diff.con commit Merge with master. (e764a10)
   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
  12static const char *diff_opts = "-pu";
  13static unsigned char null_sha1[20] = { 0, };
  14
  15static int reverse_diff;
  16static int use_size_cache;
  17
  18static const char *external_diff(void)
  19{
  20        static const char *external_diff_cmd = NULL;
  21        static int done_preparing = 0;
  22
  23        if (done_preparing)
  24                return external_diff_cmd;
  25
  26        /*
  27         * Default values above are meant to match the
  28         * Linux kernel development style.  Examples of
  29         * alternative styles you can specify via environment
  30         * variables are:
  31         *
  32         * GIT_DIFF_OPTS="-c";
  33         */
  34        if (gitenv("GIT_EXTERNAL_DIFF"))
  35                external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
  36
  37        /* In case external diff fails... */
  38        diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
  39
  40        done_preparing = 1;
  41        return external_diff_cmd;
  42}
  43
  44#define TEMPFILE_PATH_LEN               50
  45
  46static struct diff_tempfile {
  47        const char *name; /* filename external diff should read from */
  48        char hex[41];
  49        char mode[10];
  50        char tmp_path[TEMPFILE_PATH_LEN];
  51} diff_temp[2];
  52
  53static int count_lines(const char *filename)
  54{
  55        FILE *in;
  56        int count, ch, completely_empty = 1, nl_just_seen = 0;
  57        in = fopen(filename, "r");
  58        count = 0;
  59        while ((ch = fgetc(in)) != EOF)
  60                if (ch == '\n') {
  61                        count++;
  62                        nl_just_seen = 1;
  63                        completely_empty = 0;
  64                }
  65                else {
  66                        nl_just_seen = 0;
  67                        completely_empty = 0;
  68                }
  69        fclose(in);
  70        if (completely_empty)
  71                return 0;
  72        if (!nl_just_seen)
  73                count++; /* no trailing newline */
  74        return count;
  75}
  76
  77static void print_line_count(int count)
  78{
  79        switch (count) {
  80        case 0:
  81                printf("0,0");
  82                break;
  83        case 1:
  84                printf("1");
  85                break;
  86        default:
  87                printf("1,%d", count);
  88                break;
  89        }
  90}
  91
  92static void copy_file(int prefix, const char *filename)
  93{
  94        FILE *in;
  95        int ch, nl_just_seen = 1;
  96        in = fopen(filename, "r");
  97        while ((ch = fgetc(in)) != EOF) {
  98                if (nl_just_seen)
  99                        putchar(prefix);
 100                putchar(ch);
 101                if (ch == '\n')
 102                        nl_just_seen = 1;
 103                else
 104                        nl_just_seen = 0;
 105        }
 106        fclose(in);
 107        if (!nl_just_seen)
 108                printf("\n\\ No newline at end of file\n");
 109}
 110
 111static void emit_rewrite_diff(const char *name_a,
 112                              const char *name_b,
 113                              struct diff_tempfile *temp)
 114{
 115        /* Use temp[i].name as input, name_a and name_b as labels */
 116        int lc_a, lc_b;
 117        lc_a = count_lines(temp[0].name);
 118        lc_b = count_lines(temp[1].name);
 119        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 120        print_line_count(lc_a);
 121        printf(" +");
 122        print_line_count(lc_b);
 123        printf(" @@\n");
 124        if (lc_a)
 125                copy_file('-', temp[0].name);
 126        if (lc_b)
 127                copy_file('+', temp[1].name);
 128}
 129
 130static void builtin_diff(const char *name_a,
 131                         const char *name_b,
 132                         struct diff_tempfile *temp,
 133                         const char *xfrm_msg,
 134                         int complete_rewrite)
 135{
 136        int i, next_at, cmd_size;
 137        const char *diff_cmd = "diff -L%s%s -L%s%s";
 138        const char *diff_arg  = "%s %s||:"; /* "||:" is to return 0 */
 139        const char *input_name_sq[2];
 140        const char *path0[2];
 141        const char *path1[2];
 142        const char *name_sq[2];
 143        char *cmd;
 144
 145        name_sq[0] = sq_quote(name_a);
 146        name_sq[1] = sq_quote(name_b);
 147
 148        /* diff_cmd and diff_arg have 6 %s in total which makes
 149         * the sum of these strings 12 bytes larger than required.
 150         * we use 2 spaces around diff-opts, and we need to count
 151         * terminating NUL, so we subtract 9 here.
