c575c452f16fb781d86f5fe748a216c192c5ad41
   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#include "argv-array.h"
  20
  21#ifdef NO_FAST_WORKING_DIRECTORY
  22#define FAST_WORKING_DIRECTORY 0
  23#else
  24#define FAST_WORKING_DIRECTORY 1
  25#endif
  26
  27static int diff_detect_rename_default;
  28static int diff_rename_limit_default = 400;
  29static int diff_suppress_blank_empty;
  30static int diff_use_color_default = -1;
  31static int diff_context_default = 3;
  32static const char *diff_word_regex_cfg;
  33static const char *external_diff_cmd_cfg;
  34static const char *diff_order_file_cfg;
  35int diff_auto_refresh_index = 1;
  36static int diff_mnemonic_prefix;
  37static int diff_no_prefix;
  38static int diff_stat_graph_width;
  39static int diff_dirstat_permille_default = 30;
  40static struct diff_options default_diff_options;
  41static long diff_algorithm;
  42
  43static char diff_colors[][COLOR_MAXLEN] = {
  44        GIT_COLOR_RESET,
  45        GIT_COLOR_NORMAL,       /* PLAIN */
  46        GIT_COLOR_BOLD,         /* METAINFO */
  47        GIT_COLOR_CYAN,         /* FRAGINFO */
  48        GIT_COLOR_RED,          /* OLD */
  49        GIT_COLOR_GREEN,        /* NEW */
  50        GIT_COLOR_YELLOW,       /* COMMIT */
  51        GIT_COLOR_BG_RED,       /* WHITESPACE */
  52        GIT_COLOR_NORMAL,       /* FUNCINFO */
  53};
  54
  55static int parse_diff_color_slot(const char *var)
  56{
  57        if (!strcasecmp(var, "plain"))
  58                return DIFF_PLAIN;
  59        if (!strcasecmp(var, "meta"))
  60                return DIFF_METAINFO;
  61        if (!strcasecmp(var, "frag"))
  62                return DIFF_FRAGINFO;
  63        if (!strcasecmp(var, "old"))
  64                return DIFF_FILE_OLD;
  65        if (!strcasecmp(var, "new"))
  66                return DIFF_FILE_NEW;
  67        if (!strcasecmp(var, "commit"))
  68                return DIFF_COMMIT;
  69        if (!strcasecmp(var, "whitespace"))
  70                return DIFF_WHITESPACE;
  71        if (!strcasecmp(var, "func"))
  72                return DIFF_FUNCINFO;
  73        return -1;
  74}
  75
  76static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  77                                struct strbuf *errmsg)
  78{
  79        char *params_copy = xstrdup(params_string);
  80        struct string_list params = STRING_LIST_INIT_NODUP;
  81        int ret = 0;
  82        int i;
  83
  84        if (*params_copy)
  85                string_list_split_in_place(&params, params_copy, ',', -1);
  86        for (i = 0; i < params.nr; i++) {
  87                const char *p = params.items[i].string;
  88                if (!strcmp(p, "changes")) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  90                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  91                } else if (!strcmp(p, "lines")) {
  92                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  93                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  94                } else if (!strcmp(p, "files")) {
  95                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  96                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  97                } else if (!strcmp(p, "noncumulative")) {
  98                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  99                } else if (!strcmp(p, "cumulative")) {
 100                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 101                } else if (isdigit(*p)) {
 102                        char *end;
 103                        int permille = strtoul(p, &end, 10) * 10;
 104                        if (*end == '.' && isdigit(*++end)) {
 105                                /* only use first digit */
 106                                permille += *end - '0';
 107                                /* .. and ignore any further digits */
 108                                while (isdigit(*++end))
 109                                        ; /* nothing */
 110                        }
 111                        if (!*end)
 112                                options->dirstat_permille = permille;
 113                        else {
 114                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 115                                            p);
 116                                ret++;
 117                        }
 118                } else {
 119                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 120                        ret++;
 121                }
 122
 123        }
 124        string_list_clear(&params, 0);
 125        free(params_copy);
 126        return ret;
 127}
 128
 129static int parse_submodule_params(struct diff_options *options, const char *value)
 130{
 131        if (!strcmp(value, "log"))
 132                DIFF_OPT_SET(options, SUBMODULE_LOG);
 133        else if (!strcmp(value, "short"))
 134                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 135        else
 136                return -1;
 137        return 0;
 138}
 139
 140static int git_config_rename(const char *var, const char *value)
 141{
 142        if (!value)
 143                return DIFF_DETECT_RENAME;
 144        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 145                return  DIFF_DETECT_COPY;
 146        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 147}
 148
 149long parse_algorithm_value(const char *value)
 150{
 151        if (!value)
 152                return -1;
 153        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 154                return 0;
 155        else if (!strcasecmp(value, "minimal"))
 156                return XDF_NEED_MINIMAL;
 157        else if (!strcasecmp(value, "patience"))
 158                return XDF_PATIENCE_DIFF;
 159        else if (!strcasecmp(value, "histogram"))
 160                return XDF_HISTOGRAM_DIFF;
 161        return -1;
 162}
 163
 164/*
 165 * These are to give UI layer defaults.
 166 * The core-level commands such as git-diff-files should
 167 * never be affected by the setting of diff.renames
 168 * the user happens to have in the configuration file.
 169 */
 170int git_diff_ui_config(const char *var, const char *value, void *cb)
 171{
 172        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 173                diff_use_color_default = git_config_colorbool(var, value);
 174                return 0;
 175        }
 176        if (!strcmp(var, "diff.context")) {
 177                diff_context_default = git_config_int(var, value);
 178                if (diff_context_default < 0)
 179                        return -1;
 180                return 0;
 181        }
 182        if (!strcmp(var, "diff.renames")) {
 183                diff_detect_rename_default = git_config_rename(var, value);
 184                return 0;
 185        }
 186        if (!strcmp(var, "diff.autorefreshindex")) {
 187                diff_auto_refresh_index = git_config_bool(var, value);
 188                return 0;
 189        }
 190        if (!strcmp(var, "diff.mnemonicprefix")) {
 191                diff_mnemonic_prefix = git_config_bool(var, value);
 192                return 0;
 193        }
 194        if (!strcmp(var, "diff.noprefix")) {
 195                diff_no_prefix = git_config_bool(var, value);
 196                return 0;
 197        }
 198        if (!strcmp(var, "diff.statgraphwidth")) {
 199                diff_stat_graph_width = git_config_int(var, value);
 200                return 0;
 201        }
 202        if (!strcmp(var, "diff.external"))
 203                return git_config_string(&external_diff_cmd_cfg, var, value);
 204        if (!strcmp(var, "diff.wordregex"))
 205                return git_config_string(&diff_word_regex_cfg, var, value);
 206        if (!strcmp(var, "diff.orderfile"))
 207                return git_config_pathname(&diff_order_file_cfg, var, value);
 208
 209        if (!strcmp(var, "diff.ignoresubmodules"))
 210                handle_ignore_submodules_arg(&default_diff_options, value);
 211
 212        if (!strcmp(var, "diff.submodule")) {
 213                if (parse_submodule_params(&default_diff_options, value))
 214                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 215                                value);
 216                return 0;
 217        }
 218
 219        if (!strcmp(var, "diff.algorithm")) {
 220                diff_algorithm = parse_algorithm_value(value);
 221                if (diff_algorithm < 0)
 222                        return -1;
 223                return 0;
 224        }
 225
 226        if (git_color_config(var, value, cb) < 0)
 227                return -1;
 228
 229        return git_diff_basic_config(var, value, cb);
 230}
 231
 232int git_diff_basic_config(const char *var, const char *value, void *cb)
 233{
 234        const char *name;
 235
 236        if (!strcmp(var, "diff.renamelimit")) {
 237                diff_rename_limit_default = git_config_int(var, value);
 238                return 0;
 239        }
 240
 241        if (userdiff_config(var, value) < 0)
 242                return -1;
 243
 244        if (skip_prefix(var, "diff.color.", &name) ||
 245            skip_prefix(var, "color.diff.", &name)) {
 246                int slot = parse_diff_color_slot(name);
 247                if (slot < 0)
 248                        return 0;
 249                if (!value)
 250                        return config_error_nonbool(var);
 251                return color_parse(value, diff_colors[slot]);
 252        }
 253
 254        /* like GNU diff's --suppress-blank-empty option  */
 255        if (!strcmp(var, "diff.suppressblankempty") ||
 256                        /* for backwards compatibility */
 257                        !strcmp(var, "diff.suppress-blank-empty")) {
 258                diff_suppress_blank_empty = git_config_bool(var, value);
 259                return 0;
 260        }
 261
 262        if (!strcmp(var, "diff.dirstat")) {
 263                struct strbuf errmsg = STRBUF_INIT;
 264                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 265                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 266                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 267                                errmsg.buf);
 268                strbuf_release(&errmsg);
 269                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 270                return 0;
 271        }
 272
 273        if (starts_with(var, "submodule."))
 274                return parse_submodule_config_option(var, value);
 275
 276        return git_default_config(var, value, cb);
 277}
 278
 279static char *quote_two(const char *one, const char *two)
 280{
 281        int need_one = quote_c_style(one, NULL, NULL, 1);
 282        int need_two = quote_c_style(two, NULL, NULL, 1);
 283        struct strbuf res = STRBUF_INIT;
 284
 285        if (need_one + need_two) {
 286                strbuf_addch(&res, '"');
 287                quote_c_style(one, &res, NULL, 1);
 288                quote_c_style(two, &res, NULL, 1);
 289                strbuf_addch(&res, '"');
 290        } else {
 291                strbuf_addstr(&res, one);
 292                strbuf_addstr(&res, two);
 293        }
 294        return strbuf_detach(&res, NULL);
 295}
 296
 297static const char *external_diff(void)
 298{
 299        static const char *external_diff_cmd = NULL;
 300        static int done_preparing = 0;
 301
 302        if (done_preparing)
 303                return external_diff_cmd;
 304        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 305        if (!external_diff_cmd)
 306                external_diff_cmd = external_diff_cmd_cfg;
 307        done_preparing = 1;
 308        return external_diff_cmd;
 309}
 310
 311static struct diff_tempfile {
 312        const char *name; /* filename external diff should read from */
 313        char hex[41];
 314        char mode[10];
 315        char tmp_path[PATH_MAX];
 316} diff_temp[2];
 317
 318typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 319
 320struct emit_callback {
 321        int color_diff;
 322        unsigned ws_rule;
 323        int blank_at_eof_in_preimage;
 324        int blank_at_eof_in_postimage;
 325        int lno_in_preimage;
 326        int lno_in_postimage;
 327        sane_truncate_fn truncate;
 328        const char **label_path;
 329        struct diff_words_data *diff_words;
 330        struct diff_options *opt;
 331        int *found_changesp;
 332        struct strbuf *header;
 333};
 334
 335static int count_lines(const char *data, int size)
 336{
 337        int count, ch, completely_empty = 1, nl_just_seen = 0;
 338        count = 0;
 339        while (0 < size--) {
 340                ch = *data++;
 341                if (ch == '\n') {
 342                        count++;
 343                        nl_just_seen = 1;
 344                        completely_empty = 0;
 345                }
 346                else {
 347                        nl_just_seen = 0;
 348                        completely_empty = 0;
 349                }
 350        }
 351        if (completely_empty)
 352                return 0;
 353        if (!nl_just_seen)
 354                count++; /* no trailing newline */
 355        return count;
 356}
 357
 358static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 359{
 360        if (!DIFF_FILE_VALID(one)) {
 361                mf->ptr = (char *)""; /* does not matter */
 362                mf->size = 0;
 363                return 0;
 364        }
 365        else if (diff_populate_filespec(one, 0))
 366                return -1;
 367
 368        mf->ptr = one->data;
 369        mf->size = one->size;
 370        return 0;
 371}
 372
 373/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 374static unsigned long diff_filespec_size(struct diff_filespec *one)
 375{
 376        if (!DIFF_FILE_VALID(one))
 377                return 0;
 378        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 379        return one->size;
 380}
 381
 382static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 383{
 384        char *ptr = mf->ptr;
 385        long size = mf->size;
 386        int cnt = 0;
 387
 388        if (!size)
 389                return cnt;
 390        ptr += size - 1; /* pointing at the very end */
 391        if (*ptr != '\n')
 392                ; /* incomplete line */
 393        else
 394                ptr--; /* skip the last LF */
 395        while (mf->ptr < ptr) {
 396                char *prev_eol;
 397                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 398                        if (*prev_eol == '\n')
 399                                break;
 400                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 401                        break;
 402                cnt++;
 403                ptr = prev_eol - 1;
 404        }
 405        return cnt;
 406}
 407
 408static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 409                               struct emit_callback *ecbdata)
 410{
 411        int l1, l2, at;
 412        unsigned ws_rule = ecbdata->ws_rule;
 413        l1 = count_trailing_blank(mf1, ws_rule);
 414        l2 = count_trailing_blank(mf2, ws_rule);
 415        if (l2 <= l1) {
 416                ecbdata->blank_at_eof_in_preimage = 0;
 417                ecbdata->blank_at_eof_in_postimage = 0;
 418                return;
 419        }
 420        at = count_lines(mf1->ptr, mf1->size);
 421        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 422
 423        at = count_lines(mf2->ptr, mf2->size);
 424        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 425}
 426
 427static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 428                        int first, const char *line, int len)
 429{
 430        int has_trailing_newline, has_trailing_carriage_return;
 431        int nofirst;
 432        FILE *file = o->file;
 433
 434        fputs(diff_line_prefix(o), file);
 435
 436        if (len == 0) {
 437                has_trailing_newline = (first == '\n');
 438                has_trailing_carriage_return = (!has_trailing_newline &&
 439                                                (first == '\r'));
 440                nofirst = has_trailing_newline || has_trailing_carriage_return;
 441        } else {
 442                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 443                if (has_trailing_newline)
 444                        len--;
 445                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 446                if (has_trailing_carriage_return)
 447                        len--;
 448                nofirst = 0;
 449        }
 450
 451        if (len || !nofirst) {
 452                fputs(set, file);
 453                if (!nofirst)
 454                        fputc(first, file);
 455                fwrite(line, len, 1, file);
 456                fputs(reset, file);
 457        }
 458        if (has_trailing_carriage_return)
 459                fputc('\r', file);
 460        if (has_trailing_newline)
 461                fputc('\n', file);
 462}
 463
 464static void emit_line(struct diff_options *o, const char *set, const char *reset,
 465                      const char *line, int len)
 466{
 467        emit_line_0(o, set, reset, line[0], line+1, len-1);
 468}
 469
 470static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 471{
 472        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 473              ecbdata->blank_at_eof_in_preimage &&
 474              ecbdata->blank_at_eof_in_postimage &&
 475              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 476              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 477                return 0;
 478        return ws_blank_line(line, len, ecbdata->ws_rule);
 479}
 480
 481static void emit_add_line(const char *reset,
 482                          struct emit_callback *ecbdata,
 483                          const char *line, int len)
 484{
 485        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 486        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 487
 488        if (!*ws)
 489                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 490        else if (new_blank_line_at_eof(ecbdata, line, len))
 491                /* Blank line at EOF - paint '+' as well */
 492                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 493        else {
 494                /* Emit just the prefix, then the rest. */
 495                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 496                ws_check_emit(line, len, ecbdata->ws_rule,
 497                              ecbdata->opt->file, set, reset, ws);
 498        }
 499}
 500
 501static void emit_del_line(const char *reset,
 502                          struct emit_callback *ecbdata,
 503                          const char *line, int len)
 504{
 505        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_OLD);
 506
 507        emit_line_0(ecbdata->opt, set, reset, '-', line, len);
 508}
 509
 510static void emit_context_line(const char *reset,
 511                              struct emit_callback *ecbdata,
 512                              const char *line, int len)
 513{
 514        const char *set = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 515
 516        emit_line_0(ecbdata->opt, set, reset, ' ', line, len);
 517}
 518
 519static void emit_hunk_header(struct emit_callback *ecbdata,
 520                             const char *line, int len)
 521{
 522        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 523        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 524        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 525        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 526        static const char atat[2] = { '@', '@' };
 527        const char *cp, *ep;
 528        struct strbuf msgbuf = STRBUF_INIT;
 529        int org_len = len;
 530        int i = 1;
 531
 532        /*
 533         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 534         * it always is at least 10 bytes long.
