diff.con commit Merge branch 'lt/oneway' (8701ea0)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include <sys/types.h>
   5#include <sys/wait.h>
   6#include <signal.h>
   7#include "cache.h"
   8#include "quote.h"
   9#include "diff.h"
  10#include "diffcore.h"
  11#include "delta.h"
  12#include "xdiff-interface.h"
  13
  14static int use_size_cache;
  15
  16int diff_rename_limit_default = -1;
  17
  18int git_diff_config(const char *var, const char *value)
  19{
  20        if (!strcmp(var, "diff.renamelimit")) {
  21                diff_rename_limit_default = git_config_int(var, value);
  22                return 0;
  23        }
  24
  25        return git_default_config(var, value);
  26}
  27
  28static char *quote_one(const char *str)
  29{
  30        int needlen;
  31        char *xp;
  32
  33        if (!str)
  34                return NULL;
  35        needlen = quote_c_style(str, NULL, NULL, 0);
  36        if (!needlen)
  37                return strdup(str);
  38        xp = xmalloc(needlen + 1);
  39        quote_c_style(str, xp, NULL, 0);
  40        return xp;
  41}
  42
  43static char *quote_two(const char *one, const char *two)
  44{
  45        int need_one = quote_c_style(one, NULL, NULL, 1);
  46        int need_two = quote_c_style(two, NULL, NULL, 1);
  47        char *xp;
  48
  49        if (need_one + need_two) {
  50                if (!need_one) need_one = strlen(one);
  51                if (!need_two) need_one = strlen(two);
  52
  53                xp = xmalloc(need_one + need_two + 3);
  54                xp[0] = '"';
  55                quote_c_style(one, xp + 1, NULL, 1);
  56                quote_c_style(two, xp + need_one + 1, NULL, 1);
  57                strcpy(xp + need_one + need_two + 1, "\"");
  58                return xp;
  59        }
  60        need_one = strlen(one);
  61        need_two = strlen(two);
  62        xp = xmalloc(need_one + need_two + 1);
  63        strcpy(xp, one);
  64        strcpy(xp + need_one, two);
  65        return xp;
  66}
  67
  68static const char *external_diff(void)
  69{
  70        static const char *external_diff_cmd = NULL;
  71        static int done_preparing = 0;
  72
  73        if (done_preparing)
  74                return external_diff_cmd;
  75        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
  76        done_preparing = 1;
  77        return external_diff_cmd;
  78}
  79
  80#define TEMPFILE_PATH_LEN               50
  81
  82static struct diff_tempfile {
  83        const char *name; /* filename external diff should read from */
  84        char hex[41];
  85        char mode[10];
  86        char tmp_path[TEMPFILE_PATH_LEN];
  87} diff_temp[2];
  88
  89static int count_lines(const char *data, int size)
  90{
  91        int count, ch, completely_empty = 1, nl_just_seen = 0;
  92        count = 0;
  93        while (0 < size--) {
  94                ch = *data++;
  95                if (ch == '\n') {
  96                        count++;
  97                        nl_just_seen = 1;
  98                        completely_empty = 0;
  99                }
 100                else {
 101                        nl_just_seen = 0;
 102                        completely_empty = 0;
 103                }
 104        }
 105        if (completely_empty)
 106                return 0;
 107        if (!nl_just_seen)
 108                count++; /* no trailing newline */
 109        return count;
 110}
 111
 112static void print_line_count(int count)
 113{
 114        switch (count) {
 115        case 0:
 116                printf("0,0");
 117                break;
 118        case 1:
 119                printf("1");
 120                break;
 121        default:
 122                printf("1,%d", count);
 123                break;
 124        }
 125}
 126
 127static void copy_file(int prefix, const char *data, int size)
 128{
 129        int ch, nl_just_seen = 1;
 130        while (0 < size--) {
 131                ch = *data++;
 132                if (nl_just_seen)
 133                        putchar(prefix);
 134                putchar(ch);
 135                if (ch == '\n')
 136                        nl_just_seen = 1;
 137                else
 138                        nl_just_seen = 0;
 139        }
 140        if (!nl_just_seen)
 141                printf("\n\\ No newline at end of file\n");
 142}
 143
 144static void emit_rewrite_diff(const char *name_a,
 145                              const char *name_b,
 146                              struct diff_filespec *one,
 147                              struct diff_filespec *two)
 148{
 149        int lc_a, lc_b;
 150        diff_populate_filespec(one, 0);
 151        diff_populate_filespec(two, 0);
 152        lc_a = count_lines(one->data, one->size);
 153        lc_b = count_lines(two->data, two->size);
 154        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 155        print_line_count(lc_a);
 156        printf(" +");
 157        print_line_count(lc_b);
 158        printf(" @@\n");
 159        if (lc_a)
 160                copy_file('-', one->data, one->size);
 161        if (lc_b)
 162                copy_file('+', two->data, two->size);
 163}
 164
 165static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 166{
 167        if (!DIFF_FILE_VALID(one)) {
 168                mf->ptr = ""; /* does not matter */
 169                mf->size = 0;
 170                return 0;
 171        }
 172        else if (diff_populate_filespec(one, 0))
 173                return -1;
 174        mf->ptr = one->data;
 175        mf->size = one->size;
 176        return 0;
 177}
 178
 179struct emit_callback {
 180        const char **label_path;
 181};
 182
 183static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
 184{
 185        int i;
 186        struct emit_callback *ecbdata = priv;
 187
 188        if (ecbdata->label_path[0]) {
 189                printf("--- %s\n", ecbdata->label_path[0]);
 190                printf("+++ %s\n", ecbdata->label_path[1]);
 191                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 192        }
 193        for (i = 0; i < nbuf; i++)
 194                if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
 195                        return -1;
 196        return 0;
 197}
 198
 199static char *pprint_rename(const char *a, const char *b)
 200{
 201        const char *old = a;
 202        const char *new = b;
 203        char *name = NULL;
 204        int pfx_length, sfx_length;
 205        int len_a = strlen(a);
 206        int len_b = strlen(b);
 207
 208        /* Find common prefix */
 209        pfx_length = 0;
 210        while (*old && *new && *old == *new) {
 211                if (*old == '/')
 212                        pfx_length = old - a + 1;
 213                old++;
 214                new++;
 215        }
 216
 217        /* Find common suffix */
 218        old = a + len_a;
 219        new = b + len_b;
 220        sfx_length = 0;
 221        while (a <= old && b <= new && *old == *new) {
 222                if (*old == '/')
 223                        sfx_length = len_a - (old - a);
 224                old--;
 225                new--;
 226        }
 227
 228        /*
 229         * pfx{mid-a => mid-b}sfx
 230         * {pfx-a => pfx-b}sfx
 231         * pfx{sfx-a => sfx-b}
 232         * name-a => name-b
 233         */
 234        if (pfx_length + sfx_length) {
 235                int a_midlen = len_a - pfx_length - sfx_length;
 236                int b_midlen = len_b - pfx_length - sfx_length;
 237                if (a_midlen < 0) a_midlen = 0;
 238                if (b_midlen < 0) b_midlen = 0;
 239
 240                name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
 241                sprintf(name, "%.*s{%.*s => %.*s}%s",
 242                        pfx_length, a,
 243                        a_midlen, a + pfx_length,
 244                        b_midlen, b + pfx_length,
 245                        a + len_a - sfx_length);
 246        }
 247        else {
 248                name = xmalloc(len_a + len_b + 5);
 249                sprintf(name, "%s => %s", a, b);
 250        }
 251        return name;
 252}
 253
 254struct diffstat_t {
 255        struct xdiff_emit_state xm;
 256
 257        int nr;
 258        int alloc;
 259        struct diffstat_file {
 260                char *name;
 261                unsigned is_unmerged:1;
 262                unsigned is_binary:1;
 263                unsigned is_renamed:1;
 264                unsigned int added, deleted;
 265        } **files;
 266};
 267
 268static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 269                                          const char *name_a,
 270                                          const char *name_b)
 271{
 272        struct diffstat_file *x;
 273        x = xcalloc(sizeof (*x), 1);
 274        if (diffstat->nr == diffstat->alloc) {
 275                diffstat->alloc = alloc_nr(diffstat->alloc);
 276                diffstat->files = xrealloc(diffstat->files,
 277                                diffstat->alloc * sizeof(x));
 278        }
 279        diffstat->files[diffstat->nr++] = x;
 280        if (name_b) {
 281                x->name = pprint_rename(name_a, name_b);
 282                x->is_renamed = 1;
 283        }
 284        else
 285                x->name = strdup(name_a);