 152         */
 153        cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
 154                        strlen(diff_arg) - 9);
 155        for (i = 0; i < 2; i++) {
 156                input_name_sq[i] = sq_quote(temp[i].name);
 157                if (!strcmp(temp[i].name, "/dev/null")) {
 158                        path0[i] = "/dev/null";
 159                        path1[i] = "";
 160                } else {
 161                        path0[i] = i ? "b/" : "a/";
 162                        path1[i] = name_sq[i];
 163                }
 164                cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
 165                             strlen(input_name_sq[i]));
 166        }
 167
 168        cmd = xmalloc(cmd_size);
 169
 170        next_at = 0;
 171        next_at += snprintf(cmd+next_at, cmd_size-next_at,
 172                            diff_cmd,
 173                            path0[0], path1[0], path0[1], path1[1]);
 174        next_at += snprintf(cmd+next_at, cmd_size-next_at,
 175                            " %s ", diff_opts);
 176        next_at += snprintf(cmd+next_at, cmd_size-next_at,
 177                            diff_arg, input_name_sq[0], input_name_sq[1]);
 178
 179        printf("diff --git a/%s b/%s\n", name_a, name_b);
 180        if (!path1[0][0]) {
 181                printf("new file mode %s\n", temp[1].mode);
 182                if (xfrm_msg && xfrm_msg[0])
 183                        puts(xfrm_msg);
 184        }
 185        else if (!path1[1][0]) {
 186                printf("deleted file mode %s\n", temp[0].mode);
 187                if (xfrm_msg && xfrm_msg[0])
 188                        puts(xfrm_msg);
 189        }
 190        else {
 191                if (strcmp(temp[0].mode, temp[1].mode)) {
 192                        printf("old mode %s\n", temp[0].mode);
 193                        printf("new mode %s\n", temp[1].mode);
 194                }
 195                if (xfrm_msg && xfrm_msg[0])
 196                        puts(xfrm_msg);
 197                if (strncmp(temp[0].mode, temp[1].mode, 3))
 198                        /* we do not run diff between different kind
 199                         * of objects.
 200                         */
 201                        exit(0);
 202                if (complete_rewrite) {
 203                        fflush(NULL);
 204                        emit_rewrite_diff(name_a, name_b, temp);
 205                        exit(0);
 206                }
 207        }
 208        fflush(NULL);
 209        execlp("/bin/sh","sh", "-c", cmd, NULL);
 210}
 211
 212struct diff_filespec *alloc_filespec(const char *path)
 213{
 214        int namelen = strlen(path);
 215        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 216        spec->path = (char *)(spec + 1);
 217        strcpy(spec->path, path);
 218        spec->should_free = spec->should_munmap = 0;
 219        spec->xfrm_flags = 0;
 220        spec->size = 0;
 221        spec->data = NULL;
 222        spec->mode = 0;
 223        memset(spec->sha1, 0, 20);
 224        return spec;
 225}
 226
 227void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 228                   unsigned short mode)
 229{
 230        if (mode) {
 231                spec->mode = DIFF_FILE_CANON_MODE(mode);
 232                memcpy(spec->sha1, sha1, 20);
 233                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 234        }
 235}
 236
 237/*
 238 * Given a name and sha1 pair, if the dircache tells us the file in
 239 * the work tree has that object contents, return true, so that
 240 * prepare_temp_file() does not have to inflate and extract.
 241 */
 242static int work_tree_matches(const char *name, const unsigned char *sha1)
 243{
 244        struct cache_entry *ce;
 245        struct stat st;
 246        int pos, len;
 247
 248        /* We do not read the cache ourselves here, because the
 249         * benchmark with my previous version that always reads cache
 250         * shows that it makes things worse for diff-tree comparing
 251         * two linux-2.6 kernel trees in an already checked out work
 252         * tree.  This is because most diff-tree comparisons deal with
 253         * only a small number of files, while reading the cache is
 254         * expensive for a large project, and its cost outweighs the
 255         * savings we get by not inflating the object to a temporary
 256         * file.  Practically, this code only helps when we are used
 257         * by diff-cache --cached, which does read the cache before
 258         * calling us.
 259         */
 260        if (!active_cache)
 261                return 0;
 262
 263        len = strlen(name);
 264        pos = cache_name_pos(name, len);
 265        if (pos < 0)
 266                return 0;
 267        ce = active_cache[pos];
 268        if ((lstat(name, &st) < 0) ||
 269            !S_ISREG(st.st_mode) || /* careful! */
 270            ce_match_stat(ce, &st) ||
 271            memcmp(sha1, ce->sha1, 20))
 272                return 0;
 273        /* we return 1 only when we can stat, it is a regular file,
 274         * stat information matches, and sha1 recorded in the cache
 275         * matches.  I.e. we know the file in the work tree really is
 276         * the same as the <name, sha1> pair.