 535         */
 536        if (len < 10 ||
 537            memcmp(line, atat, 2) ||
 538            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 539                emit_line(ecbdata->opt, plain, reset, line, len);
 540                return;
 541        }
 542        ep += 2; /* skip over @@ */
 543
 544        /* The hunk header in fraginfo color */
 545        strbuf_addstr(&msgbuf, frag);
 546        strbuf_add(&msgbuf, line, ep - line);
 547        strbuf_addstr(&msgbuf, reset);
 548
 549        /*
 550         * trailing "\r\n"
 551         */
 552        for ( ; i < 3; i++)
 553                if (line[len - i] == '\r' || line[len - i] == '\n')
 554                        len--;
 555
 556        /* blank before the func header */
 557        for (cp = ep; ep - line < len; ep++)
 558                if (*ep != ' ' && *ep != '\t')
 559                        break;
 560        if (ep != cp) {
 561                strbuf_addstr(&msgbuf, plain);
 562                strbuf_add(&msgbuf, cp, ep - cp);
 563                strbuf_addstr(&msgbuf, reset);
 564        }
 565
 566        if (ep < line + len) {
 567                strbuf_addstr(&msgbuf, func);
 568                strbuf_add(&msgbuf, ep, line + len - ep);
 569                strbuf_addstr(&msgbuf, reset);
 570        }
 571
 572        strbuf_add(&msgbuf, line + len, org_len - len);
 573        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 574        strbuf_release(&msgbuf);
 575}
 576
 577static struct diff_tempfile *claim_diff_tempfile(void) {
 578        int i;
 579        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 580                if (!diff_temp[i].name)
 581                        return diff_temp + i;
 582        die("BUG: diff is failing to clean up its tempfiles");
 583}
 584
 585static int remove_tempfile_installed;
 586
 587static void remove_tempfile(void)
 588{
 589        int i;
 590        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 591                if (diff_temp[i].name == diff_temp[i].tmp_path)
 592                        unlink_or_warn(diff_temp[i].name);
 593                diff_temp[i].name = NULL;
 594        }
 595}
 596
 597static void remove_tempfile_on_signal(int signo)
 598{
 599        remove_tempfile();
 600        sigchain_pop(signo);
 601        raise(signo);
 602}
 603
 604static void print_line_count(FILE *file, int count)
 605{
 606        switch (count) {
 607        case 0:
 608                fprintf(file, "0,0");
 609                break;
 610        case 1:
 611                fprintf(file, "1");
 612                break;
 613        default:
 614                fprintf(file, "1,%d", count);
 615                break;
 616        }
 617}
 618
 619static void emit_rewrite_lines(struct emit_callback *ecb,
 620                               int prefix, const char *data, int size)
 621{
 622        const char *endp = NULL;
 623        static const char *nneof = " No newline at end of file\n";
 624        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 625
 626        while (0 < size) {
 627                int len;
 628
 629                endp = memchr(data, '\n', size);
 630                len = endp ? (endp - data + 1) : size;
 631                if (prefix != '+') {
 632                        ecb->lno_in_preimage++;
 633                        emit_del_line(reset, ecb, data, len);
 634                } else {
 635                        ecb->lno_in_postimage++;
 636                        emit_add_line(reset, ecb, data, len);
 637                }
 638                size -= len;
 639                data += len;
 640        }
 641        if (!endp) {
 642                const char *plain = diff_get_color(ecb->color_diff,
 643                                                   DIFF_PLAIN);
 644                putc('\n', ecb->opt->file);
 645                emit_line_0(ecb->opt, plain, reset, '\\',
 646                            nneof, strlen(nneof));
 647        }
 648}
 649
 650static void emit_rewrite_diff(const char *name_a,
 651                              const char *name_b,
 652                              struct diff_filespec *one,
 653                              struct diff_filespec *two,
 654                              struct userdiff_driver *textconv_one,
 655                              struct userdiff_driver *textconv_two,
 656                              struct diff_options *o)
 657{
 658        int lc_a, lc_b;
 659        const char *name_a_tab, *name_b_tab;
 660        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 661        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 662        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 663        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 664        const char *a_prefix, *b_prefix;
 665        char *data_one, *data_two;
 666        size_t size_one, size_two;
 667        struct emit_callback ecbdata;
 668        const char *line_prefix = diff_line_prefix(o);
 669
 670        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 671                a_prefix = o->b_prefix;
 672                b_prefix = o->a_prefix;
 673        } else {
 674                a_prefix = o->a_prefix;
 675                b_prefix = o->b_prefix;
 676        }
 677
 678        name_a += (*name_a == '/');
 679        name_b += (*name_b == '/');
 680        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 681        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 682
 683        strbuf_reset(&a_name);
 684        strbuf_reset(&b_name);
 685        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 686        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 687
 688        size_one = fill_textconv(textconv_one, one, &data_one);
 689        size_two = fill_textconv(textconv_two, two, &data_two);
 690
 691        memset(&ecbdata, 0, sizeof(ecbdata));
 692        ecbdata.color_diff = want_color(o->use_color);
 693        ecbdata.found_changesp = &o->found_changes;
 694        ecbdata.ws_rule = whitespace_rule(name_b);
 695        ecbdata.opt = o;
 696        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 697                mmfile_t mf1, mf2;
 698                mf1.ptr = (char *)data_one;
 699                mf2.ptr = (char *)data_two;
 700                mf1.size = size_one;
 701                mf2.size = size_two;
 702                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 703        }
 704        ecbdata.lno_in_preimage = 1;
 705        ecbdata.lno_in_postimage = 1;
 706
 707        lc_a = count_lines(data_one, size_one);
 708        lc_b = count_lines(data_two, size_two);
 709        fprintf(o->file,
 710                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 711                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 712                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 713                line_prefix, fraginfo);
 714        if (!o->irreversible_delete)
 715                print_line_count(o->file, lc_a);
 716        else
 717                fprintf(o->file, "?,?");
 718        fprintf(o->file, " +");
 719        print_line_count(o->file, lc_b);
 720        fprintf(o->file, " @@%s\n", reset);
 721        if (lc_a && !o->irreversible_delete)
 722                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 723        if (lc_b)
 724                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 725        if (textconv_one)
 726                free((char *)data_one);
 727        if (textconv_two)
 728                free((char *)data_two);
 729}
 730
 731struct diff_words_buffer {
 732        mmfile_t text;
 733        long alloc;
 734        struct diff_words_orig {
 735                const char *begin, *end;
 736        } *orig;
 737        int orig_nr, orig_alloc;
 738};
 739
 740static void diff_words_append(char *line, unsigned long len,
 741                struct diff_words_buffer *buffer)
 742{
 743        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 744        line++;
 745        len--;
 746        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 747        buffer->text.size += len;
 748        buffer->text.ptr[buffer->text.size] = '\0';
 749}
 750
 751struct diff_words_style_elem {
 752        const char *prefix;
 753        const char *suffix;
 754        const char *color; /* NULL; filled in by the setup code if
 755                            * color is enabled */
 756};
 757
 758struct diff_words_style {
 759        enum diff_words_type type;
 760        struct diff_words_style_elem new, old, ctx;
 761        const char *newline;
 762};
 763
 764static struct diff_words_style diff_words_styles[] = {
 765        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 766        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 767        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 768};
 769
 770struct diff_words_data {
 771        struct diff_words_buffer minus, plus;
 772        const char *current_plus;
 773        int last_minus;
 774        struct diff_options *opt;
 775        regex_t *word_regex;
 776        enum diff_words_type type;
 777        struct diff_words_style *style;
 778};
 779
 780static int fn_out_diff_words_write_helper(FILE *fp,
 781                                          struct diff_words_style_elem *st_el,
 782                                          const char *newline,
 783                                          size_t count, const char *buf,
 784                                          const char *line_prefix)
 785{
 786        int print = 0;
 787
 788        while (count) {
 789                char *p = memchr(buf, '\n', count);
 790                if (print)
 791                        fputs(line_prefix, fp);
 792                if (p != buf) {
 793                        if (st_el->color && fputs(st_el->color, fp) < 0)
 794                                return -1;
 795                        if (fputs(st_el->prefix, fp) < 0 ||
 796                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 797                            fputs(st_el->suffix, fp) < 0)
 798                                return -1;
 799                        if (st_el->color && *st_el->color
 800                            && fputs(GIT_COLOR_RESET, fp) < 0)
 801                                return -1;
 802                }
 803                if (!p)
 804                        return 0;
 805                if (fputs(newline, fp) < 0)
 806                        return -1;
 807                count -= p + 1 - buf;
 808                buf = p + 1;
 809                print = 1;
 810        }
 811        return 0;
 812}
 813
 814/*
 815 * '--color-words' algorithm can be described as:
 816 *
 817 *   1. collect a the minus/plus lines of a diff hunk, divided into
 818 *      minus-lines and plus-lines;
 819 *
 820 *   2. break both minus-lines and plus-lines into words and
 821 *      place them into two mmfile_t with one word for each line;
 822 *
 823 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 824 *
 825 * And for the common parts of the both file, we output the plus side text.
 826 * diff_words->current_plus is used to trace the current position of the plus file
 827 * which printed. diff_words->last_minus is used to trace the last minus word
 828 * printed.
 829 *
 830 * For '--graph' to work with '--color-words', we need to output the graph prefix
 831 * on each line of color words output. Generally, there are two conditions on
 832 * which we should output the prefix.
 833 *
 834 *   1. diff_words->last_minus == 0 &&
 835 *      diff_words->current_plus == diff_words->plus.text.ptr
 836 *
 837 *      that is: the plus text must start as a new line, and if there is no minus
 838 *      word printed, a graph prefix must be printed.
 839 *
 840 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 841 *      *(diff_words->current_plus - 1) == '\n'
 842 *
 843 *      that is: a graph prefix must be printed following a '\n'
 844 */
 845static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 846{
 847        if ((diff_words->last_minus == 0 &&
 848                diff_words->current_plus == diff_words->plus.text.ptr) ||
 849                (diff_words->current_plus > diff_words->plus.text.ptr &&
 850                *(diff_words->current_plus - 1) == '\n')) {
 851                return 1;
 852        } else {
 853                return 0;
 854        }
 855}
 856
 857static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 858{
 859        struct diff_words_data *diff_words = priv;
 860        struct diff_words_style *style = diff_words->style;
 861        int minus_first, minus_len, plus_first, plus_len;
 862        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 863        struct diff_options *opt = diff_words->opt;
 864        const char *line_prefix;
 865
 866        if (line[0] != '@' || parse_hunk_header(line, len,
 867                        &minus_first, &minus_len, &plus_first, &plus_len))
 868                return;
 869
 870        assert(opt);
 871        line_prefix = diff_line_prefix(opt);
 872
 873        /* POSIX requires that first be decremented by one if len == 0... */
 874        if (minus_len) {
 875                minus_begin = diff_words->minus.orig[minus_first].begin;
 876                minus_end =
 877                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 878        } else
 879                minus_begin = minus_end =
 880                        diff_words->minus.orig[minus_first].end;
 881
 882        if (plus_len) {
 883                plus_begin = diff_words->plus.orig[plus_first].begin;
 884                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 885        } else
 886                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 887
 888        if (color_words_output_graph_prefix(diff_words)) {
 889                fputs(line_prefix, diff_words->opt->file);
 890        }
 891        if (diff_words->current_plus != plus_begin) {
 892                fn_out_diff_words_write_helper(diff_words->opt->file,
 893                                &style->ctx, style->newline,
 894                                plus_begin - diff_words->current_plus,
 895                                diff_words->current_plus, line_prefix);
 896                if (*(plus_begin - 1) == '\n')
 897                        fputs(line_prefix, diff_words->opt->file);
 898        }
 899        if (minus_begin != minus_end) {
 900                fn_out_diff_words_write_helper(diff_words->opt->file,
 901                                &style->old, style->newline,
 902                                minus_end - minus_begin, minus_begin,
 903                                line_prefix);
 904        }
 905        if (plus_begin != plus_end) {
 906                fn_out_diff_words_write_helper(diff_words->opt->file,
 907                                &style->new, style->newline,
 908                                plus_end - plus_begin, plus_begin,
 909                                line_prefix);
 910        }
 911
 912        diff_words->current_plus = plus_end;
 913        diff_words->last_minus = minus_first;
 914}
 915
 916/* This function starts looking at *begin, and returns 0 iff a word was found. */
 917static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 918                int *begin, int *end)
 919{
 920        if (word_regex && *begin < buffer->size) {
 921                regmatch_t match[1];
 922                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 923                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 924                                        '\n', match[0].rm_eo - match[0].rm_so);
 925                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 926                        *begin += match[0].rm_so;
 927                        return *begin >= *end;
 928                }
 929                return -1;
 930        }
 931
 932        /* find the next word */
 933        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 934                (*begin)++;
 935        if (*begin >= buffer->size)
 936                return -1;
 937
 938        /* find the end of the word */
 939        *end = *begin + 1;
 940        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 941                (*end)++;
 942
 943        return 0;
 944}
 945
 946/*
 947 * This function splits the words in buffer->text, stores the list with
 948 * newline separator into out, and saves the offsets of the original words
 949 * in buffer->orig.
 950 */
 951static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 952                regex_t *word_regex)
 953{
 954        int i, j;
 955        long alloc = 0;
 956
 957        out->size = 0;
 958        out->ptr = NULL;
 959
 960        /* fake an empty "0th" word */
 961        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 962        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 963        buffer->orig_nr = 1;
 964
 965        for (i = 0; i < buffer->text.size; i++) {
 966                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 967                        return;
 968
 969                /* store original boundaries */
 970                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 971                                buffer->orig_alloc);
 972                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 973                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 974                buffer->orig_nr++;
 975
 976                /* store one word */
 977                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 978                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 979                out->ptr[out->size + j - i] = '\n';
 980                out->size += j - i + 1;
 981
 982                i = j - 1;
 983        }
 984}
 985
 986/* this executes the word diff on the accumulated buffers */
 987static void diff_words_show(struct diff_words_data *diff_words)
 988{
 989        xpparam_t xpp;
 990        xdemitconf_t xecfg;
 991        mmfile_t minus, plus;
 992        struct diff_words_style *style = diff_words->style;
 993
 994        struct diff_options *opt = diff_words->opt;
 995        const char *line_prefix;
 996
 997        assert(opt);
 998        line_prefix = diff_line_prefix(opt);
 999
1000        /* special case: only removal */
1001        if (!diff_words->plus.text.size) {
1002                fputs(line_prefix, diff_words->opt->file);
1003                fn_out_diff_words_write_helper(diff_words->opt->file,
1004                        &style->old, style->newline,
1005                        diff_words->minus.text.size,
1006                        diff_words->minus.text.ptr, line_prefix);
1007                diff_words->minus.text.size = 0;
1008                return;
1009        }
1010
1011        diff_words->current_plus = diff_words->plus.text.ptr;
1012        diff_words->last_minus = 0;
1013
1014        memset(&xpp, 0, sizeof(xpp));
1015        memset(&xecfg, 0, sizeof(xecfg));
1016        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1017        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1018        xpp.flags = 0;
1019        /* as only the hunk header will be parsed, we need a 0-context */
1020        xecfg.ctxlen = 0;
1021        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1022                      &xpp, &xecfg);
1023        free(minus.ptr);
1024        free(plus.ptr);
1025        if (diff_words->current_plus != diff_words->plus.text.ptr +
1026                        diff_words->plus.text.size) {
1027                if (color_words_output_graph_prefix(diff_words))
1028                        fputs(line_prefix, diff_words->opt->file);
1029                fn_out_diff_words_write_helper(diff_words->opt->file,
1030                        &style->ctx, style->newline,
1031                        diff_words->plus.text.ptr + diff_words->plus.text.size
1032                        - diff_words->current_plus, diff_words->current_plus,
1033                        line_prefix);
1034        }
1035        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1036}
1037
1038/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1039static void diff_words_flush(struct emit_callback *ecbdata)
1040{
1041        if (ecbdata->diff_words->minus.text.size ||
1042            ecbdata->diff_words->plus.text.size)
1043                diff_words_show(ecbdata->diff_words);
1044}
1045
1046static void diff_filespec_load_driver(struct diff_filespec *one)
1047{
1048        /* Use already-loaded driver */
1049        if (one->driver)
1050                return;
1051
1052        if (S_ISREG(one->mode))
1053                one->driver = userdiff_find_by_path(one->path);
1054
1055        /* Fallback to default settings */
1056        if (!one->driver)
1057                one->driver = userdiff_find_by_name("default");
1058}
1059
1060static const char *userdiff_word_regex(struct diff_filespec *one)
1061{
1062        diff_filespec_load_driver(one);
1063        return one->driver->word_regex;
1064}
1065
1066static void init_diff_words_data(struct emit_callback *ecbdata,
1067                                 struct diff_options *orig_opts,
1068                                 struct diff_filespec *one,
1069                                 struct diff_filespec *two)
1070{
1071        int i;
1072        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1073        memcpy(o, orig_opts, sizeof(struct diff_options));
1074
1075        ecbdata->diff_words =
1076                xcalloc(1, sizeof(struct diff_words_data));
1077        ecbdata->diff_words->type = o->word_diff;
1078        ecbdata->diff_words->opt = o;
1079        if (!o->word_regex)
1080                o->word_regex = userdiff_word_regex(one);
1081        if (!o->word_regex)
1082                o->word_regex = userdiff_word_regex(two);
1083        if (!o->word_regex)
1084                o->word_regex = diff_word_regex_cfg;
1085        if (o->word_regex) {
1086                ecbdata->diff_words->word_regex = (regex_t *)
1087                        xmalloc(sizeof(regex_t));
1088                if (regcomp(ecbdata->diff_words->word_regex,
1089                            o->word_regex,
1090                            REG_EXTENDED | REG_NEWLINE))
1091                        die ("Invalid regular expression: %s",
1092                             o->word_regex);
1093        }
1094        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1095                if (o->word_diff == diff_words_styles[i].type) {
1096                        ecbdata->diff_words->style =
1097                                &diff_words_styles[i];
1098                        break;
1099                }
1100        }
1101        if (want_color(o->use_color)) {
1102                struct diff_words_style *st = ecbdata->diff_words->style;
1103                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1104                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1105                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1106        }
1107}
1108
1109static void free_diff_words_data(struct emit_callback *ecbdata)
1110{
1111        if (ecbdata->diff_words) {
1112                diff_words_flush(ecbdata);
1113                free (ecbdata->diff_words->opt);
1114                free (ecbdata->diff_words->minus.text.ptr);
1115                free (ecbdata->diff_words->minus.orig);
1116                free (ecbdata->diff_words->plus.text.ptr);
1117                free (ecbdata->diff_words->plus.orig);
1118                if (ecbdata->diff_words->word_regex) {
1119                        regfree(ecbdata->diff_words->word_regex);
1120                        free(ecbdata->diff_words->word_regex);
1121                }
1122                free(ecbdata->diff_words);
1123                ecbdata->diff_words = NULL;
1124        }
1125}
1126
1127const char *diff_get_color(int diff_use_color, enum color_diff ix)
1128{
1129        if (want_color(diff_use_color))
1130                return diff_colors[ix];
1131        return "";
1132}
1133
1134const char *diff_line_prefix(struct diff_options *opt)
1135{
1136        struct strbuf *msgbuf;
1137        if (!opt->output_prefix)
1138                return "";
1139
1140        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1141        return msgbuf->buf;
1142}
1143
1144static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1145{
1146        const char *cp;
1147        unsigned long allot;
1148        size_t l = len;
1149
1150        if (ecb->truncate)
1151                return ecb->truncate(line, len);
1152        cp = line;
1153        allot = l;
1154        while (0 < l) {
1155                (void) utf8_width(&cp, &l);
1156                if (!cp)
1157                        break; /* truncated in the middle? */
1158        }
1159        return allot - l;
1160}
1161
1162static void find_lno(const char *line, struct emit_callback *ecbdata)
1163{
1164        const char *p;
1165        ecbdata->lno_in_preimage = 0;
1166        ecbdata->lno_in_postimage = 0;
1167        p = strchr(line, '-');
1168        if (!p)
1169                return; /* cannot happen */
1170        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1171        p = strchr(p, '+');
1172        if (!p)
1173                return; /* cannot happen */
1174        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1175}
1176
1177static void fn_out_consume(void *priv, char *line, unsigned long len)
1178{
1179        struct emit_callback *ecbdata = priv;
1180        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1181        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1182        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1183        struct diff_options *o = ecbdata->opt;
1184        const char *line_prefix = diff_line_prefix(o);
1185
1186        if (ecbdata->header) {
1187                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1188                strbuf_reset(ecbdata->header);
1189                ecbdata->header = NULL;
1190        }
1191        *(ecbdata->found_changesp) = 1;
1192
1193        if (ecbdata->label_path[0]) {
1194                const char *name_a_tab, *name_b_tab;
1195
1196                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1197                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1198
1199                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1200                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1201                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1202                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1203                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1204        }
1205
1206        if (diff_suppress_blank_empty
1207            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1208                line[0] = '\n';
1209                len = 1;
1210        }
1211
1212        if (line[0] == '@') {
1213                if (ecbdata->diff_words)
1214                        diff_words_flush(ecbdata);
1215                len = sane_truncate_line(ecbdata, line, len);
1216                find_lno(line, ecbdata);
1217                emit_hunk_header(ecbdata, line, len);
1218                if (line[len-1] != '\n')
1219                        putc('\n', ecbdata->opt->file);
1220                return;
1221        }
1222
1223        if (len < 1) {
1224                emit_line(ecbdata->opt, reset, reset, line, len);
1225                if (ecbdata->diff_words
1226                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1227                        fputs("~\n", ecbdata->opt->file);
1228                return;
1229        }
1230
1231        if (ecbdata->diff_words) {
1232                if (line[0] == '-') {
1233                        diff_words_append(line, len,
1234                                          &ecbdata->diff_words->minus);
1235                        return;
1236                } else if (line[0] == '+') {
1237                        diff_words_append(line, len,
1238                                          &ecbdata->diff_words->plus);
1239                        return;
1240                } else if (starts_with(line, "\\ ")) {
1241                        /*
1242                         * Eat the "no newline at eof" marker as if we
1243                         * saw a "+" or "-" line with nothing on it,
1244                         * and return without diff_words_flush() to
1245                         * defer processing. If this is the end of
1246                         * preimage, more "+" lines may come after it.
1247                         */
1248                        return;
1249                }
1250                diff_words_flush(ecbdata);
1251                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1252                        emit_line(ecbdata->opt, plain, reset, line, len);
1253                        fputs("~\n", ecbdata->opt->file);
1254                } else {
1255                        /*
1256                         * Skip the prefix character, if any.  With
1257                         * diff_suppress_blank_empty, there may be
1258                         * none.
