diff.con commit autoconf: Checks for libraries (ebdf532)
   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
  16static int diff_rename_limit_default = -1;
  17static int diff_use_color_default = 0;
  18
  19enum color_diff {
  20        DIFF_RESET = 0,
  21        DIFF_PLAIN = 1,
  22        DIFF_METAINFO = 2,
  23        DIFF_FRAGINFO = 3,
  24        DIFF_FILE_OLD = 4,
  25        DIFF_FILE_NEW = 5,
  26};
  27
  28#define COLOR_NORMAL  ""
  29#define COLOR_BOLD    "\033[1m"
  30#define COLOR_DIM     "\033[2m"
  31#define COLOR_UL      "\033[4m"
  32#define COLOR_BLINK   "\033[5m"
  33#define COLOR_REVERSE "\033[7m"
  34#define COLOR_RESET   "\033[m"
  35
  36#define COLOR_BLACK   "\033[30m"
  37#define COLOR_RED     "\033[31m"
  38#define COLOR_GREEN   "\033[32m"
  39#define COLOR_YELLOW  "\033[33m"
  40#define COLOR_BLUE    "\033[34m"
  41#define COLOR_MAGENTA "\033[35m"
  42#define COLOR_CYAN    "\033[36m"
  43#define COLOR_WHITE   "\033[37m"
  44
  45static const char *diff_colors[] = {
  46        [DIFF_RESET]    = COLOR_RESET,
  47        [DIFF_PLAIN]    = COLOR_NORMAL,
  48        [DIFF_METAINFO] = COLOR_BOLD,
  49        [DIFF_FRAGINFO] = COLOR_CYAN,
  50        [DIFF_FILE_OLD] = COLOR_RED,
  51        [DIFF_FILE_NEW] = COLOR_GREEN,
  52};
  53
  54static int parse_diff_color_slot(const char *var, int ofs)
  55{
  56        if (!strcasecmp(var+ofs, "plain"))
  57                return DIFF_PLAIN;
  58        if (!strcasecmp(var+ofs, "meta"))
  59                return DIFF_METAINFO;
  60        if (!strcasecmp(var+ofs, "frag"))
  61                return DIFF_FRAGINFO;
  62        if (!strcasecmp(var+ofs, "old"))
  63                return DIFF_FILE_OLD;
  64        if (!strcasecmp(var+ofs, "new"))
  65                return DIFF_FILE_NEW;
  66        die("bad config variable '%s'", var);
  67}
  68
  69static const char *parse_diff_color_value(const char *value, const char *var)
  70{
  71        if (!strcasecmp(value, "normal"))
  72                return COLOR_NORMAL;
  73        if (!strcasecmp(value, "bold"))
  74                return COLOR_BOLD;
  75        if (!strcasecmp(value, "dim"))
  76                return COLOR_DIM;
  77        if (!strcasecmp(value, "ul"))
  78                return COLOR_UL;
  79        if (!strcasecmp(value, "blink"))
  80                return COLOR_BLINK;
  81        if (!strcasecmp(value, "reverse"))
  82                return COLOR_REVERSE;
  83        if (!strcasecmp(value, "reset"))
  84                return COLOR_RESET;
  85        if (!strcasecmp(value, "black"))
  86                return COLOR_BLACK;
  87        if (!strcasecmp(value, "red"))
  88                return COLOR_RED;
  89        if (!strcasecmp(value, "green"))
  90                return COLOR_GREEN;
  91        if (!strcasecmp(value, "yellow"))
  92                return COLOR_YELLOW;
  93        if (!strcasecmp(value, "blue"))
  94                return COLOR_BLUE;
  95        if (!strcasecmp(value, "magenta"))
  96                return COLOR_MAGENTA;
  97        if (!strcasecmp(value, "cyan"))
  98                return COLOR_CYAN;
  99        if (!strcasecmp(value, "white"))
 100                return COLOR_WHITE;
 101        die("bad config value '%s' for variable '%s'", value, var);
 102}
 103
 104int git_diff_config(const char *var, const char *value)
 105{
 106        if (!strcmp(var, "diff.renamelimit")) {
 107                diff_rename_limit_default = git_config_int(var, value);
 108                return 0;
 109        }
 110        if (!strcmp(var, "diff.color")) {
 111                if (!value)
 112                        diff_use_color_default = 1; /* bool */
 113                else if (!strcasecmp(value, "auto"))
 114                        diff_use_color_default = isatty(1);
 115                else if (!strcasecmp(value, "never"))
 116                        diff_use_color_default = 0;
 117                else if (!strcasecmp(value, "always"))
 118                        diff_use_color_default = 1;
 119                else
 120                        diff_use_color_default = git_config_bool(var, value);
 121                return 0;
 122        }
 123        if (!strncmp(var, "diff.color.", 11)) {
 124                int slot = parse_diff_color_slot(var, 11);
 125                diff_colors[slot] = parse_diff_color_value(value, var);
 126                return 0;
 127        }
 128        return git_default_config(var, value);
 129}
 130
 131static char *quote_one(const char *str)
 132{
 133        int needlen;
 134        char *xp;
 135
 136        if (!str)
 137                return NULL;
 138        needlen = quote_c_style(str, NULL, NULL, 0);
 139        if (!needlen)
 140                return strdup(str);
 141        xp = xmalloc(needlen + 1);
 142        quote_c_style(str, xp, NULL, 0);
 143        return xp;
 144}
 145
 146static char *quote_two(const char *one, const char *two)
 147{
 148        int need_one = quote_c_style(one, NULL, NULL, 1);
 149        int need_two = quote_c_style(two, NULL, NULL, 1);
 150        char *xp;
 151
 152        if (need_one + need_two) {
 153                if (!need_one) need_one = strlen(one);
 154                if (!need_two) need_one = strlen(two);
 155
 156                xp = xmalloc(need_one + need_two + 3);
 157                xp[0] = '"';
 158                quote_c_style(one, xp + 1, NULL, 1);
 159                quote_c_style(two, xp + need_one + 1, NULL, 1);
 160                strcpy(xp + need_one + need_two + 1, "\"");
 161                return xp;
 162        }
 163        need_one = strlen(one);
 164        need_two = strlen(two);
 165        xp = xmalloc(need_one + need_two + 1);
 166        strcpy(xp, one);
 167        strcpy(xp + need_one, two);
 168        return xp;
 169}
 170
 171static const char *external_diff(void)
 172{
 173        static const char *external_diff_cmd = NULL;
 174        static int done_preparing = 0;
 175
 176        if (done_preparing)
 177                return external_diff_cmd;
 178        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 179        done_preparing = 1;
 180        return external_diff_cmd;
 181}
 182
 183#define TEMPFILE_PATH_LEN               50
 184
 185static struct diff_tempfile {
 186        const char *name; /* filename external diff should read from */
 187        char hex[41];
 188        char mode[10];
 189        char tmp_path[TEMPFILE_PATH_LEN];
 190} diff_temp[2];
 191
 192static int count_lines(const char *data, int size)
 193{
 194        int count, ch, completely_empty = 1, nl_just_seen = 0;
 195        count = 0;
 196        while (0 < size--) {
 197                ch = *data++;
 198                if (ch == '\n') {
 199                        count++;
 200                        nl_just_seen = 1;
 201                        completely_empty = 0;
 202                }
 203                else {
 204                        nl_just_seen = 0;
 205                        completely_empty = 0;
 206                }
 207        }
 208        if (completely_empty)
 209                return 0;
 210        if (!nl_just_seen)
 211                count++; /* no trailing newline */
 212        return count;
 213}
 214
 215static void print_line_count(int count)
 216{
 217        switch (count) {
 218        case 0:
 219                printf("0,0");
 220                break;
 221        case 1:
 222                printf("1");
 223                break;
 224        default:
 225                printf("1,%d", count);
 226                break;
 227        }
 228}
 229
 230static void copy_file(int prefix, const char *data, int size)
 231{
 232        int ch, nl_just_seen = 1;
 233        while (0 < size--) {
 234                ch = *data++;
 235                if (nl_just_seen)
 236                        putchar(prefix);
 237                putchar(ch);
 238                if (ch == '\n')
 239                        nl_just_seen = 1;
 240                else
 241                        nl_just_seen = 0;
 242        }
 243        if (!nl_just_seen)
 244                printf("\n\\ No newline at end of file\n");
 245}
 246
 247static void emit_rewrite_diff(const char *name_a,
 248                              const char *name_b,
 249                              struct diff_filespec *one,
 250                              struct diff_filespec *two)
 251{
 252        int lc_a, lc_b;
 253        diff_populate_filespec(one, 0);
 254        diff_populate_filespec(two, 0);
 255        lc_a = count_lines(one->data, one->size);
 256        lc_b = count_lines(two->data, two->size);
 257        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 258        print_line_count(lc_a);
 259        printf(" +");
 260        print_line_count(lc_b);
 261        printf(" @@\n");
 262        if (lc_a)
 263                copy_file('-', one->data, one->size);
 264        if (lc_b)
 265                copy_file('+', two->data, two->size);
 266}
 267
 268static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 269{
 270        if (!DIFF_FILE_VALID(one)) {
 271                mf->ptr = (char *)""; /* does not matter */
 272                mf->size = 0;
 273                return 0;
 274        }
 275        else if (diff_populate_filespec(one, 0))
 276                return -1;
 277        mf->ptr = one->data;
 278        mf->size = one->size;
 279        return 0;
 280}
 281
 282struct emit_callback {
 283        struct xdiff_emit_state xm;
 284        int nparents, color_diff;
 285        const char **label_path;
 286};
 287
 288static inline const char *get_color(int diff_use_color, enum color_diff ix)
 289{
 290        if (diff_use_color)
 291                return diff_colors[ix];
 292        return "";
 293}
 294
 295static void fn_out_consume(void *priv, char *line, unsigned long len)
 296{
 297        int i;
 298        struct emit_callback *ecbdata = priv;
 299        const char *set = get_color(ecbdata->color_diff, DIFF_METAINFO);
 300        const char *reset = get_color(ecbdata->color_diff, DIFF_RESET);
 301
 302        if (ecbdata->label_path[0]) {
 303                printf("%s--- %s%s\n", set, ecbdata->label_path[0], reset);
 304                printf("%s+++ %s%s\n", set, ecbdata->label_path[1], reset);
 305                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 306        }
 307
 308        /* This is not really necessary for now because
 309         * this codepath only deals with two-way diffs.
