they want,
3908          * and filter and clean them up here before producing the output.
3909          */
3910         struct diff_filespec *one = p->one, *two = p->two;
3911
3912         if (DIFF_PAIR_UNMERGED(p))
3913                 return 0; /* unmerged is interesting */
3914
3915         /* deletion, addition, mode or type change
3916          * and rename are all interesting.
3917          */
3918         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3919             DIFF_PAIR_MODE_CHANGED(p) ||
3920             strcmp(one->path, two->path))
3921                 return 0;
3922
3923         /* both are valid and point at the same path.  that is, we are
3924          * dealing with a change.
3925          */
3926         if (one->sha1_valid && two->sha1_valid &&
3927             !hashcmp(one->sha1, two->sha1) &&
3928             !one->dirty_submodule && !two->dirty_submodule)
3929                 return 1; /* no change */
3930         if (!one->sha1_valid && !two->sha1_valid)
3931                 return 1; /* both look at the same file on the filesystem. */
3932         return 0;
3933 }
3934
3935 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3936 {
3937         if (diff_unmodified_pair(p))
3938                 return;
3939
3940         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3941             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3942                 return; /* no tree diffs in patch format */
3943
3944         run_diff(p, o);
3945 }
3946
3947 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3948                             struct diffstat_t *diffstat)
3949 {
3950         if (diff_unmodified_pair(p))
3951                 return;
3952
3953         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3954             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3955                 return; /* no useful stat for tree diffs */
3956
3957         run_diffstat(p, o, diffstat);
3958 }
3959
3960 static void diff_flush_checkdiff(struct diff_filepair *p,
3961                 struct diff_options *o)
3962 {
3963         if (diff_unmodified_pair(p))
3964                 return;
3965
3966         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3967             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3968                 return; /* nothing to check in tree diffs */
3969
3970         run_checkdiff(p, o);
3971 }
3972
3973 int diff_queue_is_empty(void)
3974 {
3975         struct diff_queue_struct *q = &diff_queued_diff;
3976         int i;
3977         for (i = 0; i < q->nr; i++)
3978                 if (!diff_unmodified_pair(q->queue[i]))
3979                         return 0;
3980         return 1;
3981 }
3982
3983 #if DIFF_DEBUG
3984 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3985 {
3986         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3987                 x, one ? one : "",
3988                 s->path,
3989                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
3990                 s->mode,
3991                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3992         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3993                 x, one ? one : "",
3994                 s->size, s->xfrm_flags);
3995 }
3996
3997 void diff_debug_filepair(const struct diff_filepair *p, int i)
3998 {
3999         diff_debug_filespec(p->one, i, "one");
4000         diff_debug_filespec(p->two, i, "two");
4001         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4002                 p->score, p->status ? p->status : '?',
4003                 p->one->rename_used, p->broken_pair);
4004 }
4005
4006 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4007 {
4008         int i;
4009         if (msg)
4010                 fprintf(stderr, "%s\n", msg);
4011         fprintf(stderr, "q->nr = %d\n", q->nr);
4012         for (i = 0; i < q->nr; i++) {
4013                 struct diff_filepair *p = q->queue[i];
4014                 diff_debug_filepair(p, i);
4015         }
4016 }
4017 #endif
4018
4019 static void diff_resolve_rename_copy(void)
4020 {
4021         int i;
4022         struct diff_filepair *p;
4023         struct diff_queue_struct *q = &diff_queued_diff;
4024
4025         diff_debug_queue("resolve-rename-copy", q);
4026
4027         for (i = 0; i < q->nr; i++) {
4028                 p = q->queue[i];
4029                 p->status = 0; /* undecided */
4030                 if (DIFF_PAIR_UNMERGED(p))
4031                         p->status = DIFF_STATUS_UNMERGED;
4032                 else if (!DIFF_FILE_VALID(p->one))
4033                         p->status = DIFF_STATUS_ADDED;
4034                 else if (!DIFF_FILE_VALID(p->two))
4035                         p->status = DIFF_STATUS_DELETED;
4036                 else if (DIFF_PAIR_TYPE_CHANGED(p))
4037                         p->status = DIFF_STATUS_TYPE_CHANGED;
4038
4039                 /* from this point on, we are dealing with a pair
4040                  * whose both sides are valid and of the same type, i.e.
