diff.con commit Merge branch 'jc/cache-tree' into next (fbc0f28)
   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 "xdiff-interface.h"
  12
  13static int use_size_cache;
  14
  15int diff_rename_limit_default = -1;
  16
  17int git_diff_config(const char *var, const char *value)
  18{
  19        if (!strcmp(var, "diff.renamelimit")) {
  20                diff_rename_limit_default = git_config_int(var, value);
  21                return 0;
  22        }
  23
  24        return git_default_config(var, value);
  25}
  26
  27static char *quote_one(const char *str)
  28{
  29        int needlen;
  30        char *xp;
  31
  32        if (!str)
  33                return NULL;
  34        needlen = quote_c_style(str, NULL, NULL, 0);
  35        if (!needlen)
  36                return strdup(str);
  37        xp = xmalloc(needlen + 1);
  38        quote_c_style(str, xp, NULL, 0);
  39        return xp;
  40}
  41
  42static char *quote_two(const char *one, const char *two)
  43{
  44        int need_one = quote_c_style(one, NULL, NULL, 1);
  45        int need_two = quote_c_style(two, NULL, NULL, 1);
  46        char *xp;
  47
  48        if (need_one + need_two) {
  49                if (!need_one) need_one = strlen(one);
  50                if (!need_two) need_one = strlen(two);
  51
  52                xp = xmalloc(need_one + need_two + 3);
  53                xp[0] = '"';
  54                quote_c_style(one, xp + 1, NULL, 1);
  55                quote_c_style(two, xp + need_one + 1, NULL, 1);
  56                strcpy(xp + need_one + need_two + 1, "\"");
  57                return xp;
  58        }
  59        need_one = strlen(one);
  60        need_two = strlen(two);
  61        xp = xmalloc(need_one + need_two + 1);
  62        strcpy(xp, one);
  63        strcpy(xp + need_one, two);
  64        return xp;
  65}
  66
  67static const char *external_diff(void)
  68{
  69        static const char *external_diff_cmd = NULL;
  70        static int done_preparing = 0;
  71
  72        if (done_preparing)
  73                return external_diff_cmd;
  74        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
  75        done_preparing = 1;
  76        return external_diff_cmd;
  77}
  78
  79#define TEMPFILE_PATH_LEN               50
  80
  81static struct diff_tempfile {
  82        const char *name; /* filename external diff should read from */
  83        char hex[41];
  84        char mode[10];
  85        char tmp_path[TEMPFILE_PATH_LEN];
  86} diff_temp[2];
  87
  88static int count_lines(const char *data, int size)
  89{
  90        int count, ch, completely_empty = 1, nl_just_seen = 0;
  91        count = 0;
  92        while (0 < size--) {
  93                ch = *data++;
  94                if (ch == '\n') {
  95                        count++;
  96                        nl_just_seen = 1;
  97                        completely_empty = 0;
  98                }
  99                else {
 100                        nl_just_seen = 0;
 101                        completely_empty = 0;
 102                }
 103        }
 104        if (completely_empty)
 105                return 0;
 106        if (!nl_just_seen)
 107                count++; /* no trailing newline */
 108        return count;
 109}
 110
 111static void print_line_count(int count)
 112{
 113        switch (count) {
 114        case 0:
 115                printf("0,0");
 116                break;
 117        case 1:
 118                printf("1");
 119                break;
 120        default:
 121                printf("1,%d", count);
 122                break;
 123        }
 124}
 125
 126static void copy_file(int prefix, const char *data, int size)
 127{
 128        int ch, nl_just_seen = 1;
 129        while (0 < size--) {
 130                ch = *data++;
 131                if (nl_just_seen)
 132                        putchar(prefix);
 133                putchar(ch);
 134                if (ch == '\n')
 135                        nl_just_seen = 1;
 136                else
 137                        nl_just_seen = 0;
 138        }
 139        if (!nl_just_seen)
 140                printf("\n\\ No newline at end of file\n");
 141}
 142
 143static void emit_rewrite_diff(const char *name_a,
 144                              const char *name_b,
 145                              struct diff_filespec *one,
 146                              struct diff_filespec *two)
 147{
 148        int lc_a, lc_b;
 149        diff_populate_filespec(one, 0);
 150        diff_populate_filespec(two, 0);
 151        lc_a = count_lines(one->data, one->size);
 152        lc_b = count_lines(two->data, two->size);
 153        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 154        print_line_count(lc_a);
 155        printf(" +");
 156        print_line_count(lc_b);
 157        printf(" @@\n");
 158        if (lc_a)
 159                copy_file('-', one->data, one->size);
 160        if (lc_b)
 161                copy_file('+', two->data, two->size);
 162}
 163
 164static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 165{
 166        if (!DIFF_FILE_VALID(one)) {
 167                mf->ptr = ""; /* does not matter */
 168                mf->size = 0;
 169                return 0;
 170        }
 171        else if (diff_populate_filespec(one, 0))
 172                return -1;
 173        mf->ptr = one->data;
 174        mf->size = one->size;
 175        return 0;
 176}
 177
 178struct emit_callback {
 179        const char **label_path;
 180};
 181
 182static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
 183{
 184        int i;
 185        struct emit_callback *ecbdata = priv;
 186
 187        if (ecbdata->label_path[0]) {
 188                printf("--- %s\n", ecbdata->label_path[0]);
 189                printf("+++ %s\n", ecbdata->label_path[1]);
 190                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 191        }
 192        for (i = 0; i < nbuf; i++)
 193                if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
 194                        return -1;
 195        return 0;
 196}
 197
 198static char *pprint_rename(const char *a, const char *b)
 199{
 200        const char *old = a;
 201        const char *new = b;
 202        char *name = NULL;
 203        int pfx_length, sfx_length;
 204        int len_a = strlen(a);
 205        int len_b = strlen(b);
 206
 207        /* Find common prefix */
 208        pfx_length = 0;
 209        while (*old && *new && *old == *new) {
 210                if (*old == '/')
 211                        pfx_length = old - a + 1;
 212                old++;
 213                new++;
 214        }
 215
 216        /* Find common suffix */
 217        old = a + len_a;
 218        new = b + len_b;
 219        sfx_length = 0;
 220        while (a <= old && b <= new && *old == *new) {
 221                if (*old == '/')
 222                        sfx_length = len_a - (old - a);
 223                old--;
 224                new--;
 225        }
 226
 227        /*
 228         * pfx{mid-a => mid-b}sfx
 229         * {pfx-a => pfx-b}sfx
 230         * pfx{sfx-a => sfx-b}
 231         * name-a => name-b
 232         */
 233        if (pfx_length + sfx_length) {
 234                name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
 235                sprintf(name, "%.*s{%.*s => %.*s}%s",
 236                        pfx_length, a,
 237                        len_a - pfx_length - sfx_length, a + pfx_length,
 238                        len_b - pfx_length - sfx_length, b + pfx_length,
 239                        a + len_a - sfx_length);
