diff.con commit git-apply --reject (57dc397)
   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_detect_rename_default;
  17static int diff_rename_limit_default = -1;
  18static int diff_use_color_default;
  19
  20/* "\033[1;38;5;2xx;48;5;2xxm\0" is 23 bytes */
  21static char diff_colors[][24] = {
  22        "\033[m",       /* reset */
  23        "",             /* normal */
  24        "\033[1m",      /* bold */
  25        "\033[36m",     /* cyan */
  26        "\033[31m",     /* red */
  27        "\033[32m",     /* green */
  28        "\033[33m"      /* yellow */
  29};
  30
  31static int parse_diff_color_slot(const char *var, int ofs)
  32{
  33        if (!strcasecmp(var+ofs, "plain"))
  34                return DIFF_PLAIN;
  35        if (!strcasecmp(var+ofs, "meta"))
  36                return DIFF_METAINFO;
  37        if (!strcasecmp(var+ofs, "frag"))
  38                return DIFF_FRAGINFO;
  39        if (!strcasecmp(var+ofs, "old"))
  40                return DIFF_FILE_OLD;
  41        if (!strcasecmp(var+ofs, "new"))
  42                return DIFF_FILE_NEW;
  43        if (!strcasecmp(var+ofs, "commit"))
  44                return DIFF_COMMIT;
  45        die("bad config variable '%s'", var);
  46}
  47
  48static int parse_color(const char *name, int len)
  49{
  50        static const char * const color_names[] = {
  51                "normal", "black", "red", "green", "yellow",
  52                "blue", "magenta", "cyan", "white"
  53        };
  54        char *end;
  55        int i;
  56        for (i = 0; i < ARRAY_SIZE(color_names); i++) {
  57                const char *str = color_names[i];
  58                if (!strncasecmp(name, str, len) && !str[len])
  59                        return i - 1;
  60        }
  61        i = strtol(name, &end, 10);
  62        if (*name && !*end && i >= -1 && i <= 255)
  63                return i;
  64        return -2;
  65}
  66
  67static int parse_attr(const char *name, int len)
  68{
  69        static const int attr_values[] = { 1, 2, 4, 5, 7 };
  70        static const char * const attr_names[] = {
  71                "bold", "dim", "ul", "blink", "reverse"
  72        };
  73        int i;
  74        for (i = 0; i < ARRAY_SIZE(attr_names); i++) {
  75                const char *str = attr_names[i];
  76                if (!strncasecmp(name, str, len) && !str[len])
  77                        return attr_values[i];
  78        }
  79        return -1;
  80}
  81
  82static void parse_diff_color_value(const char *value, const char *var, char *dst)
  83{
  84        const char *ptr = value;
  85        int attr = -1;
  86        int fg = -2;
  87        int bg = -2;
  88
  89        if (!strcasecmp(value, "reset")) {
  90                strcpy(dst, "\033[m");
  91                return;
  92        }
  93
  94        /* [fg [bg]] [attr] */
  95        while (*ptr) {
  96                const char *word = ptr;
  97                int val, len = 0;
  98
  99                while (word[len] && !isspace(word[len]))
 100                        len++;
 101
 102                ptr = word + len;
 103                while (*ptr && isspace(*ptr))
 104                        ptr++;
 105
 106                val = parse_color(word, len);
 107                if (val >= -1) {
 108                        if (fg == -2) {
 109                                fg = val;
 110                                continue;
 111                        }
 112                        if (bg == -2) {
 113                                bg = val;
 114                                continue;
 115                        }
 116                        goto bad;
 117                }
 118                val = parse_attr(word, len);
 119                if (val < 0 || attr != -1)
 120                        goto bad;
 121                attr = val;
 122        }
 123
 124        if (attr >= 0 || fg >= 0 || bg >= 0) {
 125                int sep = 0;
 126
 127                *dst++ = '\033';
 128                *dst++ = '[';
 129                if (attr >= 0) {
 130                        *dst++ = '0' + attr;
 131                        sep++;
 132                }
 133                if (fg >= 0) {
 134                        if (sep++)
 135                                *dst++ = ';';
 136                        if (fg < 8) {
 137                                *dst++ = '3';
 138                                *dst++ = '0' + fg;
 139                        } else {
 140                                dst += sprintf(dst, "38;5;%d", fg);
 141                        }
 142                }
 143                if (bg >= 0) {
 144                        if (sep++)
 145                                *dst++ = ';';
 146                        if (bg < 8) {
 147                                *dst++ = '4';
 148                                *dst++ = '0' + bg;
 149                        } else {
 150                                dst += sprintf(dst, "48;5;%d", bg);
 151                        }
 152                }
 153                *dst++ = 'm';
 154        }
 155        *dst = 0;
 156        return;
 157bad:
 158        die("bad config value '%s' for variable '%s'", value, var);
 159}
 160
 161/*
 162 * These are to give UI layer defaults.
 163 * The core-level commands such as git-diff-files should
 164 * never be affected by the setting of diff.renames
 165 * the user happens to have in the configuration file.
 166 */
 167int git_diff_ui_config(const char *var, const char *value)
 168{
 169        if (!strcmp(var, "diff.renamelimit")) {
 170                diff_rename_limit_default = git_config_int(var, value);
 171                return 0;
 172        }
 173        if (!strcmp(var, "diff.color")) {
 174                if (!value)
 175                        diff_use_color_default = 1; /* bool */
 176                else if (!strcasecmp(value, "auto")) {
 177                        diff_use_color_default = 0;
 178                        if (isatty(1) || (pager_in_use && pager_use_color)) {
 179                                char *term = getenv("TERM");
 180                                if (term && strcmp(term, "dumb"))
 181                                        diff_use_color_default = 1;
 182                        }
 183                }
 184                else if (!strcasecmp(value, "never"))
 185                        diff_use_color_default = 0;
 186                else if (!strcasecmp(value, "always"))
 187                        diff_use_color_default = 1;
 188                else
 189                        diff_use_color_default = git_config_bool(var, value);
 190                return 0;
 191        }
 192        if (!strcmp(var, "diff.renames")) {
 193                if (!value)
 194                        diff_detect_rename_default = DIFF_DETECT_RENAME;
 195                else if (!strcasecmp(value, "copies") ||
 196                         !strcasecmp(value, "copy"))
 197                        diff_detect_rename_default = DIFF_DETECT_COPY;
 198                else if (git_config_bool(var,value))
 199                        diff_detect_rename_default = DIFF_DETECT_RENAME;
 200                return 0;
 201        }
 202        if (!strncmp(var, "diff.color.", 11)) {
 203                int slot = parse_diff_color_slot(var, 11);
 204                parse_diff_color_value(value, var, diff_colors[slot]);
 205                return 0;
 206        }
 207        return git_default_config(var, value);
 208}
 209
 210static char *quote_one(const char *str)
 211{
 212        int needlen;
 213        char *xp;
 214
 215        if (!str)
 216                return NULL;
 217        needlen = quote_c_style(str, NULL, NULL, 0);
 218        if (!needlen)
 219                return strdup(str);
 220        xp = xmalloc(needlen + 1);
 221        quote_c_style(str, xp, NULL, 0);
 222        return xp;
 223}
 224
 225static char *quote_two(const char *one, const char *two)
 226{
 227        int need_one = quote_c_style(one, NULL, NULL, 1);
 228        int need_two = quote_c_style(two, NULL, NULL, 1);
 229        char *xp;
 230
 231        if (need_one + need_two) {
 232                if (!need_one) need_one = strlen(one);
 233                if (!need_two) need_one = strlen(two);
 234
 235                xp = xmalloc(need_one + need_two + 3);
 236                xp[0] = '"';
 237                quote_c_style(one, xp + 1, NULL, 1);
 238                quote_c_style(two, xp + need_one + 1, NULL, 1);
 239                strcpy(xp + need_one + need_two + 1, "\"");
 240                return xp;
 241        }
 242        need_one = strlen(one);
 243        need_two = strlen(two);
 244        xp = xmalloc(need_one + need_two + 1);
 245        strcpy(xp, one);
 246        strcpy(xp + need_one, two);
 247        return xp;
 248}
 249
 250static const char *external_diff(void)
 251{
 252        static const char *external_diff_cmd = NULL;
 253        static int done_preparing = 0;
 254
 255        if (done_preparing)
 256                return external_diff_cmd;
 257        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 258        done_preparing = 1;
 259        return external_diff_cmd;
 260}
 261
 262#define TEMPFILE_PATH_LEN               50
 263
 264static struct diff_tempfile {
 265        const char *name; /* filename external diff should read from */
 266        char hex[41];
 267        char mode[10];
 268        char tmp_path[TEMPFILE_PATH_LEN];
 269} diff_temp[2];
 270
 271static int count_lines(const char *data, int size)
 272{
 273        int count, ch, completely_empty = 1, nl_just_seen = 0;
 274        count = 0;
 275        while (0 < size--) {
 276                ch = *data++;
 277                if (ch == '\n') {
 278                        count++;
 279                        nl_just_seen = 1;
 280                        completely_empty = 0;
 281                }
 282                else {
 283                        nl_just_seen = 0;
 284                        completely_empty = 0;
 285                }
 286        }
 287        if (completely_empty)
 288                return 0;
 289        if (!nl_just_seen)
 290                count++; /* no trailing newline */
 291        return count;
 292}
 293
 294static void print_line_count(int count)
 295{
 296        switch (count) {
 297        case 0:
 298                printf("0,0");
 299                break;
 300        case 1:
 301                printf("1");
 302                break;
 303        default:
 304                printf("1,%d", count);
 305                break;
 306        }
 307}
 308
 309static void copy_file(int prefix, const char *data, int size)
 310{
 311        int ch, nl_just_seen = 1;
 312        while (0 < size--) {
 313                ch = *data++;
 314                if (nl_just_seen)
 315                        putchar(prefix);
 316                putchar(ch);
 317                if (ch == '\n')
 318                        nl_just_seen = 1;
 319                else
 320                        nl_just_seen = 0;
 321        }
 322        if (!nl_just_seen)
 323                printf("\n\\ No newline at end of file\n");
 324}
 325
 326static void emit_rewrite_diff(const char *name_a,
 327                              const char *name_b,
 328                              struct diff_filespec *one,
 329                              struct diff_filespec *two)
 330{
 331        int lc_a, lc_b;
 332        diff_populate_filespec(one, 0);
 333        diff_populate_filespec(two, 0);
 334        lc_a = count_lines(one->data, one->size);
 335        lc_b = count_lines(two->data, two->size);
 336        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 337        print_line_count(lc_a);
 338        printf(" +");
 339        print_line_count(lc_b);
 340        printf(" @@\n");
 341        if (lc_a)
 342                copy_file('-', one->data, one->size);
 343        if (lc_b)
 344                copy_file('+', two->data, two->size);
 345}
 346
 347static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 348{
 349        if (!DIFF_FILE_VALID(one)) {
 350                mf->ptr = (char *)""; /* does not matter */
 351                mf->size = 0;
 352                return 0;
 353        }
 354        else if (diff_populate_filespec(one, 0))
 355                return -1;
 356        mf->ptr = one->data;
 357        mf->size = one->size;
 358        return 0;
 359}
 360
 361struct diff_words_buffer {
 362        mmfile_t text;
 363        long alloc;
 364        long current; /* output pointer */
 365        int suppressed_newline;
 366};
 367
 368static void diff_words_append(char *line, unsigned long len,
 369                struct diff_words_buffer *buffer)
 370{
 371        if (buffer->text.size + len > buffer->alloc) {
 372                buffer->alloc = (buffer->text.size + len) * 3 / 2;
 373                buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 374        }
 375        line++;
 376        len--;
 377        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 378        buffer->text.size += len;
 379}
 380
 381struct diff_words_data {
 382        struct xdiff_emit_state xm;
 383        struct diff_words_buffer minus, plus;
 384};
 385
 386static void print_word(struct diff_words_buffer *buffer, int len, int color,
 387                int suppress_newline)
 388{
 389        const char *ptr;
 390        int eol = 0;
 391
 392        if (len == 0)
 393                return;
 394
 395        ptr  = buffer->text.ptr + buffer->current;
 396        buffer->current += len;
 397
 398        if (ptr[len - 1] == '\n') {
 399                eol = 1;
 400                len--;
 401        }
 402
 403        fputs(diff_get_color(1, color), stdout);
 404        fwrite(ptr, len, 1, stdout);
 405        fputs(diff_get_color(1, DIFF_RESET), stdout);