 310         */
 311        for (i = 0; i < len && line[i] == '@'; i++)
 312                ;
 313        if (2 <= i && i < len && line[i] == ' ') {
 314                ecbdata->nparents = i - 1;
 315                set = get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 316        }
 317        else if (len < ecbdata->nparents)
 318                set = reset;
 319        else {
 320                int nparents = ecbdata->nparents;
 321                int color = DIFF_PLAIN;
 322                for (i = 0; i < nparents && len; i++) {
 323                        if (line[i] == '-')
 324                                color = DIFF_FILE_OLD;
 325                        else if (line[i] == '+')
 326                                color = DIFF_FILE_NEW;
 327                }
 328                set = get_color(ecbdata->color_diff, color);
 329        }
 330        if (len > 0 && line[len-1] == '\n')
 331                len--;
 332        printf("%s%.*s%s\n", set, (int) len, line, reset);
 333}
 334
 335static char *pprint_rename(const char *a, const char *b)
 336{
 337        const char *old = a;
 338        const char *new = b;
 339        char *name = NULL;
 340        int pfx_length, sfx_length;
 341        int len_a = strlen(a);
 342        int len_b = strlen(b);
 343
 344        /* Find common prefix */
 345        pfx_length = 0;
 346        while (*old && *new && *old == *new) {
 347                if (*old == '/')
 348                        pfx_length = old - a + 1;
 349                old++;
 350                new++;
 351        }
 352
 353        /* Find common suffix */
 354        old = a + len_a;
 355        new = b + len_b;
 356        sfx_length = 0;
 357        while (a <= old && b <= new && *old == *new) {
 358                if (*old == '/')
 359                        sfx_length = len_a - (old - a);
 360                old--;
 361                new--;
 362        }
 363
 364        /*
 365         * pfx{mid-a => mid-b}sfx
 366         * {pfx-a => pfx-b}sfx
 367         * pfx{sfx-a => sfx-b}
 368         * name-a => name-b
 369         */
 370        if (pfx_length + sfx_length) {
 371                int a_midlen = len_a - pfx_length - sfx_length;
 372                int b_midlen = len_b - pfx_length - sfx_length;
 373                if (a_midlen < 0) a_midlen = 0;
 374                if (b_midlen < 0) b_midlen = 0;
 375
 376                name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
 377                sprintf(name, "%.*s{%.*s => %.*s}%s",
 378                        pfx_length, a,
 379                        a_midlen, a + pfx_length,
 380                        b_midlen, b + pfx_length,
 381                        a + len_a - sfx_length);
 382        }
 383        else {
 384                name = xmalloc(len_a + len_b + 5);
 385                sprintf(name, "%s => %s", a, b);
 386        }
 387        return name;
 388}
 389
 390struct diffstat_t {
 391        struct xdiff_emit_state xm;
 392
 393        int nr;
 394        int alloc;
 395        struct diffstat_file {
 396                char *name;
 397                unsigned is_unmerged:1;
 398                unsigned is_binary:1;
 399                unsigned is_renamed:1;
 400                unsigned int added, deleted;
 401        } **files;
 402};
 403
 404static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 405                                          const char *name_a,
 406                                          const char *name_b)
 407{
 408        struct diffstat_file *x;
 409        x = xcalloc(sizeof (*x), 1);
 410        if (diffstat->nr == diffstat->alloc) {
 411                diffstat->alloc = alloc_nr(diffstat->alloc);
 412                diffstat->files = xrealloc(diffstat->files,
 413                                diffstat->alloc * sizeof(x));
 414        }
 415        diffstat->files[diffstat->nr++] = x;
 416        if (name_b) {
 417                x->name = pprint_rename(name_a, name_b);
 418                x->is_renamed = 1;
 419        }
 420        else
 421                x->name = strdup(name_a);
 422        return x;
 423}
 424
 425static void diffstat_consume(void *priv, char *line, unsigned long len)
 426{
 427        struct diffstat_t *diffstat = priv;
 428        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 429
 430        if (line[0] == '+')
 431                x->added++;
 432        else if (line[0] == '-')
 433                x->deleted++;
 434}
 435
 436static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 437static const char minuses[]= "----------------------------------------------------------------------";
 438const char mime_boundary_leader[] = "------------";
 439
 440static void show_stats(struct diffstat_t* data)
 441{
 442        int i, len, add, del, total, adds = 0, dels = 0;
 443        int max, max_change = 0, max_len = 0;
 444        int total_files = data->nr;
 445
 446        if (data->nr == 0)
 447                return;
 448
 449        for (i = 0; i < data->nr; i++) {
 450                struct diffstat_file *file = data->files[i];
 451
 452                len = strlen(file->name);
 453                if (max_len < len)
 454                        max_len = len;
 455
 456                if (file->is_binary || file->is_unmerged)
 457                        continue;
 458                if (max_change < file->added + file->deleted)
 459                        max_change = file->added + file->deleted;
 460        }
 461
 462        for (i = 0; i < data->nr; i++) {
 463                const char *prefix = "";
 464                char *name = data->files[i]->name;
 465                int added = data->files[i]->added;
 466                int deleted = data->files[i]->deleted;
 467
 468                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 469                        char *qname = xmalloc(len + 1);
 470                        quote_c_style(name, qname, NULL, 0);
 471                        free(name);
 472                        data->files[i]->name = name = qname;
 473                }
 474
 475                /*
 476                 * "scale" the filename
 477                 */
 478                len = strlen(name);
 479                max = max_len;
 480                if (max > 50)
 481                        max = 50;
 482                if (len > max) {
 483                        char *slash;
 484                        prefix = "...";
 485                        max -= 3;
 486                        name += len - max;
 487                        slash = strchr(name, '/');
 488                        if (slash)
 489                                name = slash;
 490                }
 491                len = max;
 492
 493                /*
 494                 * scale the add/delete
 495                 */
 496                max = max_change;
 497                if (max + len > 70)
 498                        max = 70 - len;
 499
 500                if (data->files[i]->is_binary) {
 501                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 502                        goto free_diffstat_file;
 503                }
 504                else if (data->files[i]->is_unmerged) {
 505                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 506                        goto free_diffstat_file;
 507                }
 508                else if (!data->files[i]->is_renamed &&
 509                         (added + deleted == 0)) {
 510                        total_files--;
 511                        goto free_diffstat_file;
 512                }
 513
 514                add = added;
 515                del = deleted;
 516                total = add + del;
 517                adds += add;
 518                dels += del;
 519
 520                if (max_change > 0) {
 521                        total = (total * max + max_change / 2) / max_change;
 522                        add = (add * max + max_change / 2) / max_change;
 523                        del = total - add;
 524                }
 525                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 526                                len, name, added + deleted,
 527                                add, pluses, del, minuses);
 528        free_diffstat_file:
 529                free(data->files[i]->name);
 530                free(data->files[i]);
 531        }
 532        free(data->files);
 533        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 534                        total_files, adds, dels);
 535}
 536
 537struct checkdiff_t {
 538        struct xdiff_emit_state xm;
 539        const char *filename;
 540        int lineno;
 541};
 542
 543static void checkdiff_consume(void *priv, char *line, unsigned long len)
 544{
 545        struct checkdiff_t *data = priv;
 546
 547        if (line[0] == '+') {
 548                int i, spaces = 0;
 549
 550                data->lineno++;
 551
 552                /* check space before tab */
 553                for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
 554                        if (line[i] == ' ')
 555                                spaces++;
 556                if (line[i - 1] == '\t' && spaces)
 557                        printf("%s:%d: space before tab:%.*s\n",
 558                                data->filename, data->lineno, (int)len, line);
 559
 560                /* check white space at line end */
 561                if (line[len - 1] == '\n')
 562                        len--;
 563                if (isspace(line[len - 1]))
 564                        printf("%s:%d: white space at end: %.*s\n",
 565                                data->filename, data->lineno, (int)len, line);
 566        } else if (line[0] == ' ')
 567                data->lineno++;
 568        else if (line[0] == '@') {
 569                char *plus = strchr(line, '+');
 570                if (plus)
 571                        data->lineno = strtol(plus, NULL, 10);
 572                else
 573                        die("invalid diff");
 574        }
 575}
 576
 577static unsigned char *deflate_it(char *data,
 578                                 unsigned long size,
 579                                 unsigned long *result_size)
 580{
 581        int bound;
 582        unsigned char *deflated;
 583        z_stream stream;
 584
 585        memset(&stream, 0, sizeof(stream));
 586        deflateInit(&stream, Z_BEST_COMPRESSION);
 587        bound = deflateBound(&stream, size);
 588        deflated = xmalloc(bound);
 589        stream.next_out = deflated;
 590        stream.avail_out = bound;
 591
 592        stream.next_in = (unsigned char *)data;
 593        stream.avail_in = size;
 594        while (deflate(&stream, Z_FINISH) == Z_OK)
 595                ; /* nothing */
 596        deflateEnd(&stream);
 597        *result_size = stream.total_out;
 598        return deflated;
 599}
 600
 601static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 602{
 603        void *cp;
 604        void *delta;
 605        void *deflated;
 606        void *data;
 607        unsigned long orig_size;
 608        unsigned long delta_size;
 609        unsigned long deflate_size;
 610        unsigned long data_size;
 611
 612        printf("GIT binary patch\n");
 613        /* We could do deflated delta, or we could do just deflated two,
 614         * whichever is smaller.
