diff.con commit Merge branch 'mk/old-expat' (bfc1f6a)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18#include "string-list.h"
  19
  20#ifdef NO_FAST_WORKING_DIRECTORY
  21#define FAST_WORKING_DIRECTORY 0
  22#else
  23#define FAST_WORKING_DIRECTORY 1
  24#endif
  25
  26static int diff_detect_rename_default;
  27static int diff_rename_limit_default = 400;
  28static int diff_suppress_blank_empty;
  29static int diff_use_color_default = -1;
  30static int diff_context_default = 3;
  31static const char *diff_word_regex_cfg;
  32static const char *external_diff_cmd_cfg;
  33int diff_auto_refresh_index = 1;
  34static int diff_mnemonic_prefix;
  35static int diff_no_prefix;
  36static int diff_stat_graph_width;
  37static int diff_dirstat_permille_default = 30;
  38static struct diff_options default_diff_options;
  39
  40static char diff_colors[][COLOR_MAXLEN] = {
  41        GIT_COLOR_RESET,
  42        GIT_COLOR_NORMAL,       /* PLAIN */
  43        GIT_COLOR_BOLD,         /* METAINFO */
  44        GIT_COLOR_CYAN,         /* FRAGINFO */
  45        GIT_COLOR_RED,          /* OLD */
  46        GIT_COLOR_GREEN,        /* NEW */
  47        GIT_COLOR_YELLOW,       /* COMMIT */
  48        GIT_COLOR_BG_RED,       /* WHITESPACE */
  49        GIT_COLOR_NORMAL,       /* FUNCINFO */
  50};
  51
  52static int parse_diff_color_slot(const char *var, int ofs)
  53{
  54        if (!strcasecmp(var+ofs, "plain"))
  55                return DIFF_PLAIN;
  56        if (!strcasecmp(var+ofs, "meta"))
  57                return DIFF_METAINFO;
  58        if (!strcasecmp(var+ofs, "frag"))
  59                return DIFF_FRAGINFO;
  60        if (!strcasecmp(var+ofs, "old"))
  61                return DIFF_FILE_OLD;
  62        if (!strcasecmp(var+ofs, "new"))
  63                return DIFF_FILE_NEW;
  64        if (!strcasecmp(var+ofs, "commit"))
  65                return DIFF_COMMIT;
  66        if (!strcasecmp(var+ofs, "whitespace"))
  67                return DIFF_WHITESPACE;
  68        if (!strcasecmp(var+ofs, "func"))
  69                return DIFF_FUNCINFO;
  70        return -1;
  71}
  72
  73static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  74                                struct strbuf *errmsg)
  75{
  76        char *params_copy = xstrdup(params_string);
  77        struct string_list params = STRING_LIST_INIT_NODUP;
  78        int ret = 0;
  79        int i;
  80
  81        if (*params_copy)
  82                string_list_split_in_place(&params, params_copy, ',', -1);
  83        for (i = 0; i < params.nr; i++) {
  84                const char *p = params.items[i].string;
  85                if (!strcmp(p, "changes")) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  88                } else if (!strcmp(p, "lines")) {
  89                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  90                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  91                } else if (!strcmp(p, "files")) {
  92                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  93                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  94                } else if (!strcmp(p, "noncumulative")) {
  95                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  96                } else if (!strcmp(p, "cumulative")) {
  97                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  98                } else if (isdigit(*p)) {
  99                        char *end;
 100                        int permille = strtoul(p, &end, 10) * 10;
 101                        if (*end == '.' && isdigit(*++end)) {
 102                                /* only use first digit */
 103                                permille += *end - '0';
 104                                /* .. and ignore any further digits */
 105                                while (isdigit(*++end))
 106                                        ; /* nothing */
 107                        }
 108                        if (!*end)
 109                                options->dirstat_permille = permille;
 110                        else {
 111                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 112                                            p);
 113                                ret++;
 114                        }
 115                } else {
 116                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 117                        ret++;
 118                }
 119
 120        }
 121        string_list_clear(&params, 0);
 122        free(params_copy);
 123        return ret;
 124}
 125
 126static int parse_submodule_params(struct diff_options *options, const char *value)
 127{
 128        if (!strcmp(value, "log"))
 129                DIFF_OPT_SET(options, SUBMODULE_LOG);
 130        else if (!strcmp(value, "short"))
 131                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 132        else
 133                return -1;
 134        return 0;
 135}
 136
 137static int git_config_rename(const char *var, const char *value)
 138{
 139        if (!value)
 140                return DIFF_DETECT_RENAME;
 141        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 142                return  DIFF_DETECT_COPY;
 143        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 144}
 145
 146/*
 147 * These are to give UI layer defaults.
 148 * The core-level commands such as git-diff-files should
 149 * never be affected by the setting of diff.renames
 150 * the user happens to have in the configuration file.
 151 */
 152int git_diff_ui_config(const char *var, const char *value, void *cb)
 153{
 154        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 155                diff_use_color_default = git_config_colorbool(var, value);
 156                return 0;
 157        }
 158        if (!strcmp(var, "diff.context")) {
 159                diff_context_default = git_config_int(var, value);
 160                if (diff_context_default < 0)
 161                        return -1;
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.renames")) {
 165                diff_detect_rename_default = git_config_rename(var, value);
 166                return 0;
 167        }
 168        if (!strcmp(var, "diff.autorefreshindex")) {
 169                diff_auto_refresh_index = git_config_bool(var, value);
 170                return 0;
 171        }
 172        if (!strcmp(var, "diff.mnemonicprefix")) {
 173                diff_mnemonic_prefix = git_config_bool(var, value);
 174                return 0;
 175        }
 176        if (!strcmp(var, "diff.noprefix")) {
 177                diff_no_prefix = git_config_bool(var, value);
 178                return 0;
 179        }
 180        if (!strcmp(var, "diff.statgraphwidth")) {
 181                diff_stat_graph_width = git_config_int(var, value);
 182                return 0;
 183        }
 184        if (!strcmp(var, "diff.external"))
 185                return git_config_string(&external_diff_cmd_cfg, var, value);
 186        if (!strcmp(var, "diff.wordregex"))
 187                return git_config_string(&diff_word_regex_cfg, var, value);
 188
 189        if (!strcmp(var, "diff.ignoresubmodules"))
 190                handle_ignore_submodules_arg(&default_diff_options, value);
 191
 192        if (!strcmp(var, "diff.submodule")) {
 193                if (parse_submodule_params(&default_diff_options, value))
 194                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 195                                value);
 196                return 0;
 197        }
 198
 199        if (git_color_config(var, value, cb) < 0)
 200                return -1;
 201
 202        return git_diff_basic_config(var, value, cb);
 203}
 204
 205int git_diff_basic_config(const char *var, const char *value, void *cb)
 206{
 207        if (!strcmp(var, "diff.renamelimit")) {
 208                diff_rename_limit_default = git_config_int(var, value);
 209                return 0;
 210        }
 211
 212        if (userdiff_config(var, value) < 0)
 213                return -1;
 214
 215        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 216                int slot = parse_diff_color_slot(var, 11);
 217                if (slot < 0)
 218                        return 0;
 219                if (!value)
 220                        return config_error_nonbool(var);
 221                color_parse(value, var, diff_colors[slot]);
 222                return 0;
 223        }
 224
 225        /* like GNU diff's --suppress-blank-empty option  */
 226        if (!strcmp(var, "diff.suppressblankempty") ||
 227                        /* for backwards compatibility */
 228                        !strcmp(var, "diff.suppress-blank-empty")) {
 229                diff_suppress_blank_empty = git_config_bool(var, value);
 230                return 0;
 231        }
 232
 233        if (!strcmp(var, "diff.dirstat")) {
 234                struct strbuf errmsg = STRBUF_INIT;
 235                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 236                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 237                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 238                                errmsg.buf);
 239                strbuf_release(&errmsg);
 240                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 241                return 0;
 242        }
 243
 244        if (!prefixcmp(var, "submodule."))
 245                return parse_submodule_config_option(var, value);
 246
 247        return git_default_config(var, value, cb);
 248}
 249
 250static char *quote_two(const char *one, const char *two)
 251{
 252        int need_one = quote_c_style(one, NULL, NULL, 1);
 253        int need_two = quote_c_style(two, NULL, NULL, 1);
 254        struct strbuf res = STRBUF_INIT;
 255
 256        if (need_one + need_two) {
 257                strbuf_addch(&res, '"');
 258                quote_c_style(one, &res, NULL, 1);
 259                quote_c_style(two, &res, NULL, 1);
 260                strbuf_addch(&res, '"');
 261        } else {
 262                strbuf_addstr(&res, one);
 263                strbuf_addstr(&res, two);
 264        }
 265        return strbuf_detach(&res, NULL);
 266}
 267
 268static const char *external_diff(void)
 269{
 270        static const char *external_diff_cmd = NULL;
 271        static int done_preparing = 0;
 272
 273        if (done_preparing)
 274                return external_diff_cmd;
 275        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 276        if (!external_diff_cmd)
 277                external_diff_cmd = external_diff_cmd_cfg;
 278        done_preparing = 1;
 279        return external_diff_cmd;
 280}
 281
 282static struct diff_tempfile {
 283        const char *name; /* filename external diff should read from */
 284        char hex[41];
 285        char mode[10];
 286        char tmp_path[PATH_MAX];
 287} diff_temp[2];
 288
 289typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 290
 291struct emit_callback {
 292        int color_diff;
 293        unsigned ws_rule;
 294        int blank_at_eof_in_preimage;
 295        int blank_at_eof_in_postimage;
 296        int lno_in_preimage;
 297        int lno_in_postimage;
 298        sane_truncate_fn truncate;
 299        const char **label_path;
 300        struct diff_words_data *diff_words;
 301        struct diff_options *opt;
 302        int *found_changesp;
 303        struct strbuf *header;
 304};
 305
 306static int count_lines(const char *data, int size)
 307{
 308        int count, ch, completely_empty = 1, nl_just_seen = 0;
 309        count = 0;
 310        while (0 < size--) {
 311                ch = *data++;
 312                if (ch == '\n') {
 313                        count++;
 314                        nl_just_seen = 1;
 315                        completely_empty = 0;
 316                }
 317                else {
 318                        nl_just_seen = 0;
 319                        completely_empty = 0;
 320                }
 321        }
 322        if (completely_empty)
 323                return 0;
 324        if (!nl_just_seen)
 325                count++; /* no trailing newline */
 326        return count;
 327}
 328
 329static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 330{
 331        if (!DIFF_FILE_VALID(one)) {
 332                mf->ptr = (char *)""; /* does not matter */
 333                mf->size = 0;
 334                return 0;
 335        }
 336        else if (diff_populate_filespec(one, 0))
 337                return -1;
 338
 339        mf->ptr = one->data;
 340        mf->size = one->size;
 341        return 0;
 342}
 343
 344/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 345static unsigned long diff_filespec_size(struct diff_filespec *one)
 346{
 347        if (!DIFF_FILE_VALID(one))
 348                return 0;
 349        diff_populate_filespec(one, 1);
 350        return one->size;
 351}
 352
 353static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 354{
 355        char *ptr = mf->ptr;
 356        long size = mf->size;
 357        int cnt = 0;
 358
 359        if (!size)
 360                return cnt;
 361        ptr += size - 1; /* pointing at the very end */
 362        if (*ptr != '\n')
 363                ; /* incomplete line */
 364        else
 365                ptr--; /* skip the last LF */
 366        while (mf->ptr < ptr) {
 367                char *prev_eol;
 368                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 369                        if (*prev_eol == '\n')
 370                                break;
 371                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 372                        break;
 373                cnt++;
 374                ptr = prev_eol - 1;
 375        }
 376        return cnt;
 377}
 378
 379static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 380                               struct emit_callback *ecbdata)
 381{
 382        int l1, l2, at;
 383        unsigned ws_rule = ecbdata->ws_rule;
 384        l1 = count_trailing_blank(mf1, ws_rule);
 385        l2 = count_trailing_blank(mf2, ws_rule);
 386        if (l2 <= l1) {
 387                ecbdata->blank_at_eof_in_preimage = 0;
 388                ecbdata->blank_at_eof_in_postimage = 0;
 389                return;
 390        }
 391        at = count_lines(mf1->ptr, mf1->size);
 392        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 393
 394        at = count_lines(mf2->ptr, mf2->size);
 395        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 396}
 397
 398static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 399                        int first, const char *line, int len)
 400{
 401        int has_trailing_newline, has_trailing_carriage_return;
 402        int nofirst;
 403        FILE *file = o->file;
 404
 405        fputs(diff_line_prefix(o), file);
 406
 407        if (len == 0) {
 408                has_trailing_newline = (first == '\n');
 409                has_trailing_carriage_return = (!has_trailing_newline &&
 410                                                (first == '\r'));
 411                nofirst = has_trailing_newline || has_trailing_carriage_return;
 412        } else {
 413                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 414                if (has_trailing_newline)
 415                        len--;
 416                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 417                if (has_trailing_carriage_return)
 418                        len--;
 419                nofirst = 0;
 420        }
 421
 422        if (len || !nofirst) {
 423                fputs(set, file);
 424                if (!nofirst)
 425                        fputc(first, file);
 426                fwrite(line, len, 1, file);
 427                fputs(reset, file);
 428        }
 429        if (has_trailing_carriage_return)
 430                fputc('\r', file);
 431        if (has_trailing_newline)
 432                fputc('\n', file);
 433}
 434
 435static void emit_line(struct diff_options *o, const char *set, const char *reset,
 436                      const char *line, int len)
 437{
 438        emit_line_0(o, set, reset, line[0], line+1, len-1);
 439}
 440
 441static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 442{
 443        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 444              ecbdata->blank_at_eof_in_preimage &&
 445              ecbdata->blank_at_eof_in_postimage &&
 446              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 447              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 448                return 0;
 449        return ws_blank_line(line, len, ecbdata->ws_rule);
 450}
 451
 452static void emit_add_line(const char *reset,
 453                          struct emit_callback *ecbdata,
 454                          const char *line, int len)
 455{
 456        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 457        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 458
 459        if (!*ws)
 460                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 461        else if (new_blank_line_at_eof(ecbdata, line, len))
 462                /* Blank line at EOF - paint '+' as well */
 463                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 464        else {
 465                /* Emit just the prefix, then the rest. */
 466                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 467                ws_check_emit(line, len, ecbdata->ws_rule,
 468                              ecbdata->opt->file, set, reset, ws);
 469        }
 470}
 471
 472static void emit_hunk_header(struct emit_callback *ecbdata,
 473                             const char *line, int len)
 474{
 475        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 476        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 477        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 478        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 479        static const char atat[2] = { '@', '@' };
 480        const char *cp, *ep;
 481        struct strbuf msgbuf = STRBUF_INIT;
 482        int org_len = len;
 483        int i = 1;
 484
 485        /*
 486         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 487         * it always is at least 10 bytes long.
 488         */
 489        if (len < 10 ||
 490            memcmp(line, atat, 2) ||
 491            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 492                emit_line(ecbdata->opt, plain, reset, line, len);
 493                return;
 494        }
 495        ep += 2; /* skip over @@ */
 496
 497        /* The hunk header in fraginfo color */
 498        strbuf_add(&msgbuf, frag, strlen(frag));
 499        strbuf_add(&msgbuf, line, ep - line);
 500        strbuf_add(&msgbuf, reset, strlen(reset));
 501
 502        /*
 503         * trailing "\r\n"
 504         */
 505        for ( ; i < 3; i++)
 506                if (line[len - i] == '\r' || line[len - i] == '\n')
 507                        len--;
 508
 509        /* blank before the func header */
 510        for (cp = ep; ep - line < len; ep++)
 511                if (*ep != ' ' && *ep != '\t')
 512                        break;
 513        if (ep != cp) {
 514                strbuf_add(&msgbuf, plain, strlen(plain));
 515                strbuf_add(&msgbuf, cp, ep - cp);
 516                strbuf_add(&msgbuf, reset, strlen(reset));
 517        }
 518
 519        if (ep < line + len) {
 520                strbuf_add(&msgbuf, func, strlen(func));
 521                strbuf_add(&msgbuf, ep, line + len - ep);
 522                strbuf_add(&msgbuf, reset, strlen(reset));
 523        }
 524
 525        strbuf_add(&msgbuf, line + len, org_len - len);
 526        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 527        strbuf_release(&msgbuf);
 528}
 529
 530static struct diff_tempfile *claim_diff_tempfile(void) {
 531        int i;
 532        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 533                if (!diff_temp[i].name)
 534                        return diff_temp + i;
 535        die("BUG: diff is failing to clean up its tempfiles");
 536}
 537
 538static int remove_tempfile_installed;
 539
 540static void remove_tempfile(void)
 541{
 542        int i;
 543        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 544                if (diff_temp[i].name == diff_temp[i].tmp_path)
 545                        unlink_or_warn(diff_temp[i].name);
 546                diff_temp[i].name = NULL;
 547        }
 548}
 549
 550static void remove_tempfile_on_signal(int signo)
 551{
 552        remove_tempfile();
 553        sigchain_pop(signo);
 554        raise(signo);
 555}
 556
 557static void print_line_count(FILE *file, int count)
 558{
 559        switch (count) {
 560        case 0:
 561                fprintf(file, "0,0");
 562                break;
 563        case 1:
 564                fprintf(file, "1");
 565                break;
 566        default:
 567                fprintf(file, "1,%d", count);
 568                break;
 569        }
 570}
 571
 572static void emit_rewrite_lines(struct emit_callback *ecb,
 573                               int prefix, const char *data, int size)
 574{
 575        const char *endp = NULL;
 576        static const char *nneof = " No newline at end of file\n";
 577        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 578        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 579
 580        while (0 < size) {
 581                int len;
 582
 583                endp = memchr(data, '\n', size);
 584                len = endp ? (endp - data + 1) : size;
 585                if (prefix != '+') {
 586                        ecb->lno_in_preimage++;
 587                        emit_line_0(ecb->opt, old, reset, '-',
 588                                    data, len);
 589                } else {
 590                        ecb->lno_in_postimage++;
 591                        emit_add_line(reset, ecb, data, len);
 592                }
 593                size -= len;
 594                data += len;
 595        }
 596        if (!endp) {
 597                const char *plain = diff_get_color(ecb->color_diff,
 598                                                   DIFF_PLAIN);
 599                putc('\n', ecb->opt->file);
 600                emit_line_0(ecb->opt, plain, reset, '\\',
 601                            nneof, strlen(nneof));
 602        }
 603}
 604
 605static void emit_rewrite_diff(const char *name_a,
 606                              const char *name_b,
 607                              struct diff_filespec *one,
 608                              struct diff_filespec *two,
 609                              struct userdiff_driver *textconv_one,
 610                              struct userdiff_driver *textconv_two,
 611                              struct diff_options *o)
 612{
 613        int lc_a, lc_b;
 614        const char *name_a_tab, *name_b_tab;
 615        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 616        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 617        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 618        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 619        const char *a_prefix, *b_prefix;
 620        char *data_one, *data_two;
 621        size_t size_one, size_two;
 622        struct emit_callback ecbdata;
 623        const char *line_prefix = diff_line_prefix(o);
 624
 625        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 626                a_prefix = o->b_prefix;
 627                b_prefix = o->a_prefix;
 628        } else {
 629                a_prefix = o->a_prefix;
 630                b_prefix = o->b_prefix;
 631        }
 632
 633        name_a += (*name_a == '/');
 634        name_b += (*name_b == '/');
 635        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 636        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 637
 638        strbuf_reset(&a_name);
 639        strbuf_reset(&b_name);
 640        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 641        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 642
 643        size_one = fill_textconv(textconv_one, one, &data_one);
 644        size_two = fill_textconv(textconv_two, two, &data_two);
 645
 646        memset(&ecbdata, 0, sizeof(ecbdata));
 647        ecbdata.color_diff = want_color(o->use_color);
 648        ecbdata.found_changesp = &o->found_changes;
 649        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 650        ecbdata.opt = o;
 651        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 652                mmfile_t mf1, mf2;
 653                mf1.ptr = (char *)data_one;
 654                mf2.ptr = (char *)data_two;
 655                mf1.size = size_one;
 656                mf2.size = size_two;
 657                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 658        }
 659        ecbdata.lno_in_preimage = 1;
 660        ecbdata.lno_in_postimage = 1;
 661
 662        lc_a = count_lines(data_one, size_one);
 663        lc_b = count_lines(data_two, size_two);
 664        fprintf(o->file,
 665                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 666                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 667                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 668                line_prefix, fraginfo);
 669        if (!o->irreversible_delete)
 670                print_line_count(o->file, lc_a);
 671        else
 672                fprintf(o->file, "?,?");
 673        fprintf(o->file, " +");
 674        print_line_count(o->file, lc_b);
 675        fprintf(o->file, " @@%s\n", reset);
 676        if (lc_a && !o->irreversible_delete)
 677                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 678        if (lc_b)
 679                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 680        if (textconv_one)
 681                free((char *)data_one);
 682        if (textconv_two)
 683                free((char *)data_two);
 684}
 685
 686struct diff_words_buffer {
 687        mmfile_t text;
 688        long alloc;
 689        struct diff_words_orig {
 690                const char *begin, *end;
 691        } *orig;
 692        int orig_nr, orig_alloc;
 693};
 694
 695static void diff_words_append(char *line, unsigned long len,
 696                struct diff_words_buffer *buffer)
 697{
 698        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 699        line++;
 700        len--;
 701        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 702        buffer->text.size += len;
 703        buffer->text.ptr[buffer->text.size] = '\0';
 704}
 705
 706struct diff_words_style_elem {
 707        const char *prefix;
 708        const char *suffix;
 709        const char *color; /* NULL; filled in by the setup code if
 710                            * color is enabled */
 711};
 712
 713struct diff_words_style {
 714        enum diff_words_type type;
 715        struct diff_words_style_elem new, old, ctx;
 716        const char *newline;
 717};
 718
 719static struct diff_words_style diff_words_styles[] = {
 720        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 721        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 722        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 723};
 724
 725struct diff_words_data {
 726        struct diff_words_buffer minus, plus;
 727        const char *current_plus;
 728        int last_minus;
 729        struct diff_options *opt;
 730        regex_t *word_regex;
 731        enum diff_words_type type;
 732        struct diff_words_style *style;
 733};
 734
 735static int fn_out_diff_words_write_helper(FILE *fp,
 736                                          struct diff_words_style_elem *st_el,
 737                                          const char *newline,
 738                                          size_t count, const char *buf,
 739                                          const char *line_prefix)
 740{
 741        int print = 0;
 742
 743        while (count) {
 744                char *p = memchr(buf, '\n', count);
 745                if (print)
 746                        fputs(line_prefix, fp);
 747                if (p != buf) {
 748                        if (st_el->color && fputs(st_el->color, fp) < 0)
 749                                return -1;
 750                        if (fputs(st_el->prefix, fp) < 0 ||
 751                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 752                            fputs(st_el->suffix, fp) < 0)
 753                                return -1;
 754                        if (st_el->color && *st_el->color
 755                            && fputs(GIT_COLOR_RESET, fp) < 0)
 756                                return -1;
 757                }
 758                if (!p)
 759                        return 0;
 760                if (fputs(newline, fp) < 0)
 761                        return -1;
 762                count -= p + 1 - buf;
 763                buf = p + 1;
 764                print = 1;
 765        }
 766        return 0;
 767}
 768
 769/*
 770 * '--color-words' algorithm can be described as:
 771 *
 772 *   1. collect a the minus/plus lines of a diff hunk, divided into
 773 *      minus-lines and plus-lines;
 774 *
 775 *   2. break both minus-lines and plus-lines into words and
 776 *      place them into two mmfile_t with one word for each line;
 777 *
 778 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 779 *
 780 * And for the common parts of the both file, we output the plus side text.
