diff.con commit daemon: move daemonize() to libgit.a (de0957c)
   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;
  33static const char *diff_order_file_cfg;
  34int diff_auto_refresh_index = 1;
  35static int diff_mnemonic_prefix;
  36static int diff_no_prefix;
  37static int diff_stat_graph_width;
  38static int diff_dirstat_permille_default = 30;
  39static struct diff_options default_diff_options;
  40static long diff_algorithm;
  41
  42static char diff_colors[][COLOR_MAXLEN] = {
  43        GIT_COLOR_RESET,
  44        GIT_COLOR_NORMAL,       /* PLAIN */
  45        GIT_COLOR_BOLD,         /* METAINFO */
  46        GIT_COLOR_CYAN,         /* FRAGINFO */
  47        GIT_COLOR_RED,          /* OLD */
  48        GIT_COLOR_GREEN,        /* NEW */
  49        GIT_COLOR_YELLOW,       /* COMMIT */
  50        GIT_COLOR_BG_RED,       /* WHITESPACE */
  51        GIT_COLOR_NORMAL,       /* FUNCINFO */
  52};
  53
  54static int parse_diff_color_slot(const char *var, int ofs)
  55{
  56        if (!strcasecmp(var+ofs, "plain"))
  57                return DIFF_PLAIN;
  58        if (!strcasecmp(var+ofs, "meta"))
  59                return DIFF_METAINFO;
  60        if (!strcasecmp(var+ofs, "frag"))
  61                return DIFF_FRAGINFO;
  62        if (!strcasecmp(var+ofs, "old"))
  63                return DIFF_FILE_OLD;
  64        if (!strcasecmp(var+ofs, "new"))
  65                return DIFF_FILE_NEW;
  66        if (!strcasecmp(var+ofs, "commit"))
  67                return DIFF_COMMIT;
  68        if (!strcasecmp(var+ofs, "whitespace"))
  69                return DIFF_WHITESPACE;
  70        if (!strcasecmp(var+ofs, "func"))
  71                return DIFF_FUNCINFO;
  72        return -1;
  73}
  74
  75static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  76                                struct strbuf *errmsg)
  77{
  78        char *params_copy = xstrdup(params_string);
  79        struct string_list params = STRING_LIST_INIT_NODUP;
  80        int ret = 0;
  81        int i;
  82
  83        if (*params_copy)
  84                string_list_split_in_place(&params, params_copy, ',', -1);
  85        for (i = 0; i < params.nr; i++) {
  86                const char *p = params.items[i].string;
  87                if (!strcmp(p, "changes")) {
  88                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  89                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  90                } else if (!strcmp(p, "lines")) {
  91                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  92                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  93                } else if (!strcmp(p, "files")) {
  94                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  95                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  96                } else if (!strcmp(p, "noncumulative")) {
  97                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  98                } else if (!strcmp(p, "cumulative")) {
  99                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 100                } else if (isdigit(*p)) {
 101                        char *end;
 102                        int permille = strtoul(p, &end, 10) * 10;
 103                        if (*end == '.' && isdigit(*++end)) {
 104                                /* only use first digit */
 105                                permille += *end - '0';
 106                                /* .. and ignore any further digits */
 107                                while (isdigit(*++end))
 108                                        ; /* nothing */
 109                        }
 110                        if (!*end)
 111                                options->dirstat_permille = permille;
 112                        else {
 113                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 114                                            p);
 115                                ret++;
 116                        }
 117                } else {
 118                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 119                        ret++;
 120                }
 121
 122        }
 123        string_list_clear(&params, 0);
 124        free(params_copy);
 125        return ret;
 126}
 127
 128static int parse_submodule_params(struct diff_options *options, const char *value)
 129{
 130        if (!strcmp(value, "log"))
 131                DIFF_OPT_SET(options, SUBMODULE_LOG);
 132        else if (!strcmp(value, "short"))
 133                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 134        else
 135                return -1;
 136        return 0;
 137}
 138
 139static int git_config_rename(const char *var, const char *value)
 140{
 141        if (!value)
 142                return DIFF_DETECT_RENAME;
 143        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 144                return  DIFF_DETECT_COPY;
 145        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 146}
 147
 148long parse_algorithm_value(const char *value)
 149{
 150        if (!value)
 151                return -1;
 152        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 153                return 0;
 154        else if (!strcasecmp(value, "minimal"))
 155                return XDF_NEED_MINIMAL;
 156        else if (!strcasecmp(value, "patience"))
 157                return XDF_PATIENCE_DIFF;
 158        else if (!strcasecmp(value, "histogram"))
 159                return XDF_HISTOGRAM_DIFF;
 160        return -1;
 161}
 162
 163/*
 164 * These are to give UI layer defaults.
 165 * The core-level commands such as git-diff-files should
 166 * never be affected by the setting of diff.renames
 167 * the user happens to have in the configuration file.
 168 */
 169int git_diff_ui_config(const char *var, const char *value, void *cb)
 170{
 171        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 172                diff_use_color_default = git_config_colorbool(var, value);
 173                return 0;
 174        }
 175        if (!strcmp(var, "diff.context")) {
 176                diff_context_default = git_config_int(var, value);
 177                if (diff_context_default < 0)
 178                        return -1;
 179                return 0;
 180        }
 181        if (!strcmp(var, "diff.renames")) {
 182                diff_detect_rename_default = git_config_rename(var, value);
 183                return 0;
 184        }
 185        if (!strcmp(var, "diff.autorefreshindex")) {
 186                diff_auto_refresh_index = git_config_bool(var, value);
 187                return 0;
 188        }
 189        if (!strcmp(var, "diff.mnemonicprefix")) {
 190                diff_mnemonic_prefix = git_config_bool(var, value);
 191                return 0;
 192        }
 193        if (!strcmp(var, "diff.noprefix")) {
 194                diff_no_prefix = git_config_bool(var, value);
 195                return 0;
 196        }
 197        if (!strcmp(var, "diff.statgraphwidth")) {
 198                diff_stat_graph_width = git_config_int(var, value);
 199                return 0;
 200        }
 201        if (!strcmp(var, "diff.external"))
 202                return git_config_string(&external_diff_cmd_cfg, var, value);
 203        if (!strcmp(var, "diff.wordregex"))
 204                return git_config_string(&diff_word_regex_cfg, var, value);
 205        if (!strcmp(var, "diff.orderfile"))
 206                return git_config_pathname(&diff_order_file_cfg, var, value);
 207
 208        if (!strcmp(var, "diff.ignoresubmodules"))
 209                handle_ignore_submodules_arg(&default_diff_options, value);
 210
 211        if (!strcmp(var, "diff.submodule")) {
 212                if (parse_submodule_params(&default_diff_options, value))
 213                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 214                                value);
 215                return 0;
 216        }
 217
 218        if (!strcmp(var, "diff.algorithm")) {
 219                diff_algorithm = parse_algorithm_value(value);
 220                if (diff_algorithm < 0)
 221                        return -1;
 222                return 0;
 223        }
 224
 225        if (git_color_config(var, value, cb) < 0)
 226                return -1;
 227
 228        return git_diff_basic_config(var, value, cb);
 229}
 230
 231int git_diff_basic_config(const char *var, const char *value, void *cb)
 232{
 233        if (!strcmp(var, "diff.renamelimit")) {
 234                diff_rename_limit_default = git_config_int(var, value);
 235                return 0;
 236        }
 237
 238        if (userdiff_config(var, value) < 0)
 239                return -1;
 240
 241        if (starts_with(var, "diff.color.") || starts_with(var, "color.diff.")) {
 242                int slot = parse_diff_color_slot(var, 11);
 243                if (slot < 0)
 244                        return 0;
 245                if (!value)
 246                        return config_error_nonbool(var);
 247                color_parse(value, var, diff_colors[slot]);
 248                return 0;
 249        }
 250
 251        /* like GNU diff's --suppress-blank-empty option  */
 252        if (!strcmp(var, "diff.suppressblankempty") ||
 253                        /* for backwards compatibility */
 254                        !strcmp(var, "diff.suppress-blank-empty")) {
 255                diff_suppress_blank_empty = git_config_bool(var, value);
 256                return 0;
 257        }
 258
 259        if (!strcmp(var, "diff.dirstat")) {
 260                struct strbuf errmsg = STRBUF_INIT;
 261                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 262                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 263                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 264                                errmsg.buf);
 265                strbuf_release(&errmsg);
 266                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 267                return 0;
 268        }
 269
 270        if (starts_with(var, "submodule."))
 271                return parse_submodule_config_option(var, value);
 272
 273        return git_default_config(var, value, cb);
 274}
 275
 276static char *quote_two(const char *one, const char *two)
 277{
 278        int need_one = quote_c_style(one, NULL, NULL, 1);
 279        int need_two = quote_c_style(two, NULL, NULL, 1);
 280        struct strbuf res = STRBUF_INIT;
 281
 282        if (need_one + need_two) {
 283                strbuf_addch(&res, '"');
 284                quote_c_style(one, &res, NULL, 1);
 285                quote_c_style(two, &res, NULL, 1);
 286                strbuf_addch(&res, '"');
 287        } else {
 288                strbuf_addstr(&res, one);
 289                strbuf_addstr(&res, two);
 290        }
 291        return strbuf_detach(&res, NULL);
 292}
 293
 294static const char *external_diff(void)
 295{
 296        static const char *external_diff_cmd = NULL;
 297        static int done_preparing = 0;
 298
 299        if (done_preparing)
 300                return external_diff_cmd;
 301        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 302        if (!external_diff_cmd)
 303                external_diff_cmd = external_diff_cmd_cfg;
 304        done_preparing = 1;
 305        return external_diff_cmd;
 306}
 307
 308static struct diff_tempfile {
 309        const char *name; /* filename external diff should read from */
 310        char hex[41];
 311        char mode[10];
 312        char tmp_path[PATH_MAX];
 313} diff_temp[2];
 314
 315typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 316
 317struct emit_callback {
 318        int color_diff;
 319        unsigned ws_rule;
 320        int blank_at_eof_in_preimage;
 321        int blank_at_eof_in_postimage;
 322        int lno_in_preimage;
 323        int lno_in_postimage;
 324        sane_truncate_fn truncate;
 325        const char **label_path;
 326        struct diff_words_data *diff_words;
 327        struct diff_options *opt;
 328        int *found_changesp;
 329        struct strbuf *header;
 330};
 331
 332static int count_lines(const char *data, int size)
 333{
 334        int count, ch, completely_empty = 1, nl_just_seen = 0;
 335        count = 0;
 336        while (0 < size--) {
 337                ch = *data++;
 338                if (ch == '\n') {
 339                        count++;
 340                        nl_just_seen = 1;
 341                        completely_empty = 0;
 342                }
 343                else {
 344                        nl_just_seen = 0;
 345                        completely_empty = 0;
 346                }
 347        }
 348        if (completely_empty)
 349                return 0;
 350        if (!nl_just_seen)
 351                count++; /* no trailing newline */
 352        return count;
 353}
 354
 355static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 356{
 357        if (!DIFF_FILE_VALID(one)) {
 358                mf->ptr = (char *)""; /* does not matter */
 359                mf->size = 0;
 360                return 0;
 361        }
 362        else if (diff_populate_filespec(one, 0))
 363                return -1;
 364
 365        mf->ptr = one->data;
 366        mf->size = one->size;
 367        return 0;
 368}
 369
 370/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 371static unsigned long diff_filespec_size(struct diff_filespec *one)
 372{
 373        if (!DIFF_FILE_VALID(one))
 374                return 0;
 375        diff_populate_filespec(one, 1);
 376        return one->size;
 377}
 378
 379static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 380{
 381        char *ptr = mf->ptr;
 382        long size = mf->size;
 383        int cnt = 0;
 384
 385        if (!size)
 386                return cnt;
 387        ptr += size - 1; /* pointing at the very end */
 388        if (*ptr != '\n')
 389                ; /* incomplete line */
 390        else
 391                ptr--; /* skip the last LF */
 392        while (mf->ptr < ptr) {
 393                char *prev_eol;
 394                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 395                        if (*prev_eol == '\n')
 396                                break;
 397                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 398                        break;
 399                cnt++;
 400                ptr = prev_eol - 1;
 401        }
 402        return cnt;
 403}
 404
 405static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 406                               struct emit_callback *ecbdata)
 407{
 408        int l1, l2, at;
 409        unsigned ws_rule = ecbdata->ws_rule;
 410        l1 = count_trailing_blank(mf1, ws_rule);
 411        l2 = count_trailing_blank(mf2, ws_rule);
 412        if (l2 <= l1) {
 413                ecbdata->blank_at_eof_in_preimage = 0;
 414                ecbdata->blank_at_eof_in_postimage = 0;
 415                return;
 416        }
 417        at = count_lines(mf1->ptr, mf1->size);
 418        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 419
 420        at = count_lines(mf2->ptr, mf2->size);
 421        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 422}
 423
 424static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 425                        int first, const char *line, int len)
 426{
 427        int has_trailing_newline, has_trailing_carriage_return;
 428        int nofirst;
 429        FILE *file = o->file;
 430
 431        fputs(diff_line_prefix(o), file);
 432
 433        if (len == 0) {
 434                has_trailing_newline = (first == '\n');
 435                has_trailing_carriage_return = (!has_trailing_newline &&
 436                                                (first == '\r'));
 437                nofirst = has_trailing_newline || has_trailing_carriage_return;
 438        } else {
 439                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 440                if (has_trailing_newline)
 441                        len--;
 442                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 443                if (has_trailing_carriage_return)
 444                        len--;
 445                nofirst = 0;
 446        }
 447
 448        if (len || !nofirst) {
 449                fputs(set, file);
 450                if (!nofirst)
 451                        fputc(first, file);
 452                fwrite(line, len, 1, file);
 453                fputs(reset, file);
 454        }
 455        if (has_trailing_carriage_return)
 456                fputc('\r', file);
 457        if (has_trailing_newline)
 458                fputc('\n', file);
 459}
 460
 461static void emit_line(struct diff_options *o, const char *set, const char *reset,
 462                      const char *line, int len)
 463{
 464        emit_line_0(o, set, reset, line[0], line+1, len-1);
 465}
 466
 467static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 468{
 469        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 470              ecbdata->blank_at_eof_in_preimage &&
 471              ecbdata->blank_at_eof_in_postimage &&
 472              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 473              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 474                return 0;
 475        return ws_blank_line(line, len, ecbdata->ws_rule);
 476}
 477
 478static void emit_add_line(const char *reset,
 479                          struct emit_callback *ecbdata,
 480                          const char *line, int len)
 481{
 482        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 483        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 484
 485        if (!*ws)
 486                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 487        else if (new_blank_line_at_eof(ecbdata, line, len))
 488                /* Blank line at EOF - paint '+' as well */
 489                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 490        else {
 491                /* Emit just the prefix, then the rest. */
 492                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 493                ws_check_emit(line, len, ecbdata->ws_rule,
 494                              ecbdata->opt->file, set, reset, ws);
 495        }
 496}
 497
 498static void emit_hunk_header(struct emit_callback *ecbdata,
 499                             const char *line, int len)
 500{
 501        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 502        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 503        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 504        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 505        static const char atat[2] = { '@', '@' };
 506        const char *cp, *ep;
 507        struct strbuf msgbuf = STRBUF_INIT;
 508        int org_len = len;
 509        int i = 1;
 510
 511        /*
 512         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 513         * it always is at least 10 bytes long.
 514         */
 515        if (len < 10 ||
 516            memcmp(line, atat, 2) ||
 517            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 518                emit_line(ecbdata->opt, plain, reset, line, len);
 519                return;
 520        }
 521        ep += 2; /* skip over @@ */
 522
 523        /* The hunk header in fraginfo color */
 524        strbuf_add(&msgbuf, frag, strlen(frag));
 525        strbuf_add(&msgbuf, line, ep - line);
 526        strbuf_add(&msgbuf, reset, strlen(reset));
 527
 528        /*
 529         * trailing "\r\n"
 530         */
 531        for ( ; i < 3; i++)
 532                if (line[len - i] == '\r' || line[len - i] == '\n')
 533                        len--;
 534
 535        /* blank before the func header */
 536        for (cp = ep; ep - line < len; ep++)
 537                if (*ep != ' ' && *ep != '\t')
 538                        break;
 539        if (ep != cp) {
 540                strbuf_add(&msgbuf, plain, strlen(plain));
 541                strbuf_add(&msgbuf, cp, ep - cp);
 542                strbuf_add(&msgbuf, reset, strlen(reset));
 543        }
 544
 545        if (ep < line + len) {
 546                strbuf_add(&msgbuf, func, strlen(func));
 547                strbuf_add(&msgbuf, ep, line + len - ep);
 548                strbuf_add(&msgbuf, reset, strlen(reset));
 549        }
 550
 551        strbuf_add(&msgbuf, line + len, org_len - len);
 552        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 553        strbuf_release(&msgbuf);
 554}
 555
 556static struct diff_tempfile *claim_diff_tempfile(void) {
 557        int i;
 558        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 559                if (!diff_temp[i].name)
 560                        return diff_temp + i;
 561        die("BUG: diff is failing to clean up its tempfiles");
 562}
 563
 564static int remove_tempfile_installed;
 565
 566static void remove_tempfile(void)
 567{
 568        int i;
 569        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 570                if (diff_temp[i].name == diff_temp[i].tmp_path)
 571                        unlink_or_warn(diff_temp[i].name);
 572                diff_temp[i].name = NULL;
 573        }
 574}
 575
 576static void remove_tempfile_on_signal(int signo)
 577{
 578        remove_tempfile();
 579        sigchain_pop(signo);
 580        raise(signo);
 581}
 582
 583static void print_line_count(FILE *file, int count)
 584{
 585        switch (count) {
 586        case 0:
 587                fprintf(file, "0,0");
 588                break;
 589        case 1:
 590                fprintf(file, "1");
 591                break;
 592        default:
 593                fprintf(file, "1,%d", count);
 594                break;
 595        }
 596}
 597
 598static void emit_rewrite_lines(struct emit_callback *ecb,
 599                               int prefix, const char *data, int size)
 600{
 601        const char *endp = NULL;
 602        static const char *nneof = " No newline at end of file\n";
 603        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 604        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 605
 606        while (0 < size) {
 607                int len;
 608
 609                endp = memchr(data, '\n', size);
 610                len = endp ? (endp - data + 1) : size;
 611                if (prefix != '+') {
 612                        ecb->lno_in_preimage++;
 613                        emit_line_0(ecb->opt, old, reset, '-',
 614                                    data, len);
 615                } else {
 616                        ecb->lno_in_postimage++;
 617                        emit_add_line(reset, ecb, data, len);
 618                }
 619                size -= len;
 620                data += len;
 621        }
 622        if (!endp) {
 623                const char *plain = diff_get_color(ecb->color_diff,
 624                                                   DIFF_PLAIN);
 625                putc('\n', ecb->opt->file);
 626                emit_line_0(ecb->opt, plain, reset, '\\',
 627                            nneof, strlen(nneof));
 628        }
 629}
 630
 631static void emit_rewrite_diff(const char *name_a,
 632                              const char *name_b,
 633                              struct diff_filespec *one,
 634                              struct diff_filespec *two,
 635                              struct userdiff_driver *textconv_one,
 636                              struct userdiff_driver *textconv_two,
 637                              struct diff_options *o)
 638{
 639        int lc_a, lc_b;
 640        const char *name_a_tab, *name_b_tab;
 641        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 642        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 643        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 644        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 645        const char *a_prefix, *b_prefix;
 646        char *data_one, *data_two;
 647        size_t size_one, size_two;
 648        struct emit_callback ecbdata;
 649        const char *line_prefix = diff_line_prefix(o);
 650
 651        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 652                a_prefix = o->b_prefix;
 653                b_prefix = o->a_prefix;
 654        } else {
 655                a_prefix = o->a_prefix;
 656                b_prefix = o->b_prefix;
 657        }
 658
 659        name_a += (*name_a == '/');
 660        name_b += (*name_b == '/');
 661        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 662        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 663
 664        strbuf_reset(&a_name);
 665        strbuf_reset(&b_name);
 666        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 667        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 668
 669        size_one = fill_textconv(textconv_one, one, &data_one);
 670        size_two = fill_textconv(textconv_two, two, &data_two);
 671
 672        memset(&ecbdata, 0, sizeof(ecbdata));
 673        ecbdata.color_diff = want_color(o->use_color);
 674        ecbdata.found_changesp = &o->found_changes;
 675        ecbdata.ws_rule = whitespace_rule(name_b);
 676        ecbdata.opt = o;
 677        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 678                mmfile_t mf1, mf2;
 679                mf1.ptr = (char *)data_one;
 680                mf2.ptr = (char *)data_two;
 681                mf1.size = size_one;
 682                mf2.size = size_two;
 683                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 684        }
 685        ecbdata.lno_in_preimage = 1;
 686        ecbdata.lno_in_postimage = 1;
 687
 688        lc_a = count_lines(data_one, size_one);
 689        lc_b = count_lines(data_two, size_two);
 690        fprintf(o->file,
 691                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 692                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 693                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 694                line_prefix, fraginfo);
 695        if (!o->irreversible_delete)
 696                print_line_count(o->file, lc_a);
 697        else
 698                fprintf(o->file, "?,?");
 699        fprintf(o->file, " +");
 700        print_line_count(o->file, lc_b);
 701        fprintf(o->file, " @@%s\n", reset);
 702        if (lc_a && !o->irreversible_delete)
 703                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 704        if (lc_b)
 705                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 706        if (textconv_one)
 707                free((char *)data_one);
 708        if (textconv_two)
 709                free((char *)data_two);
 710}
 711
 712struct diff_words_buffer {
 713        mmfile_t text;
 714        long alloc;
 715        struct diff_words_orig {
 716                const char *begin, *end;
 717        } *orig;
 718        int orig_nr, orig_alloc;
 719};
 720
 721static void diff_words_append(char *line, unsigned long len,
 722                struct diff_words_buffer *buffer)
 723{
 724        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 725        line++;
 726        len--;
 727        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 728        buffer->text.size += len;
 729        buffer->text.ptr[buffer->text.size] = '\0';
 730}
 731
 732struct diff_words_style_elem {
 733        const char *prefix;
 734        const char *suffix;
 735        const char *color; /* NULL; filled in by the setup code if
 736                            * color is enabled */
 737};
 738
 739struct diff_words_style {
 740        enum diff_words_type type;
 741        struct diff_words_style_elem new, old, ctx;
 742        const char *newline;
 743};
 744
 745static struct diff_words_style diff_words_styles[] = {
 746        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 747        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 748        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 749};
 750
 751struct diff_words_data {
 752        struct diff_words_buffer minus, plus;
 753        const char *current_plus;
 754        int last_minus;
 755        struct diff_options *opt;
 756        regex_t *word_regex;
 757        enum diff_words_type type;
 758        struct diff_words_style *style;
 759};
 760
 761static int fn_out_diff_words_write_helper(FILE *fp,
 762                                          struct diff_words_style_elem *st_el,
 763                                          const char *newline,
 764                                          size_t count, const char *buf,
 765                                          const char *line_prefix)
 766{
 767        int print = 0;
 768
 769        while (count) {
 770                char *p = memchr(buf, '\n', count);
 771                if (print)
 772                        fputs(line_prefix, fp);
 773                if (p != buf) {
 774                        if (st_el->color && fputs(st_el->color, fp) < 0)
 775                                return -1;
 776                        if (fputs(st_el->prefix, fp) < 0 ||
 777                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 778                            fputs(st_el->suffix, fp) < 0)
 779                                return -1;
 780                        if (st_el->color && *st_el->color
 781                            && fputs(GIT_COLOR_RESET, fp) < 0)
 782                                return -1;
 783                }
 784                if (!p)
 785                        return 0;
 786                if (fputs(newline, fp) < 0)
 787                        return -1;
 788                count -= p + 1 - buf;
 789                buf = p + 1;
 790                print = 1;
 791        }
 792        return 0;
 793}
 794
 795/*
 796 * '--color-words' algorithm can be described as:
 797 *
 798 *   1. collect a the minus/plus lines of a diff hunk, divided into
 799 *      minus-lines and plus-lines;
 800 *
 801 *   2. break both minus-lines and plus-lines into words and
 802 *      place them into two mmfile_t with one word for each line;
 803 *
 804 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 805 *
 806 * And for the common parts of the both file, we output the plus side text.