4041                  * either in-place edit or rename/copy edit.
4042                  */
4043                 else if (DIFF_PAIR_RENAME(p)) {
4044                         /*
4045                          * A rename might have re-connected a broken
4046                          * pair up, causing the pathnames to be the
4047                          * same again. If so, that's not a rename at
4048                          * all, just a modification..
4049                          *
4050                          * Otherwise, see if this source was used for
4051                          * multiple renames, in which case we decrement
4052                          * the count, and call it a copy.
4053                          */
4054                         if (!strcmp(p->one->path, p->two->path))
4055                                 p->status = DIFF_STATUS_MODIFIED;
4056                         else if (--p->one->rename_used > 0)
4057                                 p->status = DIFF_STATUS_COPIED;
4058                         else
4059                                 p->status = DIFF_STATUS_RENAMED;
4060                 }
4061                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
4062                          p->one->mode != p->two->mode ||
4063                          p->one->dirty_submodule ||
4064                          p->two->dirty_submodule ||
4065                          is_null_sha1(p->one->sha1))
4066                         p->status = DIFF_STATUS_MODIFIED;
4067                 else {
4068                         /* This is a "no-change" entry and should not
4069                          * happen anymore, but prepare for broken callers.
4070                          */
4071                         error("feeding unmodified %s to diffcore",
4072                               p->one->path);
4073                         p->status = DIFF_STATUS_UNKNOWN;
4074                 }
4075         }
4076         diff_debug_queue("resolve-rename-copy done", q);
4077 }
4078
4079 static int check_pair_status(struct diff_filepair *p)
4080 {
4081         switch (p->status) {
4082         case DIFF_STATUS_UNKNOWN:
4083                 return 0;
4084         case 0:
4085                 die("internal error in diff-resolve-rename-copy");
4086         default:
4087                 return 1;
4088         }
4089 }
4090
4091 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4092 {
4093         int fmt = opt->output_format;
4094
4095         if (fmt & DIFF_FORMAT_CHECKDIFF)
4096                 diff_flush_checkdiff(p, opt);
4097         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4098                 diff_flush_raw(p, opt);
4099         else if (fmt & DIFF_FORMAT_NAME) {
4100                 const char *name_a, *name_b;
4101                 name_a = p->two->path;
4102                 name_b = NULL;
4103                 strip_prefix(opt->prefix_length, &name_a, &name_b);
4104                 write_name_quoted(name_a, opt->file, opt->line_termination);
4105         }
4106 }
4107
4108 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4109 {
4110         if (fs->mode)
4111                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4112         else
4113                 fprintf(file, " %s ", newdelete);
4114         write_name_quoted(fs->path, file, '\n');
4115 }
4116
4117
4118 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4119                 const char *line_prefix)
4120 {
4121         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4122                 fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4123                         p->two->mode, show_name ? ' ' : '\n');
4124                 if (show_name) {
4125                         write_name_quoted(p->two->path, file, '\n');
4126                 }
4127         }
4128 }
4129
4130 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4131                         const char *line_prefix)
4132 {
4133         char *names = pprint_rename(p->one->path, p->two->path);
4134
4135         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4136         free(names);
4137         show_mode_change(file, p, 0, line_prefix);
4138 }
4139
4140 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4141 {
4142         FILE *file = opt->file;
4143         char *line_prefix = "";
4144
4145         if (opt->output_prefix) {
4146                 struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4147                 line_prefix = buf->buf;
4148         }
4149
4150         switch(p->status) {
4151         case DIFF_STATUS_DELETED:
4152                 fputs(line_prefix, file);
4153                 show_file_mode_name(file, "delete", p->one);
4154                 break;
4155         case DIFF_STATUS_ADDED:
4156                 fputs(line_prefix, file);
4157                 show_file_mode_name(file, "create", p->two);
4158                 break;
4159         case DIFF_STATUS_COPIED:
4160                 fputs(line_prefix, file);
4161                 show_rename_copy(file, "copy", p, line_prefix);
4162                 break;
4163         case DIFF_STATUS_RENAMED:
4164                 fputs(line_prefix, file);
4165                 show_rename_copy(file, "rename", p, line_prefix);
4166                 break;
4167         default:
4168                 if (p->score) {
4169                         fprintf(file, "%s rewrite ", line_prefix);