 781 * diff_words->current_plus is used to trace the current position of the plus file
 782 * which printed. diff_words->last_minus is used to trace the last minus word
 783 * printed.
 784 *
 785 * For '--graph' to work with '--color-words', we need to output the graph prefix
 786 * on each line of color words output. Generally, there are two conditions on
 787 * which we should output the prefix.
 788 *
 789 *   1. diff_words->last_minus == 0 &&
 790 *      diff_words->current_plus == diff_words->plus.text.ptr
 791 *
 792 *      that is: the plus text must start as a new line, and if there is no minus
 793 *      word printed, a graph prefix must be printed.
 794 *
 795 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 796 *      *(diff_words->current_plus - 1) == '\n'
 797 *
 798 *      that is: a graph prefix must be printed following a '\n'
 799 */
 800static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 801{
 802        if ((diff_words->last_minus == 0 &&
 803                diff_words->current_plus == diff_words->plus.text.ptr) ||
 804                (diff_words->current_plus > diff_words->plus.text.ptr &&
 805                *(diff_words->current_plus - 1) == '\n')) {
 806                return 1;
 807        } else {
 808                return 0;
 809        }
 810}
 811
 812static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 813{
 814        struct diff_words_data *diff_words = priv;
 815        struct diff_words_style *style = diff_words->style;
 816        int minus_first, minus_len, plus_first, plus_len;
 817        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 818        struct diff_options *opt = diff_words->opt;
 819        const char *line_prefix;
 820
 821        if (line[0] != '@' || parse_hunk_header(line, len,
 822                        &minus_first, &minus_len, &plus_first, &plus_len))
 823                return;
 824
 825        assert(opt);
 826        line_prefix = diff_line_prefix(opt);
 827
 828        /* POSIX requires that first be decremented by one if len == 0... */
 829        if (minus_len) {
 830                minus_begin = diff_words->minus.orig[minus_first].begin;
 831                minus_end =
 832                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 833        } else
 834                minus_begin = minus_end =
 835                        diff_words->minus.orig[minus_first].end;
 836
 837        if (plus_len) {
 838                plus_begin = diff_words->plus.orig[plus_first].begin;
 839                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 840        } else
 841                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 842
 843        if (color_words_output_graph_prefix(diff_words)) {
 844                fputs(line_prefix, diff_words->opt->file);
 845        }
 846        if (diff_words->current_plus != plus_begin) {
 847                fn_out_diff_words_write_helper(diff_words->opt->file,
 848                                &style->ctx, style->newline,
 849                                plus_begin - diff_words->current_plus,
 850                                diff_words->current_plus, line_prefix);
 851                if (*(plus_begin - 1) == '\n')
 852                        fputs(line_prefix, diff_words->opt->file);
 853        }
 854        if (minus_begin != minus_end) {
 855                fn_out_diff_words_write_helper(diff_words->opt->file,
 856                                &style->old, style->newline,
 857                                minus_end - minus_begin, minus_begin,
 858                                line_prefix);
 859        }
 860        if (plus_begin != plus_end) {
 861                fn_out_diff_words_write_helper(diff_words->opt->file,
 862                                &style->new, style->newline,
 863                                plus_end - plus_begin, plus_begin,
 864                                line_prefix);
 865        }
 866
 867        diff_words->current_plus = plus_end;
 868        diff_words->last_minus = minus_first;
 869}
 870
 871/* This function starts looking at *begin, and returns 0 iff a word was found. */
 872static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 873                int *begin, int *end)
 874{
 875        if (word_regex && *begin < buffer->size) {
 876                regmatch_t match[1];
 877                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 878                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 879                                        '\n', match[0].rm_eo - match[0].rm_so);
 880                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 881                        *begin += match[0].rm_so;
 882                        return *begin >= *end;
 883                }
 884                return -1;
 885        }
 886
 887        /* find the next word */
 888        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 889                (*begin)++;
 890        if (*begin >= buffer->size)
 891                return -1;
 892
 893        /* find the end of the word */
 894        *end = *begin + 1;
 895        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 896                (*end)++;
 897
 898        return 0;
 899}
 900
 901/*
 902 * This function splits the words in buffer->text, stores the list with
 903 * newline separator into out, and saves the offsets of the original words
 904 * in buffer->orig.
 905 */
 906static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 907                regex_t *word_regex)
 908{
 909        int i, j;
 910        long alloc = 0;
 911
 912        out->size = 0;
 913        out->ptr = NULL;
 914
 915        /* fake an empty "0th" word */
 916        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 917        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 918        buffer->orig_nr = 1;
 919
 920        for (i = 0; i < buffer->text.size; i++) {
 921                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 922                        return;
 923
 924                /* store original boundaries */
 925                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 926                                buffer->orig_alloc);
 927                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 928                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 929                buffer->orig_nr++;
 930
 931                /* store one word */
 932                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 933                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 934                out->ptr[out->size + j - i] = '\n';
 935                out->size += j - i + 1;
 936
 937                i = j - 1;
 938        }
 939}
 940
 941/* this executes the word diff on the accumulated buffers */
 942static void diff_words_show(struct diff_words_data *diff_words)
 943{
 944        xpparam_t xpp;
 945        xdemitconf_t xecfg;
 946        mmfile_t minus, plus;
 947        struct diff_words_style *style = diff_words->style;
 948
 949        struct diff_options *opt = diff_words->opt;
 950        const char *line_prefix;
 951
 952        assert(opt);
 953        line_prefix = diff_line_prefix(opt);
 954
 955        /* special case: only removal */
 956        if (!diff_words->plus.text.size) {
 957                fputs(line_prefix, diff_words->opt->file);
 958                fn_out_diff_words_write_helper(diff_words->opt->file,
 959                        &style->old, style->newline,
 960                        diff_words->minus.text.size,
 961                        diff_words->minus.text.ptr, line_prefix);
 962                diff_words->minus.text.size = 0;
 963                return;
 964        }
 965
 966        diff_words->current_plus = diff_words->plus.text.ptr;
 967        diff_words->last_minus = 0;
 968
 969        memset(&xpp, 0, sizeof(xpp));
 970        memset(&xecfg, 0, sizeof(xecfg));
 971        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 972        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 973        xpp.flags = 0;
 974        /* as only the hunk header will be parsed, we need a 0-context */
 975        xecfg.ctxlen = 0;
 976        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 977                      &xpp, &xecfg);
 978        free(minus.ptr);
 979        free(plus.ptr);
 980        if (diff_words->current_plus != diff_words->plus.text.ptr +
 981                        diff_words->plus.text.size) {
 982                if (color_words_output_graph_prefix(diff_words))
 983                        fputs(line_prefix, diff_words->opt->file);
 984                fn_out_diff_words_write_helper(diff_words->opt->file,
 985                        &style->ctx, style->newline,
 986                        diff_words->plus.text.ptr + diff_words->plus.text.size
 987                        - diff_words->current_plus, diff_words->current_plus,
 988                        line_prefix);
 989        }
 990        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 991}
 992
 993/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 994static void diff_words_flush(struct emit_callback *ecbdata)
 995{
 996        if (ecbdata->diff_words->minus.text.size ||
 997            ecbdata->diff_words->plus.text.size)
 998                diff_words_show(ecbdata->diff_words);
 999}
1000
1001static void diff_filespec_load_driver(struct diff_filespec *one)
1002{
1003        /* Use already-loaded driver */
1004        if (one->driver)
1005                return;
1006
1007        if (S_ISREG(one->mode))
1008                one->driver = userdiff_find_by_path(one->path);
1009
1010        /* Fallback to default settings */
1011        if (!one->driver)
1012                one->driver = userdiff_find_by_name("default");
1013}
1014
1015static const char *userdiff_word_regex(struct diff_filespec *one)
1016{
1017        diff_filespec_load_driver(one);
1018        return one->driver->word_regex;
1019}
1020
1021static void init_diff_words_data(struct emit_callback *ecbdata,
1022                                 struct diff_options *orig_opts,
1023                                 struct diff_filespec *one,
1024                                 struct diff_filespec *two)
1025{
1026        int i;
1027        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1028        memcpy(o, orig_opts, sizeof(struct diff_options));
1029
1030        ecbdata->diff_words =
1031                xcalloc(1, sizeof(struct diff_words_data));
1032        ecbdata->diff_words->type = o->word_diff;
1033        ecbdata->diff_words->opt = o;
1034        if (!o->word_regex)
1035                o->word_regex = userdiff_word_regex(one);
1036        if (!o->word_regex)
1037                o->word_regex = userdiff_word_regex(two);
1038        if (!o->word_regex)
1039                o->word_regex = diff_word_regex_cfg;
1040        if (o->word_regex) {
1041                ecbdata->diff_words->word_regex = (regex_t *)
1042                        xmalloc(sizeof(regex_t));
1043                if (regcomp(ecbdata->diff_words->word_regex,
1044                            o->word_regex,
1045                            REG_EXTENDED | REG_NEWLINE))
1046                        die ("Invalid regular expression: %s",
1047                             o->word_regex);
1048        }
1049        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1050                if (o->word_diff == diff_words_styles[i].type) {
1051                        ecbdata->diff_words->style =
1052                                &diff_words_styles[i];
1053                        break;
1054                }
1055        }
1056        if (want_color(o->use_color)) {
1057                struct diff_words_style *st = ecbdata->diff_words->style;
1058                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1059                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1060                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1061        }
1062}
1063
1064static void free_diff_words_data(struct emit_callback *ecbdata)
1065{
1066        if (ecbdata->diff_words) {
1067                diff_words_flush(ecbdata);
1068                free (ecbdata->diff_words->opt);
1069                free (ecbdata->diff_words->minus.text.ptr);
1070                free (ecbdata->diff_words->minus.orig);
1071                free (ecbdata->diff_words->plus.text.ptr);
1072                free (ecbdata->diff_words->plus.orig);
1073                if (ecbdata->diff_words->word_regex) {
1074                        regfree(ecbdata->diff_words->word_regex);
1075                        free(ecbdata->diff_words->word_regex);
1076                }
1077                free(ecbdata->diff_words);
1078                ecbdata->diff_words = NULL;
1079        }
1080}
1081
1082const char *diff_get_color(int diff_use_color, enum color_diff ix)
1083{
1084        if (want_color(diff_use_color))
1085                return diff_colors[ix];
1086        return "";
1087}
1088
1089const char *diff_line_prefix(struct diff_options *opt)
1090{
1091        struct strbuf *msgbuf;
1092        if (!opt->output_prefix)
1093                return "";
1094
1095        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1096        return msgbuf->buf;
1097}
1098
1099static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1100{
1101        const char *cp;
1102        unsigned long allot;
1103        size_t l = len;
1104
1105        if (ecb->truncate)
1106                return ecb->truncate(line, len);
1107        cp = line;
1108        allot = l;
1109        while (0 < l) {
1110                (void) utf8_width(&cp, &l);
1111                if (!cp)
1112                        break; /* truncated in the middle? */
1113        }
1114        return allot - l;
1115}
1116
1117static void find_lno(const char *line, struct emit_callback *ecbdata)
1118{
1119        const char *p;
1120        ecbdata->lno_in_preimage = 0;
1121        ecbdata->lno_in_postimage = 0;
1122        p = strchr(line, '-');
1123        if (!p)
1124                return; /* cannot happen */
1125        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1126        p = strchr(p, '+');
1127        if (!p)
1128                return; /* cannot happen */
1129        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1130}
1131
1132static void fn_out_consume(void *priv, char *line, unsigned long len)
1133{
1134        struct emit_callback *ecbdata = priv;
1135        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1136        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1137        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1138        struct diff_options *o = ecbdata->opt;
1139        const char *line_prefix = diff_line_prefix(o);
1140
1141        if (ecbdata->header) {
1142                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1143                strbuf_reset(ecbdata->header);
1144                ecbdata->header = NULL;
1145        }
1146        *(ecbdata->found_changesp) = 1;
1147
1148        if (ecbdata->label_path[0]) {
1149                const char *name_a_tab, *name_b_tab;
1150
1151                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1152                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1153
1154                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1155                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1156                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1157                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1158                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1159        }
1160
1161        if (diff_suppress_blank_empty
1162            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1163                line[0] = '\n';
1164                len = 1;
1165        }
1166
1167        if (line[0] == '@') {
1168                if (ecbdata->diff_words)
1169                        diff_words_flush(ecbdata);
1170                len = sane_truncate_line(ecbdata, line, len);
1171                find_lno(line, ecbdata);
1172                emit_hunk_header(ecbdata, line, len);
1173                if (line[len-1] != '\n')
1174                        putc('\n', ecbdata->opt->file);
1175                return;
1176        }
1177
1178        if (len < 1) {
1179                emit_line(ecbdata->opt, reset, reset, line, len);
1180                if (ecbdata->diff_words
1181                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1182                        fputs("~\n", ecbdata->opt->file);
1183                return;
1184        }
1185
1186        if (ecbdata->diff_words) {
1187                if (line[0] == '-') {
1188                        diff_words_append(line, len,
1189                                          &ecbdata->diff_words->minus);
1190                        return;
1191                } else if (line[0] == '+') {
1192                        diff_words_append(line, len,
1193                                          &ecbdata->diff_words->plus);
1194                        return;
1195                } else if (!prefixcmp(line, "\\ ")) {
1196                        /*
1197                         * Eat the "no newline at eof" marker as if we
1198                         * saw a "+" or "-" line with nothing on it,
1199                         * and return without diff_words_flush() to
1200                         * defer processing. If this is the end of
1201                         * preimage, more "+" lines may come after it.
1202                         */
1203                        return;
1204                }
1205                diff_words_flush(ecbdata);
1206                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1207                        emit_line(ecbdata->opt, plain, reset, line, len);
1208                        fputs("~\n", ecbdata->opt->file);
1209                } else {
1210                        /*
1211                         * Skip the prefix character, if any.  With
1212                         * diff_suppress_blank_empty, there may be
1213                         * none.
