diff.con commit Merge branch 'maint' (c9c3470)
   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 = 0;
  17static int diff_rename_limit_default = -1;
  18static int diff_use_color_default = 0;
  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(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        printf("GIT binary patch\n");
 853        /* We could do deflated delta, or we could do just deflated two,
 854         * whichever is smaller.
 855         */
 856        delta = NULL;
 857        deflated = deflate_it(two->ptr, two->size, &deflate_size);
 858        if (one->size && two->size) {
 859                delta = diff_delta(one->ptr, one->size,
 860                                   two->ptr, two->size,
 861                                   &delta_size, deflate_size);
 862                if (delta) {
 863                        void *to_free = delta;
 864                        orig_size = delta_size;
 865                        delta = deflate_it(delta, delta_size, &delta_size);
 866                        free(to_free);
 867                }
 868        }
 869
 870        if (delta && delta_size < deflate_size) {
 871                printf("delta %lu\n", orig_size);
 872                free(deflated);
 873                data = delta;
 874                data_size = delta_size;
 875        }
 876        else {
 877                printf("literal %lu\n", two->size);
 878                free(delta);
 879                data = deflated;
 880                data_size = deflate_size;
 881        }
 882
 883        /* emit data encoded in base85 */
 884        cp = data;
 885        while (data_size) {
 886                int bytes = (52 < data_size) ? 52 : data_size;
 887                char line[70];
 888                data_size -= bytes;
 889                if (bytes <= 26)
 890                        line[0] = bytes + 'A' - 1;
 891                else
 892                        line[0] = bytes - 26 + 'a' - 1;
 893                encode_85(line + 1, cp, bytes);
 894                cp = (char *) cp + bytes;
 895                puts(line);
 896        }
 897        printf("\n");
 898        free(data);
 899}
 900
 901#define FIRST_FEW_BYTES 8000
 902static int mmfile_is_binary(mmfile_t *mf)
 903{
 904        long sz = mf->size;
 905        if (FIRST_FEW_BYTES < sz)
 906                sz = FIRST_FEW_BYTES;
 907        return !!memchr(mf->ptr, 0, sz);
 908}
 909
 910static void builtin_diff(const char *name_a,
 911                         const char *name_b,
 912                         struct diff_filespec *one,
 913                         struct diff_filespec *two,
 914                         const char *xfrm_msg,
 915                         struct diff_options *o,
 916                         int complete_rewrite)
 917{
 918        mmfile_t mf1, mf2;
 919        const char *lbl[2];
 920        char *a_one, *b_two;
 921        const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
 922        const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
 923
 924        a_one = quote_two("a/", name_a);
 925        b_two = quote_two("b/", name_b);
 926        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 927        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 928        printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
 929        if (lbl[0][0] == '/') {
 930                /* /dev/null */
 931                printf("%snew file mode %06o%s\n", set, two->mode, reset);
 932                if (xfrm_msg && xfrm_msg[0])
 933                        printf("%s%s%s\n", set, xfrm_msg, reset);
 934        }
 935        else if (lbl[1][0] == '/') {
 936                printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
 937                if (xfrm_msg && xfrm_msg[0])
 938                        printf("%s%s%s\n", set, xfrm_msg, reset);
 939        }
 940        else {
 941                if (one->mode != two->mode) {
 942                        printf("%sold mode %06o%s\n", set, one->mode, reset);
 943                        printf("%snew mode %06o%s\n", set, two->mode, reset);
 944                }
 945                if (xfrm_msg && xfrm_msg[0])
 946                        printf("%s%s%s\n", set, xfrm_msg, reset);
 947                /*
 948                 * we do not run diff between different kind
 949                 * of objects.
 950                 */
 951                if ((one->mode ^ two->mode) & S_IFMT)
 952                        goto free_ab_and_return;
 953                if (complete_rewrite) {
 954                        emit_rewrite_diff(name_a, name_b, one, two);
 955                        goto free_ab_and_return;
 956                }
 957        }
 958
 959        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 960                die("unable to read files to diff");
 961
 962        if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
 963                /* Quite common confusing case */
 964                if (mf1.size == mf2.size &&
 965                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 966                        goto free_ab_and_return;
 967                if (o->binary)
 968                        emit_binary_diff(&mf1, &mf2);
 969                else
 970                        printf("Binary files %s and %s differ\n",
 971                               lbl[0], lbl[1]);
 972        }
 973        else {
 974                /* Crazy xdl interfaces.. */
 975                const char *diffopts = getenv("GIT_DIFF_OPTS");
 976                xpparam_t xpp;
 977                xdemitconf_t xecfg;
 978                xdemitcb_t ecb;
 979                struct emit_callback ecbdata;
 980
 981                memset(&ecbdata, 0, sizeof(ecbdata));
 982                ecbdata.label_path = lbl;
 983                ecbdata.color_diff = o->color_diff;
 984                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 985                xecfg.ctxlen = o->context;
 986                xecfg.flags = XDL_EMIT_FUNCNAMES;
 987                if (!diffopts)
 988                        ;
 989                else if (!strncmp(diffopts, "--unified=", 10))
 990                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 991                else if (!strncmp(diffopts, "-u", 2))
 992                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 993                ecb.outf = xdiff_outf;
 994                ecb.priv = &ecbdata;
 995                ecbdata.xm.consume = fn_out_consume;
 996                if (o->color_diff_words)
 997                        ecbdata.diff_words =
 998                                xcalloc(1, sizeof(struct diff_words_data));
 999                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1000                if (o->color_diff_words)
1001                        free_diff_words_data(&ecbdata);
1002        }
1003
1004 free_ab_and_return:
1005        free(a_one);
1006        free(b_two);
1007        return;
1008}
1009
1010static void builtin_diffstat(const char *name_a, const char *name_b,
1011                             struct diff_filespec *one,
1012                             struct diff_filespec *two,
1013                             struct diffstat_t *diffstat,
1014                             struct diff_options *o,
1015                             int complete_rewrite)
1016{
1017        mmfile_t mf1, mf2;
1018        struct diffstat_file *data;
1019
1020        data = diffstat_add(diffstat, name_a, name_b);
1021
1022        if (!one || !two) {
1023                data->is_unmerged = 1;
1024                return;
1025        }
1026        if (complete_rewrite) {
1027                diff_populate_filespec(one, 0);
1028                diff_populate_filespec(two, 0);
1029                data->deleted = count_lines(one->data, one->size);
1030                data->added = count_lines(two->data, two->size);
1031                return;
1032        }
1033        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1034                die("unable to read files to diff");
1035
1036        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
1037                data->is_binary = 1;
1038        else {
1039                /* Crazy xdl interfaces.. */
1040                xpparam_t xpp;
1041                xdemitconf_t xecfg;
1042                xdemitcb_t ecb;
1043
1044                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1045                xecfg.ctxlen = 0;
1046                xecfg.flags = 0;
1047                ecb.outf = xdiff_outf;
1048                ecb.priv = diffstat;
1049                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1050        }
1051}
1052
1053static void builtin_checkdiff(const char *name_a, const char *name_b,
1054                             struct diff_filespec *one,
1055                             struct diff_filespec *two)
1056{
1057        mmfile_t mf1, mf2;
1058        struct checkdiff_t data;
1059
1060        if (!two)
1061                return;
1062
1063        memset(&data, 0, sizeof(data));
1064        data.xm.consume = checkdiff_consume;
1065        data.filename = name_b ? name_b : name_a;
1066        data.lineno = 0;
1067
1068        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1069                die("unable to read files to diff");
1070
1071        if (mmfile_is_binary(&mf2))
1072                return;
1073        else {
1074                /* Crazy xdl interfaces.. */
1075                xpparam_t xpp;
1076                xdemitconf_t xecfg;
1077                xdemitcb_t ecb;
1078
1079                xpp.flags = XDF_NEED_MINIMAL;
1080                xecfg.ctxlen = 0;
1081                xecfg.flags = 0;
1082                ecb.outf = xdiff_outf;
1083                ecb.priv = &data;
1084                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1085        }
1086}
1087
1088struct diff_filespec *alloc_filespec(const char *path)
1089{
1090        int namelen = strlen(path);
1091        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1092
1093        memset(spec, 0, sizeof(*spec));
1094        spec->path = (char *)(spec + 1);
1095        memcpy(spec->path, path, namelen+1);
1096        return spec;
1097}
1098
1099void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1100                   unsigned short mode)
1101{
1102        if (mode) {
1103                spec->mode = canon_mode(mode);
1104                memcpy(spec->sha1, sha1, 20);
1105                spec->sha1_valid = !is_null_sha1(sha1);
1106        }
1107}
1108
1109/*
1110 * Given a name and sha1 pair, if the dircache tells us the file in
1111 * the work tree has that object contents, return true, so that
1112 * prepare_temp_file() does not have to inflate and extract.
