diff.con commit simple euristic for further free packing improvements (4e8da19)
   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                name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
 236                sprintf(name, "%.*s{%.*s => %.*s}%s",
 237                        pfx_length, a,
 238                        len_a - pfx_length - sfx_length, a + pfx_length,
 239                        len_b - pfx_length - sfx_length, b + pfx_length,
 240                        a + len_a - sfx_length);
 241        }
 242        else {
 243                name = xmalloc(len_a + len_b + 5);
 244                sprintf(name, "%s => %s", a, b);
 245        }
 246        return name;
 247}
 248
 249struct diffstat_t {
 250        struct xdiff_emit_state xm;
 251
 252        int nr;
 253        int alloc;
 254        struct diffstat_file {
 255                char *name;
 256                unsigned is_unmerged:1;
 257                unsigned is_binary:1;
 258                unsigned is_renamed:1;
 259                unsigned int added, deleted;
 260        } **files;
 261};
 262
 263static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 264                                          const char *name_a,
 265                                          const char *name_b)
 266{
 267        struct diffstat_file *x;
 268        x = xcalloc(sizeof (*x), 1);
 269        if (diffstat->nr == diffstat->alloc) {
 270                diffstat->alloc = alloc_nr(diffstat->alloc);
 271                diffstat->files = xrealloc(diffstat->files,
 272                                diffstat->alloc * sizeof(x));
 273        }
 274        diffstat->files[diffstat->nr++] = x;
 275        if (name_b) {
 276                x->name = pprint_rename(name_a, name_b);
 277                x->is_renamed = 1;
 278        }
 279        else
 280                x->name = strdup(name_a);
 281        return x;
 282}
 283
 284static void diffstat_consume(void *priv, char *line, unsigned long len)
 285{
 286        struct diffstat_t *diffstat = priv;
 287        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 288
 289        if (line[0] == '+')
 290                x->added++;
 291        else if (line[0] == '-')
 292                x->deleted++;
 293}
 294
 295static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 296static const char minuses[]= "----------------------------------------------------------------------";
 297
 298static void show_stats(struct diffstat_t* data)
 299{
 300        int i, len, add, del, total, adds = 0, dels = 0;
 301        int max, max_change = 0, max_len = 0;
 302        int total_files = data->nr;
 303
 304        if (data->nr == 0)
 305                return;
 306
 307        for (i = 0; i < data->nr; i++) {
 308                struct diffstat_file *file = data->files[i];
 309
 310                len = strlen(file->name);
 311                if (max_len < len)
 312                        max_len = len;
 313
 314                if (file->is_binary || file->is_unmerged)
 315                        continue;
 316                if (max_change < file->added + file->deleted)
 317                        max_change = file->added + file->deleted;
 318        }
 319
 320        for (i = 0; i < data->nr; i++) {
 321                char *prefix = "";
 322                char *name = data->files[i]->name;
 323                int added = data->files[i]->added;
 324                int deleted = data->files[i]->deleted;
 325
 326                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 327                        char *qname = xmalloc(len + 1);
 328                        quote_c_style(name, qname, NULL, 0);
 329                        free(name);
 330                        data->files[i]->name = name = qname;
 331                }
 332
 333                /*
 334                 * "scale" the filename
 335                 */
 336                len = strlen(name);
 337                max = max_len;
 338                if (max > 50)
 339                        max = 50;
 340                if (len > max) {
 341                        char *slash;
 342                        prefix = "...";
 343                        max -= 3;
 344                        name += len - max;
 345                        slash = strchr(name, '/');
 346                        if (slash)
 347                                name = slash;
 348                }
 349                len = max;
 350
 351                /*
 352                 * scale the add/delete
 353                 */
 354                max = max_change;
 355                if (max + len > 70)
 356                        max = 70 - len;
 357
 358                if (data->files[i]->is_binary) {
 359                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 360                        goto free_diffstat_file;
 361                }
 362                else if (data->files[i]->is_unmerged) {
 363                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 364                        goto free_diffstat_file;
 365                }
 366                else if (!data->files[i]->is_renamed &&
 367                         (added + deleted == 0)) {
 368                        total_files--;
 369                        goto free_diffstat_file;
 370                }
 371
 372                add = added;
 373                del = deleted;
 374                total = add + del;
 375                adds += add;
 376                dels += del;
 377
 378                if (max_change > 0) {
 379                        total = (total * max + max_change / 2) / max_change;
 380                        add = (add * max + max_change / 2) / max_change;
 381                        del = total - add;
 382                }
 383                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 384                                len, name, added + deleted,
 385                                add, pluses, del, minuses);
 386        free_diffstat_file:
 387                free(data->files[i]->name);
 388                free(data->files[i]);
 389        }
 390        free(data->files);
 391        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 392                        total_files, adds, dels);
 393}
 394
 395static unsigned char *deflate_it(char *data,
 396                                 unsigned long size,
 397                                 unsigned long *result_size)
 398{
 399        int bound;
 400        unsigned char *deflated;
 401        z_stream stream;
 402
 403        memset(&stream, 0, sizeof(stream));
 404        deflateInit(&stream, Z_BEST_COMPRESSION);
 405        bound = deflateBound(&stream, size);
 406        deflated = xmalloc(bound);
 407        stream.next_out = deflated;
 408        stream.avail_out = bound;
 409
 410        stream.next_in = (unsigned char *)data;
 411        stream.avail_in = size;
 412        while (deflate(&stream, Z_FINISH) == Z_OK)
 413                ; /* nothing */
 414        deflateEnd(&stream);
 415        *result_size = stream.total_out;
 416        return deflated;
 417}
 418
 419static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 420{
 421        void *cp;
 422        void *delta;
 423        void *deflated;
 424        void *data;
 425        unsigned long orig_size;
 426        unsigned long delta_size;
 427        unsigned long deflate_size;
 428        unsigned long data_size;
 429
 430        printf("GIT binary patch\n");
 431        /* We could do deflated delta, or we could do just deflated two,
 432         * whichever is smaller.