 615         */
 616        delta = NULL;
 617        deflated = deflate_it(two->ptr, two->size, &deflate_size);
 618        if (one->size && two->size) {
 619                delta = diff_delta(one->ptr, one->size,
 620                                   two->ptr, two->size,
 621                                   &delta_size, deflate_size);
 622                if (delta) {
 623                        void *to_free = delta;
 624                        orig_size = delta_size;
 625                        delta = deflate_it(delta, delta_size, &delta_size);
 626                        free(to_free);
 627                }
 628        }
 629
 630        if (delta && delta_size < deflate_size) {
 631                printf("delta %lu\n", orig_size);
 632                free(deflated);
 633                data = delta;
 634                data_size = delta_size;
 635        }
 636        else {
 637                printf("literal %lu\n", two->size);
 638                free(delta);
 639                data = deflated;
 640                data_size = deflate_size;
 641        }
 642
 643        /* emit data encoded in base85 */
 644        cp = data;
 645        while (data_size) {
 646                int bytes = (52 < data_size) ? 52 : data_size;
 647                char line[70];
 648                data_size -= bytes;
 649                if (bytes <= 26)
 650                        line[0] = bytes + 'A' - 1;
 651                else
 652                        line[0] = bytes - 26 + 'a' - 1;
 653                encode_85(line + 1, cp, bytes);
 654                cp = (char *) cp + bytes;
 655                puts(line);
 656        }
 657        printf("\n");
 658        free(data);
 659}
 660
 661#define FIRST_FEW_BYTES 8000
 662static int mmfile_is_binary(mmfile_t *mf)
 663{
 664        long sz = mf->size;
 665        if (FIRST_FEW_BYTES < sz)
 666                sz = FIRST_FEW_BYTES;
 667        if (memchr(mf->ptr, 0, sz))
 668                return 1;
 669        return 0;
 670}
 671
 672static void builtin_diff(const char *name_a,
 673                         const char *name_b,
 674                         struct diff_filespec *one,
 675                         struct diff_filespec *two,
 676                         const char *xfrm_msg,
 677                         struct diff_options *o,
 678                         int complete_rewrite)
 679{
 680        mmfile_t mf1, mf2;
 681        const char *lbl[2];
 682        char *a_one, *b_two;
 683        const char *set = get_color(o->color_diff, DIFF_METAINFO);
 684        const char *reset = get_color(o->color_diff, DIFF_RESET);
 685
 686        a_one = quote_two("a/", name_a);
 687        b_two = quote_two("b/", name_b);
 688        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 689        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 690        printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
 691        if (lbl[0][0] == '/') {
 692                /* /dev/null */
 693                printf("%snew file mode %06o%s\n", set, two->mode, reset);
 694                if (xfrm_msg && xfrm_msg[0])
 695                        printf("%s%s%s\n", set, xfrm_msg, reset);
 696        }
 697        else if (lbl[1][0] == '/') {
 698                printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
 699                if (xfrm_msg && xfrm_msg[0])
 700                        printf("%s%s%s\n", set, xfrm_msg, reset);
 701        }
 702        else {
 703                if (one->mode != two->mode) {
 704                        printf("%sold mode %06o%s\n", set, one->mode, reset);
 705                        printf("%snew mode %06o%s\n", set, two->mode, reset);
 706                }
 707                if (xfrm_msg && xfrm_msg[0])
 708                        printf("%s%s%s\n", set, xfrm_msg, reset);
 709                /*
 710                 * we do not run diff between different kind
 711                 * of objects.
 712                 */
 713                if ((one->mode ^ two->mode) & S_IFMT)
 714                        goto free_ab_and_return;
 715                if (complete_rewrite) {
 716                        emit_rewrite_diff(name_a, name_b, one, two);
 717                        goto free_ab_and_return;
 718                }
 719        }
 720
 721        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 722                die("unable to read files to diff");
 723
 724        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
 725                /* Quite common confusing case */
 726                if (mf1.size == mf2.size &&
 727                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 728                        goto free_ab_and_return;
 729                if (o->binary)
 730                        emit_binary_diff(&mf1, &mf2);
 731                else
 732                        printf("Binary files %s and %s differ\n",
 733                               lbl[0], lbl[1]);
 734        }
 735        else {
 736                /* Crazy xdl interfaces.. */
 737                const char *diffopts = getenv("GIT_DIFF_OPTS");
 738                xpparam_t xpp;
 739                xdemitconf_t xecfg;
 740                xdemitcb_t ecb;
 741                struct emit_callback ecbdata;
 742
 743                memset(&ecbdata, 0, sizeof(ecbdata));
 744                ecbdata.label_path = lbl;
 745                ecbdata.color_diff = o->color_diff;
 746                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 747                xecfg.ctxlen = o->context;
 748                xecfg.flags = XDL_EMIT_FUNCNAMES;
 749                if (!diffopts)
 750                        ;
 751                else if (!strncmp(diffopts, "--unified=", 10))
 752                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 753                else if (!strncmp(diffopts, "-u", 2))
 754                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 755                ecb.outf = xdiff_outf;
 756                ecb.priv = &ecbdata;
 757                ecbdata.xm.consume = fn_out_consume;
 758                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 759        }
 760
 761 free_ab_and_return:
 762        free(a_one);
 763        free(b_two);
 764        return;
 765}
 766
 767static void builtin_diffstat(const char *name_a, const char *name_b,
 768                             struct diff_filespec *one,
 769                             struct diff_filespec *two,
 770                             struct diffstat_t *diffstat,
 771                             struct diff_options *o,
 772                             int complete_rewrite)
 773{
 774        mmfile_t mf1, mf2;
 775        struct diffstat_file *data;
 776
 777        data = diffstat_add(diffstat, name_a, name_b);
 778
 779        if (!one || !two) {
 780                data->is_unmerged = 1;
 781                return;
 782        }
 783        if (complete_rewrite) {
 784                diff_populate_filespec(one, 0);
 785                diff_populate_filespec(two, 0);
 786                data->deleted = count_lines(one->data, one->size);
 787                data->added = count_lines(two->data, two->size);
 788                return;
 789        }
 790        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 791                die("unable to read files to diff");
 792
 793        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 794                data->is_binary = 1;
 795        else {
 796                /* Crazy xdl interfaces.. */
 797                xpparam_t xpp;
 798                xdemitconf_t xecfg;
 799                xdemitcb_t ecb;
 800
 801                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 802                xecfg.ctxlen = 0;
 803                xecfg.flags = 0;
 804                ecb.outf = xdiff_outf;
 805                ecb.priv = diffstat;
 806                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 807        }
 808}
 809
 810static void builtin_checkdiff(const char *name_a, const char *name_b,
 811                             struct diff_filespec *one,
 812                             struct diff_filespec *two)
 813{
 814        mmfile_t mf1, mf2;
 815        struct checkdiff_t data;
 816
 817        if (!two)
 818                return;
 819
 820        memset(&data, 0, sizeof(data));
 821        data.xm.consume = checkdiff_consume;
 822        data.filename = name_b ? name_b : name_a;
 823        data.lineno = 0;
 824
 825        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 826                die("unable to read files to diff");
 827
 828        if (mmfile_is_binary(&mf2))
 829                return;
 830        else {
 831                /* Crazy xdl interfaces.. */
 832                xpparam_t xpp;
 833                xdemitconf_t xecfg;
 834                xdemitcb_t ecb;
 835
 836                xpp.flags = XDF_NEED_MINIMAL;
 837                xecfg.ctxlen = 0;
 838                xecfg.flags = 0;
 839                ecb.outf = xdiff_outf;
 840                ecb.priv = &data;
 841                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 842        }
 843}
 844
 845struct diff_filespec *alloc_filespec(const char *path)
 846{
 847        int namelen = strlen(path);
 848        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 849
 850        memset(spec, 0, sizeof(*spec));
 851        spec->path = (char *)(spec + 1);
 852        memcpy(spec->path, path, namelen+1);
 853        return spec;
 854}
 855
 856void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 857                   unsigned short mode)
 858{
 859        if (mode) {
 860                spec->mode = canon_mode(mode);
 861                memcpy(spec->sha1, sha1, 20);
 862                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 863        }
 864}
 865
 866/*
 867 * Given a name and sha1 pair, if the dircache tells us the file in
 868 * the work tree has that object contents, return true, so that
 869 * prepare_temp_file() does not have to inflate and extract.
 870 */
 871static int work_tree_matches(const char *name, const unsigned char *sha1)
 872{
 873        struct cache_entry *ce;
 874        struct stat st;
 875        int pos, len;
 876
 877        /* We do not read the cache ourselves here, because the
 878         * benchmark with my previous version that always reads cache
 879         * shows that it makes things worse for diff-tree comparing
 880         * two linux-2.6 kernel trees in an already checked out work
 881         * tree.  This is because most diff-tree comparisons deal with
 882         * only a small number of files, while reading the cache is
 883         * expensive for a large project, and its cost outweighs the
 884         * savings we get by not inflating the object to a temporary
 885         * file.  Practically, this code only helps when we are used
 886         * by diff-cache --cached, which does read the cache before
 887         * calling us.
 888         */
 889        if (!active_cache)
 890                return 0;
 891
 892        len = strlen(name);
 893        pos = cache_name_pos(name, len);
 894        if (pos < 0)
 895                return 0;
 896        ce = active_cache[pos];
 897        if ((lstat(name, &st) < 0) ||
 898            !S_ISREG(st.st_mode) || /* careful! */
 899            ce_match_stat(ce, &st, 0) ||
 900            memcmp(sha1, ce->sha1, 20))
 901                return 0;
 902        /* we return 1 only when we can stat, it is a regular file,
 903         * stat information matches, and sha1 recorded in the cache
 904         * matches.  I.e. we know the file in the work tree really is
 905         * the same as the <name, sha1> pair.
