diff.con commit Merge branch 'maint' of git://github.com/git-l10n/git-po (69f8d44)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "hashmap.h"
  20#include "ll-merge.h"
  21#include "string-list.h"
  22#include "argv-array.h"
  23#include "graph.h"
  24#include "packfile.h"
  25
  26#ifdef NO_FAST_WORKING_DIRECTORY
  27#define FAST_WORKING_DIRECTORY 0
  28#else
  29#define FAST_WORKING_DIRECTORY 1
  30#endif
  31
  32static int diff_detect_rename_default;
  33static int diff_indent_heuristic = 1;
  34static int diff_rename_limit_default = 400;
  35static int diff_suppress_blank_empty;
  36static int diff_use_color_default = -1;
  37static int diff_color_moved_default;
  38static int diff_context_default = 3;
  39static int diff_interhunk_context_default;
  40static const char *diff_word_regex_cfg;
  41static const char *external_diff_cmd_cfg;
  42static const char *diff_order_file_cfg;
  43int diff_auto_refresh_index = 1;
  44static int diff_mnemonic_prefix;
  45static int diff_no_prefix;
  46static int diff_stat_graph_width;
  47static int diff_dirstat_permille_default = 30;
  48static struct diff_options default_diff_options;
  49static long diff_algorithm;
  50static unsigned ws_error_highlight_default = WSEH_NEW;
  51
  52static char diff_colors[][COLOR_MAXLEN] = {
  53        GIT_COLOR_RESET,
  54        GIT_COLOR_NORMAL,       /* CONTEXT */
  55        GIT_COLOR_BOLD,         /* METAINFO */
  56        GIT_COLOR_CYAN,         /* FRAGINFO */
  57        GIT_COLOR_RED,          /* OLD */
  58        GIT_COLOR_GREEN,        /* NEW */
  59        GIT_COLOR_YELLOW,       /* COMMIT */
  60        GIT_COLOR_BG_RED,       /* WHITESPACE */
  61        GIT_COLOR_NORMAL,       /* FUNCINFO */
  62        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  63        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  64        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  65        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  66        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  67        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  68        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  69        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  70};
  71
  72static NORETURN void die_want_option(const char *option_name)
  73{
  74        die(_("option '%s' requires a value"), option_name);
  75}
  76
  77static int parse_diff_color_slot(const char *var)
  78{
  79        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  80                return DIFF_CONTEXT;
  81        if (!strcasecmp(var, "meta"))
  82                return DIFF_METAINFO;
  83        if (!strcasecmp(var, "frag"))
  84                return DIFF_FRAGINFO;
  85        if (!strcasecmp(var, "old"))
  86                return DIFF_FILE_OLD;
  87        if (!strcasecmp(var, "new"))
  88                return DIFF_FILE_NEW;
  89        if (!strcasecmp(var, "commit"))
  90                return DIFF_COMMIT;
  91        if (!strcasecmp(var, "whitespace"))
  92                return DIFF_WHITESPACE;
  93        if (!strcasecmp(var, "func"))
  94                return DIFF_FUNCINFO;
  95        if (!strcasecmp(var, "oldmoved"))
  96                return DIFF_FILE_OLD_MOVED;
  97        if (!strcasecmp(var, "oldmovedalternative"))
  98                return DIFF_FILE_OLD_MOVED_ALT;
  99        if (!strcasecmp(var, "oldmoveddimmed"))
 100                return DIFF_FILE_OLD_MOVED_DIM;
 101        if (!strcasecmp(var, "oldmovedalternativedimmed"))
 102                return DIFF_FILE_OLD_MOVED_ALT_DIM;
 103        if (!strcasecmp(var, "newmoved"))
 104                return DIFF_FILE_NEW_MOVED;
 105        if (!strcasecmp(var, "newmovedalternative"))
 106                return DIFF_FILE_NEW_MOVED_ALT;
 107        if (!strcasecmp(var, "newmoveddimmed"))
 108                return DIFF_FILE_NEW_MOVED_DIM;
 109        if (!strcasecmp(var, "newmovedalternativedimmed"))
 110                return DIFF_FILE_NEW_MOVED_ALT_DIM;
 111        return -1;
 112}
 113
 114static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 115                                struct strbuf *errmsg)
 116{
 117        char *params_copy = xstrdup(params_string);
 118        struct string_list params = STRING_LIST_INIT_NODUP;
 119        int ret = 0;
 120        int i;
 121
 122        if (*params_copy)
 123                string_list_split_in_place(&params, params_copy, ',', -1);
 124        for (i = 0; i < params.nr; i++) {
 125                const char *p = params.items[i].string;
 126                if (!strcmp(p, "changes")) {
 127                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 128                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 129                } else if (!strcmp(p, "lines")) {
 130                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 131                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 132                } else if (!strcmp(p, "files")) {
 133                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 134                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 135                } else if (!strcmp(p, "noncumulative")) {
 136                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 137                } else if (!strcmp(p, "cumulative")) {
 138                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 139                } else if (isdigit(*p)) {
 140                        char *end;
 141                        int permille = strtoul(p, &end, 10) * 10;
 142                        if (*end == '.' && isdigit(*++end)) {
 143                                /* only use first digit */
 144                                permille += *end - '0';
 145                                /* .. and ignore any further digits */
 146                                while (isdigit(*++end))
 147                                        ; /* nothing */
 148                        }
 149                        if (!*end)
 150                                options->dirstat_permille = permille;
 151                        else {
 152                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 153                                            p);
 154                                ret++;
 155                        }
 156                } else {
 157                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 158                        ret++;
 159                }
 160
 161        }
 162        string_list_clear(&params, 0);
 163        free(params_copy);
 164        return ret;
 165}
 166
 167static int parse_submodule_params(struct diff_options *options, const char *value)
 168{
 169        if (!strcmp(value, "log"))
 170                options->submodule_format = DIFF_SUBMODULE_LOG;
 171        else if (!strcmp(value, "short"))
 172                options->submodule_format = DIFF_SUBMODULE_SHORT;
 173        else if (!strcmp(value, "diff"))
 174                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 175        else
 176                return -1;
 177        return 0;
 178}
 179
 180static int git_config_rename(const char *var, const char *value)
 181{
 182        if (!value)
 183                return DIFF_DETECT_RENAME;
 184        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 185                return  DIFF_DETECT_COPY;
 186        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 187}
 188
 189long parse_algorithm_value(const char *value)
 190{
 191        if (!value)
 192                return -1;
 193        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 194                return 0;
 195        else if (!strcasecmp(value, "minimal"))
 196                return XDF_NEED_MINIMAL;
 197        else if (!strcasecmp(value, "patience"))
 198                return XDF_PATIENCE_DIFF;
 199        else if (!strcasecmp(value, "histogram"))
 200                return XDF_HISTOGRAM_DIFF;
 201        return -1;
 202}
 203
 204static int parse_one_token(const char **arg, const char *token)
 205{
 206        const char *rest;
 207        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 208                *arg = rest;
 209                return 1;
 210        }
 211        return 0;
 212}
 213
 214static int parse_ws_error_highlight(const char *arg)
 215{
 216        const char *orig_arg = arg;
 217        unsigned val = 0;
 218
 219        while (*arg) {
 220                if (parse_one_token(&arg, "none"))
 221                        val = 0;
 222                else if (parse_one_token(&arg, "default"))
 223                        val = WSEH_NEW;
 224                else if (parse_one_token(&arg, "all"))
 225                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 226                else if (parse_one_token(&arg, "new"))
 227                        val |= WSEH_NEW;
 228                else if (parse_one_token(&arg, "old"))
 229                        val |= WSEH_OLD;
 230                else if (parse_one_token(&arg, "context"))
 231                        val |= WSEH_CONTEXT;
 232                else {
 233                        return -1 - (int)(arg - orig_arg);
 234                }
 235                if (*arg)
 236                        arg++;
 237        }
 238        return val;
 239}
 240
 241/*
 242 * These are to give UI layer defaults.
 243 * The core-level commands such as git-diff-files should
 244 * never be affected by the setting of diff.renames
 245 * the user happens to have in the configuration file.
 246 */
 247void init_diff_ui_defaults(void)
 248{
 249        diff_detect_rename_default = 1;
 250}
 251
 252int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 253{
 254        if (!strcmp(var, "diff.indentheuristic"))
 255                diff_indent_heuristic = git_config_bool(var, value);
 256        return 0;
 257}
 258
 259static int parse_color_moved(const char *arg)
 260{
 261        switch (git_parse_maybe_bool(arg)) {
 262        case 0:
 263                return COLOR_MOVED_NO;
 264        case 1:
 265                return COLOR_MOVED_DEFAULT;
 266        default:
 267                break;
 268        }
 269
 270        if (!strcmp(arg, "no"))
 271                return COLOR_MOVED_NO;
 272        else if (!strcmp(arg, "plain"))
 273                return COLOR_MOVED_PLAIN;
 274        else if (!strcmp(arg, "zebra"))
 275                return COLOR_MOVED_ZEBRA;
 276        else if (!strcmp(arg, "default"))
 277                return COLOR_MOVED_DEFAULT;
 278        else if (!strcmp(arg, "dimmed_zebra"))
 279                return COLOR_MOVED_ZEBRA_DIM;
 280        else
 281                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 282}
 283
 284int git_diff_ui_config(const char *var, const char *value, void *cb)
 285{
 286        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 287                diff_use_color_default = git_config_colorbool(var, value);
 288                return 0;
 289        }
 290        if (!strcmp(var, "diff.colormoved")) {
 291                int cm = parse_color_moved(value);
 292                if (cm < 0)
 293                        return -1;
 294                diff_color_moved_default = cm;
 295                return 0;
 296        }
 297        if (!strcmp(var, "diff.context")) {
 298                diff_context_default = git_config_int(var, value);
 299                if (diff_context_default < 0)
 300                        return -1;
 301                return 0;
 302        }
 303        if (!strcmp(var, "diff.interhunkcontext")) {
 304                diff_interhunk_context_default = git_config_int(var, value);
 305                if (diff_interhunk_context_default < 0)
 306                        return -1;
 307                return 0;
 308        }
 309        if (!strcmp(var, "diff.renames")) {
 310                diff_detect_rename_default = git_config_rename(var, value);
 311                return 0;
 312        }
 313        if (!strcmp(var, "diff.autorefreshindex")) {
 314                diff_auto_refresh_index = git_config_bool(var, value);
 315                return 0;
 316        }
 317        if (!strcmp(var, "diff.mnemonicprefix")) {
 318                diff_mnemonic_prefix = git_config_bool(var, value);
 319                return 0;
 320        }
 321        if (!strcmp(var, "diff.noprefix")) {
 322                diff_no_prefix = git_config_bool(var, value);
 323                return 0;
 324        }
 325        if (!strcmp(var, "diff.statgraphwidth")) {
 326                diff_stat_graph_width = git_config_int(var, value);
 327                return 0;
 328        }
 329        if (!strcmp(var, "diff.external"))
 330                return git_config_string(&external_diff_cmd_cfg, var, value);
 331        if (!strcmp(var, "diff.wordregex"))
 332                return git_config_string(&diff_word_regex_cfg, var, value);
 333        if (!strcmp(var, "diff.orderfile"))
 334                return git_config_pathname(&diff_order_file_cfg, var, value);
 335
 336        if (!strcmp(var, "diff.ignoresubmodules"))
 337                handle_ignore_submodules_arg(&default_diff_options, value);
 338
 339        if (!strcmp(var, "diff.submodule")) {
 340                if (parse_submodule_params(&default_diff_options, value))
 341                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 342                                value);
 343                return 0;
 344        }
 345
 346        if (!strcmp(var, "diff.algorithm")) {
 347                diff_algorithm = parse_algorithm_value(value);
 348                if (diff_algorithm < 0)
 349                        return -1;
 350                return 0;
 351        }
 352
 353        if (!strcmp(var, "diff.wserrorhighlight")) {
 354                int val = parse_ws_error_highlight(value);
 355                if (val < 0)
 356                        return -1;
 357                ws_error_highlight_default = val;
 358                return 0;
 359        }
 360
 361        return git_diff_basic_config(var, value, cb);
 362}
 363
 364int git_diff_basic_config(const char *var, const char *value, void *cb)
 365{
 366        const char *name;
 367
 368        if (!strcmp(var, "diff.renamelimit")) {
 369                diff_rename_limit_default = git_config_int(var, value);
 370                return 0;
 371        }
 372
 373        if (userdiff_config(var, value) < 0)
 374                return -1;
 375
 376        if (skip_prefix(var, "diff.color.", &name) ||
 377            skip_prefix(var, "color.diff.", &name)) {
 378                int slot = parse_diff_color_slot(name);
 379                if (slot < 0)
 380                        return 0;
 381                if (!value)
 382                        return config_error_nonbool(var);
 383                return color_parse(value, diff_colors[slot]);
 384        }
 385
 386        /* like GNU diff's --suppress-blank-empty option  */
 387        if (!strcmp(var, "diff.suppressblankempty") ||
 388                        /* for backwards compatibility */
 389                        !strcmp(var, "diff.suppress-blank-empty")) {
 390                diff_suppress_blank_empty = git_config_bool(var, value);
 391                return 0;
 392        }
 393
 394        if (!strcmp(var, "diff.dirstat")) {
 395                struct strbuf errmsg = STRBUF_INIT;
 396                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 397                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 398                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 399                                errmsg.buf);
 400                strbuf_release(&errmsg);
 401                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 402                return 0;
 403        }
 404
 405        if (git_diff_heuristic_config(var, value, cb) < 0)
 406                return -1;
 407
 408        return git_default_config(var, value, cb);
 409}
 410
 411static char *quote_two(const char *one, const char *two)
 412{
 413        int need_one = quote_c_style(one, NULL, NULL, 1);
 414        int need_two = quote_c_style(two, NULL, NULL, 1);
 415        struct strbuf res = STRBUF_INIT;
 416
 417        if (need_one + need_two) {
 418                strbuf_addch(&res, '"');
 419                quote_c_style(one, &res, NULL, 1);
 420                quote_c_style(two, &res, NULL, 1);
 421                strbuf_addch(&res, '"');
 422        } else {
 423                strbuf_addstr(&res, one);
 424                strbuf_addstr(&res, two);
 425        }
 426        return strbuf_detach(&res, NULL);
 427}
 428
 429static const char *external_diff(void)
 430{
 431        static const char *external_diff_cmd = NULL;
 432        static int done_preparing = 0;
 433
 434        if (done_preparing)
 435                return external_diff_cmd;
 436        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 437        if (!external_diff_cmd)
 438                external_diff_cmd = external_diff_cmd_cfg;
 439        done_preparing = 1;
 440        return external_diff_cmd;
 441}
 442
 443/*
 444 * Keep track of files used for diffing. Sometimes such an entry
 445 * refers to a temporary file, sometimes to an existing file, and
 446 * sometimes to "/dev/null".
 447 */
 448static struct diff_tempfile {
 449        /*
 450         * filename external diff should read from, or NULL if this
 451         * entry is currently not in use:
 452         */
 453        const char *name;
 454
 455        char hex[GIT_MAX_HEXSZ + 1];
 456        char mode[10];
 457
 458        /*
 459         * If this diff_tempfile instance refers to a temporary file,
 460         * this tempfile object is used to manage its lifetime.
 461         */
 462        struct tempfile *tempfile;
 463} diff_temp[2];
 464
 465struct emit_callback {
 466        int color_diff;
 467        unsigned ws_rule;
 468        int blank_at_eof_in_preimage;
 469        int blank_at_eof_in_postimage;
 470        int lno_in_preimage;
 471        int lno_in_postimage;
 472        const char **label_path;
 473        struct diff_words_data *diff_words;
 474        struct diff_options *opt;
 475        struct strbuf *header;
 476};
 477
 478static int count_lines(const char *data, int size)
 479{
 480        int count, ch, completely_empty = 1, nl_just_seen = 0;
 481        count = 0;
 482        while (0 < size--) {
 483                ch = *data++;
 484                if (ch == '\n') {
 485                        count++;
 486                        nl_just_seen = 1;
 487                        completely_empty = 0;
 488                }
 489                else {
 490                        nl_just_seen = 0;
 491                        completely_empty = 0;
 492                }
 493        }
 494        if (completely_empty)
 495                return 0;
 496        if (!nl_just_seen)
 497                count++; /* no trailing newline */
 498        return count;
 499}
 500
 501static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 502{
 503        if (!DIFF_FILE_VALID(one)) {
 504                mf->ptr = (char *)""; /* does not matter */
 505                mf->size = 0;
 506                return 0;
 507        }
 508        else if (diff_populate_filespec(one, 0))
 509                return -1;
 510
 511        mf->ptr = one->data;
 512        mf->size = one->size;
 513        return 0;
 514}
 515
 516/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 517static unsigned long diff_filespec_size(struct diff_filespec *one)
 518{
 519        if (!DIFF_FILE_VALID(one))
 520                return 0;
 521        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 522        return one->size;
 523}
 524
 525static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 526{
 527        char *ptr = mf->ptr;
 528        long size = mf->size;
 529        int cnt = 0;
 530
 531        if (!size)
 532                return cnt;
 533        ptr += size - 1; /* pointing at the very end */
 534        if (*ptr != '\n')
 535                ; /* incomplete line */
 536        else
 537                ptr--; /* skip the last LF */
 538        while (mf->ptr < ptr) {
 539                char *prev_eol;
 540                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 541                        if (*prev_eol == '\n')
 542                                break;
 543                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 544                        break;
 545                cnt++;
 546                ptr = prev_eol - 1;
 547        }
 548        return cnt;
 549}
 550
 551static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 552                               struct emit_callback *ecbdata)
 553{
 554        int l1, l2, at;
 555        unsigned ws_rule = ecbdata->ws_rule;
 556        l1 = count_trailing_blank(mf1, ws_rule);
 557        l2 = count_trailing_blank(mf2, ws_rule);
 558        if (l2 <= l1) {
 559                ecbdata->blank_at_eof_in_preimage = 0;
 560                ecbdata->blank_at_eof_in_postimage = 0;
 561                return;
 562        }
 563        at = count_lines(mf1->ptr, mf1->size);
 564        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 565
 566        at = count_lines(mf2->ptr, mf2->size);
 567        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 568}
 569
 570static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 571                        int first, const char *line, int len)
 572{
 573        int has_trailing_newline, has_trailing_carriage_return;
 574        int nofirst;
 575        FILE *file = o->file;
 576
 577        fputs(diff_line_prefix(o), file);
 578
 579        if (len == 0) {
 580                has_trailing_newline = (first == '\n');
 581                has_trailing_carriage_return = (!has_trailing_newline &&
 582                                                (first == '\r'));
 583                nofirst = has_trailing_newline || has_trailing_carriage_return;
 584        } else {
 585                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 586                if (has_trailing_newline)
 587                        len--;
 588                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 589                if (has_trailing_carriage_return)
 590                        len--;
 591                nofirst = 0;
 592        }
 593
 594        if (len || !nofirst) {
 595                fputs(set, file);
 596                if (!nofirst)
 597                        fputc(first, file);
 598                fwrite(line, len, 1, file);
 599                fputs(reset, file);
 600        }
 601        if (has_trailing_carriage_return)
 602                fputc('\r', file);
 603        if (has_trailing_newline)
 604                fputc('\n', file);
 605}
 606
 607static void emit_line(struct diff_options *o, const char *set, const char *reset,
 608                      const char *line, int len)
 609{
 610        emit_line_0(o, set, reset, line[0], line+1, len-1);
 611}
 612
 613enum diff_symbol {
 614        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 615        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 616        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 617        DIFF_SYMBOL_BINARY_DIFF_BODY,
 618        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 619        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 620        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 621        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 622        DIFF_SYMBOL_STATS_LINE,
 623        DIFF_SYMBOL_WORD_DIFF,
 624        DIFF_SYMBOL_STAT_SEP,
 625        DIFF_SYMBOL_SUMMARY,
 626        DIFF_SYMBOL_SUBMODULE_ADD,
 627        DIFF_SYMBOL_SUBMODULE_DEL,
 628        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 629        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 630        DIFF_SYMBOL_SUBMODULE_HEADER,
 631        DIFF_SYMBOL_SUBMODULE_ERROR,
 632        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 633        DIFF_SYMBOL_REWRITE_DIFF,
 634        DIFF_SYMBOL_BINARY_FILES,
 635        DIFF_SYMBOL_HEADER,
 636        DIFF_SYMBOL_FILEPAIR_PLUS,
 637        DIFF_SYMBOL_FILEPAIR_MINUS,
 638        DIFF_SYMBOL_WORDS_PORCELAIN,
 639        DIFF_SYMBOL_WORDS,
 640        DIFF_SYMBOL_CONTEXT,
 641        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 642        DIFF_SYMBOL_PLUS,
 643        DIFF_SYMBOL_MINUS,
 644        DIFF_SYMBOL_NO_LF_EOF,
 645        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 646        DIFF_SYMBOL_CONTEXT_MARKER,
 647        DIFF_SYMBOL_SEPARATOR
 648};
 649/*
 650 * Flags for content lines:
 651 * 0..12 are whitespace rules
 652 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 653 * 16 is marking if the line is blank at EOF
 654 */
 655#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 656#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 657#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 658#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 659#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 660
 661/*
 662 * This struct is used when we need to buffer the output of the diff output.
 663 *
 664 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 665 * into the pre/post image file. This pointer could be a union with the
 666 * line pointer. By storing an offset into the file instead of the literal line,
 667 * we can decrease the memory footprint for the buffered output. At first we
 668 * may want to only have indirection for the content lines, but we could also
 669 * enhance the state for emitting prefabricated lines, e.g. the similarity
 670 * score line or hunk/file headers would only need to store a number or path
 671 * and then the output can be constructed later on depending on state.
 672 */
 673struct emitted_diff_symbol {
 674        const char *line;
 675        int len;
 676        int flags;
 677        enum diff_symbol s;
 678};
 679#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 680
 681struct emitted_diff_symbols {
 682        struct emitted_diff_symbol *buf;
 683        int nr, alloc;
 684};
 685#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 686
 687static void append_emitted_diff_symbol(struct diff_options *o,
 688                                       struct emitted_diff_symbol *e)
 689{
 690        struct emitted_diff_symbol *f;
 691
 692        ALLOC_GROW(o->emitted_symbols->buf,
 693                   o->emitted_symbols->nr + 1,
 694                   o->emitted_symbols->alloc);
 695        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 696
 697        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 698        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 699}
 700
 701struct moved_entry {
 702        struct hashmap_entry ent;
 703        const struct emitted_diff_symbol *es;
 704        struct moved_entry *next_line;
 705};
 706
 707static int next_byte(const char **cp, const char **endp,
 708                     const struct diff_options *diffopt)
 709{
 710        int retval;
 711
 712        if (*cp > *endp)
 713                return -1;
 714
 715        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_CHANGE)) {
 716                while (*cp < *endp && isspace(**cp))
 717                        (*cp)++;
 718                /*
 719                 * After skipping a couple of whitespaces, we still have to
 720                 * account for one space.