1214                         */
1215                        if (line[0] != '\n') {
1216                              line++;
1217                              len--;
1218                        }
1219                        emit_line(ecbdata->opt, plain, reset, line, len);
1220                }
1221                return;
1222        }
1223
1224        if (line[0] != '+') {
1225                const char *color =
1226                        diff_get_color(ecbdata->color_diff,
1227                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1228                ecbdata->lno_in_preimage++;
1229                if (line[0] == ' ')
1230                        ecbdata->lno_in_postimage++;
1231                emit_line(ecbdata->opt, color, reset, line, len);
1232        } else {
1233                ecbdata->lno_in_postimage++;
1234                emit_add_line(reset, ecbdata, line + 1, len - 1);
1235        }
1236}
1237
1238static char *pprint_rename(const char *a, const char *b)
1239{
1240        const char *old = a;
1241        const char *new = b;
1242        struct strbuf name = STRBUF_INIT;
1243        int pfx_length, sfx_length;
1244        int len_a = strlen(a);
1245        int len_b = strlen(b);
1246        int a_midlen, b_midlen;
1247        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1248        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1249
1250        if (qlen_a || qlen_b) {
1251                quote_c_style(a, &name, NULL, 0);
1252                strbuf_addstr(&name, " => ");
1253                quote_c_style(b, &name, NULL, 0);
1254                return strbuf_detach(&name, NULL);
1255        }
1256
1257        /* Find common prefix */
1258        pfx_length = 0;
1259        while (*old && *new && *old == *new) {
1260                if (*old == '/')
1261                        pfx_length = old - a + 1;
1262                old++;
1263                new++;
1264        }
1265
1266        /* Find common suffix */
1267        old = a + len_a;
1268        new = b + len_b;
1269        sfx_length = 0;
1270        while (a <= old && b <= new && *old == *new) {
1271                if (*old == '/')
1272                        sfx_length = len_a - (old - a);
1273                old--;
1274                new--;
1275        }
1276
1277        /*
1278         * pfx{mid-a => mid-b}sfx
1279         * {pfx-a => pfx-b}sfx
1280         * pfx{sfx-a => sfx-b}
1281         * name-a => name-b
1282         */
1283        a_midlen = len_a - pfx_length - sfx_length;
1284        b_midlen = len_b - pfx_length - sfx_length;
1285        if (a_midlen < 0)
1286                a_midlen = 0;
1287        if (b_midlen < 0)
1288                b_midlen = 0;
1289
1290        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1291        if (pfx_length + sfx_length) {
1292                strbuf_add(&name, a, pfx_length);
1293                strbuf_addch(&name, '{');
1294        }
1295        strbuf_add(&name, a + pfx_length, a_midlen);
1296        strbuf_addstr(&name, " => ");
1297        strbuf_add(&name, b + pfx_length, b_midlen);
1298        if (pfx_length + sfx_length) {
1299                strbuf_addch(&name, '}');
1300                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1301        }
1302        return strbuf_detach(&name, NULL);
1303}
1304
1305struct diffstat_t {
1306        int nr;
1307        int alloc;
1308        struct diffstat_file {
1309                char *from_name;
1310                char *name;
1311                char *print_name;
1312                unsigned is_unmerged:1;
1313                unsigned is_binary:1;
1314                unsigned is_renamed:1;
1315                unsigned is_interesting:1;
1316                uintmax_t added, deleted;
1317        } **files;
1318};
1319
1320static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1321                                          const char *name_a,
1322                                          const char *name_b)
1323{
1324        struct diffstat_file *x;
1325        x = xcalloc(sizeof (*x), 1);
1326        if (diffstat->nr == diffstat->alloc) {
1327                diffstat->alloc = alloc_nr(diffstat->alloc);
1328                diffstat->files = xrealloc(diffstat->files,
1329                                diffstat->alloc * sizeof(x));
1330        }
1331        diffstat->files[diffstat->nr++] = x;
1332        if (name_b) {
1333                x->from_name = xstrdup(name_a);
1334                x->name = xstrdup(name_b);
1335                x->is_renamed = 1;
1336        }
1337        else {
1338                x->from_name = NULL;
1339                x->name = xstrdup(name_a);
1340        }
1341        return x;
1342}
1343
1344static void diffstat_consume(void *priv, char *line, unsigned long len)
1345{
1346        struct diffstat_t *diffstat = priv;
1347        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1348
1349        if (line[0] == '+')
1350                x->added++;
1351        else if (line[0] == '-')
1352                x->deleted++;
1353}
1354
1355const char mime_boundary_leader[] = "------------";
1356
1357static int scale_linear(int it, int width, int max_change)
1358{
1359        if (!it)
1360                return 0;
1361        /*
1362         * make sure that at least one '-' or '+' is printed if
1363         * there is any change to this path. The easiest way is to
1364         * scale linearly as if the alloted width is one column shorter
1365         * than it is, and then add 1 to the result.
1366         */
1367        return 1 + (it * (width - 1) / max_change);
1368}
1369
1370static void show_name(FILE *file,
1371                      const char *prefix, const char *name, int len)
1372{
1373        fprintf(file, " %s%-*s |", prefix, len, name);
1374}
1375
1376static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1377{
1378        if (cnt <= 0)
1379                return;
1380        fprintf(file, "%s", set);
1381        while (cnt--)
1382                putc(ch, file);
1383        fprintf(file, "%s", reset);
1384}
1385
1386static void fill_print_name(struct diffstat_file *file)
1387{
1388        char *pname;
1389
1390        if (file->print_name)
1391                return;
1392
1393        if (!file->is_renamed) {
1394                struct strbuf buf = STRBUF_INIT;
1395                if (quote_c_style(file->name, &buf, NULL, 0)) {
1396                        pname = strbuf_detach(&buf, NULL);
1397                } else {
1398                        pname = file->name;
1399                        strbuf_release(&buf);
1400                }
1401        } else {
1402                pname = pprint_rename(file->from_name, file->name);
1403        }
1404        file->print_name = pname;
1405}
1406
1407int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1408{
1409        struct strbuf sb = STRBUF_INIT;
1410        int ret;
1411
1412        if (!files) {
1413                assert(insertions == 0 && deletions == 0);
1414                return fprintf(fp, "%s\n", " 0 files changed");
1415        }
1416
1417        strbuf_addf(&sb,
1418                    (files == 1) ? " %d file changed" : " %d files changed",
1419                    files);
1420
1421        /*
1422         * For binary diff, the caller may want to print "x files
1423         * changed" with insertions == 0 && deletions == 0.
1424         *
1425         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1426         * is probably less confusing (i.e skip over "2 files changed
1427         * but nothing about added/removed lines? Is this a bug in Git?").
1428         */
1429        if (insertions || deletions == 0) {
1430                /*
1431                 * TRANSLATORS: "+" in (+) is a line addition marker;
1432                 * do not translate it.
1433                 */
1434                strbuf_addf(&sb,
1435                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1436                            insertions);
1437        }
1438
1439        if (deletions || insertions == 0) {
1440                /*
1441                 * TRANSLATORS: "-" in (-) is a line removal marker;
1442                 * do not translate it.
1443                 */
1444                strbuf_addf(&sb,
1445                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1446                            deletions);
1447        }
1448        strbuf_addch(&sb, '\n');
1449        ret = fputs(sb.buf, fp);
1450        strbuf_release(&sb);
1451        return ret;
1452}
1453
1454static void show_stats(struct diffstat_t *data, struct diff_options *options)
1455{
1456        int i, len, add, del, adds = 0, dels = 0;
1457        uintmax_t max_change = 0, max_len = 0;
1458        int total_files = data->nr, count;
1459        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1460        const char *reset, *add_c, *del_c;
1461        const char *line_prefix = "";
1462        int extra_shown = 0;
1463
1464        if (data->nr == 0)
1465                return;
1466
1467        line_prefix = diff_line_prefix(options);
1468        count = options->stat_count ? options->stat_count : data->nr;
1469
1470        reset = diff_get_color_opt(options, DIFF_RESET);
1471        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1472        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1473
1474        /*
1475         * Find the longest filename and max number of changes
1476         */
1477        for (i = 0; (i < count) && (i < data->nr); i++) {
1478                struct diffstat_file *file = data->files[i];
1479                uintmax_t change = file->added + file->deleted;
1480
1481                if (!file->is_interesting && (change == 0)) {
1482                        count++; /* not shown == room for one more */
1483                        continue;
1484                }
1485                fill_print_name(file);
1486                len = strlen(file->print_name);
1487                if (max_len < len)
1488                        max_len = len;
1489
1490                if (file->is_unmerged) {
1491                        /* "Unmerged" is 8 characters */
1492                        bin_width = bin_width < 8 ? 8 : bin_width;
1493                        continue;
1494                }
1495                if (file->is_binary) {
1496                        /* "Bin XXX -> YYY bytes" */
1497                        int w = 14 + decimal_width(file->added)
1498                                + decimal_width(file->deleted);
1499                        bin_width = bin_width < w ? w : bin_width;
1500                        /* Display change counts aligned with "Bin" */
1501                        number_width = 3;
1502                        continue;
1503                }
1504
1505                if (max_change < change)
1506                        max_change = change;
1507        }
1508        count = i; /* where we can stop scanning in data->files[] */
1509
1510        /*
1511         * We have width = stat_width or term_columns() columns total.
1512         * We want a maximum of min(max_len, stat_name_width) for the name part.
1513         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1514         * We also need 1 for " " and 4 + decimal_width(max_change)
1515         * for " | NNNN " and one the empty column at the end, altogether
1516         * 6 + decimal_width(max_change).
1517         *
1518         * If there's not enough space, we will use the smaller of
1519         * stat_name_width (if set) and 5/8*width for the filename,
1520         * and the rest for constant elements + graph part, but no more
1521         * than stat_graph_width for the graph part.
1522         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1523         * for the standard terminal size).
1524         *
1525         * In other words: stat_width limits the maximum width, and
1526         * stat_name_width fixes the maximum width of the filename,
1527         * and is also used to divide available columns if there
1528         * aren't enough.
1529         *
1530         * Binary files are displayed with "Bin XXX -> YYY bytes"
1531         * instead of the change count and graph. This part is treated
1532         * similarly to the graph part, except that it is not
1533         * "scaled". If total width is too small to accomodate the
1534         * guaranteed minimum width of the filename part and the
1535         * separators and this message, this message will "overflow"
1536         * making the line longer than the maximum width.
1537         */
1538
1539        if (options->stat_width == -1)
1540                width = term_columns() - options->output_prefix_length;
1541        else
1542                width = options->stat_width ? options->stat_width : 80;
1543        number_width = decimal_width(max_change) > number_width ?
1544                decimal_width(max_change) : number_width;
1545
1546        if (options->stat_graph_width == -1)
1547                options->stat_graph_width = diff_stat_graph_width;
1548
1549        /*
1550         * Guarantee 3/8*16==6 for the graph part
1551         * and 5/8*16==10 for the filename part
1552         */
1553        if (width < 16 + 6 + number_width)
1554                width = 16 + 6 + number_width;
1555
1556        /*
1557         * First assign sizes that are wanted, ignoring available width.
1558         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1559         * starting from "XXX" should fit in graph_width.
1560         */
1561        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1562        if (options->stat_graph_width &&
1563            options->stat_graph_width < graph_width)
1564                graph_width = options->stat_graph_width;
1565
1566        name_width = (options->stat_name_width > 0 &&
1567                      options->stat_name_width < max_len) ?
1568                options->stat_name_width : max_len;
1569
1570        /*
1571         * Adjust adjustable widths not to exceed maximum width
1572         */
1573        if (name_width + number_width + 6 + graph_width > width) {
1574                if (graph_width > width * 3/8 - number_width - 6) {
1575                        graph_width = width * 3/8 - number_width - 6;
1576                        if (graph_width < 6)
1577                                graph_width = 6;
1578                }
1579
1580                if (options->stat_graph_width &&
1581                    graph_width > options->stat_graph_width)
1582                        graph_width = options->stat_graph_width;
1583                if (name_width > width - number_width - 6 - graph_width)
1584                        name_width = width - number_width - 6 - graph_width;
1585                else
1586                        graph_width = width - number_width - 6 - name_width;
1587        }
1588
1589        /*
1590         * From here name_width is the width of the name area,
1591         * and graph_width is the width of the graph area.
1592         * max_change is used to scale graph properly.
1593         */
1594        for (i = 0; i < count; i++) {
1595                const char *prefix = "";
1596                struct diffstat_file *file = data->files[i];
1597                char *name = file->print_name;
1598                uintmax_t added = file->added;
1599                uintmax_t deleted = file->deleted;
1600                int name_len;
1601
1602                if (!file->is_interesting && (added + deleted == 0))
1603                        continue;
1604
1605                /*
1606                 * "scale" the filename
1607                 */
1608                len = name_width;
1609                name_len = strlen(name);
1610                if (name_width < name_len) {
1611                        char *slash;
1612                        prefix = "...";
1613                        len -= 3;
1614                        name += name_len - len;
1615                        slash = strchr(name, '/');
1616                        if (slash)
1617                                name = slash;
1618                }
1619
1620                if (file->is_binary) {
1621                        fprintf(options->file, "%s", line_prefix);
1622                        show_name(options->file, prefix, name, len);
1623                        fprintf(options->file, " %*s", number_width, "Bin");
1624                        if (!added && !deleted) {
1625                                putc('\n', options->file);
1626                                continue;
1627                        }
1628                        fprintf(options->file, " %s%"PRIuMAX"%s",
1629                                del_c, deleted, reset);
1630                        fprintf(options->file, " -> ");
1631                        fprintf(options->file, "%s%"PRIuMAX"%s",
1632                                add_c, added, reset);
1633                        fprintf(options->file, " bytes");
1634                        fprintf(options->file, "\n");
1635                        continue;
1636                }
1637                else if (file->is_unmerged) {
1638                        fprintf(options->file, "%s", line_prefix);
1639                        show_name(options->file, prefix, name, len);
1640                        fprintf(options->file, " Unmerged\n");
1641                        continue;
1642                }
1643
1644                /*
1645                 * scale the add/delete
1646                 */
1647                add = added;
1648                del = deleted;
1649
1650                if (graph_width <= max_change) {
1651                        int total = add + del;
1652
1653                        total = scale_linear(add + del, graph_width, max_change);
1654                        if (total < 2 && add && del)
1655                                /* width >= 2 due to the sanity check */
1656                                total = 2;
1657                        if (add < del) {
1658                                add = scale_linear(add, graph_width, max_change);
1659                                del = total - add;
1660                        } else {
1661                                del = scale_linear(del, graph_width, max_change);
1662                                add = total - del;
1663                        }
1664                }
1665                fprintf(options->file, "%s", line_prefix);
1666                show_name(options->file, prefix, name, len);
1667                fprintf(options->file, " %*"PRIuMAX"%s",
1668                        number_width, added + deleted,
1669                        added + deleted ? " " : "");
1670                show_graph(options->file, '+', add, add_c, reset);
1671                show_graph(options->file, '-', del, del_c, reset);
1672                fprintf(options->file, "\n");
1673        }
1674
1675        for (i = 0; i < data->nr; i++) {
1676                struct diffstat_file *file = data->files[i];
1677                uintmax_t added = file->added;
1678                uintmax_t deleted = file->deleted;
1679
1680                if (file->is_unmerged ||
1681                    (!file->is_interesting && (added + deleted == 0))) {
1682                        total_files--;
1683                        continue;
1684                }
1685
1686                if (!file->is_binary) {
1687                        adds += added;
1688                        dels += deleted;
1689                }
1690                if (i < count)
1691                        continue;
1692                if (!extra_shown)
1693                        fprintf(options->file, "%s ...\n", line_prefix);
1694                extra_shown = 1;
1695        }
1696        fprintf(options->file, "%s", line_prefix);
1697        print_stat_summary(options->file, total_files, adds, dels);
1698}
1699
1700static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1701{
1702        int i, adds = 0, dels = 0, total_files = data->nr;
1703
1704        if (data->nr == 0)
1705                return;
1706
1707        for (i = 0; i < data->nr; i++) {
1708                int added = data->files[i]->added;
1709                int deleted= data->files[i]->deleted;
1710
1711                if (data->files[i]->is_unmerged ||
1712                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1713                        total_files--;
1714                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1715                        adds += added;
1716                        dels += deleted;
1717                }
1718        }
1719        fprintf(options->file, "%s", diff_line_prefix(options));
1720        print_stat_summary(options->file, total_files, adds, dels);
1721}
1722
1723static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1724{
1725        int i;
1726
1727        if (data->nr == 0)
1728                return;
1729
1730        for (i = 0; i < data->nr; i++) {
1731                struct diffstat_file *file = data->files[i];
1732
1733                fprintf(options->file, "%s", diff_line_prefix(options));
1734
1735                if (file->is_binary)
1736                        fprintf(options->file, "-\t-\t");
1737                else
1738                        fprintf(options->file,
1739                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1740                                file->added, file->deleted);
1741                if (options->line_termination) {
1742                        fill_print_name(file);
1743                        if (!file->is_renamed)
1744                                write_name_quoted(file->name, options->file,
1745                                                  options->line_termination);
1746                        else {
1747                                fputs(file->print_name, options->file);
1748                                putc(options->line_termination, options->file);
1749                        }
1750                } else {
1751                        if (file->is_renamed) {
1752                                putc('\0', options->file);
1753                                write_name_quoted(file->from_name, options->file, '\0');
1754                        }
1755                        write_name_quoted(file->name, options->file, '\0');
1756                }
1757        }
1758}
1759
1760struct dirstat_file {
1761        const char *name;
1762        unsigned long changed;
1763};
1764
1765struct dirstat_dir {
1766        struct dirstat_file *files;
1767        int alloc, nr, permille, cumulative;
1768};
1769
1770static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1771                unsigned long changed, const char *base, int baselen)
1772{
1773        unsigned long this_dir = 0;
1774        unsigned int sources = 0;
1775        const char *line_prefix = diff_line_prefix(opt);
1776
1777        while (dir->nr) {
1778                struct dirstat_file *f = dir->files;
1779                int namelen = strlen(f->name);
1780                unsigned long this;
1781                char *slash;
1782
1783                if (namelen < baselen)
1784                        break;
1785                if (memcmp(f->name, base, baselen))
1786                        break;
1787                slash = strchr(f->name + baselen, '/');
1788                if (slash) {
1789                        int newbaselen = slash + 1 - f->name;
1790                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1791                        sources++;
1792                } else {
1793                        this = f->changed;
1794                        dir->files++;
1795                        dir->nr--;
1796                        sources += 2;
1797                }
1798                this_dir += this;
1799        }
1800
1801        /*
1802         * We don't report dirstat's for
1803         *  - the top level
1804         *  - or cases where everything came from a single directory
1805         *    under this directory (sources == 1).
1806         */
1807        if (baselen && sources != 1) {
1808                if (this_dir) {
1809                        int permille = this_dir * 1000 / changed;
1810                        if (permille >= dir->permille) {
1811                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1812                                        permille / 10, permille % 10, baselen, base);
1813                                if (!dir->cumulative)
1814                                        return 0;
1815                        }
1816                }
1817        }
1818        return this_dir;
1819}
1820
1821static int dirstat_compare(const void *_a, const void *_b)
1822{
1823        const struct dirstat_file *a = _a;
1824        const struct dirstat_file *b = _b;
1825        return strcmp(a->name, b->name);
1826}
1827
1828static void show_dirstat(struct diff_options *options)
1829{
1830        int i;
1831        unsigned long changed;
1832        struct dirstat_dir dir;
1833        struct diff_queue_struct *q = &diff_queued_diff;
1834
1835        dir.files = NULL;
1836        dir.alloc = 0;
1837        dir.nr = 0;
1838        dir.permille = options->dirstat_permille;
1839        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1840
1841        changed = 0;
1842        for (i = 0; i < q->nr; i++) {
1843                struct diff_filepair *p = q->queue[i];
1844                const char *name;
1845                unsigned long copied, added, damage;
1846                int content_changed;
1847
1848                name = p->two->path ? p->two->path : p->one->path;
1849
1850                if (p->one->sha1_valid && p->two->sha1_valid)
1851                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1852                else
1853                        content_changed = 1;
1854
1855                if (!content_changed) {
1856                        /*
1857                         * The SHA1 has not changed, so pre-/post-content is
1858                         * identical. We can therefore skip looking at the
1859                         * file contents altogether.