 240        }
 241        else {
 242                name = xmalloc(len_a + len_b + 5);
 243                sprintf(name, "%s => %s", a, b);
 244        }
 245        return name;
 246}
 247
 248struct diffstat_t {
 249        struct xdiff_emit_state xm;
 250
 251        int nr;
 252        int alloc;
 253        struct diffstat_file {
 254                char *name;
 255                unsigned is_unmerged:1;
 256                unsigned is_binary:1;
 257                unsigned is_renamed:1;
 258                unsigned int added, deleted;
 259        } **files;
 260};
 261
 262static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 263                                          const char *name_a,
 264                                          const char *name_b)
 265{
 266        struct diffstat_file *x;
 267        x = xcalloc(sizeof (*x), 1);
 268        if (diffstat->nr == diffstat->alloc) {
 269                diffstat->alloc = alloc_nr(diffstat->alloc);
 270                diffstat->files = xrealloc(diffstat->files,
 271                                diffstat->alloc * sizeof(x));
 272        }
 273        diffstat->files[diffstat->nr++] = x;
 274        if (name_b) {
 275                x->name = pprint_rename(name_a, name_b);
 276                x->is_renamed = 1;
 277        }
 278        else
 279                x->name = strdup(name_a);
 280        return x;
 281}
 282
 283static void diffstat_consume(void *priv, char *line, unsigned long len)
 284{
 285        struct diffstat_t *diffstat = priv;
 286        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 287
 288        if (line[0] == '+')
 289                x->added++;
 290        else if (line[0] == '-')
 291                x->deleted++;
 292}
 293
 294static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 295static const char minuses[]= "----------------------------------------------------------------------";
 296
 297static void show_stats(struct diffstat_t* data)
 298{
 299        char *prefix = "";
 300        int i, len, add, del, total, adds = 0, dels = 0;
 301        int max, max_change = 0, max_len = 0;
 302        int total_files = data->nr;
 303
 304        if (data->nr == 0)
 305                return;
 306
 307        for (i = 0; i < data->nr; i++) {
 308                struct diffstat_file *file = data->files[i];
 309
 310                len = strlen(file->name);
 311                if (max_len < len)
 312                        max_len = len;
 313
 314                if (file->is_binary || file->is_unmerged)
 315                        continue;
 316                if (max_change < file->added + file->deleted)
 317                        max_change = file->added + file->deleted;
 318        }
 319
 320        for (i = 0; i < data->nr; i++) {
 321                char *name = data->files[i]->name;
 322                int added = data->files[i]->added;
 323                int deleted = data->files[i]->deleted;
 324
 325                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 326                        char *qname = xmalloc(len + 1);
 327                        quote_c_style(name, qname, NULL, 0);
 328                        free(name);
 329                        data->files[i]->name = name = qname;
 330                }
 331
 332                /*
 333                 * "scale" the filename
 334                 */
 335                len = strlen(name);
 336                max = max_len;
 337                if (max > 50)
 338                        max = 50;
 339                if (len > max) {
 340                        char *slash;
 341                        prefix = "...";
 342                        max -= 3;
 343                        name += len - max;
 344                        slash = strchr(name, '/');
 345                        if (slash)
 346                                name = slash;
 347                }
 348                len = max;
 349
 350                /*
 351                 * scale the add/delete
 352                 */
 353                max = max_change;
 354                if (max + len > 70)
 355                        max = 70 - len;
 356
 357                if (data->files[i]->is_binary) {
 358                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 359                        goto free_diffstat_file;
 360                }
 361                else if (data->files[i]->is_unmerged) {
 362                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 363                        goto free_diffstat_file;
 364                }
 365                else if (!data->files[i]->is_renamed &&
 366                         (added + deleted == 0)) {
 367                        total_files--;
 368                        goto free_diffstat_file;
 369                }
 370
 371                add = added;
 372                del = deleted;
 373                total = add + del;
 374                adds += add;
 375                dels += del;
 376
 377                if (max_change > 0) {
 378                        total = (total * max + max_change / 2) / max_change;
 379                        add = (add * max + max_change / 2) / max_change;
 380                        del = total - add;
 381                }
 382                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 383                                len, name, added + deleted,
 384                                add, pluses, del, minuses);
 385        free_diffstat_file:
 386                free(data->files[i]->name);
 387                free(data->files[i]);
 388        }
 389        free(data->files);
 390        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 391                        total_files, adds, dels);
 392}
 393
 394#define FIRST_FEW_BYTES 8000
 395static int mmfile_is_binary(mmfile_t *mf)
 396{
 397        long sz = mf->size;
 398        if (FIRST_FEW_BYTES < sz)
 399                sz = FIRST_FEW_BYTES;
 400        if (memchr(mf->ptr, 0, sz))
 401                return 1;
 402        return 0;
 403}
 404
 405static void builtin_diff(const char *name_a,
 406                         const char *name_b,
 407                         struct diff_filespec *one,
 408                         struct diff_filespec *two,
 409                         const char *xfrm_msg,
 410                         int complete_rewrite)
 411{
 412        mmfile_t mf1, mf2;
 413        const char *lbl[2];
 414        char *a_one, *b_two;
 415
 416        a_one = quote_two("a/", name_a);
 417        b_two = quote_two("b/", name_b);
 418        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 419        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 420        printf("diff --git %s %s\n", a_one, b_two);
 421        if (lbl[0][0] == '/') {
 422                /* /dev/null */
 423                printf("new file mode %06o\n", two->mode);
 424                if (xfrm_msg && xfrm_msg[0])
 425                        puts(xfrm_msg);
 426        }
 427        else if (lbl[1][0] == '/') {
 428                printf("deleted file mode %06o\n", one->mode);
 429                if (xfrm_msg && xfrm_msg[0])
 430                        puts(xfrm_msg);
 431        }
 432        else {
 433                if (one->mode != two->mode) {
 434                        printf("old mode %06o\n", one->mode);
 435                        printf("new mode %06o\n", two->mode);
 436                }
 437                if (xfrm_msg && xfrm_msg[0])
 438                        puts(xfrm_msg);
 439                /*
 440                 * we do not run diff between different kind
 441                 * of objects.
