diff.con commit run-command: dup_devnull(): guard against syscalls failing (a77f106)
   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        if (o->output_prefix) {
 406                struct strbuf *msg = NULL;
 407                msg = o->output_prefix(o, o->output_prefix_data);
 408                assert(msg);
 409                fwrite(msg->buf, msg->len, 1, file);
 410        }
 411
 412        if (len == 0) {
 413                has_trailing_newline = (first == '\n');
 414                has_trailing_carriage_return = (!has_trailing_newline &&
 415                                                (first == '\r'));
 416                nofirst = has_trailing_newline || has_trailing_carriage_return;
 417        } else {
 418                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 419                if (has_trailing_newline)
 420                        len--;
 421                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 422                if (has_trailing_carriage_return)
 423                        len--;
 424                nofirst = 0;
 425        }
 426
 427        if (len || !nofirst) {
 428                fputs(set, file);
 429                if (!nofirst)
 430                        fputc(first, file);
 431                fwrite(line, len, 1, file);
 432                fputs(reset, file);
 433        }
 434        if (has_trailing_carriage_return)
 435                fputc('\r', file);
 436        if (has_trailing_newline)
 437                fputc('\n', file);
 438}
 439
 440static void emit_line(struct diff_options *o, const char *set, const char *reset,
 441                      const char *line, int len)
 442{
 443        emit_line_0(o, set, reset, line[0], line+1, len-1);
 444}
 445
 446static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 447{
 448        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 449              ecbdata->blank_at_eof_in_preimage &&
 450              ecbdata->blank_at_eof_in_postimage &&
 451              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 452              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 453                return 0;
 454        return ws_blank_line(line, len, ecbdata->ws_rule);
 455}
 456
 457static void emit_add_line(const char *reset,
 458                          struct emit_callback *ecbdata,
 459                          const char *line, int len)
 460{
 461        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 462        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 463
 464        if (!*ws)
 465                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 466        else if (new_blank_line_at_eof(ecbdata, line, len))
 467                /* Blank line at EOF - paint '+' as well */
 468                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 469        else {
 470                /* Emit just the prefix, then the rest. */
 471                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 472                ws_check_emit(line, len, ecbdata->ws_rule,
 473                              ecbdata->opt->file, set, reset, ws);
 474        }
 475}
 476
 477static void emit_hunk_header(struct emit_callback *ecbdata,
 478                             const char *line, int len)
 479{
 480        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 481        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 482        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 483        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 484        static const char atat[2] = { '@', '@' };
 485        const char *cp, *ep;
 486        struct strbuf msgbuf = STRBUF_INIT;
 487        int org_len = len;
 488        int i = 1;
 489
 490        /*
 491         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 492         * it always is at least 10 bytes long.
 493         */
 494        if (len < 10 ||
 495            memcmp(line, atat, 2) ||
 496            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 497                emit_line(ecbdata->opt, plain, reset, line, len);
 498                return;
 499        }
 500        ep += 2; /* skip over @@ */
 501
 502        /* The hunk header in fraginfo color */
 503        strbuf_add(&msgbuf, frag, strlen(frag));
 504        strbuf_add(&msgbuf, line, ep - line);
 505        strbuf_add(&msgbuf, reset, strlen(reset));
 506
 507        /*
 508         * trailing "\r\n"
 509         */
 510        for ( ; i < 3; i++)
 511                if (line[len - i] == '\r' || line[len - i] == '\n')
 512                        len--;
 513
 514        /* blank before the func header */
 515        for (cp = ep; ep - line < len; ep++)
 516                if (*ep != ' ' && *ep != '\t')
 517                        break;
 518        if (ep != cp) {
 519                strbuf_add(&msgbuf, plain, strlen(plain));
 520                strbuf_add(&msgbuf, cp, ep - cp);
 521                strbuf_add(&msgbuf, reset, strlen(reset));
 522        }
 523
 524        if (ep < line + len) {
 525                strbuf_add(&msgbuf, func, strlen(func));
 526                strbuf_add(&msgbuf, ep, line + len - ep);
 527                strbuf_add(&msgbuf, reset, strlen(reset));
 528        }
 529
 530        strbuf_add(&msgbuf, line + len, org_len - len);
 531        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 532        strbuf_release(&msgbuf);
 533}
 534
 535static struct diff_tempfile *claim_diff_tempfile(void) {
 536        int i;
 537        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 538                if (!diff_temp[i].name)
 539                        return diff_temp + i;
 540        die("BUG: diff is failing to clean up its tempfiles");
 541}
 542
 543static int remove_tempfile_installed;
 544
 545static void remove_tempfile(void)
 546{
 547        int i;
 548        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 549                if (diff_temp[i].name == diff_temp[i].tmp_path)
 550                        unlink_or_warn(diff_temp[i].name);
 551                diff_temp[i].name = NULL;
 552        }
 553}
 554
 555static void remove_tempfile_on_signal(int signo)
 556{
 557        remove_tempfile();
 558        sigchain_pop(signo);
 559        raise(signo);
 560}
 561
 562static void print_line_count(FILE *file, int count)
 563{
 564        switch (count) {
 565        case 0:
 566                fprintf(file, "0,0");
 567                break;
 568        case 1:
 569                fprintf(file, "1");
 570                break;
 571        default:
 572                fprintf(file, "1,%d", count);
 573                break;
 574        }
 575}
 576
 577static void emit_rewrite_lines(struct emit_callback *ecb,
 578                               int prefix, const char *data, int size)
 579{
 580        const char *endp = NULL;
 581        static const char *nneof = " No newline at end of file\n";
 582        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 583        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 584
 585        while (0 < size) {
 586                int len;
 587
 588                endp = memchr(data, '\n', size);
 589                len = endp ? (endp - data + 1) : size;
 590                if (prefix != '+') {
 591                        ecb->lno_in_preimage++;
 592                        emit_line_0(ecb->opt, old, reset, '-',
 593                                    data, len);
 594                } else {
 595                        ecb->lno_in_postimage++;
 596                        emit_add_line(reset, ecb, data, len);
 597                }
 598                size -= len;
 599                data += len;
 600        }
 601        if (!endp) {
 602                const char *plain = diff_get_color(ecb->color_diff,
 603                                                   DIFF_PLAIN);
 604                putc('\n', ecb->opt->file);
 605                emit_line_0(ecb->opt, plain, reset, '\\',
 606                            nneof, strlen(nneof));
 607        }
 608}
 609
 610static void emit_rewrite_diff(const char *name_a,
 611                              const char *name_b,
 612                              struct diff_filespec *one,
 613                              struct diff_filespec *two,
 614                              struct userdiff_driver *textconv_one,
 615                              struct userdiff_driver *textconv_two,
 616                              struct diff_options *o)
 617{
 618        int lc_a, lc_b;
 619        const char *name_a_tab, *name_b_tab;
 620        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 621        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 622        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 623        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 624        const char *a_prefix, *b_prefix;
 625        char *data_one, *data_two;
 626        size_t size_one, size_two;
 627        struct emit_callback ecbdata;
 628        char *line_prefix = "";
 629        struct strbuf *msgbuf;
 630
 631        if (o && o->output_prefix) {
 632                msgbuf = o->output_prefix(o, o->output_prefix_data);
 633                line_prefix = msgbuf->buf;
 634        }
 635
 636        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 637                a_prefix = o->b_prefix;
 638                b_prefix = o->a_prefix;
 639        } else {
 640                a_prefix = o->a_prefix;
 641                b_prefix = o->b_prefix;
 642        }
 643
 644        name_a += (*name_a == '/');
 645        name_b += (*name_b == '/');
 646        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 647        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 648
 649        strbuf_reset(&a_name);
 650        strbuf_reset(&b_name);
 651        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 652        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 653
 654        size_one = fill_textconv(textconv_one, one, &data_one);
 655        size_two = fill_textconv(textconv_two, two, &data_two);
 656
 657        memset(&ecbdata, 0, sizeof(ecbdata));
 658        ecbdata.color_diff = want_color(o->use_color);
 659        ecbdata.found_changesp = &o->found_changes;
 660        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 661        ecbdata.opt = o;
 662        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 663                mmfile_t mf1, mf2;
 664                mf1.ptr = (char *)data_one;
 665                mf2.ptr = (char *)data_two;
 666                mf1.size = size_one;
 667                mf2.size = size_two;
 668                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 669        }
 670        ecbdata.lno_in_preimage = 1;
 671        ecbdata.lno_in_postimage = 1;
 672
 673        lc_a = count_lines(data_one, size_one);
 674        lc_b = count_lines(data_two, size_two);
 675        fprintf(o->file,
 676                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 677                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 678                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 679                line_prefix, fraginfo);
 680        if (!o->irreversible_delete)
 681                print_line_count(o->file, lc_a);
 682        else
 683                fprintf(o->file, "?,?");
 684        fprintf(o->file, " +");
 685        print_line_count(o->file, lc_b);
 686        fprintf(o->file, " @@%s\n", reset);
 687        if (lc_a && !o->irreversible_delete)
 688                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 689        if (lc_b)
 690                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 691        if (textconv_one)
 692                free((char *)data_one);
 693        if (textconv_two)
 694                free((char *)data_two);
 695}
 696
 697struct diff_words_buffer {
 698        mmfile_t text;
 699        long alloc;
 700        struct diff_words_orig {
 701                const char *begin, *end;
 702        } *orig;
 703        int orig_nr, orig_alloc;
 704};
 705
 706static void diff_words_append(char *line, unsigned long len,
 707                struct diff_words_buffer *buffer)
 708{
 709        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 710        line++;
 711        len--;
 712        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 713        buffer->text.size += len;
 714        buffer->text.ptr[buffer->text.size] = '\0';
 715}
 716
 717struct diff_words_style_elem {
 718        const char *prefix;
 719        const char *suffix;
 720        const char *color; /* NULL; filled in by the setup code if
 721                            * color is enabled */
 722};
 723
 724struct diff_words_style {
 725        enum diff_words_type type;
 726        struct diff_words_style_elem new, old, ctx;
 727        const char *newline;
 728};
 729
 730static struct diff_words_style diff_words_styles[] = {
 731        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 732        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 733        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 734};
 735
 736struct diff_words_data {
 737        struct diff_words_buffer minus, plus;
 738        const char *current_plus;
 739        int last_minus;
 740        struct diff_options *opt;
 741        regex_t *word_regex;
 742        enum diff_words_type type;
 743        struct diff_words_style *style;
 744};
 745
 746static int fn_out_diff_words_write_helper(FILE *fp,
 747                                          struct diff_words_style_elem *st_el,
 748                                          const char *newline,
 749                                          size_t count, const char *buf,
 750                                          const char *line_prefix)
 751{
 752        int print = 0;
 753
 754        while (count) {
 755                char *p = memchr(buf, '\n', count);
 756                if (print)
 757                        fputs(line_prefix, fp);
 758                if (p != buf) {
 759                        if (st_el->color && fputs(st_el->color, fp) < 0)
 760                                return -1;
 761                        if (fputs(st_el->prefix, fp) < 0 ||
 762                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 763                            fputs(st_el->suffix, fp) < 0)
 764                                return -1;
 765                        if (st_el->color && *st_el->color
 766                            && fputs(GIT_COLOR_RESET, fp) < 0)
 767                                return -1;
 768                }
 769                if (!p)
 770                        return 0;
 771                if (fputs(newline, fp) < 0)
 772                        return -1;
 773                count -= p + 1 - buf;
 774                buf = p + 1;
 775                print = 1;
 776        }
 777        return 0;
 778}
 779
 780/*
 781 * '--color-words' algorithm can be described as:
 782 *
 783 *   1. collect a the minus/plus lines of a diff hunk, divided into
 784 *      minus-lines and plus-lines;
 785 *
 786 *   2. break both minus-lines and plus-lines into words and
 787 *      place them into two mmfile_t with one word for each line;
 788 *
 789 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 790 *
 791 * And for the common parts of the both file, we output the plus side text.
 792 * diff_words->current_plus is used to trace the current position of the plus file
 793 * which printed. diff_words->last_minus is used to trace the last minus word
 794 * printed.
 795 *
 796 * For '--graph' to work with '--color-words', we need to output the graph prefix
 797 * on each line of color words output. Generally, there are two conditions on
 798 * which we should output the prefix.
 799 *
 800 *   1. diff_words->last_minus == 0 &&
 801 *      diff_words->current_plus == diff_words->plus.text.ptr
 802 *
 803 *      that is: the plus text must start as a new line, and if there is no minus
 804 *      word printed, a graph prefix must be printed.
 805 *
 806 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 807 *      *(diff_words->current_plus - 1) == '\n'
 808 *
 809 *      that is: a graph prefix must be printed following a '\n'
 810 */
 811static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 812{
 813        if ((diff_words->last_minus == 0 &&
 814                diff_words->current_plus == diff_words->plus.text.ptr) ||
 815                (diff_words->current_plus > diff_words->plus.text.ptr &&
 816                *(diff_words->current_plus - 1) == '\n')) {
 817                return 1;
 818        } else {
 819                return 0;
 820        }
 821}
 822
 823static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 824{
 825        struct diff_words_data *diff_words = priv;
 826        struct diff_words_style *style = diff_words->style;
 827        int minus_first, minus_len, plus_first, plus_len;
 828        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 829        struct diff_options *opt = diff_words->opt;
 830        struct strbuf *msgbuf;
 831        char *line_prefix = "";
 832
 833        if (line[0] != '@' || parse_hunk_header(line, len,
 834                        &minus_first, &minus_len, &plus_first, &plus_len))
 835                return;
 836
 837        assert(opt);
 838        if (opt->output_prefix) {
 839                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 840                line_prefix = msgbuf->buf;
 841        }
 842
 843        /* POSIX requires that first be decremented by one if len == 0... */
 844        if (minus_len) {
 845                minus_begin = diff_words->minus.orig[minus_first].begin;
 846                minus_end =
 847                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 848        } else
 849                minus_begin = minus_end =
 850                        diff_words->minus.orig[minus_first].end;
 851
 852        if (plus_len) {
 853                plus_begin = diff_words->plus.orig[plus_first].begin;
 854                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 855        } else
 856                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 857
 858        if (color_words_output_graph_prefix(diff_words)) {
 859                fputs(line_prefix, diff_words->opt->file);
 860        }
 861        if (diff_words->current_plus != plus_begin) {
 862                fn_out_diff_words_write_helper(diff_words->opt->file,
 863                                &style->ctx, style->newline,
 864                                plus_begin - diff_words->current_plus,
 865                                diff_words->current_plus, line_prefix);
 866                if (*(plus_begin - 1) == '\n')
 867                        fputs(line_prefix, diff_words->opt->file);
 868        }
 869        if (minus_begin != minus_end) {
 870                fn_out_diff_words_write_helper(diff_words->opt->file,
 871                                &style->old, style->newline,
 872                                minus_end - minus_begin, minus_begin,
 873                                line_prefix);
 874        }
 875        if (plus_begin != plus_end) {
 876                fn_out_diff_words_write_helper(diff_words->opt->file,
 877                                &style->new, style->newline,
 878                                plus_end - plus_begin, plus_begin,
 879                                line_prefix);
 880        }
 881
 882        diff_words->current_plus = plus_end;
 883        diff_words->last_minus = minus_first;
 884}
 885
 886/* This function starts looking at *begin, and returns 0 iff a word was found. */
 887static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 888                int *begin, int *end)
 889{
 890        if (word_regex && *begin < buffer->size) {
 891                regmatch_t match[1];
 892                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 893                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 894                                        '\n', match[0].rm_eo - match[0].rm_so);
 895                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 896                        *begin += match[0].rm_so;
 897                        return *begin >= *end;
 898                }
 899                return -1;
 900        }
 901
 902        /* find the next word */
 903        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 904                (*begin)++;
 905        if (*begin >= buffer->size)
 906                return -1;
 907
 908        /* find the end of the word */
 909        *end = *begin + 1;
 910        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 911                (*end)++;
 912
 913        return 0;
 914}
 915
 916/*
 917 * This function splits the words in buffer->text, stores the list with
 918 * newline separator into out, and saves the offsets of the original words
 919 * in buffer->orig.
