git.oblomov.eu Git - git/blob - 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
  15 #ifdef NO_FAST_WORKING_DIRECTORY
  16 #define FAST_WORKING_DIRECTORY 0
  17 #else
  18 #define FAST_WORKING_DIRECTORY 1
  19 #endif
  20
  21 static int diff_detect_rename_default;
  22 static int diff_rename_limit_default = 200;
  23 static int diff_suppress_blank_empty;
  24 int diff_use_color_default = -1;
  25 static const char *external_diff_cmd_cfg;
  26 int diff_auto_refresh_index = 1;
  27
  28 static char diff_colors[][COLOR_MAXLEN] = {
  29         "\033[m",       /* reset */
  30         "",             /* PLAIN (normal) */
  31         "\033[1m",      /* METAINFO (bold) */
  32         "\033[36m",     /* FRAGINFO (cyan) */
  33         "\033[31m",     /* OLD (red) */
  34         "\033[32m",     /* NEW (green) */
  35         "\033[33m",     /* COMMIT (yellow) */
  36         "\033[41m",     /* WHITESPACE (red background) */
  37 };
  38
  39 static int parse_diff_color_slot(const char *var, int ofs)
  40 {
  41         if (!strcasecmp(var+ofs, "plain"))
  42                 return DIFF_PLAIN;
  43         if (!strcasecmp(var+ofs, "meta"))
  44                 return DIFF_METAINFO;
  45         if (!strcasecmp(var+ofs, "frag"))
  46                 return DIFF_FRAGINFO;
  47         if (!strcasecmp(var+ofs, "old"))
  48                 return DIFF_FILE_OLD;
  49         if (!strcasecmp(var+ofs, "new"))
  50                 return DIFF_FILE_NEW;
  51         if (!strcasecmp(var+ofs, "commit"))
  52                 return DIFF_COMMIT;
  53         if (!strcasecmp(var+ofs, "whitespace"))
  54                 return DIFF_WHITESPACE;
  55         die("bad config variable '%s'", var);
  56 }
  57
  58 static struct ll_diff_driver {
  59         const char *name;
  60         struct ll_diff_driver *next;
  61         const char *cmd;
  62 } *user_diff, **user_diff_tail;
  63
  64 /*
  65  * Currently there is only "diff.<drivername>.command" variable;
  66  * because there are "diff.color.<slot>" variables, we are parsing
  67  * this in a bit convoluted way to allow low level diff driver
  68  * called "color".
  69  */
  70 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
  71 {
  72         const char *name;
  73         int namelen;
  74         struct ll_diff_driver *drv;
  75
  76         name = var + 5;
  77         namelen = ep - name;
  78         for (drv = user_diff; drv; drv = drv->next)
  79                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
  80                         break;
  81         if (!drv) {
  82                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
  83                 drv->name = xmemdupz(name, namelen);
  84                 if (!user_diff_tail)
  85                         user_diff_tail = &user_diff;
  86                 *user_diff_tail = drv;
  87                 user_diff_tail = &(drv->next);
  88         }
  89
  90         return git_config_string(&(drv->cmd), var, value);
  91 }
  92
  93 /*
  94  * 'diff.<what>.funcname' attribute can be specified in the configuration
  95  * to define a customized regexp to find the beginning of a function to
  96  * be used for hunk header lines of "diff -p" style output.
  97  */
  98 static struct funcname_pattern {
  99         char *name;
 100         char *pattern;
 101         struct funcname_pattern *next;
 102 } *funcname_pattern_list;
 103
 104 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
 105 {
 106         const char *name;
 107         int namelen;
 108         struct funcname_pattern *pp;
 109
 110         name = var + 5; /* "diff." */
 111         namelen = ep - name;
 112
 113         for (pp = funcname_pattern_list; pp; pp = pp->next)
 114                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
 115                         break;
 116         if (!pp) {
 117                 pp = xcalloc(1, sizeof(*pp));
 118                 pp->name = xmemdupz(name, namelen);
 119                 pp->next = funcname_pattern_list;
 120                 funcname_pattern_list = pp;
 121         }
 122         free(pp->pattern);
 123         pp->pattern = xstrdup(value);
 124         return 0;
 125 }
 126
 127 /*
 128  * These are to give UI layer defaults.
 129  * The core-level commands such as git-diff-files should
 130  * never be affected by the setting of diff.renames
 131  * the user happens to have in the configuration file.
 132  */
 133 int git_diff_ui_config(const char *var, const char *value, void *cb)
 134 {
 135         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 136                 diff_use_color_default = git_config_colorbool(var, value, -1);
 137                 return 0;
 138         }
 139         if (!strcmp(var, "diff.renames")) {
 140                 if (!value)
 141                         diff_detect_rename_default = DIFF_DETECT_RENAME;
 142                 else if (!strcasecmp(value, "copies") ||
 143                          !strcasecmp(value, "copy"))
 144                         diff_detect_rename_default = DIFF_DETECT_COPY;
 145                 else if (git_config_bool(var,value))
 146                         diff_detect_rename_default = DIFF_DETECT_RENAME;
 147                 return 0;
 148         }
 149         if (!strcmp(var, "diff.autorefreshindex")) {
 150                 diff_auto_refresh_index = git_config_bool(var, value);
 151                 return 0;
 152         }
 153         if (!strcmp(var, "diff.external"))
 154                 return git_config_string(&external_diff_cmd_cfg, var, value);
 155         if (!prefixcmp(var, "diff.")) {
 156                 const char *ep = strrchr(var, '.');
 157
 158                 if (ep != var + 4 && !strcmp(ep, ".command"))
 159                         return parse_lldiff_command(var, ep, value);
 160         }
 161
 162         return git_diff_basic_config(var, value, cb);
 163 }
 164
 165 int git_diff_basic_config(const char *var, const char *value, void *cb)
 166 {
 167         if (!strcmp(var, "diff.renamelimit")) {
 168                 diff_rename_limit_default = git_config_int(var, value);
 169                 return 0;
 170         }
 171
 172         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 173                 int slot = parse_diff_color_slot(var, 11);
 174                 if (!value)
 175                         return config_error_nonbool(var);
 176                 color_parse(value, var, diff_colors[slot]);
 177                 return 0;
 178         }
 179
 180         /* like GNU diff's --suppress-blank-empty option  */
 181         if (!strcmp(var, "diff.suppress-blank-empty")) {
 182                 diff_suppress_blank_empty = git_config_bool(var, value);
 183                 return 0;
 184         }
 185
 186         if (!prefixcmp(var, "diff.")) {
 187                 const char *ep = strrchr(var, '.');
 188                 if (ep != var + 4) {
 189                         if (!strcmp(ep, ".funcname")) {
 190                                 if (!value)
 191                                         return config_error_nonbool(var);
 192                                 return parse_funcname_pattern(var, ep, value);
 193                         }
 194                 }
 195         }
 196
 197         return git_color_default_config(var, value, cb);
 198 }
 199
 200 static char *quote_two(const char *one, const char *two)
 201 {
 202         int need_one = quote_c_style(one, NULL, NULL, 1);
 203         int need_two = quote_c_style(two, NULL, NULL, 1);
 204         struct strbuf res;
 205
 206         strbuf_init(&res, 0);
 207         if (need_one + need_two) {
 208                 strbuf_addch(&res, '"');
 209                 quote_c_style(one, &res, NULL, 1);
 210                 quote_c_style(two, &res, NULL, 1);
 211                 strbuf_addch(&res, '"');
 212         } else {
 213                 strbuf_addstr(&res, one);
 214                 strbuf_addstr(&res, two);
 215         }
 216         return strbuf_detach(&res, NULL);
 217 }
 218
 219 static const char *external_diff(void)
 220 {
 221         static const char *external_diff_cmd = NULL;
 222         static int done_preparing = 0;
 223
 224         if (done_preparing)
 225                 return external_diff_cmd;
 226         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 227         if (!external_diff_cmd)
 228                 external_diff_cmd = external_diff_cmd_cfg;
 229         done_preparing = 1;
 230         return external_diff_cmd;
 231 }
 232
 233 static struct diff_tempfile {
 234         const char *name; /* filename external diff should read from */
 235         char hex[41];
 236         char mode[10];
 237         char tmp_path[PATH_MAX];
 238 } diff_temp[2];
 239
 240 static int count_lines(const char *data, int size)
 241 {
 242         int count, ch, completely_empty = 1, nl_just_seen = 0;
 243         count = 0;
 244         while (0 < size--) {
 245                 ch = *data++;
 246                 if (ch == '\n') {
 247                         count++;
 248                         nl_just_seen = 1;
 249                         completely_empty = 0;
 250                 }
 251                 else {
 252                         nl_just_seen = 0;
 253                         completely_empty = 0;
 254                 }
 255         }
 256         if (completely_empty)
 257                 return 0;
 258         if (!nl_just_seen)
 259                 count++; /* no trailing newline */
 260         return count;
 261 }
 262
 263 static void print_line_count(FILE *file, int count)
 264 {
 265         switch (count) {
 266         case 0:
 267                 fprintf(file, "0,0");
 268                 break;
 269         case 1:
 270                 fprintf(file, "1");
 271                 break;
 272         default:
 273                 fprintf(file, "1,%d", count);
 274                 break;
 275         }
 276 }
 277
 278 static void copy_file_with_prefix(FILE *file,
 279                                   int prefix, const char *data, int size,
 280                                   const char *set, const char *reset)
 281 {
 282         int ch, nl_just_seen = 1;
 283         while (0 < size--) {
 284                 ch = *data++;
 285                 if (nl_just_seen) {
 286                         fputs(set, file);
 287                         putc(prefix, file);
 288                 }
 289                 if (ch == '\n') {
 290                         nl_just_seen = 1;
 291                         fputs(reset, file);
 292                 } else
 293                         nl_just_seen = 0;
 294                 putc(ch, file);
 295         }
 296         if (!nl_just_seen)
 297                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 298 }
 299
 300 static void emit_rewrite_diff(const char *name_a,
 301                               const char *name_b,
 302                               struct diff_filespec *one,
 303                               struct diff_filespec *two,
 304                               struct diff_options *o)
 305 {
 306         int lc_a, lc_b;
 307         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 308         const char *name_a_tab, *name_b_tab;
 309         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 310         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 311         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 312         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 313         const char *reset = diff_get_color(color_diff, DIFF_RESET);
 314         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 315
 316         name_a += (*name_a == '/');
 317         name_b += (*name_b == '/');
 318         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 319         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 320
 321         strbuf_reset(&a_name);
 322         strbuf_reset(&b_name);
 323         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
 324         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
 325
 326         diff_populate_filespec(one, 0);
 327         diff_populate_filespec(two, 0);
 328         lc_a = count_lines(one->data, one->size);
 329         lc_b = count_lines(two->data, two->size);
 330         fprintf(o->file,
 331                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 332                 metainfo, a_name.buf, name_a_tab, reset,
 333                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 334         print_line_count(o->file, lc_a);
 335         fprintf(o->file, " +");
 336         print_line_count(o->file, lc_b);
 337         fprintf(o->file, " @@%s\n", reset);
 338         if (lc_a)
 339                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
 340         if (lc_b)
 341                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
 342 }
 343
 344 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 345 {
 346         if (!DIFF_FILE_VALID(one)) {
 347                 mf->ptr = (char *)""; /* does not matter */
 348                 mf->size = 0;
 349                 return 0;
 350         }
 351         else if (diff_populate_filespec(one, 0))
 352                 return -1;
 353         mf->ptr = one->data;
 354         mf->size = one->size;
 355         return 0;
 356 }
 357
 358 struct diff_words_buffer {
 359         mmfile_t text;
 360         long alloc;
 361         long current; /* output pointer */
 362         int suppressed_newline;
 363 };
 364
 365 static void diff_words_append(char *line, unsigned long len,
 366                 struct diff_words_buffer *buffer)
 367 {
 368         if (buffer->text.size + len > buffer->alloc) {
 369                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
 370                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 371         }
 372         line++;
 373         len--;
 374         memcpy(buffer->text.ptr + buffer->text.size, line, len);
 375         buffer->text.size += len;
 376 }
 377
 378 struct diff_words_data {
 379         struct diff_words_buffer minus, plus;
 380         FILE *file;
 381 };
 382
 383 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
 384                 int suppress_newline)
 385 {
 386         const char *ptr;
 387         int eol = 0;
 388
 389         if (len == 0)
 390                 return;
 391
 392         ptr  = buffer->text.ptr + buffer->current;
 393         buffer->current += len;
 394
 395         if (ptr[len - 1] == '\n') {
 396                 eol = 1;
 397                 len--;
 398         }
 399
 400         fputs(diff_get_color(1, color), file);
 401         fwrite(ptr, len, 1, file);
 402         fputs(diff_get_color(1, DIFF_RESET), file);
 403
 404         if (eol) {
 405                 if (suppress_newline)
 406                         buffer->suppressed_newline = 1;
 407                 else
 408                         putc('\n', file);
 409         }
 410 }
 411
 412 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 413 {
 414         struct diff_words_data *diff_words = priv;
 415
 416         if (diff_words->minus.suppressed_newline) {
 417                 if (line[0] != '+')
 418                         putc('\n', diff_words->file);
 419                 diff_words->minus.suppressed_newline = 0;
 420         }
 421
 422         len--;
 423         switch (line[0]) {
 424                 case '-':
 425                         print_word(diff_words->file,
 426                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
 427                         break;
 428                 case '+':
 429                         print_word(diff_words->file,
 430                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
 431                         break;
 432                 case ' ':
 433                         print_word(diff_words->file,
 434                                    &diff_words->plus, len, DIFF_PLAIN, 0);
 435                         diff_words->minus.current += len;
 436                         break;
 437         }
 438 }
 439
 440 /* this executes the word diff on the accumulated buffers */