4170                         write_name_quoted(p->two->path, file, ' ');
4171                         fprintf(file, "(%d%%)\n", similarity_index(p));
4172                 }
4173                 show_mode_change(file, p, !p->score, line_prefix);
4174                 break;
4175         }
4176 }
4177
4178 struct patch_id_t {
4179         git_SHA_CTX *ctx;
4180         int patchlen;
4181 };
4182
4183 static int remove_space(char *line, int len)
4184 {
4185         int i;
4186         char *dst = line;
4187         unsigned char c;
4188
4189         for (i = 0; i < len; i++)
4190                 if (!isspace((c = line[i])))
4191                         *dst++ = c;
4192
4193         return dst - line;
4194 }
4195
4196 static void patch_id_consume(void *priv, char *line, unsigned long len)
4197 {
4198         struct patch_id_t *data = priv;
4199         int new_len;
4200
4201         /* Ignore line numbers when computing the SHA1 of the patch */
4202         if (!prefixcmp(line, "@@ -"))
4203                 return;
4204
4205         new_len = remove_space(line, len);
4206
4207         git_SHA1_Update(data->ctx, line, new_len);
4208         data->patchlen += new_len;
4209 }
4210
4211 /* returns 0 upon success, and writes result into sha1 */
4212 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4213 {
4214         struct diff_queue_struct *q = &diff_queued_diff;
4215         int i;
4216         git_SHA_CTX ctx;
4217         struct patch_id_t data;
4218         char buffer[PATH_MAX * 4 + 20];
4219
4220         git_SHA1_Init(&ctx);
4221         memset(&data, 0, sizeof(struct patch_id_t));
4222         data.ctx = &ctx;
4223
4224         for (i = 0; i < q->nr; i++) {
4225                 xpparam_t xpp;
4226                 xdemitconf_t xecfg;
4227                 mmfile_t mf1, mf2;
4228                 struct diff_filepair *p = q->queue[i];
4229                 int len1, len2;
4230
4231                 memset(&xpp, 0, sizeof(xpp));
4232                 memset(&xecfg, 0, sizeof(xecfg));
4233                 if (p->status == 0)
4234                         return error("internal diff status error");
4235                 if (p->status == DIFF_STATUS_UNKNOWN)
4236                         continue;
4237                 if (diff_unmodified_pair(p))
4238                         continue;
4239                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4240                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4241                         continue;
4242                 if (DIFF_PAIR_UNMERGED(p))
4243                         continue;
4244
4245                 diff_fill_sha1_info(p->one);
4246                 diff_fill_sha1_info(p->two);
4247                 if (fill_mmfile(&mf1, p->one) < 0 ||
4248                                 fill_mmfile(&mf2, p->two) < 0)
4249                         return error("unable to read files to diff");
4250
4251                 len1 = remove_space(p->one->path, strlen(p->one->path));
4252                 len2 = remove_space(p->two->path, strlen(p->two->path));
4253                 if (p->one->mode == 0)
4254                         len1 = snprintf(buffer, sizeof(buffer),
4255                                         "diff--gita/%.*sb/%.*s"
4256                                         "newfilemode%06o"
4257                                         "---/dev/null"
4258                                         "+++b/%.*s",
4259                                         len1, p->one->path,
4260                                         len2, p->two->path,
4261                                         p->two->mode,
4262                                         len2, p->two->path);
4263                 else if (p->two->mode == 0)
4264                         len1 = snprintf(buffer, sizeof(buffer),
4265                                         "diff--gita/%.*sb/%.*s"
4266                                         "deletedfilemode%06o"
4267                                         "---a/%.*s"
4268                                         "+++/dev/null",
4269                                         len1, p->one->path,
4270                                         len2, p->two->path,
4271                                         p->one->mode,
4272                                         len1, p->one->path);
4273                 else
4274                         len1 = snprintf(buffer, sizeof(buffer),
4275                                         "diff--gita/%.*sb/%.*s"
4276                                         "---a/%.*s"
4277                                         "+++b/%.*s",
4278                                         len1, p->one->path,
4279                                         len2, p->two->path,
4280                                         len1, p->one->path,
4281                                         len2, p->two->path);
4282                 git_SHA1_Update(&ctx, buffer, len1);
4283
4284                 if (diff_filespec_is_binary(p->one) ||
4285                     diff_filespec_is_binary(p->two)) {
4286                         git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4287                         git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4288                         continue;
4289                 }
4290
4291                 xpp.flags = 0;
4292                 xecfg.ctxlen = 3;
4293                 xecfg.flags = 0;