1113 */
1114static int work_tree_matches(const char *name, const unsigned char *sha1)
1115{
1116        struct cache_entry *ce;
1117        struct stat st;
1118        int pos, len;
1119
1120        /* We do not read the cache ourselves here, because the
1121         * benchmark with my previous version that always reads cache
1122         * shows that it makes things worse for diff-tree comparing
1123         * two linux-2.6 kernel trees in an already checked out work
1124         * tree.  This is because most diff-tree comparisons deal with
1125         * only a small number of files, while reading the cache is
1126         * expensive for a large project, and its cost outweighs the
1127         * savings we get by not inflating the object to a temporary
1128         * file.  Practically, this code only helps when we are used
1129         * by diff-cache --cached, which does read the cache before
1130         * calling us.
1131         */
1132        if (!active_cache)
1133                return 0;
1134
1135        len = strlen(name);
1136        pos = cache_name_pos(name, len);
1137        if (pos < 0)
1138                return 0;
1139        ce = active_cache[pos];
1140        if ((lstat(name, &st) < 0) ||
1141            !S_ISREG(st.st_mode) || /* careful! */
1142            ce_match_stat(ce, &st, 0) ||
1143            memcmp(sha1, ce->sha1, 20))
1144                return 0;
1145        /* we return 1 only when we can stat, it is a regular file,
1146         * stat information matches, and sha1 recorded in the cache
1147         * matches.  I.e. we know the file in the work tree really is
1148         * the same as the <name, sha1> pair.
1149         */
1150        return 1;
1151}
1152
1153static struct sha1_size_cache {
1154        unsigned char sha1[20];
1155        unsigned long size;
1156} **sha1_size_cache;
1157static int sha1_size_cache_nr, sha1_size_cache_alloc;
1158
1159static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
1160                                                 int find_only,
1161                                                 unsigned long size)
1162{
1163        int first, last;
1164        struct sha1_size_cache *e;
1165
1166        first = 0;
1167        last = sha1_size_cache_nr;
1168        while (last > first) {
1169                int cmp, next = (last + first) >> 1;
1170                e = sha1_size_cache[next];
1171                cmp = memcmp(e->sha1, sha1, 20);
1172                if (!cmp)
1173                        return e;
1174                if (cmp < 0) {
1175                        last = next;
1176                        continue;
1177                }
1178                first = next+1;
1179        }
1180        /* not found */
1181        if (find_only)
1182                return NULL;
1183        /* insert to make it at "first" */
1184        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
1185                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
1186                sha1_size_cache = xrealloc(sha1_size_cache,
1187                                           sha1_size_cache_alloc *
1188                                           sizeof(*sha1_size_cache));
1189        }
1190        sha1_size_cache_nr++;
1191        if (first < sha1_size_cache_nr)
1192                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
1193                        (sha1_size_cache_nr - first - 1) *
1194                        sizeof(*sha1_size_cache));
1195        e = xmalloc(sizeof(struct sha1_size_cache));
1196        sha1_size_cache[first] = e;
1197        memcpy(e->sha1, sha1, 20);
1198        e->size = size;
1199        return e;
1200}
1201
1202/*
1203 * While doing rename detection and pickaxe operation, we may need to
1204 * grab the data for the blob (or file) for our own in-core comparison.
1205 * diff_filespec has data and size fields for this purpose.
1206 */
1207int diff_populate_filespec(struct diff_filespec *s, int size_only)
1208{
1209        int err = 0;
1210        if (!DIFF_FILE_VALID(s))
1211                die("internal error: asking to populate invalid file.");
1212        if (S_ISDIR(s->mode))
1213                return -1;
1214
1215        if (!use_size_cache)
1216                size_only = 0;
1217
1218        if (s->data)
1219                return err;
1220        if (!s->sha1_valid ||
1221            work_tree_matches(s->path, s->sha1)) {
1222                struct stat st;
1223                int fd;
1224                if (lstat(s->path, &st) < 0) {
1225                        if (errno == ENOENT) {
1226                        err_empty:
1227                                err = -1;
1228                        empty:
1229                                s->data = (char *)"";
1230                                s->size = 0;
1231                                return err;
1232                        }
1233                }
1234                s->size = st.st_size;
1235                if (!s->size)
1236                        goto empty;
1237                if (size_only)
1238                        return 0;
1239                if (S_ISLNK(st.st_mode)) {
1240                        int ret;
1241                        s->data = xmalloc(s->size);
1242                        s->should_free = 1;
1243                        ret = readlink(s->path, s->data, s->size);
1244                        if (ret < 0) {
1245                                free(s->data);
1246                                goto err_empty;
1247                        }
1248                        return 0;
1249                }
1250                fd = open(s->path, O_RDONLY);
1251                if (fd < 0)
1252                        goto err_empty;
1253                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1254                close(fd);
1255                if (s->data == MAP_FAILED)
1256                        goto err_empty;
1257                s->should_munmap = 1;
1258        }
1259        else {
1260                char type[20];
1261                struct sha1_size_cache *e;
1262
1263                if (size_only) {
1264                        e = locate_size_cache(s->sha1, 1, 0);
1265                        if (e) {
1266                                s->size = e->size;
1267                                return 0;
1268                        }
1269                        if (!sha1_object_info(s->sha1, type, &s->size))
1270                                locate_size_cache(s->sha1, 0, s->size);
1271                }
1272                else {
1273                        s->data = read_sha1_file(s->sha1, type, &s->size);
1274                        s->should_free = 1;
1275                }
1276        }
1277        return 0;
1278}
1279
1280void diff_free_filespec_data(struct diff_filespec *s)
1281{
1282        if (s->should_free)
1283                free(s->data);
1284        else if (s->should_munmap)
1285                munmap(s->data, s->size);
1286        s->should_free = s->should_munmap = 0;
1287        s->data = NULL;
1288        free(s->cnt_data);
1289        s->cnt_data = NULL;
1290}
1291
1292static void prep_temp_blob(struct diff_tempfile *temp,
1293                           void *blob,
1294                           unsigned long size,
1295                           const unsigned char *sha1,
1296                           int mode)
1297{
1298        int fd;
1299
1300        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1301        if (fd < 0)
1302                die("unable to create temp-file");
1303        if (write(fd, blob, size) != size)
1304                die("unable to write temp-file");
1305        close(fd);
1306        temp->name = temp->tmp_path;
1307        strcpy(temp->hex, sha1_to_hex(sha1));
1308        temp->hex[40] = 0;
1309        sprintf(temp->mode, "%06o", mode);
1310}
1311
1312static void prepare_temp_file(const char *name,
1313                              struct diff_tempfile *temp,
1314                              struct diff_filespec *one)
1315{
1316        if (!DIFF_FILE_VALID(one)) {
1317        not_a_valid_file:
1318                /* A '-' entry produces this for file-2, and
1319                 * a '+' entry produces this for file-1.