 721                 */
 722                return (int)' ';
 723        }
 724
 725        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE)) {
 726                while (*cp < *endp && isspace(**cp))
 727                        (*cp)++;
 728                /* return the first non-ws character via the usual below */
 729        }
 730
 731        retval = (unsigned char)(**cp);
 732        (*cp)++;
 733        return retval;
 734}
 735
 736static int moved_entry_cmp(const struct diff_options *diffopt,
 737                           const struct moved_entry *a,
 738                           const struct moved_entry *b,
 739                           const void *keydata)
 740{
 741        const char *ap = a->es->line, *ae = a->es->line + a->es->len;
 742        const char *bp = b->es->line, *be = b->es->line + b->es->len;
 743
 744        if (!(diffopt->xdl_opts & XDF_WHITESPACE_FLAGS))
 745                return a->es->len != b->es->len  || memcmp(ap, bp, a->es->len);
 746
 747        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_AT_EOL)) {
 748                while (ae > ap && isspace(*ae))
 749                        ae--;
 750                while (be > bp && isspace(*be))
 751                        be--;
 752        }
 753
 754        while (1) {
 755                int ca, cb;
 756                ca = next_byte(&ap, &ae, diffopt);
 757                cb = next_byte(&bp, &be, diffopt);
 758                if (ca != cb)
 759                        return 1;
 760                if (ca < 0)
 761                        return 0;
 762        }
 763}
 764
 765static unsigned get_string_hash(struct emitted_diff_symbol *es, struct diff_options *o)
 766{
 767        if (o->xdl_opts & XDF_WHITESPACE_FLAGS) {
 768                static struct strbuf sb = STRBUF_INIT;
 769                const char *ap = es->line, *ae = es->line + es->len;
 770                int c;
 771
 772                strbuf_reset(&sb);
 773                while (ae > ap && isspace(*ae))
 774                        ae--;
 775                while ((c = next_byte(&ap, &ae, o)) > 0)
 776                        strbuf_addch(&sb, c);
 777
 778                return memhash(sb.buf, sb.len);
 779        } else {
 780                return memhash(es->line, es->len);
 781        }
 782}
 783
 784static struct moved_entry *prepare_entry(struct diff_options *o,
 785                                         int line_no)
 786{
 787        struct moved_entry *ret = xmalloc(sizeof(*ret));
 788        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 789
 790        ret->ent.hash = get_string_hash(l, o);
 791        ret->es = l;
 792        ret->next_line = NULL;
 793
 794        return ret;
 795}
 796
 797static void add_lines_to_move_detection(struct diff_options *o,
 798                                        struct hashmap *add_lines,
 799                                        struct hashmap *del_lines)
 800{
 801        struct moved_entry *prev_line = NULL;
 802
 803        int n;
 804        for (n = 0; n < o->emitted_symbols->nr; n++) {
 805                struct hashmap *hm;
 806                struct moved_entry *key;
 807
 808                switch (o->emitted_symbols->buf[n].s) {
 809                case DIFF_SYMBOL_PLUS:
 810                        hm = add_lines;
 811                        break;
 812                case DIFF_SYMBOL_MINUS:
 813                        hm = del_lines;
 814                        break;
 815                default:
 816                        prev_line = NULL;
 817                        continue;
 818                }
 819
 820                key = prepare_entry(o, n);
 821                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 822                        prev_line->next_line = key;
 823
 824                hashmap_add(hm, key);
 825                prev_line = key;
 826        }
 827}
 828
 829static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 830                                         int pmb_nr)
 831{
 832        int lp, rp;
 833
 834        /* Shrink the set of potential block to the remaining running */
 835        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 836                while (lp < pmb_nr && pmb[lp])
 837                        lp++;
 838                /* lp points at the first NULL now */
 839
 840                while (rp > -1 && !pmb[rp])
 841                        rp--;
 842                /* rp points at the last non-NULL */
 843
 844                if (lp < pmb_nr && rp > -1 && lp < rp) {
 845                        pmb[lp] = pmb[rp];
 846                        pmb[rp] = NULL;
 847                        rp--;
 848                        lp++;
 849                }
 850        }
 851
 852        /* Remember the number of running sets */
 853        return rp + 1;
 854}
 855
 856/*
 857 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 858 *
 859 * Otherwise, if the last block has fewer alphanumeric characters than
 860 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 861 * that block.
 862 *
 863 * The last block consists of the (n - block_length)'th line up to but not
 864 * including the nth line.
 865 *
 866 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 867 * Think of a way to unify them.
 868 */
 869static void adjust_last_block(struct diff_options *o, int n, int block_length)
 870{
 871        int i, alnum_count = 0;
 872        if (o->color_moved == COLOR_MOVED_PLAIN)
 873                return;
 874        for (i = 1; i < block_length + 1; i++) {
 875                const char *c = o->emitted_symbols->buf[n - i].line;
 876                for (; *c; c++) {
 877                        if (!isalnum(*c))
 878                                continue;
 879                        alnum_count++;
 880                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 881                                return;
 882                }
 883        }
 884        for (i = 1; i < block_length + 1; i++)
 885                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 886}
 887
 888/* Find blocks of moved code, delegate actual coloring decision to helper */
 889static void mark_color_as_moved(struct diff_options *o,
 890                                struct hashmap *add_lines,
 891                                struct hashmap *del_lines)
 892{
 893        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 894        int pmb_nr = 0, pmb_alloc = 0;
 895        int n, flipped_block = 1, block_length = 0;
 896
 897
 898        for (n = 0; n < o->emitted_symbols->nr; n++) {
 899                struct hashmap *hm = NULL;
 900                struct moved_entry *key;
 901                struct moved_entry *match = NULL;
 902                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 903                int i;
 904
 905                switch (l->s) {
 906                case DIFF_SYMBOL_PLUS:
 907                        hm = del_lines;
 908                        key = prepare_entry(o, n);
 909                        match = hashmap_get(hm, key, o);
 910                        free(key);
 911                        break;
 912                case DIFF_SYMBOL_MINUS:
 913                        hm = add_lines;
 914                        key = prepare_entry(o, n);
 915                        match = hashmap_get(hm, key, o);
 916                        free(key);
 917                        break;
 918                default:
 919                        flipped_block = 1;
 920                }
 921
 922                if (!match) {
 923                        adjust_last_block(o, n, block_length);
 924                        pmb_nr = 0;
 925                        block_length = 0;
 926                        continue;
 927                }
 928
 929                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 930
 931                if (o->color_moved == COLOR_MOVED_PLAIN)
 932                        continue;
 933
 934                /* Check any potential block runs, advance each or nullify */
 935                for (i = 0; i < pmb_nr; i++) {
 936                        struct moved_entry *p = pmb[i];
 937                        struct moved_entry *pnext = (p && p->next_line) ?
 938                                        p->next_line : NULL;
 939                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 940                                pmb[i] = p->next_line;
 941                        } else {
 942                                pmb[i] = NULL;
 943                        }
 944                }
 945
 946                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 947
 948                if (pmb_nr == 0) {
 949                        /*
 950                         * The current line is the start of a new block.
 951                         * Setup the set of potential blocks.
 952                         */
 953                        for (; match; match = hashmap_get_next(hm, match)) {
 954                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 955                                pmb[pmb_nr++] = match;
 956                        }
 957
 958                        flipped_block = (flipped_block + 1) % 2;
 959
 960                        adjust_last_block(o, n, block_length);
 961                        block_length = 0;
 962                }
 963
 964                block_length++;
 965
 966                if (flipped_block)
 967                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 968        }
 969        adjust_last_block(o, n, block_length);
 970
 971        free(pmb);
 972}
 973
 974#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 975  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 976static void dim_moved_lines(struct diff_options *o)
 977{
 978        int n;
 979        for (n = 0; n < o->emitted_symbols->nr; n++) {
 980                struct emitted_diff_symbol *prev = (n != 0) ?
 981                                &o->emitted_symbols->buf[n - 1] : NULL;
 982                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 983                struct emitted_diff_symbol *next =
 984                                (n < o->emitted_symbols->nr - 1) ?
 985                                &o->emitted_symbols->buf[n + 1] : NULL;
 986
 987                /* Not a plus or minus line? */
 988                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 989                        continue;
 990
 991                /* Not a moved line? */
 992                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 993                        continue;
 994
 995                /*
 996                 * If prev or next are not a plus or minus line,
 997                 * pretend they don't exist
 998                 */
 999                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1000                            prev->s != DIFF_SYMBOL_MINUS)
1001                        prev = NULL;
1002                if (next && next->s != DIFF_SYMBOL_PLUS &&
1003                            next->s != DIFF_SYMBOL_MINUS)
1004                        next = NULL;
1005
1006                /* Inside a block? */
1007                if ((prev &&
1008                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1009                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1010                    (next &&
1011                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1012                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1013                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1014                        continue;
1015                }
1016
1017                /* Check if we are at an interesting bound: */
1018                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1019                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1020                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1021                        continue;
1022                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1023                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1024                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1025                        continue;
1026
1027                /*
1028                 * The boundary to prev and next are not interesting,
1029                 * so this line is not interesting as a whole
1030                 */
1031                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1032        }
1033}
1034
1035static void emit_line_ws_markup(struct diff_options *o,
1036                                const char *set, const char *reset,
1037                                const char *line, int len, char sign,
1038                                unsigned ws_rule, int blank_at_eof)
1039{
1040        const char *ws = NULL;
1041
1042        if (o->ws_error_highlight & ws_rule) {
1043                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1044                if (!*ws)
1045                        ws = NULL;
1046        }
1047
1048        if (!ws)
1049                emit_line_0(o, set, reset, sign, line, len);
1050        else if (blank_at_eof)
1051                /* Blank line at EOF - paint '+' as well */
1052                emit_line_0(o, ws, reset, sign, line, len);
1053        else {
1054                /* Emit just the prefix, then the rest. */
1055                emit_line_0(o, set, reset, sign, "", 0);
1056                ws_check_emit(line, len, ws_rule,
1057                              o->file, set, reset, ws);
1058        }
1059}
1060
1061static void emit_diff_symbol_from_struct(struct diff_options *o,
1062                                         struct emitted_diff_symbol *eds)
1063{
1064        static const char *nneof = " No newline at end of file\n";
1065        const char *context, *reset, *set, *meta, *fraginfo;
1066        struct strbuf sb = STRBUF_INIT;
1067
1068        enum diff_symbol s = eds->s;
1069        const char *line = eds->line;
1070        int len = eds->len;
1071        unsigned flags = eds->flags;
1072
1073        switch (s) {
1074        case DIFF_SYMBOL_NO_LF_EOF:
1075                context = diff_get_color_opt(o, DIFF_CONTEXT);
1076                reset = diff_get_color_opt(o, DIFF_RESET);
1077                putc('\n', o->file);
1078                emit_line_0(o, context, reset, '\\',
1079                            nneof, strlen(nneof));
1080                break;
1081        case DIFF_SYMBOL_SUBMODULE_HEADER:
1082        case DIFF_SYMBOL_SUBMODULE_ERROR:
1083        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1084        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1085        case DIFF_SYMBOL_SUMMARY:
1086        case DIFF_SYMBOL_STATS_LINE:
1087        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1088        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1089                emit_line(o, "", "", line, len);
1090                break;
1091        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1092        case DIFF_SYMBOL_CONTEXT_MARKER:
1093                context = diff_get_color_opt(o, DIFF_CONTEXT);
1094                reset = diff_get_color_opt(o, DIFF_RESET);
1095                emit_line(o, context, reset, line, len);
1096                break;
1097        case DIFF_SYMBOL_SEPARATOR:
1098                fprintf(o->file, "%s%c",
1099                        diff_line_prefix(o),
1100                        o->line_termination);
1101                break;
1102        case DIFF_SYMBOL_CONTEXT:
1103                set = diff_get_color_opt(o, DIFF_CONTEXT);
1104                reset = diff_get_color_opt(o, DIFF_RESET);
1105                emit_line_ws_markup(o, set, reset, line, len, ' ',
1106                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1107                break;
1108        case DIFF_SYMBOL_PLUS:
1109                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1110                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1111                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1112                case DIFF_SYMBOL_MOVED_LINE |
1113                     DIFF_SYMBOL_MOVED_LINE_ALT |
1114                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1115                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1116                        break;
1117                case DIFF_SYMBOL_MOVED_LINE |
1118                     DIFF_SYMBOL_MOVED_LINE_ALT:
1119                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1120                        break;
1121                case DIFF_SYMBOL_MOVED_LINE |
1122                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1123                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1124                        break;
1125                case DIFF_SYMBOL_MOVED_LINE:
1126                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1127                        break;
1128                default:
1129                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1130                }
1131                reset = diff_get_color_opt(o, DIFF_RESET);
1132                emit_line_ws_markup(o, set, reset, line, len, '+',
1133                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1134                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1135                break;
1136        case DIFF_SYMBOL_MINUS:
1137                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1138                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1139                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1140                case DIFF_SYMBOL_MOVED_LINE |
1141                     DIFF_SYMBOL_MOVED_LINE_ALT |
1142                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1143                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1144                        break;
1145                case DIFF_SYMBOL_MOVED_LINE |
1146                     DIFF_SYMBOL_MOVED_LINE_ALT:
1147                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1148                        break;
1149                case DIFF_SYMBOL_MOVED_LINE |
1150                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1151                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1152                        break;
1153                case DIFF_SYMBOL_MOVED_LINE:
1154                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1155                        break;
1156                default:
1157                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1158                }
1159                reset = diff_get_color_opt(o, DIFF_RESET);
1160                emit_line_ws_markup(o, set, reset, line, len, '-',
1161                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1162                break;
1163        case DIFF_SYMBOL_WORDS_PORCELAIN:
1164                context = diff_get_color_opt(o, DIFF_CONTEXT);
1165                reset = diff_get_color_opt(o, DIFF_RESET);
1166                emit_line(o, context, reset, line, len);
1167                fputs("~\n", o->file);
1168                break;
1169        case DIFF_SYMBOL_WORDS:
1170                context = diff_get_color_opt(o, DIFF_CONTEXT);
1171                reset = diff_get_color_opt(o, DIFF_RESET);
1172                /*
1173                 * Skip the prefix character, if any.  With
1174                 * diff_suppress_blank_empty, there may be
1175                 * none.
1176                 */
1177                if (line[0] != '\n') {
1178                        line++;
1179                        len--;
1180                }
1181                emit_line(o, context, reset, line, len);
1182                break;
1183        case DIFF_SYMBOL_FILEPAIR_PLUS:
1184                meta = diff_get_color_opt(o, DIFF_METAINFO);
1185                reset = diff_get_color_opt(o, DIFF_RESET);
1186                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1187                        line, reset,
1188                        strchr(line, ' ') ? "\t" : "");
1189                break;
1190        case DIFF_SYMBOL_FILEPAIR_MINUS:
1191                meta = diff_get_color_opt(o, DIFF_METAINFO);
1192                reset = diff_get_color_opt(o, DIFF_RESET);
1193                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1194                        line, reset,
1195                        strchr(line, ' ') ? "\t" : "");
1196                break;
1197        case DIFF_SYMBOL_BINARY_FILES:
1198        case DIFF_SYMBOL_HEADER:
1199                fprintf(o->file, "%s", line);
1200                break;
1201        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1202                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1203                break;
1204        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1205                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1206                break;
1207        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1208                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1209                break;
1210        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1211                fputs(diff_line_prefix(o), o->file);
1212                fputc('\n', o->file);
1213                break;
1214        case DIFF_SYMBOL_REWRITE_DIFF:
1215                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1216                reset = diff_get_color_opt(o, DIFF_RESET);
1217                emit_line(o, fraginfo, reset, line, len);
1218                break;
1219        case DIFF_SYMBOL_SUBMODULE_ADD:
1220                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1221                reset = diff_get_color_opt(o, DIFF_RESET);
1222                emit_line(o, set, reset, line, len);
1223                break;
1224        case DIFF_SYMBOL_SUBMODULE_DEL:
1225                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1226                reset = diff_get_color_opt(o, DIFF_RESET);
1227                emit_line(o, set, reset, line, len);
1228                break;
1229        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1230                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1231                        diff_line_prefix(o), line);
1232                break;
1233        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1234                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1235                        diff_line_prefix(o), line);
1236                break;
1237        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1238                emit_line(o, "", "", " 0 files changed\n",
1239                          strlen(" 0 files changed\n"));
1240                break;
1241        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1242                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1243                break;
1244        case DIFF_SYMBOL_WORD_DIFF:
1245                fprintf(o->file, "%.*s", len, line);
1246                break;
1247        case DIFF_SYMBOL_STAT_SEP:
1248                fputs(o->stat_sep, o->file);
1249                break;
1250        default:
1251                die("BUG: unknown diff symbol");
1252        }
1253        strbuf_release(&sb);
1254}
1255
1256static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1257                             const char *line, int len, unsigned flags)
1258{
1259        struct emitted_diff_symbol e = {line, len, flags, s};
1260
1261        if (o->emitted_symbols)
1262                append_emitted_diff_symbol(o, &e);
1263        else
1264                emit_diff_symbol_from_struct(o, &e);
1265}
1266
1267void diff_emit_submodule_del(struct diff_options *o, const char *line)
1268{
1269        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1270}
1271
1272void diff_emit_submodule_add(struct diff_options *o, const char *line)
1273{
1274        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1275}
1276
1277void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1278{
1279        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1280                         path, strlen(path), 0);
1281}
1282
1283void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1284{
1285        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1286                         path, strlen(path), 0);
1287}
1288
1289void diff_emit_submodule_header(struct diff_options *o, const char *header)
1290{
1291        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1292                         header, strlen(header), 0);
1293}
1294
1295void diff_emit_submodule_error(struct diff_options *o, const char *err)
1296{
1297        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1298}
1299
1300void diff_emit_submodule_pipethrough(struct diff_options *o,
1301                                     const char *line, int len)
1302{
1303        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1304}
1305
1306static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1307{
1308        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1309              ecbdata->blank_at_eof_in_preimage &&
1310              ecbdata->blank_at_eof_in_postimage &&
1311              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1312              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1313                return 0;
1314        return ws_blank_line(line, len, ecbdata->ws_rule);
1315}
1316
1317static void emit_add_line(const char *reset,
1318                          struct emit_callback *ecbdata,
1319                          const char *line, int len)
1320{
1321        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1322        if (new_blank_line_at_eof(ecbdata, line, len))
1323                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1324
1325        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1326}
1327
1328static void emit_del_line(const char *reset,
1329                          struct emit_callback *ecbdata,
1330                          const char *line, int len)
1331{
1332        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1333        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1334}
1335
1336static void emit_context_line(const char *reset,
1337                              struct emit_callback *ecbdata,
1338                              const char *line, int len)
1339{
1340        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1341        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1342}
1343
1344static void emit_hunk_header(struct emit_callback *ecbdata,
1345                             const char *line, int len)
1346{
1347        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1348        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1349        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1350        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1351        static const char atat[2] = { '@', '@' };
1352        const char *cp, *ep;
1353        struct strbuf msgbuf = STRBUF_INIT;
1354        int org_len = len;
1355        int i = 1;
1356
1357        /*
1358         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1359         * it always is at least 10 bytes long.
1360         */
1361        if (len < 10 ||
1362            memcmp(line, atat, 2) ||
1363            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1364                emit_diff_symbol(ecbdata->opt,
1365                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1366                return;
1367        }
1368        ep += 2; /* skip over @@ */
1369
1370        /* The hunk header in fraginfo color */
1371        strbuf_addstr(&msgbuf, frag);
1372        strbuf_add(&msgbuf, line, ep - line);
1373        strbuf_addstr(&msgbuf, reset);
1374
1375        /*
1376         * trailing "\r\n"
1377         */
1378        for ( ; i < 3; i++)
1379                if (line[len - i] == '\r' || line[len - i] == '\n')
1380                        len--;
1381
1382        /* blank before the func header */
1383        for (cp = ep; ep - line < len; ep++)
1384                if (*ep != ' ' && *ep != '\t')
1385                        break;
1386        if (ep != cp) {
1387                strbuf_addstr(&msgbuf, context);
1388                strbuf_add(&msgbuf, cp, ep - cp);
1389                strbuf_addstr(&msgbuf, reset);
1390        }
1391
1392        if (ep < line + len) {
1393                strbuf_addstr(&msgbuf, func);
1394                strbuf_add(&msgbuf, ep, line + len - ep);
1395                strbuf_addstr(&msgbuf, reset);
1396        }
1397
1398        strbuf_add(&msgbuf, line + len, org_len - len);
1399        strbuf_complete_line(&msgbuf);
1400        emit_diff_symbol(ecbdata->opt,
1401                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1402        strbuf_release(&msgbuf);
1403}
1404
1405static struct diff_tempfile *claim_diff_tempfile(void) {
1406        int i;
1407        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1408                if (!diff_temp[i].name)
1409                        return diff_temp + i;
1410        die("BUG: diff is failing to clean up its tempfiles");
1411}
1412
1413static void remove_tempfile(void)
1414{
1415        int i;
1416        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1417                if (is_tempfile_active(diff_temp[i].tempfile))
1418                        delete_tempfile(&diff_temp[i].tempfile);
1419                diff_temp[i].name = NULL;
1420        }
1421}
1422
1423static void add_line_count(struct strbuf *out, int count)
1424{
1425        switch (count) {
1426        case 0:
1427                strbuf_addstr(out, "0,0");
1428                break;
1429        case 1:
1430                strbuf_addstr(out, "1");
1431                break;
1432        default:
1433                strbuf_addf(out, "1,%d", count);
1434                break;
1435        }
1436}
1437
1438static void emit_rewrite_lines(struct emit_callback *ecb,
1439                               int prefix, const char *data, int size)
1440{
1441        const char *endp = NULL;
1442        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1443
1444        while (0 < size) {
1445                int len;
1446
1447                endp = memchr(data, '\n', size);
1448                len = endp ? (endp - data + 1) : size;
1449                if (prefix != '+') {
1450                        ecb->lno_in_preimage++;
1451                        emit_del_line(reset, ecb, data, len);
1452                } else {
1453                        ecb->lno_in_postimage++;
1454                        emit_add_line(reset, ecb, data, len);
1455                }
1456                size -= len;
1457                data += len;
1458        }
1459        if (!endp)
1460                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1461}
1462
1463static void emit_rewrite_diff(const char *name_a,
1464                              const char *name_b,
1465                              struct diff_filespec *one,
1466                              struct diff_filespec *two,
1467                              struct userdiff_driver *textconv_one,
1468                              struct userdiff_driver *textconv_two,
1469                              struct diff_options *o)
1470{
1471        int lc_a, lc_b;
1472        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1473        const char *a_prefix, *b_prefix;
1474        char *data_one, *data_two;
1475        size_t size_one, size_two;
1476        struct emit_callback ecbdata;
1477        struct strbuf out = STRBUF_INIT;
1478
1479        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
1480                a_prefix = o->b_prefix;
1481                b_prefix = o->a_prefix;
1482        } else {
1483                a_prefix = o->a_prefix;
1484                b_prefix = o->b_prefix;
1485        }
1486
1487        name_a += (*name_a == '/');
1488        name_b += (*name_b == '/');
1489
1490        strbuf_reset(&a_name);
1491        strbuf_reset(&b_name);
1492        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1493        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1494
1495        size_one = fill_textconv(textconv_one, one, &data_one);
1496        size_two = fill_textconv(textconv_two, two, &data_two);
1497
1498        memset(&ecbdata, 0, sizeof(ecbdata));
1499        ecbdata.color_diff = want_color(o->use_color);
1500        ecbdata.ws_rule = whitespace_rule(name_b);
1501        ecbdata.opt = o;
1502        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1503                mmfile_t mf1, mf2;
1504                mf1.ptr = (char *)data_one;
1505                mf2.ptr = (char *)data_two;
1506                mf1.size = size_one;
1507                mf2.size = size_two;
1508                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1509        }
1510        ecbdata.lno_in_preimage = 1;
1511        ecbdata.lno_in_postimage = 1;
1512
1513        lc_a = count_lines(data_one, size_one);
1514        lc_b = count_lines(data_two, size_two);
1515
1516        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1517                         a_name.buf, a_name.len, 0);
1518        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1519                         b_name.buf, b_name.len, 0);
1520
1521        strbuf_addstr(&out, "@@ -");
1522        if (!o->irreversible_delete)
1523                add_line_count(&out, lc_a);
1524        else
1525                strbuf_addstr(&out, "?,?");
1526        strbuf_addstr(&out, " +");
1527        add_line_count(&out, lc_b);
1528        strbuf_addstr(&out, " @@\n");
1529        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1530        strbuf_release(&out);
1531
1532        if (lc_a && !o->irreversible_delete)
1533                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1534        if (lc_b)
1535                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1536        if (textconv_one)
1537                free((char *)data_one);
1538        if (textconv_two)
1539                free((char *)data_two);
1540}
1541
1542struct diff_words_buffer {
1543        mmfile_t text;
1544        unsigned long alloc;
1545        struct diff_words_orig {
1546                const char *begin, *end;
1547        } *orig;
1548        int orig_nr, orig_alloc;
1549};
1550
1551static void diff_words_append(char *line, unsigned long len,
1552                struct diff_words_buffer *buffer)
1553{
1554        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1555        line++;
1556        len--;
1557        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1558        buffer->text.size += len;
1559        buffer->text.ptr[buffer->text.size] = '\0';
1560}
1561
1562struct diff_words_style_elem {
1563        const char *prefix;
1564        const char *suffix;
1565        const char *color; /* NULL; filled in by the setup code if
1566                            * color is enabled */
1567};
1568
1569struct diff_words_style {
1570        enum diff_words_type type;
1571        struct diff_words_style_elem new, old, ctx;
1572        const char *newline;
1573};
1574
1575static struct diff_words_style diff_words_styles[] = {
1576        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1577        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1578        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1579};
1580
1581struct diff_words_data {
1582        struct diff_words_buffer minus, plus;
1583        const char *current_plus;
1584        int last_minus;
1585        struct diff_options *opt;
1586        regex_t *word_regex;
1587        enum diff_words_type type;
1588        struct diff_words_style *style;
1589};
1590
1591static int fn_out_diff_words_write_helper(struct diff_options *o,
1592                                          struct diff_words_style_elem *st_el,
1593                                          const char *newline,
1594                                          size_t count, const char *buf)
1595{
1596        int print = 0;
1597        struct strbuf sb = STRBUF_INIT;
1598
1599        while (count) {
1600                char *p = memchr(buf, '\n', count);
1601                if (print)
1602                        strbuf_addstr(&sb, diff_line_prefix(o));
1603
1604                if (p != buf) {
1605                        const char *reset = st_el->color && *st_el->color ?