 807 * diff_words->current_plus is used to trace the current position of the plus file
 808 * which printed. diff_words->last_minus is used to trace the last minus word
 809 * printed.
 810 *
 811 * For '--graph' to work with '--color-words', we need to output the graph prefix
 812 * on each line of color words output. Generally, there are two conditions on
 813 * which we should output the prefix.
 814 *
 815 *   1. diff_words->last_minus == 0 &&
 816 *      diff_words->current_plus == diff_words->plus.text.ptr
 817 *
 818 *      that is: the plus text must start as a new line, and if there is no minus
 819 *      word printed, a graph prefix must be printed.
 820 *
 821 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 822 *      *(diff_words->current_plus - 1) == '\n'
 823 *
 824 *      that is: a graph prefix must be printed following a '\n'
 825 */
 826static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 827{
 828        if ((diff_words->last_minus == 0 &&
 829                diff_words->current_plus == diff_words->plus.text.ptr) ||
 830                (diff_words->current_plus > diff_words->plus.text.ptr &&
 831                *(diff_words->current_plus - 1) == '\n')) {
 832                return 1;
 833        } else {
 834                return 0;
 835        }
 836}
 837
 838static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 839{
 840        struct diff_words_data *diff_words = priv;
 841        struct diff_words_style *style = diff_words->style;
 842        int minus_first, minus_len, plus_first, plus_len;
 843        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 844        struct diff_options *opt = diff_words->opt;
 845        const char *line_prefix;
 846
 847        if (line[0] != '@' || parse_hunk_header(line, len,
 848                        &minus_first, &minus_len, &plus_first, &plus_len))
 849                return;
 850
 851        assert(opt);
 852        line_prefix = diff_line_prefix(opt);
 853
 854        /* POSIX requires that first be decremented by one if len == 0... */
 855        if (minus_len) {
 856                minus_begin = diff_words->minus.orig[minus_first].begin;
 857                minus_end =
 858                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 859        } else
 860                minus_begin = minus_end =
 861                        diff_words->minus.orig[minus_first].end;
 862
 863        if (plus_len) {
 864                plus_begin = diff_words->plus.orig[plus_first].begin;
 865                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 866        } else
 867                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 868
 869        if (color_words_output_graph_prefix(diff_words)) {
 870                fputs(line_prefix, diff_words->opt->file);
 871        }
 872        if (diff_words->current_plus != plus_begin) {
 873                fn_out_diff_words_write_helper(diff_words->opt->file,
 874                                &style->ctx, style->newline,
 875                                plus_begin - diff_words->current_plus,
 876                                diff_words->current_plus, line_prefix);
 877                if (*(plus_begin - 1) == '\n')
 878                        fputs(line_prefix, diff_words->opt->file);
 879        }
 880        if (minus_begin != minus_end) {
 881                fn_out_diff_words_write_helper(diff_words->opt->file,
 882                                &style->old, style->newline,
 883                                minus_end - minus_begin, minus_begin,
 884                                line_prefix);
 885        }
 886        if (plus_begin != plus_end) {
 887                fn_out_diff_words_write_helper(diff_words->opt->file,
 888                                &style->new, style->newline,
 889                                plus_end - plus_begin, plus_begin,
 890                                line_prefix);
 891        }
 892
 893        diff_words->current_plus = plus_end;
 894        diff_words->last_minus = minus_first;
 895}
 896
 897/* This function starts looking at *begin, and returns 0 iff a word was found. */
 898static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 899                int *begin, int *end)
 900{
 901        if (word_regex && *begin < buffer->size) {
 902                regmatch_t match[1];
 903                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 904                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 905                                        '\n', match[0].rm_eo - match[0].rm_so);
 906                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 907                        *begin += match[0].rm_so;
 908                        return *begin >= *end;
 909                }
 910                return -1;
 911        }
 912
 913        /* find the next word */
 914        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 915                (*begin)++;
 916        if (*begin >= buffer->size)
 917                return -1;
 918
 919        /* find the end of the word */
 920        *end = *begin + 1;
 921        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 922                (*end)++;
 923
 924        return 0;
 925}
 926
 927/*
 928 * This function splits the words in buffer->text, stores the list with
 929 * newline separator into out, and saves the offsets of the original words
 930 * in buffer->orig.
 931 */
 932static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 933                regex_t *word_regex)
 934{
 935        int i, j;
 936        long alloc = 0;
 937
 938        out->size = 0;
 939        out->ptr = NULL;
 940
 941        /* fake an empty "0th" word */
 942        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 943        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 944        buffer->orig_nr = 1;
 945
 946        for (i = 0; i < buffer->text.size; i++) {
 947                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 948                        return;
 949
 950                /* store original boundaries */
 951                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 952                                buffer->orig_alloc);
 953                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 954                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 955                buffer->orig_nr++;
 956
 957                /* store one word */
 958                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 959                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 960                out->ptr[out->size + j - i] = '\n';
 961                out->size += j - i + 1;
 962
 963                i = j - 1;
 964        }
 965}
 966
 967/* this executes the word diff on the accumulated buffers */
 968static void diff_words_show(struct diff_words_data *diff_words)
 969{
 970        xpparam_t xpp;
 971        xdemitconf_t xecfg;
 972        mmfile_t minus, plus;
 973        struct diff_words_style *style = diff_words->style;
 974
 975        struct diff_options *opt = diff_words->opt;
 976        const char *line_prefix;
 977
 978        assert(opt);
 979        line_prefix = diff_line_prefix(opt);
 980
 981        /* special case: only removal */
 982        if (!diff_words->plus.text.size) {
 983                fputs(line_prefix, diff_words->opt->file);
 984                fn_out_diff_words_write_helper(diff_words->opt->file,
 985                        &style->old, style->newline,
 986                        diff_words->minus.text.size,
 987                        diff_words->minus.text.ptr, line_prefix);
 988                diff_words->minus.text.size = 0;
 989                return;
 990        }
 991
 992        diff_words->current_plus = diff_words->plus.text.ptr;
 993        diff_words->last_minus = 0;
 994
 995        memset(&xpp, 0, sizeof(xpp));
 996        memset(&xecfg, 0, sizeof(xecfg));
 997        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 998        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 999        xpp.flags = 0;
1000        /* as only the hunk header will be parsed, we need a 0-context */
1001        xecfg.ctxlen = 0;
1002        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1003                      &xpp, &xecfg);
1004        free(minus.ptr);
1005        free(plus.ptr);
1006        if (diff_words->current_plus != diff_words->plus.text.ptr +
1007                        diff_words->plus.text.size) {
1008                if (color_words_output_graph_prefix(diff_words))
1009                        fputs(line_prefix, diff_words->opt->file);
1010                fn_out_diff_words_write_helper(diff_words->opt->file,
1011                        &style->ctx, style->newline,
1012                        diff_words->plus.text.ptr + diff_words->plus.text.size
1013                        - diff_words->current_plus, diff_words->current_plus,
1014                        line_prefix);
1015        }
1016        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1017}
1018
1019/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1020static void diff_words_flush(struct emit_callback *ecbdata)
1021{
1022        if (ecbdata->diff_words->minus.text.size ||
1023            ecbdata->diff_words->plus.text.size)
1024                diff_words_show(ecbdata->diff_words);
1025}
1026
1027static void diff_filespec_load_driver(struct diff_filespec *one)
1028{
1029        /* Use already-loaded driver */
1030        if (one->driver)
1031                return;
1032
1033        if (S_ISREG(one->mode))
1034                one->driver = userdiff_find_by_path(one->path);
1035
1036        /* Fallback to default settings */
1037        if (!one->driver)
1038                one->driver = userdiff_find_by_name("default");
1039}
1040
1041static const char *userdiff_word_regex(struct diff_filespec *one)
1042{
1043        diff_filespec_load_driver(one);
1044        return one->driver->word_regex;
1045}
1046
1047static void init_diff_words_data(struct emit_callback *ecbdata,
1048                                 struct diff_options *orig_opts,
1049                                 struct diff_filespec *one,
1050                                 struct diff_filespec *two)
1051{
1052        int i;
1053        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1054        memcpy(o, orig_opts, sizeof(struct diff_options));
1055
1056        ecbdata->diff_words =
1057                xcalloc(1, sizeof(struct diff_words_data));
1058        ecbdata->diff_words->type = o->word_diff;
1059        ecbdata->diff_words->opt = o;
1060        if (!o->word_regex)
1061                o->word_regex = userdiff_word_regex(one);
1062        if (!o->word_regex)
1063                o->word_regex = userdiff_word_regex(two);
1064        if (!o->word_regex)
1065                o->word_regex = diff_word_regex_cfg;
1066        if (o->word_regex) {
1067                ecbdata->diff_words->word_regex = (regex_t *)
1068                        xmalloc(sizeof(regex_t));
1069                if (regcomp(ecbdata->diff_words->word_regex,
1070                            o->word_regex,
1071                            REG_EXTENDED | REG_NEWLINE))
1072                        die ("Invalid regular expression: %s",
1073                             o->word_regex);
1074        }
1075        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1076                if (o->word_diff == diff_words_styles[i].type) {
1077                        ecbdata->diff_words->style =
1078                                &diff_words_styles[i];
1079                        break;
1080                }
1081        }
1082        if (want_color(o->use_color)) {
1083                struct diff_words_style *st = ecbdata->diff_words->style;
1084                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1085                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1086                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1087        }
1088}
1089
1090static void free_diff_words_data(struct emit_callback *ecbdata)
1091{
1092        if (ecbdata->diff_words) {
1093                diff_words_flush(ecbdata);
1094                free (ecbdata->diff_words->opt);
1095                free (ecbdata->diff_words->minus.text.ptr);
1096                free (ecbdata->diff_words->minus.orig);
1097                free (ecbdata->diff_words->plus.text.ptr);
1098                free (ecbdata->diff_words->plus.orig);
1099                if (ecbdata->diff_words->word_regex) {
1100                        regfree(ecbdata->diff_words->word_regex);
1101                        free(ecbdata->diff_words->word_regex);
1102                }
1103                free(ecbdata->diff_words);
1104                ecbdata->diff_words = NULL;
1105        }
1106}
1107
1108const char *diff_get_color(int diff_use_color, enum color_diff ix)
1109{
1110        if (want_color(diff_use_color))
1111                return diff_colors[ix];
1112        return "";
1113}
1114
1115const char *diff_line_prefix(struct diff_options *opt)
1116{
1117        struct strbuf *msgbuf;
1118        if (!opt->output_prefix)
1119                return "";
1120
1121        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1122        return msgbuf->buf;
1123}
1124
1125static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1126{
1127        const char *cp;
1128        unsigned long allot;
1129        size_t l = len;
1130
1131        if (ecb->truncate)
1132                return ecb->truncate(line, len);
1133        cp = line;
1134        allot = l;
1135        while (0 < l) {
1136                (void) utf8_width(&cp, &l);
1137                if (!cp)
1138                        break; /* truncated in the middle? */
1139        }
1140        return allot - l;
1141}
1142
1143static void find_lno(const char *line, struct emit_callback *ecbdata)
1144{
1145        const char *p;
1146        ecbdata->lno_in_preimage = 0;
1147        ecbdata->lno_in_postimage = 0;
1148        p = strchr(line, '-');
1149        if (!p)
1150                return; /* cannot happen */
1151        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1152        p = strchr(p, '+');
1153        if (!p)
1154                return; /* cannot happen */
1155        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1156}
1157
1158static void fn_out_consume(void *priv, char *line, unsigned long len)
1159{
1160        struct emit_callback *ecbdata = priv;
1161        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1162        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1163        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1164        struct diff_options *o = ecbdata->opt;
1165        const char *line_prefix = diff_line_prefix(o);
1166
1167        if (ecbdata->header) {
1168                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1169                strbuf_reset(ecbdata->header);
1170                ecbdata->header = NULL;
1171        }
1172        *(ecbdata->found_changesp) = 1;
1173
1174        if (ecbdata->label_path[0]) {
1175                const char *name_a_tab, *name_b_tab;
1176
1177                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1178                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1179
1180                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1181                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1182                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1183                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1184                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1185        }
1186
1187        if (diff_suppress_blank_empty
1188            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1189                line[0] = '\n';
1190                len = 1;
1191        }
1192
1193        if (line[0] == '@') {
1194                if (ecbdata->diff_words)
1195                        diff_words_flush(ecbdata);
1196                len = sane_truncate_line(ecbdata, line, len);
1197                find_lno(line, ecbdata);
1198                emit_hunk_header(ecbdata, line, len);
1199                if (line[len-1] != '\n')
1200                        putc('\n', ecbdata->opt->file);
1201                return;
1202        }
1203
1204        if (len < 1) {
1205                emit_line(ecbdata->opt, reset, reset, line, len);
1206                if (ecbdata->diff_words
1207                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1208                        fputs("~\n", ecbdata->opt->file);
1209                return;
1210        }
1211
1212        if (ecbdata->diff_words) {
1213                if (line[0] == '-') {
1214                        diff_words_append(line, len,
1215                                          &ecbdata->diff_words->minus);
1216                        return;
1217                } else if (line[0] == '+') {
1218                        diff_words_append(line, len,
1219                                          &ecbdata->diff_words->plus);
1220                        return;
1221                } else if (starts_with(line, "\\ ")) {
1222                        /*
1223                         * Eat the "no newline at eof" marker as if we
1224                         * saw a "+" or "-" line with nothing on it,
1225                         * and return without diff_words_flush() to
1226                         * defer processing. If this is the end of
1227                         * preimage, more "+" lines may come after it.
1228                         */
1229                        return;
1230                }
1231                diff_words_flush(ecbdata);
1232                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1233                        emit_line(ecbdata->opt, plain, reset, line, len);
1234                        fputs("~\n", ecbdata->opt->file);
1235                } else {
1236                        /*
1237                         * Skip the prefix character, if any.  With
1238                         * diff_suppress_blank_empty, there may be
1239                         * none.
1240                         */
1241                        if (line[0] != '\n') {
1242                              line++;
1243                              len--;
1244                        }
1245                        emit_line(ecbdata->opt, plain, reset, line, len);
1246                }
1247                return;
1248        }
1249
1250        if (line[0] != '+') {
1251                const char *color =
1252                        diff_get_color(ecbdata->color_diff,
1253                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1254                ecbdata->lno_in_preimage++;
1255                if (line[0] == ' ')
1256                        ecbdata->lno_in_postimage++;
1257                emit_line(ecbdata->opt, color, reset, line, len);
1258        } else {
1259                ecbdata->lno_in_postimage++;
1260                emit_add_line(reset, ecbdata, line + 1, len - 1);
1261        }
1262}
1263
1264static char *pprint_rename(const char *a, const char *b)
1265{
1266        const char *old = a;
1267        const char *new = b;
1268        struct strbuf name = STRBUF_INIT;
1269        int pfx_length, sfx_length;
1270        int pfx_adjust_for_slash;
1271        int len_a = strlen(a);
1272        int len_b = strlen(b);
1273        int a_midlen, b_midlen;
1274        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1275        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1276
1277        if (qlen_a || qlen_b) {
1278                quote_c_style(a, &name, NULL, 0);
1279                strbuf_addstr(&name, " => ");
1280                quote_c_style(b, &name, NULL, 0);
1281                return strbuf_detach(&name, NULL);
1282        }
1283
1284        /* Find common prefix */
1285        pfx_length = 0;
1286        while (*old && *new && *old == *new) {
1287                if (*old == '/')
1288                        pfx_length = old - a + 1;
1289                old++;
1290                new++;
1291        }
1292
1293        /* Find common suffix */
1294        old = a + len_a;
1295        new = b + len_b;
1296        sfx_length = 0;
1297        /*
1298         * If there is a common prefix, it must end in a slash.  In
1299         * that case we let this loop run 1 into the prefix to see the
1300         * same slash.