1259                         */
1260                        if (line[0] != '\n') {
1261                              line++;
1262                              len--;
1263                        }
1264                        emit_line(ecbdata->opt, plain, reset, line, len);
1265                }
1266                return;
1267        }
1268
1269        switch (line[0]) {
1270        case '+':
1271                ecbdata->lno_in_postimage++;
1272                emit_add_line(reset, ecbdata, line + 1, len - 1);
1273                break;
1274        case '-':
1275                ecbdata->lno_in_preimage++;
1276                emit_del_line(reset, ecbdata, line + 1, len - 1);
1277                break;
1278        case ' ':
1279                ecbdata->lno_in_postimage++;
1280                ecbdata->lno_in_preimage++;
1281                emit_context_line(reset, ecbdata, line + 1, len - 1);
1282                break;
1283        default:
1284                /* incomplete line at the end */
1285                ecbdata->lno_in_preimage++;
1286                emit_line(ecbdata->opt,
1287                          diff_get_color(ecbdata->color_diff, DIFF_PLAIN),
1288                          reset, line, len);
1289                break;
1290        }
1291}
1292
1293static char *pprint_rename(const char *a, const char *b)
1294{
1295        const char *old = a;
1296        const char *new = b;
1297        struct strbuf name = STRBUF_INIT;
1298        int pfx_length, sfx_length;
1299        int pfx_adjust_for_slash;
1300        int len_a = strlen(a);
1301        int len_b = strlen(b);
1302        int a_midlen, b_midlen;
1303        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1304        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1305
1306        if (qlen_a || qlen_b) {
1307                quote_c_style(a, &name, NULL, 0);
1308                strbuf_addstr(&name, " => ");
1309                quote_c_style(b, &name, NULL, 0);
1310                return strbuf_detach(&name, NULL);
1311        }
1312
1313        /* Find common prefix */
1314        pfx_length = 0;
1315        while (*old && *new && *old == *new) {
1316                if (*old == '/')
1317                        pfx_length = old - a + 1;
1318                old++;
1319                new++;
1320        }
1321
1322        /* Find common suffix */
1323        old = a + len_a;
1324        new = b + len_b;
1325        sfx_length = 0;
1326        /*
1327         * If there is a common prefix, it must end in a slash.  In
1328         * that case we let this loop run 1 into the prefix to see the
1329         * same slash.
1330         *
1331         * If there is no common prefix, we cannot do this as it would
1332         * underrun the input strings.
1333         */
1334        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1335        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1336               b + pfx_length - pfx_adjust_for_slash <= new &&
1337               *old == *new) {
1338                if (*old == '/')
1339                        sfx_length = len_a - (old - a);
1340                old--;
1341                new--;
1342        }
1343
1344        /*
1345         * pfx{mid-a => mid-b}sfx
1346         * {pfx-a => pfx-b}sfx
1347         * pfx{sfx-a => sfx-b}
1348         * name-a => name-b
1349         */
1350        a_midlen = len_a - pfx_length - sfx_length;
1351        b_midlen = len_b - pfx_length - sfx_length;
1352        if (a_midlen < 0)
1353                a_midlen = 0;
1354        if (b_midlen < 0)
1355                b_midlen = 0;
1356
1357        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1358        if (pfx_length + sfx_length) {
1359                strbuf_add(&name, a, pfx_length);
1360                strbuf_addch(&name, '{');
1361        }
1362        strbuf_add(&name, a + pfx_length, a_midlen);
1363        strbuf_addstr(&name, " => ");
1364        strbuf_add(&name, b + pfx_length, b_midlen);
1365        if (pfx_length + sfx_length) {
1366                strbuf_addch(&name, '}');
1367                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1368        }
1369        return strbuf_detach(&name, NULL);
1370}
1371
1372struct diffstat_t {
1373        int nr;
1374        int alloc;
1375        struct diffstat_file {
1376                char *from_name;
1377                char *name;
1378                char *print_name;
1379                unsigned is_unmerged:1;
1380                unsigned is_binary:1;
1381                unsigned is_renamed:1;
1382                unsigned is_interesting:1;
1383                uintmax_t added, deleted;
1384        } **files;
1385};
1386
1387static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1388                                          const char *name_a,
1389                                          const char *name_b)
1390{
1391        struct diffstat_file *x;
1392        x = xcalloc(1, sizeof(*x));
1393        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1394        diffstat->files[diffstat->nr++] = x;
1395        if (name_b) {
1396                x->from_name = xstrdup(name_a);
1397                x->name = xstrdup(name_b);
1398                x->is_renamed = 1;
1399        }
1400        else {
1401                x->from_name = NULL;
1402                x->name = xstrdup(name_a);
1403        }
1404        return x;
1405}
1406
1407static void diffstat_consume(void *priv, char *line, unsigned long len)
1408{
1409        struct diffstat_t *diffstat = priv;
1410        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1411
1412        if (line[0] == '+')
1413                x->added++;
1414        else if (line[0] == '-')
1415                x->deleted++;
1416}
1417
1418const char mime_boundary_leader[] = "------------";
1419
1420static int scale_linear(int it, int width, int max_change)
1421{
1422        if (!it)
1423                return 0;
1424        /*
1425         * make sure that at least one '-' or '+' is printed if
1426         * there is any change to this path. The easiest way is to
1427         * scale linearly as if the alloted width is one column shorter
1428         * than it is, and then add 1 to the result.
1429         */
1430        return 1 + (it * (width - 1) / max_change);
1431}
1432
1433static void show_name(FILE *file,
1434                      const char *prefix, const char *name, int len)
1435{
1436        fprintf(file, " %s%-*s |", prefix, len, name);
1437}
1438
1439static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1440{
1441        if (cnt <= 0)
1442                return;
1443        fprintf(file, "%s", set);
1444        while (cnt--)
1445                putc(ch, file);
1446        fprintf(file, "%s", reset);
1447}
1448
1449static void fill_print_name(struct diffstat_file *file)
1450{
1451        char *pname;
1452
1453        if (file->print_name)
1454                return;
1455
1456        if (!file->is_renamed) {
1457                struct strbuf buf = STRBUF_INIT;
1458                if (quote_c_style(file->name, &buf, NULL, 0)) {
1459                        pname = strbuf_detach(&buf, NULL);
1460                } else {
1461                        pname = file->name;
1462                        strbuf_release(&buf);
1463                }
1464        } else {
1465                pname = pprint_rename(file->from_name, file->name);
1466        }
1467        file->print_name = pname;
1468}
1469
1470int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1471{
1472        struct strbuf sb = STRBUF_INIT;
1473        int ret;
1474
1475        if (!files) {
1476                assert(insertions == 0 && deletions == 0);
1477                return fprintf(fp, "%s\n", " 0 files changed");
1478        }
1479
1480        strbuf_addf(&sb,
1481                    (files == 1) ? " %d file changed" : " %d files changed",
1482                    files);
1483
1484        /*
1485         * For binary diff, the caller may want to print "x files
1486         * changed" with insertions == 0 && deletions == 0.
1487         *
1488         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1489         * is probably less confusing (i.e skip over "2 files changed
1490         * but nothing about added/removed lines? Is this a bug in Git?").
1491         */
1492        if (insertions || deletions == 0) {
1493                strbuf_addf(&sb,
1494                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1495                            insertions);
1496        }
1497
1498        if (deletions || insertions == 0) {
1499                strbuf_addf(&sb,
1500                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1501                            deletions);
1502        }
1503        strbuf_addch(&sb, '\n');
1504        ret = fputs(sb.buf, fp);
1505        strbuf_release(&sb);
1506        return ret;
1507}
1508
1509static void show_stats(struct diffstat_t *data, struct diff_options *options)
1510{
1511        int i, len, add, del, adds = 0, dels = 0;
1512        uintmax_t max_change = 0, max_len = 0;
1513        int total_files = data->nr, count;
1514        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1515        const char *reset, *add_c, *del_c;
1516        const char *line_prefix = "";
1517        int extra_shown = 0;
1518
1519        if (data->nr == 0)
1520                return;
1521
1522        line_prefix = diff_line_prefix(options);
1523        count = options->stat_count ? options->stat_count : data->nr;
1524
1525        reset = diff_get_color_opt(options, DIFF_RESET);
1526        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1527        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1528
1529        /*
1530         * Find the longest filename and max number of changes
1531         */
1532        for (i = 0; (i < count) && (i < data->nr); i++) {
1533                struct diffstat_file *file = data->files[i];
1534                uintmax_t change = file->added + file->deleted;
1535
1536                if (!file->is_interesting && (change == 0)) {
1537                        count++; /* not shown == room for one more */
1538                        continue;
1539                }
1540                fill_print_name(file);
1541                len = strlen(file->print_name);
1542                if (max_len < len)
1543                        max_len = len;
1544
1545                if (file->is_unmerged) {
1546                        /* "Unmerged" is 8 characters */
1547                        bin_width = bin_width < 8 ? 8 : bin_width;
1548                        continue;
1549                }
1550                if (file->is_binary) {
1551                        /* "Bin XXX -> YYY bytes" */
1552                        int w = 14 + decimal_width(file->added)
1553                                + decimal_width(file->deleted);
1554                        bin_width = bin_width < w ? w : bin_width;
1555                        /* Display change counts aligned with "Bin" */
1556                        number_width = 3;
1557                        continue;
1558                }
1559
1560                if (max_change < change)
1561                        max_change = change;
1562        }
1563        count = i; /* where we can stop scanning in data->files[] */
1564
1565        /*
1566         * We have width = stat_width or term_columns() columns total.
1567         * We want a maximum of min(max_len, stat_name_width) for the name part.
1568         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1569         * We also need 1 for " " and 4 + decimal_width(max_change)
1570         * for " | NNNN " and one the empty column at the end, altogether
1571         * 6 + decimal_width(max_change).
1572         *
1573         * If there's not enough space, we will use the smaller of
1574         * stat_name_width (if set) and 5/8*width for the filename,
1575         * and the rest for constant elements + graph part, but no more
1576         * than stat_graph_width for the graph part.
1577         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1578         * for the standard terminal size).
1579         *
1580         * In other words: stat_width limits the maximum width, and
1581         * stat_name_width fixes the maximum width of the filename,
1582         * and is also used to divide available columns if there
1583         * aren't enough.
1584         *
1585         * Binary files are displayed with "Bin XXX -> YYY bytes"
1586         * instead of the change count and graph. This part is treated
1587         * similarly to the graph part, except that it is not
1588         * "scaled". If total width is too small to accommodate the
1589         * guaranteed minimum width of the filename part and the
1590         * separators and this message, this message will "overflow"
1591         * making the line longer than the maximum width.
1592         */
1593
1594        if (options->stat_width == -1)
1595                width = term_columns() - options->output_prefix_length;
1596        else
1597                width = options->stat_width ? options->stat_width : 80;
1598        number_width = decimal_width(max_change) > number_width ?
1599                decimal_width(max_change) : number_width;
1600
1601        if (options->stat_graph_width == -1)
1602                options->stat_graph_width = diff_stat_graph_width;
1603
1604        /*
1605         * Guarantee 3/8*16==6 for the graph part
1606         * and 5/8*16==10 for the filename part
1607         */
1608        if (width < 16 + 6 + number_width)
1609                width = 16 + 6 + number_width;
1610
1611        /*
1612         * First assign sizes that are wanted, ignoring available width.
1613         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1614         * starting from "XXX" should fit in graph_width.
1615         */
1616        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1617        if (options->stat_graph_width &&
1618            options->stat_graph_width < graph_width)
1619                graph_width = options->stat_graph_width;
1620
1621        name_width = (options->stat_name_width > 0 &&
1622                      options->stat_name_width < max_len) ?
1623                options->stat_name_width : max_len;
1624
1625        /*
1626         * Adjust adjustable widths not to exceed maximum width
1627         */
1628        if (name_width + number_width + 6 + graph_width > width) {
1629                if (graph_width > width * 3/8 - number_width - 6) {
1630                        graph_width = width * 3/8 - number_width - 6;
1631                        if (graph_width < 6)
1632                                graph_width = 6;
1633                }
1634
1635                if (options->stat_graph_width &&
1636                    graph_width > options->stat_graph_width)
1637                        graph_width = options->stat_graph_width;
1638                if (name_width > width - number_width - 6 - graph_width)
1639                        name_width = width - number_width - 6 - graph_width;
1640                else
1641                        graph_width = width - number_width - 6 - name_width;
1642        }
1643
1644        /*
1645         * From here name_width is the width of the name area,
1646         * and graph_width is the width of the graph area.
1647         * max_change is used to scale graph properly.
1648         */
1649        for (i = 0; i < count; i++) {
1650                const char *prefix = "";
1651                struct diffstat_file *file = data->files[i];
1652                char *name = file->print_name;
1653                uintmax_t added = file->added;
1654                uintmax_t deleted = file->deleted;
1655                int name_len;
1656
1657                if (!file->is_interesting && (added + deleted == 0))
1658                        continue;
1659
1660                /*
1661                 * "scale" the filename
1662                 */
1663                len = name_width;
1664                name_len = strlen(name);
1665                if (name_width < name_len) {
1666                        char *slash;
1667                        prefix = "...";
1668                        len -= 3;
1669                        name += name_len - len;
1670                        slash = strchr(name, '/');
1671                        if (slash)
1672                                name = slash;
1673                }
1674
1675                if (file->is_binary) {
1676                        fprintf(options->file, "%s", line_prefix);
1677                        show_name(options->file, prefix, name, len);
1678                        fprintf(options->file, " %*s", number_width, "Bin");
1679                        if (!added && !deleted) {
1680                                putc('\n', options->file);
1681                                continue;
1682                        }
1683                        fprintf(options->file, " %s%"PRIuMAX"%s",
1684                                del_c, deleted, reset);
1685                        fprintf(options->file, " -> ");
1686                        fprintf(options->file, "%s%"PRIuMAX"%s",
1687                                add_c, added, reset);
1688                        fprintf(options->file, " bytes");
1689                        fprintf(options->file, "\n");
1690                        continue;
1691                }
1692                else if (file->is_unmerged) {
1693                        fprintf(options->file, "%s", line_prefix);
1694                        show_name(options->file, prefix, name, len);
1695                        fprintf(options->file, " Unmerged\n");
1696                        continue;
1697                }
1698
1699                /*
1700                 * scale the add/delete
1701                 */
1702                add = added;
1703                del = deleted;
1704
1705                if (graph_width <= max_change) {
1706                        int total = scale_linear(add + del, graph_width, max_change);
1707                        if (total < 2 && add && del)
1708                                /* width >= 2 due to the sanity check */
1709                                total = 2;
1710                        if (add < del) {
1711                                add = scale_linear(add, graph_width, max_change);
1712                                del = total - add;
1713                        } else {
1714                                del = scale_linear(del, graph_width, max_change);
1715                                add = total - del;
1716                        }
1717                }
1718                fprintf(options->file, "%s", line_prefix);
1719                show_name(options->file, prefix, name, len);
1720                fprintf(options->file, " %*"PRIuMAX"%s",
1721                        number_width, added + deleted,
1722                        added + deleted ? " " : "");
1723                show_graph(options->file, '+', add, add_c, reset);
1724                show_graph(options->file, '-', del, del_c, reset);
1725                fprintf(options->file, "\n");
1726        }
1727
1728        for (i = 0; i < data->nr; i++) {
1729                struct diffstat_file *file = data->files[i];
1730                uintmax_t added = file->added;
1731                uintmax_t deleted = file->deleted;
1732
1733                if (file->is_unmerged ||
1734                    (!file->is_interesting && (added + deleted == 0))) {
1735                        total_files--;
1736                        continue;
1737                }
1738
1739                if (!file->is_binary) {
1740                        adds += added;
1741                        dels += deleted;
1742                }
1743                if (i < count)
1744                        continue;
1745                if (!extra_shown)
1746                        fprintf(options->file, "%s ...\n", line_prefix);
1747                extra_shown = 1;
1748        }
1749        fprintf(options->file, "%s", line_prefix);
1750        print_stat_summary(options->file, total_files, adds, dels);
1751}
1752
1753static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1754{
1755        int i, adds = 0, dels = 0, total_files = data->nr;
1756
1757        if (data->nr == 0)
1758                return;
1759
1760        for (i = 0; i < data->nr; i++) {
1761                int added = data->files[i]->added;
1762                int deleted= data->files[i]->deleted;
1763
1764                if (data->files[i]->is_unmerged ||
1765                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1766                        total_files--;
1767                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1768                        adds += added;
1769                        dels += deleted;
1770                }
1771        }
1772        fprintf(options->file, "%s", diff_line_prefix(options));
1773        print_stat_summary(options->file, total_files, adds, dels);
1774}
1775
1776static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1777{
1778        int i;
1779
1780        if (data->nr == 0)
1781                return;
1782
1783        for (i = 0; i < data->nr; i++) {
1784                struct diffstat_file *file = data->files[i];
1785
1786                fprintf(options->file, "%s", diff_line_prefix(options));
1787
1788                if (file->is_binary)
1789                        fprintf(options->file, "-\t-\t");
1790                else
1791                        fprintf(options->file,
1792                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1793                                file->added, file->deleted);
1794                if (options->line_termination) {
1795                        fill_print_name(file);
1796                        if (!file->is_renamed)
1797                                write_name_quoted(file->name, options->file,
1798                                                  options->line_termination);
1799                        else {
1800                                fputs(file->print_name, options->file);
1801                                putc(options->line_termination, options->file);
1802                        }
1803                } else {
1804                        if (file->is_renamed) {
1805                                putc('\0', options->file);
1806                                write_name_quoted(file->from_name, options->file, '\0');
1807                        }
1808                        write_name_quoted(file->name, options->file, '\0');
1809                }
1810        }
1811}
1812
1813struct dirstat_file {
1814        const char *name;
1815        unsigned long changed;
1816};
1817
1818struct dirstat_dir {
1819        struct dirstat_file *files;
1820        int alloc, nr, permille, cumulative;
1821};
1822
1823static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1824                unsigned long changed, const char *base, int baselen)
1825{
1826        unsigned long this_dir = 0;
1827        unsigned int sources = 0;
1828        const char *line_prefix = diff_line_prefix(opt);
1829
1830        while (dir->nr) {
1831                struct dirstat_file *f = dir->files;
1832                int namelen = strlen(f->name);
1833                unsigned long this;
1834                char *slash;
1835
1836                if (namelen < baselen)
1837                        break;
1838                if (memcmp(f->name, base, baselen))
1839                        break;
1840                slash = strchr(f->name + baselen, '/');
1841                if (slash) {
1842                        int newbaselen = slash + 1 - f->name;
1843                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1844                        sources++;
1845                } else {
1846                        this = f->changed;
1847                        dir->files++;
1848                        dir->nr--;
1849                        sources += 2;
1850                }
1851                this_dir += this;
1852        }
1853
1854        /*
1855         * We don't report dirstat's for
1856         *  - the top level
1857         *  - or cases where everything came from a single directory
1858         *    under this directory (sources == 1).
1859         */
1860        if (baselen && sources != 1) {
1861                if (this_dir) {
1862                        int permille = this_dir * 1000 / changed;
1863                        if (permille >= dir->permille) {
1864                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1865                                        permille / 10, permille % 10, baselen, base);
1866                                if (!dir->cumulative)
1867                                        return 0;
1868                        }
1869                }
1870        }
1871        return this_dir;
1872}
1873
1874static int dirstat_compare(const void *_a, const void *_b)
1875{
1876        const struct dirstat_file *a = _a;
1877        const struct dirstat_file *b = _b;
1878        return strcmp(a->name, b->name);
1879}
1880
1881static void show_dirstat(struct diff_options *options)
1882{
1883        int i;
1884        unsigned long changed;
1885        struct dirstat_dir dir;
1886        struct diff_queue_struct *q = &diff_queued_diff;
1887
1888        dir.files = NULL;
1889        dir.alloc = 0;
1890        dir.nr = 0;
1891        dir.permille = options->dirstat_permille;
1892        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1893
1894        changed = 0;
1895        for (i = 0; i < q->nr; i++) {
1896                struct diff_filepair *p = q->queue[i];
1897                const char *name;
1898                unsigned long copied, added, damage;
1899                int content_changed;
1900
1901                name = p->two->path ? p->two->path : p->one->path;
1902
1903                if (p->one->sha1_valid && p->two->sha1_valid)
1904                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1905                else
1906                        content_changed = 1;
1907
1908                if (!content_changed) {
1909                        /*
1910                         * The SHA1 has not changed, so pre-/post-content is
1911                         * identical. We can therefore skip looking at the
1912                         * file contents altogether.
1913                         */
1914                        damage = 0;
1915                        goto found_damage;
1916                }
1917
1918                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1919                        /*
1920                         * In --dirstat-by-file mode, we don't really need to
1921                         * look at the actual file contents at all.
1922                         * The fact that the SHA1 changed is enough for us to
1923                         * add this file to the list of results
1924                         * (with each file contributing equal damage).
