diff.con commit diff.c: color moved lines differently (2e2d5ac)
   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
  25#ifdef NO_FAST_WORKING_DIRECTORY
  26#define FAST_WORKING_DIRECTORY 0
  27#else
  28#define FAST_WORKING_DIRECTORY 1
  29#endif
  30
  31static int diff_detect_rename_default;
  32static int diff_indent_heuristic = 1;
  33static int diff_rename_limit_default = 400;
  34static int diff_suppress_blank_empty;
  35static int diff_use_color_default = -1;
  36static int diff_color_moved_default;
  37static int diff_context_default = 3;
  38static int diff_interhunk_context_default;
  39static const char *diff_word_regex_cfg;
  40static const char *external_diff_cmd_cfg;
  41static const char *diff_order_file_cfg;
  42int diff_auto_refresh_index = 1;
  43static int diff_mnemonic_prefix;
  44static int diff_no_prefix;
  45static int diff_stat_graph_width;
  46static int diff_dirstat_permille_default = 30;
  47static struct diff_options default_diff_options;
  48static long diff_algorithm;
  49static unsigned ws_error_highlight_default = WSEH_NEW;
  50
  51static char diff_colors[][COLOR_MAXLEN] = {
  52        GIT_COLOR_RESET,
  53        GIT_COLOR_NORMAL,       /* CONTEXT */
  54        GIT_COLOR_BOLD,         /* METAINFO */
  55        GIT_COLOR_CYAN,         /* FRAGINFO */
  56        GIT_COLOR_RED,          /* OLD */
  57        GIT_COLOR_GREEN,        /* NEW */
  58        GIT_COLOR_YELLOW,       /* COMMIT */
  59        GIT_COLOR_BG_RED,       /* WHITESPACE */
  60        GIT_COLOR_NORMAL,       /* FUNCINFO */
  61        GIT_COLOR_MAGENTA,      /* OLD_MOVED */
  62        GIT_COLOR_BLUE,         /* OLD_MOVED ALTERNATIVE */
  63        GIT_COLOR_CYAN,         /* NEW_MOVED */
  64        GIT_COLOR_YELLOW,       /* NEW_MOVED ALTERNATIVE */
  65};
  66
  67static NORETURN void die_want_option(const char *option_name)
  68{
  69        die(_("option '%s' requires a value"), option_name);
  70}
  71
  72static int parse_diff_color_slot(const char *var)
  73{
  74        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  75                return DIFF_CONTEXT;
  76        if (!strcasecmp(var, "meta"))
  77                return DIFF_METAINFO;
  78        if (!strcasecmp(var, "frag"))
  79                return DIFF_FRAGINFO;
  80        if (!strcasecmp(var, "old"))
  81                return DIFF_FILE_OLD;
  82        if (!strcasecmp(var, "new"))
  83                return DIFF_FILE_NEW;
  84        if (!strcasecmp(var, "commit"))
  85                return DIFF_COMMIT;
  86        if (!strcasecmp(var, "whitespace"))
  87                return DIFF_WHITESPACE;
  88        if (!strcasecmp(var, "func"))
  89                return DIFF_FUNCINFO;
  90        if (!strcasecmp(var, "oldmoved"))
  91                return DIFF_FILE_OLD_MOVED;
  92        if (!strcasecmp(var, "oldmovedalternative"))
  93                return DIFF_FILE_OLD_MOVED_ALT;
  94        if (!strcasecmp(var, "newmoved"))
  95                return DIFF_FILE_NEW_MOVED;
  96        if (!strcasecmp(var, "newmovedalternative"))
  97                return DIFF_FILE_NEW_MOVED_ALT;
  98        return -1;
  99}
 100
 101static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 102                                struct strbuf *errmsg)
 103{
 104        char *params_copy = xstrdup(params_string);
 105        struct string_list params = STRING_LIST_INIT_NODUP;
 106        int ret = 0;
 107        int i;
 108
 109        if (*params_copy)
 110                string_list_split_in_place(&params, params_copy, ',', -1);
 111        for (i = 0; i < params.nr; i++) {
 112                const char *p = params.items[i].string;
 113                if (!strcmp(p, "changes")) {
 114                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 115                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 116                } else if (!strcmp(p, "lines")) {
 117                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 118                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 119                } else if (!strcmp(p, "files")) {
 120                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 121                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 122                } else if (!strcmp(p, "noncumulative")) {
 123                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 124                } else if (!strcmp(p, "cumulative")) {
 125                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 126                } else if (isdigit(*p)) {
 127                        char *end;
 128                        int permille = strtoul(p, &end, 10) * 10;
 129                        if (*end == '.' && isdigit(*++end)) {
 130                                /* only use first digit */
 131                                permille += *end - '0';
 132                                /* .. and ignore any further digits */
 133                                while (isdigit(*++end))
 134                                        ; /* nothing */
 135                        }
 136                        if (!*end)
 137                                options->dirstat_permille = permille;
 138                        else {
 139                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 140                                            p);
 141                                ret++;
 142                        }
 143                } else {
 144                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 145                        ret++;
 146                }
 147
 148        }
 149        string_list_clear(&params, 0);
 150        free(params_copy);
 151        return ret;
 152}
 153
 154static int parse_submodule_params(struct diff_options *options, const char *value)
 155{
 156        if (!strcmp(value, "log"))
 157                options->submodule_format = DIFF_SUBMODULE_LOG;
 158        else if (!strcmp(value, "short"))
 159                options->submodule_format = DIFF_SUBMODULE_SHORT;
 160        else if (!strcmp(value, "diff"))
 161                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 162        else
 163                return -1;
 164        return 0;
 165}
 166
 167static int git_config_rename(const char *var, const char *value)
 168{
 169        if (!value)
 170                return DIFF_DETECT_RENAME;
 171        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 172                return  DIFF_DETECT_COPY;
 173        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 174}
 175
 176long parse_algorithm_value(const char *value)
 177{
 178        if (!value)
 179                return -1;
 180        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 181                return 0;
 182        else if (!strcasecmp(value, "minimal"))
 183                return XDF_NEED_MINIMAL;
 184        else if (!strcasecmp(value, "patience"))
 185                return XDF_PATIENCE_DIFF;
 186        else if (!strcasecmp(value, "histogram"))
 187                return XDF_HISTOGRAM_DIFF;
 188        return -1;
 189}
 190
 191static int parse_one_token(const char **arg, const char *token)
 192{
 193        const char *rest;
 194        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 195                *arg = rest;
 196                return 1;
 197        }
 198        return 0;
 199}
 200
 201static int parse_ws_error_highlight(const char *arg)
 202{
 203        const char *orig_arg = arg;
 204        unsigned val = 0;
 205
 206        while (*arg) {
 207                if (parse_one_token(&arg, "none"))
 208                        val = 0;
 209                else if (parse_one_token(&arg, "default"))
 210                        val = WSEH_NEW;
 211                else if (parse_one_token(&arg, "all"))
 212                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 213                else if (parse_one_token(&arg, "new"))
 214                        val |= WSEH_NEW;
 215                else if (parse_one_token(&arg, "old"))
 216                        val |= WSEH_OLD;
 217                else if (parse_one_token(&arg, "context"))
 218                        val |= WSEH_CONTEXT;
 219                else {
 220                        return -1 - (int)(arg - orig_arg);
 221                }
 222                if (*arg)
 223                        arg++;
 224        }
 225        return val;
 226}
 227
 228/*
 229 * These are to give UI layer defaults.
 230 * The core-level commands such as git-diff-files should
 231 * never be affected by the setting of diff.renames
 232 * the user happens to have in the configuration file.
 233 */
 234void init_diff_ui_defaults(void)
 235{
 236        diff_detect_rename_default = 1;
 237}
 238
 239int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 240{
 241        if (!strcmp(var, "diff.indentheuristic"))
 242                diff_indent_heuristic = git_config_bool(var, value);
 243        return 0;
 244}
 245
 246static int parse_color_moved(const char *arg)
 247{
 248        switch (git_parse_maybe_bool(arg)) {
 249        case 0:
 250                return COLOR_MOVED_NO;
 251        case 1:
 252                return COLOR_MOVED_DEFAULT;
 253        default:
 254                break;
 255        }
 256
 257        if (!strcmp(arg, "no"))
 258                return COLOR_MOVED_NO;
 259        else if (!strcmp(arg, "zebra"))
 260                return COLOR_MOVED_ZEBRA;
 261        else if (!strcmp(arg, "default"))
 262                return COLOR_MOVED_DEFAULT;
 263        else
 264                return error(_("color moved setting must be one of 'no', 'default', 'zebra'"));
 265}
 266
 267int git_diff_ui_config(const char *var, const char *value, void *cb)
 268{
 269        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 270                diff_use_color_default = git_config_colorbool(var, value);
 271                return 0;
 272        }
 273        if (!strcmp(var, "diff.colormoved")) {
 274                int cm = parse_color_moved(value);
 275                if (cm < 0)
 276                        return -1;
 277                diff_color_moved_default = cm;
 278                return 0;
 279        }
 280        if (!strcmp(var, "diff.context")) {
 281                diff_context_default = git_config_int(var, value);
 282                if (diff_context_default < 0)
 283                        return -1;
 284                return 0;
 285        }
 286        if (!strcmp(var, "diff.interhunkcontext")) {
 287                diff_interhunk_context_default = git_config_int(var, value);
 288                if (diff_interhunk_context_default < 0)
 289                        return -1;
 290                return 0;
 291        }
 292        if (!strcmp(var, "diff.renames")) {
 293                diff_detect_rename_default = git_config_rename(var, value);
 294                return 0;
 295        }
 296        if (!strcmp(var, "diff.autorefreshindex")) {
 297                diff_auto_refresh_index = git_config_bool(var, value);
 298                return 0;
 299        }
 300        if (!strcmp(var, "diff.mnemonicprefix")) {
 301                diff_mnemonic_prefix = git_config_bool(var, value);
 302                return 0;
 303        }
 304        if (!strcmp(var, "diff.noprefix")) {
 305                diff_no_prefix = git_config_bool(var, value);
 306                return 0;
 307        }
 308        if (!strcmp(var, "diff.statgraphwidth")) {
 309                diff_stat_graph_width = git_config_int(var, value);
 310                return 0;
 311        }
 312        if (!strcmp(var, "diff.external"))
 313                return git_config_string(&external_diff_cmd_cfg, var, value);
 314        if (!strcmp(var, "diff.wordregex"))
 315                return git_config_string(&diff_word_regex_cfg, var, value);
 316        if (!strcmp(var, "diff.orderfile"))
 317                return git_config_pathname(&diff_order_file_cfg, var, value);
 318
 319        if (!strcmp(var, "diff.ignoresubmodules"))
 320                handle_ignore_submodules_arg(&default_diff_options, value);
 321
 322        if (!strcmp(var, "diff.submodule")) {
 323                if (parse_submodule_params(&default_diff_options, value))
 324                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 325                                value);
 326                return 0;
 327        }
 328
 329        if (!strcmp(var, "diff.algorithm")) {
 330                diff_algorithm = parse_algorithm_value(value);
 331                if (diff_algorithm < 0)
 332                        return -1;
 333                return 0;
 334        }
 335
 336        if (!strcmp(var, "diff.wserrorhighlight")) {
 337                int val = parse_ws_error_highlight(value);
 338                if (val < 0)
 339                        return -1;
 340                ws_error_highlight_default = val;
 341                return 0;
 342        }
 343
 344        if (git_color_config(var, value, cb) < 0)
 345                return -1;
 346
 347        return git_diff_basic_config(var, value, cb);
 348}
 349
 350int git_diff_basic_config(const char *var, const char *value, void *cb)
 351{
 352        const char *name;
 353
 354        if (!strcmp(var, "diff.renamelimit")) {
 355                diff_rename_limit_default = git_config_int(var, value);
 356                return 0;
 357        }
 358
 359        if (userdiff_config(var, value) < 0)
 360                return -1;
 361
 362        if (skip_prefix(var, "diff.color.", &name) ||
 363            skip_prefix(var, "color.diff.", &name)) {
 364                int slot = parse_diff_color_slot(name);
 365                if (slot < 0)
 366                        return 0;
 367                if (!value)
 368                        return config_error_nonbool(var);
 369                return color_parse(value, diff_colors[slot]);
 370        }
 371
 372        /* like GNU diff's --suppress-blank-empty option  */
 373        if (!strcmp(var, "diff.suppressblankempty") ||
 374                        /* for backwards compatibility */
 375                        !strcmp(var, "diff.suppress-blank-empty")) {
 376                diff_suppress_blank_empty = git_config_bool(var, value);
 377                return 0;
 378        }
 379
 380        if (!strcmp(var, "diff.dirstat")) {
 381                struct strbuf errmsg = STRBUF_INIT;
 382                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 383                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 384                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 385                                errmsg.buf);
 386                strbuf_release(&errmsg);
 387                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 388                return 0;
 389        }
 390
 391        if (starts_with(var, "submodule."))