 286        return x;
 287}
 288
 289static void diffstat_consume(void *priv, char *line, unsigned long len)
 290{
 291        struct diffstat_t *diffstat = priv;
 292        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 293
 294        if (line[0] == '+')
 295                x->added++;
 296        else if (line[0] == '-')
 297                x->deleted++;
 298}
 299
 300static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 301static const char minuses[]= "----------------------------------------------------------------------";
 302
 303static void show_stats(struct diffstat_t* data)
 304{
 305        int i, len, add, del, total, adds = 0, dels = 0;
 306        int max, max_change = 0, max_len = 0;
 307        int total_files = data->nr;
 308
 309        if (data->nr == 0)
 310                return;
 311
 312        for (i = 0; i < data->nr; i++) {
 313                struct diffstat_file *file = data->files[i];
 314
 315                len = strlen(file->name);
 316                if (max_len < len)
 317                        max_len = len;
 318
 319                if (file->is_binary || file->is_unmerged)
 320                        continue;
 321                if (max_change < file->added + file->deleted)
 322                        max_change = file->added + file->deleted;
 323        }
 324
 325        for (i = 0; i < data->nr; i++) {
 326                char *prefix = "";
 327                char *name = data->files[i]->name;
 328                int added = data->files[i]->added;
 329                int deleted = data->files[i]->deleted;
 330
 331                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 332                        char *qname = xmalloc(len + 1);
 333                        quote_c_style(name, qname, NULL, 0);
 334                        free(name);
 335                        data->files[i]->name = name = qname;
 336                }
 337
 338                /*
 339                 * "scale" the filename
 340                 */
 341                len = strlen(name);
 342                max = max_len;
 343                if (max > 50)
 344                        max = 50;
 345                if (len > max) {
 346                        char *slash;
 347                        prefix = "...";
 348                        max -= 3;
 349                        name += len - max;
 350                        slash = strchr(name, '/');
 351                        if (slash)
 352                                name = slash;
 353                }
 354                len = max;
 355
 356                /*
 357                 * scale the add/delete
 358                 */
 359                max = max_change;
 360                if (max + len > 70)
 361                        max = 70 - len;
 362
 363                if (data->files[i]->is_binary) {
 364                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 365                        goto free_diffstat_file;
 366                }
 367                else if (data->files[i]->is_unmerged) {
 368                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 369                        goto free_diffstat_file;
 370                }
 371                else if (!data->files[i]->is_renamed &&
 372                         (added + deleted == 0)) {
 373                        total_files--;
 374                        goto free_diffstat_file;
 375                }
 376
 377                add = added;
 378                del = deleted;
 379                total = add + del;
 380                adds += add;
 381                dels += del;
 382
 383                if (max_change > 0) {
 384                        total = (total * max + max_change / 2) / max_change;
 385                        add = (add * max + max_change / 2) / max_change;
 386                        del = total - add;
 387                }
 388                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 389                                len, name, added + deleted,
 390                                add, pluses, del, minuses);
 391        free_diffstat_file:
 392                free(data->files[i]->name);
 393                free(data->files[i]);
 394        }
 395        free(data->files);
 396        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 397                        total_files, adds, dels);
 398}
 399
 400static unsigned char *deflate_it(char *data,
 401                                 unsigned long size,
 402                                 unsigned long *result_size)
 403{
 404        int bound;
 405        unsigned char *deflated;
 406        z_stream stream;
 407
 408        memset(&stream, 0, sizeof(stream));
 409        deflateInit(&stream, Z_BEST_COMPRESSION);
 410        bound = deflateBound(&stream, size);
 411        deflated = xmalloc(bound);
 412        stream.next_out = deflated;
 413        stream.avail_out = bound;
 414
 415        stream.next_in = (unsigned char *)data;
 416        stream.avail_in = size;
 417        while (deflate(&stream, Z_FINISH) == Z_OK)
 418                ; /* nothing */
 419        deflateEnd(&stream);
 420        *result_size = stream.total_out;
 421        return deflated;
 422}
 423
 424static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 425{
 426        void *cp;
 427        void *delta;
 428        void *deflated;
 429        void *data;
 430        unsigned long orig_size;
 431        unsigned long delta_size;
 432        unsigned long deflate_size;
 433        unsigned long data_size;
 434
 435        printf("GIT binary patch\n");
 436        /* We could do deflated delta, or we could do just deflated two,
 437         * whichever is smaller.
 438         */
 439        delta = NULL;
 440        deflated = deflate_it(two->ptr, two->size, &deflate_size);
 441        if (one->size && two->size) {
 442                delta = diff_delta(one->ptr, one->size,
 443                                   two->ptr, two->size,
 444                                   &delta_size, deflate_size);
 445                if (delta) {
 446                        void *to_free = delta;
 447                        orig_size = delta_size;
 448                        delta = deflate_it(delta, delta_size, &delta_size);
 449                        free(to_free);
 450                }
 451        }
 452
 453        if (delta && delta_size < deflate_size) {
 454                printf("delta %lu\n", orig_size);
 455                free(deflated);
 456                data = delta;
 457                data_size = delta_size;
 458        }
 459        else {
 460                printf("literal %lu\n", two->size);
 461                free(delta);
 462                data = deflated;
 463                data_size = deflate_size;
 464        }
 465
 466        /* emit data encoded in base85 */
 467        cp = data;
 468        while (data_size) {
 469                int bytes = (52 < data_size) ? 52 : data_size;
 470                char line[70];
 471                data_size -= bytes;
 472                if (bytes <= 26)
 473                        line[0] = bytes + 'A' - 1;
 474                else
 475                        line[0] = bytes - 26 + 'a' - 1;
 476                encode_85(line + 1, cp, bytes);
 477                cp += bytes;
 478                puts(line);
 479        }
 480        printf("\n");
 481        free(data);
 482}
 483
 484#define FIRST_FEW_BYTES 8000
 485static int mmfile_is_binary(mmfile_t *mf)
 486{
 487        long sz = mf->size;
 488        if (FIRST_FEW_BYTES < sz)
 489                sz = FIRST_FEW_BYTES;
 490        if (memchr(mf->ptr, 0, sz))
 491                return 1;
 492        return 0;
 493}
 494
 495static void builtin_diff(const char *name_a,
 496                         const char *name_b,
 497                         struct diff_filespec *one,
 498                         struct diff_filespec *two,
 499                         const char *xfrm_msg,
 500                         struct diff_options *o,
 501                         int complete_rewrite)
 502{
 503        mmfile_t mf1, mf2;
 504        const char *lbl[2];
 505        char *a_one, *b_two;
 506
 507        a_one = quote_two("a/", name_a);
 508        b_two = quote_two("b/", name_b);
 509        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 510        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 511        printf("diff --git %s %s\n", a_one, b_two);
 512        if (lbl[0][0] == '/') {
 513                /* /dev/null */
 514                printf("new file mode %06o\n", two->mode);
 515                if (xfrm_msg && xfrm_msg[0])
 516                        puts(xfrm_msg);
 517        }
 518        else if (lbl[1][0] == '/') {
 519                printf("deleted file mode %06o\n", one->mode);
 520                if (xfrm_msg && xfrm_msg[0])
 521                        puts(xfrm_msg);
 522        }
 523        else {
 524                if (one->mode != two->mode) {
 525                        printf("old mode %06o\n", one->mode);
 526                        printf("new mode %06o\n", two->mode);
 527                }
 528                if (xfrm_msg && xfrm_msg[0])
 529                        puts(xfrm_msg);
 530                /*
 531                 * we do not run diff between different kind
 532                 * of objects.