1925                         */
1926                        damage = 1;
1927                        goto found_damage;
1928                }
1929
1930                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1931                        diff_populate_filespec(p->one, 0);
1932                        diff_populate_filespec(p->two, 0);
1933                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1934                                               &copied, &added);
1935                        diff_free_filespec_data(p->one);
1936                        diff_free_filespec_data(p->two);
1937                } else if (DIFF_FILE_VALID(p->one)) {
1938                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1939                        copied = added = 0;
1940                        diff_free_filespec_data(p->one);
1941                } else if (DIFF_FILE_VALID(p->two)) {
1942                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1943                        copied = 0;
1944                        added = p->two->size;
1945                        diff_free_filespec_data(p->two);
1946                } else
1947                        continue;
1948
1949                /*
1950                 * Original minus copied is the removed material,
1951                 * added is the new material.  They are both damages
1952                 * made to the preimage.
1953                 * If the resulting damage is zero, we know that
1954                 * diffcore_count_changes() considers the two entries to
1955                 * be identical, but since content_changed is true, we
1956                 * know that there must have been _some_ kind of change,
1957                 * so we force all entries to have damage > 0.
1958                 */
1959                damage = (p->one->size - copied) + added;
1960                if (!damage)
1961                        damage = 1;
1962
1963found_damage:
1964                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1965                dir.files[dir.nr].name = name;
1966                dir.files[dir.nr].changed = damage;
1967                changed += damage;
1968                dir.nr++;
1969        }
1970
1971        /* This can happen even with many files, if everything was renames */
1972        if (!changed)
1973                return;
1974
1975        /* Show all directories with more than x% of the changes */
1976        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1977        gather_dirstat(options, &dir, changed, "", 0);
1978}
1979
1980static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1981{
1982        int i;
1983        unsigned long changed;
1984        struct dirstat_dir dir;
1985
1986        if (data->nr == 0)
1987                return;
1988
1989        dir.files = NULL;
1990        dir.alloc = 0;
1991        dir.nr = 0;
1992        dir.permille = options->dirstat_permille;
1993        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1994
1995        changed = 0;
1996        for (i = 0; i < data->nr; i++) {
1997                struct diffstat_file *file = data->files[i];
1998                unsigned long damage = file->added + file->deleted;
1999                if (file->is_binary)
2000                        /*
2001                         * binary files counts bytes, not lines. Must find some
2002                         * way to normalize binary bytes vs. textual lines.
2003                         * The following heuristic assumes that there are 64
2004                         * bytes per "line".
2005                         * This is stupid and ugly, but very cheap...
2006                         */
2007                        damage = (damage + 63) / 64;
2008                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2009                dir.files[dir.nr].name = file->name;
2010                dir.files[dir.nr].changed = damage;
2011                changed += damage;
2012                dir.nr++;
2013        }
2014
2015        /* This can happen even with many files, if everything was renames */
2016        if (!changed)
2017                return;
2018
2019        /* Show all directories with more than x% of the changes */
2020        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2021        gather_dirstat(options, &dir, changed, "", 0);
2022}
2023
2024static void free_diffstat_info(struct diffstat_t *diffstat)
2025{
2026        int i;
2027        for (i = 0; i < diffstat->nr; i++) {
2028                struct diffstat_file *f = diffstat->files[i];
2029                if (f->name != f->print_name)
2030                        free(f->print_name);
2031                free(f->name);
2032                free(f->from_name);
2033                free(f);
2034        }
2035        free(diffstat->files);
2036}
2037
2038struct checkdiff_t {
2039        const char *filename;
2040        int lineno;
2041        int conflict_marker_size;
2042        struct diff_options *o;
2043        unsigned ws_rule;
2044        unsigned status;
2045};
2046
2047static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2048{
2049        char firstchar;
2050        int cnt;
2051
2052        if (len < marker_size + 1)
2053                return 0;
2054        firstchar = line[0];
2055        switch (firstchar) {
2056        case '=': case '>': case '<': case '|':
2057                break;
2058        default:
2059                return 0;
2060        }
2061        for (cnt = 1; cnt < marker_size; cnt++)
2062                if (line[cnt] != firstchar)
2063                        return 0;
2064        /* line[1] thru line[marker_size-1] are same as firstchar */
2065        if (len < marker_size + 1 || !isspace(line[marker_size]))
2066                return 0;
2067        return 1;
2068}
2069
2070static void checkdiff_consume(void *priv, char *line, unsigned long len)
2071{
2072        struct checkdiff_t *data = priv;
2073        int marker_size = data->conflict_marker_size;
2074        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2075        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2076        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2077        char *err;
2078        const char *line_prefix;
2079
2080        assert(data->o);
2081        line_prefix = diff_line_prefix(data->o);
2082
2083        if (line[0] == '+') {
2084                unsigned bad;
2085                data->lineno++;
2086                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2087                        data->status |= 1;
2088                        fprintf(data->o->file,
2089                                "%s%s:%d: leftover conflict marker\n",
2090                                line_prefix, data->filename, data->lineno);
2091                }
2092                bad = ws_check(line + 1, len - 1, data->ws_rule);
2093                if (!bad)
2094                        return;
2095                data->status |= bad;
2096                err = whitespace_error_string(bad);
2097                fprintf(data->o->file, "%s%s:%d: %s.\n",
2098                        line_prefix, data->filename, data->lineno, err);
2099                free(err);
2100                emit_line(data->o, set, reset, line, 1);
2101                ws_check_emit(line + 1, len - 1, data->ws_rule,
2102                              data->o->file, set, reset, ws);
2103        } else if (line[0] == ' ') {
2104                data->lineno++;
2105        } else if (line[0] == '@') {
2106                char *plus = strchr(line, '+');
2107                if (plus)
2108                        data->lineno = strtol(plus, NULL, 10) - 1;
2109                else
2110                        die("invalid diff");
2111        }
2112}
2113
2114static unsigned char *deflate_it(char *data,
2115                                 unsigned long size,
2116                                 unsigned long *result_size)
2117{
2118        int bound;
2119        unsigned char *deflated;
2120        git_zstream stream;
2121
2122        memset(&stream, 0, sizeof(stream));
2123        git_deflate_init(&stream, zlib_compression_level);
2124        bound = git_deflate_bound(&stream, size);
2125        deflated = xmalloc(bound);
2126        stream.next_out = deflated;
2127        stream.avail_out = bound;
2128
2129        stream.next_in = (unsigned char *)data;
2130        stream.avail_in = size;
2131        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2132                ; /* nothing */
2133        git_deflate_end(&stream);
2134        *result_size = stream.total_out;
2135        return deflated;
2136}
2137
2138static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2139                                  const char *prefix)
2140{
2141        void *cp;
2142        void *delta;
2143        void *deflated;
2144        void *data;
2145        unsigned long orig_size;
2146        unsigned long delta_size;
2147        unsigned long deflate_size;
2148        unsigned long data_size;
2149
2150        /* We could do deflated delta, or we could do just deflated two,
2151         * whichever is smaller.
2152         */
2153        delta = NULL;
2154        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2155        if (one->size && two->size) {
2156                delta = diff_delta(one->ptr, one->size,
2157                                   two->ptr, two->size,
2158                                   &delta_size, deflate_size);
2159                if (delta) {
2160                        void *to_free = delta;
2161                        orig_size = delta_size;
2162                        delta = deflate_it(delta, delta_size, &delta_size);
2163                        free(to_free);
2164                }
2165        }
2166
2167        if (delta && delta_size < deflate_size) {
2168                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2169                free(deflated);
2170                data = delta;
2171                data_size = delta_size;
2172        }
2173        else {
2174                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2175                free(delta);
2176                data = deflated;
2177                data_size = deflate_size;
2178        }
2179
2180        /* emit data encoded in base85 */
2181        cp = data;
2182        while (data_size) {
2183                int bytes = (52 < data_size) ? 52 : data_size;
2184                char line[70];
2185                data_size -= bytes;
2186                if (bytes <= 26)
2187                        line[0] = bytes + 'A' - 1;
2188                else
2189                        line[0] = bytes - 26 + 'a' - 1;
2190                encode_85(line + 1, cp, bytes);
2191                cp = (char *) cp + bytes;
2192                fprintf(file, "%s", prefix);
2193                fputs(line, file);
2194                fputc('\n', file);
2195        }
2196        fprintf(file, "%s\n", prefix);
2197        free(data);
2198}
2199
2200static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2201                             const char *prefix)
2202{
2203        fprintf(file, "%sGIT binary patch\n", prefix);
2204        emit_binary_diff_body(file, one, two, prefix);
2205        emit_binary_diff_body(file, two, one, prefix);
2206}
2207
2208int diff_filespec_is_binary(struct diff_filespec *one)
2209{
2210        if (one->is_binary == -1) {
2211                diff_filespec_load_driver(one);
2212                if (one->driver->binary != -1)
2213                        one->is_binary = one->driver->binary;
2214                else {
2215                        if (!one->data && DIFF_FILE_VALID(one))
2216                                diff_populate_filespec(one, CHECK_BINARY);
2217                        if (one->is_binary == -1 && one->data)
2218                                one->is_binary = buffer_is_binary(one->data,
2219                                                one->size);
2220                        if (one->is_binary == -1)
2221                                one->is_binary = 0;
2222                }
2223        }
2224        return one->is_binary;
2225}
2226
2227static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2228{
2229        diff_filespec_load_driver(one);
2230        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2231}
2232
2233void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2234{
2235        if (!options->a_prefix)
2236                options->a_prefix = a;
2237        if (!options->b_prefix)
2238                options->b_prefix = b;
2239}
2240
2241struct userdiff_driver *get_textconv(struct diff_filespec *one)
2242{
2243        if (!DIFF_FILE_VALID(one))
2244                return NULL;
2245
2246        diff_filespec_load_driver(one);
2247        return userdiff_get_textconv(one->driver);
2248}
2249
2250static void builtin_diff(const char *name_a,
2251                         const char *name_b,
2252                         struct diff_filespec *one,
2253                         struct diff_filespec *two,
2254                         const char *xfrm_msg,
2255                         int must_show_header,
2256                         struct diff_options *o,
2257                         int complete_rewrite)
2258{
2259        mmfile_t mf1, mf2;
2260        const char *lbl[2];
2261        char *a_one, *b_two;
2262        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2263        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2264        const char *a_prefix, *b_prefix;
2265        struct userdiff_driver *textconv_one = NULL;
2266        struct userdiff_driver *textconv_two = NULL;
2267        struct strbuf header = STRBUF_INIT;
2268        const char *line_prefix = diff_line_prefix(o);
2269
2270        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2271                        (!one->mode || S_ISGITLINK(one->mode)) &&
2272                        (!two->mode || S_ISGITLINK(two->mode))) {
2273                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2274                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2275                show_submodule_summary(o->file, one->path ? one->path : two->path,
2276                                line_prefix,
2277                                one->sha1, two->sha1, two->dirty_submodule,
2278                                meta, del, add, reset);
2279                return;
2280        }
2281
2282        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2283                textconv_one = get_textconv(one);
2284                textconv_two = get_textconv(two);
2285        }
2286
2287        diff_set_mnemonic_prefix(o, "a/", "b/");
2288        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2289                a_prefix = o->b_prefix;
2290                b_prefix = o->a_prefix;
2291        } else {
2292                a_prefix = o->a_prefix;
2293                b_prefix = o->b_prefix;
2294        }
2295
2296        /* Never use a non-valid filename anywhere if at all possible */
2297        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2298        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2299
2300        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2301        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2302        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2303        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2304        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2305        if (lbl[0][0] == '/') {
2306                /* /dev/null */
2307                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2308                if (xfrm_msg)
2309                        strbuf_addstr(&header, xfrm_msg);
2310                must_show_header = 1;
2311        }
2312        else if (lbl[1][0] == '/') {
2313                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2314                if (xfrm_msg)
2315                        strbuf_addstr(&header, xfrm_msg);
2316                must_show_header = 1;
2317        }
2318        else {
2319                if (one->mode != two->mode) {
2320                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2321                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2322                        must_show_header = 1;
2323                }
2324                if (xfrm_msg)
2325                        strbuf_addstr(&header, xfrm_msg);
2326
2327                /*
2328                 * we do not run diff between different kind
2329                 * of objects.
2330                 */
2331                if ((one->mode ^ two->mode) & S_IFMT)
2332                        goto free_ab_and_return;
2333                if (complete_rewrite &&
2334                    (textconv_one || !diff_filespec_is_binary(one)) &&
2335                    (textconv_two || !diff_filespec_is_binary(two))) {
2336                        fprintf(o->file, "%s", header.buf);
2337                        strbuf_reset(&header);
2338                        emit_rewrite_diff(name_a, name_b, one, two,
2339                                                textconv_one, textconv_two, o);
2340                        o->found_changes = 1;
2341                        goto free_ab_and_return;
2342                }
2343        }
2344
2345        if (o->irreversible_delete && lbl[1][0] == '/') {
2346                fprintf(o->file, "%s", header.buf);
2347                strbuf_reset(&header);
2348                goto free_ab_and_return;
2349        } else if (!DIFF_OPT_TST(o, TEXT) &&
2350            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2351              (!textconv_two && diff_filespec_is_binary(two)) )) {
2352                if (!one->data && !two->data &&
2353                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2354                    !DIFF_OPT_TST(o, BINARY)) {
2355                        if (!hashcmp(one->sha1, two->sha1)) {
2356                                if (must_show_header)
2357                                        fprintf(o->file, "%s", header.buf);
2358                                goto free_ab_and_return;
2359                        }
2360                        fprintf(o->file, "%s", header.buf);
2361                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2362                                line_prefix, lbl[0], lbl[1]);
2363                        goto free_ab_and_return;
2364                }
2365                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2366                        die("unable to read files to diff");
2367                /* Quite common confusing case */
2368                if (mf1.size == mf2.size &&
2369                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2370                        if (must_show_header)
2371                                fprintf(o->file, "%s", header.buf);
2372                        goto free_ab_and_return;
2373                }
2374                fprintf(o->file, "%s", header.buf);
2375                strbuf_reset(&header);
2376                if (DIFF_OPT_TST(o, BINARY))
2377                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2378                else
2379                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2380                                line_prefix, lbl[0], lbl[1]);
2381                o->found_changes = 1;
2382        } else {
2383                /* Crazy xdl interfaces.. */
2384                const char *diffopts = getenv("GIT_DIFF_OPTS");
2385                const char *v;
2386                xpparam_t xpp;
2387                xdemitconf_t xecfg;
2388                struct emit_callback ecbdata;
2389                const struct userdiff_funcname *pe;
2390
2391                if (must_show_header) {
2392                        fprintf(o->file, "%s", header.buf);
2393                        strbuf_reset(&header);
2394                }
2395
2396                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2397                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2398
2399                pe = diff_funcname_pattern(one);
2400                if (!pe)
2401                        pe = diff_funcname_pattern(two);
2402
2403                memset(&xpp, 0, sizeof(xpp));
2404                memset(&xecfg, 0, sizeof(xecfg));
2405                memset(&ecbdata, 0, sizeof(ecbdata));
2406                ecbdata.label_path = lbl;
2407                ecbdata.color_diff = want_color(o->use_color);
2408                ecbdata.found_changesp = &o->found_changes;
2409                ecbdata.ws_rule = whitespace_rule(name_b);
2410                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2411                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2412                ecbdata.opt = o;
2413                ecbdata.header = header.len ? &header : NULL;
2414                xpp.flags = o->xdl_opts;
2415                xecfg.ctxlen = o->context;
2416                xecfg.interhunkctxlen = o->interhunkcontext;
2417                xecfg.flags = XDL_EMIT_FUNCNAMES;
2418                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2419                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2420                if (pe)
2421                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2422                if (!diffopts)
2423                        ;
2424                else if (skip_prefix(diffopts, "--unified=", &v))
2425                        xecfg.ctxlen = strtoul(v, NULL, 10);
2426                else if (skip_prefix(diffopts, "-u", &v))
2427                        xecfg.ctxlen = strtoul(v, NULL, 10);
2428                if (o->word_diff)
2429                        init_diff_words_data(&ecbdata, o, one, two);
2430                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2431                              &xpp, &xecfg);
2432                if (o->word_diff)
2433                        free_diff_words_data(&ecbdata);
2434                if (textconv_one)
2435                        free(mf1.ptr);
2436                if (textconv_two)
2437                        free(mf2.ptr);
2438                xdiff_clear_find_func(&xecfg);
2439        }
2440
2441 free_ab_and_return:
2442        strbuf_release(&header);
2443        diff_free_filespec_data(one);
2444        diff_free_filespec_data(two);
2445        free(a_one);
2446        free(b_two);
2447        return;
2448}
2449
2450static void builtin_diffstat(const char *name_a, const char *name_b,
2451                             struct diff_filespec *one,
2452                             struct diff_filespec *two,
2453                             struct diffstat_t *diffstat,
2454                             struct diff_options *o,
2455                             struct diff_filepair *p)
2456{
2457        mmfile_t mf1, mf2;
2458        struct diffstat_file *data;
2459        int same_contents;
2460        int complete_rewrite = 0;
2461
2462        if (!DIFF_PAIR_UNMERGED(p)) {
2463                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2464                        complete_rewrite = 1;
2465        }
2466
2467        data = diffstat_add(diffstat, name_a, name_b);
2468        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2469
2470        if (!one || !two) {
2471                data->is_unmerged = 1;
2472                return;
2473        }
2474
2475        same_contents = !hashcmp(one->sha1, two->sha1);
2476
2477        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2478                data->is_binary = 1;
2479                if (same_contents) {
2480                        data->added = 0;
2481                        data->deleted = 0;
2482                } else {
2483                        data->added = diff_filespec_size(two);
2484                        data->deleted = diff_filespec_size(one);
2485                }
2486        }
2487
2488        else if (complete_rewrite) {
2489                diff_populate_filespec(one, 0);
2490                diff_populate_filespec(two, 0);
2491                data->deleted = count_lines(one->data, one->size);
2492                data->added = count_lines(two->data, two->size);
2493        }
2494
2495        else if (!same_contents) {
2496                /* Crazy xdl interfaces.. */
2497                xpparam_t xpp;
2498                xdemitconf_t xecfg;
2499
2500                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2501                        die("unable to read files to diff");
2502
2503                memset(&xpp, 0, sizeof(xpp));
2504                memset(&xecfg, 0, sizeof(xecfg));
2505                xpp.flags = o->xdl_opts;
2506                xecfg.ctxlen = o->context;
2507                xecfg.interhunkctxlen = o->interhunkcontext;
2508                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2509                              &xpp, &xecfg);
2510        }
2511
2512        diff_free_filespec_data(one);
2513        diff_free_filespec_data(two);
2514}
2515
2516static void builtin_checkdiff(const char *name_a, const char *name_b,
2517                              const char *attr_path,
2518                              struct diff_filespec *one,
2519                              struct diff_filespec *two,
2520                              struct diff_options *o)
2521{
2522        mmfile_t mf1, mf2;
2523        struct checkdiff_t data;
2524
2525        if (!two)
2526                return;
2527
2528        memset(&data, 0, sizeof(data));
2529        data.filename = name_b ? name_b : name_a;
2530        data.lineno = 0;
2531        data.o = o;
2532        data.ws_rule = whitespace_rule(attr_path);
2533        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2534
2535        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2536                die("unable to read files to diff");
2537
2538        /*
2539         * All the other codepaths check both sides, but not checking
2540         * the "old" side here is deliberate.  We are checking the newly
2541         * introduced changes, and as long as the "new" side is text, we
2542         * can and should check what it introduces.
