git.oblomov.eu Git - git/blob - diff.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include <sys/types.h>
   5 #include <sys/wait.h>
   6 #include <signal.h>
   7 #include "cache.h"
   8 #include "quote.h"
   9 #include "diff.h"
  10 #include "diffcore.h"
  11 #include "delta.h"
  12 #include "xdiff-interface.h"
  13
  14 static int use_size_cache;
  15
  16 int diff_rename_limit_default = -1;
  17
  18 int git_diff_config(const char *var, const char *value)
  19 {
  20         if (!strcmp(var, "diff.renamelimit")) {
  21                 diff_rename_limit_default = git_config_int(var, value);
  22                 return 0;
  23         }
  24
  25         return git_default_config(var, value);
  26 }
  27
  28 enum color_diff {
  29         DIFF_PLAIN = 0,
  30         DIFF_METAINFO = 1,
  31         DIFF_FILE_OLD = 2,
  32         DIFF_FILE_NEW = 3,
  33 };
  34
  35 static const char *diff_colors[] = {
  36         "\033[0;0m",
  37         "\033[1;35m",
  38         "\033[1;31m",
  39         "\033[1;34m",
  40 };
  41
  42 static char *quote_one(const char *str)
  43 {
  44         int needlen;
  45         char *xp;
  46
  47         if (!str)
  48                 return NULL;
  49         needlen = quote_c_style(str, NULL, NULL, 0);
  50         if (!needlen)
  51                 return strdup(str);
  52         xp = xmalloc(needlen + 1);
  53         quote_c_style(str, xp, NULL, 0);
  54         return xp;
  55 }
  56
  57 static char *quote_two(const char *one, const char *two)
  58 {
  59         int need_one = quote_c_style(one, NULL, NULL, 1);
  60         int need_two = quote_c_style(two, NULL, NULL, 1);
  61         char *xp;
  62
  63         if (need_one + need_two) {
  64                 if (!need_one) need_one = strlen(one);
  65                 if (!need_two) need_one = strlen(two);
  66
  67                 xp = xmalloc(need_one + need_two + 3);
  68                 xp[0] = '"';
  69                 quote_c_style(one, xp + 1, NULL, 1);
  70                 quote_c_style(two, xp + need_one + 1, NULL, 1);
  71                 strcpy(xp + need_one + need_two + 1, "\"");
  72                 return xp;
  73         }
  74         need_one = strlen(one);
  75         need_two = strlen(two);
  76         xp = xmalloc(need_one + need_two + 1);
  77         strcpy(xp, one);
  78         strcpy(xp + need_one, two);
  79         return xp;
  80 }
  81
  82 static const char *external_diff(void)
  83 {
  84         static const char *external_diff_cmd = NULL;
  85         static int done_preparing = 0;
  86
  87         if (done_preparing)
  88                 return external_diff_cmd;
  89         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
  90         done_preparing = 1;
  91         return external_diff_cmd;
  92 }
  93
  94 #define TEMPFILE_PATH_LEN               50
  95
  96 static struct diff_tempfile {
  97         const char *name; /* filename external diff should read from */
  98         char hex[41];
  99         char mode[10];
 100         char tmp_path[TEMPFILE_PATH_LEN];
 101 } diff_temp[2];
 102
 103 static int count_lines(const char *data, int size)
 104 {
 105         int count, ch, completely_empty = 1, nl_just_seen = 0;
 106         count = 0;
 107         while (0 < size--) {
 108                 ch = *data++;
 109                 if (ch == '\n') {
 110                         count++;
 111                         nl_just_seen = 1;
 112                         completely_empty = 0;
 113                 }
 114                 else {
 115                         nl_just_seen = 0;
 116                         completely_empty = 0;
 117                 }
 118         }
 119         if (completely_empty)
 120                 return 0;
 121         if (!nl_just_seen)
 122                 count++; /* no trailing newline */
 123         return count;
 124 }
 125
 126 static void print_line_count(int count)
 127 {
 128         switch (count) {
 129         case 0:
 130                 printf("0,0");
 131                 break;
 132         case 1:
 133                 printf("1");
 134                 break;
 135         default:
 136                 printf("1,%d", count);
 137                 break;
 138         }
 139 }
 140
 141 static void copy_file(int prefix, const char *data, int size)
 142 {
 143         int ch, nl_just_seen = 1;
 144         while (0 < size--) {
 145                 ch = *data++;
 146                 if (nl_just_seen)
 147                         putchar(prefix);
 148                 putchar(ch);
 149                 if (ch == '\n')
 150                         nl_just_seen = 1;
 151                 else
 152                         nl_just_seen = 0;
 153         }
 154         if (!nl_just_seen)
 155                 printf("\n\\ No newline at end of file\n");
 156 }
 157
 158 static void emit_rewrite_diff(const char *name_a,
 159                               const char *name_b,
 160                               struct diff_filespec *one,
 161                               struct diff_filespec *two)
 162 {
 163         int lc_a, lc_b;
 164         diff_populate_filespec(one, 0);
 165         diff_populate_filespec(two, 0);
 166         lc_a = count_lines(one->data, one->size);
 167         lc_b = count_lines(two->data, two->size);
 168         printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 169         print_line_count(lc_a);
 170         printf(" +");
 171         print_line_count(lc_b);
 172         printf(" @@\n");
 173         if (lc_a)
 174                 copy_file('-', one->data, one->size);
 175         if (lc_b)
 176                 copy_file('+', two->data, two->size);
 177 }
 178
 179 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 180 {
 181         if (!DIFF_FILE_VALID(one)) {
 182                 mf->ptr = ""; /* does not matter */
 183                 mf->size = 0;
 184                 return 0;
 185         }
 186         else if (diff_populate_filespec(one, 0))
 187                 return -1;
 188         mf->ptr = one->data;
 189         mf->size = one->size;
 190         return 0;
 191 }
 192
 193 struct emit_callback {
 194         struct xdiff_emit_state xm;
 195         int nparents, color_diff;
 196         const char **label_path;
 197 };
 198
 199 static inline void color_diff(int diff_use_color, enum color_diff ix)
 200 {
 201         if (diff_use_color)
 202                 fputs(diff_colors[ix], stdout);
 203 }
 204
 205 static void fn_out_consume(void *priv, char *line, unsigned long len)
 206 {
 207         int i;
 208         struct emit_callback *ecbdata = priv;
 209
 210         if (ecbdata->label_path[0]) {
 211                 color_diff(ecbdata->color_diff, DIFF_METAINFO);
 212                 printf("--- %s\n", ecbdata->label_path[0]);
 213                 color_diff(ecbdata->color_diff, DIFF_METAINFO);
 214                 printf("+++ %s\n", ecbdata->label_path[1]);
 215                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 216         }
 217
 218         /* This is not really necessary for now because
 219          * this codepath only deals with two-way diffs.