1301         *
1302         * If there is no common prefix, we cannot do this as it would
1303         * underrun the input strings.
1304         */
1305        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1306        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1307               b + pfx_length - pfx_adjust_for_slash <= new &&
1308               *old == *new) {
1309                if (*old == '/')
1310                        sfx_length = len_a - (old - a);
1311                old--;
1312                new--;
1313        }
1314
1315        /*
1316         * pfx{mid-a => mid-b}sfx
1317         * {pfx-a => pfx-b}sfx
1318         * pfx{sfx-a => sfx-b}
1319         * name-a => name-b
1320         */
1321        a_midlen = len_a - pfx_length - sfx_length;
1322        b_midlen = len_b - pfx_length - sfx_length;
1323        if (a_midlen < 0)
1324                a_midlen = 0;
1325        if (b_midlen < 0)
1326                b_midlen = 0;
1327
1328        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1329        if (pfx_length + sfx_length) {
1330                strbuf_add(&name, a, pfx_length);
1331                strbuf_addch(&name, '{');
1332        }
1333        strbuf_add(&name, a + pfx_length, a_midlen);
1334        strbuf_addstr(&name, " => ");
1335        strbuf_add(&name, b + pfx_length, b_midlen);
1336        if (pfx_length + sfx_length) {
1337                strbuf_addch(&name, '}');
1338                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1339        }
1340        return strbuf_detach(&name, NULL);
1341}
1342
1343struct diffstat_t {
1344        int nr;
1345        int alloc;
1346        struct diffstat_file {
1347                char *from_name;
1348                char *name;
1349                char *print_name;
1350                unsigned is_unmerged:1;
1351                unsigned is_binary:1;
1352                unsigned is_renamed:1;
1353                unsigned is_interesting:1;
1354                uintmax_t added, deleted;
1355        } **files;
1356};
1357
1358static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1359                                          const char *name_a,
1360                                          const char *name_b)
1361{
1362        struct diffstat_file *x;
1363        x = xcalloc(sizeof (*x), 1);
1364        if (diffstat->nr == diffstat->alloc) {
1365                diffstat->alloc = alloc_nr(diffstat->alloc);
1366                diffstat->files = xrealloc(diffstat->files,
1367                                diffstat->alloc * sizeof(x));
1368        }
1369        diffstat->files[diffstat->nr++] = x;
1370        if (name_b) {
1371                x->from_name = xstrdup(name_a);
1372                x->name = xstrdup(name_b);
1373                x->is_renamed = 1;
1374        }
1375        else {
1376                x->from_name = NULL;
1377                x->name = xstrdup(name_a);
1378        }
1379        return x;
1380}
1381
1382static void diffstat_consume(void *priv, char *line, unsigned long len)
1383{
1384        struct diffstat_t *diffstat = priv;
1385        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1386
1387        if (line[0] == '+')
1388                x->added++;
1389        else if (line[0] == '-')
1390                x->deleted++;
1391}
1392
1393const char mime_boundary_leader[] = "------------";
1394
1395static int scale_linear(int it, int width, int max_change)
1396{
1397        if (!it)
1398                return 0;
1399        /*
1400         * make sure that at least one '-' or '+' is printed if
1401         * there is any change to this path. The easiest way is to
1402         * scale linearly as if the alloted width is one column shorter
1403         * than it is, and then add 1 to the result.
1404         */
1405        return 1 + (it * (width - 1) / max_change);
1406}
1407
1408static void show_name(FILE *file,
1409                      const char *prefix, const char *name, int len)
1410{
1411        fprintf(file, " %s%-*s |", prefix, len, name);
1412}
1413
1414static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1415{
1416        if (cnt <= 0)
1417                return;
1418        fprintf(file, "%s", set);
1419        while (cnt--)
1420                putc(ch, file);
1421        fprintf(file, "%s", reset);
1422}
1423
1424static void fill_print_name(struct diffstat_file *file)
1425{
1426        char *pname;
1427
1428        if (file->print_name)
1429                return;
1430
1431        if (!file->is_renamed) {
1432                struct strbuf buf = STRBUF_INIT;
1433                if (quote_c_style(file->name, &buf, NULL, 0)) {
1434                        pname = strbuf_detach(&buf, NULL);
1435                } else {
1436                        pname = file->name;
1437                        strbuf_release(&buf);
1438                }
1439        } else {
1440                pname = pprint_rename(file->from_name, file->name);
1441        }
1442        file->print_name = pname;
1443}
1444
1445int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1446{
1447        struct strbuf sb = STRBUF_INIT;
1448        int ret;
1449
1450        if (!files) {
1451                assert(insertions == 0 && deletions == 0);
1452                return fprintf(fp, "%s\n", " 0 files changed");
1453        }
1454
1455        strbuf_addf(&sb,
1456                    (files == 1) ? " %d file changed" : " %d files changed",
1457                    files);
1458
1459        /*
1460         * For binary diff, the caller may want to print "x files
1461         * changed" with insertions == 0 && deletions == 0.
1462         *
1463         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1464         * is probably less confusing (i.e skip over "2 files changed
1465         * but nothing about added/removed lines? Is this a bug in Git?").
1466         */
1467        if (insertions || deletions == 0) {
1468                /*
1469                 * TRANSLATORS: "+" in (+) is a line addition marker;
1470                 * do not translate it.
1471                 */
1472                strbuf_addf(&sb,
1473                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1474                            insertions);
1475        }
1476
1477        if (deletions || insertions == 0) {
1478                /*
1479                 * TRANSLATORS: "-" in (-) is a line removal marker;
1480                 * do not translate it.
1481                 */
1482                strbuf_addf(&sb,
1483                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1484                            deletions);
1485        }
1486        strbuf_addch(&sb, '\n');
1487        ret = fputs(sb.buf, fp);
1488        strbuf_release(&sb);
1489        return ret;
1490}
1491
1492static void show_stats(struct diffstat_t *data, struct diff_options *options)
1493{
1494        int i, len, add, del, adds = 0, dels = 0;
1495        uintmax_t max_change = 0, max_len = 0;
1496        int total_files = data->nr, count;
1497        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1498        const char *reset, *add_c, *del_c;
1499        const char *line_prefix = "";
1500        int extra_shown = 0;
1501
1502        if (data->nr == 0)
1503                return;
1504
1505        line_prefix = diff_line_prefix(options);
1506        count = options->stat_count ? options->stat_count : data->nr;
1507
1508        reset = diff_get_color_opt(options, DIFF_RESET);
1509        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1510        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1511
1512        /*
1513         * Find the longest filename and max number of changes
1514         */
1515        for (i = 0; (i < count) && (i < data->nr); i++) {
1516                struct diffstat_file *file = data->files[i];
1517                uintmax_t change = file->added + file->deleted;
1518
1519                if (!file->is_interesting && (change == 0)) {
1520                        count++; /* not shown == room for one more */
1521                        continue;
1522                }
1523                fill_print_name(file);
1524                len = strlen(file->print_name);
1525                if (max_len < len)
1526                        max_len = len;
1527
1528                if (file->is_unmerged) {
1529                        /* "Unmerged" is 8 characters */
1530                        bin_width = bin_width < 8 ? 8 : bin_width;
1531                        continue;
1532                }
1533                if (file->is_binary) {
1534                        /* "Bin XXX -> YYY bytes" */
1535                        int w = 14 + decimal_width(file->added)
1536                                + decimal_width(file->deleted);
1537                        bin_width = bin_width < w ? w : bin_width;
1538                        /* Display change counts aligned with "Bin" */
1539                        number_width = 3;
1540                        continue;
1541                }
1542
1543                if (max_change < change)
1544                        max_change = change;
1545        }
1546        count = i; /* where we can stop scanning in data->files[] */
1547
1548        /*
1549         * We have width = stat_width or term_columns() columns total.
1550         * We want a maximum of min(max_len, stat_name_width) for the name part.
1551         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1552         * We also need 1 for " " and 4 + decimal_width(max_change)
1553         * for " | NNNN " and one the empty column at the end, altogether
1554         * 6 + decimal_width(max_change).
1555         *
1556         * If there's not enough space, we will use the smaller of
1557         * stat_name_width (if set) and 5/8*width for the filename,
1558         * and the rest for constant elements + graph part, but no more
1559         * than stat_graph_width for the graph part.
1560         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1561         * for the standard terminal size).
1562         *
1563         * In other words: stat_width limits the maximum width, and
1564         * stat_name_width fixes the maximum width of the filename,
1565         * and is also used to divide available columns if there
1566         * aren't enough.
1567         *
1568         * Binary files are displayed with "Bin XXX -> YYY bytes"
1569         * instead of the change count and graph. This part is treated
1570         * similarly to the graph part, except that it is not
1571         * "scaled". If total width is too small to accommodate the
1572         * guaranteed minimum width of the filename part and the
1573         * separators and this message, this message will "overflow"
1574         * making the line longer than the maximum width.
1575         */
1576
1577        if (options->stat_width == -1)
1578                width = term_columns() - options->output_prefix_length;
1579        else
1580                width = options->stat_width ? options->stat_width : 80;
1581        number_width = decimal_width(max_change) > number_width ?
1582                decimal_width(max_change) : number_width;
1583
1584        if (options->stat_graph_width == -1)
1585                options->stat_graph_width = diff_stat_graph_width;
1586
1587        /*
1588         * Guarantee 3/8*16==6 for the graph part
1589         * and 5/8*16==10 for the filename part
1590         */
1591        if (width < 16 + 6 + number_width)
1592                width = 16 + 6 + number_width;
1593
1594        /*
1595         * First assign sizes that are wanted, ignoring available width.
1596         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1597         * starting from "XXX" should fit in graph_width.
1598         */
1599        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1600        if (options->stat_graph_width &&
1601            options->stat_graph_width < graph_width)
1602                graph_width = options->stat_graph_width;
1603
1604        name_width = (options->stat_name_width > 0 &&
1605                      options->stat_name_width < max_len) ?
1606                options->stat_name_width : max_len;
1607
1608        /*
1609         * Adjust adjustable widths not to exceed maximum width
1610         */
1611        if (name_width + number_width + 6 + graph_width > width) {
1612                if (graph_width > width * 3/8 - number_width - 6) {
1613                        graph_width = width * 3/8 - number_width - 6;
1614                        if (graph_width < 6)
1615                                graph_width = 6;
1616                }
1617
1618                if (options->stat_graph_width &&
1619                    graph_width > options->stat_graph_width)
1620                        graph_width = options->stat_graph_width;
1621                if (name_width > width - number_width - 6 - graph_width)
1622                        name_width = width - number_width - 6 - graph_width;
1623                else
1624                        graph_width = width - number_width - 6 - name_width;
1625        }
1626
1627        /*
1628         * From here name_width is the width of the name area,
1629         * and graph_width is the width of the graph area.
1630         * max_change is used to scale graph properly.
1631         */
1632        for (i = 0; i < count; i++) {
1633                const char *prefix = "";
1634                struct diffstat_file *file = data->files[i];
1635                char *name = file->print_name;
1636                uintmax_t added = file->added;
1637                uintmax_t deleted = file->deleted;
1638                int name_len;
1639
1640                if (!file->is_interesting && (added + deleted == 0))
1641                        continue;
1642
1643                /*
1644                 * "scale" the filename
1645                 */
1646                len = name_width;
1647                name_len = strlen(name);
1648                if (name_width < name_len) {
1649                        char *slash;
1650                        prefix = "...";
1651                        len -= 3;
1652                        name += name_len - len;
1653                        slash = strchr(name, '/');
1654                        if (slash)
1655                                name = slash;
1656                }
1657
1658                if (file->is_binary) {
1659                        fprintf(options->file, "%s", line_prefix);
1660                        show_name(options->file, prefix, name, len);
1661                        fprintf(options->file, " %*s", number_width, "Bin");
1662                        if (!added && !deleted) {
1663                                putc('\n', options->file);
1664                                continue;
1665                        }
1666                        fprintf(options->file, " %s%"PRIuMAX"%s",
1667                                del_c, deleted, reset);
1668                        fprintf(options->file, " -> ");
1669                        fprintf(options->file, "%s%"PRIuMAX"%s",
1670                                add_c, added, reset);
1671                        fprintf(options->file, " bytes");
1672                        fprintf(options->file, "\n");
1673                        continue;
1674                }
1675                else if (file->is_unmerged) {
1676                        fprintf(options->file, "%s", line_prefix);
1677                        show_name(options->file, prefix, name, len);
1678                        fprintf(options->file, " Unmerged\n");
1679                        continue;
1680                }
1681
1682                /*
1683                 * scale the add/delete
1684                 */
1685                add = added;
1686                del = deleted;
1687
1688                if (graph_width <= max_change) {
1689                        int total = scale_linear(add + del, graph_width, max_change);
1690                        if (total < 2 && add && del)
1691                                /* width >= 2 due to the sanity check */
1692                                total = 2;
1693                        if (add < del) {
1694                                add = scale_linear(add, graph_width, max_change);
1695                                del = total - add;
1696                        } else {
1697                                del = scale_linear(del, graph_width, max_change);
1698                                add = total - del;
1699                        }
1700                }
1701                fprintf(options->file, "%s", line_prefix);
1702                show_name(options->file, prefix, name, len);
1703                fprintf(options->file, " %*"PRIuMAX"%s",
1704                        number_width, added + deleted,
1705                        added + deleted ? " " : "");
1706                show_graph(options->file, '+', add, add_c, reset);
1707                show_graph(options->file, '-', del, del_c, reset);
1708                fprintf(options->file, "\n");
1709        }
1710
1711        for (i = 0; i < data->nr; i++) {
1712                struct diffstat_file *file = data->files[i];
1713                uintmax_t added = file->added;
1714                uintmax_t deleted = file->deleted;
1715
1716                if (file->is_unmerged ||
1717                    (!file->is_interesting && (added + deleted == 0))) {
1718                        total_files--;
1719                        continue;
1720                }
1721
1722                if (!file->is_binary) {
1723                        adds += added;
1724                        dels += deleted;
1725                }
1726                if (i < count)
1727                        continue;
1728                if (!extra_shown)
1729                        fprintf(options->file, "%s ...\n", line_prefix);
1730                extra_shown = 1;
1731        }
1732        fprintf(options->file, "%s", line_prefix);
1733        print_stat_summary(options->file, total_files, adds, dels);
1734}
1735
1736static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1737{
1738        int i, adds = 0, dels = 0, total_files = data->nr;
1739
1740        if (data->nr == 0)
1741                return;
1742
1743        for (i = 0; i < data->nr; i++) {
1744                int added = data->files[i]->added;
1745                int deleted= data->files[i]->deleted;
1746
1747                if (data->files[i]->is_unmerged ||
1748                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1749                        total_files--;
1750                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1751                        adds += added;
1752                        dels += deleted;
1753                }
1754        }
1755        fprintf(options->file, "%s", diff_line_prefix(options));
1756        print_stat_summary(options->file, total_files, adds, dels);
1757}
1758
1759static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1760{
1761        int i;
1762
1763        if (data->nr == 0)
1764                return;
1765
1766        for (i = 0; i < data->nr; i++) {
1767                struct diffstat_file *file = data->files[i];
1768
1769                fprintf(options->file, "%s", diff_line_prefix(options));
1770
1771                if (file->is_binary)
1772                        fprintf(options->file, "-\t-\t");
1773                else
1774                        fprintf(options->file,
1775                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1776                                file->added, file->deleted);
1777                if (options->line_termination) {
1778                        fill_print_name(file);
1779                        if (!file->is_renamed)
1780                                write_name_quoted(file->name, options->file,
1781                                                  options->line_termination);
1782                        else {
1783                                fputs(file->print_name, options->file);
1784                                putc(options->line_termination, options->file);
1785                        }
1786                } else {
1787                        if (file->is_renamed) {
1788                                putc('\0', options->file);
1789                                write_name_quoted(file->from_name, options->file, '\0');
1790                        }
1791                        write_name_quoted(file->name, options->file, '\0');
1792                }
1793        }
1794}
1795
1796struct dirstat_file {
1797        const char *name;
1798        unsigned long changed;
1799};
1800
1801struct dirstat_dir {
1802        struct dirstat_file *files;
1803        int alloc, nr, permille, cumulative;
1804};
1805
1806static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1807                unsigned long changed, const char *base, int baselen)
1808{
1809        unsigned long this_dir = 0;
1810        unsigned int sources = 0;
1811        const char *line_prefix = diff_line_prefix(opt);
1812
1813        while (dir->nr) {
1814                struct dirstat_file *f = dir->files;
1815                int namelen = strlen(f->name);
1816                unsigned long this;
1817                char *slash;
1818
1819                if (namelen < baselen)
1820                        break;
1821                if (memcmp(f->name, base, baselen))
1822                        break;
1823                slash = strchr(f->name + baselen, '/');
1824                if (slash) {
1825                        int newbaselen = slash + 1 - f->name;
1826                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1827                        sources++;
1828                } else {
1829                        this = f->changed;
1830                        dir->files++;
1831                        dir->nr--;
1832                        sources += 2;
1833                }
1834                this_dir += this;
1835        }
1836
1837        /*
1838         * We don't report dirstat's for
1839         *  - the top level
1840         *  - or cases where everything came from a single directory
1841         *    under this directory (sources == 1).
1842         */
1843        if (baselen && sources != 1) {
1844                if (this_dir) {
1845                        int permille = this_dir * 1000 / changed;
1846                        if (permille >= dir->permille) {
1847                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1848                                        permille / 10, permille % 10, baselen, base);
1849                                if (!dir->cumulative)
1850                                        return 0;
1851                        }
1852                }
1853        }
1854        return this_dir;
1855}
1856
1857static int dirstat_compare(const void *_a, const void *_b)
1858{
1859        const struct dirstat_file *a = _a;
1860        const struct dirstat_file *b = _b;
1861        return strcmp(a->name, b->name);
1862}
1863
1864static void show_dirstat(struct diff_options *options)
1865{
1866        int i;
1867        unsigned long changed;
1868        struct dirstat_dir dir;
1869        struct diff_queue_struct *q = &diff_queued_diff;
1870
1871        dir.files = NULL;
1872        dir.alloc = 0;
1873        dir.nr = 0;
1874        dir.permille = options->dirstat_permille;
1875        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1876
1877        changed = 0;
1878        for (i = 0; i < q->nr; i++) {
1879                struct diff_filepair *p = q->queue[i];
1880                const char *name;
1881                unsigned long copied, added, damage;
1882                int content_changed;
1883
1884                name = p->two->path ? p->two->path : p->one->path;
1885
1886                if (p->one->sha1_valid && p->two->sha1_valid)
1887                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1888                else
1889                        content_changed = 1;
1890
1891                if (!content_changed) {
1892                        /*
1893                         * The SHA1 has not changed, so pre-/post-content is
1894                         * identical. We can therefore skip looking at the
1895                         * file contents altogether.
1896                         */
1897                        damage = 0;
1898                        goto found_damage;
1899                }
1900
1901                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1902                        /*
1903                         * In --dirstat-by-file mode, we don't really need to
1904                         * look at the actual file contents at all.
1905                         * The fact that the SHA1 changed is enough for us to
1906                         * add this file to the list of results
1907                         * (with each file contributing equal damage).