 392                return parse_submodule_config_option(var, value);
 393
 394        if (git_diff_heuristic_config(var, value, cb) < 0)
 395                return -1;
 396
 397        return git_default_config(var, value, cb);
 398}
 399
 400static char *quote_two(const char *one, const char *two)
 401{
 402        int need_one = quote_c_style(one, NULL, NULL, 1);
 403        int need_two = quote_c_style(two, NULL, NULL, 1);
 404        struct strbuf res = STRBUF_INIT;
 405
 406        if (need_one + need_two) {
 407                strbuf_addch(&res, '"');
 408                quote_c_style(one, &res, NULL, 1);
 409                quote_c_style(two, &res, NULL, 1);
 410                strbuf_addch(&res, '"');
 411        } else {
 412                strbuf_addstr(&res, one);
 413                strbuf_addstr(&res, two);
 414        }
 415        return strbuf_detach(&res, NULL);
 416}
 417
 418static const char *external_diff(void)
 419{
 420        static const char *external_diff_cmd = NULL;
 421        static int done_preparing = 0;
 422
 423        if (done_preparing)
 424                return external_diff_cmd;
 425        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 426        if (!external_diff_cmd)
 427                external_diff_cmd = external_diff_cmd_cfg;
 428        done_preparing = 1;
 429        return external_diff_cmd;
 430}
 431
 432/*
 433 * Keep track of files used for diffing. Sometimes such an entry
 434 * refers to a temporary file, sometimes to an existing file, and
 435 * sometimes to "/dev/null".
 436 */
 437static struct diff_tempfile {
 438        /*
 439         * filename external diff should read from, or NULL if this
 440         * entry is currently not in use:
 441         */
 442        const char *name;
 443
 444        char hex[GIT_MAX_HEXSZ + 1];
 445        char mode[10];
 446
 447        /*
 448         * If this diff_tempfile instance refers to a temporary file,
 449         * this tempfile object is used to manage its lifetime.
 450         */
 451        struct tempfile tempfile;
 452} diff_temp[2];
 453
 454typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 455
 456struct emit_callback {
 457        int color_diff;
 458        unsigned ws_rule;
 459        int blank_at_eof_in_preimage;
 460        int blank_at_eof_in_postimage;
 461        int lno_in_preimage;
 462        int lno_in_postimage;
 463        sane_truncate_fn truncate;
 464        const char **label_path;
 465        struct diff_words_data *diff_words;
 466        struct diff_options *opt;
 467        struct strbuf *header;
 468};
 469
 470static int count_lines(const char *data, int size)
 471{
 472        int count, ch, completely_empty = 1, nl_just_seen = 0;
 473        count = 0;
 474        while (0 < size--) {
 475                ch = *data++;
 476                if (ch == '\n') {
 477                        count++;
 478                        nl_just_seen = 1;
 479                        completely_empty = 0;
 480                }
 481                else {
 482                        nl_just_seen = 0;
 483                        completely_empty = 0;
 484                }
 485        }
 486        if (completely_empty)
 487                return 0;
 488        if (!nl_just_seen)
 489                count++; /* no trailing newline */
 490        return count;
 491}
 492
 493static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 494{
 495        if (!DIFF_FILE_VALID(one)) {
 496                mf->ptr = (char *)""; /* does not matter */
 497                mf->size = 0;
 498                return 0;
 499        }
 500        else if (diff_populate_filespec(one, 0))
 501                return -1;
 502
 503        mf->ptr = one->data;
 504        mf->size = one->size;
 505        return 0;
 506}
 507
 508/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 509static unsigned long diff_filespec_size(struct diff_filespec *one)
 510{
 511        if (!DIFF_FILE_VALID(one))
 512                return 0;
 513        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 514        return one->size;
 515}
 516
 517static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 518{
 519        char *ptr = mf->ptr;
 520        long size = mf->size;
 521        int cnt = 0;
 522
 523        if (!size)
 524                return cnt;
 525        ptr += size - 1; /* pointing at the very end */
 526        if (*ptr != '\n')
 527                ; /* incomplete line */
 528        else
 529                ptr--; /* skip the last LF */
 530        while (mf->ptr < ptr) {
 531                char *prev_eol;
 532                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 533                        if (*prev_eol == '\n')
 534                                break;
 535                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 536                        break;
 537                cnt++;
 538                ptr = prev_eol - 1;
 539        }
 540        return cnt;
 541}
 542
 543static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 544                               struct emit_callback *ecbdata)
 545{
 546        int l1, l2, at;
 547        unsigned ws_rule = ecbdata->ws_rule;
 548        l1 = count_trailing_blank(mf1, ws_rule);
 549        l2 = count_trailing_blank(mf2, ws_rule);
 550        if (l2 <= l1) {
 551                ecbdata->blank_at_eof_in_preimage = 0;
 552                ecbdata->blank_at_eof_in_postimage = 0;
 553                return;
 554        }
 555        at = count_lines(mf1->ptr, mf1->size);
 556        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 557
 558        at = count_lines(mf2->ptr, mf2->size);
 559        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 560}
 561
 562static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 563                        int first, const char *line, int len)
 564{
 565        int has_trailing_newline, has_trailing_carriage_return;
 566        int nofirst;
 567        FILE *file = o->file;
 568
 569        fputs(diff_line_prefix(o), file);
 570
 571        if (len == 0) {
 572                has_trailing_newline = (first == '\n');
 573                has_trailing_carriage_return = (!has_trailing_newline &&
 574                                                (first == '\r'));
 575                nofirst = has_trailing_newline || has_trailing_carriage_return;
 576        } else {
 577                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 578                if (has_trailing_newline)
 579                        len--;
 580                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 581                if (has_trailing_carriage_return)
 582                        len--;
 583                nofirst = 0;
 584        }
 585
 586        if (len || !nofirst) {
 587                fputs(set, file);
 588                if (!nofirst)
 589                        fputc(first, file);
 590                fwrite(line, len, 1, file);
 591                fputs(reset, file);
 592        }
 593        if (has_trailing_carriage_return)
 594                fputc('\r', file);
 595        if (has_trailing_newline)
 596                fputc('\n', file);
 597}
 598
 599static void emit_line(struct diff_options *o, const char *set, const char *reset,
 600                      const char *line, int len)
 601{
 602        emit_line_0(o, set, reset, line[0], line+1, len-1);
 603}
 604
 605enum diff_symbol {
 606        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 607        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 608        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 609        DIFF_SYMBOL_BINARY_DIFF_BODY,
 610        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 611        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 612        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 613        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 614        DIFF_SYMBOL_STATS_LINE,
 615        DIFF_SYMBOL_WORD_DIFF,
 616        DIFF_SYMBOL_STAT_SEP,
 617        DIFF_SYMBOL_SUMMARY,
 618        DIFF_SYMBOL_SUBMODULE_ADD,
 619        DIFF_SYMBOL_SUBMODULE_DEL,
 620        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 621        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 622        DIFF_SYMBOL_SUBMODULE_HEADER,
 623        DIFF_SYMBOL_SUBMODULE_ERROR,
 624        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 625        DIFF_SYMBOL_REWRITE_DIFF,
 626        DIFF_SYMBOL_BINARY_FILES,
 627        DIFF_SYMBOL_HEADER,
 628        DIFF_SYMBOL_FILEPAIR_PLUS,
 629        DIFF_SYMBOL_FILEPAIR_MINUS,
 630        DIFF_SYMBOL_WORDS_PORCELAIN,
 631        DIFF_SYMBOL_WORDS,
 632        DIFF_SYMBOL_CONTEXT,
 633        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 634        DIFF_SYMBOL_PLUS,
 635        DIFF_SYMBOL_MINUS,
 636        DIFF_SYMBOL_NO_LF_EOF,
 637        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 638        DIFF_SYMBOL_CONTEXT_MARKER,
 639        DIFF_SYMBOL_SEPARATOR
 640};
 641/*
 642 * Flags for content lines:
 643 * 0..12 are whitespace rules
 644 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 645 * 16 is marking if the line is blank at EOF
 646 */
 647#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 648#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 649#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 650#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 651
 652/*
 653 * This struct is used when we need to buffer the output of the diff output.
 654 *
 655 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 656 * into the pre/post image file. This pointer could be a union with the
 657 * line pointer. By storing an offset into the file instead of the literal line,
 658 * we can decrease the memory footprint for the buffered output. At first we
 659 * may want to only have indirection for the content lines, but we could also
 660 * enhance the state for emitting prefabricated lines, e.g. the similarity
 661 * score line or hunk/file headers would only need to store a number or path
 662 * and then the output can be constructed later on depending on state.
 663 */
 664struct emitted_diff_symbol {
 665        const char *line;
 666        int len;
 667        int flags;
 668        enum diff_symbol s;
 669};
 670#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 671
 672struct emitted_diff_symbols {
 673        struct emitted_diff_symbol *buf;
 674        int nr, alloc;
 675};
 676#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 677
 678static void append_emitted_diff_symbol(struct diff_options *o,
 679                                       struct emitted_diff_symbol *e)
 680{
 681        struct emitted_diff_symbol *f;
 682
 683        ALLOC_GROW(o->emitted_symbols->buf,
 684                   o->emitted_symbols->nr + 1,
 685                   o->emitted_symbols->alloc);
 686        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 687
 688        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 689        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 690}
 691
 692struct moved_entry {
 693        struct hashmap_entry ent;
 694        const struct emitted_diff_symbol *es;
 695        struct moved_entry *next_line;
 696};
 697
 698static int next_byte(const char **cp, const char **endp,
 699                     const struct diff_options *diffopt)
 700{
 701        int retval;
 702
 703        if (*cp > *endp)
 704                return -1;
 705
 706        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_CHANGE)) {
 707                while (*cp < *endp && isspace(**cp))
 708                        (*cp)++;
 709                /*
 710                 * After skipping a couple of whitespaces, we still have to
 711                 * account for one space.