 433         */
 434        delta = NULL;
 435        deflated = deflate_it(two->ptr, two->size, &deflate_size);
 436        if (one->size && two->size) {
 437                delta = diff_delta(one->ptr, one->size,
 438                                   two->ptr, two->size,
 439                                   &delta_size, deflate_size);
 440                if (delta) {
 441                        void *to_free = delta;
 442                        orig_size = delta_size;
 443                        delta = deflate_it(delta, delta_size, &delta_size);
 444                        free(to_free);
 445                }
 446        }
 447
 448        if (delta && delta_size < deflate_size) {
 449                printf("delta %lu\n", orig_size);
 450                free(deflated);
 451                data = delta;
 452                data_size = delta_size;
 453        }
 454        else {
 455                printf("literal %lu\n", two->size);
 456                free(delta);
 457                data = deflated;
 458                data_size = deflate_size;
 459        }
 460
 461        /* emit data encoded in base85 */
 462        cp = data;
 463        while (data_size) {
 464                int bytes = (52 < data_size) ? 52 : data_size;
 465                char line[70];
 466                data_size -= bytes;
 467                if (bytes <= 26)
 468                        line[0] = bytes + 'A' - 1;
 469                else
 470                        line[0] = bytes - 26 + 'a' - 1;
 471                encode_85(line + 1, cp, bytes);
 472                cp += bytes;
 473                puts(line);
 474        }
 475        printf("\n");
 476        free(data);
 477}
 478
 479#define FIRST_FEW_BYTES 8000
 480static int mmfile_is_binary(mmfile_t *mf)
 481{
 482        long sz = mf->size;
 483        if (FIRST_FEW_BYTES < sz)
 484                sz = FIRST_FEW_BYTES;
 485        if (memchr(mf->ptr, 0, sz))
 486                return 1;
 487        return 0;
 488}
 489
 490static void builtin_diff(const char *name_a,
 491                         const char *name_b,
 492                         struct diff_filespec *one,
 493                         struct diff_filespec *two,
 494                         const char *xfrm_msg,
 495                         struct diff_options *o,
 496                         int complete_rewrite)
 497{
 498        mmfile_t mf1, mf2;
 499        const char *lbl[2];
 500        char *a_one, *b_two;
 501
 502        a_one = quote_two("a/", name_a);
 503        b_two = quote_two("b/", name_b);
 504        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 505        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 506        printf("diff --git %s %s\n", a_one, b_two);
 507        if (lbl[0][0] == '/') {
 508                /* /dev/null */
 509                printf("new file mode %06o\n", two->mode);
 510                if (xfrm_msg && xfrm_msg[0])
 511                        puts(xfrm_msg);
 512        }
 513        else if (lbl[1][0] == '/') {
 514                printf("deleted file mode %06o\n", one->mode);
 515                if (xfrm_msg && xfrm_msg[0])
 516                        puts(xfrm_msg);
 517        }
 518        else {
 519                if (one->mode != two->mode) {
 520                        printf("old mode %06o\n", one->mode);
 521                        printf("new mode %06o\n", two->mode);
 522                }
 523                if (xfrm_msg && xfrm_msg[0])
 524                        puts(xfrm_msg);
 525                /*
 526                 * we do not run diff between different kind
 527                 * of objects.
 528                 */
 529                if ((one->mode ^ two->mode) & S_IFMT)
 530                        goto free_ab_and_return;
 531                if (complete_rewrite) {
 532                        emit_rewrite_diff(name_a, name_b, one, two);
 533                        goto free_ab_and_return;
 534                }
 535        }
 536
 537        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 538                die("unable to read files to diff");
 539
 540        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
 541                /* Quite common confusing case */
 542                if (mf1.size == mf2.size &&
 543                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 544                        goto free_ab_and_return;
 545                if (o->binary)
 546                        emit_binary_diff(&mf1, &mf2);
 547                else
 548                        printf("Binary files %s and %s differ\n",
 549                               lbl[0], lbl[1]);
 550        }
 551        else {
 552                /* Crazy xdl interfaces.. */
 553                const char *diffopts = getenv("GIT_DIFF_OPTS");
 554                xpparam_t xpp;
 555                xdemitconf_t xecfg;
 556                xdemitcb_t ecb;
 557                struct emit_callback ecbdata;
 558
 559                ecbdata.label_path = lbl;
 560                xpp.flags = XDF_NEED_MINIMAL;
 561                xecfg.ctxlen = 3;
 562                xecfg.flags = XDL_EMIT_FUNCNAMES;
 563                if (!diffopts)
 564                        ;
 565                else if (!strncmp(diffopts, "--unified=", 10))
 566                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 567                else if (!strncmp(diffopts, "-u", 2))
 568                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 569                ecb.outf = fn_out;
 570                ecb.priv = &ecbdata;
 571                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 572        }
 573
 574 free_ab_and_return:
 575        free(a_one);
 576        free(b_two);
 577        return;
 578}
 579
 580static void builtin_diffstat(const char *name_a, const char *name_b,
 581                             struct diff_filespec *one,
 582                             struct diff_filespec *two,
 583                             struct diffstat_t *diffstat,
 584                             int complete_rewrite)
 585{
 586        mmfile_t mf1, mf2;
 587        struct diffstat_file *data;
 588
 589        data = diffstat_add(diffstat, name_a, name_b);
 590
 591        if (!one || !two) {
 592                data->is_unmerged = 1;
 593                return;
 594        }
 595        if (complete_rewrite) {
 596                diff_populate_filespec(one, 0);
 597                diff_populate_filespec(two, 0);
 598                data->deleted = count_lines(one->data, one->size);
 599                data->added = count_lines(two->data, two->size);
 600                return;
 601        }
 602        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 603                die("unable to read files to diff");
 604
 605        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 606                data->is_binary = 1;
 607        else {
 608                /* Crazy xdl interfaces.. */
 609                xpparam_t xpp;
 610                xdemitconf_t xecfg;
 611                xdemitcb_t ecb;
 612
 613                xpp.flags = XDF_NEED_MINIMAL;
 614                xecfg.ctxlen = 0;
 615                xecfg.flags = 0;
 616                ecb.outf = xdiff_outf;
 617                ecb.priv = diffstat;
 618                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 619        }
 620}
 621
 622struct diff_filespec *alloc_filespec(const char *path)
 623{
 624        int namelen = strlen(path);
 625        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 626
 627        memset(spec, 0, sizeof(*spec));
 628        spec->path = (char *)(spec + 1);
 629        memcpy(spec->path, path, namelen+1);
 630        return spec;
 631}
 632
 633void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 634                   unsigned short mode)
 635{
 636        if (mode) {
 637                spec->mode = canon_mode(mode);
 638                memcpy(spec->sha1, sha1, 20);
 639                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 640        }
 641}
 642
 643/*
 644 * Given a name and sha1 pair, if the dircache tells us the file in
 645 * the work tree has that object contents, return true, so that
 646 * prepare_temp_file() does not have to inflate and extract.
 647 */
 648static int work_tree_matches(const char *name, const unsigned char *sha1)
 649{
 650        struct cache_entry *ce;
 651        struct stat st;
 652        int pos, len;
 653
 654        /* We do not read the cache ourselves here, because the
 655         * benchmark with my previous version that always reads cache
 656         * shows that it makes things worse for diff-tree comparing
 657         * two linux-2.6 kernel trees in an already checked out work
 658         * tree.  This is because most diff-tree comparisons deal with
 659         * only a small number of files, while reading the cache is
 660         * expensive for a large project, and its cost outweighs the
 661         * savings we get by not inflating the object to a temporary
 662         * file.  Practically, this code only helps when we are used
 663         * by diff-cache --cached, which does read the cache before
 664         * calling us.