1908                         */
1909                        damage = 1;
1910                        goto found_damage;
1911                }
1912
1913                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1914                        diff_populate_filespec(p->one, 0);
1915                        diff_populate_filespec(p->two, 0);
1916                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1917                                               &copied, &added);
1918                        diff_free_filespec_data(p->one);
1919                        diff_free_filespec_data(p->two);
1920                } else if (DIFF_FILE_VALID(p->one)) {
1921                        diff_populate_filespec(p->one, 1);
1922                        copied = added = 0;
1923                        diff_free_filespec_data(p->one);
1924                } else if (DIFF_FILE_VALID(p->two)) {
1925                        diff_populate_filespec(p->two, 1);
1926                        copied = 0;
1927                        added = p->two->size;
1928                        diff_free_filespec_data(p->two);
1929                } else
1930                        continue;
1931
1932                /*
1933                 * Original minus copied is the removed material,
1934                 * added is the new material.  They are both damages
1935                 * made to the preimage.
1936                 * If the resulting damage is zero, we know that
1937                 * diffcore_count_changes() considers the two entries to
1938                 * be identical, but since content_changed is true, we
1939                 * know that there must have been _some_ kind of change,
1940                 * so we force all entries to have damage > 0.
1941                 */
1942                damage = (p->one->size - copied) + added;
1943                if (!damage)
1944                        damage = 1;
1945
1946found_damage:
1947                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1948                dir.files[dir.nr].name = name;
1949                dir.files[dir.nr].changed = damage;
1950                changed += damage;
1951                dir.nr++;
1952        }
1953
1954        /* This can happen even with many files, if everything was renames */
1955        if (!changed)
1956                return;
1957
1958        /* Show all directories with more than x% of the changes */
1959        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1960        gather_dirstat(options, &dir, changed, "", 0);
1961}
1962
1963static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1964{
1965        int i;
1966        unsigned long changed;
1967        struct dirstat_dir dir;
1968
1969        if (data->nr == 0)
1970                return;
1971
1972        dir.files = NULL;
1973        dir.alloc = 0;
1974        dir.nr = 0;
1975        dir.permille = options->dirstat_permille;
1976        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1977
1978        changed = 0;
1979        for (i = 0; i < data->nr; i++) {
1980                struct diffstat_file *file = data->files[i];
1981                unsigned long damage = file->added + file->deleted;
1982                if (file->is_binary)
1983                        /*
1984                         * binary files counts bytes, not lines. Must find some
1985                         * way to normalize binary bytes vs. textual lines.
1986                         * The following heuristic assumes that there are 64
1987                         * bytes per "line".
1988                         * This is stupid and ugly, but very cheap...
1989                         */
1990                        damage = (damage + 63) / 64;
1991                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1992                dir.files[dir.nr].name = file->name;
1993                dir.files[dir.nr].changed = damage;
1994                changed += damage;
1995                dir.nr++;
1996        }
1997
1998        /* This can happen even with many files, if everything was renames */
1999        if (!changed)
2000                return;
2001
2002        /* Show all directories with more than x% of the changes */
2003        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2004        gather_dirstat(options, &dir, changed, "", 0);
2005}
2006
2007static void free_diffstat_info(struct diffstat_t *diffstat)
2008{
2009        int i;
2010        for (i = 0; i < diffstat->nr; i++) {
2011                struct diffstat_file *f = diffstat->files[i];
2012                if (f->name != f->print_name)
2013                        free(f->print_name);
2014                free(f->name);
2015                free(f->from_name);
2016                free(f);
2017        }
2018        free(diffstat->files);
2019}
2020
2021struct checkdiff_t {
2022        const char *filename;
2023        int lineno;
2024        int conflict_marker_size;
2025        struct diff_options *o;
2026        unsigned ws_rule;
2027        unsigned status;
2028};
2029
2030static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2031{
2032        char firstchar;
2033        int cnt;
2034
2035        if (len < marker_size + 1)
2036                return 0;
2037        firstchar = line[0];
2038        switch (firstchar) {
2039        case '=': case '>': case '<': case '|':
2040                break;
2041        default:
2042                return 0;
2043        }
2044        for (cnt = 1; cnt < marker_size; cnt++)
2045                if (line[cnt] != firstchar)
2046                        return 0;
2047        /* line[1] thru line[marker_size-1] are same as firstchar */
2048        if (len < marker_size + 1 || !isspace(line[marker_size]))
2049                return 0;
2050        return 1;
2051}
2052
2053static void checkdiff_consume(void *priv, char *line, unsigned long len)
2054{
2055        struct checkdiff_t *data = priv;
2056        int marker_size = data->conflict_marker_size;
2057        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2058        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2059        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2060        char *err;
2061        const char *line_prefix;
2062
2063        assert(data->o);
2064        line_prefix = diff_line_prefix(data->o);
2065
2066        if (line[0] == '+') {
2067                unsigned bad;
2068                data->lineno++;
2069                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2070                        data->status |= 1;
2071                        fprintf(data->o->file,
2072                                "%s%s:%d: leftover conflict marker\n",
2073                                line_prefix, data->filename, data->lineno);
2074                }
2075                bad = ws_check(line + 1, len - 1, data->ws_rule);
2076                if (!bad)
2077                        return;
2078                data->status |= bad;
2079                err = whitespace_error_string(bad);
2080                fprintf(data->o->file, "%s%s:%d: %s.\n",
2081                        line_prefix, data->filename, data->lineno, err);
2082                free(err);
2083                emit_line(data->o, set, reset, line, 1);
2084                ws_check_emit(line + 1, len - 1, data->ws_rule,
2085                              data->o->file, set, reset, ws);
2086        } else if (line[0] == ' ') {
2087                data->lineno++;
2088        } else if (line[0] == '@') {
2089                char *plus = strchr(line, '+');
2090                if (plus)
2091                        data->lineno = strtol(plus, NULL, 10) - 1;
2092                else
2093                        die("invalid diff");
2094        }
2095}
2096
2097static unsigned char *deflate_it(char *data,
2098                                 unsigned long size,
2099                                 unsigned long *result_size)
2100{
2101        int bound;
2102        unsigned char *deflated;
2103        git_zstream stream;
2104
2105        memset(&stream, 0, sizeof(stream));
2106        git_deflate_init(&stream, zlib_compression_level);
2107        bound = git_deflate_bound(&stream, size);
2108        deflated = xmalloc(bound);
2109        stream.next_out = deflated;
2110        stream.avail_out = bound;
2111
2112        stream.next_in = (unsigned char *)data;
2113        stream.avail_in = size;
2114        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2115                ; /* nothing */
2116        git_deflate_end(&stream);
2117        *result_size = stream.total_out;
2118        return deflated;
2119}
2120
2121static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2122                                  const char *prefix)
2123{
2124        void *cp;
2125        void *delta;
2126        void *deflated;
2127        void *data;
2128        unsigned long orig_size;
2129        unsigned long delta_size;
2130        unsigned long deflate_size;
2131        unsigned long data_size;
2132
2133        /* We could do deflated delta, or we could do just deflated two,
2134         * whichever is smaller.
2135         */
2136        delta = NULL;
2137        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2138        if (one->size && two->size) {
2139                delta = diff_delta(one->ptr, one->size,
2140                                   two->ptr, two->size,
2141                                   &delta_size, deflate_size);
2142                if (delta) {
2143                        void *to_free = delta;
2144                        orig_size = delta_size;
2145                        delta = deflate_it(delta, delta_size, &delta_size);
2146                        free(to_free);
2147                }
2148        }
2149
2150        if (delta && delta_size < deflate_size) {
2151                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2152                free(deflated);
2153                data = delta;
2154                data_size = delta_size;
2155        }
2156        else {
2157                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2158                free(delta);
2159                data = deflated;
2160                data_size = deflate_size;
2161        }
2162
2163        /* emit data encoded in base85 */
2164        cp = data;
2165        while (data_size) {
2166                int bytes = (52 < data_size) ? 52 : data_size;
2167                char line[70];
2168                data_size -= bytes;
2169                if (bytes <= 26)
2170                        line[0] = bytes + 'A' - 1;
2171                else
2172                        line[0] = bytes - 26 + 'a' - 1;
2173                encode_85(line + 1, cp, bytes);
2174                cp = (char *) cp + bytes;
2175                fprintf(file, "%s", prefix);
2176                fputs(line, file);
2177                fputc('\n', file);
2178        }
2179        fprintf(file, "%s\n", prefix);
2180        free(data);
2181}
2182
2183static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2184                             const char *prefix)
2185{
2186        fprintf(file, "%sGIT binary patch\n", prefix);
2187        emit_binary_diff_body(file, one, two, prefix);
2188        emit_binary_diff_body(file, two, one, prefix);
2189}
2190
2191int diff_filespec_is_binary(struct diff_filespec *one)
2192{
2193        if (one->is_binary == -1) {
2194                diff_filespec_load_driver(one);
2195                if (one->driver->binary != -1)
2196                        one->is_binary = one->driver->binary;
2197                else {
2198                        if (!one->data && DIFF_FILE_VALID(one))
2199                                diff_populate_filespec(one, 0);
2200                        if (one->data)
2201                                one->is_binary = buffer_is_binary(one->data,
2202                                                one->size);
2203                        if (one->is_binary == -1)
2204                                one->is_binary = 0;
2205                }
2206        }
2207        return one->is_binary;
2208}
2209
2210static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2211{
2212        diff_filespec_load_driver(one);
2213        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2214}
2215
2216void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2217{
2218        if (!options->a_prefix)
2219                options->a_prefix = a;
2220        if (!options->b_prefix)
2221                options->b_prefix = b;
2222}
2223
2224struct userdiff_driver *get_textconv(struct diff_filespec *one)
2225{
2226        if (!DIFF_FILE_VALID(one))
2227                return NULL;
2228
2229        diff_filespec_load_driver(one);
2230        return userdiff_get_textconv(one->driver);
2231}
2232
2233static void builtin_diff(const char *name_a,
2234                         const char *name_b,
2235                         struct diff_filespec *one,
2236                         struct diff_filespec *two,
2237                         const char *xfrm_msg,
2238                         int must_show_header,
2239                         struct diff_options *o,
2240                         int complete_rewrite)
2241{
2242        mmfile_t mf1, mf2;
2243        const char *lbl[2];
2244        char *a_one, *b_two;
2245        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2246        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2247        const char *a_prefix, *b_prefix;
2248        struct userdiff_driver *textconv_one = NULL;
2249        struct userdiff_driver *textconv_two = NULL;
2250        struct strbuf header = STRBUF_INIT;
2251        const char *line_prefix = diff_line_prefix(o);
2252
2253        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2254                        (!one->mode || S_ISGITLINK(one->mode)) &&
2255                        (!two->mode || S_ISGITLINK(two->mode))) {
2256                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2257                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2258                show_submodule_summary(o->file, one->path ? one->path : two->path,
2259                                line_prefix,
2260                                one->sha1, two->sha1, two->dirty_submodule,
2261                                meta, del, add, reset);
2262                return;
2263        }
2264
2265        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2266                textconv_one = get_textconv(one);
2267                textconv_two = get_textconv(two);
2268        }
2269
2270        diff_set_mnemonic_prefix(o, "a/", "b/");
2271        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2272                a_prefix = o->b_prefix;
2273                b_prefix = o->a_prefix;
2274        } else {
2275                a_prefix = o->a_prefix;
2276                b_prefix = o->b_prefix;
2277        }
2278
2279        /* Never use a non-valid filename anywhere if at all possible */
2280        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2281        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2282
2283        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2284        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2285        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2286        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2287        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2288        if (lbl[0][0] == '/') {
2289                /* /dev/null */
2290                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2291                if (xfrm_msg)
2292                        strbuf_addstr(&header, xfrm_msg);
2293                must_show_header = 1;
2294        }
2295        else if (lbl[1][0] == '/') {
2296                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2297                if (xfrm_msg)
2298                        strbuf_addstr(&header, xfrm_msg);
2299                must_show_header = 1;
2300        }
2301        else {
2302                if (one->mode != two->mode) {
2303                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2304                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2305                        must_show_header = 1;
2306                }
2307                if (xfrm_msg)
2308                        strbuf_addstr(&header, xfrm_msg);
2309
2310                /*
2311                 * we do not run diff between different kind
2312                 * of objects.
2313                 */
2314                if ((one->mode ^ two->mode) & S_IFMT)
2315                        goto free_ab_and_return;
2316                if (complete_rewrite &&
2317                    (textconv_one || !diff_filespec_is_binary(one)) &&
2318                    (textconv_two || !diff_filespec_is_binary(two))) {
2319                        fprintf(o->file, "%s", header.buf);
2320                        strbuf_reset(&header);
2321                        emit_rewrite_diff(name_a, name_b, one, two,
2322                                                textconv_one, textconv_two, o);
2323                        o->found_changes = 1;
2324                        goto free_ab_and_return;
2325                }
2326        }
2327
2328        if (o->irreversible_delete && lbl[1][0] == '/') {
2329                fprintf(o->file, "%s", header.buf);
2330                strbuf_reset(&header);
2331                goto free_ab_and_return;
2332        } else if (!DIFF_OPT_TST(o, TEXT) &&
2333            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2334              (!textconv_two && diff_filespec_is_binary(two)) )) {
2335                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2336                        die("unable to read files to diff");
2337                /* Quite common confusing case */
2338                if (mf1.size == mf2.size &&
2339                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2340                        if (must_show_header)
2341                                fprintf(o->file, "%s", header.buf);
2342                        goto free_ab_and_return;
2343                }
2344                fprintf(o->file, "%s", header.buf);
2345                strbuf_reset(&header);
2346                if (DIFF_OPT_TST(o, BINARY))
2347                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2348                else
2349                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2350                                line_prefix, lbl[0], lbl[1]);
2351                o->found_changes = 1;
2352        } else {
2353                /* Crazy xdl interfaces.. */
2354                const char *diffopts = getenv("GIT_DIFF_OPTS");
2355                xpparam_t xpp;
2356                xdemitconf_t xecfg;
2357                struct emit_callback ecbdata;
2358                const struct userdiff_funcname *pe;
2359
2360                if (must_show_header) {
2361                        fprintf(o->file, "%s", header.buf);
2362                        strbuf_reset(&header);
2363                }
2364
2365                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2366                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2367
2368                pe = diff_funcname_pattern(one);
2369                if (!pe)
2370                        pe = diff_funcname_pattern(two);
2371
2372                memset(&xpp, 0, sizeof(xpp));
2373                memset(&xecfg, 0, sizeof(xecfg));
2374                memset(&ecbdata, 0, sizeof(ecbdata));
2375                ecbdata.label_path = lbl;
2376                ecbdata.color_diff = want_color(o->use_color);
2377                ecbdata.found_changesp = &o->found_changes;
2378                ecbdata.ws_rule = whitespace_rule(name_b);
2379                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2380                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2381                ecbdata.opt = o;
2382                ecbdata.header = header.len ? &header : NULL;
2383                xpp.flags = o->xdl_opts;
2384                xecfg.ctxlen = o->context;
2385                xecfg.interhunkctxlen = o->interhunkcontext;
2386                xecfg.flags = XDL_EMIT_FUNCNAMES;
2387                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2388                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2389                if (pe)
2390                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2391                if (!diffopts)
2392                        ;
2393                else if (starts_with(diffopts, "--unified="))
2394                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2395                else if (starts_with(diffopts, "-u"))
2396                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2397                if (o->word_diff)
2398                        init_diff_words_data(&ecbdata, o, one, two);
2399                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2400                              &xpp, &xecfg);
2401                if (o->word_diff)
2402                        free_diff_words_data(&ecbdata);
2403                if (textconv_one)
2404                        free(mf1.ptr);
2405                if (textconv_two)
2406                        free(mf2.ptr);
2407                xdiff_clear_find_func(&xecfg);
2408        }
2409
2410 free_ab_and_return:
2411        strbuf_release(&header);
2412        diff_free_filespec_data(one);
2413        diff_free_filespec_data(two);
2414        free(a_one);
2415        free(b_two);
2416        return;
2417}
2418
2419static void builtin_diffstat(const char *name_a, const char *name_b,
2420                             struct diff_filespec *one,
2421                             struct diff_filespec *two,
2422                             struct diffstat_t *diffstat,
2423                             struct diff_options *o,
2424                             struct diff_filepair *p)
2425{
2426        mmfile_t mf1, mf2;
2427        struct diffstat_file *data;
2428        int same_contents;
2429        int complete_rewrite = 0;
2430
2431        if (!DIFF_PAIR_UNMERGED(p)) {
2432                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2433                        complete_rewrite = 1;
2434        }
2435
2436        data = diffstat_add(diffstat, name_a, name_b);
2437        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2438
2439        if (!one || !two) {
2440                data->is_unmerged = 1;
2441                return;
2442        }
2443
2444        same_contents = !hashcmp(one->sha1, two->sha1);
2445
2446        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2447                data->is_binary = 1;
2448                if (same_contents) {
2449                        data->added = 0;
2450                        data->deleted = 0;
2451                } else {
2452                        data->added = diff_filespec_size(two);
2453                        data->deleted = diff_filespec_size(one);
2454                }
2455        }
2456
2457        else if (complete_rewrite) {
2458                diff_populate_filespec(one, 0);
2459                diff_populate_filespec(two, 0);
2460                data->deleted = count_lines(one->data, one->size);
2461                data->added = count_lines(two->data, two->size);
2462        }
2463
2464        else if (!same_contents) {
2465                /* Crazy xdl interfaces.. */
2466                xpparam_t xpp;
2467                xdemitconf_t xecfg;
2468
2469                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2470                        die("unable to read files to diff");
2471
2472                memset(&xpp, 0, sizeof(xpp));
2473                memset(&xecfg, 0, sizeof(xecfg));
2474                xpp.flags = o->xdl_opts;
2475                xecfg.ctxlen = o->context;
2476                xecfg.interhunkctxlen = o->interhunkcontext;
2477                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2478                              &xpp, &xecfg);
2479        }
2480
2481        diff_free_filespec_data(one);
2482        diff_free_filespec_data(two);
2483}
2484
2485static void builtin_checkdiff(const char *name_a, const char *name_b,
2486                              const char *attr_path,
2487                              struct diff_filespec *one,
2488                              struct diff_filespec *two,
2489                              struct diff_options *o)
2490{
2491        mmfile_t mf1, mf2;
2492        struct checkdiff_t data;
2493
2494        if (!two)
2495                return;
2496
2497        memset(&data, 0, sizeof(data));
2498        data.filename = name_b ? name_b : name_a;
2499        data.lineno = 0;
2500        data.o = o;
2501        data.ws_rule = whitespace_rule(attr_path);
2502        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2503
2504        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2505                die("unable to read files to diff");
2506
2507        /*
2508         * All the other codepaths check both sides, but not checking
2509         * the "old" side here is deliberate.  We are checking the newly
2510         * introduced changes, and as long as the "new" side is text, we
2511         * can and should check what it introduces.
2512         */
2513        if (diff_filespec_is_binary(two))
2514                goto free_and_return;
2515        else {
2516                /* Crazy xdl interfaces.. */
2517                xpparam_t xpp;
2518                xdemitconf_t xecfg;
2519
2520                memset(&xpp, 0, sizeof(xpp));
2521                memset(&xecfg, 0, sizeof(xecfg));
2522                xecfg.ctxlen = 1; /* at least one context line */
2523                xpp.flags = 0;
2524                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2525                              &xpp, &xecfg);
2526
2527                if (data.ws_rule & WS_BLANK_AT_EOF) {
2528                        struct emit_callback ecbdata;
2529                        int blank_at_eof;
2530
2531                        ecbdata.ws_rule = data.ws_rule;
2532                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2533                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2534
2535                        if (blank_at_eof) {
2536                                static char *err;
2537                                if (!err)
2538                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2539                                fprintf(o->file, "%s:%d: %s.\n",
2540                                        data.filename, blank_at_eof, err);
2541                                data.status = 1; /* report errors */
2542                        }
2543                }
2544        }
2545 free_and_return:
2546        diff_free_filespec_data(one);
2547        diff_free_filespec_data(two);
2548        if (data.status)
2549                DIFF_OPT_SET(o, CHECK_FAILED);
2550}
2551
2552struct diff_filespec *alloc_filespec(const char *path)
2553{
2554        int namelen = strlen(path);
2555        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2556
2557        memset(spec, 0, sizeof(*spec));
2558        spec->path = (char *)(spec + 1);
2559        memcpy(spec->path, path, namelen+1);
2560        spec->count = 1;
2561        spec->is_binary = -1;
2562        return spec;
2563}
2564
2565void free_filespec(struct diff_filespec *spec)
2566{
2567        if (!--spec->count) {
2568                diff_free_filespec_data(spec);
2569                free(spec);
2570        }
2571}
2572
2573void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2574                   int sha1_valid, unsigned short mode)
2575{
2576        if (mode) {
2577                spec->mode = canon_mode(mode);
2578                hashcpy(spec->sha1, sha1);
2579                spec->sha1_valid = sha1_valid;
2580        }
2581}
2582
2583/*
2584 * Given a name and sha1 pair, if the index tells us the file in
2585 * the work tree has that object contents, return true, so that
2586 * prepare_temp_file() does not have to inflate and extract.