 277         */
 278        return 1;
 279}
 280
 281static struct sha1_size_cache {
 282        unsigned char sha1[20];
 283        unsigned long size;
 284} **sha1_size_cache;
 285static int sha1_size_cache_nr, sha1_size_cache_alloc;
 286
 287static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 288                                                 int find_only,
 289                                                 unsigned long size)
 290{
 291        int first, last;
 292        struct sha1_size_cache *e;
 293
 294        first = 0;
 295        last = sha1_size_cache_nr;
 296        while (last > first) {
 297                int cmp, next = (last + first) >> 1;
 298                e = sha1_size_cache[next];
 299                cmp = memcmp(e->sha1, sha1, 20);
 300                if (!cmp)
 301                        return e;
 302                if (cmp < 0) {
 303                        last = next;
 304                        continue;
 305                }
 306                first = next+1;
 307        }
 308        /* not found */
 309        if (find_only)
 310                return NULL;
 311        /* insert to make it at "first" */
 312        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 313                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 314                sha1_size_cache = xrealloc(sha1_size_cache,
 315                                           sha1_size_cache_alloc *
 316                                           sizeof(*sha1_size_cache));
 317        }
 318        sha1_size_cache_nr++;
 319        if (first < sha1_size_cache_nr)
 320                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 321                        (sha1_size_cache_nr - first - 1) *
 322                        sizeof(*sha1_size_cache));
 323        e = xmalloc(sizeof(struct sha1_size_cache));
 324        sha1_size_cache[first] = e;
 325        memcpy(e->sha1, sha1, 20);
 326        e->size = size;
 327        return e;
 328}
 329
 330/*
 331 * While doing rename detection and pickaxe operation, we may need to
 332 * grab the data for the blob (or file) for our own in-core comparison.
 333 * diff_filespec has data and size fields for this purpose.
 334 */
 335int diff_populate_filespec(struct diff_filespec *s, int size_only)
 336{
 337        int err = 0;
 338        if (!DIFF_FILE_VALID(s))
 339                die("internal error: asking to populate invalid file.");
 340        if (S_ISDIR(s->mode))
 341                return -1;
 342
 343        if (!use_size_cache)
 344                size_only = 0;
 345
 346        if (s->data)
 347                return err;
 348        if (!s->sha1_valid ||
 349            work_tree_matches(s->path, s->sha1)) {
 350                struct stat st;
 351                int fd;
 352                if (lstat(s->path, &st) < 0) {
 353                        if (errno == ENOENT) {
 354                        err_empty:
 355                                err = -1;
 356                        empty:
 357                                s->data = "";
 358                                s->size = 0;
 359                                return err;
 360                        }
 361                }
 362                s->size = st.st_size;
 363                if (!s->size)
 364                        goto empty;
 365                if (size_only)
 366                        return 0;
 367                if (S_ISLNK(st.st_mode)) {
 368                        int ret;
 369                        s->data = xmalloc(s->size);
 370                        s->should_free = 1;
 371                        ret = readlink(s->path, s->data, s->size);
 372                        if (ret < 0) {
 373                                free(s->data);
 374                                goto err_empty;
 375                        }
 376                        return 0;
 377                }
 378                fd = open(s->path, O_RDONLY);
 379                if (fd < 0)
 380                        goto err_empty;
 381                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 382                close(fd);
 383                if (s->data == MAP_FAILED)
 384                        goto err_empty;
 385                s->should_munmap = 1;
 386        }
 387        else {
 388                char type[20];
 389                struct sha1_size_cache *e;
 390
 391                if (size_only) {
 392                        e = locate_size_cache(s->sha1, 1, 0);
 393                        if (e) {
 394                                s->size = e->size;
 395                                return 0;
 396                        }
 397                        if (!sha1_object_info(s->sha1, type, &s->size))
 398                                locate_size_cache(s->sha1, 0, s->size);
 399                }
 400                else {
 401                        s->data = read_sha1_file(s->sha1, type, &s->size);
 402                        s->should_free = 1;
 403                }
 404        }
 405        return 0;
 406}
 407
 408void diff_free_filespec_data(struct diff_filespec *s)
 409{
 410        if (s->should_free)
 411                free(s->data);
 412        else if (s->should_munmap)
 413                munmap(s->data, s->size);
 414        s->should_free = s->should_munmap = 0;
 415        s->data = NULL;
 416}
 417
 418static void prep_temp_blob(struct diff_tempfile *temp,
 419                           void *blob,
 420                           unsigned long size,
 421                           unsigned char *sha1,
 422                           int mode)
 423{
 424        int fd;
 425
 426        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 427        if (fd < 0)
 428                die("unable to create temp-file");
 429        if (write(fd, blob, size) != size)
 430                die("unable to write temp-file");
 431        close(fd);
 432        temp->name = temp->tmp_path;
 433        strcpy(temp->hex, sha1_to_hex(sha1));
 434        temp->hex[40] = 0;
 435        sprintf(temp->mode, "%06o", mode);
 436}
 437
 438static void prepare_temp_file(const char *name,
 439                              struct diff_tempfile *temp,
 440                              struct diff_filespec *one)
 441{
 442        if (!DIFF_FILE_VALID(one)) {
 443        not_a_valid_file:
 444                /* A '-' entry produces this for file-2, and
 445                 * a '+' entry produces this for file-1.
 446                 */
 447                temp->name = "/dev/null";
 448                strcpy(temp->hex, ".");
 449                strcpy(temp->mode, ".");
 450                return;
 451        }
 452
 453        if (!one->sha1_valid ||
 454            work_tree_matches(name, one->sha1)) {
 455                struct stat st;
 456                if (lstat(name, &st) < 0) {
 457                        if (errno == ENOENT)
 458                                goto not_a_valid_file;
 459                        die("stat(%s): %s", name, strerror(errno));
 460                }
 461                if (S_ISLNK(st.st_mode)) {
 462                        int ret;
 463                        char *buf, buf_[1024];
 464                        buf = ((sizeof(buf_) < st.st_size) ?