 442                 */
 443                if ((one->mode ^ two->mode) & S_IFMT)
 444                        goto free_ab_and_return;
 445                if (complete_rewrite) {
 446                        emit_rewrite_diff(name_a, name_b, one, two);
 447                        goto free_ab_and_return;
 448                }
 449        }
 450
 451        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 452                die("unable to read files to diff");
 453
 454        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 455                printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
 456        else {
 457                /* Crazy xdl interfaces.. */
 458                const char *diffopts = getenv("GIT_DIFF_OPTS");
 459                xpparam_t xpp;
 460                xdemitconf_t xecfg;
 461                xdemitcb_t ecb;
 462                struct emit_callback ecbdata;
 463
 464                ecbdata.label_path = lbl;
 465                xpp.flags = XDF_NEED_MINIMAL;
 466                xecfg.ctxlen = 3;
 467                xecfg.flags = XDL_EMIT_FUNCNAMES;
 468                if (!diffopts)
 469                        ;
 470                else if (!strncmp(diffopts, "--unified=", 10))
 471                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 472                else if (!strncmp(diffopts, "-u", 2))
 473                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 474                ecb.outf = fn_out;
 475                ecb.priv = &ecbdata;
 476                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 477        }
 478
 479 free_ab_and_return:
 480        free(a_one);
 481        free(b_two);
 482        return;
 483}
 484
 485static void builtin_diffstat(const char *name_a, const char *name_b,
 486                             struct diff_filespec *one,
 487                             struct diff_filespec *two,
 488                             struct diffstat_t *diffstat,
 489                             int complete_rewrite)
 490{
 491        mmfile_t mf1, mf2;
 492        struct diffstat_file *data;
 493
 494        data = diffstat_add(diffstat, name_a, name_b);
 495
 496        if (!one || !two) {
 497                data->is_unmerged = 1;
 498                return;
 499        }
 500        if (complete_rewrite) {
 501                diff_populate_filespec(one, 0);
 502                diff_populate_filespec(two, 0);
 503                data->deleted = count_lines(one->data, one->size);
 504                data->added = count_lines(two->data, two->size);
 505                return;
 506        }
 507        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 508                die("unable to read files to diff");
 509
 510        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 511                data->is_binary = 1;
 512        else {
 513                /* Crazy xdl interfaces.. */
 514                xpparam_t xpp;
 515                xdemitconf_t xecfg;
 516                xdemitcb_t ecb;
 517
 518                xpp.flags = XDF_NEED_MINIMAL;
 519                xecfg.ctxlen = 0;
 520                xecfg.flags = 0;
 521                ecb.outf = xdiff_outf;
 522                ecb.priv = diffstat;
 523                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 524        }
 525}
 526
 527struct diff_filespec *alloc_filespec(const char *path)
 528{
 529        int namelen = strlen(path);
 530        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 531
 532        memset(spec, 0, sizeof(*spec));
 533        spec->path = (char *)(spec + 1);
 534        memcpy(spec->path, path, namelen+1);
 535        return spec;
 536}
 537
 538void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 539                   unsigned short mode)
 540{
 541        if (mode) {
 542                spec->mode = canon_mode(mode);
 543                memcpy(spec->sha1, sha1, 20);
 544                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 545        }
 546}
 547
 548/*
 549 * Given a name and sha1 pair, if the dircache tells us the file in
 550 * the work tree has that object contents, return true, so that
 551 * prepare_temp_file() does not have to inflate and extract.
 552 */
 553static int work_tree_matches(const char *name, const unsigned char *sha1)
 554{
 555        struct cache_entry *ce;
 556        struct stat st;
 557        int pos, len;
 558
 559        /* We do not read the cache ourselves here, because the
 560         * benchmark with my previous version that always reads cache
 561         * shows that it makes things worse for diff-tree comparing
 562         * two linux-2.6 kernel trees in an already checked out work
 563         * tree.  This is because most diff-tree comparisons deal with
 564         * only a small number of files, while reading the cache is
 565         * expensive for a large project, and its cost outweighs the
 566         * savings we get by not inflating the object to a temporary
 567         * file.  Practically, this code only helps when we are used
 568         * by diff-cache --cached, which does read the cache before
 569         * calling us.
 570         */
 571        if (!active_cache)
 572                return 0;
 573
 574        len = strlen(name);
 575        pos = cache_name_pos(name, len);
 576        if (pos < 0)
 577                return 0;
 578        ce = active_cache[pos];
 579        if ((lstat(name, &st) < 0) ||
 580            !S_ISREG(st.st_mode) || /* careful! */
 581            ce_match_stat(ce, &st, 0) ||
 582            memcmp(sha1, ce->sha1, 20))
 583                return 0;
 584        /* we return 1 only when we can stat, it is a regular file,
 585         * stat information matches, and sha1 recorded in the cache
 586         * matches.  I.e. we know the file in the work tree really is
 587         * the same as the <name, sha1> pair.
 588         */
 589        return 1;
 590}
 591
 592static struct sha1_size_cache {
 593        unsigned char sha1[20];
 594        unsigned long size;
 595} **sha1_size_cache;
 596static int sha1_size_cache_nr, sha1_size_cache_alloc;
 597
 598static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 599                                                 int find_only,
 600                                                 unsigned long size)
 601{
 602        int first, last;
 603        struct sha1_size_cache *e;
 604
 605        first = 0;
 606        last = sha1_size_cache_nr;
 607        while (last > first) {
 608                int cmp, next = (last + first) >> 1;
 609                e = sha1_size_cache[next];
 610                cmp = memcmp(e->sha1, sha1, 20);
 611                if (!cmp)
 612                        return e;
 613                if (cmp < 0) {
 614                        last = next;
 615                        continue;
 616                }
 617                first = next+1;
 618        }
 619        /* not found */
 620        if (find_only)
 621                return NULL;
 622        /* insert to make it at "first" */
 623        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 624                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 625                sha1_size_cache = xrealloc(sha1_size_cache,
 626                                           sha1_size_cache_alloc *
 627                                           sizeof(*sha1_size_cache));
 628        }
 629        sha1_size_cache_nr++;
 630        if (first < sha1_size_cache_nr)
 631                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 632                        (sha1_size_cache_nr - first - 1) *
 633                        sizeof(*sha1_size_cache));
 634        e = xmalloc(sizeof(struct sha1_size_cache));
 635        sha1_size_cache[first] = e;
 636        memcpy(e->sha1, sha1, 20);
 637        e->size = size;
 638        return e;
 639}
 640
 641/*
 642 * While doing rename detection and pickaxe operation, we may need to
 643 * grab the data for the blob (or file) for our own in-core comparison.
 644 * diff_filespec has data and size fields for this purpose.
 645 */
 646int diff_populate_filespec(struct diff_filespec *s, int size_only)
 647{
 648        int err = 0;
 649        if (!DIFF_FILE_VALID(s))
 650                die("internal error: asking to populate invalid file.");
 651        if (S_ISDIR(s->mode))
 652                return -1;
 653
 654        if (!use_size_cache)
 655                size_only = 0;
 656
 657        if (s->data)
 658                return err;
 659        if (!s->sha1_valid ||
 660            work_tree_matches(s->path, s->sha1)) {
 661                struct stat st;
 662                int fd;
 663                if (lstat(s->path, &st) < 0) {
 664                        if (errno == ENOENT) {
 665                        err_empty:
 666                                err = -1;
 667                        empty:
 668                                s->data = "";
 669                                s->size = 0;
 670                                return err;
 671                        }
 672                }
 673                s->size = st.st_size;
 674                if (!s->size)
 675                        goto empty;
 676                if (size_only)
 677                        return 0;
 678                if (S_ISLNK(st.st_mode)) {
 679                        int ret;
 680                        s->data = xmalloc(s->size);
 681                        s->should_free = 1;
 682                        ret = readlink(s->path, s->data, s->size);
 683                        if (ret < 0) {
 684                                free(s->data);
 685                                goto err_empty;
 686                        }
 687                        return 0;
 688                }
 689                fd = open(s->path, O_RDONLY);
 690                if (fd < 0)
 691                        goto err_empty;
 692                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 693                close(fd);
 694                if (s->data == MAP_FAILED)
 695                        goto err_empty;
 696                s->should_munmap = 1;
 697        }
 698        else {
 699                char type[20];
 700                struct sha1_size_cache *e;
 701
 702                if (size_only) {
 703                        e = locate_size_cache(s->sha1, 1, 0);
 704                        if (e) {
 705                                s->size = e->size;
 706                                return 0;
 707                        }
 708                        if (!sha1_object_info(s->sha1, type, &s->size))
 709                                locate_size_cache(s->sha1, 0, s->size);
 710                }
 711                else {
 712                        s->data = read_sha1_file(s->sha1, type, &s->size);
 713                        s->should_free = 1;
 714                }
 715        }
 716        return 0;
 717}
 718
 719void diff_free_filespec_data(struct diff_filespec *s)
 720{
 721        if (s->should_free)
 722                free(s->data);
 723        else if (s->should_munmap)
 724                munmap(s->data, s->size);
 725        s->should_free = s->should_munmap = 0;
 726        s->data = NULL;
 727        free(s->cnt_data);
 728        s->cnt_data = NULL;
 729}
 730
 731static void prep_temp_blob(struct diff_tempfile *temp,
 732                           void *blob,
 733                           unsigned long size,
 734                           const unsigned char *sha1,
 735                           int mode)
 736{
 737        int fd;
 738
 739        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 740        if (fd < 0)
 741                die("unable to create temp-file");
 742        if (write(fd, blob, size) != size)
 743                die("unable to write temp-file");
 744        close(fd);
 745        temp->name = temp->tmp_path;
 746        strcpy(temp->hex, sha1_to_hex(sha1));
 747        temp->hex[40] = 0;
 748        sprintf(temp->mode, "%06o", mode);
 749}
 750
 751static void prepare_temp_file(const char *name,
 752                              struct diff_tempfile *temp,
 753                              struct diff_filespec *one)
 754{
 755        if (!DIFF_FILE_VALID(one)) {
 756        not_a_valid_file:
 757                /* A '-' entry produces this for file-2, and
 758                 * a '+' entry produces this for file-1.