 665         */
 666        if (!active_cache)
 667                return 0;
 668
 669        len = strlen(name);
 670        pos = cache_name_pos(name, len);
 671        if (pos < 0)
 672                return 0;
 673        ce = active_cache[pos];
 674        if ((lstat(name, &st) < 0) ||
 675            !S_ISREG(st.st_mode) || /* careful! */
 676            ce_match_stat(ce, &st, 0) ||
 677            memcmp(sha1, ce->sha1, 20))
 678                return 0;
 679        /* we return 1 only when we can stat, it is a regular file,
 680         * stat information matches, and sha1 recorded in the cache
 681         * matches.  I.e. we know the file in the work tree really is
 682         * the same as the <name, sha1> pair.
 683         */
 684        return 1;
 685}
 686
 687static struct sha1_size_cache {
 688        unsigned char sha1[20];
 689        unsigned long size;
 690} **sha1_size_cache;
 691static int sha1_size_cache_nr, sha1_size_cache_alloc;
 692
 693static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 694                                                 int find_only,
 695                                                 unsigned long size)
 696{
 697        int first, last;
 698        struct sha1_size_cache *e;
 699
 700        first = 0;
 701        last = sha1_size_cache_nr;
 702        while (last > first) {
 703                int cmp, next = (last + first) >> 1;
 704                e = sha1_size_cache[next];
 705                cmp = memcmp(e->sha1, sha1, 20);
 706                if (!cmp)
 707                        return e;
 708                if (cmp < 0) {
 709                        last = next;
 710                        continue;
 711                }
 712                first = next+1;
 713        }
 714        /* not found */
 715        if (find_only)
 716                return NULL;
 717        /* insert to make it at "first" */
 718        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 719                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 720                sha1_size_cache = xrealloc(sha1_size_cache,
 721                                           sha1_size_cache_alloc *
 722                                           sizeof(*sha1_size_cache));
 723        }
 724        sha1_size_cache_nr++;
 725        if (first < sha1_size_cache_nr)
 726                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 727                        (sha1_size_cache_nr - first - 1) *
 728                        sizeof(*sha1_size_cache));
 729        e = xmalloc(sizeof(struct sha1_size_cache));
 730        sha1_size_cache[first] = e;
 731        memcpy(e->sha1, sha1, 20);
 732        e->size = size;
 733        return e;
 734}
 735
 736/*
 737 * While doing rename detection and pickaxe operation, we may need to
 738 * grab the data for the blob (or file) for our own in-core comparison.
 739 * diff_filespec has data and size fields for this purpose.
 740 */
 741int diff_populate_filespec(struct diff_filespec *s, int size_only)
 742{
 743        int err = 0;
 744        if (!DIFF_FILE_VALID(s))
 745                die("internal error: asking to populate invalid file.");
 746        if (S_ISDIR(s->mode))
 747                return -1;
 748
 749        if (!use_size_cache)
 750                size_only = 0;
 751
 752        if (s->data)
 753                return err;
 754        if (!s->sha1_valid ||
 755            work_tree_matches(s->path, s->sha1)) {
 756                struct stat st;
 757                int fd;
 758                if (lstat(s->path, &st) < 0) {
 759                        if (errno == ENOENT) {
 760                        err_empty:
 761                                err = -1;
 762                        empty:
 763                                s->data = "";
 764                                s->size = 0;
 765                                return err;
 766                        }
 767                }
 768                s->size = st.st_size;
 769                if (!s->size)
 770                        goto empty;
 771                if (size_only)
 772                        return 0;
 773                if (S_ISLNK(st.st_mode)) {
 774                        int ret;
 775                        s->data = xmalloc(s->size);
 776                        s->should_free = 1;
 777                        ret = readlink(s->path, s->data, s->size);
 778                        if (ret < 0) {
 779                                free(s->data);
 780                                goto err_empty;
 781                        }
 782                        return 0;
 783                }
 784                fd = open(s->path, O_RDONLY);
 785                if (fd < 0)
 786                        goto err_empty;
 787                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 788                close(fd);
 789                if (s->data == MAP_FAILED)
 790                        goto err_empty;
 791                s->should_munmap = 1;
 792        }
 793        else {
 794                char type[20];
 795                struct sha1_size_cache *e;
 796
 797                if (size_only) {
 798                        e = locate_size_cache(s->sha1, 1, 0);
 799                        if (e) {
 800                                s->size = e->size;
 801                                return 0;
 802                        }
 803                        if (!sha1_object_info(s->sha1, type, &s->size))
 804                                locate_size_cache(s->sha1, 0, s->size);
 805                }
 806                else {
 807                        s->data = read_sha1_file(s->sha1, type, &s->size);
 808                        s->should_free = 1;
 809                }
 810        }
 811        return 0;
 812}
 813
 814void diff_free_filespec_data(struct diff_filespec *s)
 815{
 816        if (s->should_free)
 817                free(s->data);
 818        else if (s->should_munmap)
 819                munmap(s->data, s->size);
 820        s->should_free = s->should_munmap = 0;
 821        s->data = NULL;
 822        free(s->cnt_data);
 823        s->cnt_data = NULL;
 824}
 825
 826static void prep_temp_blob(struct diff_tempfile *temp,
 827                           void *blob,
 828                           unsigned long size,
 829                           const unsigned char *sha1,
 830                           int mode)
 831{
 832        int fd;
 833
 834        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 835        if (fd < 0)
 836                die("unable to create temp-file");
 837        if (write(fd, blob, size) != size)
 838                die("unable to write temp-file");
 839        close(fd);
 840        temp->name = temp->tmp_path;
 841        strcpy(temp->hex, sha1_to_hex(sha1));
 842        temp->hex[40] = 0;
 843        sprintf(temp->mode, "%06o", mode);
 844}
 845
 846static void prepare_temp_file(const char *name,
 847                              struct diff_tempfile *temp,
 848                              struct diff_filespec *one)
 849{
 850        if (!DIFF_FILE_VALID(one)) {
 851        not_a_valid_file:
 852                /* A '-' entry produces this for file-2, and
 853                 * a '+' entry produces this for file-1.