 712                 */
 713                return (int)' ';
 714        }
 715
 716        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE)) {
 717                while (*cp < *endp && isspace(**cp))
 718                        (*cp)++;
 719                /* return the first non-ws character via the usual below */
 720        }
 721
 722        retval = (unsigned char)(**cp);
 723        (*cp)++;
 724        return retval;
 725}
 726
 727static int moved_entry_cmp(const struct diff_options *diffopt,
 728                           const struct moved_entry *a,
 729                           const struct moved_entry *b,
 730                           const void *keydata)
 731{
 732        const char *ap = a->es->line, *ae = a->es->line + a->es->len;
 733        const char *bp = b->es->line, *be = b->es->line + b->es->len;
 734
 735        if (!(diffopt->xdl_opts & XDF_WHITESPACE_FLAGS))
 736                return a->es->len != b->es->len  || memcmp(ap, bp, a->es->len);
 737
 738        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_AT_EOL)) {
 739                while (ae > ap && isspace(*ae))
 740                        ae--;
 741                while (be > bp && isspace(*be))
 742                        be--;
 743        }
 744
 745        while (1) {
 746                int ca, cb;
 747                ca = next_byte(&ap, &ae, diffopt);
 748                cb = next_byte(&bp, &be, diffopt);
 749                if (ca != cb)
 750                        return 1;
 751                if (ca < 0)
 752                        return 0;
 753        }
 754}
 755
 756static unsigned get_string_hash(struct emitted_diff_symbol *es, struct diff_options *o)
 757{
 758        if (o->xdl_opts & XDF_WHITESPACE_FLAGS) {
 759                static struct strbuf sb = STRBUF_INIT;
 760                const char *ap = es->line, *ae = es->line + es->len;
 761                int c;
 762
 763                strbuf_reset(&sb);
 764                while (ae > ap && isspace(*ae))
 765                        ae--;
 766                while ((c = next_byte(&ap, &ae, o)) > 0)
 767                        strbuf_addch(&sb, c);
 768
 769                return memhash(sb.buf, sb.len);
 770        } else {
 771                return memhash(es->line, es->len);
 772        }
 773}
 774
 775static struct moved_entry *prepare_entry(struct diff_options *o,
 776                                         int line_no)
 777{
 778        struct moved_entry *ret = xmalloc(sizeof(*ret));
 779        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 780
 781        ret->ent.hash = get_string_hash(l, o);
 782        ret->es = l;
 783        ret->next_line = NULL;
 784
 785        return ret;
 786}
 787
 788static void add_lines_to_move_detection(struct diff_options *o,
 789                                        struct hashmap *add_lines,
 790                                        struct hashmap *del_lines)
 791{
 792        struct moved_entry *prev_line = NULL;
 793
 794        int n;
 795        for (n = 0; n < o->emitted_symbols->nr; n++) {
 796                struct hashmap *hm;
 797                struct moved_entry *key;
 798
 799                switch (o->emitted_symbols->buf[n].s) {
 800                case DIFF_SYMBOL_PLUS:
 801                        hm = add_lines;
 802                        break;
 803                case DIFF_SYMBOL_MINUS:
 804                        hm = del_lines;
 805                        break;
 806                default:
 807                        prev_line = NULL;
 808                        continue;
 809                }
 810
 811                key = prepare_entry(o, n);
 812                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 813                        prev_line->next_line = key;
 814
 815                hashmap_add(hm, key);
 816                prev_line = key;
 817        }
 818}
 819
 820static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 821                                         int pmb_nr)
 822{
 823        int lp, rp;
 824
 825        /* Shrink the set of potential block to the remaining running */
 826        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 827                while (lp < pmb_nr && pmb[lp])
 828                        lp++;
 829                /* lp points at the first NULL now */
 830
 831                while (rp > -1 && !pmb[rp])
 832                        rp--;
 833                /* rp points at the last non-NULL */
 834
 835                if (lp < pmb_nr && rp > -1 && lp < rp) {
 836                        pmb[lp] = pmb[rp];
 837                        pmb[rp] = NULL;
 838                        rp--;
 839                        lp++;
 840                }
 841        }
 842
 843        /* Remember the number of running sets */
 844        return rp + 1;
 845}
 846
 847/* Find blocks of moved code, delegate actual coloring decision to helper */
 848static void mark_color_as_moved(struct diff_options *o,
 849                                struct hashmap *add_lines,
 850                                struct hashmap *del_lines)
 851{
 852        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 853        int pmb_nr = 0, pmb_alloc = 0;
 854        int n, flipped_block = 1, block_length = 0;
 855
 856
 857        for (n = 0; n < o->emitted_symbols->nr; n++) {
 858                struct hashmap *hm = NULL;
 859                struct moved_entry *key;
 860                struct moved_entry *match = NULL;
 861                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 862                int i;
 863
 864                switch (l->s) {
 865                case DIFF_SYMBOL_PLUS:
 866                        hm = del_lines;
 867                        key = prepare_entry(o, n);
 868                        match = hashmap_get(hm, key, o);
 869                        free(key);
 870                        break;
 871                case DIFF_SYMBOL_MINUS:
 872                        hm = add_lines;
 873                        key = prepare_entry(o, n);
 874                        match = hashmap_get(hm, key, o);
 875                        free(key);
 876                        break;
 877                default:
 878                        flipped_block = 1;
 879                }
 880
 881                if (!match) {
 882                        if (block_length < COLOR_MOVED_MIN_BLOCK_LENGTH) {
 883                                for (i = 0; i < block_length + 1; i++) {
 884                                        l = &o->emitted_symbols->buf[n - i];
 885                                        l->flags &= ~DIFF_SYMBOL_MOVED_LINE;
 886                                }
 887                        }
 888                        pmb_nr = 0;
 889                        block_length = 0;
 890                        continue;
 891                }
 892
 893                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 894                block_length++;
 895
 896                /* Check any potential block runs, advance each or nullify */
 897                for (i = 0; i < pmb_nr; i++) {
 898                        struct moved_entry *p = pmb[i];
 899                        struct moved_entry *pnext = (p && p->next_line) ?
 900                                        p->next_line : NULL;
 901                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 902                                pmb[i] = p->next_line;
 903                        } else {
 904                                pmb[i] = NULL;
 905                        }
 906                }
 907
 908                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 909
 910                if (pmb_nr == 0) {
 911                        /*
 912                         * The current line is the start of a new block.
 913                         * Setup the set of potential blocks.
 914                         */
 915                        for (; match; match = hashmap_get_next(hm, match)) {
 916                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 917                                pmb[pmb_nr++] = match;
 918                        }
 919
 920                        flipped_block = (flipped_block + 1) % 2;
 921                }
 922
 923                if (flipped_block)
 924                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 925        }
 926
 927        free(pmb);
 928}
 929
 930static void emit_line_ws_markup(struct diff_options *o,
 931                                const char *set, const char *reset,
 932                                const char *line, int len, char sign,
 933                                unsigned ws_rule, int blank_at_eof)
 934{
 935        const char *ws = NULL;
 936
 937        if (o->ws_error_highlight & ws_rule) {
 938                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 939                if (!*ws)
 940                        ws = NULL;
 941        }
 942
 943        if (!ws)
 944                emit_line_0(o, set, reset, sign, line, len);
 945        else if (blank_at_eof)
 946                /* Blank line at EOF - paint '+' as well */
 947                emit_line_0(o, ws, reset, sign, line, len);
 948        else {
 949                /* Emit just the prefix, then the rest. */
 950                emit_line_0(o, set, reset, sign, "", 0);
 951                ws_check_emit(line, len, ws_rule,
 952                              o->file, set, reset, ws);
 953        }
 954}
 955
 956static void emit_diff_symbol_from_struct(struct diff_options *o,
 957                                         struct emitted_diff_symbol *eds)
 958{
 959        static const char *nneof = " No newline at end of file\n";
 960        const char *context, *reset, *set, *meta, *fraginfo;
 961        struct strbuf sb = STRBUF_INIT;
 962
 963        enum diff_symbol s = eds->s;
 964        const char *line = eds->line;
 965        int len = eds->len;
 966        unsigned flags = eds->flags;
 967
 968        switch (s) {
 969        case DIFF_SYMBOL_NO_LF_EOF:
 970                context = diff_get_color_opt(o, DIFF_CONTEXT);
 971                reset = diff_get_color_opt(o, DIFF_RESET);
 972                putc('\n', o->file);
 973                emit_line_0(o, context, reset, '\\',
 974                            nneof, strlen(nneof));
 975                break;
 976        case DIFF_SYMBOL_SUBMODULE_HEADER:
 977        case DIFF_SYMBOL_SUBMODULE_ERROR:
 978        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
 979        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
 980        case DIFF_SYMBOL_SUMMARY:
 981        case DIFF_SYMBOL_STATS_LINE:
 982        case DIFF_SYMBOL_BINARY_DIFF_BODY:
 983        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 984                emit_line(o, "", "", line, len);
 985                break;
 986        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 987        case DIFF_SYMBOL_CONTEXT_MARKER:
 988                context = diff_get_color_opt(o, DIFF_CONTEXT);
 989                reset = diff_get_color_opt(o, DIFF_RESET);
 990                emit_line(o, context, reset, line, len);
 991                break;
 992        case DIFF_SYMBOL_SEPARATOR:
 993                fprintf(o->file, "%s%c",
 994                        diff_line_prefix(o),
 995                        o->line_termination);
 996                break;
 997        case DIFF_SYMBOL_CONTEXT:
 998                set = diff_get_color_opt(o, DIFF_CONTEXT);
 999                reset = diff_get_color_opt(o, DIFF_RESET);
1000                emit_line_ws_markup(o, set, reset, line, len, ' ',
1001                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1002                break;
1003        case DIFF_SYMBOL_PLUS:
1004                if (flags & DIFF_SYMBOL_MOVED_LINE_ALT)
1005                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1006                else if (flags & DIFF_SYMBOL_MOVED_LINE)
1007                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1008                else
1009                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1010                reset = diff_get_color_opt(o, DIFF_RESET);
1011                emit_line_ws_markup(o, set, reset, line, len, '+',
1012                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1013                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1014                break;
1015        case DIFF_SYMBOL_MINUS:
1016                if (flags & DIFF_SYMBOL_MOVED_LINE_ALT)
1017                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1018                else if (flags & DIFF_SYMBOL_MOVED_LINE)
1019                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1020                else
1021                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1022                reset = diff_get_color_opt(o, DIFF_RESET);
1023                emit_line_ws_markup(o, set, reset, line, len, '-',
1024                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1025                break;
1026        case DIFF_SYMBOL_WORDS_PORCELAIN:
1027                context = diff_get_color_opt(o, DIFF_CONTEXT);
1028                reset = diff_get_color_opt(o, DIFF_RESET);
1029                emit_line(o, context, reset, line, len);
1030                fputs("~\n", o->file);
1031                break;
1032        case DIFF_SYMBOL_WORDS:
1033                context = diff_get_color_opt(o, DIFF_CONTEXT);
1034                reset = diff_get_color_opt(o, DIFF_RESET);
1035                /*
1036                 * Skip the prefix character, if any.  With
1037                 * diff_suppress_blank_empty, there may be
1038                 * none.