 465                               xmalloc(st.st_size) : buf_);
 466                        ret = readlink(name, buf, st.st_size);
 467                        if (ret < 0)
 468                                die("readlink(%s)", name);
 469                        prep_temp_blob(temp, buf, st.st_size,
 470                                       (one->sha1_valid ?
 471                                        one->sha1 : null_sha1),
 472                                       (one->sha1_valid ?
 473                                        one->mode : S_IFLNK));
 474                }
 475                else {
 476                        /* we can borrow from the file in the work tree */
 477                        temp->name = name;
 478                        if (!one->sha1_valid)
 479                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 480                        else
 481                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 482                        /* Even though we may sometimes borrow the
 483                         * contents from the work tree, we always want
 484                         * one->mode.  mode is trustworthy even when
 485                         * !(one->sha1_valid), as long as
 486                         * DIFF_FILE_VALID(one).
 487                         */
 488                        sprintf(temp->mode, "%06o", one->mode);
 489                }
 490                return;
 491        }
 492        else {
 493                if (diff_populate_filespec(one, 0))
 494                        die("cannot read data blob for %s", one->path);
 495                prep_temp_blob(temp, one->data, one->size,
 496                               one->sha1, one->mode);
 497        }
 498}
 499
 500static void remove_tempfile(void)
 501{
 502        int i;
 503
 504        for (i = 0; i < 2; i++)
 505                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 506                        unlink(diff_temp[i].name);
 507                        diff_temp[i].name = NULL;
 508                }
 509}
 510
 511static void remove_tempfile_on_signal(int signo)
 512{
 513        remove_tempfile();
 514}
 515
 516/* An external diff command takes:
 517 *
 518 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 519 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 520 *
 521 */
 522static void run_external_diff(const char *pgm,
 523                              const char *name,
 524                              const char *other,
 525                              struct diff_filespec *one,
 526                              struct diff_filespec *two,
 527                              const char *xfrm_msg,
 528                              int complete_rewrite)
 529{
 530        struct diff_tempfile *temp = diff_temp;
 531        pid_t pid;
 532        int status;
 533        static int atexit_asked = 0;
 534
 535        if (one && two) {
 536                prepare_temp_file(name, &temp[0], one);
 537                prepare_temp_file(other ? : name, &temp[1], two);
 538                if (! atexit_asked &&
 539                    (temp[0].name == temp[0].tmp_path ||
 540                     temp[1].name == temp[1].tmp_path)) {
 541                        atexit_asked = 1;
 542                        atexit(remove_tempfile);
 543                }
 544                signal(SIGINT, remove_tempfile_on_signal);
 545        }
 546
 547        fflush(NULL);
 548        pid = fork();
 549        if (pid < 0)
 550                die("unable to fork");
 551        if (!pid) {
 552                if (pgm) {
 553                        if (one && two) {
 554                                const char *exec_arg[10];
 555                                const char **arg = &exec_arg[0];
 556                                *arg++ = pgm;
 557                                *arg++ = name;
 558                                *arg++ = temp[0].name;
 559                                *arg++ = temp[0].hex;
 560                                *arg++ = temp[0].mode;
 561                                *arg++ = temp[1].name;
 562                                *arg++ = temp[1].hex;
 563                                *arg++ = temp[1].mode;
 564                                if (other) {
 565                                        *arg++ = other;
 566                                        *arg++ = xfrm_msg;
 567                                }
 568                                *arg = NULL;
 569                                execvp(pgm, (char *const*) exec_arg);
 570                        }
 571                        else
 572                                execlp(pgm, pgm, name, NULL);
 573                }
 574                /*
 575                 * otherwise we use the built-in one.
 576                 */
 577                if (one && two)
 578                        builtin_diff(name, other ? : name, temp, xfrm_msg,
 579                                     complete_rewrite);
 580                else
 581                        printf("* Unmerged path %s\n", name);
 582                exit(0);
 583        }
 584        if (waitpid(pid, &status, 0) < 0 ||
 585            !WIFEXITED(status) || WEXITSTATUS(status)) {
 586                /* Earlier we did not check the exit status because
 587                 * diff exits non-zero if files are different, and
 588                 * we are not interested in knowing that.  It was a
 589                 * mistake which made it harder to quit a diff-*
 590                 * session that uses the git-apply-patch-script as
 591                 * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 592                 * should also exit non-zero only when it wants to
 593                 * abort the entire diff-* session.