 854                 */
 855                temp->name = "/dev/null";
 856                strcpy(temp->hex, ".");
 857                strcpy(temp->mode, ".");
 858                return;
 859        }
 860
 861        if (!one->sha1_valid ||
 862            work_tree_matches(name, one->sha1)) {
 863                struct stat st;
 864                if (lstat(name, &st) < 0) {
 865                        if (errno == ENOENT)
 866                                goto not_a_valid_file;
 867                        die("stat(%s): %s", name, strerror(errno));
 868                }
 869                if (S_ISLNK(st.st_mode)) {
 870                        int ret;
 871                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 872                        if (sizeof(buf) <= st.st_size)
 873                                die("symlink too long: %s", name);
 874                        ret = readlink(name, buf, st.st_size);
 875                        if (ret < 0)
 876                                die("readlink(%s)", name);
 877                        prep_temp_blob(temp, buf, st.st_size,
 878                                       (one->sha1_valid ?
 879                                        one->sha1 : null_sha1),
 880                                       (one->sha1_valid ?
 881                                        one->mode : S_IFLNK));
 882                }
 883                else {
 884                        /* we can borrow from the file in the work tree */
 885                        temp->name = name;
 886                        if (!one->sha1_valid)
 887                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 888                        else
 889                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 890                        /* Even though we may sometimes borrow the
 891                         * contents from the work tree, we always want
 892                         * one->mode.  mode is trustworthy even when
 893                         * !(one->sha1_valid), as long as
 894                         * DIFF_FILE_VALID(one).
 895                         */
 896                        sprintf(temp->mode, "%06o", one->mode);
 897                }
 898                return;
 899        }
 900        else {
 901                if (diff_populate_filespec(one, 0))
 902                        die("cannot read data blob for %s", one->path);
 903                prep_temp_blob(temp, one->data, one->size,
 904                               one->sha1, one->mode);
 905        }
 906}
 907
 908static void remove_tempfile(void)
 909{
 910        int i;
 911
 912        for (i = 0; i < 2; i++)
 913                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 914                        unlink(diff_temp[i].name);
 915                        diff_temp[i].name = NULL;
 916                }
 917}
 918
 919static void remove_tempfile_on_signal(int signo)
 920{
 921        remove_tempfile();
 922        signal(SIGINT, SIG_DFL);
 923        raise(signo);
 924}
 925
 926static int spawn_prog(const char *pgm, const char **arg)
 927{
 928        pid_t pid;
 929        int status;
 930
 931        fflush(NULL);
 932        pid = fork();
 933        if (pid < 0)
 934                die("unable to fork");
 935        if (!pid) {
 936                execvp(pgm, (char *const*) arg);
 937                exit(255);
 938        }
 939
 940        while (waitpid(pid, &status, 0) < 0) {
 941                if (errno == EINTR)
 942                        continue;
 943                return -1;
 944        }
 945
 946        /* Earlier we did not check the exit status because
 947         * diff exits non-zero if files are different, and
 948         * we are not interested in knowing that.  It was a
 949         * mistake which made it harder to quit a diff-*
 950         * session that uses the git-apply-patch-script as
 951         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 952         * should also exit non-zero only when it wants to
 953         * abort the entire diff-* session.
 954         */
 955        if (WIFEXITED(status) && !WEXITSTATUS(status))
 956                return 0;
 957        return -1;
 958}
 959
 960/* An external diff command takes:
 961 *
 962 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 963 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 964 *
 965 */
 966static void run_external_diff(const char *pgm,
 967                              const char *name,
 968                              const char *other,
 969                              struct diff_filespec *one,
 970                              struct diff_filespec *two,
 971                              const char *xfrm_msg,
 972                              int complete_rewrite)
 973{
 974        const char *spawn_arg[10];
 975        struct diff_tempfile *temp = diff_temp;
 976        int retval;
 977        static int atexit_asked = 0;
 978        const char *othername;
 979        const char **arg = &spawn_arg[0];
 980
 981        othername = (other? other : name);
 982        if (one && two) {
 983                prepare_temp_file(name, &temp[0], one);
 984                prepare_temp_file(othername, &temp[1], two);
 985                if (! atexit_asked &&
 986                    (temp[0].name == temp[0].tmp_path ||
 987                     temp[1].name == temp[1].tmp_path)) {
 988                        atexit_asked = 1;
 989                        atexit(remove_tempfile);
 990                }
 991                signal(SIGINT, remove_tempfile_on_signal);
 992        }
 993
 994        if (one && two) {
 995                *arg++ = pgm;
 996                *arg++ = name;
 997                *arg++ = temp[0].name;
 998                *arg++ = temp[0].hex;
 999                *arg++ = temp[0].mode;
1000                *arg++ = temp[1].name;
1001                *arg++ = temp[1].hex;
1002                *arg++ = temp[1].mode;
1003                if (other) {
1004                        *arg++ = other;
1005                        *arg++ = xfrm_msg;
1006                }
1007        } else {
1008                *arg++ = pgm;
1009                *arg++ = name;
1010        }
1011        *arg = NULL;
1012        retval = spawn_prog(pgm, spawn_arg);
1013        remove_tempfile();
1014        if (retval) {
1015                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1016                exit(1);
1017        }
1018}
1019
1020static void run_diff_cmd(const char *pgm,
1021                         const char *name,
1022                         const char *other,
1023                         struct diff_filespec *one,
1024                         struct diff_filespec *two,
1025                         const char *xfrm_msg,
1026                         struct diff_options *o,
1027                         int complete_rewrite)
1028{
1029        if (pgm) {
1030                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1031                                  complete_rewrite);
1032                return;
1033        }
1034        if (one && two)
1035                builtin_diff(name, other ? other : name,
1036                             one, two, xfrm_msg, o, complete_rewrite);
1037        else
1038                printf("* Unmerged path %s\n", name);
1039}
1040
1041static void diff_fill_sha1_info(struct diff_filespec *one)
1042{
1043        if (DIFF_FILE_VALID(one)) {
1044                if (!one->sha1_valid) {
1045                        struct stat st;
1046                        if (lstat(one->path, &st) < 0)
1047                                die("stat %s", one->path);
1048                        if (index_path(one->sha1, one->path, &st, 0))
1049                                die("cannot hash %s\n", one->path);
1050                }
1051        }
1052        else
1053                memset(one->sha1, 0, 20);
1054}
1055
1056static void run_diff(struct diff_filepair *p, struct diff_options *o)
1057{
1058        const char *pgm = external_diff();
1059        char msg[PATH_MAX*2+300], *xfrm_msg;
1060        struct diff_filespec *one;
1061        struct diff_filespec *two;
1062        const char *name;
1063        const char *other;
1064        char *name_munged, *other_munged;
1065        int complete_rewrite = 0;
1066        int len;
1067
1068        if (DIFF_PAIR_UNMERGED(p)) {
1069                /* unmerged */
1070                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1071                return;
1072        }
1073
1074        name = p->one->path;
1075        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1076        name_munged = quote_one(name);
1077        other_munged = quote_one(other);
1078        one = p->one; two = p->two;
1079
1080        diff_fill_sha1_info(one);
1081        diff_fill_sha1_info(two);
1082
1083        len = 0;
1084        switch (p->status) {
1085        case DIFF_STATUS_COPIED:
1086                len += snprintf(msg + len, sizeof(msg) - len,
1087                                "similarity index %d%%\n"
1088                                "copy from %s\n"
1089                                "copy to %s\n",
1090                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1091                                name_munged, other_munged);
1092                break;
1093        case DIFF_STATUS_RENAMED:
1094                len += snprintf(msg + len, sizeof(msg) - len,
1095                                "similarity index %d%%\n"
1096                                "rename from %s\n"
1097                                "rename to %s\n",
1098                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1099                                name_munged, other_munged);
1100                break;
1101        case DIFF_STATUS_MODIFIED:
1102                if (p->score) {
1103                        len += snprintf(msg + len, sizeof(msg) - len,
1104                                        "dissimilarity index %d%%\n",
1105                                        (int)(0.5 + p->score *
1106                                              100.0/MAX_SCORE));
1107                        complete_rewrite = 1;
1108                        break;
1109                }
1110                /* fallthru */
1111        default:
1112                /* nothing */
1113                ;
1114        }
1115
1116        if (memcmp(one->sha1, two->sha1, 20)) {
1117                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1118
1119                len += snprintf(msg + len, sizeof(msg) - len,
1120                                "index %.*s..%.*s",
1121                                abbrev, sha1_to_hex(one->sha1),
1122                                abbrev, sha1_to_hex(two->sha1));
1123                if (one->mode == two->mode)
1124                        len += snprintf(msg + len, sizeof(msg) - len,
1125                                        " %06o", one->mode);
1126                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1127        }
1128
1129        if (len)
1130                msg[--len] = 0;
1131        xfrm_msg = len ? msg : NULL;
1132
1133        if (!pgm &&
1134            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1135            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1136                /* a filepair that changes between file and symlink
1137                 * needs to be split into deletion and creation.