 441 static void diff_words_show(struct diff_words_data *diff_words)
 442 {
 443         xpparam_t xpp;
 444         xdemitconf_t xecfg;
 445         xdemitcb_t ecb;
 446         mmfile_t minus, plus;
 447         int i;
 448
 449         memset(&xecfg, 0, sizeof(xecfg));
 450         minus.size = diff_words->minus.text.size;
 451         minus.ptr = xmalloc(minus.size);
 452         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 453         for (i = 0; i < minus.size; i++)
 454                 if (isspace(minus.ptr[i]))
 455                         minus.ptr[i] = '\n';
 456         diff_words->minus.current = 0;
 457
 458         plus.size = diff_words->plus.text.size;
 459         plus.ptr = xmalloc(plus.size);
 460         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 461         for (i = 0; i < plus.size; i++)
 462                 if (isspace(plus.ptr[i]))
 463                         plus.ptr[i] = '\n';
 464         diff_words->plus.current = 0;
 465
 466         xpp.flags = XDF_NEED_MINIMAL;
 467         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 468         xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 469                       &xpp, &xecfg, &ecb);
 470         free(minus.ptr);
 471         free(plus.ptr);
 472         diff_words->minus.text.size = diff_words->plus.text.size = 0;
 473
 474         if (diff_words->minus.suppressed_newline) {
 475                 putc('\n', diff_words->file);
 476                 diff_words->minus.suppressed_newline = 0;
 477         }
 478 }
 479
 480 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 481
 482 struct emit_callback {
 483         int nparents, color_diff;
 484         unsigned ws_rule;
 485         sane_truncate_fn truncate;
 486         const char **label_path;
 487         struct diff_words_data *diff_words;
 488         int *found_changesp;
 489         FILE *file;
 490 };
 491
 492 static void free_diff_words_data(struct emit_callback *ecbdata)
 493 {
 494         if (ecbdata->diff_words) {
 495                 /* flush buffers */
 496                 if (ecbdata->diff_words->minus.text.size ||
 497                                 ecbdata->diff_words->plus.text.size)
 498                         diff_words_show(ecbdata->diff_words);
 499
 500                 free (ecbdata->diff_words->minus.text.ptr);
 501                 free (ecbdata->diff_words->plus.text.ptr);
 502                 free(ecbdata->diff_words);
 503                 ecbdata->diff_words = NULL;
 504         }
 505 }
 506
 507 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 508 {
 509         if (diff_use_color)
 510                 return diff_colors[ix];
 511         return "";
 512 }
 513
 514 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 515 {
 516         int has_trailing_newline = (len > 0 && line[len-1] == '\n');
 517         if (has_trailing_newline)
 518                 len--;
 519
 520         fputs(set, file);
 521         fwrite(line, len, 1, file);
 522         fputs(reset, file);
 523         if (has_trailing_newline)
 524                 fputc('\n', file);
 525 }
 526
 527 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 528 {
 529         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 530         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 531
 532         if (!*ws)
 533                 emit_line(ecbdata->file, set, reset, line, len);
 534         else {
 535                 /* Emit just the prefix, then the rest. */
 536                 emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 537                 ws_check_emit(line + ecbdata->nparents,
 538                               len - ecbdata->nparents, ecbdata->ws_rule,
 539                               ecbdata->file, set, reset, ws);
 540         }
 541 }
 542
 543 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 544 {
 545         const char *cp;
 546         unsigned long allot;
 547         size_t l = len;
 548
 549         if (ecb->truncate)
 550                 return ecb->truncate(line, len);
 551         cp = line;
 552         allot = l;
 553         while (0 < l) {
 554                 (void) utf8_width(&cp, &l);
 555                 if (!cp)
 556                         break; /* truncated in the middle? */
 557         }
 558         return allot - l;
 559 }
 560
 561 static void fn_out_consume(void *priv, char *line, unsigned long len)
 562 {
 563         int i;
 564         int color;
 565         struct emit_callback *ecbdata = priv;
 566         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 567         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 568         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 569
 570         *(ecbdata->found_changesp) = 1;
 571
 572         if (ecbdata->label_path[0]) {
 573                 const char *name_a_tab, *name_b_tab;
 574
 575                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 576                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 577
 578                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
 579                         meta, ecbdata->label_path[0], reset, name_a_tab);
 580                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 581                         meta, ecbdata->label_path[1], reset, name_b_tab);
 582                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 583         }
 584
 585         if (diff_suppress_blank_empty
 586             && len == 2 && line[0] == ' ' && line[1] == '\n') {
 587                 line[0] = '\n';
 588                 len = 1;
 589         }
 590
 591         /* This is not really necessary for now because
 592          * this codepath only deals with two-way diffs.
 593          */
 594         for (i = 0; i < len && line[i] == '@'; i++)
 595                 ;
 596         if (2 <= i && i < len && line[i] == ' ') {
 597                 ecbdata->nparents = i - 1;
 598                 len = sane_truncate_line(ecbdata, line, len);
 599                 emit_line(ecbdata->file,
 600                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 601                           reset, line, len);
 602                 if (line[len-1] != '\n')
 603                         putc('\n', ecbdata->file);
 604                 return;
 605         }
 606
 607         if (len < ecbdata->nparents) {
 608                 emit_line(ecbdata->file, reset, reset, line, len);
 609                 return;
 610         }
 611
 612         color = DIFF_PLAIN;
 613         if (ecbdata->diff_words && ecbdata->nparents != 1)
 614                 /* fall back to normal diff */
 615                 free_diff_words_data(ecbdata);
 616         if (ecbdata->diff_words) {
 617                 if (line[0] == '-') {
 618                         diff_words_append(line, len,
 619                                           &ecbdata->diff_words->minus);
 620                         return;
 621                 } else if (line[0] == '+') {
 622                         diff_words_append(line, len,
 623                                           &ecbdata->diff_words->plus);
 624                         return;
 625                 }
 626                 if (ecbdata->diff_words->minus.text.size ||
 627                     ecbdata->diff_words->plus.text.size)
 628                         diff_words_show(ecbdata->diff_words);
 629                 line++;
 630                 len--;
 631                 emit_line(ecbdata->file, plain, reset, line, len);
 632                 return;
 633         }
 634         for (i = 0; i < ecbdata->nparents && len; i++) {
 635                 if (line[i] == '-')
 636                         color = DIFF_FILE_OLD;
 637                 else if (line[i] == '+')
 638                         color = DIFF_FILE_NEW;
 639         }
 640
 641         if (color != DIFF_FILE_NEW) {
 642                 emit_line(ecbdata->file,
 643                           diff_get_color(ecbdata->color_diff, color),
 644                           reset, line, len);
 645                 return;
 646         }
 647         emit_add_line(reset, ecbdata, line, len);
 648 }
 649
 650 static char *pprint_rename(const char *a, const char *b)
 651 {
 652         const char *old = a;
 653         const char *new = b;
 654         struct strbuf name;
 655         int pfx_length, sfx_length;
 656         int len_a = strlen(a);
 657         int len_b = strlen(b);
 658         int a_midlen, b_midlen;
 659         int qlen_a = quote_c_style(a, NULL, NULL, 0);
 660         int qlen_b = quote_c_style(b, NULL, NULL, 0);
 661
 662         strbuf_init(&name, 0);
 663         if (qlen_a || qlen_b) {
 664                 quote_c_style(a, &name, NULL, 0);
 665                 strbuf_addstr(&name, " => ");
 666                 quote_c_style(b, &name, NULL, 0);
 667                 return strbuf_detach(&name, NULL);
 668         }
 669
 670         /* Find common prefix */
 671         pfx_length = 0;
 672         while (*old && *new && *old == *new) {
 673                 if (*old == '/')
 674                         pfx_length = old - a + 1;
 675                 old++;
 676                 new++;
 677         }
 678
 679         /* Find common suffix */
 680         old = a + len_a;
 681         new = b + len_b;
 682         sfx_length = 0;
 683         while (a <= old && b <= new && *old == *new) {
 684                 if (*old == '/')
 685                         sfx_length = len_a - (old - a);
 686                 old--;
 687                 new--;
 688         }
 689
 690         /*
 691          * pfx{mid-a => mid-b}sfx
 692          * {pfx-a => pfx-b}sfx
 693          * pfx{sfx-a => sfx-b}
 694          * name-a => name-b
 695          */
 696         a_midlen = len_a - pfx_length - sfx_length;
 697         b_midlen = len_b - pfx_length - sfx_length;
 698         if (a_midlen < 0)
 699                 a_midlen = 0;
 700         if (b_midlen < 0)
 701                 b_midlen = 0;
 702
 703         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 704         if (pfx_length + sfx_length) {
 705                 strbuf_add(&name, a, pfx_length);
 706                 strbuf_addch(&name, '{');
 707         }
 708         strbuf_add(&name, a + pfx_length, a_midlen);
 709         strbuf_addstr(&name, " => ");
 710         strbuf_add(&name, b + pfx_length, b_midlen);
 711         if (pfx_length + sfx_length) {
 712                 strbuf_addch(&name, '}');
 713                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 714         }
 715         return strbuf_detach(&name, NULL);
 716 }
 717
 718 struct diffstat_t {
 719         int nr;
 720         int alloc;
 721         struct diffstat_file {
 722                 char *from_name;
 723                 char *name;
 724                 char *print_name;
 725                 unsigned is_unmerged:1;
 726                 unsigned is_binary:1;
 727                 unsigned is_renamed:1;
 728                 unsigned int added, deleted;
 729         } **files;
 730 };
 731
 732 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 733                                           const char *name_a,
 734                                           const char *name_b)
 735 {
 736         struct diffstat_file *x;
 737         x = xcalloc(sizeof (*x), 1);
 738         if (diffstat->nr == diffstat->alloc) {
 739                 diffstat->alloc = alloc_nr(diffstat->alloc);
 740                 diffstat->files = xrealloc(diffstat->files,
 741                                 diffstat->alloc * sizeof(x));
 742         }
 743         diffstat->files[diffstat->nr++] = x;
 744         if (name_b) {
 745                 x->from_name = xstrdup(name_a);
 746                 x->name = xstrdup(name_b);
 747                 x->is_renamed = 1;
 748         }
 749         else {
 750                 x->from_name = NULL;
 751                 x->name = xstrdup(name_a);
 752         }
 753         return x;
 754 }
 755
 756 static void diffstat_consume(void *priv, char *line, unsigned long len)
 757 {
 758         struct diffstat_t *diffstat = priv;
 759         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 760
 761         if (line[0] == '+')
 762                 x->added++;
 763         else if (line[0] == '-')
 764                 x->deleted++;
 765 }
 766
 767 const char mime_boundary_leader[] = "------------";
 768
 769 static int scale_linear(int it, int width, int max_change)
 770 {
 771         /*
 772          * make sure that at least one '-' is printed if there were deletions,
 773          * and likewise for '+'.
 774          */
 775         if (max_change < 2)
 776                 return it;
 777         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 778 }
 779
 780 static void show_name(FILE *file,
 781                       const char *prefix, const char *name, int len,
 782                       const char *reset, const char *set)
 783 {
 784         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 785 }
 786
 787 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 788 {
 789         if (cnt <= 0)
 790                 return;
 791         fprintf(file, "%s", set);
 792         while (cnt--)
 793                 putc(ch, file);
 794         fprintf(file, "%s", reset);
 795 }
 796
 797 static void fill_print_name(struct diffstat_file *file)
 798 {
 799         char *pname;
 800
 801         if (file->print_name)
 802                 return;
 803
 804         if (!file->is_renamed) {
 805                 struct strbuf buf;
 806                 strbuf_init(&buf, 0);
 807                 if (quote_c_style(file->name, &buf, NULL, 0)) {
 808                         pname = strbuf_detach(&buf, NULL);
 809                 } else {
 810                         pname = file->name;
 811                         strbuf_release(&buf);
 812                 }
 813         } else {
 814                 pname = pprint_rename(file->from_name, file->name);
 815         }
 816         file->print_name = pname;
 817 }
 818
 819 static void show_stats(struct diffstat_t* data, struct diff_options *options)
 820 {
 821         int i, len, add, del, total, adds = 0, dels = 0;
 822         int max_change = 0, max_len = 0;
 823         int total_files = data->nr;
 824         int width, name_width;
 825         const char *reset, *set, *add_c, *del_c;
 826
 827         if (data->nr == 0)
 828                 return;
 829
 830         width = options->stat_width ? options->stat_width : 80;
 831         name_width = options->stat_name_width ? options->stat_name_width : 50;
 832
 833         /* Sanity: give at least 5 columns to the graph,
 834          * but leave at least 10 columns for the name.
 835          */
 836         if (width < 25)
 837                 width = 25;
 838         if (name_width < 10)
 839                 name_width = 10;
 840         else if (width < name_width + 15)
 841                 name_width = width - 15;
 842
 843         /* Find the longest filename and max number of changes */
 844         reset = diff_get_color_opt(options, DIFF_RESET);
 845         set   = diff_get_color_opt(options, DIFF_PLAIN);
 846         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 847         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 848
 849         for (i = 0; i < data->nr; i++) {
 850                 struct diffstat_file *file = data->files[i];
 851                 int change = file->added + file->deleted;
 852                 fill_print_name(file);
 853                 len = strlen(file->print_name);
 854                 if (max_len < len)
 855                         max_len = len;
 856
 857                 if (file->is_binary || file->is_unmerged)
 858                         continue;
 859                 if (max_change < change)
 860                         max_change = change;
 861         }
 862
 863         /* Compute the width of the graph part;
 864          * 10 is for one blank at the beginning of the line plus
 865          * " | count " between the name and the graph.
 866          *
 867          * From here on, name_width is the width of the name area,
 868          * and width is the width of the graph area.