 906         */
 907        return 1;
 908}
 909
 910static struct sha1_size_cache {
 911        unsigned char sha1[20];
 912        unsigned long size;
 913} **sha1_size_cache;
 914static int sha1_size_cache_nr, sha1_size_cache_alloc;
 915
 916static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 917                                                 int find_only,
 918                                                 unsigned long size)
 919{
 920        int first, last;
 921        struct sha1_size_cache *e;
 922
 923        first = 0;
 924        last = sha1_size_cache_nr;
 925        while (last > first) {
 926                int cmp, next = (last + first) >> 1;
 927                e = sha1_size_cache[next];
 928                cmp = memcmp(e->sha1, sha1, 20);
 929                if (!cmp)
 930                        return e;
 931                if (cmp < 0) {
 932                        last = next;
 933                        continue;
 934                }
 935                first = next+1;
 936        }
 937        /* not found */
 938        if (find_only)
 939                return NULL;
 940        /* insert to make it at "first" */
 941        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 942                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 943                sha1_size_cache = xrealloc(sha1_size_cache,
 944                                           sha1_size_cache_alloc *
 945                                           sizeof(*sha1_size_cache));
 946        }
 947        sha1_size_cache_nr++;
 948        if (first < sha1_size_cache_nr)
 949                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 950                        (sha1_size_cache_nr - first - 1) *
 951                        sizeof(*sha1_size_cache));
 952        e = xmalloc(sizeof(struct sha1_size_cache));
 953        sha1_size_cache[first] = e;
 954        memcpy(e->sha1, sha1, 20);
 955        e->size = size;
 956        return e;
 957}
 958
 959/*
 960 * While doing rename detection and pickaxe operation, we may need to
 961 * grab the data for the blob (or file) for our own in-core comparison.
 962 * diff_filespec has data and size fields for this purpose.
 963 */
 964int diff_populate_filespec(struct diff_filespec *s, int size_only)
 965{
 966        int err = 0;
 967        if (!DIFF_FILE_VALID(s))
 968                die("internal error: asking to populate invalid file.");
 969        if (S_ISDIR(s->mode))
 970                return -1;
 971
 972        if (!use_size_cache)
 973                size_only = 0;
 974
 975        if (s->data)
 976                return err;
 977        if (!s->sha1_valid ||
 978            work_tree_matches(s->path, s->sha1)) {
 979                struct stat st;
 980                int fd;
 981                if (lstat(s->path, &st) < 0) {
 982                        if (errno == ENOENT) {
 983                        err_empty:
 984                                err = -1;
 985                        empty:
 986                                s->data = (char *)"";
 987                                s->size = 0;
 988                                return err;
 989                        }
 990                }
 991                s->size = st.st_size;
 992                if (!s->size)
 993                        goto empty;
 994                if (size_only)
 995                        return 0;
 996                if (S_ISLNK(st.st_mode)) {
 997                        int ret;
 998                        s->data = xmalloc(s->size);
 999                        s->should_free = 1;
1000                        ret = readlink(s->path, s->data, s->size);
1001                        if (ret < 0) {
1002                                free(s->data);
1003                                goto err_empty;
1004                        }
1005                        return 0;
1006                }
1007                fd = open(s->path, O_RDONLY);
1008                if (fd < 0)
1009                        goto err_empty;
1010                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1011                close(fd);
1012                if (s->data == MAP_FAILED)
1013                        goto err_empty;
1014                s->should_munmap = 1;
1015        }
1016        else {
1017                char type[20];
1018                struct sha1_size_cache *e;
1019
1020                if (size_only) {
1021                        e = locate_size_cache(s->sha1, 1, 0);
1022                        if (e) {
1023                                s->size = e->size;
1024                                return 0;
1025                        }
1026                        if (!sha1_object_info(s->sha1, type, &s->size))
1027                                locate_size_cache(s->sha1, 0, s->size);
1028                }
1029                else {
1030                        s->data = read_sha1_file(s->sha1, type, &s->size);
1031                        s->should_free = 1;
1032                }
1033        }
1034        return 0;
1035}
1036
1037void diff_free_filespec_data(struct diff_filespec *s)
1038{
1039        if (s->should_free)
1040                free(s->data);
1041        else if (s->should_munmap)
1042                munmap(s->data, s->size);
1043        s->should_free = s->should_munmap = 0;
1044        s->data = NULL;
1045        free(s->cnt_data);
1046        s->cnt_data = NULL;
1047}
1048
1049static void prep_temp_blob(struct diff_tempfile *temp,
1050                           void *blob,
1051                           unsigned long size,
1052                           const unsigned char *sha1,
1053                           int mode)
1054{
1055        int fd;
1056
1057        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1058        if (fd < 0)
1059                die("unable to create temp-file");
1060        if (write(fd, blob, size) != size)
1061                die("unable to write temp-file");
1062        close(fd);
1063        temp->name = temp->tmp_path;
1064        strcpy(temp->hex, sha1_to_hex(sha1));
1065        temp->hex[40] = 0;
1066        sprintf(temp->mode, "%06o", mode);
1067}
1068
1069static void prepare_temp_file(const char *name,
1070                              struct diff_tempfile *temp,
1071                              struct diff_filespec *one)
1072{
1073        if (!DIFF_FILE_VALID(one)) {
1074        not_a_valid_file:
1075                /* A '-' entry produces this for file-2, and
1076                 * a '+' entry produces this for file-1.
1077                 */
1078                temp->name = "/dev/null";
1079                strcpy(temp->hex, ".");
1080                strcpy(temp->mode, ".");
1081                return;
1082        }
1083
1084        if (!one->sha1_valid ||
1085            work_tree_matches(name, one->sha1)) {
1086                struct stat st;
1087                if (lstat(name, &st) < 0) {
1088                        if (errno == ENOENT)
1089                                goto not_a_valid_file;
1090                        die("stat(%s): %s", name, strerror(errno));
1091                }
1092                if (S_ISLNK(st.st_mode)) {
1093                        int ret;
1094                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1095                        if (sizeof(buf) <= st.st_size)
1096                                die("symlink too long: %s", name);
1097                        ret = readlink(name, buf, st.st_size);
1098                        if (ret < 0)
1099                                die("readlink(%s)", name);
1100                        prep_temp_blob(temp, buf, st.st_size,
1101                                       (one->sha1_valid ?
1102                                        one->sha1 : null_sha1),
1103                                       (one->sha1_valid ?
1104                                        one->mode : S_IFLNK));
1105                }
1106                else {
1107                        /* we can borrow from the file in the work tree */
1108                        temp->name = name;
1109                        if (!one->sha1_valid)
1110                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1111                        else
1112                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1113                        /* Even though we may sometimes borrow the
1114                         * contents from the work tree, we always want
1115                         * one->mode.  mode is trustworthy even when
1116                         * !(one->sha1_valid), as long as
1117                         * DIFF_FILE_VALID(one).
1118                         */
1119                        sprintf(temp->mode, "%06o", one->mode);
1120                }
1121                return;
1122        }
1123        else {
1124                if (diff_populate_filespec(one, 0))
1125                        die("cannot read data blob for %s", one->path);
1126                prep_temp_blob(temp, one->data, one->size,
1127                               one->sha1, one->mode);
1128        }
1129}
1130
1131static void remove_tempfile(void)
1132{
1133        int i;
1134
1135        for (i = 0; i < 2; i++)
1136                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1137                        unlink(diff_temp[i].name);
1138                        diff_temp[i].name = NULL;
1139                }
1140}
1141
1142static void remove_tempfile_on_signal(int signo)
1143{
1144        remove_tempfile();
1145        signal(SIGINT, SIG_DFL);
1146        raise(signo);
1147}
1148
1149static int spawn_prog(const char *pgm, const char **arg)
1150{
1151        pid_t pid;
1152        int status;
1153
1154        fflush(NULL);
1155        pid = fork();
1156        if (pid < 0)
1157                die("unable to fork");
1158        if (!pid) {
1159                execvp(pgm, (char *const*) arg);
1160                exit(255);
1161        }
1162
1163        while (waitpid(pid, &status, 0) < 0) {
1164                if (errno == EINTR)
1165                        continue;
1166                return -1;
1167        }
1168
1169        /* Earlier we did not check the exit status because
1170         * diff exits non-zero if files are different, and
1171         * we are not interested in knowing that.  It was a
1172         * mistake which made it harder to quit a diff-*
1173         * session that uses the git-apply-patch-script as
1174         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1175         * should also exit non-zero only when it wants to
1176         * abort the entire diff-* session.