 533                 */
 534                if ((one->mode ^ two->mode) & S_IFMT)
 535                        goto free_ab_and_return;
 536                if (complete_rewrite) {
 537                        emit_rewrite_diff(name_a, name_b, one, two);
 538                        goto free_ab_and_return;
 539                }
 540        }
 541
 542        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 543                die("unable to read files to diff");
 544
 545        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
 546                /* Quite common confusing case */
 547                if (mf1.size == mf2.size &&
 548                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 549                        goto free_ab_and_return;
 550                if (o->binary)
 551                        emit_binary_diff(&mf1, &mf2);
 552                else
 553                        printf("Binary files %s and %s differ\n",
 554                               lbl[0], lbl[1]);
 555        }
 556        else {
 557                /* Crazy xdl interfaces.. */
 558                const char *diffopts = getenv("GIT_DIFF_OPTS");
 559                xpparam_t xpp;
 560                xdemitconf_t xecfg;
 561                xdemitcb_t ecb;
 562                struct emit_callback ecbdata;
 563
 564                ecbdata.label_path = lbl;
 565                xpp.flags = XDF_NEED_MINIMAL;
 566                xecfg.ctxlen = o->context;
 567                xecfg.flags = XDL_EMIT_FUNCNAMES;
 568                if (!diffopts)
 569                        ;
 570                else if (!strncmp(diffopts, "--unified=", 10))
 571                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 572                else if (!strncmp(diffopts, "-u", 2))
 573                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 574                ecb.outf = fn_out;
 575                ecb.priv = &ecbdata;
 576                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 577        }
 578
 579 free_ab_and_return:
 580        free(a_one);
 581        free(b_two);
 582        return;
 583}
 584
 585static void builtin_diffstat(const char *name_a, const char *name_b,
 586                             struct diff_filespec *one,
 587                             struct diff_filespec *two,
 588                             struct diffstat_t *diffstat,
 589                             int complete_rewrite)
 590{
 591        mmfile_t mf1, mf2;
 592        struct diffstat_file *data;
 593
 594        data = diffstat_add(diffstat, name_a, name_b);
 595
 596        if (!one || !two) {
 597                data->is_unmerged = 1;
 598                return;
 599        }
 600        if (complete_rewrite) {
 601                diff_populate_filespec(one, 0);
 602                diff_populate_filespec(two, 0);
 603                data->deleted = count_lines(one->data, one->size);
 604                data->added = count_lines(two->data, two->size);
 605                return;
 606        }
 607        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 608                die("unable to read files to diff");
 609
 610        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 611                data->is_binary = 1;
 612        else {
 613                /* Crazy xdl interfaces.. */
 614                xpparam_t xpp;
 615                xdemitconf_t xecfg;
 616                xdemitcb_t ecb;
 617
 618                xpp.flags = XDF_NEED_MINIMAL;
 619                xecfg.ctxlen = 0;
 620                xecfg.flags = 0;
 621                ecb.outf = xdiff_outf;
 622                ecb.priv = diffstat;
 623                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 624        }
 625}
 626
 627struct diff_filespec *alloc_filespec(const char *path)
 628{
 629        int namelen = strlen(path);
 630        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 631
 632        memset(spec, 0, sizeof(*spec));
 633        spec->path = (char *)(spec + 1);
 634        memcpy(spec->path, path, namelen+1);
 635        return spec;
 636}
 637
 638void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 639                   unsigned short mode)
 640{
 641        if (mode) {
 642                spec->mode = canon_mode(mode);
 643                memcpy(spec->sha1, sha1, 20);
 644                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 645        }
 646}
 647
 648/*
 649 * Given a name and sha1 pair, if the dircache tells us the file in
 650 * the work tree has that object contents, return true, so that
 651 * prepare_temp_file() does not have to inflate and extract.
 652 */
 653static int work_tree_matches(const char *name, const unsigned char *sha1)
 654{
 655        struct cache_entry *ce;
 656        struct stat st;
 657        int pos, len;
 658
 659        /* We do not read the cache ourselves here, because the
 660         * benchmark with my previous version that always reads cache
 661         * shows that it makes things worse for diff-tree comparing
 662         * two linux-2.6 kernel trees in an already checked out work
 663         * tree.  This is because most diff-tree comparisons deal with
 664         * only a small number of files, while reading the cache is
 665         * expensive for a large project, and its cost outweighs the
 666         * savings we get by not inflating the object to a temporary
 667         * file.  Practically, this code only helps when we are used
 668         * by diff-cache --cached, which does read the cache before
 669         * calling us.
 670         */
 671        if (!active_cache)
 672                return 0;
 673
 674        len = strlen(name);
 675        pos = cache_name_pos(name, len);
 676        if (pos < 0)
 677                return 0;
 678        ce = active_cache[pos];
 679        if ((lstat(name, &st) < 0) ||
 680            !S_ISREG(st.st_mode) || /* careful! */
 681            ce_match_stat(ce, &st, 0) ||
 682            memcmp(sha1, ce->sha1, 20))
 683                return 0;
 684        /* we return 1 only when we can stat, it is a regular file,
 685         * stat information matches, and sha1 recorded in the cache
 686         * matches.  I.e. we know the file in the work tree really is
 687         * the same as the <name, sha1> pair.
 688         */
 689        return 1;
 690}
 691
 692static struct sha1_size_cache {
 693        unsigned char sha1[20];
 694        unsigned long size;
 695} **sha1_size_cache;
 696static int sha1_size_cache_nr, sha1_size_cache_alloc;
 697
 698static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 699                                                 int find_only,
 700                                                 unsigned long size)
 701{
 702        int first, last;
 703        struct sha1_size_cache *e;
 704
 705        first = 0;
 706        last = sha1_size_cache_nr;
 707        while (last > first) {
 708                int cmp, next = (last + first) >> 1;
 709                e = sha1_size_cache[next];
 710                cmp = memcmp(e->sha1, sha1, 20);
 711                if (!cmp)
 712                        return e;
 713                if (cmp < 0) {
 714                        last = next;
 715                        continue;
 716                }
 717                first = next+1;
 718        }
 719        /* not found */
 720        if (find_only)
 721                return NULL;
 722        /* insert to make it at "first" */
 723        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 724                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 725                sha1_size_cache = xrealloc(sha1_size_cache,
 726                                           sha1_size_cache_alloc *
 727                                           sizeof(*sha1_size_cache));
 728        }
 729        sha1_size_cache_nr++;
 730        if (first < sha1_size_cache_nr)
 731                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 732                        (sha1_size_cache_nr - first - 1) *
 733                        sizeof(*sha1_size_cache));
 734        e = xmalloc(sizeof(struct sha1_size_cache));
 735        sha1_size_cache[first] = e;
 736        memcpy(e->sha1, sha1, 20);
 737        e->size = size;
 738        return e;
 739}
 740
 741/*
 742 * While doing rename detection and pickaxe operation, we may need to
 743 * grab the data for the blob (or file) for our own in-core comparison.
 744 * diff_filespec has data and size fields for this purpose.