1138                 */
1139                struct diff_filespec *null = alloc_filespec(two->path);
1140                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1141                free(null);
1142                null = alloc_filespec(one->path);
1143                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1144                free(null);
1145        }
1146        else
1147                run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1148                             complete_rewrite);
1149
1150        free(name_munged);
1151        free(other_munged);
1152}
1153
1154static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1155                         struct diffstat_t *diffstat)
1156{
1157        const char *name;
1158        const char *other;
1159        int complete_rewrite = 0;
1160
1161        if (DIFF_PAIR_UNMERGED(p)) {
1162                /* unmerged */
1163                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
1164                return;
1165        }
1166
1167        name = p->one->path;
1168        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1169
1170        diff_fill_sha1_info(p->one);
1171        diff_fill_sha1_info(p->two);
1172
1173        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1174                complete_rewrite = 1;
1175        builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
1176}
1177
1178void diff_setup(struct diff_options *options)
1179{
1180        memset(options, 0, sizeof(*options));
1181        options->output_format = DIFF_FORMAT_RAW;
1182        options->line_termination = '\n';
1183        options->break_opt = -1;
1184        options->rename_limit = -1;
1185
1186        options->change = diff_change;
1187        options->add_remove = diff_addremove;
1188}
1189
1190int diff_setup_done(struct diff_options *options)
1191{
1192        if ((options->find_copies_harder &&
1193             options->detect_rename != DIFF_DETECT_COPY) ||
1194            (0 <= options->rename_limit && !options->detect_rename))
1195                return -1;
1196
1197        /*
1198         * These cases always need recursive; we do not drop caller-supplied
1199         * recursive bits for other formats here.
1200         */
1201        if ((options->output_format == DIFF_FORMAT_PATCH) ||
1202            (options->output_format == DIFF_FORMAT_DIFFSTAT))
1203                options->recursive = 1;
1204
1205        if (options->detect_rename && options->rename_limit < 0)
1206                options->rename_limit = diff_rename_limit_default;
1207        if (options->setup & DIFF_SETUP_USE_CACHE) {
1208                if (!active_cache)
1209                        /* read-cache does not die even when it fails
1210                         * so it is safe for us to do this here.  Also
1211                         * it does not smudge active_cache or active_nr
1212                         * when it fails, so we do not have to worry about
1213                         * cleaning it up ourselves either.
1214                         */
1215                        read_cache();
1216        }
1217        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1218                use_size_cache = 1;
1219        if (options->abbrev <= 0 || 40 < options->abbrev)
1220                options->abbrev = 40; /* full */
1221
1222        return 0;
1223}
1224
1225int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1226{
1227        const char *arg = av[0];
1228        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1229                options->output_format = DIFF_FORMAT_PATCH;
1230        else if (!strcmp(arg, "--patch-with-raw")) {
1231                options->output_format = DIFF_FORMAT_PATCH;
1232                options->with_raw = 1;
1233        }
1234        else if (!strcmp(arg, "--stat"))
1235                options->output_format = DIFF_FORMAT_DIFFSTAT;
1236        else if (!strcmp(arg, "--patch-with-stat")) {
1237                options->output_format = DIFF_FORMAT_PATCH;
1238                options->with_stat = 1;
1239        }
1240        else if (!strcmp(arg, "-z"))
1241                options->line_termination = 0;
1242        else if (!strncmp(arg, "-l", 2))
1243                options->rename_limit = strtoul(arg+2, NULL, 10);
1244        else if (!strcmp(arg, "--full-index"))
1245                options->full_index = 1;
1246        else if (!strcmp(arg, "--binary")) {
1247                options->output_format = DIFF_FORMAT_PATCH;
1248                options->full_index = options->binary = 1;
1249        }
1250        else if (!strcmp(arg, "--name-only"))
1251                options->output_format = DIFF_FORMAT_NAME;
1252        else if (!strcmp(arg, "--name-status"))
1253                options->output_format = DIFF_FORMAT_NAME_STATUS;
1254        else if (!strcmp(arg, "-R"))
1255                options->reverse_diff = 1;
1256        else if (!strncmp(arg, "-S", 2))
1257                options->pickaxe = arg + 2;
1258        else if (!strcmp(arg, "-s"))
1259                options->output_format = DIFF_FORMAT_NO_OUTPUT;
1260        else if (!strncmp(arg, "-O", 2))
1261                options->orderfile = arg + 2;
1262        else if (!strncmp(arg, "--diff-filter=", 14))
1263                options->filter = arg + 14;
1264        else if (!strcmp(arg, "--pickaxe-all"))
1265                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1266        else if (!strcmp(arg, "--pickaxe-regex"))
1267                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1268        else if (!strncmp(arg, "-B", 2)) {
1269                if ((options->break_opt =
1270                     diff_scoreopt_parse(arg)) == -1)
1271                        return -1;
1272        }
1273        else if (!strncmp(arg, "-M", 2)) {
1274                if ((options->rename_score =
1275                     diff_scoreopt_parse(arg)) == -1)
1276                        return -1;
1277                options->detect_rename = DIFF_DETECT_RENAME;
1278        }
1279        else if (!strncmp(arg, "-C", 2)) {
1280                if ((options->rename_score =
1281                     diff_scoreopt_parse(arg)) == -1)
1282                        return -1;
1283                options->detect_rename = DIFF_DETECT_COPY;
1284        }
1285        else if (!strcmp(arg, "--find-copies-harder"))
1286                options->find_copies_harder = 1;
1287        else if (!strcmp(arg, "--abbrev"))
1288                options->abbrev = DEFAULT_ABBREV;
1289        else if (!strncmp(arg, "--abbrev=", 9)) {
1290                options->abbrev = strtoul(arg + 9, NULL, 10);
1291                if (options->abbrev < MINIMUM_ABBREV)
1292                        options->abbrev = MINIMUM_ABBREV;
1293                else if (40 < options->abbrev)
1294                        options->abbrev = 40;
1295        }
1296        else
1297                return 0;
1298        return 1;
1299}
1300
1301static int parse_num(const char **cp_p)
1302{