2543         */
2544        if (diff_filespec_is_binary(two))
2545                goto free_and_return;
2546        else {
2547                /* Crazy xdl interfaces.. */
2548                xpparam_t xpp;
2549                xdemitconf_t xecfg;
2550
2551                memset(&xpp, 0, sizeof(xpp));
2552                memset(&xecfg, 0, sizeof(xecfg));
2553                xecfg.ctxlen = 1; /* at least one context line */
2554                xpp.flags = 0;
2555                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2556                              &xpp, &xecfg);
2557
2558                if (data.ws_rule & WS_BLANK_AT_EOF) {
2559                        struct emit_callback ecbdata;
2560                        int blank_at_eof;
2561
2562                        ecbdata.ws_rule = data.ws_rule;
2563                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2564                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2565
2566                        if (blank_at_eof) {
2567                                static char *err;
2568                                if (!err)
2569                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2570                                fprintf(o->file, "%s:%d: %s.\n",
2571                                        data.filename, blank_at_eof, err);
2572                                data.status = 1; /* report errors */
2573                        }
2574                }
2575        }
2576 free_and_return:
2577        diff_free_filespec_data(one);
2578        diff_free_filespec_data(two);
2579        if (data.status)
2580                DIFF_OPT_SET(o, CHECK_FAILED);
2581}
2582
2583struct diff_filespec *alloc_filespec(const char *path)
2584{
2585        int namelen = strlen(path);
2586        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2587
2588        memset(spec, 0, sizeof(*spec));
2589        spec->path = (char *)(spec + 1);
2590        memcpy(spec->path, path, namelen+1);
2591        spec->count = 1;
2592        spec->is_binary = -1;
2593        return spec;
2594}
2595
2596void free_filespec(struct diff_filespec *spec)
2597{
2598        if (!--spec->count) {
2599                diff_free_filespec_data(spec);
2600                free(spec);
2601        }
2602}
2603
2604void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2605                   int sha1_valid, unsigned short mode)
2606{
2607        if (mode) {
2608                spec->mode = canon_mode(mode);
2609                hashcpy(spec->sha1, sha1);
2610                spec->sha1_valid = sha1_valid;
2611        }
2612}
2613
2614/*
2615 * Given a name and sha1 pair, if the index tells us the file in
2616 * the work tree has that object contents, return true, so that
2617 * prepare_temp_file() does not have to inflate and extract.
2618 */
2619static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2620{
2621        const struct cache_entry *ce;
2622        struct stat st;
2623        int pos, len;
2624
2625        /*
2626         * We do not read the cache ourselves here, because the
2627         * benchmark with my previous version that always reads cache
2628         * shows that it makes things worse for diff-tree comparing
2629         * two linux-2.6 kernel trees in an already checked out work
2630         * tree.  This is because most diff-tree comparisons deal with
2631         * only a small number of files, while reading the cache is
2632         * expensive for a large project, and its cost outweighs the
2633         * savings we get by not inflating the object to a temporary
2634         * file.  Practically, this code only helps when we are used
2635         * by diff-cache --cached, which does read the cache before
2636         * calling us.
2637         */
2638        if (!active_cache)
2639                return 0;
2640
2641        /* We want to avoid the working directory if our caller
2642         * doesn't need the data in a normal file, this system
2643         * is rather slow with its stat/open/mmap/close syscalls,
2644         * and the object is contained in a pack file.  The pack
2645         * is probably already open and will be faster to obtain
2646         * the data through than the working directory.  Loose
2647         * objects however would tend to be slower as they need
2648         * to be individually opened and inflated.
2649         */
2650        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2651                return 0;
2652
2653        len = strlen(name);
2654        pos = cache_name_pos(name, len);
2655        if (pos < 0)
2656                return 0;
2657        ce = active_cache[pos];
2658
2659        /*
2660         * This is not the sha1 we are looking for, or
2661         * unreusable because it is not a regular file.
2662         */
2663        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2664                return 0;
2665
2666        /*
2667         * If ce is marked as "assume unchanged", there is no
2668         * guarantee that work tree matches what we are looking for.
2669         */
2670        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2671                return 0;
2672
2673        /*
2674         * If ce matches the file in the work tree, we can reuse it.
2675         */
2676        if (ce_uptodate(ce) ||
2677            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2678                return 1;
2679
2680        return 0;
2681}
2682
2683static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2684{
2685        int len;
2686        char *data = xmalloc(100), *dirty = "";
2687
2688        /* Are we looking at the work tree? */
2689        if (s->dirty_submodule)
2690                dirty = "-dirty";
2691
2692        len = snprintf(data, 100,
2693                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2694        s->data = data;
2695        s->size = len;
2696        s->should_free = 1;
2697        if (size_only) {
2698                s->data = NULL;
2699                free(data);
2700        }
2701        return 0;
2702}
2703
2704/*
2705 * While doing rename detection and pickaxe operation, we may need to
2706 * grab the data for the blob (or file) for our own in-core comparison.
2707 * diff_filespec has data and size fields for this purpose.
2708 */
2709int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2710{
2711        int size_only = flags & CHECK_SIZE_ONLY;
2712        int err = 0;
2713        /*
2714         * demote FAIL to WARN to allow inspecting the situation
2715         * instead of refusing.
2716         */
2717        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2718                                    ? SAFE_CRLF_WARN
2719                                    : safe_crlf);
2720
2721        if (!DIFF_FILE_VALID(s))
2722                die("internal error: asking to populate invalid file.");
2723        if (S_ISDIR(s->mode))
2724                return -1;
2725
2726        if (s->data)
2727                return 0;
2728
2729        if (size_only && 0 < s->size)
2730                return 0;
2731
2732        if (S_ISGITLINK(s->mode))
2733                return diff_populate_gitlink(s, size_only);
2734
2735        if (!s->sha1_valid ||
2736            reuse_worktree_file(s->path, s->sha1, 0)) {
2737                struct strbuf buf = STRBUF_INIT;
2738                struct stat st;
2739                int fd;
2740
2741                if (lstat(s->path, &st) < 0) {
2742                        if (errno == ENOENT) {
2743                        err_empty:
2744                                err = -1;
2745                        empty:
2746                                s->data = (char *)"";
2747                                s->size = 0;
2748                                return err;
2749                        }
2750                }
2751                s->size = xsize_t(st.st_size);
2752                if (!s->size)
2753                        goto empty;
2754                if (S_ISLNK(st.st_mode)) {
2755                        struct strbuf sb = STRBUF_INIT;
2756
2757                        if (strbuf_readlink(&sb, s->path, s->size))
2758                                goto err_empty;
2759                        s->size = sb.len;
2760                        s->data = strbuf_detach(&sb, NULL);
2761                        s->should_free = 1;
2762                        return 0;
2763                }
2764                if (size_only)
2765                        return 0;
2766                if ((flags & CHECK_BINARY) &&
2767                    s->size > big_file_threshold && s->is_binary == -1) {
2768                        s->is_binary = 1;
2769                        return 0;
2770                }
2771                fd = open(s->path, O_RDONLY);
2772                if (fd < 0)
2773                        goto err_empty;
2774                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2775                close(fd);
2776                s->should_munmap = 1;
2777
2778                /*
2779                 * Convert from working tree format to canonical git format
2780                 */
2781                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2782                        size_t size = 0;
2783                        munmap(s->data, s->size);
2784                        s->should_munmap = 0;
2785                        s->data = strbuf_detach(&buf, &size);
2786                        s->size = size;
2787                        s->should_free = 1;
2788                }
2789        }
2790        else {
2791                enum object_type type;
2792                if (size_only || (flags & CHECK_BINARY)) {
2793                        type = sha1_object_info(s->sha1, &s->size);
2794                        if (type < 0)
2795                                die("unable to read %s", sha1_to_hex(s->sha1));
2796                        if (size_only)
2797                                return 0;
2798                        if (s->size > big_file_threshold && s->is_binary == -1) {
2799                                s->is_binary = 1;
2800                                return 0;
2801                        }
2802                }
2803                s->data = read_sha1_file(s->sha1, &type, &s->size);
2804                if (!s->data)
2805                        die("unable to read %s", sha1_to_hex(s->sha1));
2806                s->should_free = 1;
2807        }
2808        return 0;
2809}
2810
2811void diff_free_filespec_blob(struct diff_filespec *s)
2812{
2813        if (s->should_free)
2814                free(s->data);
2815        else if (s->should_munmap)
2816                munmap(s->data, s->size);
2817
2818        if (s->should_free || s->should_munmap) {
2819                s->should_free = s->should_munmap = 0;
2820                s->data = NULL;
2821        }
2822}
2823
2824void diff_free_filespec_data(struct diff_filespec *s)
2825{
2826        diff_free_filespec_blob(s);
2827        free(s->cnt_data);
2828        s->cnt_data = NULL;
2829}
2830
2831static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2832                           void *blob,
2833                           unsigned long size,
2834                           const unsigned char *sha1,
2835                           int mode)
2836{
2837        int fd;
2838        struct strbuf buf = STRBUF_INIT;
2839        struct strbuf template = STRBUF_INIT;
2840        char *path_dup = xstrdup(path);
2841        const char *base = basename(path_dup);
2842
2843        /* Generate "XXXXXX_basename.ext" */
2844        strbuf_addstr(&template, "XXXXXX_");
2845        strbuf_addstr(&template, base);
2846
2847        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2848                        strlen(base) + 1);
2849        if (fd < 0)
2850                die_errno("unable to create temp-file");
2851        if (convert_to_working_tree(path,
2852                        (const char *)blob, (size_t)size, &buf)) {
2853                blob = buf.buf;
2854                size = buf.len;
2855        }
2856        if (write_in_full(fd, blob, size) != size)
2857                die_errno("unable to write temp-file");
2858        close(fd);
2859        temp->name = temp->tmp_path;
2860        strcpy(temp->hex, sha1_to_hex(sha1));
2861        temp->hex[40] = 0;
2862        sprintf(temp->mode, "%06o", mode);
2863        strbuf_release(&buf);
2864        strbuf_release(&template);
2865        free(path_dup);
2866}
2867
2868static struct diff_tempfile *prepare_temp_file(const char *name,
2869                struct diff_filespec *one)
2870{
2871        struct diff_tempfile *temp = claim_diff_tempfile();
2872
2873        if (!DIFF_FILE_VALID(one)) {
2874        not_a_valid_file:
2875                /* A '-' entry produces this for file-2, and
2876                 * a '+' entry produces this for file-1.
2877                 */
2878                temp->name = "/dev/null";
2879                strcpy(temp->hex, ".");
2880                strcpy(temp->mode, ".");
2881                return temp;
2882        }
2883
2884        if (!remove_tempfile_installed) {
2885                atexit(remove_tempfile);
2886                sigchain_push_common(remove_tempfile_on_signal);
2887                remove_tempfile_installed = 1;
2888        }
2889
2890        if (!S_ISGITLINK(one->mode) &&
2891            (!one->sha1_valid ||
2892             reuse_worktree_file(name, one->sha1, 1))) {
2893                struct stat st;
2894                if (lstat(name, &st) < 0) {
2895                        if (errno == ENOENT)
2896                                goto not_a_valid_file;
2897                        die_errno("stat(%s)", name);
2898                }
2899                if (S_ISLNK(st.st_mode)) {
2900                        struct strbuf sb = STRBUF_INIT;
2901                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2902                                die_errno("readlink(%s)", name);
2903                        prep_temp_blob(name, temp, sb.buf, sb.len,
2904                                       (one->sha1_valid ?
2905                                        one->sha1 : null_sha1),
2906                                       (one->sha1_valid ?
2907                                        one->mode : S_IFLNK));
2908                        strbuf_release(&sb);
2909                }
2910                else {
2911                        /* we can borrow from the file in the work tree */
2912                        temp->name = name;
2913                        if (!one->sha1_valid)
2914                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2915                        else
2916                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2917                        /* Even though we may sometimes borrow the
2918                         * contents from the work tree, we always want
2919                         * one->mode.  mode is trustworthy even when
2920                         * !(one->sha1_valid), as long as
2921                         * DIFF_FILE_VALID(one).
2922                         */
2923                        sprintf(temp->mode, "%06o", one->mode);
2924                }
2925                return temp;
2926        }
2927        else {
2928                if (diff_populate_filespec(one, 0))
2929                        die("cannot read data blob for %s", one->path);
2930                prep_temp_blob(name, temp, one->data, one->size,
2931                               one->sha1, one->mode);
2932        }
2933        return temp;
2934}
2935
2936static void add_external_diff_name(struct argv_array *argv,
2937                                   const char *name,
2938                                   struct diff_filespec *df)
2939{
2940        struct diff_tempfile *temp = prepare_temp_file(name, df);
2941        argv_array_push(argv, temp->name);
2942        argv_array_push(argv, temp->hex);
2943        argv_array_push(argv, temp->mode);
2944}
2945
2946/* An external diff command takes:
2947 *
2948 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2949 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2950 *
2951 */
2952static void run_external_diff(const char *pgm,
2953                              const char *name,
2954                              const char *other,
2955                              struct diff_filespec *one,
2956                              struct diff_filespec *two,
2957                              const char *xfrm_msg,
2958                              int complete_rewrite,
2959                              struct diff_options *o)
2960{
2961        struct argv_array argv = ARGV_ARRAY_INIT;
2962        struct argv_array env = ARGV_ARRAY_INIT;
2963        struct diff_queue_struct *q = &diff_queued_diff;
2964
2965        argv_array_push(&argv, pgm);
2966        argv_array_push(&argv, name);
2967
2968        if (one && two) {
2969                add_external_diff_name(&argv, name, one);
2970                if (!other)
2971                        add_external_diff_name(&argv, name, two);
2972                else {
2973                        add_external_diff_name(&argv, other, two);
2974                        argv_array_push(&argv, other);
2975                        argv_array_push(&argv, xfrm_msg);
2976                }
2977        }
2978
2979        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
2980        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
2981
2982        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
2983                die(_("external diff died, stopping at %s"), name);
2984
2985        remove_tempfile();
2986        argv_array_clear(&argv);
2987        argv_array_clear(&env);
2988}
2989
2990static int similarity_index(struct diff_filepair *p)
2991{
2992        return p->score * 100 / MAX_SCORE;
2993}
2994
2995static void fill_metainfo(struct strbuf *msg,
2996                          const char *name,
2997                          const char *other,
2998                          struct diff_filespec *one,
2999                          struct diff_filespec *two,
3000                          struct diff_options *o,
3001                          struct diff_filepair *p,
3002                          int *must_show_header,
3003                          int use_color)
3004{
3005        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3006        const char *reset = diff_get_color(use_color, DIFF_RESET);
3007        const char *line_prefix = diff_line_prefix(o);
3008
3009        *must_show_header = 1;
3010        strbuf_init(msg, PATH_MAX * 2 + 300);
3011        switch (p->status) {
3012        case DIFF_STATUS_COPIED:
3013                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3014                            line_prefix, set, similarity_index(p));
3015                strbuf_addf(msg, "%s\n%s%scopy from ",
3016                            reset,  line_prefix, set);
3017                quote_c_style(name, msg, NULL, 0);
3018                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3019                quote_c_style(other, msg, NULL, 0);
3020                strbuf_addf(msg, "%s\n", reset);
3021                break;
3022        case DIFF_STATUS_RENAMED:
3023                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3024                            line_prefix, set, similarity_index(p));
3025                strbuf_addf(msg, "%s\n%s%srename from ",
3026                            reset, line_prefix, set);
3027                quote_c_style(name, msg, NULL, 0);
3028                strbuf_addf(msg, "%s\n%s%srename to ",
3029                            reset, line_prefix, set);
3030                quote_c_style(other, msg, NULL, 0);
3031                strbuf_addf(msg, "%s\n", reset);
3032                break;
3033        case DIFF_STATUS_MODIFIED:
3034                if (p->score) {
3035                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3036                                    line_prefix,
3037                                    set, similarity_index(p), reset);
3038                        break;
3039                }
3040                /* fallthru */
3041        default:
3042                *must_show_header = 0;
3043        }
3044        if (one && two && hashcmp(one->sha1, two->sha1)) {
3045                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3046
3047                if (DIFF_OPT_TST(o, BINARY)) {
3048                        mmfile_t mf;
3049                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3050                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3051                                abbrev = 40;
3052                }
3053                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3054                            find_unique_abbrev(one->sha1, abbrev));
3055                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3056                if (one->mode == two->mode)
3057                        strbuf_addf(msg, " %06o", one->mode);
3058                strbuf_addf(msg, "%s\n", reset);
3059        }
3060}
3061
3062static void run_diff_cmd(const char *pgm,
3063                         const char *name,
3064                         const char *other,
3065                         const char *attr_path,
3066                         struct diff_filespec *one,
3067                         struct diff_filespec *two,
3068                         struct strbuf *msg,
3069                         struct diff_options *o,
3070                         struct diff_filepair *p)
3071{
3072        const char *xfrm_msg = NULL;
3073        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3074        int must_show_header = 0;
3075
3076
3077        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3078                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3079                if (drv && drv->external)
3080                        pgm = drv->external;
3081        }
3082
3083        if (msg) {
3084                /*
3085                 * don't use colors when the header is intended for an
3086                 * external diff driver
3087                 */
3088                fill_metainfo(msg, name, other, one, two, o, p,
3089                              &must_show_header,
3090                              want_color(o->use_color) && !pgm);
3091                xfrm_msg = msg->len ? msg->buf : NULL;
3092        }
3093
3094        if (pgm) {
3095                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3096                                  complete_rewrite, o);
3097                return;
3098        }
3099        if (one && two)
3100                builtin_diff(name, other ? other : name,
3101                             one, two, xfrm_msg, must_show_header,
3102                             o, complete_rewrite);
3103        else
3104                fprintf(o->file, "* Unmerged path %s\n", name);
3105}
3106
3107static void diff_fill_sha1_info(struct diff_filespec *one)
3108{
3109        if (DIFF_FILE_VALID(one)) {
3110                if (!one->sha1_valid) {
3111                        struct stat st;
3112                        if (one->is_stdin) {
3113                                hashcpy(one->sha1, null_sha1);
3114                                return;
3115                        }
3116                        if (lstat(one->path, &st) < 0)
3117                                die_errno("stat '%s'", one->path);
3118                        if (index_path(one->sha1, one->path, &st, 0))
3119                                die("cannot hash %s", one->path);
3120                }
3121        }
3122        else
3123                hashclr(one->sha1);
3124}
3125
3126static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3127{
3128        /* Strip the prefix but do not molest /dev/null and absolute paths */
3129        if (*namep && **namep != '/') {
3130                *namep += prefix_length;
3131                if (**namep == '/')
3132                        ++*namep;
3133        }
3134        if (*otherp && **otherp != '/') {
3135                *otherp += prefix_length;
3136                if (**otherp == '/')
3137                        ++*otherp;
3138        }
3139}
3140
3141static void run_diff(struct diff_filepair *p, struct diff_options *o)
3142{
3143        const char *pgm = external_diff();
3144        struct strbuf msg;
3145        struct diff_filespec *one = p->one;
3146        struct diff_filespec *two = p->two;
3147        const char *name;
3148        const char *other;
3149        const char *attr_path;
3150
3151        name  = p->one->path;
3152        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3153        attr_path = name;
3154        if (o->prefix_length)
3155                strip_prefix(o->prefix_length, &name, &other);
3156
3157        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3158                pgm = NULL;
3159
3160        if (DIFF_PAIR_UNMERGED(p)) {
3161                run_diff_cmd(pgm, name, NULL, attr_path,
3162                             NULL, NULL, NULL, o, p);
3163                return;
3164        }
3165
3166        diff_fill_sha1_info(one);
3167        diff_fill_sha1_info(two);
3168
3169        if (!pgm &&
3170            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3171            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3172                /*
3173                 * a filepair that changes between file and symlink
3174                 * needs to be split into deletion and creation.