 745 */
 746int diff_populate_filespec(struct diff_filespec *s, int size_only)
 747{
 748        int err = 0;
 749        if (!DIFF_FILE_VALID(s))
 750                die("internal error: asking to populate invalid file.");
 751        if (S_ISDIR(s->mode))
 752                return -1;
 753
 754        if (!use_size_cache)
 755                size_only = 0;
 756
 757        if (s->data)
 758                return err;
 759        if (!s->sha1_valid ||
 760            work_tree_matches(s->path, s->sha1)) {
 761                struct stat st;
 762                int fd;
 763                if (lstat(s->path, &st) < 0) {
 764                        if (errno == ENOENT) {
 765                        err_empty:
 766                                err = -1;
 767                        empty:
 768                                s->data = "";
 769                                s->size = 0;
 770                                return err;
 771                        }
 772                }
 773                s->size = st.st_size;
 774                if (!s->size)
 775                        goto empty;
 776                if (size_only)
 777                        return 0;
 778                if (S_ISLNK(st.st_mode)) {
 779                        int ret;
 780                        s->data = xmalloc(s->size);
 781                        s->should_free = 1;
 782                        ret = readlink(s->path, s->data, s->size);
 783                        if (ret < 0) {
 784                                free(s->data);
 785                                goto err_empty;
 786                        }
 787                        return 0;
 788                }
 789                fd = open(s->path, O_RDONLY);
 790                if (fd < 0)
 791                        goto err_empty;
 792                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 793                close(fd);
 794                if (s->data == MAP_FAILED)
 795                        goto err_empty;
 796                s->should_munmap = 1;
 797        }
 798        else {
 799                char type[20];
 800                struct sha1_size_cache *e;
 801
 802                if (size_only) {
 803                        e = locate_size_cache(s->sha1, 1, 0);
 804                        if (e) {
 805                                s->size = e->size;
 806                                return 0;
 807                        }
 808                        if (!sha1_object_info(s->sha1, type, &s->size))
 809                                locate_size_cache(s->sha1, 0, s->size);
 810                }
 811                else {
 812                        s->data = read_sha1_file(s->sha1, type, &s->size);
 813                        s->should_free = 1;
 814                }
 815        }
 816        return 0;
 817}
 818
 819void diff_free_filespec_data(struct diff_filespec *s)
 820{
 821        if (s->should_free)
 822                free(s->data);
 823        else if (s->should_munmap)
 824                munmap(s->data, s->size);
 825        s->should_free = s->should_munmap = 0;
 826        s->data = NULL;
 827        free(s->cnt_data);
 828        s->cnt_data = NULL;
 829}
 830
 831static void prep_temp_blob(struct diff_tempfile *temp,
 832                           void *blob,
 833                           unsigned long size,
 834                           const unsigned char *sha1,
 835                           int mode)
 836{
 837        int fd;
 838
 839        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 840        if (fd < 0)
 841                die("unable to create temp-file");
 842        if (write(fd, blob, size) != size)
 843                die("unable to write temp-file");
 844        close(fd);
 845        temp->name = temp->tmp_path;
 846        strcpy(temp->hex, sha1_to_hex(sha1));
 847        temp->hex[40] = 0;
 848        sprintf(temp->mode, "%06o", mode);
 849}
 850
 851static void prepare_temp_file(const char *name,
 852                              struct diff_tempfile *temp,
 853                              struct diff_filespec *one)
 854{
 855        if (!DIFF_FILE_VALID(one)) {
 856        not_a_valid_file:
 857                /* A '-' entry produces this for file-2, and
 858                 * a '+' entry produces this for file-1.
 859                 */
 860                temp->name = "/dev/null";
 861                strcpy(temp->hex, ".");
 862                strcpy(temp->mode, ".");
 863                return;
 864        }
 865
 866        if (!one->sha1_valid ||
 867            work_tree_matches(name, one->sha1)) {
 868                struct stat st;
 869                if (lstat(name, &st) < 0) {
 870                        if (errno == ENOENT)
 871                                goto not_a_valid_file;
 872                        die("stat(%s): %s", name, strerror(errno));
 873                }
 874                if (S_ISLNK(st.st_mode)) {
 875                        int ret;
 876                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 877                        if (sizeof(buf) <= st.st_size)
 878                                die("symlink too long: %s", name);
 879                        ret = readlink(name, buf, st.st_size);
 880                        if (ret < 0)
 881                                die("readlink(%s)", name);
 882                        prep_temp_blob(temp, buf, st.st_size,
 883                                       (one->sha1_valid ?
 884                                        one->sha1 : null_sha1),
 885                                       (one->sha1_valid ?
 886                                        one->mode : S_IFLNK));
 887                }
 888                else {
 889                        /* we can borrow from the file in the work tree */
 890                        temp->name = name;
 891                        if (!one->sha1_valid)
 892                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 893                        else
 894                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 895                        /* Even though we may sometimes borrow the
 896                         * contents from the work tree, we always want
 897                         * one->mode.  mode is trustworthy even when
 898                         * !(one->sha1_valid), as long as
 899                         * DIFF_FILE_VALID(one).
 900                         */
 901                        sprintf(temp->mode, "%06o", one->mode);
 902                }
 903                return;
 904        }
 905        else {
 906                if (diff_populate_filespec(one, 0))
 907                        die("cannot read data blob for %s", one->path);
 908                prep_temp_blob(temp, one->data, one->size,
 909                               one->sha1, one->mode);
 910        }
 911}
 912
 913static void remove_tempfile(void)
 914{
 915        int i;
 916
 917        for (i = 0; i < 2; i++)
 918                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 919                        unlink(diff_temp[i].name);
 920                        diff_temp[i].name = NULL;
 921                }
 922}
 923
 924static void remove_tempfile_on_signal(int signo)
 925{
 926        remove_tempfile();
 927        signal(SIGINT, SIG_DFL);
 928        raise(signo);
 929}
 930
 931static int spawn_prog(const char *pgm, const char **arg)
 932{
 933        pid_t pid;
 934        int status;
 935
 936        fflush(NULL);
 937        pid = fork();
 938        if (pid < 0)
 939                die("unable to fork");
 940        if (!pid) {
 941                execvp(pgm, (char *const*) arg);
 942                exit(255);
 943        }
 944
 945        while (waitpid(pid, &status, 0) < 0) {
 946                if (errno == EINTR)
 947                        continue;
 948                return -1;
 949        }
 950
 951        /* Earlier we did not check the exit status because
 952         * diff exits non-zero if files are different, and
 953         * we are not interested in knowing that.  It was a
 954         * mistake which made it harder to quit a diff-*
 955         * session that uses the git-apply-patch-script as
 956         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 957         * should also exit non-zero only when it wants to
 958         * abort the entire diff-* session.