1039                 */
1040                if (line[0] != '\n') {
1041                        line++;
1042                        len--;
1043                }
1044                emit_line(o, context, reset, line, len);
1045                break;
1046        case DIFF_SYMBOL_FILEPAIR_PLUS:
1047                meta = diff_get_color_opt(o, DIFF_METAINFO);
1048                reset = diff_get_color_opt(o, DIFF_RESET);
1049                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1050                        line, reset,
1051                        strchr(line, ' ') ? "\t" : "");
1052                break;
1053        case DIFF_SYMBOL_FILEPAIR_MINUS:
1054                meta = diff_get_color_opt(o, DIFF_METAINFO);
1055                reset = diff_get_color_opt(o, DIFF_RESET);
1056                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1057                        line, reset,
1058                        strchr(line, ' ') ? "\t" : "");
1059                break;
1060        case DIFF_SYMBOL_BINARY_FILES:
1061        case DIFF_SYMBOL_HEADER:
1062                fprintf(o->file, "%s", line);
1063                break;
1064        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1065                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1066                break;
1067        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1068                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1069                break;
1070        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1071                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1072                break;
1073        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1074                fputs(diff_line_prefix(o), o->file);
1075                fputc('\n', o->file);
1076                break;
1077        case DIFF_SYMBOL_REWRITE_DIFF:
1078                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1079                reset = diff_get_color_opt(o, DIFF_RESET);
1080                emit_line(o, fraginfo, reset, line, len);
1081                break;
1082        case DIFF_SYMBOL_SUBMODULE_ADD:
1083                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1084                reset = diff_get_color_opt(o, DIFF_RESET);
1085                emit_line(o, set, reset, line, len);
1086                break;
1087        case DIFF_SYMBOL_SUBMODULE_DEL:
1088                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1089                reset = diff_get_color_opt(o, DIFF_RESET);
1090                emit_line(o, set, reset, line, len);
1091                break;
1092        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1093                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1094                        diff_line_prefix(o), line);
1095                break;
1096        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1097                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1098                        diff_line_prefix(o), line);
1099                break;
1100        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1101                emit_line(o, "", "", " 0 files changed\n",
1102                          strlen(" 0 files changed\n"));
1103                break;
1104        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1105                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1106                break;
1107        case DIFF_SYMBOL_WORD_DIFF:
1108                fprintf(o->file, "%.*s", len, line);
1109                break;
1110        case DIFF_SYMBOL_STAT_SEP:
1111                fputs(o->stat_sep, o->file);
1112                break;
1113        default:
1114                die("BUG: unknown diff symbol");
1115        }
1116        strbuf_release(&sb);
1117}
1118
1119static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1120                             const char *line, int len, unsigned flags)
1121{
1122        struct emitted_diff_symbol e = {line, len, flags, s};
1123
1124        if (o->emitted_symbols)
1125                append_emitted_diff_symbol(o, &e);
1126        else
1127                emit_diff_symbol_from_struct(o, &e);
1128}
1129
1130void diff_emit_submodule_del(struct diff_options *o, const char *line)
1131{
1132        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1133}
1134
1135void diff_emit_submodule_add(struct diff_options *o, const char *line)
1136{
1137        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1138}
1139
1140void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1141{
1142        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1143                         path, strlen(path), 0);
1144}
1145
1146void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1147{
1148        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1149                         path, strlen(path), 0);
1150}
1151
1152void diff_emit_submodule_header(struct diff_options *o, const char *header)
1153{
1154        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1155                         header, strlen(header), 0);
1156}
1157
1158void diff_emit_submodule_error(struct diff_options *o, const char *err)
1159{
1160        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1161}
1162
1163void diff_emit_submodule_pipethrough(struct diff_options *o,
1164                                     const char *line, int len)
1165{
1166        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1167}
1168
1169static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1170{
1171        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1172              ecbdata->blank_at_eof_in_preimage &&
1173              ecbdata->blank_at_eof_in_postimage &&
1174              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1175              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1176                return 0;
1177        return ws_blank_line(line, len, ecbdata->ws_rule);
1178}
1179
1180static void emit_add_line(const char *reset,
1181                          struct emit_callback *ecbdata,
1182                          const char *line, int len)
1183{
1184        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1185        if (new_blank_line_at_eof(ecbdata, line, len))
1186                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1187
1188        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1189}
1190
1191static void emit_del_line(const char *reset,
1192                          struct emit_callback *ecbdata,
1193                          const char *line, int len)
1194{
1195        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1196        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1197}
1198
1199static void emit_context_line(const char *reset,
1200                              struct emit_callback *ecbdata,
1201                              const char *line, int len)
1202{
1203        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1204        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1205}
1206
1207static void emit_hunk_header(struct emit_callback *ecbdata,
1208                             const char *line, int len)
1209{
1210        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1211        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1212        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1213        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1214        static const char atat[2] = { '@', '@' };
1215        const char *cp, *ep;
1216        struct strbuf msgbuf = STRBUF_INIT;
1217        int org_len = len;
1218        int i = 1;
1219
1220        /*
1221         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1222         * it always is at least 10 bytes long.
1223         */
1224        if (len < 10 ||
1225            memcmp(line, atat, 2) ||
1226            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1227                emit_diff_symbol(ecbdata->opt,
1228                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1229                return;
1230        }
1231        ep += 2; /* skip over @@ */
1232
1233        /* The hunk header in fraginfo color */
1234        strbuf_addstr(&msgbuf, frag);
1235        strbuf_add(&msgbuf, line, ep - line);
1236        strbuf_addstr(&msgbuf, reset);
1237
1238        /*
1239         * trailing "\r\n"
1240         */
1241        for ( ; i < 3; i++)
1242                if (line[len - i] == '\r' || line[len - i] == '\n')
1243                        len--;
1244
1245        /* blank before the func header */
1246        for (cp = ep; ep - line < len; ep++)
1247                if (*ep != ' ' && *ep != '\t')
1248                        break;
1249        if (ep != cp) {
1250                strbuf_addstr(&msgbuf, context);
1251                strbuf_add(&msgbuf, cp, ep - cp);
1252                strbuf_addstr(&msgbuf, reset);
1253        }
1254
1255        if (ep < line + len) {
1256                strbuf_addstr(&msgbuf, func);
1257                strbuf_add(&msgbuf, ep, line + len - ep);
1258                strbuf_addstr(&msgbuf, reset);
1259        }
1260
1261        strbuf_add(&msgbuf, line + len, org_len - len);
1262        strbuf_complete_line(&msgbuf);
1263        emit_diff_symbol(ecbdata->opt,
1264                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1265        strbuf_release(&msgbuf);
1266}
1267
1268static struct diff_tempfile *claim_diff_tempfile(void) {
1269        int i;
1270        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1271                if (!diff_temp[i].name)
1272                        return diff_temp + i;
1273        die("BUG: diff is failing to clean up its tempfiles");
1274}
1275
1276static void remove_tempfile(void)
1277{
1278        int i;
1279        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1280                if (is_tempfile_active(&diff_temp[i].tempfile))
1281                        delete_tempfile(&diff_temp[i].tempfile);
1282                diff_temp[i].name = NULL;
1283        }
1284}
1285
1286static void add_line_count(struct strbuf *out, int count)
1287{
1288        switch (count) {
1289        case 0:
1290                strbuf_addstr(out, "0,0");
1291                break;
1292        case 1:
1293                strbuf_addstr(out, "1");
1294                break;
1295        default:
1296                strbuf_addf(out, "1,%d", count);
1297                break;
1298        }
1299}
1300
1301static void emit_rewrite_lines(struct emit_callback *ecb,
1302                               int prefix, const char *data, int size)
1303{
1304        const char *endp = NULL;
1305        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1306
1307        while (0 < size) {
1308                int len;
1309
1310                endp = memchr(data, '\n', size);
1311                len = endp ? (endp - data + 1) : size;
1312                if (prefix != '+') {
1313                        ecb->lno_in_preimage++;
1314                        emit_del_line(reset, ecb, data, len);
1315                } else {
1316                        ecb->lno_in_postimage++;
1317                        emit_add_line(reset, ecb, data, len);
1318                }
1319                size -= len;
1320                data += len;
1321        }
1322        if (!endp)
1323                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1324}
1325
1326static void emit_rewrite_diff(const char *name_a,
1327                              const char *name_b,
1328                              struct diff_filespec *one,
1329                              struct diff_filespec *two,
1330                              struct userdiff_driver *textconv_one,
1331                              struct userdiff_driver *textconv_two,
1332                              struct diff_options *o)
1333{
1334        int lc_a, lc_b;
1335        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1336        const char *a_prefix, *b_prefix;
1337        char *data_one, *data_two;
1338        size_t size_one, size_two;
1339        struct emit_callback ecbdata;
1340        struct strbuf out = STRBUF_INIT;
1341
1342        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
1343                a_prefix = o->b_prefix;
1344                b_prefix = o->a_prefix;
1345        } else {
1346                a_prefix = o->a_prefix;
1347                b_prefix = o->b_prefix;
1348        }
1349
1350        name_a += (*name_a == '/');
1351        name_b += (*name_b == '/');
1352
1353        strbuf_reset(&a_name);
1354        strbuf_reset(&b_name);
1355        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1356        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1357
1358        size_one = fill_textconv(textconv_one, one, &data_one);
1359        size_two = fill_textconv(textconv_two, two, &data_two);
1360
1361        memset(&ecbdata, 0, sizeof(ecbdata));
1362        ecbdata.color_diff = want_color(o->use_color);
1363        ecbdata.ws_rule = whitespace_rule(name_b);
1364        ecbdata.opt = o;
1365        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1366                mmfile_t mf1, mf2;
1367                mf1.ptr = (char *)data_one;
1368                mf2.ptr = (char *)data_two;
1369                mf1.size = size_one;
1370                mf2.size = size_two;
1371                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1372        }
1373        ecbdata.lno_in_preimage = 1;
1374        ecbdata.lno_in_postimage = 1;
1375
1376        lc_a = count_lines(data_one, size_one);
1377        lc_b = count_lines(data_two, size_two);
1378
1379        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1380                         a_name.buf, a_name.len, 0);
1381        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1382                         b_name.buf, b_name.len, 0);
1383
1384        strbuf_addstr(&out, "@@ -");
1385        if (!o->irreversible_delete)
1386                add_line_count(&out, lc_a);
1387        else
1388                strbuf_addstr(&out, "?,?");
1389        strbuf_addstr(&out, " +");
1390        add_line_count(&out, lc_b);
1391        strbuf_addstr(&out, " @@\n");
1392        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1393        strbuf_release(&out);
1394
1395        if (lc_a && !o->irreversible_delete)
1396                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1397        if (lc_b)
1398                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1399        if (textconv_one)
1400                free((char *)data_one);
1401        if (textconv_two)
1402                free((char *)data_two);
1403}
1404
1405struct diff_words_buffer {
1406        mmfile_t text;
1407        long alloc;
1408        struct diff_words_orig {
1409                const char *begin, *end;
1410        } *orig;
1411        int orig_nr, orig_alloc;
1412};
1413
1414static void diff_words_append(char *line, unsigned long len,
1415                struct diff_words_buffer *buffer)
1416{
1417        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1418        line++;
1419        len--;
1420        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1421        buffer->text.size += len;
1422        buffer->text.ptr[buffer->text.size] = '\0';
1423}
1424
1425struct diff_words_style_elem {
1426        const char *prefix;
1427        const char *suffix;
1428        const char *color; /* NULL; filled in by the setup code if
1429                            * color is enabled */
1430};
1431
1432struct diff_words_style {
1433        enum diff_words_type type;
1434        struct diff_words_style_elem new, old, ctx;
1435        const char *newline;
1436};
1437
1438static struct diff_words_style diff_words_styles[] = {
1439        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1440        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1441        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1442};
1443
1444struct diff_words_data {
1445        struct diff_words_buffer minus, plus;
1446        const char *current_plus;
1447        int last_minus;
1448        struct diff_options *opt;
1449        regex_t *word_regex;
1450        enum diff_words_type type;
1451        struct diff_words_style *style;
1452};
1453
1454static int fn_out_diff_words_write_helper(struct diff_options *o,
1455                                          struct diff_words_style_elem *st_el,
1456                                          const char *newline,
1457                                          size_t count, const char *buf)
1458{
1459        int print = 0;
1460        struct strbuf sb = STRBUF_INIT;
1461
1462        while (count) {
1463                char *p = memchr(buf, '\n', count);
1464                if (print)
1465                        strbuf_addstr(&sb, diff_line_prefix(o));
1466
1467                if (p != buf) {
1468                        const char *reset = st_el->color && *st_el->color ?