1860                         */
1861                        damage = 0;
1862                        goto found_damage;
1863                }
1864
1865                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1866                        /*
1867                         * In --dirstat-by-file mode, we don't really need to
1868                         * look at the actual file contents at all.
1869                         * The fact that the SHA1 changed is enough for us to
1870                         * add this file to the list of results
1871                         * (with each file contributing equal damage).
1872                         */
1873                        damage = 1;
1874                        goto found_damage;
1875                }
1876
1877                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1878                        diff_populate_filespec(p->one, 0);
1879                        diff_populate_filespec(p->two, 0);
1880                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1881                                               &copied, &added);
1882                        diff_free_filespec_data(p->one);
1883                        diff_free_filespec_data(p->two);
1884                } else if (DIFF_FILE_VALID(p->one)) {
1885                        diff_populate_filespec(p->one, 1);
1886                        copied = added = 0;
1887                        diff_free_filespec_data(p->one);
1888                } else if (DIFF_FILE_VALID(p->two)) {
1889                        diff_populate_filespec(p->two, 1);
1890                        copied = 0;
1891                        added = p->two->size;
1892                        diff_free_filespec_data(p->two);
1893                } else
1894                        continue;
1895
1896                /*
1897                 * Original minus copied is the removed material,
1898                 * added is the new material.  They are both damages
1899                 * made to the preimage.
1900                 * If the resulting damage is zero, we know that
1901                 * diffcore_count_changes() considers the two entries to
1902                 * be identical, but since content_changed is true, we
1903                 * know that there must have been _some_ kind of change,
1904                 * so we force all entries to have damage > 0.
1905                 */
1906                damage = (p->one->size - copied) + added;
1907                if (!damage)
1908                        damage = 1;
1909
1910found_damage:
1911                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1912                dir.files[dir.nr].name = name;
1913                dir.files[dir.nr].changed = damage;
1914                changed += damage;
1915                dir.nr++;
1916        }
1917
1918        /* This can happen even with many files, if everything was renames */
1919        if (!changed)
1920                return;
1921
1922        /* Show all directories with more than x% of the changes */
1923        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1924        gather_dirstat(options, &dir, changed, "", 0);
1925}
1926
1927static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1928{
1929        int i;
1930        unsigned long changed;
1931        struct dirstat_dir dir;
1932
1933        if (data->nr == 0)
1934                return;
1935
1936        dir.files = NULL;
1937        dir.alloc = 0;
1938        dir.nr = 0;
1939        dir.permille = options->dirstat_permille;
1940        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1941
1942        changed = 0;
1943        for (i = 0; i < data->nr; i++) {
1944                struct diffstat_file *file = data->files[i];
1945                unsigned long damage = file->added + file->deleted;
1946                if (file->is_binary)
1947                        /*
1948                         * binary files counts bytes, not lines. Must find some
1949                         * way to normalize binary bytes vs. textual lines.
1950                         * The following heuristic assumes that there are 64
1951                         * bytes per "line".
1952                         * This is stupid and ugly, but very cheap...
1953                         */
1954                        damage = (damage + 63) / 64;
1955                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1956                dir.files[dir.nr].name = file->name;
1957                dir.files[dir.nr].changed = damage;
1958                changed += damage;
1959                dir.nr++;
1960        }
1961
1962        /* This can happen even with many files, if everything was renames */
1963        if (!changed)
1964                return;
1965
1966        /* Show all directories with more than x% of the changes */
1967        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1968        gather_dirstat(options, &dir, changed, "", 0);
1969}
1970
1971static void free_diffstat_info(struct diffstat_t *diffstat)
1972{
1973        int i;
1974        for (i = 0; i < diffstat->nr; i++) {
1975                struct diffstat_file *f = diffstat->files[i];
1976                if (f->name != f->print_name)
1977                        free(f->print_name);
1978                free(f->name);
1979                free(f->from_name);
1980                free(f);
1981        }
1982        free(diffstat->files);
1983}
1984
1985struct checkdiff_t {
1986        const char *filename;
1987        int lineno;
1988        int conflict_marker_size;
1989        struct diff_options *o;
1990        unsigned ws_rule;
1991        unsigned status;
1992};
1993
1994static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1995{
1996        char firstchar;
1997        int cnt;
1998
1999        if (len < marker_size + 1)
2000                return 0;
2001        firstchar = line[0];
2002        switch (firstchar) {
2003        case '=': case '>': case '<': case '|':
2004                break;
2005        default:
2006                return 0;
2007        }
2008        for (cnt = 1; cnt < marker_size; cnt++)
2009                if (line[cnt] != firstchar)
2010                        return 0;
2011        /* line[1] thru line[marker_size-1] are same as firstchar */
2012        if (len < marker_size + 1 || !isspace(line[marker_size]))
2013                return 0;
2014        return 1;
2015}
2016
2017static void checkdiff_consume(void *priv, char *line, unsigned long len)
2018{
2019        struct checkdiff_t *data = priv;
2020        int marker_size = data->conflict_marker_size;
2021        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2022        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2023        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2024        char *err;
2025        const char *line_prefix;
2026
2027        assert(data->o);
2028        line_prefix = diff_line_prefix(data->o);
2029
2030        if (line[0] == '+') {
2031                unsigned bad;
2032                data->lineno++;
2033                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2034                        data->status |= 1;
2035                        fprintf(data->o->file,
2036                                "%s%s:%d: leftover conflict marker\n",
2037                                line_prefix, data->filename, data->lineno);
2038                }
2039                bad = ws_check(line + 1, len - 1, data->ws_rule);
2040                if (!bad)
2041                        return;
2042                data->status |= bad;
2043                err = whitespace_error_string(bad);
2044                fprintf(data->o->file, "%s%s:%d: %s.\n",
2045                        line_prefix, data->filename, data->lineno, err);
2046                free(err);
2047                emit_line(data->o, set, reset, line, 1);
2048                ws_check_emit(line + 1, len - 1, data->ws_rule,
2049                              data->o->file, set, reset, ws);
2050        } else if (line[0] == ' ') {
2051                data->lineno++;
2052        } else if (line[0] == '@') {
2053                char *plus = strchr(line, '+');
2054                if (plus)
2055                        data->lineno = strtol(plus, NULL, 10) - 1;
2056                else
2057                        die("invalid diff");
2058        }
2059}
2060
2061static unsigned char *deflate_it(char *data,
2062                                 unsigned long size,
2063                                 unsigned long *result_size)
2064{
2065        int bound;
2066        unsigned char *deflated;
2067        git_zstream stream;
2068
2069        memset(&stream, 0, sizeof(stream));
2070        git_deflate_init(&stream, zlib_compression_level);
2071        bound = git_deflate_bound(&stream, size);
2072        deflated = xmalloc(bound);
2073        stream.next_out = deflated;
2074        stream.avail_out = bound;
2075
2076        stream.next_in = (unsigned char *)data;
2077        stream.avail_in = size;
2078        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2079                ; /* nothing */
2080        git_deflate_end(&stream);
2081        *result_size = stream.total_out;
2082        return deflated;
2083}
2084
2085static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2086                                  const char *prefix)
2087{
2088        void *cp;
2089        void *delta;
2090        void *deflated;
2091        void *data;
2092        unsigned long orig_size;
2093        unsigned long delta_size;
2094        unsigned long deflate_size;
2095        unsigned long data_size;
2096
2097        /* We could do deflated delta, or we could do just deflated two,
2098         * whichever is smaller.
2099         */
2100        delta = NULL;
2101        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2102        if (one->size && two->size) {
2103                delta = diff_delta(one->ptr, one->size,
2104                                   two->ptr, two->size,
2105                                   &delta_size, deflate_size);
2106                if (delta) {
2107                        void *to_free = delta;
2108                        orig_size = delta_size;
2109                        delta = deflate_it(delta, delta_size, &delta_size);
2110                        free(to_free);
2111                }
2112        }
2113
2114        if (delta && delta_size < deflate_size) {
2115                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2116                free(deflated);
2117                data = delta;
2118                data_size = delta_size;
2119        }
2120        else {
2121                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2122                free(delta);
2123                data = deflated;
2124                data_size = deflate_size;
2125        }
2126
2127        /* emit data encoded in base85 */
2128        cp = data;
2129        while (data_size) {
2130                int bytes = (52 < data_size) ? 52 : data_size;
2131                char line[70];
2132                data_size -= bytes;
2133                if (bytes <= 26)
2134                        line[0] = bytes + 'A' - 1;
2135                else
2136                        line[0] = bytes - 26 + 'a' - 1;
2137                encode_85(line + 1, cp, bytes);
2138                cp = (char *) cp + bytes;
2139                fprintf(file, "%s", prefix);
2140                fputs(line, file);
2141                fputc('\n', file);
2142        }
2143        fprintf(file, "%s\n", prefix);
2144        free(data);
2145}
2146
2147static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2148                             const char *prefix)
2149{
2150        fprintf(file, "%sGIT binary patch\n", prefix);
2151        emit_binary_diff_body(file, one, two, prefix);
2152        emit_binary_diff_body(file, two, one, prefix);
2153}
2154
2155int diff_filespec_is_binary(struct diff_filespec *one)
2156{
2157        if (one->is_binary == -1) {
2158                diff_filespec_load_driver(one);
2159                if (one->driver->binary != -1)
2160                        one->is_binary = one->driver->binary;
2161                else {
2162                        if (!one->data && DIFF_FILE_VALID(one))
2163                                diff_populate_filespec(one, 0);
2164                        if (one->data)
2165                                one->is_binary = buffer_is_binary(one->data,
2166                                                one->size);
2167                        if (one->is_binary == -1)
2168                                one->is_binary = 0;
2169                }
2170        }
2171        return one->is_binary;
2172}
2173
2174static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2175{
2176        diff_filespec_load_driver(one);
2177        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2178}
2179
2180void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2181{
2182        if (!options->a_prefix)
2183                options->a_prefix = a;
2184        if (!options->b_prefix)
2185                options->b_prefix = b;
2186}
2187
2188struct userdiff_driver *get_textconv(struct diff_filespec *one)
2189{
2190        if (!DIFF_FILE_VALID(one))
2191                return NULL;
2192
2193        diff_filespec_load_driver(one);
2194        return userdiff_get_textconv(one->driver);
2195}
2196
2197static void builtin_diff(const char *name_a,
2198                         const char *name_b,
2199                         struct diff_filespec *one,
2200                         struct diff_filespec *two,
2201                         const char *xfrm_msg,
2202                         int must_show_header,
2203                         struct diff_options *o,
2204                         int complete_rewrite)
2205{
2206        mmfile_t mf1, mf2;
2207        const char *lbl[2];
2208        char *a_one, *b_two;
2209        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2210        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2211        const char *a_prefix, *b_prefix;
2212        struct userdiff_driver *textconv_one = NULL;
2213        struct userdiff_driver *textconv_two = NULL;
2214        struct strbuf header = STRBUF_INIT;
2215        const char *line_prefix = diff_line_prefix(o);
2216
2217        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2218                        (!one->mode || S_ISGITLINK(one->mode)) &&
2219                        (!two->mode || S_ISGITLINK(two->mode))) {
2220                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2221                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2222                show_submodule_summary(o->file, one ? one->path : two->path,
2223                                one->sha1, two->sha1, two->dirty_submodule,
2224                                meta, del, add, reset);
2225                return;
2226        }
2227
2228        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2229                textconv_one = get_textconv(one);
2230                textconv_two = get_textconv(two);
2231        }
2232
2233        diff_set_mnemonic_prefix(o, "a/", "b/");
2234        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2235                a_prefix = o->b_prefix;
2236                b_prefix = o->a_prefix;
2237        } else {
2238                a_prefix = o->a_prefix;
2239                b_prefix = o->b_prefix;
2240        }
2241
2242        /* Never use a non-valid filename anywhere if at all possible */
2243        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2244        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2245
2246        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2247        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2248        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2249        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2250        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2251        if (lbl[0][0] == '/') {
2252                /* /dev/null */
2253                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2254                if (xfrm_msg)
2255                        strbuf_addstr(&header, xfrm_msg);
2256                must_show_header = 1;
2257        }
2258        else if (lbl[1][0] == '/') {
2259                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2260                if (xfrm_msg)
2261                        strbuf_addstr(&header, xfrm_msg);
2262                must_show_header = 1;
2263        }
2264        else {
2265                if (one->mode != two->mode) {
2266                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2267                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2268                        must_show_header = 1;
2269                }
2270                if (xfrm_msg)
2271                        strbuf_addstr(&header, xfrm_msg);
2272
2273                /*
2274                 * we do not run diff between different kind
2275                 * of objects.
2276                 */
2277                if ((one->mode ^ two->mode) & S_IFMT)
2278                        goto free_ab_and_return;
2279                if (complete_rewrite &&
2280                    (textconv_one || !diff_filespec_is_binary(one)) &&
2281                    (textconv_two || !diff_filespec_is_binary(two))) {
2282                        fprintf(o->file, "%s", header.buf);
2283                        strbuf_reset(&header);
2284                        emit_rewrite_diff(name_a, name_b, one, two,
2285                                                textconv_one, textconv_two, o);
2286                        o->found_changes = 1;
2287                        goto free_ab_and_return;
2288                }
2289        }
2290
2291        if (o->irreversible_delete && lbl[1][0] == '/') {
2292                fprintf(o->file, "%s", header.buf);
2293                strbuf_reset(&header);
2294                goto free_ab_and_return;
2295        } else if (!DIFF_OPT_TST(o, TEXT) &&
2296            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2297              (!textconv_two && diff_filespec_is_binary(two)) )) {
2298                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2299                        die("unable to read files to diff");
2300                /* Quite common confusing case */
2301                if (mf1.size == mf2.size &&
2302                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2303                        if (must_show_header)
2304                                fprintf(o->file, "%s", header.buf);
2305                        goto free_ab_and_return;
2306                }
2307                fprintf(o->file, "%s", header.buf);
2308                strbuf_reset(&header);
2309                if (DIFF_OPT_TST(o, BINARY))
2310                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2311                else
2312                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2313                                line_prefix, lbl[0], lbl[1]);
2314                o->found_changes = 1;
2315        } else {
2316                /* Crazy xdl interfaces.. */
2317                const char *diffopts = getenv("GIT_DIFF_OPTS");
2318                xpparam_t xpp;
2319                xdemitconf_t xecfg;
2320                struct emit_callback ecbdata;
2321                const struct userdiff_funcname *pe;
2322
2323                if (must_show_header) {
2324                        fprintf(o->file, "%s", header.buf);
2325                        strbuf_reset(&header);
2326                }
2327
2328                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2329                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2330
2331                pe = diff_funcname_pattern(one);
2332                if (!pe)
2333                        pe = diff_funcname_pattern(two);
2334
2335                memset(&xpp, 0, sizeof(xpp));
2336                memset(&xecfg, 0, sizeof(xecfg));
2337                memset(&ecbdata, 0, sizeof(ecbdata));
2338                ecbdata.label_path = lbl;
2339                ecbdata.color_diff = want_color(o->use_color);
2340                ecbdata.found_changesp = &o->found_changes;
2341                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2342                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2343                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2344                ecbdata.opt = o;
2345                ecbdata.header = header.len ? &header : NULL;
2346                xpp.flags = o->xdl_opts;
2347                xecfg.ctxlen = o->context;
2348                xecfg.interhunkctxlen = o->interhunkcontext;
2349                xecfg.flags = XDL_EMIT_FUNCNAMES;
2350                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2351                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2352                if (pe)
2353                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2354                if (!diffopts)
2355                        ;
2356                else if (!prefixcmp(diffopts, "--unified="))
2357                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2358                else if (!prefixcmp(diffopts, "-u"))
2359                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2360                if (o->word_diff)
2361                        init_diff_words_data(&ecbdata, o, one, two);
2362                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2363                              &xpp, &xecfg);
2364                if (o->word_diff)
2365                        free_diff_words_data(&ecbdata);
2366                if (textconv_one)
2367                        free(mf1.ptr);
2368                if (textconv_two)
2369                        free(mf2.ptr);
2370                xdiff_clear_find_func(&xecfg);
2371        }
2372
2373 free_ab_and_return:
2374        strbuf_release(&header);
2375        diff_free_filespec_data(one);
2376        diff_free_filespec_data(two);
2377        free(a_one);
2378        free(b_two);
2379        return;
2380}
2381
2382static void builtin_diffstat(const char *name_a, const char *name_b,
2383                             struct diff_filespec *one,
2384                             struct diff_filespec *two,
2385                             struct diffstat_t *diffstat,
2386                             struct diff_options *o,
2387                             struct diff_filepair *p)
2388{
2389        mmfile_t mf1, mf2;
2390        struct diffstat_file *data;
2391        int same_contents;
2392        int complete_rewrite = 0;
2393
2394        if (!DIFF_PAIR_UNMERGED(p)) {
2395                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2396                        complete_rewrite = 1;
2397        }
2398
2399        data = diffstat_add(diffstat, name_a, name_b);
2400        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2401
2402        if (!one || !two) {
2403                data->is_unmerged = 1;
2404                return;
2405        }
2406
2407        same_contents = !hashcmp(one->sha1, two->sha1);
2408
2409        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2410                data->is_binary = 1;
2411                if (same_contents) {
2412                        data->added = 0;
2413                        data->deleted = 0;
2414                } else {
2415                        data->added = diff_filespec_size(two);
2416                        data->deleted = diff_filespec_size(one);
2417                }
2418        }
2419
2420        else if (complete_rewrite) {
2421                diff_populate_filespec(one, 0);
2422                diff_populate_filespec(two, 0);
2423                data->deleted = count_lines(one->data, one->size);
2424                data->added = count_lines(two->data, two->size);
2425        }
2426
2427        else if (!same_contents) {
2428                /* Crazy xdl interfaces.. */
2429                xpparam_t xpp;
2430                xdemitconf_t xecfg;
2431
2432                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2433                        die("unable to read files to diff");
2434
2435                memset(&xpp, 0, sizeof(xpp));
2436                memset(&xecfg, 0, sizeof(xecfg));
2437                xpp.flags = o->xdl_opts;
2438                xecfg.ctxlen = o->context;
2439                xecfg.interhunkctxlen = o->interhunkcontext;
2440                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2441                              &xpp, &xecfg);
2442        }
2443
2444        diff_free_filespec_data(one);
2445        diff_free_filespec_data(two);
2446}
2447
2448static void builtin_checkdiff(const char *name_a, const char *name_b,
2449                              const char *attr_path,
2450                              struct diff_filespec *one,
2451                              struct diff_filespec *two,
2452                              struct diff_options *o)
2453{
2454        mmfile_t mf1, mf2;
2455        struct checkdiff_t data;
2456
2457        if (!two)
2458                return;
2459
2460        memset(&data, 0, sizeof(data));
2461        data.filename = name_b ? name_b : name_a;
2462        data.lineno = 0;
2463        data.o = o;
2464        data.ws_rule = whitespace_rule(attr_path);
2465        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2466
2467        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2468                die("unable to read files to diff");
2469
2470        /*
2471         * All the other codepaths check both sides, but not checking
2472         * the "old" side here is deliberate.  We are checking the newly
2473         * introduced changes, and as long as the "new" side is text, we
2474         * can and should check what it introduces.