 594                 */
 595                remove_tempfile();
 596                fprintf(stderr, "external diff died, stopping at %s.\n", name);
 597                exit(1);
 598        }
 599        remove_tempfile();
 600}
 601
 602static void run_diff(struct diff_filepair *p)
 603{
 604        const char *pgm = external_diff();
 605        char msg_[PATH_MAX*2+200], *xfrm_msg;
 606        struct diff_filespec *one;
 607        struct diff_filespec *two;
 608        const char *name;
 609        const char *other;
 610        int complete_rewrite = 0;
 611
 612        if (DIFF_PAIR_UNMERGED(p)) {
 613                /* unmerged */
 614                run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
 615                                  0);
 616                return;
 617        }
 618
 619        name = p->one->path;
 620        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 621        one = p->one; two = p->two;
 622        switch (p->status) {
 623        case DIFF_STATUS_COPIED:
 624                sprintf(msg_,
 625                        "similarity index %d%%\n"
 626                        "copy from %s\n"
 627                        "copy to %s",
 628                        (int)(0.5 + p->score * 100.0/MAX_SCORE),
 629                        name, other);
 630                xfrm_msg = msg_;
 631                break;
 632        case DIFF_STATUS_RENAMED:
 633                sprintf(msg_,
 634                        "similarity index %d%%\n"
 635                        "rename from %s\n"
 636                        "rename to %s",
 637                        (int)(0.5 + p->score * 100.0/MAX_SCORE),
 638                        name, other);
 639                xfrm_msg = msg_;
 640                break;
 641        case DIFF_STATUS_MODIFIED:
 642                if (p->score) {
 643                        sprintf(msg_,
 644                                "dissimilarity index %d%%",
 645                                (int)(0.5 + p->score * 100.0/MAX_SCORE));
 646                        xfrm_msg = msg_;
 647                        complete_rewrite = 1;
 648                        break;
 649                }
 650                /* fallthru */
 651        default:
 652                xfrm_msg = NULL;
 653        }
 654
 655        if (!pgm &&
 656            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
 657            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
 658                /* a filepair that changes between file and symlink
 659                 * needs to be split into deletion and creation.
 660                 */
 661                struct diff_filespec *null = alloc_filespec(two->path);
 662                run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
 663                free(null);
 664                null = alloc_filespec(one->path);
 665                run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
 666                free(null);
 667        }
 668        else
 669                run_external_diff(pgm, name, other, one, two, xfrm_msg,
 670                                  complete_rewrite);
 671}
 672
 673void diff_setup(int flags)
 674{
 675        if (flags & DIFF_SETUP_REVERSE)
 676                reverse_diff = 1;
 677        if (flags & DIFF_SETUP_USE_CACHE) {
 678                if (!active_cache)
 679                        /* read-cache does not die even when it fails
 680                         * so it is safe for us to do this here.  Also
 681                         * it does not smudge active_cache or active_nr
 682                         * when it fails, so we do not have to worry about
 683                         * cleaning it up oufselves either.
 684                         */
 685                        read_cache();
 686        }
 687        if (flags & DIFF_SETUP_USE_SIZE_CACHE)
 688                use_size_cache = 1;
 689        
 690}
 691
 692static int parse_num(const char **cp_p)
 693{
 694        int num, scale, ch, cnt;
 695        const char *cp = *cp_p;
 696
 697        cnt = num = 0;
 698        scale = 1;
 699        while ('0' <= (ch = *cp) && ch <= '9') {
 700                if (cnt++ < 5) {
 701                        /* We simply ignore more than 5 digits precision. */
 702                        scale *= 10;
 703                        num = num * 10 + ch - '0';
 704                }
 705                *cp++;
 706        }
 707        *cp_p = cp;
 708
 709        /* user says num divided by scale and we say internally that
 710         * is MAX_SCORE * num / scale.
 711         */
 712        return (MAX_SCORE * num / scale);
 713}
 714
 715int diff_scoreopt_parse(const char *opt)
 716{
 717        int opt1, opt2, cmd;
 718
 719        if (*opt++ != '-')
 720                return -1;
 721        cmd = *opt++;
 722        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 723                return -1; /* that is not a -M, -C nor -B option */
 724
 725        opt1 = parse_num(&opt);
 726        if (cmd != 'B')
 727                opt2 = 0;
 728        else {
 729                if (*opt == 0)
 730                        opt2 = 0;
 731                else if (*opt != '/')
 732                        return -1; /* we expect -B80/99 or -B80 */
 733                else {
 734                        opt++;
 735                        opt2 = parse_num(&opt);
 736                }
 737        }
 738        if (*opt != 0)
 739                return -1;
 740        return opt1 | (opt2 << 16);
 741}
 742
 743struct diff_queue_struct diff_queued_diff;
 744
 745void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 746{
 747        if (queue->alloc <= queue->nr) {
 748                queue->alloc = alloc_nr(queue->alloc);
 749                queue->queue = xrealloc(queue->queue,
 750                                        sizeof(dp) * queue->alloc);
 751        }
 752        queue->queue[queue->nr++] = dp;
 753}
 754
 755struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 756                                 struct diff_filespec *one,
 757                                 struct diff_filespec *two)
 758{
 759        struct diff_filepair *dp = xmalloc(sizeof(*dp));
 760        dp->one = one;
 761        dp->two = two;
 762        dp->score = 0;
 763        dp->status = 0;
 764        dp->source_stays = 0;
 765        dp->broken_pair = 0;
 766        diff_q(queue, dp);
 767        return dp;
 768}
 769
 770void diff_free_filepair(struct diff_filepair *p)