1177         */
1178        if (WIFEXITED(status) && !WEXITSTATUS(status))
1179                return 0;
1180        return -1;
1181}
1182
1183/* An external diff command takes:
1184 *
1185 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1186 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1187 *
1188 */
1189static void run_external_diff(const char *pgm,
1190                              const char *name,
1191                              const char *other,
1192                              struct diff_filespec *one,
1193                              struct diff_filespec *two,
1194                              const char *xfrm_msg,
1195                              int complete_rewrite)
1196{
1197        const char *spawn_arg[10];
1198        struct diff_tempfile *temp = diff_temp;
1199        int retval;
1200        static int atexit_asked = 0;
1201        const char *othername;
1202        const char **arg = &spawn_arg[0];
1203
1204        othername = (other? other : name);
1205        if (one && two) {
1206                prepare_temp_file(name, &temp[0], one);
1207                prepare_temp_file(othername, &temp[1], two);
1208                if (! atexit_asked &&
1209                    (temp[0].name == temp[0].tmp_path ||
1210                     temp[1].name == temp[1].tmp_path)) {
1211                        atexit_asked = 1;
1212                        atexit(remove_tempfile);
1213                }
1214                signal(SIGINT, remove_tempfile_on_signal);
1215        }
1216
1217        if (one && two) {
1218                *arg++ = pgm;
1219                *arg++ = name;
1220                *arg++ = temp[0].name;
1221                *arg++ = temp[0].hex;
1222                *arg++ = temp[0].mode;
1223                *arg++ = temp[1].name;
1224                *arg++ = temp[1].hex;
1225                *arg++ = temp[1].mode;
1226                if (other) {
1227                        *arg++ = other;
1228                        *arg++ = xfrm_msg;
1229                }
1230        } else {
1231                *arg++ = pgm;
1232                *arg++ = name;
1233        }
1234        *arg = NULL;
1235        retval = spawn_prog(pgm, spawn_arg);
1236        remove_tempfile();
1237        if (retval) {
1238                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1239                exit(1);
1240        }
1241}
1242
1243static void run_diff_cmd(const char *pgm,
1244                         const char *name,
1245                         const char *other,
1246                         struct diff_filespec *one,
1247                         struct diff_filespec *two,
1248                         const char *xfrm_msg,
1249                         struct diff_options *o,
1250                         int complete_rewrite)
1251{
1252        if (pgm) {
1253                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1254                                  complete_rewrite);
1255                return;
1256        }
1257        if (one && two)
1258                builtin_diff(name, other ? other : name,
1259                             one, two, xfrm_msg, o, complete_rewrite);
1260        else
1261                printf("* Unmerged path %s\n", name);
1262}
1263
1264static void diff_fill_sha1_info(struct diff_filespec *one)
1265{
1266        if (DIFF_FILE_VALID(one)) {
1267                if (!one->sha1_valid) {
1268                        struct stat st;
1269                        if (lstat(one->path, &st) < 0)
1270                                die("stat %s", one->path);
1271                        if (index_path(one->sha1, one->path, &st, 0))
1272                                die("cannot hash %s\n", one->path);
1273                }
1274        }
1275        else
1276                memset(one->sha1, 0, 20);
1277}
1278
1279static void run_diff(struct diff_filepair *p, struct diff_options *o)
1280{
1281        const char *pgm = external_diff();
1282        char msg[PATH_MAX*2+300], *xfrm_msg;
1283        struct diff_filespec *one;
1284        struct diff_filespec *two;
1285        const char *name;
1286        const char *other;
1287        char *name_munged, *other_munged;
1288        int complete_rewrite = 0;
1289        int len;
1290
1291        if (DIFF_PAIR_UNMERGED(p)) {
1292                /* unmerged */
1293                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1294                return;
1295        }
1296
1297        name = p->one->path;
1298        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1299        name_munged = quote_one(name);
1300        other_munged = quote_one(other);
1301        one = p->one; two = p->two;
1302
1303        diff_fill_sha1_info(one);
1304        diff_fill_sha1_info(two);
1305
1306        len = 0;
1307        switch (p->status) {
1308        case DIFF_STATUS_COPIED:
1309                len += snprintf(msg + len, sizeof(msg) - len,
1310                                "similarity index %d%%\n"
1311                                "copy from %s\n"
1312                                "copy to %s\n",
1313                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1314                                name_munged, other_munged);
1315                break;
1316        case DIFF_STATUS_RENAMED:
1317                len += snprintf(msg + len, sizeof(msg) - len,
1318                                "similarity index %d%%\n"
1319                                "rename from %s\n"
1320                                "rename to %s\n",
1321                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1322                                name_munged, other_munged);
1323                break;
1324        case DIFF_STATUS_MODIFIED:
1325                if (p->score) {
1326                        len += snprintf(msg + len, sizeof(msg) - len,
1327                                        "dissimilarity index %d%%\n",
1328                                        (int)(0.5 + p->score *
1329                                              100.0/MAX_SCORE));
1330                        complete_rewrite = 1;
1331                        break;
1332                }
1333                /* fallthru */
1334        default:
1335                /* nothing */
1336                ;
1337        }
1338
1339        if (memcmp(one->sha1, two->sha1, 20)) {
1340                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1341
1342                len += snprintf(msg + len, sizeof(msg) - len,
1343                                "index %.*s..%.*s",
1344                                abbrev, sha1_to_hex(one->sha1),
1345                                abbrev, sha1_to_hex(two->sha1));
1346                if (one->mode == two->mode)
1347                        len += snprintf(msg + len, sizeof(msg) - len,
1348                                        " %06o", one->mode);
1349                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1350        }
1351
1352        if (len)
1353                msg[--len] = 0;
1354        xfrm_msg = len ? msg : NULL;
1355
1356        if (!pgm &&
1357            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1358            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1359                /* a filepair that changes between file and symlink
1360                 * needs to be split into deletion and creation.
1361                 */
1362                struct diff_filespec *null = alloc_filespec(two->path);
1363                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1364                free(null);
1365                null = alloc_filespec(one->path);
1366                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1367                free(null);
1368        }
1369        else
1370                run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1371                             complete_rewrite);
1372
1373        free(name_munged);
1374        free(other_munged);
1375}
1376
1377static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1378                         struct diffstat_t *diffstat)
1379{
1380        const char *name;
1381        const char *other;
1382        int complete_rewrite = 0;
1383
1384        if (DIFF_PAIR_UNMERGED(p)) {
1385                /* unmerged */
1386                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1387                return;
1388        }
1389
1390        name = p->one->path;
1391        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1392
1393        diff_fill_sha1_info(p->one);
1394        diff_fill_sha1_info(p->two);
1395
1396        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1397                complete_rewrite = 1;
1398        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1399}
1400
1401static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1402{
1403        const char *name;
1404        const char *other;
1405
1406        if (DIFF_PAIR_UNMERGED(p)) {
1407                /* unmerged */
1408                return;
1409        }
1410
1411        name = p->one->path;
1412        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1413
1414        diff_fill_sha1_info(p->one);
1415        diff_fill_sha1_info(p->two);
1416
1417        builtin_checkdiff(name, other, p->one, p->two);
1418}
1419
1420void diff_setup(struct diff_options *options)
1421{
1422        memset(options, 0, sizeof(*options));
1423        options->output_format = DIFF_FORMAT_RAW;
1424        options->line_termination = '\n';
1425        options->break_opt = -1;
1426        options->rename_limit = -1;
1427        options->context = 3;
1428
1429        options->change = diff_change;
1430        options->add_remove = diff_addremove;
1431        options->color_diff = diff_use_color_default;
1432}
1433
1434int diff_setup_done(struct diff_options *options)
1435{
1436        if ((options->find_copies_harder &&
1437             options->detect_rename != DIFF_DETECT_COPY) ||
1438            (0 <= options->rename_limit && !options->detect_rename))
1439                return -1;
1440
1441        /*
1442         * These cases always need recursive; we do not drop caller-supplied
1443         * recursive bits for other formats here.
1444         */
1445        if ((options->output_format == DIFF_FORMAT_PATCH) ||
1446            (options->output_format == DIFF_FORMAT_DIFFSTAT) ||
1447            (options->output_format == DIFF_FORMAT_CHECKDIFF))
1448                options->recursive = 1;
1449
1450        /*
1451         * These combinations do not make sense.
1452         */
1453        if (options->output_format == DIFF_FORMAT_RAW)
1454                options->with_raw = 0;
1455        if (options->output_format == DIFF_FORMAT_DIFFSTAT)
1456                options->with_stat  = 0;
1457
1458        if (options->detect_rename && options->rename_limit < 0)
1459                options->rename_limit = diff_rename_limit_default;
1460        if (options->setup & DIFF_SETUP_USE_CACHE) {
1461                if (!active_cache)
1462                        /* read-cache does not die even when it fails
1463                         * so it is safe for us to do this here.  Also
1464                         * it does not smudge active_cache or active_nr
1465                         * when it fails, so we do not have to worry about
1466                         * cleaning it up ourselves either.