2475         */
2476        if (diff_filespec_is_binary(two))
2477                goto free_and_return;
2478        else {
2479                /* Crazy xdl interfaces.. */
2480                xpparam_t xpp;
2481                xdemitconf_t xecfg;
2482
2483                memset(&xpp, 0, sizeof(xpp));
2484                memset(&xecfg, 0, sizeof(xecfg));
2485                xecfg.ctxlen = 1; /* at least one context line */
2486                xpp.flags = 0;
2487                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2488                              &xpp, &xecfg);
2489
2490                if (data.ws_rule & WS_BLANK_AT_EOF) {
2491                        struct emit_callback ecbdata;
2492                        int blank_at_eof;
2493
2494                        ecbdata.ws_rule = data.ws_rule;
2495                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2496                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2497
2498                        if (blank_at_eof) {
2499                                static char *err;
2500                                if (!err)
2501                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2502                                fprintf(o->file, "%s:%d: %s.\n",
2503                                        data.filename, blank_at_eof, err);
2504                                data.status = 1; /* report errors */
2505                        }
2506                }
2507        }
2508 free_and_return:
2509        diff_free_filespec_data(one);
2510        diff_free_filespec_data(two);
2511        if (data.status)
2512                DIFF_OPT_SET(o, CHECK_FAILED);
2513}
2514
2515struct diff_filespec *alloc_filespec(const char *path)
2516{
2517        int namelen = strlen(path);
2518        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2519
2520        memset(spec, 0, sizeof(*spec));
2521        spec->path = (char *)(spec + 1);
2522        memcpy(spec->path, path, namelen+1);
2523        spec->count = 1;
2524        spec->is_binary = -1;
2525        return spec;
2526}
2527
2528void free_filespec(struct diff_filespec *spec)
2529{
2530        if (!--spec->count) {
2531                diff_free_filespec_data(spec);
2532                free(spec);
2533        }
2534}
2535
2536void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2537                   int sha1_valid, unsigned short mode)
2538{
2539        if (mode) {
2540                spec->mode = canon_mode(mode);
2541                hashcpy(spec->sha1, sha1);
2542                spec->sha1_valid = sha1_valid;
2543        }
2544}
2545
2546/*
2547 * Given a name and sha1 pair, if the index tells us the file in
2548 * the work tree has that object contents, return true, so that
2549 * prepare_temp_file() does not have to inflate and extract.
2550 */
2551static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2552{
2553        struct cache_entry *ce;
2554        struct stat st;
2555        int pos, len;
2556
2557        /*
2558         * We do not read the cache ourselves here, because the
2559         * benchmark with my previous version that always reads cache
2560         * shows that it makes things worse for diff-tree comparing
2561         * two linux-2.6 kernel trees in an already checked out work
2562         * tree.  This is because most diff-tree comparisons deal with
2563         * only a small number of files, while reading the cache is
2564         * expensive for a large project, and its cost outweighs the
2565         * savings we get by not inflating the object to a temporary
2566         * file.  Practically, this code only helps when we are used
2567         * by diff-cache --cached, which does read the cache before
2568         * calling us.
2569         */
2570        if (!active_cache)
2571                return 0;
2572
2573        /* We want to avoid the working directory if our caller
2574         * doesn't need the data in a normal file, this system
2575         * is rather slow with its stat/open/mmap/close syscalls,
2576         * and the object is contained in a pack file.  The pack
2577         * is probably already open and will be faster to obtain
2578         * the data through than the working directory.  Loose
2579         * objects however would tend to be slower as they need
2580         * to be individually opened and inflated.
2581         */
2582        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2583                return 0;
2584
2585        len = strlen(name);
2586        pos = cache_name_pos(name, len);
2587        if (pos < 0)
2588                return 0;
2589        ce = active_cache[pos];
2590
2591        /*
2592         * This is not the sha1 we are looking for, or
2593         * unreusable because it is not a regular file.
2594         */
2595        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2596                return 0;
2597
2598        /*
2599         * If ce is marked as "assume unchanged", there is no
2600         * guarantee that work tree matches what we are looking for.
2601         */
2602        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2603                return 0;
2604
2605        /*
2606         * If ce matches the file in the work tree, we can reuse it.
2607         */
2608        if (ce_uptodate(ce) ||
2609            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2610                return 1;
2611
2612        return 0;
2613}
2614
2615static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2616{
2617        int len;
2618        char *data = xmalloc(100), *dirty = "";
2619
2620        /* Are we looking at the work tree? */
2621        if (s->dirty_submodule)
2622                dirty = "-dirty";
2623
2624        len = snprintf(data, 100,
2625                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2626        s->data = data;
2627        s->size = len;
2628        s->should_free = 1;
2629        if (size_only) {
2630                s->data = NULL;
2631                free(data);
2632        }
2633        return 0;
2634}
2635
2636/*
2637 * While doing rename detection and pickaxe operation, we may need to
2638 * grab the data for the blob (or file) for our own in-core comparison.
2639 * diff_filespec has data and size fields for this purpose.
2640 */
2641int diff_populate_filespec(struct diff_filespec *s, int size_only)
2642{
2643        int err = 0;
2644        if (!DIFF_FILE_VALID(s))
2645                die("internal error: asking to populate invalid file.");
2646        if (S_ISDIR(s->mode))
2647                return -1;
2648
2649        if (s->data)
2650                return 0;
2651
2652        if (size_only && 0 < s->size)
2653                return 0;
2654
2655        if (S_ISGITLINK(s->mode))
2656                return diff_populate_gitlink(s, size_only);
2657
2658        if (!s->sha1_valid ||
2659            reuse_worktree_file(s->path, s->sha1, 0)) {
2660                struct strbuf buf = STRBUF_INIT;
2661                struct stat st;
2662                int fd;
2663
2664                if (lstat(s->path, &st) < 0) {
2665                        if (errno == ENOENT) {
2666                        err_empty:
2667                                err = -1;
2668                        empty:
2669                                s->data = (char *)"";
2670                                s->size = 0;
2671                                return err;
2672                        }
2673                }
2674                s->size = xsize_t(st.st_size);
2675                if (!s->size)
2676                        goto empty;
2677                if (S_ISLNK(st.st_mode)) {
2678                        struct strbuf sb = STRBUF_INIT;
2679
2680                        if (strbuf_readlink(&sb, s->path, s->size))
2681                                goto err_empty;
2682                        s->size = sb.len;
2683                        s->data = strbuf_detach(&sb, NULL);
2684                        s->should_free = 1;
2685                        return 0;
2686                }
2687                if (size_only)
2688                        return 0;
2689                fd = open(s->path, O_RDONLY);
2690                if (fd < 0)
2691                        goto err_empty;
2692                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2693                close(fd);
2694                s->should_munmap = 1;
2695
2696                /*
2697                 * Convert from working tree format to canonical git format
2698                 */
2699                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2700                        size_t size = 0;
2701                        munmap(s->data, s->size);
2702                        s->should_munmap = 0;
2703                        s->data = strbuf_detach(&buf, &size);
2704                        s->size = size;
2705                        s->should_free = 1;
2706                }
2707        }
2708        else {
2709                enum object_type type;
2710                if (size_only) {
2711                        type = sha1_object_info(s->sha1, &s->size);
2712                        if (type < 0)
2713                                die("unable to read %s", sha1_to_hex(s->sha1));
2714                } else {
2715                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2716                        if (!s->data)
2717                                die("unable to read %s", sha1_to_hex(s->sha1));
2718                        s->should_free = 1;
2719                }
2720        }
2721        return 0;
2722}
2723
2724void diff_free_filespec_blob(struct diff_filespec *s)
2725{
2726        if (s->should_free)
2727                free(s->data);
2728        else if (s->should_munmap)
2729                munmap(s->data, s->size);
2730
2731        if (s->should_free || s->should_munmap) {
2732                s->should_free = s->should_munmap = 0;
2733                s->data = NULL;
2734        }
2735}
2736
2737void diff_free_filespec_data(struct diff_filespec *s)
2738{
2739        diff_free_filespec_blob(s);
2740        free(s->cnt_data);
2741        s->cnt_data = NULL;
2742}
2743
2744static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2745                           void *blob,
2746                           unsigned long size,
2747                           const unsigned char *sha1,
2748                           int mode)
2749{
2750        int fd;
2751        struct strbuf buf = STRBUF_INIT;
2752        struct strbuf template = STRBUF_INIT;
2753        char *path_dup = xstrdup(path);
2754        const char *base = basename(path_dup);
2755
2756        /* Generate "XXXXXX_basename.ext" */
2757        strbuf_addstr(&template, "XXXXXX_");
2758        strbuf_addstr(&template, base);
2759
2760        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2761                        strlen(base) + 1);
2762        if (fd < 0)
2763                die_errno("unable to create temp-file");
2764        if (convert_to_working_tree(path,
2765                        (const char *)blob, (size_t)size, &buf)) {
2766                blob = buf.buf;
2767                size = buf.len;
2768        }
2769        if (write_in_full(fd, blob, size) != size)
2770                die_errno("unable to write temp-file");
2771        close(fd);
2772        temp->name = temp->tmp_path;
2773        strcpy(temp->hex, sha1_to_hex(sha1));
2774        temp->hex[40] = 0;
2775        sprintf(temp->mode, "%06o", mode);
2776        strbuf_release(&buf);
2777        strbuf_release(&template);
2778        free(path_dup);
2779}
2780
2781static struct diff_tempfile *prepare_temp_file(const char *name,
2782                struct diff_filespec *one)
2783{
2784        struct diff_tempfile *temp = claim_diff_tempfile();
2785
2786        if (!DIFF_FILE_VALID(one)) {
2787        not_a_valid_file:
2788                /* A '-' entry produces this for file-2, and
2789                 * a '+' entry produces this for file-1.
2790                 */
2791                temp->name = "/dev/null";
2792                strcpy(temp->hex, ".");
2793                strcpy(temp->mode, ".");
2794                return temp;
2795        }
2796
2797        if (!remove_tempfile_installed) {
2798                atexit(remove_tempfile);
2799                sigchain_push_common(remove_tempfile_on_signal);
2800                remove_tempfile_installed = 1;
2801        }
2802
2803        if (!one->sha1_valid ||
2804            reuse_worktree_file(name, one->sha1, 1)) {
2805                struct stat st;
2806                if (lstat(name, &st) < 0) {
2807                        if (errno == ENOENT)
2808                                goto not_a_valid_file;
2809                        die_errno("stat(%s)", name);
2810                }
2811                if (S_ISLNK(st.st_mode)) {
2812                        struct strbuf sb = STRBUF_INIT;
2813                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2814                                die_errno("readlink(%s)", name);
2815                        prep_temp_blob(name, temp, sb.buf, sb.len,
2816                                       (one->sha1_valid ?
2817                                        one->sha1 : null_sha1),
2818                                       (one->sha1_valid ?
2819                                        one->mode : S_IFLNK));
2820                        strbuf_release(&sb);
2821                }
2822                else {
2823                        /* we can borrow from the file in the work tree */
2824                        temp->name = name;
2825                        if (!one->sha1_valid)
2826                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2827                        else
2828                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2829                        /* Even though we may sometimes borrow the
2830                         * contents from the work tree, we always want
2831                         * one->mode.  mode is trustworthy even when
2832                         * !(one->sha1_valid), as long as
2833                         * DIFF_FILE_VALID(one).
2834                         */
2835                        sprintf(temp->mode, "%06o", one->mode);
2836                }
2837                return temp;
2838        }
2839        else {
2840                if (diff_populate_filespec(one, 0))
2841                        die("cannot read data blob for %s", one->path);
2842                prep_temp_blob(name, temp, one->data, one->size,
2843                               one->sha1, one->mode);
2844        }
2845        return temp;
2846}
2847
2848/* An external diff command takes:
2849 *
2850 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2851 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2852 *
2853 */
2854static void run_external_diff(const char *pgm,
2855                              const char *name,
2856                              const char *other,
2857                              struct diff_filespec *one,
2858                              struct diff_filespec *two,
2859                              const char *xfrm_msg,
2860                              int complete_rewrite)
2861{
2862        const char *spawn_arg[10];
2863        int retval;
2864        const char **arg = &spawn_arg[0];
2865
2866        if (one && two) {
2867                struct diff_tempfile *temp_one, *temp_two;
2868                const char *othername = (other ? other : name);
2869                temp_one = prepare_temp_file(name, one);
2870                temp_two = prepare_temp_file(othername, two);
2871                *arg++ = pgm;
2872                *arg++ = name;
2873                *arg++ = temp_one->name;
2874                *arg++ = temp_one->hex;
2875                *arg++ = temp_one->mode;
2876                *arg++ = temp_two->name;
2877                *arg++ = temp_two->hex;
2878                *arg++ = temp_two->mode;
2879                if (other) {
2880                        *arg++ = other;
2881                        *arg++ = xfrm_msg;
2882                }
2883        } else {
2884                *arg++ = pgm;
2885                *arg++ = name;
2886        }
2887        *arg = NULL;
2888        fflush(NULL);
2889        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2890        remove_tempfile();
2891        if (retval) {
2892                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2893                exit(1);
2894        }
2895}
2896
2897static int similarity_index(struct diff_filepair *p)
2898{
2899        return p->score * 100 / MAX_SCORE;
2900}
2901
2902static void fill_metainfo(struct strbuf *msg,
2903                          const char *name,
2904                          const char *other,
2905                          struct diff_filespec *one,
2906                          struct diff_filespec *two,
2907                          struct diff_options *o,
2908                          struct diff_filepair *p,
2909                          int *must_show_header,
2910                          int use_color)
2911{
2912        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2913        const char *reset = diff_get_color(use_color, DIFF_RESET);
2914        const char *line_prefix = diff_line_prefix(o);
2915
2916        *must_show_header = 1;
2917        strbuf_init(msg, PATH_MAX * 2 + 300);
2918        switch (p->status) {
2919        case DIFF_STATUS_COPIED:
2920                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2921                            line_prefix, set, similarity_index(p));
2922                strbuf_addf(msg, "%s\n%s%scopy from ",
2923                            reset,  line_prefix, set);
2924                quote_c_style(name, msg, NULL, 0);
2925                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2926                quote_c_style(other, msg, NULL, 0);
2927                strbuf_addf(msg, "%s\n", reset);
2928                break;
2929        case DIFF_STATUS_RENAMED:
2930                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2931                            line_prefix, set, similarity_index(p));
2932                strbuf_addf(msg, "%s\n%s%srename from ",
2933                            reset, line_prefix, set);
2934                quote_c_style(name, msg, NULL, 0);
2935                strbuf_addf(msg, "%s\n%s%srename to ",
2936                            reset, line_prefix, set);
2937                quote_c_style(other, msg, NULL, 0);
2938                strbuf_addf(msg, "%s\n", reset);
2939                break;
2940        case DIFF_STATUS_MODIFIED:
2941                if (p->score) {
2942                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2943                                    line_prefix,
2944                                    set, similarity_index(p), reset);
2945                        break;
2946                }
2947                /* fallthru */
2948        default:
2949                *must_show_header = 0;
2950        }
2951        if (one && two && hashcmp(one->sha1, two->sha1)) {
2952                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2953
2954                if (DIFF_OPT_TST(o, BINARY)) {
2955                        mmfile_t mf;
2956                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2957                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2958                                abbrev = 40;
2959                }
2960                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2961                            find_unique_abbrev(one->sha1, abbrev));
2962                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2963                if (one->mode == two->mode)
2964                        strbuf_addf(msg, " %06o", one->mode);
2965                strbuf_addf(msg, "%s\n", reset);
2966        }
2967}
2968
2969static void run_diff_cmd(const char *pgm,
2970                         const char *name,
2971                         const char *other,
2972                         const char *attr_path,
2973                         struct diff_filespec *one,
2974                         struct diff_filespec *two,
2975                         struct strbuf *msg,
2976                         struct diff_options *o,
2977                         struct diff_filepair *p)
2978{
2979        const char *xfrm_msg = NULL;
2980        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2981        int must_show_header = 0;
2982
2983
2984        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
2985                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2986                if (drv && drv->external)
2987                        pgm = drv->external;
2988        }
2989
2990        if (msg) {
2991                /*
2992                 * don't use colors when the header is intended for an
2993                 * external diff driver
2994                 */
2995                fill_metainfo(msg, name, other, one, two, o, p,
2996                              &must_show_header,
2997                              want_color(o->use_color) && !pgm);
2998                xfrm_msg = msg->len ? msg->buf : NULL;
2999        }
3000
3001        if (pgm) {
3002                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3003                                  complete_rewrite);
3004                return;
3005        }
3006        if (one && two)
3007                builtin_diff(name, other ? other : name,
3008                             one, two, xfrm_msg, must_show_header,
3009                             o, complete_rewrite);
3010        else
3011                fprintf(o->file, "* Unmerged path %s\n", name);
3012}
3013
3014static void diff_fill_sha1_info(struct diff_filespec *one)
3015{
3016        if (DIFF_FILE_VALID(one)) {
3017                if (!one->sha1_valid) {
3018                        struct stat st;
3019                        if (one->is_stdin) {
3020                                hashcpy(one->sha1, null_sha1);
3021                                return;
3022                        }
3023                        if (lstat(one->path, &st) < 0)
3024                                die_errno("stat '%s'", one->path);
3025                        if (index_path(one->sha1, one->path, &st, 0))
3026                                die("cannot hash %s", one->path);
3027                }
3028        }
3029        else
3030                hashclr(one->sha1);
3031}
3032
3033static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3034{
3035        /* Strip the prefix but do not molest /dev/null and absolute paths */
3036        if (*namep && **namep != '/') {
3037                *namep += prefix_length;
3038                if (**namep == '/')
3039                        ++*namep;
3040        }
3041        if (*otherp && **otherp != '/') {
3042                *otherp += prefix_length;
3043                if (**otherp == '/')
3044                        ++*otherp;
3045        }
3046}
3047
3048static void run_diff(struct diff_filepair *p, struct diff_options *o)
3049{
3050        const char *pgm = external_diff();
3051        struct strbuf msg;
3052        struct diff_filespec *one = p->one;
3053        struct diff_filespec *two = p->two;
3054        const char *name;
3055        const char *other;
3056        const char *attr_path;
3057
3058        name  = p->one->path;
3059        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3060        attr_path = name;
3061        if (o->prefix_length)
3062                strip_prefix(o->prefix_length, &name, &other);
3063
3064        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3065                pgm = NULL;
3066
3067        if (DIFF_PAIR_UNMERGED(p)) {
3068                run_diff_cmd(pgm, name, NULL, attr_path,
3069                             NULL, NULL, NULL, o, p);
3070                return;
3071        }
3072
3073        diff_fill_sha1_info(one);
3074        diff_fill_sha1_info(two);
3075
3076        if (!pgm &&
3077            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3078            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3079                /*
3080                 * a filepair that changes between file and symlink
3081                 * needs to be split into deletion and creation.