 220          */
 221         for (i = 0; i < len && line[i] == '@'; i++)
 222                 ;
 223         if (2 <= i && i < len && line[i] == ' ') {
 224                 ecbdata->nparents = i - 1;
 225                 color_diff(ecbdata->color_diff, DIFF_METAINFO);
 226         }
 227         else if (len < ecbdata->nparents)
 228                 color_diff(ecbdata->color_diff, DIFF_PLAIN);
 229         else {
 230                 int nparents = ecbdata->nparents;
 231                 int color = DIFF_PLAIN;
 232                 for (i = 0; i < nparents && len; i++) {
 233                         if (line[i] == '-')
 234                                 color = DIFF_FILE_OLD;
 235                         else if (line[i] == '+')
 236                                 color = DIFF_FILE_NEW;
 237                 }
 238                 color_diff(ecbdata->color_diff, color);
 239         }
 240         fwrite(line, len, 1, stdout);
 241         color_diff(ecbdata->color_diff, DIFF_PLAIN);
 242 }
 243
 244 static char *pprint_rename(const char *a, const char *b)
 245 {
 246         const char *old = a;
 247         const char *new = b;
 248         char *name = NULL;
 249         int pfx_length, sfx_length;
 250         int len_a = strlen(a);
 251         int len_b = strlen(b);
 252
 253         /* Find common prefix */
 254         pfx_length = 0;
 255         while (*old && *new && *old == *new) {
 256                 if (*old == '/')
 257                         pfx_length = old - a + 1;
 258                 old++;
 259                 new++;
 260         }
 261
 262         /* Find common suffix */
 263         old = a + len_a;
 264         new = b + len_b;
 265         sfx_length = 0;
 266         while (a <= old && b <= new && *old == *new) {
 267                 if (*old == '/')
 268                         sfx_length = len_a - (old - a);
 269                 old--;
 270                 new--;
 271         }
 272
 273         /*
 274          * pfx{mid-a => mid-b}sfx
 275          * {pfx-a => pfx-b}sfx
 276          * pfx{sfx-a => sfx-b}
 277          * name-a => name-b
 278          */
 279         if (pfx_length + sfx_length) {
 280                 int a_midlen = len_a - pfx_length - sfx_length;
 281                 int b_midlen = len_b - pfx_length - sfx_length;
 282                 if (a_midlen < 0) a_midlen = 0;
 283                 if (b_midlen < 0) b_midlen = 0;
 284
 285                 name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
 286                 sprintf(name, "%.*s{%.*s => %.*s}%s",
 287                         pfx_length, a,
 288                         a_midlen, a + pfx_length,
 289                         b_midlen, b + pfx_length,
 290                         a + len_a - sfx_length);
 291         }
 292         else {
 293                 name = xmalloc(len_a + len_b + 5);
 294                 sprintf(name, "%s => %s", a, b);
 295         }
 296         return name;
 297 }
 298
 299 struct diffstat_t {
 300         struct xdiff_emit_state xm;
 301
 302         int nr;
 303         int alloc;
 304         struct diffstat_file {
 305                 char *name;
 306                 unsigned is_unmerged:1;
 307                 unsigned is_binary:1;
 308                 unsigned is_renamed:1;
 309                 unsigned int added, deleted;
 310         } **files;
 311 };
 312
 313 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 314                                           const char *name_a,
 315                                           const char *name_b)
 316 {
 317         struct diffstat_file *x;
 318         x = xcalloc(sizeof (*x), 1);
 319         if (diffstat->nr == diffstat->alloc) {
 320                 diffstat->alloc = alloc_nr(diffstat->alloc);
 321                 diffstat->files = xrealloc(diffstat->files,
 322                                 diffstat->alloc * sizeof(x));
 323         }
 324         diffstat->files[diffstat->nr++] = x;
 325         if (name_b) {
 326                 x->name = pprint_rename(name_a, name_b);
 327                 x->is_renamed = 1;
 328         }
 329         else
 330                 x->name = strdup(name_a);
 331         return x;
 332 }
 333
 334 static void diffstat_consume(void *priv, char *line, unsigned long len)
 335 {
 336         struct diffstat_t *diffstat = priv;
 337         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 338
 339         if (line[0] == '+')
 340                 x->added++;
 341         else if (line[0] == '-')
 342                 x->deleted++;
 343 }
 344
 345 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 346 static const char minuses[]= "----------------------------------------------------------------------";
 347 const char mime_boundary_leader[] = "------------";
 348
 349 static void show_stats(struct diffstat_t* data)
 350 {
 351         int i, len, add, del, total, adds = 0, dels = 0;
 352         int max, max_change = 0, max_len = 0;
 353         int total_files = data->nr;
 354
 355         if (data->nr == 0)
 356                 return;
 357
 358         for (i = 0; i < data->nr; i++) {
 359                 struct diffstat_file *file = data->files[i];
 360
 361                 len = strlen(file->name);
 362                 if (max_len < len)
 363                         max_len = len;
 364
 365                 if (file->is_binary || file->is_unmerged)
 366                         continue;
 367                 if (max_change < file->added + file->deleted)
 368                         max_change = file->added + file->deleted;
 369         }
 370
 371         for (i = 0; i < data->nr; i++) {
 372                 char *prefix = "";
 373                 char *name = data->files[i]->name;
 374                 int added = data->files[i]->added;
 375                 int deleted = data->files[i]->deleted;
 376
 377                 if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 378                         char *qname = xmalloc(len + 1);
 379                         quote_c_style(name, qname, NULL, 0);
 380                         free(name);
 381                         data->files[i]->name = name = qname;
 382                 }
 383
 384                 /*
 385                  * "scale" the filename
 386                  */
 387                 len = strlen(name);
 388                 max = max_len;
 389                 if (max > 50)
 390                         max = 50;
 391                 if (len > max) {
 392                         char *slash;
 393                         prefix = "...";
 394                         max -= 3;
 395                         name += len - max;
 396                         slash = strchr(name, '/');
 397                         if (slash)
 398                                 name = slash;
 399                 }
 400                 len = max;
 401
 402                 /*
 403                  * scale the add/delete
 404                  */
 405                 max = max_change;
 406                 if (max + len > 70)
 407                         max = 70 - len;
 408
 409                 if (data->files[i]->is_binary) {
 410                         printf(" %s%-*s |  Bin\n", prefix, len, name);
 411                         goto free_diffstat_file;
 412                 }
 413                 else if (data->files[i]->is_unmerged) {
 414                         printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 415                         goto free_diffstat_file;
 416                 }
 417                 else if (!data->files[i]->is_renamed &&
 418                          (added + deleted == 0)) {
 419                         total_files--;
 420                         goto free_diffstat_file;
 421                 }
 422
 423                 add = added;
 424                 del = deleted;
 425                 total = add + del;
 426                 adds += add;
 427                 dels += del;
 428
 429                 if (max_change > 0) {
 430                         total = (total * max + max_change / 2) / max_change;
 431                         add = (add * max + max_change / 2) / max_change;
 432                         del = total - add;
 433                 }
 434                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 435                                 len, name, added + deleted,
 436                                 add, pluses, del, minuses);
 437         free_diffstat_file:
 438                 free(data->files[i]->name);
 439                 free(data->files[i]);
 440         }
 441         free(data->files);
 442         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 443                         total_files, adds, dels);
 444 }
 445
 446 struct checkdiff_t {
 447         struct xdiff_emit_state xm;
 448         const char *filename;
 449         int lineno;
 450 };
 451
 452 static void checkdiff_consume(void *priv, char *line, unsigned long len)
 453 {
 454         struct checkdiff_t *data = priv;
 455
 456         if (line[0] == '+') {
 457                 int i, spaces = 0;
 458
 459                 data->lineno++;
 460
 461                 /* check space before tab */
 462                 for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
 463                         if (line[i] == ' ')
 464                                 spaces++;
 465                 if (line[i - 1] == '\t' && spaces)
 466                         printf("%s:%d: space before tab:%.*s\n",
 467                                 data->filename, data->lineno, (int)len, line);
 468
 469                 /* check white space at line end */
 470                 if (line[len - 1] == '\n')
 471                         len--;
 472                 if (isspace(line[len - 1]))
 473                         printf("%s:%d: white space at end: %.*s\n",
 474                                 data->filename, data->lineno, (int)len, line);
 475         } else if (line[0] == ' ')
 476                 data->lineno++;
 477         else if (line[0] == '@') {
 478                 char *plus = strchr(line, '+');
 479                 if (plus)
 480                         data->lineno = strtol(plus, NULL, 10);
 481                 else
 482                         die("invalid diff");
 483         }
 484 }
 485
 486 static unsigned char *deflate_it(char *data,
 487                                  unsigned long size,
 488                                  unsigned long *result_size)
 489 {
 490         int bound;
 491         unsigned char *deflated;
 492         z_stream stream;
 493
 494         memset(&stream, 0, sizeof(stream));
 495         deflateInit(&stream, Z_BEST_COMPRESSION);
 496         bound = deflateBound(&stream, size);
 497         deflated = xmalloc(bound);
 498         stream.next_out = deflated;
 499         stream.avail_out = bound;
 500
 501         stream.next_in = (unsigned char *)data;
 502         stream.avail_in = size;
 503         while (deflate(&stream, Z_FINISH) == Z_OK)
 504                 ; /* nothing */
 505         deflateEnd(&stream);
 506         *result_size = stream.total_out;
 507         return deflated;
 508 }
 509
 510 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 511 {
 512         void *cp;
 513         void *delta;
 514         void *deflated;
 515         void *data;
 516         unsigned long orig_size;
 517         unsigned long delta_size;
 518         unsigned long deflate_size;
 519         unsigned long data_size;
 520
 521         printf("GIT binary patch\n");
 522         /* We could do deflated delta, or we could do just deflated two,
 523          * whichever is smaller.