3175                 */
3176                struct diff_filespec *null = alloc_filespec(two->path);
3177                run_diff_cmd(NULL, name, other, attr_path,
3178                             one, null, &msg, o, p);
3179                free(null);
3180                strbuf_release(&msg);
3181
3182                null = alloc_filespec(one->path);
3183                run_diff_cmd(NULL, name, other, attr_path,
3184                             null, two, &msg, o, p);
3185                free(null);
3186        }
3187        else
3188                run_diff_cmd(pgm, name, other, attr_path,
3189                             one, two, &msg, o, p);
3190
3191        strbuf_release(&msg);
3192}
3193
3194static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3195                         struct diffstat_t *diffstat)
3196{
3197        const char *name;
3198        const char *other;
3199
3200        if (DIFF_PAIR_UNMERGED(p)) {
3201                /* unmerged */
3202                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3203                return;
3204        }
3205
3206        name = p->one->path;
3207        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3208
3209        if (o->prefix_length)
3210                strip_prefix(o->prefix_length, &name, &other);
3211
3212        diff_fill_sha1_info(p->one);
3213        diff_fill_sha1_info(p->two);
3214
3215        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3216}
3217
3218static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3219{
3220        const char *name;
3221        const char *other;
3222        const char *attr_path;
3223
3224        if (DIFF_PAIR_UNMERGED(p)) {
3225                /* unmerged */
3226                return;
3227        }
3228
3229        name = p->one->path;
3230        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3231        attr_path = other ? other : name;
3232
3233        if (o->prefix_length)
3234                strip_prefix(o->prefix_length, &name, &other);
3235
3236        diff_fill_sha1_info(p->one);
3237        diff_fill_sha1_info(p->two);
3238
3239        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3240}
3241
3242void diff_setup(struct diff_options *options)
3243{
3244        memcpy(options, &default_diff_options, sizeof(*options));
3245
3246        options->file = stdout;
3247
3248        options->line_termination = '\n';
3249        options->break_opt = -1;
3250        options->rename_limit = -1;
3251        options->dirstat_permille = diff_dirstat_permille_default;
3252        options->context = diff_context_default;
3253        DIFF_OPT_SET(options, RENAME_EMPTY);
3254
3255        /* pathchange left =NULL by default */
3256        options->change = diff_change;
3257        options->add_remove = diff_addremove;
3258        options->use_color = diff_use_color_default;
3259        options->detect_rename = diff_detect_rename_default;
3260        options->xdl_opts |= diff_algorithm;
3261
3262        options->orderfile = diff_order_file_cfg;
3263
3264        if (diff_no_prefix) {
3265                options->a_prefix = options->b_prefix = "";
3266        } else if (!diff_mnemonic_prefix) {
3267                options->a_prefix = "a/";
3268                options->b_prefix = "b/";
3269        }
3270}
3271
3272void diff_setup_done(struct diff_options *options)
3273{
3274        int count = 0;
3275
3276        if (options->set_default)
3277                options->set_default(options);
3278
3279        if (options->output_format & DIFF_FORMAT_NAME)
3280                count++;
3281        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3282                count++;
3283        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3284                count++;
3285        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3286                count++;
3287        if (count > 1)
3288                die("--name-only, --name-status, --check and -s are mutually exclusive");
3289
3290        /*
3291         * Most of the time we can say "there are changes"
3292         * only by checking if there are changed paths, but
3293         * --ignore-whitespace* options force us to look
3294         * inside contents.
3295         */
3296
3297        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3298            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3299            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3300                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3301        else
3302                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3303
3304        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3305                options->detect_rename = DIFF_DETECT_COPY;
3306
3307        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3308                options->prefix = NULL;
3309        if (options->prefix)
3310                options->prefix_length = strlen(options->prefix);
3311        else
3312                options->prefix_length = 0;
3313
3314        if (options->output_format & (DIFF_FORMAT_NAME |
3315                                      DIFF_FORMAT_NAME_STATUS |
3316                                      DIFF_FORMAT_CHECKDIFF |
3317                                      DIFF_FORMAT_NO_OUTPUT))
3318                options->output_format &= ~(DIFF_FORMAT_RAW |
3319                                            DIFF_FORMAT_NUMSTAT |
3320                                            DIFF_FORMAT_DIFFSTAT |
3321                                            DIFF_FORMAT_SHORTSTAT |
3322                                            DIFF_FORMAT_DIRSTAT |
3323                                            DIFF_FORMAT_SUMMARY |
3324                                            DIFF_FORMAT_PATCH);
3325
3326        /*
3327         * These cases always need recursive; we do not drop caller-supplied
3328         * recursive bits for other formats here.
3329         */
3330        if (options->output_format & (DIFF_FORMAT_PATCH |
3331                                      DIFF_FORMAT_NUMSTAT |
3332                                      DIFF_FORMAT_DIFFSTAT |
3333                                      DIFF_FORMAT_SHORTSTAT |
3334                                      DIFF_FORMAT_DIRSTAT |
3335                                      DIFF_FORMAT_SUMMARY |
3336                                      DIFF_FORMAT_CHECKDIFF))
3337                DIFF_OPT_SET(options, RECURSIVE);
3338        /*
3339         * Also pickaxe would not work very well if you do not say recursive
3340         */
3341        if (options->pickaxe)
3342                DIFF_OPT_SET(options, RECURSIVE);
3343        /*
3344         * When patches are generated, submodules diffed against the work tree
3345         * must be checked for dirtiness too so it can be shown in the output
3346         */
3347        if (options->output_format & DIFF_FORMAT_PATCH)
3348                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3349
3350        if (options->detect_rename && options->rename_limit < 0)
3351                options->rename_limit = diff_rename_limit_default;
3352        if (options->setup & DIFF_SETUP_USE_CACHE) {
3353                if (!active_cache)
3354                        /* read-cache does not die even when it fails
3355                         * so it is safe for us to do this here.  Also
3356                         * it does not smudge active_cache or active_nr
3357                         * when it fails, so we do not have to worry about
3358                         * cleaning it up ourselves either.
3359                         */
3360                        read_cache();
3361        }
3362        if (options->abbrev <= 0 || 40 < options->abbrev)
3363                options->abbrev = 40; /* full */
3364
3365        /*
3366         * It does not make sense to show the first hit we happened
3367         * to have found.  It does not make sense not to return with
3368         * exit code in such a case either.
3369         */
3370        if (DIFF_OPT_TST(options, QUICK)) {
3371                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3372                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3373        }
3374
3375        options->diff_path_counter = 0;
3376
3377        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3378                die(_("--follow requires exactly one pathspec"));
3379}
3380
3381static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3382{
3383        char c, *eq;
3384        int len;
3385
3386        if (*arg != '-')
3387                return 0;
3388        c = *++arg;
3389        if (!c)
3390                return 0;
3391        if (c == arg_short) {
3392                c = *++arg;
3393                if (!c)
3394                        return 1;
3395                if (val && isdigit(c)) {
3396                        char *end;
3397                        int n = strtoul(arg, &end, 10);
3398                        if (*end)
3399                                return 0;
3400                        *val = n;
3401                        return 1;
3402                }
3403                return 0;
3404        }
3405        if (c != '-')
3406                return 0;
3407        arg++;
3408        eq = strchrnul(arg, '=');
3409        len = eq - arg;
3410        if (!len || strncmp(arg, arg_long, len))
3411                return 0;
3412        if (*eq) {
3413                int n;
3414                char *end;
3415                if (!isdigit(*++eq))
3416                        return 0;
3417                n = strtoul(eq, &end, 10);
3418                if (*end)
3419                        return 0;
3420                *val = n;
3421        }
3422        return 1;
3423}
3424
3425static int diff_scoreopt_parse(const char *opt);
3426
3427static inline int short_opt(char opt, const char **argv,
3428                            const char **optarg)
3429{
3430        const char *arg = argv[0];
3431        if (arg[0] != '-' || arg[1] != opt)
3432                return 0;
3433        if (arg[2] != '\0') {
3434                *optarg = arg + 2;
3435                return 1;
3436        }
3437        if (!argv[1])
3438                die("Option '%c' requires a value", opt);
3439        *optarg = argv[1];
3440        return 2;
3441}
3442
3443int parse_long_opt(const char *opt, const char **argv,
3444                   const char **optarg)
3445{
3446        const char *arg = argv[0];
3447        if (!skip_prefix(arg, "--", &arg))
3448                return 0;
3449        if (!skip_prefix(arg, opt, &arg))
3450                return 0;
3451        if (*arg == '=') { /* stuck form: --option=value */
3452                *optarg = arg + 1;
3453                return 1;
3454        }
3455        if (*arg != '\0')
3456                return 0;
3457        /* separate form: --option value */
3458        if (!argv[1])
3459                die("Option '--%s' requires a value", opt);
3460        *optarg = argv[1];
3461        return 2;
3462}
3463
3464static int stat_opt(struct diff_options *options, const char **av)
3465{
3466        const char *arg = av[0];
3467        char *end;
3468        int width = options->stat_width;
3469        int name_width = options->stat_name_width;
3470        int graph_width = options->stat_graph_width;
3471        int count = options->stat_count;
3472        int argcount = 1;
3473
3474        if (!skip_prefix(arg, "--stat", &arg))
3475                die("BUG: stat option does not begin with --stat: %s", arg);
3476        end = (char *)arg;
3477
3478        switch (*arg) {
3479        case '-':
3480                if (skip_prefix(arg, "-width", &arg)) {
3481                        if (*arg == '=')
3482                                width = strtoul(arg + 1, &end, 10);
3483                        else if (!*arg && !av[1])
3484                                die("Option '--stat-width' requires a value");
3485                        else if (!*arg) {
3486                                width = strtoul(av[1], &end, 10);
3487                                argcount = 2;
3488                        }
3489                } else if (skip_prefix(arg, "-name-width", &arg)) {
3490                        if (*arg == '=')
3491                                name_width = strtoul(arg + 1, &end, 10);
3492                        else if (!*arg && !av[1])
3493                                die("Option '--stat-name-width' requires a value");
3494                        else if (!*arg) {
3495                                name_width = strtoul(av[1], &end, 10);
3496                                argcount = 2;
3497                        }
3498                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3499                        if (*arg == '=')
3500                                graph_width = strtoul(arg + 1, &end, 10);
3501                        else if (!*arg && !av[1])
3502                                die("Option '--stat-graph-width' requires a value");
3503                        else if (!*arg) {
3504                                graph_width = strtoul(av[1], &end, 10);
3505                                argcount = 2;
3506                        }
3507                } else if (skip_prefix(arg, "-count", &arg)) {
3508                        if (*arg == '=')
3509                                count = strtoul(arg + 1, &end, 10);
3510                        else if (!*arg && !av[1])
3511                                die("Option '--stat-count' requires a value");
3512                        else if (!*arg) {
3513                                count = strtoul(av[1], &end, 10);
3514                                argcount = 2;
3515                        }
3516                }
3517                break;
3518        case '=':
3519                width = strtoul(arg+1, &end, 10);
3520                if (*end == ',')
3521                        name_width = strtoul(end+1, &end, 10);
3522                if (*end == ',')
3523                        count = strtoul(end+1, &end, 10);
3524        }
3525
3526        /* Important! This checks all the error cases! */
3527        if (*end)
3528                return 0;
3529        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3530        options->stat_name_width = name_width;
3531        options->stat_graph_width = graph_width;
3532        options->stat_width = width;
3533        options->stat_count = count;
3534        return argcount;
3535}
3536
3537static int parse_dirstat_opt(struct diff_options *options, const char *params)
3538{
3539        struct strbuf errmsg = STRBUF_INIT;
3540        if (parse_dirstat_params(options, params, &errmsg))
3541                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3542                    errmsg.buf);
3543        strbuf_release(&errmsg);
3544        /*
3545         * The caller knows a dirstat-related option is given from the command
3546         * line; allow it to say "return this_function();"
3547         */
3548        options->output_format |= DIFF_FORMAT_DIRSTAT;
3549        return 1;
3550}
3551
3552static int parse_submodule_opt(struct diff_options *options, const char *value)
3553{
3554        if (parse_submodule_params(options, value))
3555                die(_("Failed to parse --submodule option parameter: '%s'"),
3556                        value);
3557        return 1;
3558}
3559
3560static const char diff_status_letters[] = {
3561        DIFF_STATUS_ADDED,
3562        DIFF_STATUS_COPIED,
3563        DIFF_STATUS_DELETED,
3564        DIFF_STATUS_MODIFIED,
3565        DIFF_STATUS_RENAMED,
3566        DIFF_STATUS_TYPE_CHANGED,
3567        DIFF_STATUS_UNKNOWN,
3568        DIFF_STATUS_UNMERGED,
3569        DIFF_STATUS_FILTER_AON,
3570        DIFF_STATUS_FILTER_BROKEN,
3571        '\0',
3572};
3573
3574static unsigned int filter_bit['Z' + 1];
3575
3576static void prepare_filter_bits(void)
3577{
3578        int i;
3579
3580        if (!filter_bit[DIFF_STATUS_ADDED]) {
3581                for (i = 0; diff_status_letters[i]; i++)
3582                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3583        }
3584}
3585
3586static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3587{
3588        return opt->filter & filter_bit[(int) status];
3589}
3590
3591static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3592{
3593        int i, optch;
3594
3595        prepare_filter_bits();
3596
3597        /*
3598         * If there is a negation e.g. 'd' in the input, and we haven't
3599         * initialized the filter field with another --diff-filter, start
3600         * from full set of bits, except for AON.
3601         */
3602        if (!opt->filter) {
3603                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3604                        if (optch < 'a' || 'z' < optch)
3605                                continue;
3606                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3607                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3608                        break;
3609                }
3610        }
3611
3612        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3613                unsigned int bit;
3614                int negate;
3615
3616                if ('a' <= optch && optch <= 'z') {
3617                        negate = 1;
3618                        optch = toupper(optch);
3619                } else {
3620                        negate = 0;
3621                }
3622
3623                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3624                if (!bit)
3625                        return optarg[i];
3626                if (negate)
3627                        opt->filter &= ~bit;
3628                else
3629                        opt->filter |= bit;
3630        }
3631        return 0;
3632}
3633
3634static void enable_patch_output(int *fmt) {
3635        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3636        *fmt |= DIFF_FORMAT_PATCH;
3637}
3638
3639int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3640{
3641        const char *arg = av[0];
3642        const char *optarg;
3643        int argcount;
3644
3645        /* Output format options */
3646        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3647            || opt_arg(arg, 'U', "unified", &options->context))
3648                enable_patch_output(&options->output_format);
3649        else if (!strcmp(arg, "--raw"))
3650                options->output_format |= DIFF_FORMAT_RAW;
3651        else if (!strcmp(arg, "--patch-with-raw")) {
3652                enable_patch_output(&options->output_format);
3653                options->output_format |= DIFF_FORMAT_RAW;
3654        } else if (!strcmp(arg, "--numstat"))
3655                options->output_format |= DIFF_FORMAT_NUMSTAT;
3656        else if (!strcmp(arg, "--shortstat"))
3657                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3658        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3659                return parse_dirstat_opt(options, "");
3660        else if (skip_prefix(arg, "-X", &arg))
3661                return parse_dirstat_opt(options, arg);
3662        else if (skip_prefix(arg, "--dirstat=", &arg))
3663                return parse_dirstat_opt(options, arg);
3664        else if (!strcmp(arg, "--cumulative"))
3665                return parse_dirstat_opt(options, "cumulative");
3666        else if (!strcmp(arg, "--dirstat-by-file"))
3667                return parse_dirstat_opt(options, "files");
3668        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3669                parse_dirstat_opt(options, "files");
3670                return parse_dirstat_opt(options, arg);
3671        }
3672        else if (!strcmp(arg, "--check"))
3673                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3674        else if (!strcmp(arg, "--summary"))
3675                options->output_format |= DIFF_FORMAT_SUMMARY;
3676        else if (!strcmp(arg, "--patch-with-stat")) {
3677                enable_patch_output(&options->output_format);
3678                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3679        } else if (!strcmp(arg, "--name-only"))
3680                options->output_format |= DIFF_FORMAT_NAME;
3681        else if (!strcmp(arg, "--name-status"))
3682                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3683        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3684                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3685        else if (starts_with(arg, "--stat"))
3686                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3687                return stat_opt(options, av);
3688
3689        /* renames options */
3690        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3691                 !strcmp(arg, "--break-rewrites")) {
3692                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3693                        return error("invalid argument to -B: %s", arg+2);
3694        }
3695        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3696                 !strcmp(arg, "--find-renames")) {
3697                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3698                        return error("invalid argument to -M: %s", arg+2);
3699                options->detect_rename = DIFF_DETECT_RENAME;
3700        }
3701        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3702                options->irreversible_delete = 1;
3703        }
3704        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3705                 !strcmp(arg, "--find-copies")) {
3706                if (options->detect_rename == DIFF_DETECT_COPY)
3707                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3708                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3709                        return error("invalid argument to -C: %s", arg+2);
3710                options->detect_rename = DIFF_DETECT_COPY;
3711        }
3712        else if (!strcmp(arg, "--no-renames"))
3713                options->detect_rename = 0;
3714        else if (!strcmp(arg, "--rename-empty"))
3715                DIFF_OPT_SET(options, RENAME_EMPTY);
3716        else if (!strcmp(arg, "--no-rename-empty"))
3717                DIFF_OPT_CLR(options, RENAME_EMPTY);
3718        else if (!strcmp(arg, "--relative"))
3719                DIFF_OPT_SET(options, RELATIVE_NAME);
3720        else if (skip_prefix(arg, "--relative=", &arg)) {
3721                DIFF_OPT_SET(options, RELATIVE_NAME);
3722                options->prefix = arg;
3723        }
3724
3725        /* xdiff options */
3726        else if (!strcmp(arg, "--minimal"))
3727                DIFF_XDL_SET(options, NEED_MINIMAL);
3728        else if (!strcmp(arg, "--no-minimal"))
3729                DIFF_XDL_CLR(options, NEED_MINIMAL);
3730        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3731                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3732        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3733                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3734        else if (!strcmp(arg, "--ignore-space-at-eol"))
3735                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3736        else if (!strcmp(arg, "--ignore-blank-lines"))
3737                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3738        else if (!strcmp(arg, "--patience"))
3739                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3740        else if (!strcmp(arg, "--histogram"))
3741                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3742        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3743                long value = parse_algorithm_value(optarg);
3744                if (value < 0)
3745                        return error("option diff-algorithm accepts \"myers\", "
3746                                     "\"minimal\", \"patience\" and \"histogram\"");
3747                /* clear out previous settings */
3748                DIFF_XDL_CLR(options, NEED_MINIMAL);
3749                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3750                options->xdl_opts |= value;
3751                return argcount;
3752        }
3753
3754        /* flags options */
3755        else if (!strcmp(arg, "--binary")) {
3756                enable_patch_output(&options->output_format);
3757                DIFF_OPT_SET(options, BINARY);
3758        }
3759        else if (!strcmp(arg, "--full-index"))
3760                DIFF_OPT_SET(options, FULL_INDEX);
3761        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3762                DIFF_OPT_SET(options, TEXT);
3763        else if (!strcmp(arg, "-R"))
3764                DIFF_OPT_SET(options, REVERSE_DIFF);
3765        else if (!strcmp(arg, "--find-copies-harder"))
3766                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3767        else if (!strcmp(arg, "--follow"))
3768                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3769        else if (!strcmp(arg, "--no-follow"))
3770                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3771        else if (!strcmp(arg, "--color"))
3772                options->use_color = 1;
3773        else if (skip_prefix(arg, "--color=", &arg)) {
3774                int value = git_config_colorbool(NULL, arg);
3775                if (value < 0)
3776                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3777                options->use_color = value;
3778        }
3779        else if (!strcmp(arg, "--no-color"))
3780                options->use_color = 0;
3781        else if (!strcmp(arg, "--color-words")) {
3782                options->use_color = 1;
3783                options->word_diff = DIFF_WORDS_COLOR;
3784        }
3785        else if (skip_prefix(arg, "--color-words=", &arg)) {
3786                options->use_color = 1;
3787                options->word_diff = DIFF_WORDS_COLOR;
3788                options->word_regex = arg;
3789        }
3790        else if (!strcmp(arg, "--word-diff")) {
3791                if (options->word_diff == DIFF_WORDS_NONE)
3792                        options->word_diff = DIFF_WORDS_PLAIN;
3793        }
3794        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3795                if (!strcmp(arg, "plain"))
3796                        options->word_diff = DIFF_WORDS_PLAIN;
3797                else if (!strcmp(arg, "color")) {
3798                        options->use_color = 1;
3799                        options->word_diff = DIFF_WORDS_COLOR;
3800                }
3801                else if (!strcmp(arg, "porcelain"))
3802                        options->word_diff = DIFF_WORDS_PORCELAIN;
3803                else if (!strcmp(arg, "none"))
3804                        options->word_diff = DIFF_WORDS_NONE;
3805                else
3806                        die("bad --word-diff argument: %s", arg);
3807        }
3808        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3809                if (options->word_diff == DIFF_WORDS_NONE)
3810                        options->word_diff = DIFF_WORDS_PLAIN;
3811                options->word_regex = optarg;
3812                return argcount;
3813        }
3814        else if (!strcmp(arg, "--exit-code"))
3815                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3816        else if (!strcmp(arg, "--quiet"))
3817                DIFF_OPT_SET(options, QUICK);
3818        else if (!strcmp(arg, "--ext-diff"))
3819                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3820        else if (!strcmp(arg, "--no-ext-diff"))
3821                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3822        else if (!strcmp(arg, "--textconv"))
3823                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3824        else if (!strcmp(arg, "--no-textconv"))
3825                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3826        else if (!strcmp(arg, "--ignore-submodules")) {
3827                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3828                handle_ignore_submodules_arg(options, "all");
3829        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3830                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3831                handle_ignore_submodules_arg(options, arg);
3832        } else if (!strcmp(arg, "--submodule"))
3833                DIFF_OPT_SET(options, SUBMODULE_LOG);
3834        else if (skip_prefix(arg, "--submodule=", &arg))
3835                return parse_submodule_opt(options, arg);
3836
3837        /* misc options */
3838        else if (!strcmp(arg, "-z"))
3839                options->line_termination = 0;
3840        else if ((argcount = short_opt('l', av, &optarg))) {
3841                options->rename_limit = strtoul(optarg, NULL, 10);
3842                return argcount;
3843        }
3844        else if ((argcount = short_opt('S', av, &optarg))) {
3845                options->pickaxe = optarg;
3846                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3847                return argcount;
3848        } else if ((argcount = short_opt('G', av, &optarg))) {
3849                options->pickaxe = optarg;
3850                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3851                return argcount;
3852        }
3853        else if (!strcmp(arg, "--pickaxe-all"))
3854                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3855        else if (!strcmp(arg, "--pickaxe-regex"))
3856                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3857        else if ((argcount = short_opt('O', av, &optarg))) {
3858                options->orderfile = optarg;
3859                return argcount;
3860        }
3861        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3862                int offending = parse_diff_filter_opt(optarg, options);
3863                if (offending)
3864                        die("unknown change class '%c' in --diff-filter=%s",
3865                            offending, optarg);
3866                return argcount;
3867        }
3868        else if (!strcmp(arg, "--abbrev"))
3869                options->abbrev = DEFAULT_ABBREV;
3870        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3871                options->abbrev = strtoul(arg, NULL, 10);
3872                if (options->abbrev < MINIMUM_ABBREV)
3873                        options->abbrev = MINIMUM_ABBREV;
3874                else if (40 < options->abbrev)
3875                        options->abbrev = 40;
3876        }
3877        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3878                options->a_prefix = optarg;
3879                return argcount;
3880        }
3881        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3882                options->b_prefix = optarg;
3883                return argcount;
3884        }
3885        else if (!strcmp(arg, "--no-prefix"))
3886                options->a_prefix = options->b_prefix = "";
3887        else if (opt_arg(arg, '\0', "inter-hunk-context",
3888                         &options->interhunkcontext))
3889                ;
3890        else if (!strcmp(arg, "-W"))
3891                DIFF_OPT_SET(options, FUNCCONTEXT);
3892        else if (!strcmp(arg, "--function-context"))
3893                DIFF_OPT_SET(options, FUNCCONTEXT);
3894        else if (!strcmp(arg, "--no-function-context"))
3895                DIFF_OPT_CLR(options, FUNCCONTEXT);
3896        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3897                options->file = fopen(optarg, "w");
3898                if (!options->file)
3899                        die_errno("Could not open '%s'", optarg);
3900                options->close_file = 1;
3901                return argcount;
3902        } else
3903                return 0;
3904        return 1;
3905}
3906
3907int parse_rename_score(const char **cp_p)
3908{
3909        unsigned long num, scale;
3910        int ch, dot;
3911        const char *cp = *cp_p;
3912
3913        num = 0;
3914        scale = 1;
3915        dot = 0;
3916        for (;;) {
3917                ch = *cp;
3918                if ( !dot && ch == '.' ) {
3919                        scale = 1;
3920                        dot = 1;
3921                } else if ( ch == '%' ) {
3922                        scale = dot ? scale*100 : 100;
3923                        cp++;   /* % is always at the end */
3924                        break;
3925                } else if ( ch >= '0' && ch <= '9' ) {
3926                        if ( scale < 100000 ) {
3927                                scale *= 10;
3928                                num = (num*10) + (ch-'0');
3929                        }
3930                } else {
3931                        break;
3932                }
3933                cp++;
3934        }
3935        *cp_p = cp;
3936
3937        /* user says num divided by scale and we say internally that
3938         * is MAX_SCORE * num / scale.