1320                 */
1321                temp->name = "/dev/null";
1322                strcpy(temp->hex, ".");
1323                strcpy(temp->mode, ".");
1324                return;
1325        }
1326
1327        if (!one->sha1_valid ||
1328            work_tree_matches(name, one->sha1)) {
1329                struct stat st;
1330                if (lstat(name, &st) < 0) {
1331                        if (errno == ENOENT)
1332                                goto not_a_valid_file;
1333                        die("stat(%s): %s", name, strerror(errno));
1334                }
1335                if (S_ISLNK(st.st_mode)) {
1336                        int ret;
1337                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1338                        if (sizeof(buf) <= st.st_size)
1339                                die("symlink too long: %s", name);
1340                        ret = readlink(name, buf, st.st_size);
1341                        if (ret < 0)
1342                                die("readlink(%s)", name);
1343                        prep_temp_blob(temp, buf, st.st_size,
1344                                       (one->sha1_valid ?
1345                                        one->sha1 : null_sha1),
1346                                       (one->sha1_valid ?
1347                                        one->mode : S_IFLNK));
1348                }
1349                else {
1350                        /* we can borrow from the file in the work tree */
1351                        temp->name = name;
1352                        if (!one->sha1_valid)
1353                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1354                        else
1355                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1356                        /* Even though we may sometimes borrow the
1357                         * contents from the work tree, we always want
1358                         * one->mode.  mode is trustworthy even when
1359                         * !(one->sha1_valid), as long as
1360                         * DIFF_FILE_VALID(one).
1361                         */
1362                        sprintf(temp->mode, "%06o", one->mode);
1363                }
1364                return;
1365        }
1366        else {
1367                if (diff_populate_filespec(one, 0))
1368                        die("cannot read data blob for %s", one->path);
1369                prep_temp_blob(temp, one->data, one->size,
1370                               one->sha1, one->mode);
1371        }
1372}
1373
1374static void remove_tempfile(void)
1375{
1376        int i;
1377
1378        for (i = 0; i < 2; i++)
1379                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1380                        unlink(diff_temp[i].name);
1381                        diff_temp[i].name = NULL;
1382                }
1383}
1384
1385static void remove_tempfile_on_signal(int signo)
1386{
1387        remove_tempfile();
1388        signal(SIGINT, SIG_DFL);
1389        raise(signo);
1390}
1391
1392static int spawn_prog(const char *pgm, const char **arg)
1393{
1394        pid_t pid;
1395        int status;
1396
1397        fflush(NULL);
1398        pid = fork();
1399        if (pid < 0)
1400                die("unable to fork");
1401        if (!pid) {
1402                execvp(pgm, (char *const*) arg);
1403                exit(255);
1404        }
1405
1406        while (waitpid(pid, &status, 0) < 0) {
1407                if (errno == EINTR)
1408                        continue;
1409                return -1;
1410        }
1411
1412        /* Earlier we did not check the exit status because
1413         * diff exits non-zero if files are different, and
1414         * we are not interested in knowing that.  It was a
1415         * mistake which made it harder to quit a diff-*
1416         * session that uses the git-apply-patch-script as
1417         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1418         * should also exit non-zero only when it wants to
1419         * abort the entire diff-* session.
1420         */
1421        if (WIFEXITED(status) && !WEXITSTATUS(status))
1422                return 0;
1423        return -1;
1424}
1425
1426/* An external diff command takes:
1427 *
1428 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1429 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1430 *
1431 */
1432static void run_external_diff(const char *pgm,
1433                              const char *name,
1434                              const char *other,
1435                              struct diff_filespec *one,
1436                              struct diff_filespec *two,
1437                              const char *xfrm_msg,
1438                              int complete_rewrite)
1439{
1440        const char *spawn_arg[10];
1441        struct diff_tempfile *temp = diff_temp;
1442        int retval;
1443        static int atexit_asked = 0;
1444        const char *othername;
1445        const char **arg = &spawn_arg[0];
1446
1447        othername = (other? other : name);
1448        if (one && two) {
1449                prepare_temp_file(name, &temp[0], one);
1450                prepare_temp_file(othername, &temp[1], two);
1451                if (! atexit_asked &&
1452                    (temp[0].name == temp[0].tmp_path ||
1453                     temp[1].name == temp[1].tmp_path)) {
1454                        atexit_asked = 1;
1455                        atexit(remove_tempfile);
1456                }
1457                signal(SIGINT, remove_tempfile_on_signal);
1458        }
1459
1460        if (one && two) {
1461                *arg++ = pgm;
1462                *arg++ = name;
1463                *arg++ = temp[0].name;
1464                *arg++ = temp[0].hex;
1465                *arg++ = temp[0].mode;
1466                *arg++ = temp[1].name;
1467                *arg++ = temp[1].hex;
1468                *arg++ = temp[1].mode;
1469                if (other) {
1470                        *arg++ = other;
1471                        *arg++ = xfrm_msg;
1472                }
1473        } else {
1474                *arg++ = pgm;
1475                *arg++ = name;
1476        }
1477        *arg = NULL;
1478        retval = spawn_prog(pgm, spawn_arg);
1479        remove_tempfile();
1480        if (retval) {
1481                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1482                exit(1);
1483        }
1484}
1485
1486static void run_diff_cmd(const char *pgm,
1487                         const char *name,
1488                         const char *other,
1489                         struct diff_filespec *one,
1490                         struct diff_filespec *two,
1491                         const char *xfrm_msg,
1492                         struct diff_options *o,
1493                         int complete_rewrite)
1494{
1495        if (pgm) {
1496                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1497                                  complete_rewrite);
1498                return;
1499        }
1500        if (one && two)
1501                builtin_diff(name, other ? other : name,
1502                             one, two, xfrm_msg, o, complete_rewrite);
1503        else
1504                printf("* Unmerged path %s\n", name);
1505}
1506
1507static void diff_fill_sha1_info(struct diff_filespec *one)
1508{
1509        if (DIFF_FILE_VALID(one)) {
1510                if (!one->sha1_valid) {
1511                        struct stat st;
1512                        if (lstat(one->path, &st) < 0)
1513                                die("stat %s", one->path);
1514                        if (index_path(one->sha1, one->path, &st, 0))
1515                                die("cannot hash %s\n", one->path);
1516                }
1517        }
1518        else
1519                memset(one->sha1, 0, 20);
1520}
1521
1522static void run_diff(struct diff_filepair *p, struct diff_options *o)
1523{
1524        const char *pgm = external_diff();
1525        char msg[PATH_MAX*2+300], *xfrm_msg;
1526        struct diff_filespec *one;
1527        struct diff_filespec *two;
1528        const char *name;
1529        const char *other;
1530        char *name_munged, *other_munged;
1531        int complete_rewrite = 0;
1532        int len;
1533
1534        if (DIFF_PAIR_UNMERGED(p)) {
1535                /* unmerged */
1536                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1537                return;
1538        }
1539
1540        name = p->one->path;
1541        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1542        name_munged = quote_one(name);
1543        other_munged = quote_one(other);
1544        one = p->one; two = p->two;
1545
1546        diff_fill_sha1_info(one);
1547        diff_fill_sha1_info(two);
1548
1549        len = 0;
1550        switch (p->status) {
1551        case DIFF_STATUS_COPIED:
1552                len += snprintf(msg + len, sizeof(msg) - len,
1553                                "similarity index %d%%\n"
1554                                "copy from %s\n"
1555                                "copy to %s\n",
1556                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1557                                name_munged, other_munged);
1558                break;
1559        case DIFF_STATUS_RENAMED:
1560                len += snprintf(msg + len, sizeof(msg) - len,
1561                                "similarity index %d%%\n"
1562                                "rename from %s\n"
1563                                "rename to %s\n",
1564                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1565                                name_munged, other_munged);
1566                break;
1567        case DIFF_STATUS_MODIFIED:
1568                if (p->score) {
1569                        len += snprintf(msg + len, sizeof(msg) - len,
1570                                        "dissimilarity index %d%%\n",
1571                                        (int)(0.5 + p->score *
1572                                              100.0/MAX_SCORE));
1573                        complete_rewrite = 1;
1574                        break;
1575                }
1576                /* fallthru */
1577        default:
1578                /* nothing */
1579                ;
1580        }
1581
1582        if (memcmp(one->sha1, two->sha1, 20)) {
1583                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1584
1585                len += snprintf(msg + len, sizeof(msg) - len,
1586                                "index %.*s..%.*s",
1587                                abbrev, sha1_to_hex(one->sha1),
1588                                abbrev, sha1_to_hex(two->sha1));
1589                if (one->mode == two->mode)
1590                        len += snprintf(msg + len, sizeof(msg) - len,
1591                                        " %06o", one->mode);
1592                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1593        }
1594
1595        if (len)
1596                msg[--len] = 0;
1597        xfrm_msg = len ? msg : NULL;
1598
1599        if (!pgm &&
1600            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1601            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1602                /* a filepair that changes between file and symlink
1603                 * needs to be split into deletion and creation.