1606                                            GIT_COLOR_RESET : NULL;
1607                        if (st_el->color && *st_el->color)
1608                                strbuf_addstr(&sb, st_el->color);
1609                        strbuf_addstr(&sb, st_el->prefix);
1610                        strbuf_add(&sb, buf, p ? p - buf : count);
1611                        strbuf_addstr(&sb, st_el->suffix);
1612                        if (reset)
1613                                strbuf_addstr(&sb, reset);
1614                }
1615                if (!p)
1616                        goto out;
1617
1618                strbuf_addstr(&sb, newline);
1619                count -= p + 1 - buf;
1620                buf = p + 1;
1621                print = 1;
1622                if (count) {
1623                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1624                                         sb.buf, sb.len, 0);
1625                        strbuf_reset(&sb);
1626                }
1627        }
1628
1629out:
1630        if (sb.len)
1631                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1632                                 sb.buf, sb.len, 0);
1633        strbuf_release(&sb);
1634        return 0;
1635}
1636
1637/*
1638 * '--color-words' algorithm can be described as:
1639 *
1640 *   1. collect the minus/plus lines of a diff hunk, divided into
1641 *      minus-lines and plus-lines;
1642 *
1643 *   2. break both minus-lines and plus-lines into words and
1644 *      place them into two mmfile_t with one word for each line;
1645 *
1646 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1647 *
1648 * And for the common parts of the both file, we output the plus side text.
1649 * diff_words->current_plus is used to trace the current position of the plus file
1650 * which printed. diff_words->last_minus is used to trace the last minus word
1651 * printed.
1652 *
1653 * For '--graph' to work with '--color-words', we need to output the graph prefix
1654 * on each line of color words output. Generally, there are two conditions on
1655 * which we should output the prefix.
1656 *
1657 *   1. diff_words->last_minus == 0 &&
1658 *      diff_words->current_plus == diff_words->plus.text.ptr
1659 *
1660 *      that is: the plus text must start as a new line, and if there is no minus
1661 *      word printed, a graph prefix must be printed.
1662 *
1663 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1664 *      *(diff_words->current_plus - 1) == '\n'
1665 *
1666 *      that is: a graph prefix must be printed following a '\n'
1667 */
1668static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1669{
1670        if ((diff_words->last_minus == 0 &&
1671                diff_words->current_plus == diff_words->plus.text.ptr) ||
1672                (diff_words->current_plus > diff_words->plus.text.ptr &&
1673                *(diff_words->current_plus - 1) == '\n')) {
1674                return 1;
1675        } else {
1676                return 0;
1677        }
1678}
1679
1680static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1681{
1682        struct diff_words_data *diff_words = priv;
1683        struct diff_words_style *style = diff_words->style;
1684        int minus_first, minus_len, plus_first, plus_len;
1685        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1686        struct diff_options *opt = diff_words->opt;
1687        const char *line_prefix;
1688
1689        if (line[0] != '@' || parse_hunk_header(line, len,
1690                        &minus_first, &minus_len, &plus_first, &plus_len))
1691                return;
1692
1693        assert(opt);
1694        line_prefix = diff_line_prefix(opt);
1695
1696        /* POSIX requires that first be decremented by one if len == 0... */
1697        if (minus_len) {
1698                minus_begin = diff_words->minus.orig[minus_first].begin;
1699                minus_end =
1700                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1701        } else
1702                minus_begin = minus_end =
1703                        diff_words->minus.orig[minus_first].end;
1704
1705        if (plus_len) {
1706                plus_begin = diff_words->plus.orig[plus_first].begin;
1707                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1708        } else
1709                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1710
1711        if (color_words_output_graph_prefix(diff_words)) {
1712                fputs(line_prefix, diff_words->opt->file);
1713        }
1714        if (diff_words->current_plus != plus_begin) {
1715                fn_out_diff_words_write_helper(diff_words->opt,
1716                                &style->ctx, style->newline,
1717                                plus_begin - diff_words->current_plus,
1718                                diff_words->current_plus);
1719        }
1720        if (minus_begin != minus_end) {
1721                fn_out_diff_words_write_helper(diff_words->opt,
1722                                &style->old, style->newline,
1723                                minus_end - minus_begin, minus_begin);
1724        }
1725        if (plus_begin != plus_end) {
1726                fn_out_diff_words_write_helper(diff_words->opt,
1727                                &style->new, style->newline,
1728                                plus_end - plus_begin, plus_begin);
1729        }
1730
1731        diff_words->current_plus = plus_end;
1732        diff_words->last_minus = minus_first;
1733}
1734
1735/* This function starts looking at *begin, and returns 0 iff a word was found. */
1736static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1737                int *begin, int *end)
1738{
1739        if (word_regex && *begin < buffer->size) {
1740                regmatch_t match[1];
1741                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1742                                 buffer->size - *begin, 1, match, 0)) {
1743                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1744                                        '\n', match[0].rm_eo - match[0].rm_so);
1745                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1746                        *begin += match[0].rm_so;
1747                        return *begin >= *end;
1748                }
1749                return -1;
1750        }
1751
1752        /* find the next word */
1753        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1754                (*begin)++;
1755        if (*begin >= buffer->size)
1756                return -1;
1757
1758        /* find the end of the word */
1759        *end = *begin + 1;
1760        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1761                (*end)++;
1762
1763        return 0;
1764}
1765
1766/*
1767 * This function splits the words in buffer->text, stores the list with
1768 * newline separator into out, and saves the offsets of the original words
1769 * in buffer->orig.
1770 */
1771static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1772                regex_t *word_regex)
1773{
1774        int i, j;
1775        long alloc = 0;
1776
1777        out->size = 0;
1778        out->ptr = NULL;
1779
1780        /* fake an empty "0th" word */
1781        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1782        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1783        buffer->orig_nr = 1;
1784
1785        for (i = 0; i < buffer->text.size; i++) {
1786                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1787                        return;
1788
1789                /* store original boundaries */
1790                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1791                                buffer->orig_alloc);
1792                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1793                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1794                buffer->orig_nr++;
1795
1796                /* store one word */
1797                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1798                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1799                out->ptr[out->size + j - i] = '\n';
1800                out->size += j - i + 1;
1801
1802                i = j - 1;
1803        }
1804}
1805
1806/* this executes the word diff on the accumulated buffers */
1807static void diff_words_show(struct diff_words_data *diff_words)
1808{
1809        xpparam_t xpp;
1810        xdemitconf_t xecfg;
1811        mmfile_t minus, plus;
1812        struct diff_words_style *style = diff_words->style;
1813
1814        struct diff_options *opt = diff_words->opt;
1815        const char *line_prefix;
1816
1817        assert(opt);
1818        line_prefix = diff_line_prefix(opt);
1819
1820        /* special case: only removal */
1821        if (!diff_words->plus.text.size) {
1822                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1823                                 line_prefix, strlen(line_prefix), 0);
1824                fn_out_diff_words_write_helper(diff_words->opt,
1825                        &style->old, style->newline,
1826                        diff_words->minus.text.size,
1827                        diff_words->minus.text.ptr);
1828                diff_words->minus.text.size = 0;
1829                return;
1830        }
1831
1832        diff_words->current_plus = diff_words->plus.text.ptr;
1833        diff_words->last_minus = 0;
1834
1835        memset(&xpp, 0, sizeof(xpp));
1836        memset(&xecfg, 0, sizeof(xecfg));
1837        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1838        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1839        xpp.flags = 0;
1840        /* as only the hunk header will be parsed, we need a 0-context */
1841        xecfg.ctxlen = 0;
1842        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1843                          &xpp, &xecfg))
1844                die("unable to generate word diff");
1845        free(minus.ptr);
1846        free(plus.ptr);
1847        if (diff_words->current_plus != diff_words->plus.text.ptr +
1848                        diff_words->plus.text.size) {
1849                if (color_words_output_graph_prefix(diff_words))
1850                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1851                                         line_prefix, strlen(line_prefix), 0);
1852                fn_out_diff_words_write_helper(diff_words->opt,
1853                        &style->ctx, style->newline,
1854                        diff_words->plus.text.ptr + diff_words->plus.text.size
1855                        - diff_words->current_plus, diff_words->current_plus);
1856        }
1857        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1858}
1859
1860/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1861static void diff_words_flush(struct emit_callback *ecbdata)
1862{
1863        struct diff_options *wo = ecbdata->diff_words->opt;
1864
1865        if (ecbdata->diff_words->minus.text.size ||
1866            ecbdata->diff_words->plus.text.size)
1867                diff_words_show(ecbdata->diff_words);
1868
1869        if (wo->emitted_symbols) {
1870                struct diff_options *o = ecbdata->opt;
1871                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1872                int i;
1873
1874                /*
1875                 * NEEDSWORK:
1876                 * Instead of appending each, concat all words to a line?
1877                 */
1878                for (i = 0; i < wol->nr; i++)
1879                        append_emitted_diff_symbol(o, &wol->buf[i]);
1880
1881                for (i = 0; i < wol->nr; i++)
1882                        free((void *)wol->buf[i].line);
1883
1884                wol->nr = 0;
1885        }
1886}
1887
1888static void diff_filespec_load_driver(struct diff_filespec *one)
1889{
1890        /* Use already-loaded driver */
1891        if (one->driver)
1892                return;
1893
1894        if (S_ISREG(one->mode))
1895                one->driver = userdiff_find_by_path(one->path);
1896
1897        /* Fallback to default settings */
1898        if (!one->driver)
1899                one->driver = userdiff_find_by_name("default");
1900}
1901
1902static const char *userdiff_word_regex(struct diff_filespec *one)
1903{
1904        diff_filespec_load_driver(one);
1905        return one->driver->word_regex;
1906}
1907
1908static void init_diff_words_data(struct emit_callback *ecbdata,
1909                                 struct diff_options *orig_opts,
1910                                 struct diff_filespec *one,
1911                                 struct diff_filespec *two)
1912{
1913        int i;
1914        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1915        memcpy(o, orig_opts, sizeof(struct diff_options));
1916
1917        ecbdata->diff_words =
1918                xcalloc(1, sizeof(struct diff_words_data));
1919        ecbdata->diff_words->type = o->word_diff;
1920        ecbdata->diff_words->opt = o;
1921
1922        if (orig_opts->emitted_symbols)
1923                o->emitted_symbols =
1924                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1925
1926        if (!o->word_regex)
1927                o->word_regex = userdiff_word_regex(one);
1928        if (!o->word_regex)
1929                o->word_regex = userdiff_word_regex(two);
1930        if (!o->word_regex)
1931                o->word_regex = diff_word_regex_cfg;
1932        if (o->word_regex) {
1933                ecbdata->diff_words->word_regex = (regex_t *)
1934                        xmalloc(sizeof(regex_t));
1935                if (regcomp(ecbdata->diff_words->word_regex,
1936                            o->word_regex,
1937                            REG_EXTENDED | REG_NEWLINE))
1938                        die ("Invalid regular expression: %s",
1939                             o->word_regex);
1940        }
1941        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1942                if (o->word_diff == diff_words_styles[i].type) {
1943                        ecbdata->diff_words->style =
1944                                &diff_words_styles[i];
1945                        break;
1946                }
1947        }
1948        if (want_color(o->use_color)) {
1949                struct diff_words_style *st = ecbdata->diff_words->style;
1950                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1951                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1952                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1953        }
1954}
1955
1956static void free_diff_words_data(struct emit_callback *ecbdata)
1957{
1958        if (ecbdata->diff_words) {
1959                diff_words_flush(ecbdata);
1960                free (ecbdata->diff_words->opt->emitted_symbols);
1961                free (ecbdata->diff_words->opt);
1962                free (ecbdata->diff_words->minus.text.ptr);
1963                free (ecbdata->diff_words->minus.orig);
1964                free (ecbdata->diff_words->plus.text.ptr);
1965                free (ecbdata->diff_words->plus.orig);
1966                if (ecbdata->diff_words->word_regex) {
1967                        regfree(ecbdata->diff_words->word_regex);
1968                        free(ecbdata->diff_words->word_regex);
1969                }
1970                FREE_AND_NULL(ecbdata->diff_words);
1971        }
1972}
1973
1974const char *diff_get_color(int diff_use_color, enum color_diff ix)
1975{
1976        if (want_color(diff_use_color))
1977                return diff_colors[ix];
1978        return "";
1979}
1980
1981const char *diff_line_prefix(struct diff_options *opt)
1982{
1983        struct strbuf *msgbuf;
1984        if (!opt->output_prefix)
1985                return "";
1986
1987        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1988        return msgbuf->buf;
1989}
1990
1991static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1992{
1993        const char *cp;
1994        unsigned long allot;
1995        size_t l = len;
1996
1997        cp = line;
1998        allot = l;
1999        while (0 < l) {
2000                (void) utf8_width(&cp, &l);
2001                if (!cp)
2002                        break; /* truncated in the middle? */
2003        }
2004        return allot - l;
2005}
2006
2007static void find_lno(const char *line, struct emit_callback *ecbdata)
2008{
2009        const char *p;
2010        ecbdata->lno_in_preimage = 0;
2011        ecbdata->lno_in_postimage = 0;
2012        p = strchr(line, '-');
2013        if (!p)
2014                return; /* cannot happen */
2015        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2016        p = strchr(p, '+');
2017        if (!p)
2018                return; /* cannot happen */
2019        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2020}
2021
2022static void fn_out_consume(void *priv, char *line, unsigned long len)
2023{
2024        struct emit_callback *ecbdata = priv;
2025        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2026        struct diff_options *o = ecbdata->opt;
2027
2028        o->found_changes = 1;
2029
2030        if (ecbdata->header) {
2031                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2032                                 ecbdata->header->buf, ecbdata->header->len, 0);
2033                strbuf_reset(ecbdata->header);
2034                ecbdata->header = NULL;
2035        }
2036
2037        if (ecbdata->label_path[0]) {
2038                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2039                                 ecbdata->label_path[0],
2040                                 strlen(ecbdata->label_path[0]), 0);
2041                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2042                                 ecbdata->label_path[1],
2043                                 strlen(ecbdata->label_path[1]), 0);
2044                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2045        }
2046
2047        if (diff_suppress_blank_empty
2048            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2049                line[0] = '\n';
2050                len = 1;
2051        }
2052
2053        if (line[0] == '@') {
2054                if (ecbdata->diff_words)
2055                        diff_words_flush(ecbdata);
2056                len = sane_truncate_line(ecbdata, line, len);
2057                find_lno(line, ecbdata);
2058                emit_hunk_header(ecbdata, line, len);
2059                return;
2060        }
2061
2062        if (ecbdata->diff_words) {
2063                enum diff_symbol s =
2064                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2065                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2066                if (line[0] == '-') {
2067                        diff_words_append(line, len,
2068                                          &ecbdata->diff_words->minus);
2069                        return;
2070                } else if (line[0] == '+') {
2071                        diff_words_append(line, len,
2072                                          &ecbdata->diff_words->plus);
2073                        return;
2074                } else if (starts_with(line, "\\ ")) {
2075                        /*
2076                         * Eat the "no newline at eof" marker as if we
2077                         * saw a "+" or "-" line with nothing on it,
2078                         * and return without diff_words_flush() to
2079                         * defer processing. If this is the end of
2080                         * preimage, more "+" lines may come after it.
2081                         */
2082                        return;
2083                }
2084                diff_words_flush(ecbdata);
2085                emit_diff_symbol(o, s, line, len, 0);
2086                return;
2087        }
2088
2089        switch (line[0]) {
2090        case '+':
2091                ecbdata->lno_in_postimage++;
2092                emit_add_line(reset, ecbdata, line + 1, len - 1);
2093                break;
2094        case '-':
2095                ecbdata->lno_in_preimage++;
2096                emit_del_line(reset, ecbdata, line + 1, len - 1);
2097                break;
2098        case ' ':
2099                ecbdata->lno_in_postimage++;
2100                ecbdata->lno_in_preimage++;
2101                emit_context_line(reset, ecbdata, line + 1, len - 1);
2102                break;
2103        default:
2104                /* incomplete line at the end */
2105                ecbdata->lno_in_preimage++;
2106                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2107                                 line, len, 0);
2108                break;
2109        }
2110}
2111
2112static char *pprint_rename(const char *a, const char *b)
2113{
2114        const char *old = a;
2115        const char *new = b;
2116        struct strbuf name = STRBUF_INIT;
2117        int pfx_length, sfx_length;
2118        int pfx_adjust_for_slash;
2119        int len_a = strlen(a);
2120        int len_b = strlen(b);
2121        int a_midlen, b_midlen;
2122        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2123        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2124
2125        if (qlen_a || qlen_b) {
2126                quote_c_style(a, &name, NULL, 0);
2127                strbuf_addstr(&name, " => ");
2128                quote_c_style(b, &name, NULL, 0);
2129                return strbuf_detach(&name, NULL);
2130        }
2131
2132        /* Find common prefix */
2133        pfx_length = 0;
2134        while (*old && *new && *old == *new) {
2135                if (*old == '/')
2136                        pfx_length = old - a + 1;
2137                old++;
2138                new++;
2139        }
2140
2141        /* Find common suffix */
2142        old = a + len_a;
2143        new = b + len_b;
2144        sfx_length = 0;
2145        /*
2146         * If there is a common prefix, it must end in a slash.  In
2147         * that case we let this loop run 1 into the prefix to see the
2148         * same slash.
2149         *
2150         * If there is no common prefix, we cannot do this as it would
2151         * underrun the input strings.
2152         */
2153        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2154        while (a + pfx_length - pfx_adjust_for_slash <= old &&
2155               b + pfx_length - pfx_adjust_for_slash <= new &&
2156               *old == *new) {
2157                if (*old == '/')
2158                        sfx_length = len_a - (old - a);
2159                old--;
2160                new--;
2161        }
2162
2163        /*
2164         * pfx{mid-a => mid-b}sfx
2165         * {pfx-a => pfx-b}sfx
2166         * pfx{sfx-a => sfx-b}
2167         * name-a => name-b
2168         */
2169        a_midlen = len_a - pfx_length - sfx_length;
2170        b_midlen = len_b - pfx_length - sfx_length;
2171        if (a_midlen < 0)
2172                a_midlen = 0;
2173        if (b_midlen < 0)
2174                b_midlen = 0;
2175
2176        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2177        if (pfx_length + sfx_length) {
2178                strbuf_add(&name, a, pfx_length);
2179                strbuf_addch(&name, '{');
2180        }
2181        strbuf_add(&name, a + pfx_length, a_midlen);
2182        strbuf_addstr(&name, " => ");
2183        strbuf_add(&name, b + pfx_length, b_midlen);
2184        if (pfx_length + sfx_length) {
2185                strbuf_addch(&name, '}');
2186                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
2187        }
2188        return strbuf_detach(&name, NULL);
2189}
2190
2191struct diffstat_t {
2192        int nr;
2193        int alloc;
2194        struct diffstat_file {
2195                char *from_name;
2196                char *name;
2197                char *print_name;
2198                unsigned is_unmerged:1;
2199                unsigned is_binary:1;
2200                unsigned is_renamed:1;
2201                unsigned is_interesting:1;
2202                uintmax_t added, deleted;
2203        } **files;
2204};
2205
2206static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2207                                          const char *name_a,
2208                                          const char *name_b)
2209{
2210        struct diffstat_file *x;
2211        x = xcalloc(1, sizeof(*x));
2212        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2213        diffstat->files[diffstat->nr++] = x;
2214        if (name_b) {
2215                x->from_name = xstrdup(name_a);
2216                x->name = xstrdup(name_b);
2217                x->is_renamed = 1;
2218        }
2219        else {
2220                x->from_name = NULL;
2221                x->name = xstrdup(name_a);
2222        }
2223        return x;
2224}
2225
2226static void diffstat_consume(void *priv, char *line, unsigned long len)
2227{
2228        struct diffstat_t *diffstat = priv;
2229        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2230
2231        if (line[0] == '+')
2232                x->added++;
2233        else if (line[0] == '-')
2234                x->deleted++;
2235}
2236
2237const char mime_boundary_leader[] = "------------";
2238
2239static int scale_linear(int it, int width, int max_change)
2240{
2241        if (!it)
2242                return 0;
2243        /*
2244         * make sure that at least one '-' or '+' is printed if
2245         * there is any change to this path. The easiest way is to
2246         * scale linearly as if the alloted width is one column shorter
2247         * than it is, and then add 1 to the result.
2248         */
2249        return 1 + (it * (width - 1) / max_change);
2250}
2251
2252static void show_graph(struct strbuf *out, char ch, int cnt,
2253                       const char *set, const char *reset)
2254{
2255        if (cnt <= 0)
2256                return;
2257        strbuf_addstr(out, set);
2258        strbuf_addchars(out, ch, cnt);
2259        strbuf_addstr(out, reset);
2260}
2261
2262static void fill_print_name(struct diffstat_file *file)
2263{
2264        char *pname;
2265
2266        if (file->print_name)
2267                return;
2268
2269        if (!file->is_renamed) {
2270                struct strbuf buf = STRBUF_INIT;
2271                if (quote_c_style(file->name, &buf, NULL, 0)) {
2272                        pname = strbuf_detach(&buf, NULL);
2273                } else {
2274                        pname = file->name;
2275                        strbuf_release(&buf);
2276                }
2277        } else {
2278                pname = pprint_rename(file->from_name, file->name);
2279        }
2280        file->print_name = pname;
2281}
2282
2283static void print_stat_summary_inserts_deletes(struct diff_options *options,
2284                int files, int insertions, int deletions)
2285{
2286        struct strbuf sb = STRBUF_INIT;
2287
2288        if (!files) {
2289                assert(insertions == 0 && deletions == 0);
2290                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2291                                 NULL, 0, 0);
2292                return;
2293        }
2294
2295        strbuf_addf(&sb,
2296                    (files == 1) ? " %d file changed" : " %d files changed",
2297                    files);
2298
2299        /*
2300         * For binary diff, the caller may want to print "x files
2301         * changed" with insertions == 0 && deletions == 0.
2302         *
2303         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2304         * is probably less confusing (i.e skip over "2 files changed
2305         * but nothing about added/removed lines? Is this a bug in Git?").