1469                                            GIT_COLOR_RESET : NULL;
1470                        if (st_el->color && *st_el->color)
1471                                strbuf_addstr(&sb, st_el->color);
1472                        strbuf_addstr(&sb, st_el->prefix);
1473                        strbuf_add(&sb, buf, p ? p - buf : count);
1474                        strbuf_addstr(&sb, st_el->suffix);
1475                        if (reset)
1476                                strbuf_addstr(&sb, reset);
1477                }
1478                if (!p)
1479                        goto out;
1480
1481                strbuf_addstr(&sb, newline);
1482                count -= p + 1 - buf;
1483                buf = p + 1;
1484                print = 1;
1485                if (count) {
1486                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1487                                         sb.buf, sb.len, 0);
1488                        strbuf_reset(&sb);
1489                }
1490        }
1491
1492out:
1493        if (sb.len)
1494                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1495                                 sb.buf, sb.len, 0);
1496        strbuf_release(&sb);
1497        return 0;
1498}
1499
1500/*
1501 * '--color-words' algorithm can be described as:
1502 *
1503 *   1. collect the minus/plus lines of a diff hunk, divided into
1504 *      minus-lines and plus-lines;
1505 *
1506 *   2. break both minus-lines and plus-lines into words and
1507 *      place them into two mmfile_t with one word for each line;
1508 *
1509 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1510 *
1511 * And for the common parts of the both file, we output the plus side text.
1512 * diff_words->current_plus is used to trace the current position of the plus file
1513 * which printed. diff_words->last_minus is used to trace the last minus word
1514 * printed.
1515 *
1516 * For '--graph' to work with '--color-words', we need to output the graph prefix
1517 * on each line of color words output. Generally, there are two conditions on
1518 * which we should output the prefix.
1519 *
1520 *   1. diff_words->last_minus == 0 &&
1521 *      diff_words->current_plus == diff_words->plus.text.ptr
1522 *
1523 *      that is: the plus text must start as a new line, and if there is no minus
1524 *      word printed, a graph prefix must be printed.
1525 *
1526 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1527 *      *(diff_words->current_plus - 1) == '\n'
1528 *
1529 *      that is: a graph prefix must be printed following a '\n'
1530 */
1531static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1532{
1533        if ((diff_words->last_minus == 0 &&
1534                diff_words->current_plus == diff_words->plus.text.ptr) ||
1535                (diff_words->current_plus > diff_words->plus.text.ptr &&
1536                *(diff_words->current_plus - 1) == '\n')) {
1537                return 1;
1538        } else {
1539                return 0;
1540        }
1541}
1542
1543static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1544{
1545        struct diff_words_data *diff_words = priv;
1546        struct diff_words_style *style = diff_words->style;
1547        int minus_first, minus_len, plus_first, plus_len;
1548        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1549        struct diff_options *opt = diff_words->opt;
1550        const char *line_prefix;
1551
1552        if (line[0] != '@' || parse_hunk_header(line, len,
1553                        &minus_first, &minus_len, &plus_first, &plus_len))
1554                return;
1555
1556        assert(opt);
1557        line_prefix = diff_line_prefix(opt);
1558
1559        /* POSIX requires that first be decremented by one if len == 0... */
1560        if (minus_len) {
1561                minus_begin = diff_words->minus.orig[minus_first].begin;
1562                minus_end =
1563                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1564        } else
1565                minus_begin = minus_end =
1566                        diff_words->minus.orig[minus_first].end;
1567
1568        if (plus_len) {
1569                plus_begin = diff_words->plus.orig[plus_first].begin;
1570                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1571        } else
1572                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1573
1574        if (color_words_output_graph_prefix(diff_words)) {
1575                fputs(line_prefix, diff_words->opt->file);
1576        }
1577        if (diff_words->current_plus != plus_begin) {
1578                fn_out_diff_words_write_helper(diff_words->opt,
1579                                &style->ctx, style->newline,
1580                                plus_begin - diff_words->current_plus,
1581                                diff_words->current_plus);
1582        }
1583        if (minus_begin != minus_end) {
1584                fn_out_diff_words_write_helper(diff_words->opt,
1585                                &style->old, style->newline,
1586                                minus_end - minus_begin, minus_begin);
1587        }
1588        if (plus_begin != plus_end) {
1589                fn_out_diff_words_write_helper(diff_words->opt,
1590                                &style->new, style->newline,
1591                                plus_end - plus_begin, plus_begin);
1592        }
1593
1594        diff_words->current_plus = plus_end;
1595        diff_words->last_minus = minus_first;
1596}
1597
1598/* This function starts looking at *begin, and returns 0 iff a word was found. */
1599static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1600                int *begin, int *end)
1601{
1602        if (word_regex && *begin < buffer->size) {
1603                regmatch_t match[1];
1604                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1605                                 buffer->size - *begin, 1, match, 0)) {
1606                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1607                                        '\n', match[0].rm_eo - match[0].rm_so);
1608                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1609                        *begin += match[0].rm_so;
1610                        return *begin >= *end;
1611                }
1612                return -1;
1613        }
1614
1615        /* find the next word */
1616        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1617                (*begin)++;
1618        if (*begin >= buffer->size)
1619                return -1;
1620
1621        /* find the end of the word */
1622        *end = *begin + 1;
1623        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1624                (*end)++;
1625
1626        return 0;
1627}
1628
1629/*
1630 * This function splits the words in buffer->text, stores the list with
1631 * newline separator into out, and saves the offsets of the original words
1632 * in buffer->orig.
1633 */
1634static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1635                regex_t *word_regex)
1636{
1637        int i, j;
1638        long alloc = 0;
1639
1640        out->size = 0;
1641        out->ptr = NULL;
1642
1643        /* fake an empty "0th" word */
1644        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1645        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1646        buffer->orig_nr = 1;
1647
1648        for (i = 0; i < buffer->text.size; i++) {
1649                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1650                        return;
1651
1652                /* store original boundaries */
1653                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1654                                buffer->orig_alloc);
1655                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1656                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1657                buffer->orig_nr++;
1658
1659                /* store one word */
1660                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1661                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1662                out->ptr[out->size + j - i] = '\n';
1663                out->size += j - i + 1;
1664
1665                i = j - 1;
1666        }
1667}
1668
1669/* this executes the word diff on the accumulated buffers */
1670static void diff_words_show(struct diff_words_data *diff_words)
1671{
1672        xpparam_t xpp;
1673        xdemitconf_t xecfg;
1674        mmfile_t minus, plus;
1675        struct diff_words_style *style = diff_words->style;
1676
1677        struct diff_options *opt = diff_words->opt;
1678        const char *line_prefix;
1679
1680        assert(opt);
1681        line_prefix = diff_line_prefix(opt);
1682
1683        /* special case: only removal */
1684        if (!diff_words->plus.text.size) {
1685                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1686                                 line_prefix, strlen(line_prefix), 0);
1687                fn_out_diff_words_write_helper(diff_words->opt,
1688                        &style->old, style->newline,
1689                        diff_words->minus.text.size,
1690                        diff_words->minus.text.ptr);
1691                diff_words->minus.text.size = 0;
1692                return;
1693        }
1694
1695        diff_words->current_plus = diff_words->plus.text.ptr;
1696        diff_words->last_minus = 0;
1697
1698        memset(&xpp, 0, sizeof(xpp));
1699        memset(&xecfg, 0, sizeof(xecfg));
1700        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1701        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1702        xpp.flags = 0;
1703        /* as only the hunk header will be parsed, we need a 0-context */
1704        xecfg.ctxlen = 0;
1705        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1706                          &xpp, &xecfg))
1707                die("unable to generate word diff");
1708        free(minus.ptr);
1709        free(plus.ptr);
1710        if (diff_words->current_plus != diff_words->plus.text.ptr +
1711                        diff_words->plus.text.size) {
1712                if (color_words_output_graph_prefix(diff_words))
1713                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1714                                         line_prefix, strlen(line_prefix), 0);
1715                fn_out_diff_words_write_helper(diff_words->opt,
1716                        &style->ctx, style->newline,
1717                        diff_words->plus.text.ptr + diff_words->plus.text.size
1718                        - diff_words->current_plus, diff_words->current_plus);
1719        }
1720        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1721}
1722
1723/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1724static void diff_words_flush(struct emit_callback *ecbdata)
1725{
1726        struct diff_options *wo = ecbdata->diff_words->opt;
1727
1728        if (ecbdata->diff_words->minus.text.size ||
1729            ecbdata->diff_words->plus.text.size)
1730                diff_words_show(ecbdata->diff_words);
1731
1732        if (wo->emitted_symbols) {
1733                struct diff_options *o = ecbdata->opt;
1734                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1735                int i;
1736
1737                /*
1738                 * NEEDSWORK:
1739                 * Instead of appending each, concat all words to a line?