2587 */
2588static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2589{
2590        const struct cache_entry *ce;
2591        struct stat st;
2592        int pos, len;
2593
2594        /*
2595         * We do not read the cache ourselves here, because the
2596         * benchmark with my previous version that always reads cache
2597         * shows that it makes things worse for diff-tree comparing
2598         * two linux-2.6 kernel trees in an already checked out work
2599         * tree.  This is because most diff-tree comparisons deal with
2600         * only a small number of files, while reading the cache is
2601         * expensive for a large project, and its cost outweighs the
2602         * savings we get by not inflating the object to a temporary
2603         * file.  Practically, this code only helps when we are used
2604         * by diff-cache --cached, which does read the cache before
2605         * calling us.
2606         */
2607        if (!active_cache)
2608                return 0;
2609
2610        /* We want to avoid the working directory if our caller
2611         * doesn't need the data in a normal file, this system
2612         * is rather slow with its stat/open/mmap/close syscalls,
2613         * and the object is contained in a pack file.  The pack
2614         * is probably already open and will be faster to obtain
2615         * the data through than the working directory.  Loose
2616         * objects however would tend to be slower as they need
2617         * to be individually opened and inflated.
2618         */
2619        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2620                return 0;
2621
2622        len = strlen(name);
2623        pos = cache_name_pos(name, len);
2624        if (pos < 0)
2625                return 0;
2626        ce = active_cache[pos];
2627
2628        /*
2629         * This is not the sha1 we are looking for, or
2630         * unreusable because it is not a regular file.
2631         */
2632        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2633                return 0;
2634
2635        /*
2636         * If ce is marked as "assume unchanged", there is no
2637         * guarantee that work tree matches what we are looking for.
2638         */
2639        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2640                return 0;
2641
2642        /*
2643         * If ce matches the file in the work tree, we can reuse it.
2644         */
2645        if (ce_uptodate(ce) ||
2646            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2647                return 1;
2648
2649        return 0;
2650}
2651
2652static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2653{
2654        int len;
2655        char *data = xmalloc(100), *dirty = "";
2656
2657        /* Are we looking at the work tree? */
2658        if (s->dirty_submodule)
2659                dirty = "-dirty";
2660
2661        len = snprintf(data, 100,
2662                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2663        s->data = data;
2664        s->size = len;
2665        s->should_free = 1;
2666        if (size_only) {
2667                s->data = NULL;
2668                free(data);
2669        }
2670        return 0;
2671}
2672
2673/*
2674 * While doing rename detection and pickaxe operation, we may need to
2675 * grab the data for the blob (or file) for our own in-core comparison.
2676 * diff_filespec has data and size fields for this purpose.
2677 */
2678int diff_populate_filespec(struct diff_filespec *s, int size_only)
2679{
2680        int err = 0;
2681        /*
2682         * demote FAIL to WARN to allow inspecting the situation
2683         * instead of refusing.
2684         */
2685        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2686                                    ? SAFE_CRLF_WARN
2687                                    : safe_crlf);
2688
2689        if (!DIFF_FILE_VALID(s))
2690                die("internal error: asking to populate invalid file.");
2691        if (S_ISDIR(s->mode))
2692                return -1;
2693
2694        if (s->data)
2695                return 0;
2696
2697        if (size_only && 0 < s->size)
2698                return 0;
2699
2700        if (S_ISGITLINK(s->mode))
2701                return diff_populate_gitlink(s, size_only);
2702
2703        if (!s->sha1_valid ||
2704            reuse_worktree_file(s->path, s->sha1, 0)) {
2705                struct strbuf buf = STRBUF_INIT;
2706                struct stat st;
2707                int fd;
2708
2709                if (lstat(s->path, &st) < 0) {
2710                        if (errno == ENOENT) {
2711                        err_empty:
2712                                err = -1;
2713                        empty:
2714                                s->data = (char *)"";
2715                                s->size = 0;
2716                                return err;
2717                        }
2718                }
2719                s->size = xsize_t(st.st_size);
2720                if (!s->size)
2721                        goto empty;
2722                if (S_ISLNK(st.st_mode)) {
2723                        struct strbuf sb = STRBUF_INIT;
2724
2725                        if (strbuf_readlink(&sb, s->path, s->size))
2726                                goto err_empty;
2727                        s->size = sb.len;
2728                        s->data = strbuf_detach(&sb, NULL);
2729                        s->should_free = 1;
2730                        return 0;
2731                }
2732                if (size_only)
2733                        return 0;
2734                fd = open(s->path, O_RDONLY);
2735                if (fd < 0)
2736                        goto err_empty;
2737                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2738                close(fd);
2739                s->should_munmap = 1;
2740
2741                /*
2742                 * Convert from working tree format to canonical git format
2743                 */
2744                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2745                        size_t size = 0;
2746                        munmap(s->data, s->size);
2747                        s->should_munmap = 0;
2748                        s->data = strbuf_detach(&buf, &size);
2749                        s->size = size;
2750                        s->should_free = 1;
2751                }
2752        }
2753        else {
2754                enum object_type type;
2755                if (size_only) {
2756                        type = sha1_object_info(s->sha1, &s->size);
2757                        if (type < 0)
2758                                die("unable to read %s", sha1_to_hex(s->sha1));
2759                } else {
2760                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2761                        if (!s->data)
2762                                die("unable to read %s", sha1_to_hex(s->sha1));
2763                        s->should_free = 1;
2764                }
2765        }
2766        return 0;
2767}
2768
2769void diff_free_filespec_blob(struct diff_filespec *s)
2770{
2771        if (s->should_free)
2772                free(s->data);
2773        else if (s->should_munmap)
2774                munmap(s->data, s->size);
2775
2776        if (s->should_free || s->should_munmap) {
2777                s->should_free = s->should_munmap = 0;
2778                s->data = NULL;
2779        }
2780}
2781
2782void diff_free_filespec_data(struct diff_filespec *s)
2783{
2784        diff_free_filespec_blob(s);
2785        free(s->cnt_data);
2786        s->cnt_data = NULL;
2787}
2788
2789static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2790                           void *blob,
2791                           unsigned long size,
2792                           const unsigned char *sha1,
2793                           int mode)
2794{
2795        int fd;
2796        struct strbuf buf = STRBUF_INIT;
2797        struct strbuf template = STRBUF_INIT;
2798        char *path_dup = xstrdup(path);
2799        const char *base = basename(path_dup);
2800
2801        /* Generate "XXXXXX_basename.ext" */
2802        strbuf_addstr(&template, "XXXXXX_");
2803        strbuf_addstr(&template, base);
2804
2805        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2806                        strlen(base) + 1);
2807        if (fd < 0)
2808                die_errno("unable to create temp-file");
2809        if (convert_to_working_tree(path,
2810                        (const char *)blob, (size_t)size, &buf)) {
2811                blob = buf.buf;
2812                size = buf.len;
2813        }
2814        if (write_in_full(fd, blob, size) != size)
2815                die_errno("unable to write temp-file");
2816        close(fd);
2817        temp->name = temp->tmp_path;
2818        strcpy(temp->hex, sha1_to_hex(sha1));
2819        temp->hex[40] = 0;
2820        sprintf(temp->mode, "%06o", mode);
2821        strbuf_release(&buf);
2822        strbuf_release(&template);
2823        free(path_dup);
2824}
2825
2826static struct diff_tempfile *prepare_temp_file(const char *name,
2827                struct diff_filespec *one)
2828{
2829        struct diff_tempfile *temp = claim_diff_tempfile();
2830
2831        if (!DIFF_FILE_VALID(one)) {
2832        not_a_valid_file:
2833                /* A '-' entry produces this for file-2, and
2834                 * a '+' entry produces this for file-1.
2835                 */
2836                temp->name = "/dev/null";
2837                strcpy(temp->hex, ".");
2838                strcpy(temp->mode, ".");
2839                return temp;
2840        }
2841
2842        if (!remove_tempfile_installed) {
2843                atexit(remove_tempfile);
2844                sigchain_push_common(remove_tempfile_on_signal);
2845                remove_tempfile_installed = 1;
2846        }
2847
2848        if (!one->sha1_valid ||
2849            reuse_worktree_file(name, one->sha1, 1)) {
2850                struct stat st;
2851                if (lstat(name, &st) < 0) {
2852                        if (errno == ENOENT)
2853                                goto not_a_valid_file;
2854                        die_errno("stat(%s)", name);
2855                }
2856                if (S_ISLNK(st.st_mode)) {
2857                        struct strbuf sb = STRBUF_INIT;
2858                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2859                                die_errno("readlink(%s)", name);
2860                        prep_temp_blob(name, temp, sb.buf, sb.len,
2861                                       (one->sha1_valid ?
2862                                        one->sha1 : null_sha1),
2863                                       (one->sha1_valid ?
2864                                        one->mode : S_IFLNK));
2865                        strbuf_release(&sb);
2866                }
2867                else {
2868                        /* we can borrow from the file in the work tree */
2869                        temp->name = name;
2870                        if (!one->sha1_valid)
2871                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2872                        else
2873                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2874                        /* Even though we may sometimes borrow the
2875                         * contents from the work tree, we always want
2876                         * one->mode.  mode is trustworthy even when
2877                         * !(one->sha1_valid), as long as
2878                         * DIFF_FILE_VALID(one).
2879                         */
2880                        sprintf(temp->mode, "%06o", one->mode);
2881                }
2882                return temp;
2883        }
2884        else {
2885                if (diff_populate_filespec(one, 0))
2886                        die("cannot read data blob for %s", one->path);
2887                prep_temp_blob(name, temp, one->data, one->size,
2888                               one->sha1, one->mode);
2889        }
2890        return temp;
2891}
2892
2893/* An external diff command takes:
2894 *
2895 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2896 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2897 *
2898 */
2899static void run_external_diff(const char *pgm,
2900                              const char *name,
2901                              const char *other,
2902                              struct diff_filespec *one,
2903                              struct diff_filespec *two,
2904                              const char *xfrm_msg,
2905                              int complete_rewrite,
2906                              struct diff_options *o)
2907{
2908        const char *spawn_arg[10];
2909        int retval;
2910        const char **arg = &spawn_arg[0];
2911        struct diff_queue_struct *q = &diff_queued_diff;
2912        const char *env[3] = { NULL };
2913        char env_counter[50];
2914        char env_total[50];
2915
2916        if (one && two) {
2917                struct diff_tempfile *temp_one, *temp_two;
2918                const char *othername = (other ? other : name);
2919                temp_one = prepare_temp_file(name, one);
2920                temp_two = prepare_temp_file(othername, two);
2921                *arg++ = pgm;
2922                *arg++ = name;
2923                *arg++ = temp_one->name;
2924                *arg++ = temp_one->hex;
2925                *arg++ = temp_one->mode;
2926                *arg++ = temp_two->name;
2927                *arg++ = temp_two->hex;
2928                *arg++ = temp_two->mode;
2929                if (other) {
2930                        *arg++ = other;
2931                        *arg++ = xfrm_msg;
2932                }
2933        } else {
2934                *arg++ = pgm;
2935                *arg++ = name;
2936        }
2937        *arg = NULL;
2938        fflush(NULL);
2939
2940        env[0] = env_counter;
2941        snprintf(env_counter, sizeof(env_counter), "GIT_DIFF_PATH_COUNTER=%d",
2942                 ++o->diff_path_counter);
2943        env[1] = env_total;
2944        snprintf(env_total, sizeof(env_total), "GIT_DIFF_PATH_TOTAL=%d", q->nr);
2945
2946        retval = run_command_v_opt_cd_env(spawn_arg, RUN_USING_SHELL, NULL, env);
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        const char *line_prefix = diff_line_prefix(o);
2972
2973        *must_show_header = 1;
2974        strbuf_init(msg, PATH_MAX * 2 + 300);
2975        switch (p->status) {
2976        case DIFF_STATUS_COPIED:
2977                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2978                            line_prefix, set, similarity_index(p));
2979                strbuf_addf(msg, "%s\n%s%scopy from ",
2980                            reset,  line_prefix, set);
2981                quote_c_style(name, msg, NULL, 0);
2982                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2983                quote_c_style(other, msg, NULL, 0);
2984                strbuf_addf(msg, "%s\n", reset);
2985                break;
2986        case DIFF_STATUS_RENAMED:
2987                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2988                            line_prefix, set, similarity_index(p));
2989                strbuf_addf(msg, "%s\n%s%srename from ",
2990                            reset, line_prefix, set);
2991                quote_c_style(name, msg, NULL, 0);
2992                strbuf_addf(msg, "%s\n%s%srename to ",
2993                            reset, line_prefix, set);
2994                quote_c_style(other, msg, NULL, 0);
2995                strbuf_addf(msg, "%s\n", reset);
2996                break;
2997        case DIFF_STATUS_MODIFIED:
2998                if (p->score) {
2999                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3000                                    line_prefix,
3001                                    set, similarity_index(p), reset);
3002                        break;
3003                }
3004                /* fallthru */
3005        default:
3006                *must_show_header = 0;
3007        }
3008        if (one && two && hashcmp(one->sha1, two->sha1)) {
3009                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3010
3011                if (DIFF_OPT_TST(o, BINARY)) {
3012                        mmfile_t mf;
3013                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3014                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3015                                abbrev = 40;
3016                }
3017                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3018                            find_unique_abbrev(one->sha1, abbrev));
3019                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3020                if (one->mode == two->mode)
3021                        strbuf_addf(msg, " %06o", one->mode);
3022                strbuf_addf(msg, "%s\n", reset);
3023        }
3024}
3025
3026static void run_diff_cmd(const char *pgm,
3027                         const char *name,
3028                         const char *other,
3029                         const char *attr_path,
3030                         struct diff_filespec *one,
3031                         struct diff_filespec *two,
3032                         struct strbuf *msg,
3033                         struct diff_options *o,
3034                         struct diff_filepair *p)
3035{
3036        const char *xfrm_msg = NULL;
3037        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3038        int must_show_header = 0;
3039
3040
3041        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3042                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3043                if (drv && drv->external)
3044                        pgm = drv->external;
3045        }
3046
3047        if (msg) {
3048                /*
3049                 * don't use colors when the header is intended for an
3050                 * external diff driver
3051                 */
3052                fill_metainfo(msg, name, other, one, two, o, p,
3053                              &must_show_header,
3054                              want_color(o->use_color) && !pgm);
3055                xfrm_msg = msg->len ? msg->buf : NULL;
3056        }
3057
3058        if (pgm) {
3059                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3060                                  complete_rewrite, o);
3061                return;
3062        }
3063        if (one && two)
3064                builtin_diff(name, other ? other : name,
3065                             one, two, xfrm_msg, must_show_header,
3066                             o, complete_rewrite);
3067        else
3068                fprintf(o->file, "* Unmerged path %s\n", name);
3069}
3070
3071static void diff_fill_sha1_info(struct diff_filespec *one)
3072{
3073        if (DIFF_FILE_VALID(one)) {
3074                if (!one->sha1_valid) {
3075                        struct stat st;
3076                        if (one->is_stdin) {
3077                                hashcpy(one->sha1, null_sha1);
3078                                return;
3079                        }
3080                        if (lstat(one->path, &st) < 0)
3081                                die_errno("stat '%s'", one->path);
3082                        if (index_path(one->sha1, one->path, &st, 0))
3083                                die("cannot hash %s", one->path);
3084                }
3085        }
3086        else
3087                hashclr(one->sha1);
3088}
3089
3090static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3091{
3092        /* Strip the prefix but do not molest /dev/null and absolute paths */
3093        if (*namep && **namep != '/') {
3094                *namep += prefix_length;
3095                if (**namep == '/')
3096                        ++*namep;
3097        }
3098        if (*otherp && **otherp != '/') {
3099                *otherp += prefix_length;
3100                if (**otherp == '/')
3101                        ++*otherp;
3102        }
3103}
3104
3105static void run_diff(struct diff_filepair *p, struct diff_options *o)
3106{
3107        const char *pgm = external_diff();
3108        struct strbuf msg;
3109        struct diff_filespec *one = p->one;
3110        struct diff_filespec *two = p->two;
3111        const char *name;
3112        const char *other;
3113        const char *attr_path;
3114
3115        name  = p->one->path;
3116        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3117        attr_path = name;
3118        if (o->prefix_length)
3119                strip_prefix(o->prefix_length, &name, &other);
3120
3121        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3122                pgm = NULL;
3123
3124        if (DIFF_PAIR_UNMERGED(p)) {
3125                run_diff_cmd(pgm, name, NULL, attr_path,
3126                             NULL, NULL, NULL, o, p);
3127                return;
3128        }
3129
3130        diff_fill_sha1_info(one);
3131        diff_fill_sha1_info(two);
3132
3133        if (!pgm &&
3134            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3135            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3136                /*
3137                 * a filepair that changes between file and symlink
3138                 * needs to be split into deletion and creation.
3139                 */
3140                struct diff_filespec *null = alloc_filespec(two->path);
3141                run_diff_cmd(NULL, name, other, attr_path,
3142                             one, null, &msg, o, p);
3143                free(null);
3144                strbuf_release(&msg);
3145
3146                null = alloc_filespec(one->path);
3147                run_diff_cmd(NULL, name, other, attr_path,
3148                             null, two, &msg, o, p);
3149                free(null);
3150        }
3151        else
3152                run_diff_cmd(pgm, name, other, attr_path,
3153                             one, two, &msg, o, p);
3154
3155        strbuf_release(&msg);
3156}
3157
3158static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3159                         struct diffstat_t *diffstat)
3160{
3161        const char *name;
3162        const char *other;
3163
3164        if (DIFF_PAIR_UNMERGED(p)) {
3165                /* unmerged */
3166                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3167                return;
3168        }
3169
3170        name = p->one->path;
3171        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3172
3173        if (o->prefix_length)
3174                strip_prefix(o->prefix_length, &name, &other);
3175
3176        diff_fill_sha1_info(p->one);
3177        diff_fill_sha1_info(p->two);
3178
3179        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3180}
3181
3182static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3183{
3184        const char *name;
3185        const char *other;
3186        const char *attr_path;
3187
3188        if (DIFF_PAIR_UNMERGED(p)) {
3189                /* unmerged */
3190                return;
3191        }
3192
3193        name = p->one->path;
3194        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3195        attr_path = other ? other : name;
3196
3197        if (o->prefix_length)
3198                strip_prefix(o->prefix_length, &name, &other);
3199
3200        diff_fill_sha1_info(p->one);
3201        diff_fill_sha1_info(p->two);
3202
3203        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3204}
3205
3206void diff_setup(struct diff_options *options)
3207{
3208        memcpy(options, &default_diff_options, sizeof(*options));
3209
3210        options->file = stdout;
3211
3212        options->line_termination = '\n';
3213        options->break_opt = -1;
3214        options->rename_limit = -1;
3215        options->dirstat_permille = diff_dirstat_permille_default;
3216        options->context = diff_context_default;
3217        DIFF_OPT_SET(options, RENAME_EMPTY);
3218
3219        options->change = diff_change;
3220        options->add_remove = diff_addremove;
3221        options->use_color = diff_use_color_default;
3222        options->detect_rename = diff_detect_rename_default;
3223        options->xdl_opts |= diff_algorithm;
3224
3225        options->orderfile = diff_order_file_cfg;
3226
3227        if (diff_no_prefix) {
3228                options->a_prefix = options->b_prefix = "";
3229        } else if (!diff_mnemonic_prefix) {
3230                options->a_prefix = "a/";
3231                options->b_prefix = "b/";
3232        }
3233}
3234
3235void diff_setup_done(struct diff_options *options)
3236{
3237        int count = 0;
3238
3239        if (options->set_default)
3240                options->set_default(options);
3241
3242        if (options->output_format & DIFF_FORMAT_NAME)
3243                count++;
3244        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3245                count++;
3246        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3247                count++;
3248        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3249                count++;
3250        if (count > 1)
3251                die("--name-only, --name-status, --check and -s are mutually exclusive");
3252
3253        /*
3254         * Most of the time we can say "there are changes"
3255         * only by checking if there are changed paths, but
3256         * --ignore-whitespace* options force us to look
3257         * inside contents.