 771{
 772        diff_free_filespec_data(p->one);
 773        diff_free_filespec_data(p->two);
 774        free(p);
 775}
 776
 777static void diff_flush_raw(struct diff_filepair *p,
 778                           int line_termination,
 779                           int inter_name_termination)
 780{
 781        int two_paths;
 782        char status[10];
 783
 784        if (line_termination) {
 785                const char *err = "path %s cannot be expressed without -z";
 786                if (strchr(p->one->path, line_termination) ||
 787                    strchr(p->one->path, inter_name_termination))
 788                        die(err, p->one->path);
 789                if (strchr(p->two->path, line_termination) ||
 790                    strchr(p->two->path, inter_name_termination))
 791                        die(err, p->two->path);
 792        }
 793
 794        if (p->score)
 795                sprintf(status, "%c%03d", p->status,
 796                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
 797        else {
 798                status[0] = p->status;
 799                status[1] = 0;
 800        }
 801        switch (p->status) {
 802        case DIFF_STATUS_COPIED:
 803        case DIFF_STATUS_RENAMED:
 804                two_paths = 1;
 805                break;
 806        case DIFF_STATUS_ADDED:
 807        case DIFF_STATUS_DELETED:
 808                two_paths = 0;
 809                break;
 810        default:
 811                two_paths = 0;
 812                break;
 813        }
 814        printf(":%06o %06o %s ",
 815               p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
 816        printf("%s %s%c%s",
 817               sha1_to_hex(p->two->sha1),
 818               status,
 819               inter_name_termination,
 820               p->one->path);
 821        if (two_paths)
 822                printf("%c%s", inter_name_termination, p->two->path);
 823        putchar(line_termination);
 824}
 825
 826static void diff_flush_name(struct diff_filepair *p,
 827                            int line_termination)
 828{
 829        printf("%s%c", p->two->path, line_termination);
 830}
 831
 832int diff_unmodified_pair(struct diff_filepair *p)
 833{
 834        /* This function is written stricter than necessary to support
 835         * the currently implemented transformers, but the idea is to
 836         * let transformers to produce diff_filepairs any way they want,
 837         * and filter and clean them up here before producing the output.
 838         */
 839        struct diff_filespec *one, *two;
 840
 841        if (DIFF_PAIR_UNMERGED(p))
 842                return 0; /* unmerged is interesting */
 843
 844        one = p->one;
 845        two = p->two;
 846
 847        /* deletion, addition, mode or type change
 848         * and rename are all interesting.
 849         */
 850        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
 851            DIFF_PAIR_MODE_CHANGED(p) ||
 852            strcmp(one->path, two->path))
 853                return 0;
 854
 855        /* both are valid and point at the same path.  that is, we are
 856         * dealing with a change.
 857         */
 858        if (one->sha1_valid && two->sha1_valid &&
 859            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
 860                return 1; /* no change */
 861        if (!one->sha1_valid && !two->sha1_valid)
 862                return 1; /* both look at the same file on the filesystem. */
 863        return 0;
 864}
 865
 866static void diff_flush_patch(struct diff_filepair *p)
 867{
 868        if (diff_unmodified_pair(p))
 869                return;
 870
 871        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
 872            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 873                return; /* no tree diffs in patch format */ 
 874
 875        run_diff(p);
 876}
 877
 878int diff_queue_is_empty(void)
 879{
 880        struct diff_queue_struct *q = &diff_queued_diff;
 881        int i;
 882        for (i = 0; i < q->nr; i++)
 883                if (!diff_unmodified_pair(q->queue[i]))
 884                        return 0;
 885        return 1;
 886}
 887
 888#if DIFF_DEBUG
 889void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
 890{
 891        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
 892                x, one ? : "",
 893                s->path,
 894                DIFF_FILE_VALID(s) ? "valid" : "invalid",
 895                s->mode,
 896                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
 897        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
 898                x, one ? : "",
 899                s->size, s->xfrm_flags);
 900}
 901
 902void diff_debug_filepair(const struct diff_filepair *p, int i)
 903{
 904        diff_debug_filespec(p->one, i, "one");
 905        diff_debug_filespec(p->two, i, "two");
 906        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
 907                p->score, p->status ? : '?',
 908                p->source_stays, p->broken_pair);
 909}
 910
 911void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
 912{
 913        int i;
 914        if (msg)
 915                fprintf(stderr, "%s\n", msg);
 916        fprintf(stderr, "q->nr = %d\n", q->nr);
 917        for (i = 0; i < q->nr; i++) {
 918                struct diff_filepair *p = q->queue[i];
 919                diff_debug_filepair(p, i);
 920        }
 921}
 922#endif
 923
 924static void diff_resolve_rename_copy(void)
 925{
 926        int i, j;
 927        struct diff_filepair *p, *pp;
 928        struct diff_queue_struct *q = &diff_queued_diff;
 929
 930        diff_debug_queue("resolve-rename-copy", q);
 931
 932        for (i = 0; i < q->nr; i++) {
 933                p = q->queue[i];
 934                p->status = 0; /* undecided */
 935                if (DIFF_PAIR_UNMERGED(p))
 936                        p->status = DIFF_STATUS_UNMERGED;
 937                else if (!DIFF_FILE_VALID(p->one))
 938                        p->status = DIFF_STATUS_ADDED;
 939                else if (!DIFF_FILE_VALID(p->two))
 940                        p->status = DIFF_STATUS_DELETED;
 941                else if (DIFF_PAIR_TYPE_CHANGED(p))
 942                        p->status = DIFF_STATUS_TYPE_CHANGED;
 943
 944                /* from this point on, we are dealing with a pair
 945                 * whose both sides are valid and of the same type, i.e.