 524          */
 525         delta = NULL;
 526         deflated = deflate_it(two->ptr, two->size, &deflate_size);
 527         if (one->size && two->size) {
 528                 delta = diff_delta(one->ptr, one->size,
 529                                    two->ptr, two->size,
 530                                    &delta_size, deflate_size);
 531                 if (delta) {
 532                         void *to_free = delta;
 533                         orig_size = delta_size;
 534                         delta = deflate_it(delta, delta_size, &delta_size);
 535                         free(to_free);
 536                 }
 537         }
 538
 539         if (delta && delta_size < deflate_size) {
 540                 printf("delta %lu\n", orig_size);
 541                 free(deflated);
 542                 data = delta;
 543                 data_size = delta_size;
 544         }
 545         else {
 546                 printf("literal %lu\n", two->size);
 547                 free(delta);
 548                 data = deflated;
 549                 data_size = deflate_size;
 550         }
 551
 552         /* emit data encoded in base85 */
 553         cp = data;
 554         while (data_size) {
 555                 int bytes = (52 < data_size) ? 52 : data_size;
 556                 char line[70];
 557                 data_size -= bytes;
 558                 if (bytes <= 26)
 559                         line[0] = bytes + 'A' - 1;
 560                 else
 561                         line[0] = bytes - 26 + 'a' - 1;
 562                 encode_85(line + 1, cp, bytes);
 563                 cp = (char *) cp + bytes;
 564                 puts(line);
 565         }
 566         printf("\n");
 567         free(data);
 568 }
 569
 570 #define FIRST_FEW_BYTES 8000
 571 static int mmfile_is_binary(mmfile_t *mf)
 572 {
 573         long sz = mf->size;
 574         if (FIRST_FEW_BYTES < sz)
 575                 sz = FIRST_FEW_BYTES;
 576         if (memchr(mf->ptr, 0, sz))
 577                 return 1;
 578         return 0;
 579 }
 580
 581 static void builtin_diff(const char *name_a,
 582                          const char *name_b,
 583                          struct diff_filespec *one,
 584                          struct diff_filespec *two,
 585                          const char *xfrm_msg,
 586                          struct diff_options *o,
 587                          int complete_rewrite)
 588 {
 589         mmfile_t mf1, mf2;
 590         const char *lbl[2];
 591         char *a_one, *b_two;
 592
 593         a_one = quote_two("a/", name_a);
 594         b_two = quote_two("b/", name_b);
 595         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 596         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 597         color_diff(o->color_diff, DIFF_METAINFO);
 598         printf("diff --git %s %s\n", a_one, b_two);
 599         if (lbl[0][0] == '/') {
 600                 /* /dev/null */
 601                 color_diff(o->color_diff, DIFF_METAINFO);
 602                 printf("new file mode %06o\n", two->mode);
 603                 if (xfrm_msg && xfrm_msg[0]) {
 604                         color_diff(o->color_diff, DIFF_METAINFO);
 605                         puts(xfrm_msg);
 606                 }
 607         }
 608         else if (lbl[1][0] == '/') {
 609                 printf("deleted file mode %06o\n", one->mode);
 610                 if (xfrm_msg && xfrm_msg[0]) {
 611                         color_diff(o->color_diff, DIFF_METAINFO);
 612                         puts(xfrm_msg);
 613                 }
 614         }
 615         else {
 616                 if (one->mode != two->mode) {
 617                         color_diff(o->color_diff, DIFF_METAINFO);
 618                         printf("old mode %06o\n", one->mode);
 619                         color_diff(o->color_diff, DIFF_METAINFO);
 620                         printf("new mode %06o\n", two->mode);
 621                 }
 622                 if (xfrm_msg && xfrm_msg[0]) {
 623                         color_diff(o->color_diff, DIFF_METAINFO);
 624                         puts(xfrm_msg);
 625                 }
 626                 /*
 627                  * we do not run diff between different kind
 628                  * of objects.
 629                  */
 630                 if ((one->mode ^ two->mode) & S_IFMT)
 631                         goto free_ab_and_return;
 632                 if (complete_rewrite) {
 633                         color_diff(o->color_diff, DIFF_PLAIN);
 634                         emit_rewrite_diff(name_a, name_b, one, two);
 635                         goto free_ab_and_return;
 636                 }
 637         }
 638
 639         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 640                 die("unable to read files to diff");
 641
 642         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
 643                 /* Quite common confusing case */
 644                 if (mf1.size == mf2.size &&
 645                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 646                         goto free_ab_and_return;
 647                 if (o->binary)
 648                         emit_binary_diff(&mf1, &mf2);
 649                 else
 650                         printf("Binary files %s and %s differ\n",
 651                                lbl[0], lbl[1]);
 652         }
 653         else {
 654                 /* Crazy xdl interfaces.. */
 655                 const char *diffopts = getenv("GIT_DIFF_OPTS");
 656                 xpparam_t xpp;
 657                 xdemitconf_t xecfg;
 658                 xdemitcb_t ecb;
 659                 struct emit_callback ecbdata;
 660
 661                 memset(&ecbdata, 0, sizeof(ecbdata));
 662                 ecbdata.label_path = lbl;
 663                 ecbdata.color_diff = o->color_diff;
 664                 xpp.flags = XDF_NEED_MINIMAL;
 665                 xecfg.ctxlen = o->context;
 666                 xecfg.flags = XDL_EMIT_FUNCNAMES;
 667                 if (!diffopts)
 668                         ;
 669                 else if (!strncmp(diffopts, "--unified=", 10))
 670                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 671                 else if (!strncmp(diffopts, "-u", 2))
 672                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 673                 ecb.outf = xdiff_outf;
 674                 ecb.priv = &ecbdata;
 675                 ecbdata.xm.consume = fn_out_consume;
 676                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 677         }
 678
 679  free_ab_and_return:
 680         free(a_one);
 681         free(b_two);
 682         return;
 683 }
 684
 685 static void builtin_diffstat(const char *name_a, const char *name_b,
 686                              struct diff_filespec *one,
 687                              struct diff_filespec *two,
 688                              struct diffstat_t *diffstat,
 689                              int complete_rewrite)
 690 {
 691         mmfile_t mf1, mf2;
 692         struct diffstat_file *data;
 693
 694         data = diffstat_add(diffstat, name_a, name_b);
 695
 696         if (!one || !two) {
 697                 data->is_unmerged = 1;
 698                 return;
 699         }
 700         if (complete_rewrite) {
 701                 diff_populate_filespec(one, 0);
 702                 diff_populate_filespec(two, 0);
 703                 data->deleted = count_lines(one->data, one->size);
 704                 data->added = count_lines(two->data, two->size);
 705                 return;
 706         }
 707         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 708                 die("unable to read files to diff");
 709
 710         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 711                 data->is_binary = 1;
 712         else {
 713                 /* Crazy xdl interfaces.. */
 714                 xpparam_t xpp;
 715                 xdemitconf_t xecfg;
 716                 xdemitcb_t ecb;
 717
 718                 xpp.flags = XDF_NEED_MINIMAL;
 719                 xecfg.ctxlen = 0;
 720                 xecfg.flags = 0;
 721                 ecb.outf = xdiff_outf;
 722                 ecb.priv = diffstat;
 723                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 724         }
 725 }
 726
 727 static void builtin_checkdiff(const char *name_a, const char *name_b,
 728                              struct diff_filespec *one,
 729                              struct diff_filespec *two)
 730 {
 731         mmfile_t mf1, mf2;
 732         struct checkdiff_t data;
 733
 734         if (!two)
 735                 return;
 736
 737         memset(&data, 0, sizeof(data));
 738         data.xm.consume = checkdiff_consume;
 739         data.filename = name_b ? name_b : name_a;
 740         data.lineno = 0;
 741
 742         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 743                 die("unable to read files to diff");
 744
 745         if (mmfile_is_binary(&mf2))
 746                 return;
 747         else {
 748                 /* Crazy xdl interfaces.. */
 749                 xpparam_t xpp;
 750                 xdemitconf_t xecfg;
 751                 xdemitcb_t ecb;
 752
 753                 xpp.flags = XDF_NEED_MINIMAL;
 754                 xecfg.ctxlen = 0;
 755                 xecfg.flags = 0;
 756                 ecb.outf = xdiff_outf;
 757                 ecb.priv = &data;
 758                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 759         }
 760 }
 761
 762 struct diff_filespec *alloc_filespec(const char *path)
 763 {
 764         int namelen = strlen(path);
 765         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 766
 767         memset(spec, 0, sizeof(*spec));
 768         spec->path = (char *)(spec + 1);
 769         memcpy(spec->path, path, namelen+1);
 770         return spec;
 771 }
 772
 773 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 774                    unsigned short mode)
 775 {
 776         if (mode) {
 777                 spec->mode = canon_mode(mode);
 778                 memcpy(spec->sha1, sha1, 20);
 779                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 780         }
 781 }
 782
 783 /*
 784  * Given a name and sha1 pair, if the dircache tells us the file in
 785  * the work tree has that object contents, return true, so that
 786  * prepare_temp_file() does not have to inflate and extract.
 787  */
 788 static int work_tree_matches(const char *name, const unsigned char *sha1)
 789 {
 790         struct cache_entry *ce;
 791         struct stat st;
 792         int pos, len;
 793
 794         /* We do not read the cache ourselves here, because the
 795          * benchmark with my previous version that always reads cache
 796          * shows that it makes things worse for diff-tree comparing
 797          * two linux-2.6 kernel trees in an already checked out work
 798          * tree.  This is because most diff-tree comparisons deal with
 799          * only a small number of files, while reading the cache is
 800          * expensive for a large project, and its cost outweighs the
 801          * savings we get by not inflating the object to a temporary
 802          * file.  Practically, this code only helps when we are used
 803          * by diff-cache --cached, which does read the cache before
 804          * calling us.
 805          */
 806         if (!active_cache)
 807                 return 0;
 808
 809         len = strlen(name);
 810         pos = cache_name_pos(name, len);
 811         if (pos < 0)
 812                 return 0;
 813         ce = active_cache[pos];
 814         if ((lstat(name, &st) < 0) ||
 815             !S_ISREG(st.st_mode) || /* careful! */
 816             ce_match_stat(ce, &st, 0) ||
 817             memcmp(sha1, ce->sha1, 20))
 818                 return 0;
 819         /* we return 1 only when we can stat, it is a regular file,
 820          * stat information matches, and sha1 recorded in the cache
 821          * matches.  I.e. we know the file in the work tree really is
 822          * the same as the <name, sha1> pair.