1740                 */
1741                for (i = 0; i < wol->nr; i++)
1742                        append_emitted_diff_symbol(o, &wol->buf[i]);
1743
1744                for (i = 0; i < wol->nr; i++)
1745                        free((void *)wol->buf[i].line);
1746
1747                wol->nr = 0;
1748        }
1749}
1750
1751static void diff_filespec_load_driver(struct diff_filespec *one)
1752{
1753        /* Use already-loaded driver */
1754        if (one->driver)
1755                return;
1756
1757        if (S_ISREG(one->mode))
1758                one->driver = userdiff_find_by_path(one->path);
1759
1760        /* Fallback to default settings */
1761        if (!one->driver)
1762                one->driver = userdiff_find_by_name("default");
1763}
1764
1765static const char *userdiff_word_regex(struct diff_filespec *one)
1766{
1767        diff_filespec_load_driver(one);
1768        return one->driver->word_regex;
1769}
1770
1771static void init_diff_words_data(struct emit_callback *ecbdata,
1772                                 struct diff_options *orig_opts,
1773                                 struct diff_filespec *one,
1774                                 struct diff_filespec *two)
1775{
1776        int i;
1777        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1778        memcpy(o, orig_opts, sizeof(struct diff_options));
1779
1780        ecbdata->diff_words =
1781                xcalloc(1, sizeof(struct diff_words_data));
1782        ecbdata->diff_words->type = o->word_diff;
1783        ecbdata->diff_words->opt = o;
1784
1785        if (orig_opts->emitted_symbols)
1786                o->emitted_symbols =
1787                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1788
1789        if (!o->word_regex)
1790                o->word_regex = userdiff_word_regex(one);
1791        if (!o->word_regex)
1792                o->word_regex = userdiff_word_regex(two);
1793        if (!o->word_regex)
1794                o->word_regex = diff_word_regex_cfg;
1795        if (o->word_regex) {
1796                ecbdata->diff_words->word_regex = (regex_t *)
1797                        xmalloc(sizeof(regex_t));
1798                if (regcomp(ecbdata->diff_words->word_regex,
1799                            o->word_regex,
1800                            REG_EXTENDED | REG_NEWLINE))
1801                        die ("Invalid regular expression: %s",
1802                             o->word_regex);
1803        }
1804        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1805                if (o->word_diff == diff_words_styles[i].type) {
1806                        ecbdata->diff_words->style =
1807                                &diff_words_styles[i];
1808                        break;
1809                }
1810        }
1811        if (want_color(o->use_color)) {
1812                struct diff_words_style *st = ecbdata->diff_words->style;
1813                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1814                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1815                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1816        }
1817}
1818
1819static void free_diff_words_data(struct emit_callback *ecbdata)
1820{
1821        if (ecbdata->diff_words) {
1822                diff_words_flush(ecbdata);
1823                free (ecbdata->diff_words->opt->emitted_symbols);
1824                free (ecbdata->diff_words->opt);
1825                free (ecbdata->diff_words->minus.text.ptr);
1826                free (ecbdata->diff_words->minus.orig);
1827                free (ecbdata->diff_words->plus.text.ptr);
1828                free (ecbdata->diff_words->plus.orig);
1829                if (ecbdata->diff_words->word_regex) {
1830                        regfree(ecbdata->diff_words->word_regex);
1831                        free(ecbdata->diff_words->word_regex);
1832                }
1833                FREE_AND_NULL(ecbdata->diff_words);
1834        }
1835}
1836
1837const char *diff_get_color(int diff_use_color, enum color_diff ix)
1838{
1839        if (want_color(diff_use_color))
1840                return diff_colors[ix];
1841        return "";
1842}
1843
1844const char *diff_line_prefix(struct diff_options *opt)
1845{
1846        struct strbuf *msgbuf;
1847        if (!opt->output_prefix)
1848                return "";
1849
1850        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1851        return msgbuf->buf;
1852}
1853
1854static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1855{
1856        const char *cp;
1857        unsigned long allot;
1858        size_t l = len;
1859
1860        if (ecb->truncate)
1861                return ecb->truncate(line, len);
1862        cp = line;
1863        allot = l;
1864        while (0 < l) {
1865                (void) utf8_width(&cp, &l);
1866                if (!cp)
1867                        break; /* truncated in the middle? */
1868        }
1869        return allot - l;
1870}
1871
1872static void find_lno(const char *line, struct emit_callback *ecbdata)
1873{
1874        const char *p;
1875        ecbdata->lno_in_preimage = 0;
1876        ecbdata->lno_in_postimage = 0;
1877        p = strchr(line, '-');
1878        if (!p)
1879                return; /* cannot happen */
1880        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1881        p = strchr(p, '+');
1882        if (!p)
1883                return; /* cannot happen */
1884        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1885}
1886
1887static void fn_out_consume(void *priv, char *line, unsigned long len)
1888{
1889        struct emit_callback *ecbdata = priv;
1890        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1891        struct diff_options *o = ecbdata->opt;
1892
1893        o->found_changes = 1;
1894
1895        if (ecbdata->header) {
1896                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1897                                 ecbdata->header->buf, ecbdata->header->len, 0);
1898                strbuf_reset(ecbdata->header);
1899                ecbdata->header = NULL;
1900        }
1901
1902        if (ecbdata->label_path[0]) {
1903                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1904                                 ecbdata->label_path[0],
1905                                 strlen(ecbdata->label_path[0]), 0);
1906                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1907                                 ecbdata->label_path[1],
1908                                 strlen(ecbdata->label_path[1]), 0);
1909                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1910        }
1911
1912        if (diff_suppress_blank_empty
1913            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1914                line[0] = '\n';
1915                len = 1;
1916        }
1917
1918        if (line[0] == '@') {
1919                if (ecbdata->diff_words)
1920                        diff_words_flush(ecbdata);
1921                len = sane_truncate_line(ecbdata, line, len);
1922                find_lno(line, ecbdata);
1923                emit_hunk_header(ecbdata, line, len);
1924                return;
1925        }
1926
1927        if (ecbdata->diff_words) {
1928                enum diff_symbol s =
1929                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1930                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1931                if (line[0] == '-') {
1932                        diff_words_append(line, len,
1933                                          &ecbdata->diff_words->minus);
1934                        return;
1935                } else if (line[0] == '+') {
1936                        diff_words_append(line, len,
1937                                          &ecbdata->diff_words->plus);
1938                        return;
1939                } else if (starts_with(line, "\\ ")) {
1940                        /*
1941                         * Eat the "no newline at eof" marker as if we
1942                         * saw a "+" or "-" line with nothing on it,
1943                         * and return without diff_words_flush() to
1944                         * defer processing. If this is the end of
1945                         * preimage, more "+" lines may come after it.
1946                         */
1947                        return;
1948                }
1949                diff_words_flush(ecbdata);
1950                emit_diff_symbol(o, s, line, len, 0);
1951                return;
1952        }
1953
1954        switch (line[0]) {
1955        case '+':
1956                ecbdata->lno_in_postimage++;
1957                emit_add_line(reset, ecbdata, line + 1, len - 1);
1958                break;
1959        case '-':
1960                ecbdata->lno_in_preimage++;
1961                emit_del_line(reset, ecbdata, line + 1, len - 1);
1962                break;
1963        case ' ':
1964                ecbdata->lno_in_postimage++;
1965                ecbdata->lno_in_preimage++;
1966                emit_context_line(reset, ecbdata, line + 1, len - 1);
1967                break;
1968        default:
1969                /* incomplete line at the end */
1970                ecbdata->lno_in_preimage++;
1971                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
1972                                 line, len, 0);
1973                break;
1974        }
1975}
1976
1977static char *pprint_rename(const char *a, const char *b)
1978{
1979        const char *old = a;
1980        const char *new = b;
1981        struct strbuf name = STRBUF_INIT;
1982        int pfx_length, sfx_length;
1983        int pfx_adjust_for_slash;
1984        int len_a = strlen(a);
1985        int len_b = strlen(b);
1986        int a_midlen, b_midlen;
1987        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1988        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1989
1990        if (qlen_a || qlen_b) {
1991                quote_c_style(a, &name, NULL, 0);
1992                strbuf_addstr(&name, " => ");
1993                quote_c_style(b, &name, NULL, 0);
1994                return strbuf_detach(&name, NULL);
1995        }
1996
1997        /* Find common prefix */
1998        pfx_length = 0;
1999        while (*old && *new && *old == *new) {
2000                if (*old == '/')
2001                        pfx_length = old - a + 1;
2002                old++;
2003                new++;
2004        }
2005
2006        /* Find common suffix */
2007        old = a + len_a;
2008        new = b + len_b;
2009        sfx_length = 0;
2010        /*
2011         * If there is a common prefix, it must end in a slash.  In
2012         * that case we let this loop run 1 into the prefix to see the
2013         * same slash.
2014         *
2015         * If there is no common prefix, we cannot do this as it would
2016         * underrun the input strings.
2017         */
2018        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2019        while (a + pfx_length - pfx_adjust_for_slash <= old &&
2020               b + pfx_length - pfx_adjust_for_slash <= new &&
2021               *old == *new) {
2022                if (*old == '/')
2023                        sfx_length = len_a - (old - a);
2024                old--;
2025                new--;
2026        }
2027
2028        /*
2029         * pfx{mid-a => mid-b}sfx
2030         * {pfx-a => pfx-b}sfx
2031         * pfx{sfx-a => sfx-b}
2032         * name-a => name-b
2033         */
2034        a_midlen = len_a - pfx_length - sfx_length;
2035        b_midlen = len_b - pfx_length - sfx_length;
2036        if (a_midlen < 0)
2037                a_midlen = 0;
2038        if (b_midlen < 0)
2039                b_midlen = 0;
2040
2041        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2042        if (pfx_length + sfx_length) {
2043                strbuf_add(&name, a, pfx_length);
2044                strbuf_addch(&name, '{');
2045        }
2046        strbuf_add(&name, a + pfx_length, a_midlen);
2047        strbuf_addstr(&name, " => ");
2048        strbuf_add(&name, b + pfx_length, b_midlen);
2049        if (pfx_length + sfx_length) {
2050                strbuf_addch(&name, '}');
2051                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
2052        }
2053        return strbuf_detach(&name, NULL);
2054}
2055
2056struct diffstat_t {
2057        int nr;
2058        int alloc;
2059        struct diffstat_file {
2060                char *from_name;
2061                char *name;
2062                char *print_name;
2063                unsigned is_unmerged:1;
2064                unsigned is_binary:1;
2065                unsigned is_renamed:1;
2066                unsigned is_interesting:1;
2067                uintmax_t added, deleted;
2068        } **files;
2069};
2070
2071static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2072                                          const char *name_a,
2073                                          const char *name_b)
2074{
2075        struct diffstat_file *x;
2076        x = xcalloc(1, sizeof(*x));
2077        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2078        diffstat->files[diffstat->nr++] = x;
2079        if (name_b) {
2080                x->from_name = xstrdup(name_a);
2081                x->name = xstrdup(name_b);
2082                x->is_renamed = 1;
2083        }
2084        else {
2085                x->from_name = NULL;
2086                x->name = xstrdup(name_a);
2087        }
2088        return x;
2089}
2090
2091static void diffstat_consume(void *priv, char *line, unsigned long len)
2092{
2093        struct diffstat_t *diffstat = priv;
2094        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2095
2096        if (line[0] == '+')
2097                x->added++;
2098        else if (line[0] == '-')
2099                x->deleted++;
2100}
2101
2102const char mime_boundary_leader[] = "------------";
2103
2104static int scale_linear(int it, int width, int max_change)
2105{
2106        if (!it)
2107                return 0;
2108        /*
2109         * make sure that at least one '-' or '+' is printed if
2110         * there is any change to this path. The easiest way is to
2111         * scale linearly as if the alloted width is one column shorter
2112         * than it is, and then add 1 to the result.