3258         */
3259
3260        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3261            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3262            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3263                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3264        else
3265                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3266
3267        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3268                options->detect_rename = DIFF_DETECT_COPY;
3269
3270        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3271                options->prefix = NULL;
3272        if (options->prefix)
3273                options->prefix_length = strlen(options->prefix);
3274        else
3275                options->prefix_length = 0;
3276
3277        if (options->output_format & (DIFF_FORMAT_NAME |
3278                                      DIFF_FORMAT_NAME_STATUS |
3279                                      DIFF_FORMAT_CHECKDIFF |
3280                                      DIFF_FORMAT_NO_OUTPUT))
3281                options->output_format &= ~(DIFF_FORMAT_RAW |
3282                                            DIFF_FORMAT_NUMSTAT |
3283                                            DIFF_FORMAT_DIFFSTAT |
3284                                            DIFF_FORMAT_SHORTSTAT |
3285                                            DIFF_FORMAT_DIRSTAT |
3286                                            DIFF_FORMAT_SUMMARY |
3287                                            DIFF_FORMAT_PATCH);
3288
3289        /*
3290         * These cases always need recursive; we do not drop caller-supplied
3291         * recursive bits for other formats here.
3292         */
3293        if (options->output_format & (DIFF_FORMAT_PATCH |
3294                                      DIFF_FORMAT_NUMSTAT |
3295                                      DIFF_FORMAT_DIFFSTAT |
3296                                      DIFF_FORMAT_SHORTSTAT |
3297                                      DIFF_FORMAT_DIRSTAT |
3298                                      DIFF_FORMAT_SUMMARY |
3299                                      DIFF_FORMAT_CHECKDIFF))
3300                DIFF_OPT_SET(options, RECURSIVE);
3301        /*
3302         * Also pickaxe would not work very well if you do not say recursive
3303         */
3304        if (options->pickaxe)
3305                DIFF_OPT_SET(options, RECURSIVE);
3306        /*
3307         * When patches are generated, submodules diffed against the work tree
3308         * must be checked for dirtiness too so it can be shown in the output
3309         */
3310        if (options->output_format & DIFF_FORMAT_PATCH)
3311                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3312
3313        if (options->detect_rename && options->rename_limit < 0)
3314                options->rename_limit = diff_rename_limit_default;
3315        if (options->setup & DIFF_SETUP_USE_CACHE) {
3316                if (!active_cache)
3317                        /* read-cache does not die even when it fails
3318                         * so it is safe for us to do this here.  Also
3319                         * it does not smudge active_cache or active_nr
3320                         * when it fails, so we do not have to worry about
3321                         * cleaning it up ourselves either.
3322                         */
3323                        read_cache();
3324        }
3325        if (options->abbrev <= 0 || 40 < options->abbrev)
3326                options->abbrev = 40; /* full */
3327
3328        /*
3329         * It does not make sense to show the first hit we happened
3330         * to have found.  It does not make sense not to return with
3331         * exit code in such a case either.
3332         */
3333        if (DIFF_OPT_TST(options, QUICK)) {
3334                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3335                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3336        }
3337
3338        options->diff_path_counter = 0;
3339}
3340
3341static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3342{
3343        char c, *eq;
3344        int len;
3345
3346        if (*arg != '-')
3347                return 0;
3348        c = *++arg;
3349        if (!c)
3350                return 0;
3351        if (c == arg_short) {
3352                c = *++arg;
3353                if (!c)
3354                        return 1;
3355                if (val && isdigit(c)) {
3356                        char *end;
3357                        int n = strtoul(arg, &end, 10);
3358                        if (*end)
3359                                return 0;
3360                        *val = n;
3361                        return 1;
3362                }
3363                return 0;
3364        }
3365        if (c != '-')
3366                return 0;
3367        arg++;
3368        eq = strchr(arg, '=');
3369        if (eq)
3370                len = eq - arg;
3371        else
3372                len = strlen(arg);
3373        if (!len || strncmp(arg, arg_long, len))
3374                return 0;
3375        if (eq) {
3376                int n;
3377                char *end;
3378                if (!isdigit(*++eq))
3379                        return 0;
3380                n = strtoul(eq, &end, 10);
3381                if (*end)
3382                        return 0;
3383                *val = n;
3384        }
3385        return 1;
3386}
3387
3388static int diff_scoreopt_parse(const char *opt);
3389
3390static inline int short_opt(char opt, const char **argv,
3391                            const char **optarg)
3392{
3393        const char *arg = argv[0];
3394        if (arg[0] != '-' || arg[1] != opt)
3395                return 0;
3396        if (arg[2] != '\0') {
3397                *optarg = arg + 2;
3398                return 1;
3399        }
3400        if (!argv[1])
3401                die("Option '%c' requires a value", opt);
3402        *optarg = argv[1];
3403        return 2;
3404}
3405
3406int parse_long_opt(const char *opt, const char **argv,
3407                   const char **optarg)
3408{
3409        const char *arg = argv[0];
3410        if (arg[0] != '-' || arg[1] != '-')
3411                return 0;
3412        arg += strlen("--");
3413        if (!starts_with(arg, opt))
3414                return 0;
3415        arg += strlen(opt);
3416        if (*arg == '=') { /* stuck form: --option=value */
3417                *optarg = arg + 1;
3418                return 1;
3419        }
3420        if (*arg != '\0')
3421                return 0;
3422        /* separate form: --option value */
3423        if (!argv[1])
3424                die("Option '--%s' requires a value", opt);
3425        *optarg = argv[1];
3426        return 2;
3427}
3428
3429static int stat_opt(struct diff_options *options, const char **av)
3430{
3431        const char *arg = av[0];
3432        char *end;
3433        int width = options->stat_width;
3434        int name_width = options->stat_name_width;
3435        int graph_width = options->stat_graph_width;
3436        int count = options->stat_count;
3437        int argcount = 1;
3438
3439        arg += strlen("--stat");
3440        end = (char *)arg;
3441
3442        switch (*arg) {
3443        case '-':
3444                if (starts_with(arg, "-width")) {
3445                        arg += strlen("-width");
3446                        if (*arg == '=')
3447                                width = strtoul(arg + 1, &end, 10);
3448                        else if (!*arg && !av[1])
3449                                die("Option '--stat-width' requires a value");
3450                        else if (!*arg) {
3451                                width = strtoul(av[1], &end, 10);
3452                                argcount = 2;
3453                        }
3454                } else if (starts_with(arg, "-name-width")) {
3455                        arg += strlen("-name-width");
3456                        if (*arg == '=')
3457                                name_width = strtoul(arg + 1, &end, 10);
3458                        else if (!*arg && !av[1])
3459                                die("Option '--stat-name-width' requires a value");
3460                        else if (!*arg) {
3461                                name_width = strtoul(av[1], &end, 10);
3462                                argcount = 2;
3463                        }
3464                } else if (starts_with(arg, "-graph-width")) {
3465                        arg += strlen("-graph-width");
3466                        if (*arg == '=')
3467                                graph_width = strtoul(arg + 1, &end, 10);
3468                        else if (!*arg && !av[1])
3469                                die("Option '--stat-graph-width' requires a value");
3470                        else if (!*arg) {
3471                                graph_width = strtoul(av[1], &end, 10);
3472                                argcount = 2;
3473                        }
3474                } else if (starts_with(arg, "-count")) {
3475                        arg += strlen("-count");
3476                        if (*arg == '=')
3477                                count = strtoul(arg + 1, &end, 10);
3478                        else if (!*arg && !av[1])
3479                                die("Option '--stat-count' requires a value");
3480                        else if (!*arg) {
3481                                count = strtoul(av[1], &end, 10);
3482                                argcount = 2;
3483                        }
3484                }
3485                break;
3486        case '=':
3487                width = strtoul(arg+1, &end, 10);
3488                if (*end == ',')
3489                        name_width = strtoul(end+1, &end, 10);
3490                if (*end == ',')
3491                        count = strtoul(end+1, &end, 10);
3492        }
3493
3494        /* Important! This checks all the error cases! */
3495        if (*end)
3496                return 0;
3497        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3498        options->stat_name_width = name_width;
3499        options->stat_graph_width = graph_width;
3500        options->stat_width = width;
3501        options->stat_count = count;
3502        return argcount;
3503}
3504
3505static int parse_dirstat_opt(struct diff_options *options, const char *params)
3506{
3507        struct strbuf errmsg = STRBUF_INIT;
3508        if (parse_dirstat_params(options, params, &errmsg))
3509                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3510                    errmsg.buf);
3511        strbuf_release(&errmsg);
3512        /*
3513         * The caller knows a dirstat-related option is given from the command
3514         * line; allow it to say "return this_function();"
3515         */
3516        options->output_format |= DIFF_FORMAT_DIRSTAT;
3517        return 1;
3518}
3519
3520static int parse_submodule_opt(struct diff_options *options, const char *value)
3521{
3522        if (parse_submodule_params(options, value))
3523                die(_("Failed to parse --submodule option parameter: '%s'"),
3524                        value);
3525        return 1;
3526}
3527
3528static const char diff_status_letters[] = {
3529        DIFF_STATUS_ADDED,
3530        DIFF_STATUS_COPIED,
3531        DIFF_STATUS_DELETED,
3532        DIFF_STATUS_MODIFIED,
3533        DIFF_STATUS_RENAMED,
3534        DIFF_STATUS_TYPE_CHANGED,
3535        DIFF_STATUS_UNKNOWN,
3536        DIFF_STATUS_UNMERGED,
3537        DIFF_STATUS_FILTER_AON,
3538        DIFF_STATUS_FILTER_BROKEN,
3539        '\0',
3540};
3541
3542static unsigned int filter_bit['Z' + 1];
3543
3544static void prepare_filter_bits(void)
3545{
3546        int i;
3547
3548        if (!filter_bit[DIFF_STATUS_ADDED]) {
3549                for (i = 0; diff_status_letters[i]; i++)
3550                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3551        }
3552}
3553
3554static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3555{
3556        return opt->filter & filter_bit[(int) status];
3557}
3558
3559static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3560{
3561        int i, optch;
3562
3563        prepare_filter_bits();
3564
3565        /*
3566         * If there is a negation e.g. 'd' in the input, and we haven't
3567         * initialized the filter field with another --diff-filter, start
3568         * from full set of bits, except for AON.
3569         */
3570        if (!opt->filter) {
3571                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3572                        if (optch < 'a' || 'z' < optch)
3573                                continue;
3574                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3575                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3576                        break;
3577                }
3578        }
3579
3580        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3581                unsigned int bit;
3582                int negate;
3583
3584                if ('a' <= optch && optch <= 'z') {
3585                        negate = 1;
3586                        optch = toupper(optch);
3587                } else {
3588                        negate = 0;
3589                }
3590
3591                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3592                if (!bit)
3593                        return optarg[i];
3594                if (negate)
3595                        opt->filter &= ~bit;
3596                else
3597                        opt->filter |= bit;
3598        }
3599        return 0;
3600}
3601
3602/* Used only by "diff-files" and "diff --no-index" */
3603void handle_deprecated_show_diff_q(struct diff_options *opt)
3604{
3605        warning("'diff -q' and 'diff-files -q' are deprecated.");
3606        warning("Use 'diff --diff-filter=d' instead to ignore deleted filepairs.");
3607        parse_diff_filter_opt("d", opt);
3608}
3609
3610static void enable_patch_output(int *fmt) {
3611        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3612        *fmt |= DIFF_FORMAT_PATCH;
3613}
3614
3615int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3616{
3617        const char *arg = av[0];
3618        const char *optarg;
3619        int argcount;
3620
3621        /* Output format options */
3622        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3623            || opt_arg(arg, 'U', "unified", &options->context))
3624                enable_patch_output(&options->output_format);
3625        else if (!strcmp(arg, "--raw"))
3626                options->output_format |= DIFF_FORMAT_RAW;
3627        else if (!strcmp(arg, "--patch-with-raw")) {
3628                enable_patch_output(&options->output_format);
3629                options->output_format |= DIFF_FORMAT_RAW;
3630        } else if (!strcmp(arg, "--numstat"))
3631                options->output_format |= DIFF_FORMAT_NUMSTAT;
3632        else if (!strcmp(arg, "--shortstat"))
3633                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3634        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3635                return parse_dirstat_opt(options, "");
3636        else if (starts_with(arg, "-X"))
3637                return parse_dirstat_opt(options, arg + 2);
3638        else if (starts_with(arg, "--dirstat="))
3639                return parse_dirstat_opt(options, arg + 10);
3640        else if (!strcmp(arg, "--cumulative"))
3641                return parse_dirstat_opt(options, "cumulative");
3642        else if (!strcmp(arg, "--dirstat-by-file"))
3643                return parse_dirstat_opt(options, "files");
3644        else if (starts_with(arg, "--dirstat-by-file=")) {
3645                parse_dirstat_opt(options, "files");
3646                return parse_dirstat_opt(options, arg + 18);
3647        }
3648        else if (!strcmp(arg, "--check"))
3649                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3650        else if (!strcmp(arg, "--summary"))
3651                options->output_format |= DIFF_FORMAT_SUMMARY;
3652        else if (!strcmp(arg, "--patch-with-stat")) {
3653                enable_patch_output(&options->output_format);
3654                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3655        } else if (!strcmp(arg, "--name-only"))
3656                options->output_format |= DIFF_FORMAT_NAME;
3657        else if (!strcmp(arg, "--name-status"))
3658                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3659        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3660                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3661        else if (starts_with(arg, "--stat"))
3662                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3663                return stat_opt(options, av);
3664
3665        /* renames options */
3666        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3667                 !strcmp(arg, "--break-rewrites")) {
3668                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3669                        return error("invalid argument to -B: %s", arg+2);
3670        }
3671        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3672                 !strcmp(arg, "--find-renames")) {
3673                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3674                        return error("invalid argument to -M: %s", arg+2);
3675                options->detect_rename = DIFF_DETECT_RENAME;
3676        }
3677        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3678                options->irreversible_delete = 1;
3679        }
3680        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3681                 !strcmp(arg, "--find-copies")) {
3682                if (options->detect_rename == DIFF_DETECT_COPY)
3683                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3684                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3685                        return error("invalid argument to -C: %s", arg+2);
3686                options->detect_rename = DIFF_DETECT_COPY;
3687        }
3688        else if (!strcmp(arg, "--no-renames"))
3689                options->detect_rename = 0;
3690        else if (!strcmp(arg, "--rename-empty"))
3691                DIFF_OPT_SET(options, RENAME_EMPTY);
3692        else if (!strcmp(arg, "--no-rename-empty"))
3693                DIFF_OPT_CLR(options, RENAME_EMPTY);
3694        else if (!strcmp(arg, "--relative"))
3695                DIFF_OPT_SET(options, RELATIVE_NAME);
3696        else if (starts_with(arg, "--relative=")) {
3697                DIFF_OPT_SET(options, RELATIVE_NAME);
3698                options->prefix = arg + 11;
3699        }
3700
3701        /* xdiff options */
3702        else if (!strcmp(arg, "--minimal"))
3703                DIFF_XDL_SET(options, NEED_MINIMAL);
3704        else if (!strcmp(arg, "--no-minimal"))
3705                DIFF_XDL_CLR(options, NEED_MINIMAL);
3706        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3707                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3708        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3709                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3710        else if (!strcmp(arg, "--ignore-space-at-eol"))
3711                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3712        else if (!strcmp(arg, "--ignore-blank-lines"))
3713                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3714        else if (!strcmp(arg, "--patience"))
3715                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3716        else if (!strcmp(arg, "--histogram"))
3717                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3718        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3719                long value = parse_algorithm_value(optarg);
3720                if (value < 0)
3721                        return error("option diff-algorithm accepts \"myers\", "
3722                                     "\"minimal\", \"patience\" and \"histogram\"");
3723                /* clear out previous settings */
3724                DIFF_XDL_CLR(options, NEED_MINIMAL);
3725                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3726                options->xdl_opts |= value;
3727                return argcount;
3728        }
3729
3730        /* flags options */
3731        else if (!strcmp(arg, "--binary")) {
3732                enable_patch_output(&options->output_format);
3733                DIFF_OPT_SET(options, BINARY);
3734        }
3735        else if (!strcmp(arg, "--full-index"))
3736                DIFF_OPT_SET(options, FULL_INDEX);
3737        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3738                DIFF_OPT_SET(options, TEXT);
3739        else if (!strcmp(arg, "-R"))
3740                DIFF_OPT_SET(options, REVERSE_DIFF);
3741        else if (!strcmp(arg, "--find-copies-harder"))
3742                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3743        else if (!strcmp(arg, "--follow"))
3744                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3745        else if (!strcmp(arg, "--no-follow"))
3746                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3747        else if (!strcmp(arg, "--color"))
3748                options->use_color = 1;
3749        else if (starts_with(arg, "--color=")) {
3750                int value = git_config_colorbool(NULL, arg+8);
3751                if (value < 0)
3752                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3753                options->use_color = value;
3754        }
3755        else if (!strcmp(arg, "--no-color"))
3756                options->use_color = 0;
3757        else if (!strcmp(arg, "--color-words")) {
3758                options->use_color = 1;
3759                options->word_diff = DIFF_WORDS_COLOR;
3760        }
3761        else if (starts_with(arg, "--color-words=")) {
3762                options->use_color = 1;
3763                options->word_diff = DIFF_WORDS_COLOR;
3764                options->word_regex = arg + 14;
3765        }
3766        else if (!strcmp(arg, "--word-diff")) {
3767                if (options->word_diff == DIFF_WORDS_NONE)
3768                        options->word_diff = DIFF_WORDS_PLAIN;
3769        }
3770        else if (starts_with(arg, "--word-diff=")) {
3771                const char *type = arg + 12;
3772                if (!strcmp(type, "plain"))
3773                        options->word_diff = DIFF_WORDS_PLAIN;
3774                else if (!strcmp(type, "color")) {
3775                        options->use_color = 1;
3776                        options->word_diff = DIFF_WORDS_COLOR;
3777                }
3778                else if (!strcmp(type, "porcelain"))
3779                        options->word_diff = DIFF_WORDS_PORCELAIN;
3780                else if (!strcmp(type, "none"))
3781                        options->word_diff = DIFF_WORDS_NONE;
3782                else
3783                        die("bad --word-diff argument: %s", type);
3784        }
3785        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3786                if (options->word_diff == DIFF_WORDS_NONE)
3787                        options->word_diff = DIFF_WORDS_PLAIN;
3788                options->word_regex = optarg;
3789                return argcount;
3790        }
3791        else if (!strcmp(arg, "--exit-code"))
3792                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3793        else if (!strcmp(arg, "--quiet"))
3794                DIFF_OPT_SET(options, QUICK);
3795        else if (!strcmp(arg, "--ext-diff"))
3796                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3797        else if (!strcmp(arg, "--no-ext-diff"))
3798                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3799        else if (!strcmp(arg, "--textconv"))
3800                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3801        else if (!strcmp(arg, "--no-textconv"))
3802                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3803        else if (!strcmp(arg, "--ignore-submodules")) {
3804                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3805                handle_ignore_submodules_arg(options, "all");
3806        } else if (starts_with(arg, "--ignore-submodules=")) {
3807                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3808                handle_ignore_submodules_arg(options, arg + 20);
3809        } else if (!strcmp(arg, "--submodule"))
3810                DIFF_OPT_SET(options, SUBMODULE_LOG);
3811        else if (starts_with(arg, "--submodule="))
3812                return parse_submodule_opt(options, arg + 12);
3813
3814        /* misc options */
3815        else if (!strcmp(arg, "-z"))
3816                options->line_termination = 0;
3817        else if ((argcount = short_opt('l', av, &optarg))) {
3818                options->rename_limit = strtoul(optarg, NULL, 10);
3819                return argcount;
3820        }
3821        else if ((argcount = short_opt('S', av, &optarg))) {
3822                options->pickaxe = optarg;
3823                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3824                return argcount;
3825        } else if ((argcount = short_opt('G', av, &optarg))) {
3826                options->pickaxe = optarg;
3827                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3828                return argcount;
3829        }
3830        else if (!strcmp(arg, "--pickaxe-all"))
3831                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3832        else if (!strcmp(arg, "--pickaxe-regex"))
3833                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3834        else if ((argcount = short_opt('O', av, &optarg))) {
3835                options->orderfile = optarg;
3836                return argcount;
3837        }
3838        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3839                int offending = parse_diff_filter_opt(optarg, options);
3840                if (offending)
3841                        die("unknown change class '%c' in --diff-filter=%s",
3842                            offending, optarg);
3843                return argcount;
3844        }
3845        else if (!strcmp(arg, "--abbrev"))
3846                options->abbrev = DEFAULT_ABBREV;
3847        else if (starts_with(arg, "--abbrev=")) {
3848                options->abbrev = strtoul(arg + 9, NULL, 10);
3849                if (options->abbrev < MINIMUM_ABBREV)
3850                        options->abbrev = MINIMUM_ABBREV;
3851                else if (40 < options->abbrev)
3852                        options->abbrev = 40;
3853        }
3854        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3855                options->a_prefix = optarg;
3856                return argcount;
3857        }
3858        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3859                options->b_prefix = optarg;
3860                return argcount;
3861        }
3862        else if (!strcmp(arg, "--no-prefix"))
3863                options->a_prefix = options->b_prefix = "";
3864        else if (opt_arg(arg, '\0', "inter-hunk-context",
3865                         &options->interhunkcontext))
3866                ;
3867        else if (!strcmp(arg, "-W"))
3868                DIFF_OPT_SET(options, FUNCCONTEXT);
3869        else if (!strcmp(arg, "--function-context"))
3870                DIFF_OPT_SET(options, FUNCCONTEXT);
3871        else if (!strcmp(arg, "--no-function-context"))
3872                DIFF_OPT_CLR(options, FUNCCONTEXT);
3873        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3874                options->file = fopen(optarg, "w");
3875                if (!options->file)
3876                        die_errno("Could not open '%s'", optarg);
3877                options->close_file = 1;
3878                return argcount;
3879        } else
3880                return 0;
3881        return 1;
3882}
3883
3884int parse_rename_score(const char **cp_p)
3885{
3886        unsigned long num, scale;
3887        int ch, dot;
3888        const char *cp = *cp_p;
3889
3890        num = 0;
3891        scale = 1;
3892        dot = 0;
3893        for (;;) {
3894                ch = *cp;
3895                if ( !dot && ch == '.' ) {
3896                        scale = 1;
3897                        dot = 1;
3898                } else if ( ch == '%' ) {
3899                        scale = dot ? scale*100 : 100;
3900                        cp++;   /* % is always at the end */
3901                        break;
3902                } else if ( ch >= '0' && ch <= '9' ) {
3903                        if ( scale < 100000 ) {
3904                                scale *= 10;
3905                                num = (num*10) + (ch-'0');
3906                        }
3907                } else {
3908                        break;
3909                }
3910                cp++;
3911        }
3912        *cp_p = cp;
3913
3914        /* user says num divided by scale and we say internally that
3915         * is MAX_SCORE * num / scale.