 759                 */
 760                temp->name = "/dev/null";
 761                strcpy(temp->hex, ".");
 762                strcpy(temp->mode, ".");
 763                return;
 764        }
 765
 766        if (!one->sha1_valid ||
 767            work_tree_matches(name, one->sha1)) {
 768                struct stat st;
 769                if (lstat(name, &st) < 0) {
 770                        if (errno == ENOENT)
 771                                goto not_a_valid_file;
 772                        die("stat(%s): %s", name, strerror(errno));
 773                }
 774                if (S_ISLNK(st.st_mode)) {
 775                        int ret;
 776                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 777                        if (sizeof(buf) <= st.st_size)
 778                                die("symlink too long: %s", name);
 779                        ret = readlink(name, buf, st.st_size);
 780                        if (ret < 0)
 781                                die("readlink(%s)", name);
 782                        prep_temp_blob(temp, buf, st.st_size,
 783                                       (one->sha1_valid ?
 784                                        one->sha1 : null_sha1),
 785                                       (one->sha1_valid ?
 786                                        one->mode : S_IFLNK));
 787                }
 788                else {
 789                        /* we can borrow from the file in the work tree */
 790                        temp->name = name;
 791                        if (!one->sha1_valid)
 792                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 793                        else
 794                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 795                        /* Even though we may sometimes borrow the
 796                         * contents from the work tree, we always want
 797                         * one->mode.  mode is trustworthy even when
 798                         * !(one->sha1_valid), as long as
 799                         * DIFF_FILE_VALID(one).
 800                         */
 801                        sprintf(temp->mode, "%06o", one->mode);
 802                }
 803                return;
 804        }
 805        else {
 806                if (diff_populate_filespec(one, 0))
 807                        die("cannot read data blob for %s", one->path);
 808                prep_temp_blob(temp, one->data, one->size,
 809                               one->sha1, one->mode);
 810        }
 811}
 812
 813static void remove_tempfile(void)
 814{
 815        int i;
 816
 817        for (i = 0; i < 2; i++)
 818                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 819                        unlink(diff_temp[i].name);
 820                        diff_temp[i].name = NULL;
 821                }
 822}
 823
 824static void remove_tempfile_on_signal(int signo)
 825{
 826        remove_tempfile();
 827        signal(SIGINT, SIG_DFL);
 828        raise(signo);
 829}
 830
 831static int spawn_prog(const char *pgm, const char **arg)
 832{
 833        pid_t pid;
 834        int status;
 835
 836        fflush(NULL);
 837        pid = fork();
 838        if (pid < 0)
 839                die("unable to fork");
 840        if (!pid) {
 841                execvp(pgm, (char *const*) arg);
 842                exit(255);
 843        }
 844
 845        while (waitpid(pid, &status, 0) < 0) {
 846                if (errno == EINTR)
 847                        continue;
 848                return -1;
 849        }
 850
 851        /* Earlier we did not check the exit status because
 852         * diff exits non-zero if files are different, and
 853         * we are not interested in knowing that.  It was a
 854         * mistake which made it harder to quit a diff-*
 855         * session that uses the git-apply-patch-script as
 856         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 857         * should also exit non-zero only when it wants to
 858         * abort the entire diff-* session.
 859         */
 860        if (WIFEXITED(status) && !WEXITSTATUS(status))
 861                return 0;
 862        return -1;
 863}
 864
 865/* An external diff command takes:
 866 *
 867 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 868 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 869 *
 870 */
 871static void run_external_diff(const char *pgm,
 872                              const char *name,
 873                              const char *other,
 874                              struct diff_filespec *one,
 875                              struct diff_filespec *two,
 876                              const char *xfrm_msg,
 877                              int complete_rewrite)
 878{
 879        const char *spawn_arg[10];
 880        struct diff_tempfile *temp = diff_temp;
 881        int retval;
 882        static int atexit_asked = 0;
 883        const char *othername;
 884        const char **arg = &spawn_arg[0];
 885
 886        othername = (other? other : name);
 887        if (one && two) {
 888                prepare_temp_file(name, &temp[0], one);
 889                prepare_temp_file(othername, &temp[1], two);
 890                if (! atexit_asked &&
 891                    (temp[0].name == temp[0].tmp_path ||
 892                     temp[1].name == temp[1].tmp_path)) {
 893                        atexit_asked = 1;
 894                        atexit(remove_tempfile);
 895                }
 896                signal(SIGINT, remove_tempfile_on_signal);
 897        }
 898
 899        if (one && two) {
 900                *arg++ = pgm;
 901                *arg++ = name;
 902                *arg++ = temp[0].name;
 903                *arg++ = temp[0].hex;
 904                *arg++ = temp[0].mode;
 905                *arg++ = temp[1].name;
 906                *arg++ = temp[1].hex;
 907                *arg++ = temp[1].mode;
 908                if (other) {
 909                        *arg++ = other;
 910                        *arg++ = xfrm_msg;
 911                }
 912        } else {
 913                *arg++ = pgm;
 914                *arg++ = name;
 915        }
 916        *arg = NULL;
 917        retval = spawn_prog(pgm, spawn_arg);
 918        remove_tempfile();
 919        if (retval) {
 920                fprintf(stderr, "external diff died, stopping at %s.\n", name);
 921                exit(1);
 922        }
 923}
 924
 925static void run_diff_cmd(const char *pgm,
 926                         const char *name,
 927                         const char *other,
 928                         struct diff_filespec *one,
 929                         struct diff_filespec *two,
 930                         const char *xfrm_msg,
 931                         int complete_rewrite)
 932{
 933        if (pgm) {
 934                run_external_diff(pgm, name, other, one, two, xfrm_msg,
 935                                  complete_rewrite);
 936                return;
 937        }
 938        if (one && two)
 939                builtin_diff(name, other ? other : name,
 940                             one, two, xfrm_msg, complete_rewrite);
 941        else
 942                printf("* Unmerged path %s\n", name);