1604                 */
1605                struct diff_filespec *null = alloc_filespec(two->path);
1606                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1607                free(null);
1608                null = alloc_filespec(one->path);
1609                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1610                free(null);
1611        }
1612        else
1613                run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1614                             complete_rewrite);
1615
1616        free(name_munged);
1617        free(other_munged);
1618}
1619
1620static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1621                         struct diffstat_t *diffstat)
1622{
1623        const char *name;
1624        const char *other;
1625        int complete_rewrite = 0;
1626
1627        if (DIFF_PAIR_UNMERGED(p)) {
1628                /* unmerged */
1629                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1630                return;
1631        }
1632
1633        name = p->one->path;
1634        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1635
1636        diff_fill_sha1_info(p->one);
1637        diff_fill_sha1_info(p->two);
1638
1639        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1640                complete_rewrite = 1;
1641        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1642}
1643
1644static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1645{
1646        const char *name;
1647        const char *other;
1648
1649        if (DIFF_PAIR_UNMERGED(p)) {
1650                /* unmerged */
1651                return;
1652        }
1653
1654        name = p->one->path;
1655        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1656
1657        diff_fill_sha1_info(p->one);
1658        diff_fill_sha1_info(p->two);
1659
1660        builtin_checkdiff(name, other, p->one, p->two);
1661}
1662
1663void diff_setup(struct diff_options *options)
1664{
1665        memset(options, 0, sizeof(*options));
1666        options->line_termination = '\n';
1667        options->break_opt = -1;
1668        options->rename_limit = -1;
1669        options->context = 3;
1670        options->msg_sep = "";
1671
1672        options->change = diff_change;
1673        options->add_remove = diff_addremove;
1674        options->color_diff = diff_use_color_default;
1675        options->detect_rename = diff_detect_rename_default;
1676}
1677
1678int diff_setup_done(struct diff_options *options)
1679{
1680        int count = 0;
1681
1682        if (options->output_format & DIFF_FORMAT_NAME)
1683                count++;
1684        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
1685                count++;
1686        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
1687                count++;
1688        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
1689                count++;
1690        if (count > 1)
1691                die("--name-only, --name-status, --check and -s are mutually exclusive");
1692
1693        if (options->find_copies_harder)
1694                options->detect_rename = DIFF_DETECT_COPY;
1695
1696        if (options->output_format & (DIFF_FORMAT_NAME |
1697                                      DIFF_FORMAT_NAME_STATUS |
1698                                      DIFF_FORMAT_CHECKDIFF |
1699                                      DIFF_FORMAT_NO_OUTPUT))
1700                options->output_format &= ~(DIFF_FORMAT_RAW |
1701                                            DIFF_FORMAT_DIFFSTAT |
1702                                            DIFF_FORMAT_SUMMARY |
1703                                            DIFF_FORMAT_PATCH);
1704
1705        /*
1706         * These cases always need recursive; we do not drop caller-supplied
1707         * recursive bits for other formats here.
1708         */
1709        if (options->output_format & (DIFF_FORMAT_PATCH |
1710                                      DIFF_FORMAT_DIFFSTAT |
1711                                      DIFF_FORMAT_CHECKDIFF))
1712                options->recursive = 1;
1713        /*
1714         * Also pickaxe would not work very well if you do not say recursive
1715         */
1716        if (options->pickaxe)
1717                options->recursive = 1;
1718
1719        if (options->detect_rename && options->rename_limit < 0)
1720                options->rename_limit = diff_rename_limit_default;
1721        if (options->setup & DIFF_SETUP_USE_CACHE) {
1722                if (!active_cache)
1723                        /* read-cache does not die even when it fails
1724                         * so it is safe for us to do this here.  Also
1725                         * it does not smudge active_cache or active_nr
1726                         * when it fails, so we do not have to worry about
1727                         * cleaning it up ourselves either.
1728                         */
1729                        read_cache();
1730        }
1731        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1732                use_size_cache = 1;
1733        if (options->abbrev <= 0 || 40 < options->abbrev)
1734                options->abbrev = 40; /* full */
1735
1736        return 0;
1737}
1738
1739static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1740{
1741        char c, *eq;
1742        int len;
1743
1744        if (*arg != '-')
1745                return 0;
1746        c = *++arg;
1747        if (!c)
1748                return 0;
1749        if (c == arg_short) {
1750                c = *++arg;
1751                if (!c)
1752                        return 1;
1753                if (val && isdigit(c)) {
1754                        char *end;
1755                        int n = strtoul(arg, &end, 10);
1756                        if (*end)
1757                                return 0;
1758                        *val = n;
1759                        return 1;
1760                }
1761                return 0;
1762        }
1763        if (c != '-')
1764                return 0;
1765        arg++;
1766        eq = strchr(arg, '=');
1767        if (eq)
1768                len = eq - arg;
1769        else
1770                len = strlen(arg);
1771        if (!len || strncmp(arg, arg_long, len))
1772                return 0;
1773        if (eq) {
1774                int n;
1775                char *end;
1776                if (!isdigit(*++eq))
1777                        return 0;
1778                n = strtoul(eq, &end, 10);
1779                if (*end)
1780                        return 0;
1781                *val = n;
1782        }
1783        return 1;
1784}
1785
1786int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1787{
1788        const char *arg = av[0];
1789        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1790                options->output_format |= DIFF_FORMAT_PATCH;
1791        else if (opt_arg(arg, 'U', "unified", &options->context))
1792                options->output_format |= DIFF_FORMAT_PATCH;
1793        else if (!strcmp(arg, "--raw"))
1794                options->output_format |= DIFF_FORMAT_RAW;
1795        else if (!strcmp(arg, "--patch-with-raw")) {
1796                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
1797        }
1798        else if (!strcmp(arg, "--stat"))
1799                options->output_format |= DIFF_FORMAT_DIFFSTAT;
1800        else if (!strcmp(arg, "--check"))
1801                options->output_format |= DIFF_FORMAT_CHECKDIFF;
1802        else if (!strcmp(arg, "--summary"))
1803                options->output_format |= DIFF_FORMAT_SUMMARY;
1804        else if (!strcmp(arg, "--patch-with-stat")) {
1805                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
1806        }
1807        else if (!strcmp(arg, "-z"))
1808                options->line_termination = 0;
1809        else if (!strncmp(arg, "-l", 2))
1810                options->rename_limit = strtoul(arg+2, NULL, 10);
1811        else if (!strcmp(arg, "--full-index"))
1812                options->full_index = 1;
1813        else if (!strcmp(arg, "--binary")) {
1814                options->output_format |= DIFF_FORMAT_PATCH;
1815                options->full_index = options->binary = 1;
1816        }
1817        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
1818                options->text = 1;
1819        }
1820        else if (!strcmp(arg, "--name-only"))
1821                options->output_format |= DIFF_FORMAT_NAME;
1822        else if (!strcmp(arg, "--name-status"))
1823                options->output_format |= DIFF_FORMAT_NAME_STATUS;
1824        else if (!strcmp(arg, "-R"))
1825                options->reverse_diff = 1;
1826        else if (!strncmp(arg, "-S", 2))
1827                options->pickaxe = arg + 2;
1828        else if (!strcmp(arg, "-s")) {
1829                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
1830        }
1831        else if (!strncmp(arg, "-O", 2))
1832                options->orderfile = arg + 2;
1833        else if (!strncmp(arg, "--diff-filter=", 14))
1834                options->filter = arg + 14;
1835        else if (!strcmp(arg, "--pickaxe-all"))