2306         */
2307        if (insertions || deletions == 0) {
2308                strbuf_addf(&sb,
2309                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2310                            insertions);
2311        }
2312
2313        if (deletions || insertions == 0) {
2314                strbuf_addf(&sb,
2315                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2316                            deletions);
2317        }
2318        strbuf_addch(&sb, '\n');
2319        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2320                         sb.buf, sb.len, 0);
2321        strbuf_release(&sb);
2322}
2323
2324void print_stat_summary(FILE *fp, int files,
2325                        int insertions, int deletions)
2326{
2327        struct diff_options o;
2328        memset(&o, 0, sizeof(o));
2329        o.file = fp;
2330
2331        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2332}
2333
2334static void show_stats(struct diffstat_t *data, struct diff_options *options)
2335{
2336        int i, len, add, del, adds = 0, dels = 0;
2337        uintmax_t max_change = 0, max_len = 0;
2338        int total_files = data->nr, count;
2339        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2340        const char *reset, *add_c, *del_c;
2341        int extra_shown = 0;
2342        const char *line_prefix = diff_line_prefix(options);
2343        struct strbuf out = STRBUF_INIT;
2344
2345        if (data->nr == 0)
2346                return;
2347
2348        count = options->stat_count ? options->stat_count : data->nr;
2349
2350        reset = diff_get_color_opt(options, DIFF_RESET);
2351        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2352        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2353
2354        /*
2355         * Find the longest filename and max number of changes
2356         */
2357        for (i = 0; (i < count) && (i < data->nr); i++) {
2358                struct diffstat_file *file = data->files[i];
2359                uintmax_t change = file->added + file->deleted;
2360
2361                if (!file->is_interesting && (change == 0)) {
2362                        count++; /* not shown == room for one more */
2363                        continue;
2364                }
2365                fill_print_name(file);
2366                len = strlen(file->print_name);
2367                if (max_len < len)
2368                        max_len = len;
2369
2370                if (file->is_unmerged) {
2371                        /* "Unmerged" is 8 characters */
2372                        bin_width = bin_width < 8 ? 8 : bin_width;
2373                        continue;
2374                }
2375                if (file->is_binary) {
2376                        /* "Bin XXX -> YYY bytes" */
2377                        int w = 14 + decimal_width(file->added)
2378                                + decimal_width(file->deleted);
2379                        bin_width = bin_width < w ? w : bin_width;
2380                        /* Display change counts aligned with "Bin" */
2381                        number_width = 3;
2382                        continue;
2383                }
2384
2385                if (max_change < change)
2386                        max_change = change;
2387        }
2388        count = i; /* where we can stop scanning in data->files[] */
2389
2390        /*
2391         * We have width = stat_width or term_columns() columns total.
2392         * We want a maximum of min(max_len, stat_name_width) for the name part.
2393         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2394         * We also need 1 for " " and 4 + decimal_width(max_change)
2395         * for " | NNNN " and one the empty column at the end, altogether
2396         * 6 + decimal_width(max_change).
2397         *
2398         * If there's not enough space, we will use the smaller of
2399         * stat_name_width (if set) and 5/8*width for the filename,
2400         * and the rest for constant elements + graph part, but no more
2401         * than stat_graph_width for the graph part.
2402         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2403         * for the standard terminal size).
2404         *
2405         * In other words: stat_width limits the maximum width, and
2406         * stat_name_width fixes the maximum width of the filename,
2407         * and is also used to divide available columns if there
2408         * aren't enough.
2409         *
2410         * Binary files are displayed with "Bin XXX -> YYY bytes"
2411         * instead of the change count and graph. This part is treated
2412         * similarly to the graph part, except that it is not
2413         * "scaled". If total width is too small to accommodate the
2414         * guaranteed minimum width of the filename part and the
2415         * separators and this message, this message will "overflow"
2416         * making the line longer than the maximum width.
2417         */
2418
2419        if (options->stat_width == -1)
2420                width = term_columns() - strlen(line_prefix);
2421        else
2422                width = options->stat_width ? options->stat_width : 80;
2423        number_width = decimal_width(max_change) > number_width ?
2424                decimal_width(max_change) : number_width;
2425
2426        if (options->stat_graph_width == -1)
2427                options->stat_graph_width = diff_stat_graph_width;
2428
2429        /*
2430         * Guarantee 3/8*16==6 for the graph part
2431         * and 5/8*16==10 for the filename part
2432         */
2433        if (width < 16 + 6 + number_width)
2434                width = 16 + 6 + number_width;
2435
2436        /*
2437         * First assign sizes that are wanted, ignoring available width.
2438         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2439         * starting from "XXX" should fit in graph_width.
2440         */
2441        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2442        if (options->stat_graph_width &&
2443            options->stat_graph_width < graph_width)
2444                graph_width = options->stat_graph_width;
2445
2446        name_width = (options->stat_name_width > 0 &&
2447                      options->stat_name_width < max_len) ?
2448                options->stat_name_width : max_len;
2449
2450        /*
2451         * Adjust adjustable widths not to exceed maximum width
2452         */
2453        if (name_width + number_width + 6 + graph_width > width) {
2454                if (graph_width > width * 3/8 - number_width - 6) {
2455                        graph_width = width * 3/8 - number_width - 6;
2456                        if (graph_width < 6)
2457                                graph_width = 6;
2458                }
2459
2460                if (options->stat_graph_width &&
2461                    graph_width > options->stat_graph_width)
2462                        graph_width = options->stat_graph_width;
2463                if (name_width > width - number_width - 6 - graph_width)
2464                        name_width = width - number_width - 6 - graph_width;
2465                else
2466                        graph_width = width - number_width - 6 - name_width;
2467        }
2468
2469        /*
2470         * From here name_width is the width of the name area,
2471         * and graph_width is the width of the graph area.
2472         * max_change is used to scale graph properly.
2473         */
2474        for (i = 0; i < count; i++) {
2475                const char *prefix = "";
2476                struct diffstat_file *file = data->files[i];
2477                char *name = file->print_name;
2478                uintmax_t added = file->added;
2479                uintmax_t deleted = file->deleted;
2480                int name_len;
2481
2482                if (!file->is_interesting && (added + deleted == 0))
2483                        continue;
2484
2485                /*
2486                 * "scale" the filename
2487                 */
2488                len = name_width;
2489                name_len = strlen(name);
2490                if (name_width < name_len) {
2491                        char *slash;
2492                        prefix = "...";
2493                        len -= 3;
2494                        name += name_len - len;
2495                        slash = strchr(name, '/');
2496                        if (slash)
2497                                name = slash;
2498                }
2499
2500                if (file->is_binary) {
2501                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2502                        strbuf_addf(&out, " %*s", number_width, "Bin");
2503                        if (!added && !deleted) {
2504                                strbuf_addch(&out, '\n');
2505                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2506                                                 out.buf, out.len, 0);
2507                                strbuf_reset(&out);
2508                                continue;
2509                        }
2510                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2511                                del_c, deleted, reset);
2512                        strbuf_addstr(&out, " -> ");
2513                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2514                                add_c, added, reset);
2515                        strbuf_addstr(&out, " bytes\n");
2516                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2517                                         out.buf, out.len, 0);
2518                        strbuf_reset(&out);
2519                        continue;
2520                }
2521                else if (file->is_unmerged) {
2522                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2523                        strbuf_addstr(&out, " Unmerged\n");
2524                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2525                                         out.buf, out.len, 0);
2526                        strbuf_reset(&out);
2527                        continue;
2528                }
2529
2530                /*
2531                 * scale the add/delete
2532                 */
2533                add = added;
2534                del = deleted;
2535
2536                if (graph_width <= max_change) {
2537                        int total = scale_linear(add + del, graph_width, max_change);
2538                        if (total < 2 && add && del)
2539                                /* width >= 2 due to the sanity check */
2540                                total = 2;
2541                        if (add < del) {
2542                                add = scale_linear(add, graph_width, max_change);
2543                                del = total - add;
2544                        } else {
2545                                del = scale_linear(del, graph_width, max_change);
2546                                add = total - del;
2547                        }
2548                }
2549                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2550                strbuf_addf(&out, " %*"PRIuMAX"%s",
2551                        number_width, added + deleted,
2552                        added + deleted ? " " : "");
2553                show_graph(&out, '+', add, add_c, reset);
2554                show_graph(&out, '-', del, del_c, reset);
2555                strbuf_addch(&out, '\n');
2556                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2557                                 out.buf, out.len, 0);
2558                strbuf_reset(&out);
2559        }
2560
2561        for (i = 0; i < data->nr; i++) {
2562                struct diffstat_file *file = data->files[i];
2563                uintmax_t added = file->added;
2564                uintmax_t deleted = file->deleted;
2565
2566                if (file->is_unmerged ||
2567                    (!file->is_interesting && (added + deleted == 0))) {
2568                        total_files--;
2569                        continue;
2570                }
2571
2572                if (!file->is_binary) {
2573                        adds += added;
2574                        dels += deleted;
2575                }
2576                if (i < count)
2577                        continue;
2578                if (!extra_shown)
2579                        emit_diff_symbol(options,
2580                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2581                                         NULL, 0, 0);
2582                extra_shown = 1;
2583        }
2584
2585        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2586        strbuf_release(&out);
2587}
2588
2589static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2590{
2591        int i, adds = 0, dels = 0, total_files = data->nr;
2592
2593        if (data->nr == 0)
2594                return;
2595
2596        for (i = 0; i < data->nr; i++) {
2597                int added = data->files[i]->added;
2598                int deleted = data->files[i]->deleted;
2599
2600                if (data->files[i]->is_unmerged ||
2601                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2602                        total_files--;
2603                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2604                        adds += added;
2605                        dels += deleted;
2606                }
2607        }
2608        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2609}
2610
2611static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2612{
2613        int i;
2614
2615        if (data->nr == 0)
2616                return;
2617
2618        for (i = 0; i < data->nr; i++) {
2619                struct diffstat_file *file = data->files[i];
2620
2621                fprintf(options->file, "%s", diff_line_prefix(options));
2622
2623                if (file->is_binary)
2624                        fprintf(options->file, "-\t-\t");
2625                else
2626                        fprintf(options->file,
2627                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2628                                file->added, file->deleted);
2629                if (options->line_termination) {
2630                        fill_print_name(file);
2631                        if (!file->is_renamed)
2632                                write_name_quoted(file->name, options->file,
2633                                                  options->line_termination);
2634                        else {
2635                                fputs(file->print_name, options->file);
2636                                putc(options->line_termination, options->file);
2637                        }
2638                } else {
2639                        if (file->is_renamed) {
2640                                putc('\0', options->file);
2641                                write_name_quoted(file->from_name, options->file, '\0');
2642                        }
2643                        write_name_quoted(file->name, options->file, '\0');
2644                }
2645        }
2646}
2647
2648struct dirstat_file {
2649        const char *name;
2650        unsigned long changed;
2651};
2652
2653struct dirstat_dir {
2654        struct dirstat_file *files;
2655        int alloc, nr, permille, cumulative;
2656};
2657
2658static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2659                unsigned long changed, const char *base, int baselen)
2660{
2661        unsigned long this_dir = 0;
2662        unsigned int sources = 0;
2663        const char *line_prefix = diff_line_prefix(opt);
2664
2665        while (dir->nr) {
2666                struct dirstat_file *f = dir->files;
2667                int namelen = strlen(f->name);
2668                unsigned long this;
2669                char *slash;
2670
2671                if (namelen < baselen)
2672                        break;
2673                if (memcmp(f->name, base, baselen))
2674                        break;
2675                slash = strchr(f->name + baselen, '/');
2676                if (slash) {
2677                        int newbaselen = slash + 1 - f->name;
2678                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2679                        sources++;
2680                } else {
2681                        this = f->changed;
2682                        dir->files++;
2683                        dir->nr--;
2684                        sources += 2;
2685                }
2686                this_dir += this;
2687        }
2688
2689        /*
2690         * We don't report dirstat's for
2691         *  - the top level
2692         *  - or cases where everything came from a single directory
2693         *    under this directory (sources == 1).
2694         */
2695        if (baselen && sources != 1) {
2696                if (this_dir) {
2697                        int permille = this_dir * 1000 / changed;
2698                        if (permille >= dir->permille) {
2699                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2700                                        permille / 10, permille % 10, baselen, base);
2701                                if (!dir->cumulative)
2702                                        return 0;
2703                        }
2704                }
2705        }
2706        return this_dir;
2707}
2708
2709static int dirstat_compare(const void *_a, const void *_b)
2710{
2711        const struct dirstat_file *a = _a;
2712        const struct dirstat_file *b = _b;
2713        return strcmp(a->name, b->name);
2714}
2715
2716static void show_dirstat(struct diff_options *options)
2717{
2718        int i;
2719        unsigned long changed;
2720        struct dirstat_dir dir;
2721        struct diff_queue_struct *q = &diff_queued_diff;
2722
2723        dir.files = NULL;
2724        dir.alloc = 0;
2725        dir.nr = 0;
2726        dir.permille = options->dirstat_permille;
2727        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2728
2729        changed = 0;
2730        for (i = 0; i < q->nr; i++) {
2731                struct diff_filepair *p = q->queue[i];
2732                const char *name;
2733                unsigned long copied, added, damage;
2734                int content_changed;
2735
2736                name = p->two->path ? p->two->path : p->one->path;
2737
2738                if (p->one->oid_valid && p->two->oid_valid)
2739                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2740                else
2741                        content_changed = 1;
2742
2743                if (!content_changed) {
2744                        /*
2745                         * The SHA1 has not changed, so pre-/post-content is
2746                         * identical. We can therefore skip looking at the
2747                         * file contents altogether.
2748                         */
2749                        damage = 0;
2750                        goto found_damage;
2751                }
2752
2753                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2754                        /*
2755                         * In --dirstat-by-file mode, we don't really need to
2756                         * look at the actual file contents at all.
2757                         * The fact that the SHA1 changed is enough for us to
2758                         * add this file to the list of results
2759                         * (with each file contributing equal damage).
2760                         */
2761                        damage = 1;
2762                        goto found_damage;
2763                }
2764
2765                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2766                        diff_populate_filespec(p->one, 0);
2767                        diff_populate_filespec(p->two, 0);
2768                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2769                                               &copied, &added);
2770                        diff_free_filespec_data(p->one);
2771                        diff_free_filespec_data(p->two);
2772                } else if (DIFF_FILE_VALID(p->one)) {
2773                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2774                        copied = added = 0;
2775                        diff_free_filespec_data(p->one);
2776                } else if (DIFF_FILE_VALID(p->two)) {
2777                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2778                        copied = 0;
2779                        added = p->two->size;
2780                        diff_free_filespec_data(p->two);
2781                } else
2782                        continue;
2783
2784                /*
2785                 * Original minus copied is the removed material,
2786                 * added is the new material.  They are both damages
2787                 * made to the preimage.
2788                 * If the resulting damage is zero, we know that
2789                 * diffcore_count_changes() considers the two entries to
2790                 * be identical, but since content_changed is true, we
2791                 * know that there must have been _some_ kind of change,
2792                 * so we force all entries to have damage > 0.
2793                 */
2794                damage = (p->one->size - copied) + added;
2795                if (!damage)
2796                        damage = 1;
2797
2798found_damage:
2799                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2800                dir.files[dir.nr].name = name;
2801                dir.files[dir.nr].changed = damage;
2802                changed += damage;
2803                dir.nr++;
2804        }
2805
2806        /* This can happen even with many files, if everything was renames */
2807        if (!changed)
2808                return;
2809
2810        /* Show all directories with more than x% of the changes */
2811        QSORT(dir.files, dir.nr, dirstat_compare);
2812        gather_dirstat(options, &dir, changed, "", 0);
2813}
2814
2815static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2816{
2817        int i;
2818        unsigned long changed;
2819        struct dirstat_dir dir;
2820
2821        if (data->nr == 0)
2822                return;
2823
2824        dir.files = NULL;
2825        dir.alloc = 0;
2826        dir.nr = 0;
2827        dir.permille = options->dirstat_permille;
2828        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2829
2830        changed = 0;
2831        for (i = 0; i < data->nr; i++) {
2832                struct diffstat_file *file = data->files[i];
2833                unsigned long damage = file->added + file->deleted;
2834                if (file->is_binary)
2835                        /*
2836                         * binary files counts bytes, not lines. Must find some
2837                         * way to normalize binary bytes vs. textual lines.
2838                         * The following heuristic assumes that there are 64
2839                         * bytes per "line".
2840                         * This is stupid and ugly, but very cheap...
2841                         */
2842                        damage = DIV_ROUND_UP(damage, 64);
2843                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2844                dir.files[dir.nr].name = file->name;
2845                dir.files[dir.nr].changed = damage;
2846                changed += damage;
2847                dir.nr++;
2848        }
2849
2850        /* This can happen even with many files, if everything was renames */
2851        if (!changed)
2852                return;
2853
2854        /* Show all directories with more than x% of the changes */
2855        QSORT(dir.files, dir.nr, dirstat_compare);
2856        gather_dirstat(options, &dir, changed, "", 0);
2857}
2858
2859static void free_diffstat_info(struct diffstat_t *diffstat)
2860{
2861        int i;
2862        for (i = 0; i < diffstat->nr; i++) {
2863                struct diffstat_file *f = diffstat->files[i];
2864                if (f->name != f->print_name)
2865                        free(f->print_name);
2866                free(f->name);
2867                free(f->from_name);
2868                free(f);
2869        }
2870        free(diffstat->files);
2871}
2872
2873struct checkdiff_t {
2874        const char *filename;
2875        int lineno;
2876        int conflict_marker_size;
2877        struct diff_options *o;
2878        unsigned ws_rule;
2879        unsigned status;
2880};
2881
2882static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2883{
2884        char firstchar;
2885        int cnt;
2886
2887        if (len < marker_size + 1)
2888                return 0;
2889        firstchar = line[0];
2890        switch (firstchar) {
2891        case '=': case '>': case '<': case '|':
2892                break;
2893        default:
2894                return 0;
2895        }
2896        for (cnt = 1; cnt < marker_size; cnt++)
2897                if (line[cnt] != firstchar)
2898                        return 0;
2899        /* line[1] thru line[marker_size-1] are same as firstchar */
2900        if (len < marker_size + 1 || !isspace(line[marker_size]))
2901                return 0;
2902        return 1;
2903}
2904
2905static void checkdiff_consume(void *priv, char *line, unsigned long len)
2906{
2907        struct checkdiff_t *data = priv;
2908        int marker_size = data->conflict_marker_size;
2909        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2910        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2911        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2912        char *err;
2913        const char *line_prefix;
2914
2915        assert(data->o);
2916        line_prefix = diff_line_prefix(data->o);
2917
2918        if (line[0] == '+') {
2919                unsigned bad;
2920                data->lineno++;
2921                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2922                        data->status |= 1;
2923                        fprintf(data->o->file,
2924                                "%s%s:%d: leftover conflict marker\n",
2925                                line_prefix, data->filename, data->lineno);
2926                }
2927                bad = ws_check(line + 1, len - 1, data->ws_rule);
2928                if (!bad)
2929                        return;
2930                data->status |= bad;
2931                err = whitespace_error_string(bad);
2932                fprintf(data->o->file, "%s%s:%d: %s.\n",
2933                        line_prefix, data->filename, data->lineno, err);
2934                free(err);
2935                emit_line(data->o, set, reset, line, 1);
2936                ws_check_emit(line + 1, len - 1, data->ws_rule,
2937                              data->o->file, set, reset, ws);
2938        } else if (line[0] == ' ') {
2939                data->lineno++;
2940        } else if (line[0] == '@') {
2941                char *plus = strchr(line, '+');
2942                if (plus)
2943                        data->lineno = strtol(plus, NULL, 10) - 1;
2944                else
2945                        die("invalid diff");
2946        }
2947}
2948
2949static unsigned char *deflate_it(char *data,
2950                                 unsigned long size,
2951                                 unsigned long *result_size)
2952{
2953        int bound;
2954        unsigned char *deflated;
2955        git_zstream stream;
2956
2957        git_deflate_init(&stream, zlib_compression_level);
2958        bound = git_deflate_bound(&stream, size);
2959        deflated = xmalloc(bound);
2960        stream.next_out = deflated;
2961        stream.avail_out = bound;
2962
2963        stream.next_in = (unsigned char *)data;
2964        stream.avail_in = size;
2965        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2966                ; /* nothing */
2967        git_deflate_end(&stream);
2968        *result_size = stream.total_out;
2969        return deflated;
2970}
2971
2972static void emit_binary_diff_body(struct diff_options *o,
2973                                  mmfile_t *one, mmfile_t *two)
2974{
2975        void *cp;
2976        void *delta;
2977        void *deflated;
2978        void *data;
2979        unsigned long orig_size;
2980        unsigned long delta_size;
2981        unsigned long deflate_size;
2982        unsigned long data_size;
2983
2984        /* We could do deflated delta, or we could do just deflated two,
2985         * whichever is smaller.
2986         */
2987        delta = NULL;
2988        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2989        if (one->size && two->size) {
2990                delta = diff_delta(one->ptr, one->size,
2991                                   two->ptr, two->size,
2992                                   &delta_size, deflate_size);
2993                if (delta) {
2994                        void *to_free = delta;
2995                        orig_size = delta_size;
2996                        delta = deflate_it(delta, delta_size, &delta_size);
2997                        free(to_free);
2998                }
2999        }
3000
3001        if (delta && delta_size < deflate_size) {
3002                char *s = xstrfmt("%lu", orig_size);
3003                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3004                                 s, strlen(s), 0);
3005                free(s);
3006                free(deflated);
3007                data = delta;
3008                data_size = delta_size;
3009        } else {
3010                char *s = xstrfmt("%lu", two->size);
3011                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3012                                 s, strlen(s), 0);
3013                free(s);
3014                free(delta);
3015                data = deflated;
3016                data_size = deflate_size;
3017        }
3018
3019        /* emit data encoded in base85 */
3020        cp = data;
3021        while (data_size) {
3022                int len;
3023                int bytes = (52 < data_size) ? 52 : data_size;
3024                char line[71];
3025                data_size -= bytes;
3026                if (bytes <= 26)
3027                        line[0] = bytes + 'A' - 1;
3028                else
3029                        line[0] = bytes - 26 + 'a' - 1;
3030                encode_85(line + 1, cp, bytes);
3031                cp = (char *) cp + bytes;
3032
3033                len = strlen(line);
3034                line[len++] = '\n';
3035                line[len] = '\0';
3036
3037                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3038                                 line, len, 0);
3039        }
3040        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3041        free(data);
3042}
3043
3044static void emit_binary_diff(struct diff_options *o,
3045                             mmfile_t *one, mmfile_t *two)
3046{
3047        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3048        emit_binary_diff_body(o, one, two);
3049        emit_binary_diff_body(o, two, one);
3050}
3051
3052int diff_filespec_is_binary(struct diff_filespec *one)
3053{
3054        if (one->is_binary == -1) {
3055                diff_filespec_load_driver(one);
3056                if (one->driver->binary != -1)
3057                        one->is_binary = one->driver->binary;
3058                else {
3059                        if (!one->data && DIFF_FILE_VALID(one))
3060                                diff_populate_filespec(one, CHECK_BINARY);
3061                        if (one->is_binary == -1 && one->data)
3062                                one->is_binary = buffer_is_binary(one->data,
3063                                                one->size);
3064                        if (one->is_binary == -1)
3065                                one->is_binary = 0;
3066                }
3067        }
3068        return one->is_binary;
3069}
3070
3071static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3072{
3073        diff_filespec_load_driver(one);
3074        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3075}
3076
3077void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3078{
3079        if (!options->a_prefix)
3080                options->a_prefix = a;
3081        if (!options->b_prefix)
3082                options->b_prefix = b;
3083}
3084
3085struct userdiff_driver *get_textconv(struct diff_filespec *one)
3086{
3087        if (!DIFF_FILE_VALID(one))
3088                return NULL;
3089
3090        diff_filespec_load_driver(one);
3091        return userdiff_get_textconv(one->driver);
3092}
3093
3094static void builtin_diff(const char *name_a,
3095                         const char *name_b,
3096                         struct diff_filespec *one,
3097                         struct diff_filespec *two,
3098                         const char *xfrm_msg,
3099                         int must_show_header,
3100                         struct diff_options *o,
3101                         int complete_rewrite)
3102{
3103        mmfile_t mf1, mf2;
3104        const char *lbl[2];
3105        char *a_one, *b_two;
3106        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3107        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3108        const char *a_prefix, *b_prefix;
3109        struct userdiff_driver *textconv_one = NULL;
3110        struct userdiff_driver *textconv_two = NULL;
3111        struct strbuf header = STRBUF_INIT;
3112        const char *line_prefix = diff_line_prefix(o);
3113
3114        diff_set_mnemonic_prefix(o, "a/", "b/");
3115        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
3116                a_prefix = o->b_prefix;
3117                b_prefix = o->a_prefix;
3118        } else {
3119                a_prefix = o->a_prefix;
3120                b_prefix = o->b_prefix;
3121        }
3122
3123        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3124            (!one->mode || S_ISGITLINK(one->mode)) &&
3125            (!two->mode || S_ISGITLINK(two->mode))) {
3126                show_submodule_summary(o, one->path ? one->path : two->path,
3127                                &one->oid, &two->oid,
3128                                two->dirty_submodule);
3129                return;
3130        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3131                   (!one->mode || S_ISGITLINK(one->mode)) &&
3132                   (!two->mode || S_ISGITLINK(two->mode))) {
3133                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3134                                &one->oid, &two->oid,
3135                                two->dirty_submodule);
3136                return;
3137        }
3138
3139        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
3140                textconv_one = get_textconv(one);
3141                textconv_two = get_textconv(two);
3142        }
3143
3144        /* Never use a non-valid filename anywhere if at all possible */
3145        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3146        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3147
3148        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3149        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3150        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3151        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3152        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3153        if (lbl[0][0] == '/') {
3154                /* /dev/null */
3155                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3156                if (xfrm_msg)
3157                        strbuf_addstr(&header, xfrm_msg);
3158                must_show_header = 1;
3159        }
3160        else if (lbl[1][0] == '/') {
3161                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3162                if (xfrm_msg)
3163                        strbuf_addstr(&header, xfrm_msg);
3164                must_show_header = 1;
3165        }
3166        else {
3167                if (one->mode != two->mode) {
3168                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3169                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3170                        must_show_header = 1;
3171                }
3172                if (xfrm_msg)
3173                        strbuf_addstr(&header, xfrm_msg);
3174
3175                /*
3176                 * we do not run diff between different kind
3177                 * of objects.