2113         */
2114        return 1 + (it * (width - 1) / max_change);
2115}
2116
2117static void show_graph(struct strbuf *out, char ch, int cnt,
2118                       const char *set, const char *reset)
2119{
2120        if (cnt <= 0)
2121                return;
2122        strbuf_addstr(out, set);
2123        strbuf_addchars(out, ch, cnt);
2124        strbuf_addstr(out, reset);
2125}
2126
2127static void fill_print_name(struct diffstat_file *file)
2128{
2129        char *pname;
2130
2131        if (file->print_name)
2132                return;
2133
2134        if (!file->is_renamed) {
2135                struct strbuf buf = STRBUF_INIT;
2136                if (quote_c_style(file->name, &buf, NULL, 0)) {
2137                        pname = strbuf_detach(&buf, NULL);
2138                } else {
2139                        pname = file->name;
2140                        strbuf_release(&buf);
2141                }
2142        } else {
2143                pname = pprint_rename(file->from_name, file->name);
2144        }
2145        file->print_name = pname;
2146}
2147
2148static void print_stat_summary_inserts_deletes(struct diff_options *options,
2149                int files, int insertions, int deletions)
2150{
2151        struct strbuf sb = STRBUF_INIT;
2152
2153        if (!files) {
2154                assert(insertions == 0 && deletions == 0);
2155                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2156                                 NULL, 0, 0);
2157                return;
2158        }
2159
2160        strbuf_addf(&sb,
2161                    (files == 1) ? " %d file changed" : " %d files changed",
2162                    files);
2163
2164        /*
2165         * For binary diff, the caller may want to print "x files
2166         * changed" with insertions == 0 && deletions == 0.
2167         *
2168         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2169         * is probably less confusing (i.e skip over "2 files changed
2170         * but nothing about added/removed lines? Is this a bug in Git?").
2171         */
2172        if (insertions || deletions == 0) {
2173                strbuf_addf(&sb,
2174                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2175                            insertions);
2176        }
2177
2178        if (deletions || insertions == 0) {
2179                strbuf_addf(&sb,
2180                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2181                            deletions);
2182        }
2183        strbuf_addch(&sb, '\n');
2184        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2185                         sb.buf, sb.len, 0);
2186        strbuf_release(&sb);
2187}
2188
2189void print_stat_summary(FILE *fp, int files,
2190                        int insertions, int deletions)
2191{
2192        struct diff_options o;
2193        memset(&o, 0, sizeof(o));
2194        o.file = fp;
2195
2196        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2197}
2198
2199static void show_stats(struct diffstat_t *data, struct diff_options *options)
2200{
2201        int i, len, add, del, adds = 0, dels = 0;
2202        uintmax_t max_change = 0, max_len = 0;
2203        int total_files = data->nr, count;
2204        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2205        const char *reset, *add_c, *del_c;
2206        int extra_shown = 0;
2207        const char *line_prefix = diff_line_prefix(options);
2208        struct strbuf out = STRBUF_INIT;
2209
2210        if (data->nr == 0)
2211                return;
2212
2213        count = options->stat_count ? options->stat_count : data->nr;
2214
2215        reset = diff_get_color_opt(options, DIFF_RESET);
2216        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2217        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2218
2219        /*
2220         * Find the longest filename and max number of changes
2221         */
2222        for (i = 0; (i < count) && (i < data->nr); i++) {
2223                struct diffstat_file *file = data->files[i];
2224                uintmax_t change = file->added + file->deleted;
2225
2226                if (!file->is_interesting && (change == 0)) {
2227                        count++; /* not shown == room for one more */
2228                        continue;
2229                }
2230                fill_print_name(file);
2231                len = strlen(file->print_name);
2232                if (max_len < len)
2233                        max_len = len;
2234
2235                if (file->is_unmerged) {
2236                        /* "Unmerged" is 8 characters */
2237                        bin_width = bin_width < 8 ? 8 : bin_width;
2238                        continue;
2239                }
2240                if (file->is_binary) {
2241                        /* "Bin XXX -> YYY bytes" */
2242                        int w = 14 + decimal_width(file->added)
2243                                + decimal_width(file->deleted);
2244                        bin_width = bin_width < w ? w : bin_width;
2245                        /* Display change counts aligned with "Bin" */
2246                        number_width = 3;
2247                        continue;
2248                }
2249
2250                if (max_change < change)
2251                        max_change = change;
2252        }
2253        count = i; /* where we can stop scanning in data->files[] */
2254
2255        /*
2256         * We have width = stat_width or term_columns() columns total.
2257         * We want a maximum of min(max_len, stat_name_width) for the name part.
2258         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2259         * We also need 1 for " " and 4 + decimal_width(max_change)
2260         * for " | NNNN " and one the empty column at the end, altogether
2261         * 6 + decimal_width(max_change).
2262         *
2263         * If there's not enough space, we will use the smaller of
2264         * stat_name_width (if set) and 5/8*width for the filename,
2265         * and the rest for constant elements + graph part, but no more
2266         * than stat_graph_width for the graph part.
2267         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2268         * for the standard terminal size).
2269         *
2270         * In other words: stat_width limits the maximum width, and
2271         * stat_name_width fixes the maximum width of the filename,
2272         * and is also used to divide available columns if there
2273         * aren't enough.
2274         *
2275         * Binary files are displayed with "Bin XXX -> YYY bytes"
2276         * instead of the change count and graph. This part is treated
2277         * similarly to the graph part, except that it is not
2278         * "scaled". If total width is too small to accommodate the
2279         * guaranteed minimum width of the filename part and the
2280         * separators and this message, this message will "overflow"
2281         * making the line longer than the maximum width.
2282         */
2283
2284        if (options->stat_width == -1)
2285                width = term_columns() - strlen(line_prefix);
2286        else
2287                width = options->stat_width ? options->stat_width : 80;
2288        number_width = decimal_width(max_change) > number_width ?
2289                decimal_width(max_change) : number_width;
2290
2291        if (options->stat_graph_width == -1)
2292                options->stat_graph_width = diff_stat_graph_width;
2293
2294        /*
2295         * Guarantee 3/8*16==6 for the graph part
2296         * and 5/8*16==10 for the filename part
2297         */
2298        if (width < 16 + 6 + number_width)
2299                width = 16 + 6 + number_width;
2300
2301        /*
2302         * First assign sizes that are wanted, ignoring available width.
2303         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2304         * starting from "XXX" should fit in graph_width.
2305         */
2306        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2307        if (options->stat_graph_width &&
2308            options->stat_graph_width < graph_width)
2309                graph_width = options->stat_graph_width;
2310
2311        name_width = (options->stat_name_width > 0 &&
2312                      options->stat_name_width < max_len) ?
2313                options->stat_name_width : max_len;
2314
2315        /*
2316         * Adjust adjustable widths not to exceed maximum width
2317         */
2318        if (name_width + number_width + 6 + graph_width > width) {
2319                if (graph_width > width * 3/8 - number_width - 6) {
2320                        graph_width = width * 3/8 - number_width - 6;
2321                        if (graph_width < 6)
2322                                graph_width = 6;
2323                }
2324
2325                if (options->stat_graph_width &&
2326                    graph_width > options->stat_graph_width)
2327                        graph_width = options->stat_graph_width;
2328                if (name_width > width - number_width - 6 - graph_width)
2329                        name_width = width - number_width - 6 - graph_width;
2330                else
2331                        graph_width = width - number_width - 6 - name_width;
2332        }
2333
2334        /*
2335         * From here name_width is the width of the name area,
2336         * and graph_width is the width of the graph area.
2337         * max_change is used to scale graph properly.
2338         */
2339        for (i = 0; i < count; i++) {
2340                const char *prefix = "";
2341                struct diffstat_file *file = data->files[i];
2342                char *name = file->print_name;
2343                uintmax_t added = file->added;
2344                uintmax_t deleted = file->deleted;
2345                int name_len;
2346
2347                if (!file->is_interesting && (added + deleted == 0))
2348                        continue;
2349
2350                /*
2351                 * "scale" the filename
2352                 */
2353                len = name_width;
2354                name_len = strlen(name);
2355                if (name_width < name_len) {
2356                        char *slash;
2357                        prefix = "...";
2358                        len -= 3;
2359                        name += name_len - len;
2360                        slash = strchr(name, '/');
2361                        if (slash)
2362                                name = slash;
2363                }
2364
2365                if (file->is_binary) {
2366                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2367                        strbuf_addf(&out, " %*s", number_width, "Bin");
2368                        if (!added && !deleted) {
2369                                strbuf_addch(&out, '\n');
2370                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2371                                                 out.buf, out.len, 0);
2372                                strbuf_reset(&out);
2373                                continue;
2374                        }
2375                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2376                                del_c, deleted, reset);
2377                        strbuf_addstr(&out, " -> ");
2378                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2379                                add_c, added, reset);
2380                        strbuf_addstr(&out, " bytes\n");
2381                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2382                                         out.buf, out.len, 0);
2383                        strbuf_reset(&out);
2384                        continue;
2385                }
2386                else if (file->is_unmerged) {
2387                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2388                        strbuf_addstr(&out, " Unmerged\n");
2389                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2390                                         out.buf, out.len, 0);
2391                        strbuf_reset(&out);
2392                        continue;
2393                }
2394
2395                /*
2396                 * scale the add/delete
2397                 */
2398                add = added;
2399                del = deleted;
2400
2401                if (graph_width <= max_change) {
2402                        int total = scale_linear(add + del, graph_width, max_change);
2403                        if (total < 2 && add && del)
2404                                /* width >= 2 due to the sanity check */
2405                                total = 2;
2406                        if (add < del) {
2407                                add = scale_linear(add, graph_width, max_change);
2408                                del = total - add;
2409                        } else {
2410                                del = scale_linear(del, graph_width, max_change);
2411                                add = total - del;
2412                        }
2413                }
2414                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2415                strbuf_addf(&out, " %*"PRIuMAX"%s",
2416                        number_width, added + deleted,
2417                        added + deleted ? " " : "");
2418                show_graph(&out, '+', add, add_c, reset);
2419                show_graph(&out, '-', del, del_c, reset);
2420                strbuf_addch(&out, '\n');
2421                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2422                                 out.buf, out.len, 0);
2423                strbuf_reset(&out);
2424        }
2425
2426        for (i = 0; i < data->nr; i++) {
2427                struct diffstat_file *file = data->files[i];
2428                uintmax_t added = file->added;
2429                uintmax_t deleted = file->deleted;
2430
2431                if (file->is_unmerged ||
2432                    (!file->is_interesting && (added + deleted == 0))) {
2433                        total_files--;
2434                        continue;
2435                }
2436
2437                if (!file->is_binary) {
2438                        adds += added;
2439                        dels += deleted;
2440                }
2441                if (i < count)
2442                        continue;
2443                if (!extra_shown)
2444                        emit_diff_symbol(options,
2445                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2446                                         NULL, 0, 0);
2447                extra_shown = 1;
2448        }
2449
2450        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2451}
2452
2453static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2454{
2455        int i, adds = 0, dels = 0, total_files = data->nr;
2456
2457        if (data->nr == 0)
2458                return;
2459
2460        for (i = 0; i < data->nr; i++) {
2461                int added = data->files[i]->added;
2462                int deleted = data->files[i]->deleted;
2463
2464                if (data->files[i]->is_unmerged ||
2465                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2466                        total_files--;
2467                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2468                        adds += added;
2469                        dels += deleted;
2470                }
2471        }
2472        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2473}
2474
2475static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2476{
2477        int i;
2478
2479        if (data->nr == 0)
2480                return;
2481
2482        for (i = 0; i < data->nr; i++) {
2483                struct diffstat_file *file = data->files[i];
2484
2485                fprintf(options->file, "%s", diff_line_prefix(options));
2486
2487                if (file->is_binary)
2488                        fprintf(options->file, "-\t-\t");
2489                else
2490                        fprintf(options->file,
2491                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2492                                file->added, file->deleted);
2493                if (options->line_termination) {
2494                        fill_print_name(file);
2495                        if (!file->is_renamed)
2496                                write_name_quoted(file->name, options->file,
2497                                                  options->line_termination);
2498                        else {
2499                                fputs(file->print_name, options->file);
2500                                putc(options->line_termination, options->file);
2501                        }
2502                } else {
2503                        if (file->is_renamed) {
2504                                putc('\0', options->file);
2505                                write_name_quoted(file->from_name, options->file, '\0');
2506                        }
2507                        write_name_quoted(file->name, options->file, '\0');
2508                }
2509        }
2510}
2511
2512struct dirstat_file {
2513        const char *name;
2514        unsigned long changed;
2515};
2516
2517struct dirstat_dir {
2518        struct dirstat_file *files;
2519        int alloc, nr, permille, cumulative;
2520};
2521
2522static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2523                unsigned long changed, const char *base, int baselen)
2524{
2525        unsigned long this_dir = 0;
2526        unsigned int sources = 0;
2527        const char *line_prefix = diff_line_prefix(opt);
2528
2529        while (dir->nr) {
2530                struct dirstat_file *f = dir->files;
2531                int namelen = strlen(f->name);
2532                unsigned long this;
2533                char *slash;
2534
2535                if (namelen < baselen)
2536                        break;
2537                if (memcmp(f->name, base, baselen))
2538                        break;
2539                slash = strchr(f->name + baselen, '/');
2540                if (slash) {
2541                        int newbaselen = slash + 1 - f->name;
2542                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2543                        sources++;
2544                } else {
2545                        this = f->changed;
2546                        dir->files++;
2547                        dir->nr--;
2548                        sources += 2;
2549                }
2550                this_dir += this;
2551        }
2552
2553        /*
2554         * We don't report dirstat's for
2555         *  - the top level
2556         *  - or cases where everything came from a single directory
2557         *    under this directory (sources == 1).