4294                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4295                               &xpp, &xecfg);
4296         }
4297
4298         git_SHA1_Final(sha1, &ctx);
4299         return 0;
4300 }
4301
4302 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4303 {
4304         struct diff_queue_struct *q = &diff_queued_diff;
4305         int i;
4306         int result = diff_get_patch_id(options, sha1);
4307
4308         for (i = 0; i < q->nr; i++)
4309                 diff_free_filepair(q->queue[i]);
4310
4311         free(q->queue);
4312         DIFF_QUEUE_CLEAR(q);
4313
4314         return result;
4315 }
4316
4317 static int is_summary_empty(const struct diff_queue_struct *q)
4318 {
4319         int i;
4320
4321         for (i = 0; i < q->nr; i++) {
4322                 const struct diff_filepair *p = q->queue[i];
4323
4324                 switch (p->status) {
4325                 case DIFF_STATUS_DELETED:
4326                 case DIFF_STATUS_ADDED:
4327                 case DIFF_STATUS_COPIED:
4328                 case DIFF_STATUS_RENAMED:
4329                         return 0;
4330                 default:
4331                         if (p->score)
4332                                 return 0;
4333                         if (p->one->mode && p->two->mode &&
4334                             p->one->mode != p->two->mode)
4335                                 return 0;
4336                         break;
4337                 }
4338         }
4339         return 1;
4340 }
4341
4342 static const char rename_limit_warning[] =
4343 "inexact rename detection was skipped due to too many files.";
4344
4345 static const char degrade_cc_to_c_warning[] =
4346 "only found copies from modified paths due to too many files.";
4347
4348 static const char rename_limit_advice[] =
4349 "you may want to set your %s variable to at least "
4350 "%d and retry the command.";
4351
4352 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4353 {
4354         if (degraded_cc)
4355                 warning(degrade_cc_to_c_warning);
4356         else if (needed)
4357                 warning(rename_limit_warning);
4358         else
4359                 return;
4360         if (0 < needed && needed < 32767)
4361                 warning(rename_limit_advice, varname, needed);
4362 }
4363
4364 void diff_flush(struct diff_options *options)
4365 {
4366         struct diff_queue_struct *q = &diff_queued_diff;
4367         int i, output_format = options->output_format;
4368         int separator = 0;
4369         int dirstat_by_line = 0;
4370
4371         /*
4372          * Order: raw, stat, summary, patch
4373          * or:    name/name-status/checkdiff (other bits clear)
4374          */
4375         if (!q->nr)
4376                 goto free_queue;
4377
4378         if (output_format & (DIFF_FORMAT_RAW |
4379                              DIFF_FORMAT_NAME |
4380                              DIFF_FORMAT_NAME_STATUS |
4381                              DIFF_FORMAT_CHECKDIFF)) {
4382                 for (i = 0; i < q->nr; i++) {
4383                         struct diff_filepair *p = q->queue[i];
4384                         if (check_pair_status(p))
4385                                 flush_one_pair(p, options);
4386                 }
4387                 separator++;
4388         }
4389
4390         if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4391                 dirstat_by_line = 1;
4392
4393         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4394             dirstat_by_line) {
4395                 struct diffstat_t diffstat;
4396
4397                 memset(&diffstat, 0, sizeof(struct diffstat_t));
4398                 for (i = 0; i < q->nr; i++) {
4399                         struct diff_filepair *p = q->queue[i];
4400                         if (check_pair_status(p))
4401                                 diff_flush_stat(p, options, &diffstat);
4402                 }
4403                 if (output_format & DIFF_FORMAT_NUMSTAT)
4404                         show_numstat(&diffstat, options);
4405                 if (output_format & DIFF_FORMAT_DIFFSTAT)
4406                         show_stats(&diffstat, options);
4407                 if (output_format & DIFF_FORMAT_SHORTSTAT)
4408                         show_shortstats(&diffstat, options);
4409                 if (output_format & DIFF_FORMAT_DIRSTAT)
4410                         show_dirstat_by_line(&diffstat, options);
4411                 free_diffstat_info(&diffstat);
4412                 separator++;
4413         }
4414         if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4415                 show_dirstat(options);
4416
4417         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4418                 for (i = 0; i < q->nr; i++) {
4419                         diff_summary(options, q->queue[i]);
4420                 }
4421                 separator++;
4422         }
4423
4424         if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4425             DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4426             DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4427                 /*
4428                  * run diff_flush_patch for the exit status. setting
4429                  * options->file to /dev/null should be safe, becaue we
4430                  * aren't supposed to produce any output anyway.