1836                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1837        else if (!strcmp(arg, "--pickaxe-regex"))
1838                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1839        else if (!strncmp(arg, "-B", 2)) {
1840                if ((options->break_opt =
1841                     diff_scoreopt_parse(arg)) == -1)
1842                        return -1;
1843        }
1844        else if (!strncmp(arg, "-M", 2)) {
1845                if ((options->rename_score =
1846                     diff_scoreopt_parse(arg)) == -1)
1847                        return -1;
1848                options->detect_rename = DIFF_DETECT_RENAME;
1849        }
1850        else if (!strncmp(arg, "-C", 2)) {
1851                if ((options->rename_score =
1852                     diff_scoreopt_parse(arg)) == -1)
1853                        return -1;
1854                options->detect_rename = DIFF_DETECT_COPY;
1855        }
1856        else if (!strcmp(arg, "--find-copies-harder"))
1857                options->find_copies_harder = 1;
1858        else if (!strcmp(arg, "--abbrev"))
1859                options->abbrev = DEFAULT_ABBREV;
1860        else if (!strncmp(arg, "--abbrev=", 9)) {
1861                options->abbrev = strtoul(arg + 9, NULL, 10);
1862                if (options->abbrev < MINIMUM_ABBREV)
1863                        options->abbrev = MINIMUM_ABBREV;
1864                else if (40 < options->abbrev)
1865                        options->abbrev = 40;
1866        }
1867        else if (!strcmp(arg, "--color"))
1868                options->color_diff = 1;
1869        else if (!strcmp(arg, "--no-color"))
1870                options->color_diff = 0;
1871        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
1872                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
1873        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
1874                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1875        else if (!strcmp(arg, "--color-words"))
1876                options->color_diff = options->color_diff_words = 1;
1877        else if (!strcmp(arg, "--no-renames"))
1878                options->detect_rename = 0;
1879        else
1880                return 0;
1881        return 1;
1882}
1883
1884static int parse_num(const char **cp_p)
1885{
1886        unsigned long num, scale;
1887        int ch, dot;
1888        const char *cp = *cp_p;
1889
1890        num = 0;
1891        scale = 1;
1892        dot = 0;
1893        for(;;) {
1894                ch = *cp;
1895                if ( !dot && ch == '.' ) {
1896                        scale = 1;
1897                        dot = 1;
1898                } else if ( ch == '%' ) {
1899                        scale = dot ? scale*100 : 100;
1900                        cp++;   /* % is always at the end */
1901                        break;
1902                } else if ( ch >= '0' && ch <= '9' ) {
1903                        if ( scale < 100000 ) {
1904                                scale *= 10;
1905                                num = (num*10) + (ch-'0');
1906                        }
1907                } else {
1908                        break;
1909                }
1910                cp++;
1911        }
1912        *cp_p = cp;
1913
1914        /* user says num divided by scale and we say internally that
1915         * is MAX_SCORE * num / scale.
1916         */
1917        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1918}
1919
1920int diff_scoreopt_parse(const char *opt)
1921{
1922        int opt1, opt2, cmd;
1923
1924        if (*opt++ != '-')
1925                return -1;
1926        cmd = *opt++;
1927        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1928                return -1; /* that is not a -M, -C nor -B option */
1929
1930        opt1 = parse_num(&opt);
1931        if (cmd != 'B')
1932                opt2 = 0;
1933        else {
1934                if (*opt == 0)
1935                        opt2 = 0;
1936                else if (*opt != '/')
1937                        return -1; /* we expect -B80/99 or -B80 */
1938                else {
1939                        opt++;
1940                        opt2 = parse_num(&opt);
1941                }
1942        }
1943        if (*opt != 0)
1944                return -1;
1945        return opt1 | (opt2 << 16);
1946}
1947
1948struct diff_queue_struct diff_queued_diff;
1949
1950void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1951{
1952        if (queue->alloc <= queue->nr) {
1953                queue->alloc = alloc_nr(queue->alloc);
1954                queue->queue = xrealloc(queue->queue,
1955                                        sizeof(dp) * queue->alloc);
1956        }
1957        queue->queue[queue->nr++] = dp;
1958}
1959
1960struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1961                                 struct diff_filespec *one,
1962                                 struct diff_filespec *two)
1963{
1964        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
1965        dp->one = one;
1966        dp->two = two;
1967        if (queue)
1968                diff_q(queue, dp);
1969        return dp;
1970}
1971
1972void diff_free_filepair(struct diff_filepair *p)
1973{
1974        diff_free_filespec_data(p->one);
1975        diff_free_filespec_data(p->two);
1976        free(p->one);
1977        free(p->two);
1978        free(p);
1979}
1980
1981/* This is different from find_unique_abbrev() in that
1982 * it stuffs the result with dots for alignment.
1983 */
1984const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1985{
1986        int abblen;
1987        const char *abbrev;
1988        if (len == 40)
1989                return sha1_to_hex(sha1);
1990
1991        abbrev = find_unique_abbrev(sha1, len);
1992        if (!abbrev)
1993                return sha1_to_hex(sha1);
1994        abblen = strlen(abbrev);
1995        if (abblen < 37) {
1996                static char hex[41];
1997                if (len < abblen && abblen <= len + 2)
1998                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1999                else
2000                        sprintf(hex, "%s...", abbrev);
2001                return hex;
2002        }
2003        return sha1_to_hex(sha1);
2004}
2005
2006static void diff_flush_raw(struct diff_filepair *p,
2007                           struct diff_options *options)
2008{
2009        int two_paths;
2010        char status[10];
2011        int abbrev = options->abbrev;
2012        const char *path_one, *path_two;
2013        int inter_name_termination = '\t';
2014        int line_termination = options->line_termination;
2015
2016        if (!line_termination)
2017                inter_name_termination = 0;
2018
2019        path_one = p->one->path;
2020        path_two = p->two->path;
2021        if (line_termination) {
2022                path_one = quote_one(path_one);
2023                path_two = quote_one(path_two);
2024        }
2025
2026        if (p->score)
2027                sprintf(status, "%c%03d", p->status,
2028                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
2029        else {
2030                status[0] = p->status;
2031                status[1] = 0;
2032        }
2033        switch (p->status) {
2034        case DIFF_STATUS_COPIED:
2035        case DIFF_STATUS_RENAMED:
2036                two_paths = 1;
2037                break;
2038        case DIFF_STATUS_ADDED:
2039        case DIFF_STATUS_DELETED:
2040                two_paths = 0;
2041                break;
2042        default:
2043                two_paths = 0;
2044                break;
2045        }
2046        if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
2047                printf(":%06o %06o %s ",
2048                       p->one->mode, p->two->mode,
2049                       diff_unique_abbrev(p->one->sha1, abbrev));
2050                printf("%s ",
2051                       diff_unique_abbrev(p->two->sha1, abbrev));
2052        }
2053        printf("%s%c%s", status, inter_name_termination, path_one);
2054        if (two_paths)
2055                printf("%c%s", inter_name_termination, path_two);
2056        putchar(line_termination);
2057        if (path_one != p->one->path)
2058                free((void*)path_one);
2059        if (path_two != p->two->path)
2060                free((void*)path_two);
2061}
2062
2063static void diff_flush_name(struct diff_filepair *p, int line_termination)
2064{
2065        char *path = p->two->path;
2066
2067        if (line_termination)
2068                path = quote_one(p->two->path);
2069        printf("%s%c", path, line_termination);
2070        if (p->two->path != path)
2071                free(path);
2072}
2073
2074int diff_unmodified_pair(struct diff_filepair *p)
2075{
2076        /* This function is written stricter than necessary to support
2077         * the currently implemented transformers, but the idea is to
2078         * let transformers to produce diff_filepairs any way they want,
2079         * and filter and clean them up here before producing the output.