 869          */
 870         name_width = (name_width < max_len) ? name_width : max_len;
 871         if (width < (name_width + 10) + max_change)
 872                 width = width - (name_width + 10);
 873         else
 874                 width = max_change;
 875
 876         for (i = 0; i < data->nr; i++) {
 877                 const char *prefix = "";
 878                 char *name = data->files[i]->print_name;
 879                 int added = data->files[i]->added;
 880                 int deleted = data->files[i]->deleted;
 881                 int name_len;
 882
 883                 /*
 884                  * "scale" the filename
 885                  */
 886                 len = name_width;
 887                 name_len = strlen(name);
 888                 if (name_width < name_len) {
 889                         char *slash;
 890                         prefix = "...";
 891                         len -= 3;
 892                         name += name_len - len;
 893                         slash = strchr(name, '/');
 894                         if (slash)
 895                                 name = slash;
 896                 }
 897
 898                 if (data->files[i]->is_binary) {
 899                         show_name(options->file, prefix, name, len, reset, set);
 900                         fprintf(options->file, "  Bin ");
 901                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 902                         fprintf(options->file, " -> ");
 903                         fprintf(options->file, "%s%d%s", add_c, added, reset);
 904                         fprintf(options->file, " bytes");
 905                         fprintf(options->file, "\n");
 906                         continue;
 907                 }
 908                 else if (data->files[i]->is_unmerged) {
 909                         show_name(options->file, prefix, name, len, reset, set);
 910                         fprintf(options->file, "  Unmerged\n");
 911                         continue;
 912                 }
 913                 else if (!data->files[i]->is_renamed &&
 914                          (added + deleted == 0)) {
 915                         total_files--;
 916                         continue;
 917                 }
 918
 919                 /*
 920                  * scale the add/delete
 921                  */
 922                 add = added;
 923                 del = deleted;
 924                 total = add + del;
 925                 adds += add;
 926                 dels += del;
 927
 928                 if (width <= max_change) {
 929                         add = scale_linear(add, width, max_change);
 930                         del = scale_linear(del, width, max_change);
 931                         total = add + del;
 932                 }
 933                 show_name(options->file, prefix, name, len, reset, set);
 934                 fprintf(options->file, "%5d%s", added + deleted,
 935                                 added + deleted ? " " : "");
 936                 show_graph(options->file, '+', add, add_c, reset);
 937                 show_graph(options->file, '-', del, del_c, reset);
 938                 fprintf(options->file, "\n");
 939         }
 940         fprintf(options->file,
 941                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 942                set, total_files, adds, dels, reset);
 943 }
 944
 945 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 946 {
 947         int i, adds = 0, dels = 0, total_files = data->nr;
 948
 949         if (data->nr == 0)
 950                 return;
 951
 952         for (i = 0; i < data->nr; i++) {
 953                 if (!data->files[i]->is_binary &&
 954                     !data->files[i]->is_unmerged) {
 955                         int added = data->files[i]->added;
 956                         int deleted= data->files[i]->deleted;
 957                         if (!data->files[i]->is_renamed &&
 958                             (added + deleted == 0)) {
 959                                 total_files--;
 960                         } else {
 961                                 adds += added;
 962                                 dels += deleted;
 963                         }
 964                 }
 965         }
 966         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 967                total_files, adds, dels);
 968 }
 969
 970 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 971 {
 972         int i;
 973
 974         if (data->nr == 0)
 975                 return;
 976
 977         for (i = 0; i < data->nr; i++) {
 978                 struct diffstat_file *file = data->files[i];
 979
 980                 if (file->is_binary)
 981                         fprintf(options->file, "-\t-\t");
 982                 else
 983                         fprintf(options->file,
 984                                 "%d\t%d\t", file->added, file->deleted);
 985                 if (options->line_termination) {
 986                         fill_print_name(file);
 987                         if (!file->is_renamed)
 988                                 write_name_quoted(file->name, options->file,
 989                                                   options->line_termination);
 990                         else {
 991                                 fputs(file->print_name, options->file);
 992                                 putc(options->line_termination, options->file);
 993                         }
 994                 } else {
 995                         if (file->is_renamed) {
 996                                 putc('\0', options->file);
 997                                 write_name_quoted(file->from_name, options->file, '\0');
 998                         }
 999                         write_name_quoted(file->name, options->file, '\0');
1000                 }
1001         }
1002 }
1003
1004 struct dirstat_file {
1005         const char *name;
1006         unsigned long changed;
1007 };
1008
1009 struct dirstat_dir {
1010         struct dirstat_file *files;
1011         int alloc, nr, percent, cumulative;
1012 };
1013
1014 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1015 {
1016         unsigned long this_dir = 0;
1017         unsigned int sources = 0;
1018
1019         while (dir->nr) {
1020                 struct dirstat_file *f = dir->files;
1021                 int namelen = strlen(f->name);
1022                 unsigned long this;
1023                 char *slash;
1024
1025                 if (namelen < baselen)
1026                         break;
1027                 if (memcmp(f->name, base, baselen))
1028                         break;
1029                 slash = strchr(f->name + baselen, '/');
1030                 if (slash) {
1031                         int newbaselen = slash + 1 - f->name;
1032                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1033                         sources++;
1034                 } else {
1035                         this = f->changed;
1036                         dir->files++;
1037                         dir->nr--;
1038                         sources += 2;
1039                 }
1040                 this_dir += this;
1041         }
1042
1043         /*
1044          * We don't report dirstat's for
1045          *  - the top level
1046          *  - or cases where everything came from a single directory
1047          *    under this directory (sources == 1).
1048          */
1049         if (baselen && sources != 1) {
1050                 int permille = this_dir * 1000 / changed;
1051                 if (permille) {
1052                         int percent = permille / 10;
1053                         if (percent >= dir->percent) {
1054                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1055                                 if (!dir->cumulative)
1056                                         return 0;
1057                         }
1058                 }
1059         }
1060         return this_dir;
1061 }
1062
1063 static void show_dirstat(struct diff_options *options)
1064 {
1065         int i;
1066         unsigned long changed;
1067         struct dirstat_dir dir;
1068         struct diff_queue_struct *q = &diff_queued_diff;
1069
1070         dir.files = NULL;
1071         dir.alloc = 0;
1072         dir.nr = 0;
1073         dir.percent = options->dirstat_percent;
1074         dir.cumulative = options->output_format & DIFF_FORMAT_CUMULATIVE;
1075
1076         changed = 0;
1077         for (i = 0; i < q->nr; i++) {
1078                 struct diff_filepair *p = q->queue[i];
1079                 const char *name;
1080                 unsigned long copied, added, damage;
1081
1082                 name = p->one->path ? p->one->path : p->two->path;
1083
1084                 if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1085                         diff_populate_filespec(p->one, 0);
1086                         diff_populate_filespec(p->two, 0);
1087                         diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1088                                                &copied, &added);
1089                         diff_free_filespec_data(p->one);
1090                         diff_free_filespec_data(p->two);
1091                 } else if (DIFF_FILE_VALID(p->one)) {
1092                         diff_populate_filespec(p->one, 1);
1093                         copied = added = 0;
1094                         diff_free_filespec_data(p->one);
1095                 } else if (DIFF_FILE_VALID(p->two)) {
1096                         diff_populate_filespec(p->two, 1);
1097                         copied = 0;
1098                         added = p->two->size;
1099                         diff_free_filespec_data(p->two);
1100                 } else
1101                         continue;
1102
1103                 /*
1104                  * Original minus copied is the removed material,
1105                  * added is the new material.  They are both damages
1106                  * made to the preimage.
1107                  */
1108                 damage = (p->one->size - copied) + added;
1109
1110                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1111                 dir.files[dir.nr].name = name;
1112                 dir.files[dir.nr].changed = damage;
1113                 changed += damage;
1114                 dir.nr++;
1115         }
1116
1117         /* This can happen even with many files, if everything was renames */
1118         if (!changed)
1119                 return;
1120
1121         /* Show all directories with more than x% of the changes */
1122         gather_dirstat(options->file, &dir, changed, "", 0);
1123 }
1124
1125 static void free_diffstat_info(struct diffstat_t *diffstat)
1126 {
1127         int i;
1128         for (i = 0; i < diffstat->nr; i++) {
1129                 struct diffstat_file *f = diffstat->files[i];
1130                 if (f->name != f->print_name)
1131                         free(f->print_name);
1132                 free(f->name);
1133                 free(f->from_name);
1134                 free(f);
1135         }
1136         free(diffstat->files);
1137 }
1138
1139 struct checkdiff_t {
1140         const char *filename;
1141         int lineno;
1142         struct diff_options *o;
1143         unsigned ws_rule;
1144         unsigned status;
1145         int trailing_blanks_start;
1146 };
1147
1148 static int is_conflict_marker(const char *line, unsigned long len)
1149 {
1150         char firstchar;
1151         int cnt;
1152
1153         if (len < 8)
1154                 return 0;
1155         firstchar = line[0];
1156         switch (firstchar) {
1157         case '=': case '>': case '<':
1158                 break;
1159         default:
1160                 return 0;
1161         }
1162         for (cnt = 1; cnt < 7; cnt++)
1163                 if (line[cnt] != firstchar)
1164                         return 0;
1165         /* line[0] thru line[6] are same as firstchar */
1166         if (firstchar == '=') {
1167                 /* divider between ours and theirs? */
1168                 if (len != 8 || line[7] != '\n')
1169                         return 0;
1170         } else if (len < 8 || !isspace(line[7])) {
1171                 /* not divider before ours nor after theirs */
1172                 return 0;
1173         }
1174         return 1;
1175 }
1176
1177 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1178 {
1179         struct checkdiff_t *data = priv;
1180         int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1181         const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1182         const char *reset = diff_get_color(color_diff, DIFF_RESET);
1183         const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1184         char *err;
1185
1186         if (line[0] == '+') {
1187                 unsigned bad;
1188                 data->lineno++;
1189                 if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1190                         data->trailing_blanks_start = 0;
1191                 else if (!data->trailing_blanks_start)
1192                         data->trailing_blanks_start = data->lineno;
1193                 if (is_conflict_marker(line + 1, len - 1)) {
1194                         data->status |= 1;
1195                         fprintf(data->o->file,
1196                                 "%s:%d: leftover conflict marker\n",
1197                                 data->filename, data->lineno);
1198                 }
1199                 bad = ws_check(line + 1, len - 1, data->ws_rule);
1200                 if (!bad)
1201                         return;
1202                 data->status |= bad;
1203                 err = whitespace_error_string(bad);
1204                 fprintf(data->o->file, "%s:%d: %s.\n",
1205                         data->filename, data->lineno, err);
1206                 free(err);
1207                 emit_line(data->o->file, set, reset, line, 1);
1208                 ws_check_emit(line + 1, len - 1, data->ws_rule,
1209                               data->o->file, set, reset, ws);
1210         } else if (line[0] == ' ') {
1211                 data->lineno++;
1212                 data->trailing_blanks_start = 0;
1213         } else if (line[0] == '@') {
1214                 char *plus = strchr(line, '+');
1215                 if (plus)
1216                         data->lineno = strtol(plus, NULL, 10) - 1;
1217                 else
1218                         die("invalid diff");
1219                 data->trailing_blanks_start = 0;
1220         }
1221 }
1222
1223 static unsigned char *deflate_it(char *data,
1224                                  unsigned long size,
1225                                  unsigned long *result_size)
1226 {
1227         int bound;
1228         unsigned char *deflated;
1229         z_stream stream;
1230
1231         memset(&stream, 0, sizeof(stream));
1232         deflateInit(&stream, zlib_compression_level);
1233         bound = deflateBound(&stream, size);
1234         deflated = xmalloc(bound);
1235         stream.next_out = deflated;
1236         stream.avail_out = bound;
1237
1238         stream.next_in = (unsigned char *)data;
1239         stream.avail_in = size;
1240         while (deflate(&stream, Z_FINISH) == Z_OK)
1241                 ; /* nothing */
1242         deflateEnd(&stream);
1243         *result_size = stream.total_out;
1244         return deflated;
1245 }
1246
1247 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1248 {
1249         void *cp;
1250         void *delta;
1251         void *deflated;
1252         void *data;
1253         unsigned long orig_size;
1254         unsigned long delta_size;
1255         unsigned long deflate_size;
1256         unsigned long data_size;
1257
1258         /* We could do deflated delta, or we could do just deflated two,
1259          * whichever is smaller.