 943}
 944
 945static void diff_fill_sha1_info(struct diff_filespec *one)
 946{
 947        if (DIFF_FILE_VALID(one)) {
 948                if (!one->sha1_valid) {
 949                        struct stat st;
 950                        if (lstat(one->path, &st) < 0)
 951                                die("stat %s", one->path);
 952                        if (index_path(one->sha1, one->path, &st, 0))
 953                                die("cannot hash %s\n", one->path);
 954                }
 955        }
 956        else
 957                memset(one->sha1, 0, 20);
 958}
 959
 960static void run_diff(struct diff_filepair *p, struct diff_options *o)
 961{
 962        const char *pgm = external_diff();
 963        char msg[PATH_MAX*2+300], *xfrm_msg;
 964        struct diff_filespec *one;
 965        struct diff_filespec *two;
 966        const char *name;
 967        const char *other;
 968        char *name_munged, *other_munged;
 969        int complete_rewrite = 0;
 970        int len;
 971
 972        if (DIFF_PAIR_UNMERGED(p)) {
 973                /* unmerged */
 974                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
 975                return;
 976        }
 977
 978        name = p->one->path;
 979        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 980        name_munged = quote_one(name);
 981        other_munged = quote_one(other);
 982        one = p->one; two = p->two;
 983
 984        diff_fill_sha1_info(one);
 985        diff_fill_sha1_info(two);
 986
 987        len = 0;
 988        switch (p->status) {
 989        case DIFF_STATUS_COPIED:
 990                len += snprintf(msg + len, sizeof(msg) - len,
 991                                "similarity index %d%%\n"
 992                                "copy from %s\n"
 993                                "copy to %s\n",
 994                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
 995                                name_munged, other_munged);
 996                break;
 997        case DIFF_STATUS_RENAMED:
 998                len += snprintf(msg + len, sizeof(msg) - len,
 999                                "similarity index %d%%\n"
1000                                "rename from %s\n"
1001                                "rename to %s\n",
1002                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1003                                name_munged, other_munged);
1004                break;
1005        case DIFF_STATUS_MODIFIED:
1006                if (p->score) {
1007                        len += snprintf(msg + len, sizeof(msg) - len,
1008                                        "dissimilarity index %d%%\n",
1009                                        (int)(0.5 + p->score *
1010                                              100.0/MAX_SCORE));
1011                        complete_rewrite = 1;
1012                        break;
1013                }
1014                /* fallthru */
1015        default:
1016                /* nothing */
1017                ;
1018        }
1019
1020        if (memcmp(one->sha1, two->sha1, 20)) {
1021                char one_sha1[41];
1022                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1023                memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
1024
1025                len += snprintf(msg + len, sizeof(msg) - len,
1026                                "index %.*s..%.*s",
1027                                abbrev, one_sha1, abbrev,
1028                                sha1_to_hex(two->sha1));
1029                if (one->mode == two->mode)
1030                        len += snprintf(msg + len, sizeof(msg) - len,
1031                                        " %06o", one->mode);
1032                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1033        }
1034
1035        if (len)
1036                msg[--len] = 0;
1037        xfrm_msg = len ? msg : NULL;
1038
1039        if (!pgm &&
1040            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1041            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1042                /* a filepair that changes between file and symlink
1043                 * needs to be split into deletion and creation.
1044                 */
1045                struct diff_filespec *null = alloc_filespec(two->path);
1046                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
1047                free(null);
1048                null = alloc_filespec(one->path);
1049                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
1050                free(null);
1051        }
1052        else
1053                run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
1054                             complete_rewrite);
1055
1056        free(name_munged);
1057        free(other_munged);
1058}
1059
1060static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1061                         struct diffstat_t *diffstat)
1062{
1063        const char *name;
1064        const char *other;
1065        int complete_rewrite = 0;
1066
1067        if (DIFF_PAIR_UNMERGED(p)) {
1068                /* unmerged */
1069                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
1070                return;
1071        }
1072
1073        name = p->one->path;
1074        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1075
1076        diff_fill_sha1_info(p->one);
1077        diff_fill_sha1_info(p->two);
1078
1079        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1080                complete_rewrite = 1;
1081        builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
1082}
1083
1084void diff_setup(struct diff_options *options)
1085{
1086        memset(options, 0, sizeof(*options));
1087        options->output_format = DIFF_FORMAT_RAW;
1088        options->line_termination = '\n';
1089        options->break_opt = -1;
1090        options->rename_limit = -1;
1091
1092        options->change = diff_change;
1093        options->add_remove = diff_addremove;
1094}
1095
1096int diff_setup_done(struct diff_options *options)
1097{
1098        if ((options->find_copies_harder &&
1099             options->detect_rename != DIFF_DETECT_COPY) ||
1100            (0 <= options->rename_limit && !options->detect_rename))
1101                return -1;
1102
1103        /*
1104         * These cases always need recursive; we do not drop caller-supplied
1105         * recursive bits for other formats here.
1106         */
1107        if ((options->output_format == DIFF_FORMAT_PATCH) ||
1108            (options->output_format == DIFF_FORMAT_DIFFSTAT))
1109                options->recursive = 1;
1110
1111        if (options->detect_rename && options->rename_limit < 0)
1112                options->rename_limit = diff_rename_limit_default;
1113        if (options->setup & DIFF_SETUP_USE_CACHE) {
1114                if (!active_cache)
1115                        /* read-cache does not die even when it fails
1116                         * so it is safe for us to do this here.  Also
1117                         * it does not smudge active_cache or active_nr
1118                         * when it fails, so we do not have to worry about
1119                         * cleaning it up ourselves either.