3178                 */
3179                if ((one->mode ^ two->mode) & S_IFMT)
3180                        goto free_ab_and_return;
3181                if (complete_rewrite &&
3182                    (textconv_one || !diff_filespec_is_binary(one)) &&
3183                    (textconv_two || !diff_filespec_is_binary(two))) {
3184                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3185                                         header.buf, header.len, 0);
3186                        strbuf_reset(&header);
3187                        emit_rewrite_diff(name_a, name_b, one, two,
3188                                                textconv_one, textconv_two, o);
3189                        o->found_changes = 1;
3190                        goto free_ab_and_return;
3191                }
3192        }
3193
3194        if (o->irreversible_delete && lbl[1][0] == '/') {
3195                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3196                                 header.len, 0);
3197                strbuf_reset(&header);
3198                goto free_ab_and_return;
3199        } else if (!DIFF_OPT_TST(o, TEXT) &&
3200            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3201              (!textconv_two && diff_filespec_is_binary(two)) )) {
3202                struct strbuf sb = STRBUF_INIT;
3203                if (!one->data && !two->data &&
3204                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3205                    !DIFF_OPT_TST(o, BINARY)) {
3206                        if (!oidcmp(&one->oid, &two->oid)) {
3207                                if (must_show_header)
3208                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3209                                                         header.buf, header.len,
3210                                                         0);
3211                                goto free_ab_and_return;
3212                        }
3213                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3214                                         header.buf, header.len, 0);
3215                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3216                                    diff_line_prefix(o), lbl[0], lbl[1]);
3217                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3218                                         sb.buf, sb.len, 0);
3219                        strbuf_release(&sb);
3220                        goto free_ab_and_return;
3221                }
3222                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3223                        die("unable to read files to diff");
3224                /* Quite common confusing case */
3225                if (mf1.size == mf2.size &&
3226                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3227                        if (must_show_header)
3228                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3229                                                 header.buf, header.len, 0);
3230                        goto free_ab_and_return;
3231                }
3232                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3233                strbuf_reset(&header);
3234                if (DIFF_OPT_TST(o, BINARY))
3235                        emit_binary_diff(o, &mf1, &mf2);
3236                else {
3237                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3238                                    diff_line_prefix(o), lbl[0], lbl[1]);
3239                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3240                                         sb.buf, sb.len, 0);
3241                        strbuf_release(&sb);
3242                }
3243                o->found_changes = 1;
3244        } else {
3245                /* Crazy xdl interfaces.. */
3246                const char *diffopts = getenv("GIT_DIFF_OPTS");
3247                const char *v;
3248                xpparam_t xpp;
3249                xdemitconf_t xecfg;
3250                struct emit_callback ecbdata;
3251                const struct userdiff_funcname *pe;
3252
3253                if (must_show_header) {
3254                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3255                                         header.buf, header.len, 0);
3256                        strbuf_reset(&header);
3257                }
3258
3259                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3260                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3261
3262                pe = diff_funcname_pattern(one);
3263                if (!pe)
3264                        pe = diff_funcname_pattern(two);
3265
3266                memset(&xpp, 0, sizeof(xpp));
3267                memset(&xecfg, 0, sizeof(xecfg));
3268                memset(&ecbdata, 0, sizeof(ecbdata));
3269                ecbdata.label_path = lbl;
3270                ecbdata.color_diff = want_color(o->use_color);
3271                ecbdata.ws_rule = whitespace_rule(name_b);
3272                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3273                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3274                ecbdata.opt = o;
3275                ecbdata.header = header.len ? &header : NULL;
3276                xpp.flags = o->xdl_opts;
3277                xecfg.ctxlen = o->context;
3278                xecfg.interhunkctxlen = o->interhunkcontext;
3279                xecfg.flags = XDL_EMIT_FUNCNAMES;
3280                if (DIFF_OPT_TST(o, FUNCCONTEXT))
3281                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3282                if (pe)
3283                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3284                if (!diffopts)
3285                        ;
3286                else if (skip_prefix(diffopts, "--unified=", &v))
3287                        xecfg.ctxlen = strtoul(v, NULL, 10);
3288                else if (skip_prefix(diffopts, "-u", &v))
3289                        xecfg.ctxlen = strtoul(v, NULL, 10);
3290                if (o->word_diff)
3291                        init_diff_words_data(&ecbdata, o, one, two);
3292                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3293                                  &xpp, &xecfg))
3294                        die("unable to generate diff for %s", one->path);
3295                if (o->word_diff)
3296                        free_diff_words_data(&ecbdata);
3297                if (textconv_one)
3298                        free(mf1.ptr);
3299                if (textconv_two)
3300                        free(mf2.ptr);
3301                xdiff_clear_find_func(&xecfg);
3302        }
3303
3304 free_ab_and_return:
3305        strbuf_release(&header);
3306        diff_free_filespec_data(one);
3307        diff_free_filespec_data(two);
3308        free(a_one);
3309        free(b_two);
3310        return;
3311}
3312
3313static void builtin_diffstat(const char *name_a, const char *name_b,
3314                             struct diff_filespec *one,
3315                             struct diff_filespec *two,
3316                             struct diffstat_t *diffstat,
3317                             struct diff_options *o,
3318                             struct diff_filepair *p)
3319{
3320        mmfile_t mf1, mf2;
3321        struct diffstat_file *data;
3322        int same_contents;
3323        int complete_rewrite = 0;
3324
3325        if (!DIFF_PAIR_UNMERGED(p)) {
3326                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3327                        complete_rewrite = 1;
3328        }
3329
3330        data = diffstat_add(diffstat, name_a, name_b);
3331        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3332
3333        if (!one || !two) {
3334                data->is_unmerged = 1;
3335                return;
3336        }
3337
3338        same_contents = !oidcmp(&one->oid, &two->oid);
3339
3340        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3341                data->is_binary = 1;
3342                if (same_contents) {
3343                        data->added = 0;
3344                        data->deleted = 0;
3345                } else {
3346                        data->added = diff_filespec_size(two);
3347                        data->deleted = diff_filespec_size(one);
3348                }
3349        }
3350
3351        else if (complete_rewrite) {
3352                diff_populate_filespec(one, 0);
3353                diff_populate_filespec(two, 0);
3354                data->deleted = count_lines(one->data, one->size);
3355                data->added = count_lines(two->data, two->size);
3356        }
3357
3358        else if (!same_contents) {
3359                /* Crazy xdl interfaces.. */
3360                xpparam_t xpp;
3361                xdemitconf_t xecfg;
3362
3363                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3364                        die("unable to read files to diff");
3365
3366                memset(&xpp, 0, sizeof(xpp));
3367                memset(&xecfg, 0, sizeof(xecfg));
3368                xpp.flags = o->xdl_opts;
3369                xecfg.ctxlen = o->context;
3370                xecfg.interhunkctxlen = o->interhunkcontext;
3371                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3372                                  &xpp, &xecfg))
3373                        die("unable to generate diffstat for %s", one->path);
3374        }
3375
3376        diff_free_filespec_data(one);
3377        diff_free_filespec_data(two);
3378}
3379
3380static void builtin_checkdiff(const char *name_a, const char *name_b,
3381                              const char *attr_path,
3382                              struct diff_filespec *one,
3383                              struct diff_filespec *two,
3384                              struct diff_options *o)
3385{
3386        mmfile_t mf1, mf2;
3387        struct checkdiff_t data;
3388
3389        if (!two)
3390                return;
3391
3392        memset(&data, 0, sizeof(data));
3393        data.filename = name_b ? name_b : name_a;
3394        data.lineno = 0;
3395        data.o = o;
3396        data.ws_rule = whitespace_rule(attr_path);
3397        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3398
3399        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3400                die("unable to read files to diff");
3401
3402        /*
3403         * All the other codepaths check both sides, but not checking
3404         * the "old" side here is deliberate.  We are checking the newly
3405         * introduced changes, and as long as the "new" side is text, we
3406         * can and should check what it introduces.
3407         */
3408        if (diff_filespec_is_binary(two))
3409                goto free_and_return;
3410        else {
3411                /* Crazy xdl interfaces.. */
3412                xpparam_t xpp;
3413                xdemitconf_t xecfg;
3414
3415                memset(&xpp, 0, sizeof(xpp));
3416                memset(&xecfg, 0, sizeof(xecfg));
3417                xecfg.ctxlen = 1; /* at least one context line */
3418                xpp.flags = 0;
3419                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3420                                  &xpp, &xecfg))
3421                        die("unable to generate checkdiff for %s", one->path);
3422
3423                if (data.ws_rule & WS_BLANK_AT_EOF) {
3424                        struct emit_callback ecbdata;
3425                        int blank_at_eof;
3426
3427                        ecbdata.ws_rule = data.ws_rule;
3428                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3429                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3430
3431                        if (blank_at_eof) {
3432                                static char *err;
3433                                if (!err)
3434                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3435                                fprintf(o->file, "%s:%d: %s.\n",
3436                                        data.filename, blank_at_eof, err);
3437                                data.status = 1; /* report errors */
3438                        }
3439                }
3440        }
3441 free_and_return:
3442        diff_free_filespec_data(one);
3443        diff_free_filespec_data(two);
3444        if (data.status)
3445                DIFF_OPT_SET(o, CHECK_FAILED);
3446}
3447
3448struct diff_filespec *alloc_filespec(const char *path)
3449{
3450        struct diff_filespec *spec;
3451
3452        FLEXPTR_ALLOC_STR(spec, path, path);
3453        spec->count = 1;
3454        spec->is_binary = -1;
3455        return spec;
3456}
3457
3458void free_filespec(struct diff_filespec *spec)
3459{
3460        if (!--spec->count) {
3461                diff_free_filespec_data(spec);
3462                free(spec);
3463        }
3464}
3465
3466void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3467                   int oid_valid, unsigned short mode)
3468{
3469        if (mode) {
3470                spec->mode = canon_mode(mode);
3471                oidcpy(&spec->oid, oid);
3472                spec->oid_valid = oid_valid;
3473        }
3474}
3475
3476/*
3477 * Given a name and sha1 pair, if the index tells us the file in
3478 * the work tree has that object contents, return true, so that
3479 * prepare_temp_file() does not have to inflate and extract.
3480 */
3481static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3482{
3483        const struct cache_entry *ce;
3484        struct stat st;
3485        int pos, len;
3486
3487        /*
3488         * We do not read the cache ourselves here, because the
3489         * benchmark with my previous version that always reads cache
3490         * shows that it makes things worse for diff-tree comparing
3491         * two linux-2.6 kernel trees in an already checked out work
3492         * tree.  This is because most diff-tree comparisons deal with
3493         * only a small number of files, while reading the cache is
3494         * expensive for a large project, and its cost outweighs the
3495         * savings we get by not inflating the object to a temporary
3496         * file.  Practically, this code only helps when we are used
3497         * by diff-cache --cached, which does read the cache before
3498         * calling us.
3499         */
3500        if (!active_cache)
3501                return 0;
3502
3503        /* We want to avoid the working directory if our caller
3504         * doesn't need the data in a normal file, this system
3505         * is rather slow with its stat/open/mmap/close syscalls,
3506         * and the object is contained in a pack file.  The pack
3507         * is probably already open and will be faster to obtain
3508         * the data through than the working directory.  Loose
3509         * objects however would tend to be slower as they need
3510         * to be individually opened and inflated.
3511         */
3512        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3513                return 0;
3514
3515        /*
3516         * Similarly, if we'd have to convert the file contents anyway, that
3517         * makes the optimization not worthwhile.
3518         */
3519        if (!want_file && would_convert_to_git(&the_index, name))
3520                return 0;
3521
3522        len = strlen(name);
3523        pos = cache_name_pos(name, len);
3524        if (pos < 0)
3525                return 0;
3526        ce = active_cache[pos];
3527
3528        /*
3529         * This is not the sha1 we are looking for, or
3530         * unreusable because it is not a regular file.
3531         */
3532        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3533                return 0;
3534
3535        /*
3536         * If ce is marked as "assume unchanged", there is no
3537         * guarantee that work tree matches what we are looking for.
3538         */
3539        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3540                return 0;
3541
3542        /*
3543         * If ce matches the file in the work tree, we can reuse it.
3544         */
3545        if (ce_uptodate(ce) ||
3546            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3547                return 1;
3548
3549        return 0;
3550}
3551
3552static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3553{
3554        struct strbuf buf = STRBUF_INIT;
3555        char *dirty = "";
3556
3557        /* Are we looking at the work tree? */
3558        if (s->dirty_submodule)
3559                dirty = "-dirty";
3560
3561        strbuf_addf(&buf, "Subproject commit %s%s\n",
3562                    oid_to_hex(&s->oid), dirty);
3563        s->size = buf.len;
3564        if (size_only) {
3565                s->data = NULL;
3566                strbuf_release(&buf);
3567        } else {
3568                s->data = strbuf_detach(&buf, NULL);
3569                s->should_free = 1;
3570        }
3571        return 0;
3572}
3573
3574/*
3575 * While doing rename detection and pickaxe operation, we may need to
3576 * grab the data for the blob (or file) for our own in-core comparison.
3577 * diff_filespec has data and size fields for this purpose.
3578 */
3579int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3580{
3581        int size_only = flags & CHECK_SIZE_ONLY;
3582        int err = 0;
3583        /*
3584         * demote FAIL to WARN to allow inspecting the situation
3585         * instead of refusing.
3586         */
3587        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3588                                    ? SAFE_CRLF_WARN
3589                                    : safe_crlf);
3590
3591        if (!DIFF_FILE_VALID(s))
3592                die("internal error: asking to populate invalid file.");
3593        if (S_ISDIR(s->mode))
3594                return -1;
3595
3596        if (s->data)
3597                return 0;
3598
3599        if (size_only && 0 < s->size)
3600                return 0;
3601
3602        if (S_ISGITLINK(s->mode))
3603                return diff_populate_gitlink(s, size_only);
3604
3605        if (!s->oid_valid ||
3606            reuse_worktree_file(s->path, &s->oid, 0)) {
3607                struct strbuf buf = STRBUF_INIT;
3608                struct stat st;
3609                int fd;
3610
3611                if (lstat(s->path, &st) < 0) {
3612                        if (errno == ENOENT) {
3613                        err_empty:
3614                                err = -1;
3615                        empty:
3616                                s->data = (char *)"";
3617                                s->size = 0;
3618                                return err;
3619                        }
3620                }
3621                s->size = xsize_t(st.st_size);
3622                if (!s->size)
3623                        goto empty;
3624                if (S_ISLNK(st.st_mode)) {
3625                        struct strbuf sb = STRBUF_INIT;
3626
3627                        if (strbuf_readlink(&sb, s->path, s->size))
3628                                goto err_empty;
3629                        s->size = sb.len;
3630                        s->data = strbuf_detach(&sb, NULL);
3631                        s->should_free = 1;
3632                        return 0;
3633                }
3634
3635                /*
3636                 * Even if the caller would be happy with getting
3637                 * only the size, we cannot return early at this
3638                 * point if the path requires us to run the content
3639                 * conversion.
3640                 */
3641                if (size_only && !would_convert_to_git(&the_index, s->path))
3642                        return 0;
3643
3644                /*
3645                 * Note: this check uses xsize_t(st.st_size) that may
3646                 * not be the true size of the blob after it goes
3647                 * through convert_to_git().  This may not strictly be
3648                 * correct, but the whole point of big_file_threshold
3649                 * and is_binary check being that we want to avoid
3650                 * opening the file and inspecting the contents, this
3651                 * is probably fine.
3652                 */
3653                if ((flags & CHECK_BINARY) &&
3654                    s->size > big_file_threshold && s->is_binary == -1) {
3655                        s->is_binary = 1;
3656                        return 0;
3657                }
3658                fd = open(s->path, O_RDONLY);
3659                if (fd < 0)
3660                        goto err_empty;
3661                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3662                close(fd);
3663                s->should_munmap = 1;
3664
3665                /*
3666                 * Convert from working tree format to canonical git format
3667                 */
3668                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3669                        size_t size = 0;
3670                        munmap(s->data, s->size);
3671                        s->should_munmap = 0;
3672                        s->data = strbuf_detach(&buf, &size);
3673                        s->size = size;
3674                        s->should_free = 1;
3675                }
3676        }
3677        else {
3678                enum object_type type;
3679                if (size_only || (flags & CHECK_BINARY)) {
3680                        type = sha1_object_info(s->oid.hash, &s->size);
3681                        if (type < 0)
3682                                die("unable to read %s",
3683                                    oid_to_hex(&s->oid));
3684                        if (size_only)
3685                                return 0;
3686                        if (s->size > big_file_threshold && s->is_binary == -1) {
3687                                s->is_binary = 1;
3688                                return 0;
3689                        }
3690                }
3691                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3692                if (!s->data)
3693                        die("unable to read %s", oid_to_hex(&s->oid));
3694                s->should_free = 1;
3695        }
3696        return 0;
3697}
3698
3699void diff_free_filespec_blob(struct diff_filespec *s)
3700{
3701        if (s->should_free)
3702                free(s->data);
3703        else if (s->should_munmap)
3704                munmap(s->data, s->size);
3705
3706        if (s->should_free || s->should_munmap) {
3707                s->should_free = s->should_munmap = 0;
3708                s->data = NULL;
3709        }
3710}
3711
3712void diff_free_filespec_data(struct diff_filespec *s)
3713{
3714        diff_free_filespec_blob(s);
3715        FREE_AND_NULL(s->cnt_data);
3716}
3717
3718static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3719                           void *blob,
3720                           unsigned long size,
3721                           const struct object_id *oid,
3722                           int mode)
3723{
3724        struct strbuf buf = STRBUF_INIT;
3725        struct strbuf template = STRBUF_INIT;
3726        char *path_dup = xstrdup(path);
3727        const char *base = basename(path_dup);
3728
3729        /* Generate "XXXXXX_basename.ext" */
3730        strbuf_addstr(&template, "XXXXXX_");
3731        strbuf_addstr(&template, base);
3732
3733        temp->tempfile = mks_tempfile_ts(template.buf, strlen(base) + 1);
3734        if (!temp->tempfile)
3735                die_errno("unable to create temp-file");
3736        if (convert_to_working_tree(path,
3737                        (const char *)blob, (size_t)size, &buf)) {
3738                blob = buf.buf;
3739                size = buf.len;
3740        }
3741        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3742            close_tempfile_gently(temp->tempfile))
3743                die_errno("unable to write temp-file");
3744        temp->name = get_tempfile_path(temp->tempfile);
3745        oid_to_hex_r(temp->hex, oid);
3746        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3747        strbuf_release(&buf);
3748        strbuf_release(&template);
3749        free(path_dup);
3750}
3751
3752static struct diff_tempfile *prepare_temp_file(const char *name,
3753                struct diff_filespec *one)
3754{
3755        struct diff_tempfile *temp = claim_diff_tempfile();
3756
3757        if (!DIFF_FILE_VALID(one)) {
3758        not_a_valid_file:
3759                /* A '-' entry produces this for file-2, and
3760                 * a '+' entry produces this for file-1.
3761                 */
3762                temp->name = "/dev/null";
3763                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3764                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3765                return temp;
3766        }
3767
3768        if (!S_ISGITLINK(one->mode) &&
3769            (!one->oid_valid ||
3770             reuse_worktree_file(name, &one->oid, 1))) {
3771                struct stat st;
3772                if (lstat(name, &st) < 0) {
3773                        if (errno == ENOENT)
3774                                goto not_a_valid_file;
3775                        die_errno("stat(%s)", name);
3776                }
3777                if (S_ISLNK(st.st_mode)) {
3778                        struct strbuf sb = STRBUF_INIT;
3779                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3780                                die_errno("readlink(%s)", name);
3781                        prep_temp_blob(name, temp, sb.buf, sb.len,
3782                                       (one->oid_valid ?
3783                                        &one->oid : &null_oid),
3784                                       (one->oid_valid ?
3785                                        one->mode : S_IFLNK));
3786                        strbuf_release(&sb);
3787                }
3788                else {
3789                        /* we can borrow from the file in the work tree */
3790                        temp->name = name;
3791                        if (!one->oid_valid)
3792                                oid_to_hex_r(temp->hex, &null_oid);
3793                        else
3794                                oid_to_hex_r(temp->hex, &one->oid);
3795                        /* Even though we may sometimes borrow the
3796                         * contents from the work tree, we always want
3797                         * one->mode.  mode is trustworthy even when
3798                         * !(one->oid_valid), as long as
3799                         * DIFF_FILE_VALID(one).