1260          */
1261         delta = NULL;
1262         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1263         if (one->size && two->size) {
1264                 delta = diff_delta(one->ptr, one->size,
1265                                    two->ptr, two->size,
1266                                    &delta_size, deflate_size);
1267                 if (delta) {
1268                         void *to_free = delta;
1269                         orig_size = delta_size;
1270                         delta = deflate_it(delta, delta_size, &delta_size);
1271                         free(to_free);
1272                 }
1273         }
1274
1275         if (delta && delta_size < deflate_size) {
1276                 fprintf(file, "delta %lu\n", orig_size);
1277                 free(deflated);
1278                 data = delta;
1279                 data_size = delta_size;
1280         }
1281         else {
1282                 fprintf(file, "literal %lu\n", two->size);
1283                 free(delta);
1284                 data = deflated;
1285                 data_size = deflate_size;
1286         }
1287
1288         /* emit data encoded in base85 */
1289         cp = data;
1290         while (data_size) {
1291                 int bytes = (52 < data_size) ? 52 : data_size;
1292                 char line[70];
1293                 data_size -= bytes;
1294                 if (bytes <= 26)
1295                         line[0] = bytes + 'A' - 1;
1296                 else
1297                         line[0] = bytes - 26 + 'a' - 1;
1298                 encode_85(line + 1, cp, bytes);
1299                 cp = (char *) cp + bytes;
1300                 fputs(line, file);
1301                 fputc('\n', file);
1302         }
1303         fprintf(file, "\n");
1304         free(data);
1305 }
1306
1307 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1308 {
1309         fprintf(file, "GIT binary patch\n");
1310         emit_binary_diff_body(file, one, two);
1311         emit_binary_diff_body(file, two, one);
1312 }
1313
1314 static void setup_diff_attr_check(struct git_attr_check *check)
1315 {
1316         static struct git_attr *attr_diff;
1317
1318         if (!attr_diff) {
1319                 attr_diff = git_attr("diff", 4);
1320         }
1321         check[0].attr = attr_diff;
1322 }
1323
1324 static void diff_filespec_check_attr(struct diff_filespec *one)
1325 {
1326         struct git_attr_check attr_diff_check;
1327         int check_from_data = 0;
1328
1329         if (one->checked_attr)
1330                 return;
1331
1332         setup_diff_attr_check(&attr_diff_check);
1333         one->is_binary = 0;
1334         one->funcname_pattern_ident = NULL;
1335
1336         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1337                 const char *value;
1338
1339                 /* binaryness */
1340                 value = attr_diff_check.value;
1341                 if (ATTR_TRUE(value))
1342                         ;
1343                 else if (ATTR_FALSE(value))
1344                         one->is_binary = 1;
1345                 else
1346                         check_from_data = 1;
1347
1348                 /* funcname pattern ident */
1349                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1350                         ;
1351                 else
1352                         one->funcname_pattern_ident = value;
1353         }
1354
1355         if (check_from_data) {
1356                 if (!one->data && DIFF_FILE_VALID(one))
1357                         diff_populate_filespec(one, 0);
1358
1359                 if (one->data)
1360                         one->is_binary = buffer_is_binary(one->data, one->size);
1361         }
1362 }
1363
1364 int diff_filespec_is_binary(struct diff_filespec *one)
1365 {
1366         diff_filespec_check_attr(one);
1367         return one->is_binary;
1368 }
1369
1370 static const char *funcname_pattern(const char *ident)
1371 {
1372         struct funcname_pattern *pp;
1373
1374         for (pp = funcname_pattern_list; pp; pp = pp->next)
1375                 if (!strcmp(ident, pp->name))
1376                         return pp->pattern;
1377         return NULL;
1378 }
1379
1380 static struct builtin_funcname_pattern {
1381         const char *name;
1382         const char *pattern;
1383 } builtin_funcname_pattern[] = {
1384         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1385                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1386                         "^[     ]*\\(\\([       ]*"
1387                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1388                         "[      ]*([^;]*\\)$" },
1389         { "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
1390                         "destructor\\|interface\\|implementation\\|"
1391                         "initialization\\|finalization\\)[ \t]*.*\\)$"
1392                         "\\|"
1393                         "^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
1394                         },
1395         { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
1396         { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
1397         { "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
1398 };
1399
1400 static const char *diff_funcname_pattern(struct diff_filespec *one)
1401 {
1402         const char *ident, *pattern;
1403         int i;
1404
1405         diff_filespec_check_attr(one);
1406         ident = one->funcname_pattern_ident;
1407
1408         if (!ident)
1409                 /*
1410                  * If the config file has "funcname.default" defined, that
1411                  * regexp is used; otherwise NULL is returned and xemit uses
1412                  * the built-in default.
1413                  */
1414                 return funcname_pattern("default");
1415
1416         /* Look up custom "funcname.$ident" regexp from config. */
1417         pattern = funcname_pattern(ident);
1418         if (pattern)
1419                 return pattern;
1420
1421         /*
1422          * And define built-in fallback patterns here.  Note that
1423          * these can be overridden by the user's config settings.
1424          */
1425         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1426                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1427                         return builtin_funcname_pattern[i].pattern;
1428
1429         return NULL;
1430 }
1431
1432 static void builtin_diff(const char *name_a,
1433                          const char *name_b,
1434                          struct diff_filespec *one,
1435                          struct diff_filespec *two,
1436                          const char *xfrm_msg,
1437                          struct diff_options *o,
1438                          int complete_rewrite)
1439 {
1440         mmfile_t mf1, mf2;
1441         const char *lbl[2];
1442         char *a_one, *b_two;
1443         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1444         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1445
1446         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1447         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1448         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1449         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1450         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1451         if (lbl[0][0] == '/') {
1452                 /* /dev/null */
1453                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1454                 if (xfrm_msg && xfrm_msg[0])
1455                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1456         }
1457         else if (lbl[1][0] == '/') {
1458                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1459                 if (xfrm_msg && xfrm_msg[0])
1460                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1461         }
1462         else {
1463                 if (one->mode != two->mode) {
1464                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1465                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1466                 }
1467                 if (xfrm_msg && xfrm_msg[0])
1468                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1469                 /*
1470                  * we do not run diff between different kind
1471                  * of objects.
1472                  */
1473                 if ((one->mode ^ two->mode) & S_IFMT)
1474                         goto free_ab_and_return;
1475                 if (complete_rewrite) {
1476                         emit_rewrite_diff(name_a, name_b, one, two, o);
1477                         o->found_changes = 1;
1478                         goto free_ab_and_return;
1479                 }
1480         }
1481
1482         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1483                 die("unable to read files to diff");
1484
1485         if (!DIFF_OPT_TST(o, TEXT) &&
1486             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1487                 /* Quite common confusing case */
1488                 if (mf1.size == mf2.size &&
1489                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1490                         goto free_ab_and_return;
1491                 if (DIFF_OPT_TST(o, BINARY))
1492                         emit_binary_diff(o->file, &mf1, &mf2);
1493                 else
1494                         fprintf(o->file, "Binary files %s and %s differ\n",
1495                                 lbl[0], lbl[1]);
1496                 o->found_changes = 1;
1497         }
1498         else {
1499                 /* Crazy xdl interfaces.. */
1500                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1501                 xpparam_t xpp;
1502                 xdemitconf_t xecfg;
1503                 xdemitcb_t ecb;
1504                 struct emit_callback ecbdata;
1505                 const char *funcname_pattern;
1506
1507                 funcname_pattern = diff_funcname_pattern(one);
1508                 if (!funcname_pattern)
1509                         funcname_pattern = diff_funcname_pattern(two);
1510
1511                 memset(&xecfg, 0, sizeof(xecfg));
1512                 memset(&ecbdata, 0, sizeof(ecbdata));
1513                 ecbdata.label_path = lbl;
1514                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1515                 ecbdata.found_changesp = &o->found_changes;
1516                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1517                 ecbdata.file = o->file;
1518                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1519                 xecfg.ctxlen = o->context;
1520                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1521                 if (funcname_pattern)
1522                         xdiff_set_find_func(&xecfg, funcname_pattern);
1523                 if (!diffopts)
1524                         ;
1525                 else if (!prefixcmp(diffopts, "--unified="))
1526                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1527                 else if (!prefixcmp(diffopts, "-u"))
1528                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1529                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1530                         ecbdata.diff_words =
1531                                 xcalloc(1, sizeof(struct diff_words_data));
1532                         ecbdata.diff_words->file = o->file;
1533                 }
1534                 xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1535                               &xpp, &xecfg, &ecb);
1536                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1537                         free_diff_words_data(&ecbdata);
1538         }
1539
1540  free_ab_and_return:
1541         diff_free_filespec_data(one);
1542         diff_free_filespec_data(two);
1543         free(a_one);
1544         free(b_two);
1545         return;
1546 }
1547
1548 static void builtin_diffstat(const char *name_a, const char *name_b,
1549                              struct diff_filespec *one,
1550                              struct diff_filespec *two,
1551                              struct diffstat_t *diffstat,
1552                              struct diff_options *o,
1553                              int complete_rewrite)
1554 {
1555         mmfile_t mf1, mf2;
1556         struct diffstat_file *data;
1557
1558         data = diffstat_add(diffstat, name_a, name_b);
1559
1560         if (!one || !two) {
1561                 data->is_unmerged = 1;
1562                 return;
1563         }
1564         if (complete_rewrite) {
1565                 diff_populate_filespec(one, 0);
1566                 diff_populate_filespec(two, 0);
1567                 data->deleted = count_lines(one->data, one->size);
1568                 data->added = count_lines(two->data, two->size);
1569                 goto free_and_return;
1570         }
1571         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1572                 die("unable to read files to diff");
1573
1574         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1575                 data->is_binary = 1;
1576                 data->added = mf2.size;
1577                 data->deleted = mf1.size;
1578         } else {
1579                 /* Crazy xdl interfaces.. */
1580                 xpparam_t xpp;
1581                 xdemitconf_t xecfg;
1582                 xdemitcb_t ecb;
1583
1584                 memset(&xecfg, 0, sizeof(xecfg));
1585                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1586                 xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1587                               &xpp, &xecfg, &ecb);
1588         }
1589
1590  free_and_return:
1591         diff_free_filespec_data(one);
1592         diff_free_filespec_data(two);
1593 }
1594
1595 static void builtin_checkdiff(const char *name_a, const char *name_b,
1596                               const char *attr_path,
1597                               struct diff_filespec *one,
1598                               struct diff_filespec *two,
1599                               struct diff_options *o)
1600 {
1601         mmfile_t mf1, mf2;
1602         struct checkdiff_t data;
1603
1604         if (!two)
1605                 return;
1606
1607         memset(&data, 0, sizeof(data));
1608         data.filename = name_b ? name_b : name_a;
1609         data.lineno = 0;
1610         data.o = o;
1611         data.ws_rule = whitespace_rule(attr_path);
1612
1613         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1614                 die("unable to read files to diff");
1615
1616         /*
1617          * All the other codepaths check both sides, but not checking
1618          * the "old" side here is deliberate.  We are checking the newly
1619          * introduced changes, and as long as the "new" side is text, we
1620          * can and should check what it introduces.
1621          */
1622         if (diff_filespec_is_binary(two))
1623                 goto free_and_return;
1624         else {
1625                 /* Crazy xdl interfaces.. */
1626                 xpparam_t xpp;
1627                 xdemitconf_t xecfg;
1628                 xdemitcb_t ecb;
1629
1630                 memset(&xecfg, 0, sizeof(xecfg));
1631                 xecfg.ctxlen = 1; /* at least one context line */
1632                 xpp.flags = XDF_NEED_MINIMAL;
1633                 xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1634                               &xpp, &xecfg, &ecb);
1635
1636                 if ((data.ws_rule & WS_TRAILING_SPACE) &&
1637                     data.trailing_blanks_start) {
1638                         fprintf(o->file, "%s:%d: ends with blank lines.\n",
1639                                 data.filename, data.trailing_blanks_start);
1640                         data.status = 1; /* report errors */
1641                 }
1642         }
1643  free_and_return:
1644         diff_free_filespec_data(one);
1645         diff_free_filespec_data(two);
1646         if (data.status)
1647                 DIFF_OPT_SET(o, CHECK_FAILED);
1648 }
1649
1650 struct diff_filespec *alloc_filespec(const char *path)
1651 {
1652         int namelen = strlen(path);
1653         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1654
1655         memset(spec, 0, sizeof(*spec));
1656         spec->path = (char *)(spec + 1);
1657         memcpy(spec->path, path, namelen+1);
1658         spec->count = 1;
1659         return spec;
1660 }
1661
1662 void free_filespec(struct diff_filespec *spec)
1663 {
1664         if (!--spec->count) {
1665                 diff_free_filespec_data(spec);
1666                 free(spec);
1667         }
1668 }
1669
1670 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1671                    unsigned short mode)
1672 {
1673         if (mode) {
1674                 spec->mode = canon_mode(mode);
1675                 hashcpy(spec->sha1, sha1);
1676                 spec->sha1_valid = !is_null_sha1(sha1);
1677         }
1678 }
1679
1680 /*
1681  * Given a name and sha1 pair, if the index tells us the file in
1682  * the work tree has that object contents, return true, so that
1683  * prepare_temp_file() does not have to inflate and extract.
1684  */
1685 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1686 {
1687         struct cache_entry *ce;
1688         struct stat st;
1689         int pos, len;
1690
1691         /* We do not read the cache ourselves here, because the
1692          * benchmark with my previous version that always reads cache
1693          * shows that it makes things worse for diff-tree comparing
1694          * two linux-2.6 kernel trees in an already checked out work
1695          * tree.  This is because most diff-tree comparisons deal with
1696          * only a small number of files, while reading the cache is
1697          * expensive for a large project, and its cost outweighs the
1698          * savings we get by not inflating the object to a temporary
1699          * file.  Practically, this code only helps when we are used
1700          * by diff-cache --cached, which does read the cache before
1701          * calling us.
1702          */
1703         if (!active_cache)
1704                 return 0;
1705
1706         /* We want to avoid the working directory if our caller
1707          * doesn't need the data in a normal file, this system
1708          * is rather slow with its stat/open/mmap/close syscalls,
1709          * and the object is contained in a pack file.  The pack
1710          * is probably already open and will be faster to obtain
1711          * the data through than the working directory.  Loose
1712          * objects however would tend to be slower as they need
1713          * to be individually opened and inflated.
1714          */
1715         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1716                 return 0;
1717
1718         len = strlen(name);
1719         pos = cache_name_pos(name, len);
1720         if (pos < 0)
1721                 return 0;
1722         ce = active_cache[pos];
1723
1724         /*
1725          * This is not the sha1 we are looking for, or
1726          * unreusable because it is not a regular file.
1727          */
1728         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1729                 return 0;
1730
1731         /*
1732          * If ce matches the file in the work tree, we can reuse it.
1733          */
1734         if (ce_uptodate(ce) ||
1735             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1736                 return 1;
1737
1738         return 0;
1739 }
1740
1741 static int populate_from_stdin(struct diff_filespec *s)
1742 {
1743         struct strbuf buf;
1744         size_t size = 0;
1745
1746         strbuf_init(&buf, 0);
1747         if (strbuf_read(&buf, 0, 0) < 0)
1748                 return error("error while reading from stdin %s",
1749                                      strerror(errno));
1750
1751         s->should_munmap = 0;
1752         s->data = strbuf_detach(&buf, &size);
1753         s->size = size;
1754         s->should_free = 1;
1755         return 0;
1756 }
1757
1758 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1759 {
1760         int len;
1761         char *data = xmalloc(100);
1762         len = snprintf(data, 100,
1763                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1764         s->data = data;
1765         s->size = len;
1766         s->should_free = 1;
1767         if (size_only) {
1768                 s->data = NULL;
1769                 free(data);
1770         }
1771         return 0;
1772 }
1773
1774 /*
1775  * While doing rename detection and pickaxe operation, we may need to
1776  * grab the data for the blob (or file) for our own in-core comparison.
1777  * diff_filespec has data and size fields for this purpose.