 920 */
 921static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 922                regex_t *word_regex)
 923{
 924        int i, j;
 925        long alloc = 0;
 926
 927        out->size = 0;
 928        out->ptr = NULL;
 929
 930        /* fake an empty "0th" word */
 931        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 932        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 933        buffer->orig_nr = 1;
 934
 935        for (i = 0; i < buffer->text.size; i++) {
 936                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 937                        return;
 938
 939                /* store original boundaries */
 940                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 941                                buffer->orig_alloc);
 942                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 943                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 944                buffer->orig_nr++;
 945
 946                /* store one word */
 947                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 948                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 949                out->ptr[out->size + j - i] = '\n';
 950                out->size += j - i + 1;
 951
 952                i = j - 1;
 953        }
 954}
 955
 956/* this executes the word diff on the accumulated buffers */
 957static void diff_words_show(struct diff_words_data *diff_words)
 958{
 959        xpparam_t xpp;
 960        xdemitconf_t xecfg;
 961        mmfile_t minus, plus;
 962        struct diff_words_style *style = diff_words->style;
 963
 964        struct diff_options *opt = diff_words->opt;
 965        struct strbuf *msgbuf;
 966        char *line_prefix = "";
 967
 968        assert(opt);
 969        if (opt->output_prefix) {
 970                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 971                line_prefix = msgbuf->buf;
 972        }
 973
 974        /* special case: only removal */
 975        if (!diff_words->plus.text.size) {
 976                fputs(line_prefix, diff_words->opt->file);
 977                fn_out_diff_words_write_helper(diff_words->opt->file,
 978                        &style->old, style->newline,
 979                        diff_words->minus.text.size,
 980                        diff_words->minus.text.ptr, line_prefix);
 981                diff_words->minus.text.size = 0;
 982                return;
 983        }
 984
 985        diff_words->current_plus = diff_words->plus.text.ptr;
 986        diff_words->last_minus = 0;
 987
 988        memset(&xpp, 0, sizeof(xpp));
 989        memset(&xecfg, 0, sizeof(xecfg));
 990        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 991        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 992        xpp.flags = 0;
 993        /* as only the hunk header will be parsed, we need a 0-context */
 994        xecfg.ctxlen = 0;
 995        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 996                      &xpp, &xecfg);
 997        free(minus.ptr);
 998        free(plus.ptr);
 999        if (diff_words->current_plus != diff_words->plus.text.ptr +
1000                        diff_words->plus.text.size) {
1001                if (color_words_output_graph_prefix(diff_words))
1002                        fputs(line_prefix, diff_words->opt->file);
1003                fn_out_diff_words_write_helper(diff_words->opt->file,
1004                        &style->ctx, style->newline,
1005                        diff_words->plus.text.ptr + diff_words->plus.text.size
1006                        - diff_words->current_plus, diff_words->current_plus,
1007                        line_prefix);
1008        }
1009        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1010}
1011
1012/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1013static void diff_words_flush(struct emit_callback *ecbdata)
1014{
1015        if (ecbdata->diff_words->minus.text.size ||
1016            ecbdata->diff_words->plus.text.size)
1017                diff_words_show(ecbdata->diff_words);
1018}
1019
1020static void diff_filespec_load_driver(struct diff_filespec *one)
1021{
1022        /* Use already-loaded driver */
1023        if (one->driver)
1024                return;
1025
1026        if (S_ISREG(one->mode))
1027                one->driver = userdiff_find_by_path(one->path);
1028
1029        /* Fallback to default settings */
1030        if (!one->driver)
1031                one->driver = userdiff_find_by_name("default");
1032}
1033
1034static const char *userdiff_word_regex(struct diff_filespec *one)
1035{
1036        diff_filespec_load_driver(one);
1037        return one->driver->word_regex;
1038}
1039
1040static void init_diff_words_data(struct emit_callback *ecbdata,
1041                                 struct diff_options *orig_opts,
1042                                 struct diff_filespec *one,
1043                                 struct diff_filespec *two)
1044{
1045        int i;
1046        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1047        memcpy(o, orig_opts, sizeof(struct diff_options));
1048
1049        ecbdata->diff_words =
1050                xcalloc(1, sizeof(struct diff_words_data));
1051        ecbdata->diff_words->type = o->word_diff;
1052        ecbdata->diff_words->opt = o;
1053        if (!o->word_regex)
1054                o->word_regex = userdiff_word_regex(one);
1055        if (!o->word_regex)
1056                o->word_regex = userdiff_word_regex(two);
1057        if (!o->word_regex)
1058                o->word_regex = diff_word_regex_cfg;
1059        if (o->word_regex) {
1060                ecbdata->diff_words->word_regex = (regex_t *)
1061                        xmalloc(sizeof(regex_t));
1062                if (regcomp(ecbdata->diff_words->word_regex,
1063                            o->word_regex,
1064                            REG_EXTENDED | REG_NEWLINE))
1065                        die ("Invalid regular expression: %s",
1066                             o->word_regex);
1067        }
1068        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1069                if (o->word_diff == diff_words_styles[i].type) {
1070                        ecbdata->diff_words->style =
1071                                &diff_words_styles[i];
1072                        break;
1073                }
1074        }
1075        if (want_color(o->use_color)) {
1076                struct diff_words_style *st = ecbdata->diff_words->style;
1077                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1078                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1079                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1080        }
1081}
1082
1083static void free_diff_words_data(struct emit_callback *ecbdata)
1084{
1085        if (ecbdata->diff_words) {
1086                diff_words_flush(ecbdata);
1087                free (ecbdata->diff_words->opt);
1088                free (ecbdata->diff_words->minus.text.ptr);
1089                free (ecbdata->diff_words->minus.orig);
1090                free (ecbdata->diff_words->plus.text.ptr);
1091                free (ecbdata->diff_words->plus.orig);
1092                if (ecbdata->diff_words->word_regex) {
1093                        regfree(ecbdata->diff_words->word_regex);
1094                        free(ecbdata->diff_words->word_regex);
1095                }
1096                free(ecbdata->diff_words);
1097                ecbdata->diff_words = NULL;
1098        }
1099}
1100
1101const char *diff_get_color(int diff_use_color, enum color_diff ix)
1102{
1103        if (want_color(diff_use_color))
1104                return diff_colors[ix];
1105        return "";
1106}
1107
1108static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1109{
1110        const char *cp;
1111        unsigned long allot;
1112        size_t l = len;
1113
1114        if (ecb->truncate)
1115                return ecb->truncate(line, len);
1116        cp = line;
1117        allot = l;
1118        while (0 < l) {
1119                (void) utf8_width(&cp, &l);
1120                if (!cp)
1121                        break; /* truncated in the middle? */
1122        }
1123        return allot - l;
1124}
1125
1126static void find_lno(const char *line, struct emit_callback *ecbdata)
1127{
1128        const char *p;
1129        ecbdata->lno_in_preimage = 0;
1130        ecbdata->lno_in_postimage = 0;
1131        p = strchr(line, '-');
1132        if (!p)
1133                return; /* cannot happen */
1134        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1135        p = strchr(p, '+');
1136        if (!p)
1137                return; /* cannot happen */
1138        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1139}
1140
1141static void fn_out_consume(void *priv, char *line, unsigned long len)
1142{
1143        struct emit_callback *ecbdata = priv;
1144        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1145        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1146        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1147        struct diff_options *o = ecbdata->opt;
1148        char *line_prefix = "";
1149        struct strbuf *msgbuf;
1150
1151        if (o && o->output_prefix) {
1152                msgbuf = o->output_prefix(o, o->output_prefix_data);
1153                line_prefix = msgbuf->buf;
1154        }
1155
1156        if (ecbdata->header) {
1157                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1158                strbuf_reset(ecbdata->header);
1159                ecbdata->header = NULL;
1160        }
1161        *(ecbdata->found_changesp) = 1;
1162
1163        if (ecbdata->label_path[0]) {
1164                const char *name_a_tab, *name_b_tab;
1165
1166                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1167                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1168
1169                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1170                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1171                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1172                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1173                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1174        }
1175
1176        if (diff_suppress_blank_empty
1177            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1178                line[0] = '\n';
1179                len = 1;
1180        }
1181
1182        if (line[0] == '@') {
1183                if (ecbdata->diff_words)
1184                        diff_words_flush(ecbdata);
1185                len = sane_truncate_line(ecbdata, line, len);
1186                find_lno(line, ecbdata);
1187                emit_hunk_header(ecbdata, line, len);
1188                if (line[len-1] != '\n')
1189                        putc('\n', ecbdata->opt->file);
1190                return;
1191        }
1192
1193        if (len < 1) {
1194                emit_line(ecbdata->opt, reset, reset, line, len);
1195                if (ecbdata->diff_words
1196                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1197                        fputs("~\n", ecbdata->opt->file);
1198                return;
1199        }
1200
1201        if (ecbdata->diff_words) {
1202                if (line[0] == '-') {
1203                        diff_words_append(line, len,
1204                                          &ecbdata->diff_words->minus);
1205                        return;
1206                } else if (line[0] == '+') {
1207                        diff_words_append(line, len,
1208                                          &ecbdata->diff_words->plus);
1209                        return;
1210                } else if (!prefixcmp(line, "\\ ")) {
1211                        /*
1212                         * Eat the "no newline at eof" marker as if we
1213                         * saw a "+" or "-" line with nothing on it,
1214                         * and return without diff_words_flush() to
1215                         * defer processing. If this is the end of
1216                         * preimage, more "+" lines may come after it.
1217                         */
1218                        return;
1219                }
1220                diff_words_flush(ecbdata);
1221                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1222                        emit_line(ecbdata->opt, plain, reset, line, len);
1223                        fputs("~\n", ecbdata->opt->file);
1224                } else {
1225                        /*
1226                         * Skip the prefix character, if any.  With
1227                         * diff_suppress_blank_empty, there may be
1228                         * none.
1229                         */
1230                        if (line[0] != '\n') {
1231                              line++;
1232                              len--;
1233                        }
1234                        emit_line(ecbdata->opt, plain, reset, line, len);
1235                }
1236                return;
1237        }
1238
1239        if (line[0] != '+') {
1240                const char *color =
1241                        diff_get_color(ecbdata->color_diff,
1242                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1243                ecbdata->lno_in_preimage++;
1244                if (line[0] == ' ')
1245                        ecbdata->lno_in_postimage++;
1246                emit_line(ecbdata->opt, color, reset, line, len);
1247        } else {
1248                ecbdata->lno_in_postimage++;
1249                emit_add_line(reset, ecbdata, line + 1, len - 1);
1250        }
1251}
1252
1253static char *pprint_rename(const char *a, const char *b)
1254{
1255        const char *old = a;
1256        const char *new = b;
1257        struct strbuf name = STRBUF_INIT;
1258        int pfx_length, sfx_length;
1259        int pfx_adjust_for_slash;
1260        int len_a = strlen(a);
1261        int len_b = strlen(b);
1262        int a_midlen, b_midlen;
1263        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1264        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1265
1266        if (qlen_a || qlen_b) {
1267                quote_c_style(a, &name, NULL, 0);
1268                strbuf_addstr(&name, " => ");
1269                quote_c_style(b, &name, NULL, 0);
1270                return strbuf_detach(&name, NULL);
1271        }
1272
1273        /* Find common prefix */
1274        pfx_length = 0;
1275        while (*old && *new && *old == *new) {
1276                if (*old == '/')
1277                        pfx_length = old - a + 1;
1278                old++;
1279                new++;
1280        }
1281
1282        /* Find common suffix */
1283        old = a + len_a;
1284        new = b + len_b;
1285        sfx_length = 0;
1286        /*
1287         * If there is a common prefix, it must end in a slash.  In
1288         * that case we let this loop run 1 into the prefix to see the
1289         * same slash.
1290         *
1291         * If there is no common prefix, we cannot do this as it would
1292         * underrun the input strings.
1293         */
1294        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1295        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1296               b + pfx_length - pfx_adjust_for_slash <= new &&
1297               *old == *new) {
1298                if (*old == '/')
1299                        sfx_length = len_a - (old - a);
1300                old--;
1301                new--;
1302        }
1303
1304        /*
1305         * pfx{mid-a => mid-b}sfx
1306         * {pfx-a => pfx-b}sfx
1307         * pfx{sfx-a => sfx-b}
1308         * name-a => name-b
1309         */
1310        a_midlen = len_a - pfx_length - sfx_length;
1311        b_midlen = len_b - pfx_length - sfx_length;
1312        if (a_midlen < 0)
1313                a_midlen = 0;
1314        if (b_midlen < 0)
1315                b_midlen = 0;
1316
1317        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1318        if (pfx_length + sfx_length) {
1319                strbuf_add(&name, a, pfx_length);
1320                strbuf_addch(&name, '{');
1321        }
1322        strbuf_add(&name, a + pfx_length, a_midlen);
1323        strbuf_addstr(&name, " => ");
1324        strbuf_add(&name, b + pfx_length, b_midlen);
1325        if (pfx_length + sfx_length) {
1326                strbuf_addch(&name, '}');
1327                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1328        }
1329        return strbuf_detach(&name, NULL);
1330}
1331
1332struct diffstat_t {
1333        int nr;
1334        int alloc;
1335        struct diffstat_file {
1336                char *from_name;
1337                char *name;
1338                char *print_name;
1339                unsigned is_unmerged:1;
1340                unsigned is_binary:1;
1341                unsigned is_renamed:1;
1342                unsigned is_interesting:1;
1343                uintmax_t added, deleted;
1344        } **files;
1345};
1346
1347static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1348                                          const char *name_a,
1349                                          const char *name_b)
1350{
1351        struct diffstat_file *x;
1352        x = xcalloc(sizeof (*x), 1);
1353        if (diffstat->nr == diffstat->alloc) {
1354                diffstat->alloc = alloc_nr(diffstat->alloc);
1355                diffstat->files = xrealloc(diffstat->files,
1356                                diffstat->alloc * sizeof(x));
1357        }
1358        diffstat->files[diffstat->nr++] = x;
1359        if (name_b) {
1360                x->from_name = xstrdup(name_a);
1361                x->name = xstrdup(name_b);
1362                x->is_renamed = 1;
1363        }
1364        else {
1365                x->from_name = NULL;
1366                x->name = xstrdup(name_a);
1367        }
1368        return x;
1369}
1370
1371static void diffstat_consume(void *priv, char *line, unsigned long len)
1372{
1373        struct diffstat_t *diffstat = priv;
1374        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1375
1376        if (line[0] == '+')
1377                x->added++;
1378        else if (line[0] == '-')
1379                x->deleted++;
1380}
1381
1382const char mime_boundary_leader[] = "------------";
1383
1384static int scale_linear(int it, int width, int max_change)
1385{
1386        if (!it)
1387                return 0;
1388        /*
1389         * make sure that at least one '-' or '+' is printed if
1390         * there is any change to this path. The easiest way is to
1391         * scale linearly as if the alloted width is one column shorter
1392         * than it is, and then add 1 to the result.
1393         */
1394        return 1 + (it * (width - 1) / max_change);
1395}
1396
1397static void show_name(FILE *file,
1398                      const char *prefix, const char *name, int len)
1399{
1400        fprintf(file, " %s%-*s |", prefix, len, name);
1401}
1402
1403static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1404{
1405        if (cnt <= 0)
1406                return;
1407        fprintf(file, "%s", set);
1408        while (cnt--)
1409                putc(ch, file);
1410        fprintf(file, "%s", reset);
1411}
1412
1413static void fill_print_name(struct diffstat_file *file)
1414{
1415        char *pname;
1416
1417        if (file->print_name)
1418                return;
1419
1420        if (!file->is_renamed) {
1421                struct strbuf buf = STRBUF_INIT;
1422                if (quote_c_style(file->name, &buf, NULL, 0)) {
1423                        pname = strbuf_detach(&buf, NULL);
1424                } else {
1425                        pname = file->name;
1426                        strbuf_release(&buf);
1427                }
1428        } else {
1429                pname = pprint_rename(file->from_name, file->name);
1430        }
1431        file->print_name = pname;
1432}
1433
1434int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1435{
1436        struct strbuf sb = STRBUF_INIT;
1437        int ret;
1438
1439        if (!files) {
1440                assert(insertions == 0 && deletions == 0);
1441                return fprintf(fp, "%s\n", " 0 files changed");
1442        }
1443
1444        strbuf_addf(&sb,
1445                    (files == 1) ? " %d file changed" : " %d files changed",
1446                    files);
1447
1448        /*
1449         * For binary diff, the caller may want to print "x files
1450         * changed" with insertions == 0 && deletions == 0.
1451         *
1452         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1453         * is probably less confusing (i.e skip over "2 files changed
1454         * but nothing about added/removed lines? Is this a bug in Git?").
1455         */
1456        if (insertions || deletions == 0) {
1457                /*
1458                 * TRANSLATORS: "+" in (+) is a line addition marker;
1459                 * do not translate it.
1460                 */
1461                strbuf_addf(&sb,
1462                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1463                            insertions);
1464        }
1465
1466        if (deletions || insertions == 0) {
1467                /*
1468                 * TRANSLATORS: "-" in (-) is a line removal marker;
1469                 * do not translate it.
1470                 */
1471                strbuf_addf(&sb,
1472                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1473                            deletions);
1474        }
1475        strbuf_addch(&sb, '\n');
1476        ret = fputs(sb.buf, fp);
1477        strbuf_release(&sb);
1478        return ret;
1479}
1480
1481static void show_stats(struct diffstat_t *data, struct diff_options *options)
1482{
1483        int i, len, add, del, adds = 0, dels = 0;
1484        uintmax_t max_change = 0, max_len = 0;
1485        int total_files = data->nr, count;
1486        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1487        const char *reset, *add_c, *del_c;
1488        const char *line_prefix = "";
1489        int extra_shown = 0;
1490        struct strbuf *msg = NULL;
1491
1492        if (data->nr == 0)
1493                return;
1494
1495        if (options->output_prefix) {
1496                msg = options->output_prefix(options, options->output_prefix_data);
1497                line_prefix = msg->buf;
1498        }
1499
1500        count = options->stat_count ? options->stat_count : data->nr;
1501
1502        reset = diff_get_color_opt(options, DIFF_RESET);
1503        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1504        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1505
1506        /*
1507         * Find the longest filename and max number of changes
1508         */
1509        for (i = 0; (i < count) && (i < data->nr); i++) {
1510                struct diffstat_file *file = data->files[i];
1511                uintmax_t change = file->added + file->deleted;
1512
1513                if (!file->is_interesting && (change == 0)) {
1514                        count++; /* not shown == room for one more */
1515                        continue;
1516                }
1517                fill_print_name(file);
1518                len = strlen(file->print_name);
1519                if (max_len < len)
1520                        max_len = len;
1521
1522                if (file->is_unmerged) {
1523                        /* "Unmerged" is 8 characters */
1524                        bin_width = bin_width < 8 ? 8 : bin_width;
1525                        continue;
1526                }
1527                if (file->is_binary) {
1528                        /* "Bin XXX -> YYY bytes" */
1529                        int w = 14 + decimal_width(file->added)
1530                                + decimal_width(file->deleted);
1531                        bin_width = bin_width < w ? w : bin_width;
1532                        /* Display change counts aligned with "Bin" */
1533                        number_width = 3;
1534                        continue;
1535                }
1536
1537                if (max_change < change)
1538                        max_change = change;
1539        }
1540        count = i; /* where we can stop scanning in data->files[] */
1541
1542        /*
1543         * We have width = stat_width or term_columns() columns total.
1544         * We want a maximum of min(max_len, stat_name_width) for the name part.
1545         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1546         * We also need 1 for " " and 4 + decimal_width(max_change)
1547         * for " | NNNN " and one the empty column at the end, altogether
1548         * 6 + decimal_width(max_change).
1549         *
1550         * If there's not enough space, we will use the smaller of
1551         * stat_name_width (if set) and 5/8*width for the filename,
1552         * and the rest for constant elements + graph part, but no more
1553         * than stat_graph_width for the graph part.
1554         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1555         * for the standard terminal size).
1556         *
1557         * In other words: stat_width limits the maximum width, and
1558         * stat_name_width fixes the maximum width of the filename,
1559         * and is also used to divide available columns if there
1560         * aren't enough.