 946                 * either in-place edit or rename/copy edit.
 947                 */
 948                else if (DIFF_PAIR_RENAME(p)) {
 949                        if (p->source_stays) {
 950                                p->status = DIFF_STATUS_COPIED;
 951                                continue;
 952                        }
 953                        /* See if there is some other filepair that
 954                         * copies from the same source as us.  If so
 955                         * we are a copy.  Otherwise we are a rename.
 956                         */
 957                        for (j = i + 1; j < q->nr; j++) {
 958                                pp = q->queue[j];
 959                                if (strcmp(pp->one->path, p->one->path))
 960                                        continue; /* not us */
 961                                if (!DIFF_PAIR_RENAME(pp))
 962                                        continue; /* not a rename/copy */
 963                                /* pp is a rename/copy from the same source */
 964                                p->status = DIFF_STATUS_COPIED;
 965                                break;
 966                        }
 967                        if (!p->status)
 968                                p->status = DIFF_STATUS_RENAMED;
 969                }
 970                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
 971                         p->one->mode != p->two->mode)
 972                        p->status = DIFF_STATUS_MODIFIED;
 973                else {
 974                        /* This is a "no-change" entry and should not
 975                         * happen anymore, but prepare for broken callers.
 976                         */
 977                        error("feeding unmodified %s to diffcore",
 978                              p->one->path);
 979                        p->status = DIFF_STATUS_UNKNOWN;
 980                }
 981        }
 982        diff_debug_queue("resolve-rename-copy done", q);
 983}
 984
 985void diff_flush(int diff_output_style, int line_termination)
 986{
 987        struct diff_queue_struct *q = &diff_queued_diff;
 988        int i;
 989        int inter_name_termination = '\t';
 990
 991        if (!line_termination)
 992                inter_name_termination = 0;
 993
 994        for (i = 0; i < q->nr; i++) {
 995                struct diff_filepair *p = q->queue[i];
 996                if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
 997                    (p->status == DIFF_STATUS_UNKNOWN))
 998                        continue;
 999                if (p->status == 0)
1000                        die("internal error in diff-resolve-rename-copy");
1001                switch (diff_output_style) {
1002                case DIFF_FORMAT_PATCH:
1003                        diff_flush_patch(p);
1004                        break;
1005                case DIFF_FORMAT_RAW:
1006                        diff_flush_raw(p, line_termination,
1007                                       inter_name_termination);
1008                        break;
1009                case DIFF_FORMAT_NAME:
1010                        diff_flush_name(p, line_termination);
1011                        break;
1012                }
1013        }
1014        for (i = 0; i < q->nr; i++)
1015                diff_free_filepair(q->queue[i]);
1016        free(q->queue);
1017        q->queue = NULL;
1018        q->nr = q->alloc = 0;
1019}
1020
1021static void diffcore_apply_filter(const char *filter)
1022{
1023        int i;
1024        struct diff_queue_struct *q = &diff_queued_diff;
1025        struct diff_queue_struct outq;
1026        outq.queue = NULL;
1027        outq.nr = outq.alloc = 0;
1028
1029        if (!filter)
1030                return;
1031
1032        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1033                int found;
1034                for (i = found = 0; !found && i < q->nr; i++) {
1035                        struct diff_filepair *p = q->queue[i];
1036                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1037                             ((p->score &&
1038                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1039                              (!p->score &&
1040                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1041                            ((p->status != DIFF_STATUS_MODIFIED) &&
1042                             strchr(filter, p->status)))
1043                                found++;
1044                }
1045                if (found)
1046                        return;
1047
1048                /* otherwise we will clear the whole queue
1049                 * by copying the empty outq at the end of this
1050                 * function, but first clear the current entries
1051                 * in the queue.