1303        unsigned long num, scale;
1304        int ch, dot;
1305        const char *cp = *cp_p;
1306
1307        num = 0;
1308        scale = 1;
1309        dot = 0;
1310        for(;;) {
1311                ch = *cp;
1312                if ( !dot && ch == '.' ) {
1313                        scale = 1;
1314                        dot = 1;
1315                } else if ( ch == '%' ) {
1316                        scale = dot ? scale*100 : 100;
1317                        cp++;   /* % is always at the end */
1318                        break;
1319                } else if ( ch >= '0' && ch <= '9' ) {
1320                        if ( scale < 100000 ) {
1321                                scale *= 10;
1322                                num = (num*10) + (ch-'0');
1323                        }
1324                } else {
1325                        break;
1326                }
1327                cp++;
1328        }
1329        *cp_p = cp;
1330
1331        /* user says num divided by scale and we say internally that
1332         * is MAX_SCORE * num / scale.
1333         */
1334        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1335}
1336
1337int diff_scoreopt_parse(const char *opt)
1338{
1339        int opt1, opt2, cmd;
1340
1341        if (*opt++ != '-')
1342                return -1;
1343        cmd = *opt++;
1344        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1345                return -1; /* that is not a -M, -C nor -B option */
1346
1347        opt1 = parse_num(&opt);
1348        if (cmd != 'B')
1349                opt2 = 0;
1350        else {
1351                if (*opt == 0)
1352                        opt2 = 0;
1353                else if (*opt != '/')
1354                        return -1; /* we expect -B80/99 or -B80 */
1355                else {
1356                        opt++;
1357                        opt2 = parse_num(&opt);
1358                }
1359        }
1360        if (*opt != 0)
1361                return -1;
1362        return opt1 | (opt2 << 16);
1363}
1364
1365struct diff_queue_struct diff_queued_diff;
1366
1367void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1368{
1369        if (queue->alloc <= queue->nr) {
1370                queue->alloc = alloc_nr(queue->alloc);
1371                queue->queue = xrealloc(queue->queue,
1372                                        sizeof(dp) * queue->alloc);
1373        }
1374        queue->queue[queue->nr++] = dp;
1375}
1376
1377struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1378                                 struct diff_filespec *one,
1379                                 struct diff_filespec *two)
1380{
1381        struct diff_filepair *dp = xmalloc(sizeof(*dp));
1382        dp->one = one;
1383        dp->two = two;
1384        dp->score = 0;
1385        dp->status = 0;
1386        dp->source_stays = 0;
1387        dp->broken_pair = 0;
1388        if (queue)
1389                diff_q(queue, dp);
1390        return dp;
1391}
1392
1393void diff_free_filepair(struct diff_filepair *p)
1394{
1395        diff_free_filespec_data(p->one);
1396        diff_free_filespec_data(p->two);
1397        free(p->one);
1398        free(p->two);
1399        free(p);
1400}
1401
1402/* This is different from find_unique_abbrev() in that
1403 * it stuffs the result with dots for alignment.
1404 */
1405const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1406{
1407        int abblen;
1408        const char *abbrev;
1409        if (len == 40)
1410                return sha1_to_hex(sha1);
1411
1412        abbrev = find_unique_abbrev(sha1, len);
1413        if (!abbrev)
1414                return sha1_to_hex(sha1);
1415        abblen = strlen(abbrev);
1416        if (abblen < 37) {
1417                static char hex[41];
1418                if (len < abblen && abblen <= len + 2)
1419                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1420                else
1421                        sprintf(hex, "%s...", abbrev);
1422                return hex;
1423        }
1424        return sha1_to_hex(sha1);
1425}
1426
1427static void diff_flush_raw(struct diff_filepair *p,
1428                           int line_termination,
1429                           int inter_name_termination,
1430                           struct diff_options *options,
1431                           int output_format)
1432{
1433        int two_paths;
1434        char status[10];
1435        int abbrev = options->abbrev;
1436        const char *path_one, *path_two;
1437
1438        path_one = p->one->path;
1439        path_two = p->two->path;
1440        if (line_termination) {
1441                path_one = quote_one(path_one);
1442                path_two = quote_one(path_two);
1443        }
1444
1445        if (p->score)
1446                sprintf(status, "%c%03d", p->status,
1447                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1448        else {
1449                status[0] = p->status;
1450                status[1] = 0;
1451        }
1452        switch (p->status) {
1453        case DIFF_STATUS_COPIED:
1454        case DIFF_STATUS_RENAMED:
1455                two_paths = 1;
1456                break;
1457        case DIFF_STATUS_ADDED:
1458        case DIFF_STATUS_DELETED:
1459                two_paths = 0;
1460                break;
1461        default:
1462                two_paths = 0;
1463                break;
1464        }
1465        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1466                printf(":%06o %06o %s ",
1467                       p->one->mode, p->two->mode,
1468                       diff_unique_abbrev(p->one->sha1, abbrev));
1469                printf("%s ",
1470                       diff_unique_abbrev(p->two->sha1, abbrev));
1471        }
1472        printf("%s%c%s", status, inter_name_termination, path_one);
1473        if (two_paths)
1474                printf("%c%s", inter_name_termination, path_two);
1475        putchar(line_termination);
1476        if (path_one != p->one->path)
1477                free((void*)path_one);
1478        if (path_two != p->two->path)
1479                free((void*)path_two);
1480}
1481
1482static void diff_flush_name(struct diff_filepair *p,
1483                            int inter_name_termination,
1484                            int line_termination)
1485{
1486        char *path = p->two->path;
1487
1488        if (line_termination)
1489                path = quote_one(p->two->path);
1490        else
1491                path = p->two->path;
1492        printf("%s%c", path, line_termination);
1493        if (p->two->path != path)
1494                free(path);
1495}
1496
1497int diff_unmodified_pair(struct diff_filepair *p)
1498{
1499        /* This function is written stricter than necessary to support
1500         * the currently implemented transformers, but the idea is to
1501         * let transformers to produce diff_filepairs any way they want,
1502         * and filter and clean them up here before producing the output.