 406
 407        if (eol) {
 408                if (suppress_newline)
 409                        buffer->suppressed_newline = 1;
 410                else
 411                        putchar('\n');
 412        }
 413}
 414
 415static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 416{
 417        struct diff_words_data *diff_words = priv;
 418
 419        if (diff_words->minus.suppressed_newline) {
 420                if (line[0] != '+')
 421                        putchar('\n');
 422                diff_words->minus.suppressed_newline = 0;
 423        }
 424
 425        len--;
 426        switch (line[0]) {
 427                case '-':
 428                        print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
 429                        break;
 430                case '+':
 431                        print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
 432                        break;
 433                case ' ':
 434                        print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
 435                        diff_words->minus.current += len;
 436                        break;
 437        }
 438}
 439
 440/* this executes the word diff on the accumulated buffers */
 441static void diff_words_show(struct diff_words_data *diff_words)
 442{
 443        xpparam_t xpp;
 444        xdemitconf_t xecfg;
 445        xdemitcb_t ecb;
 446        mmfile_t minus, plus;
 447        int i;
 448
 449        minus.size = diff_words->minus.text.size;
 450        minus.ptr = xmalloc(minus.size);
 451        memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 452        for (i = 0; i < minus.size; i++)
 453                if (isspace(minus.ptr[i]))
 454                        minus.ptr[i] = '\n';
 455        diff_words->minus.current = 0;
 456
 457        plus.size = diff_words->plus.text.size;
 458        plus.ptr = xmalloc(plus.size);
 459        memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 460        for (i = 0; i < plus.size; i++)
 461                if (isspace(plus.ptr[i]))
 462                        plus.ptr[i] = '\n';
 463        diff_words->plus.current = 0;
 464
 465        xpp.flags = XDF_NEED_MINIMAL;
 466        xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 467        xecfg.flags = 0;
 468        ecb.outf = xdiff_outf;
 469        ecb.priv = diff_words;
 470        diff_words->xm.consume = fn_out_diff_words_aux;
 471        xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 472
 473        free(minus.ptr);
 474        free(plus.ptr);
 475        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 476
 477        if (diff_words->minus.suppressed_newline) {
 478                putchar('\n');
 479                diff_words->minus.suppressed_newline = 0;
 480        }
 481}
 482
 483struct emit_callback {
 484        struct xdiff_emit_state xm;
 485        int nparents, color_diff;
 486        const char **label_path;
 487        struct diff_words_data *diff_words;
 488};
 489
 490static void free_diff_words_data(struct emit_callback *ecbdata)
 491{
 492        if (ecbdata->diff_words) {
 493                /* flush buffers */
 494                if (ecbdata->diff_words->minus.text.size ||
 495                                ecbdata->diff_words->plus.text.size)
 496                        diff_words_show(ecbdata->diff_words);
 497
 498                if (ecbdata->diff_words->minus.text.ptr)
 499                        free (ecbdata->diff_words->minus.text.ptr);
 500                if (ecbdata->diff_words->plus.text.ptr)
 501                        free (ecbdata->diff_words->plus.text.ptr);
 502                free(ecbdata->diff_words);
 503                ecbdata->diff_words = NULL;
 504        }
 505}
 506
 507const char *diff_get_color(int diff_use_color, enum color_diff ix)
 508{
 509        if (diff_use_color)
 510                return diff_colors[ix];
 511        return "";
 512}
 513
 514static void fn_out_consume(void *priv, char *line, unsigned long len)
 515{
 516        int i;
 517        struct emit_callback *ecbdata = priv;
 518        const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 519        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 520
 521        if (ecbdata->label_path[0]) {
 522                printf("%s--- %s%s\n", set, ecbdata->label_path[0], reset);
 523                printf("%s+++ %s%s\n", set, ecbdata->label_path[1], reset);
 524                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 525        }
 526
 527        /* This is not really necessary for now because
 528         * this codepath only deals with two-way diffs.
 529         */
 530        for (i = 0; i < len && line[i] == '@'; i++)
 531                ;
 532        if (2 <= i && i < len && line[i] == ' ') {
 533                ecbdata->nparents = i - 1;
 534                set = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 535        }
 536        else if (len < ecbdata->nparents)
 537                set = reset;
 538        else {
 539                int nparents = ecbdata->nparents;
 540                int color = DIFF_PLAIN;
 541                if (ecbdata->diff_words && nparents != 1)
 542                        /* fall back to normal diff */
 543                        free_diff_words_data(ecbdata);
 544                if (ecbdata->diff_words) {
 545                        if (line[0] == '-') {
 546                                diff_words_append(line, len,
 547                                                &ecbdata->diff_words->minus);
 548                                return;
 549                        } else if (line[0] == '+') {
 550                                diff_words_append(line, len,
 551                                                &ecbdata->diff_words->plus);
 552                                return;
 553                        }
 554                        if (ecbdata->diff_words->minus.text.size ||
 555                                        ecbdata->diff_words->plus.text.size)
 556                                diff_words_show(ecbdata->diff_words);
 557                        line++;
 558                        len--;
 559                } else
 560                        for (i = 0; i < nparents && len; i++) {
 561                                if (line[i] == '-')
 562                                        color = DIFF_FILE_OLD;
 563                                else if (line[i] == '+')
 564                                        color = DIFF_FILE_NEW;
 565                        }
 566                set = diff_get_color(ecbdata->color_diff, color);
 567        }
 568        if (len > 0 && line[len-1] == '\n')
 569                len--;
 570        fputs (set, stdout);
 571        fwrite (line, len, 1, stdout);
 572        puts (reset);
 573}
 574
 575static char *pprint_rename(const char *a, const char *b)
 576{
 577        const char *old = a;
 578        const char *new = b;
 579        char *name = NULL;
 580        int pfx_length, sfx_length;
 581        int len_a = strlen(a);
 582        int len_b = strlen(b);
 583
 584        /* Find common prefix */
 585        pfx_length = 0;
 586        while (*old && *new && *old == *new) {
 587                if (*old == '/')
 588                        pfx_length = old - a + 1;
 589                old++;
 590                new++;
 591        }
 592
 593        /* Find common suffix */
 594        old = a + len_a;
 595        new = b + len_b;
 596        sfx_length = 0;
 597        while (a <= old && b <= new && *old == *new) {
 598                if (*old == '/')
 599                        sfx_length = len_a - (old - a);
 600                old--;
 601                new--;
 602        }
 603
 604        /*
 605         * pfx{mid-a => mid-b}sfx
 606         * {pfx-a => pfx-b}sfx
 607         * pfx{sfx-a => sfx-b}
 608         * name-a => name-b
 609         */
 610        if (pfx_length + sfx_length) {
 611                int a_midlen = len_a - pfx_length - sfx_length;
 612                int b_midlen = len_b - pfx_length - sfx_length;
 613                if (a_midlen < 0) a_midlen = 0;
 614                if (b_midlen < 0) b_midlen = 0;
 615
 616                name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
 617                sprintf(name, "%.*s{%.*s => %.*s}%s",
 618                        pfx_length, a,
 619                        a_midlen, a + pfx_length,
 620                        b_midlen, b + pfx_length,
 621                        a + len_a - sfx_length);
 622        }
 623        else {
 624                name = xmalloc(len_a + len_b + 5);
 625                sprintf(name, "%s => %s", a, b);
 626        }
 627        return name;
 628}
 629
 630struct diffstat_t {
 631        struct xdiff_emit_state xm;
 632
 633        int nr;
 634        int alloc;
 635        struct diffstat_file {
 636                char *name;
 637                unsigned is_unmerged:1;
 638                unsigned is_binary:1;
 639                unsigned is_renamed:1;
 640                unsigned int added, deleted;
 641        } **files;
 642};
 643
 644static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 645                                          const char *name_a,
 646                                          const char *name_b)
 647{
 648        struct diffstat_file *x;
 649        x = xcalloc(sizeof (*x), 1);
 650        if (diffstat->nr == diffstat->alloc) {
 651                diffstat->alloc = alloc_nr(diffstat->alloc);
 652                diffstat->files = xrealloc(diffstat->files,
 653                                diffstat->alloc * sizeof(x));
 654        }
 655        diffstat->files[diffstat->nr++] = x;
 656        if (name_b) {
 657                x->name = pprint_rename(name_a, name_b);
 658                x->is_renamed = 1;
 659        }
 660        else
 661                x->name = strdup(name_a);
 662        return x;
 663}
 664
 665static void diffstat_consume(void *priv, char *line, unsigned long len)
 666{
 667        struct diffstat_t *diffstat = priv;
 668        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 669
 670        if (line[0] == '+')
 671                x->added++;
 672        else if (line[0] == '-')
 673                x->deleted++;
 674}
 675
 676static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 677static const char minuses[]= "----------------------------------------------------------------------";
 678const char mime_boundary_leader[] = "------------";
 679
 680static void show_stats(struct diffstat_t* data)
 681{
 682        int i, len, add, del, total, adds = 0, dels = 0;
 683        int max, max_change = 0, max_len = 0;
 684        int total_files = data->nr;
 685
 686        if (data->nr == 0)
 687                return;
 688
 689        for (i = 0; i < data->nr; i++) {
 690                struct diffstat_file *file = data->files[i];
 691
 692                len = strlen(file->name);
 693                if (max_len < len)
 694                        max_len = len;
 695
 696                if (file->is_binary || file->is_unmerged)
 697                        continue;
 698                if (max_change < file->added + file->deleted)
 699                        max_change = file->added + file->deleted;
 700        }
 701
 702        for (i = 0; i < data->nr; i++) {
 703                const char *prefix = "";
 704                char *name = data->files[i]->name;
 705                int added = data->files[i]->added;
 706                int deleted = data->files[i]->deleted;
 707
 708                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 709                        char *qname = xmalloc(len + 1);
 710                        quote_c_style(name, qname, NULL, 0);
 711                        free(name);
 712                        data->files[i]->name = name = qname;
 713                }
 714
 715                /*
 716                 * "scale" the filename
 717                 */
 718                len = strlen(name);
 719                max = max_len;
 720                if (max > 50)
 721                        max = 50;
 722                if (len > max) {
 723                        char *slash;
 724                        prefix = "...";
 725                        max -= 3;
 726                        name += len - max;
 727                        slash = strchr(name, '/');
 728                        if (slash)
 729                                name = slash;
 730                }
 731                len = max;
 732
 733                /*
 734                 * scale the add/delete
 735                 */
 736                max = max_change;
 737                if (max + len > 70)
 738                        max = 70 - len;
 739
 740                if (data->files[i]->is_binary) {
 741                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 742                        goto free_diffstat_file;
 743                }
 744                else if (data->files[i]->is_unmerged) {
 745                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 746                        goto free_diffstat_file;
 747                }
 748                else if (!data->files[i]->is_renamed &&
 749                         (added + deleted == 0)) {
 750                        total_files--;
 751                        goto free_diffstat_file;
 752                }
 753
 754                add = added;
 755                del = deleted;
 756                total = add + del;
 757                adds += add;
 758                dels += del;
 759
 760                if (max_change > 0) {
 761                        total = (total * max + max_change / 2) / max_change;
 762                        add = (add * max + max_change / 2) / max_change;
 763                        del = total - add;