 959         */
 960        if (WIFEXITED(status) && !WEXITSTATUS(status))
 961                return 0;
 962        return -1;
 963}
 964
 965/* An external diff command takes:
 966 *
 967 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 968 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 969 *
 970 */
 971static void run_external_diff(const char *pgm,
 972                              const char *name,
 973                              const char *other,
 974                              struct diff_filespec *one,
 975                              struct diff_filespec *two,
 976                              const char *xfrm_msg,
 977                              int complete_rewrite)
 978{
 979        const char *spawn_arg[10];
 980        struct diff_tempfile *temp = diff_temp;
 981        int retval;
 982        static int atexit_asked = 0;
 983        const char *othername;
 984        const char **arg = &spawn_arg[0];
 985
 986        othername = (other? other : name);
 987        if (one && two) {
 988                prepare_temp_file(name, &temp[0], one);
 989                prepare_temp_file(othername, &temp[1], two);
 990                if (! atexit_asked &&
 991                    (temp[0].name == temp[0].tmp_path ||
 992                     temp[1].name == temp[1].tmp_path)) {
 993                        atexit_asked = 1;
 994                        atexit(remove_tempfile);
 995                }
 996                signal(SIGINT, remove_tempfile_on_signal);
 997        }
 998
 999        if (one && two) {
1000                *arg++ = pgm;
1001                *arg++ = name;
1002                *arg++ = temp[0].name;
1003                *arg++ = temp[0].hex;
1004                *arg++ = temp[0].mode;
1005                *arg++ = temp[1].name;
1006                *arg++ = temp[1].hex;
1007                *arg++ = temp[1].mode;
1008                if (other) {
1009                        *arg++ = other;
1010                        *arg++ = xfrm_msg;
1011                }
1012        } else {
1013                *arg++ = pgm;
1014                *arg++ = name;
1015        }
1016        *arg = NULL;
1017        retval = spawn_prog(pgm, spawn_arg);
1018        remove_tempfile();
1019        if (retval) {
1020                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1021                exit(1);
1022        }
1023}
1024
1025static void run_diff_cmd(const char *pgm,
1026                         const char *name,
1027                         const char *other,
1028                         struct diff_filespec *one,
1029                         struct diff_filespec *two,
1030                         const char *xfrm_msg,
1031                         struct diff_options *o,
1032                         int complete_rewrite)
1033{
1034        if (pgm) {
1035                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1036                                  complete_rewrite);
1037                return;
1038        }
1039        if (one && two)
1040                builtin_diff(name, other ? other : name,
1041                             one, two, xfrm_msg, o, complete_rewrite);
1042        else
1043                printf("* Unmerged path %s\n", name);
1044}
1045
1046static void diff_fill_sha1_info(struct diff_filespec *one)
1047{
1048        if (DIFF_FILE_VALID(one)) {
1049                if (!one->sha1_valid) {
1050                        struct stat st;
1051                        if (lstat(one->path, &st) < 0)
1052                                die("stat %s", one->path);
1053                        if (index_path(one->sha1, one->path, &st, 0))
1054                                die("cannot hash %s\n", one->path);
1055                }
1056        }
1057        else
1058                memset(one->sha1, 0, 20);
1059}
1060
1061static void run_diff(struct diff_filepair *p, struct diff_options *o)
1062{
1063        const char *pgm = external_diff();
1064        char msg[PATH_MAX*2+300], *xfrm_msg;
1065        struct diff_filespec *one;
1066        struct diff_filespec *two;
1067        const char *name;
1068        const char *other;
1069        char *name_munged, *other_munged;
1070        int complete_rewrite = 0;
1071        int len;
1072
1073        if (DIFF_PAIR_UNMERGED(p)) {
1074                /* unmerged */
1075                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1076                return;
1077        }
1078
1079        name = p->one->path;
1080        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1081        name_munged = quote_one(name);
1082        other_munged = quote_one(other);
1083        one = p->one; two = p->two;
1084
1085        diff_fill_sha1_info(one);
1086        diff_fill_sha1_info(two);
1087
1088        len = 0;
1089        switch (p->status) {
1090        case DIFF_STATUS_COPIED:
1091                len += snprintf(msg + len, sizeof(msg) - len,
1092                                "similarity index %d%%\n"
1093                                "copy from %s\n"
1094                                "copy to %s\n",
1095                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1096                                name_munged, other_munged);
1097                break;
1098        case DIFF_STATUS_RENAMED:
1099                len += snprintf(msg + len, sizeof(msg) - len,
1100                                "similarity index %d%%\n"
1101                                "rename from %s\n"
1102                                "rename to %s\n",
1103                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1104                                name_munged, other_munged);
1105                break;
1106        case DIFF_STATUS_MODIFIED:
1107                if (p->score) {
1108                        len += snprintf(msg + len, sizeof(msg) - len,
1109                                        "dissimilarity index %d%%\n",
1110                                        (int)(0.5 + p->score *
1111                                              100.0/MAX_SCORE));
1112                        complete_rewrite = 1;
1113                        break;
1114                }
1115                /* fallthru */
1116        default:
1117                /* nothing */
1118                ;
1119        }
1120
1121        if (memcmp(one->sha1, two->sha1, 20)) {
1122                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1123
1124                len += snprintf(msg + len, sizeof(msg) - len,
1125                                "index %.*s..%.*s",
1126                                abbrev, sha1_to_hex(one->sha1),
1127                                abbrev, sha1_to_hex(two->sha1));
1128                if (one->mode == two->mode)
1129                        len += snprintf(msg + len, sizeof(msg) - len,
1130                                        " %06o", one->mode);
1131                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1132        }
1133
1134        if (len)
1135                msg[--len] = 0;
1136        xfrm_msg = len ? msg : NULL;
1137
1138        if (!pgm &&
1139            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1140            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1141                /* a filepair that changes between file and symlink
1142                 * needs to be split into deletion and creation.
1143                 */
1144                struct diff_filespec *null = alloc_filespec(two->path);
1145                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1146                free(null);
1147                null = alloc_filespec(one->path);
1148                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1149                free(null);
1150        }
1151        else
1152                run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1153                             complete_rewrite);
1154
1155        free(name_munged);
1156        free(other_munged);
1157}
1158
1159static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1160                         struct diffstat_t *diffstat)
1161{
1162        const char *name;
1163        const char *other;
1164        int complete_rewrite = 0;
1165
1166        if (DIFF_PAIR_UNMERGED(p)) {
1167                /* unmerged */
1168                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
1169                return;
1170        }
1171
1172        name = p->one->path;
1173        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1174
1175        diff_fill_sha1_info(p->one);
1176        diff_fill_sha1_info(p->two);
1177
1178        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1179                complete_rewrite = 1;
1180        builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
1181}
1182
1183void diff_setup(struct diff_options *options)
1184{
1185        memset(options, 0, sizeof(*options));
1186        options->output_format = DIFF_FORMAT_RAW;
1187        options->line_termination = '\n';
1188        options->break_opt = -1;
1189        options->rename_limit = -1;
1190        options->context = 3;
1191
1192        options->change = diff_change;
1193        options->add_remove = diff_addremove;
1194}
1195
1196int diff_setup_done(struct diff_options *options)
1197{
1198        if ((options->find_copies_harder &&
1199             options->detect_rename != DIFF_DETECT_COPY) ||
1200            (0 <= options->rename_limit && !options->detect_rename))
1201                return -1;
1202
1203        /*
1204         * These cases always need recursive; we do not drop caller-supplied
1205         * recursive bits for other formats here.
1206         */
1207        if ((options->output_format == DIFF_FORMAT_PATCH) ||
1208            (options->output_format == DIFF_FORMAT_DIFFSTAT))
1209                options->recursive = 1;
1210
1211        if (options->detect_rename && options->rename_limit < 0)
1212                options->rename_limit = diff_rename_limit_default;
1213        if (options->setup & DIFF_SETUP_USE_CACHE) {
1214                if (!active_cache)
1215                        /* read-cache does not die even when it fails
1216                         * so it is safe for us to do this here.  Also
1217                         * it does not smudge active_cache or active_nr
1218                         * when it fails, so we do not have to worry about
1219                         * cleaning it up ourselves either.