3939         */
3940        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3941}
3942
3943static int diff_scoreopt_parse(const char *opt)
3944{
3945        int opt1, opt2, cmd;
3946
3947        if (*opt++ != '-')
3948                return -1;
3949        cmd = *opt++;
3950        if (cmd == '-') {
3951                /* convert the long-form arguments into short-form versions */
3952                if (skip_prefix(opt, "break-rewrites", &opt)) {
3953                        if (*opt == 0 || *opt++ == '=')
3954                                cmd = 'B';
3955                } else if (skip_prefix(opt, "find-copies", &opt)) {
3956                        if (*opt == 0 || *opt++ == '=')
3957                                cmd = 'C';
3958                } else if (skip_prefix(opt, "find-renames", &opt)) {
3959                        if (*opt == 0 || *opt++ == '=')
3960                                cmd = 'M';
3961                }
3962        }
3963        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3964                return -1; /* that is not a -M, -C, or -B option */
3965
3966        opt1 = parse_rename_score(&opt);
3967        if (cmd != 'B')
3968                opt2 = 0;
3969        else {
3970                if (*opt == 0)
3971                        opt2 = 0;
3972                else if (*opt != '/')
3973                        return -1; /* we expect -B80/99 or -B80 */
3974                else {
3975                        opt++;
3976                        opt2 = parse_rename_score(&opt);
3977                }
3978        }
3979        if (*opt != 0)
3980                return -1;
3981        return opt1 | (opt2 << 16);
3982}
3983
3984struct diff_queue_struct diff_queued_diff;
3985
3986void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3987{
3988        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
3989        queue->queue[queue->nr++] = dp;
3990}
3991
3992struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3993                                 struct diff_filespec *one,
3994                                 struct diff_filespec *two)
3995{
3996        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3997        dp->one = one;
3998        dp->two = two;
3999        if (queue)
4000                diff_q(queue, dp);
4001        return dp;
4002}
4003
4004void diff_free_filepair(struct diff_filepair *p)
4005{
4006        free_filespec(p->one);
4007        free_filespec(p->two);
4008        free(p);
4009}
4010
4011/* This is different from find_unique_abbrev() in that
4012 * it stuffs the result with dots for alignment.
4013 */
4014const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4015{
4016        int abblen;
4017        const char *abbrev;
4018        if (len == 40)
4019                return sha1_to_hex(sha1);
4020
4021        abbrev = find_unique_abbrev(sha1, len);
4022        abblen = strlen(abbrev);
4023        if (abblen < 37) {
4024                static char hex[41];
4025                if (len < abblen && abblen <= len + 2)
4026                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
4027                else
4028                        sprintf(hex, "%s...", abbrev);
4029                return hex;
4030        }
4031        return sha1_to_hex(sha1);
4032}
4033
4034static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4035{
4036        int line_termination = opt->line_termination;
4037        int inter_name_termination = line_termination ? '\t' : '\0';
4038
4039        fprintf(opt->file, "%s", diff_line_prefix(opt));
4040        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4041                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4042                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4043                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4044        }
4045        if (p->score) {
4046                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4047                        inter_name_termination);
4048        } else {
4049                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4050        }
4051
4052        if (p->status == DIFF_STATUS_COPIED ||
4053            p->status == DIFF_STATUS_RENAMED) {
4054                const char *name_a, *name_b;
4055                name_a = p->one->path;
4056                name_b = p->two->path;
4057                strip_prefix(opt->prefix_length, &name_a, &name_b);
4058                write_name_quoted(name_a, opt->file, inter_name_termination);
4059                write_name_quoted(name_b, opt->file, line_termination);
4060        } else {
4061                const char *name_a, *name_b;
4062                name_a = p->one->mode ? p->one->path : p->two->path;
4063                name_b = NULL;
4064                strip_prefix(opt->prefix_length, &name_a, &name_b);
4065                write_name_quoted(name_a, opt->file, line_termination);
4066        }
4067}
4068
4069int diff_unmodified_pair(struct diff_filepair *p)
4070{
4071        /* This function is written stricter than necessary to support
4072         * the currently implemented transformers, but the idea is to
4073         * let transformers to produce diff_filepairs any way they want,
4074         * and filter and clean them up here before producing the output.
4075         */
4076        struct diff_filespec *one = p->one, *two = p->two;
4077
4078        if (DIFF_PAIR_UNMERGED(p))
4079                return 0; /* unmerged is interesting */
4080
4081        /* deletion, addition, mode or type change
4082         * and rename are all interesting.
4083         */
4084        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4085            DIFF_PAIR_MODE_CHANGED(p) ||
4086            strcmp(one->path, two->path))
4087                return 0;
4088
4089        /* both are valid and point at the same path.  that is, we are
4090         * dealing with a change.
4091         */
4092        if (one->sha1_valid && two->sha1_valid &&
4093            !hashcmp(one->sha1, two->sha1) &&
4094            !one->dirty_submodule && !two->dirty_submodule)
4095                return 1; /* no change */
4096        if (!one->sha1_valid && !two->sha1_valid)
4097                return 1; /* both look at the same file on the filesystem. */
4098        return 0;
4099}
4100
4101static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4102{
4103        if (diff_unmodified_pair(p))
4104                return;
4105
4106        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4107            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4108                return; /* no tree diffs in patch format */
4109
4110        run_diff(p, o);
4111}
4112
4113static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4114                            struct diffstat_t *diffstat)
4115{
4116        if (diff_unmodified_pair(p))
4117                return;
4118
4119        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4120            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4121                return; /* no useful stat for tree diffs */
4122
4123        run_diffstat(p, o, diffstat);
4124}
4125
4126static void diff_flush_checkdiff(struct diff_filepair *p,
4127                struct diff_options *o)
4128{
4129        if (diff_unmodified_pair(p))
4130                return;
4131
4132        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4133            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4134                return; /* nothing to check in tree diffs */
4135
4136        run_checkdiff(p, o);
4137}
4138
4139int diff_queue_is_empty(void)
4140{
4141        struct diff_queue_struct *q = &diff_queued_diff;
4142        int i;
4143        for (i = 0; i < q->nr; i++)
4144                if (!diff_unmodified_pair(q->queue[i]))
4145                        return 0;
4146        return 1;
4147}
4148
4149#if DIFF_DEBUG
4150void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4151{
4152        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4153                x, one ? one : "",
4154                s->path,
4155                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4156                s->mode,
4157                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4158        fprintf(stderr, "queue[%d] %s size %lu\n",
4159                x, one ? one : "",
4160                s->size);
4161}
4162
4163void diff_debug_filepair(const struct diff_filepair *p, int i)
4164{
4165        diff_debug_filespec(p->one, i, "one");
4166        diff_debug_filespec(p->two, i, "two");
4167        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4168                p->score, p->status ? p->status : '?',
4169                p->one->rename_used, p->broken_pair);
4170}
4171
4172void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4173{
4174        int i;
4175        if (msg)
4176                fprintf(stderr, "%s\n", msg);
4177        fprintf(stderr, "q->nr = %d\n", q->nr);
4178        for (i = 0; i < q->nr; i++) {
4179                struct diff_filepair *p = q->queue[i];
4180                diff_debug_filepair(p, i);
4181        }
4182}
4183#endif
4184
4185static void diff_resolve_rename_copy(void)
4186{
4187        int i;
4188        struct diff_filepair *p;
4189        struct diff_queue_struct *q = &diff_queued_diff;
4190
4191        diff_debug_queue("resolve-rename-copy", q);
4192
4193        for (i = 0; i < q->nr; i++) {
4194                p = q->queue[i];
4195                p->status = 0; /* undecided */
4196                if (DIFF_PAIR_UNMERGED(p))
4197                        p->status = DIFF_STATUS_UNMERGED;
4198                else if (!DIFF_FILE_VALID(p->one))
4199                        p->status = DIFF_STATUS_ADDED;
4200                else if (!DIFF_FILE_VALID(p->two))
4201                        p->status = DIFF_STATUS_DELETED;
4202                else if (DIFF_PAIR_TYPE_CHANGED(p))
4203                        p->status = DIFF_STATUS_TYPE_CHANGED;
4204
4205                /* from this point on, we are dealing with a pair
4206                 * whose both sides are valid and of the same type, i.e.
4207                 * either in-place edit or rename/copy edit.
4208                 */
4209                else if (DIFF_PAIR_RENAME(p)) {
4210                        /*
4211                         * A rename might have re-connected a broken
4212                         * pair up, causing the pathnames to be the
4213                         * same again. If so, that's not a rename at
4214                         * all, just a modification..
4215                         *
4216                         * Otherwise, see if this source was used for
4217                         * multiple renames, in which case we decrement
4218                         * the count, and call it a copy.
4219                         */
4220                        if (!strcmp(p->one->path, p->two->path))
4221                                p->status = DIFF_STATUS_MODIFIED;
4222                        else if (--p->one->rename_used > 0)
4223                                p->status = DIFF_STATUS_COPIED;
4224                        else
4225                                p->status = DIFF_STATUS_RENAMED;
4226                }
4227                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4228                         p->one->mode != p->two->mode ||
4229                         p->one->dirty_submodule ||
4230                         p->two->dirty_submodule ||
4231                         is_null_sha1(p->one->sha1))
4232                        p->status = DIFF_STATUS_MODIFIED;
4233                else {
4234                        /* This is a "no-change" entry and should not
4235                         * happen anymore, but prepare for broken callers.
4236                         */
4237                        error("feeding unmodified %s to diffcore",
4238                              p->one->path);
4239                        p->status = DIFF_STATUS_UNKNOWN;
4240                }
4241        }
4242        diff_debug_queue("resolve-rename-copy done", q);
4243}
4244
4245static int check_pair_status(struct diff_filepair *p)
4246{
4247        switch (p->status) {
4248        case DIFF_STATUS_UNKNOWN:
4249                return 0;
4250        case 0:
4251                die("internal error in diff-resolve-rename-copy");
4252        default:
4253                return 1;
4254        }
4255}
4256
4257static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4258{
4259        int fmt = opt->output_format;
4260
4261        if (fmt & DIFF_FORMAT_CHECKDIFF)
4262                diff_flush_checkdiff(p, opt);
4263        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4264                diff_flush_raw(p, opt);
4265        else if (fmt & DIFF_FORMAT_NAME) {
4266                const char *name_a, *name_b;
4267                name_a = p->two->path;
4268                name_b = NULL;
4269                strip_prefix(opt->prefix_length, &name_a, &name_b);
4270                write_name_quoted(name_a, opt->file, opt->line_termination);
4271        }
4272}
4273
4274static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4275{
4276        if (fs->mode)
4277                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4278        else
4279                fprintf(file, " %s ", newdelete);
4280        write_name_quoted(fs->path, file, '\n');
4281}
4282
4283
4284static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4285                const char *line_prefix)
4286{
4287        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4288                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4289                        p->two->mode, show_name ? ' ' : '\n');
4290                if (show_name) {
4291                        write_name_quoted(p->two->path, file, '\n');
4292                }
4293        }
4294}
4295
4296static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4297                        const char *line_prefix)
4298{
4299        char *names = pprint_rename(p->one->path, p->two->path);
4300
4301        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4302        free(names);
4303        show_mode_change(file, p, 0, line_prefix);
4304}
4305
4306static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4307{
4308        FILE *file = opt->file;
4309        const char *line_prefix = diff_line_prefix(opt);
4310
4311        switch(p->status) {
4312        case DIFF_STATUS_DELETED:
4313                fputs(line_prefix, file);
4314                show_file_mode_name(file, "delete", p->one);
4315                break;
4316        case DIFF_STATUS_ADDED:
4317                fputs(line_prefix, file);
4318                show_file_mode_name(file, "create", p->two);
4319                break;
4320        case DIFF_STATUS_COPIED:
4321                fputs(line_prefix, file);
4322                show_rename_copy(file, "copy", p, line_prefix);
4323                break;
4324        case DIFF_STATUS_RENAMED:
4325                fputs(line_prefix, file);
4326                show_rename_copy(file, "rename", p, line_prefix);
4327                break;
4328        default:
4329                if (p->score) {
4330                        fprintf(file, "%s rewrite ", line_prefix);
4331                        write_name_quoted(p->two->path, file, ' ');
4332                        fprintf(file, "(%d%%)\n", similarity_index(p));
4333                }
4334                show_mode_change(file, p, !p->score, line_prefix);
4335                break;
4336        }
4337}
4338
4339struct patch_id_t {
4340        git_SHA_CTX *ctx;
4341        int patchlen;
4342};
4343
4344static int remove_space(char *line, int len)
4345{
4346        int i;
4347        char *dst = line;
4348        unsigned char c;
4349
4350        for (i = 0; i < len; i++)
4351                if (!isspace((c = line[i])))
4352                        *dst++ = c;
4353
4354        return dst - line;
4355}
4356
4357static void patch_id_consume(void *priv, char *line, unsigned long len)
4358{
4359        struct patch_id_t *data = priv;
4360        int new_len;
4361
4362        /* Ignore line numbers when computing the SHA1 of the patch */
4363        if (starts_with(line, "@@ -"))
4364                return;
4365
4366        new_len = remove_space(line, len);
4367
4368        git_SHA1_Update(data->ctx, line, new_len);
4369        data->patchlen += new_len;
4370}
4371
4372/* returns 0 upon success, and writes result into sha1 */
4373static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4374{
4375        struct diff_queue_struct *q = &diff_queued_diff;
4376        int i;
4377        git_SHA_CTX ctx;
4378        struct patch_id_t data;
4379        char buffer[PATH_MAX * 4 + 20];
4380
4381        git_SHA1_Init(&ctx);
4382        memset(&data, 0, sizeof(struct patch_id_t));
4383        data.ctx = &ctx;
4384
4385        for (i = 0; i < q->nr; i++) {
4386                xpparam_t xpp;
4387                xdemitconf_t xecfg;
4388                mmfile_t mf1, mf2;
4389                struct diff_filepair *p = q->queue[i];
4390                int len1, len2;
4391
4392                memset(&xpp, 0, sizeof(xpp));
4393                memset(&xecfg, 0, sizeof(xecfg));
4394                if (p->status == 0)
4395                        return error("internal diff status error");
4396                if (p->status == DIFF_STATUS_UNKNOWN)
4397                        continue;
4398                if (diff_unmodified_pair(p))
4399                        continue;
4400                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4401                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4402                        continue;
4403                if (DIFF_PAIR_UNMERGED(p))
4404                        continue;
4405
4406                diff_fill_sha1_info(p->one);
4407                diff_fill_sha1_info(p->two);
4408                if (fill_mmfile(&mf1, p->one) < 0 ||
4409                                fill_mmfile(&mf2, p->two) < 0)
4410                        return error("unable to read files to diff");
4411
4412                len1 = remove_space(p->one->path, strlen(p->one->path));
4413                len2 = remove_space(p->two->path, strlen(p->two->path));
4414                if (p->one->mode == 0)
4415                        len1 = snprintf(buffer, sizeof(buffer),
4416                                        "diff--gita/%.*sb/%.*s"
4417                                        "newfilemode%06o"
4418                                        "---/dev/null"
4419                                        "+++b/%.*s",
4420                                        len1, p->one->path,
4421                                        len2, p->two->path,
4422                                        p->two->mode,
4423                                        len2, p->two->path);
4424                else if (p->two->mode == 0)
4425                        len1 = snprintf(buffer, sizeof(buffer),
4426                                        "diff--gita/%.*sb/%.*s"
4427                                        "deletedfilemode%06o"
4428                                        "---a/%.*s"
4429                                        "+++/dev/null",
4430                                        len1, p->one->path,
4431                                        len2, p->two->path,
4432                                        p->one->mode,
4433                                        len1, p->one->path);
4434                else
4435                        len1 = snprintf(buffer, sizeof(buffer),
4436                                        "diff--gita/%.*sb/%.*s"
4437                                        "---a/%.*s"
4438                                        "+++b/%.*s",
4439                                        len1, p->one->path,
4440                                        len2, p->two->path,
4441                                        len1, p->one->path,
4442                                        len2, p->two->path);
4443                git_SHA1_Update(&ctx, buffer, len1);
4444
4445                if (diff_filespec_is_binary(p->one) ||
4446                    diff_filespec_is_binary(p->two)) {
4447                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4448                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4449                        continue;
4450                }
4451
4452                xpp.flags = 0;
4453                xecfg.ctxlen = 3;
4454                xecfg.flags = 0;
4455                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4456                              &xpp, &xecfg);
4457        }
4458
4459        git_SHA1_Final(sha1, &ctx);
4460        return 0;
4461}
4462
4463int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4464{
4465        struct diff_queue_struct *q = &diff_queued_diff;
4466        int i;
4467        int result = diff_get_patch_id(options, sha1);
4468
4469        for (i = 0; i < q->nr; i++)
4470                diff_free_filepair(q->queue[i]);
4471
4472        free(q->queue);
4473        DIFF_QUEUE_CLEAR(q);
4474
4475        return result;
4476}
4477
4478static int is_summary_empty(const struct diff_queue_struct *q)
4479{
4480        int i;
4481
4482        for (i = 0; i < q->nr; i++) {
4483                const struct diff_filepair *p = q->queue[i];
4484
4485                switch (p->status) {
4486                case DIFF_STATUS_DELETED:
4487                case DIFF_STATUS_ADDED:
4488                case DIFF_STATUS_COPIED:
4489                case DIFF_STATUS_RENAMED:
4490                        return 0;
4491                default:
4492                        if (p->score)
4493                                return 0;
4494                        if (p->one->mode && p->two->mode &&
4495                            p->one->mode != p->two->mode)
4496                                return 0;
4497                        break;
4498                }
4499        }
4500        return 1;
4501}
4502
4503static const char rename_limit_warning[] =
4504"inexact rename detection was skipped due to too many files.";
4505
4506static const char degrade_cc_to_c_warning[] =
4507"only found copies from modified paths due to too many files.";
4508
4509static const char rename_limit_advice[] =
4510"you may want to set your %s variable to at least "
4511"%d and retry the command.";
4512
4513void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4514{
4515        if (degraded_cc)
4516                warning(degrade_cc_to_c_warning);
4517        else if (needed)
4518                warning(rename_limit_warning);
4519        else
4520                return;
4521        if (0 < needed && needed < 32767)
4522                warning(rename_limit_advice, varname, needed);
4523}
4524
4525void diff_flush(struct diff_options *options)
4526{
4527        struct diff_queue_struct *q = &diff_queued_diff;
4528        int i, output_format = options->output_format;
4529        int separator = 0;
4530        int dirstat_by_line = 0;
4531
4532        /*
4533         * Order: raw, stat, summary, patch
4534         * or:    name/name-status/checkdiff (other bits clear)
4535         */
4536        if (!q->nr)
4537                goto free_queue;
4538
4539        if (output_format & (DIFF_FORMAT_RAW |
4540                             DIFF_FORMAT_NAME |
4541                             DIFF_FORMAT_NAME_STATUS |
4542                             DIFF_FORMAT_CHECKDIFF)) {
4543                for (i = 0; i < q->nr; i++) {
4544                        struct diff_filepair *p = q->queue[i];
4545                        if (check_pair_status(p))
4546                                flush_one_pair(p, options);
4547                }
4548                separator++;
4549        }
4550
4551        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4552                dirstat_by_line = 1;
4553
4554        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4555            dirstat_by_line) {
4556                struct diffstat_t diffstat;
4557
4558                memset(&diffstat, 0, sizeof(struct diffstat_t));
4559                for (i = 0; i < q->nr; i++) {
4560                        struct diff_filepair *p = q->queue[i];
4561                        if (check_pair_status(p))
4562                                diff_flush_stat(p, options, &diffstat);
4563                }
4564                if (output_format & DIFF_FORMAT_NUMSTAT)
4565                        show_numstat(&diffstat, options);
4566                if (output_format & DIFF_FORMAT_DIFFSTAT)
4567                        show_stats(&diffstat, options);
4568                if (output_format & DIFF_FORMAT_SHORTSTAT)
4569                        show_shortstats(&diffstat, options);
4570                if (output_format & DIFF_FORMAT_DIRSTAT)
4571                        show_dirstat_by_line(&diffstat, options);
4572                free_diffstat_info(&diffstat);
4573                separator++;
4574        }
4575        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4576                show_dirstat(options);
4577
4578        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4579                for (i = 0; i < q->nr; i++) {
4580                        diff_summary(options, q->queue[i]);
4581                }
4582                separator++;
4583        }
4584
4585        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4586            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4587            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4588                /*
4589                 * run diff_flush_patch for the exit status. setting
4590                 * options->file to /dev/null should be safe, because we
4591                 * aren't supposed to produce any output anyway.