 764                }
 765                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 766                                len, name, added + deleted,
 767                                add, pluses, del, minuses);
 768        free_diffstat_file:
 769                free(data->files[i]->name);
 770                free(data->files[i]);
 771        }
 772        free(data->files);
 773        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 774                        total_files, adds, dels);
 775}
 776
 777struct checkdiff_t {
 778        struct xdiff_emit_state xm;
 779        const char *filename;
 780        int lineno;
 781};
 782
 783static void checkdiff_consume(void *priv, char *line, unsigned long len)
 784{
 785        struct checkdiff_t *data = priv;
 786
 787        if (line[0] == '+') {
 788                int i, spaces = 0;
 789
 790                data->lineno++;
 791
 792                /* check space before tab */
 793                for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
 794                        if (line[i] == ' ')
 795                                spaces++;
 796                if (line[i - 1] == '\t' && spaces)
 797                        printf("%s:%d: space before tab:%.*s\n",
 798                                data->filename, data->lineno, (int)len, line);
 799
 800                /* check white space at line end */
 801                if (line[len - 1] == '\n')
 802                        len--;
 803                if (isspace(line[len - 1]))
 804                        printf("%s:%d: white space at end: %.*s\n",
 805                                data->filename, data->lineno, (int)len, line);
 806        } else if (line[0] == ' ')
 807                data->lineno++;
 808        else if (line[0] == '@') {
 809                char *plus = strchr(line, '+');
 810                if (plus)
 811                        data->lineno = strtol(plus, NULL, 10);
 812                else
 813                        die("invalid diff");
 814        }
 815}
 816
 817static unsigned char *deflate_it(char *data,
 818                                 unsigned long size,
 819                                 unsigned long *result_size)
 820{
 821        int bound;
 822        unsigned char *deflated;
 823        z_stream stream;
 824
 825        memset(&stream, 0, sizeof(stream));
 826        deflateInit(&stream, zlib_compression_level);
 827        bound = deflateBound(&stream, size);
 828        deflated = xmalloc(bound);
 829        stream.next_out = deflated;
 830        stream.avail_out = bound;
 831
 832        stream.next_in = (unsigned char *)data;
 833        stream.avail_in = size;
 834        while (deflate(&stream, Z_FINISH) == Z_OK)
 835                ; /* nothing */
 836        deflateEnd(&stream);
 837        *result_size = stream.total_out;
 838        return deflated;
 839}
 840
 841static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
 842{
 843        void *cp;
 844        void *delta;
 845        void *deflated;
 846        void *data;
 847        unsigned long orig_size;
 848        unsigned long delta_size;
 849        unsigned long deflate_size;
 850        unsigned long data_size;
 851
 852        /* We could do deflated delta, or we could do just deflated two,
 853         * whichever is smaller.
 854         */
 855        delta = NULL;
 856        deflated = deflate_it(two->ptr, two->size, &deflate_size);
 857        if (one->size && two->size) {
 858                delta = diff_delta(one->ptr, one->size,
 859                                   two->ptr, two->size,
 860                                   &delta_size, deflate_size);
 861                if (delta) {
 862                        void *to_free = delta;
 863                        orig_size = delta_size;
 864                        delta = deflate_it(delta, delta_size, &delta_size);
 865                        free(to_free);
 866                }
 867        }
 868
 869        if (delta && delta_size < deflate_size) {
 870                printf("delta %lu\n", orig_size);
 871                free(deflated);
 872                data = delta;
 873                data_size = delta_size;
 874        }
 875        else {
 876                printf("literal %lu\n", two->size);
 877                free(delta);
 878                data = deflated;
 879                data_size = deflate_size;
 880        }
 881
 882        /* emit data encoded in base85 */
 883        cp = data;
 884        while (data_size) {
 885                int bytes = (52 < data_size) ? 52 : data_size;
 886                char line[70];
 887                data_size -= bytes;
 888                if (bytes <= 26)
 889                        line[0] = bytes + 'A' - 1;
 890                else
 891                        line[0] = bytes - 26 + 'a' - 1;
 892                encode_85(line + 1, cp, bytes);
 893                cp = (char *) cp + bytes;
 894                puts(line);
 895        }
 896        printf("\n");
 897        free(data);
 898}
 899
 900static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 901{
 902        printf("GIT binary patch\n");
 903        emit_binary_diff_body(one, two);
 904        emit_binary_diff_body(two, one);
 905}
 906
 907#define FIRST_FEW_BYTES 8000
 908static int mmfile_is_binary(mmfile_t *mf)
 909{
 910        long sz = mf->size;
 911        if (FIRST_FEW_BYTES < sz)
 912                sz = FIRST_FEW_BYTES;
 913        return !!memchr(mf->ptr, 0, sz);
 914}
 915
 916static void builtin_diff(const char *name_a,
 917                         const char *name_b,
 918                         struct diff_filespec *one,
 919                         struct diff_filespec *two,
 920                         const char *xfrm_msg,
 921                         struct diff_options *o,
 922                         int complete_rewrite)
 923{
 924        mmfile_t mf1, mf2;
 925        const char *lbl[2];
 926        char *a_one, *b_two;
 927        const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
 928        const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
 929
 930        a_one = quote_two("a/", name_a);
 931        b_two = quote_two("b/", name_b);
 932        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 933        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 934        printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
 935        if (lbl[0][0] == '/') {
 936                /* /dev/null */
 937                printf("%snew file mode %06o%s\n", set, two->mode, reset);
 938                if (xfrm_msg && xfrm_msg[0])
 939                        printf("%s%s%s\n", set, xfrm_msg, reset);
 940        }
 941        else if (lbl[1][0] == '/') {
 942                printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
 943                if (xfrm_msg && xfrm_msg[0])
 944                        printf("%s%s%s\n", set, xfrm_msg, reset);
 945        }
 946        else {
 947                if (one->mode != two->mode) {
 948                        printf("%sold mode %06o%s\n", set, one->mode, reset);
 949                        printf("%snew mode %06o%s\n", set, two->mode, reset);
 950                }
 951                if (xfrm_msg && xfrm_msg[0])
 952                        printf("%s%s%s\n", set, xfrm_msg, reset);
 953                /*
 954                 * we do not run diff between different kind
 955                 * of objects.
 956                 */
 957                if ((one->mode ^ two->mode) & S_IFMT)
 958                        goto free_ab_and_return;
 959                if (complete_rewrite) {
 960                        emit_rewrite_diff(name_a, name_b, one, two);
 961                        goto free_ab_and_return;
 962                }
 963        }
 964
 965        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 966                die("unable to read files to diff");
 967
 968        if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
 969                /* Quite common confusing case */
 970                if (mf1.size == mf2.size &&
 971                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 972                        goto free_ab_and_return;
 973                if (o->binary)
 974                        emit_binary_diff(&mf1, &mf2);
 975                else
 976                        printf("Binary files %s and %s differ\n",
 977                               lbl[0], lbl[1]);
 978        }
 979        else {
 980                /* Crazy xdl interfaces.. */
 981                const char *diffopts = getenv("GIT_DIFF_OPTS");
 982                xpparam_t xpp;
 983                xdemitconf_t xecfg;
 984                xdemitcb_t ecb;
 985                struct emit_callback ecbdata;
 986
 987                memset(&ecbdata, 0, sizeof(ecbdata));
 988                ecbdata.label_path = lbl;
 989                ecbdata.color_diff = o->color_diff;
 990                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 991                xecfg.ctxlen = o->context;
 992                xecfg.flags = XDL_EMIT_FUNCNAMES;
 993                if (!diffopts)
 994                        ;
 995                else if (!strncmp(diffopts, "--unified=", 10))
 996                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 997                else if (!strncmp(diffopts, "-u", 2))
 998                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 999                ecb.outf = xdiff_outf;
1000                ecb.priv = &ecbdata;
1001                ecbdata.xm.consume = fn_out_consume;
1002                if (o->color_diff_words)
1003                        ecbdata.diff_words =
1004                                xcalloc(1, sizeof(struct diff_words_data));
1005                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1006                if (o->color_diff_words)
1007                        free_diff_words_data(&ecbdata);
1008        }
1009
1010 free_ab_and_return:
1011        free(a_one);
1012        free(b_two);
1013        return;
1014}
1015
1016static void builtin_diffstat(const char *name_a, const char *name_b,
1017                             struct diff_filespec *one,
1018                             struct diff_filespec *two,
1019                             struct diffstat_t *diffstat,
1020                             struct diff_options *o,
1021                             int complete_rewrite)
1022{
1023        mmfile_t mf1, mf2;
1024        struct diffstat_file *data;
1025
1026        data = diffstat_add(diffstat, name_a, name_b);
1027
1028        if (!one || !two) {
1029                data->is_unmerged = 1;
1030                return;
1031        }
1032        if (complete_rewrite) {
1033                diff_populate_filespec(one, 0);
1034                diff_populate_filespec(two, 0);
1035                data->deleted = count_lines(one->data, one->size);
1036                data->added = count_lines(two->data, two->size);
1037                return;
1038        }
1039        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1040                die("unable to read files to diff");
1041
1042        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
1043                data->is_binary = 1;
1044        else {
1045                /* Crazy xdl interfaces.. */
1046                xpparam_t xpp;
1047                xdemitconf_t xecfg;
1048                xdemitcb_t ecb;
1049
1050                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1051                xecfg.ctxlen = 0;
1052                xecfg.flags = 0;
1053                ecb.outf = xdiff_outf;
1054                ecb.priv = diffstat;
1055                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1056        }
1057}
1058
1059static void builtin_checkdiff(const char *name_a, const char *name_b,
1060                             struct diff_filespec *one,
1061                             struct diff_filespec *two)
1062{
1063        mmfile_t mf1, mf2;
1064        struct checkdiff_t data;
1065
1066        if (!two)
1067                return;
1068
1069        memset(&data, 0, sizeof(data));
1070        data.xm.consume = checkdiff_consume;
1071        data.filename = name_b ? name_b : name_a;
1072        data.lineno = 0;
1073
1074        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1075                die("unable to read files to diff");
1076
1077        if (mmfile_is_binary(&mf2))
1078                return;
1079        else {
1080                /* Crazy xdl interfaces.. */
1081                xpparam_t xpp;
1082                xdemitconf_t xecfg;
1083                xdemitcb_t ecb;
1084
1085                xpp.flags = XDF_NEED_MINIMAL;
1086                xecfg.ctxlen = 0;
1087                xecfg.flags = 0;
1088                ecb.outf = xdiff_outf;
1089                ecb.priv = &data;
1090                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1091        }
1092}
1093
1094struct diff_filespec *alloc_filespec(const char *path)
1095{
1096        int namelen = strlen(path);
1097        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1098
1099        memset(spec, 0, sizeof(*spec));
1100        spec->path = (char *)(spec + 1);
1101        memcpy(spec->path, path, namelen+1);
1102        return spec;
1103}
1104
1105void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1106                   unsigned short mode)
1107{
1108        if (mode) {
1109                spec->mode = canon_mode(mode);
1110                memcpy(spec->sha1, sha1, 20);
1111                spec->sha1_valid = !is_null_sha1(sha1);
1112        }
1113}
1114
1115/*
1116 * Given a name and sha1 pair, if the dircache tells us the file in
1117 * the work tree has that object contents, return true, so that
1118 * prepare_temp_file() does not have to inflate and extract.