1220                         */
1221                        read_cache();
1222        }
1223        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1224                use_size_cache = 1;
1225        if (options->abbrev <= 0 || 40 < options->abbrev)
1226                options->abbrev = 40; /* full */
1227
1228        return 0;
1229}
1230
1231int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1232{
1233        char c, *eq;
1234        int len;
1235
1236        if (*arg != '-')
1237                return 0;
1238        c = *++arg;
1239        if (!c)
1240                return 0;
1241        if (c == arg_short) {
1242                c = *++arg;
1243                if (!c)
1244                        return 1;
1245                if (val && isdigit(c)) {
1246                        char *end;
1247                        int n = strtoul(arg, &end, 10);
1248                        if (*end)
1249                                return 0;
1250                        *val = n;
1251                        return 1;
1252                }
1253                return 0;
1254        }
1255        if (c != '-')
1256                return 0;
1257        arg++;
1258        eq = strchr(arg, '=');
1259        if (eq)
1260                len = eq - arg;
1261        else
1262                len = strlen(arg);
1263        if (!len || strncmp(arg, arg_long, len))
1264                return 0;
1265        if (eq) {
1266                int n;
1267                char *end;
1268                if (!isdigit(*++eq))
1269                        return 0;
1270                n = strtoul(eq, &end, 10);
1271                if (*end)
1272                        return 0;
1273                *val = n;
1274        }
1275        return 1;
1276}
1277
1278int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1279{
1280        const char *arg = av[0];
1281        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1282                options->output_format = DIFF_FORMAT_PATCH;
1283        else if (opt_arg(arg, 'U', "unified", &options->context))
1284                options->output_format = DIFF_FORMAT_PATCH;
1285        else if (!strcmp(arg, "--patch-with-raw")) {
1286                options->output_format = DIFF_FORMAT_PATCH;
1287                options->with_raw = 1;
1288        }
1289        else if (!strcmp(arg, "--stat"))
1290                options->output_format = DIFF_FORMAT_DIFFSTAT;
1291        else if (!strcmp(arg, "--patch-with-stat")) {
1292                options->output_format = DIFF_FORMAT_PATCH;
1293                options->with_stat = 1;
1294        }
1295        else if (!strcmp(arg, "-z"))
1296                options->line_termination = 0;
1297        else if (!strncmp(arg, "-l", 2))
1298                options->rename_limit = strtoul(arg+2, NULL, 10);
1299        else if (!strcmp(arg, "--full-index"))
1300                options->full_index = 1;
1301        else if (!strcmp(arg, "--binary")) {
1302                options->output_format = DIFF_FORMAT_PATCH;
1303                options->full_index = options->binary = 1;
1304        }
1305        else if (!strcmp(arg, "--name-only"))
1306                options->output_format = DIFF_FORMAT_NAME;
1307        else if (!strcmp(arg, "--name-status"))
1308                options->output_format = DIFF_FORMAT_NAME_STATUS;
1309        else if (!strcmp(arg, "-R"))
1310                options->reverse_diff = 1;
1311        else if (!strncmp(arg, "-S", 2))
1312                options->pickaxe = arg + 2;
1313        else if (!strcmp(arg, "-s"))
1314                options->output_format = DIFF_FORMAT_NO_OUTPUT;
1315        else if (!strncmp(arg, "-O", 2))
1316                options->orderfile = arg + 2;
1317        else if (!strncmp(arg, "--diff-filter=", 14))
1318                options->filter = arg + 14;
1319        else if (!strcmp(arg, "--pickaxe-all"))
1320                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1321        else if (!strcmp(arg, "--pickaxe-regex"))
1322                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1323        else if (!strncmp(arg, "-B", 2)) {
1324                if ((options->break_opt =
1325                     diff_scoreopt_parse(arg)) == -1)
1326                        return -1;
1327        }
1328        else if (!strncmp(arg, "-M", 2)) {
1329                if ((options->rename_score =
1330                     diff_scoreopt_parse(arg)) == -1)
1331                        return -1;
1332                options->detect_rename = DIFF_DETECT_RENAME;
1333        }
1334        else if (!strncmp(arg, "-C", 2)) {
1335                if ((options->rename_score =
1336                     diff_scoreopt_parse(arg)) == -1)
1337                        return -1;
1338                options->detect_rename = DIFF_DETECT_COPY;
1339        }
1340        else if (!strcmp(arg, "--find-copies-harder"))
1341                options->find_copies_harder = 1;
1342        else if (!strcmp(arg, "--abbrev"))
1343                options->abbrev = DEFAULT_ABBREV;
1344        else if (!strncmp(arg, "--abbrev=", 9)) {
1345                options->abbrev = strtoul(arg + 9, NULL, 10);
1346                if (options->abbrev < MINIMUM_ABBREV)
1347                        options->abbrev = MINIMUM_ABBREV;
1348                else if (40 < options->abbrev)
1349                        options->abbrev = 40;
1350        }
1351        else
1352                return 0;
1353        return 1;
1354}
1355
1356static int parse_num(const char **cp_p)
1357{
1358        unsigned long num, scale;
1359        int ch, dot;
1360        const char *cp = *cp_p;
1361
1362        num = 0;
1363        scale = 1;
1364        dot = 0;
1365        for(;;) {
1366                ch = *cp;
1367                if ( !dot && ch == '.' ) {
1368                        scale = 1;
1369                        dot = 1;
1370                } else if ( ch == '%' ) {
1371                        scale = dot ? scale*100 : 100;
1372                        cp++;   /* % is always at the end */
1373                        break;
1374                } else if ( ch >= '0' && ch <= '9' ) {
1375                        if ( scale < 100000 ) {
1376                                scale *= 10;
1377                                num = (num*10) + (ch-'0');
1378                        }
1379                } else {
1380                        break;
1381                }
1382                cp++;
1383        }
1384        *cp_p = cp;
1385
1386        /* user says num divided by scale and we say internally that
1387         * is MAX_SCORE * num / scale.
1388         */
1389        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1390}
1391
1392int diff_scoreopt_parse(const char *opt)
1393{
1394        int opt1, opt2, cmd;
1395
1396        if (*opt++ != '-')
1397                return -1;
1398        cmd = *opt++;
1399        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1400                return -1; /* that is not a -M, -C nor -B option */
1401
1402        opt1 = parse_num(&opt);
1403        if (cmd != 'B')
1404                opt2 = 0;
1405        else {
1406                if (*opt == 0)
1407                        opt2 = 0;
1408                else if (*opt != '/')
1409                        return -1; /* we expect -B80/99 or -B80 */
1410                else {
1411                        opt++;
1412                        opt2 = parse_num(&opt);
1413                }
1414        }
1415        if (*opt != 0)
1416                return -1;
1417        return opt1 | (opt2 << 16);
1418}
1419
1420struct diff_queue_struct diff_queued_diff;
1421
1422void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1423{
1424        if (queue->alloc <= queue->nr) {
1425                queue->alloc = alloc_nr(queue->alloc);
1426                queue->queue = xrealloc(queue->queue,
1427                                        sizeof(dp) * queue->alloc);
1428        }
1429        queue->queue[queue->nr++] = dp;
1430}
1431
1432struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1433                                 struct diff_filespec *one,
1434                                 struct diff_filespec *two)
1435{
1436        struct diff_filepair *dp = xmalloc(sizeof(*dp));
1437        dp->one = one;
1438        dp->two = two;
1439        dp->score = 0;
1440        dp->status = 0;
1441        dp->source_stays = 0;
1442        dp->broken_pair = 0;
1443        if (queue)
1444                diff_q(queue, dp);
1445        return dp;
1446}
1447
1448void diff_free_filepair(struct diff_filepair *p)
1449{
1450        diff_free_filespec_data(p->one);
1451        diff_free_filespec_data(p->two);
1452        free(p->one);
1453        free(p->two);
1454        free(p);
1455}
1456
1457/* This is different from find_unique_abbrev() in that
1458 * it stuffs the result with dots for alignment.