 823          */
 824         return 1;
 825 }
 826
 827 static struct sha1_size_cache {
 828         unsigned char sha1[20];
 829         unsigned long size;
 830 } **sha1_size_cache;
 831 static int sha1_size_cache_nr, sha1_size_cache_alloc;
 832
 833 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 834                                                  int find_only,
 835                                                  unsigned long size)
 836 {
 837         int first, last;
 838         struct sha1_size_cache *e;
 839
 840         first = 0;
 841         last = sha1_size_cache_nr;
 842         while (last > first) {
 843                 int cmp, next = (last + first) >> 1;
 844                 e = sha1_size_cache[next];
 845                 cmp = memcmp(e->sha1, sha1, 20);
 846                 if (!cmp)
 847                         return e;
 848                 if (cmp < 0) {
 849                         last = next;
 850                         continue;
 851                 }
 852                 first = next+1;
 853         }
 854         /* not found */
 855         if (find_only)
 856                 return NULL;
 857         /* insert to make it at "first" */
 858         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 859                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 860                 sha1_size_cache = xrealloc(sha1_size_cache,
 861                                            sha1_size_cache_alloc *
 862                                            sizeof(*sha1_size_cache));
 863         }
 864         sha1_size_cache_nr++;
 865         if (first < sha1_size_cache_nr)
 866                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 867                         (sha1_size_cache_nr - first - 1) *
 868                         sizeof(*sha1_size_cache));
 869         e = xmalloc(sizeof(struct sha1_size_cache));
 870         sha1_size_cache[first] = e;
 871         memcpy(e->sha1, sha1, 20);
 872         e->size = size;
 873         return e;
 874 }
 875
 876 /*
 877  * While doing rename detection and pickaxe operation, we may need to
 878  * grab the data for the blob (or file) for our own in-core comparison.
 879  * diff_filespec has data and size fields for this purpose.
 880  */
 881 int diff_populate_filespec(struct diff_filespec *s, int size_only)
 882 {
 883         int err = 0;
 884         if (!DIFF_FILE_VALID(s))
 885                 die("internal error: asking to populate invalid file.");
 886         if (S_ISDIR(s->mode))
 887                 return -1;
 888
 889         if (!use_size_cache)
 890                 size_only = 0;
 891
 892         if (s->data)
 893                 return err;
 894         if (!s->sha1_valid ||
 895             work_tree_matches(s->path, s->sha1)) {
 896                 struct stat st;
 897                 int fd;
 898                 if (lstat(s->path, &st) < 0) {
 899                         if (errno == ENOENT) {
 900                         err_empty:
 901                                 err = -1;
 902                         empty:
 903                                 s->data = "";
 904                                 s->size = 0;
 905                                 return err;
 906                         }
 907                 }
 908                 s->size = st.st_size;
 909                 if (!s->size)
 910                         goto empty;
 911                 if (size_only)
 912                         return 0;
 913                 if (S_ISLNK(st.st_mode)) {
 914                         int ret;
 915                         s->data = xmalloc(s->size);
 916                         s->should_free = 1;
 917                         ret = readlink(s->path, s->data, s->size);
 918                         if (ret < 0) {
 919                                 free(s->data);
 920                                 goto err_empty;
 921                         }
 922                         return 0;
 923                 }
 924                 fd = open(s->path, O_RDONLY);
 925                 if (fd < 0)
 926                         goto err_empty;
 927                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 928                 close(fd);
 929                 if (s->data == MAP_FAILED)
 930                         goto err_empty;
 931                 s->should_munmap = 1;
 932         }
 933         else {
 934                 char type[20];
 935                 struct sha1_size_cache *e;
 936
 937                 if (size_only) {
 938                         e = locate_size_cache(s->sha1, 1, 0);
 939                         if (e) {
 940                                 s->size = e->size;
 941                                 return 0;
 942                         }
 943                         if (!sha1_object_info(s->sha1, type, &s->size))
 944                                 locate_size_cache(s->sha1, 0, s->size);
 945                 }
 946                 else {
 947                         s->data = read_sha1_file(s->sha1, type, &s->size);
 948                         s->should_free = 1;
 949                 }
 950         }
 951         return 0;
 952 }
 953
 954 void diff_free_filespec_data(struct diff_filespec *s)
 955 {
 956         if (s->should_free)
 957                 free(s->data);
 958         else if (s->should_munmap)
 959                 munmap(s->data, s->size);
 960         s->should_free = s->should_munmap = 0;
 961         s->data = NULL;
 962         free(s->cnt_data);
 963         s->cnt_data = NULL;
 964 }
 965
 966 static void prep_temp_blob(struct diff_tempfile *temp,
 967                            void *blob,
 968                            unsigned long size,
 969                            const unsigned char *sha1,
 970                            int mode)
 971 {
 972         int fd;
 973
 974         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 975         if (fd < 0)
 976                 die("unable to create temp-file");
 977         if (write(fd, blob, size) != size)
 978                 die("unable to write temp-file");
 979         close(fd);
 980         temp->name = temp->tmp_path;
 981         strcpy(temp->hex, sha1_to_hex(sha1));
 982         temp->hex[40] = 0;
 983         sprintf(temp->mode, "%06o", mode);
 984 }
 985
 986 static void prepare_temp_file(const char *name,
 987                               struct diff_tempfile *temp,
 988                               struct diff_filespec *one)
 989 {
 990         if (!DIFF_FILE_VALID(one)) {
 991         not_a_valid_file:
 992                 /* A '-' entry produces this for file-2, and
 993                  * a '+' entry produces this for file-1.
 994                  */
 995                 temp->name = "/dev/null";
 996                 strcpy(temp->hex, ".");
 997                 strcpy(temp->mode, ".");
 998                 return;
 999         }
1000
1001         if (!one->sha1_valid ||
1002             work_tree_matches(name, one->sha1)) {
1003                 struct stat st;
1004                 if (lstat(name, &st) < 0) {
1005                         if (errno == ENOENT)
1006                                 goto not_a_valid_file;
1007                         die("stat(%s): %s", name, strerror(errno));
1008                 }
1009                 if (S_ISLNK(st.st_mode)) {
1010                         int ret;
1011                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1012                         if (sizeof(buf) <= st.st_size)
1013                                 die("symlink too long: %s", name);
1014                         ret = readlink(name, buf, st.st_size);
1015                         if (ret < 0)
1016                                 die("readlink(%s)", name);
1017                         prep_temp_blob(temp, buf, st.st_size,
1018                                        (one->sha1_valid ?
1019                                         one->sha1 : null_sha1),
1020                                        (one->sha1_valid ?
1021                                         one->mode : S_IFLNK));
1022                 }
1023                 else {
1024                         /* we can borrow from the file in the work tree */
1025                         temp->name = name;
1026                         if (!one->sha1_valid)
1027                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1028                         else
1029                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1030                         /* Even though we may sometimes borrow the
1031                          * contents from the work tree, we always want
1032                          * one->mode.  mode is trustworthy even when
1033                          * !(one->sha1_valid), as long as
1034                          * DIFF_FILE_VALID(one).
1035                          */
1036                         sprintf(temp->mode, "%06o", one->mode);
1037                 }
1038                 return;
1039         }
1040         else {
1041                 if (diff_populate_filespec(one, 0))
1042                         die("cannot read data blob for %s", one->path);
1043                 prep_temp_blob(temp, one->data, one->size,
1044                                one->sha1, one->mode);
1045         }
1046 }
1047
1048 static void remove_tempfile(void)
1049 {
1050         int i;
1051
1052         for (i = 0; i < 2; i++)
1053                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1054                         unlink(diff_temp[i].name);
1055                         diff_temp[i].name = NULL;
1056                 }
1057 }
1058
1059 static void remove_tempfile_on_signal(int signo)
1060 {
1061         remove_tempfile();
1062         signal(SIGINT, SIG_DFL);
1063         raise(signo);
1064 }
1065
1066 static int spawn_prog(const char *pgm, const char **arg)
1067 {
1068         pid_t pid;
1069         int status;
1070
1071         fflush(NULL);
1072         pid = fork();
1073         if (pid < 0)
1074                 die("unable to fork");
1075         if (!pid) {
1076                 execvp(pgm, (char *const*) arg);
1077                 exit(255);
1078         }
1079
1080         while (waitpid(pid, &status, 0) < 0) {
1081                 if (errno == EINTR)
1082                         continue;
1083                 return -1;
1084         }
1085
1086         /* Earlier we did not check the exit status because
1087          * diff exits non-zero if files are different, and
1088          * we are not interested in knowing that.  It was a
1089          * mistake which made it harder to quit a diff-*
1090          * session that uses the git-apply-patch-script as
1091          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1092          * should also exit non-zero only when it wants to
1093          * abort the entire diff-* session.