1778  */
1779 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1780 {
1781         int err = 0;
1782         if (!DIFF_FILE_VALID(s))
1783                 die("internal error: asking to populate invalid file.");
1784         if (S_ISDIR(s->mode))
1785                 return -1;
1786
1787         if (s->data)
1788                 return 0;
1789
1790         if (size_only && 0 < s->size)
1791                 return 0;
1792
1793         if (S_ISGITLINK(s->mode))
1794                 return diff_populate_gitlink(s, size_only);
1795
1796         if (!s->sha1_valid ||
1797             reuse_worktree_file(s->path, s->sha1, 0)) {
1798                 struct strbuf buf;
1799                 struct stat st;
1800                 int fd;
1801
1802                 if (!strcmp(s->path, "-"))
1803                         return populate_from_stdin(s);
1804
1805                 if (lstat(s->path, &st) < 0) {
1806                         if (errno == ENOENT) {
1807                         err_empty:
1808                                 err = -1;
1809                         empty:
1810                                 s->data = (char *)"";
1811                                 s->size = 0;
1812                                 return err;
1813                         }
1814                 }
1815                 s->size = xsize_t(st.st_size);
1816                 if (!s->size)
1817                         goto empty;
1818                 if (size_only)
1819                         return 0;
1820                 if (S_ISLNK(st.st_mode)) {
1821                         int ret;
1822                         s->data = xmalloc(s->size);
1823                         s->should_free = 1;
1824                         ret = readlink(s->path, s->data, s->size);
1825                         if (ret < 0) {
1826                                 free(s->data);
1827                                 goto err_empty;
1828                         }
1829                         return 0;
1830                 }
1831                 fd = open(s->path, O_RDONLY);
1832                 if (fd < 0)
1833                         goto err_empty;
1834                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1835                 close(fd);
1836                 s->should_munmap = 1;
1837
1838                 /*
1839                  * Convert from working tree format to canonical git format
1840                  */
1841                 strbuf_init(&buf, 0);
1842                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1843                         size_t size = 0;
1844                         munmap(s->data, s->size);
1845                         s->should_munmap = 0;
1846                         s->data = strbuf_detach(&buf, &size);
1847                         s->size = size;
1848                         s->should_free = 1;
1849                 }
1850         }
1851         else {
1852                 enum object_type type;
1853                 if (size_only)
1854                         type = sha1_object_info(s->sha1, &s->size);
1855                 else {
1856                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1857                         s->should_free = 1;
1858                 }
1859         }
1860         return 0;
1861 }
1862
1863 void diff_free_filespec_blob(struct diff_filespec *s)
1864 {
1865         if (s->should_free)
1866                 free(s->data);
1867         else if (s->should_munmap)
1868                 munmap(s->data, s->size);
1869
1870         if (s->should_free || s->should_munmap) {
1871                 s->should_free = s->should_munmap = 0;
1872                 s->data = NULL;
1873         }
1874 }
1875
1876 void diff_free_filespec_data(struct diff_filespec *s)
1877 {
1878         diff_free_filespec_blob(s);
1879         free(s->cnt_data);
1880         s->cnt_data = NULL;
1881 }
1882
1883 static void prep_temp_blob(struct diff_tempfile *temp,
1884                            void *blob,
1885                            unsigned long size,
1886                            const unsigned char *sha1,
1887                            int mode)
1888 {
1889         int fd;
1890
1891         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1892         if (fd < 0)
1893                 die("unable to create temp-file: %s", strerror(errno));
1894         if (write_in_full(fd, blob, size) != size)
1895                 die("unable to write temp-file");
1896         close(fd);
1897         temp->name = temp->tmp_path;
1898         strcpy(temp->hex, sha1_to_hex(sha1));
1899         temp->hex[40] = 0;
1900         sprintf(temp->mode, "%06o", mode);
1901 }
1902
1903 static void prepare_temp_file(const char *name,
1904                               struct diff_tempfile *temp,
1905                               struct diff_filespec *one)
1906 {
1907         if (!DIFF_FILE_VALID(one)) {
1908         not_a_valid_file:
1909                 /* A '-' entry produces this for file-2, and
1910                  * a '+' entry produces this for file-1.
1911                  */
1912                 temp->name = "/dev/null";
1913                 strcpy(temp->hex, ".");
1914                 strcpy(temp->mode, ".");
1915                 return;
1916         }
1917
1918         if (!one->sha1_valid ||
1919             reuse_worktree_file(name, one->sha1, 1)) {
1920                 struct stat st;
1921                 if (lstat(name, &st) < 0) {
1922                         if (errno == ENOENT)
1923                                 goto not_a_valid_file;
1924                         die("stat(%s): %s", name, strerror(errno));
1925                 }
1926                 if (S_ISLNK(st.st_mode)) {
1927                         int ret;
1928                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1929                         size_t sz = xsize_t(st.st_size);
1930                         if (sizeof(buf) <= st.st_size)
1931                                 die("symlink too long: %s", name);
1932                         ret = readlink(name, buf, sz);
1933                         if (ret < 0)
1934                                 die("readlink(%s)", name);
1935                         prep_temp_blob(temp, buf, sz,
1936                                        (one->sha1_valid ?
1937                                         one->sha1 : null_sha1),
1938                                        (one->sha1_valid ?
1939                                         one->mode : S_IFLNK));
1940                 }
1941                 else {
1942                         /* we can borrow from the file in the work tree */
1943                         temp->name = name;
1944                         if (!one->sha1_valid)
1945                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1946                         else
1947                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1948                         /* Even though we may sometimes borrow the
1949                          * contents from the work tree, we always want
1950                          * one->mode.  mode is trustworthy even when
1951                          * !(one->sha1_valid), as long as
1952                          * DIFF_FILE_VALID(one).
1953                          */
1954                         sprintf(temp->mode, "%06o", one->mode);
1955                 }
1956                 return;
1957         }
1958         else {
1959                 if (diff_populate_filespec(one, 0))
1960                         die("cannot read data blob for %s", one->path);
1961                 prep_temp_blob(temp, one->data, one->size,
1962                                one->sha1, one->mode);
1963         }
1964 }
1965
1966 static void remove_tempfile(void)
1967 {
1968         int i;
1969
1970         for (i = 0; i < 2; i++)
1971                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1972                         unlink(diff_temp[i].name);
1973                         diff_temp[i].name = NULL;
1974                 }
1975 }
1976
1977 static void remove_tempfile_on_signal(int signo)
1978 {
1979         remove_tempfile();
1980         signal(SIGINT, SIG_DFL);
1981         raise(signo);
1982 }
1983
1984 /* An external diff command takes:
1985  *
1986  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1987  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1988  *
1989  */
1990 static void run_external_diff(const char *pgm,
1991                               const char *name,
1992                               const char *other,
1993                               struct diff_filespec *one,
1994                               struct diff_filespec *two,
1995                               const char *xfrm_msg,
1996                               int complete_rewrite)
1997 {
1998         const char *spawn_arg[10];
1999         struct diff_tempfile *temp = diff_temp;
2000         int retval;
2001         static int atexit_asked = 0;
2002         const char *othername;
2003         const char **arg = &spawn_arg[0];
2004
2005         othername = (other? other : name);
2006         if (one && two) {
2007                 prepare_temp_file(name, &temp[0], one);
2008                 prepare_temp_file(othername, &temp[1], two);
2009                 if (! atexit_asked &&
2010                     (temp[0].name == temp[0].tmp_path ||
2011                      temp[1].name == temp[1].tmp_path)) {
2012                         atexit_asked = 1;
2013                         atexit(remove_tempfile);
2014                 }
2015                 signal(SIGINT, remove_tempfile_on_signal);
2016         }
2017
2018         if (one && two) {
2019                 *arg++ = pgm;
2020                 *arg++ = name;
2021                 *arg++ = temp[0].name;
2022                 *arg++ = temp[0].hex;
2023                 *arg++ = temp[0].mode;
2024                 *arg++ = temp[1].name;
2025                 *arg++ = temp[1].hex;
2026                 *arg++ = temp[1].mode;
2027                 if (other) {
2028                         *arg++ = other;
2029                         *arg++ = xfrm_msg;
2030                 }
2031         } else {
2032                 *arg++ = pgm;
2033                 *arg++ = name;
2034         }
2035         *arg = NULL;
2036         fflush(NULL);
2037         retval = run_command_v_opt(spawn_arg, 0);
2038         remove_tempfile();
2039         if (retval) {
2040                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
2041                 exit(1);
2042         }
2043 }
2044
2045 static const char *external_diff_attr(const char *name)
2046 {
2047         struct git_attr_check attr_diff_check;
2048
2049         if (!name)
2050                 return NULL;
2051
2052         setup_diff_attr_check(&attr_diff_check);
2053         if (!git_checkattr(name, 1, &attr_diff_check)) {
2054                 const char *value = attr_diff_check.value;
2055                 if (!ATTR_TRUE(value) &&
2056                     !ATTR_FALSE(value) &&
2057                     !ATTR_UNSET(value)) {
2058                         struct ll_diff_driver *drv;
2059
2060                         for (drv = user_diff; drv; drv = drv->next)
2061                                 if (!strcmp(drv->name, value))
2062                                         return drv->cmd;
2063                 }
2064         }
2065         return NULL;
2066 }
2067
2068 static void run_diff_cmd(const char *pgm,
2069                          const char *name,
2070                          const char *other,
2071                          const char *attr_path,
2072                          struct diff_filespec *one,
2073                          struct diff_filespec *two,
2074                          const char *xfrm_msg,
2075                          struct diff_options *o,
2076                          int complete_rewrite)
2077 {
2078         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2079                 pgm = NULL;
2080         else {
2081                 const char *cmd = external_diff_attr(attr_path);
2082                 if (cmd)
2083                         pgm = cmd;
2084         }
2085
2086         if (pgm) {
2087                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2088                                   complete_rewrite);
2089                 return;
2090         }
2091         if (one && two)
2092                 builtin_diff(name, other ? other : name,
2093                              one, two, xfrm_msg, o, complete_rewrite);
2094         else
2095                 fprintf(o->file, "* Unmerged path %s\n", name);
2096 }
2097
2098 static void diff_fill_sha1_info(struct diff_filespec *one)
2099 {
2100         if (DIFF_FILE_VALID(one)) {
2101                 if (!one->sha1_valid) {
2102                         struct stat st;
2103                         if (!strcmp(one->path, "-")) {
2104                                 hashcpy(one->sha1, null_sha1);
2105                                 return;
2106                         }
2107                         if (lstat(one->path, &st) < 0)
2108                                 die("stat %s", one->path);
2109                         if (index_path(one->sha1, one->path, &st, 0))
2110                                 die("cannot hash %s\n", one->path);
2111                 }
2112         }
2113         else
2114                 hashclr(one->sha1);
2115 }
2116
2117 static int similarity_index(struct diff_filepair *p)
2118 {
2119         return p->score * 100 / MAX_SCORE;
2120 }
2121
2122 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2123 {
2124         /* Strip the prefix but do not molest /dev/null and absolute paths */
2125         if (*namep && **namep != '/')
2126                 *namep += prefix_length;
2127         if (*otherp && **otherp != '/')
2128                 *otherp += prefix_length;
2129 }
2130
2131 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2132 {
2133         const char *pgm = external_diff();
2134         struct strbuf msg;
2135         char *xfrm_msg;
2136         struct diff_filespec *one = p->one;
2137         struct diff_filespec *two = p->two;
2138         const char *name;
2139         const char *other;
2140         const char *attr_path;
2141         int complete_rewrite = 0;
2142
2143         name  = p->one->path;
2144         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2145         attr_path = name;
2146         if (o->prefix_length)
2147                 strip_prefix(o->prefix_length, &name, &other);
2148
2149         if (DIFF_PAIR_UNMERGED(p)) {
2150                 run_diff_cmd(pgm, name, NULL, attr_path,
2151                              NULL, NULL, NULL, o, 0);
2152                 return;
2153         }
2154
2155         diff_fill_sha1_info(one);
2156         diff_fill_sha1_info(two);
2157
2158         strbuf_init(&msg, PATH_MAX * 2 + 300);
2159         switch (p->status) {
2160         case DIFF_STATUS_COPIED:
2161                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2162                 strbuf_addstr(&msg, "\ncopy from ");
2163                 quote_c_style(name, &msg, NULL, 0);
2164                 strbuf_addstr(&msg, "\ncopy to ");
2165                 quote_c_style(other, &msg, NULL, 0);
2166                 strbuf_addch(&msg, '\n');
2167                 break;
2168         case DIFF_STATUS_RENAMED:
2169                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2170                 strbuf_addstr(&msg, "\nrename from ");
2171                 quote_c_style(name, &msg, NULL, 0);
2172                 strbuf_addstr(&msg, "\nrename to ");
2173                 quote_c_style(other, &msg, NULL, 0);
2174                 strbuf_addch(&msg, '\n');
2175                 break;
2176         case DIFF_STATUS_MODIFIED:
2177                 if (p->score) {
2178                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2179                                         similarity_index(p));
2180                         complete_rewrite = 1;
2181                         break;
2182                 }
2183                 /* fallthru */
2184         default:
2185                 /* nothing */
2186                 ;
2187         }
2188
2189         if (hashcmp(one->sha1, two->sha1)) {
2190                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2191
2192                 if (DIFF_OPT_TST(o, BINARY)) {
2193                         mmfile_t mf;
2194                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2195                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2196                                 abbrev = 40;
2197                 }
2198                 strbuf_addf(&msg, "index %.*s..%.*s",
2199                                 abbrev, sha1_to_hex(one->sha1),
2200                                 abbrev, sha1_to_hex(two->sha1));
2201                 if (one->mode == two->mode)
2202                         strbuf_addf(&msg, " %06o", one->mode);
2203                 strbuf_addch(&msg, '\n');
2204         }
2205
2206         if (msg.len)
2207                 strbuf_setlen(&msg, msg.len - 1);
2208         xfrm_msg = msg.len ? msg.buf : NULL;
2209
2210         if (!pgm &&
2211             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2212             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2213                 /* a filepair that changes between file and symlink
2214                  * needs to be split into deletion and creation.