3082                 */
3083                struct diff_filespec *null = alloc_filespec(two->path);
3084                run_diff_cmd(NULL, name, other, attr_path,
3085                             one, null, &msg, o, p);
3086                free(null);
3087                strbuf_release(&msg);
3088
3089                null = alloc_filespec(one->path);
3090                run_diff_cmd(NULL, name, other, attr_path,
3091                             null, two, &msg, o, p);
3092                free(null);
3093        }
3094        else
3095                run_diff_cmd(pgm, name, other, attr_path,
3096                             one, two, &msg, o, p);
3097
3098        strbuf_release(&msg);
3099}
3100
3101static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3102                         struct diffstat_t *diffstat)
3103{
3104        const char *name;
3105        const char *other;
3106
3107        if (DIFF_PAIR_UNMERGED(p)) {
3108                /* unmerged */
3109                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3110                return;
3111        }
3112
3113        name = p->one->path;
3114        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3115
3116        if (o->prefix_length)
3117                strip_prefix(o->prefix_length, &name, &other);
3118
3119        diff_fill_sha1_info(p->one);
3120        diff_fill_sha1_info(p->two);
3121
3122        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3123}
3124
3125static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3126{
3127        const char *name;
3128        const char *other;
3129        const char *attr_path;
3130
3131        if (DIFF_PAIR_UNMERGED(p)) {
3132                /* unmerged */
3133                return;
3134        }
3135
3136        name = p->one->path;
3137        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3138        attr_path = other ? other : name;
3139
3140        if (o->prefix_length)
3141                strip_prefix(o->prefix_length, &name, &other);
3142
3143        diff_fill_sha1_info(p->one);
3144        diff_fill_sha1_info(p->two);
3145
3146        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3147}
3148
3149void diff_setup(struct diff_options *options)
3150{
3151        memcpy(options, &default_diff_options, sizeof(*options));
3152
3153        options->file = stdout;
3154
3155        options->line_termination = '\n';
3156        options->break_opt = -1;
3157        options->rename_limit = -1;
3158        options->dirstat_permille = diff_dirstat_permille_default;
3159        options->context = diff_context_default;
3160        DIFF_OPT_SET(options, RENAME_EMPTY);
3161
3162        options->change = diff_change;
3163        options->add_remove = diff_addremove;
3164        options->use_color = diff_use_color_default;
3165        options->detect_rename = diff_detect_rename_default;
3166
3167        if (diff_no_prefix) {
3168                options->a_prefix = options->b_prefix = "";
3169        } else if (!diff_mnemonic_prefix) {
3170                options->a_prefix = "a/";
3171                options->b_prefix = "b/";
3172        }
3173}
3174
3175void diff_setup_done(struct diff_options *options)
3176{
3177        int count = 0;
3178
3179        if (options->output_format & DIFF_FORMAT_NAME)
3180                count++;
3181        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3182                count++;
3183        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3184                count++;
3185        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3186                count++;
3187        if (count > 1)
3188                die("--name-only, --name-status, --check and -s are mutually exclusive");
3189
3190        /*
3191         * Most of the time we can say "there are changes"
3192         * only by checking if there are changed paths, but
3193         * --ignore-whitespace* options force us to look
3194         * inside contents.
3195         */
3196
3197        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3198            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3199            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3200                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3201        else
3202                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3203
3204        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3205                options->detect_rename = DIFF_DETECT_COPY;
3206
3207        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3208                options->prefix = NULL;
3209        if (options->prefix)
3210                options->prefix_length = strlen(options->prefix);
3211        else
3212                options->prefix_length = 0;
3213
3214        if (options->output_format & (DIFF_FORMAT_NAME |
3215                                      DIFF_FORMAT_NAME_STATUS |
3216                                      DIFF_FORMAT_CHECKDIFF |
3217                                      DIFF_FORMAT_NO_OUTPUT))
3218                options->output_format &= ~(DIFF_FORMAT_RAW |
3219                                            DIFF_FORMAT_NUMSTAT |
3220                                            DIFF_FORMAT_DIFFSTAT |
3221                                            DIFF_FORMAT_SHORTSTAT |
3222                                            DIFF_FORMAT_DIRSTAT |
3223                                            DIFF_FORMAT_SUMMARY |
3224                                            DIFF_FORMAT_PATCH);
3225
3226        /*
3227         * These cases always need recursive; we do not drop caller-supplied
3228         * recursive bits for other formats here.
3229         */
3230        if (options->output_format & (DIFF_FORMAT_PATCH |
3231                                      DIFF_FORMAT_NUMSTAT |
3232                                      DIFF_FORMAT_DIFFSTAT |
3233                                      DIFF_FORMAT_SHORTSTAT |
3234                                      DIFF_FORMAT_DIRSTAT |
3235                                      DIFF_FORMAT_SUMMARY |
3236                                      DIFF_FORMAT_CHECKDIFF))
3237                DIFF_OPT_SET(options, RECURSIVE);
3238        /*
3239         * Also pickaxe would not work very well if you do not say recursive
3240         */
3241        if (options->pickaxe)
3242                DIFF_OPT_SET(options, RECURSIVE);
3243        /*
3244         * When patches are generated, submodules diffed against the work tree
3245         * must be checked for dirtiness too so it can be shown in the output
3246         */
3247        if (options->output_format & DIFF_FORMAT_PATCH)
3248                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3249
3250        if (options->detect_rename && options->rename_limit < 0)
3251                options->rename_limit = diff_rename_limit_default;
3252        if (options->setup & DIFF_SETUP_USE_CACHE) {
3253                if (!active_cache)
3254                        /* read-cache does not die even when it fails
3255                         * so it is safe for us to do this here.  Also
3256                         * it does not smudge active_cache or active_nr
3257                         * when it fails, so we do not have to worry about
3258                         * cleaning it up ourselves either.
3259                         */
3260                        read_cache();
3261        }
3262        if (options->abbrev <= 0 || 40 < options->abbrev)
3263                options->abbrev = 40; /* full */
3264
3265        /*
3266         * It does not make sense to show the first hit we happened
3267         * to have found.  It does not make sense not to return with
3268         * exit code in such a case either.
3269         */
3270        if (DIFF_OPT_TST(options, QUICK)) {
3271                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3272                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3273        }
3274}
3275
3276static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3277{
3278        char c, *eq;
3279        int len;
3280
3281        if (*arg != '-')
3282                return 0;
3283        c = *++arg;
3284        if (!c)
3285                return 0;
3286        if (c == arg_short) {
3287                c = *++arg;
3288                if (!c)
3289                        return 1;
3290                if (val && isdigit(c)) {
3291                        char *end;
3292                        int n = strtoul(arg, &end, 10);
3293                        if (*end)
3294                                return 0;
3295                        *val = n;
3296                        return 1;
3297                }
3298                return 0;
3299        }
3300        if (c != '-')
3301                return 0;
3302        arg++;
3303        eq = strchr(arg, '=');
3304        if (eq)
3305                len = eq - arg;
3306        else
3307                len = strlen(arg);
3308        if (!len || strncmp(arg, arg_long, len))
3309                return 0;
3310        if (eq) {
3311                int n;
3312                char *end;
3313                if (!isdigit(*++eq))
3314                        return 0;
3315                n = strtoul(eq, &end, 10);
3316                if (*end)
3317                        return 0;
3318                *val = n;
3319        }
3320        return 1;
3321}
3322
3323static int diff_scoreopt_parse(const char *opt);
3324
3325static inline int short_opt(char opt, const char **argv,
3326                            const char **optarg)
3327{
3328        const char *arg = argv[0];
3329        if (arg[0] != '-' || arg[1] != opt)
3330                return 0;
3331        if (arg[2] != '\0') {
3332                *optarg = arg + 2;
3333                return 1;
3334        }
3335        if (!argv[1])
3336                die("Option '%c' requires a value", opt);
3337        *optarg = argv[1];
3338        return 2;
3339}
3340
3341int parse_long_opt(const char *opt, const char **argv,
3342                   const char **optarg)
3343{
3344        const char *arg = argv[0];
3345        if (arg[0] != '-' || arg[1] != '-')
3346                return 0;
3347        arg += strlen("--");
3348        if (prefixcmp(arg, opt))
3349                return 0;
3350        arg += strlen(opt);
3351        if (*arg == '=') { /* sticked form: --option=value */
3352                *optarg = arg + 1;
3353                return 1;
3354        }
3355        if (*arg != '\0')
3356                return 0;
3357        /* separate form: --option value */
3358        if (!argv[1])
3359                die("Option '--%s' requires a value", opt);
3360        *optarg = argv[1];
3361        return 2;
3362}
3363
3364static int stat_opt(struct diff_options *options, const char **av)
3365{
3366        const char *arg = av[0];
3367        char *end;
3368        int width = options->stat_width;
3369        int name_width = options->stat_name_width;
3370        int graph_width = options->stat_graph_width;
3371        int count = options->stat_count;
3372        int argcount = 1;
3373
3374        arg += strlen("--stat");
3375        end = (char *)arg;
3376
3377        switch (*arg) {
3378        case '-':
3379                if (!prefixcmp(arg, "-width")) {
3380                        arg += strlen("-width");
3381                        if (*arg == '=')
3382                                width = strtoul(arg + 1, &end, 10);
3383                        else if (!*arg && !av[1])
3384                                die("Option '--stat-width' requires a value");
3385                        else if (!*arg) {
3386                                width = strtoul(av[1], &end, 10);
3387                                argcount = 2;
3388                        }
3389                } else if (!prefixcmp(arg, "-name-width")) {
3390                        arg += strlen("-name-width");
3391                        if (*arg == '=')
3392                                name_width = strtoul(arg + 1, &end, 10);
3393                        else if (!*arg && !av[1])
3394                                die("Option '--stat-name-width' requires a value");
3395                        else if (!*arg) {
3396                                name_width = strtoul(av[1], &end, 10);
3397                                argcount = 2;
3398                        }
3399                } else if (!prefixcmp(arg, "-graph-width")) {
3400                        arg += strlen("-graph-width");
3401                        if (*arg == '=')
3402                                graph_width = strtoul(arg + 1, &end, 10);
3403                        else if (!*arg && !av[1])
3404                                die("Option '--stat-graph-width' requires a value");
3405                        else if (!*arg) {
3406                                graph_width = strtoul(av[1], &end, 10);
3407                                argcount = 2;
3408                        }
3409                } else if (!prefixcmp(arg, "-count")) {
3410                        arg += strlen("-count");
3411                        if (*arg == '=')
3412                                count = strtoul(arg + 1, &end, 10);
3413                        else if (!*arg && !av[1])
3414                                die("Option '--stat-count' requires a value");
3415                        else if (!*arg) {
3416                                count = strtoul(av[1], &end, 10);
3417                                argcount = 2;
3418                        }
3419                }
3420                break;
3421        case '=':
3422                width = strtoul(arg+1, &end, 10);
3423                if (*end == ',')
3424                        name_width = strtoul(end+1, &end, 10);
3425                if (*end == ',')
3426                        count = strtoul(end+1, &end, 10);
3427        }
3428
3429        /* Important! This checks all the error cases! */
3430        if (*end)
3431                return 0;
3432        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3433        options->stat_name_width = name_width;
3434        options->stat_graph_width = graph_width;
3435        options->stat_width = width;
3436        options->stat_count = count;
3437        return argcount;
3438}
3439
3440static int parse_dirstat_opt(struct diff_options *options, const char *params)
3441{
3442        struct strbuf errmsg = STRBUF_INIT;
3443        if (parse_dirstat_params(options, params, &errmsg))
3444                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3445                    errmsg.buf);
3446        strbuf_release(&errmsg);
3447        /*
3448         * The caller knows a dirstat-related option is given from the command
3449         * line; allow it to say "return this_function();"
3450         */
3451        options->output_format |= DIFF_FORMAT_DIRSTAT;
3452        return 1;
3453}
3454
3455static int parse_submodule_opt(struct diff_options *options, const char *value)
3456{
3457        if (parse_submodule_params(options, value))
3458                die(_("Failed to parse --submodule option parameter: '%s'"),
3459                        value);
3460        return 1;
3461}
3462
3463int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3464{
3465        const char *arg = av[0];
3466        const char *optarg;
3467        int argcount;
3468
3469        /* Output format options */
3470        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3471                options->output_format |= DIFF_FORMAT_PATCH;
3472        else if (opt_arg(arg, 'U', "unified", &options->context))
3473                options->output_format |= DIFF_FORMAT_PATCH;
3474        else if (!strcmp(arg, "--raw"))
3475                options->output_format |= DIFF_FORMAT_RAW;
3476        else if (!strcmp(arg, "--patch-with-raw"))
3477                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3478        else if (!strcmp(arg, "--numstat"))
3479                options->output_format |= DIFF_FORMAT_NUMSTAT;
3480        else if (!strcmp(arg, "--shortstat"))
3481                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3482        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3483                return parse_dirstat_opt(options, "");
3484        else if (!prefixcmp(arg, "-X"))
3485                return parse_dirstat_opt(options, arg + 2);
3486        else if (!prefixcmp(arg, "--dirstat="))
3487                return parse_dirstat_opt(options, arg + 10);
3488        else if (!strcmp(arg, "--cumulative"))
3489                return parse_dirstat_opt(options, "cumulative");
3490        else if (!strcmp(arg, "--dirstat-by-file"))
3491                return parse_dirstat_opt(options, "files");
3492        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3493                parse_dirstat_opt(options, "files");
3494                return parse_dirstat_opt(options, arg + 18);
3495        }
3496        else if (!strcmp(arg, "--check"))
3497                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3498        else if (!strcmp(arg, "--summary"))
3499                options->output_format |= DIFF_FORMAT_SUMMARY;
3500        else if (!strcmp(arg, "--patch-with-stat"))
3501                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3502        else if (!strcmp(arg, "--name-only"))
3503                options->output_format |= DIFF_FORMAT_NAME;
3504        else if (!strcmp(arg, "--name-status"))
3505                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3506        else if (!strcmp(arg, "-s"))
3507                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3508        else if (!prefixcmp(arg, "--stat"))
3509                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3510                return stat_opt(options, av);
3511
3512        /* renames options */
3513        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3514                 !strcmp(arg, "--break-rewrites")) {
3515                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3516                        return error("invalid argument to -B: %s", arg+2);
3517        }
3518        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3519                 !strcmp(arg, "--find-renames")) {
3520                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3521                        return error("invalid argument to -M: %s", arg+2);
3522                options->detect_rename = DIFF_DETECT_RENAME;
3523        }
3524        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3525                options->irreversible_delete = 1;
3526        }
3527        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3528                 !strcmp(arg, "--find-copies")) {
3529                if (options->detect_rename == DIFF_DETECT_COPY)
3530                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3531                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3532                        return error("invalid argument to -C: %s", arg+2);
3533                options->detect_rename = DIFF_DETECT_COPY;
3534        }
3535        else if (!strcmp(arg, "--no-renames"))
3536                options->detect_rename = 0;
3537        else if (!strcmp(arg, "--rename-empty"))
3538                DIFF_OPT_SET(options, RENAME_EMPTY);
3539        else if (!strcmp(arg, "--no-rename-empty"))
3540                DIFF_OPT_CLR(options, RENAME_EMPTY);
3541        else if (!strcmp(arg, "--relative"))
3542                DIFF_OPT_SET(options, RELATIVE_NAME);
3543        else if (!prefixcmp(arg, "--relative=")) {
3544                DIFF_OPT_SET(options, RELATIVE_NAME);
3545                options->prefix = arg + 11;
3546        }
3547
3548        /* xdiff options */
3549        else if (!strcmp(arg, "--minimal"))
3550                DIFF_XDL_SET(options, NEED_MINIMAL);
3551        else if (!strcmp(arg, "--no-minimal"))
3552                DIFF_XDL_CLR(options, NEED_MINIMAL);
3553        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3554                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3555        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3556                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3557        else if (!strcmp(arg, "--ignore-space-at-eol"))
3558                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3559        else if (!strcmp(arg, "--patience"))
3560                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3561        else if (!strcmp(arg, "--histogram"))
3562                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3563
3564        /* flags options */
3565        else if (!strcmp(arg, "--binary")) {
3566                options->output_format |= DIFF_FORMAT_PATCH;
3567                DIFF_OPT_SET(options, BINARY);
3568        }
3569        else if (!strcmp(arg, "--full-index"))
3570                DIFF_OPT_SET(options, FULL_INDEX);
3571        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3572                DIFF_OPT_SET(options, TEXT);
3573        else if (!strcmp(arg, "-R"))
3574                DIFF_OPT_SET(options, REVERSE_DIFF);
3575        else if (!strcmp(arg, "--find-copies-harder"))
3576                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3577        else if (!strcmp(arg, "--follow"))
3578                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3579        else if (!strcmp(arg, "--no-follow"))
3580                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3581        else if (!strcmp(arg, "--color"))
3582                options->use_color = 1;
3583        else if (!prefixcmp(arg, "--color=")) {
3584                int value = git_config_colorbool(NULL, arg+8);
3585                if (value < 0)
3586                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3587                options->use_color = value;
3588        }
3589        else if (!strcmp(arg, "--no-color"))
3590                options->use_color = 0;
3591        else if (!strcmp(arg, "--color-words")) {
3592                options->use_color = 1;
3593                options->word_diff = DIFF_WORDS_COLOR;
3594        }
3595        else if (!prefixcmp(arg, "--color-words=")) {
3596                options->use_color = 1;
3597                options->word_diff = DIFF_WORDS_COLOR;
3598                options->word_regex = arg + 14;
3599        }
3600        else if (!strcmp(arg, "--word-diff")) {
3601                if (options->word_diff == DIFF_WORDS_NONE)
3602                        options->word_diff = DIFF_WORDS_PLAIN;
3603        }
3604        else if (!prefixcmp(arg, "--word-diff=")) {
3605                const char *type = arg + 12;
3606                if (!strcmp(type, "plain"))
3607                        options->word_diff = DIFF_WORDS_PLAIN;
3608                else if (!strcmp(type, "color")) {
3609                        options->use_color = 1;
3610                        options->word_diff = DIFF_WORDS_COLOR;
3611                }
3612                else if (!strcmp(type, "porcelain"))
3613                        options->word_diff = DIFF_WORDS_PORCELAIN;
3614                else if (!strcmp(type, "none"))
3615                        options->word_diff = DIFF_WORDS_NONE;
3616                else
3617                        die("bad --word-diff argument: %s", type);
3618        }
3619        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3620                if (options->word_diff == DIFF_WORDS_NONE)
3621                        options->word_diff = DIFF_WORDS_PLAIN;
3622                options->word_regex = optarg;
3623                return argcount;
3624        }
3625        else if (!strcmp(arg, "--exit-code"))
3626                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3627        else if (!strcmp(arg, "--quiet"))
3628                DIFF_OPT_SET(options, QUICK);
3629        else if (!strcmp(arg, "--ext-diff"))
3630                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3631        else if (!strcmp(arg, "--no-ext-diff"))
3632                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3633        else if (!strcmp(arg, "--textconv"))
3634                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3635        else if (!strcmp(arg, "--no-textconv"))
3636                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3637        else if (!strcmp(arg, "--ignore-submodules")) {
3638                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3639                handle_ignore_submodules_arg(options, "all");
3640        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3641                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3642                handle_ignore_submodules_arg(options, arg + 20);
3643        } else if (!strcmp(arg, "--submodule"))
3644                DIFF_OPT_SET(options, SUBMODULE_LOG);
3645        else if (!prefixcmp(arg, "--submodule="))
3646                return parse_submodule_opt(options, arg + 12);
3647
3648        /* misc options */
3649        else if (!strcmp(arg, "-z"))
3650                options->line_termination = 0;
3651        else if ((argcount = short_opt('l', av, &optarg))) {
3652                options->rename_limit = strtoul(optarg, NULL, 10);
3653                return argcount;
3654        }
3655        else if ((argcount = short_opt('S', av, &optarg))) {
3656                options->pickaxe = optarg;
3657                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3658                return argcount;
3659        } else if ((argcount = short_opt('G', av, &optarg))) {
3660                options->pickaxe = optarg;
3661                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3662                return argcount;
3663        }
3664        else if (!strcmp(arg, "--pickaxe-all"))
3665                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3666        else if (!strcmp(arg, "--pickaxe-regex"))
3667                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3668        else if ((argcount = short_opt('O', av, &optarg))) {
3669                options->orderfile = optarg;
3670                return argcount;
3671        }
3672        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3673                options->filter = optarg;
3674                return argcount;
3675        }
3676        else if (!strcmp(arg, "--abbrev"))
3677                options->abbrev = DEFAULT_ABBREV;
3678        else if (!prefixcmp(arg, "--abbrev=")) {
3679                options->abbrev = strtoul(arg + 9, NULL, 10);
3680                if (options->abbrev < MINIMUM_ABBREV)
3681                        options->abbrev = MINIMUM_ABBREV;
3682                else if (40 < options->abbrev)
3683                        options->abbrev = 40;
3684        }
3685        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3686                options->a_prefix = optarg;
3687                return argcount;
3688        }
3689        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3690                options->b_prefix = optarg;
3691                return argcount;
3692        }
3693        else if (!strcmp(arg, "--no-prefix"))
3694                options->a_prefix = options->b_prefix = "";
3695        else if (opt_arg(arg, '\0', "inter-hunk-context",
3696                         &options->interhunkcontext))
3697                ;
3698        else if (!strcmp(arg, "-W"))
3699                DIFF_OPT_SET(options, FUNCCONTEXT);
3700        else if (!strcmp(arg, "--function-context"))
3701                DIFF_OPT_SET(options, FUNCCONTEXT);
3702        else if (!strcmp(arg, "--no-function-context"))
3703                DIFF_OPT_CLR(options, FUNCCONTEXT);
3704        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3705                options->file = fopen(optarg, "w");
3706                if (!options->file)
3707                        die_errno("Could not open '%s'", optarg);
3708                options->close_file = 1;
3709                return argcount;
3710        } else
3711                return 0;
3712        return 1;
3713}
3714
3715int parse_rename_score(const char **cp_p)
3716{
3717        unsigned long num, scale;
3718        int ch, dot;
3719        const char *cp = *cp_p;
3720
3721        num = 0;
3722        scale = 1;
3723        dot = 0;
3724        for (;;) {
3725                ch = *cp;
3726                if ( !dot && ch == '.' ) {
3727                        scale = 1;
3728                        dot = 1;
3729                } else if ( ch == '%' ) {
3730                        scale = dot ? scale*100 : 100;
3731                        cp++;   /* % is always at the end */
3732                        break;
3733                } else if ( ch >= '0' && ch <= '9' ) {
3734                        if ( scale < 100000 ) {
3735                                scale *= 10;
3736                                num = (num*10) + (ch-'0');
3737                        }
3738                } else {
3739                        break;
3740                }
3741                cp++;
3742        }
3743        *cp_p = cp;
3744
3745        /* user says num divided by scale and we say internally that
3746         * is MAX_SCORE * num / scale.