1094          */
1095         if (WIFEXITED(status) && !WEXITSTATUS(status))
1096                 return 0;
1097         return -1;
1098 }
1099
1100 /* An external diff command takes:
1101  *
1102  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1103  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1104  *
1105  */
1106 static void run_external_diff(const char *pgm,
1107                               const char *name,
1108                               const char *other,
1109                               struct diff_filespec *one,
1110                               struct diff_filespec *two,
1111                               const char *xfrm_msg,
1112                               int complete_rewrite)
1113 {
1114         const char *spawn_arg[10];
1115         struct diff_tempfile *temp = diff_temp;
1116         int retval;
1117         static int atexit_asked = 0;
1118         const char *othername;
1119         const char **arg = &spawn_arg[0];
1120
1121         othername = (other? other : name);
1122         if (one && two) {
1123                 prepare_temp_file(name, &temp[0], one);
1124                 prepare_temp_file(othername, &temp[1], two);
1125                 if (! atexit_asked &&
1126                     (temp[0].name == temp[0].tmp_path ||
1127                      temp[1].name == temp[1].tmp_path)) {
1128                         atexit_asked = 1;
1129                         atexit(remove_tempfile);
1130                 }
1131                 signal(SIGINT, remove_tempfile_on_signal);
1132         }
1133
1134         if (one && two) {
1135                 *arg++ = pgm;
1136                 *arg++ = name;
1137                 *arg++ = temp[0].name;
1138                 *arg++ = temp[0].hex;
1139                 *arg++ = temp[0].mode;
1140                 *arg++ = temp[1].name;
1141                 *arg++ = temp[1].hex;
1142                 *arg++ = temp[1].mode;
1143                 if (other) {
1144                         *arg++ = other;
1145                         *arg++ = xfrm_msg;
1146                 }
1147         } else {
1148                 *arg++ = pgm;
1149                 *arg++ = name;
1150         }
1151         *arg = NULL;
1152         retval = spawn_prog(pgm, spawn_arg);
1153         remove_tempfile();
1154         if (retval) {
1155                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1156                 exit(1);
1157         }
1158 }
1159
1160 static void run_diff_cmd(const char *pgm,
1161                          const char *name,
1162                          const char *other,
1163                          struct diff_filespec *one,
1164                          struct diff_filespec *two,
1165                          const char *xfrm_msg,
1166                          struct diff_options *o,
1167                          int complete_rewrite)
1168 {
1169         if (pgm) {
1170                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1171                                   complete_rewrite);
1172                 return;
1173         }
1174         if (one && two)
1175                 builtin_diff(name, other ? other : name,
1176                              one, two, xfrm_msg, o, complete_rewrite);
1177         else
1178                 printf("* Unmerged path %s\n", name);
1179 }
1180
1181 static void diff_fill_sha1_info(struct diff_filespec *one)
1182 {
1183         if (DIFF_FILE_VALID(one)) {
1184                 if (!one->sha1_valid) {
1185                         struct stat st;
1186                         if (lstat(one->path, &st) < 0)
1187                                 die("stat %s", one->path);
1188                         if (index_path(one->sha1, one->path, &st, 0))
1189                                 die("cannot hash %s\n", one->path);
1190                 }
1191         }
1192         else
1193                 memset(one->sha1, 0, 20);
1194 }
1195
1196 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1197 {
1198         const char *pgm = external_diff();
1199         char msg[PATH_MAX*2+300], *xfrm_msg;
1200         struct diff_filespec *one;
1201         struct diff_filespec *two;
1202         const char *name;
1203         const char *other;
1204         char *name_munged, *other_munged;
1205         int complete_rewrite = 0;
1206         int len;
1207
1208         if (DIFF_PAIR_UNMERGED(p)) {
1209                 /* unmerged */
1210                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1211                 return;
1212         }
1213
1214         name = p->one->path;
1215         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1216         name_munged = quote_one(name);
1217         other_munged = quote_one(other);
1218         one = p->one; two = p->two;
1219
1220         diff_fill_sha1_info(one);
1221         diff_fill_sha1_info(two);
1222
1223         len = 0;
1224         switch (p->status) {
1225         case DIFF_STATUS_COPIED:
1226                 len += snprintf(msg + len, sizeof(msg) - len,
1227                                 "similarity index %d%%\n"
1228                                 "copy from %s\n"
1229                                 "copy to %s\n",
1230                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1231                                 name_munged, other_munged);
1232                 break;
1233         case DIFF_STATUS_RENAMED:
1234                 len += snprintf(msg + len, sizeof(msg) - len,
1235                                 "similarity index %d%%\n"
1236                                 "rename from %s\n"
1237                                 "rename to %s\n",
1238                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1239                                 name_munged, other_munged);
1240                 break;
1241         case DIFF_STATUS_MODIFIED:
1242                 if (p->score) {
1243                         len += snprintf(msg + len, sizeof(msg) - len,
1244                                         "dissimilarity index %d%%\n",
1245                                         (int)(0.5 + p->score *
1246                                               100.0/MAX_SCORE));
1247                         complete_rewrite = 1;
1248                         break;
1249                 }
1250                 /* fallthru */
1251         default:
1252                 /* nothing */
1253                 ;
1254         }
1255
1256         if (memcmp(one->sha1, two->sha1, 20)) {
1257                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1258
1259                 len += snprintf(msg + len, sizeof(msg) - len,
1260                                 "index %.*s..%.*s",
1261                                 abbrev, sha1_to_hex(one->sha1),
1262                                 abbrev, sha1_to_hex(two->sha1));
1263                 if (one->mode == two->mode)
1264                         len += snprintf(msg + len, sizeof(msg) - len,
1265                                         " %06o", one->mode);
1266                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
1267         }
1268
1269         if (len)
1270                 msg[--len] = 0;
1271         xfrm_msg = len ? msg : NULL;
1272
1273         if (!pgm &&
1274             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1275             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1276                 /* a filepair that changes between file and symlink
1277                  * needs to be split into deletion and creation.
1278                  */
1279                 struct diff_filespec *null = alloc_filespec(two->path);
1280                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1281                 free(null);
1282                 null = alloc_filespec(one->path);
1283                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1284                 free(null);
1285         }
1286         else
1287                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1288                              complete_rewrite);
1289
1290         free(name_munged);
1291         free(other_munged);
1292 }
1293
1294 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1295                          struct diffstat_t *diffstat)
1296 {
1297         const char *name;
1298         const char *other;
1299         int complete_rewrite = 0;
1300
1301         if (DIFF_PAIR_UNMERGED(p)) {
1302                 /* unmerged */
1303                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
1304                 return;
1305         }
1306
1307         name = p->one->path;
1308         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1309
1310         diff_fill_sha1_info(p->one);
1311         diff_fill_sha1_info(p->two);
1312
1313         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1314                 complete_rewrite = 1;
1315         builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
1316 }
1317
1318 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1319 {
1320         const char *name;
1321         const char *other;
1322
1323         if (DIFF_PAIR_UNMERGED(p)) {
1324                 /* unmerged */
1325                 return;
1326         }
1327
1328         name = p->one->path;
1329         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1330
1331         diff_fill_sha1_info(p->one);
1332         diff_fill_sha1_info(p->two);
1333
1334         builtin_checkdiff(name, other, p->one, p->two);
1335 }
1336
1337 void diff_setup(struct diff_options *options)
1338 {
1339         memset(options, 0, sizeof(*options));
1340         options->output_format = DIFF_FORMAT_RAW;
1341         options->line_termination = '\n';
1342         options->break_opt = -1;
1343         options->rename_limit = -1;
1344         options->context = 3;
1345
1346         options->change = diff_change;
1347         options->add_remove = diff_addremove;
1348 }
1349
1350 int diff_setup_done(struct diff_options *options)
1351 {
1352         if ((options->find_copies_harder &&
1353              options->detect_rename != DIFF_DETECT_COPY) ||
1354             (0 <= options->rename_limit && !options->detect_rename))
1355                 return -1;
1356
1357         /*
1358          * These cases always need recursive; we do not drop caller-supplied
1359          * recursive bits for other formats here.
1360          */
1361         if ((options->output_format == DIFF_FORMAT_PATCH) ||
1362             (options->output_format == DIFF_FORMAT_DIFFSTAT) ||
1363             (options->output_format == DIFF_FORMAT_CHECKDIFF))
1364                 options->recursive = 1;
1365
1366         /*
1367          * These combinations do not make sense.
1368          */
1369         if (options->output_format == DIFF_FORMAT_RAW)
1370                 options->with_raw = 0;
1371         if (options->output_format == DIFF_FORMAT_DIFFSTAT)
1372                 options->with_stat  = 0;
1373
1374         if (options->detect_rename && options->rename_limit < 0)
1375                 options->rename_limit = diff_rename_limit_default;
1376         if (options->setup & DIFF_SETUP_USE_CACHE) {
1377                 if (!active_cache)
1378                         /* read-cache does not die even when it fails
1379                          * so it is safe for us to do this here.  Also
1380                          * it does not smudge active_cache or active_nr
1381                          * when it fails, so we do not have to worry about
1382                          * cleaning it up ourselves either.