2080         */
2081        struct diff_filespec *one, *two;
2082
2083        if (DIFF_PAIR_UNMERGED(p))
2084                return 0; /* unmerged is interesting */
2085
2086        one = p->one;
2087        two = p->two;
2088
2089        /* deletion, addition, mode or type change
2090         * and rename are all interesting.
2091         */
2092        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2093            DIFF_PAIR_MODE_CHANGED(p) ||
2094            strcmp(one->path, two->path))
2095                return 0;
2096
2097        /* both are valid and point at the same path.  that is, we are
2098         * dealing with a change.
2099         */
2100        if (one->sha1_valid && two->sha1_valid &&
2101            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
2102                return 1; /* no change */
2103        if (!one->sha1_valid && !two->sha1_valid)
2104                return 1; /* both look at the same file on the filesystem. */
2105        return 0;
2106}
2107
2108static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2109{
2110        if (diff_unmodified_pair(p))
2111                return;
2112
2113        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2114            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2115                return; /* no tree diffs in patch format */
2116
2117        run_diff(p, o);
2118}
2119
2120static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2121                            struct diffstat_t *diffstat)
2122{
2123        if (diff_unmodified_pair(p))
2124                return;
2125
2126        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2127            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2128                return; /* no tree diffs in patch format */
2129
2130        run_diffstat(p, o, diffstat);
2131}
2132
2133static void diff_flush_checkdiff(struct diff_filepair *p,
2134                struct diff_options *o)
2135{
2136        if (diff_unmodified_pair(p))
2137                return;
2138
2139        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2140            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2141                return; /* no tree diffs in patch format */
2142
2143        run_checkdiff(p, o);
2144}
2145
2146int diff_queue_is_empty(void)
2147{
2148        struct diff_queue_struct *q = &diff_queued_diff;
2149        int i;
2150        for (i = 0; i < q->nr; i++)
2151                if (!diff_unmodified_pair(q->queue[i]))
2152                        return 0;
2153        return 1;
2154}
2155
2156#if DIFF_DEBUG
2157void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2158{
2159        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2160                x, one ? one : "",
2161                s->path,
2162                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2163                s->mode,
2164                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2165        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2166                x, one ? one : "",
2167                s->size, s->xfrm_flags);
2168}
2169
2170void diff_debug_filepair(const struct diff_filepair *p, int i)
2171{
2172        diff_debug_filespec(p->one, i, "one");
2173        diff_debug_filespec(p->two, i, "two");
2174        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
2175                p->score, p->status ? p->status : '?',
2176                p->source_stays, p->broken_pair);
2177}
2178
2179void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2180{
2181        int i;
2182        if (msg)
2183                fprintf(stderr, "%s\n", msg);
2184        fprintf(stderr, "q->nr = %d\n", q->nr);
2185        for (i = 0; i < q->nr; i++) {
2186                struct diff_filepair *p = q->queue[i];
2187                diff_debug_filepair(p, i);
2188        }
2189}
2190#endif
2191
2192static void diff_resolve_rename_copy(void)
2193{
2194        int i, j;
2195        struct diff_filepair *p, *pp;
2196        struct diff_queue_struct *q = &diff_queued_diff;
2197
2198        diff_debug_queue("resolve-rename-copy", q);
2199
2200        for (i = 0; i < q->nr; i++) {
2201                p = q->queue[i];
2202                p->status = 0; /* undecided */
2203                if (DIFF_PAIR_UNMERGED(p))
2204                        p->status = DIFF_STATUS_UNMERGED;
2205                else if (!DIFF_FILE_VALID(p->one))
2206                        p->status = DIFF_STATUS_ADDED;
2207                else if (!DIFF_FILE_VALID(p->two))
2208                        p->status = DIFF_STATUS_DELETED;
2209                else if (DIFF_PAIR_TYPE_CHANGED(p))
2210                        p->status = DIFF_STATUS_TYPE_CHANGED;
2211
2212                /* from this point on, we are dealing with a pair
2213                 * whose both sides are valid and of the same type, i.e.
2214                 * either in-place edit or rename/copy edit.
2215                 */
2216                else if (DIFF_PAIR_RENAME(p)) {
2217                        if (p->source_stays) {
2218                                p->status = DIFF_STATUS_COPIED;
2219                                continue;
2220                        }
2221                        /* See if there is some other filepair that
2222                         * copies from the same source as us.  If so
2223                         * we are a copy.  Otherwise we are either a
2224                         * copy if the path stays, or a rename if it
2225                         * does not, but we already handled "stays" case.
2226                         */
2227                        for (j = i + 1; j < q->nr; j++) {
2228                                pp = q->queue[j];
2229                                if (strcmp(pp->one->path, p->one->path))
2230                                        continue; /* not us */
2231                                if (!DIFF_PAIR_RENAME(pp))
2232                                        continue; /* not a rename/copy */
2233                                /* pp is a rename/copy from the same source */
2234                                p->status = DIFF_STATUS_COPIED;
2235                                break;
2236                        }
2237                        if (!p->status)
2238                                p->status = DIFF_STATUS_RENAMED;
2239                }
2240                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
2241                         p->one->mode != p->two->mode)
2242                        p->status = DIFF_STATUS_MODIFIED;
2243                else {
2244                        /* This is a "no-change" entry and should not
2245                         * happen anymore, but prepare for broken callers.