1561         *
1562         * Binary files are displayed with "Bin XXX -> YYY bytes"
1563         * instead of the change count and graph. This part is treated
1564         * similarly to the graph part, except that it is not
1565         * "scaled". If total width is too small to accomodate the
1566         * guaranteed minimum width of the filename part and the
1567         * separators and this message, this message will "overflow"
1568         * making the line longer than the maximum width.
1569         */
1570
1571        if (options->stat_width == -1)
1572                width = term_columns() - options->output_prefix_length;
1573        else
1574                width = options->stat_width ? options->stat_width : 80;
1575        number_width = decimal_width(max_change) > number_width ?
1576                decimal_width(max_change) : number_width;
1577
1578        if (options->stat_graph_width == -1)
1579                options->stat_graph_width = diff_stat_graph_width;
1580
1581        /*
1582         * Guarantee 3/8*16==6 for the graph part
1583         * and 5/8*16==10 for the filename part
1584         */
1585        if (width < 16 + 6 + number_width)
1586                width = 16 + 6 + number_width;
1587
1588        /*
1589         * First assign sizes that are wanted, ignoring available width.
1590         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1591         * starting from "XXX" should fit in graph_width.
1592         */
1593        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1594        if (options->stat_graph_width &&
1595            options->stat_graph_width < graph_width)
1596                graph_width = options->stat_graph_width;
1597
1598        name_width = (options->stat_name_width > 0 &&
1599                      options->stat_name_width < max_len) ?
1600                options->stat_name_width : max_len;
1601
1602        /*
1603         * Adjust adjustable widths not to exceed maximum width
1604         */
1605        if (name_width + number_width + 6 + graph_width > width) {
1606                if (graph_width > width * 3/8 - number_width - 6) {
1607                        graph_width = width * 3/8 - number_width - 6;
1608                        if (graph_width < 6)
1609                                graph_width = 6;
1610                }
1611
1612                if (options->stat_graph_width &&
1613                    graph_width > options->stat_graph_width)
1614                        graph_width = options->stat_graph_width;
1615                if (name_width > width - number_width - 6 - graph_width)
1616                        name_width = width - number_width - 6 - graph_width;
1617                else
1618                        graph_width = width - number_width - 6 - name_width;
1619        }
1620
1621        /*
1622         * From here name_width is the width of the name area,
1623         * and graph_width is the width of the graph area.
1624         * max_change is used to scale graph properly.
1625         */
1626        for (i = 0; i < count; i++) {
1627                const char *prefix = "";
1628                struct diffstat_file *file = data->files[i];
1629                char *name = file->print_name;
1630                uintmax_t added = file->added;
1631                uintmax_t deleted = file->deleted;
1632                int name_len;
1633
1634                if (!file->is_interesting && (added + deleted == 0))
1635                        continue;
1636
1637                /*
1638                 * "scale" the filename
1639                 */
1640                len = name_width;
1641                name_len = strlen(name);
1642                if (name_width < name_len) {
1643                        char *slash;
1644                        prefix = "...";
1645                        len -= 3;
1646                        name += name_len - len;
1647                        slash = strchr(name, '/');
1648                        if (slash)
1649                                name = slash;
1650                }
1651
1652                if (file->is_binary) {
1653                        fprintf(options->file, "%s", line_prefix);
1654                        show_name(options->file, prefix, name, len);
1655                        fprintf(options->file, " %*s", number_width, "Bin");
1656                        if (!added && !deleted) {
1657                                putc('\n', options->file);
1658                                continue;
1659                        }
1660                        fprintf(options->file, " %s%"PRIuMAX"%s",
1661                                del_c, deleted, reset);
1662                        fprintf(options->file, " -> ");
1663                        fprintf(options->file, "%s%"PRIuMAX"%s",
1664                                add_c, added, reset);
1665                        fprintf(options->file, " bytes");
1666                        fprintf(options->file, "\n");
1667                        continue;
1668                }
1669                else if (file->is_unmerged) {
1670                        fprintf(options->file, "%s", line_prefix);
1671                        show_name(options->file, prefix, name, len);
1672                        fprintf(options->file, " Unmerged\n");
1673                        continue;
1674                }
1675
1676                /*
1677                 * scale the add/delete
1678                 */
1679                add = added;
1680                del = deleted;
1681
1682                if (graph_width <= max_change) {
1683                        int total = add + del;
1684
1685                        total = scale_linear(add + del, graph_width, max_change);
1686                        if (total < 2 && add && del)
1687                                /* width >= 2 due to the sanity check */
1688                                total = 2;
1689                        if (add < del) {
1690                                add = scale_linear(add, graph_width, max_change);
1691                                del = total - add;
1692                        } else {
1693                                del = scale_linear(del, graph_width, max_change);
1694                                add = total - del;
1695                        }
1696                }
1697                fprintf(options->file, "%s", line_prefix);
1698                show_name(options->file, prefix, name, len);
1699                fprintf(options->file, " %*"PRIuMAX"%s",
1700                        number_width, added + deleted,
1701                        added + deleted ? " " : "");
1702                show_graph(options->file, '+', add, add_c, reset);
1703                show_graph(options->file, '-', del, del_c, reset);
1704                fprintf(options->file, "\n");
1705        }
1706
1707        for (i = 0; i < data->nr; i++) {
1708                struct diffstat_file *file = data->files[i];
1709                uintmax_t added = file->added;
1710                uintmax_t deleted = file->deleted;
1711
1712                if (file->is_unmerged ||
1713                    (!file->is_interesting && (added + deleted == 0))) {
1714                        total_files--;
1715                        continue;
1716                }
1717
1718                if (!file->is_binary) {
1719                        adds += added;
1720                        dels += deleted;
1721                }
1722                if (i < count)
1723                        continue;
1724                if (!extra_shown)
1725                        fprintf(options->file, "%s ...\n", line_prefix);
1726                extra_shown = 1;
1727        }
1728        fprintf(options->file, "%s", line_prefix);
1729        print_stat_summary(options->file, total_files, adds, dels);
1730}
1731
1732static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1733{
1734        int i, adds = 0, dels = 0, total_files = data->nr;
1735
1736        if (data->nr == 0)
1737                return;
1738
1739        for (i = 0; i < data->nr; i++) {
1740                int added = data->files[i]->added;
1741                int deleted= data->files[i]->deleted;
1742
1743                if (data->files[i]->is_unmerged ||
1744                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1745                        total_files--;
1746                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1747                        adds += added;
1748                        dels += deleted;
1749                }
1750        }
1751        if (options->output_prefix) {
1752                struct strbuf *msg = NULL;
1753                msg = options->output_prefix(options,
1754                                options->output_prefix_data);
1755                fprintf(options->file, "%s", msg->buf);
1756        }
1757        print_stat_summary(options->file, total_files, adds, dels);
1758}
1759
1760static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1761{
1762        int i;
1763
1764        if (data->nr == 0)
1765                return;
1766
1767        for (i = 0; i < data->nr; i++) {
1768                struct diffstat_file *file = data->files[i];
1769
1770                if (options->output_prefix) {
1771                        struct strbuf *msg = NULL;
1772                        msg = options->output_prefix(options,
1773                                        options->output_prefix_data);
1774                        fprintf(options->file, "%s", msg->buf);
1775                }
1776
1777                if (file->is_binary)
1778                        fprintf(options->file, "-\t-\t");
1779                else
1780                        fprintf(options->file,
1781                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1782                                file->added, file->deleted);
1783                if (options->line_termination) {
1784                        fill_print_name(file);
1785                        if (!file->is_renamed)
1786                                write_name_quoted(file->name, options->file,
1787                                                  options->line_termination);
1788                        else {
1789                                fputs(file->print_name, options->file);
1790                                putc(options->line_termination, options->file);
1791                        }
1792                } else {
1793                        if (file->is_renamed) {
1794                                putc('\0', options->file);
1795                                write_name_quoted(file->from_name, options->file, '\0');
1796                        }
1797                        write_name_quoted(file->name, options->file, '\0');
1798                }
1799        }
1800}
1801
1802struct dirstat_file {
1803        const char *name;
1804        unsigned long changed;
1805};
1806
1807struct dirstat_dir {
1808        struct dirstat_file *files;
1809        int alloc, nr, permille, cumulative;
1810};
1811
1812static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1813                unsigned long changed, const char *base, int baselen)
1814{
1815        unsigned long this_dir = 0;
1816        unsigned int sources = 0;
1817        const char *line_prefix = "";
1818        struct strbuf *msg = NULL;
1819
1820        if (opt->output_prefix) {
1821                msg = opt->output_prefix(opt, opt->output_prefix_data);
1822                line_prefix = msg->buf;
1823        }
1824
1825        while (dir->nr) {
1826                struct dirstat_file *f = dir->files;
1827                int namelen = strlen(f->name);
1828                unsigned long this;
1829                char *slash;
1830
1831                if (namelen < baselen)
1832                        break;
1833                if (memcmp(f->name, base, baselen))
1834                        break;
1835                slash = strchr(f->name + baselen, '/');
1836                if (slash) {
1837                        int newbaselen = slash + 1 - f->name;
1838                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1839                        sources++;
1840                } else {
1841                        this = f->changed;
1842                        dir->files++;
1843                        dir->nr--;
1844                        sources += 2;
1845                }
1846                this_dir += this;
1847        }
1848
1849        /*
1850         * We don't report dirstat's for
1851         *  - the top level
1852         *  - or cases where everything came from a single directory
1853         *    under this directory (sources == 1).
1854         */
1855        if (baselen && sources != 1) {
1856                if (this_dir) {
1857                        int permille = this_dir * 1000 / changed;
1858                        if (permille >= dir->permille) {
1859                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1860                                        permille / 10, permille % 10, baselen, base);
1861                                if (!dir->cumulative)
1862                                        return 0;
1863                        }
1864                }
1865        }
1866        return this_dir;
1867}
1868
1869static int dirstat_compare(const void *_a, const void *_b)
1870{
1871        const struct dirstat_file *a = _a;
1872        const struct dirstat_file *b = _b;
1873        return strcmp(a->name, b->name);
1874}
1875
1876static void show_dirstat(struct diff_options *options)
1877{
1878        int i;
1879        unsigned long changed;
1880        struct dirstat_dir dir;
1881        struct diff_queue_struct *q = &diff_queued_diff;
1882
1883        dir.files = NULL;
1884        dir.alloc = 0;
1885        dir.nr = 0;
1886        dir.permille = options->dirstat_permille;
1887        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1888
1889        changed = 0;
1890        for (i = 0; i < q->nr; i++) {
1891                struct diff_filepair *p = q->queue[i];
1892                const char *name;
1893                unsigned long copied, added, damage;
1894                int content_changed;
1895
1896                name = p->two->path ? p->two->path : p->one->path;
1897
1898                if (p->one->sha1_valid && p->two->sha1_valid)
1899                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1900                else
1901                        content_changed = 1;
1902
1903                if (!content_changed) {
1904                        /*
1905                         * The SHA1 has not changed, so pre-/post-content is
1906                         * identical. We can therefore skip looking at the
1907                         * file contents altogether.
1908                         */
1909                        damage = 0;
1910                        goto found_damage;
1911                }
1912
1913                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1914                        /*
1915                         * In --dirstat-by-file mode, we don't really need to
1916                         * look at the actual file contents at all.
1917                         * The fact that the SHA1 changed is enough for us to
1918                         * add this file to the list of results
1919                         * (with each file contributing equal damage).
1920                         */
1921                        damage = 1;
1922                        goto found_damage;
1923                }
1924
1925                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1926                        diff_populate_filespec(p->one, 0);
1927                        diff_populate_filespec(p->two, 0);
1928                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1929                                               &copied, &added);
1930                        diff_free_filespec_data(p->one);
1931                        diff_free_filespec_data(p->two);
1932                } else if (DIFF_FILE_VALID(p->one)) {
1933                        diff_populate_filespec(p->one, 1);
1934                        copied = added = 0;
1935                        diff_free_filespec_data(p->one);
1936                } else if (DIFF_FILE_VALID(p->two)) {
1937                        diff_populate_filespec(p->two, 1);
1938                        copied = 0;
1939                        added = p->two->size;
1940                        diff_free_filespec_data(p->two);
1941                } else
1942                        continue;
1943
1944                /*
1945                 * Original minus copied is the removed material,
1946                 * added is the new material.  They are both damages
1947                 * made to the preimage.
1948                 * If the resulting damage is zero, we know that
1949                 * diffcore_count_changes() considers the two entries to
1950                 * be identical, but since content_changed is true, we
1951                 * know that there must have been _some_ kind of change,
1952                 * so we force all entries to have damage > 0.
1953                 */
1954                damage = (p->one->size - copied) + added;
1955                if (!damage)
1956                        damage = 1;
1957
1958found_damage:
1959                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1960                dir.files[dir.nr].name = name;
1961                dir.files[dir.nr].changed = damage;
1962                changed += damage;
1963                dir.nr++;
1964        }
1965
1966        /* This can happen even with many files, if everything was renames */
1967        if (!changed)
1968                return;
1969
1970        /* Show all directories with more than x% of the changes */
1971        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1972        gather_dirstat(options, &dir, changed, "", 0);
1973}
1974
1975static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1976{
1977        int i;
1978        unsigned long changed;
1979        struct dirstat_dir dir;
1980
1981        if (data->nr == 0)
1982                return;
1983
1984        dir.files = NULL;
1985        dir.alloc = 0;
1986        dir.nr = 0;
1987        dir.permille = options->dirstat_permille;
1988        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1989
1990        changed = 0;
1991        for (i = 0; i < data->nr; i++) {
1992                struct diffstat_file *file = data->files[i];
1993                unsigned long damage = file->added + file->deleted;
1994                if (file->is_binary)
1995                        /*
1996                         * binary files counts bytes, not lines. Must find some
1997                         * way to normalize binary bytes vs. textual lines.
1998                         * The following heuristic assumes that there are 64
1999                         * bytes per "line".
2000                         * This is stupid and ugly, but very cheap...
2001                         */
2002                        damage = (damage + 63) / 64;
2003                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2004                dir.files[dir.nr].name = file->name;
2005                dir.files[dir.nr].changed = damage;
2006                changed += damage;
2007                dir.nr++;
2008        }
2009
2010        /* This can happen even with many files, if everything was renames */
2011        if (!changed)
2012                return;
2013
2014        /* Show all directories with more than x% of the changes */
2015        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2016        gather_dirstat(options, &dir, changed, "", 0);
2017}
2018
2019static void free_diffstat_info(struct diffstat_t *diffstat)
2020{
2021        int i;
2022        for (i = 0; i < diffstat->nr; i++) {
2023                struct diffstat_file *f = diffstat->files[i];
2024                if (f->name != f->print_name)
2025                        free(f->print_name);
2026                free(f->name);
2027                free(f->from_name);
2028                free(f);
2029        }
2030        free(diffstat->files);
2031}
2032
2033struct checkdiff_t {
2034        const char *filename;
2035        int lineno;
2036        int conflict_marker_size;
2037        struct diff_options *o;
2038        unsigned ws_rule;
2039        unsigned status;
2040};
2041
2042static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2043{
2044        char firstchar;
2045        int cnt;
2046
2047        if (len < marker_size + 1)
2048                return 0;
2049        firstchar = line[0];
2050        switch (firstchar) {
2051        case '=': case '>': case '<': case '|':
2052                break;
2053        default:
2054                return 0;
2055        }
2056        for (cnt = 1; cnt < marker_size; cnt++)
2057                if (line[cnt] != firstchar)
2058                        return 0;
2059        /* line[1] thru line[marker_size-1] are same as firstchar */
2060        if (len < marker_size + 1 || !isspace(line[marker_size]))
2061                return 0;
2062        return 1;
2063}
2064
2065static void checkdiff_consume(void *priv, char *line, unsigned long len)
2066{
2067        struct checkdiff_t *data = priv;
2068        int marker_size = data->conflict_marker_size;
2069        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2070        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2071        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2072        char *err;
2073        char *line_prefix = "";
2074        struct strbuf *msgbuf;
2075
2076        assert(data->o);
2077        if (data->o->output_prefix) {
2078                msgbuf = data->o->output_prefix(data->o,
2079                        data->o->output_prefix_data);
2080                line_prefix = msgbuf->buf;
2081        }
2082
2083        if (line[0] == '+') {
2084                unsigned bad;
2085                data->lineno++;
2086                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2087                        data->status |= 1;
2088                        fprintf(data->o->file,
2089                                "%s%s:%d: leftover conflict marker\n",
2090                                line_prefix, data->filename, data->lineno);
2091                }
2092                bad = ws_check(line + 1, len - 1, data->ws_rule);
2093                if (!bad)
2094                        return;
2095                data->status |= bad;
2096                err = whitespace_error_string(bad);
2097                fprintf(data->o->file, "%s%s:%d: %s.\n",
2098                        line_prefix, data->filename, data->lineno, err);
2099                free(err);
2100                emit_line(data->o, set, reset, line, 1);
2101                ws_check_emit(line + 1, len - 1, data->ws_rule,
2102                              data->o->file, set, reset, ws);
2103        } else if (line[0] == ' ') {
2104                data->lineno++;
2105        } else if (line[0] == '@') {
2106                char *plus = strchr(line, '+');
2107                if (plus)
2108                        data->lineno = strtol(plus, NULL, 10) - 1;
2109                else
2110                        die("invalid diff");
2111        }
2112}
2113
2114static unsigned char *deflate_it(char *data,
2115                                 unsigned long size,
2116                                 unsigned long *result_size)
2117{
2118        int bound;
2119        unsigned char *deflated;
2120        git_zstream stream;
2121
2122        memset(&stream, 0, sizeof(stream));
2123        git_deflate_init(&stream, zlib_compression_level);
2124        bound = git_deflate_bound(&stream, size);
2125        deflated = xmalloc(bound);
2126        stream.next_out = deflated;
2127        stream.avail_out = bound;
2128
2129        stream.next_in = (unsigned char *)data;
2130        stream.avail_in = size;
2131        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2132                ; /* nothing */
2133        git_deflate_end(&stream);
2134        *result_size = stream.total_out;
2135        return deflated;
2136}
2137
2138static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2139{
2140        void *cp;
2141        void *delta;
2142        void *deflated;
2143        void *data;
2144        unsigned long orig_size;
2145        unsigned long delta_size;
2146        unsigned long deflate_size;
2147        unsigned long data_size;
2148
2149        /* We could do deflated delta, or we could do just deflated two,
2150         * whichever is smaller.