4431                  */
4432                 if (options->close_file)
4433                         fclose(options->file);
4434                 options->file = fopen("/dev/null", "w");
4435                 if (!options->file)
4436                         die_errno("Could not open /dev/null");
4437                 options->close_file = 1;
4438                 for (i = 0; i < q->nr; i++) {
4439                         struct diff_filepair *p = q->queue[i];
4440                         if (check_pair_status(p))
4441                                 diff_flush_patch(p, options);
4442                         if (options->found_changes)
4443                                 break;
4444                 }
4445         }
4446
4447         if (output_format & DIFF_FORMAT_PATCH) {
4448                 if (separator) {
4449                         if (options->output_prefix) {
4450                                 struct strbuf *msg = NULL;
4451                                 msg = options->output_prefix(options,
4452                                         options->output_prefix_data);
4453                                 fwrite(msg->buf, msg->len, 1, stdout);
4454                         }
4455                         putc(options->line_termination, options->file);
4456                         if (options->stat_sep) {
4457                                 /* attach patch instead of inline */
4458                                 fputs(options->stat_sep, options->file);
4459                         }
4460                 }
4461
4462                 for (i = 0; i < q->nr; i++) {
4463                         struct diff_filepair *p = q->queue[i];
4464                         if (check_pair_status(p))
4465                                 diff_flush_patch(p, options);
4466                 }
4467         }
4468
4469         if (output_format & DIFF_FORMAT_CALLBACK)
4470                 options->format_callback(q, options, options->format_callback_data);
4471
4472         for (i = 0; i < q->nr; i++)
4473                 diff_free_filepair(q->queue[i]);
4474 free_queue:
4475         free(q->queue);
4476         DIFF_QUEUE_CLEAR(q);
4477         if (options->close_file)
4478                 fclose(options->file);
4479
4480         /*
4481          * Report the content-level differences with HAS_CHANGES;
4482          * diff_addremove/diff_change does not set the bit when
4483          * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4484          */
4485         if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4486                 if (options->found_changes)
4487                         DIFF_OPT_SET(options, HAS_CHANGES);
4488                 else
4489                         DIFF_OPT_CLR(options, HAS_CHANGES);
4490         }
4491 }
4492
4493 static void diffcore_apply_filter(const char *filter)
4494 {
4495         int i;
4496         struct diff_queue_struct *q = &diff_queued_diff;
4497         struct diff_queue_struct outq;
4498         DIFF_QUEUE_CLEAR(&outq);
4499
4500         if (!filter)
4501                 return;
4502
4503         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4504                 int found;
4505                 for (i = found = 0; !found && i < q->nr; i++) {
4506                         struct diff_filepair *p = q->queue[i];
4507                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4508                              ((p->score &&
4509                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4510                               (!p->score &&
4511                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4512                             ((p->status != DIFF_STATUS_MODIFIED) &&
4513                              strchr(filter, p->status)))
4514                                 found++;
4515                 }
4516                 if (found)
4517                         return;
4518
4519                 /* otherwise we will clear the whole queue
4520                  * by copying the empty outq at the end of this
4521                  * function, but first clear the current entries
4522                  * in the queue.