1119 */
1120static int work_tree_matches(const char *name, const unsigned char *sha1)
1121{
1122        struct cache_entry *ce;
1123        struct stat st;
1124        int pos, len;
1125
1126        /* We do not read the cache ourselves here, because the
1127         * benchmark with my previous version that always reads cache
1128         * shows that it makes things worse for diff-tree comparing
1129         * two linux-2.6 kernel trees in an already checked out work
1130         * tree.  This is because most diff-tree comparisons deal with
1131         * only a small number of files, while reading the cache is
1132         * expensive for a large project, and its cost outweighs the
1133         * savings we get by not inflating the object to a temporary
1134         * file.  Practically, this code only helps when we are used
1135         * by diff-cache --cached, which does read the cache before
1136         * calling us.
1137         */
1138        if (!active_cache)
1139                return 0;
1140
1141        len = strlen(name);
1142        pos = cache_name_pos(name, len);
1143        if (pos < 0)
1144                return 0;
1145        ce = active_cache[pos];
1146        if ((lstat(name, &st) < 0) ||
1147            !S_ISREG(st.st_mode) || /* careful! */
1148            ce_match_stat(ce, &st, 0) ||
1149            memcmp(sha1, ce->sha1, 20))
1150                return 0;
1151        /* we return 1 only when we can stat, it is a regular file,
1152         * stat information matches, and sha1 recorded in the cache
1153         * matches.  I.e. we know the file in the work tree really is
1154         * the same as the <name, sha1> pair.
1155         */
1156        return 1;
1157}
1158
1159static struct sha1_size_cache {
1160        unsigned char sha1[20];
1161        unsigned long size;
1162} **sha1_size_cache;
1163static int sha1_size_cache_nr, sha1_size_cache_alloc;
1164
1165static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
1166                                                 int find_only,
1167                                                 unsigned long size)
1168{
1169        int first, last;
1170        struct sha1_size_cache *e;
1171
1172        first = 0;
1173        last = sha1_size_cache_nr;
1174        while (last > first) {
1175                int cmp, next = (last + first) >> 1;
1176                e = sha1_size_cache[next];
1177                cmp = memcmp(e->sha1, sha1, 20);
1178                if (!cmp)
1179                        return e;
1180                if (cmp < 0) {
1181                        last = next;
1182                        continue;
1183                }
1184                first = next+1;
1185        }
1186        /* not found */
1187        if (find_only)
1188                return NULL;
1189        /* insert to make it at "first" */
1190        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
1191                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
1192                sha1_size_cache = xrealloc(sha1_size_cache,
1193                                           sha1_size_cache_alloc *
1194                                           sizeof(*sha1_size_cache));
1195        }
1196        sha1_size_cache_nr++;
1197        if (first < sha1_size_cache_nr)
1198                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
1199                        (sha1_size_cache_nr - first - 1) *
1200                        sizeof(*sha1_size_cache));
1201        e = xmalloc(sizeof(struct sha1_size_cache));
1202        sha1_size_cache[first] = e;
1203        memcpy(e->sha1, sha1, 20);
1204        e->size = size;
1205        return e;
1206}
1207
1208/*
1209 * While doing rename detection and pickaxe operation, we may need to
1210 * grab the data for the blob (or file) for our own in-core comparison.
1211 * diff_filespec has data and size fields for this purpose.
1212 */
1213int diff_populate_filespec(struct diff_filespec *s, int size_only)
1214{
1215        int err = 0;
1216        if (!DIFF_FILE_VALID(s))
1217                die("internal error: asking to populate invalid file.");
1218        if (S_ISDIR(s->mode))
1219                return -1;
1220
1221        if (!use_size_cache)
1222                size_only = 0;
1223
1224        if (s->data)
1225                return err;
1226        if (!s->sha1_valid ||
1227            work_tree_matches(s->path, s->sha1)) {
1228                struct stat st;
1229                int fd;
1230                if (lstat(s->path, &st) < 0) {
1231                        if (errno == ENOENT) {
1232                        err_empty:
1233                                err = -1;
1234                        empty:
1235                                s->data = (char *)"";
1236                                s->size = 0;
1237                                return err;
1238                        }
1239                }
1240                s->size = st.st_size;
1241                if (!s->size)
1242                        goto empty;
1243                if (size_only)
1244                        return 0;
1245                if (S_ISLNK(st.st_mode)) {
1246                        int ret;
1247                        s->data = xmalloc(s->size);
1248                        s->should_free = 1;
1249                        ret = readlink(s->path, s->data, s->size);
1250                        if (ret < 0) {
1251                                free(s->data);
1252                                goto err_empty;
1253                        }
1254                        return 0;
1255                }
1256                fd = open(s->path, O_RDONLY);
1257                if (fd < 0)
1258                        goto err_empty;
1259                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1260                close(fd);
1261                if (s->data == MAP_FAILED)
1262                        goto err_empty;
1263                s->should_munmap = 1;
1264        }
1265        else {
1266                char type[20];
1267                struct sha1_size_cache *e;
1268
1269                if (size_only) {
1270                        e = locate_size_cache(s->sha1, 1, 0);
1271                        if (e) {
1272                                s->size = e->size;
1273                                return 0;
1274                        }
1275                        if (!sha1_object_info(s->sha1, type, &s->size))
1276                                locate_size_cache(s->sha1, 0, s->size);
1277                }
1278                else {
1279                        s->data = read_sha1_file(s->sha1, type, &s->size);
1280                        s->should_free = 1;
1281                }
1282        }
1283        return 0;
1284}
1285
1286void diff_free_filespec_data(struct diff_filespec *s)
1287{
1288        if (s->should_free)
1289                free(s->data);
1290        else if (s->should_munmap)
1291                munmap(s->data, s->size);
1292        s->should_free = s->should_munmap = 0;
1293        s->data = NULL;
1294        free(s->cnt_data);
1295        s->cnt_data = NULL;
1296}
1297
1298static void prep_temp_blob(struct diff_tempfile *temp,
1299                           void *blob,
1300                           unsigned long size,
1301                           const unsigned char *sha1,
1302                           int mode)
1303{
1304        int fd;
1305
1306        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1307        if (fd < 0)
1308                die("unable to create temp-file");
1309        if (write(fd, blob, size) != size)
1310                die("unable to write temp-file");
1311        close(fd);
1312        temp->name = temp->tmp_path;
1313        strcpy(temp->hex, sha1_to_hex(sha1));
1314        temp->hex[40] = 0;
1315        sprintf(temp->mode, "%06o", mode);
1316}
1317
1318static void prepare_temp_file(const char *name,
1319                              struct diff_tempfile *temp,
1320                              struct diff_filespec *one)
1321{
1322        if (!DIFF_FILE_VALID(one)) {
1323        not_a_valid_file:
1324                /* A '-' entry produces this for file-2, and
1325                 * a '+' entry produces this for file-1.
1326                 */
1327                temp->name = "/dev/null";
1328                strcpy(temp->hex, ".");
1329                strcpy(temp->mode, ".");
1330                return;
1331        }
1332
1333        if (!one->sha1_valid ||
1334            work_tree_matches(name, one->sha1)) {
1335                struct stat st;
1336                if (lstat(name, &st) < 0) {
1337                        if (errno == ENOENT)
1338                                goto not_a_valid_file;
1339                        die("stat(%s): %s", name, strerror(errno));
1340                }
1341                if (S_ISLNK(st.st_mode)) {
1342                        int ret;
1343                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1344                        if (sizeof(buf) <= st.st_size)
1345                                die("symlink too long: %s", name);
1346                        ret = readlink(name, buf, st.st_size);
1347                        if (ret < 0)
1348                                die("readlink(%s)", name);
1349                        prep_temp_blob(temp, buf, st.st_size,
1350                                       (one->sha1_valid ?
1351                                        one->sha1 : null_sha1),
1352                                       (one->sha1_valid ?
1353                                        one->mode : S_IFLNK));
1354                }
1355                else {
1356                        /* we can borrow from the file in the work tree */
1357                        temp->name = name;
1358                        if (!one->sha1_valid)
1359                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1360                        else
1361                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1362                        /* Even though we may sometimes borrow the
1363                         * contents from the work tree, we always want
1364                         * one->mode.  mode is trustworthy even when
1365                         * !(one->sha1_valid), as long as
1366                         * DIFF_FILE_VALID(one).