1459 */
1460const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1461{
1462        int abblen;
1463        const char *abbrev;
1464        if (len == 40)
1465                return sha1_to_hex(sha1);
1466
1467        abbrev = find_unique_abbrev(sha1, len);
1468        if (!abbrev)
1469                return sha1_to_hex(sha1);
1470        abblen = strlen(abbrev);
1471        if (abblen < 37) {
1472                static char hex[41];
1473                if (len < abblen && abblen <= len + 2)
1474                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1475                else
1476                        sprintf(hex, "%s...", abbrev);
1477                return hex;
1478        }
1479        return sha1_to_hex(sha1);
1480}
1481
1482static void diff_flush_raw(struct diff_filepair *p,
1483                           int line_termination,
1484                           int inter_name_termination,
1485                           struct diff_options *options,
1486                           int output_format)
1487{
1488        int two_paths;
1489        char status[10];
1490        int abbrev = options->abbrev;
1491        const char *path_one, *path_two;
1492
1493        path_one = p->one->path;
1494        path_two = p->two->path;
1495        if (line_termination) {
1496                path_one = quote_one(path_one);
1497                path_two = quote_one(path_two);
1498        }
1499
1500        if (p->score)
1501                sprintf(status, "%c%03d", p->status,
1502                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1503        else {
1504                status[0] = p->status;
1505                status[1] = 0;
1506        }
1507        switch (p->status) {
1508        case DIFF_STATUS_COPIED:
1509        case DIFF_STATUS_RENAMED:
1510                two_paths = 1;
1511                break;
1512        case DIFF_STATUS_ADDED:
1513        case DIFF_STATUS_DELETED:
1514                two_paths = 0;
1515                break;
1516        default:
1517                two_paths = 0;
1518                break;
1519        }
1520        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1521                printf(":%06o %06o %s ",
1522                       p->one->mode, p->two->mode,
1523                       diff_unique_abbrev(p->one->sha1, abbrev));
1524                printf("%s ",
1525                       diff_unique_abbrev(p->two->sha1, abbrev));
1526        }
1527        printf("%s%c%s", status, inter_name_termination, path_one);
1528        if (two_paths)
1529                printf("%c%s", inter_name_termination, path_two);
1530        putchar(line_termination);
1531        if (path_one != p->one->path)
1532                free((void*)path_one);
1533        if (path_two != p->two->path)
1534                free((void*)path_two);
1535}
1536
1537static void diff_flush_name(struct diff_filepair *p,
1538                            int inter_name_termination,
1539                            int line_termination)
1540{
1541        char *path = p->two->path;
1542
1543        if (line_termination)
1544                path = quote_one(p->two->path);
1545        else
1546                path = p->two->path;
1547        printf("%s%c", path, line_termination);
1548        if (p->two->path != path)
1549                free(path);
1550}
1551
1552int diff_unmodified_pair(struct diff_filepair *p)
1553{
1554        /* This function is written stricter than necessary to support
1555         * the currently implemented transformers, but the idea is to
1556         * let transformers to produce diff_filepairs any way they want,
1557         * and filter and clean them up here before producing the output.
1558         */
1559        struct diff_filespec *one, *two;
1560
1561        if (DIFF_PAIR_UNMERGED(p))
1562                return 0; /* unmerged is interesting */
1563
1564        one = p->one;
1565        two = p->two;
1566
1567        /* deletion, addition, mode or type change
1568         * and rename are all interesting.
1569         */
1570        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1571            DIFF_PAIR_MODE_CHANGED(p) ||
1572            strcmp(one->path, two->path))
1573                return 0;
1574
1575        /* both are valid and point at the same path.  that is, we are
1576         * dealing with a change.
1577         */
1578        if (one->sha1_valid && two->sha1_valid &&
1579            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1580                return 1; /* no change */
1581        if (!one->sha1_valid && !two->sha1_valid)
1582                return 1; /* both look at the same file on the filesystem. */
1583        return 0;
1584}
1585
1586static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1587{
1588        if (diff_unmodified_pair(p))
1589                return;
1590
1591        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1592            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1593                return; /* no tree diffs in patch format */
1594
1595        run_diff(p, o);
1596}
1597
1598static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1599                            struct diffstat_t *diffstat)
1600{
1601        if (diff_unmodified_pair(p))
1602                return;
1603
1604        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1605            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1606                return; /* no tree diffs in patch format */
1607
1608        run_diffstat(p, o, diffstat);
1609}
1610
1611int diff_queue_is_empty(void)
1612{
1613        struct diff_queue_struct *q = &diff_queued_diff;
1614        int i;
1615        for (i = 0; i < q->nr; i++)
1616                if (!diff_unmodified_pair(q->queue[i]))
1617                        return 0;
1618        return 1;
1619}
1620
1621#if DIFF_DEBUG
1622void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1623{
1624        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1625                x, one ? one : "",
1626                s->path,
1627                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1628                s->mode,
1629                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1630        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1631                x, one ? one : "",
1632                s->size, s->xfrm_flags);
1633}
1634
1635void diff_debug_filepair(const struct diff_filepair *p, int i)
1636{
1637        diff_debug_filespec(p->one, i, "one");
1638        diff_debug_filespec(p->two, i, "two");
1639        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1640                p->score, p->status ? p->status : '?',
1641                p->source_stays, p->broken_pair);
1642}
1643
1644void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1645{
1646        int i;
1647        if (msg)
1648                fprintf(stderr, "%s\n", msg);
1649        fprintf(stderr, "q->nr = %d\n", q->nr);
1650        for (i = 0; i < q->nr; i++) {
1651                struct diff_filepair *p = q->queue[i];
1652                diff_debug_filepair(p, i);
1653        }
1654}
1655#endif
1656
1657static void diff_resolve_rename_copy(void)
1658{
1659        int i, j;
1660        struct diff_filepair *p, *pp;
1661        struct diff_queue_struct *q = &diff_queued_diff;
1662
1663        diff_debug_queue("resolve-rename-copy", q);
1664
1665        for (i = 0; i < q->nr; i++) {
1666                p = q->queue[i];
1667                p->status = 0; /* undecided */
1668                if (DIFF_PAIR_UNMERGED(p))
1669                        p->status = DIFF_STATUS_UNMERGED;
1670                else if (!DIFF_FILE_VALID(p->one))
1671                        p->status = DIFF_STATUS_ADDED;
1672                else if (!DIFF_FILE_VALID(p->two))
1673                        p->status = DIFF_STATUS_DELETED;
1674                else if (DIFF_PAIR_TYPE_CHANGED(p))
1675                        p->status = DIFF_STATUS_TYPE_CHANGED;
1676
1677                /* from this point on, we are dealing with a pair
1678                 * whose both sides are valid and of the same type, i.e.
1679                 * either in-place edit or rename/copy edit.
1680                 */
1681                else if (DIFF_PAIR_RENAME(p)) {
1682                        if (p->source_stays) {
1683                                p->status = DIFF_STATUS_COPIED;
1684                                continue;
1685                        }
1686                        /* See if there is some other filepair that
1687                         * copies from the same source as us.  If so
1688                         * we are a copy.  Otherwise we are either a
1689                         * copy if the path stays, or a rename if it
1690                         * does not, but we already handled "stays" case.
1691                         */
1692                        for (j = i + 1; j < q->nr; j++) {
1693                                pp = q->queue[j];
1694                                if (strcmp(pp->one->path, p->one->path))
1695                                        continue; /* not us */
1696                                if (!DIFF_PAIR_RENAME(pp))
1697                                        continue; /* not a rename/copy */
1698                                /* pp is a rename/copy from the same source */
1699                                p->status = DIFF_STATUS_COPIED;
1700                                break;
1701                        }
1702                        if (!p->status)
1703                                p->status = DIFF_STATUS_RENAMED;
1704                }
1705                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1706                         p->one->mode != p->two->mode)
1707                        p->status = DIFF_STATUS_MODIFIED;
1708                else {
1709                        /* This is a "no-change" entry and should not
1710                         * happen anymore, but prepare for broken callers.