4592                 */
4593                if (options->close_file)
4594                        fclose(options->file);
4595                options->file = fopen("/dev/null", "w");
4596                if (!options->file)
4597                        die_errno("Could not open /dev/null");
4598                options->close_file = 1;
4599                for (i = 0; i < q->nr; i++) {
4600                        struct diff_filepair *p = q->queue[i];
4601                        if (check_pair_status(p))
4602                                diff_flush_patch(p, options);
4603                        if (options->found_changes)
4604                                break;
4605                }
4606        }
4607
4608        if (output_format & DIFF_FORMAT_PATCH) {
4609                if (separator) {
4610                        fprintf(options->file, "%s%c",
4611                                diff_line_prefix(options),
4612                                options->line_termination);
4613                        if (options->stat_sep) {
4614                                /* attach patch instead of inline */
4615                                fputs(options->stat_sep, options->file);
4616                        }
4617                }
4618
4619                for (i = 0; i < q->nr; i++) {
4620                        struct diff_filepair *p = q->queue[i];
4621                        if (check_pair_status(p))
4622                                diff_flush_patch(p, options);
4623                }
4624        }
4625
4626        if (output_format & DIFF_FORMAT_CALLBACK)
4627                options->format_callback(q, options, options->format_callback_data);
4628
4629        for (i = 0; i < q->nr; i++)
4630                diff_free_filepair(q->queue[i]);
4631free_queue:
4632        free(q->queue);
4633        DIFF_QUEUE_CLEAR(q);
4634        if (options->close_file)
4635                fclose(options->file);
4636
4637        /*
4638         * Report the content-level differences with HAS_CHANGES;
4639         * diff_addremove/diff_change does not set the bit when
4640         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4641         */
4642        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4643                if (options->found_changes)
4644                        DIFF_OPT_SET(options, HAS_CHANGES);
4645                else
4646                        DIFF_OPT_CLR(options, HAS_CHANGES);
4647        }
4648}
4649
4650static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4651{
4652        return (((p->status == DIFF_STATUS_MODIFIED) &&
4653                 ((p->score &&
4654                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4655                  (!p->score &&
4656                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4657                ((p->status != DIFF_STATUS_MODIFIED) &&
4658                 filter_bit_tst(p->status, options)));
4659}
4660
4661static void diffcore_apply_filter(struct diff_options *options)
4662{
4663        int i;
4664        struct diff_queue_struct *q = &diff_queued_diff;
4665        struct diff_queue_struct outq;
4666
4667        DIFF_QUEUE_CLEAR(&outq);
4668
4669        if (!options->filter)
4670                return;
4671
4672        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4673                int found;
4674                for (i = found = 0; !found && i < q->nr; i++) {
4675                        if (match_filter(options, q->queue[i]))
4676                                found++;
4677                }
4678                if (found)
4679                        return;
4680
4681                /* otherwise we will clear the whole queue
4682                 * by copying the empty outq at the end of this
4683                 * function, but first clear the current entries
4684                 * in the queue.
4685                 */
4686                for (i = 0; i < q->nr; i++)
4687                        diff_free_filepair(q->queue[i]);
4688        }
4689        else {
4690                /* Only the matching ones */
4691                for (i = 0; i < q->nr; i++) {
4692                        struct diff_filepair *p = q->queue[i];
4693                        if (match_filter(options, p))
4694                                diff_q(&outq, p);
4695                        else
4696                                diff_free_filepair(p);
4697                }
4698        }
4699        free(q->queue);
4700        *q = outq;
4701}
4702
4703/* Check whether two filespecs with the same mode and size are identical */
4704static int diff_filespec_is_identical(struct diff_filespec *one,
4705                                      struct diff_filespec *two)
4706{
4707        if (S_ISGITLINK(one->mode))
4708                return 0;
4709        if (diff_populate_filespec(one, 0))
4710                return 0;
4711        if (diff_populate_filespec(two, 0))
4712                return 0;
4713        return !memcmp(one->data, two->data, one->size);
4714}
4715
4716static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4717{
4718        if (p->done_skip_stat_unmatch)
4719                return p->skip_stat_unmatch_result;
4720
4721        p->done_skip_stat_unmatch = 1;
4722        p->skip_stat_unmatch_result = 0;
4723        /*
4724         * 1. Entries that come from stat info dirtiness
4725         *    always have both sides (iow, not create/delete),
4726         *    one side of the object name is unknown, with
4727         *    the same mode and size.  Keep the ones that
4728         *    do not match these criteria.  They have real
4729         *    differences.
4730         *
4731         * 2. At this point, the file is known to be modified,
4732         *    with the same mode and size, and the object
4733         *    name of one side is unknown.  Need to inspect
4734         *    the identical contents.
4735         */
4736        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4737            !DIFF_FILE_VALID(p->two) ||
4738            (p->one->sha1_valid && p->two->sha1_valid) ||
4739            (p->one->mode != p->two->mode) ||
4740            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4741            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4742            (p->one->size != p->two->size) ||
4743            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4744                p->skip_stat_unmatch_result = 1;
4745        return p->skip_stat_unmatch_result;
4746}
4747
4748static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4749{
4750        int i;
4751        struct diff_queue_struct *q = &diff_queued_diff;
4752        struct diff_queue_struct outq;
4753        DIFF_QUEUE_CLEAR(&outq);
4754
4755        for (i = 0; i < q->nr; i++) {
4756                struct diff_filepair *p = q->queue[i];
4757
4758                if (diff_filespec_check_stat_unmatch(p))
4759                        diff_q(&outq, p);
4760                else {
4761                        /*
4762                         * The caller can subtract 1 from skip_stat_unmatch
4763                         * to determine how many paths were dirty only
4764                         * due to stat info mismatch.
4765                         */
4766                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4767                                diffopt->skip_stat_unmatch++;
4768                        diff_free_filepair(p);
4769                }
4770        }
4771        free(q->queue);
4772        *q = outq;
4773}
4774
4775static int diffnamecmp(const void *a_, const void *b_)
4776{
4777        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4778        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4779        const char *name_a, *name_b;
4780
4781        name_a = a->one ? a->one->path : a->two->path;
4782        name_b = b->one ? b->one->path : b->two->path;
4783        return strcmp(name_a, name_b);
4784}
4785
4786void diffcore_fix_diff_index(struct diff_options *options)
4787{
4788        struct diff_queue_struct *q = &diff_queued_diff;
4789        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4790}
4791
4792void diffcore_std(struct diff_options *options)
4793{
4794        /* NOTE please keep the following in sync with diff_tree_combined() */
4795        if (options->skip_stat_unmatch)
4796                diffcore_skip_stat_unmatch(options);
4797        if (!options->found_follow) {
4798                /* See try_to_follow_renames() in tree-diff.c */
4799                if (options->break_opt != -1)
4800                        diffcore_break(options->break_opt);
4801                if (options->detect_rename)
4802                        diffcore_rename(options);
4803                if (options->break_opt != -1)
4804                        diffcore_merge_broken();
4805        }
4806        if (options->pickaxe)
4807                diffcore_pickaxe(options);
4808        if (options->orderfile)
4809                diffcore_order(options->orderfile);
4810        if (!options->found_follow)
4811                /* See try_to_follow_renames() in tree-diff.c */
4812                diff_resolve_rename_copy();
4813        diffcore_apply_filter(options);
4814
4815        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4816                DIFF_OPT_SET(options, HAS_CHANGES);
4817        else
4818                DIFF_OPT_CLR(options, HAS_CHANGES);
4819
4820        options->found_follow = 0;
4821}
4822
4823int diff_result_code(struct diff_options *opt, int status)
4824{
4825        int result = 0;
4826
4827        diff_warn_rename_limit("diff.renameLimit",
4828                               opt->needed_rename_limit,
4829                               opt->degraded_cc_to_c);
4830        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4831            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4832                return status;
4833        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4834            DIFF_OPT_TST(opt, HAS_CHANGES))
4835                result |= 01;
4836        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4837            DIFF_OPT_TST(opt, CHECK_FAILED))
4838                result |= 02;
4839        return result;
4840}
4841
4842int diff_can_quit_early(struct diff_options *opt)
4843{
4844        return (DIFF_OPT_TST(opt, QUICK) &&
4845                !opt->filter &&
4846                DIFF_OPT_TST(opt, HAS_CHANGES));
4847}
4848
4849/*
4850 * Shall changes to this submodule be ignored?
4851 *
4852 * Submodule changes can be configured to be ignored separately for each path,
4853 * but that configuration can be overridden from the command line.
4854 */
4855static int is_submodule_ignored(const char *path, struct diff_options *options)
4856{
4857        int ignored = 0;
4858        unsigned orig_flags = options->flags;
4859        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4860                set_diffopt_flags_from_submodule_config(options, path);
4861        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4862                ignored = 1;
4863        options->flags = orig_flags;
4864        return ignored;
4865}
4866
4867void diff_addremove(struct diff_options *options,
4868                    int addremove, unsigned mode,
4869                    const unsigned char *sha1,
4870                    int sha1_valid,
4871                    const char *concatpath, unsigned dirty_submodule)
4872{
4873        struct diff_filespec *one, *two;
4874
4875        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4876                return;
4877
4878        /* This may look odd, but it is a preparation for
4879         * feeding "there are unchanged files which should
4880         * not produce diffs, but when you are doing copy
4881         * detection you would need them, so here they are"
4882         * entries to the diff-core.  They will be prefixed
4883         * with something like '=' or '*' (I haven't decided
4884         * which but should not make any difference).
4885         * Feeding the same new and old to diff_change()
4886         * also has the same effect.
4887         * Before the final output happens, they are pruned after
4888         * merged into rename/copy pairs as appropriate.
4889         */
4890        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4891                addremove = (addremove == '+' ? '-' :
4892                             addremove == '-' ? '+' : addremove);
4893
4894        if (options->prefix &&
4895            strncmp(concatpath, options->prefix, options->prefix_length))
4896                return;
4897
4898        one = alloc_filespec(concatpath);
4899        two = alloc_filespec(concatpath);
4900
4901        if (addremove != '+')
4902                fill_filespec(one, sha1, sha1_valid, mode);
4903        if (addremove != '-') {
4904                fill_filespec(two, sha1, sha1_valid, mode);
4905                two->dirty_submodule = dirty_submodule;
4906        }
4907
4908        diff_queue(&diff_queued_diff, one, two);
4909        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4910                DIFF_OPT_SET(options, HAS_CHANGES);
4911}
4912
4913void diff_change(struct diff_options *options,
4914                 unsigned old_mode, unsigned new_mode,
4915                 const unsigned char *old_sha1,
4916                 const unsigned char *new_sha1,
4917                 int old_sha1_valid, int new_sha1_valid,
4918                 const char *concatpath,
4919                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4920{
4921        struct diff_filespec *one, *two;
4922        struct diff_filepair *p;
4923
4924        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4925            is_submodule_ignored(concatpath, options))
4926                return;
4927
4928        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4929                unsigned tmp;
4930                const unsigned char *tmp_c;
4931                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4932                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4933                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4934                        new_sha1_valid = tmp;
4935                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4936                        new_dirty_submodule = tmp;
4937        }
4938
4939        if (options->prefix &&
4940            strncmp(concatpath, options->prefix, options->prefix_length))
4941                return;
4942
4943        one = alloc_filespec(concatpath);
4944        two = alloc_filespec(concatpath);
4945        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4946        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4947        one->dirty_submodule = old_dirty_submodule;
4948        two->dirty_submodule = new_dirty_submodule;
4949        p = diff_queue(&diff_queued_diff, one, two);
4950
4951        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4952                return;
4953
4954        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
4955            !diff_filespec_check_stat_unmatch(p))
4956                return;
4957
4958        DIFF_OPT_SET(options, HAS_CHANGES);
4959}
4960
4961struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4962{
4963        struct diff_filepair *pair;
4964        struct diff_filespec *one, *two;
4965
4966        if (options->prefix &&
4967            strncmp(path, options->prefix, options->prefix_length))
4968                return NULL;
4969
4970        one = alloc_filespec(path);
4971        two = alloc_filespec(path);
4972        pair = diff_queue(&diff_queued_diff, one, two);
4973        pair->is_unmerged = 1;
4974        return pair;
4975}
4976
4977static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4978                size_t *outsize)
4979{
4980        struct diff_tempfile *temp;
4981        const char *argv[3];
4982        const char **arg = argv;
4983        struct child_process child = CHILD_PROCESS_INIT;
4984        struct strbuf buf = STRBUF_INIT;
4985        int err = 0;
4986
4987        temp = prepare_temp_file(spec->path, spec);
4988        *arg++ = pgm;
4989        *arg++ = temp->name;
4990        *arg = NULL;
4991
4992        child.use_shell = 1;
4993        child.argv = argv;
4994        child.out = -1;
4995        if (start_command(&child)) {
4996                remove_tempfile();
4997                return NULL;
4998        }
4999
5000        if (strbuf_read(&buf, child.out, 0) < 0)
5001                err = error("error reading from textconv command '%s'", pgm);
5002        close(child.out);
5003
5004        if (finish_command(&child) || err) {
5005                strbuf_release(&buf);
5006                remove_tempfile();
5007                return NULL;
5008        }
5009        remove_tempfile();
5010
5011        return strbuf_detach(&buf, outsize);
5012}
5013
5014size_t fill_textconv(struct userdiff_driver *driver,
5015                     struct diff_filespec *df,
5016                     char **outbuf)
5017{
5018        size_t size;
5019
5020        if (!driver || !driver->textconv) {
5021                if (!DIFF_FILE_VALID(df)) {
5022                        *outbuf = "";
5023                        return 0;
5024                }
5025                if (diff_populate_filespec(df, 0))
5026                        die("unable to read files to diff");
5027                *outbuf = df->data;
5028                return df->size;
5029        }
5030
5031        if (driver->textconv_cache && df->sha1_valid) {
5032                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
5033                                          &size);
5034                if (*outbuf)
5035                        return size;
5036        }
5037
5038        *outbuf = run_textconv(driver->textconv, df, &size);
5039        if (!*outbuf)
5040                die("unable to read files to diff");
5041
5042        if (driver->textconv_cache && df->sha1_valid) {
5043                /* ignore errors, as we might be in a readonly repository */
5044                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
5045                                size);
5046                /*
5047                 * we could save up changes and flush them all at the end,
5048                 * but we would need an extra call after all diffing is done.
5049                 * Since generating a cache entry is the slow path anyway,
5050                 * this extra overhead probably isn't a big deal.
5051                 */
5052                notes_cache_write(driver->textconv_cache);
5053        }
5054
5055        return size;
5056}
5057
5058void setup_diff_pager(struct diff_options *opt)
5059{
5060        /*
5061         * If the user asked for our exit code, then either they want --quiet
5062         * or --exit-code. We should definitely not bother with a pager in the
5063         * former case, as we will generate no output. Since we still properly
5064         * report our exit code even when a pager is run, we _could_ run a
5065         * pager with --exit-code. But since we have not done so historically,
5066         * and because it is easy to find people oneline advising "git diff
5067         * --exit-code" in hooks and other scripts, we do not do so.
5068         */
5069        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5070            check_pager_config("diff") != 0)
5071                setup_pager();
5072}