1467                         */
1468                        read_cache();
1469        }
1470        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1471                use_size_cache = 1;
1472        if (options->abbrev <= 0 || 40 < options->abbrev)
1473                options->abbrev = 40; /* full */
1474
1475        return 0;
1476}
1477
1478static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1479{
1480        char c, *eq;
1481        int len;
1482
1483        if (*arg != '-')
1484                return 0;
1485        c = *++arg;
1486        if (!c)
1487                return 0;
1488        if (c == arg_short) {
1489                c = *++arg;
1490                if (!c)
1491                        return 1;
1492                if (val && isdigit(c)) {
1493                        char *end;
1494                        int n = strtoul(arg, &end, 10);
1495                        if (*end)
1496                                return 0;
1497                        *val = n;
1498                        return 1;
1499                }
1500                return 0;
1501        }
1502        if (c != '-')
1503                return 0;
1504        arg++;
1505        eq = strchr(arg, '=');
1506        if (eq)
1507                len = eq - arg;
1508        else
1509                len = strlen(arg);
1510        if (!len || strncmp(arg, arg_long, len))
1511                return 0;
1512        if (eq) {
1513                int n;
1514                char *end;
1515                if (!isdigit(*++eq))
1516                        return 0;
1517                n = strtoul(eq, &end, 10);
1518                if (*end)
1519                        return 0;
1520                *val = n;
1521        }
1522        return 1;
1523}
1524
1525int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1526{
1527        const char *arg = av[0];
1528        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1529                options->output_format = DIFF_FORMAT_PATCH;
1530        else if (opt_arg(arg, 'U', "unified", &options->context))
1531                options->output_format = DIFF_FORMAT_PATCH;
1532        else if (!strcmp(arg, "--patch-with-raw")) {
1533                options->output_format = DIFF_FORMAT_PATCH;
1534                options->with_raw = 1;
1535        }
1536        else if (!strcmp(arg, "--stat"))
1537                options->output_format = DIFF_FORMAT_DIFFSTAT;
1538        else if (!strcmp(arg, "--check"))
1539                options->output_format = DIFF_FORMAT_CHECKDIFF;
1540        else if (!strcmp(arg, "--summary"))
1541                options->summary = 1;
1542        else if (!strcmp(arg, "--patch-with-stat")) {
1543                options->output_format = DIFF_FORMAT_PATCH;
1544                options->with_stat = 1;
1545        }
1546        else if (!strcmp(arg, "-z"))
1547                options->line_termination = 0;
1548        else if (!strncmp(arg, "-l", 2))
1549                options->rename_limit = strtoul(arg+2, NULL, 10);
1550        else if (!strcmp(arg, "--full-index"))
1551                options->full_index = 1;
1552        else if (!strcmp(arg, "--binary")) {
1553                options->output_format = DIFF_FORMAT_PATCH;
1554                options->full_index = options->binary = 1;
1555        }
1556        else if (!strcmp(arg, "--name-only"))
1557                options->output_format = DIFF_FORMAT_NAME;
1558        else if (!strcmp(arg, "--name-status"))
1559                options->output_format = DIFF_FORMAT_NAME_STATUS;
1560        else if (!strcmp(arg, "-R"))
1561                options->reverse_diff = 1;
1562        else if (!strncmp(arg, "-S", 2))
1563                options->pickaxe = arg + 2;
1564        else if (!strcmp(arg, "-s"))
1565                options->output_format = DIFF_FORMAT_NO_OUTPUT;
1566        else if (!strncmp(arg, "-O", 2))
1567                options->orderfile = arg + 2;
1568        else if (!strncmp(arg, "--diff-filter=", 14))
1569                options->filter = arg + 14;
1570        else if (!strcmp(arg, "--pickaxe-all"))
1571                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1572        else if (!strcmp(arg, "--pickaxe-regex"))
1573                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1574        else if (!strncmp(arg, "-B", 2)) {
1575                if ((options->break_opt =
1576                     diff_scoreopt_parse(arg)) == -1)
1577                        return -1;
1578        }
1579        else if (!strncmp(arg, "-M", 2)) {
1580                if ((options->rename_score =
1581                     diff_scoreopt_parse(arg)) == -1)
1582                        return -1;
1583                options->detect_rename = DIFF_DETECT_RENAME;
1584        }
1585        else if (!strncmp(arg, "-C", 2)) {
1586                if ((options->rename_score =
1587                     diff_scoreopt_parse(arg)) == -1)
1588                        return -1;
1589                options->detect_rename = DIFF_DETECT_COPY;
1590        }
1591        else if (!strcmp(arg, "--find-copies-harder"))
1592                options->find_copies_harder = 1;
1593        else if (!strcmp(arg, "--abbrev"))
1594                options->abbrev = DEFAULT_ABBREV;
1595        else if (!strncmp(arg, "--abbrev=", 9)) {
1596                options->abbrev = strtoul(arg + 9, NULL, 10);
1597                if (options->abbrev < MINIMUM_ABBREV)
1598                        options->abbrev = MINIMUM_ABBREV;
1599                else if (40 < options->abbrev)
1600                        options->abbrev = 40;
1601        }
1602        else if (!strcmp(arg, "--color"))
1603                options->color_diff = 1;
1604        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
1605                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
1606        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
1607                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1608        else
1609                return 0;
1610        return 1;
1611}
1612
1613static int parse_num(const char **cp_p)
1614{
1615        unsigned long num, scale;
1616        int ch, dot;
1617        const char *cp = *cp_p;
1618
1619        num = 0;
1620        scale = 1;
1621        dot = 0;
1622        for(;;) {
1623                ch = *cp;
1624                if ( !dot && ch == '.' ) {
1625                        scale = 1;
1626                        dot = 1;
1627                } else if ( ch == '%' ) {
1628                        scale = dot ? scale*100 : 100;
1629                        cp++;   /* % is always at the end */
1630                        break;
1631                } else if ( ch >= '0' && ch <= '9' ) {
1632                        if ( scale < 100000 ) {
1633                                scale *= 10;
1634                                num = (num*10) + (ch-'0');
1635                        }
1636                } else {
1637                        break;
1638                }
1639                cp++;
1640        }
1641        *cp_p = cp;
1642
1643        /* user says num divided by scale and we say internally that
1644         * is MAX_SCORE * num / scale.
1645         */
1646        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1647}
1648
1649int diff_scoreopt_parse(const char *opt)
1650{
1651        int opt1, opt2, cmd;
1652
1653        if (*opt++ != '-')
1654                return -1;
1655        cmd = *opt++;
1656        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1657                return -1; /* that is not a -M, -C nor -B option */
1658
1659        opt1 = parse_num(&opt);
1660        if (cmd != 'B')
1661                opt2 = 0;
1662        else {
1663                if (*opt == 0)
1664                        opt2 = 0;
1665                else if (*opt != '/')
1666                        return -1; /* we expect -B80/99 or -B80 */
1667                else {
1668                        opt++;
1669                        opt2 = parse_num(&opt);
1670                }
1671        }
1672        if (*opt != 0)
1673                return -1;
1674        return opt1 | (opt2 << 16);
1675}
1676
1677struct diff_queue_struct diff_queued_diff;
1678
1679void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1680{
1681        if (queue->alloc <= queue->nr) {
1682                queue->alloc = alloc_nr(queue->alloc);
1683                queue->queue = xrealloc(queue->queue,
1684                                        sizeof(dp) * queue->alloc);
1685        }
1686        queue->queue[queue->nr++] = dp;
1687}
1688
1689struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1690                                 struct diff_filespec *one,
1691                                 struct diff_filespec *two)
1692{
1693        struct diff_filepair *dp = xmalloc(sizeof(*dp));
1694        dp->one = one;
1695        dp->two = two;
1696        dp->score = 0;
1697        dp->status = 0;
1698        dp->source_stays = 0;
1699        dp->broken_pair = 0;
1700        if (queue)
1701                diff_q(queue, dp);
1702        return dp;
1703}
1704
1705void diff_free_filepair(struct diff_filepair *p)
1706{
1707        diff_free_filespec_data(p->one);
1708        diff_free_filespec_data(p->two);
1709        free(p->one);
1710        free(p->two);
1711        free(p);
1712}
1713
1714/* This is different from find_unique_abbrev() in that
1715 * it stuffs the result with dots for alignment.
1716 */
1717const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1718{
1719        int abblen;
1720        const char *abbrev;
1721        if (len == 40)
1722                return sha1_to_hex(sha1);
1723
1724        abbrev = find_unique_abbrev(sha1, len);
1725        if (!abbrev)
1726                return sha1_to_hex(sha1);
1727        abblen = strlen(abbrev);
1728        if (abblen < 37) {
1729                static char hex[41];
1730                if (len < abblen && abblen <= len + 2)
1731                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1732                else
1733                        sprintf(hex, "%s...", abbrev);
1734                return hex;
1735        }
1736        return sha1_to_hex(sha1);
1737}
1738
1739static void diff_flush_raw(struct diff_filepair *p,
1740                           int line_termination,
1741                           int inter_name_termination,
1742                           struct diff_options *options,
1743                           int output_format)
1744{
1745        int two_paths;
1746        char status[10];
1747        int abbrev = options->abbrev;
1748        const char *path_one, *path_two;
1749
1750        path_one = p->one->path;
1751        path_two = p->two->path;
1752        if (line_termination) {
1753                path_one = quote_one(path_one);
1754                path_two = quote_one(path_two);
1755        }
1756
1757        if (p->score)
1758                sprintf(status, "%c%03d", p->status,
1759                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1760        else {
1761                status[0] = p->status;
1762                status[1] = 0;
1763        }
1764        switch (p->status) {
1765        case DIFF_STATUS_COPIED:
1766        case DIFF_STATUS_RENAMED:
1767                two_paths = 1;
1768                break;
1769        case DIFF_STATUS_ADDED:
1770        case DIFF_STATUS_DELETED:
1771                two_paths = 0;
1772                break;
1773        default:
1774                two_paths = 0;
1775                break;
1776        }
1777        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1778                printf(":%06o %06o %s ",
1779                       p->one->mode, p->two->mode,
1780                       diff_unique_abbrev(p->one->sha1, abbrev));
1781                printf("%s ",
1782                       diff_unique_abbrev(p->two->sha1, abbrev));
1783        }
1784        printf("%s%c%s", status, inter_name_termination, path_one);
1785        if (two_paths)
1786                printf("%c%s", inter_name_termination, path_two);
1787        putchar(line_termination);
1788        if (path_one != p->one->path)
1789                free((void*)path_one);
1790        if (path_two != p->two->path)
1791                free((void*)path_two);
1792}
1793
1794static void diff_flush_name(struct diff_filepair *p, int line_termination)
1795{
1796        char *path = p->two->path;
1797
1798        if (line_termination)
1799                path = quote_one(p->two->path);
1800        printf("%s%c", path, line_termination);
1801        if (p->two->path != path)
1802                free(path);
1803}
1804
1805int diff_unmodified_pair(struct diff_filepair *p)
1806{
1807        /* This function is written stricter than necessary to support
1808         * the currently implemented transformers, but the idea is to
1809         * let transformers to produce diff_filepairs any way they want,
1810         * and filter and clean them up here before producing the output.
1811         */
1812        struct diff_filespec *one, *two;
1813
1814        if (DIFF_PAIR_UNMERGED(p))
1815                return 0; /* unmerged is interesting */
1816
1817        one = p->one;
1818        two = p->two;
1819
1820        /* deletion, addition, mode or type change
1821         * and rename are all interesting.
1822         */
1823        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1824            DIFF_PAIR_MODE_CHANGED(p) ||
1825            strcmp(one->path, two->path))
1826                return 0;
1827
1828        /* both are valid and point at the same path.  that is, we are
1829         * dealing with a change.