1052                 */
1053                for (i = 0; i < q->nr; i++)
1054                        diff_free_filepair(q->queue[i]);
1055        }
1056        else {
1057                /* Only the matching ones */
1058                for (i = 0; i < q->nr; i++) {
1059                        struct diff_filepair *p = q->queue[i];
1060
1061                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1062                             ((p->score &&
1063                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1064                              (!p->score &&
1065                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1066                            ((p->status != DIFF_STATUS_MODIFIED) &&
1067                             strchr(filter, p->status)))
1068                                diff_q(&outq, p);
1069                        else
1070                                diff_free_filepair(p);
1071                }
1072        }
1073        free(q->queue);
1074        *q = outq;
1075}
1076
1077void diffcore_std(const char **paths,
1078                  int detect_rename, int rename_score,
1079                  const char *pickaxe, int pickaxe_opts,
1080                  int break_opt,
1081                  const char *orderfile,
1082                  const char *filter)
1083{
1084        if (paths && paths[0])
1085                diffcore_pathspec(paths);
1086        if (break_opt != -1)
1087                diffcore_break(break_opt);
1088        if (detect_rename)
1089                diffcore_rename(detect_rename, rename_score);
1090        if (break_opt != -1)
1091                diffcore_merge_broken();
1092        if (pickaxe)
1093                diffcore_pickaxe(pickaxe, pickaxe_opts);
1094        if (orderfile)
1095                diffcore_order(orderfile);
1096        diff_resolve_rename_copy();
1097        diffcore_apply_filter(filter);
1098}
1099
1100
1101void diffcore_std_no_resolve(const char **paths,
1102                             const char *pickaxe, int pickaxe_opts,
1103                             const char *orderfile,
1104                             const char *filter)
1105{
1106        if (paths && paths[0])
1107                diffcore_pathspec(paths);
1108        if (pickaxe)
1109                diffcore_pickaxe(pickaxe, pickaxe_opts);
1110        if (orderfile)
1111                diffcore_order(orderfile);
1112        diffcore_apply_filter(filter);
1113}
1114
1115void diff_addremove(int addremove, unsigned mode,
1116                    const unsigned char *sha1,
1117                    const char *base, const char *path)
1118{
1119        char concatpath[PATH_MAX];
1120        struct diff_filespec *one, *two;
1121
1122        /* This may look odd, but it is a preparation for
1123         * feeding "there are unchanged files which should
1124         * not produce diffs, but when you are doing copy
1125         * detection you would need them, so here they are"
1126         * entries to the diff-core.  They will be prefixed
1127         * with something like '=' or '*' (I haven't decided
1128         * which but should not make any difference).
1129         * Feeding the same new and old to diff_change() 
1130         * also has the same effect.
1131         * Before the final output happens, they are pruned after
1132         * merged into rename/copy pairs as appropriate.
1133         */
1134        if (reverse_diff)
1135                addremove = (addremove == '+' ? '-' :
1136                             addremove == '-' ? '+' : addremove);
1137
1138        if (!path) path = "";
1139        sprintf(concatpath, "%s%s", base, path);
1140        one = alloc_filespec(concatpath);
1141        two = alloc_filespec(concatpath);
1142
1143        if (addremove != '+')
1144                fill_filespec(one, sha1, mode);
1145        if (addremove != '-')
1146                fill_filespec(two, sha1, mode);
1147
1148        diff_queue(&diff_queued_diff, one, two);
1149}
1150
1151void diff_helper_input(unsigned old_mode,
1152                       unsigned new_mode,
1153                       const unsigned char *old_sha1,
1154                       const unsigned char *new_sha1,
1155                       const char *old_path,
1156                       int status,
1157                       int score,
1158                       const char *new_path)
1159{
1160        struct diff_filespec *one, *two;
1161        struct diff_filepair *dp;
1162
1163        one = alloc_filespec(old_path);
1164        two = alloc_filespec(new_path);
1165        if (old_mode)
1166                fill_filespec(one, old_sha1, old_mode);
1167        if (new_mode)
1168                fill_filespec(two, new_sha1, new_mode);
1169        dp = diff_queue(&diff_queued_diff, one, two);
1170        dp->score = score * MAX_SCORE / 100;
1171        dp->status = status;
1172}
1173
1174void diff_change(unsigned old_mode, unsigned new_mode,
1175                 const unsigned char *old_sha1,
1176                 const unsigned char *new_sha1,
1177                 const char *base, const char *path) 
1178{
1179        char concatpath[PATH_MAX];
1180        struct diff_filespec *one, *two;
1181
1182        if (reverse_diff) {
1183                unsigned tmp;
1184                const unsigned char *tmp_c;
1185                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1186                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1187        }
1188        if (!path) path = "";
1189        sprintf(concatpath, "%s%s", base, path);
1190        one = alloc_filespec(concatpath);
1191        two = alloc_filespec(concatpath);
1192        fill_filespec(one, old_sha1, old_mode);
1193        fill_filespec(two, new_sha1, new_mode);
1194
1195        diff_queue(&diff_queued_diff, one, two);
1196}
1197
1198void diff_unmerge(const char *path)
1199{
1200        struct diff_filespec *one, *two;
1201        one = alloc_filespec(path);
1202        two = alloc_filespec(path);
1203        diff_queue(&diff_queued_diff, one, two);
1204}