1503         */
1504        struct diff_filespec *one, *two;
1505
1506        if (DIFF_PAIR_UNMERGED(p))
1507                return 0; /* unmerged is interesting */
1508
1509        one = p->one;
1510        two = p->two;
1511
1512        /* deletion, addition, mode or type change
1513         * and rename are all interesting.
1514         */
1515        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1516            DIFF_PAIR_MODE_CHANGED(p) ||
1517            strcmp(one->path, two->path))
1518                return 0;
1519
1520        /* both are valid and point at the same path.  that is, we are
1521         * dealing with a change.
1522         */
1523        if (one->sha1_valid && two->sha1_valid &&
1524            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1525                return 1; /* no change */
1526        if (!one->sha1_valid && !two->sha1_valid)
1527                return 1; /* both look at the same file on the filesystem. */
1528        return 0;
1529}
1530
1531static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1532{
1533        if (diff_unmodified_pair(p))
1534                return;
1535
1536        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1537            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1538                return; /* no tree diffs in patch format */
1539
1540        run_diff(p, o);
1541}
1542
1543static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1544                            struct diffstat_t *diffstat)
1545{
1546        if (diff_unmodified_pair(p))
1547                return;
1548
1549        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1550            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1551                return; /* no tree diffs in patch format */
1552
1553        run_diffstat(p, o, diffstat);
1554}
1555
1556int diff_queue_is_empty(void)
1557{
1558        struct diff_queue_struct *q = &diff_queued_diff;
1559        int i;
1560        for (i = 0; i < q->nr; i++)
1561                if (!diff_unmodified_pair(q->queue[i]))
1562                        return 0;
1563        return 1;
1564}
1565
1566#if DIFF_DEBUG
1567void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1568{
1569        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1570                x, one ? one : "",
1571                s->path,
1572                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1573                s->mode,
1574                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1575        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1576                x, one ? one : "",
1577                s->size, s->xfrm_flags);
1578}
1579
1580void diff_debug_filepair(const struct diff_filepair *p, int i)
1581{
1582        diff_debug_filespec(p->one, i, "one");
1583        diff_debug_filespec(p->two, i, "two");
1584        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1585                p->score, p->status ? p->status : '?',
1586                p->source_stays, p->broken_pair);
1587}
1588
1589void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1590{
1591        int i;
1592        if (msg)
1593                fprintf(stderr, "%s\n", msg);
1594        fprintf(stderr, "q->nr = %d\n", q->nr);
1595        for (i = 0; i < q->nr; i++) {
1596                struct diff_filepair *p = q->queue[i];
1597                diff_debug_filepair(p, i);
1598        }
1599}
1600#endif
1601
1602static void diff_resolve_rename_copy(void)
1603{
1604        int i, j;
1605        struct diff_filepair *p, *pp;
1606        struct diff_queue_struct *q = &diff_queued_diff;
1607
1608        diff_debug_queue("resolve-rename-copy", q);
1609
1610        for (i = 0; i < q->nr; i++) {
1611                p = q->queue[i];
1612                p->status = 0; /* undecided */
1613                if (DIFF_PAIR_UNMERGED(p))
1614                        p->status = DIFF_STATUS_UNMERGED;
1615                else if (!DIFF_FILE_VALID(p->one))
1616                        p->status = DIFF_STATUS_ADDED;
1617                else if (!DIFF_FILE_VALID(p->two))
1618                        p->status = DIFF_STATUS_DELETED;
1619                else if (DIFF_PAIR_TYPE_CHANGED(p))
1620                        p->status = DIFF_STATUS_TYPE_CHANGED;
1621
1622                /* from this point on, we are dealing with a pair
1623                 * whose both sides are valid and of the same type, i.e.
1624                 * either in-place edit or rename/copy edit.
1625                 */
1626                else if (DIFF_PAIR_RENAME(p)) {
1627                        if (p->source_stays) {
1628                                p->status = DIFF_STATUS_COPIED;
1629                                continue;
1630                        }
1631                        /* See if there is some other filepair that
1632                         * copies from the same source as us.  If so
1633                         * we are a copy.  Otherwise we are either a
1634                         * copy if the path stays, or a rename if it
1635                         * does not, but we already handled "stays" case.
1636                         */
1637                        for (j = i + 1; j < q->nr; j++) {
1638                                pp = q->queue[j];
1639                                if (strcmp(pp->one->path, p->one->path))
1640                                        continue; /* not us */
1641                                if (!DIFF_PAIR_RENAME(pp))
1642                                        continue; /* not a rename/copy */
1643                                /* pp is a rename/copy from the same source */
1644                                p->status = DIFF_STATUS_COPIED;
1645                                break;
1646                        }
1647                        if (!p->status)
1648                                p->status = DIFF_STATUS_RENAMED;
1649                }
1650                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1651                         p->one->mode != p->two->mode)
1652                        p->status = DIFF_STATUS_MODIFIED;
1653                else {
1654                        /* This is a "no-change" entry and should not
1655                         * happen anymore, but prepare for broken callers.