3747         */
3748        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3749}
3750
3751static int diff_scoreopt_parse(const char *opt)
3752{
3753        int opt1, opt2, cmd;
3754
3755        if (*opt++ != '-')
3756                return -1;
3757        cmd = *opt++;
3758        if (cmd == '-') {
3759                /* convert the long-form arguments into short-form versions */
3760                if (!prefixcmp(opt, "break-rewrites")) {
3761                        opt += strlen("break-rewrites");
3762                        if (*opt == 0 || *opt++ == '=')
3763                                cmd = 'B';
3764                } else if (!prefixcmp(opt, "find-copies")) {
3765                        opt += strlen("find-copies");
3766                        if (*opt == 0 || *opt++ == '=')
3767                                cmd = 'C';
3768                } else if (!prefixcmp(opt, "find-renames")) {
3769                        opt += strlen("find-renames");
3770                        if (*opt == 0 || *opt++ == '=')
3771                                cmd = 'M';
3772                }
3773        }
3774        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3775                return -1; /* that is not a -M, -C nor -B option */
3776
3777        opt1 = parse_rename_score(&opt);
3778        if (cmd != 'B')
3779                opt2 = 0;
3780        else {
3781                if (*opt == 0)
3782                        opt2 = 0;
3783                else if (*opt != '/')
3784                        return -1; /* we expect -B80/99 or -B80 */
3785                else {
3786                        opt++;
3787                        opt2 = parse_rename_score(&opt);
3788                }
3789        }
3790        if (*opt != 0)
3791                return -1;
3792        return opt1 | (opt2 << 16);
3793}
3794
3795struct diff_queue_struct diff_queued_diff;
3796
3797void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3798{
3799        if (queue->alloc <= queue->nr) {
3800                queue->alloc = alloc_nr(queue->alloc);
3801                queue->queue = xrealloc(queue->queue,
3802                                        sizeof(dp) * queue->alloc);
3803        }
3804        queue->queue[queue->nr++] = dp;
3805}
3806
3807struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3808                                 struct diff_filespec *one,
3809                                 struct diff_filespec *two)
3810{
3811        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3812        dp->one = one;
3813        dp->two = two;
3814        if (queue)
3815                diff_q(queue, dp);
3816        return dp;
3817}
3818
3819void diff_free_filepair(struct diff_filepair *p)
3820{
3821        free_filespec(p->one);
3822        free_filespec(p->two);
3823        free(p);
3824}
3825
3826/* This is different from find_unique_abbrev() in that
3827 * it stuffs the result with dots for alignment.
3828 */
3829const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3830{
3831        int abblen;
3832        const char *abbrev;
3833        if (len == 40)
3834                return sha1_to_hex(sha1);
3835
3836        abbrev = find_unique_abbrev(sha1, len);
3837        abblen = strlen(abbrev);
3838        if (abblen < 37) {
3839                static char hex[41];
3840                if (len < abblen && abblen <= len + 2)
3841                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3842                else
3843                        sprintf(hex, "%s...", abbrev);
3844                return hex;
3845        }
3846        return sha1_to_hex(sha1);
3847}
3848
3849static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3850{
3851        int line_termination = opt->line_termination;
3852        int inter_name_termination = line_termination ? '\t' : '\0';
3853
3854        fprintf(opt->file, "%s", diff_line_prefix(opt));
3855        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3856                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3857                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3858                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3859        }
3860        if (p->score) {
3861                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3862                        inter_name_termination);
3863        } else {
3864                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3865        }
3866
3867        if (p->status == DIFF_STATUS_COPIED ||
3868            p->status == DIFF_STATUS_RENAMED) {
3869                const char *name_a, *name_b;
3870                name_a = p->one->path;
3871                name_b = p->two->path;
3872                strip_prefix(opt->prefix_length, &name_a, &name_b);
3873                write_name_quoted(name_a, opt->file, inter_name_termination);
3874                write_name_quoted(name_b, opt->file, line_termination);
3875        } else {
3876                const char *name_a, *name_b;
3877                name_a = p->one->mode ? p->one->path : p->two->path;
3878                name_b = NULL;
3879                strip_prefix(opt->prefix_length, &name_a, &name_b);
3880                write_name_quoted(name_a, opt->file, line_termination);
3881        }
3882}
3883
3884int diff_unmodified_pair(struct diff_filepair *p)
3885{
3886        /* This function is written stricter than necessary to support
3887         * the currently implemented transformers, but the idea is to
3888         * let transformers to produce diff_filepairs any way they want,
3889         * and filter and clean them up here before producing the output.
3890         */
3891        struct diff_filespec *one = p->one, *two = p->two;
3892
3893        if (DIFF_PAIR_UNMERGED(p))
3894                return 0; /* unmerged is interesting */
3895
3896        /* deletion, addition, mode or type change
3897         * and rename are all interesting.
3898         */
3899        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3900            DIFF_PAIR_MODE_CHANGED(p) ||
3901            strcmp(one->path, two->path))
3902                return 0;
3903
3904        /* both are valid and point at the same path.  that is, we are
3905         * dealing with a change.
3906         */
3907        if (one->sha1_valid && two->sha1_valid &&
3908            !hashcmp(one->sha1, two->sha1) &&
3909            !one->dirty_submodule && !two->dirty_submodule)
3910                return 1; /* no change */
3911        if (!one->sha1_valid && !two->sha1_valid)
3912                return 1; /* both look at the same file on the filesystem. */
3913        return 0;
3914}
3915
3916static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3917{
3918        if (diff_unmodified_pair(p))
3919                return;
3920
3921        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3922            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3923                return; /* no tree diffs in patch format */
3924
3925        run_diff(p, o);
3926}
3927
3928static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3929                            struct diffstat_t *diffstat)
3930{
3931        if (diff_unmodified_pair(p))
3932                return;
3933
3934        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3935            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3936                return; /* no useful stat for tree diffs */
3937
3938        run_diffstat(p, o, diffstat);
3939}
3940
3941static void diff_flush_checkdiff(struct diff_filepair *p,
3942                struct diff_options *o)
3943{
3944        if (diff_unmodified_pair(p))
3945                return;
3946
3947        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3948            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3949                return; /* nothing to check in tree diffs */
3950
3951        run_checkdiff(p, o);
3952}
3953
3954int diff_queue_is_empty(void)
3955{
3956        struct diff_queue_struct *q = &diff_queued_diff;
3957        int i;
3958        for (i = 0; i < q->nr; i++)
3959                if (!diff_unmodified_pair(q->queue[i]))
3960                        return 0;
3961        return 1;
3962}
3963
3964#if DIFF_DEBUG
3965void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3966{
3967        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3968                x, one ? one : "",
3969                s->path,
3970                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3971                s->mode,
3972                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3973        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3974                x, one ? one : "",
3975                s->size, s->xfrm_flags);
3976}
3977
3978void diff_debug_filepair(const struct diff_filepair *p, int i)
3979{
3980        diff_debug_filespec(p->one, i, "one");
3981        diff_debug_filespec(p->two, i, "two");
3982        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3983                p->score, p->status ? p->status : '?',
3984                p->one->rename_used, p->broken_pair);
3985}
3986
3987void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3988{
3989        int i;
3990        if (msg)
3991                fprintf(stderr, "%s\n", msg);
3992        fprintf(stderr, "q->nr = %d\n", q->nr);
3993        for (i = 0; i < q->nr; i++) {
3994                struct diff_filepair *p = q->queue[i];
3995                diff_debug_filepair(p, i);
3996        }
3997}
3998#endif
3999
4000static void diff_resolve_rename_copy(void)
4001{
4002        int i;
4003        struct diff_filepair *p;
4004        struct diff_queue_struct *q = &diff_queued_diff;
4005
4006        diff_debug_queue("resolve-rename-copy", q);
4007
4008        for (i = 0; i < q->nr; i++) {
4009                p = q->queue[i];
4010                p->status = 0; /* undecided */
4011                if (DIFF_PAIR_UNMERGED(p))
4012                        p->status = DIFF_STATUS_UNMERGED;
4013                else if (!DIFF_FILE_VALID(p->one))
4014                        p->status = DIFF_STATUS_ADDED;
4015                else if (!DIFF_FILE_VALID(p->two))
4016                        p->status = DIFF_STATUS_DELETED;
4017                else if (DIFF_PAIR_TYPE_CHANGED(p))
4018                        p->status = DIFF_STATUS_TYPE_CHANGED;
4019
4020                /* from this point on, we are dealing with a pair
4021                 * whose both sides are valid and of the same type, i.e.
4022                 * either in-place edit or rename/copy edit.
4023                 */
4024                else if (DIFF_PAIR_RENAME(p)) {
4025                        /*
4026                         * A rename might have re-connected a broken
4027                         * pair up, causing the pathnames to be the
4028                         * same again. If so, that's not a rename at
4029                         * all, just a modification..
4030                         *
4031                         * Otherwise, see if this source was used for
4032                         * multiple renames, in which case we decrement
4033                         * the count, and call it a copy.
4034                         */
4035                        if (!strcmp(p->one->path, p->two->path))
4036                                p->status = DIFF_STATUS_MODIFIED;
4037                        else if (--p->one->rename_used > 0)
4038                                p->status = DIFF_STATUS_COPIED;
4039                        else
4040                                p->status = DIFF_STATUS_RENAMED;
4041                }
4042                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4043                         p->one->mode != p->two->mode ||
4044                         p->one->dirty_submodule ||
4045                         p->two->dirty_submodule ||
4046                         is_null_sha1(p->one->sha1))
4047                        p->status = DIFF_STATUS_MODIFIED;
4048                else {
4049                        /* This is a "no-change" entry and should not
4050                         * happen anymore, but prepare for broken callers.
4051                         */
4052                        error("feeding unmodified %s to diffcore",
4053                              p->one->path);
4054                        p->status = DIFF_STATUS_UNKNOWN;
4055                }
4056        }
4057        diff_debug_queue("resolve-rename-copy done", q);
4058}
4059
4060static int check_pair_status(struct diff_filepair *p)
4061{
4062        switch (p->status) {
4063        case DIFF_STATUS_UNKNOWN:
4064                return 0;
4065        case 0:
4066                die("internal error in diff-resolve-rename-copy");
4067        default:
4068                return 1;
4069        }
4070}
4071
4072static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4073{
4074        int fmt = opt->output_format;
4075
4076        if (fmt & DIFF_FORMAT_CHECKDIFF)
4077                diff_flush_checkdiff(p, opt);
4078        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4079                diff_flush_raw(p, opt);
4080        else if (fmt & DIFF_FORMAT_NAME) {
4081                const char *name_a, *name_b;
4082                name_a = p->two->path;
4083                name_b = NULL;
4084                strip_prefix(opt->prefix_length, &name_a, &name_b);
4085                write_name_quoted(name_a, opt->file, opt->line_termination);
4086        }
4087}
4088
4089static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4090{
4091        if (fs->mode)
4092                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4093        else
4094                fprintf(file, " %s ", newdelete);
4095        write_name_quoted(fs->path, file, '\n');
4096}
4097
4098
4099static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4100                const char *line_prefix)
4101{
4102        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4103                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4104                        p->two->mode, show_name ? ' ' : '\n');
4105                if (show_name) {
4106                        write_name_quoted(p->two->path, file, '\n');
4107                }
4108        }
4109}
4110
4111static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4112                        const char *line_prefix)
4113{
4114        char *names = pprint_rename(p->one->path, p->two->path);
4115
4116        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4117        free(names);
4118        show_mode_change(file, p, 0, line_prefix);
4119}
4120
4121static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4122{
4123        FILE *file = opt->file;
4124        const char *line_prefix = diff_line_prefix(opt);
4125
4126        switch(p->status) {
4127        case DIFF_STATUS_DELETED:
4128                fputs(line_prefix, file);
4129                show_file_mode_name(file, "delete", p->one);
4130                break;
4131        case DIFF_STATUS_ADDED:
4132                fputs(line_prefix, file);
4133                show_file_mode_name(file, "create", p->two);
4134                break;
4135        case DIFF_STATUS_COPIED:
4136                fputs(line_prefix, file);
4137                show_rename_copy(file, "copy", p, line_prefix);
4138                break;
4139        case DIFF_STATUS_RENAMED:
4140                fputs(line_prefix, file);
4141                show_rename_copy(file, "rename", p, line_prefix);
4142                break;
4143        default:
4144                if (p->score) {
4145                        fprintf(file, "%s rewrite ", line_prefix);
4146                        write_name_quoted(p->two->path, file, ' ');
4147                        fprintf(file, "(%d%%)\n", similarity_index(p));
4148                }
4149                show_mode_change(file, p, !p->score, line_prefix);
4150                break;
4151        }
4152}
4153
4154struct patch_id_t {
4155        git_SHA_CTX *ctx;
4156        int patchlen;
4157};
4158
4159static int remove_space(char *line, int len)
4160{
4161        int i;
4162        char *dst = line;
4163        unsigned char c;
4164
4165        for (i = 0; i < len; i++)
4166                if (!isspace((c = line[i])))
4167                        *dst++ = c;
4168
4169        return dst - line;
4170}
4171
4172static void patch_id_consume(void *priv, char *line, unsigned long len)
4173{
4174        struct patch_id_t *data = priv;
4175        int new_len;
4176
4177        /* Ignore line numbers when computing the SHA1 of the patch */
4178        if (!prefixcmp(line, "@@ -"))
4179                return;
4180
4181        new_len = remove_space(line, len);
4182
4183        git_SHA1_Update(data->ctx, line, new_len);
4184        data->patchlen += new_len;
4185}
4186
4187/* returns 0 upon success, and writes result into sha1 */
4188static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4189{
4190        struct diff_queue_struct *q = &diff_queued_diff;
4191        int i;
4192        git_SHA_CTX ctx;
4193        struct patch_id_t data;
4194        char buffer[PATH_MAX * 4 + 20];
4195
4196        git_SHA1_Init(&ctx);
4197        memset(&data, 0, sizeof(struct patch_id_t));
4198        data.ctx = &ctx;
4199
4200        for (i = 0; i < q->nr; i++) {
4201                xpparam_t xpp;
4202                xdemitconf_t xecfg;
4203                mmfile_t mf1, mf2;
4204                struct diff_filepair *p = q->queue[i];
4205                int len1, len2;
4206
4207                memset(&xpp, 0, sizeof(xpp));
4208                memset(&xecfg, 0, sizeof(xecfg));
4209                if (p->status == 0)
4210                        return error("internal diff status error");
4211                if (p->status == DIFF_STATUS_UNKNOWN)
4212                        continue;
4213                if (diff_unmodified_pair(p))
4214                        continue;
4215                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4216                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4217                        continue;
4218                if (DIFF_PAIR_UNMERGED(p))
4219                        continue;
4220
4221                diff_fill_sha1_info(p->one);
4222                diff_fill_sha1_info(p->two);
4223                if (fill_mmfile(&mf1, p->one) < 0 ||
4224                                fill_mmfile(&mf2, p->two) < 0)
4225                        return error("unable to read files to diff");
4226
4227                len1 = remove_space(p->one->path, strlen(p->one->path));
4228                len2 = remove_space(p->two->path, strlen(p->two->path));
4229                if (p->one->mode == 0)
4230                        len1 = snprintf(buffer, sizeof(buffer),
4231                                        "diff--gita/%.*sb/%.*s"
4232                                        "newfilemode%06o"
4233                                        "---/dev/null"
4234                                        "+++b/%.*s",
4235                                        len1, p->one->path,
4236                                        len2, p->two->path,
4237                                        p->two->mode,
4238                                        len2, p->two->path);
4239                else if (p->two->mode == 0)
4240                        len1 = snprintf(buffer, sizeof(buffer),
4241                                        "diff--gita/%.*sb/%.*s"
4242                                        "deletedfilemode%06o"
4243                                        "---a/%.*s"
4244                                        "+++/dev/null",
4245                                        len1, p->one->path,
4246                                        len2, p->two->path,
4247                                        p->one->mode,
4248                                        len1, p->one->path);
4249                else
4250                        len1 = snprintf(buffer, sizeof(buffer),
4251                                        "diff--gita/%.*sb/%.*s"
4252                                        "---a/%.*s"
4253                                        "+++b/%.*s",
4254                                        len1, p->one->path,
4255                                        len2, p->two->path,
4256                                        len1, p->one->path,
4257                                        len2, p->two->path);
4258                git_SHA1_Update(&ctx, buffer, len1);
4259
4260                if (diff_filespec_is_binary(p->one) ||
4261                    diff_filespec_is_binary(p->two)) {
4262                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4263                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4264                        continue;
4265                }
4266
4267                xpp.flags = 0;
4268                xecfg.ctxlen = 3;
4269                xecfg.flags = 0;
4270                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4271                              &xpp, &xecfg);
4272        }
4273
4274        git_SHA1_Final(sha1, &ctx);
4275        return 0;
4276}
4277
4278int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4279{
4280        struct diff_queue_struct *q = &diff_queued_diff;
4281        int i;
4282        int result = diff_get_patch_id(options, sha1);
4283
4284        for (i = 0; i < q->nr; i++)
4285                diff_free_filepair(q->queue[i]);
4286
4287        free(q->queue);
4288        DIFF_QUEUE_CLEAR(q);
4289
4290        return result;
4291}
4292
4293static int is_summary_empty(const struct diff_queue_struct *q)
4294{
4295        int i;
4296
4297        for (i = 0; i < q->nr; i++) {
4298                const struct diff_filepair *p = q->queue[i];
4299
4300                switch (p->status) {
4301                case DIFF_STATUS_DELETED:
4302                case DIFF_STATUS_ADDED:
4303                case DIFF_STATUS_COPIED:
4304                case DIFF_STATUS_RENAMED:
4305                        return 0;
4306                default:
4307                        if (p->score)
4308                                return 0;
4309                        if (p->one->mode && p->two->mode &&
4310                            p->one->mode != p->two->mode)
4311                                return 0;
4312                        break;
4313                }
4314        }
4315        return 1;
4316}
4317
4318static const char rename_limit_warning[] =
4319"inexact rename detection was skipped due to too many files.";
4320
4321static const char degrade_cc_to_c_warning[] =
4322"only found copies from modified paths due to too many files.";
4323
4324static const char rename_limit_advice[] =
4325"you may want to set your %s variable to at least "
4326"%d and retry the command.";
4327
4328void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4329{
4330        if (degraded_cc)
4331                warning(degrade_cc_to_c_warning);
4332        else if (needed)
4333                warning(rename_limit_warning);
4334        else
4335                return;
4336        if (0 < needed && needed < 32767)
4337                warning(rename_limit_advice, varname, needed);
4338}
4339
4340void diff_flush(struct diff_options *options)
4341{
4342        struct diff_queue_struct *q = &diff_queued_diff;
4343        int i, output_format = options->output_format;
4344        int separator = 0;
4345        int dirstat_by_line = 0;
4346
4347        /*
4348         * Order: raw, stat, summary, patch
4349         * or:    name/name-status/checkdiff (other bits clear)
4350         */
4351        if (!q->nr)
4352                goto free_queue;
4353
4354        if (output_format & (DIFF_FORMAT_RAW |
4355                             DIFF_FORMAT_NAME |
4356                             DIFF_FORMAT_NAME_STATUS |
4357                             DIFF_FORMAT_CHECKDIFF)) {
4358                for (i = 0; i < q->nr; i++) {
4359                        struct diff_filepair *p = q->queue[i];
4360                        if (check_pair_status(p))
4361                                flush_one_pair(p, options);
4362                }
4363                separator++;
4364        }
4365
4366        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4367                dirstat_by_line = 1;
4368
4369        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4370            dirstat_by_line) {
4371                struct diffstat_t diffstat;
4372
4373                memset(&diffstat, 0, sizeof(struct diffstat_t));
4374                for (i = 0; i < q->nr; i++) {
4375                        struct diff_filepair *p = q->queue[i];
4376                        if (check_pair_status(p))
4377                                diff_flush_stat(p, options, &diffstat);
4378                }
4379                if (output_format & DIFF_FORMAT_NUMSTAT)
4380                        show_numstat(&diffstat, options);
4381                if (output_format & DIFF_FORMAT_DIFFSTAT)
4382                        show_stats(&diffstat, options);
4383                if (output_format & DIFF_FORMAT_SHORTSTAT)
4384                        show_shortstats(&diffstat, options);
4385                if (output_format & DIFF_FORMAT_DIRSTAT)
4386                        show_dirstat_by_line(&diffstat, options);
4387                free_diffstat_info(&diffstat);
4388                separator++;
4389        }
4390        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4391                show_dirstat(options);
4392
4393        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4394                for (i = 0; i < q->nr; i++) {
4395                        diff_summary(options, q->queue[i]);
4396                }
4397                separator++;
4398        }
4399
4400        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4401            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4402            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4403                /*
4404                 * run diff_flush_patch for the exit status. setting
4405                 * options->file to /dev/null should be safe, becaue we
4406                 * aren't supposed to produce any output anyway.