1367                         */
1368                        sprintf(temp->mode, "%06o", one->mode);
1369                }
1370                return;
1371        }
1372        else {
1373                if (diff_populate_filespec(one, 0))
1374                        die("cannot read data blob for %s", one->path);
1375                prep_temp_blob(temp, one->data, one->size,
1376                               one->sha1, one->mode);
1377        }
1378}
1379
1380static void remove_tempfile(void)
1381{
1382        int i;
1383
1384        for (i = 0; i < 2; i++)
1385                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1386                        unlink(diff_temp[i].name);
1387                        diff_temp[i].name = NULL;
1388                }
1389}
1390
1391static void remove_tempfile_on_signal(int signo)
1392{
1393        remove_tempfile();
1394        signal(SIGINT, SIG_DFL);
1395        raise(signo);
1396}
1397
1398static int spawn_prog(const char *pgm, const char **arg)
1399{
1400        pid_t pid;
1401        int status;
1402
1403        fflush(NULL);
1404        pid = fork();
1405        if (pid < 0)
1406                die("unable to fork");
1407        if (!pid) {
1408                execvp(pgm, (char *const*) arg);
1409                exit(255);
1410        }
1411
1412        while (waitpid(pid, &status, 0) < 0) {
1413                if (errno == EINTR)
1414                        continue;
1415                return -1;
1416        }
1417
1418        /* Earlier we did not check the exit status because
1419         * diff exits non-zero if files are different, and
1420         * we are not interested in knowing that.  It was a
1421         * mistake which made it harder to quit a diff-*
1422         * session that uses the git-apply-patch-script as
1423         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1424         * should also exit non-zero only when it wants to
1425         * abort the entire diff-* session.
1426         */
1427        if (WIFEXITED(status) && !WEXITSTATUS(status))
1428                return 0;
1429        return -1;
1430}
1431
1432/* An external diff command takes:
1433 *
1434 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1435 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1436 *
1437 */
1438static void run_external_diff(const char *pgm,
1439                              const char *name,
1440                              const char *other,
1441                              struct diff_filespec *one,
1442                              struct diff_filespec *two,
1443                              const char *xfrm_msg,
1444                              int complete_rewrite)
1445{
1446        const char *spawn_arg[10];
1447        struct diff_tempfile *temp = diff_temp;
1448        int retval;
1449        static int atexit_asked = 0;
1450        const char *othername;
1451        const char **arg = &spawn_arg[0];
1452
1453        othername = (other? other : name);
1454        if (one && two) {
1455                prepare_temp_file(name, &temp[0], one);
1456                prepare_temp_file(othername, &temp[1], two);
1457                if (! atexit_asked &&
1458                    (temp[0].name == temp[0].tmp_path ||
1459                     temp[1].name == temp[1].tmp_path)) {
1460                        atexit_asked = 1;
1461                        atexit(remove_tempfile);
1462                }
1463                signal(SIGINT, remove_tempfile_on_signal);
1464        }
1465
1466        if (one && two) {
1467                *arg++ = pgm;
1468                *arg++ = name;
1469                *arg++ = temp[0].name;
1470                *arg++ = temp[0].hex;
1471                *arg++ = temp[0].mode;
1472                *arg++ = temp[1].name;
1473                *arg++ = temp[1].hex;
1474                *arg++ = temp[1].mode;
1475                if (other) {
1476                        *arg++ = other;
1477                        *arg++ = xfrm_msg;
1478                }
1479        } else {
1480                *arg++ = pgm;
1481                *arg++ = name;
1482        }
1483        *arg = NULL;
1484        retval = spawn_prog(pgm, spawn_arg);
1485        remove_tempfile();
1486        if (retval) {
1487                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1488                exit(1);
1489        }
1490}
1491
1492static void run_diff_cmd(const char *pgm,
1493                         const char *name,
1494                         const char *other,
1495                         struct diff_filespec *one,
1496                         struct diff_filespec *two,
1497                         const char *xfrm_msg,
1498                         struct diff_options *o,
1499                         int complete_rewrite)
1500{
1501        if (pgm) {
1502                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1503                                  complete_rewrite);
1504                return;
1505        }
1506        if (one && two)
1507                builtin_diff(name, other ? other : name,
1508                             one, two, xfrm_msg, o, complete_rewrite);
1509        else
1510                printf("* Unmerged path %s\n", name);
1511}
1512
1513static void diff_fill_sha1_info(struct diff_filespec *one)
1514{
1515        if (DIFF_FILE_VALID(one)) {
1516                if (!one->sha1_valid) {
1517                        struct stat st;
1518                        if (lstat(one->path, &st) < 0)
1519                                die("stat %s", one->path);
1520                        if (index_path(one->sha1, one->path, &st, 0))
1521                                die("cannot hash %s\n", one->path);
1522                }
1523        }
1524        else
1525                memset(one->sha1, 0, 20);
1526}
1527
1528static void run_diff(struct diff_filepair *p, struct diff_options *o)
1529{
1530        const char *pgm = external_diff();
1531        char msg[PATH_MAX*2+300], *xfrm_msg;
1532        struct diff_filespec *one;
1533        struct diff_filespec *two;
1534        const char *name;
1535        const char *other;
1536        char *name_munged, *other_munged;
1537        int complete_rewrite = 0;
1538        int len;
1539
1540        if (DIFF_PAIR_UNMERGED(p)) {
1541                /* unmerged */
1542                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1543                return;
1544        }
1545
1546        name = p->one->path;
1547        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1548        name_munged = quote_one(name);
1549        other_munged = quote_one(other);
1550        one = p->one; two = p->two;
1551
1552        diff_fill_sha1_info(one);
1553        diff_fill_sha1_info(two);
1554
1555        len = 0;
1556        switch (p->status) {
1557        case DIFF_STATUS_COPIED:
1558                len += snprintf(msg + len, sizeof(msg) - len,
1559                                "similarity index %d%%\n"
1560                                "copy from %s\n"
1561                                "copy to %s\n",
1562                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1563                                name_munged, other_munged);
1564                break;
1565        case DIFF_STATUS_RENAMED:
1566                len += snprintf(msg + len, sizeof(msg) - len,
1567                                "similarity index %d%%\n"
1568                                "rename from %s\n"
1569                                "rename to %s\n",
1570                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1571                                name_munged, other_munged);
1572                break;
1573        case DIFF_STATUS_MODIFIED:
1574                if (p->score) {
1575                        len += snprintf(msg + len, sizeof(msg) - len,
1576                                        "dissimilarity index %d%%\n",
1577                                        (int)(0.5 + p->score *
1578                                              100.0/MAX_SCORE));
1579                        complete_rewrite = 1;
1580                        break;
1581                }
1582                /* fallthru */
1583        default:
1584                /* nothing */
1585                ;
1586        }
1587
1588        if (memcmp(one->sha1, two->sha1, 20)) {
1589                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1590
1591                len += snprintf(msg + len, sizeof(msg) - len,
1592                                "index %.*s..%.*s",
1593                                abbrev, sha1_to_hex(one->sha1),
1594                                abbrev, sha1_to_hex(two->sha1));
1595                if (one->mode == two->mode)
1596                        len += snprintf(msg + len, sizeof(msg) - len,
1597                                        " %06o", one->mode);
1598                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1599        }
1600
1601        if (len)
1602                msg[--len] = 0;
1603        xfrm_msg = len ? msg : NULL;
1604
1605        if (!pgm &&
1606            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1607            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1608                /* a filepair that changes between file and symlink
1609                 * needs to be split into deletion and creation.
1610                 */
1611                struct diff_filespec *null = alloc_filespec(two->path);
1612                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1613                free(null);
1614                null = alloc_filespec(one->path);
1615                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1616                free(null);
1617        }
1618        else
1619                run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1620                             complete_rewrite);
1621
1622        free(name_munged);
1623        free(other_munged);
1624}
1625
1626static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1627                         struct diffstat_t *diffstat)
1628{
1629        const char *name;
1630        const char *other;
1631        int complete_rewrite = 0;
1632
1633        if (DIFF_PAIR_UNMERGED(p)) {
1634                /* unmerged */
1635                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1636                return;
1637        }
1638
1639        name = p->one->path;
1640        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1641
1642        diff_fill_sha1_info(p->one);
1643        diff_fill_sha1_info(p->two);
1644
1645        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1646                complete_rewrite = 1;
1647        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1648}
1649
1650static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1651{
1652        const char *name;
1653        const char *other;
1654
1655        if (DIFF_PAIR_UNMERGED(p)) {
1656                /* unmerged */
1657                return;
1658        }
1659
1660        name = p->one->path;
1661        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1662
1663        diff_fill_sha1_info(p->one);
1664        diff_fill_sha1_info(p->two);
1665
1666        builtin_checkdiff(name, other, p->one, p->two);
1667}
1668
1669void diff_setup(struct diff_options *options)
1670{
1671        memset(options, 0, sizeof(*options));
1672        options->line_termination = '\n';
1673        options->break_opt = -1;
1674        options->rename_limit = -1;
1675        options->context = 3;
1676        options->msg_sep = "";
1677
1678        options->change = diff_change;
1679        options->add_remove = diff_addremove;
1680        options->color_diff = diff_use_color_default;
1681        options->detect_rename = diff_detect_rename_default;
1682}
1683
1684int diff_setup_done(struct diff_options *options)
1685{
1686        int count = 0;
1687
1688        if (options->output_format & DIFF_FORMAT_NAME)
1689                count++;
1690        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
1691                count++;
1692        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
1693                count++;
1694        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
1695                count++;
1696        if (count > 1)
1697                die("--name-only, --name-status, --check and -s are mutually exclusive");
1698
1699        if (options->find_copies_harder)
1700                options->detect_rename = DIFF_DETECT_COPY;
1701
1702        if (options->output_format & (DIFF_FORMAT_NAME |
1703                                      DIFF_FORMAT_NAME_STATUS |
1704                                      DIFF_FORMAT_CHECKDIFF |
1705                                      DIFF_FORMAT_NO_OUTPUT))
1706                options->output_format &= ~(DIFF_FORMAT_RAW |
1707                                            DIFF_FORMAT_DIFFSTAT |
1708                                            DIFF_FORMAT_SUMMARY |
1709                                            DIFF_FORMAT_PATCH);
1710
1711        /*
1712         * These cases always need recursive; we do not drop caller-supplied
1713         * recursive bits for other formats here.
1714         */
1715        if (options->output_format & (DIFF_FORMAT_PATCH |
1716                                      DIFF_FORMAT_DIFFSTAT |
1717                                      DIFF_FORMAT_CHECKDIFF))
1718                options->recursive = 1;
1719        /*
1720         * Also pickaxe would not work very well if you do not say recursive
1721         */
1722        if (options->pickaxe)
1723                options->recursive = 1;
1724
1725        if (options->detect_rename && options->rename_limit < 0)
1726                options->rename_limit = diff_rename_limit_default;
1727        if (options->setup & DIFF_SETUP_USE_CACHE) {
1728                if (!active_cache)
1729                        /* read-cache does not die even when it fails
1730                         * so it is safe for us to do this here.  Also
1731                         * it does not smudge active_cache or active_nr
1732                         * when it fails, so we do not have to worry about
1733                         * cleaning it up ourselves either.