3916         */
3917        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3918}
3919
3920static int diff_scoreopt_parse(const char *opt)
3921{
3922        int opt1, opt2, cmd;
3923
3924        if (*opt++ != '-')
3925                return -1;
3926        cmd = *opt++;
3927        if (cmd == '-') {
3928                /* convert the long-form arguments into short-form versions */
3929                if (starts_with(opt, "break-rewrites")) {
3930                        opt += strlen("break-rewrites");
3931                        if (*opt == 0 || *opt++ == '=')
3932                                cmd = 'B';
3933                } else if (starts_with(opt, "find-copies")) {
3934                        opt += strlen("find-copies");
3935                        if (*opt == 0 || *opt++ == '=')
3936                                cmd = 'C';
3937                } else if (starts_with(opt, "find-renames")) {
3938                        opt += strlen("find-renames");
3939                        if (*opt == 0 || *opt++ == '=')
3940                                cmd = 'M';
3941                }
3942        }
3943        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3944                return -1; /* that is not a -M, -C nor -B option */
3945
3946        opt1 = parse_rename_score(&opt);
3947        if (cmd != 'B')
3948                opt2 = 0;
3949        else {
3950                if (*opt == 0)
3951                        opt2 = 0;
3952                else if (*opt != '/')
3953                        return -1; /* we expect -B80/99 or -B80 */
3954                else {
3955                        opt++;
3956                        opt2 = parse_rename_score(&opt);
3957                }
3958        }
3959        if (*opt != 0)
3960                return -1;
3961        return opt1 | (opt2 << 16);
3962}
3963
3964struct diff_queue_struct diff_queued_diff;
3965
3966void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3967{
3968        if (queue->alloc <= queue->nr) {
3969                queue->alloc = alloc_nr(queue->alloc);
3970                queue->queue = xrealloc(queue->queue,
3971                                        sizeof(dp) * queue->alloc);
3972        }
3973        queue->queue[queue->nr++] = dp;
3974}
3975
3976struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3977                                 struct diff_filespec *one,
3978                                 struct diff_filespec *two)
3979{
3980        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3981        dp->one = one;
3982        dp->two = two;
3983        if (queue)
3984                diff_q(queue, dp);
3985        return dp;
3986}
3987
3988void diff_free_filepair(struct diff_filepair *p)
3989{
3990        free_filespec(p->one);
3991        free_filespec(p->two);
3992        free(p);
3993}
3994
3995/* This is different from find_unique_abbrev() in that
3996 * it stuffs the result with dots for alignment.
3997 */
3998const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3999{
4000        int abblen;
4001        const char *abbrev;
4002        if (len == 40)
4003                return sha1_to_hex(sha1);
4004
4005        abbrev = find_unique_abbrev(sha1, len);
4006        abblen = strlen(abbrev);
4007        if (abblen < 37) {
4008                static char hex[41];
4009                if (len < abblen && abblen <= len + 2)
4010                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
4011                else
4012                        sprintf(hex, "%s...", abbrev);
4013                return hex;
4014        }
4015        return sha1_to_hex(sha1);
4016}
4017
4018static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4019{
4020        int line_termination = opt->line_termination;
4021        int inter_name_termination = line_termination ? '\t' : '\0';
4022
4023        fprintf(opt->file, "%s", diff_line_prefix(opt));
4024        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4025                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4026                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4027                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4028        }
4029        if (p->score) {
4030                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4031                        inter_name_termination);
4032        } else {
4033                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4034        }
4035
4036        if (p->status == DIFF_STATUS_COPIED ||
4037            p->status == DIFF_STATUS_RENAMED) {
4038                const char *name_a, *name_b;
4039                name_a = p->one->path;
4040                name_b = p->two->path;
4041                strip_prefix(opt->prefix_length, &name_a, &name_b);
4042                write_name_quoted(name_a, opt->file, inter_name_termination);
4043                write_name_quoted(name_b, opt->file, line_termination);
4044        } else {
4045                const char *name_a, *name_b;
4046                name_a = p->one->mode ? p->one->path : p->two->path;
4047                name_b = NULL;
4048                strip_prefix(opt->prefix_length, &name_a, &name_b);
4049                write_name_quoted(name_a, opt->file, line_termination);
4050        }
4051}
4052
4053int diff_unmodified_pair(struct diff_filepair *p)
4054{
4055        /* This function is written stricter than necessary to support
4056         * the currently implemented transformers, but the idea is to
4057         * let transformers to produce diff_filepairs any way they want,
4058         * and filter and clean them up here before producing the output.
4059         */
4060        struct diff_filespec *one = p->one, *two = p->two;
4061
4062        if (DIFF_PAIR_UNMERGED(p))
4063                return 0; /* unmerged is interesting */
4064
4065        /* deletion, addition, mode or type change
4066         * and rename are all interesting.
4067         */
4068        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4069            DIFF_PAIR_MODE_CHANGED(p) ||
4070            strcmp(one->path, two->path))
4071                return 0;
4072
4073        /* both are valid and point at the same path.  that is, we are
4074         * dealing with a change.
4075         */
4076        if (one->sha1_valid && two->sha1_valid &&
4077            !hashcmp(one->sha1, two->sha1) &&
4078            !one->dirty_submodule && !two->dirty_submodule)
4079                return 1; /* no change */
4080        if (!one->sha1_valid && !two->sha1_valid)
4081                return 1; /* both look at the same file on the filesystem. */
4082        return 0;
4083}
4084
4085static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4086{
4087        if (diff_unmodified_pair(p))
4088                return;
4089
4090        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4091            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4092                return; /* no tree diffs in patch format */
4093
4094        run_diff(p, o);
4095}
4096
4097static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4098                            struct diffstat_t *diffstat)
4099{
4100        if (diff_unmodified_pair(p))
4101                return;
4102
4103        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4104            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4105                return; /* no useful stat for tree diffs */
4106
4107        run_diffstat(p, o, diffstat);
4108}
4109
4110static void diff_flush_checkdiff(struct diff_filepair *p,
4111                struct diff_options *o)
4112{
4113        if (diff_unmodified_pair(p))
4114                return;
4115
4116        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4117            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4118                return; /* nothing to check in tree diffs */
4119
4120        run_checkdiff(p, o);
4121}
4122
4123int diff_queue_is_empty(void)
4124{
4125        struct diff_queue_struct *q = &diff_queued_diff;
4126        int i;
4127        for (i = 0; i < q->nr; i++)
4128                if (!diff_unmodified_pair(q->queue[i]))
4129                        return 0;
4130        return 1;
4131}
4132
4133#if DIFF_DEBUG
4134void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4135{
4136        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4137                x, one ? one : "",
4138                s->path,
4139                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4140                s->mode,
4141                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4142        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
4143                x, one ? one : "",
4144                s->size, s->xfrm_flags);
4145}
4146
4147void diff_debug_filepair(const struct diff_filepair *p, int i)
4148{
4149        diff_debug_filespec(p->one, i, "one");
4150        diff_debug_filespec(p->two, i, "two");
4151        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4152                p->score, p->status ? p->status : '?',
4153                p->one->rename_used, p->broken_pair);
4154}
4155
4156void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4157{
4158        int i;
4159        if (msg)
4160                fprintf(stderr, "%s\n", msg);
4161        fprintf(stderr, "q->nr = %d\n", q->nr);
4162        for (i = 0; i < q->nr; i++) {
4163                struct diff_filepair *p = q->queue[i];
4164                diff_debug_filepair(p, i);
4165        }
4166}
4167#endif
4168
4169static void diff_resolve_rename_copy(void)
4170{
4171        int i;
4172        struct diff_filepair *p;
4173        struct diff_queue_struct *q = &diff_queued_diff;
4174
4175        diff_debug_queue("resolve-rename-copy", q);
4176
4177        for (i = 0; i < q->nr; i++) {
4178                p = q->queue[i];
4179                p->status = 0; /* undecided */
4180                if (DIFF_PAIR_UNMERGED(p))
4181                        p->status = DIFF_STATUS_UNMERGED;
4182                else if (!DIFF_FILE_VALID(p->one))
4183                        p->status = DIFF_STATUS_ADDED;
4184                else if (!DIFF_FILE_VALID(p->two))
4185                        p->status = DIFF_STATUS_DELETED;
4186                else if (DIFF_PAIR_TYPE_CHANGED(p))
4187                        p->status = DIFF_STATUS_TYPE_CHANGED;
4188
4189                /* from this point on, we are dealing with a pair
4190                 * whose both sides are valid and of the same type, i.e.
4191                 * either in-place edit or rename/copy edit.
4192                 */
4193                else if (DIFF_PAIR_RENAME(p)) {
4194                        /*
4195                         * A rename might have re-connected a broken
4196                         * pair up, causing the pathnames to be the
4197                         * same again. If so, that's not a rename at
4198                         * all, just a modification..
4199                         *
4200                         * Otherwise, see if this source was used for
4201                         * multiple renames, in which case we decrement
4202                         * the count, and call it a copy.
4203                         */
4204                        if (!strcmp(p->one->path, p->two->path))
4205                                p->status = DIFF_STATUS_MODIFIED;
4206                        else if (--p->one->rename_used > 0)
4207                                p->status = DIFF_STATUS_COPIED;
4208                        else
4209                                p->status = DIFF_STATUS_RENAMED;
4210                }
4211                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4212                         p->one->mode != p->two->mode ||
4213                         p->one->dirty_submodule ||
4214                         p->two->dirty_submodule ||
4215                         is_null_sha1(p->one->sha1))
4216                        p->status = DIFF_STATUS_MODIFIED;
4217                else {
4218                        /* This is a "no-change" entry and should not
4219                         * happen anymore, but prepare for broken callers.
4220                         */
4221                        error("feeding unmodified %s to diffcore",
4222                              p->one->path);
4223                        p->status = DIFF_STATUS_UNKNOWN;
4224                }
4225        }
4226        diff_debug_queue("resolve-rename-copy done", q);
4227}
4228
4229static int check_pair_status(struct diff_filepair *p)
4230{
4231        switch (p->status) {
4232        case DIFF_STATUS_UNKNOWN:
4233                return 0;
4234        case 0:
4235                die("internal error in diff-resolve-rename-copy");
4236        default:
4237                return 1;
4238        }
4239}
4240
4241static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4242{
4243        int fmt = opt->output_format;
4244
4245        if (fmt & DIFF_FORMAT_CHECKDIFF)
4246                diff_flush_checkdiff(p, opt);
4247        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4248                diff_flush_raw(p, opt);
4249        else if (fmt & DIFF_FORMAT_NAME) {
4250                const char *name_a, *name_b;
4251                name_a = p->two->path;
4252                name_b = NULL;
4253                strip_prefix(opt->prefix_length, &name_a, &name_b);
4254                write_name_quoted(name_a, opt->file, opt->line_termination);
4255        }
4256}
4257
4258static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4259{
4260        if (fs->mode)
4261                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4262        else
4263                fprintf(file, " %s ", newdelete);
4264        write_name_quoted(fs->path, file, '\n');
4265}
4266
4267
4268static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4269                const char *line_prefix)
4270{
4271        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4272                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4273                        p->two->mode, show_name ? ' ' : '\n');
4274                if (show_name) {
4275                        write_name_quoted(p->two->path, file, '\n');
4276                }
4277        }
4278}
4279
4280static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4281                        const char *line_prefix)
4282{
4283        char *names = pprint_rename(p->one->path, p->two->path);
4284
4285        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4286        free(names);
4287        show_mode_change(file, p, 0, line_prefix);
4288}
4289
4290static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4291{
4292        FILE *file = opt->file;
4293        const char *line_prefix = diff_line_prefix(opt);
4294
4295        switch(p->status) {
4296        case DIFF_STATUS_DELETED:
4297                fputs(line_prefix, file);
4298                show_file_mode_name(file, "delete", p->one);
4299                break;
4300        case DIFF_STATUS_ADDED:
4301                fputs(line_prefix, file);
4302                show_file_mode_name(file, "create", p->two);
4303                break;
4304        case DIFF_STATUS_COPIED:
4305                fputs(line_prefix, file);
4306                show_rename_copy(file, "copy", p, line_prefix);
4307                break;
4308        case DIFF_STATUS_RENAMED:
4309                fputs(line_prefix, file);
4310                show_rename_copy(file, "rename", p, line_prefix);
4311                break;
4312        default:
4313                if (p->score) {
4314                        fprintf(file, "%s rewrite ", line_prefix);
4315                        write_name_quoted(p->two->path, file, ' ');
4316                        fprintf(file, "(%d%%)\n", similarity_index(p));
4317                }
4318                show_mode_change(file, p, !p->score, line_prefix);
4319                break;
4320        }
4321}
4322
4323struct patch_id_t {
4324        git_SHA_CTX *ctx;
4325        int patchlen;
4326};
4327
4328static int remove_space(char *line, int len)
4329{
4330        int i;
4331        char *dst = line;
4332        unsigned char c;
4333
4334        for (i = 0; i < len; i++)
4335                if (!isspace((c = line[i])))
4336                        *dst++ = c;
4337
4338        return dst - line;
4339}
4340
4341static void patch_id_consume(void *priv, char *line, unsigned long len)
4342{
4343        struct patch_id_t *data = priv;
4344        int new_len;
4345
4346        /* Ignore line numbers when computing the SHA1 of the patch */
4347        if (starts_with(line, "@@ -"))
4348                return;
4349
4350        new_len = remove_space(line, len);
4351
4352        git_SHA1_Update(data->ctx, line, new_len);
4353        data->patchlen += new_len;
4354}
4355
4356/* returns 0 upon success, and writes result into sha1 */
4357static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4358{
4359        struct diff_queue_struct *q = &diff_queued_diff;
4360        int i;
4361        git_SHA_CTX ctx;
4362        struct patch_id_t data;
4363        char buffer[PATH_MAX * 4 + 20];
4364
4365        git_SHA1_Init(&ctx);
4366        memset(&data, 0, sizeof(struct patch_id_t));
4367        data.ctx = &ctx;
4368
4369        for (i = 0; i < q->nr; i++) {
4370                xpparam_t xpp;
4371                xdemitconf_t xecfg;
4372                mmfile_t mf1, mf2;
4373                struct diff_filepair *p = q->queue[i];
4374                int len1, len2;
4375
4376                memset(&xpp, 0, sizeof(xpp));
4377                memset(&xecfg, 0, sizeof(xecfg));
4378                if (p->status == 0)
4379                        return error("internal diff status error");
4380                if (p->status == DIFF_STATUS_UNKNOWN)
4381                        continue;
4382                if (diff_unmodified_pair(p))
4383                        continue;
4384                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4385                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4386                        continue;
4387                if (DIFF_PAIR_UNMERGED(p))
4388                        continue;
4389
4390                diff_fill_sha1_info(p->one);
4391                diff_fill_sha1_info(p->two);
4392                if (fill_mmfile(&mf1, p->one) < 0 ||
4393                                fill_mmfile(&mf2, p->two) < 0)
4394                        return error("unable to read files to diff");
4395
4396                len1 = remove_space(p->one->path, strlen(p->one->path));
4397                len2 = remove_space(p->two->path, strlen(p->two->path));
4398                if (p->one->mode == 0)
4399                        len1 = snprintf(buffer, sizeof(buffer),
4400                                        "diff--gita/%.*sb/%.*s"
4401                                        "newfilemode%06o"
4402                                        "---/dev/null"
4403                                        "+++b/%.*s",
4404                                        len1, p->one->path,
4405                                        len2, p->two->path,
4406                                        p->two->mode,
4407                                        len2, p->two->path);
4408                else if (p->two->mode == 0)
4409                        len1 = snprintf(buffer, sizeof(buffer),
4410                                        "diff--gita/%.*sb/%.*s"
4411                                        "deletedfilemode%06o"
4412                                        "---a/%.*s"
4413                                        "+++/dev/null",
4414                                        len1, p->one->path,
4415                                        len2, p->two->path,
4416                                        p->one->mode,
4417                                        len1, p->one->path);
4418                else
4419                        len1 = snprintf(buffer, sizeof(buffer),
4420                                        "diff--gita/%.*sb/%.*s"
4421                                        "---a/%.*s"
4422                                        "+++b/%.*s",
4423                                        len1, p->one->path,
4424                                        len2, p->two->path,
4425                                        len1, p->one->path,
4426                                        len2, p->two->path);
4427                git_SHA1_Update(&ctx, buffer, len1);
4428
4429                if (diff_filespec_is_binary(p->one) ||
4430                    diff_filespec_is_binary(p->two)) {
4431                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4432                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4433                        continue;
4434                }
4435
4436                xpp.flags = 0;
4437                xecfg.ctxlen = 3;
4438                xecfg.flags = 0;
4439                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4440                              &xpp, &xecfg);
4441        }
4442
4443        git_SHA1_Final(sha1, &ctx);
4444        return 0;
4445}
4446
4447int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4448{
4449        struct diff_queue_struct *q = &diff_queued_diff;
4450        int i;
4451        int result = diff_get_patch_id(options, sha1);
4452
4453        for (i = 0; i < q->nr; i++)
4454                diff_free_filepair(q->queue[i]);
4455
4456        free(q->queue);
4457        DIFF_QUEUE_CLEAR(q);
4458
4459        return result;
4460}
4461
4462static int is_summary_empty(const struct diff_queue_struct *q)
4463{
4464        int i;
4465
4466        for (i = 0; i < q->nr; i++) {
4467                const struct diff_filepair *p = q->queue[i];
4468
4469                switch (p->status) {
4470                case DIFF_STATUS_DELETED:
4471                case DIFF_STATUS_ADDED:
4472                case DIFF_STATUS_COPIED:
4473                case DIFF_STATUS_RENAMED:
4474                        return 0;
4475                default:
4476                        if (p->score)
4477                                return 0;
4478                        if (p->one->mode && p->two->mode &&
4479                            p->one->mode != p->two->mode)
4480                                return 0;
4481                        break;
4482                }
4483        }
4484        return 1;
4485}
4486
4487static const char rename_limit_warning[] =
4488"inexact rename detection was skipped due to too many files.";
4489
4490static const char degrade_cc_to_c_warning[] =
4491"only found copies from modified paths due to too many files.";
4492
4493static const char rename_limit_advice[] =
4494"you may want to set your %s variable to at least "
4495"%d and retry the command.";
4496
4497void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4498{
4499        if (degraded_cc)
4500                warning(degrade_cc_to_c_warning);
4501        else if (needed)
4502                warning(rename_limit_warning);
4503        else
4504                return;
4505        if (0 < needed && needed < 32767)
4506                warning(rename_limit_advice, varname, needed);
4507}
4508
4509void diff_flush(struct diff_options *options)
4510{
4511        struct diff_queue_struct *q = &diff_queued_diff;
4512        int i, output_format = options->output_format;
4513        int separator = 0;
4514        int dirstat_by_line = 0;
4515
4516        /*
4517         * Order: raw, stat, summary, patch
4518         * or:    name/name-status/checkdiff (other bits clear)
4519         */
4520        if (!q->nr)
4521                goto free_queue;
4522
4523        if (output_format & (DIFF_FORMAT_RAW |
4524                             DIFF_FORMAT_NAME |
4525                             DIFF_FORMAT_NAME_STATUS |
4526                             DIFF_FORMAT_CHECKDIFF)) {
4527                for (i = 0; i < q->nr; i++) {
4528                        struct diff_filepair *p = q->queue[i];
4529                        if (check_pair_status(p))
4530                                flush_one_pair(p, options);
4531                }
4532                separator++;
4533        }
4534
4535        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4536                dirstat_by_line = 1;
4537
4538        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4539            dirstat_by_line) {
4540                struct diffstat_t diffstat;
4541
4542                memset(&diffstat, 0, sizeof(struct diffstat_t));
4543                for (i = 0; i < q->nr; i++) {
4544                        struct diff_filepair *p = q->queue[i];
4545                        if (check_pair_status(p))
4546                                diff_flush_stat(p, options, &diffstat);
4547                }
4548                if (output_format & DIFF_FORMAT_NUMSTAT)
4549                        show_numstat(&diffstat, options);
4550                if (output_format & DIFF_FORMAT_DIFFSTAT)
4551                        show_stats(&diffstat, options);
4552                if (output_format & DIFF_FORMAT_SHORTSTAT)
4553                        show_shortstats(&diffstat, options);
4554                if (output_format & DIFF_FORMAT_DIRSTAT)
4555                        show_dirstat_by_line(&diffstat, options);
4556                free_diffstat_info(&diffstat);
4557                separator++;
4558        }
4559        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4560                show_dirstat(options);
4561
4562        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4563                for (i = 0; i < q->nr; i++) {
4564                        diff_summary(options, q->queue[i]);
4565                }
4566                separator++;
4567        }
4568
4569        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4570            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4571            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4572                /*
4573                 * run diff_flush_patch for the exit status. setting
4574                 * options->file to /dev/null should be safe, because we
4575                 * aren't supposed to produce any output anyway.