4523                  */
4524                 for (i = 0; i < q->nr; i++)
4525                         diff_free_filepair(q->queue[i]);
4526         }
4527         else {
4528                 /* Only the matching ones */
4529                 for (i = 0; i < q->nr; i++) {
4530                         struct diff_filepair *p = q->queue[i];
4531
4532                         if (((p->status == DIFF_STATUS_MODIFIED) &&
4533                              ((p->score &&
4534                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4535                               (!p->score &&
4536                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4537                             ((p->status != DIFF_STATUS_MODIFIED) &&
4538                              strchr(filter, p->status)))
4539                                 diff_q(&outq, p);
4540                         else
4541                                 diff_free_filepair(p);
4542                 }
4543         }
4544         free(q->queue);
4545         *q = outq;
4546 }
4547
4548 /* Check whether two filespecs with the same mode and size are identical */
4549 static int diff_filespec_is_identical(struct diff_filespec *one,
4550                                       struct diff_filespec *two)
4551 {
4552         if (S_ISGITLINK(one->mode))
4553                 return 0;
4554         if (diff_populate_filespec(one, 0))
4555                 return 0;
4556         if (diff_populate_filespec(two, 0))
4557                 return 0;
4558         return !memcmp(one->data, two->data, one->size);
4559 }
4560
4561 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4562 {
4563         int i;
4564         struct diff_queue_struct *q = &diff_queued_diff;
4565         struct diff_queue_struct outq;
4566         DIFF_QUEUE_CLEAR(&outq);
4567
4568         for (i = 0; i < q->nr; i++) {
4569                 struct diff_filepair *p = q->queue[i];
4570
4571                 /*
4572                  * 1. Entries that come from stat info dirtiness
4573                  *    always have both sides (iow, not create/delete),
4574                  *    one side of the object name is unknown, with
4575                  *    the same mode and size.  Keep the ones that
4576                  *    do not match these criteria.  They have real
4577                  *    differences.
4578                  *
4579                  * 2. At this point, the file is known to be modified,
4580                  *    with the same mode and size, and the object
4581                  *    name of one side is unknown.  Need to inspect
4582                  *    the identical contents.
4583                  */
4584                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
4585                     !DIFF_FILE_VALID(p->two) ||
4586                     (p->one->sha1_valid && p->two->sha1_valid) ||
4587                     (p->one->mode != p->two->mode) ||
4588                     diff_populate_filespec(p->one, 1) ||
4589                     diff_populate_filespec(p->two, 1) ||
4590                     (p->one->size != p->two->size) ||
4591                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4592                         diff_q(&outq, p);
4593                 else {
4594                         /*
4595                          * The caller can subtract 1 from skip_stat_unmatch
4596                          * to determine how many paths were dirty only
4597                          * due to stat info mismatch.
4598                          */
4599                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4600                                 diffopt->skip_stat_unmatch++;
4601                         diff_free_filepair(p);
4602                 }
4603         }
4604         free(q->queue);
4605         *q = outq;
4606 }
4607
4608 static int diffnamecmp(const void *a_, const void *b_)
4609 {
4610         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4611         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4612         const char *name_a, *name_b;
4613
4614         name_a = a->one ? a->one->path : a->two->path;
4615         name_b = b->one ? b->one->path : b->two->path;
4616         return strcmp(name_a, name_b);
4617 }
4618
4619 void diffcore_fix_diff_index(struct diff_options *options)
4620 {
4621         struct diff_queue_struct *q = &diff_queued_diff;
4622         qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4623 }
4624
4625 void diffcore_std(struct diff_options *options)
4626 {
4627         if (options->skip_stat_unmatch)
4628                 diffcore_skip_stat_unmatch(options);
4629         if (!options->found_follow) {
4630                 /* See try_to_follow_renames() in tree-diff.c */
4631                 if (options->break_opt != -1)
4632                         diffcore_break(options->break_opt);
4633                 if (options->detect_rename)
4634                         diffcore_rename(options);
4635                 if (options->break_opt != -1)
4636                         diffcore_merge_broken();
4637         }
4638         if (options->pickaxe)
4639                 diffcore_pickaxe(options);
4640         if (options->orderfile)
4641                 diffcore_order(options->orderfile);
4642         if (!options->found_follow)
4643                 /* See try_to_follow_renames() in tree-diff.c */
4644                 diff_resolve_rename_copy();
4645         diffcore_apply_filter(options->filter);
4646
4647         if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4648                 DIFF_OPT_SET(options, HAS_CHANGES);
4649         else
4650                 DIFF_OPT_CLR(options, HAS_CHANGES);
4651
4652         options->found_follow = 0;
4653 }
4654
4655 int diff_result_code(struct diff_options *opt, int status)
4656 {
4657         int result = 0;
4658
4659         diff_warn_rename_limit("diff.renamelimit",
4660                                opt->needed_rename_limit,
4661                                opt->degraded_cc_to_c);
4662         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4663             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4664                 return status;
4665         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4666             DIFF_OPT_TST(opt, HAS_CHANGES))
4667                 result |= 01;
4668         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4669             DIFF_OPT_TST(opt, CHECK_FAILED))
4670                 result |= 02;
4671         return result;
4672 }
4673
4674 int diff_can_quit_early(struct diff_options *opt)
4675 {
4676         return (DIFF_OPT_TST(opt, QUICK) &&
4677                 !opt->filter &&
4678                 DIFF_OPT_TST(opt, HAS_CHANGES));
4679 }
4680
4681 /*
4682  * Shall changes to this submodule be ignored?