2151         */
2152        delta = NULL;
2153        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2154        if (one->size && two->size) {
2155                delta = diff_delta(one->ptr, one->size,
2156                                   two->ptr, two->size,
2157                                   &delta_size, deflate_size);
2158                if (delta) {
2159                        void *to_free = delta;
2160                        orig_size = delta_size;
2161                        delta = deflate_it(delta, delta_size, &delta_size);
2162                        free(to_free);
2163                }
2164        }
2165
2166        if (delta && delta_size < deflate_size) {
2167                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2168                free(deflated);
2169                data = delta;
2170                data_size = delta_size;
2171        }
2172        else {
2173                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2174                free(delta);
2175                data = deflated;
2176                data_size = deflate_size;
2177        }
2178
2179        /* emit data encoded in base85 */
2180        cp = data;
2181        while (data_size) {
2182                int bytes = (52 < data_size) ? 52 : data_size;
2183                char line[70];
2184                data_size -= bytes;
2185                if (bytes <= 26)
2186                        line[0] = bytes + 'A' - 1;
2187                else
2188                        line[0] = bytes - 26 + 'a' - 1;
2189                encode_85(line + 1, cp, bytes);
2190                cp = (char *) cp + bytes;
2191                fprintf(file, "%s", prefix);
2192                fputs(line, file);
2193                fputc('\n', file);
2194        }
2195        fprintf(file, "%s\n", prefix);
2196        free(data);
2197}
2198
2199static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2200{
2201        fprintf(file, "%sGIT binary patch\n", prefix);
2202        emit_binary_diff_body(file, one, two, prefix);
2203        emit_binary_diff_body(file, two, one, prefix);
2204}
2205
2206int diff_filespec_is_binary(struct diff_filespec *one)
2207{
2208        if (one->is_binary == -1) {
2209                diff_filespec_load_driver(one);
2210                if (one->driver->binary != -1)
2211                        one->is_binary = one->driver->binary;
2212                else {
2213                        if (!one->data && DIFF_FILE_VALID(one))
2214                                diff_populate_filespec(one, 0);
2215                        if (one->data)
2216                                one->is_binary = buffer_is_binary(one->data,
2217                                                one->size);
2218                        if (one->is_binary == -1)
2219                                one->is_binary = 0;
2220                }
2221        }
2222        return one->is_binary;
2223}
2224
2225static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2226{
2227        diff_filespec_load_driver(one);
2228        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2229}
2230
2231void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2232{
2233        if (!options->a_prefix)
2234                options->a_prefix = a;
2235        if (!options->b_prefix)
2236                options->b_prefix = b;
2237}
2238
2239struct userdiff_driver *get_textconv(struct diff_filespec *one)
2240{
2241        if (!DIFF_FILE_VALID(one))
2242                return NULL;
2243
2244        diff_filespec_load_driver(one);
2245        return userdiff_get_textconv(one->driver);
2246}
2247
2248static void builtin_diff(const char *name_a,
2249                         const char *name_b,
2250                         struct diff_filespec *one,
2251                         struct diff_filespec *two,
2252                         const char *xfrm_msg,
2253                         int must_show_header,
2254                         struct diff_options *o,
2255                         int complete_rewrite)
2256{
2257        mmfile_t mf1, mf2;
2258        const char *lbl[2];
2259        char *a_one, *b_two;
2260        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2261        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2262        const char *a_prefix, *b_prefix;
2263        struct userdiff_driver *textconv_one = NULL;
2264        struct userdiff_driver *textconv_two = NULL;
2265        struct strbuf header = STRBUF_INIT;
2266        struct strbuf *msgbuf;
2267        char *line_prefix = "";
2268
2269        if (o->output_prefix) {
2270                msgbuf = o->output_prefix(o, o->output_prefix_data);
2271                line_prefix = msgbuf->buf;
2272        }
2273
2274        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2275                        (!one->mode || S_ISGITLINK(one->mode)) &&
2276                        (!two->mode || S_ISGITLINK(two->mode))) {
2277                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2278                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2279                show_submodule_summary(o->file, one ? one->path : two->path,
2280                                one->sha1, two->sha1, two->dirty_submodule,
2281                                meta, del, add, reset);
2282                return;
2283        }
2284
2285        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2286                textconv_one = get_textconv(one);
2287                textconv_two = get_textconv(two);
2288        }
2289
2290        diff_set_mnemonic_prefix(o, "a/", "b/");
2291        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2292                a_prefix = o->b_prefix;
2293                b_prefix = o->a_prefix;
2294        } else {
2295                a_prefix = o->a_prefix;
2296                b_prefix = o->b_prefix;
2297        }
2298
2299        /* Never use a non-valid filename anywhere if at all possible */
2300        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2301        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2302
2303        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2304        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2305        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2306        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2307        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2308        if (lbl[0][0] == '/') {
2309                /* /dev/null */
2310                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2311                if (xfrm_msg)
2312                        strbuf_addstr(&header, xfrm_msg);
2313                must_show_header = 1;
2314        }
2315        else if (lbl[1][0] == '/') {
2316                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2317                if (xfrm_msg)
2318                        strbuf_addstr(&header, xfrm_msg);
2319                must_show_header = 1;
2320        }
2321        else {
2322                if (one->mode != two->mode) {
2323                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2324                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2325                        must_show_header = 1;
2326                }
2327                if (xfrm_msg)
2328                        strbuf_addstr(&header, xfrm_msg);
2329
2330                /*
2331                 * we do not run diff between different kind
2332                 * of objects.
2333                 */
2334                if ((one->mode ^ two->mode) & S_IFMT)
2335                        goto free_ab_and_return;
2336                if (complete_rewrite &&
2337                    (textconv_one || !diff_filespec_is_binary(one)) &&
2338                    (textconv_two || !diff_filespec_is_binary(two))) {
2339                        fprintf(o->file, "%s", header.buf);
2340                        strbuf_reset(&header);
2341                        emit_rewrite_diff(name_a, name_b, one, two,
2342                                                textconv_one, textconv_two, o);
2343                        o->found_changes = 1;
2344                        goto free_ab_and_return;
2345                }
2346        }
2347
2348        if (o->irreversible_delete && lbl[1][0] == '/') {
2349                fprintf(o->file, "%s", header.buf);
2350                strbuf_reset(&header);
2351                goto free_ab_and_return;
2352        } else if (!DIFF_OPT_TST(o, TEXT) &&
2353            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2354              (!textconv_two && diff_filespec_is_binary(two)) )) {
2355                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2356                        die("unable to read files to diff");
2357                /* Quite common confusing case */
2358                if (mf1.size == mf2.size &&
2359                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2360                        if (must_show_header)
2361                                fprintf(o->file, "%s", header.buf);
2362                        goto free_ab_and_return;
2363                }
2364                fprintf(o->file, "%s", header.buf);
2365                strbuf_reset(&header);
2366                if (DIFF_OPT_TST(o, BINARY))
2367                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2368                else
2369                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2370                                line_prefix, lbl[0], lbl[1]);
2371                o->found_changes = 1;
2372        } else {
2373                /* Crazy xdl interfaces.. */
2374                const char *diffopts = getenv("GIT_DIFF_OPTS");
2375                xpparam_t xpp;
2376                xdemitconf_t xecfg;
2377                struct emit_callback ecbdata;
2378                const struct userdiff_funcname *pe;
2379
2380                if (must_show_header) {
2381                        fprintf(o->file, "%s", header.buf);
2382                        strbuf_reset(&header);
2383                }
2384
2385                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2386                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2387
2388                pe = diff_funcname_pattern(one);
2389                if (!pe)
2390                        pe = diff_funcname_pattern(two);
2391
2392                memset(&xpp, 0, sizeof(xpp));
2393                memset(&xecfg, 0, sizeof(xecfg));
2394                memset(&ecbdata, 0, sizeof(ecbdata));
2395                ecbdata.label_path = lbl;
2396                ecbdata.color_diff = want_color(o->use_color);
2397                ecbdata.found_changesp = &o->found_changes;
2398                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2399                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2400                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2401                ecbdata.opt = o;
2402                ecbdata.header = header.len ? &header : NULL;
2403                xpp.flags = o->xdl_opts;
2404                xecfg.ctxlen = o->context;
2405                xecfg.interhunkctxlen = o->interhunkcontext;
2406                xecfg.flags = XDL_EMIT_FUNCNAMES;
2407                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2408                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2409                if (pe)
2410                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2411                if (!diffopts)
2412                        ;
2413                else if (!prefixcmp(diffopts, "--unified="))
2414                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2415                else if (!prefixcmp(diffopts, "-u"))
2416                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2417                if (o->word_diff)
2418                        init_diff_words_data(&ecbdata, o, one, two);
2419                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2420                              &xpp, &xecfg);
2421                if (o->word_diff)
2422                        free_diff_words_data(&ecbdata);
2423                if (textconv_one)
2424                        free(mf1.ptr);
2425                if (textconv_two)
2426                        free(mf2.ptr);
2427                xdiff_clear_find_func(&xecfg);
2428        }
2429
2430 free_ab_and_return:
2431        strbuf_release(&header);
2432        diff_free_filespec_data(one);
2433        diff_free_filespec_data(two);
2434        free(a_one);
2435        free(b_two);
2436        return;
2437}
2438
2439static void builtin_diffstat(const char *name_a, const char *name_b,
2440                             struct diff_filespec *one,
2441                             struct diff_filespec *two,
2442                             struct diffstat_t *diffstat,
2443                             struct diff_options *o,
2444                             struct diff_filepair *p)
2445{
2446        mmfile_t mf1, mf2;
2447        struct diffstat_file *data;
2448        int same_contents;
2449        int complete_rewrite = 0;
2450
2451        if (!DIFF_PAIR_UNMERGED(p)) {
2452                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2453                        complete_rewrite = 1;
2454        }
2455
2456        data = diffstat_add(diffstat, name_a, name_b);
2457        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2458
2459        if (!one || !two) {
2460                data->is_unmerged = 1;
2461                return;
2462        }
2463
2464        same_contents = !hashcmp(one->sha1, two->sha1);
2465
2466        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2467                data->is_binary = 1;
2468                if (same_contents) {
2469                        data->added = 0;
2470                        data->deleted = 0;
2471                } else {
2472                        data->added = diff_filespec_size(two);
2473                        data->deleted = diff_filespec_size(one);
2474                }
2475        }
2476
2477        else if (complete_rewrite) {
2478                diff_populate_filespec(one, 0);
2479                diff_populate_filespec(two, 0);
2480                data->deleted = count_lines(one->data, one->size);
2481                data->added = count_lines(two->data, two->size);
2482        }
2483
2484        else if (!same_contents) {
2485                /* Crazy xdl interfaces.. */
2486                xpparam_t xpp;
2487                xdemitconf_t xecfg;
2488
2489                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2490                        die("unable to read files to diff");
2491
2492                memset(&xpp, 0, sizeof(xpp));
2493                memset(&xecfg, 0, sizeof(xecfg));
2494                xpp.flags = o->xdl_opts;
2495                xecfg.ctxlen = o->context;
2496                xecfg.interhunkctxlen = o->interhunkcontext;
2497                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2498                              &xpp, &xecfg);
2499        }
2500
2501        diff_free_filespec_data(one);
2502        diff_free_filespec_data(two);
2503}
2504
2505static void builtin_checkdiff(const char *name_a, const char *name_b,
2506                              const char *attr_path,
2507                              struct diff_filespec *one,
2508                              struct diff_filespec *two,
2509                              struct diff_options *o)
2510{
2511        mmfile_t mf1, mf2;
2512        struct checkdiff_t data;
2513
2514        if (!two)
2515                return;
2516
2517        memset(&data, 0, sizeof(data));
2518        data.filename = name_b ? name_b : name_a;
2519        data.lineno = 0;
2520        data.o = o;
2521        data.ws_rule = whitespace_rule(attr_path);
2522        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2523
2524        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2525                die("unable to read files to diff");
2526
2527        /*
2528         * All the other codepaths check both sides, but not checking
2529         * the "old" side here is deliberate.  We are checking the newly
2530         * introduced changes, and as long as the "new" side is text, we
2531         * can and should check what it introduces.
2532         */
2533        if (diff_filespec_is_binary(two))
2534                goto free_and_return;
2535        else {
2536                /* Crazy xdl interfaces.. */
2537                xpparam_t xpp;
2538                xdemitconf_t xecfg;
2539
2540                memset(&xpp, 0, sizeof(xpp));
2541                memset(&xecfg, 0, sizeof(xecfg));
2542                xecfg.ctxlen = 1; /* at least one context line */
2543                xpp.flags = 0;
2544                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2545                              &xpp, &xecfg);
2546
2547                if (data.ws_rule & WS_BLANK_AT_EOF) {
2548                        struct emit_callback ecbdata;
2549                        int blank_at_eof;
2550
2551                        ecbdata.ws_rule = data.ws_rule;
2552                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2553                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2554
2555                        if (blank_at_eof) {
2556                                static char *err;
2557                                if (!err)
2558                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2559                                fprintf(o->file, "%s:%d: %s.\n",
2560                                        data.filename, blank_at_eof, err);
2561                                data.status = 1; /* report errors */
2562                        }
2563                }
2564        }
2565 free_and_return:
2566        diff_free_filespec_data(one);
2567        diff_free_filespec_data(two);
2568        if (data.status)
2569                DIFF_OPT_SET(o, CHECK_FAILED);
2570}
2571
2572struct diff_filespec *alloc_filespec(const char *path)
2573{
2574        int namelen = strlen(path);
2575        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2576
2577        memset(spec, 0, sizeof(*spec));
2578        spec->path = (char *)(spec + 1);
2579        memcpy(spec->path, path, namelen+1);
2580        spec->count = 1;
2581        spec->is_binary = -1;
2582        return spec;
2583}
2584
2585void free_filespec(struct diff_filespec *spec)
2586{
2587        if (!--spec->count) {
2588                diff_free_filespec_data(spec);
2589                free(spec);
2590        }
2591}
2592
2593void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2594                   int sha1_valid, unsigned short mode)
2595{
2596        if (mode) {
2597                spec->mode = canon_mode(mode);
2598                hashcpy(spec->sha1, sha1);
2599                spec->sha1_valid = sha1_valid;
2600        }
2601}
2602
2603/*
2604 * Given a name and sha1 pair, if the index tells us the file in
2605 * the work tree has that object contents, return true, so that
2606 * prepare_temp_file() does not have to inflate and extract.
2607 */
2608static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2609{
2610        struct cache_entry *ce;
2611        struct stat st;
2612        int pos, len;
2613
2614        /*
2615         * We do not read the cache ourselves here, because the
2616         * benchmark with my previous version that always reads cache
2617         * shows that it makes things worse for diff-tree comparing
2618         * two linux-2.6 kernel trees in an already checked out work
2619         * tree.  This is because most diff-tree comparisons deal with
2620         * only a small number of files, while reading the cache is
2621         * expensive for a large project, and its cost outweighs the
2622         * savings we get by not inflating the object to a temporary
2623         * file.  Practically, this code only helps when we are used
2624         * by diff-cache --cached, which does read the cache before
2625         * calling us.
2626         */
2627        if (!active_cache)
2628                return 0;
2629
2630        /* We want to avoid the working directory if our caller
2631         * doesn't need the data in a normal file, this system
2632         * is rather slow with its stat/open/mmap/close syscalls,
2633         * and the object is contained in a pack file.  The pack
2634         * is probably already open and will be faster to obtain
2635         * the data through than the working directory.  Loose
2636         * objects however would tend to be slower as they need
2637         * to be individually opened and inflated.
2638         */
2639        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2640                return 0;
2641
2642        len = strlen(name);
2643        pos = cache_name_pos(name, len);
2644        if (pos < 0)
2645                return 0;
2646        ce = active_cache[pos];
2647
2648        /*
2649         * This is not the sha1 we are looking for, or
2650         * unreusable because it is not a regular file.
2651         */
2652        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2653                return 0;
2654
2655        /*
2656         * If ce is marked as "assume unchanged", there is no
2657         * guarantee that work tree matches what we are looking for.
2658         */
2659        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2660                return 0;
2661
2662        /*
2663         * If ce matches the file in the work tree, we can reuse it.
2664         */
2665        if (ce_uptodate(ce) ||
2666            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2667                return 1;
2668
2669        return 0;
2670}
2671
2672static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2673{
2674        int len;
2675        char *data = xmalloc(100), *dirty = "";
2676
2677        /* Are we looking at the work tree? */
2678        if (s->dirty_submodule)
2679                dirty = "-dirty";
2680
2681        len = snprintf(data, 100,
2682                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2683        s->data = data;
2684        s->size = len;
2685        s->should_free = 1;
2686        if (size_only) {
2687                s->data = NULL;
2688                free(data);
2689        }
2690        return 0;
2691}
2692
2693/*
2694 * While doing rename detection and pickaxe operation, we may need to
2695 * grab the data for the blob (or file) for our own in-core comparison.
2696 * diff_filespec has data and size fields for this purpose.