1383                          */
1384                         read_cache();
1385         }
1386         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1387                 use_size_cache = 1;
1388         if (options->abbrev <= 0 || 40 < options->abbrev)
1389                 options->abbrev = 40; /* full */
1390
1391         return 0;
1392 }
1393
1394 int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1395 {
1396         char c, *eq;
1397         int len;
1398
1399         if (*arg != '-')
1400                 return 0;
1401         c = *++arg;
1402         if (!c)
1403                 return 0;
1404         if (c == arg_short) {
1405                 c = *++arg;
1406                 if (!c)
1407                         return 1;
1408                 if (val && isdigit(c)) {
1409                         char *end;
1410                         int n = strtoul(arg, &end, 10);
1411                         if (*end)
1412                                 return 0;
1413                         *val = n;
1414                         return 1;
1415                 }
1416                 return 0;
1417         }
1418         if (c != '-')
1419                 return 0;
1420         arg++;
1421         eq = strchr(arg, '=');
1422         if (eq)
1423                 len = eq - arg;
1424         else
1425                 len = strlen(arg);
1426         if (!len || strncmp(arg, arg_long, len))
1427                 return 0;
1428         if (eq) {
1429                 int n;
1430                 char *end;
1431                 if (!isdigit(*++eq))
1432                         return 0;
1433                 n = strtoul(eq, &end, 10);
1434                 if (*end)
1435                         return 0;
1436                 *val = n;
1437         }
1438         return 1;
1439 }
1440
1441 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1442 {
1443         const char *arg = av[0];
1444         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1445                 options->output_format = DIFF_FORMAT_PATCH;
1446         else if (opt_arg(arg, 'U', "unified", &options->context))
1447                 options->output_format = DIFF_FORMAT_PATCH;
1448         else if (!strcmp(arg, "--patch-with-raw")) {
1449                 options->output_format = DIFF_FORMAT_PATCH;
1450                 options->with_raw = 1;
1451         }
1452         else if (!strcmp(arg, "--stat"))
1453                 options->output_format = DIFF_FORMAT_DIFFSTAT;
1454         else if (!strcmp(arg, "--check"))
1455                 options->output_format = DIFF_FORMAT_CHECKDIFF;
1456         else if (!strcmp(arg, "--summary"))
1457                 options->summary = 1;
1458         else if (!strcmp(arg, "--patch-with-stat")) {
1459                 options->output_format = DIFF_FORMAT_PATCH;
1460                 options->with_stat = 1;
1461         }
1462         else if (!strcmp(arg, "-z"))
1463                 options->line_termination = 0;
1464         else if (!strncmp(arg, "-l", 2))
1465                 options->rename_limit = strtoul(arg+2, NULL, 10);
1466         else if (!strcmp(arg, "--full-index"))
1467                 options->full_index = 1;
1468         else if (!strcmp(arg, "--binary")) {
1469                 options->output_format = DIFF_FORMAT_PATCH;
1470                 options->full_index = options->binary = 1;
1471         }
1472         else if (!strcmp(arg, "--name-only"))
1473                 options->output_format = DIFF_FORMAT_NAME;
1474         else if (!strcmp(arg, "--name-status"))
1475                 options->output_format = DIFF_FORMAT_NAME_STATUS;
1476         else if (!strcmp(arg, "-R"))
1477                 options->reverse_diff = 1;
1478         else if (!strncmp(arg, "-S", 2))
1479                 options->pickaxe = arg + 2;
1480         else if (!strcmp(arg, "-s"))
1481                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
1482         else if (!strncmp(arg, "-O", 2))
1483                 options->orderfile = arg + 2;
1484         else if (!strncmp(arg, "--diff-filter=", 14))
1485                 options->filter = arg + 14;
1486         else if (!strcmp(arg, "--pickaxe-all"))
1487                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
1488         else if (!strcmp(arg, "--pickaxe-regex"))
1489                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1490         else if (!strncmp(arg, "-B", 2)) {
1491                 if ((options->break_opt =
1492                      diff_scoreopt_parse(arg)) == -1)
1493                         return -1;
1494         }
1495         else if (!strncmp(arg, "-M", 2)) {
1496                 if ((options->rename_score =
1497                      diff_scoreopt_parse(arg)) == -1)
1498                         return -1;
1499                 options->detect_rename = DIFF_DETECT_RENAME;
1500         }
1501         else if (!strncmp(arg, "-C", 2)) {
1502                 if ((options->rename_score =
1503                      diff_scoreopt_parse(arg)) == -1)
1504                         return -1;
1505                 options->detect_rename = DIFF_DETECT_COPY;
1506         }
1507         else if (!strcmp(arg, "--find-copies-harder"))
1508                 options->find_copies_harder = 1;
1509         else if (!strcmp(arg, "--abbrev"))
1510                 options->abbrev = DEFAULT_ABBREV;
1511         else if (!strncmp(arg, "--abbrev=", 9)) {
1512                 options->abbrev = strtoul(arg + 9, NULL, 10);
1513                 if (options->abbrev < MINIMUM_ABBREV)
1514                         options->abbrev = MINIMUM_ABBREV;
1515                 else if (40 < options->abbrev)
1516                         options->abbrev = 40;
1517         }
1518         else if (!strcmp(arg, "--color"))
1519                 options->color_diff = 1;
1520         else
1521                 return 0;
1522         return 1;
1523 }
1524
1525 static int parse_num(const char **cp_p)
1526 {
1527         unsigned long num, scale;
1528         int ch, dot;
1529         const char *cp = *cp_p;
1530
1531         num = 0;
1532         scale = 1;
1533         dot = 0;
1534         for(;;) {
1535                 ch = *cp;
1536                 if ( !dot && ch == '.' ) {
1537                         scale = 1;
1538                         dot = 1;
1539                 } else if ( ch == '%' ) {
1540                         scale = dot ? scale*100 : 100;
1541                         cp++;   /* % is always at the end */
1542                         break;
1543                 } else if ( ch >= '0' && ch <= '9' ) {
1544                         if ( scale < 100000 ) {
1545                                 scale *= 10;
1546                                 num = (num*10) + (ch-'0');
1547                         }
1548                 } else {
1549                         break;
1550                 }
1551                 cp++;
1552         }
1553         *cp_p = cp;
1554
1555         /* user says num divided by scale and we say internally that
1556          * is MAX_SCORE * num / scale.
1557          */
1558         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1559 }
1560
1561 int diff_scoreopt_parse(const char *opt)
1562 {
1563         int opt1, opt2, cmd;
1564
1565         if (*opt++ != '-')
1566                 return -1;
1567         cmd = *opt++;
1568         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1569                 return -1; /* that is not a -M, -C nor -B option */
1570
1571         opt1 = parse_num(&opt);
1572         if (cmd != 'B')
1573                 opt2 = 0;
1574         else {
1575                 if (*opt == 0)
1576                         opt2 = 0;
1577                 else if (*opt != '/')
1578                         return -1; /* we expect -B80/99 or -B80 */
1579                 else {
1580                         opt++;
1581                         opt2 = parse_num(&opt);
1582                 }
1583         }
1584         if (*opt != 0)
1585                 return -1;
1586         return opt1 | (opt2 << 16);
1587 }
1588
1589 struct diff_queue_struct diff_queued_diff;
1590
1591 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1592 {
1593         if (queue->alloc <= queue->nr) {
1594                 queue->alloc = alloc_nr(queue->alloc);
1595                 queue->queue = xrealloc(queue->queue,
1596                                         sizeof(dp) * queue->alloc);
1597         }
1598         queue->queue[queue->nr++] = dp;
1599 }
1600
1601 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1602                                  struct diff_filespec *one,
1603                                  struct diff_filespec *two)
1604 {
1605         struct diff_filepair *dp = xmalloc(sizeof(*dp));
1606         dp->one = one;
1607         dp->two = two;
1608         dp->score = 0;
1609         dp->status = 0;
1610         dp->source_stays = 0;
1611         dp->broken_pair = 0;
1612         if (queue)
1613                 diff_q(queue, dp);
1614         return dp;
1615 }
1616
1617 void diff_free_filepair(struct diff_filepair *p)
1618 {
1619         diff_free_filespec_data(p->one);
1620         diff_free_filespec_data(p->two);
1621         free(p->one);
1622         free(p->two);
1623         free(p);
1624 }
1625
1626 /* This is different from find_unique_abbrev() in that
1627  * it stuffs the result with dots for alignment.