1120                         */
1121                        read_cache();
1122        }
1123        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1124                use_size_cache = 1;
1125        if (options->abbrev <= 0 || 40 < options->abbrev)
1126                options->abbrev = 40; /* full */
1127
1128        return 0;
1129}
1130
1131int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1132{
1133        const char *arg = av[0];
1134        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1135                options->output_format = DIFF_FORMAT_PATCH;
1136        else if (!strcmp(arg, "--patch-with-raw")) {
1137                options->output_format = DIFF_FORMAT_PATCH;
1138                options->with_raw = 1;
1139        }
1140        else if (!strcmp(arg, "--stat"))
1141                options->output_format = DIFF_FORMAT_DIFFSTAT;
1142        else if (!strcmp(arg, "--patch-with-stat")) {
1143                options->output_format = DIFF_FORMAT_PATCH;
1144                options->with_stat = 1;
1145        }
1146        else if (!strcmp(arg, "-z"))
1147                options->line_termination = 0;
1148        else if (!strncmp(arg, "-l", 2))
1149                options->rename_limit = strtoul(arg+2, NULL, 10);
1150        else if (!strcmp(arg, "--full-index"))
1151                options->full_index = 1;
1152        else if (!strcmp(arg, "--name-only"))
1153                options->output_format = DIFF_FORMAT_NAME;
1154        else if (!strcmp(arg, "--name-status"))
1155                options->output_format = DIFF_FORMAT_NAME_STATUS;
1156        else if (!strcmp(arg, "-R"))
1157                options->reverse_diff = 1;
1158        else if (!strncmp(arg, "-S", 2))
1159                options->pickaxe = arg + 2;
1160        else if (!strcmp(arg, "-s"))
1161                options->output_format = DIFF_FORMAT_NO_OUTPUT;
1162        else if (!strncmp(arg, "-O", 2))
1163                options->orderfile = arg + 2;
1164        else if (!strncmp(arg, "--diff-filter=", 14))
1165                options->filter = arg + 14;
1166        else if (!strcmp(arg, "--pickaxe-all"))
1167                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1168        else if (!strcmp(arg, "--pickaxe-regex"))
1169                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1170        else if (!strncmp(arg, "-B", 2)) {
1171                if ((options->break_opt =
1172                     diff_scoreopt_parse(arg)) == -1)
1173                        return -1;
1174        }
1175        else if (!strncmp(arg, "-M", 2)) {
1176                if ((options->rename_score =
1177                     diff_scoreopt_parse(arg)) == -1)
1178                        return -1;
1179                options->detect_rename = DIFF_DETECT_RENAME;
1180        }
1181        else if (!strncmp(arg, "-C", 2)) {
1182                if ((options->rename_score =
1183                     diff_scoreopt_parse(arg)) == -1)
1184                        return -1;
1185                options->detect_rename = DIFF_DETECT_COPY;
1186        }
1187        else if (!strcmp(arg, "--find-copies-harder"))
1188                options->find_copies_harder = 1;
1189        else if (!strcmp(arg, "--abbrev"))
1190                options->abbrev = DEFAULT_ABBREV;
1191        else if (!strncmp(arg, "--abbrev=", 9)) {
1192                options->abbrev = strtoul(arg + 9, NULL, 10);
1193                if (options->abbrev < MINIMUM_ABBREV)
1194                        options->abbrev = MINIMUM_ABBREV;
1195                else if (40 < options->abbrev)
1196                        options->abbrev = 40;
1197        }
1198        else
1199                return 0;
1200        return 1;
1201}
1202
1203static int parse_num(const char **cp_p)
1204{
1205        unsigned long num, scale;
1206        int ch, dot;
1207        const char *cp = *cp_p;
1208
1209        num = 0;
1210        scale = 1;
1211        dot = 0;
1212        for(;;) {
1213                ch = *cp;
1214                if ( !dot && ch == '.' ) {
1215                        scale = 1;
1216                        dot = 1;
1217                } else if ( ch == '%' ) {
1218                        scale = dot ? scale*100 : 100;
1219                        cp++;   /* % is always at the end */
1220                        break;
1221                } else if ( ch >= '0' && ch <= '9' ) {
1222                        if ( scale < 100000 ) {
1223                                scale *= 10;
1224                                num = (num*10) + (ch-'0');
1225                        }
1226                } else {
1227                        break;
1228                }
1229                cp++;
1230        }
1231        *cp_p = cp;
1232
1233        /* user says num divided by scale and we say internally that
1234         * is MAX_SCORE * num / scale.
1235         */
1236        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1237}
1238
1239int diff_scoreopt_parse(const char *opt)
1240{
1241        int opt1, opt2, cmd;
1242
1243        if (*opt++ != '-')
1244                return -1;
1245        cmd = *opt++;
1246        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1247                return -1; /* that is not a -M, -C nor -B option */
1248
1249        opt1 = parse_num(&opt);
1250        if (cmd != 'B')
1251                opt2 = 0;
1252        else {
1253                if (*opt == 0)
1254                        opt2 = 0;
1255                else if (*opt != '/')
1256                        return -1; /* we expect -B80/99 or -B80 */
1257                else {
1258                        opt++;
1259                        opt2 = parse_num(&opt);
1260                }
1261        }
1262        if (*opt != 0)
1263                return -1;
1264        return opt1 | (opt2 << 16);
1265}
1266
1267struct diff_queue_struct diff_queued_diff;
1268
1269void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1270{
1271        if (queue->alloc <= queue->nr) {
1272                queue->alloc = alloc_nr(queue->alloc);
1273                queue->queue = xrealloc(queue->queue,
1274                                        sizeof(dp) * queue->alloc);
1275        }
1276        queue->queue[queue->nr++] = dp;
1277}
1278
1279struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1280                                 struct diff_filespec *one,
1281                                 struct diff_filespec *two)
1282{
1283        struct diff_filepair *dp = xmalloc(sizeof(*dp));
1284        dp->one = one;
1285        dp->two = two;
1286        dp->score = 0;
1287        dp->status = 0;
1288        dp->source_stays = 0;
1289        dp->broken_pair = 0;
1290        if (queue)
1291                diff_q(queue, dp);
1292        return dp;
1293}
1294
1295void diff_free_filepair(struct diff_filepair *p)
1296{
1297        diff_free_filespec_data(p->one);
1298        diff_free_filespec_data(p->two);
1299        free(p->one);
1300        free(p->two);
1301        free(p);
1302}
1303
1304/* This is different from find_unique_abbrev() in that
1305 * it stuffs the result with dots for alignment.
1306 */
1307const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1308{
1309        int abblen;
1310        const char *abbrev;
1311        if (len == 40)
1312                return sha1_to_hex(sha1);
1313
1314        abbrev = find_unique_abbrev(sha1, len);
1315        if (!abbrev)
1316                return sha1_to_hex(sha1);
1317        abblen = strlen(abbrev);
1318        if (abblen < 37) {
1319                static char hex[41];
1320                if (len < abblen && abblen <= len + 2)
1321                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1322                else
1323                        sprintf(hex, "%s...", abbrev);
1324                return hex;
1325        }
1326        return sha1_to_hex(sha1);
1327}
1328
1329static void diff_flush_raw(struct diff_filepair *p,
1330                           int line_termination,
1331                           int inter_name_termination,
1332                           struct diff_options *options,
1333                           int output_format)
1334{
1335        int two_paths;
1336        char status[10];
1337        int abbrev = options->abbrev;
1338        const char *path_one, *path_two;
1339
1340        path_one = p->one->path;
1341        path_two = p->two->path;
1342        if (line_termination) {
1343                path_one = quote_one(path_one);
1344                path_two = quote_one(path_two);
1345        }
1346
1347        if (p->score)
1348                sprintf(status, "%c%03d", p->status,
1349                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1350        else {
1351                status[0] = p->status;
1352                status[1] = 0;
1353        }
1354        switch (p->status) {
1355        case DIFF_STATUS_COPIED:
1356        case DIFF_STATUS_RENAMED:
1357                two_paths = 1;
1358                break;
1359        case DIFF_STATUS_ADDED:
1360        case DIFF_STATUS_DELETED:
1361                two_paths = 0;
1362                break;
1363        default:
1364                two_paths = 0;
1365                break;
1366        }
1367        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1368                printf(":%06o %06o %s ",
1369                       p->one->mode, p->two->mode,
1370                       diff_unique_abbrev(p->one->sha1, abbrev));
1371                printf("%s ",
1372                       diff_unique_abbrev(p->two->sha1, abbrev));
1373        }
1374        printf("%s%c%s", status, inter_name_termination, path_one);
1375        if (two_paths)
1376                printf("%c%s", inter_name_termination, path_two);
1377        putchar(line_termination);
1378        if (path_one != p->one->path)
1379                free((void*)path_one);
1380        if (path_two != p->two->path)
1381                free((void*)path_two);
1382}
1383
1384static void diff_flush_name(struct diff_filepair *p,
1385                            int inter_name_termination,
1386                            int line_termination)
1387{
1388        char *path = p->two->path;
1389
1390        if (line_termination)
1391                path = quote_one(p->two->path);
1392        else
1393                path = p->two->path;
1394        printf("%s%c", path, line_termination);
1395        if (p->two->path != path)
1396                free(path);
1397}
1398
1399int diff_unmodified_pair(struct diff_filepair *p)
1400{
1401        /* This function is written stricter than necessary to support
1402         * the currently implemented transformers, but the idea is to
1403         * let transformers to produce diff_filepairs any way they want,
1404         * and filter and clean them up here before producing the output.