4683  *
4684  * Submodule changes can be configured to be ignored separately for each path,
4685  * but that configuration can be overridden from the command line.
4686  */
4687 static int is_submodule_ignored(const char *path, struct diff_options *options)
4688 {
4689         int ignored = 0;
4690         unsigned orig_flags = options->flags;
4691         if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4692                 set_diffopt_flags_from_submodule_config(options, path);
4693         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4694                 ignored = 1;
4695         options->flags = orig_flags;
4696         return ignored;
4697 }
4698
4699 void diff_addremove(struct diff_options *options,
4700                     int addremove, unsigned mode,
4701                     const unsigned char *sha1,
4702                     int sha1_valid,
4703                     const char *concatpath, unsigned dirty_submodule)
4704 {
4705         struct diff_filespec *one, *two;
4706
4707         if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4708                 return;
4709
4710         /* This may look odd, but it is a preparation for
4711          * feeding "there are unchanged files which should
4712          * not produce diffs, but when you are doing copy
4713          * detection you would need them, so here they are"
4714          * entries to the diff-core.  They will be prefixed
4715          * with something like '=' or '*' (I haven't decided
4716          * which but should not make any difference).
4717          * Feeding the same new and old to diff_change()
4718          * also has the same effect.
4719          * Before the final output happens, they are pruned after
4720          * merged into rename/copy pairs as appropriate.
4721          */
4722         if (DIFF_OPT_TST(options, REVERSE_DIFF))
4723                 addremove = (addremove == '+' ? '-' :
4724                              addremove == '-' ? '+' : addremove);
4725
4726         if (options->prefix &&
4727             strncmp(concatpath, options->prefix, options->prefix_length))
4728                 return;
4729
4730         one = alloc_filespec(concatpath);
4731         two = alloc_filespec(concatpath);
4732
4733         if (addremove != '+')
4734                 fill_filespec(one, sha1, sha1_valid, mode);
4735         if (addremove != '-') {
4736                 fill_filespec(two, sha1, sha1_valid, mode);
4737                 two->dirty_submodule = dirty_submodule;
4738         }
4739
4740         diff_queue(&diff_queued_diff, one, two);
4741         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4742                 DIFF_OPT_SET(options, HAS_CHANGES);
4743 }
4744
4745 void diff_change(struct diff_options *options,
4746                  unsigned old_mode, unsigned new_mode,
4747                  const unsigned char *old_sha1,
4748                  const unsigned char *new_sha1,
4749                  int old_sha1_valid, int new_sha1_valid,
4750                  const char *concatpath,
4751                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4752 {
4753         struct diff_filespec *one, *two;
4754
4755         if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4756             is_submodule_ignored(concatpath, options))
4757                 return;
4758
4759         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4760                 unsigned tmp;
4761                 const unsigned char *tmp_c;
4762                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4763                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4764                 tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4765                         new_sha1_valid = tmp;
4766                 tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4767                         new_dirty_submodule = tmp;
4768         }
4769
4770         if (options->prefix &&
4771             strncmp(concatpath, options->prefix, options->prefix_length))
4772                 return;
4773
4774         one = alloc_filespec(concatpath);
4775         two = alloc_filespec(concatpath);
4776         fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4777         fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4778         one->dirty_submodule = old_dirty_submodule;
4779         two->dirty_submodule = new_dirty_submodule;
4780
4781         diff_queue(&diff_queued_diff, one, two);