1711                         */
1712                        error("feeding unmodified %s to diffcore",
1713                              p->one->path);
1714                        p->status = DIFF_STATUS_UNKNOWN;
1715                }
1716        }
1717        diff_debug_queue("resolve-rename-copy done", q);
1718}
1719
1720static void flush_one_pair(struct diff_filepair *p,
1721                           int diff_output_format,
1722                           struct diff_options *options,
1723                           struct diffstat_t *diffstat)
1724{
1725        int inter_name_termination = '\t';
1726        int line_termination = options->line_termination;
1727        if (!line_termination)
1728                inter_name_termination = 0;
1729
1730        switch (p->status) {
1731        case DIFF_STATUS_UNKNOWN:
1732                break;
1733        case 0:
1734                die("internal error in diff-resolve-rename-copy");
1735                break;
1736        default:
1737                switch (diff_output_format) {
1738                case DIFF_FORMAT_DIFFSTAT:
1739                        diff_flush_stat(p, options, diffstat);
1740                        break;
1741                case DIFF_FORMAT_PATCH:
1742                        diff_flush_patch(p, options);
1743                        break;
1744                case DIFF_FORMAT_RAW:
1745                case DIFF_FORMAT_NAME_STATUS:
1746                        diff_flush_raw(p, line_termination,
1747                                       inter_name_termination,
1748                                       options, diff_output_format);
1749                        break;
1750                case DIFF_FORMAT_NAME:
1751                        diff_flush_name(p,
1752                                        inter_name_termination,
1753                                        line_termination);
1754                        break;
1755                case DIFF_FORMAT_NO_OUTPUT:
1756                        break;
1757                }
1758        }
1759}
1760
1761void diff_flush(struct diff_options *options)
1762{
1763        struct diff_queue_struct *q = &diff_queued_diff;
1764        int i;
1765        int diff_output_format = options->output_format;
1766        struct diffstat_t *diffstat = NULL;
1767
1768        if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
1769                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
1770                diffstat->xm.consume = diffstat_consume;
1771        }
1772
1773        if (options->with_raw) {
1774                for (i = 0; i < q->nr; i++) {
1775                        struct diff_filepair *p = q->queue[i];
1776                        flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
1777                }
1778                putchar(options->line_termination);
1779        }
1780        if (options->with_stat) {
1781                for (i = 0; i < q->nr; i++) {
1782                        struct diff_filepair *p = q->queue[i];
1783                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
1784                                       diffstat);
1785                }
1786                show_stats(diffstat);
1787                free(diffstat);
1788                diffstat = NULL;
1789                putchar(options->line_termination);
1790        }
1791        for (i = 0; i < q->nr; i++) {
1792                struct diff_filepair *p = q->queue[i];
1793                flush_one_pair(p, diff_output_format, options, diffstat);
1794                diff_free_filepair(p);
1795        }
1796
1797        if (diffstat) {
1798                show_stats(diffstat);
1799                free(diffstat);
1800        }
1801
1802        free(q->queue);
1803        q->queue = NULL;
1804        q->nr = q->alloc = 0;
1805}
1806
1807static void diffcore_apply_filter(const char *filter)
1808{
1809        int i;
1810        struct diff_queue_struct *q = &diff_queued_diff;
1811        struct diff_queue_struct outq;
1812        outq.queue = NULL;
1813        outq.nr = outq.alloc = 0;
1814
1815        if (!filter)
1816                return;
1817
1818        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1819                int found;
1820                for (i = found = 0; !found && i < q->nr; i++) {
1821                        struct diff_filepair *p = q->queue[i];
1822                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1823                             ((p->score &&
1824                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1825                              (!p->score &&
1826                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1827                            ((p->status != DIFF_STATUS_MODIFIED) &&
1828                             strchr(filter, p->status)))
1829                                found++;
1830                }
1831                if (found)
1832                        return;
1833
1834                /* otherwise we will clear the whole queue
1835                 * by copying the empty outq at the end of this
1836                 * function, but first clear the current entries
1837                 * in the queue.
1838                 */
1839                for (i = 0; i < q->nr; i++)
1840                        diff_free_filepair(q->queue[i]);
1841        }
1842        else {
1843                /* Only the matching ones */
1844                for (i = 0; i < q->nr; i++) {
1845                        struct diff_filepair *p = q->queue[i];
1846
1847                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1848                             ((p->score &&
1849                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1850                              (!p->score &&
1851                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1852                            ((p->status != DIFF_STATUS_MODIFIED) &&
1853                             strchr(filter, p->status)))
1854                                diff_q(&outq, p);
1855                        else
1856                                diff_free_filepair(p);
1857                }
1858        }
1859        free(q->queue);
1860        *q = outq;
1861}
1862
1863void diffcore_std(struct diff_options *options)
1864{
1865        if (options->break_opt != -1)
1866                diffcore_break(options->break_opt);
1867        if (options->detect_rename)
1868                diffcore_rename(options);
1869        if (options->break_opt != -1)
1870                diffcore_merge_broken();
1871        if (options->pickaxe)
1872                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1873        if (options->orderfile)
1874                diffcore_order(options->orderfile);
1875        diff_resolve_rename_copy();
1876        diffcore_apply_filter(options->filter);
1877}
1878
1879
1880void diffcore_std_no_resolve(struct diff_options *options)
1881{
1882        if (options->pickaxe)
1883                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1884        if (options->orderfile)
1885                diffcore_order(options->orderfile);
1886        diffcore_apply_filter(options->filter);
1887}
1888
1889void diff_addremove(struct diff_options *options,
1890                    int addremove, unsigned mode,
1891                    const unsigned char *sha1,
1892                    const char *base, const char *path)
1893{
1894        char concatpath[PATH_MAX];
1895        struct diff_filespec *one, *two;
1896
1897        /* This may look odd, but it is a preparation for
1898         * feeding "there are unchanged files which should
1899         * not produce diffs, but when you are doing copy
1900         * detection you would need them, so here they are"
1901         * entries to the diff-core.  They will be prefixed
1902         * with something like '=' or '*' (I haven't decided
1903         * which but should not make any difference).
1904         * Feeding the same new and old to diff_change() 
1905         * also has the same effect.
1906         * Before the final output happens, they are pruned after
1907         * merged into rename/copy pairs as appropriate.
1908         */
1909        if (options->reverse_diff)
1910                addremove = (addremove == '+' ? '-' :
1911                             addremove == '-' ? '+' : addremove);
1912
1913        if (!path) path = "";
1914        sprintf(concatpath, "%s%s", base, path);
1915        one = alloc_filespec(concatpath);
1916        two = alloc_filespec(concatpath);
1917
1918        if (addremove != '+')
1919                fill_filespec(one, sha1, mode);
1920        if (addremove != '-')
1921                fill_filespec(two, sha1, mode);
1922
1923        diff_queue(&diff_queued_diff, one, two);
1924}
1925
1926void diff_change(struct diff_options *options,
1927                 unsigned old_mode, unsigned new_mode,
1928                 const unsigned char *old_sha1,
1929                 const unsigned char *new_sha1,
1930                 const char *base, const char *path) 
1931{
1932        char concatpath[PATH_MAX];
1933        struct diff_filespec *one, *two;
1934
1935        if (options->reverse_diff) {
1936                unsigned tmp;
1937                const unsigned char *tmp_c;
1938                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1939                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1940        }
1941        if (!path) path = "";
1942        sprintf(concatpath, "%s%s", base, path);
1943        one = alloc_filespec(concatpath);
1944        two = alloc_filespec(concatpath);
1945        fill_filespec(one, old_sha1, old_mode);
1946        fill_filespec(two, new_sha1, new_mode);
1947
1948        diff_queue(&diff_queued_diff, one, two);
1949}
1950
1951void diff_unmerge(struct diff_options *options,
1952                  const char *path)
1953{
1954        struct diff_filespec *one, *two;
1955        one = alloc_filespec(path);
1956        two = alloc_filespec(path);
1957        diff_queue(&diff_queued_diff, one, two);
1958}