1830         */
1831        if (one->sha1_valid && two->sha1_valid &&
1832            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1833                return 1; /* no change */
1834        if (!one->sha1_valid && !two->sha1_valid)
1835                return 1; /* both look at the same file on the filesystem. */
1836        return 0;
1837}
1838
1839static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1840{
1841        if (diff_unmodified_pair(p))
1842                return;
1843
1844        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1845            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1846                return; /* no tree diffs in patch format */
1847
1848        run_diff(p, o);
1849}
1850
1851static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1852                            struct diffstat_t *diffstat)
1853{
1854        if (diff_unmodified_pair(p))
1855                return;
1856
1857        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1858            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1859                return; /* no tree diffs in patch format */
1860
1861        run_diffstat(p, o, diffstat);
1862}
1863
1864static void diff_flush_checkdiff(struct diff_filepair *p,
1865                struct diff_options *o)
1866{
1867        if (diff_unmodified_pair(p))
1868                return;
1869
1870        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1871            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1872                return; /* no tree diffs in patch format */
1873
1874        run_checkdiff(p, o);
1875}
1876
1877int diff_queue_is_empty(void)
1878{
1879        struct diff_queue_struct *q = &diff_queued_diff;
1880        int i;
1881        for (i = 0; i < q->nr; i++)
1882                if (!diff_unmodified_pair(q->queue[i]))
1883                        return 0;
1884        return 1;
1885}
1886
1887#if DIFF_DEBUG
1888void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1889{
1890        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1891                x, one ? one : "",
1892                s->path,
1893                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1894                s->mode,
1895                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1896        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1897                x, one ? one : "",
1898                s->size, s->xfrm_flags);
1899}
1900
1901void diff_debug_filepair(const struct diff_filepair *p, int i)
1902{
1903        diff_debug_filespec(p->one, i, "one");
1904        diff_debug_filespec(p->two, i, "two");
1905        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1906                p->score, p->status ? p->status : '?',
1907                p->source_stays, p->broken_pair);
1908}
1909
1910void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1911{
1912        int i;
1913        if (msg)
1914                fprintf(stderr, "%s\n", msg);
1915        fprintf(stderr, "q->nr = %d\n", q->nr);
1916        for (i = 0; i < q->nr; i++) {
1917                struct diff_filepair *p = q->queue[i];
1918                diff_debug_filepair(p, i);
1919        }
1920}
1921#endif
1922
1923static void diff_resolve_rename_copy(void)
1924{
1925        int i, j;
1926        struct diff_filepair *p, *pp;
1927        struct diff_queue_struct *q = &diff_queued_diff;
1928
1929        diff_debug_queue("resolve-rename-copy", q);
1930
1931        for (i = 0; i < q->nr; i++) {
1932                p = q->queue[i];
1933                p->status = 0; /* undecided */
1934                if (DIFF_PAIR_UNMERGED(p))
1935                        p->status = DIFF_STATUS_UNMERGED;
1936                else if (!DIFF_FILE_VALID(p->one))
1937                        p->status = DIFF_STATUS_ADDED;
1938                else if (!DIFF_FILE_VALID(p->two))
1939                        p->status = DIFF_STATUS_DELETED;
1940                else if (DIFF_PAIR_TYPE_CHANGED(p))
1941                        p->status = DIFF_STATUS_TYPE_CHANGED;
1942
1943                /* from this point on, we are dealing with a pair
1944                 * whose both sides are valid and of the same type, i.e.
1945                 * either in-place edit or rename/copy edit.
1946                 */
1947                else if (DIFF_PAIR_RENAME(p)) {
1948                        if (p->source_stays) {
1949                                p->status = DIFF_STATUS_COPIED;
1950                                continue;
1951                        }
1952                        /* See if there is some other filepair that
1953                         * copies from the same source as us.  If so
1954                         * we are a copy.  Otherwise we are either a
1955                         * copy if the path stays, or a rename if it
1956                         * does not, but we already handled "stays" case.
1957                         */
1958                        for (j = i + 1; j < q->nr; j++) {
1959                                pp = q->queue[j];
1960                                if (strcmp(pp->one->path, p->one->path))
1961                                        continue; /* not us */
1962                                if (!DIFF_PAIR_RENAME(pp))
1963                                        continue; /* not a rename/copy */
1964                                /* pp is a rename/copy from the same source */
1965                                p->status = DIFF_STATUS_COPIED;
1966                                break;
1967                        }
1968                        if (!p->status)
1969                                p->status = DIFF_STATUS_RENAMED;
1970                }
1971                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1972                         p->one->mode != p->two->mode)
1973                        p->status = DIFF_STATUS_MODIFIED;
1974                else {
1975                        /* This is a "no-change" entry and should not
1976                         * happen anymore, but prepare for broken callers.
1977                         */
1978                        error("feeding unmodified %s to diffcore",
1979                              p->one->path);
1980                        p->status = DIFF_STATUS_UNKNOWN;
1981                }
1982        }
1983        diff_debug_queue("resolve-rename-copy done", q);
1984}
1985
1986static void flush_one_pair(struct diff_filepair *p,
1987                           int diff_output_format,
1988                           struct diff_options *options,
1989                           struct diffstat_t *diffstat)
1990{
1991        int inter_name_termination = '\t';
1992        int line_termination = options->line_termination;
1993        if (!line_termination)
1994                inter_name_termination = 0;
1995
1996        switch (p->status) {
1997        case DIFF_STATUS_UNKNOWN:
1998                break;
1999        case 0:
2000                die("internal error in diff-resolve-rename-copy");
2001                break;
2002        default:
2003                switch (diff_output_format) {
2004                case DIFF_FORMAT_DIFFSTAT:
2005                        diff_flush_stat(p, options, diffstat);
2006                        break;
2007                case DIFF_FORMAT_CHECKDIFF:
2008                        diff_flush_checkdiff(p, options);
2009                        break;
2010                case DIFF_FORMAT_PATCH:
2011                        diff_flush_patch(p, options);
2012                        break;
2013                case DIFF_FORMAT_RAW:
2014                case DIFF_FORMAT_NAME_STATUS:
2015                        diff_flush_raw(p, line_termination,
2016                                       inter_name_termination,
2017                                       options, diff_output_format);
2018                        break;
2019                case DIFF_FORMAT_NAME:
2020                        diff_flush_name(p, line_termination);
2021                        break;
2022                case DIFF_FORMAT_NO_OUTPUT:
2023                        break;
2024                }
2025        }
2026}
2027
2028static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2029{
2030        if (fs->mode)
2031                printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
2032        else
2033                printf(" %s %s\n", newdelete, fs->path);
2034}
2035
2036
2037static void show_mode_change(struct diff_filepair *p, int show_name)
2038{
2039        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2040                if (show_name)
2041                        printf(" mode change %06o => %06o %s\n",
2042                               p->one->mode, p->two->mode, p->two->path);
2043                else
2044                        printf(" mode change %06o => %06o\n",
2045                               p->one->mode, p->two->mode);
2046        }
2047}
2048
2049static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2050{
2051        const char *old, *new;
2052
2053        /* Find common prefix */
2054        old = p->one->path;
2055        new = p->two->path;
2056        while (1) {
2057                const char *slash_old, *slash_new;
2058                slash_old = strchr(old, '/');
2059                slash_new = strchr(new, '/');
2060                if (!slash_old ||
2061                    !slash_new ||
2062                    slash_old - old != slash_new - new ||
2063                    memcmp(old, new, slash_new - new))
2064                        break;
2065                old = slash_old + 1;
2066                new = slash_new + 1;
2067        }
2068        /* p->one->path thru old is the common prefix, and old and new
2069         * through the end of names are renames
2070         */
2071        if (old != p->one->path)
2072                printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2073                       (int)(old - p->one->path), p->one->path,
2074                       old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
2075        else
2076                printf(" %s %s => %s (%d%%)\n", renamecopy,
2077                       p->one->path, p->two->path,
2078                       (int)(0.5 + p->score * 100.0/MAX_SCORE));
2079        show_mode_change(p, 0);
2080}
2081
2082static void diff_summary(struct diff_filepair *p)
2083{
2084        switch(p->status) {
2085        case DIFF_STATUS_DELETED:
2086                show_file_mode_name("delete", p->one);
2087                break;
2088        case DIFF_STATUS_ADDED:
2089                show_file_mode_name("create", p->two);
2090                break;
2091        case DIFF_STATUS_COPIED:
2092                show_rename_copy("copy", p);
2093                break;
2094        case DIFF_STATUS_RENAMED:
2095                show_rename_copy("rename", p);
2096                break;
2097        default:
2098                if (p->score) {
2099                        printf(" rewrite %s (%d%%)\n", p->two->path,
2100                                (int)(0.5 + p->score * 100.0/MAX_SCORE));
2101                        show_mode_change(p, 0);
2102                } else  show_mode_change(p, 1);
2103                break;
2104        }
2105}
2106
2107struct patch_id_t {
2108        struct xdiff_emit_state xm;
2109        SHA_CTX *ctx;
2110        int patchlen;
2111};
2112
2113static int remove_space(char *line, int len)
2114{
2115        int i;
2116        char *dst = line;
2117        unsigned char c;
2118
2119        for (i = 0; i < len; i++)
2120                if (!isspace((c = line[i])))
2121                        *dst++ = c;
2122
2123        return dst - line;
2124}
2125
2126static void patch_id_consume(void *priv, char *line, unsigned long len)
2127{
2128        struct patch_id_t *data = priv;
2129        int new_len;
2130
2131        /* Ignore line numbers when computing the SHA1 of the patch */
2132        if (!strncmp(line, "@@ -", 4))
2133                return;
2134
2135        new_len = remove_space(line, len);
2136
2137        SHA1_Update(data->ctx, line, new_len);
2138        data->patchlen += new_len;
2139}
2140
2141/* returns 0 upon success, and writes result into sha1 */
2142static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2143{
2144        struct diff_queue_struct *q = &diff_queued_diff;
2145        int i;
2146        SHA_CTX ctx;
2147        struct patch_id_t data;
2148        char buffer[PATH_MAX * 4 + 20];
2149
2150        SHA1_Init(&ctx);
2151        memset(&data, 0, sizeof(struct patch_id_t));
2152        data.ctx = &ctx;
2153        data.xm.consume = patch_id_consume;