1734                         */
1735                        read_cache();
1736        }
1737        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1738                use_size_cache = 1;
1739        if (options->abbrev <= 0 || 40 < options->abbrev)
1740                options->abbrev = 40; /* full */
1741
1742        return 0;
1743}
1744
1745static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1746{
1747        char c, *eq;
1748        int len;
1749
1750        if (*arg != '-')
1751                return 0;
1752        c = *++arg;
1753        if (!c)
1754                return 0;
1755        if (c == arg_short) {
1756                c = *++arg;
1757                if (!c)
1758                        return 1;
1759                if (val && isdigit(c)) {
1760                        char *end;
1761                        int n = strtoul(arg, &end, 10);
1762                        if (*end)
1763                                return 0;
1764                        *val = n;
1765                        return 1;
1766                }
1767                return 0;
1768        }
1769        if (c != '-')
1770                return 0;
1771        arg++;
1772        eq = strchr(arg, '=');
1773        if (eq)
1774                len = eq - arg;
1775        else
1776                len = strlen(arg);
1777        if (!len || strncmp(arg, arg_long, len))
1778                return 0;
1779        if (eq) {
1780                int n;
1781                char *end;
1782                if (!isdigit(*++eq))
1783                        return 0;
1784                n = strtoul(eq, &end, 10);
1785                if (*end)
1786                        return 0;
1787                *val = n;
1788        }
1789        return 1;
1790}
1791
1792int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1793{
1794        const char *arg = av[0];
1795        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1796                options->output_format |= DIFF_FORMAT_PATCH;
1797        else if (opt_arg(arg, 'U', "unified", &options->context))
1798                options->output_format |= DIFF_FORMAT_PATCH;
1799        else if (!strcmp(arg, "--raw"))
1800                options->output_format |= DIFF_FORMAT_RAW;
1801        else if (!strcmp(arg, "--patch-with-raw")) {
1802                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
1803        }
1804        else if (!strcmp(arg, "--stat"))
1805                options->output_format |= DIFF_FORMAT_DIFFSTAT;
1806        else if (!strcmp(arg, "--check"))
1807                options->output_format |= DIFF_FORMAT_CHECKDIFF;
1808        else if (!strcmp(arg, "--summary"))
1809                options->output_format |= DIFF_FORMAT_SUMMARY;
1810        else if (!strcmp(arg, "--patch-with-stat")) {
1811                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
1812        }
1813        else if (!strcmp(arg, "-z"))
1814                options->line_termination = 0;
1815        else if (!strncmp(arg, "-l", 2))
1816                options->rename_limit = strtoul(arg+2, NULL, 10);
1817        else if (!strcmp(arg, "--full-index"))
1818                options->full_index = 1;
1819        else if (!strcmp(arg, "--binary")) {
1820                options->output_format |= DIFF_FORMAT_PATCH;
1821                options->full_index = options->binary = 1;
1822        }
1823        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
1824                options->text = 1;
1825        }
1826        else if (!strcmp(arg, "--name-only"))
1827                options->output_format |= DIFF_FORMAT_NAME;
1828        else if (!strcmp(arg, "--name-status"))
1829                options->output_format |= DIFF_FORMAT_NAME_STATUS;
1830        else if (!strcmp(arg, "-R"))
1831                options->reverse_diff = 1;
1832        else if (!strncmp(arg, "-S", 2))
1833                options->pickaxe = arg + 2;
1834        else if (!strcmp(arg, "-s")) {
1835                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
1836        }
1837        else if (!strncmp(arg, "-O", 2))
1838                options->orderfile = arg + 2;
1839        else if (!strncmp(arg, "--diff-filter=", 14))
1840                options->filter = arg + 14;
1841        else if (!strcmp(arg, "--pickaxe-all"))
1842                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1843        else if (!strcmp(arg, "--pickaxe-regex"))
1844                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1845        else if (!strncmp(arg, "-B", 2)) {
1846                if ((options->break_opt =
1847                     diff_scoreopt_parse(arg)) == -1)
1848                        return -1;
1849        }
1850        else if (!strncmp(arg, "-M", 2)) {
1851                if ((options->rename_score =
1852                     diff_scoreopt_parse(arg)) == -1)
1853                        return -1;
1854                options->detect_rename = DIFF_DETECT_RENAME;
1855        }
1856        else if (!strncmp(arg, "-C", 2)) {
1857                if ((options->rename_score =
1858                     diff_scoreopt_parse(arg)) == -1)
1859                        return -1;
1860                options->detect_rename = DIFF_DETECT_COPY;
1861        }
1862        else if (!strcmp(arg, "--find-copies-harder"))
1863                options->find_copies_harder = 1;
1864        else if (!strcmp(arg, "--abbrev"))
1865                options->abbrev = DEFAULT_ABBREV;
1866        else if (!strncmp(arg, "--abbrev=", 9)) {
1867                options->abbrev = strtoul(arg + 9, NULL, 10);
1868                if (options->abbrev < MINIMUM_ABBREV)
1869                        options->abbrev = MINIMUM_ABBREV;
1870                else if (40 < options->abbrev)
1871                        options->abbrev = 40;
1872        }
1873        else if (!strcmp(arg, "--color"))
1874                options->color_diff = 1;
1875        else if (!strcmp(arg, "--no-color"))
1876                options->color_diff = 0;
1877        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
1878                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
1879        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
1880                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1881        else if (!strcmp(arg, "--color-words"))
1882                options->color_diff = options->color_diff_words = 1;
1883        else if (!strcmp(arg, "--no-renames"))
1884                options->detect_rename = 0;
1885        else
1886                return 0;
1887        return 1;
1888}
1889
1890static int parse_num(const char **cp_p)
1891{
1892        unsigned long num, scale;
1893        int ch, dot;
1894        const char *cp = *cp_p;
1895
1896        num = 0;
1897        scale = 1;
1898        dot = 0;
1899        for(;;) {
1900                ch = *cp;
1901                if ( !dot && ch == '.' ) {
1902                        scale = 1;
1903                        dot = 1;
1904                } else if ( ch == '%' ) {
1905                        scale = dot ? scale*100 : 100;
1906                        cp++;   /* % is always at the end */
1907                        break;
1908                } else if ( ch >= '0' && ch <= '9' ) {
1909                        if ( scale < 100000 ) {
1910                                scale *= 10;
1911                                num = (num*10) + (ch-'0');
1912                        }
1913                } else {
1914                        break;
1915                }
1916                cp++;
1917        }
1918        *cp_p = cp;
1919
1920        /* user says num divided by scale and we say internally that
1921         * is MAX_SCORE * num / scale.
1922         */
1923        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1924}
1925
1926int diff_scoreopt_parse(const char *opt)
1927{
1928        int opt1, opt2, cmd;
1929
1930        if (*opt++ != '-')
1931                return -1;
1932        cmd = *opt++;
1933        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1934                return -1; /* that is not a -M, -C nor -B option */
1935
1936        opt1 = parse_num(&opt);
1937        if (cmd != 'B')
1938                opt2 = 0;
1939        else {
1940                if (*opt == 0)
1941                        opt2 = 0;
1942                else if (*opt != '/')
1943                        return -1; /* we expect -B80/99 or -B80 */
1944                else {
1945                        opt++;
1946                        opt2 = parse_num(&opt);
1947                }
1948        }
1949        if (*opt != 0)
1950                return -1;
1951        return opt1 | (opt2 << 16);
1952}
1953
1954struct diff_queue_struct diff_queued_diff;
1955
1956void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1957{
1958        if (queue->alloc <= queue->nr) {
1959                queue->alloc = alloc_nr(queue->alloc);
1960                queue->queue = xrealloc(queue->queue,
1961                                        sizeof(dp) * queue->alloc);
1962        }
1963        queue->queue[queue->nr++] = dp;
1964}
1965
1966struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1967                                 struct diff_filespec *one,
1968                                 struct diff_filespec *two)
1969{
1970        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
1971        dp->one = one;
1972        dp->two = two;
1973        if (queue)
1974                diff_q(queue, dp);
1975        return dp;
1976}
1977
1978void diff_free_filepair(struct diff_filepair *p)
1979{
1980        diff_free_filespec_data(p->one);
1981        diff_free_filespec_data(p->two);
1982        free(p->one);
1983        free(p->two);
1984        free(p);
1985}
1986
1987/* This is different from find_unique_abbrev() in that
1988 * it stuffs the result with dots for alignment.
1989 */
1990const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1991{
1992        int abblen;
1993        const char *abbrev;
1994        if (len == 40)
1995                return sha1_to_hex(sha1);
1996
1997        abbrev = find_unique_abbrev(sha1, len);
1998        if (!abbrev)
1999                return sha1_to_hex(sha1);
2000        abblen = strlen(abbrev);
2001        if (abblen < 37) {
2002                static char hex[41];
2003                if (len < abblen && abblen <= len + 2)
2004                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2005                else
2006                        sprintf(hex, "%s...", abbrev);
2007                return hex;
2008        }
2009        return sha1_to_hex(sha1);
2010}
2011
2012static void diff_flush_raw(struct diff_filepair *p,
2013                           struct diff_options *options)
2014{
2015        int two_paths;
2016        char status[10];
2017        int abbrev = options->abbrev;
2018        const char *path_one, *path_two;
2019        int inter_name_termination = '\t';
2020        int line_termination = options->line_termination;
2021
2022        if (!line_termination)
2023                inter_name_termination = 0;
2024
2025        path_one = p->one->path;
2026        path_two = p->two->path;
2027        if (line_termination) {
2028                path_one = quote_one(path_one);
2029                path_two = quote_one(path_two);
2030        }
2031
2032        if (p->score)
2033                sprintf(status, "%c%03d", p->status,
2034                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
2035        else {
2036                status[0] = p->status;
2037                status[1] = 0;
2038        }
2039        switch (p->status) {
2040        case DIFF_STATUS_COPIED:
2041        case DIFF_STATUS_RENAMED:
2042                two_paths = 1;
2043                break;
2044        case DIFF_STATUS_ADDED:
2045        case DIFF_STATUS_DELETED:
2046                two_paths = 0;
2047                break;
2048        default:
2049                two_paths = 0;
2050                break;
2051        }
2052        if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
2053                printf(":%06o %06o %s ",
2054                       p->one->mode, p->two->mode,
2055                       diff_unique_abbrev(p->one->sha1, abbrev));
2056                printf("%s ",
2057                       diff_unique_abbrev(p->two->sha1, abbrev));
2058        }
2059        printf("%s%c%s", status, inter_name_termination, path_one);
2060        if (two_paths)
2061                printf("%c%s", inter_name_termination, path_two);
2062        putchar(line_termination);
2063        if (path_one != p->one->path)
2064                free((void*)path_one);
2065        if (path_two != p->two->path)
2066                free((void*)path_two);
2067}
2068
2069static void diff_flush_name(struct diff_filepair *p, int line_termination)
2070{
2071        char *path = p->two->path;
2072
2073        if (line_termination)
2074                path = quote_one(p->two->path);
2075        printf("%s%c", path, line_termination);
2076        if (p->two->path != path)
2077                free(path);
2078}
2079
2080int diff_unmodified_pair(struct diff_filepair *p)
2081{
2082        /* This function is written stricter than necessary to support
2083         * the currently implemented transformers, but the idea is to
2084         * let transformers to produce diff_filepairs any way they want,
2085         * and filter and clean them up here before producing the output.