4407                 */
4408                if (options->close_file)
4409                        fclose(options->file);
4410                options->file = fopen("/dev/null", "w");
4411                if (!options->file)
4412                        die_errno("Could not open /dev/null");
4413                options->close_file = 1;
4414                for (i = 0; i < q->nr; i++) {
4415                        struct diff_filepair *p = q->queue[i];
4416                        if (check_pair_status(p))
4417                                diff_flush_patch(p, options);
4418                        if (options->found_changes)
4419                                break;
4420                }
4421        }
4422
4423        if (output_format & DIFF_FORMAT_PATCH) {
4424                if (separator) {
4425                        fprintf(options->file, "%s%c",
4426                                diff_line_prefix(options),
4427                                options->line_termination);
4428                        if (options->stat_sep) {
4429                                /* attach patch instead of inline */
4430                                fputs(options->stat_sep, options->file);
4431                        }
4432                }
4433
4434                for (i = 0; i < q->nr; i++) {
4435                        struct diff_filepair *p = q->queue[i];
4436                        if (check_pair_status(p))
4437                                diff_flush_patch(p, options);
4438                }
4439        }
4440
4441        if (output_format & DIFF_FORMAT_CALLBACK)
4442                options->format_callback(q, options, options->format_callback_data);
4443
4444        for (i = 0; i < q->nr; i++)
4445                diff_free_filepair(q->queue[i]);
4446free_queue:
4447        free(q->queue);
4448        DIFF_QUEUE_CLEAR(q);
4449        if (options->close_file)
4450                fclose(options->file);
4451
4452        /*
4453         * Report the content-level differences with HAS_CHANGES;
4454         * diff_addremove/diff_change does not set the bit when
4455         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4456         */
4457        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4458                if (options->found_changes)
4459                        DIFF_OPT_SET(options, HAS_CHANGES);
4460                else
4461                        DIFF_OPT_CLR(options, HAS_CHANGES);
4462        }
4463}
4464
4465static void diffcore_apply_filter(const char *filter)
4466{
4467        int i;
4468        struct diff_queue_struct *q = &diff_queued_diff;
4469        struct diff_queue_struct outq;
4470        DIFF_QUEUE_CLEAR(&outq);
4471
4472        if (!filter)
4473                return;
4474
4475        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4476                int found;
4477                for (i = found = 0; !found && i < q->nr; i++) {
4478                        struct diff_filepair *p = q->queue[i];
4479                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4480                             ((p->score &&
4481                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4482                              (!p->score &&
4483                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4484                            ((p->status != DIFF_STATUS_MODIFIED) &&
4485                             strchr(filter, p->status)))
4486                                found++;
4487                }
4488                if (found)
4489                        return;
4490
4491                /* otherwise we will clear the whole queue
4492                 * by copying the empty outq at the end of this
4493                 * function, but first clear the current entries
4494                 * in the queue.
4495                 */
4496                for (i = 0; i < q->nr; i++)
4497                        diff_free_filepair(q->queue[i]);
4498        }
4499        else {
4500                /* Only the matching ones */
4501                for (i = 0; i < q->nr; i++) {
4502                        struct diff_filepair *p = q->queue[i];
4503
4504                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4505                             ((p->score &&
4506                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4507                              (!p->score &&
4508                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4509                            ((p->status != DIFF_STATUS_MODIFIED) &&
4510                             strchr(filter, p->status)))
4511                                diff_q(&outq, p);
4512                        else
4513                                diff_free_filepair(p);
4514                }
4515        }
4516        free(q->queue);
4517        *q = outq;
4518}
4519
4520/* Check whether two filespecs with the same mode and size are identical */
4521static int diff_filespec_is_identical(struct diff_filespec *one,
4522                                      struct diff_filespec *two)
4523{
4524        if (S_ISGITLINK(one->mode))
4525                return 0;
4526        if (diff_populate_filespec(one, 0))
4527                return 0;
4528        if (diff_populate_filespec(two, 0))
4529                return 0;
4530        return !memcmp(one->data, two->data, one->size);
4531}
4532
4533static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4534{
4535        int i;
4536        struct diff_queue_struct *q = &diff_queued_diff;
4537        struct diff_queue_struct outq;
4538        DIFF_QUEUE_CLEAR(&outq);
4539
4540        for (i = 0; i < q->nr; i++) {
4541                struct diff_filepair *p = q->queue[i];
4542
4543                /*
4544                 * 1. Entries that come from stat info dirtiness
4545                 *    always have both sides (iow, not create/delete),
4546                 *    one side of the object name is unknown, with
4547                 *    the same mode and size.  Keep the ones that
4548                 *    do not match these criteria.  They have real
4549                 *    differences.
4550                 *
4551                 * 2. At this point, the file is known to be modified,
4552                 *    with the same mode and size, and the object
4553                 *    name of one side is unknown.  Need to inspect
4554                 *    the identical contents.
4555                 */
4556                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4557                    !DIFF_FILE_VALID(p->two) ||
4558                    (p->one->sha1_valid && p->two->sha1_valid) ||
4559                    (p->one->mode != p->two->mode) ||
4560                    diff_populate_filespec(p->one, 1) ||
4561                    diff_populate_filespec(p->two, 1) ||
4562                    (p->one->size != p->two->size) ||
4563                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4564                        diff_q(&outq, p);
4565                else {
4566                        /*
4567                         * The caller can subtract 1 from skip_stat_unmatch
4568                         * to determine how many paths were dirty only
4569                         * due to stat info mismatch.
4570                         */
4571                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4572                                diffopt->skip_stat_unmatch++;
4573                        diff_free_filepair(p);
4574                }
4575        }
4576        free(q->queue);
4577        *q = outq;
4578}
4579
4580static int diffnamecmp(const void *a_, const void *b_)
4581{
4582        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4583        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4584        const char *name_a, *name_b;
4585
4586        name_a = a->one ? a->one->path : a->two->path;
4587        name_b = b->one ? b->one->path : b->two->path;
4588        return strcmp(name_a, name_b);
4589}
4590
4591void diffcore_fix_diff_index(struct diff_options *options)
4592{
4593        struct diff_queue_struct *q = &diff_queued_diff;
4594        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4595}
4596
4597void diffcore_std(struct diff_options *options)
4598{
4599        if (options->skip_stat_unmatch)
4600                diffcore_skip_stat_unmatch(options);
4601        if (!options->found_follow) {
4602                /* See try_to_follow_renames() in tree-diff.c */
4603                if (options->break_opt != -1)
4604                        diffcore_break(options->break_opt);
4605                if (options->detect_rename)
4606                        diffcore_rename(options);
4607                if (options->break_opt != -1)
4608                        diffcore_merge_broken();
4609        }
4610        if (options->pickaxe)
4611                diffcore_pickaxe(options);
4612        if (options->orderfile)
4613                diffcore_order(options->orderfile);
4614        if (!options->found_follow)
4615                /* See try_to_follow_renames() in tree-diff.c */
4616                diff_resolve_rename_copy();
4617        diffcore_apply_filter(options->filter);
4618
4619        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4620                DIFF_OPT_SET(options, HAS_CHANGES);
4621        else
4622                DIFF_OPT_CLR(options, HAS_CHANGES);
4623
4624        options->found_follow = 0;
4625}
4626
4627int diff_result_code(struct diff_options *opt, int status)
4628{
4629        int result = 0;
4630
4631        diff_warn_rename_limit("diff.renamelimit",
4632                               opt->needed_rename_limit,
4633                               opt->degraded_cc_to_c);
4634        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4635            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4636                return status;
4637        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4638            DIFF_OPT_TST(opt, HAS_CHANGES))
4639                result |= 01;
4640        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4641            DIFF_OPT_TST(opt, CHECK_FAILED))
4642                result |= 02;
4643        return result;
4644}
4645
4646int diff_can_quit_early(struct diff_options *opt)
4647{
4648        return (DIFF_OPT_TST(opt, QUICK) &&
4649                !opt->filter &&
4650                DIFF_OPT_TST(opt, HAS_CHANGES));
4651}
4652
4653/*
4654 * Shall changes to this submodule be ignored?
4655 *
4656 * Submodule changes can be configured to be ignored separately for each path,
4657 * but that configuration can be overridden from the command line.
4658 */
4659static int is_submodule_ignored(const char *path, struct diff_options *options)
4660{
4661        int ignored = 0;
4662        unsigned orig_flags = options->flags;
4663        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4664                set_diffopt_flags_from_submodule_config(options, path);
4665        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4666                ignored = 1;
4667        options->flags = orig_flags;
4668        return ignored;
4669}
4670
4671void diff_addremove(struct diff_options *options,
4672                    int addremove, unsigned mode,
4673                    const unsigned char *sha1,
4674                    int sha1_valid,
4675                    const char *concatpath, unsigned dirty_submodule)
4676{
4677        struct diff_filespec *one, *two;
4678
4679        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4680                return;
4681
4682        /* This may look odd, but it is a preparation for
4683         * feeding "there are unchanged files which should
4684         * not produce diffs, but when you are doing copy
4685         * detection you would need them, so here they are"
4686         * entries to the diff-core.  They will be prefixed
4687         * with something like '=' or '*' (I haven't decided
4688         * which but should not make any difference).
4689         * Feeding the same new and old to diff_change()
4690         * also has the same effect.
4691         * Before the final output happens, they are pruned after
4692         * merged into rename/copy pairs as appropriate.
4693         */
4694        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4695                addremove = (addremove == '+' ? '-' :
4696                             addremove == '-' ? '+' : addremove);
4697
4698        if (options->prefix &&
4699            strncmp(concatpath, options->prefix, options->prefix_length))
4700                return;
4701
4702        one = alloc_filespec(concatpath);
4703        two = alloc_filespec(concatpath);
4704
4705        if (addremove != '+')
4706                fill_filespec(one, sha1, sha1_valid, mode);
4707        if (addremove != '-') {
4708                fill_filespec(two, sha1, sha1_valid, mode);
4709                two->dirty_submodule = dirty_submodule;
4710        }
4711
4712        diff_queue(&diff_queued_diff, one, two);
4713        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4714                DIFF_OPT_SET(options, HAS_CHANGES);
4715}
4716
4717void diff_change(struct diff_options *options,
4718                 unsigned old_mode, unsigned new_mode,
4719                 const unsigned char *old_sha1,
4720                 const unsigned char *new_sha1,
4721                 int old_sha1_valid, int new_sha1_valid,
4722                 const char *concatpath,
4723                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4724{
4725        struct diff_filespec *one, *two;
4726
4727        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4728            is_submodule_ignored(concatpath, options))
4729                return;
4730
4731        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4732                unsigned tmp;
4733                const unsigned char *tmp_c;
4734                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4735                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4736                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4737                        new_sha1_valid = tmp;
4738                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4739                        new_dirty_submodule = tmp;
4740        }
4741
4742        if (options->prefix &&
4743            strncmp(concatpath, options->prefix, options->prefix_length))
4744                return;
4745
4746        one = alloc_filespec(concatpath);
4747        two = alloc_filespec(concatpath);
4748        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4749        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4750        one->dirty_submodule = old_dirty_submodule;
4751        two->dirty_submodule = new_dirty_submodule;
4752
4753        diff_queue(&diff_queued_diff, one, two);
4754        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4755                DIFF_OPT_SET(options, HAS_CHANGES);
4756}
4757
4758struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4759{
4760        struct diff_filepair *pair;
4761        struct diff_filespec *one, *two;
4762
4763        if (options->prefix &&
4764            strncmp(path, options->prefix, options->prefix_length))
4765                return NULL;
4766
4767        one = alloc_filespec(path);
4768        two = alloc_filespec(path);
4769        pair = diff_queue(&diff_queued_diff, one, two);
4770        pair->is_unmerged = 1;
4771        return pair;
4772}
4773
4774static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4775                size_t *outsize)
4776{
4777        struct diff_tempfile *temp;
4778        const char *argv[3];
4779        const char **arg = argv;
4780        struct child_process child;
4781        struct strbuf buf = STRBUF_INIT;
4782        int err = 0;
4783
4784        temp = prepare_temp_file(spec->path, spec);
4785        *arg++ = pgm;
4786        *arg++ = temp->name;
4787        *arg = NULL;
4788
4789        memset(&child, 0, sizeof(child));
4790        child.use_shell = 1;
4791        child.argv = argv;
4792        child.out = -1;
4793        if (start_command(&child)) {
4794                remove_tempfile();
4795                return NULL;
4796        }
4797
4798        if (strbuf_read(&buf, child.out, 0) < 0)
4799                err = error("error reading from textconv command '%s'", pgm);
4800        close(child.out);
4801
4802        if (finish_command(&child) || err) {
4803                strbuf_release(&buf);
4804                remove_tempfile();
4805                return NULL;
4806        }
4807        remove_tempfile();
4808
4809        return strbuf_detach(&buf, outsize);
4810}
4811
4812size_t fill_textconv(struct userdiff_driver *driver,
4813                     struct diff_filespec *df,
4814                     char **outbuf)
4815{
4816        size_t size;
4817
4818        if (!driver || !driver->textconv) {
4819                if (!DIFF_FILE_VALID(df)) {
4820                        *outbuf = "";
4821                        return 0;
4822                }
4823                if (diff_populate_filespec(df, 0))
4824                        die("unable to read files to diff");
4825                *outbuf = df->data;
4826                return df->size;
4827        }
4828
4829        if (driver->textconv_cache && df->sha1_valid) {
4830                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4831                                          &size);
4832                if (*outbuf)
4833                        return size;
4834        }
4835
4836        *outbuf = run_textconv(driver->textconv, df, &size);
4837        if (!*outbuf)
4838                die("unable to read files to diff");
4839
4840        if (driver->textconv_cache && df->sha1_valid) {
4841                /* ignore errors, as we might be in a readonly repository */
4842                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4843                                size);
4844                /*
4845                 * we could save up changes and flush them all at the end,
4846                 * but we would need an extra call after all diffing is done.
4847                 * Since generating a cache entry is the slow path anyway,
4848                 * this extra overhead probably isn't a big deal.
4849                 */
4850                notes_cache_write(driver->textconv_cache);
4851        }
4852
4853        return size;
4854}
4855
4856void setup_diff_pager(struct diff_options *opt)
4857{
4858        /*
4859         * If the user asked for our exit code, then either they want --quiet
4860         * or --exit-code. We should definitely not bother with a pager in the
4861         * former case, as we will generate no output. Since we still properly
4862         * report our exit code even when a pager is run, we _could_ run a
4863         * pager with --exit-code. But since we have not done so historically,
4864         * and because it is easy to find people oneline advising "git diff
4865         * --exit-code" in hooks and other scripts, we do not do so.
4866         */
4867        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4868            check_pager_config("diff") != 0)
4869                setup_pager();
4870}