1656                         */
1657                        error("feeding unmodified %s to diffcore",
1658                              p->one->path);
1659                        p->status = DIFF_STATUS_UNKNOWN;
1660                }
1661        }
1662        diff_debug_queue("resolve-rename-copy done", q);
1663}
1664
1665static void flush_one_pair(struct diff_filepair *p,
1666                           int diff_output_format,
1667                           struct diff_options *options,
1668                           struct diffstat_t *diffstat)
1669{
1670        int inter_name_termination = '\t';
1671        int line_termination = options->line_termination;
1672        if (!line_termination)
1673                inter_name_termination = 0;
1674
1675        switch (p->status) {
1676        case DIFF_STATUS_UNKNOWN:
1677                break;
1678        case 0:
1679                die("internal error in diff-resolve-rename-copy");
1680                break;
1681        default:
1682                switch (diff_output_format) {
1683                case DIFF_FORMAT_DIFFSTAT:
1684                        diff_flush_stat(p, options, diffstat);
1685                        break;
1686                case DIFF_FORMAT_PATCH:
1687                        diff_flush_patch(p, options);
1688                        break;
1689                case DIFF_FORMAT_RAW:
1690                case DIFF_FORMAT_NAME_STATUS:
1691                        diff_flush_raw(p, line_termination,
1692                                       inter_name_termination,
1693                                       options, diff_output_format);
1694                        break;
1695                case DIFF_FORMAT_NAME:
1696                        diff_flush_name(p,
1697                                        inter_name_termination,
1698                                        line_termination);
1699                        break;
1700                case DIFF_FORMAT_NO_OUTPUT:
1701                        break;
1702                }
1703        }
1704}
1705
1706void diff_flush(struct diff_options *options)
1707{
1708        struct diff_queue_struct *q = &diff_queued_diff;
1709        int i;
1710        int diff_output_format = options->output_format;
1711        struct diffstat_t *diffstat = NULL;
1712
1713        if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
1714                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
1715                diffstat->xm.consume = diffstat_consume;
1716        }
1717
1718        if (options->with_raw) {
1719                for (i = 0; i < q->nr; i++) {
1720                        struct diff_filepair *p = q->queue[i];
1721                        flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
1722                }
1723                putchar(options->line_termination);
1724        }
1725        if (options->with_stat) {
1726                for (i = 0; i < q->nr; i++) {
1727                        struct diff_filepair *p = q->queue[i];
1728                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
1729                                       diffstat);
1730                }
1731                show_stats(diffstat);
1732                free(diffstat);
1733                diffstat = NULL;
1734                putchar(options->line_termination);
1735        }
1736        for (i = 0; i < q->nr; i++) {
1737                struct diff_filepair *p = q->queue[i];
1738                flush_one_pair(p, diff_output_format, options, diffstat);
1739                diff_free_filepair(p);
1740        }
1741
1742        if (diffstat) {
1743                show_stats(diffstat);
1744                free(diffstat);
1745        }
1746
1747        free(q->queue);
1748        q->queue = NULL;
1749        q->nr = q->alloc = 0;
1750}
1751
1752static void diffcore_apply_filter(const char *filter)
1753{
1754        int i;
1755        struct diff_queue_struct *q = &diff_queued_diff;
1756        struct diff_queue_struct outq;
1757        outq.queue = NULL;
1758        outq.nr = outq.alloc = 0;
1759
1760        if (!filter)
1761                return;
1762
1763        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1764                int found;
1765                for (i = found = 0; !found && i < q->nr; i++) {
1766                        struct diff_filepair *p = q->queue[i];
1767                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1768                             ((p->score &&
1769                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1770                              (!p->score &&
1771                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1772                            ((p->status != DIFF_STATUS_MODIFIED) &&
1773                             strchr(filter, p->status)))
1774                                found++;
1775                }
1776                if (found)
1777                        return;
1778
1779                /* otherwise we will clear the whole queue
1780                 * by copying the empty outq at the end of this
1781                 * function, but first clear the current entries
1782                 * in the queue.
1783                 */
1784                for (i = 0; i < q->nr; i++)
1785                        diff_free_filepair(q->queue[i]);
1786        }
1787        else {
1788                /* Only the matching ones */
1789                for (i = 0; i < q->nr; i++) {
1790                        struct diff_filepair *p = q->queue[i];
1791
1792                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1793                             ((p->score &&
1794                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1795                              (!p->score &&
1796                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1797                            ((p->status != DIFF_STATUS_MODIFIED) &&
1798                             strchr(filter, p->status)))
1799                                diff_q(&outq, p);
1800                        else
1801                                diff_free_filepair(p);
1802                }
1803        }
1804        free(q->queue);
1805        *q = outq;
1806}
1807
1808void diffcore_std(struct diff_options *options)
1809{
1810        if (options->break_opt != -1)
1811                diffcore_break(options->break_opt);
1812        if (options->detect_rename)
1813                diffcore_rename(options);
1814        if (options->break_opt != -1)
1815                diffcore_merge_broken();
1816        if (options->pickaxe)
1817                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1818        if (options->orderfile)
1819                diffcore_order(options->orderfile);
1820        diff_resolve_rename_copy();
1821        diffcore_apply_filter(options->filter);
1822}
1823
1824
1825void diffcore_std_no_resolve(struct diff_options *options)
1826{
1827        if (options->pickaxe)
1828                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1829        if (options->orderfile)
1830                diffcore_order(options->orderfile);
1831        diffcore_apply_filter(options->filter);
1832}
1833
1834void diff_addremove(struct diff_options *options,
1835                    int addremove, unsigned mode,
1836                    const unsigned char *sha1,
1837                    const char *base, const char *path)
1838{
1839        char concatpath[PATH_MAX];
1840        struct diff_filespec *one, *two;
1841
1842        /* This may look odd, but it is a preparation for
1843         * feeding "there are unchanged files which should
1844         * not produce diffs, but when you are doing copy
1845         * detection you would need them, so here they are"
1846         * entries to the diff-core.  They will be prefixed
1847         * with something like '=' or '*' (I haven't decided
1848         * which but should not make any difference).
1849         * Feeding the same new and old to diff_change() 
1850         * also has the same effect.
1851         * Before the final output happens, they are pruned after
1852         * merged into rename/copy pairs as appropriate.
1853         */
1854        if (options->reverse_diff)
1855                addremove = (addremove == '+' ? '-' :
1856                             addremove == '-' ? '+' : addremove);
1857
1858        if (!path) path = "";
1859        sprintf(concatpath, "%s%s", base, path);
1860        one = alloc_filespec(concatpath);
1861        two = alloc_filespec(concatpath);
1862
1863        if (addremove != '+')
1864                fill_filespec(one, sha1, mode);
1865        if (addremove != '-')
1866                fill_filespec(two, sha1, mode);
1867
1868        diff_queue(&diff_queued_diff, one, two);
1869}
1870
1871void diff_change(struct diff_options *options,
1872                 unsigned old_mode, unsigned new_mode,
1873                 const unsigned char *old_sha1,
1874                 const unsigned char *new_sha1,
1875                 const char *base, const char *path) 
1876{
1877        char concatpath[PATH_MAX];
1878        struct diff_filespec *one, *two;
1879
1880        if (options->reverse_diff) {
1881                unsigned tmp;
1882                const unsigned char *tmp_c;
1883                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1884                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1885        }
1886        if (!path) path = "";
1887        sprintf(concatpath, "%s%s", base, path);
1888        one = alloc_filespec(concatpath);
1889        two = alloc_filespec(concatpath);
1890        fill_filespec(one, old_sha1, old_mode);
1891        fill_filespec(two, new_sha1, new_mode);
1892
1893        diff_queue(&diff_queued_diff, one, two);
1894}
1895
1896void diff_unmerge(struct diff_options *options,
1897                  const char *path)
1898{
1899        struct diff_filespec *one, *two;
1900        one = alloc_filespec(path);
1901        two = alloc_filespec(path);
1902        diff_queue(&diff_queued_diff, one, two);
1903}