3800                         */
3801                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3802                }
3803                return temp;
3804        }
3805        else {
3806                if (diff_populate_filespec(one, 0))
3807                        die("cannot read data blob for %s", one->path);
3808                prep_temp_blob(name, temp, one->data, one->size,
3809                               &one->oid, one->mode);
3810        }
3811        return temp;
3812}
3813
3814static void add_external_diff_name(struct argv_array *argv,
3815                                   const char *name,
3816                                   struct diff_filespec *df)
3817{
3818        struct diff_tempfile *temp = prepare_temp_file(name, df);
3819        argv_array_push(argv, temp->name);
3820        argv_array_push(argv, temp->hex);
3821        argv_array_push(argv, temp->mode);
3822}
3823
3824/* An external diff command takes:
3825 *
3826 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3827 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3828 *
3829 */
3830static void run_external_diff(const char *pgm,
3831                              const char *name,
3832                              const char *other,
3833                              struct diff_filespec *one,
3834                              struct diff_filespec *two,
3835                              const char *xfrm_msg,
3836                              int complete_rewrite,
3837                              struct diff_options *o)
3838{
3839        struct argv_array argv = ARGV_ARRAY_INIT;
3840        struct argv_array env = ARGV_ARRAY_INIT;
3841        struct diff_queue_struct *q = &diff_queued_diff;
3842
3843        argv_array_push(&argv, pgm);
3844        argv_array_push(&argv, name);
3845
3846        if (one && two) {
3847                add_external_diff_name(&argv, name, one);
3848                if (!other)
3849                        add_external_diff_name(&argv, name, two);
3850                else {
3851                        add_external_diff_name(&argv, other, two);
3852                        argv_array_push(&argv, other);
3853                        argv_array_push(&argv, xfrm_msg);
3854                }
3855        }
3856
3857        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3858        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3859
3860        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3861                die(_("external diff died, stopping at %s"), name);
3862
3863        remove_tempfile();
3864        argv_array_clear(&argv);
3865        argv_array_clear(&env);
3866}
3867
3868static int similarity_index(struct diff_filepair *p)
3869{
3870        return p->score * 100 / MAX_SCORE;
3871}
3872
3873static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3874{
3875        if (startup_info->have_repository)
3876                return find_unique_abbrev(oid->hash, abbrev);
3877        else {
3878                char *hex = oid_to_hex(oid);
3879                if (abbrev < 0)
3880                        abbrev = FALLBACK_DEFAULT_ABBREV;
3881                if (abbrev > GIT_SHA1_HEXSZ)
3882                        die("BUG: oid abbreviation out of range: %d", abbrev);
3883                if (abbrev)
3884                        hex[abbrev] = '\0';
3885                return hex;
3886        }
3887}
3888
3889static void fill_metainfo(struct strbuf *msg,
3890                          const char *name,
3891                          const char *other,
3892                          struct diff_filespec *one,
3893                          struct diff_filespec *two,
3894                          struct diff_options *o,
3895                          struct diff_filepair *p,
3896                          int *must_show_header,
3897                          int use_color)
3898{
3899        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3900        const char *reset = diff_get_color(use_color, DIFF_RESET);
3901        const char *line_prefix = diff_line_prefix(o);
3902
3903        *must_show_header = 1;
3904        strbuf_init(msg, PATH_MAX * 2 + 300);
3905        switch (p->status) {
3906        case DIFF_STATUS_COPIED:
3907                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3908                            line_prefix, set, similarity_index(p));
3909                strbuf_addf(msg, "%s\n%s%scopy from ",
3910                            reset,  line_prefix, set);
3911                quote_c_style(name, msg, NULL, 0);
3912                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3913                quote_c_style(other, msg, NULL, 0);
3914                strbuf_addf(msg, "%s\n", reset);
3915                break;
3916        case DIFF_STATUS_RENAMED:
3917                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3918                            line_prefix, set, similarity_index(p));
3919                strbuf_addf(msg, "%s\n%s%srename from ",
3920                            reset, line_prefix, set);
3921                quote_c_style(name, msg, NULL, 0);
3922                strbuf_addf(msg, "%s\n%s%srename to ",
3923                            reset, line_prefix, set);
3924                quote_c_style(other, msg, NULL, 0);
3925                strbuf_addf(msg, "%s\n", reset);
3926                break;
3927        case DIFF_STATUS_MODIFIED:
3928                if (p->score) {
3929                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3930                                    line_prefix,
3931                                    set, similarity_index(p), reset);
3932                        break;
3933                }
3934                /* fallthru */
3935        default:
3936                *must_show_header = 0;
3937        }
3938        if (one && two && oidcmp(&one->oid, &two->oid)) {
3939                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3940
3941                if (DIFF_OPT_TST(o, BINARY)) {
3942                        mmfile_t mf;
3943                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3944                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3945                                abbrev = 40;
3946                }
3947                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3948                            diff_abbrev_oid(&one->oid, abbrev),
3949                            diff_abbrev_oid(&two->oid, abbrev));
3950                if (one->mode == two->mode)
3951                        strbuf_addf(msg, " %06o", one->mode);
3952                strbuf_addf(msg, "%s\n", reset);
3953        }
3954}
3955
3956static void run_diff_cmd(const char *pgm,
3957                         const char *name,
3958                         const char *other,
3959                         const char *attr_path,
3960                         struct diff_filespec *one,
3961                         struct diff_filespec *two,
3962                         struct strbuf *msg,
3963                         struct diff_options *o,
3964                         struct diff_filepair *p)
3965{
3966        const char *xfrm_msg = NULL;
3967        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3968        int must_show_header = 0;
3969
3970
3971        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3972                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3973                if (drv && drv->external)
3974                        pgm = drv->external;
3975        }
3976
3977        if (msg) {
3978                /*
3979                 * don't use colors when the header is intended for an
3980                 * external diff driver
3981                 */
3982                fill_metainfo(msg, name, other, one, two, o, p,
3983                              &must_show_header,
3984                              want_color(o->use_color) && !pgm);
3985                xfrm_msg = msg->len ? msg->buf : NULL;
3986        }
3987
3988        if (pgm) {
3989                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3990                                  complete_rewrite, o);
3991                return;
3992        }
3993        if (one && two)
3994                builtin_diff(name, other ? other : name,
3995                             one, two, xfrm_msg, must_show_header,
3996                             o, complete_rewrite);
3997        else
3998                fprintf(o->file, "* Unmerged path %s\n", name);
3999}
4000
4001static void diff_fill_oid_info(struct diff_filespec *one)
4002{
4003        if (DIFF_FILE_VALID(one)) {
4004                if (!one->oid_valid) {
4005                        struct stat st;
4006                        if (one->is_stdin) {
4007                                oidclr(&one->oid);
4008                                return;
4009                        }
4010                        if (lstat(one->path, &st) < 0)
4011                                die_errno("stat '%s'", one->path);
4012                        if (index_path(&one->oid, one->path, &st, 0))
4013                                die("cannot hash %s", one->path);
4014                }
4015        }
4016        else
4017                oidclr(&one->oid);
4018}
4019
4020static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4021{
4022        /* Strip the prefix but do not molest /dev/null and absolute paths */
4023        if (*namep && **namep != '/') {
4024                *namep += prefix_length;
4025                if (**namep == '/')
4026                        ++*namep;
4027        }
4028        if (*otherp && **otherp != '/') {
4029                *otherp += prefix_length;
4030                if (**otherp == '/')
4031                        ++*otherp;
4032        }
4033}
4034
4035static void run_diff(struct diff_filepair *p, struct diff_options *o)
4036{
4037        const char *pgm = external_diff();
4038        struct strbuf msg;
4039        struct diff_filespec *one = p->one;
4040        struct diff_filespec *two = p->two;
4041        const char *name;
4042        const char *other;
4043        const char *attr_path;
4044
4045        name  = one->path;
4046        other = (strcmp(name, two->path) ? two->path : NULL);
4047        attr_path = name;
4048        if (o->prefix_length)
4049                strip_prefix(o->prefix_length, &name, &other);
4050
4051        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
4052                pgm = NULL;
4053
4054        if (DIFF_PAIR_UNMERGED(p)) {
4055                run_diff_cmd(pgm, name, NULL, attr_path,
4056                             NULL, NULL, NULL, o, p);
4057                return;
4058        }
4059
4060        diff_fill_oid_info(one);
4061        diff_fill_oid_info(two);
4062
4063        if (!pgm &&
4064            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4065            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4066                /*
4067                 * a filepair that changes between file and symlink
4068                 * needs to be split into deletion and creation.
4069                 */
4070                struct diff_filespec *null = alloc_filespec(two->path);
4071                run_diff_cmd(NULL, name, other, attr_path,
4072                             one, null, &msg, o, p);
4073                free(null);
4074                strbuf_release(&msg);
4075
4076                null = alloc_filespec(one->path);
4077                run_diff_cmd(NULL, name, other, attr_path,
4078                             null, two, &msg, o, p);
4079                free(null);
4080        }
4081        else
4082                run_diff_cmd(pgm, name, other, attr_path,
4083                             one, two, &msg, o, p);
4084
4085        strbuf_release(&msg);
4086}
4087
4088static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4089                         struct diffstat_t *diffstat)
4090{
4091        const char *name;
4092        const char *other;
4093
4094        if (DIFF_PAIR_UNMERGED(p)) {
4095                /* unmerged */
4096                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4097                return;
4098        }
4099
4100        name = p->one->path;
4101        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4102
4103        if (o->prefix_length)
4104                strip_prefix(o->prefix_length, &name, &other);
4105
4106        diff_fill_oid_info(p->one);
4107        diff_fill_oid_info(p->two);
4108
4109        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4110}
4111
4112static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4113{
4114        const char *name;
4115        const char *other;
4116        const char *attr_path;
4117
4118        if (DIFF_PAIR_UNMERGED(p)) {
4119                /* unmerged */
4120                return;
4121        }
4122
4123        name = p->one->path;
4124        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4125        attr_path = other ? other : name;
4126
4127        if (o->prefix_length)
4128                strip_prefix(o->prefix_length, &name, &other);
4129
4130        diff_fill_oid_info(p->one);
4131        diff_fill_oid_info(p->two);
4132
4133        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4134}
4135
4136void diff_setup(struct diff_options *options)
4137{
4138        memcpy(options, &default_diff_options, sizeof(*options));
4139
4140        options->file = stdout;
4141
4142        options->abbrev = DEFAULT_ABBREV;
4143        options->line_termination = '\n';
4144        options->break_opt = -1;
4145        options->rename_limit = -1;
4146        options->dirstat_permille = diff_dirstat_permille_default;
4147        options->context = diff_context_default;
4148        options->interhunkcontext = diff_interhunk_context_default;
4149        options->ws_error_highlight = ws_error_highlight_default;
4150        DIFF_OPT_SET(options, RENAME_EMPTY);
4151
4152        /* pathchange left =NULL by default */
4153        options->change = diff_change;
4154        options->add_remove = diff_addremove;
4155        options->use_color = diff_use_color_default;
4156        options->detect_rename = diff_detect_rename_default;
4157        options->xdl_opts |= diff_algorithm;
4158        if (diff_indent_heuristic)
4159                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4160
4161        options->orderfile = diff_order_file_cfg;
4162
4163        if (diff_no_prefix) {
4164                options->a_prefix = options->b_prefix = "";
4165        } else if (!diff_mnemonic_prefix) {
4166                options->a_prefix = "a/";
4167                options->b_prefix = "b/";
4168        }
4169
4170        options->color_moved = diff_color_moved_default;
4171}
4172
4173void diff_setup_done(struct diff_options *options)
4174{
4175        int count = 0;
4176
4177        if (options->set_default)
4178                options->set_default(options);
4179
4180        if (options->output_format & DIFF_FORMAT_NAME)
4181                count++;
4182        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
4183                count++;
4184        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
4185                count++;
4186        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
4187                count++;
4188        if (count > 1)
4189                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4190
4191        /*
4192         * Most of the time we can say "there are changes"
4193         * only by checking if there are changed paths, but
4194         * --ignore-whitespace* options force us to look
4195         * inside contents.
4196         */
4197
4198        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
4199            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
4200            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
4201                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
4202        else
4203                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
4204
4205        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
4206                options->detect_rename = DIFF_DETECT_COPY;
4207
4208        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
4209                options->prefix = NULL;
4210        if (options->prefix)
4211                options->prefix_length = strlen(options->prefix);
4212        else
4213                options->prefix_length = 0;
4214
4215        if (options->output_format & (DIFF_FORMAT_NAME |
4216                                      DIFF_FORMAT_NAME_STATUS |
4217                                      DIFF_FORMAT_CHECKDIFF |
4218                                      DIFF_FORMAT_NO_OUTPUT))
4219                options->output_format &= ~(DIFF_FORMAT_RAW |
4220                                            DIFF_FORMAT_NUMSTAT |
4221                                            DIFF_FORMAT_DIFFSTAT |
4222                                            DIFF_FORMAT_SHORTSTAT |
4223                                            DIFF_FORMAT_DIRSTAT |
4224                                            DIFF_FORMAT_SUMMARY |
4225                                            DIFF_FORMAT_PATCH);
4226
4227        /*
4228         * These cases always need recursive; we do not drop caller-supplied
4229         * recursive bits for other formats here.
4230         */
4231        if (options->output_format & (DIFF_FORMAT_PATCH |
4232                                      DIFF_FORMAT_NUMSTAT |
4233                                      DIFF_FORMAT_DIFFSTAT |
4234                                      DIFF_FORMAT_SHORTSTAT |
4235                                      DIFF_FORMAT_DIRSTAT |
4236                                      DIFF_FORMAT_SUMMARY |
4237                                      DIFF_FORMAT_CHECKDIFF))
4238                DIFF_OPT_SET(options, RECURSIVE);
4239        /*
4240         * Also pickaxe would not work very well if you do not say recursive
4241         */
4242        if (options->pickaxe)
4243                DIFF_OPT_SET(options, RECURSIVE);
4244        /*
4245         * When patches are generated, submodules diffed against the work tree
4246         * must be checked for dirtiness too so it can be shown in the output
4247         */
4248        if (options->output_format & DIFF_FORMAT_PATCH)
4249                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
4250
4251        if (options->detect_rename && options->rename_limit < 0)
4252                options->rename_limit = diff_rename_limit_default;
4253        if (options->setup & DIFF_SETUP_USE_CACHE) {
4254                if (!active_cache)
4255                        /* read-cache does not die even when it fails
4256                         * so it is safe for us to do this here.  Also
4257                         * it does not smudge active_cache or active_nr
4258                         * when it fails, so we do not have to worry about
4259                         * cleaning it up ourselves either.
4260                         */
4261                        read_cache();
4262        }
4263        if (40 < options->abbrev)
4264                options->abbrev = 40; /* full */
4265
4266        /*
4267         * It does not make sense to show the first hit we happened
4268         * to have found.  It does not make sense not to return with
4269         * exit code in such a case either.
4270         */
4271        if (DIFF_OPT_TST(options, QUICK)) {
4272                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4273                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4274        }
4275
4276        options->diff_path_counter = 0;
4277
4278        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
4279                die(_("--follow requires exactly one pathspec"));
4280
4281        if (!options->use_color || external_diff())
4282                options->color_moved = 0;
4283}
4284
4285static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4286{
4287        char c, *eq;
4288        int len;
4289
4290        if (*arg != '-')
4291                return 0;
4292        c = *++arg;
4293        if (!c)
4294                return 0;
4295        if (c == arg_short) {
4296                c = *++arg;
4297                if (!c)
4298                        return 1;
4299                if (val && isdigit(c)) {
4300                        char *end;
4301                        int n = strtoul(arg, &end, 10);
4302                        if (*end)
4303                                return 0;
4304                        *val = n;
4305                        return 1;
4306                }
4307                return 0;
4308        }
4309        if (c != '-')
4310                return 0;
4311        arg++;
4312        eq = strchrnul(arg, '=');
4313        len = eq - arg;
4314        if (!len || strncmp(arg, arg_long, len))
4315                return 0;
4316        if (*eq) {
4317                int n;
4318                char *end;
4319                if (!isdigit(*++eq))
4320                        return 0;
4321                n = strtoul(eq, &end, 10);
4322                if (*end)
4323                        return 0;
4324                *val = n;
4325        }
4326        return 1;
4327}
4328
4329static int diff_scoreopt_parse(const char *opt);
4330
4331static inline int short_opt(char opt, const char **argv,
4332                            const char **optarg)
4333{
4334        const char *arg = argv[0];
4335        if (arg[0] != '-' || arg[1] != opt)
4336                return 0;
4337        if (arg[2] != '\0') {
4338                *optarg = arg + 2;
4339                return 1;
4340        }
4341        if (!argv[1])
4342                die("Option '%c' requires a value", opt);
4343        *optarg = argv[1];
4344        return 2;
4345}
4346
4347int parse_long_opt(const char *opt, const char **argv,
4348                   const char **optarg)
4349{
4350        const char *arg = argv[0];
4351        if (!skip_prefix(arg, "--", &arg))
4352                return 0;
4353        if (!skip_prefix(arg, opt, &arg))
4354                return 0;
4355        if (*arg == '=') { /* stuck form: --option=value */
4356                *optarg = arg + 1;
4357                return 1;
4358        }
4359        if (*arg != '\0')
4360                return 0;
4361        /* separate form: --option value */
4362        if (!argv[1])
4363                die("Option '--%s' requires a value", opt);
4364        *optarg = argv[1];
4365        return 2;
4366}
4367
4368static int stat_opt(struct diff_options *options, const char **av)
4369{
4370        const char *arg = av[0];
4371        char *end;
4372        int width = options->stat_width;
4373        int name_width = options->stat_name_width;
4374        int graph_width = options->stat_graph_width;
4375        int count = options->stat_count;
4376        int argcount = 1;
4377
4378        if (!skip_prefix(arg, "--stat", &arg))
4379                die("BUG: stat option does not begin with --stat: %s", arg);
4380        end = (char *)arg;
4381
4382        switch (*arg) {
4383        case '-':
4384                if (skip_prefix(arg, "-width", &arg)) {
4385                        if (*arg == '=')
4386                                width = strtoul(arg + 1, &end, 10);
4387                        else if (!*arg && !av[1])
4388                                die_want_option("--stat-width");
4389                        else if (!*arg) {
4390                                width = strtoul(av[1], &end, 10);
4391                                argcount = 2;
4392                        }
4393                } else if (skip_prefix(arg, "-name-width", &arg)) {
4394                        if (*arg == '=')
4395                                name_width = strtoul(arg + 1, &end, 10);
4396                        else if (!*arg && !av[1])
4397                                die_want_option("--stat-name-width");
4398                        else if (!*arg) {
4399                                name_width = strtoul(av[1], &end, 10);
4400                                argcount = 2;
4401                        }
4402                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4403                        if (*arg == '=')
4404                                graph_width = strtoul(arg + 1, &end, 10);
4405                        else if (!*arg && !av[1])
4406                                die_want_option("--stat-graph-width");
4407                        else if (!*arg) {
4408                                graph_width = strtoul(av[1], &end, 10);
4409                                argcount = 2;
4410                        }
4411                } else if (skip_prefix(arg, "-count", &arg)) {
4412                        if (*arg == '=')
4413                                count = strtoul(arg + 1, &end, 10);
4414                        else if (!*arg && !av[1])
4415                                die_want_option("--stat-count");
4416                        else if (!*arg) {
4417                                count = strtoul(av[1], &end, 10);
4418                                argcount = 2;
4419                        }
4420                }
4421                break;
4422        case '=':
4423                width = strtoul(arg+1, &end, 10);
4424                if (*end == ',')
4425                        name_width = strtoul(end+1, &end, 10);
4426                if (*end == ',')
4427                        count = strtoul(end+1, &end, 10);
4428        }
4429
4430        /* Important! This checks all the error cases! */
4431        if (*end)
4432                return 0;
4433        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4434        options->stat_name_width = name_width;
4435        options->stat_graph_width = graph_width;
4436        options->stat_width = width;
4437        options->stat_count = count;
4438        return argcount;
4439}
4440
4441static int parse_dirstat_opt(struct diff_options *options, const char *params)
4442{
4443        struct strbuf errmsg = STRBUF_INIT;
4444        if (parse_dirstat_params(options, params, &errmsg))
4445                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4446                    errmsg.buf);
4447        strbuf_release(&errmsg);
4448        /*
4449         * The caller knows a dirstat-related option is given from the command
4450         * line; allow it to say "return this_function();"
4451         */
4452        options->output_format |= DIFF_FORMAT_DIRSTAT;
4453        return 1;
4454}
4455
4456static int parse_submodule_opt(struct diff_options *options, const char *value)
4457{
4458        if (parse_submodule_params(options, value))
4459                die(_("Failed to parse --submodule option parameter: '%s'"),
4460                        value);
4461        return 1;
4462}
4463
4464static const char diff_status_letters[] = {
4465        DIFF_STATUS_ADDED,
4466        DIFF_STATUS_COPIED,
4467        DIFF_STATUS_DELETED,
4468        DIFF_STATUS_MODIFIED,
4469        DIFF_STATUS_RENAMED,
4470        DIFF_STATUS_TYPE_CHANGED,
4471        DIFF_STATUS_UNKNOWN,
4472        DIFF_STATUS_UNMERGED,
4473        DIFF_STATUS_FILTER_AON,
4474        DIFF_STATUS_FILTER_BROKEN,
4475        '\0',
4476};
4477
4478static unsigned int filter_bit['Z' + 1];
4479
4480static void prepare_filter_bits(void)
4481{
4482        int i;
4483
4484        if (!filter_bit[DIFF_STATUS_ADDED]) {
4485                for (i = 0; diff_status_letters[i]; i++)
4486                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4487        }
4488}
4489
4490static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4491{
4492        return opt->filter & filter_bit[(int) status];
4493}
4494
4495static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4496{
4497        int i, optch;
4498
4499        prepare_filter_bits();
4500
4501        /*
4502         * If there is a negation e.g. 'd' in the input, and we haven't
4503         * initialized the filter field with another --diff-filter, start
4504         * from full set of bits, except for AON.