2086         */
2087        struct diff_filespec *one, *two;
2088
2089        if (DIFF_PAIR_UNMERGED(p))
2090                return 0; /* unmerged is interesting */
2091
2092        one = p->one;
2093        two = p->two;
2094
2095        /* deletion, addition, mode or type change
2096         * and rename are all interesting.
2097         */
2098        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2099            DIFF_PAIR_MODE_CHANGED(p) ||
2100            strcmp(one->path, two->path))
2101                return 0;
2102
2103        /* both are valid and point at the same path.  that is, we are
2104         * dealing with a change.
2105         */
2106        if (one->sha1_valid && two->sha1_valid &&
2107            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
2108                return 1; /* no change */
2109        if (!one->sha1_valid && !two->sha1_valid)
2110                return 1; /* both look at the same file on the filesystem. */
2111        return 0;
2112}
2113
2114static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2115{
2116        if (diff_unmodified_pair(p))
2117                return;
2118
2119        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2120            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2121                return; /* no tree diffs in patch format */
2122
2123        run_diff(p, o);
2124}
2125
2126static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2127                            struct diffstat_t *diffstat)
2128{
2129        if (diff_unmodified_pair(p))
2130                return;
2131
2132        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2133            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2134                return; /* no tree diffs in patch format */
2135
2136        run_diffstat(p, o, diffstat);
2137}
2138
2139static void diff_flush_checkdiff(struct diff_filepair *p,
2140                struct diff_options *o)
2141{
2142        if (diff_unmodified_pair(p))
2143                return;
2144
2145        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2146            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2147                return; /* no tree diffs in patch format */
2148
2149        run_checkdiff(p, o);
2150}
2151
2152int diff_queue_is_empty(void)
2153{
2154        struct diff_queue_struct *q = &diff_queued_diff;
2155        int i;
2156        for (i = 0; i < q->nr; i++)
2157                if (!diff_unmodified_pair(q->queue[i]))
2158                        return 0;
2159        return 1;
2160}
2161
2162#if DIFF_DEBUG
2163void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2164{
2165        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2166                x, one ? one : "",
2167                s->path,
2168                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2169                s->mode,
2170                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2171        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2172                x, one ? one : "",
2173                s->size, s->xfrm_flags);
2174}
2175
2176void diff_debug_filepair(const struct diff_filepair *p, int i)
2177{
2178        diff_debug_filespec(p->one, i, "one");
2179        diff_debug_filespec(p->two, i, "two");
2180        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
2181                p->score, p->status ? p->status : '?',
2182                p->source_stays, p->broken_pair);
2183}
2184
2185void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2186{
2187        int i;
2188        if (msg)
2189                fprintf(stderr, "%s\n", msg);
2190        fprintf(stderr, "q->nr = %d\n", q->nr);
2191        for (i = 0; i < q->nr; i++) {
2192                struct diff_filepair *p = q->queue[i];
2193                diff_debug_filepair(p, i);
2194        }
2195}
2196#endif
2197
2198static void diff_resolve_rename_copy(void)
2199{
2200        int i, j;
2201        struct diff_filepair *p, *pp;
2202        struct diff_queue_struct *q = &diff_queued_diff;
2203
2204        diff_debug_queue("resolve-rename-copy", q);
2205
2206        for (i = 0; i < q->nr; i++) {
2207                p = q->queue[i];
2208                p->status = 0; /* undecided */
2209                if (DIFF_PAIR_UNMERGED(p))
2210                        p->status = DIFF_STATUS_UNMERGED;
2211                else if (!DIFF_FILE_VALID(p->one))
2212                        p->status = DIFF_STATUS_ADDED;
2213                else if (!DIFF_FILE_VALID(p->two))
2214                        p->status = DIFF_STATUS_DELETED;
2215                else if (DIFF_PAIR_TYPE_CHANGED(p))
2216                        p->status = DIFF_STATUS_TYPE_CHANGED;
2217
2218                /* from this point on, we are dealing with a pair
2219                 * whose both sides are valid and of the same type, i.e.
2220                 * either in-place edit or rename/copy edit.
2221                 */
2222                else if (DIFF_PAIR_RENAME(p)) {
2223                        if (p->source_stays) {
2224                                p->status = DIFF_STATUS_COPIED;
2225                                continue;
2226                        }
2227                        /* See if there is some other filepair that
2228                         * copies from the same source as us.  If so
2229                         * we are a copy.  Otherwise we are either a
2230                         * copy if the path stays, or a rename if it
2231                         * does not, but we already handled "stays" case.
2232                         */
2233                        for (j = i + 1; j < q->nr; j++) {
2234                                pp = q->queue[j];
2235                                if (strcmp(pp->one->path, p->one->path))
2236                                        continue; /* not us */
2237                                if (!DIFF_PAIR_RENAME(pp))
2238                                        continue; /* not a rename/copy */
2239                                /* pp is a rename/copy from the same source */
2240                                p->status = DIFF_STATUS_COPIED;
2241                                break;
2242                        }
2243                        if (!p->status)
2244                                p->status = DIFF_STATUS_RENAMED;
2245                }
2246                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
2247                         p->one->mode != p->two->mode)
2248                        p->status = DIFF_STATUS_MODIFIED;
2249                else {
2250                        /* This is a "no-change" entry and should not
2251                         * happen anymore, but prepare for broken callers.
2252                         */
2253                        error("feeding unmodified %s to diffcore",
2254                              p->one->path);
2255                        p->status = DIFF_STATUS_UNKNOWN;
2256                }
2257        }
2258        diff_debug_queue("resolve-rename-copy done", q);
2259}
2260
2261static int check_pair_status(struct diff_filepair *p)
2262{
2263        switch (p->status) {
2264        case DIFF_STATUS_UNKNOWN:
2265                return 0;
2266        case 0:
2267                die("internal error in diff-resolve-rename-copy");
2268        default:
2269                return 1;
2270        }
2271}
2272
2273static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2274{
2275        int fmt = opt->output_format;
2276
2277        if (fmt & DIFF_FORMAT_CHECKDIFF)
2278                diff_flush_checkdiff(p, opt);
2279        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2280                diff_flush_raw(p, opt);
2281        else if (fmt & DIFF_FORMAT_NAME)
2282                diff_flush_name(p, opt->line_termination);
2283}
2284
2285static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2286{
2287        if (fs->mode)
2288                printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
2289        else
2290                printf(" %s %s\n", newdelete, fs->path);
2291}
2292
2293
2294static void show_mode_change(struct diff_filepair *p, int show_name)
2295{
2296        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2297                if (show_name)
2298                        printf(" mode change %06o => %06o %s\n",
2299                               p->one->mode, p->two->mode, p->two->path);
2300                else
2301                        printf(" mode change %06o => %06o\n",
2302                               p->one->mode, p->two->mode);
2303        }
2304}
2305
2306static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2307{
2308        const char *old, *new;
2309
2310        /* Find common prefix */
2311        old = p->one->path;
2312        new = p->two->path;
2313        while (1) {
2314                const char *slash_old, *slash_new;
2315                slash_old = strchr(old, '/');
2316                slash_new = strchr(new, '/');
2317                if (!slash_old ||
2318                    !slash_new ||
2319                    slash_old - old != slash_new - new ||
2320                    memcmp(old, new, slash_new - new))
2321                        break;
2322                old = slash_old + 1;
2323                new = slash_new + 1;
2324        }
2325        /* p->one->path thru old is the common prefix, and old and new
2326         * through the end of names are renames
2327         */
2328        if (old != p->one->path)
2329                printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2330                       (int)(old - p->one->path), p->one->path,
2331                       old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
2332        else
2333                printf(" %s %s => %s (%d%%)\n", renamecopy,
2334                       p->one->path, p->two->path,
2335                       (int)(0.5 + p->score * 100.0/MAX_SCORE));
2336        show_mode_change(p, 0);
2337}
2338
2339static void diff_summary(struct diff_filepair *p)
2340{
2341        switch(p->status) {
2342        case DIFF_STATUS_DELETED:
2343                show_file_mode_name("delete", p->one);
2344                break;
2345        case DIFF_STATUS_ADDED:
2346                show_file_mode_name("create", p->two);
2347                break;
2348        case DIFF_STATUS_COPIED:
2349                show_rename_copy("copy", p);
2350                break;
2351        case DIFF_STATUS_RENAMED:
2352                show_rename_copy("rename", p);
2353                break;
2354        default:
2355                if (p->score) {
2356                        printf(" rewrite %s (%d%%)\n", p->two->path,
2357                                (int)(0.5 + p->score * 100.0/MAX_SCORE));
2358                        show_mode_change(p, 0);
2359                } else  show_mode_change(p, 1);
2360                break;
2361        }
2362}
2363
2364struct patch_id_t {
2365        struct xdiff_emit_state xm;
2366        SHA_CTX *ctx;
2367        int patchlen;
2368};
2369
2370static int remove_space(char *line, int len)
2371{
2372        int i;
2373        char *dst = line;
2374        unsigned char c;
2375
2376        for (i = 0; i < len; i++)
2377                if (!isspace((c = line[i])))
2378                        *dst++ = c;
2379
2380        return dst - line;
2381}
2382
2383static void patch_id_consume(void *priv, char *line, unsigned long len)
2384{
2385        struct patch_id_t *data = priv;
2386        int new_len;
2387
2388        /* Ignore line numbers when computing the SHA1 of the patch */
2389        if (!strncmp(line, "@@ -", 4))
2390                return;
2391
2392        new_len = remove_space(line, len);
2393
2394        SHA1_Update(data->ctx, line, new_len);
2395        data->patchlen += new_len;
2396}
2397
2398/* returns 0 upon success, and writes result into sha1 */
2399static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2400{
2401        struct diff_queue_struct *q = &diff_queued_diff;
2402        int i;
2403        SHA_CTX ctx;
2404        struct patch_id_t data;
2405        char buffer[PATH_MAX * 4 + 20];
2406
2407        SHA1_Init(&ctx);
2408        memset(&data, 0, sizeof(struct patch_id_t));
2409        data.ctx = &ctx;
2410        data.xm.consume = patch_id_consume;
2411
2412        for (i = 0; i < q->nr; i++) {
2413                xpparam_t xpp;
2414                xdemitconf_t xecfg;
2415                xdemitcb_t ecb;
2416                mmfile_t mf1, mf2;
2417                struct diff_filepair *p = q->queue[i];
2418                int len1, len2;
2419
2420                if (p->status == 0)
2421                        return error("internal diff status error");
2422                if (p->status == DIFF_STATUS_UNKNOWN)
2423                        continue;
2424                if (diff_unmodified_pair(p))
2425                        continue;
2426                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2427                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2428                        continue;
2429                if (DIFF_PAIR_UNMERGED(p))