2697 */
2698int diff_populate_filespec(struct diff_filespec *s, int size_only)
2699{
2700        int err = 0;
2701        if (!DIFF_FILE_VALID(s))
2702                die("internal error: asking to populate invalid file.");
2703        if (S_ISDIR(s->mode))
2704                return -1;
2705
2706        if (s->data)
2707                return 0;
2708
2709        if (size_only && 0 < s->size)
2710                return 0;
2711
2712        if (S_ISGITLINK(s->mode))
2713                return diff_populate_gitlink(s, size_only);
2714
2715        if (!s->sha1_valid ||
2716            reuse_worktree_file(s->path, s->sha1, 0)) {
2717                struct strbuf buf = STRBUF_INIT;
2718                struct stat st;
2719                int fd;
2720
2721                if (lstat(s->path, &st) < 0) {
2722                        if (errno == ENOENT) {
2723                        err_empty:
2724                                err = -1;
2725                        empty:
2726                                s->data = (char *)"";
2727                                s->size = 0;
2728                                return err;
2729                        }
2730                }
2731                s->size = xsize_t(st.st_size);
2732                if (!s->size)
2733                        goto empty;
2734                if (S_ISLNK(st.st_mode)) {
2735                        struct strbuf sb = STRBUF_INIT;
2736
2737                        if (strbuf_readlink(&sb, s->path, s->size))
2738                                goto err_empty;
2739                        s->size = sb.len;
2740                        s->data = strbuf_detach(&sb, NULL);
2741                        s->should_free = 1;
2742                        return 0;
2743                }
2744                if (size_only)
2745                        return 0;
2746                fd = open(s->path, O_RDONLY);
2747                if (fd < 0)
2748                        goto err_empty;
2749                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2750                close(fd);
2751                s->should_munmap = 1;
2752
2753                /*
2754                 * Convert from working tree format to canonical git format
2755                 */
2756                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2757                        size_t size = 0;
2758                        munmap(s->data, s->size);
2759                        s->should_munmap = 0;
2760                        s->data = strbuf_detach(&buf, &size);
2761                        s->size = size;
2762                        s->should_free = 1;
2763                }
2764        }
2765        else {
2766                enum object_type type;
2767                if (size_only) {
2768                        type = sha1_object_info(s->sha1, &s->size);
2769                        if (type < 0)
2770                                die("unable to read %s", sha1_to_hex(s->sha1));
2771                } else {
2772                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2773                        if (!s->data)
2774                                die("unable to read %s", sha1_to_hex(s->sha1));
2775                        s->should_free = 1;
2776                }
2777        }
2778        return 0;
2779}
2780
2781void diff_free_filespec_blob(struct diff_filespec *s)
2782{
2783        if (s->should_free)
2784                free(s->data);
2785        else if (s->should_munmap)
2786                munmap(s->data, s->size);
2787
2788        if (s->should_free || s->should_munmap) {
2789                s->should_free = s->should_munmap = 0;
2790                s->data = NULL;
2791        }
2792}
2793
2794void diff_free_filespec_data(struct diff_filespec *s)
2795{
2796        diff_free_filespec_blob(s);
2797        free(s->cnt_data);
2798        s->cnt_data = NULL;
2799}
2800
2801static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2802                           void *blob,
2803                           unsigned long size,
2804                           const unsigned char *sha1,
2805                           int mode)
2806{
2807        int fd;
2808        struct strbuf buf = STRBUF_INIT;
2809        struct strbuf template = STRBUF_INIT;
2810        char *path_dup = xstrdup(path);
2811        const char *base = basename(path_dup);
2812
2813        /* Generate "XXXXXX_basename.ext" */
2814        strbuf_addstr(&template, "XXXXXX_");
2815        strbuf_addstr(&template, base);
2816
2817        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2818                        strlen(base) + 1);
2819        if (fd < 0)
2820                die_errno("unable to create temp-file");
2821        if (convert_to_working_tree(path,
2822                        (const char *)blob, (size_t)size, &buf)) {
2823                blob = buf.buf;
2824                size = buf.len;
2825        }
2826        if (write_in_full(fd, blob, size) != size)
2827                die_errno("unable to write temp-file");
2828        close(fd);
2829        temp->name = temp->tmp_path;
2830        strcpy(temp->hex, sha1_to_hex(sha1));
2831        temp->hex[40] = 0;
2832        sprintf(temp->mode, "%06o", mode);
2833        strbuf_release(&buf);
2834        strbuf_release(&template);
2835        free(path_dup);
2836}
2837
2838static struct diff_tempfile *prepare_temp_file(const char *name,
2839                struct diff_filespec *one)
2840{
2841        struct diff_tempfile *temp = claim_diff_tempfile();
2842
2843        if (!DIFF_FILE_VALID(one)) {
2844        not_a_valid_file:
2845                /* A '-' entry produces this for file-2, and
2846                 * a '+' entry produces this for file-1.
2847                 */
2848                temp->name = "/dev/null";
2849                strcpy(temp->hex, ".");
2850                strcpy(temp->mode, ".");
2851                return temp;
2852        }
2853
2854        if (!remove_tempfile_installed) {
2855                atexit(remove_tempfile);
2856                sigchain_push_common(remove_tempfile_on_signal);
2857                remove_tempfile_installed = 1;
2858        }
2859
2860        if (!one->sha1_valid ||
2861            reuse_worktree_file(name, one->sha1, 1)) {
2862                struct stat st;
2863                if (lstat(name, &st) < 0) {
2864                        if (errno == ENOENT)
2865                                goto not_a_valid_file;
2866                        die_errno("stat(%s)", name);
2867                }
2868                if (S_ISLNK(st.st_mode)) {
2869                        struct strbuf sb = STRBUF_INIT;
2870                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2871                                die_errno("readlink(%s)", name);
2872                        prep_temp_blob(name, temp, sb.buf, sb.len,
2873                                       (one->sha1_valid ?
2874                                        one->sha1 : null_sha1),
2875                                       (one->sha1_valid ?
2876                                        one->mode : S_IFLNK));
2877                        strbuf_release(&sb);
2878                }
2879                else {
2880                        /* we can borrow from the file in the work tree */
2881                        temp->name = name;
2882                        if (!one->sha1_valid)
2883                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2884                        else
2885                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2886                        /* Even though we may sometimes borrow the
2887                         * contents from the work tree, we always want
2888                         * one->mode.  mode is trustworthy even when
2889                         * !(one->sha1_valid), as long as
2890                         * DIFF_FILE_VALID(one).
2891                         */
2892                        sprintf(temp->mode, "%06o", one->mode);
2893                }
2894                return temp;
2895        }
2896        else {
2897                if (diff_populate_filespec(one, 0))
2898                        die("cannot read data blob for %s", one->path);
2899                prep_temp_blob(name, temp, one->data, one->size,
2900                               one->sha1, one->mode);
2901        }
2902        return temp;
2903}
2904
2905/* An external diff command takes:
2906 *
2907 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2908 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2909 *
2910 */
2911static void run_external_diff(const char *pgm,
2912                              const char *name,
2913                              const char *other,
2914                              struct diff_filespec *one,
2915                              struct diff_filespec *two,
2916                              const char *xfrm_msg,
2917                              int complete_rewrite)
2918{
2919        const char *spawn_arg[10];
2920        int retval;
2921        const char **arg = &spawn_arg[0];
2922
2923        if (one && two) {
2924                struct diff_tempfile *temp_one, *temp_two;
2925                const char *othername = (other ? other : name);
2926                temp_one = prepare_temp_file(name, one);
2927                temp_two = prepare_temp_file(othername, two);
2928                *arg++ = pgm;
2929                *arg++ = name;
2930                *arg++ = temp_one->name;
2931                *arg++ = temp_one->hex;
2932                *arg++ = temp_one->mode;
2933                *arg++ = temp_two->name;
2934                *arg++ = temp_two->hex;
2935                *arg++ = temp_two->mode;
2936                if (other) {
2937                        *arg++ = other;
2938                        *arg++ = xfrm_msg;
2939                }
2940        } else {
2941                *arg++ = pgm;
2942                *arg++ = name;
2943        }
2944        *arg = NULL;
2945        fflush(NULL);
2946        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2947        remove_tempfile();
2948        if (retval) {
2949                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2950                exit(1);
2951        }
2952}
2953
2954static int similarity_index(struct diff_filepair *p)
2955{
2956        return p->score * 100 / MAX_SCORE;
2957}
2958
2959static void fill_metainfo(struct strbuf *msg,
2960                          const char *name,
2961                          const char *other,
2962                          struct diff_filespec *one,
2963                          struct diff_filespec *two,
2964                          struct diff_options *o,
2965                          struct diff_filepair *p,
2966                          int *must_show_header,
2967                          int use_color)
2968{
2969        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2970        const char *reset = diff_get_color(use_color, DIFF_RESET);
2971        struct strbuf *msgbuf;
2972        char *line_prefix = "";
2973
2974        *must_show_header = 1;
2975        if (o->output_prefix) {
2976                msgbuf = o->output_prefix(o, o->output_prefix_data);
2977                line_prefix = msgbuf->buf;
2978        }
2979        strbuf_init(msg, PATH_MAX * 2 + 300);
2980        switch (p->status) {
2981        case DIFF_STATUS_COPIED:
2982                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2983                            line_prefix, set, similarity_index(p));
2984                strbuf_addf(msg, "%s\n%s%scopy from ",
2985                            reset,  line_prefix, set);
2986                quote_c_style(name, msg, NULL, 0);
2987                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2988                quote_c_style(other, msg, NULL, 0);
2989                strbuf_addf(msg, "%s\n", reset);
2990                break;
2991        case DIFF_STATUS_RENAMED:
2992                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2993                            line_prefix, set, similarity_index(p));
2994                strbuf_addf(msg, "%s\n%s%srename from ",
2995                            reset, line_prefix, set);
2996                quote_c_style(name, msg, NULL, 0);
2997                strbuf_addf(msg, "%s\n%s%srename to ",
2998                            reset, line_prefix, set);
2999                quote_c_style(other, msg, NULL, 0);
3000                strbuf_addf(msg, "%s\n", reset);
3001                break;
3002        case DIFF_STATUS_MODIFIED:
3003                if (p->score) {
3004                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3005                                    line_prefix,
3006                                    set, similarity_index(p), reset);
3007                        break;
3008                }
3009                /* fallthru */
3010        default:
3011                *must_show_header = 0;
3012        }
3013        if (one && two && hashcmp(one->sha1, two->sha1)) {
3014                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3015
3016                if (DIFF_OPT_TST(o, BINARY)) {
3017                        mmfile_t mf;
3018                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3019                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3020                                abbrev = 40;
3021                }
3022                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3023                            find_unique_abbrev(one->sha1, abbrev));
3024                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3025                if (one->mode == two->mode)
3026                        strbuf_addf(msg, " %06o", one->mode);
3027                strbuf_addf(msg, "%s\n", reset);
3028        }
3029}
3030
3031static void run_diff_cmd(const char *pgm,
3032                         const char *name,
3033                         const char *other,
3034                         const char *attr_path,
3035                         struct diff_filespec *one,
3036                         struct diff_filespec *two,
3037                         struct strbuf *msg,
3038                         struct diff_options *o,
3039                         struct diff_filepair *p)
3040{
3041        const char *xfrm_msg = NULL;
3042        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3043        int must_show_header = 0;
3044
3045
3046        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3047                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3048                if (drv && drv->external)
3049                        pgm = drv->external;
3050        }
3051
3052        if (msg) {
3053                /*
3054                 * don't use colors when the header is intended for an
3055                 * external diff driver
3056                 */
3057                fill_metainfo(msg, name, other, one, two, o, p,
3058                              &must_show_header,
3059                              want_color(o->use_color) && !pgm);
3060                xfrm_msg = msg->len ? msg->buf : NULL;
3061        }
3062
3063        if (pgm) {
3064                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3065                                  complete_rewrite);
3066                return;
3067        }
3068        if (one && two)
3069                builtin_diff(name, other ? other : name,
3070                             one, two, xfrm_msg, must_show_header,
3071                             o, complete_rewrite);
3072        else
3073                fprintf(o->file, "* Unmerged path %s\n", name);
3074}
3075
3076static void diff_fill_sha1_info(struct diff_filespec *one)
3077{
3078        if (DIFF_FILE_VALID(one)) {
3079                if (!one->sha1_valid) {
3080                        struct stat st;
3081                        if (one->is_stdin) {
3082                                hashcpy(one->sha1, null_sha1);
3083                                return;
3084                        }
3085                        if (lstat(one->path, &st) < 0)
3086                                die_errno("stat '%s'", one->path);
3087                        if (index_path(one->sha1, one->path, &st, 0))
3088                                die("cannot hash %s", one->path);
3089                }
3090        }
3091        else
3092                hashclr(one->sha1);
3093}
3094
3095static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3096{
3097        /* Strip the prefix but do not molest /dev/null and absolute paths */
3098        if (*namep && **namep != '/') {
3099                *namep += prefix_length;
3100                if (**namep == '/')
3101                        ++*namep;
3102        }
3103        if (*otherp && **otherp != '/') {
3104                *otherp += prefix_length;
3105                if (**otherp == '/')
3106                        ++*otherp;
3107        }
3108}
3109
3110static void run_diff(struct diff_filepair *p, struct diff_options *o)
3111{
3112        const char *pgm = external_diff();
3113        struct strbuf msg;
3114        struct diff_filespec *one = p->one;
3115        struct diff_filespec *two = p->two;
3116        const char *name;
3117        const char *other;
3118        const char *attr_path;
3119
3120        name  = p->one->path;
3121        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3122        attr_path = name;
3123        if (o->prefix_length)
3124                strip_prefix(o->prefix_length, &name, &other);
3125
3126        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3127                pgm = NULL;
3128
3129        if (DIFF_PAIR_UNMERGED(p)) {
3130                run_diff_cmd(pgm, name, NULL, attr_path,
3131                             NULL, NULL, NULL, o, p);
3132                return;
3133        }
3134
3135        diff_fill_sha1_info(one);
3136        diff_fill_sha1_info(two);
3137
3138        if (!pgm &&
3139            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3140            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3141                /*
3142                 * a filepair that changes between file and symlink
3143                 * needs to be split into deletion and creation.
3144                 */
3145                struct diff_filespec *null = alloc_filespec(two->path);
3146                run_diff_cmd(NULL, name, other, attr_path,
3147                             one, null, &msg, o, p);
3148                free(null);
3149                strbuf_release(&msg);
3150
3151                null = alloc_filespec(one->path);
3152                run_diff_cmd(NULL, name, other, attr_path,
3153                             null, two, &msg, o, p);
3154                free(null);
3155        }
3156        else
3157                run_diff_cmd(pgm, name, other, attr_path,
3158                             one, two, &msg, o, p);
3159
3160        strbuf_release(&msg);
3161}
3162
3163static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3164                         struct diffstat_t *diffstat)
3165{
3166        const char *name;
3167        const char *other;
3168
3169        if (DIFF_PAIR_UNMERGED(p)) {
3170                /* unmerged */
3171                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3172                return;
3173        }
3174
3175        name = p->one->path;
3176        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3177
3178        if (o->prefix_length)
3179                strip_prefix(o->prefix_length, &name, &other);
3180
3181        diff_fill_sha1_info(p->one);
3182        diff_fill_sha1_info(p->two);
3183
3184        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3185}
3186
3187static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3188{
3189        const char *name;
3190        const char *other;
3191        const char *attr_path;
3192
3193        if (DIFF_PAIR_UNMERGED(p)) {
3194                /* unmerged */
3195                return;
3196        }
3197
3198        name = p->one->path;
3199        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3200        attr_path = other ? other : name;
3201
3202        if (o->prefix_length)
3203                strip_prefix(o->prefix_length, &name, &other);
3204
3205        diff_fill_sha1_info(p->one);
3206        diff_fill_sha1_info(p->two);
3207
3208        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3209}
3210
3211void diff_setup(struct diff_options *options)
3212{
3213        memcpy(options, &default_diff_options, sizeof(*options));
3214
3215        options->file = stdout;
3216
3217        options->line_termination = '\n';
3218        options->break_opt = -1;
3219        options->rename_limit = -1;
3220        options->dirstat_permille = diff_dirstat_permille_default;
3221        options->context = diff_context_default;
3222        DIFF_OPT_SET(options, RENAME_EMPTY);
3223
3224        options->change = diff_change;
3225        options->add_remove = diff_addremove;
3226        options->use_color = diff_use_color_default;
3227        options->detect_rename = diff_detect_rename_default;
3228
3229        if (diff_no_prefix) {
3230                options->a_prefix = options->b_prefix = "";
3231        } else if (!diff_mnemonic_prefix) {
3232                options->a_prefix = "a/";
3233                options->b_prefix = "b/";
3234        }
3235}
3236
3237void diff_setup_done(struct diff_options *options)
3238{
3239        int count = 0;
3240
3241        if (options->output_format & DIFF_FORMAT_NAME)
3242                count++;
3243        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3244                count++;
3245        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3246                count++;
3247        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3248                count++;
3249        if (count > 1)
3250                die("--name-only, --name-status, --check and -s are mutually exclusive");
3251
3252        /*
3253         * Most of the time we can say "there are changes"
3254         * only by checking if there are changed paths, but
3255         * --ignore-whitespace* options force us to look
3256         * inside contents.
3257         */
3258
3259        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3260            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3261            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3262                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3263        else
3264                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3265
3266        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3267                options->detect_rename = DIFF_DETECT_COPY;
3268
3269        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3270                options->prefix = NULL;
3271        if (options->prefix)
3272                options->prefix_length = strlen(options->prefix);
3273        else
3274                options->prefix_length = 0;
3275
3276        if (options->output_format & (DIFF_FORMAT_NAME |
3277                                      DIFF_FORMAT_NAME_STATUS |
3278                                      DIFF_FORMAT_CHECKDIFF |
3279                                      DIFF_FORMAT_NO_OUTPUT))
3280                options->output_format &= ~(DIFF_FORMAT_RAW |
3281                                            DIFF_FORMAT_NUMSTAT |
3282                                            DIFF_FORMAT_DIFFSTAT |
3283                                            DIFF_FORMAT_SHORTSTAT |
3284                                            DIFF_FORMAT_DIRSTAT |
3285                                            DIFF_FORMAT_SUMMARY |
3286                                            DIFF_FORMAT_PATCH);
3287
3288        /*
3289         * These cases always need recursive; we do not drop caller-supplied
3290         * recursive bits for other formats here.