4505         */
4506        if (!opt->filter) {
4507                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4508                        if (optch < 'a' || 'z' < optch)
4509                                continue;
4510                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4511                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4512                        break;
4513                }
4514        }
4515
4516        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4517                unsigned int bit;
4518                int negate;
4519
4520                if ('a' <= optch && optch <= 'z') {
4521                        negate = 1;
4522                        optch = toupper(optch);
4523                } else {
4524                        negate = 0;
4525                }
4526
4527                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4528                if (!bit)
4529                        return optarg[i];
4530                if (negate)
4531                        opt->filter &= ~bit;
4532                else
4533                        opt->filter |= bit;
4534        }
4535        return 0;
4536}
4537
4538static void enable_patch_output(int *fmt) {
4539        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4540        *fmt |= DIFF_FORMAT_PATCH;
4541}
4542
4543static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4544{
4545        int val = parse_ws_error_highlight(arg);
4546
4547        if (val < 0) {
4548                error("unknown value after ws-error-highlight=%.*s",
4549                      -1 - val, arg);
4550                return 0;
4551        }
4552        opt->ws_error_highlight = val;
4553        return 1;
4554}
4555
4556int diff_opt_parse(struct diff_options *options,
4557                   const char **av, int ac, const char *prefix)
4558{
4559        const char *arg = av[0];
4560        const char *optarg;
4561        int argcount;
4562
4563        if (!prefix)
4564                prefix = "";
4565
4566        /* Output format options */
4567        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4568            || opt_arg(arg, 'U', "unified", &options->context))
4569                enable_patch_output(&options->output_format);
4570        else if (!strcmp(arg, "--raw"))
4571                options->output_format |= DIFF_FORMAT_RAW;
4572        else if (!strcmp(arg, "--patch-with-raw")) {
4573                enable_patch_output(&options->output_format);
4574                options->output_format |= DIFF_FORMAT_RAW;
4575        } else if (!strcmp(arg, "--numstat"))
4576                options->output_format |= DIFF_FORMAT_NUMSTAT;
4577        else if (!strcmp(arg, "--shortstat"))
4578                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4579        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4580                return parse_dirstat_opt(options, "");
4581        else if (skip_prefix(arg, "-X", &arg))
4582                return parse_dirstat_opt(options, arg);
4583        else if (skip_prefix(arg, "--dirstat=", &arg))
4584                return parse_dirstat_opt(options, arg);
4585        else if (!strcmp(arg, "--cumulative"))
4586                return parse_dirstat_opt(options, "cumulative");
4587        else if (!strcmp(arg, "--dirstat-by-file"))
4588                return parse_dirstat_opt(options, "files");
4589        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4590                parse_dirstat_opt(options, "files");
4591                return parse_dirstat_opt(options, arg);
4592        }
4593        else if (!strcmp(arg, "--check"))
4594                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4595        else if (!strcmp(arg, "--summary"))
4596                options->output_format |= DIFF_FORMAT_SUMMARY;
4597        else if (!strcmp(arg, "--patch-with-stat")) {
4598                enable_patch_output(&options->output_format);
4599                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4600        } else if (!strcmp(arg, "--name-only"))
4601                options->output_format |= DIFF_FORMAT_NAME;
4602        else if (!strcmp(arg, "--name-status"))
4603                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4604        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4605                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4606        else if (starts_with(arg, "--stat"))
4607                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4608                return stat_opt(options, av);
4609
4610        /* renames options */
4611        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4612                 !strcmp(arg, "--break-rewrites")) {
4613                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4614                        return error("invalid argument to -B: %s", arg+2);
4615        }
4616        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4617                 !strcmp(arg, "--find-renames")) {
4618                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4619                        return error("invalid argument to -M: %s", arg+2);
4620                options->detect_rename = DIFF_DETECT_RENAME;
4621        }
4622        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4623                options->irreversible_delete = 1;
4624        }
4625        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4626                 !strcmp(arg, "--find-copies")) {
4627                if (options->detect_rename == DIFF_DETECT_COPY)
4628                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4629                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4630                        return error("invalid argument to -C: %s", arg+2);
4631                options->detect_rename = DIFF_DETECT_COPY;
4632        }
4633        else if (!strcmp(arg, "--no-renames"))
4634                options->detect_rename = 0;
4635        else if (!strcmp(arg, "--rename-empty"))
4636                DIFF_OPT_SET(options, RENAME_EMPTY);
4637        else if (!strcmp(arg, "--no-rename-empty"))
4638                DIFF_OPT_CLR(options, RENAME_EMPTY);
4639        else if (!strcmp(arg, "--relative"))
4640                DIFF_OPT_SET(options, RELATIVE_NAME);
4641        else if (skip_prefix(arg, "--relative=", &arg)) {
4642                DIFF_OPT_SET(options, RELATIVE_NAME);
4643                options->prefix = arg;
4644        }
4645
4646        /* xdiff options */
4647        else if (!strcmp(arg, "--minimal"))
4648                DIFF_XDL_SET(options, NEED_MINIMAL);
4649        else if (!strcmp(arg, "--no-minimal"))
4650                DIFF_XDL_CLR(options, NEED_MINIMAL);
4651        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4652                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4653        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4654                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4655        else if (!strcmp(arg, "--ignore-space-at-eol"))
4656                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4657        else if (!strcmp(arg, "--ignore-blank-lines"))
4658                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4659        else if (!strcmp(arg, "--indent-heuristic"))
4660                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4661        else if (!strcmp(arg, "--no-indent-heuristic"))
4662                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4663        else if (!strcmp(arg, "--patience"))
4664                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4665        else if (!strcmp(arg, "--histogram"))
4666                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4667        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4668                long value = parse_algorithm_value(optarg);
4669                if (value < 0)
4670                        return error("option diff-algorithm accepts \"myers\", "
4671                                     "\"minimal\", \"patience\" and \"histogram\"");
4672                /* clear out previous settings */
4673                DIFF_XDL_CLR(options, NEED_MINIMAL);
4674                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4675                options->xdl_opts |= value;
4676                return argcount;
4677        }
4678
4679        /* flags options */
4680        else if (!strcmp(arg, "--binary")) {
4681                enable_patch_output(&options->output_format);
4682                DIFF_OPT_SET(options, BINARY);
4683        }
4684        else if (!strcmp(arg, "--full-index"))
4685                DIFF_OPT_SET(options, FULL_INDEX);
4686        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4687                DIFF_OPT_SET(options, TEXT);
4688        else if (!strcmp(arg, "-R"))
4689                DIFF_OPT_SET(options, REVERSE_DIFF);
4690        else if (!strcmp(arg, "--find-copies-harder"))
4691                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4692        else if (!strcmp(arg, "--follow"))
4693                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4694        else if (!strcmp(arg, "--no-follow")) {
4695                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4696                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4697        } else if (!strcmp(arg, "--color"))
4698                options->use_color = 1;
4699        else if (skip_prefix(arg, "--color=", &arg)) {
4700                int value = git_config_colorbool(NULL, arg);
4701                if (value < 0)
4702                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4703                options->use_color = value;
4704        }
4705        else if (!strcmp(arg, "--no-color"))
4706                options->use_color = 0;
4707        else if (!strcmp(arg, "--color-moved")) {
4708                if (diff_color_moved_default)
4709                        options->color_moved = diff_color_moved_default;
4710                if (options->color_moved == COLOR_MOVED_NO)
4711                        options->color_moved = COLOR_MOVED_DEFAULT;
4712        } else if (!strcmp(arg, "--no-color-moved"))
4713                options->color_moved = COLOR_MOVED_NO;
4714        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4715                int cm = parse_color_moved(arg);
4716                if (cm < 0)
4717                        die("bad --color-moved argument: %s", arg);
4718                options->color_moved = cm;
4719        } else if (!strcmp(arg, "--color-words")) {
4720                options->use_color = 1;
4721                options->word_diff = DIFF_WORDS_COLOR;
4722        }
4723        else if (skip_prefix(arg, "--color-words=", &arg)) {
4724                options->use_color = 1;
4725                options->word_diff = DIFF_WORDS_COLOR;
4726                options->word_regex = arg;
4727        }
4728        else if (!strcmp(arg, "--word-diff")) {
4729                if (options->word_diff == DIFF_WORDS_NONE)
4730                        options->word_diff = DIFF_WORDS_PLAIN;
4731        }
4732        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4733                if (!strcmp(arg, "plain"))
4734                        options->word_diff = DIFF_WORDS_PLAIN;
4735                else if (!strcmp(arg, "color")) {
4736                        options->use_color = 1;
4737                        options->word_diff = DIFF_WORDS_COLOR;
4738                }
4739                else if (!strcmp(arg, "porcelain"))
4740                        options->word_diff = DIFF_WORDS_PORCELAIN;
4741                else if (!strcmp(arg, "none"))
4742                        options->word_diff = DIFF_WORDS_NONE;
4743                else
4744                        die("bad --word-diff argument: %s", arg);
4745        }
4746        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4747                if (options->word_diff == DIFF_WORDS_NONE)
4748                        options->word_diff = DIFF_WORDS_PLAIN;
4749                options->word_regex = optarg;
4750                return argcount;
4751        }
4752        else if (!strcmp(arg, "--exit-code"))
4753                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4754        else if (!strcmp(arg, "--quiet"))
4755                DIFF_OPT_SET(options, QUICK);
4756        else if (!strcmp(arg, "--ext-diff"))
4757                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4758        else if (!strcmp(arg, "--no-ext-diff"))
4759                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4760        else if (!strcmp(arg, "--textconv"))
4761                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4762        else if (!strcmp(arg, "--no-textconv"))
4763                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4764        else if (!strcmp(arg, "--ignore-submodules")) {
4765                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4766                handle_ignore_submodules_arg(options, "all");
4767        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4768                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4769                handle_ignore_submodules_arg(options, arg);
4770        } else if (!strcmp(arg, "--submodule"))
4771                options->submodule_format = DIFF_SUBMODULE_LOG;
4772        else if (skip_prefix(arg, "--submodule=", &arg))
4773                return parse_submodule_opt(options, arg);
4774        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4775                return parse_ws_error_highlight_opt(options, arg);
4776        else if (!strcmp(arg, "--ita-invisible-in-index"))
4777                options->ita_invisible_in_index = 1;
4778        else if (!strcmp(arg, "--ita-visible-in-index"))
4779                options->ita_invisible_in_index = 0;
4780
4781        /* misc options */
4782        else if (!strcmp(arg, "-z"))
4783                options->line_termination = 0;
4784        else if ((argcount = short_opt('l', av, &optarg))) {
4785                options->rename_limit = strtoul(optarg, NULL, 10);
4786                return argcount;
4787        }
4788        else if ((argcount = short_opt('S', av, &optarg))) {
4789                options->pickaxe = optarg;
4790                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4791                return argcount;
4792        } else if ((argcount = short_opt('G', av, &optarg))) {
4793                options->pickaxe = optarg;
4794                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4795                return argcount;
4796        }
4797        else if (!strcmp(arg, "--pickaxe-all"))
4798                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4799        else if (!strcmp(arg, "--pickaxe-regex"))
4800                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4801        else if ((argcount = short_opt('O', av, &optarg))) {
4802                options->orderfile = prefix_filename(prefix, optarg);
4803                return argcount;
4804        }
4805        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4806                int offending = parse_diff_filter_opt(optarg, options);
4807                if (offending)
4808                        die("unknown change class '%c' in --diff-filter=%s",
4809                            offending, optarg);
4810                return argcount;
4811        }
4812        else if (!strcmp(arg, "--no-abbrev"))
4813                options->abbrev = 0;
4814        else if (!strcmp(arg, "--abbrev"))
4815                options->abbrev = DEFAULT_ABBREV;
4816        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4817                options->abbrev = strtoul(arg, NULL, 10);
4818                if (options->abbrev < MINIMUM_ABBREV)
4819                        options->abbrev = MINIMUM_ABBREV;
4820                else if (40 < options->abbrev)
4821                        options->abbrev = 40;
4822        }
4823        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4824                options->a_prefix = optarg;
4825                return argcount;
4826        }
4827        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4828                options->line_prefix = optarg;
4829                options->line_prefix_length = strlen(options->line_prefix);
4830                graph_setup_line_prefix(options);
4831                return argcount;
4832        }
4833        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4834                options->b_prefix = optarg;
4835                return argcount;
4836        }
4837        else if (!strcmp(arg, "--no-prefix"))
4838                options->a_prefix = options->b_prefix = "";
4839        else if (opt_arg(arg, '\0', "inter-hunk-context",
4840                         &options->interhunkcontext))
4841                ;
4842        else if (!strcmp(arg, "-W"))
4843                DIFF_OPT_SET(options, FUNCCONTEXT);
4844        else if (!strcmp(arg, "--function-context"))
4845                DIFF_OPT_SET(options, FUNCCONTEXT);
4846        else if (!strcmp(arg, "--no-function-context"))
4847                DIFF_OPT_CLR(options, FUNCCONTEXT);
4848        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4849                char *path = prefix_filename(prefix, optarg);
4850                options->file = xfopen(path, "w");
4851                options->close_file = 1;
4852                if (options->use_color != GIT_COLOR_ALWAYS)
4853                        options->use_color = GIT_COLOR_NEVER;
4854                free(path);
4855                return argcount;
4856        } else
4857                return 0;
4858        return 1;
4859}
4860
4861int parse_rename_score(const char **cp_p)
4862{
4863        unsigned long num, scale;
4864        int ch, dot;
4865        const char *cp = *cp_p;
4866
4867        num = 0;
4868        scale = 1;
4869        dot = 0;
4870        for (;;) {
4871                ch = *cp;
4872                if ( !dot && ch == '.' ) {
4873                        scale = 1;
4874                        dot = 1;
4875                } else if ( ch == '%' ) {
4876                        scale = dot ? scale*100 : 100;
4877                        cp++;   /* % is always at the end */
4878                        break;
4879                } else if ( ch >= '0' && ch <= '9' ) {
4880                        if ( scale < 100000 ) {
4881                                scale *= 10;
4882                                num = (num*10) + (ch-'0');
4883                        }
4884                } else {
4885                        break;
4886                }
4887                cp++;
4888        }
4889        *cp_p = cp;
4890
4891        /* user says num divided by scale and we say internally that
4892         * is MAX_SCORE * num / scale.
4893         */
4894        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4895}
4896
4897static int diff_scoreopt_parse(const char *opt)
4898{
4899        int opt1, opt2, cmd;
4900
4901        if (*opt++ != '-')
4902                return -1;
4903        cmd = *opt++;
4904        if (cmd == '-') {
4905                /* convert the long-form arguments into short-form versions */
4906                if (skip_prefix(opt, "break-rewrites", &opt)) {
4907                        if (*opt == 0 || *opt++ == '=')
4908                                cmd = 'B';
4909                } else if (skip_prefix(opt, "find-copies", &opt)) {
4910                        if (*opt == 0 || *opt++ == '=')
4911                                cmd = 'C';
4912                } else if (skip_prefix(opt, "find-renames", &opt)) {
4913                        if (*opt == 0 || *opt++ == '=')
4914                                cmd = 'M';
4915                }
4916        }
4917        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4918                return -1; /* that is not a -M, -C, or -B option */
4919
4920        opt1 = parse_rename_score(&opt);
4921        if (cmd != 'B')
4922                opt2 = 0;
4923        else {
4924                if (*opt == 0)
4925                        opt2 = 0;
4926                else if (*opt != '/')
4927                        return -1; /* we expect -B80/99 or -B80 */
4928                else {
4929                        opt++;
4930                        opt2 = parse_rename_score(&opt);
4931                }
4932        }
4933        if (*opt != 0)
4934                return -1;
4935        return opt1 | (opt2 << 16);
4936}
4937
4938struct diff_queue_struct diff_queued_diff;
4939
4940void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4941{
4942        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4943        queue->queue[queue->nr++] = dp;
4944}
4945
4946struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4947                                 struct diff_filespec *one,
4948                                 struct diff_filespec *two)
4949{
4950        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4951        dp->one = one;
4952        dp->two = two;
4953        if (queue)
4954                diff_q(queue, dp);
4955        return dp;
4956}
4957
4958void diff_free_filepair(struct diff_filepair *p)
4959{
4960        free_filespec(p->one);
4961        free_filespec(p->two);
4962        free(p);
4963}
4964
4965const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4966{
4967        int abblen;
4968        const char *abbrev;
4969
4970        if (len == GIT_SHA1_HEXSZ)
4971                return oid_to_hex(oid);
4972
4973        abbrev = diff_abbrev_oid(oid, len);
4974        abblen = strlen(abbrev);
4975
4976        /*
4977         * In well-behaved cases, where the abbbreviated result is the
4978         * same as the requested length, append three dots after the
4979         * abbreviation (hence the whole logic is limited to the case
4980         * where abblen < 37); when the actual abbreviated result is a
4981         * bit longer than the requested length, we reduce the number
4982         * of dots so that they match the well-behaved ones.  However,
4983         * if the actual abbreviation is longer than the requested
4984         * length by more than three, we give up on aligning, and add
4985         * three dots anyway, to indicate that the output is not the
4986         * full object name.  Yes, this may be suboptimal, but this
4987         * appears only in "diff --raw --abbrev" output and it is not
4988         * worth the effort to change it now.  Note that this would
4989         * likely to work fine when the automatic sizing of default
4990         * abbreviation length is used--we would be fed -1 in "len" in
4991         * that case, and will end up always appending three-dots, but
4992         * the automatic sizing is supposed to give abblen that ensures
4993         * uniqueness across all objects (statistically speaking).
4994         */
4995        if (abblen < GIT_SHA1_HEXSZ - 3) {
4996                static char hex[GIT_MAX_HEXSZ + 1];
4997                if (len < abblen && abblen <= len + 2)
4998                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4999                else
5000                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5001                return hex;
5002        }
5003
5004        return oid_to_hex(oid);
5005}
5006
5007static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5008{
5009        int line_termination = opt->line_termination;
5010        int inter_name_termination = line_termination ? '\t' : '\0';
5011
5012        fprintf(opt->file, "%s", diff_line_prefix(opt));
5013        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5014                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5015                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5016                fprintf(opt->file, "%s ",
5017                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5018        }
5019        if (p->score) {
5020                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5021                        inter_name_termination);
5022        } else {
5023                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5024        }
5025
5026        if (p->status == DIFF_STATUS_COPIED ||
5027            p->status == DIFF_STATUS_RENAMED) {
5028                const char *name_a, *name_b;
5029                name_a = p->one->path;
5030                name_b = p->two->path;
5031                strip_prefix(opt->prefix_length, &name_a, &name_b);
5032                write_name_quoted(name_a, opt->file, inter_name_termination);
5033                write_name_quoted(name_b, opt->file, line_termination);
5034        } else {
5035                const char *name_a, *name_b;
5036                name_a = p->one->mode ? p->one->path : p->two->path;
5037                name_b = NULL;
5038                strip_prefix(opt->prefix_length, &name_a, &name_b);
5039                write_name_quoted(name_a, opt->file, line_termination);
5040        }
5041}
5042
5043int diff_unmodified_pair(struct diff_filepair *p)
5044{
5045        /* This function is written stricter than necessary to support
5046         * the currently implemented transformers, but the idea is to
5047         * let transformers to produce diff_filepairs any way they want,
5048         * and filter and clean them up here before producing the output.
5049         */
5050        struct diff_filespec *one = p->one, *two = p->two;
5051
5052        if (DIFF_PAIR_UNMERGED(p))
5053                return 0; /* unmerged is interesting */
5054
5055        /* deletion, addition, mode or type change
5056         * and rename are all interesting.
5057         */
5058        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5059            DIFF_PAIR_MODE_CHANGED(p) ||
5060            strcmp(one->path, two->path))
5061                return 0;
5062
5063        /* both are valid and point at the same path.  that is, we are
5064         * dealing with a change.
5065         */
5066        if (one->oid_valid && two->oid_valid &&
5067            !oidcmp(&one->oid, &two->oid) &&
5068            !one->dirty_submodule && !two->dirty_submodule)
5069                return 1; /* no change */
5070        if (!one->oid_valid && !two->oid_valid)
5071                return 1; /* both look at the same file on the filesystem. */
5072        return 0;
5073}
5074
5075static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5076{
5077        if (diff_unmodified_pair(p))
5078                return;
5079
5080        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5081            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5082                return; /* no tree diffs in patch format */
5083
5084        run_diff(p, o);
5085}
5086
5087static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5088                            struct diffstat_t *diffstat)
5089{
5090        if (diff_unmodified_pair(p))
5091                return;
5092
5093        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5094            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5095                return; /* no useful stat for tree diffs */
5096
5097        run_diffstat(p, o, diffstat);
5098}
5099
5100static void diff_flush_checkdiff(struct diff_filepair *p,
5101                struct diff_options *o)
5102{
5103        if (diff_unmodified_pair(p))
5104                return;
5105
5106        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5107            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5108                return; /* nothing to check in tree diffs */
5109
5110        run_checkdiff(p, o);
5111}
5112
5113int diff_queue_is_empty(void)
5114{
5115        struct diff_queue_struct *q = &diff_queued_diff;
5116        int i;
5117        for (i = 0; i < q->nr; i++)
5118                if (!diff_unmodified_pair(q->queue[i]))
5119                        return 0;
5120        return 1;
5121}
5122
5123#if DIFF_DEBUG
5124void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5125{
5126        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5127                x, one ? one : "",
5128                s->path,
5129                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5130                s->mode,
5131                s->oid_valid ? oid_to_hex(&s->oid) : "");
5132        fprintf(stderr, "queue[%d] %s size %lu\n",
5133                x, one ? one : "",
5134                s->size);
5135}
5136
5137void diff_debug_filepair(const struct diff_filepair *p, int i)
5138{
5139        diff_debug_filespec(p->one, i, "one");
5140        diff_debug_filespec(p->two, i, "two");
5141        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5142                p->score, p->status ? p->status : '?',
5143                p->one->rename_used, p->broken_pair);
5144}
5145
5146void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5147{
5148        int i;
5149        if (msg)
5150                fprintf(stderr, "%s\n", msg);
5151        fprintf(stderr, "q->nr = %d\n", q->nr);
5152        for (i = 0; i < q->nr; i++) {
5153                struct diff_filepair *p = q->queue[i];
5154                diff_debug_filepair(p, i);
5155        }
5156}
5157#endif
5158
5159static void diff_resolve_rename_copy(void)
5160{
5161        int i;
5162        struct diff_filepair *p;
5163        struct diff_queue_struct *q = &diff_queued_diff;
5164
5165        diff_debug_queue("resolve-rename-copy", q);
5166
5167        for (i = 0; i < q->nr; i++) {
5168                p = q->queue[i];
5169                p->status = 0; /* undecided */
5170                if (DIFF_PAIR_UNMERGED(p))
5171                        p->status = DIFF_STATUS_UNMERGED;
5172                else if (!DIFF_FILE_VALID(p->one))
5173                        p->status = DIFF_STATUS_ADDED;
5174                else if (!DIFF_FILE_VALID(p->two))
5175                        p->status = DIFF_STATUS_DELETED;
5176                else if (DIFF_PAIR_TYPE_CHANGED(p))
5177                        p->status = DIFF_STATUS_TYPE_CHANGED;
5178
5179                /* from this point on, we are dealing with a pair
5180                 * whose both sides are valid and of the same type, i.e.
5181                 * either in-place edit or rename/copy edit.
5182                 */
5183                else if (DIFF_PAIR_RENAME(p)) {
5184                        /*
5185                         * A rename might have re-connected a broken
5186                         * pair up, causing the pathnames to be the
5187                         * same again. If so, that's not a rename at
5188                         * all, just a modification..
5189                         *
5190                         * Otherwise, see if this source was used for
5191                         * multiple renames, in which case we decrement
5192                         * the count, and call it a copy.
5193                         */
5194                        if (!strcmp(p->one->path, p->two->path))
5195                                p->status = DIFF_STATUS_MODIFIED;
5196                        else if (--p->one->rename_used > 0)
5197                                p->status = DIFF_STATUS_COPIED;
5198                        else
5199                                p->status = DIFF_STATUS_RENAMED;
5200                }
5201                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5202                         p->one->mode != p->two->mode ||
5203                         p->one->dirty_submodule ||
5204                         p->two->dirty_submodule ||
5205                         is_null_oid(&p->one->oid))
5206                        p->status = DIFF_STATUS_MODIFIED;
5207                else {
5208                        /* This is a "no-change" entry and should not
5209                         * happen anymore, but prepare for broken callers.