1405         */
1406        struct diff_filespec *one, *two;
1407
1408        if (DIFF_PAIR_UNMERGED(p))
1409                return 0; /* unmerged is interesting */
1410
1411        one = p->one;
1412        two = p->two;
1413
1414        /* deletion, addition, mode or type change
1415         * and rename are all interesting.
1416         */
1417        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1418            DIFF_PAIR_MODE_CHANGED(p) ||
1419            strcmp(one->path, two->path))
1420                return 0;
1421
1422        /* both are valid and point at the same path.  that is, we are
1423         * dealing with a change.
1424         */
1425        if (one->sha1_valid && two->sha1_valid &&
1426            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1427                return 1; /* no change */
1428        if (!one->sha1_valid && !two->sha1_valid)
1429                return 1; /* both look at the same file on the filesystem. */
1430        return 0;
1431}
1432
1433static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1434{
1435        if (diff_unmodified_pair(p))
1436                return;
1437
1438        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1439            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1440                return; /* no tree diffs in patch format */
1441
1442        run_diff(p, o);
1443}
1444
1445static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1446                            struct diffstat_t *diffstat)
1447{
1448        if (diff_unmodified_pair(p))
1449                return;
1450
1451        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1452            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1453                return; /* no tree diffs in patch format */
1454
1455        run_diffstat(p, o, diffstat);
1456}
1457
1458int diff_queue_is_empty(void)
1459{
1460        struct diff_queue_struct *q = &diff_queued_diff;
1461        int i;
1462        for (i = 0; i < q->nr; i++)
1463                if (!diff_unmodified_pair(q->queue[i]))
1464                        return 0;
1465        return 1;
1466}
1467
1468#if DIFF_DEBUG
1469void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1470{
1471        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1472                x, one ? one : "",
1473                s->path,
1474                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1475                s->mode,
1476                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1477        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1478                x, one ? one : "",
1479                s->size, s->xfrm_flags);
1480}
1481
1482void diff_debug_filepair(const struct diff_filepair *p, int i)
1483{
1484        diff_debug_filespec(p->one, i, "one");
1485        diff_debug_filespec(p->two, i, "two");
1486        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1487                p->score, p->status ? p->status : '?',
1488                p->source_stays, p->broken_pair);
1489}
1490
1491void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1492{
1493        int i;
1494        if (msg)
1495                fprintf(stderr, "%s\n", msg);
1496        fprintf(stderr, "q->nr = %d\n", q->nr);
1497        for (i = 0; i < q->nr; i++) {
1498                struct diff_filepair *p = q->queue[i];
1499                diff_debug_filepair(p, i);
1500        }
1501}
1502#endif
1503
1504static void diff_resolve_rename_copy(void)
1505{
1506        int i, j;
1507        struct diff_filepair *p, *pp;
1508        struct diff_queue_struct *q = &diff_queued_diff;
1509
1510        diff_debug_queue("resolve-rename-copy", q);
1511
1512        for (i = 0; i < q->nr; i++) {
1513                p = q->queue[i];
1514                p->status = 0; /* undecided */
1515                if (DIFF_PAIR_UNMERGED(p))
1516                        p->status = DIFF_STATUS_UNMERGED;
1517                else if (!DIFF_FILE_VALID(p->one))
1518                        p->status = DIFF_STATUS_ADDED;
1519                else if (!DIFF_FILE_VALID(p->two))
1520                        p->status = DIFF_STATUS_DELETED;
1521                else if (DIFF_PAIR_TYPE_CHANGED(p))
1522                        p->status = DIFF_STATUS_TYPE_CHANGED;
1523
1524                /* from this point on, we are dealing with a pair
1525                 * whose both sides are valid and of the same type, i.e.
1526                 * either in-place edit or rename/copy edit.
1527                 */
1528                else if (DIFF_PAIR_RENAME(p)) {
1529                        if (p->source_stays) {
1530                                p->status = DIFF_STATUS_COPIED;
1531                                continue;
1532                        }
1533                        /* See if there is some other filepair that
1534                         * copies from the same source as us.  If so
1535                         * we are a copy.  Otherwise we are either a
1536                         * copy if the path stays, or a rename if it
1537                         * does not, but we already handled "stays" case.
1538                         */
1539                        for (j = i + 1; j < q->nr; j++) {
1540                                pp = q->queue[j];
1541                                if (strcmp(pp->one->path, p->one->path))
1542                                        continue; /* not us */
1543                                if (!DIFF_PAIR_RENAME(pp))
1544                                        continue; /* not a rename/copy */
1545                                /* pp is a rename/copy from the same source */
1546                                p->status = DIFF_STATUS_COPIED;
1547                                break;
1548                        }
1549                        if (!p->status)
1550                                p->status = DIFF_STATUS_RENAMED;
1551                }
1552                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1553                         p->one->mode != p->two->mode)
1554                        p->status = DIFF_STATUS_MODIFIED;
1555                else {
1556                        /* This is a "no-change" entry and should not
1557                         * happen anymore, but prepare for broken callers.