3291         */
3292        if (options->output_format & (DIFF_FORMAT_PATCH |
3293                                      DIFF_FORMAT_NUMSTAT |
3294                                      DIFF_FORMAT_DIFFSTAT |
3295                                      DIFF_FORMAT_SHORTSTAT |
3296                                      DIFF_FORMAT_DIRSTAT |
3297                                      DIFF_FORMAT_SUMMARY |
3298                                      DIFF_FORMAT_CHECKDIFF))
3299                DIFF_OPT_SET(options, RECURSIVE);
3300        /*
3301         * Also pickaxe would not work very well if you do not say recursive
3302         */
3303        if (options->pickaxe)
3304                DIFF_OPT_SET(options, RECURSIVE);
3305        /*
3306         * When patches are generated, submodules diffed against the work tree
3307         * must be checked for dirtiness too so it can be shown in the output
3308         */
3309        if (options->output_format & DIFF_FORMAT_PATCH)
3310                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3311
3312        if (options->detect_rename && options->rename_limit < 0)
3313                options->rename_limit = diff_rename_limit_default;
3314        if (options->setup & DIFF_SETUP_USE_CACHE) {
3315                if (!active_cache)
3316                        /* read-cache does not die even when it fails
3317                         * so it is safe for us to do this here.  Also
3318                         * it does not smudge active_cache or active_nr
3319                         * when it fails, so we do not have to worry about
3320                         * cleaning it up ourselves either.
3321                         */
3322                        read_cache();
3323        }
3324        if (options->abbrev <= 0 || 40 < options->abbrev)
3325                options->abbrev = 40; /* full */
3326
3327        /*
3328         * It does not make sense to show the first hit we happened
3329         * to have found.  It does not make sense not to return with
3330         * exit code in such a case either.
3331         */
3332        if (DIFF_OPT_TST(options, QUICK)) {
3333                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3334                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3335        }
3336}
3337
3338static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3339{
3340        char c, *eq;
3341        int len;
3342
3343        if (*arg != '-')
3344                return 0;
3345        c = *++arg;
3346        if (!c)
3347                return 0;
3348        if (c == arg_short) {
3349                c = *++arg;
3350                if (!c)
3351                        return 1;
3352                if (val && isdigit(c)) {
3353                        char *end;
3354                        int n = strtoul(arg, &end, 10);
3355                        if (*end)
3356                                return 0;
3357                        *val = n;
3358                        return 1;
3359                }
3360                return 0;
3361        }
3362        if (c != '-')
3363                return 0;
3364        arg++;
3365        eq = strchr(arg, '=');
3366        if (eq)
3367                len = eq - arg;
3368        else
3369                len = strlen(arg);
3370        if (!len || strncmp(arg, arg_long, len))
3371                return 0;
3372        if (eq) {
3373                int n;
3374                char *end;
3375                if (!isdigit(*++eq))
3376                        return 0;
3377                n = strtoul(eq, &end, 10);
3378                if (*end)
3379                        return 0;
3380                *val = n;
3381        }
3382        return 1;
3383}
3384
3385static int diff_scoreopt_parse(const char *opt);
3386
3387static inline int short_opt(char opt, const char **argv,
3388                            const char **optarg)
3389{
3390        const char *arg = argv[0];
3391        if (arg[0] != '-' || arg[1] != opt)
3392                return 0;
3393        if (arg[2] != '\0') {
3394                *optarg = arg + 2;
3395                return 1;
3396        }
3397        if (!argv[1])
3398                die("Option '%c' requires a value", opt);
3399        *optarg = argv[1];
3400        return 2;
3401}
3402
3403int parse_long_opt(const char *opt, const char **argv,
3404                   const char **optarg)
3405{
3406        const char *arg = argv[0];
3407        if (arg[0] != '-' || arg[1] != '-')
3408                return 0;
3409        arg += strlen("--");
3410        if (prefixcmp(arg, opt))
3411                return 0;
3412        arg += strlen(opt);
3413        if (*arg == '=') { /* sticked form: --option=value */
3414                *optarg = arg + 1;
3415                return 1;
3416        }
3417        if (*arg != '\0')
3418                return 0;
3419        /* separate form: --option value */
3420        if (!argv[1])
3421                die("Option '--%s' requires a value", opt);
3422        *optarg = argv[1];
3423        return 2;
3424}
3425
3426static int stat_opt(struct diff_options *options, const char **av)
3427{
3428        const char *arg = av[0];
3429        char *end;
3430        int width = options->stat_width;
3431        int name_width = options->stat_name_width;
3432        int graph_width = options->stat_graph_width;
3433        int count = options->stat_count;
3434        int argcount = 1;
3435
3436        arg += strlen("--stat");
3437        end = (char *)arg;
3438
3439        switch (*arg) {
3440        case '-':
3441                if (!prefixcmp(arg, "-width")) {
3442                        arg += strlen("-width");
3443                        if (*arg == '=')
3444                                width = strtoul(arg + 1, &end, 10);
3445                        else if (!*arg && !av[1])
3446                                die("Option '--stat-width' requires a value");
3447                        else if (!*arg) {
3448                                width = strtoul(av[1], &end, 10);
3449                                argcount = 2;
3450                        }
3451                } else if (!prefixcmp(arg, "-name-width")) {
3452                        arg += strlen("-name-width");
3453                        if (*arg == '=')
3454                                name_width = strtoul(arg + 1, &end, 10);
3455                        else if (!*arg && !av[1])
3456                                die("Option '--stat-name-width' requires a value");
3457                        else if (!*arg) {
3458                                name_width = strtoul(av[1], &end, 10);
3459                                argcount = 2;
3460                        }
3461                } else if (!prefixcmp(arg, "-graph-width")) {
3462                        arg += strlen("-graph-width");
3463                        if (*arg == '=')
3464                                graph_width = strtoul(arg + 1, &end, 10);
3465                        else if (!*arg && !av[1])
3466                                die("Option '--stat-graph-width' requires a value");
3467                        else if (!*arg) {
3468                                graph_width = strtoul(av[1], &end, 10);
3469                                argcount = 2;
3470                        }
3471                } else if (!prefixcmp(arg, "-count")) {
3472                        arg += strlen("-count");
3473                        if (*arg == '=')
3474                                count = strtoul(arg + 1, &end, 10);
3475                        else if (!*arg && !av[1])
3476                                die("Option '--stat-count' requires a value");
3477                        else if (!*arg) {
3478                                count = strtoul(av[1], &end, 10);
3479                                argcount = 2;
3480                        }
3481                }
3482                break;
3483        case '=':
3484                width = strtoul(arg+1, &end, 10);
3485                if (*end == ',')
3486                        name_width = strtoul(end+1, &end, 10);
3487                if (*end == ',')
3488                        count = strtoul(end+1, &end, 10);
3489        }
3490
3491        /* Important! This checks all the error cases! */
3492        if (*end)
3493                return 0;
3494        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3495        options->stat_name_width = name_width;
3496        options->stat_graph_width = graph_width;
3497        options->stat_width = width;
3498        options->stat_count = count;
3499        return argcount;
3500}
3501
3502static int parse_dirstat_opt(struct diff_options *options, const char *params)
3503{
3504        struct strbuf errmsg = STRBUF_INIT;
3505        if (parse_dirstat_params(options, params, &errmsg))
3506                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3507                    errmsg.buf);
3508        strbuf_release(&errmsg);
3509        /*
3510         * The caller knows a dirstat-related option is given from the command
3511         * line; allow it to say "return this_function();"
3512         */
3513        options->output_format |= DIFF_FORMAT_DIRSTAT;
3514        return 1;
3515}
3516
3517static int parse_submodule_opt(struct diff_options *options, const char *value)
3518{
3519        if (parse_submodule_params(options, value))
3520                die(_("Failed to parse --submodule option parameter: '%s'"),
3521                        value);
3522        return 1;
3523}
3524
3525int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3526{
3527        const char *arg = av[0];
3528        const char *optarg;
3529        int argcount;
3530
3531        /* Output format options */
3532        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3533                options->output_format |= DIFF_FORMAT_PATCH;
3534        else if (opt_arg(arg, 'U', "unified", &options->context))
3535                options->output_format |= DIFF_FORMAT_PATCH;
3536        else if (!strcmp(arg, "--raw"))
3537                options->output_format |= DIFF_FORMAT_RAW;
3538        else if (!strcmp(arg, "--patch-with-raw"))
3539                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3540        else if (!strcmp(arg, "--numstat"))
3541                options->output_format |= DIFF_FORMAT_NUMSTAT;
3542        else if (!strcmp(arg, "--shortstat"))
3543                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3544        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3545                return parse_dirstat_opt(options, "");
3546        else if (!prefixcmp(arg, "-X"))
3547                return parse_dirstat_opt(options, arg + 2);
3548        else if (!prefixcmp(arg, "--dirstat="))
3549                return parse_dirstat_opt(options, arg + 10);
3550        else if (!strcmp(arg, "--cumulative"))
3551                return parse_dirstat_opt(options, "cumulative");
3552        else if (!strcmp(arg, "--dirstat-by-file"))
3553                return parse_dirstat_opt(options, "files");
3554        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3555                parse_dirstat_opt(options, "files");
3556                return parse_dirstat_opt(options, arg + 18);
3557        }
3558        else if (!strcmp(arg, "--check"))
3559                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3560        else if (!strcmp(arg, "--summary"))
3561                options->output_format |= DIFF_FORMAT_SUMMARY;
3562        else if (!strcmp(arg, "--patch-with-stat"))
3563                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3564        else if (!strcmp(arg, "--name-only"))
3565                options->output_format |= DIFF_FORMAT_NAME;
3566        else if (!strcmp(arg, "--name-status"))
3567                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3568        else if (!strcmp(arg, "-s"))
3569                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3570        else if (!prefixcmp(arg, "--stat"))
3571                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3572                return stat_opt(options, av);
3573
3574        /* renames options */
3575        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3576                 !strcmp(arg, "--break-rewrites")) {
3577                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3578                        return error("invalid argument to -B: %s", arg+2);
3579        }
3580        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3581                 !strcmp(arg, "--find-renames")) {
3582                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3583                        return error("invalid argument to -M: %s", arg+2);
3584                options->detect_rename = DIFF_DETECT_RENAME;
3585        }
3586        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3587                options->irreversible_delete = 1;
3588        }
3589        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3590                 !strcmp(arg, "--find-copies")) {
3591                if (options->detect_rename == DIFF_DETECT_COPY)
3592                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3593                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3594                        return error("invalid argument to -C: %s", arg+2);
3595                options->detect_rename = DIFF_DETECT_COPY;
3596        }
3597        else if (!strcmp(arg, "--no-renames"))
3598                options->detect_rename = 0;
3599        else if (!strcmp(arg, "--rename-empty"))
3600                DIFF_OPT_SET(options, RENAME_EMPTY);
3601        else if (!strcmp(arg, "--no-rename-empty"))
3602                DIFF_OPT_CLR(options, RENAME_EMPTY);
3603        else if (!strcmp(arg, "--relative"))
3604                DIFF_OPT_SET(options, RELATIVE_NAME);
3605        else if (!prefixcmp(arg, "--relative=")) {
3606                DIFF_OPT_SET(options, RELATIVE_NAME);
3607                options->prefix = arg + 11;
3608        }
3609
3610        /* xdiff options */
3611        else if (!strcmp(arg, "--minimal"))
3612                DIFF_XDL_SET(options, NEED_MINIMAL);
3613        else if (!strcmp(arg, "--no-minimal"))
3614                DIFF_XDL_CLR(options, NEED_MINIMAL);
3615        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3616                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3617        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3618                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3619        else if (!strcmp(arg, "--ignore-space-at-eol"))
3620                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3621        else if (!strcmp(arg, "--patience"))
3622                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3623        else if (!strcmp(arg, "--histogram"))
3624                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3625
3626        /* flags options */
3627        else if (!strcmp(arg, "--binary")) {
3628                options->output_format |= DIFF_FORMAT_PATCH;
3629                DIFF_OPT_SET(options, BINARY);
3630        }
3631        else if (!strcmp(arg, "--full-index"))
3632                DIFF_OPT_SET(options, FULL_INDEX);
3633        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3634                DIFF_OPT_SET(options, TEXT);
3635        else if (!strcmp(arg, "-R"))
3636                DIFF_OPT_SET(options, REVERSE_DIFF);
3637        else if (!strcmp(arg, "--find-copies-harder"))
3638                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3639        else if (!strcmp(arg, "--follow"))
3640                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3641        else if (!strcmp(arg, "--color"))
3642                options->use_color = 1;
3643        else if (!prefixcmp(arg, "--color=")) {
3644                int value = git_config_colorbool(NULL, arg+8);
3645                if (value < 0)
3646                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3647                options->use_color = value;
3648        }
3649        else if (!strcmp(arg, "--no-color"))
3650                options->use_color = 0;
3651        else if (!strcmp(arg, "--color-words")) {
3652                options->use_color = 1;
3653                options->word_diff = DIFF_WORDS_COLOR;
3654        }
3655        else if (!prefixcmp(arg, "--color-words=")) {
3656                options->use_color = 1;
3657                options->word_diff = DIFF_WORDS_COLOR;
3658                options->word_regex = arg + 14;
3659        }
3660        else if (!strcmp(arg, "--word-diff")) {
3661                if (options->word_diff == DIFF_WORDS_NONE)
3662                        options->word_diff = DIFF_WORDS_PLAIN;
3663        }
3664        else if (!prefixcmp(arg, "--word-diff=")) {
3665                const char *type = arg + 12;
3666                if (!strcmp(type, "plain"))
3667                        options->word_diff = DIFF_WORDS_PLAIN;
3668                else if (!strcmp(type, "color")) {
3669                        options->use_color = 1;
3670                        options->word_diff = DIFF_WORDS_COLOR;
3671                }
3672                else if (!strcmp(type, "porcelain"))
3673                        options->word_diff = DIFF_WORDS_PORCELAIN;
3674                else if (!strcmp(type, "none"))
3675                        options->word_diff = DIFF_WORDS_NONE;
3676                else
3677                        die("bad --word-diff argument: %s", type);
3678        }
3679        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3680                if (options->word_diff == DIFF_WORDS_NONE)
3681                        options->word_diff = DIFF_WORDS_PLAIN;
3682                options->word_regex = optarg;
3683                return argcount;
3684        }
3685        else if (!strcmp(arg, "--exit-code"))
3686                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3687        else if (!strcmp(arg, "--quiet"))
3688                DIFF_OPT_SET(options, QUICK);
3689        else if (!strcmp(arg, "--ext-diff"))
3690                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3691        else if (!strcmp(arg, "--no-ext-diff"))
3692                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3693        else if (!strcmp(arg, "--textconv"))
3694                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3695        else if (!strcmp(arg, "--no-textconv"))
3696                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3697        else if (!strcmp(arg, "--ignore-submodules")) {
3698                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3699                handle_ignore_submodules_arg(options, "all");
3700        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3701                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3702                handle_ignore_submodules_arg(options, arg + 20);
3703        } else if (!strcmp(arg, "--submodule"))
3704                DIFF_OPT_SET(options, SUBMODULE_LOG);
3705        else if (!prefixcmp(arg, "--submodule="))
3706                return parse_submodule_opt(options, arg + 12);
3707
3708        /* misc options */
3709        else if (!strcmp(arg, "-z"))
3710                options->line_termination = 0;
3711        else if ((argcount = short_opt('l', av, &optarg))) {
3712                options->rename_limit = strtoul(optarg, NULL, 10);
3713                return argcount;
3714        }
3715        else if ((argcount = short_opt('S', av, &optarg))) {
3716                options->pickaxe = optarg;
3717                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3718                return argcount;
3719        } else if ((argcount = short_opt('G', av, &optarg))) {
3720                options->pickaxe = optarg;
3721                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3722                return argcount;
3723        }
3724        else if (!strcmp(arg, "--pickaxe-all"))
3725                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3726        else if (!strcmp(arg, "--pickaxe-regex"))
3727                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3728        else if ((argcount = short_opt('O', av, &optarg))) {
3729                options->orderfile = optarg;
3730                return argcount;
3731        }
3732        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3733                options->filter = optarg;
3734                return argcount;
3735        }
3736        else if (!strcmp(arg, "--abbrev"))
3737                options->abbrev = DEFAULT_ABBREV;
3738        else if (!prefixcmp(arg, "--abbrev=")) {
3739                options->abbrev = strtoul(arg + 9, NULL, 10);
3740                if (options->abbrev < MINIMUM_ABBREV)
3741                        options->abbrev = MINIMUM_ABBREV;
3742                else if (40 < options->abbrev)
3743                        options->abbrev = 40;
3744        }
3745        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3746                options->a_prefix = optarg;
3747                return argcount;
3748        }
3749        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3750                options->b_prefix = optarg;
3751                return argcount;
3752        }
3753        else if (!strcmp(arg, "--no-prefix"))
3754                options->a_prefix = options->b_prefix = "";
3755        else if (opt_arg(arg, '\0', "inter-hunk-context",
3756                         &options->interhunkcontext))
3757                ;
3758        else if (!strcmp(arg, "-W"))
3759                DIFF_OPT_SET(options, FUNCCONTEXT);
3760        else if (!strcmp(arg, "--function-context"))
3761                DIFF_OPT_SET(options, FUNCCONTEXT);
3762        else if (!strcmp(arg, "--no-function-context"))
3763                DIFF_OPT_CLR(options, FUNCCONTEXT);
3764        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3765                options->file = fopen(optarg, "w");
3766                if (!options->file)
3767                        die_errno("Could not open '%s'", optarg);
3768                options->close_file = 1;
3769                return argcount;
3770        } else
3771                return 0;
3772        return 1;
3773}
3774
3775int parse_rename_score(const char **cp_p)
3776{
3777        unsigned long num, scale;
3778        int ch, dot;
3779        const char *cp = *cp_p;
3780
3781        num = 0;
3782        scale = 1;
3783        dot = 0;
3784        for (;;) {
3785                ch = *cp;
3786                if ( !dot && ch == '.' ) {
3787                        scale = 1;
3788                        dot = 1;
3789                } else if ( ch == '%' ) {
3790                        scale = dot ? scale*100 : 100;
3791                        cp++;   /* % is always at the end */
3792                        break;
3793                } else if ( ch >= '0' && ch <= '9' ) {
3794                        if ( scale < 100000 ) {
3795                                scale *= 10;
3796                                num = (num*10) + (ch-'0');
3797                        }
3798                } else {
3799                        break;
3800                }
3801                cp++;
3802        }
3803        *cp_p = cp;
3804
3805        /* user says num divided by scale and we say internally that
3806         * is MAX_SCORE * num / scale.