5210                         */
5211                        error("feeding unmodified %s to diffcore",
5212                              p->one->path);
5213                        p->status = DIFF_STATUS_UNKNOWN;
5214                }
5215        }
5216        diff_debug_queue("resolve-rename-copy done", q);
5217}
5218
5219static int check_pair_status(struct diff_filepair *p)
5220{
5221        switch (p->status) {
5222        case DIFF_STATUS_UNKNOWN:
5223                return 0;
5224        case 0:
5225                die("internal error in diff-resolve-rename-copy");
5226        default:
5227                return 1;
5228        }
5229}
5230
5231static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5232{
5233        int fmt = opt->output_format;
5234
5235        if (fmt & DIFF_FORMAT_CHECKDIFF)
5236                diff_flush_checkdiff(p, opt);
5237        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5238                diff_flush_raw(p, opt);
5239        else if (fmt & DIFF_FORMAT_NAME) {
5240                const char *name_a, *name_b;
5241                name_a = p->two->path;
5242                name_b = NULL;
5243                strip_prefix(opt->prefix_length, &name_a, &name_b);
5244                fprintf(opt->file, "%s", diff_line_prefix(opt));
5245                write_name_quoted(name_a, opt->file, opt->line_termination);
5246        }
5247}
5248
5249static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5250{
5251        struct strbuf sb = STRBUF_INIT;
5252        if (fs->mode)
5253                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5254        else
5255                strbuf_addf(&sb, " %s ", newdelete);
5256
5257        quote_c_style(fs->path, &sb, NULL, 0);
5258        strbuf_addch(&sb, '\n');
5259        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5260                         sb.buf, sb.len, 0);
5261        strbuf_release(&sb);
5262}
5263
5264static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5265                int show_name)
5266{
5267        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5268                struct strbuf sb = STRBUF_INIT;
5269                strbuf_addf(&sb, " mode change %06o => %06o",
5270                            p->one->mode, p->two->mode);
5271                if (show_name) {
5272                        strbuf_addch(&sb, ' ');
5273                        quote_c_style(p->two->path, &sb, NULL, 0);
5274                }
5275                strbuf_addch(&sb, '\n');
5276                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5277                                 sb.buf, sb.len, 0);
5278                strbuf_release(&sb);
5279        }
5280}
5281
5282static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5283                struct diff_filepair *p)
5284{
5285        struct strbuf sb = STRBUF_INIT;
5286        char *names = pprint_rename(p->one->path, p->two->path);
5287        strbuf_addf(&sb, " %s %s (%d%%)\n",
5288                        renamecopy, names, similarity_index(p));
5289        free(names);
5290        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5291                                 sb.buf, sb.len, 0);
5292        show_mode_change(opt, p, 0);
5293        strbuf_release(&sb);
5294}
5295
5296static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5297{
5298        switch(p->status) {
5299        case DIFF_STATUS_DELETED:
5300                show_file_mode_name(opt, "delete", p->one);
5301                break;
5302        case DIFF_STATUS_ADDED:
5303                show_file_mode_name(opt, "create", p->two);
5304                break;
5305        case DIFF_STATUS_COPIED:
5306                show_rename_copy(opt, "copy", p);
5307                break;
5308        case DIFF_STATUS_RENAMED:
5309                show_rename_copy(opt, "rename", p);
5310                break;
5311        default:
5312                if (p->score) {
5313                        struct strbuf sb = STRBUF_INIT;
5314                        strbuf_addstr(&sb, " rewrite ");
5315                        quote_c_style(p->two->path, &sb, NULL, 0);
5316                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5317                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5318                                         sb.buf, sb.len, 0);
5319                        strbuf_release(&sb);
5320                }
5321                show_mode_change(opt, p, !p->score);
5322                break;
5323        }
5324}
5325
5326struct patch_id_t {
5327        git_SHA_CTX *ctx;
5328        int patchlen;
5329};
5330
5331static int remove_space(char *line, int len)
5332{
5333        int i;
5334        char *dst = line;
5335        unsigned char c;
5336
5337        for (i = 0; i < len; i++)
5338                if (!isspace((c = line[i])))
5339                        *dst++ = c;
5340
5341        return dst - line;
5342}
5343
5344static void patch_id_consume(void *priv, char *line, unsigned long len)
5345{
5346        struct patch_id_t *data = priv;
5347        int new_len;
5348
5349        /* Ignore line numbers when computing the SHA1 of the patch */
5350        if (starts_with(line, "@@ -"))
5351                return;
5352
5353        new_len = remove_space(line, len);
5354
5355        git_SHA1_Update(data->ctx, line, new_len);
5356        data->patchlen += new_len;
5357}
5358
5359static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5360{
5361        git_SHA1_Update(ctx, str, strlen(str));
5362}
5363
5364static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5365{
5366        /* large enough for 2^32 in octal */
5367        char buf[12];
5368        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5369        git_SHA1_Update(ctx, buf, len);
5370}
5371
5372/* returns 0 upon success, and writes result into sha1 */
5373static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5374{
5375        struct diff_queue_struct *q = &diff_queued_diff;
5376        int i;
5377        git_SHA_CTX ctx;
5378        struct patch_id_t data;
5379
5380        git_SHA1_Init(&ctx);
5381        memset(&data, 0, sizeof(struct patch_id_t));
5382        data.ctx = &ctx;
5383
5384        for (i = 0; i < q->nr; i++) {
5385                xpparam_t xpp;
5386                xdemitconf_t xecfg;
5387                mmfile_t mf1, mf2;
5388                struct diff_filepair *p = q->queue[i];
5389                int len1, len2;
5390
5391                memset(&xpp, 0, sizeof(xpp));
5392                memset(&xecfg, 0, sizeof(xecfg));
5393                if (p->status == 0)
5394                        return error("internal diff status error");
5395                if (p->status == DIFF_STATUS_UNKNOWN)
5396                        continue;
5397                if (diff_unmodified_pair(p))
5398                        continue;
5399                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5400                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5401                        continue;
5402                if (DIFF_PAIR_UNMERGED(p))
5403                        continue;
5404
5405                diff_fill_oid_info(p->one);
5406                diff_fill_oid_info(p->two);
5407
5408                len1 = remove_space(p->one->path, strlen(p->one->path));
5409                len2 = remove_space(p->two->path, strlen(p->two->path));
5410                patch_id_add_string(&ctx, "diff--git");
5411                patch_id_add_string(&ctx, "a/");
5412                git_SHA1_Update(&ctx, p->one->path, len1);
5413                patch_id_add_string(&ctx, "b/");
5414                git_SHA1_Update(&ctx, p->two->path, len2);
5415
5416                if (p->one->mode == 0) {
5417                        patch_id_add_string(&ctx, "newfilemode");
5418                        patch_id_add_mode(&ctx, p->two->mode);
5419                        patch_id_add_string(&ctx, "---/dev/null");
5420                        patch_id_add_string(&ctx, "+++b/");
5421                        git_SHA1_Update(&ctx, p->two->path, len2);
5422                } else if (p->two->mode == 0) {
5423                        patch_id_add_string(&ctx, "deletedfilemode");
5424                        patch_id_add_mode(&ctx, p->one->mode);
5425                        patch_id_add_string(&ctx, "---a/");
5426                        git_SHA1_Update(&ctx, p->one->path, len1);
5427                        patch_id_add_string(&ctx, "+++/dev/null");
5428                } else {
5429                        patch_id_add_string(&ctx, "---a/");
5430                        git_SHA1_Update(&ctx, p->one->path, len1);
5431                        patch_id_add_string(&ctx, "+++b/");
5432                        git_SHA1_Update(&ctx, p->two->path, len2);
5433                }
5434
5435                if (diff_header_only)
5436                        continue;
5437
5438                if (fill_mmfile(&mf1, p->one) < 0 ||
5439                    fill_mmfile(&mf2, p->two) < 0)
5440                        return error("unable to read files to diff");
5441
5442                if (diff_filespec_is_binary(p->one) ||
5443                    diff_filespec_is_binary(p->two)) {
5444                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5445                                        GIT_SHA1_HEXSZ);
5446                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5447                                        GIT_SHA1_HEXSZ);
5448                        continue;
5449                }
5450
5451                xpp.flags = 0;
5452                xecfg.ctxlen = 3;
5453                xecfg.flags = 0;
5454                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5455                                  &xpp, &xecfg))
5456                        return error("unable to generate patch-id diff for %s",
5457                                     p->one->path);
5458        }
5459
5460        git_SHA1_Final(oid->hash, &ctx);
5461        return 0;
5462}
5463
5464int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5465{
5466        struct diff_queue_struct *q = &diff_queued_diff;
5467        int i;
5468        int result = diff_get_patch_id(options, oid, diff_header_only);
5469
5470        for (i = 0; i < q->nr; i++)
5471                diff_free_filepair(q->queue[i]);
5472
5473        free(q->queue);
5474        DIFF_QUEUE_CLEAR(q);
5475
5476        return result;
5477}
5478
5479static int is_summary_empty(const struct diff_queue_struct *q)
5480{
5481        int i;
5482
5483        for (i = 0; i < q->nr; i++) {
5484                const struct diff_filepair *p = q->queue[i];
5485
5486                switch (p->status) {
5487                case DIFF_STATUS_DELETED:
5488                case DIFF_STATUS_ADDED:
5489                case DIFF_STATUS_COPIED:
5490                case DIFF_STATUS_RENAMED:
5491                        return 0;
5492                default:
5493                        if (p->score)
5494                                return 0;
5495                        if (p->one->mode && p->two->mode &&
5496                            p->one->mode != p->two->mode)
5497                                return 0;
5498                        break;
5499                }
5500        }
5501        return 1;
5502}
5503
5504static const char rename_limit_warning[] =
5505N_("inexact rename detection was skipped due to too many files.");
5506
5507static const char degrade_cc_to_c_warning[] =
5508N_("only found copies from modified paths due to too many files.");
5509
5510static const char rename_limit_advice[] =
5511N_("you may want to set your %s variable to at least "
5512   "%d and retry the command.");
5513
5514void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5515{
5516        if (degraded_cc)
5517                warning(_(degrade_cc_to_c_warning));
5518        else if (needed)
5519                warning(_(rename_limit_warning));
5520        else
5521                return;
5522        if (0 < needed && needed < 32767)
5523                warning(_(rename_limit_advice), varname, needed);
5524}
5525
5526static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5527{
5528        int i;
5529        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5530        struct diff_queue_struct *q = &diff_queued_diff;
5531
5532        if (WSEH_NEW & WS_RULE_MASK)
5533                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5534
5535        if (o->color_moved)
5536                o->emitted_symbols = &esm;
5537
5538        for (i = 0; i < q->nr; i++) {
5539                struct diff_filepair *p = q->queue[i];
5540                if (check_pair_status(p))
5541                        diff_flush_patch(p, o);
5542        }
5543
5544        if (o->emitted_symbols) {
5545                if (o->color_moved) {
5546                        struct hashmap add_lines, del_lines;
5547
5548                        hashmap_init(&del_lines,
5549                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5550                        hashmap_init(&add_lines,
5551                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5552
5553                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5554                        mark_color_as_moved(o, &add_lines, &del_lines);
5555                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5556                                dim_moved_lines(o);
5557
5558                        hashmap_free(&add_lines, 0);
5559                        hashmap_free(&del_lines, 0);
5560                }
5561
5562                for (i = 0; i < esm.nr; i++)
5563                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5564
5565                for (i = 0; i < esm.nr; i++)
5566                        free((void *)esm.buf[i].line);
5567        }
5568        esm.nr = 0;
5569}
5570
5571void diff_flush(struct diff_options *options)
5572{
5573        struct diff_queue_struct *q = &diff_queued_diff;
5574        int i, output_format = options->output_format;
5575        int separator = 0;
5576        int dirstat_by_line = 0;
5577
5578        /*
5579         * Order: raw, stat, summary, patch
5580         * or:    name/name-status/checkdiff (other bits clear)
5581         */
5582        if (!q->nr)
5583                goto free_queue;
5584
5585        if (output_format & (DIFF_FORMAT_RAW |
5586                             DIFF_FORMAT_NAME |
5587                             DIFF_FORMAT_NAME_STATUS |
5588                             DIFF_FORMAT_CHECKDIFF)) {
5589                for (i = 0; i < q->nr; i++) {
5590                        struct diff_filepair *p = q->queue[i];
5591                        if (check_pair_status(p))
5592                                flush_one_pair(p, options);
5593                }
5594                separator++;
5595        }
5596
5597        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
5598                dirstat_by_line = 1;
5599
5600        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5601            dirstat_by_line) {
5602                struct diffstat_t diffstat;
5603
5604                memset(&diffstat, 0, sizeof(struct diffstat_t));
5605                for (i = 0; i < q->nr; i++) {
5606                        struct diff_filepair *p = q->queue[i];
5607                        if (check_pair_status(p))
5608                                diff_flush_stat(p, options, &diffstat);
5609                }
5610                if (output_format & DIFF_FORMAT_NUMSTAT)
5611                        show_numstat(&diffstat, options);
5612                if (output_format & DIFF_FORMAT_DIFFSTAT)
5613                        show_stats(&diffstat, options);
5614                if (output_format & DIFF_FORMAT_SHORTSTAT)
5615                        show_shortstats(&diffstat, options);
5616                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5617                        show_dirstat_by_line(&diffstat, options);
5618                free_diffstat_info(&diffstat);
5619                separator++;
5620        }
5621        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5622                show_dirstat(options);
5623
5624        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5625                for (i = 0; i < q->nr; i++) {
5626                        diff_summary(options, q->queue[i]);
5627                }
5628                separator++;
5629        }
5630
5631        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5632            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5633            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5634                /*
5635                 * run diff_flush_patch for the exit status. setting
5636                 * options->file to /dev/null should be safe, because we
5637                 * aren't supposed to produce any output anyway.
5638                 */
5639                if (options->close_file)
5640                        fclose(options->file);
5641                options->file = xfopen("/dev/null", "w");
5642                options->close_file = 1;
5643                options->color_moved = 0;
5644                for (i = 0; i < q->nr; i++) {
5645                        struct diff_filepair *p = q->queue[i];
5646                        if (check_pair_status(p))
5647                                diff_flush_patch(p, options);
5648                        if (options->found_changes)
5649                                break;
5650                }
5651        }
5652
5653        if (output_format & DIFF_FORMAT_PATCH) {
5654                if (separator) {
5655                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5656                        if (options->stat_sep)
5657                                /* attach patch instead of inline */
5658                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5659                                                 NULL, 0, 0);
5660                }
5661
5662                diff_flush_patch_all_file_pairs(options);
5663        }
5664
5665        if (output_format & DIFF_FORMAT_CALLBACK)
5666                options->format_callback(q, options, options->format_callback_data);
5667
5668        for (i = 0; i < q->nr; i++)
5669                diff_free_filepair(q->queue[i]);
5670free_queue:
5671        free(q->queue);
5672        DIFF_QUEUE_CLEAR(q);
5673        if (options->close_file)
5674                fclose(options->file);
5675
5676        /*
5677         * Report the content-level differences with HAS_CHANGES;
5678         * diff_addremove/diff_change does not set the bit when
5679         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5680         */
5681        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5682                if (options->found_changes)
5683                        DIFF_OPT_SET(options, HAS_CHANGES);
5684                else
5685                        DIFF_OPT_CLR(options, HAS_CHANGES);
5686        }
5687}
5688
5689static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5690{
5691        return (((p->status == DIFF_STATUS_MODIFIED) &&
5692                 ((p->score &&
5693                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5694                  (!p->score &&
5695                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5696                ((p->status != DIFF_STATUS_MODIFIED) &&
5697                 filter_bit_tst(p->status, options)));
5698}
5699
5700static void diffcore_apply_filter(struct diff_options *options)
5701{
5702        int i;
5703        struct diff_queue_struct *q = &diff_queued_diff;
5704        struct diff_queue_struct outq;
5705
5706        DIFF_QUEUE_CLEAR(&outq);
5707
5708        if (!options->filter)
5709                return;
5710
5711        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5712                int found;
5713                for (i = found = 0; !found && i < q->nr; i++) {
5714                        if (match_filter(options, q->queue[i]))
5715                                found++;
5716                }
5717                if (found)
5718                        return;
5719
5720                /* otherwise we will clear the whole queue
5721                 * by copying the empty outq at the end of this
5722                 * function, but first clear the current entries
5723                 * in the queue.
5724                 */
5725                for (i = 0; i < q->nr; i++)
5726                        diff_free_filepair(q->queue[i]);
5727        }
5728        else {
5729                /* Only the matching ones */
5730                for (i = 0; i < q->nr; i++) {
5731                        struct diff_filepair *p = q->queue[i];
5732                        if (match_filter(options, p))
5733                                diff_q(&outq, p);
5734                        else
5735                                diff_free_filepair(p);
5736                }
5737        }
5738        free(q->queue);
5739        *q = outq;
5740}
5741
5742/* Check whether two filespecs with the same mode and size are identical */
5743static int diff_filespec_is_identical(struct diff_filespec *one,
5744                                      struct diff_filespec *two)
5745{
5746        if (S_ISGITLINK(one->mode))
5747                return 0;
5748        if (diff_populate_filespec(one, 0))
5749                return 0;
5750        if (diff_populate_filespec(two, 0))
5751                return 0;
5752        return !memcmp(one->data, two->data, one->size);
5753}
5754
5755static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5756{
5757        if (p->done_skip_stat_unmatch)
5758                return p->skip_stat_unmatch_result;
5759
5760        p->done_skip_stat_unmatch = 1;
5761        p->skip_stat_unmatch_result = 0;
5762        /*
5763         * 1. Entries that come from stat info dirtiness
5764         *    always have both sides (iow, not create/delete),
5765         *    one side of the object name is unknown, with
5766         *    the same mode and size.  Keep the ones that
5767         *    do not match these criteria.  They have real
5768         *    differences.
5769         *
5770         * 2. At this point, the file is known to be modified,
5771         *    with the same mode and size, and the object
5772         *    name of one side is unknown.  Need to inspect
5773         *    the identical contents.
5774         */
5775        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5776            !DIFF_FILE_VALID(p->two) ||
5777            (p->one->oid_valid && p->two->oid_valid) ||
5778            (p->one->mode != p->two->mode) ||
5779            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5780            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5781            (p->one->size != p->two->size) ||
5782            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5783                p->skip_stat_unmatch_result = 1;
5784        return p->skip_stat_unmatch_result;
5785}
5786
5787static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5788{
5789        int i;
5790        struct diff_queue_struct *q = &diff_queued_diff;
5791        struct diff_queue_struct outq;
5792        DIFF_QUEUE_CLEAR(&outq);
5793
5794        for (i = 0; i < q->nr; i++) {
5795                struct diff_filepair *p = q->queue[i];
5796
5797                if (diff_filespec_check_stat_unmatch(p))
5798                        diff_q(&outq, p);
5799                else {
5800                        /*
5801                         * The caller can subtract 1 from skip_stat_unmatch
5802                         * to determine how many paths were dirty only
5803                         * due to stat info mismatch.
5804                         */
5805                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5806                                diffopt->skip_stat_unmatch++;
5807                        diff_free_filepair(p);
5808                }
5809        }
5810        free(q->queue);
5811        *q = outq;
5812}
5813
5814static int diffnamecmp(const void *a_, const void *b_)
5815{
5816        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5817        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5818        const char *name_a, *name_b;
5819
5820        name_a = a->one ? a->one->path : a->two->path;
5821        name_b = b->one ? b->one->path : b->two->path;
5822        return strcmp(name_a, name_b);
5823}
5824
5825void diffcore_fix_diff_index(struct diff_options *options)
5826{
5827        struct diff_queue_struct *q = &diff_queued_diff;
5828        QSORT(q->queue, q->nr, diffnamecmp);
5829}
5830
5831void diffcore_std(struct diff_options *options)
5832{
5833        /* NOTE please keep the following in sync with diff_tree_combined() */
5834        if (options->skip_stat_unmatch)
5835                diffcore_skip_stat_unmatch(options);
5836        if (!options->found_follow) {
5837                /* See try_to_follow_renames() in tree-diff.c */
5838                if (options->break_opt != -1)
5839                        diffcore_break(options->break_opt);
5840                if (options->detect_rename)
5841                        diffcore_rename(options);
5842                if (options->break_opt != -1)
5843                        diffcore_merge_broken();
5844        }
5845        if (options->pickaxe)
5846                diffcore_pickaxe(options);
5847        if (options->orderfile)
5848                diffcore_order(options->orderfile);
5849        if (!options->found_follow)
5850                /* See try_to_follow_renames() in tree-diff.c */
5851                diff_resolve_rename_copy();
5852        diffcore_apply_filter(options);
5853
5854        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5855                DIFF_OPT_SET(options, HAS_CHANGES);
5856        else
5857                DIFF_OPT_CLR(options, HAS_CHANGES);
5858
5859        options->found_follow = 0;
5860}
5861
5862int diff_result_code(struct diff_options *opt, int status)
5863{
5864        int result = 0;
5865
5866        diff_warn_rename_limit("diff.renameLimit",
5867                               opt->needed_rename_limit,
5868                               opt->degraded_cc_to_c);
5869        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5870            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5871                return status;
5872        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5873            DIFF_OPT_TST(opt, HAS_CHANGES))
5874                result |= 01;
5875        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5876            DIFF_OPT_TST(opt, CHECK_FAILED))
5877                result |= 02;
5878        return result;
5879}
5880
5881int diff_can_quit_early(struct diff_options *opt)
5882{
5883        return (DIFF_OPT_TST(opt, QUICK) &&
5884                !opt->filter &&
5885                DIFF_OPT_TST(opt, HAS_CHANGES));
5886}
5887
5888/*
5889 * Shall changes to this submodule be ignored?
5890 *
5891 * Submodule changes can be configured to be ignored separately for each path,
5892 * but that configuration can be overridden from the command line.
5893 */
5894static int is_submodule_ignored(const char *path, struct diff_options *options)
5895{
5896        int ignored = 0;
5897        unsigned orig_flags = options->flags;
5898        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5899                set_diffopt_flags_from_submodule_config(options, path);
5900        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5901                ignored = 1;
5902        options->flags = orig_flags;
5903        return ignored;
5904}
5905
5906void diff_addremove(struct diff_options *options,
5907                    int addremove, unsigned mode,
5908                    const struct object_id *oid,
5909                    int oid_valid,
5910                    const char *concatpath, unsigned dirty_submodule)
5911{
5912        struct diff_filespec *one, *two;
5913
5914        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5915                return;
5916
5917        /* This may look odd, but it is a preparation for
5918         * feeding "there are unchanged files which should
5919         * not produce diffs, but when you are doing copy
5920         * detection you would need them, so here they are"
5921         * entries to the diff-core.  They will be prefixed
5922         * with something like '=' or '*' (I haven't decided
5923         * which but should not make any difference).
5924         * Feeding the same new and old to diff_change()
5925         * also has the same effect.
5926         * Before the final output happens, they are pruned after
5927         * merged into rename/copy pairs as appropriate.
5928         */
5929        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5930                addremove = (addremove == '+' ? '-' :
5931                             addremove == '-' ? '+' : addremove);
5932
5933        if (options->prefix &&
5934            strncmp(concatpath, options->prefix, options->prefix_length))
5935                return;
5936
5937        one = alloc_filespec(concatpath);
5938        two = alloc_filespec(concatpath);
5939
5940        if (addremove != '+')
5941                fill_filespec(one, oid, oid_valid, mode);
5942        if (addremove != '-') {
5943                fill_filespec(two, oid, oid_valid, mode);
5944                two->dirty_submodule = dirty_submodule;
5945        }
5946
5947        diff_queue(&diff_queued_diff, one, two);
5948        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5949                DIFF_OPT_SET(options, HAS_CHANGES);
5950}
5951
5952void diff_change(struct diff_options *options,
5953                 unsigned old_mode, unsigned new_mode,
5954                 const struct object_id *old_oid,
5955                 const struct object_id *new_oid,
5956                 int old_oid_valid, int new_oid_valid,
5957                 const char *concatpath,
5958                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5959{
5960        struct diff_filespec *one, *two;
5961        struct diff_filepair *p;
5962
5963        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5964            is_submodule_ignored(concatpath, options))
5965                return;
5966
5967        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5968                SWAP(old_mode, new_mode);
5969                SWAP(old_oid, new_oid);
5970                SWAP(old_oid_valid, new_oid_valid);
5971                SWAP(old_dirty_submodule, new_dirty_submodule);
5972        }
5973
5974        if (options->prefix &&
5975            strncmp(concatpath, options->prefix, options->prefix_length))
5976                return;
5977
5978        one = alloc_filespec(concatpath);
5979        two = alloc_filespec(concatpath);
5980        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5981        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5982        one->dirty_submodule = old_dirty_submodule;
5983        two->dirty_submodule = new_dirty_submodule;
5984        p = diff_queue(&diff_queued_diff, one, two);
5985
5986        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5987                return;
5988
5989        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5990            !diff_filespec_check_stat_unmatch(p))
5991                return;
5992
5993        DIFF_OPT_SET(options, HAS_CHANGES);
5994}
5995
5996struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5997{
5998        struct diff_filepair *pair;
5999        struct diff_filespec *one, *two;
6000
6001        if (options->prefix &&
6002            strncmp(path, options->prefix, options->prefix_length))
6003                return NULL;
6004
6005        one = alloc_filespec(path);
6006        two = alloc_filespec(path);
6007        pair = diff_queue(&diff_queued_diff, one, two);
6008        pair->is_unmerged = 1;
6009        return pair;
6010}
6011
6012static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6013                size_t *outsize)
6014{
6015        struct diff_tempfile *temp;
6016        const char *argv[3];
6017        const char **arg = argv;
6018        struct child_process child = CHILD_PROCESS_INIT;
6019        struct strbuf buf = STRBUF_INIT;
6020        int err = 0;
6021
6022        temp = prepare_temp_file(spec->path, spec);
6023        *arg++ = pgm;
6024        *arg++ = temp->name;
6025        *arg = NULL;
6026
6027        child.use_shell = 1;
6028        child.argv = argv;
6029        child.out = -1;
6030        if (start_command(&child)) {
6031                remove_tempfile();
6032                return NULL;
6033        }
6034
6035        if (strbuf_read(&buf, child.out, 0) < 0)
6036                err = error("error reading from textconv command '%s'", pgm);
6037        close(child.out);
6038
6039        if (finish_command(&child) || err) {
6040                strbuf_release(&buf);
6041                remove_tempfile();
6042                return NULL;
6043        }
6044        remove_tempfile();
6045
6046        return strbuf_detach(&buf, outsize);
6047}
6048
6049size_t fill_textconv(struct userdiff_driver *driver,
6050                     struct diff_filespec *df,
6051                     char **outbuf)
6052{
6053        size_t size;
6054
6055        if (!driver) {
6056                if (!DIFF_FILE_VALID(df)) {
6057                        *outbuf = "";
6058                        return 0;
6059                }
6060                if (diff_populate_filespec(df, 0))
6061                        die("unable to read files to diff");
6062                *outbuf = df->data;
6063                return df->size;
6064        }
6065
6066        if (!driver->textconv)
6067                die("BUG: fill_textconv called with non-textconv driver");
6068
6069        if (driver->textconv_cache && df->oid_valid) {
6070                *outbuf = notes_cache_get(driver->textconv_cache,
6071                                          &df->oid,
6072                                          &size);
6073                if (*outbuf)
6074                        return size;
6075        }
6076
6077        *outbuf = run_textconv(driver->textconv, df, &size);
6078        if (!*outbuf)
6079                die("unable to read files to diff");
6080
6081        if (driver->textconv_cache && df->oid_valid) {
6082                /* ignore errors, as we might be in a readonly repository */
6083                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6084                                size);
6085                /*
6086                 * we could save up changes and flush them all at the end,
6087                 * but we would need an extra call after all diffing is done.
6088                 * Since generating a cache entry is the slow path anyway,
6089                 * this extra overhead probably isn't a big deal.
6090                 */
6091                notes_cache_write(driver->textconv_cache);
6092        }
6093
6094        return size;
6095}
6096
6097int textconv_object(const char *path,
6098                    unsigned mode,
6099                    const struct object_id *oid,
6100                    int oid_valid,
6101                    char **buf,
6102                    unsigned long *buf_size)
6103{
6104        struct diff_filespec *df;
6105        struct userdiff_driver *textconv;
6106
6107        df = alloc_filespec(path);
6108        fill_filespec(df, oid, oid_valid, mode);
6109        textconv = get_textconv(df);
6110        if (!textconv) {
6111                free_filespec(df);
6112                return 0;
6113        }
6114
6115        *buf_size = fill_textconv(textconv, df, buf);
6116        free_filespec(df);
6117        return 1;
6118}
6119
6120void setup_diff_pager(struct diff_options *opt)
6121{
6122        /*
6123         * If the user asked for our exit code, then either they want --quiet
6124         * or --exit-code. We should definitely not bother with a pager in the
6125         * former case, as we will generate no output. Since we still properly
6126         * report our exit code even when a pager is run, we _could_ run a
6127         * pager with --exit-code. But since we have not done so historically,
6128         * and because it is easy to find people oneline advising "git diff
6129         * --exit-code" in hooks and other scripts, we do not do so.
6130         */
6131        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
6132            check_pager_config("diff") != 0)
6133                setup_pager();
6134}