2246                         */
2247                        error("feeding unmodified %s to diffcore",
2248                              p->one->path);
2249                        p->status = DIFF_STATUS_UNKNOWN;
2250                }
2251        }
2252        diff_debug_queue("resolve-rename-copy done", q);
2253}
2254
2255static int check_pair_status(struct diff_filepair *p)
2256{
2257        switch (p->status) {
2258        case DIFF_STATUS_UNKNOWN:
2259                return 0;
2260        case 0:
2261                die("internal error in diff-resolve-rename-copy");
2262        default:
2263                return 1;
2264        }
2265}
2266
2267static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2268{
2269        int fmt = opt->output_format;
2270
2271        if (fmt & DIFF_FORMAT_CHECKDIFF)
2272                diff_flush_checkdiff(p, opt);
2273        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2274                diff_flush_raw(p, opt);
2275        else if (fmt & DIFF_FORMAT_NAME)
2276                diff_flush_name(p, opt->line_termination);
2277}
2278
2279static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2280{
2281        if (fs->mode)
2282                printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
2283        else
2284                printf(" %s %s\n", newdelete, fs->path);
2285}
2286
2287
2288static void show_mode_change(struct diff_filepair *p, int show_name)
2289{
2290        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2291                if (show_name)
2292                        printf(" mode change %06o => %06o %s\n",
2293                               p->one->mode, p->two->mode, p->two->path);
2294                else
2295                        printf(" mode change %06o => %06o\n",
2296                               p->one->mode, p->two->mode);
2297        }
2298}
2299
2300static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2301{
2302        const char *old, *new;
2303
2304        /* Find common prefix */
2305        old = p->one->path;
2306        new = p->two->path;
2307        while (1) {
2308                const char *slash_old, *slash_new;
2309                slash_old = strchr(old, '/');
2310                slash_new = strchr(new, '/');
2311                if (!slash_old ||
2312                    !slash_new ||
2313                    slash_old - old != slash_new - new ||
2314                    memcmp(old, new, slash_new - new))
2315                        break;
2316                old = slash_old + 1;
2317                new = slash_new + 1;
2318        }
2319        /* p->one->path thru old is the common prefix, and old and new
2320         * through the end of names are renames
2321         */
2322        if (old != p->one->path)
2323                printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2324                       (int)(old - p->one->path), p->one->path,
2325                       old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
2326        else
2327                printf(" %s %s => %s (%d%%)\n", renamecopy,
2328                       p->one->path, p->two->path,
2329                       (int)(0.5 + p->score * 100.0/MAX_SCORE));
2330        show_mode_change(p, 0);
2331}
2332
2333static void diff_summary(struct diff_filepair *p)
2334{
2335        switch(p->status) {
2336        case DIFF_STATUS_DELETED:
2337                show_file_mode_name("delete", p->one);
2338                break;
2339        case DIFF_STATUS_ADDED:
2340                show_file_mode_name("create", p->two);
2341                break;
2342        case DIFF_STATUS_COPIED:
2343                show_rename_copy("copy", p);
2344                break;
2345        case DIFF_STATUS_RENAMED:
2346                show_rename_copy("rename", p);
2347                break;
2348        default:
2349                if (p->score) {
2350                        printf(" rewrite %s (%d%%)\n", p->two->path,
2351                                (int)(0.5 + p->score * 100.0/MAX_SCORE));
2352                        show_mode_change(p, 0);
2353                } else  show_mode_change(p, 1);
2354                break;
2355        }
2356}
2357
2358struct patch_id_t {
2359        struct xdiff_emit_state xm;
2360        SHA_CTX *ctx;
2361        int patchlen;
2362};
2363
2364static int remove_space(char *line, int len)
2365{
2366        int i;
2367        char *dst = line;
2368        unsigned char c;
2369
2370        for (i = 0; i < len; i++)
2371                if (!isspace((c = line[i])))
2372                        *dst++ = c;
2373
2374        return dst - line;
2375}
2376
2377static void patch_id_consume(void *priv, char *line, unsigned long len)
2378{
2379        struct patch_id_t *data = priv;
2380        int new_len;
2381
2382        /* Ignore line numbers when computing the SHA1 of the patch */
2383        if (!strncmp(line, "@@ -", 4))
2384                return;
2385
2386        new_len = remove_space(line, len);
2387
2388        SHA1_Update(data->ctx, line, new_len);
2389        data->patchlen += new_len;
2390}
2391
2392/* returns 0 upon success, and writes result into sha1 */
2393static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2394{
2395        struct diff_queue_struct *q = &diff_queued_diff;
2396        int i;
2397        SHA_CTX ctx;
2398        struct patch_id_t data;
2399        char buffer[PATH_MAX * 4 + 20];
2400
2401        SHA1_Init(&ctx);
2402        memset(&data, 0, sizeof(struct patch_id_t));
2403        data.ctx = &ctx;
2404        data.xm.consume = patch_id_consume;
2405
2406        for (i = 0; i < q->nr; i++) {
2407                xpparam_t xpp;
2408                xdemitconf_t xecfg;
2409                xdemitcb_t ecb;
2410                mmfile_t mf1, mf2;
2411                struct diff_filepair *p = q->queue[i];
2412                int len1, len2;
2413
2414                if (p->status == 0)
2415                        return error("internal diff status error");
2416                if (p->status == DIFF_STATUS_UNKNOWN)
2417                        continue;
2418                if (diff_unmodified_pair(p))
2419                        continue;
2420                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2421                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2422                        continue;
2423                if (DIFF_PAIR_UNMERGED(p))
2424                        continue;
2425
2426                diff_fill_sha1_info(p->one);
2427                diff_fill_sha1_info(p->two);
2428                if (fill_mmfile(&mf1, p->one) < 0 ||
2429                                fill_mmfile(&mf2, p->two) < 0)
2430                        return error("unable to read files to diff");
2431
2432                /* Maybe hash p->two? into the patch id? */
2433                if (mmfile_is_binary(&mf2))
2434                        continue;
2435
2436                len1 = remove_space(p->one->path, strlen(p->one->path));
2437                len2 = remove_space(p->two->path, strlen(p->two->path));
2438                if (p->one->mode == 0)
2439                        len1 = snprintf(buffer, sizeof(buffer),
2440                                        "diff--gita/%.*sb/%.*s"
2441                                        "newfilemode%06o"
2442                                        "---/dev/null"
2443                                        "+++b/%.*s",
2444                                        len1, p->one->path,
2445                                        len2, p->two->path,
2446                                        p->two->mode,
2447                                        len2, p->two->path);
2448                else if (p->two->mode == 0)
2449                        len1 = snprintf(buffer, sizeof(buffer),
2450                                        "diff--gita/%.*sb/%.*s"
2451                                        "deletedfilemode%06o"
2452                                        "---a/%.*s"
2453                                        "+++/dev/null",
2454                                        len1, p->one->path,
2455                                        len2, p->two->path,
2456                                        p->one->mode,
2457                                        len1, p->one->path);
2458                else
2459                        len1 = snprintf(buffer, sizeof(buffer),
2460                                        "diff--gita/%.*sb/%.*s"
2461                                        "---a/%.*s"
2462                                        "+++b/%.*s",
2463                                        len1, p->one->path,
2464                                        len2, p->two->path,
2465                                        len1, p->one->path,
2466                                        len2, p->two->path);
2467                SHA1_Update(&ctx, buffer, len1);
2468
2469                xpp.flags = XDF_NEED_MINIMAL;
2470                xecfg.ctxlen = 3;
2471                xecfg.flags = XDL_EMIT_FUNCNAMES;
2472                ecb.outf = xdiff_outf;
2473                ecb.priv = &data;
2474                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2475        }
2476
2477        SHA1_Final(sha1, &ctx);
2478        return 0;
2479}
2480
2481int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2482{
2483        struct diff_queue_struct *q = &diff_queued_diff;
2484        int i;
2485        int result = diff_get_patch_id(options, sha1);
2486
2487        for (i = 0; i < q->nr; i++)
2488                diff_free_filepair(q->queue[i]);
2489
2490        free(q->queue);
2491        q->queue = NULL;
2492        q->nr = q->alloc = 0;
2493
2494        return result;
2495}
2496
2497static int is_summary_empty(const struct diff_queue_struct *q)
2498{