2215                  */
2216                 struct diff_filespec *null = alloc_filespec(two->path);
2217                 run_diff_cmd(NULL, name, other, attr_path,
2218                              one, null, xfrm_msg, o, 0);
2219                 free(null);
2220                 null = alloc_filespec(one->path);
2221                 run_diff_cmd(NULL, name, other, attr_path,
2222                              null, two, xfrm_msg, o, 0);
2223                 free(null);
2224         }
2225         else
2226                 run_diff_cmd(pgm, name, other, attr_path,
2227                              one, two, xfrm_msg, o, complete_rewrite);
2228
2229         strbuf_release(&msg);
2230 }
2231
2232 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2233                          struct diffstat_t *diffstat)
2234 {
2235         const char *name;
2236         const char *other;
2237         int complete_rewrite = 0;
2238
2239         if (DIFF_PAIR_UNMERGED(p)) {
2240                 /* unmerged */
2241                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2242                 return;
2243         }
2244
2245         name = p->one->path;
2246         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2247
2248         if (o->prefix_length)
2249                 strip_prefix(o->prefix_length, &name, &other);
2250
2251         diff_fill_sha1_info(p->one);
2252         diff_fill_sha1_info(p->two);
2253
2254         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2255                 complete_rewrite = 1;
2256         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2257 }
2258
2259 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2260 {
2261         const char *name;
2262         const char *other;
2263         const char *attr_path;
2264
2265         if (DIFF_PAIR_UNMERGED(p)) {
2266                 /* unmerged */
2267                 return;
2268         }
2269
2270         name = p->one->path;
2271         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2272         attr_path = other ? other : name;
2273
2274         if (o->prefix_length)
2275                 strip_prefix(o->prefix_length, &name, &other);
2276
2277         diff_fill_sha1_info(p->one);
2278         diff_fill_sha1_info(p->two);
2279
2280         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2281 }
2282
2283 void diff_setup(struct diff_options *options)
2284 {
2285         memset(options, 0, sizeof(*options));
2286
2287         options->file = stdout;
2288
2289         options->line_termination = '\n';
2290         options->break_opt = -1;
2291         options->rename_limit = -1;
2292         options->dirstat_percent = 3;
2293         options->context = 3;
2294
2295         options->change = diff_change;
2296         options->add_remove = diff_addremove;
2297         if (diff_use_color_default > 0)
2298                 DIFF_OPT_SET(options, COLOR_DIFF);
2299         else
2300                 DIFF_OPT_CLR(options, COLOR_DIFF);
2301         options->detect_rename = diff_detect_rename_default;
2302
2303         options->a_prefix = "a/";
2304         options->b_prefix = "b/";
2305 }
2306
2307 int diff_setup_done(struct diff_options *options)
2308 {
2309         int count = 0;
2310
2311         if (options->output_format & DIFF_FORMAT_NAME)
2312                 count++;
2313         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2314                 count++;
2315         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2316                 count++;
2317         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2318                 count++;
2319         if (count > 1)
2320                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2321
2322         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2323                 options->detect_rename = DIFF_DETECT_COPY;
2324
2325         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2326                 options->prefix = NULL;
2327         if (options->prefix)
2328                 options->prefix_length = strlen(options->prefix);
2329         else
2330                 options->prefix_length = 0;
2331
2332         if (options->output_format & (DIFF_FORMAT_NAME |
2333                                       DIFF_FORMAT_NAME_STATUS |
2334                                       DIFF_FORMAT_CHECKDIFF |
2335                                       DIFF_FORMAT_NO_OUTPUT))
2336                 options->output_format &= ~(DIFF_FORMAT_RAW |
2337                                             DIFF_FORMAT_NUMSTAT |
2338                                             DIFF_FORMAT_DIFFSTAT |
2339                                             DIFF_FORMAT_SHORTSTAT |
2340                                             DIFF_FORMAT_DIRSTAT |
2341                                             DIFF_FORMAT_SUMMARY |
2342                                             DIFF_FORMAT_PATCH);
2343
2344         /*
2345          * These cases always need recursive; we do not drop caller-supplied
2346          * recursive bits for other formats here.
2347          */
2348         if (options->output_format & (DIFF_FORMAT_PATCH |
2349                                       DIFF_FORMAT_NUMSTAT |
2350                                       DIFF_FORMAT_DIFFSTAT |
2351                                       DIFF_FORMAT_SHORTSTAT |
2352                                       DIFF_FORMAT_DIRSTAT |
2353                                       DIFF_FORMAT_SUMMARY |
2354                                       DIFF_FORMAT_CHECKDIFF))
2355                 DIFF_OPT_SET(options, RECURSIVE);
2356         /*
2357          * Also pickaxe would not work very well if you do not say recursive
2358          */
2359         if (options->pickaxe)
2360                 DIFF_OPT_SET(options, RECURSIVE);
2361
2362         if (options->detect_rename && options->rename_limit < 0)
2363                 options->rename_limit = diff_rename_limit_default;
2364         if (options->setup & DIFF_SETUP_USE_CACHE) {
2365                 if (!active_cache)
2366                         /* read-cache does not die even when it fails
2367                          * so it is safe for us to do this here.  Also
2368                          * it does not smudge active_cache or active_nr
2369                          * when it fails, so we do not have to worry about
2370                          * cleaning it up ourselves either.
2371                          */
2372                         read_cache();
2373         }
2374         if (options->abbrev <= 0 || 40 < options->abbrev)
2375                 options->abbrev = 40; /* full */
2376
2377         /*
2378          * It does not make sense to show the first hit we happened
2379          * to have found.  It does not make sense not to return with
2380          * exit code in such a case either.
2381          */
2382         if (DIFF_OPT_TST(options, QUIET)) {
2383                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2384                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2385         }
2386
2387         /*
2388          * If we postprocess in diffcore, we cannot simply return
2389          * upon the first hit.  We need to run diff as usual.
2390          */
2391         if (options->pickaxe || options->filter)
2392                 DIFF_OPT_CLR(options, QUIET);
2393
2394         return 0;
2395 }
2396
2397 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2398 {
2399         char c, *eq;
2400         int len;
2401
2402         if (*arg != '-')
2403                 return 0;
2404         c = *++arg;
2405         if (!c)
2406                 return 0;
2407         if (c == arg_short) {
2408                 c = *++arg;
2409                 if (!c)
2410                         return 1;
2411                 if (val && isdigit(c)) {
2412                         char *end;
2413                         int n = strtoul(arg, &end, 10);
2414                         if (*end)
2415                                 return 0;
2416                         *val = n;
2417                         return 1;
2418                 }
2419                 return 0;
2420         }
2421         if (c != '-')
2422                 return 0;
2423         arg++;
2424         eq = strchr(arg, '=');
2425         if (eq)
2426                 len = eq - arg;
2427         else
2428                 len = strlen(arg);
2429         if (!len || strncmp(arg, arg_long, len))
2430                 return 0;
2431         if (eq) {
2432                 int n;
2433                 char *end;
2434                 if (!isdigit(*++eq))
2435                         return 0;
2436                 n = strtoul(eq, &end, 10);
2437                 if (*end)
2438                         return 0;
2439                 *val = n;
2440         }
2441         return 1;
2442 }
2443
2444 static int diff_scoreopt_parse(const char *opt);
2445
2446 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2447 {
2448         const char *arg = av[0];
2449
2450         /* Output format options */
2451         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2452                 options->output_format |= DIFF_FORMAT_PATCH;
2453         else if (opt_arg(arg, 'U', "unified", &options->context))
2454                 options->output_format |= DIFF_FORMAT_PATCH;
2455         else if (!strcmp(arg, "--raw"))
2456                 options->output_format |= DIFF_FORMAT_RAW;
2457         else if (!strcmp(arg, "--patch-with-raw"))
2458                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2459         else if (!strcmp(arg, "--numstat"))
2460                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2461         else if (!strcmp(arg, "--shortstat"))
2462                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2463         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2464                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2465         else if (!strcmp(arg, "--cumulative"))
2466                 options->output_format |= DIFF_FORMAT_CUMULATIVE;
2467         else if (!strcmp(arg, "--check"))
2468                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2469         else if (!strcmp(arg, "--summary"))
2470                 options->output_format |= DIFF_FORMAT_SUMMARY;
2471         else if (!strcmp(arg, "--patch-with-stat"))
2472                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2473         else if (!strcmp(arg, "--name-only"))
2474                 options->output_format |= DIFF_FORMAT_NAME;
2475         else if (!strcmp(arg, "--name-status"))
2476                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2477         else if (!strcmp(arg, "-s"))
2478                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2479         else if (!prefixcmp(arg, "--stat")) {
2480                 char *end;
2481                 int width = options->stat_width;
2482                 int name_width = options->stat_name_width;
2483                 arg += 6;
2484                 end = (char *)arg;
2485
2486                 switch (*arg) {
2487                 case '-':
2488                         if (!prefixcmp(arg, "-width="))
2489                                 width = strtoul(arg + 7, &end, 10);
2490                         else if (!prefixcmp(arg, "-name-width="))
2491                                 name_width = strtoul(arg + 12, &end, 10);
2492                         break;
2493                 case '=':
2494                         width = strtoul(arg+1, &end, 10);
2495                         if (*end == ',')
2496                                 name_width = strtoul(end+1, &end, 10);
2497                 }
2498
2499                 /* Important! This checks all the error cases! */
2500                 if (*end)
2501                         return 0;
2502                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2503                 options->stat_name_width = name_width;
2504                 options->stat_width = width;
2505         }
2506
2507         /* renames options */
2508         else if (!prefixcmp(arg, "-B")) {
2509                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2510                         return -1;
2511         }
2512         else if (!prefixcmp(arg, "-M")) {
2513                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2514                         return -1;
2515                 options->detect_rename = DIFF_DETECT_RENAME;
2516         }
2517         else if (!prefixcmp(arg, "-C")) {
2518                 if (options->detect_rename == DIFF_DETECT_COPY)
2519                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2520                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2521                         return -1;
2522                 options->detect_rename = DIFF_DETECT_COPY;
2523         }
2524         else if (!strcmp(arg, "--no-renames"))
2525                 options->detect_rename = 0;
2526         else if (!strcmp(arg, "--relative"))
2527                 DIFF_OPT_SET(options, RELATIVE_NAME);
2528         else if (!prefixcmp(arg, "--relative=")) {
2529                 DIFF_OPT_SET(options, RELATIVE_NAME);
2530                 options->prefix = arg + 11;
2531         }
2532
2533         /* xdiff options */
2534         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2535                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2536         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2537                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2538         else if (!strcmp(arg, "--ignore-space-at-eol"))
2539                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2540
2541         /* flags options */
2542         else if (!strcmp(arg, "--binary")) {
2543                 options->output_format |= DIFF_FORMAT_PATCH;
2544                 DIFF_OPT_SET(options, BINARY);
2545         }
2546         else if (!strcmp(arg, "--full-index"))
2547                 DIFF_OPT_SET(options, FULL_INDEX);
2548         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2549                 DIFF_OPT_SET(options, TEXT);
2550         else if (!strcmp(arg, "-R"))
2551                 DIFF_OPT_SET(options, REVERSE_DIFF);
2552         else if (!strcmp(arg, "--find-copies-harder"))
2553                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2554         else if (!strcmp(arg, "--follow"))
2555                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2556         else if (!strcmp(arg, "--color"))
2557                 DIFF_OPT_SET(options, COLOR_DIFF);
2558         else if (!strcmp(arg, "--no-color"))
2559                 DIFF_OPT_CLR(options, COLOR_DIFF);
2560         else if (!strcmp(arg, "--color-words"))
2561                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2562         else if (!strcmp(arg, "--exit-code"))
2563                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2564         else if (!strcmp(arg, "--quiet"))
2565                 DIFF_OPT_SET(options, QUIET);
2566         else if (!strcmp(arg, "--ext-diff"))
2567                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2568         else if (!strcmp(arg, "--no-ext-diff"))
2569                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2570         else if (!strcmp(arg, "--ignore-submodules"))
2571                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2572
2573         /* misc options */
2574         else if (!strcmp(arg, "-z"))
2575                 options->line_termination = 0;
2576         else if (!prefixcmp(arg, "-l"))
2577                 options->rename_limit = strtoul(arg+2, NULL, 10);
2578         else if (!prefixcmp(arg, "-S"))
2579                 options->pickaxe = arg + 2;
2580         else if (!strcmp(arg, "--pickaxe-all"))
2581                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2582         else if (!strcmp(arg, "--pickaxe-regex"))
2583                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2584         else if (!prefixcmp(arg, "-O"))
2585                 options->orderfile = arg + 2;
2586         else if (!prefixcmp(arg, "--diff-filter="))
2587                 options->filter = arg + 14;
2588         else if (!strcmp(arg, "--abbrev"))
2589                 options->abbrev = DEFAULT_ABBREV;
2590         else if (!prefixcmp(arg, "--abbrev=")) {
2591                 options->abbrev = strtoul(arg + 9, NULL, 10);
2592                 if (options->abbrev < MINIMUM_ABBREV)
2593                         options->abbrev = MINIMUM_ABBREV;
2594                 else if (40 < options->abbrev)
2595                         options->abbrev = 40;
2596         }
2597         else if (!prefixcmp(arg, "--src-prefix="))
2598                 options->a_prefix = arg + 13;
2599         else if (!prefixcmp(arg, "--dst-prefix="))
2600                 options->b_prefix = arg + 13;
2601         else if (!strcmp(arg, "--no-prefix"))
2602                 options->a_prefix = options->b_prefix = "";
2603         else if (!prefixcmp(arg, "--output=")) {
2604                 options->file = fopen(arg + strlen("--output="), "w");
2605                 options->close_file = 1;
2606         } else
2607                 return 0;
2608         return 1;
2609 }
2610
2611 static int parse_num(const char **cp_p)
2612 {
2613         unsigned long num, scale;
2614         int ch, dot;
2615         const char *cp = *cp_p;
2616
2617         num = 0;
2618         scale = 1;
2619         dot = 0;
2620         for(;;) {
2621                 ch = *cp;
2622                 if ( !dot && ch == '.' ) {
2623                         scale = 1;
2624                         dot = 1;
2625                 } else if ( ch == '%' ) {
2626                         scale = dot ? scale*100 : 100;
2627                         cp++;   /* % is always at the end */
2628                         break;
2629                 } else if ( ch >= '0' && ch <= '9' ) {
2630                         if ( scale < 100000 ) {
2631                                 scale *= 10;
2632                                 num = (num*10) + (ch-'0');
2633                         }
2634                 } else {
2635                         break;
2636                 }
2637                 cp++;
2638         }
2639         *cp_p = cp;
2640
2641         /* user says num divided by scale and we say internally that
2642          * is MAX_SCORE * num / scale.