1628  */
1629 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1630 {
1631         int abblen;
1632         const char *abbrev;
1633         if (len == 40)
1634                 return sha1_to_hex(sha1);
1635
1636         abbrev = find_unique_abbrev(sha1, len);
1637         if (!abbrev)
1638                 return sha1_to_hex(sha1);
1639         abblen = strlen(abbrev);
1640         if (abblen < 37) {
1641                 static char hex[41];
1642                 if (len < abblen && abblen <= len + 2)
1643                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1644                 else
1645                         sprintf(hex, "%s...", abbrev);
1646                 return hex;
1647         }
1648         return sha1_to_hex(sha1);
1649 }
1650
1651 static void diff_flush_raw(struct diff_filepair *p,
1652                            int line_termination,
1653                            int inter_name_termination,
1654                            struct diff_options *options,
1655                            int output_format)
1656 {
1657         int two_paths;
1658         char status[10];
1659         int abbrev = options->abbrev;
1660         const char *path_one, *path_two;
1661
1662         path_one = p->one->path;
1663         path_two = p->two->path;
1664         if (line_termination) {
1665                 path_one = quote_one(path_one);
1666                 path_two = quote_one(path_two);
1667         }
1668
1669         if (p->score)
1670                 sprintf(status, "%c%03d", p->status,
1671                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
1672         else {
1673                 status[0] = p->status;
1674                 status[1] = 0;
1675         }
1676         switch (p->status) {
1677         case DIFF_STATUS_COPIED:
1678         case DIFF_STATUS_RENAMED:
1679                 two_paths = 1;
1680                 break;
1681         case DIFF_STATUS_ADDED:
1682         case DIFF_STATUS_DELETED:
1683                 two_paths = 0;
1684                 break;
1685         default:
1686                 two_paths = 0;
1687                 break;
1688         }
1689         if (output_format != DIFF_FORMAT_NAME_STATUS) {
1690                 printf(":%06o %06o %s ",
1691                        p->one->mode, p->two->mode,
1692                        diff_unique_abbrev(p->one->sha1, abbrev));
1693                 printf("%s ",
1694                        diff_unique_abbrev(p->two->sha1, abbrev));
1695         }
1696         printf("%s%c%s", status, inter_name_termination, path_one);
1697         if (two_paths)
1698                 printf("%c%s", inter_name_termination, path_two);
1699         putchar(line_termination);
1700         if (path_one != p->one->path)
1701                 free((void*)path_one);
1702         if (path_two != p->two->path)
1703                 free((void*)path_two);
1704 }
1705
1706 static void diff_flush_name(struct diff_filepair *p,
1707                             int inter_name_termination,
1708                             int line_termination)
1709 {
1710         char *path = p->two->path;
1711
1712         if (line_termination)
1713                 path = quote_one(p->two->path);
1714         else
1715                 path = p->two->path;
1716         printf("%s%c", path, line_termination);
1717         if (p->two->path != path)
1718                 free(path);
1719 }
1720
1721 int diff_unmodified_pair(struct diff_filepair *p)
1722 {
1723         /* This function is written stricter than necessary to support
1724          * the currently implemented transformers, but the idea is to
1725          * let transformers to produce diff_filepairs any way they want,
1726          * and filter and clean them up here before producing the output.
1727          */
1728         struct diff_filespec *one, *two;
1729
1730         if (DIFF_PAIR_UNMERGED(p))
1731                 return 0; /* unmerged is interesting */
1732
1733         one = p->one;
1734         two = p->two;
1735
1736         /* deletion, addition, mode or type change
1737          * and rename are all interesting.
1738          */
1739         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1740             DIFF_PAIR_MODE_CHANGED(p) ||
1741             strcmp(one->path, two->path))
1742                 return 0;
1743
1744         /* both are valid and point at the same path.  that is, we are
1745          * dealing with a change.
1746          */
1747         if (one->sha1_valid && two->sha1_valid &&
1748             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1749                 return 1; /* no change */
1750         if (!one->sha1_valid && !two->sha1_valid)
1751                 return 1; /* both look at the same file on the filesystem. */
1752         return 0;
1753 }
1754
1755 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1756 {
1757         if (diff_unmodified_pair(p))
1758                 return;
1759
1760         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1761             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1762                 return; /* no tree diffs in patch format */
1763
1764         run_diff(p, o);
1765 }
1766
1767 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1768                             struct diffstat_t *diffstat)
1769 {
1770         if (diff_unmodified_pair(p))
1771                 return;
1772
1773         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1774             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1775                 return; /* no tree diffs in patch format */
1776
1777         run_diffstat(p, o, diffstat);
1778 }
1779
1780 static void diff_flush_checkdiff(struct diff_filepair *p,
1781                 struct diff_options *o)
1782 {
1783         if (diff_unmodified_pair(p))
1784                 return;
1785
1786         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1787             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1788                 return; /* no tree diffs in patch format */
1789
1790         run_checkdiff(p, o);
1791 }
1792
1793 int diff_queue_is_empty(void)
1794 {
1795         struct diff_queue_struct *q = &diff_queued_diff;
1796         int i;
1797         for (i = 0; i < q->nr; i++)
1798                 if (!diff_unmodified_pair(q->queue[i]))
1799                         return 0;
1800         return 1;
1801 }
1802
1803 #if DIFF_DEBUG
1804 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1805 {
1806         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1807                 x, one ? one : "",
1808                 s->path,
1809                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1810                 s->mode,
1811                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1812         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1813                 x, one ? one : "",
1814                 s->size, s->xfrm_flags);
1815 }
1816
1817 void diff_debug_filepair(const struct diff_filepair *p, int i)
1818 {
1819         diff_debug_filespec(p->one, i, "one");
1820         diff_debug_filespec(p->two, i, "two");
1821         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1822                 p->score, p->status ? p->status : '?',
1823                 p->source_stays, p->broken_pair);
1824 }
1825
1826 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1827 {
1828         int i;
1829         if (msg)
1830                 fprintf(stderr, "%s\n", msg);
1831         fprintf(stderr, "q->nr = %d\n", q->nr);
1832         for (i = 0; i < q->nr; i++) {
1833                 struct diff_filepair *p = q->queue[i];
1834                 diff_debug_filepair(p, i);
1835         }
1836 }
1837 #endif
1838
1839 static void diff_resolve_rename_copy(void)
1840 {
1841         int i, j;
1842         struct diff_filepair *p, *pp;
1843         struct diff_queue_struct *q = &diff_queued_diff;
1844
1845         diff_debug_queue("resolve-rename-copy", q);
1846
1847         for (i = 0; i < q->nr; i++) {
1848                 p = q->queue[i];
1849                 p->status = 0; /* undecided */
1850                 if (DIFF_PAIR_UNMERGED(p))
1851                         p->status = DIFF_STATUS_UNMERGED;
1852                 else if (!DIFF_FILE_VALID(p->one))
1853                         p->status = DIFF_STATUS_ADDED;
1854                 else if (!DIFF_FILE_VALID(p->two))
1855                         p->status = DIFF_STATUS_DELETED;
1856                 else if (DIFF_PAIR_TYPE_CHANGED(p))
1857                         p->status = DIFF_STATUS_TYPE_CHANGED;
1858
1859                 /* from this point on, we are dealing with a pair
1860                  * whose both sides are valid and of the same type, i.e.
1861                  * either in-place edit or rename/copy edit.
1862                  */
1863                 else if (DIFF_PAIR_RENAME(p)) {
1864                         if (p->source_stays) {
1865                                 p->status = DIFF_STATUS_COPIED;
1866                                 continue;
1867                         }
1868                         /* See if there is some other filepair that
1869                          * copies from the same source as us.  If so
1870                          * we are a copy.  Otherwise we are either a
1871                          * copy if the path stays, or a rename if it
1872                          * does not, but we already handled "stays" case.
1873                          */
1874                         for (j = i + 1; j < q->nr; j++) {
1875                                 pp = q->queue[j];
1876                                 if (strcmp(pp->one->path, p->one->path))
1877                                         continue; /* not us */
1878                                 if (!DIFF_PAIR_RENAME(pp))
1879                                         continue; /* not a rename/copy */
1880                                 /* pp is a rename/copy from the same source */
1881                                 p->status = DIFF_STATUS_COPIED;
1882                                 break;
1883                         }
1884                         if (!p->status)
1885                                 p->status = DIFF_STATUS_RENAMED;
1886                 }
1887                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1888                          p->one->mode != p->two->mode)
1889                         p->status = DIFF_STATUS_MODIFIED;
1890                 else {
1891                         /* This is a "no-change" entry and should not
1892                          * happen anymore, but prepare for broken callers.