2154
2155        for (i = 0; i < q->nr; i++) {
2156                xpparam_t xpp;
2157                xdemitconf_t xecfg;
2158                xdemitcb_t ecb;
2159                mmfile_t mf1, mf2;
2160                struct diff_filepair *p = q->queue[i];
2161                int len1, len2;
2162
2163                if (p->status == 0)
2164                        return error("internal diff status error");
2165                if (p->status == DIFF_STATUS_UNKNOWN)
2166                        continue;
2167                if (diff_unmodified_pair(p))
2168                        continue;
2169                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2170                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2171                        continue;
2172                if (DIFF_PAIR_UNMERGED(p))
2173                        continue;
2174
2175                diff_fill_sha1_info(p->one);
2176                diff_fill_sha1_info(p->two);
2177                if (fill_mmfile(&mf1, p->one) < 0 ||
2178                                fill_mmfile(&mf2, p->two) < 0)
2179                        return error("unable to read files to diff");
2180
2181                /* Maybe hash p->two? into the patch id? */
2182                if (mmfile_is_binary(&mf2))
2183                        continue;
2184
2185                len1 = remove_space(p->one->path, strlen(p->one->path));
2186                len2 = remove_space(p->two->path, strlen(p->two->path));
2187                if (p->one->mode == 0)
2188                        len1 = snprintf(buffer, sizeof(buffer),
2189                                        "diff--gita/%.*sb/%.*s"
2190                                        "newfilemode%06o"
2191                                        "---/dev/null"
2192                                        "+++b/%.*s",
2193                                        len1, p->one->path,
2194                                        len2, p->two->path,
2195                                        p->two->mode,
2196                                        len2, p->two->path);
2197                else if (p->two->mode == 0)
2198                        len1 = snprintf(buffer, sizeof(buffer),
2199                                        "diff--gita/%.*sb/%.*s"
2200                                        "deletedfilemode%06o"
2201                                        "---a/%.*s"
2202                                        "+++/dev/null",
2203                                        len1, p->one->path,
2204                                        len2, p->two->path,
2205                                        p->one->mode,
2206                                        len1, p->one->path);
2207                else
2208                        len1 = snprintf(buffer, sizeof(buffer),
2209                                        "diff--gita/%.*sb/%.*s"
2210                                        "---a/%.*s"
2211                                        "+++b/%.*s",
2212                                        len1, p->one->path,
2213                                        len2, p->two->path,
2214                                        len1, p->one->path,
2215                                        len2, p->two->path);
2216                SHA1_Update(&ctx, buffer, len1);
2217
2218                xpp.flags = XDF_NEED_MINIMAL;
2219                xecfg.ctxlen = 3;
2220                xecfg.flags = XDL_EMIT_FUNCNAMES;
2221                ecb.outf = xdiff_outf;
2222                ecb.priv = &data;
2223                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2224        }
2225
2226        SHA1_Final(sha1, &ctx);
2227        return 0;
2228}
2229
2230int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2231{
2232        struct diff_queue_struct *q = &diff_queued_diff;
2233        int i;
2234        int result = diff_get_patch_id(options, sha1);
2235
2236        for (i = 0; i < q->nr; i++)
2237                diff_free_filepair(q->queue[i]);
2238
2239        free(q->queue);
2240        q->queue = NULL;
2241        q->nr = q->alloc = 0;
2242
2243        return result;
2244}
2245
2246void diff_flush(struct diff_options *options)
2247{
2248        struct diff_queue_struct *q = &diff_queued_diff;
2249        int i;
2250        int diff_output_format = options->output_format;
2251        struct diffstat_t *diffstat = NULL;
2252
2253        if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
2254                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
2255                diffstat->xm.consume = diffstat_consume;
2256        }
2257
2258        if (options->with_raw) {
2259                for (i = 0; i < q->nr; i++) {
2260                        struct diff_filepair *p = q->queue[i];
2261                        flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
2262                }
2263                putchar(options->line_termination);
2264        }
2265        if (options->with_stat) {
2266                for (i = 0; i < q->nr; i++) {
2267                        struct diff_filepair *p = q->queue[i];
2268                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
2269                                       diffstat);
2270                }
2271                show_stats(diffstat);
2272                free(diffstat);
2273                diffstat = NULL;
2274                if (options->summary)
2275                        for (i = 0; i < q->nr; i++)
2276                                diff_summary(q->queue[i]);
2277                if (options->stat_sep)
2278                        fputs(options->stat_sep, stdout);
2279                else
2280                        putchar(options->line_termination);
2281        }
2282        for (i = 0; i < q->nr; i++) {
2283                struct diff_filepair *p = q->queue[i];
2284                flush_one_pair(p, diff_output_format, options, diffstat);
2285        }
2286
2287        if (diffstat) {
2288                show_stats(diffstat);
2289                free(diffstat);
2290        }
2291
2292        for (i = 0; i < q->nr; i++) {
2293                if (diffstat && options->summary)
2294                        diff_summary(q->queue[i]);
2295                diff_free_filepair(q->queue[i]);
2296        }
2297
2298        free(q->queue);
2299        q->queue = NULL;
2300        q->nr = q->alloc = 0;
2301}
2302
2303static void diffcore_apply_filter(const char *filter)
2304{
2305        int i;
2306        struct diff_queue_struct *q = &diff_queued_diff;
2307        struct diff_queue_struct outq;
2308        outq.queue = NULL;
2309        outq.nr = outq.alloc = 0;
2310
2311        if (!filter)
2312                return;
2313
2314        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2315                int found;
2316                for (i = found = 0; !found && i < q->nr; i++) {
2317                        struct diff_filepair *p = q->queue[i];
2318                        if (((p->status == DIFF_STATUS_MODIFIED) &&
2319                             ((p->score &&
2320                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2321                              (!p->score &&
2322                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2323                            ((p->status != DIFF_STATUS_MODIFIED) &&
2324                             strchr(filter, p->status)))
2325                                found++;
2326                }
2327                if (found)
2328                        return;
2329
2330                /* otherwise we will clear the whole queue
2331                 * by copying the empty outq at the end of this
2332                 * function, but first clear the current entries
2333                 * in the queue.
2334                 */
2335                for (i = 0; i < q->nr; i++)
2336                        diff_free_filepair(q->queue[i]);
2337        }
2338        else {
2339                /* Only the matching ones */
2340                for (i = 0; i < q->nr; i++) {
2341                        struct diff_filepair *p = q->queue[i];
2342
2343                        if (((p->status == DIFF_STATUS_MODIFIED) &&
2344                             ((p->score &&
2345                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2346                              (!p->score &&
2347                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2348                            ((p->status != DIFF_STATUS_MODIFIED) &&
2349                             strchr(filter, p->status)))
2350                                diff_q(&outq, p);
2351                        else
2352                                diff_free_filepair(p);
2353                }
2354        }
2355        free(q->queue);
2356        *q = outq;
2357}
2358
2359void diffcore_std(struct diff_options *options)
2360{
2361        if (options->break_opt != -1)
2362                diffcore_break(options->break_opt);
2363        if (options->detect_rename)
2364                diffcore_rename(options);
2365        if (options->break_opt != -1)
2366                diffcore_merge_broken();
2367        if (options->pickaxe)
2368                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2369        if (options->orderfile)
2370                diffcore_order(options->orderfile);
2371        diff_resolve_rename_copy();
2372        diffcore_apply_filter(options->filter);
2373}
2374
2375
2376void diffcore_std_no_resolve(struct diff_options *options)
2377{
2378        if (options->pickaxe)
2379                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2380        if (options->orderfile)
2381                diffcore_order(options->orderfile);
2382        diffcore_apply_filter(options->filter);
2383}
2384
2385void diff_addremove(struct diff_options *options,
2386                    int addremove, unsigned mode,
2387                    const unsigned char *sha1,
2388                    const char *base, const char *path)
2389{
2390        char concatpath[PATH_MAX];
2391        struct diff_filespec *one, *two;
2392
2393        /* This may look odd, but it is a preparation for
2394         * feeding "there are unchanged files which should
2395         * not produce diffs, but when you are doing copy
2396         * detection you would need them, so here they are"
2397         * entries to the diff-core.  They will be prefixed
2398         * with something like '=' or '*' (I haven't decided
2399         * which but should not make any difference).
2400         * Feeding the same new and old to diff_change() 
2401         * also has the same effect.
2402         * Before the final output happens, they are pruned after
2403         * merged into rename/copy pairs as appropriate.
2404         */
2405        if (options->reverse_diff)
2406                addremove = (addremove == '+' ? '-' :
2407                             addremove == '-' ? '+' : addremove);
2408
2409        if (!path) path = "";
2410        sprintf(concatpath, "%s%s", base, path);
2411        one = alloc_filespec(concatpath);
2412        two = alloc_filespec(concatpath);
2413
2414        if (addremove != '+')
2415                fill_filespec(one, sha1, mode);
2416        if (addremove != '-')
2417                fill_filespec(two, sha1, mode);
2418
2419        diff_queue(&diff_queued_diff, one, two);
2420}
2421
2422void diff_change(struct diff_options *options,
2423                 unsigned old_mode, unsigned new_mode,
2424                 const unsigned char *old_sha1,
2425                 const unsigned char *new_sha1,
2426                 const char *base, const char *path) 
2427{
2428        char concatpath[PATH_MAX];
2429        struct diff_filespec *one, *two;
2430
2431        if (options->reverse_diff) {
2432                unsigned tmp;
2433                const unsigned char *tmp_c;
2434                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2435                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2436        }
2437        if (!path) path = "";
2438        sprintf(concatpath, "%s%s", base, path);
2439        one = alloc_filespec(concatpath);
2440        two = alloc_filespec(concatpath);
2441        fill_filespec(one, old_sha1, old_mode);
2442        fill_filespec(two, new_sha1, new_mode);
2443
2444        diff_queue(&diff_queued_diff, one, two);
2445}
2446
2447void diff_unmerge(struct diff_options *options,
2448                  const char *path)
2449{
2450        struct diff_filespec *one, *two;
2451        one = alloc_filespec(path);
2452        two = alloc_filespec(path);
2453        diff_queue(&diff_queued_diff, one, two);
2454}