2643          */
2644         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2645 }
2646
2647 static int diff_scoreopt_parse(const char *opt)
2648 {
2649         int opt1, opt2, cmd;
2650
2651         if (*opt++ != '-')
2652                 return -1;
2653         cmd = *opt++;
2654         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2655                 return -1; /* that is not a -M, -C nor -B option */
2656
2657         opt1 = parse_num(&opt);
2658         if (cmd != 'B')
2659                 opt2 = 0;
2660         else {
2661                 if (*opt == 0)
2662                         opt2 = 0;
2663                 else if (*opt != '/')
2664                         return -1; /* we expect -B80/99 or -B80 */
2665                 else {
2666                         opt++;
2667                         opt2 = parse_num(&opt);
2668                 }
2669         }
2670         if (*opt != 0)
2671                 return -1;
2672         return opt1 | (opt2 << 16);
2673 }
2674
2675 struct diff_queue_struct diff_queued_diff;
2676
2677 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2678 {
2679         if (queue->alloc <= queue->nr) {
2680                 queue->alloc = alloc_nr(queue->alloc);
2681                 queue->queue = xrealloc(queue->queue,
2682                                         sizeof(dp) * queue->alloc);
2683         }
2684         queue->queue[queue->nr++] = dp;
2685 }
2686
2687 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2688                                  struct diff_filespec *one,
2689                                  struct diff_filespec *two)
2690 {
2691         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2692         dp->one = one;
2693         dp->two = two;
2694         if (queue)
2695                 diff_q(queue, dp);
2696         return dp;
2697 }
2698
2699 void diff_free_filepair(struct diff_filepair *p)
2700 {
2701         free_filespec(p->one);
2702         free_filespec(p->two);
2703         free(p);
2704 }
2705
2706 /* This is different from find_unique_abbrev() in that
2707  * it stuffs the result with dots for alignment.
2708  */
2709 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2710 {
2711         int abblen;
2712         const char *abbrev;
2713         if (len == 40)
2714                 return sha1_to_hex(sha1);
2715
2716         abbrev = find_unique_abbrev(sha1, len);
2717         abblen = strlen(abbrev);
2718         if (abblen < 37) {
2719                 static char hex[41];
2720                 if (len < abblen && abblen <= len + 2)
2721                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2722                 else
2723                         sprintf(hex, "%s...", abbrev);
2724                 return hex;
2725         }
2726         return sha1_to_hex(sha1);
2727 }
2728
2729 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2730 {
2731         int line_termination = opt->line_termination;
2732         int inter_name_termination = line_termination ? '\t' : '\0';
2733
2734         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2735                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2736                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2737                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2738         }
2739         if (p->score) {
2740                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2741                         inter_name_termination);
2742         } else {
2743                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2744         }
2745
2746         if (p->status == DIFF_STATUS_COPIED ||
2747             p->status == DIFF_STATUS_RENAMED) {
2748                 const char *name_a, *name_b;
2749                 name_a = p->one->path;
2750                 name_b = p->two->path;
2751                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2752                 write_name_quoted(name_a, opt->file, inter_name_termination);
2753                 write_name_quoted(name_b, opt->file, line_termination);
2754         } else {
2755                 const char *name_a, *name_b;
2756                 name_a = p->one->mode ? p->one->path : p->two->path;
2757                 name_b = NULL;
2758                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2759                 write_name_quoted(name_a, opt->file, line_termination);
2760         }
2761 }
2762
2763 int diff_unmodified_pair(struct diff_filepair *p)
2764 {
2765         /* This function is written stricter than necessary to support
2766          * the currently implemented transformers, but the idea is to
2767          * let transformers to produce diff_filepairs any way they want,
2768          * and filter and clean them up here before producing the output.
2769          */
2770         struct diff_filespec *one = p->one, *two = p->two;
2771
2772         if (DIFF_PAIR_UNMERGED(p))
2773                 return 0; /* unmerged is interesting */
2774
2775         /* deletion, addition, mode or type change
2776          * and rename are all interesting.
2777          */
2778         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2779             DIFF_PAIR_MODE_CHANGED(p) ||
2780             strcmp(one->path, two->path))
2781                 return 0;
2782
2783         /* both are valid and point at the same path.  that is, we are
2784          * dealing with a change.
2785          */
2786         if (one->sha1_valid && two->sha1_valid &&
2787             !hashcmp(one->sha1, two->sha1))
2788                 return 1; /* no change */
2789         if (!one->sha1_valid && !two->sha1_valid)
2790                 return 1; /* both look at the same file on the filesystem. */
2791         return 0;
2792 }
2793
2794 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2795 {
2796         if (diff_unmodified_pair(p))
2797                 return;
2798
2799         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2800             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2801                 return; /* no tree diffs in patch format */
2802
2803         run_diff(p, o);
2804 }
2805
2806 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2807                             struct diffstat_t *diffstat)
2808 {
2809         if (diff_unmodified_pair(p))
2810                 return;
2811
2812         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2813             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2814                 return; /* no tree diffs in patch format */
2815
2816         run_diffstat(p, o, diffstat);
2817 }
2818
2819 static void diff_flush_checkdiff(struct diff_filepair *p,
2820                 struct diff_options *o)
2821 {
2822         if (diff_unmodified_pair(p))
2823                 return;
2824
2825         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2826             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2827                 return; /* no tree diffs in patch format */
2828
2829         run_checkdiff(p, o);
2830 }
2831
2832 int diff_queue_is_empty(void)
2833 {
2834         struct diff_queue_struct *q = &diff_queued_diff;
2835         int i;
2836         for (i = 0; i < q->nr; i++)
2837                 if (!diff_unmodified_pair(q->queue[i]))
2838                         return 0;
2839         return 1;
2840 }
2841
2842 #if DIFF_DEBUG
2843 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2844 {
2845         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2846                 x, one ? one : "",
2847                 s->path,
2848                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2849                 s->mode,
2850                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2851         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2852                 x, one ? one : "",
2853                 s->size, s->xfrm_flags);
2854 }
2855
2856 void diff_debug_filepair(const struct diff_filepair *p, int i)
2857 {
2858         diff_debug_filespec(p->one, i, "one");
2859         diff_debug_filespec(p->two, i, "two");
2860         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2861                 p->score, p->status ? p->status : '?',
2862                 p->one->rename_used, p->broken_pair);
2863 }
2864
2865 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2866 {
2867         int i;
2868         if (msg)
2869                 fprintf(stderr, "%s\n", msg);
2870         fprintf(stderr, "q->nr = %d\n", q->nr);
2871         for (i = 0; i < q->nr; i++) {
2872                 struct diff_filepair *p = q->queue[i];
2873                 diff_debug_filepair(p, i);
2874         }
2875 }
2876 #endif
2877
2878 static void diff_resolve_rename_copy(void)
2879 {
2880         int i;
2881         struct diff_filepair *p;
2882         struct diff_queue_struct *q = &diff_queued_diff;
2883
2884         diff_debug_queue("resolve-rename-copy", q);
2885
2886         for (i = 0; i < q->nr; i++) {
2887                 p = q->queue[i];
2888                 p->status = 0; /* undecided */
2889                 if (DIFF_PAIR_UNMERGED(p))
2890                         p->status = DIFF_STATUS_UNMERGED;
2891                 else if (!DIFF_FILE_VALID(p->one))
2892                         p->status = DIFF_STATUS_ADDED;
2893                 else if (!DIFF_FILE_VALID(p->two))
2894                         p->status = DIFF_STATUS_DELETED;
2895                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2896                         p->status = DIFF_STATUS_TYPE_CHANGED;
2897
2898                 /* from this point on, we are dealing with a pair
2899                  * whose both sides are valid and of the same type, i.e.
2900                  * either in-place edit or rename/copy edit.
2901                  */
2902                 else if (DIFF_PAIR_RENAME(p)) {
2903                         /*
2904                          * A rename might have re-connected a broken
2905                          * pair up, causing the pathnames to be the
2906                          * same again. If so, that's not a rename at
2907                          * all, just a modification..
2908                          *
2909                          * Otherwise, see if this source was used for
2910                          * multiple renames, in which case we decrement
2911                          * the count, and call it a copy.
2912                          */
2913                         if (!strcmp(p->one->path, p->two->path))
2914                                 p->status = DIFF_STATUS_MODIFIED;
2915                         else if (--p->one->rename_used > 0)
2916                                 p->status = DIFF_STATUS_COPIED;
2917                         else
2918                                 p->status = DIFF_STATUS_RENAMED;
2919                 }
2920                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2921                          p->one->mode != p->two->mode ||
2922                          is_null_sha1(p->one->sha1))
2923                         p->status = DIFF_STATUS_MODIFIED;
2924                 else {
2925                         /* This is a "no-change" entry and should not
2926                          * happen anymore, but prepare for broken callers.
2927                          */
2928                         error("feeding unmodified %s to diffcore",
2929                               p->one->path);
2930                         p->status = DIFF_STATUS_UNKNOWN;
2931                 }
2932         }
2933         diff_debug_queue("resolve-rename-copy done", q);
2934 }
2935
2936 static int check_pair_status(struct diff_filepair *p)
2937 {
2938         switch (p->status) {
2939         case DIFF_STATUS_UNKNOWN:
2940                 return 0;
2941         case 0:
2942                 die("internal error in diff-resolve-rename-copy");
2943         default:
2944                 return 1;
2945         }
2946 }
2947
2948 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2949 {
2950         int fmt = opt->output_format;
2951
2952         if (fmt & DIFF_FORMAT_CHECKDIFF)
2953                 diff_flush_checkdiff(p, opt);
2954         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2955                 diff_flush_raw(p, opt);
2956         else if (fmt & DIFF_FORMAT_NAME) {
2957                 const char *name_a, *name_b;
2958                 name_a = p->two->path;
2959                 name_b = NULL;
2960                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2961                 write_name_quoted(name_a, opt->file, opt->line_termination);
2962         }
2963 }
2964
2965 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2966 {
2967         if (fs->mode)
2968                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2969         else
2970                 fprintf(file, " %s ", newdelete);
2971         write_name_quoted(fs->path, file, '\n');
2972 }
2973
2974
2975 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2976 {
2977         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2978                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2979                         show_name ? ' ' : '\n');
2980                 if (show_name) {
2981                         write_name_quoted(p->two->path, file, '\n');
2982                 }
2983         }
2984 }
2985
2986 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2987 {
2988         char *names = pprint_rename(p->one->path, p->two->path);
2989
2990         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2991         free(names);
2992         show_mode_change(file, p, 0);
2993 }
2994
2995 static void diff_summary(FILE *file, struct diff_filepair *p)
2996 {
2997         switch(p->status) {
2998         case DIFF_STATUS_DELETED:
2999                 show_file_mode_name(file, "delete", p->one);
3000                 break;
3001         case DIFF_STATUS_ADDED:
3002                 show_file_mode_name(file, "create", p->two);
3003                 break;
3004         case DIFF_STATUS_COPIED:
3005                 show_rename_copy(file, "copy", p);
3006                 break;
3007         case DIFF_STATUS_RENAMED:
3008                 show_rename_copy(file, "rename", p);
3009                 break;
3010         default:
3011                 if (p->score) {
3012                         fputs(" rewrite ", file);
3013                         write_name_quoted(p->two->path, file, ' ');
3014                         fprintf(file, "(%d%%)\n", similarity_index(p));
3015                 }
3016                 show_mode_change(file, p, !p->score);
3017                 break;
3018         }
3019 }
3020
3021 struct patch_id_t {
3022         SHA_CTX *ctx;
3023         int patchlen;
3024 };
3025
3026 static int remove_space(char *line, int len)
3027 {
3028         int i;
3029         char *dst = line;
3030         unsigned char c;
3031
3032         for (i = 0; i < len; i++)
3033                 if (!isspace((c = line[i])))
3034                         *dst++ = c;
3035
3036         return dst - line;
3037 }
3038
3039 static void patch_id_consume(void *priv, char *line, unsigned long len)
3040 {
3041         struct patch_id_t *data = priv;
3042         int new_len;
3043
3044         /* Ignore line numbers when computing the SHA1 of the patch */
3045         if (!prefixcmp(line, "@@ -"))
3046                 return;
3047
3048         new_len = remove_space(line, len);
3049
3050         SHA1_Update(data->ctx, line, new_len);
3051         data->patchlen += new_len;
3052 }
3053
3054 /* returns 0 upon success, and writes result into sha1 */
3055 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3056 {
3057         struct diff_queue_struct *q = &diff_queued_diff;
3058         int i;
3059         SHA_CTX ctx;
3060         struct patch_id_t data;
3061         char buffer[PATH_MAX * 4 + 20];
3062
3063         SHA1_Init(&ctx);
3064         memset(&data, 0, sizeof(struct patch_id_t));
3065         data.ctx = &ctx;
3066
3067         for (i = 0; i < q->nr; i++) {
3068                 xpparam_t xpp;
3069                 xdemitconf_t xecfg;
3070                 xdemitcb_t ecb;
3071                 mmfile_t mf1, mf2;
3072                 struct diff_filepair *p = q->queue[i];
3073                 int len1, len2;
3074
3075                 memset(&xecfg, 0, sizeof(xecfg));
3076                 if (p->status == 0)
3077                         return error("internal diff status error");
3078                 if (p->status == DIFF_STATUS_UNKNOWN)
3079                         continue;
3080                 if (diff_unmodified_pair(p))
3081                         continue;
3082                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3083                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3084                         continue;
3085                 if (DIFF_PAIR_UNMERGED(p))
3086                         continue;
3087
3088                 diff_fill_sha1_info(p->one);
3089                 diff_fill_sha1_info(p->two);
3090                 if (fill_mmfile(&mf1, p->one) < 0 ||
3091                                 fill_mmfile(&mf2, p->two) < 0)
3092                         return error("unable to read files to diff");
3093
3094                 len1 = remove_space(p->one->path, strlen(p->one->path));
3095                 len2 = remove_space(p->two->path, strlen(p->two->path));
3096                 if (p->one->mode == 0)