1558                         */
1559                        error("feeding unmodified %s to diffcore",
1560                              p->one->path);
1561                        p->status = DIFF_STATUS_UNKNOWN;
1562                }
1563        }
1564        diff_debug_queue("resolve-rename-copy done", q);
1565}
1566
1567static void flush_one_pair(struct diff_filepair *p,
1568                           int diff_output_format,
1569                           struct diff_options *options,
1570                           struct diffstat_t *diffstat)
1571{
1572        int inter_name_termination = '\t';
1573        int line_termination = options->line_termination;
1574        if (!line_termination)
1575                inter_name_termination = 0;
1576
1577        switch (p->status) {
1578        case DIFF_STATUS_UNKNOWN:
1579                break;
1580        case 0:
1581                die("internal error in diff-resolve-rename-copy");
1582                break;
1583        default:
1584                switch (diff_output_format) {
1585                case DIFF_FORMAT_DIFFSTAT:
1586                        diff_flush_stat(p, options, diffstat);
1587                        break;
1588                case DIFF_FORMAT_PATCH:
1589                        diff_flush_patch(p, options);
1590                        break;
1591                case DIFF_FORMAT_RAW:
1592                case DIFF_FORMAT_NAME_STATUS:
1593                        diff_flush_raw(p, line_termination,
1594                                       inter_name_termination,
1595                                       options, diff_output_format);
1596                        break;
1597                case DIFF_FORMAT_NAME:
1598                        diff_flush_name(p,
1599                                        inter_name_termination,
1600                                        line_termination);
1601                        break;
1602                case DIFF_FORMAT_NO_OUTPUT:
1603                        break;
1604                }
1605        }
1606}
1607
1608void diff_flush(struct diff_options *options)
1609{
1610        struct diff_queue_struct *q = &diff_queued_diff;
1611        int i;
1612        int diff_output_format = options->output_format;
1613        struct diffstat_t *diffstat = NULL;
1614
1615        if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
1616                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
1617                diffstat->xm.consume = diffstat_consume;
1618        }
1619
1620        if (options->with_raw) {
1621                for (i = 0; i < q->nr; i++) {
1622                        struct diff_filepair *p = q->queue[i];
1623                        flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
1624                }
1625                putchar(options->line_termination);
1626        }
1627        if (options->with_stat) {
1628                for (i = 0; i < q->nr; i++) {
1629                        struct diff_filepair *p = q->queue[i];
1630                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
1631                                       diffstat);
1632                }
1633                show_stats(diffstat);
1634                free(diffstat);
1635                diffstat = NULL;
1636                putchar(options->line_termination);
1637        }
1638        for (i = 0; i < q->nr; i++) {
1639                struct diff_filepair *p = q->queue[i];
1640                flush_one_pair(p, diff_output_format, options, diffstat);
1641                diff_free_filepair(p);
1642        }
1643
1644        if (diffstat) {
1645                show_stats(diffstat);
1646                free(diffstat);
1647        }
1648
1649        free(q->queue);
1650        q->queue = NULL;
1651        q->nr = q->alloc = 0;
1652}
1653
1654static void diffcore_apply_filter(const char *filter)
1655{
1656        int i;
1657        struct diff_queue_struct *q = &diff_queued_diff;
1658        struct diff_queue_struct outq;
1659        outq.queue = NULL;
1660        outq.nr = outq.alloc = 0;
1661
1662        if (!filter)
1663                return;
1664
1665        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1666                int found;
1667                for (i = found = 0; !found && i < q->nr; i++) {
1668                        struct diff_filepair *p = q->queue[i];
1669                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1670                             ((p->score &&
1671                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1672                              (!p->score &&
1673                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1674                            ((p->status != DIFF_STATUS_MODIFIED) &&
1675                             strchr(filter, p->status)))
1676                                found++;
1677                }
1678                if (found)
1679                        return;
1680
1681                /* otherwise we will clear the whole queue
1682                 * by copying the empty outq at the end of this
1683                 * function, but first clear the current entries
1684                 * in the queue.
1685                 */
1686                for (i = 0; i < q->nr; i++)
1687                        diff_free_filepair(q->queue[i]);
1688        }
1689        else {
1690                /* Only the matching ones */
1691                for (i = 0; i < q->nr; i++) {
1692                        struct diff_filepair *p = q->queue[i];
1693
1694                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1695                             ((p->score &&
1696                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1697                              (!p->score &&
1698                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1699                            ((p->status != DIFF_STATUS_MODIFIED) &&
1700                             strchr(filter, p->status)))
1701                                diff_q(&outq, p);
1702                        else
1703                                diff_free_filepair(p);
1704                }
1705        }
1706        free(q->queue);
1707        *q = outq;
1708}
1709
1710void diffcore_std(struct diff_options *options)
1711{
1712        if (options->break_opt != -1)
1713                diffcore_break(options->break_opt);
1714        if (options->detect_rename)
1715                diffcore_rename(options);
1716        if (options->break_opt != -1)
1717                diffcore_merge_broken();
1718        if (options->pickaxe)
1719                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1720        if (options->orderfile)
1721                diffcore_order(options->orderfile);
1722        diff_resolve_rename_copy();
1723        diffcore_apply_filter(options->filter);
1724}
1725
1726
1727void diffcore_std_no_resolve(struct diff_options *options)
1728{
1729        if (options->pickaxe)
1730                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1731        if (options->orderfile)
1732                diffcore_order(options->orderfile);
1733        diffcore_apply_filter(options->filter);
1734}
1735
1736void diff_addremove(struct diff_options *options,
1737                    int addremove, unsigned mode,
1738                    const unsigned char *sha1,
1739                    const char *base, const char *path)
1740{
1741        char concatpath[PATH_MAX];
1742        struct diff_filespec *one, *two;
1743
1744        /* This may look odd, but it is a preparation for
1745         * feeding "there are unchanged files which should
1746         * not produce diffs, but when you are doing copy
1747         * detection you would need them, so here they are"
1748         * entries to the diff-core.  They will be prefixed
1749         * with something like '=' or '*' (I haven't decided
1750         * which but should not make any difference).
1751         * Feeding the same new and old to diff_change() 
1752         * also has the same effect.
1753         * Before the final output happens, they are pruned after
1754         * merged into rename/copy pairs as appropriate.
1755         */
1756        if (options->reverse_diff)
1757                addremove = (addremove == '+' ? '-' :
1758                             addremove == '-' ? '+' : addremove);
1759
1760        if (!path) path = "";
1761        sprintf(concatpath, "%s%s", base, path);
1762        one = alloc_filespec(concatpath);
1763        two = alloc_filespec(concatpath);
1764
1765        if (addremove != '+')
1766                fill_filespec(one, sha1, mode);
1767        if (addremove != '-')
1768                fill_filespec(two, sha1, mode);
1769
1770        diff_queue(&diff_queued_diff, one, two);
1771}
1772
1773void diff_change(struct diff_options *options,
1774                 unsigned old_mode, unsigned new_mode,
1775                 const unsigned char *old_sha1,
1776                 const unsigned char *new_sha1,
1777                 const char *base, const char *path) 
1778{
1779        char concatpath[PATH_MAX];
1780        struct diff_filespec *one, *two;
1781
1782        if (options->reverse_diff) {
1783                unsigned tmp;
1784                const unsigned char *tmp_c;
1785                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1786                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1787        }
1788        if (!path) path = "";
1789        sprintf(concatpath, "%s%s", base, path);
1790        one = alloc_filespec(concatpath);
1791        two = alloc_filespec(concatpath);
1792        fill_filespec(one, old_sha1, old_mode);
1793        fill_filespec(two, new_sha1, new_mode);
1794
1795        diff_queue(&diff_queued_diff, one, two);
1796}
1797
1798void diff_unmerge(struct diff_options *options,
1799                  const char *path)
1800{
1801        struct diff_filespec *one, *two;
1802        one = alloc_filespec(path);
1803        two = alloc_filespec(path);
1804        diff_queue(&diff_queued_diff, one, two);
1805}