1893                          */
1894                         error("feeding unmodified %s to diffcore",
1895                               p->one->path);
1896                         p->status = DIFF_STATUS_UNKNOWN;
1897                 }
1898         }
1899         diff_debug_queue("resolve-rename-copy done", q);
1900 }
1901
1902 static void flush_one_pair(struct diff_filepair *p,
1903                            int diff_output_format,
1904                            struct diff_options *options,
1905                            struct diffstat_t *diffstat)
1906 {
1907         int inter_name_termination = '\t';
1908         int line_termination = options->line_termination;
1909         if (!line_termination)
1910                 inter_name_termination = 0;
1911
1912         switch (p->status) {
1913         case DIFF_STATUS_UNKNOWN:
1914                 break;
1915         case 0:
1916                 die("internal error in diff-resolve-rename-copy");
1917                 break;
1918         default:
1919                 switch (diff_output_format) {
1920                 case DIFF_FORMAT_DIFFSTAT:
1921                         diff_flush_stat(p, options, diffstat);
1922                         break;
1923                 case DIFF_FORMAT_CHECKDIFF:
1924                         diff_flush_checkdiff(p, options);
1925                         break;
1926                 case DIFF_FORMAT_PATCH:
1927                         diff_flush_patch(p, options);
1928                         break;
1929                 case DIFF_FORMAT_RAW:
1930                 case DIFF_FORMAT_NAME_STATUS:
1931                         diff_flush_raw(p, line_termination,
1932                                        inter_name_termination,
1933                                        options, diff_output_format);
1934                         break;
1935                 case DIFF_FORMAT_NAME:
1936                         diff_flush_name(p,
1937                                         inter_name_termination,
1938                                         line_termination);
1939                         break;
1940                 case DIFF_FORMAT_NO_OUTPUT:
1941                         break;
1942                 }
1943         }
1944 }
1945
1946 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
1947 {
1948         if (fs->mode)
1949                 printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
1950         else
1951                 printf(" %s %s\n", newdelete, fs->path);
1952 }
1953
1954
1955 static void show_mode_change(struct diff_filepair *p, int show_name)
1956 {
1957         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
1958                 if (show_name)
1959                         printf(" mode change %06o => %06o %s\n",
1960                                p->one->mode, p->two->mode, p->two->path);
1961                 else
1962                         printf(" mode change %06o => %06o\n",
1963                                p->one->mode, p->two->mode);
1964         }
1965 }
1966
1967 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
1968 {
1969         const char *old, *new;
1970
1971         /* Find common prefix */
1972         old = p->one->path;
1973         new = p->two->path;
1974         while (1) {
1975                 const char *slash_old, *slash_new;
1976                 slash_old = strchr(old, '/');
1977                 slash_new = strchr(new, '/');
1978                 if (!slash_old ||
1979                     !slash_new ||
1980                     slash_old - old != slash_new - new ||
1981                     memcmp(old, new, slash_new - new))
1982                         break;
1983                 old = slash_old + 1;
1984                 new = slash_new + 1;
1985         }
1986         /* p->one->path thru old is the common prefix, and old and new
1987          * through the end of names are renames
1988          */
1989         if (old != p->one->path)
1990                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1991                        (int)(old - p->one->path), p->one->path,
1992                        old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
1993         else
1994                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1995                        p->one->path, p->two->path,
1996                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1997         show_mode_change(p, 0);
1998 }
1999
2000 static void diff_summary(struct diff_filepair *p)
2001 {
2002         switch(p->status) {
2003         case DIFF_STATUS_DELETED:
2004                 show_file_mode_name("delete", p->one);
2005                 break;
2006         case DIFF_STATUS_ADDED:
2007                 show_file_mode_name("create", p->two);
2008                 break;
2009         case DIFF_STATUS_COPIED:
2010                 show_rename_copy("copy", p);
2011                 break;
2012         case DIFF_STATUS_RENAMED:
2013                 show_rename_copy("rename", p);
2014                 break;
2015         default:
2016                 if (p->score) {
2017                         printf(" rewrite %s (%d%%)\n", p->two->path,
2018                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
2019                         show_mode_change(p, 0);
2020                 } else  show_mode_change(p, 1);
2021                 break;
2022         }
2023 }
2024
2025 void diff_flush(struct diff_options *options)
2026 {
2027         struct diff_queue_struct *q = &diff_queued_diff;
2028         int i;
2029         int diff_output_format = options->output_format;
2030         struct diffstat_t *diffstat = NULL;
2031
2032         if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
2033                 diffstat = xcalloc(sizeof (struct diffstat_t), 1);
2034                 diffstat->xm.consume = diffstat_consume;
2035         }
2036
2037         if (options->with_raw) {
2038                 for (i = 0; i < q->nr; i++) {
2039                         struct diff_filepair *p = q->queue[i];
2040                         flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
2041                 }
2042                 putchar(options->line_termination);
2043         }
2044         if (options->with_stat) {
2045                 for (i = 0; i < q->nr; i++) {
2046                         struct diff_filepair *p = q->queue[i];
2047                         flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
2048                                        diffstat);
2049                 }
2050                 show_stats(diffstat);
2051                 free(diffstat);
2052                 diffstat = NULL;
2053                 if (options->summary)
2054                         for (i = 0; i < q->nr; i++)
2055                                 diff_summary(q->queue[i]);
2056                 if (options->stat_sep)
2057                         fputs(options->stat_sep, stdout);
2058                 else
2059                         putchar(options->line_termination);
2060         }
2061         for (i = 0; i < q->nr; i++) {
2062                 struct diff_filepair *p = q->queue[i];
2063                 flush_one_pair(p, diff_output_format, options, diffstat);
2064         }
2065
2066         if (diffstat) {
2067                 show_stats(diffstat);
2068                 free(diffstat);
2069         }
2070
2071         for (i = 0; i < q->nr; i++) {
2072                 if (diffstat && options->summary)
2073                         diff_summary(q->queue[i]);
2074                 diff_free_filepair(q->queue[i]);
2075         }
2076
2077         free(q->queue);
2078         q->queue = NULL;
2079         q->nr = q->alloc = 0;
2080 }
2081
2082 static void diffcore_apply_filter(const char *filter)
2083 {
2084         int i;
2085         struct diff_queue_struct *q = &diff_queued_diff;
2086         struct diff_queue_struct outq;
2087         outq.queue = NULL;
2088         outq.nr = outq.alloc = 0;
2089
2090         if (!filter)
2091                 return;
2092
2093         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2094                 int found;
2095                 for (i = found = 0; !found && i < q->nr; i++) {
2096                         struct diff_filepair *p = q->queue[i];
2097                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2098                              ((p->score &&
2099                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2100                               (!p->score &&
2101                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2102                             ((p->status != DIFF_STATUS_MODIFIED) &&
2103                              strchr(filter, p->status)))
2104                                 found++;
2105                 }
2106                 if (found)
2107                         return;
2108
2109                 /* otherwise we will clear the whole queue
2110                  * by copying the empty outq at the end of this
2111                  * function, but first clear the current entries
2112                  * in the queue.
2113                  */
2114                 for (i = 0; i < q->nr; i++)
2115                         diff_free_filepair(q->queue[i]);
2116         }
2117         else {
2118                 /* Only the matching ones */
2119                 for (i = 0; i < q->nr; i++) {
2120                         struct diff_filepair *p = q->queue[i];
2121
2122                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2123                              ((p->score &&
2124                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2125                               (!p->score &&
2126                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2127                             ((p->status != DIFF_STATUS_MODIFIED) &&
2128                              strchr(filter, p->status)))
2129                                 diff_q(&outq, p);
2130                         else
2131                                 diff_free_filepair(p);
2132                 }
2133         }
2134         free(q->queue);
2135         *q = outq;
2136 }
2137
2138 void diffcore_std(struct diff_options *options)
2139 {
2140         if (options->break_opt != -1)
2141                 diffcore_break(options->break_opt);
2142         if (options->detect_rename)
2143                 diffcore_rename(options);
2144         if (options->break_opt != -1)
2145                 diffcore_merge_broken();
2146         if (options->pickaxe)
2147                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2148         if (options->orderfile)
2149                 diffcore_order(options->orderfile);
2150         diff_resolve_rename_copy();
2151         diffcore_apply_filter(options->filter);
2152 }
2153
2154
2155 void diffcore_std_no_resolve(struct diff_options *options)
2156 {
2157         if (options->pickaxe)
2158                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2159         if (options->orderfile)
2160                 diffcore_order(options->orderfile);
2161         diffcore_apply_filter(options->filter);
2162 }
2163
2164 void diff_addremove(struct diff_options *options,
2165                     int addremove, unsigned mode,
2166                     const unsigned char *sha1,
2167                     const char *base, const char *path)
2168 {
2169         char concatpath[PATH_MAX];
2170         struct diff_filespec *one, *two;
2171
2172         /* This may look odd, but it is a preparation for
2173          * feeding "there are unchanged files which should
2174          * not produce diffs, but when you are doing copy
2175          * detection you would need them, so here they are"
2176          * entries to the diff-core.  They will be prefixed
2177          * with something like '=' or '*' (I haven't decided
2178          * which but should not make any difference).
2179          * Feeding the same new and old to diff_change()
2180          * also has the same effect.
2181          * Before the final output happens, they are pruned after
2182          * merged into rename/copy pairs as appropriate.
2183          */
2184         if (options->reverse_diff)
2185                 addremove = (addremove == '+' ? '-' :
2186                              addremove == '-' ? '+' : addremove);
2187
2188         if (!path) path = "";
2189         sprintf(concatpath, "%s%s", base, path);
2190         one = alloc_filespec(concatpath);
2191         two = alloc_filespec(concatpath);
2192
2193         if (addremove != '+')
2194                 fill_filespec(one, sha1, mode);
2195         if (addremove != '-')
2196                 fill_filespec(two, sha1, mode);
2197
2198         diff_queue(&diff_queued_diff, one, two);
2199 }
2200
2201 void diff_change(struct diff_options *options,
2202                  unsigned old_mode, unsigned new_mode,
2203                  const unsigned char *old_sha1,
2204                  const unsigned char *new_sha1,
2205                  const char *base, const char *path)
2206 {
2207         char concatpath[PATH_MAX];
2208         struct diff_filespec *one, *two;
2209
2210         if (options->reverse_diff) {
2211                 unsigned tmp;
2212                 const unsigned char *tmp_c;
2213                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2214                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2215         }
2216         if (!path) path = "";
2217         sprintf(concatpath, "%s%s", base, path);
2218         one = alloc_filespec(concatpath);
2219         two = alloc_filespec(concatpath);
2220         fill_filespec(one, old_sha1, old_mode);
2221         fill_filespec(two, new_sha1, new_mode);
2222
2223         diff_queue(&diff_queued_diff, one, two);
2224 }
2225
2226 void diff_unmerge(struct diff_options *options,
2227                   const char *path)
2228 {
2229         struct diff_filespec *one, *two;
2230         one = alloc_filespec(path);
2231         two = alloc_filespec(path);
2232         diff_queue(&diff_queued_diff, one, two);
2233 }