4782         if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4783                 DIFF_OPT_SET(options, HAS_CHANGES);
4784 }
4785
4786 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4787 {
4788         struct diff_filepair *pair;
4789         struct diff_filespec *one, *two;
4790
4791         if (options->prefix &&
4792             strncmp(path, options->prefix, options->prefix_length))
4793                 return NULL;
4794
4795         one = alloc_filespec(path);
4796         two = alloc_filespec(path);
4797         pair = diff_queue(&diff_queued_diff, one, two);
4798         pair->is_unmerged = 1;
4799         return pair;
4800 }
4801
4802 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4803                 size_t *outsize)
4804 {
4805         struct diff_tempfile *temp;
4806         const char *argv[3];
4807         const char **arg = argv;
4808         struct child_process child;
4809         struct strbuf buf = STRBUF_INIT;
4810         int err = 0;
4811
4812         temp = prepare_temp_file(spec->path, spec);
4813         *arg++ = pgm;
4814         *arg++ = temp->name;
4815         *arg = NULL;
4816
4817         memset(&child, 0, sizeof(child));
4818         child.use_shell = 1;
4819         child.argv = argv;
4820         child.out = -1;
4821         if (start_command(&child)) {
4822                 remove_tempfile();
4823                 return NULL;
4824         }
4825
4826         if (strbuf_read(&buf, child.out, 0) < 0)
4827                 err = error("error reading from textconv command '%s'", pgm);
4828         close(child.out);
4829
4830         if (finish_command(&child) || err) {
4831                 strbuf_release(&buf);
4832                 remove_tempfile();
4833                 return NULL;
4834         }
4835         remove_tempfile();
4836
4837         return strbuf_detach(&buf, outsize);
4838 }
4839
4840 size_t fill_textconv(struct userdiff_driver *driver,
4841                      struct diff_filespec *df,
4842                      char **outbuf)
4843 {
4844         size_t size;
4845
4846         if (!driver || !driver->textconv) {
4847                 if (!DIFF_FILE_VALID(df)) {
4848                         *outbuf = "";
4849                         return 0;
4850                 }
4851                 if (diff_populate_filespec(df, 0))
4852                         die("unable to read files to diff");
4853                 *outbuf = df->data;
4854                 return df->size;
4855         }
4856
4857         if (driver->textconv_cache && df->sha1_valid) {
4858                 *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4859                                           &size);
4860                 if (*outbuf)
4861                         return size;
4862         }
4863
4864         *outbuf = run_textconv(driver->textconv, df, &size);
4865         if (!*outbuf)
4866                 die("unable to read files to diff");
4867
4868         if (driver->textconv_cache && df->sha1_valid) {
4869                 /* ignore errors, as we might be in a readonly repository */
4870                 notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4871                                 size);
4872                 /*
4873                  * we could save up changes and flush them all at the end,
4874                  * but we would need an extra call after all diffing is done.
4875                  * Since generating a cache entry is the slow path anyway,
4876                  * this extra overhead probably isn't a big deal.
4877                  */
4878                 notes_cache_write(driver->textconv_cache);
4879         }
4880
4881         return size;
4882 }
4883
4884 void setup_diff_pager(struct diff_options *opt)
4885 {
4886         /*
4887          * If the user asked for our exit code, then either they want --quiet
4888          * or --exit-code. We should definitely not bother with a pager in the
4889          * former case, as we will generate no output. Since we still properly
4890          * report our exit code even when a pager is run, we _could_ run a
4891          * pager with --exit-code. But since we have not done so historically,
4892          * and because it is easy to find people oneline advising "git diff
4893          * --exit-code" in hooks and other scripts, we do not do so.
4894          */
4895         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4896             check_pager_config("diff") != 0)
4897                 setup_pager();
4898 }