3807         */
3808        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3809}
3810
3811static int diff_scoreopt_parse(const char *opt)
3812{
3813        int opt1, opt2, cmd;
3814
3815        if (*opt++ != '-')
3816                return -1;
3817        cmd = *opt++;
3818        if (cmd == '-') {
3819                /* convert the long-form arguments into short-form versions */
3820                if (!prefixcmp(opt, "break-rewrites")) {
3821                        opt += strlen("break-rewrites");
3822                        if (*opt == 0 || *opt++ == '=')
3823                                cmd = 'B';
3824                } else if (!prefixcmp(opt, "find-copies")) {
3825                        opt += strlen("find-copies");
3826                        if (*opt == 0 || *opt++ == '=')
3827                                cmd = 'C';
3828                } else if (!prefixcmp(opt, "find-renames")) {
3829                        opt += strlen("find-renames");
3830                        if (*opt == 0 || *opt++ == '=')
3831                                cmd = 'M';
3832                }
3833        }
3834        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3835                return -1; /* that is not a -M, -C nor -B option */
3836
3837        opt1 = parse_rename_score(&opt);
3838        if (cmd != 'B')
3839                opt2 = 0;
3840        else {
3841                if (*opt == 0)
3842                        opt2 = 0;
3843                else if (*opt != '/')
3844                        return -1; /* we expect -B80/99 or -B80 */
3845                else {
3846                        opt++;
3847                        opt2 = parse_rename_score(&opt);
3848                }
3849        }
3850        if (*opt != 0)
3851                return -1;
3852        return opt1 | (opt2 << 16);
3853}
3854
3855struct diff_queue_struct diff_queued_diff;
3856
3857void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3858{
3859        if (queue->alloc <= queue->nr) {
3860                queue->alloc = alloc_nr(queue->alloc);
3861                queue->queue = xrealloc(queue->queue,
3862                                        sizeof(dp) * queue->alloc);
3863        }
3864        queue->queue[queue->nr++] = dp;
3865}
3866
3867struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3868                                 struct diff_filespec *one,
3869                                 struct diff_filespec *two)
3870{
3871        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3872        dp->one = one;
3873        dp->two = two;
3874        if (queue)
3875                diff_q(queue, dp);
3876        return dp;
3877}
3878
3879void diff_free_filepair(struct diff_filepair *p)
3880{
3881        free_filespec(p->one);
3882        free_filespec(p->two);
3883        free(p);
3884}
3885
3886/* This is different from find_unique_abbrev() in that
3887 * it stuffs the result with dots for alignment.
3888 */
3889const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3890{
3891        int abblen;
3892        const char *abbrev;
3893        if (len == 40)
3894                return sha1_to_hex(sha1);
3895
3896        abbrev = find_unique_abbrev(sha1, len);
3897        abblen = strlen(abbrev);
3898        if (abblen < 37) {
3899                static char hex[41];
3900                if (len < abblen && abblen <= len + 2)
3901                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3902                else
3903                        sprintf(hex, "%s...", abbrev);
3904                return hex;
3905        }
3906        return sha1_to_hex(sha1);
3907}
3908
3909static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3910{
3911        int line_termination = opt->line_termination;
3912        int inter_name_termination = line_termination ? '\t' : '\0';
3913        if (opt->output_prefix) {
3914                struct strbuf *msg = NULL;
3915                msg = opt->output_prefix(opt, opt->output_prefix_data);
3916                fprintf(opt->file, "%s", msg->buf);
3917        }
3918
3919        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3920                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3921                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3922                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3923        }
3924        if (p->score) {
3925                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3926                        inter_name_termination);
3927        } else {
3928                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3929        }
3930
3931        if (p->status == DIFF_STATUS_COPIED ||
3932            p->status == DIFF_STATUS_RENAMED) {
3933                const char *name_a, *name_b;
3934                name_a = p->one->path;
3935                name_b = p->two->path;
3936                strip_prefix(opt->prefix_length, &name_a, &name_b);
3937                write_name_quoted(name_a, opt->file, inter_name_termination);
3938                write_name_quoted(name_b, opt->file, line_termination);
3939        } else {
3940                const char *name_a, *name_b;
3941                name_a = p->one->mode ? p->one->path : p->two->path;
3942                name_b = NULL;
3943                strip_prefix(opt->prefix_length, &name_a, &name_b);
3944                write_name_quoted(name_a, opt->file, line_termination);
3945        }
3946}
3947
3948int diff_unmodified_pair(struct diff_filepair *p)
3949{
3950        /* This function is written stricter than necessary to support
3951         * the currently implemented transformers, but the idea is to
3952         * let transformers to produce diff_filepairs any way they want,
3953         * and filter and clean them up here before producing the output.
3954         */
3955        struct diff_filespec *one = p->one, *two = p->two;
3956
3957        if (DIFF_PAIR_UNMERGED(p))
3958                return 0; /* unmerged is interesting */
3959
3960        /* deletion, addition, mode or type change
3961         * and rename are all interesting.
3962         */
3963        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3964            DIFF_PAIR_MODE_CHANGED(p) ||
3965            strcmp(one->path, two->path))
3966                return 0;
3967
3968        /* both are valid and point at the same path.  that is, we are
3969         * dealing with a change.
3970         */
3971        if (one->sha1_valid && two->sha1_valid &&
3972            !hashcmp(one->sha1, two->sha1) &&
3973            !one->dirty_submodule && !two->dirty_submodule)
3974                return 1; /* no change */
3975        if (!one->sha1_valid && !two->sha1_valid)
3976                return 1; /* both look at the same file on the filesystem. */
3977        return 0;
3978}
3979
3980static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3981{
3982        if (diff_unmodified_pair(p))
3983                return;
3984
3985        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3986            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3987                return; /* no tree diffs in patch format */
3988
3989        run_diff(p, o);
3990}
3991
3992static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3993                            struct diffstat_t *diffstat)
3994{
3995        if (diff_unmodified_pair(p))
3996                return;
3997
3998        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3999            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4000                return; /* no useful stat for tree diffs */
4001
4002        run_diffstat(p, o, diffstat);
4003}
4004
4005static void diff_flush_checkdiff(struct diff_filepair *p,
4006                struct diff_options *o)
4007{
4008        if (diff_unmodified_pair(p))
4009                return;
4010
4011        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4012            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4013                return; /* nothing to check in tree diffs */
4014
4015        run_checkdiff(p, o);
4016}
4017
4018int diff_queue_is_empty(void)
4019{
4020        struct diff_queue_struct *q = &diff_queued_diff;
4021        int i;
4022        for (i = 0; i < q->nr; i++)
4023                if (!diff_unmodified_pair(q->queue[i]))
4024                        return 0;
4025        return 1;
4026}
4027
4028#if DIFF_DEBUG
4029void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4030{
4031        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4032                x, one ? one : "",
4033                s->path,
4034                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4035                s->mode,
4036                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4037        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
4038                x, one ? one : "",
4039                s->size, s->xfrm_flags);
4040}
4041
4042void diff_debug_filepair(const struct diff_filepair *p, int i)
4043{
4044        diff_debug_filespec(p->one, i, "one");
4045        diff_debug_filespec(p->two, i, "two");
4046        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4047                p->score, p->status ? p->status : '?',
4048                p->one->rename_used, p->broken_pair);
4049}
4050
4051void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4052{
4053        int i;
4054        if (msg)
4055                fprintf(stderr, "%s\n", msg);
4056        fprintf(stderr, "q->nr = %d\n", q->nr);
4057        for (i = 0; i < q->nr; i++) {
4058                struct diff_filepair *p = q->queue[i];
4059                diff_debug_filepair(p, i);
4060        }
4061}
4062#endif
4063
4064static void diff_resolve_rename_copy(void)
4065{
4066        int i;
4067        struct diff_filepair *p;
4068        struct diff_queue_struct *q = &diff_queued_diff;
4069
4070        diff_debug_queue("resolve-rename-copy", q);
4071
4072        for (i = 0; i < q->nr; i++) {
4073                p = q->queue[i];
4074                p->status = 0; /* undecided */
4075                if (DIFF_PAIR_UNMERGED(p))
4076                        p->status = DIFF_STATUS_UNMERGED;
4077                else if (!DIFF_FILE_VALID(p->one))
4078                        p->status = DIFF_STATUS_ADDED;
4079                else if (!DIFF_FILE_VALID(p->two))
4080                        p->status = DIFF_STATUS_DELETED;
4081                else if (DIFF_PAIR_TYPE_CHANGED(p))
4082                        p->status = DIFF_STATUS_TYPE_CHANGED;
4083
4084                /* from this point on, we are dealing with a pair
4085                 * whose both sides are valid and of the same type, i.e.
4086                 * either in-place edit or rename/copy edit.
4087                 */
4088                else if (DIFF_PAIR_RENAME(p)) {
4089                        /*
4090                         * A rename might have re-connected a broken
4091                         * pair up, causing the pathnames to be the
4092                         * same again. If so, that's not a rename at
4093                         * all, just a modification..
4094                         *
4095                         * Otherwise, see if this source was used for
4096                         * multiple renames, in which case we decrement
4097                         * the count, and call it a copy.
4098                         */
4099                        if (!strcmp(p->one->path, p->two->path))
4100                                p->status = DIFF_STATUS_MODIFIED;
4101                        else if (--p->one->rename_used > 0)
4102                                p->status = DIFF_STATUS_COPIED;
4103                        else
4104                                p->status = DIFF_STATUS_RENAMED;
4105                }
4106                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4107                         p->one->mode != p->two->mode ||
4108                         p->one->dirty_submodule ||
4109                         p->two->dirty_submodule ||
4110                         is_null_sha1(p->one->sha1))
4111                        p->status = DIFF_STATUS_MODIFIED;
4112                else {
4113                        /* This is a "no-change" entry and should not
4114                         * happen anymore, but prepare for broken callers.
4115                         */
4116                        error("feeding unmodified %s to diffcore",
4117                              p->one->path);
4118                        p->status = DIFF_STATUS_UNKNOWN;
4119                }
4120        }
4121        diff_debug_queue("resolve-rename-copy done", q);
4122}
4123
4124static int check_pair_status(struct diff_filepair *p)
4125{
4126        switch (p->status) {
4127        case DIFF_STATUS_UNKNOWN:
4128                return 0;
4129        case 0:
4130                die("internal error in diff-resolve-rename-copy");
4131        default:
4132                return 1;
4133        }
4134}
4135
4136static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4137{
4138        int fmt = opt->output_format;
4139
4140        if (fmt & DIFF_FORMAT_CHECKDIFF)
4141                diff_flush_checkdiff(p, opt);
4142        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4143                diff_flush_raw(p, opt);
4144        else if (fmt & DIFF_FORMAT_NAME) {
4145                const char *name_a, *name_b;
4146                name_a = p->two->path;
4147                name_b = NULL;
4148                strip_prefix(opt->prefix_length, &name_a, &name_b);
4149                write_name_quoted(name_a, opt->file, opt->line_termination);
4150        }
4151}
4152
4153static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4154{
4155        if (fs->mode)
4156                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4157        else
4158                fprintf(file, " %s ", newdelete);
4159        write_name_quoted(fs->path, file, '\n');
4160}
4161
4162
4163static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4164                const char *line_prefix)
4165{
4166        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4167                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4168                        p->two->mode, show_name ? ' ' : '\n');
4169                if (show_name) {
4170                        write_name_quoted(p->two->path, file, '\n');
4171                }
4172        }
4173}
4174
4175static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4176                        const char *line_prefix)
4177{
4178        char *names = pprint_rename(p->one->path, p->two->path);
4179
4180        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4181        free(names);
4182        show_mode_change(file, p, 0, line_prefix);
4183}
4184
4185static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4186{
4187        FILE *file = opt->file;
4188        char *line_prefix = "";
4189
4190        if (opt->output_prefix) {
4191                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4192                line_prefix = buf->buf;
4193        }
4194
4195        switch(p->status) {
4196        case DIFF_STATUS_DELETED:
4197                fputs(line_prefix, file);
4198                show_file_mode_name(file, "delete", p->one);
4199                break;
4200        case DIFF_STATUS_ADDED:
4201                fputs(line_prefix, file);
4202                show_file_mode_name(file, "create", p->two);
4203                break;
4204        case DIFF_STATUS_COPIED:
4205                fputs(line_prefix, file);
4206                show_rename_copy(file, "copy", p, line_prefix);
4207                break;
4208        case DIFF_STATUS_RENAMED:
4209                fputs(line_prefix, file);
4210                show_rename_copy(file, "rename", p, line_prefix);
4211                break;
4212        default:
4213                if (p->score) {
4214                        fprintf(file, "%s rewrite ", line_prefix);
4215                        write_name_quoted(p->two->path, file, ' ');
4216                        fprintf(file, "(%d%%)\n", similarity_index(p));
4217                }
4218                show_mode_change(file, p, !p->score, line_prefix);
4219                break;
4220        }
4221}
4222
4223struct patch_id_t {
4224        git_SHA_CTX *ctx;
4225        int patchlen;
4226};
4227
4228static int remove_space(char *line, int len)
4229{
4230        int i;
4231        char *dst = line;
4232        unsigned char c;
4233
4234        for (i = 0; i < len; i++)
4235                if (!isspace((c = line[i])))
4236                        *dst++ = c;
4237
4238        return dst - line;
4239}
4240
4241static void patch_id_consume(void *priv, char *line, unsigned long len)
4242{
4243        struct patch_id_t *data = priv;
4244        int new_len;
4245
4246        /* Ignore line numbers when computing the SHA1 of the patch */
4247        if (!prefixcmp(line, "@@ -"))
4248                return;
4249
4250        new_len = remove_space(line, len);
4251
4252        git_SHA1_Update(data->ctx, line, new_len);
4253        data->patchlen += new_len;
4254}
4255
4256/* returns 0 upon success, and writes result into sha1 */
4257static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4258{
4259        struct diff_queue_struct *q = &diff_queued_diff;
4260        int i;
4261        git_SHA_CTX ctx;
4262        struct patch_id_t data;
4263        char buffer[PATH_MAX * 4 + 20];
4264
4265        git_SHA1_Init(&ctx);
4266        memset(&data, 0, sizeof(struct patch_id_t));
4267        data.ctx = &ctx;
4268
4269        for (i = 0; i < q->nr; i++) {
4270                xpparam_t xpp;
4271                xdemitconf_t xecfg;
4272                mmfile_t mf1, mf2;
4273                struct diff_filepair *p = q->queue[i];
4274                int len1, len2;
4275
4276                memset(&xpp, 0, sizeof(xpp));
4277                memset(&xecfg, 0, sizeof(xecfg));
4278                if (p->status == 0)
4279                        return error("internal diff status error");
4280                if (p->status == DIFF_STATUS_UNKNOWN)
4281                        continue;
4282                if (diff_unmodified_pair(p))
4283                        continue;
4284                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4285                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4286                        continue;
4287                if (DIFF_PAIR_UNMERGED(p))
4288                        continue;
4289
4290                diff_fill_sha1_info(p->one);
4291                diff_fill_sha1_info(p->two);
4292                if (fill_mmfile(&mf1, p->one) < 0 ||
4293                                fill_mmfile(&mf2, p->two) < 0)
4294                        return error("unable to read files to diff");
4295
4296                len1 = remove_space(p->one->path, strlen(p->one->path));
4297                len2 = remove_space(p->two->path, strlen(p->two->path));
4298                if (p->one->mode == 0)
4299                        len1 = snprintf(buffer, sizeof(buffer),
4300                                        "diff--gita/%.*sb/%.*s"
4301                                        "newfilemode%06o"
4302                                        "---/dev/null"
4303                                        "+++b/%.*s",
4304                                        len1, p->one->path,
4305                                        len2, p->two->path,
4306                                        p->two->mode,
4307                                        len2, p->two->path);
4308                else if (p->two->mode == 0)
4309                        len1 = snprintf(buffer, sizeof(buffer),
4310                                        "diff--gita/%.*sb/%.*s"
4311                                        "deletedfilemode%06o"
4312                                        "---a/%.*s"
4313                                        "+++/dev/null",
4314                                        len1, p->one->path,
4315                                        len2, p->two->path,
4316                                        p->one->mode,
4317                                        len1, p->one->path);
4318                else
4319                        len1 = snprintf(buffer, sizeof(buffer),
4320                                        "diff--gita/%.*sb/%.*s"
4321                                        "---a/%.*s"
4322                                        "+++b/%.*s",
4323                                        len1, p->one->path,
4324                                        len2, p->two->path,
4325                                        len1, p->one->path,
4326                                        len2, p->two->path);
4327                git_SHA1_Update(&ctx, buffer, len1);
4328
4329                if (diff_filespec_is_binary(p->one) ||
4330                    diff_filespec_is_binary(p->two)) {
4331                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4332                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4333                        continue;
4334                }
4335
4336                xpp.flags = 0;
4337                xecfg.ctxlen = 3;
4338                xecfg.flags = 0;
4339                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4340                              &xpp, &xecfg);
4341        }
4342
4343        git_SHA1_Final(sha1, &ctx);
4344        return 0;
4345}
4346
4347int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4348{
4349        struct diff_queue_struct *q = &diff_queued_diff;
4350        int i;
4351        int result = diff_get_patch_id(options, sha1);
4352
4353        for (i = 0; i < q->nr; i++)
4354                diff_free_filepair(q->queue[i]);
4355
4356        free(q->queue);
4357        DIFF_QUEUE_CLEAR(q);
4358
4359        return result;
4360}
4361
4362static int is_summary_empty(const struct diff_queue_struct *q)
4363{
4364        int i;
4365
4366        for (i = 0; i < q->nr; i++) {
4367                const struct diff_filepair *p = q->queue[i];
4368
4369                switch (p->status) {
4370                case DIFF_STATUS_DELETED:
4371                case DIFF_STATUS_ADDED:
4372                case DIFF_STATUS_COPIED:
4373                case DIFF_STATUS_RENAMED:
4374                        return 0;
4375                default:
4376                        if (p->score)
4377                                return 0;
4378                        if (p->one->mode && p->two->mode &&
4379                            p->one->mode != p->two->mode)
4380                                return 0;
4381                        break;
4382                }
4383        }
4384        return 1;
4385}
4386
4387static const char rename_limit_warning[] =
4388"inexact rename detection was skipped due to too many files.";
4389
4390static const char degrade_cc_to_c_warning[] =
4391"only found copies from modified paths due to too many files.";
4392
4393static const char rename_limit_advice[] =
4394"you may want to set your %s variable to at least "
4395"%d and retry the command.";
4396
4397void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4398{
4399        if (degraded_cc)
4400                warning(degrade_cc_to_c_warning);
4401        else if (needed)
4402                warning(rename_limit_warning);
4403        else
4404                return;
4405        if (0 < needed && needed < 32767)
4406                warning(rename_limit_advice, varname, needed);
4407}
4408
4409void diff_flush(struct diff_options *options)
4410{
4411        struct diff_queue_struct *q = &diff_queued_diff;
4412        int i, output_format = options->output_format;
4413        int separator = 0;
4414        int dirstat_by_line = 0;
4415
4416        /*
4417         * Order: raw, stat, summary, patch
4418         * or:    name/name-status/checkdiff (other bits clear)
4419         */
4420        if (!q->nr)
4421                goto free_queue;
4422
4423        if (output_format & (DIFF_FORMAT_RAW |
4424                             DIFF_FORMAT_NAME |
4425                             DIFF_FORMAT_NAME_STATUS |
4426                             DIFF_FORMAT_CHECKDIFF)) {
4427                for (i = 0; i < q->nr; i++) {
4428                        struct diff_filepair *p = q->queue[i];
4429                        if (check_pair_status(p))
4430                                flush_one_pair(p, options);
4431                }
4432                separator++;
4433        }
4434
4435        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4436                dirstat_by_line = 1;
4437
4438        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4439            dirstat_by_line) {
4440                struct diffstat_t diffstat;
4441
4442                memset(&diffstat, 0, sizeof(struct diffstat_t));
4443                for (i = 0; i < q->nr; i++) {
4444                        struct diff_filepair *p = q->queue[i];
4445                        if (check_pair_status(p))
4446                                diff_flush_stat(p, options, &diffstat);
4447                }
4448                if (output_format & DIFF_FORMAT_NUMSTAT)
4449                        show_numstat(&diffstat, options);
4450                if (output_format & DIFF_FORMAT_DIFFSTAT)
4451                        show_stats(&diffstat, options);
4452                if (output_format & DIFF_FORMAT_SHORTSTAT)
4453                        show_shortstats(&diffstat, options);
4454                if (output_format & DIFF_FORMAT_DIRSTAT)
4455                        show_dirstat_by_line(&diffstat, options);
4456                free_diffstat_info(&diffstat);
4457                separator++;
4458        }
4459        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4460                show_dirstat(options);
4461
4462        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4463                for (i = 0; i < q->nr; i++) {
4464                        diff_summary(options, q->queue[i]);
4465                }
4466                separator++;
4467        }
4468
4469        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4470            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4471            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4472                /*
4473                 * run diff_flush_patch for the exit status. setting
4474                 * options->file to /dev/null should be safe, becaue we
4475                 * aren't supposed to produce any output anyway.