2499        int i;
2500
2501        for (i = 0; i < q->nr; i++) {
2502                const struct diff_filepair *p = q->queue[i];
2503
2504                switch (p->status) {
2505                case DIFF_STATUS_DELETED:
2506                case DIFF_STATUS_ADDED:
2507                case DIFF_STATUS_COPIED:
2508                case DIFF_STATUS_RENAMED:
2509                        return 0;
2510                default:
2511                        if (p->score)
2512                                return 0;
2513                        if (p->one->mode && p->two->mode &&
2514                            p->one->mode != p->two->mode)
2515                                return 0;
2516                        break;
2517                }
2518        }
2519        return 1;
2520}
2521
2522void diff_flush(struct diff_options *options)
2523{
2524        struct diff_queue_struct *q = &diff_queued_diff;
2525        int i, output_format = options->output_format;
2526        int separator = 0;
2527
2528        /*
2529         * Order: raw, stat, summary, patch
2530         * or:    name/name-status/checkdiff (other bits clear)
2531         */
2532        if (!q->nr)
2533                goto free_queue;
2534
2535        if (output_format & (DIFF_FORMAT_RAW |
2536                             DIFF_FORMAT_NAME |
2537                             DIFF_FORMAT_NAME_STATUS |
2538                             DIFF_FORMAT_CHECKDIFF)) {
2539                for (i = 0; i < q->nr; i++) {
2540                        struct diff_filepair *p = q->queue[i];
2541                        if (check_pair_status(p))
2542                                flush_one_pair(p, options);
2543                }
2544                separator++;
2545        }
2546
2547        if (output_format & DIFF_FORMAT_DIFFSTAT) {
2548                struct diffstat_t diffstat;
2549
2550                memset(&diffstat, 0, sizeof(struct diffstat_t));
2551                diffstat.xm.consume = diffstat_consume;
2552                for (i = 0; i < q->nr; i++) {
2553                        struct diff_filepair *p = q->queue[i];
2554                        if (check_pair_status(p))
2555                                diff_flush_stat(p, options, &diffstat);
2556                }
2557                show_stats(&diffstat);
2558                separator++;
2559        }
2560
2561        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2562                for (i = 0; i < q->nr; i++)
2563                        diff_summary(q->queue[i]);
2564                separator++;
2565        }
2566
2567        if (output_format & DIFF_FORMAT_PATCH) {
2568                if (separator) {
2569                        if (options->stat_sep) {
2570                                /* attach patch instead of inline */
2571                                fputs(options->stat_sep, stdout);
2572                        } else {
2573                                putchar(options->line_termination);
2574                        }
2575                }
2576
2577                for (i = 0; i < q->nr; i++) {
2578                        struct diff_filepair *p = q->queue[i];
2579                        if (check_pair_status(p))
2580                                diff_flush_patch(p, options);
2581                }
2582        }
2583
2584        for (i = 0; i < q->nr; i++)
2585                diff_free_filepair(q->queue[i]);
2586free_queue:
2587        free(q->queue);
2588        q->queue = NULL;
2589        q->nr = q->alloc = 0;
2590}
2591
2592static void diffcore_apply_filter(const char *filter)
2593{
2594        int i;
2595        struct diff_queue_struct *q = &diff_queued_diff;
2596        struct diff_queue_struct outq;
2597        outq.queue = NULL;
2598        outq.nr = outq.alloc = 0;
2599
2600        if (!filter)
2601                return;
2602
2603        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2604                int found;
2605                for (i = found = 0; !found && i < q->nr; i++) {
2606                        struct diff_filepair *p = q->queue[i];
2607                        if (((p->status == DIFF_STATUS_MODIFIED) &&
2608                             ((p->score &&
2609                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2610                              (!p->score &&
2611                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2612                            ((p->status != DIFF_STATUS_MODIFIED) &&
2613                             strchr(filter, p->status)))
2614                                found++;
2615                }
2616                if (found)
2617                        return;
2618
2619                /* otherwise we will clear the whole queue
2620                 * by copying the empty outq at the end of this
2621                 * function, but first clear the current entries
2622                 * in the queue.
2623                 */
2624                for (i = 0; i < q->nr; i++)
2625                        diff_free_filepair(q->queue[i]);
2626        }
2627        else {
2628                /* Only the matching ones */
2629                for (i = 0; i < q->nr; i++) {
2630                        struct diff_filepair *p = q->queue[i];
2631
2632                        if (((p->status == DIFF_STATUS_MODIFIED) &&
2633                             ((p->score &&
2634                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2635                              (!p->score &&
2636                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2637                            ((p->status != DIFF_STATUS_MODIFIED) &&
2638                             strchr(filter, p->status)))
2639                                diff_q(&outq, p);
2640                        else
2641                                diff_free_filepair(p);
2642                }
2643        }
2644        free(q->queue);
2645        *q = outq;
2646}
2647
2648void diffcore_std(struct diff_options *options)
2649{
2650        if (options->break_opt != -1)
2651                diffcore_break(options->break_opt);
2652        if (options->detect_rename)
2653                diffcore_rename(options);
2654        if (options->break_opt != -1)
2655                diffcore_merge_broken();
2656        if (options->pickaxe)
2657                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2658        if (options->orderfile)
2659                diffcore_order(options->orderfile);
2660        diff_resolve_rename_copy();
2661        diffcore_apply_filter(options->filter);
2662}
2663
2664
2665void diffcore_std_no_resolve(struct diff_options *options)
2666{
2667        if (options->pickaxe)
2668                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2669        if (options->orderfile)
2670                diffcore_order(options->orderfile);
2671        diffcore_apply_filter(options->filter);
2672}
2673
2674void diff_addremove(struct diff_options *options,
2675                    int addremove, unsigned mode,
2676                    const unsigned char *sha1,
2677                    const char *base, const char *path)
2678{
2679        char concatpath[PATH_MAX];
2680        struct diff_filespec *one, *two;
2681
2682        /* This may look odd, but it is a preparation for
2683         * feeding "there are unchanged files which should
2684         * not produce diffs, but when you are doing copy
2685         * detection you would need them, so here they are"
2686         * entries to the diff-core.  They will be prefixed
2687         * with something like '=' or '*' (I haven't decided
2688         * which but should not make any difference).
2689         * Feeding the same new and old to diff_change() 
2690         * also has the same effect.
2691         * Before the final output happens, they are pruned after
2692         * merged into rename/copy pairs as appropriate.
2693         */
2694        if (options->reverse_diff)
2695                addremove = (addremove == '+' ? '-' :
2696                             addremove == '-' ? '+' : addremove);
2697
2698        if (!path) path = "";
2699        sprintf(concatpath, "%s%s", base, path);
2700        one = alloc_filespec(concatpath);
2701        two = alloc_filespec(concatpath);
2702
2703        if (addremove != '+')
2704                fill_filespec(one, sha1, mode);
2705        if (addremove != '-')
2706                fill_filespec(two, sha1, mode);
2707
2708        diff_queue(&diff_queued_diff, one, two);
2709}
2710
2711void diff_change(struct diff_options *options,
2712                 unsigned old_mode, unsigned new_mode,
2713                 const unsigned char *old_sha1,
2714                 const unsigned char *new_sha1,
2715                 const char *base, const char *path) 
2716{
2717        char concatpath[PATH_MAX];
2718        struct diff_filespec *one, *two;
2719
2720        if (options->reverse_diff) {
2721                unsigned tmp;
2722                const unsigned char *tmp_c;
2723                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2724                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2725        }
2726        if (!path) path = "";
2727        sprintf(concatpath, "%s%s", base, path);
2728        one = alloc_filespec(concatpath);
2729        two = alloc_filespec(concatpath);
2730        fill_filespec(one, old_sha1, old_mode);
2731        fill_filespec(two, new_sha1, new_mode);
2732
2733        diff_queue(&diff_queued_diff, one, two);
2734}
2735
2736void diff_unmerge(struct diff_options *options,
2737                  const char *path)
2738{
2739        struct diff_filespec *one, *two;
2740        one = alloc_filespec(path);
2741        two = alloc_filespec(path);
2742        diff_queue(&diff_queued_diff, one, two);
2743}