3097                         len1 = snprintf(buffer, sizeof(buffer),
3098                                         "diff--gita/%.*sb/%.*s"
3099                                         "newfilemode%06o"
3100                                         "---/dev/null"
3101                                         "+++b/%.*s",
3102                                         len1, p->one->path,
3103                                         len2, p->two->path,
3104                                         p->two->mode,
3105                                         len2, p->two->path);
3106                 else if (p->two->mode == 0)
3107                         len1 = snprintf(buffer, sizeof(buffer),
3108                                         "diff--gita/%.*sb/%.*s"
3109                                         "deletedfilemode%06o"
3110                                         "---a/%.*s"
3111                                         "+++/dev/null",
3112                                         len1, p->one->path,
3113                                         len2, p->two->path,
3114                                         p->one->mode,
3115                                         len1, p->one->path);
3116                 else
3117                         len1 = snprintf(buffer, sizeof(buffer),
3118                                         "diff--gita/%.*sb/%.*s"
3119                                         "---a/%.*s"
3120                                         "+++b/%.*s",
3121                                         len1, p->one->path,
3122                                         len2, p->two->path,
3123                                         len1, p->one->path,
3124                                         len2, p->two->path);
3125                 SHA1_Update(&ctx, buffer, len1);
3126
3127                 xpp.flags = XDF_NEED_MINIMAL;
3128                 xecfg.ctxlen = 3;
3129                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3130                 xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3131                               &xpp, &xecfg, &ecb);
3132         }
3133
3134         SHA1_Final(sha1, &ctx);
3135         return 0;
3136 }
3137
3138 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3139 {
3140         struct diff_queue_struct *q = &diff_queued_diff;
3141         int i;
3142         int result = diff_get_patch_id(options, sha1);
3143
3144         for (i = 0; i < q->nr; i++)
3145                 diff_free_filepair(q->queue[i]);
3146
3147         free(q->queue);
3148         q->queue = NULL;
3149         q->nr = q->alloc = 0;
3150
3151         return result;
3152 }
3153
3154 static int is_summary_empty(const struct diff_queue_struct *q)
3155 {
3156         int i;
3157
3158         for (i = 0; i < q->nr; i++) {
3159                 const struct diff_filepair *p = q->queue[i];
3160
3161                 switch (p->status) {
3162                 case DIFF_STATUS_DELETED:
3163                 case DIFF_STATUS_ADDED:
3164                 case DIFF_STATUS_COPIED:
3165                 case DIFF_STATUS_RENAMED:
3166                         return 0;
3167                 default:
3168                         if (p->score)
3169                                 return 0;
3170                         if (p->one->mode && p->two->mode &&
3171                             p->one->mode != p->two->mode)
3172                                 return 0;
3173                         break;
3174                 }
3175         }
3176         return 1;
3177 }
3178
3179 void diff_flush(struct diff_options *options)
3180 {
3181         struct diff_queue_struct *q = &diff_queued_diff;
3182         int i, output_format = options->output_format;
3183         int separator = 0;
3184
3185         /*
3186          * Order: raw, stat, summary, patch
3187          * or:    name/name-status/checkdiff (other bits clear)
3188          */
3189         if (!q->nr)
3190                 goto free_queue;
3191
3192         if (output_format & (DIFF_FORMAT_RAW |
3193                              DIFF_FORMAT_NAME |
3194                              DIFF_FORMAT_NAME_STATUS |
3195                              DIFF_FORMAT_CHECKDIFF)) {
3196                 for (i = 0; i < q->nr; i++) {
3197                         struct diff_filepair *p = q->queue[i];
3198                         if (check_pair_status(p))
3199                                 flush_one_pair(p, options);
3200                 }
3201                 separator++;
3202         }
3203
3204         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3205                 struct diffstat_t diffstat;
3206
3207                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3208                 for (i = 0; i < q->nr; i++) {
3209                         struct diff_filepair *p = q->queue[i];
3210                         if (check_pair_status(p))
3211                                 diff_flush_stat(p, options, &diffstat);
3212                 }
3213                 if (output_format & DIFF_FORMAT_NUMSTAT)
3214                         show_numstat(&diffstat, options);
3215                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3216                         show_stats(&diffstat, options);
3217                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3218                         show_shortstats(&diffstat, options);
3219                 free_diffstat_info(&diffstat);
3220                 separator++;
3221         }
3222         if (output_format & DIFF_FORMAT_DIRSTAT)
3223                 show_dirstat(options);
3224
3225         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3226                 for (i = 0; i < q->nr; i++)
3227                         diff_summary(options->file, q->queue[i]);
3228                 separator++;
3229         }
3230
3231         if (output_format & DIFF_FORMAT_PATCH) {
3232                 if (separator) {
3233                         putc(options->line_termination, options->file);
3234                         if (options->stat_sep) {
3235                                 /* attach patch instead of inline */
3236                                 fputs(options->stat_sep, options->file);
3237                         }
3238                 }
3239
3240                 for (i = 0; i < q->nr; i++) {
3241                         struct diff_filepair *p = q->queue[i];
3242                         if (check_pair_status(p))
3243                                 diff_flush_patch(p, options);
3244                 }
3245         }
3246
3247         if (output_format & DIFF_FORMAT_CALLBACK)
3248                 options->format_callback(q, options, options->format_callback_data);
3249
3250         for (i = 0; i < q->nr; i++)
3251                 diff_free_filepair(q->queue[i]);
3252 free_queue:
3253         free(q->queue);
3254         q->queue = NULL;
3255         q->nr = q->alloc = 0;
3256         if (options->close_file)
3257                 fclose(options->file);
3258 }
3259
3260 static void diffcore_apply_filter(const char *filter)
3261 {
3262         int i;
3263         struct diff_queue_struct *q = &diff_queued_diff;
3264         struct diff_queue_struct outq;
3265         outq.queue = NULL;
3266         outq.nr = outq.alloc = 0;
3267
3268         if (!filter)
3269                 return;
3270
3271         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3272                 int found;
3273                 for (i = found = 0; !found && i < q->nr; i++) {
3274                         struct diff_filepair *p = q->queue[i];
3275                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3276                              ((p->score &&
3277                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3278                               (!p->score &&
3279                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3280                             ((p->status != DIFF_STATUS_MODIFIED) &&
3281                              strchr(filter, p->status)))
3282                                 found++;
3283                 }
3284                 if (found)
3285                         return;
3286
3287                 /* otherwise we will clear the whole queue
3288                  * by copying the empty outq at the end of this
3289                  * function, but first clear the current entries
3290                  * in the queue.
3291                  */
3292                 for (i = 0; i < q->nr; i++)
3293                         diff_free_filepair(q->queue[i]);
3294         }
3295         else {
3296                 /* Only the matching ones */
3297                 for (i = 0; i < q->nr; i++) {
3298                         struct diff_filepair *p = q->queue[i];
3299
3300                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3301                              ((p->score &&
3302                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3303                               (!p->score &&
3304                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3305                             ((p->status != DIFF_STATUS_MODIFIED) &&
3306                              strchr(filter, p->status)))
3307                                 diff_q(&outq, p);
3308                         else
3309                                 diff_free_filepair(p);
3310                 }
3311         }
3312         free(q->queue);
3313         *q = outq;
3314 }
3315
3316 /* Check whether two filespecs with the same mode and size are identical */
3317 static int diff_filespec_is_identical(struct diff_filespec *one,
3318                                       struct diff_filespec *two)
3319 {
3320         if (S_ISGITLINK(one->mode))
3321                 return 0;
3322         if (diff_populate_filespec(one, 0))
3323                 return 0;
3324         if (diff_populate_filespec(two, 0))
3325                 return 0;
3326         return !memcmp(one->data, two->data, one->size);
3327 }
3328
3329 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3330 {
3331         int i;
3332         struct diff_queue_struct *q = &diff_queued_diff;
3333         struct diff_queue_struct outq;
3334         outq.queue = NULL;
3335         outq.nr = outq.alloc = 0;
3336
3337         for (i = 0; i < q->nr; i++) {
3338                 struct diff_filepair *p = q->queue[i];
3339
3340                 /*
3341                  * 1. Entries that come from stat info dirtyness
3342                  *    always have both sides (iow, not create/delete),
3343                  *    one side of the object name is unknown, with
3344                  *    the same mode and size.  Keep the ones that
3345                  *    do not match these criteria.  They have real
3346                  *    differences.
3347                  *
3348                  * 2. At this point, the file is known to be modified,
3349                  *    with the same mode and size, and the object
3350                  *    name of one side is unknown.  Need to inspect
3351                  *    the identical contents.
3352                  */
3353                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3354                     !DIFF_FILE_VALID(p->two) ||
3355                     (p->one->sha1_valid && p->two->sha1_valid) ||
3356                     (p->one->mode != p->two->mode) ||
3357                     diff_populate_filespec(p->one, 1) ||
3358                     diff_populate_filespec(p->two, 1) ||
3359                     (p->one->size != p->two->size) ||
3360                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3361                         diff_q(&outq, p);
3362                 else {
3363                         /*
3364                          * The caller can subtract 1 from skip_stat_unmatch
3365                          * to determine how many paths were dirty only
3366                          * due to stat info mismatch.
3367                          */
3368                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3369                                 diffopt->skip_stat_unmatch++;
3370                         diff_free_filepair(p);
3371                 }
3372         }
3373         free(q->queue);
3374         *q = outq;
3375 }
3376
3377 void diffcore_std(struct diff_options *options)
3378 {
3379         if (DIFF_OPT_TST(options, QUIET))
3380                 return;
3381
3382         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3383                 diffcore_skip_stat_unmatch(options);
3384         if (options->break_opt != -1)
3385                 diffcore_break(options->break_opt);
3386         if (options->detect_rename)
3387                 diffcore_rename(options);
3388         if (options->break_opt != -1)
3389                 diffcore_merge_broken();
3390         if (options->pickaxe)
3391                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3392         if (options->orderfile)
3393                 diffcore_order(options->orderfile);
3394         diff_resolve_rename_copy();
3395         diffcore_apply_filter(options->filter);
3396
3397         if (diff_queued_diff.nr)
3398                 DIFF_OPT_SET(options, HAS_CHANGES);
3399         else
3400                 DIFF_OPT_CLR(options, HAS_CHANGES);
3401 }
3402
3403 int diff_result_code(struct diff_options *opt, int status)
3404 {
3405         int result = 0;
3406         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3407             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3408                 return status;
3409         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3410             DIFF_OPT_TST(opt, HAS_CHANGES))
3411                 result |= 01;
3412         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3413             DIFF_OPT_TST(opt, CHECK_FAILED))
3414                 result |= 02;
3415         return result;
3416 }
3417
3418 void diff_addremove(struct diff_options *options,
3419                     int addremove, unsigned mode,
3420                     const unsigned char *sha1,
3421                     const char *concatpath)
3422 {
3423         struct diff_filespec *one, *two;
3424
3425         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3426                 return;
3427
3428         /* This may look odd, but it is a preparation for
3429          * feeding "there are unchanged files which should
3430          * not produce diffs, but when you are doing copy
3431          * detection you would need them, so here they are"
3432          * entries to the diff-core.  They will be prefixed
3433          * with something like '=' or '*' (I haven't decided
3434          * which but should not make any difference).
3435          * Feeding the same new and old to diff_change()
3436          * also has the same effect.
3437          * Before the final output happens, they are pruned after
3438          * merged into rename/copy pairs as appropriate.
3439          */
3440         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3441                 addremove = (addremove == '+' ? '-' :
3442                              addremove == '-' ? '+' : addremove);
3443
3444         if (options->prefix &&
3445             strncmp(concatpath, options->prefix, options->prefix_length))
3446                 return;
3447
3448         one = alloc_filespec(concatpath);
3449         two = alloc_filespec(concatpath);
3450
3451         if (addremove != '+')
3452                 fill_filespec(one, sha1, mode);
3453         if (addremove != '-')
3454                 fill_filespec(two, sha1, mode);
3455
3456         diff_queue(&diff_queued_diff, one, two);
3457         DIFF_OPT_SET(options, HAS_CHANGES);
3458 }
3459
3460 void diff_change(struct diff_options *options,
3461                  unsigned old_mode, unsigned new_mode,
3462                  const unsigned char *old_sha1,
3463                  const unsigned char *new_sha1,
3464                  const char *concatpath)
3465 {
3466         struct diff_filespec *one, *two;
3467
3468         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3469                         && S_ISGITLINK(new_mode))
3470                 return;
3471
3472         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3473                 unsigned tmp;
3474                 const unsigned char *tmp_c;
3475                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3476                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3477         }
3478
3479         if (options->prefix &&
3480             strncmp(concatpath, options->prefix, options->prefix_length))
3481                 return;
3482
3483         one = alloc_filespec(concatpath);
3484         two = alloc_filespec(concatpath);
3485         fill_filespec(one, old_sha1, old_mode);
3486         fill_filespec(two, new_sha1, new_mode);
3487
3488         diff_queue(&diff_queued_diff, one, two);
3489         DIFF_OPT_SET(options, HAS_CHANGES);
3490 }
3491
3492 void diff_unmerge(struct diff_options *options,
3493                   const char *path,
3494                   unsigned mode, const unsigned char *sha1)
3495 {
3496         struct diff_filespec *one, *two;
3497
3498         if (options->prefix &&
3499             strncmp(path, options->prefix, options->prefix_length))
3500                 return;
3501
3502         one = alloc_filespec(path);
3503         two = alloc_filespec(path);
3504         fill_filespec(one, sha1, mode);
3505         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3506 }