2430                        continue;
2431
2432                diff_fill_sha1_info(p->one);
2433                diff_fill_sha1_info(p->two);
2434                if (fill_mmfile(&mf1, p->one) < 0 ||
2435                                fill_mmfile(&mf2, p->two) < 0)
2436                        return error("unable to read files to diff");
2437
2438                /* Maybe hash p->two? into the patch id? */
2439                if (mmfile_is_binary(&mf2))
2440                        continue;
2441
2442                len1 = remove_space(p->one->path, strlen(p->one->path));
2443                len2 = remove_space(p->two->path, strlen(p->two->path));
2444                if (p->one->mode == 0)
2445                        len1 = snprintf(buffer, sizeof(buffer),
2446                                        "diff--gita/%.*sb/%.*s"
2447                                        "newfilemode%06o"
2448                                        "---/dev/null"
2449                                        "+++b/%.*s",
2450                                        len1, p->one->path,
2451                                        len2, p->two->path,
2452                                        p->two->mode,
2453                                        len2, p->two->path);
2454                else if (p->two->mode == 0)
2455                        len1 = snprintf(buffer, sizeof(buffer),
2456                                        "diff--gita/%.*sb/%.*s"
2457                                        "deletedfilemode%06o"
2458                                        "---a/%.*s"
2459                                        "+++/dev/null",
2460                                        len1, p->one->path,
2461                                        len2, p->two->path,
2462                                        p->one->mode,
2463                                        len1, p->one->path);
2464                else
2465                        len1 = snprintf(buffer, sizeof(buffer),
2466                                        "diff--gita/%.*sb/%.*s"
2467                                        "---a/%.*s"
2468                                        "+++b/%.*s",
2469                                        len1, p->one->path,
2470                                        len2, p->two->path,
2471                                        len1, p->one->path,
2472                                        len2, p->two->path);
2473                SHA1_Update(&ctx, buffer, len1);
2474
2475                xpp.flags = XDF_NEED_MINIMAL;
2476                xecfg.ctxlen = 3;
2477                xecfg.flags = XDL_EMIT_FUNCNAMES;
2478                ecb.outf = xdiff_outf;
2479                ecb.priv = &data;
2480                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2481        }
2482
2483        SHA1_Final(sha1, &ctx);
2484        return 0;
2485}
2486
2487int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2488{
2489        struct diff_queue_struct *q = &diff_queued_diff;
2490        int i;
2491        int result = diff_get_patch_id(options, sha1);
2492
2493        for (i = 0; i < q->nr; i++)
2494                diff_free_filepair(q->queue[i]);
2495
2496        free(q->queue);
2497        q->queue = NULL;
2498        q->nr = q->alloc = 0;
2499
2500        return result;
2501}
2502
2503static int is_summary_empty(const struct diff_queue_struct *q)
2504{
2505        int i;
2506
2507        for (i = 0; i < q->nr; i++) {
2508                const struct diff_filepair *p = q->queue[i];
2509
2510                switch (p->status) {
2511                case DIFF_STATUS_DELETED:
2512                case DIFF_STATUS_ADDED:
2513                case DIFF_STATUS_COPIED:
2514                case DIFF_STATUS_RENAMED:
2515                        return 0;
2516                default:
2517                        if (p->score)
2518                                return 0;
2519                        if (p->one->mode && p->two->mode &&
2520                            p->one->mode != p->two->mode)
2521                                return 0;
2522                        break;
2523                }
2524        }
2525        return 1;
2526}
2527
2528void diff_flush(struct diff_options *options)
2529{
2530        struct diff_queue_struct *q = &diff_queued_diff;
2531        int i, output_format = options->output_format;
2532        int separator = 0;
2533
2534        /*
2535         * Order: raw, stat, summary, patch
2536         * or:    name/name-status/checkdiff (other bits clear)
2537         */
2538        if (!q->nr)
2539                goto free_queue;
2540
2541        if (output_format & (DIFF_FORMAT_RAW |
2542                             DIFF_FORMAT_NAME |
2543                             DIFF_FORMAT_NAME_STATUS |
2544                             DIFF_FORMAT_CHECKDIFF)) {
2545                for (i = 0; i < q->nr; i++) {
2546                        struct diff_filepair *p = q->queue[i];
2547                        if (check_pair_status(p))
2548                                flush_one_pair(p, options);
2549                }
2550                separator++;
2551        }
2552
2553        if (output_format & DIFF_FORMAT_DIFFSTAT) {
2554                struct diffstat_t diffstat;
2555
2556                memset(&diffstat, 0, sizeof(struct diffstat_t));
2557                diffstat.xm.consume = diffstat_consume;
2558                for (i = 0; i < q->nr; i++) {
2559                        struct diff_filepair *p = q->queue[i];
2560                        if (check_pair_status(p))
2561                                diff_flush_stat(p, options, &diffstat);
2562                }
2563                show_stats(&diffstat);
2564                separator++;
2565        }
2566
2567        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2568                for (i = 0; i < q->nr; i++)
2569                        diff_summary(q->queue[i]);
2570                separator++;
2571        }
2572
2573        if (output_format & DIFF_FORMAT_PATCH) {
2574                if (separator) {
2575                        if (options->stat_sep) {
2576                                /* attach patch instead of inline */
2577                                fputs(options->stat_sep, stdout);
2578                        } else {
2579                                putchar(options->line_termination);
2580                        }
2581                }
2582
2583                for (i = 0; i < q->nr; i++) {
2584                        struct diff_filepair *p = q->queue[i];
2585                        if (check_pair_status(p))
2586                                diff_flush_patch(p, options);
2587                }
2588        }
2589
2590        for (i = 0; i < q->nr; i++)
2591                diff_free_filepair(q->queue[i]);
2592free_queue:
2593        free(q->queue);
2594        q->queue = NULL;
2595        q->nr = q->alloc = 0;
2596}
2597
2598static void diffcore_apply_filter(const char *filter)
2599{
2600        int i;
2601        struct diff_queue_struct *q = &diff_queued_diff;
2602        struct diff_queue_struct outq;
2603        outq.queue = NULL;
2604        outq.nr = outq.alloc = 0;
2605
2606        if (!filter)
2607                return;
2608
2609        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2610                int found;
2611                for (i = found = 0; !found && i < q->nr; i++) {
2612                        struct diff_filepair *p = q->queue[i];
2613                        if (((p->status == DIFF_STATUS_MODIFIED) &&
2614                             ((p->score &&
2615                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2616                              (!p->score &&
2617                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2618                            ((p->status != DIFF_STATUS_MODIFIED) &&
2619                             strchr(filter, p->status)))
2620                                found++;
2621                }
2622                if (found)
2623                        return;
2624
2625                /* otherwise we will clear the whole queue
2626                 * by copying the empty outq at the end of this
2627                 * function, but first clear the current entries
2628                 * in the queue.
2629                 */
2630                for (i = 0; i < q->nr; i++)
2631                        diff_free_filepair(q->queue[i]);
2632        }
2633        else {
2634                /* Only the matching ones */
2635                for (i = 0; i < q->nr; i++) {
2636                        struct diff_filepair *p = q->queue[i];
2637
2638                        if (((p->status == DIFF_STATUS_MODIFIED) &&
2639                             ((p->score &&
2640                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2641                              (!p->score &&
2642                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2643                            ((p->status != DIFF_STATUS_MODIFIED) &&
2644                             strchr(filter, p->status)))
2645                                diff_q(&outq, p);
2646                        else
2647                                diff_free_filepair(p);
2648                }
2649        }
2650        free(q->queue);
2651        *q = outq;
2652}
2653
2654void diffcore_std(struct diff_options *options)
2655{
2656        if (options->break_opt != -1)
2657                diffcore_break(options->break_opt);
2658        if (options->detect_rename)
2659                diffcore_rename(options);
2660        if (options->break_opt != -1)
2661                diffcore_merge_broken();
2662        if (options->pickaxe)
2663                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2664        if (options->orderfile)
2665                diffcore_order(options->orderfile);
2666        diff_resolve_rename_copy();
2667        diffcore_apply_filter(options->filter);
2668}
2669
2670
2671void diffcore_std_no_resolve(struct diff_options *options)
2672{
2673        if (options->pickaxe)
2674                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2675        if (options->orderfile)
2676                diffcore_order(options->orderfile);
2677        diffcore_apply_filter(options->filter);
2678}
2679
2680void diff_addremove(struct diff_options *options,
2681                    int addremove, unsigned mode,
2682                    const unsigned char *sha1,
2683                    const char *base, const char *path)
2684{
2685        char concatpath[PATH_MAX];
2686        struct diff_filespec *one, *two;
2687
2688        /* This may look odd, but it is a preparation for
2689         * feeding "there are unchanged files which should
2690         * not produce diffs, but when you are doing copy
2691         * detection you would need them, so here they are"
2692         * entries to the diff-core.  They will be prefixed
2693         * with something like '=' or '*' (I haven't decided
2694         * which but should not make any difference).
2695         * Feeding the same new and old to diff_change() 
2696         * also has the same effect.
2697         * Before the final output happens, they are pruned after
2698         * merged into rename/copy pairs as appropriate.
2699         */
2700        if (options->reverse_diff)
2701                addremove = (addremove == '+' ? '-' :
2702                             addremove == '-' ? '+' : addremove);
2703
2704        if (!path) path = "";
2705        sprintf(concatpath, "%s%s", base, path);
2706        one = alloc_filespec(concatpath);
2707        two = alloc_filespec(concatpath);
2708
2709        if (addremove != '+')
2710                fill_filespec(one, sha1, mode);
2711        if (addremove != '-')
2712                fill_filespec(two, sha1, mode);
2713
2714        diff_queue(&diff_queued_diff, one, two);
2715}
2716
2717void diff_change(struct diff_options *options,
2718                 unsigned old_mode, unsigned new_mode,
2719                 const unsigned char *old_sha1,
2720                 const unsigned char *new_sha1,
2721                 const char *base, const char *path) 
2722{
2723        char concatpath[PATH_MAX];
2724        struct diff_filespec *one, *two;
2725
2726        if (options->reverse_diff) {
2727                unsigned tmp;
2728                const unsigned char *tmp_c;
2729                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2730                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2731        }
2732        if (!path) path = "";
2733        sprintf(concatpath, "%s%s", base, path);
2734        one = alloc_filespec(concatpath);
2735        two = alloc_filespec(concatpath);
2736        fill_filespec(one, old_sha1, old_mode);
2737        fill_filespec(two, new_sha1, new_mode);
2738
2739        diff_queue(&diff_queued_diff, one, two);
2740}
2741
2742void diff_unmerge(struct diff_options *options,
2743                  const char *path)
2744{
2745        struct diff_filespec *one, *two;
2746        one = alloc_filespec(path);
2747        two = alloc_filespec(path);
2748        diff_queue(&diff_queued_diff, one, two);
2749}