4476                 */
4477                if (options->close_file)
4478                        fclose(options->file);
4479                options->file = fopen("/dev/null", "w");
4480                if (!options->file)
4481                        die_errno("Could not open /dev/null");
4482                options->close_file = 1;
4483                for (i = 0; i < q->nr; i++) {
4484                        struct diff_filepair *p = q->queue[i];
4485                        if (check_pair_status(p))
4486                                diff_flush_patch(p, options);
4487                        if (options->found_changes)
4488                                break;
4489                }
4490        }
4491
4492        if (output_format & DIFF_FORMAT_PATCH) {
4493                if (separator) {
4494                        if (options->output_prefix) {
4495                                struct strbuf *msg = NULL;
4496                                msg = options->output_prefix(options,
4497                                        options->output_prefix_data);
4498                                fwrite(msg->buf, msg->len, 1, stdout);
4499                        }
4500                        putc(options->line_termination, options->file);
4501                        if (options->stat_sep) {
4502                                /* attach patch instead of inline */
4503                                fputs(options->stat_sep, options->file);
4504                        }
4505                }
4506
4507                for (i = 0; i < q->nr; i++) {
4508                        struct diff_filepair *p = q->queue[i];
4509                        if (check_pair_status(p))
4510                                diff_flush_patch(p, options);
4511                }
4512        }
4513
4514        if (output_format & DIFF_FORMAT_CALLBACK)
4515                options->format_callback(q, options, options->format_callback_data);
4516
4517        for (i = 0; i < q->nr; i++)
4518                diff_free_filepair(q->queue[i]);
4519free_queue:
4520        free(q->queue);
4521        DIFF_QUEUE_CLEAR(q);
4522        if (options->close_file)
4523                fclose(options->file);
4524
4525        /*
4526         * Report the content-level differences with HAS_CHANGES;
4527         * diff_addremove/diff_change does not set the bit when
4528         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4529         */
4530        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4531                if (options->found_changes)
4532                        DIFF_OPT_SET(options, HAS_CHANGES);
4533                else
4534                        DIFF_OPT_CLR(options, HAS_CHANGES);
4535        }
4536}
4537
4538static void diffcore_apply_filter(const char *filter)
4539{
4540        int i;
4541        struct diff_queue_struct *q = &diff_queued_diff;
4542        struct diff_queue_struct outq;
4543        DIFF_QUEUE_CLEAR(&outq);
4544
4545        if (!filter)
4546                return;
4547
4548        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4549                int found;
4550                for (i = found = 0; !found && i < q->nr; i++) {
4551                        struct diff_filepair *p = q->queue[i];
4552                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4553                             ((p->score &&
4554                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4555                              (!p->score &&
4556                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4557                            ((p->status != DIFF_STATUS_MODIFIED) &&
4558                             strchr(filter, p->status)))
4559                                found++;
4560                }
4561                if (found)
4562                        return;
4563
4564                /* otherwise we will clear the whole queue
4565                 * by copying the empty outq at the end of this
4566                 * function, but first clear the current entries
4567                 * in the queue.
4568                 */
4569                for (i = 0; i < q->nr; i++)
4570                        diff_free_filepair(q->queue[i]);
4571        }
4572        else {
4573                /* Only the matching ones */
4574                for (i = 0; i < q->nr; i++) {
4575                        struct diff_filepair *p = q->queue[i];
4576
4577                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4578                             ((p->score &&
4579                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4580                              (!p->score &&
4581                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4582                            ((p->status != DIFF_STATUS_MODIFIED) &&
4583                             strchr(filter, p->status)))
4584                                diff_q(&outq, p);
4585                        else
4586                                diff_free_filepair(p);
4587                }
4588        }
4589        free(q->queue);
4590        *q = outq;
4591}
4592
4593/* Check whether two filespecs with the same mode and size are identical */
4594static int diff_filespec_is_identical(struct diff_filespec *one,
4595                                      struct diff_filespec *two)
4596{
4597        if (S_ISGITLINK(one->mode))
4598                return 0;
4599        if (diff_populate_filespec(one, 0))
4600                return 0;
4601        if (diff_populate_filespec(two, 0))
4602                return 0;
4603        return !memcmp(one->data, two->data, one->size);
4604}
4605
4606static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4607{
4608        int i;
4609        struct diff_queue_struct *q = &diff_queued_diff;
4610        struct diff_queue_struct outq;
4611        DIFF_QUEUE_CLEAR(&outq);
4612
4613        for (i = 0; i < q->nr; i++) {
4614                struct diff_filepair *p = q->queue[i];
4615
4616                /*
4617                 * 1. Entries that come from stat info dirtiness
4618                 *    always have both sides (iow, not create/delete),
4619                 *    one side of the object name is unknown, with
4620                 *    the same mode and size.  Keep the ones that
4621                 *    do not match these criteria.  They have real
4622                 *    differences.
4623                 *
4624                 * 2. At this point, the file is known to be modified,
4625                 *    with the same mode and size, and the object
4626                 *    name of one side is unknown.  Need to inspect
4627                 *    the identical contents.
4628                 */
4629                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4630                    !DIFF_FILE_VALID(p->two) ||
4631                    (p->one->sha1_valid && p->two->sha1_valid) ||
4632                    (p->one->mode != p->two->mode) ||
4633                    diff_populate_filespec(p->one, 1) ||
4634                    diff_populate_filespec(p->two, 1) ||
4635                    (p->one->size != p->two->size) ||
4636                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4637                        diff_q(&outq, p);
4638                else {
4639                        /*
4640                         * The caller can subtract 1 from skip_stat_unmatch
4641                         * to determine how many paths were dirty only
4642                         * due to stat info mismatch.
4643                         */
4644                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4645                                diffopt->skip_stat_unmatch++;
4646                        diff_free_filepair(p);
4647                }
4648        }
4649        free(q->queue);
4650        *q = outq;
4651}
4652
4653static int diffnamecmp(const void *a_, const void *b_)
4654{
4655        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4656        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4657        const char *name_a, *name_b;
4658
4659        name_a = a->one ? a->one->path : a->two->path;
4660        name_b = b->one ? b->one->path : b->two->path;
4661        return strcmp(name_a, name_b);
4662}
4663
4664void diffcore_fix_diff_index(struct diff_options *options)
4665{
4666        struct diff_queue_struct *q = &diff_queued_diff;
4667        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4668}
4669
4670void diffcore_std(struct diff_options *options)
4671{
4672        if (options->skip_stat_unmatch)
4673                diffcore_skip_stat_unmatch(options);
4674        if (!options->found_follow) {
4675                /* See try_to_follow_renames() in tree-diff.c */
4676                if (options->break_opt != -1)
4677                        diffcore_break(options->break_opt);
4678                if (options->detect_rename)
4679                        diffcore_rename(options);
4680                if (options->break_opt != -1)
4681                        diffcore_merge_broken();
4682        }
4683        if (options->pickaxe)
4684                diffcore_pickaxe(options);
4685        if (options->orderfile)
4686                diffcore_order(options->orderfile);
4687        if (!options->found_follow)
4688                /* See try_to_follow_renames() in tree-diff.c */
4689                diff_resolve_rename_copy();
4690        diffcore_apply_filter(options->filter);
4691
4692        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4693                DIFF_OPT_SET(options, HAS_CHANGES);
4694        else
4695                DIFF_OPT_CLR(options, HAS_CHANGES);
4696
4697        options->found_follow = 0;
4698}
4699
4700int diff_result_code(struct diff_options *opt, int status)
4701{
4702        int result = 0;
4703
4704        diff_warn_rename_limit("diff.renamelimit",
4705                               opt->needed_rename_limit,
4706                               opt->degraded_cc_to_c);
4707        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4708            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4709                return status;
4710        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4711            DIFF_OPT_TST(opt, HAS_CHANGES))
4712                result |= 01;
4713        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4714            DIFF_OPT_TST(opt, CHECK_FAILED))
4715                result |= 02;
4716        return result;
4717}
4718
4719int diff_can_quit_early(struct diff_options *opt)
4720{
4721        return (DIFF_OPT_TST(opt, QUICK) &&
4722                !opt->filter &&
4723                DIFF_OPT_TST(opt, HAS_CHANGES));
4724}
4725
4726/*
4727 * Shall changes to this submodule be ignored?
4728 *
4729 * Submodule changes can be configured to be ignored separately for each path,
4730 * but that configuration can be overridden from the command line.
4731 */
4732static int is_submodule_ignored(const char *path, struct diff_options *options)
4733{
4734        int ignored = 0;
4735        unsigned orig_flags = options->flags;
4736        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4737                set_diffopt_flags_from_submodule_config(options, path);
4738        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4739                ignored = 1;
4740        options->flags = orig_flags;
4741        return ignored;
4742}
4743
4744void diff_addremove(struct diff_options *options,
4745                    int addremove, unsigned mode,
4746                    const unsigned char *sha1,
4747                    int sha1_valid,
4748                    const char *concatpath, unsigned dirty_submodule)
4749{
4750        struct diff_filespec *one, *two;
4751
4752        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4753                return;
4754
4755        /* This may look odd, but it is a preparation for
4756         * feeding "there are unchanged files which should
4757         * not produce diffs, but when you are doing copy
4758         * detection you would need them, so here they are"
4759         * entries to the diff-core.  They will be prefixed
4760         * with something like '=' or '*' (I haven't decided
4761         * which but should not make any difference).
4762         * Feeding the same new and old to diff_change()
4763         * also has the same effect.
4764         * Before the final output happens, they are pruned after
4765         * merged into rename/copy pairs as appropriate.
4766         */
4767        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4768                addremove = (addremove == '+' ? '-' :
4769                             addremove == '-' ? '+' : addremove);
4770
4771        if (options->prefix &&
4772            strncmp(concatpath, options->prefix, options->prefix_length))
4773                return;
4774
4775        one = alloc_filespec(concatpath);
4776        two = alloc_filespec(concatpath);
4777
4778        if (addremove != '+')
4779                fill_filespec(one, sha1, sha1_valid, mode);
4780        if (addremove != '-') {
4781                fill_filespec(two, sha1, sha1_valid, mode);
4782                two->dirty_submodule = dirty_submodule;
4783        }
4784
4785        diff_queue(&diff_queued_diff, one, two);
4786        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4787                DIFF_OPT_SET(options, HAS_CHANGES);
4788}
4789
4790void diff_change(struct diff_options *options,
4791                 unsigned old_mode, unsigned new_mode,
4792                 const unsigned char *old_sha1,
4793                 const unsigned char *new_sha1,
4794                 int old_sha1_valid, int new_sha1_valid,
4795                 const char *concatpath,
4796                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4797{
4798        struct diff_filespec *one, *two;
4799
4800        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4801            is_submodule_ignored(concatpath, options))
4802                return;
4803
4804        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4805                unsigned tmp;
4806                const unsigned char *tmp_c;
4807                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4808                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4809                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4810                        new_sha1_valid = tmp;
4811                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4812                        new_dirty_submodule = tmp;
4813        }
4814
4815        if (options->prefix &&
4816            strncmp(concatpath, options->prefix, options->prefix_length))
4817                return;
4818
4819        one = alloc_filespec(concatpath);
4820        two = alloc_filespec(concatpath);
4821        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4822        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4823        one->dirty_submodule = old_dirty_submodule;
4824        two->dirty_submodule = new_dirty_submodule;
4825
4826        diff_queue(&diff_queued_diff, one, two);
4827        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4828                DIFF_OPT_SET(options, HAS_CHANGES);
4829}
4830
4831struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4832{
4833        struct diff_filepair *pair;
4834        struct diff_filespec *one, *two;
4835
4836        if (options->prefix &&
4837            strncmp(path, options->prefix, options->prefix_length))
4838                return NULL;
4839
4840        one = alloc_filespec(path);
4841        two = alloc_filespec(path);
4842        pair = diff_queue(&diff_queued_diff, one, two);
4843        pair->is_unmerged = 1;
4844        return pair;
4845}
4846
4847static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4848                size_t *outsize)
4849{
4850        struct diff_tempfile *temp;
4851        const char *argv[3];
4852        const char **arg = argv;
4853        struct child_process child;
4854        struct strbuf buf = STRBUF_INIT;
4855        int err = 0;
4856
4857        temp = prepare_temp_file(spec->path, spec);
4858        *arg++ = pgm;
4859        *arg++ = temp->name;
4860        *arg = NULL;
4861
4862        memset(&child, 0, sizeof(child));
4863        child.use_shell = 1;
4864        child.argv = argv;
4865        child.out = -1;
4866        if (start_command(&child)) {
4867                remove_tempfile();
4868                return NULL;
4869        }
4870
4871        if (strbuf_read(&buf, child.out, 0) < 0)
4872                err = error("error reading from textconv command '%s'", pgm);
4873        close(child.out);
4874
4875        if (finish_command(&child) || err) {
4876                strbuf_release(&buf);
4877                remove_tempfile();
4878                return NULL;
4879        }
4880        remove_tempfile();
4881
4882        return strbuf_detach(&buf, outsize);
4883}
4884
4885size_t fill_textconv(struct userdiff_driver *driver,
4886                     struct diff_filespec *df,
4887                     char **outbuf)
4888{
4889        size_t size;
4890
4891        if (!driver || !driver->textconv) {
4892                if (!DIFF_FILE_VALID(df)) {
4893                        *outbuf = "";
4894                        return 0;
4895                }
4896                if (diff_populate_filespec(df, 0))
4897                        die("unable to read files to diff");
4898                *outbuf = df->data;
4899                return df->size;
4900        }
4901
4902        if (driver->textconv_cache && df->sha1_valid) {
4903                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4904                                          &size);
4905                if (*outbuf)
4906                        return size;
4907        }
4908
4909        *outbuf = run_textconv(driver->textconv, df, &size);
4910        if (!*outbuf)
4911                die("unable to read files to diff");
4912
4913        if (driver->textconv_cache && df->sha1_valid) {
4914                /* ignore errors, as we might be in a readonly repository */
4915                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4916                                size);
4917                /*
4918                 * we could save up changes and flush them all at the end,
4919                 * but we would need an extra call after all diffing is done.
4920                 * Since generating a cache entry is the slow path anyway,
4921                 * this extra overhead probably isn't a big deal.
4922                 */
4923                notes_cache_write(driver->textconv_cache);
4924        }
4925
4926        return size;
4927}
4928
4929void setup_diff_pager(struct diff_options *opt)
4930{
4931        /*
4932         * If the user asked for our exit code, then either they want --quiet
4933         * or --exit-code. We should definitely not bother with a pager in the
4934         * former case, as we will generate no output. Since we still properly
4935         * report our exit code even when a pager is run, we _could_ run a
4936         * pager with --exit-code. But since we have not done so historically,
4937         * and because it is easy to find people oneline advising "git diff
4938         * --exit-code" in hooks and other scripts, we do not do so.
4939         */
4940        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4941            check_pager_config("diff") != 0)
4942                setup_pager();
4943}