4576                 */
4577                if (options->close_file)
4578                        fclose(options->file);
4579                options->file = fopen("/dev/null", "w");
4580                if (!options->file)
4581                        die_errno("Could not open /dev/null");
4582                options->close_file = 1;
4583                for (i = 0; i < q->nr; i++) {
4584                        struct diff_filepair *p = q->queue[i];
4585                        if (check_pair_status(p))
4586                                diff_flush_patch(p, options);
4587                        if (options->found_changes)
4588                                break;
4589                }
4590        }
4591
4592        if (output_format & DIFF_FORMAT_PATCH) {
4593                if (separator) {
4594                        fprintf(options->file, "%s%c",
4595                                diff_line_prefix(options),
4596                                options->line_termination);
4597                        if (options->stat_sep) {
4598                                /* attach patch instead of inline */
4599                                fputs(options->stat_sep, options->file);
4600                        }
4601                }
4602
4603                for (i = 0; i < q->nr; i++) {
4604                        struct diff_filepair *p = q->queue[i];
4605                        if (check_pair_status(p))
4606                                diff_flush_patch(p, options);
4607                }
4608        }
4609
4610        if (output_format & DIFF_FORMAT_CALLBACK)
4611                options->format_callback(q, options, options->format_callback_data);
4612
4613        for (i = 0; i < q->nr; i++)
4614                diff_free_filepair(q->queue[i]);
4615free_queue:
4616        free(q->queue);
4617        DIFF_QUEUE_CLEAR(q);
4618        if (options->close_file)
4619                fclose(options->file);
4620
4621        /*
4622         * Report the content-level differences with HAS_CHANGES;
4623         * diff_addremove/diff_change does not set the bit when
4624         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4625         */
4626        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4627                if (options->found_changes)
4628                        DIFF_OPT_SET(options, HAS_CHANGES);
4629                else
4630                        DIFF_OPT_CLR(options, HAS_CHANGES);
4631        }
4632}
4633
4634static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4635{
4636        return (((p->status == DIFF_STATUS_MODIFIED) &&
4637                 ((p->score &&
4638                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4639                  (!p->score &&
4640                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4641                ((p->status != DIFF_STATUS_MODIFIED) &&
4642                 filter_bit_tst(p->status, options)));
4643}
4644
4645static void diffcore_apply_filter(struct diff_options *options)
4646{
4647        int i;
4648        struct diff_queue_struct *q = &diff_queued_diff;
4649        struct diff_queue_struct outq;
4650
4651        DIFF_QUEUE_CLEAR(&outq);
4652
4653        if (!options->filter)
4654                return;
4655
4656        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4657                int found;
4658                for (i = found = 0; !found && i < q->nr; i++) {
4659                        if (match_filter(options, q->queue[i]))
4660                                found++;
4661                }
4662                if (found)
4663                        return;
4664
4665                /* otherwise we will clear the whole queue
4666                 * by copying the empty outq at the end of this
4667                 * function, but first clear the current entries
4668                 * in the queue.
4669                 */
4670                for (i = 0; i < q->nr; i++)
4671                        diff_free_filepair(q->queue[i]);
4672        }
4673        else {
4674                /* Only the matching ones */
4675                for (i = 0; i < q->nr; i++) {
4676                        struct diff_filepair *p = q->queue[i];
4677                        if (match_filter(options, p))
4678                                diff_q(&outq, p);
4679                        else
4680                                diff_free_filepair(p);
4681                }
4682        }
4683        free(q->queue);
4684        *q = outq;
4685}
4686
4687/* Check whether two filespecs with the same mode and size are identical */
4688static int diff_filespec_is_identical(struct diff_filespec *one,
4689                                      struct diff_filespec *two)
4690{
4691        if (S_ISGITLINK(one->mode))
4692                return 0;
4693        if (diff_populate_filespec(one, 0))
4694                return 0;
4695        if (diff_populate_filespec(two, 0))
4696                return 0;
4697        return !memcmp(one->data, two->data, one->size);
4698}
4699
4700static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4701{
4702        int i;
4703        struct diff_queue_struct *q = &diff_queued_diff;
4704        struct diff_queue_struct outq;
4705        DIFF_QUEUE_CLEAR(&outq);
4706
4707        for (i = 0; i < q->nr; i++) {
4708                struct diff_filepair *p = q->queue[i];
4709
4710                /*
4711                 * 1. Entries that come from stat info dirtiness
4712                 *    always have both sides (iow, not create/delete),
4713                 *    one side of the object name is unknown, with
4714                 *    the same mode and size.  Keep the ones that
4715                 *    do not match these criteria.  They have real
4716                 *    differences.
4717                 *
4718                 * 2. At this point, the file is known to be modified,
4719                 *    with the same mode and size, and the object
4720                 *    name of one side is unknown.  Need to inspect
4721                 *    the identical contents.
4722                 */
4723                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4724                    !DIFF_FILE_VALID(p->two) ||
4725                    (p->one->sha1_valid && p->two->sha1_valid) ||
4726                    (p->one->mode != p->two->mode) ||
4727                    diff_populate_filespec(p->one, 1) ||
4728                    diff_populate_filespec(p->two, 1) ||
4729                    (p->one->size != p->two->size) ||
4730                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4731                        diff_q(&outq, p);
4732                else {
4733                        /*
4734                         * The caller can subtract 1 from skip_stat_unmatch
4735                         * to determine how many paths were dirty only
4736                         * due to stat info mismatch.
4737                         */
4738                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4739                                diffopt->skip_stat_unmatch++;
4740                        diff_free_filepair(p);
4741                }
4742        }
4743        free(q->queue);
4744        *q = outq;
4745}
4746
4747static int diffnamecmp(const void *a_, const void *b_)
4748{
4749        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4750        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4751        const char *name_a, *name_b;
4752
4753        name_a = a->one ? a->one->path : a->two->path;
4754        name_b = b->one ? b->one->path : b->two->path;
4755        return strcmp(name_a, name_b);
4756}
4757
4758void diffcore_fix_diff_index(struct diff_options *options)
4759{
4760        struct diff_queue_struct *q = &diff_queued_diff;
4761        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4762}
4763
4764void diffcore_std(struct diff_options *options)
4765{
4766        if (options->skip_stat_unmatch)
4767                diffcore_skip_stat_unmatch(options);
4768        if (!options->found_follow) {
4769                /* See try_to_follow_renames() in tree-diff.c */
4770                if (options->break_opt != -1)
4771                        diffcore_break(options->break_opt);
4772                if (options->detect_rename)
4773                        diffcore_rename(options);
4774                if (options->break_opt != -1)
4775                        diffcore_merge_broken();
4776        }
4777        if (options->pickaxe)
4778                diffcore_pickaxe(options);
4779        if (options->orderfile)
4780                diffcore_order(options->orderfile);
4781        if (!options->found_follow)
4782                /* See try_to_follow_renames() in tree-diff.c */
4783                diff_resolve_rename_copy();
4784        diffcore_apply_filter(options);
4785
4786        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4787                DIFF_OPT_SET(options, HAS_CHANGES);
4788        else
4789                DIFF_OPT_CLR(options, HAS_CHANGES);
4790
4791        options->found_follow = 0;
4792}
4793
4794int diff_result_code(struct diff_options *opt, int status)
4795{
4796        int result = 0;
4797
4798        diff_warn_rename_limit("diff.renameLimit",
4799                               opt->needed_rename_limit,
4800                               opt->degraded_cc_to_c);
4801        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4802            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4803                return status;
4804        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4805            DIFF_OPT_TST(opt, HAS_CHANGES))
4806                result |= 01;
4807        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4808            DIFF_OPT_TST(opt, CHECK_FAILED))
4809                result |= 02;
4810        return result;
4811}
4812
4813int diff_can_quit_early(struct diff_options *opt)
4814{
4815        return (DIFF_OPT_TST(opt, QUICK) &&
4816                !opt->filter &&
4817                DIFF_OPT_TST(opt, HAS_CHANGES));
4818}
4819
4820/*
4821 * Shall changes to this submodule be ignored?
4822 *
4823 * Submodule changes can be configured to be ignored separately for each path,
4824 * but that configuration can be overridden from the command line.
4825 */
4826static int is_submodule_ignored(const char *path, struct diff_options *options)
4827{
4828        int ignored = 0;
4829        unsigned orig_flags = options->flags;
4830        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4831                set_diffopt_flags_from_submodule_config(options, path);
4832        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4833                ignored = 1;
4834        options->flags = orig_flags;
4835        return ignored;
4836}
4837
4838void diff_addremove(struct diff_options *options,
4839                    int addremove, unsigned mode,
4840                    const unsigned char *sha1,
4841                    int sha1_valid,
4842                    const char *concatpath, unsigned dirty_submodule)
4843{
4844        struct diff_filespec *one, *two;
4845
4846        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4847                return;
4848
4849        /* This may look odd, but it is a preparation for
4850         * feeding "there are unchanged files which should
4851         * not produce diffs, but when you are doing copy
4852         * detection you would need them, so here they are"
4853         * entries to the diff-core.  They will be prefixed
4854         * with something like '=' or '*' (I haven't decided
4855         * which but should not make any difference).
4856         * Feeding the same new and old to diff_change()
4857         * also has the same effect.
4858         * Before the final output happens, they are pruned after
4859         * merged into rename/copy pairs as appropriate.
4860         */
4861        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4862                addremove = (addremove == '+' ? '-' :
4863                             addremove == '-' ? '+' : addremove);
4864
4865        if (options->prefix &&
4866            strncmp(concatpath, options->prefix, options->prefix_length))
4867                return;
4868
4869        one = alloc_filespec(concatpath);
4870        two = alloc_filespec(concatpath);
4871
4872        if (addremove != '+')
4873                fill_filespec(one, sha1, sha1_valid, mode);
4874        if (addremove != '-') {
4875                fill_filespec(two, sha1, sha1_valid, mode);
4876                two->dirty_submodule = dirty_submodule;
4877        }
4878
4879        diff_queue(&diff_queued_diff, one, two);
4880        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4881                DIFF_OPT_SET(options, HAS_CHANGES);
4882}
4883
4884void diff_change(struct diff_options *options,
4885                 unsigned old_mode, unsigned new_mode,
4886                 const unsigned char *old_sha1,
4887                 const unsigned char *new_sha1,
4888                 int old_sha1_valid, int new_sha1_valid,
4889                 const char *concatpath,
4890                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4891{
4892        struct diff_filespec *one, *two;
4893
4894        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4895            is_submodule_ignored(concatpath, options))
4896                return;
4897
4898        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4899                unsigned tmp;
4900                const unsigned char *tmp_c;
4901                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4902                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4903                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4904                        new_sha1_valid = tmp;
4905                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4906                        new_dirty_submodule = tmp;
4907        }
4908
4909        if (options->prefix &&
4910            strncmp(concatpath, options->prefix, options->prefix_length))
4911                return;
4912
4913        one = alloc_filespec(concatpath);
4914        two = alloc_filespec(concatpath);
4915        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4916        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4917        one->dirty_submodule = old_dirty_submodule;
4918        two->dirty_submodule = new_dirty_submodule;
4919
4920        diff_queue(&diff_queued_diff, one, two);
4921        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4922                DIFF_OPT_SET(options, HAS_CHANGES);
4923}
4924
4925struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4926{
4927        struct diff_filepair *pair;
4928        struct diff_filespec *one, *two;
4929
4930        if (options->prefix &&
4931            strncmp(path, options->prefix, options->prefix_length))
4932                return NULL;
4933
4934        one = alloc_filespec(path);
4935        two = alloc_filespec(path);
4936        pair = diff_queue(&diff_queued_diff, one, two);
4937        pair->is_unmerged = 1;
4938        return pair;
4939}
4940
4941static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4942                size_t *outsize)
4943{
4944        struct diff_tempfile *temp;
4945        const char *argv[3];
4946        const char **arg = argv;
4947        struct child_process child;
4948        struct strbuf buf = STRBUF_INIT;
4949        int err = 0;
4950
4951        temp = prepare_temp_file(spec->path, spec);
4952        *arg++ = pgm;
4953        *arg++ = temp->name;
4954        *arg = NULL;
4955
4956        memset(&child, 0, sizeof(child));
4957        child.use_shell = 1;
4958        child.argv = argv;
4959        child.out = -1;
4960        if (start_command(&child)) {
4961                remove_tempfile();
4962                return NULL;
4963        }
4964
4965        if (strbuf_read(&buf, child.out, 0) < 0)
4966                err = error("error reading from textconv command '%s'", pgm);
4967        close(child.out);
4968
4969        if (finish_command(&child) || err) {
4970                strbuf_release(&buf);
4971                remove_tempfile();
4972                return NULL;
4973        }
4974        remove_tempfile();
4975
4976        return strbuf_detach(&buf, outsize);
4977}
4978
4979size_t fill_textconv(struct userdiff_driver *driver,
4980                     struct diff_filespec *df,
4981                     char **outbuf)
4982{
4983        size_t size;
4984
4985        if (!driver || !driver->textconv) {
4986                if (!DIFF_FILE_VALID(df)) {
4987                        *outbuf = "";
4988                        return 0;
4989                }
4990                if (diff_populate_filespec(df, 0))
4991                        die("unable to read files to diff");
4992                *outbuf = df->data;
4993                return df->size;
4994        }
4995
4996        if (driver->textconv_cache && df->sha1_valid) {
4997                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4998                                          &size);
4999                if (*outbuf)
5000                        return size;
5001        }
5002
5003        *outbuf = run_textconv(driver->textconv, df, &size);
5004        if (!*outbuf)
5005                die("unable to read files to diff");
5006
5007        if (driver->textconv_cache && df->sha1_valid) {
5008                /* ignore errors, as we might be in a readonly repository */
5009                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
5010                                size);
5011                /*
5012                 * we could save up changes and flush them all at the end,
5013                 * but we would need an extra call after all diffing is done.
5014                 * Since generating a cache entry is the slow path anyway,
5015                 * this extra overhead probably isn't a big deal.
5016                 */
5017                notes_cache_write(driver->textconv_cache);
5018        }
5019
5020        return size;
5021}
5022
5023void setup_diff_pager(struct diff_options *opt)
5024{
5025        /*
5026         * If the user asked for our exit code, then either they want --quiet
5027         * or --exit-code. We should definitely not bother with a pager in the
5028         * former case, as we will generate no output. Since we still properly
5029         * report our exit code even when a pager is run, we _could_ run a
5030         * pager with --exit-code. But since we have not done so historically,
5031         * and because it is easy to find people oneline advising "git diff
5032         * --exit-code" in hooks and other scripts, we do not do so.
5033         */
5034        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5035            check_pager_config("diff") != 0)
5036                setup_pager();
5037}