2558         */
2559        if (baselen && sources != 1) {
2560                if (this_dir) {
2561                        int permille = this_dir * 1000 / changed;
2562                        if (permille >= dir->permille) {
2563                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2564                                        permille / 10, permille % 10, baselen, base);
2565                                if (!dir->cumulative)
2566                                        return 0;
2567                        }
2568                }
2569        }
2570        return this_dir;
2571}
2572
2573static int dirstat_compare(const void *_a, const void *_b)
2574{
2575        const struct dirstat_file *a = _a;
2576        const struct dirstat_file *b = _b;
2577        return strcmp(a->name, b->name);
2578}
2579
2580static void show_dirstat(struct diff_options *options)
2581{
2582        int i;
2583        unsigned long changed;
2584        struct dirstat_dir dir;
2585        struct diff_queue_struct *q = &diff_queued_diff;
2586
2587        dir.files = NULL;
2588        dir.alloc = 0;
2589        dir.nr = 0;
2590        dir.permille = options->dirstat_permille;
2591        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2592
2593        changed = 0;
2594        for (i = 0; i < q->nr; i++) {
2595                struct diff_filepair *p = q->queue[i];
2596                const char *name;
2597                unsigned long copied, added, damage;
2598                int content_changed;
2599
2600                name = p->two->path ? p->two->path : p->one->path;
2601
2602                if (p->one->oid_valid && p->two->oid_valid)
2603                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2604                else
2605                        content_changed = 1;
2606
2607                if (!content_changed) {
2608                        /*
2609                         * The SHA1 has not changed, so pre-/post-content is
2610                         * identical. We can therefore skip looking at the
2611                         * file contents altogether.
2612                         */
2613                        damage = 0;
2614                        goto found_damage;
2615                }
2616
2617                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2618                        /*
2619                         * In --dirstat-by-file mode, we don't really need to
2620                         * look at the actual file contents at all.
2621                         * The fact that the SHA1 changed is enough for us to
2622                         * add this file to the list of results
2623                         * (with each file contributing equal damage).
2624                         */
2625                        damage = 1;
2626                        goto found_damage;
2627                }
2628
2629                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2630                        diff_populate_filespec(p->one, 0);
2631                        diff_populate_filespec(p->two, 0);
2632                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2633                                               &copied, &added);
2634                        diff_free_filespec_data(p->one);
2635                        diff_free_filespec_data(p->two);
2636                } else if (DIFF_FILE_VALID(p->one)) {
2637                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2638                        copied = added = 0;
2639                        diff_free_filespec_data(p->one);
2640                } else if (DIFF_FILE_VALID(p->two)) {
2641                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2642                        copied = 0;
2643                        added = p->two->size;
2644                        diff_free_filespec_data(p->two);
2645                } else
2646                        continue;
2647
2648                /*
2649                 * Original minus copied is the removed material,
2650                 * added is the new material.  They are both damages
2651                 * made to the preimage.
2652                 * If the resulting damage is zero, we know that
2653                 * diffcore_count_changes() considers the two entries to
2654                 * be identical, but since content_changed is true, we
2655                 * know that there must have been _some_ kind of change,
2656                 * so we force all entries to have damage > 0.
2657                 */
2658                damage = (p->one->size - copied) + added;
2659                if (!damage)
2660                        damage = 1;
2661
2662found_damage:
2663                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2664                dir.files[dir.nr].name = name;
2665                dir.files[dir.nr].changed = damage;
2666                changed += damage;
2667                dir.nr++;
2668        }
2669
2670        /* This can happen even with many files, if everything was renames */
2671        if (!changed)
2672                return;
2673
2674        /* Show all directories with more than x% of the changes */
2675        QSORT(dir.files, dir.nr, dirstat_compare);
2676        gather_dirstat(options, &dir, changed, "", 0);
2677}
2678
2679static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2680{
2681        int i;
2682        unsigned long changed;
2683        struct dirstat_dir dir;
2684
2685        if (data->nr == 0)
2686                return;
2687
2688        dir.files = NULL;
2689        dir.alloc = 0;
2690        dir.nr = 0;
2691        dir.permille = options->dirstat_permille;
2692        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2693
2694        changed = 0;
2695        for (i = 0; i < data->nr; i++) {
2696                struct diffstat_file *file = data->files[i];
2697                unsigned long damage = file->added + file->deleted;
2698                if (file->is_binary)
2699                        /*
2700                         * binary files counts bytes, not lines. Must find some
2701                         * way to normalize binary bytes vs. textual lines.
2702                         * The following heuristic assumes that there are 64
2703                         * bytes per "line".
2704                         * This is stupid and ugly, but very cheap...
2705                         */
2706                        damage = (damage + 63) / 64;
2707                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2708                dir.files[dir.nr].name = file->name;
2709                dir.files[dir.nr].changed = damage;
2710                changed += damage;
2711                dir.nr++;
2712        }
2713
2714        /* This can happen even with many files, if everything was renames */
2715        if (!changed)
2716                return;
2717
2718        /* Show all directories with more than x% of the changes */
2719        QSORT(dir.files, dir.nr, dirstat_compare);
2720        gather_dirstat(options, &dir, changed, "", 0);
2721}
2722
2723static void free_diffstat_info(struct diffstat_t *diffstat)
2724{
2725        int i;
2726        for (i = 0; i < diffstat->nr; i++) {
2727                struct diffstat_file *f = diffstat->files[i];
2728                if (f->name != f->print_name)
2729                        free(f->print_name);
2730                free(f->name);
2731                free(f->from_name);
2732                free(f);
2733        }
2734        free(diffstat->files);
2735}
2736
2737struct checkdiff_t {
2738        const char *filename;
2739        int lineno;
2740        int conflict_marker_size;
2741        struct diff_options *o;
2742        unsigned ws_rule;
2743        unsigned status;
2744};
2745
2746static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2747{
2748        char firstchar;
2749        int cnt;
2750
2751        if (len < marker_size + 1)
2752                return 0;
2753        firstchar = line[0];
2754        switch (firstchar) {
2755        case '=': case '>': case '<': case '|':
2756                break;
2757        default:
2758                return 0;
2759        }
2760        for (cnt = 1; cnt < marker_size; cnt++)
2761                if (line[cnt] != firstchar)
2762                        return 0;
2763        /* line[1] thru line[marker_size-1] are same as firstchar */
2764        if (len < marker_size + 1 || !isspace(line[marker_size]))
2765                return 0;
2766        return 1;
2767}
2768
2769static void checkdiff_consume(void *priv, char *line, unsigned long len)
2770{
2771        struct checkdiff_t *data = priv;
2772        int marker_size = data->conflict_marker_size;
2773        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2774        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2775        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2776        char *err;
2777        const char *line_prefix;
2778
2779        assert(data->o);
2780        line_prefix = diff_line_prefix(data->o);
2781
2782        if (line[0] == '+') {
2783                unsigned bad;
2784                data->lineno++;
2785                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2786                        data->status |= 1;
2787                        fprintf(data->o->file,
2788                                "%s%s:%d: leftover conflict marker\n",
2789                                line_prefix, data->filename, data->lineno);
2790                }
2791                bad = ws_check(line + 1, len - 1, data->ws_rule);
2792                if (!bad)
2793                        return;
2794                data->status |= bad;
2795                err = whitespace_error_string(bad);
2796                fprintf(data->o->file, "%s%s:%d: %s.\n",
2797                        line_prefix, data->filename, data->lineno, err);
2798                free(err);
2799                emit_line(data->o, set, reset, line, 1);
2800                ws_check_emit(line + 1, len - 1, data->ws_rule,
2801                              data->o->file, set, reset, ws);
2802        } else if (line[0] == ' ') {
2803                data->lineno++;
2804        } else if (line[0] == '@') {
2805                char *plus = strchr(line, '+');
2806                if (plus)
2807                        data->lineno = strtol(plus, NULL, 10) - 1;
2808                else
2809                        die("invalid diff");
2810        }
2811}
2812
2813static unsigned char *deflate_it(char *data,
2814                                 unsigned long size,
2815                                 unsigned long *result_size)
2816{
2817        int bound;
2818        unsigned char *deflated;
2819        git_zstream stream;
2820
2821        git_deflate_init(&stream, zlib_compression_level);
2822        bound = git_deflate_bound(&stream, size);
2823        deflated = xmalloc(bound);
2824        stream.next_out = deflated;
2825        stream.avail_out = bound;
2826
2827        stream.next_in = (unsigned char *)data;
2828        stream.avail_in = size;
2829        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2830                ; /* nothing */
2831        git_deflate_end(&stream);
2832        *result_size = stream.total_out;
2833        return deflated;
2834}
2835
2836static void emit_binary_diff_body(struct diff_options *o,
2837                                  mmfile_t *one, mmfile_t *two)
2838{
2839        void *cp;
2840        void *delta;
2841        void *deflated;
2842        void *data;
2843        unsigned long orig_size;
2844        unsigned long delta_size;
2845        unsigned long deflate_size;
2846        unsigned long data_size;
2847
2848        /* We could do deflated delta, or we could do just deflated two,
2849         * whichever is smaller.
2850         */
2851        delta = NULL;
2852        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2853        if (one->size && two->size) {
2854                delta = diff_delta(one->ptr, one->size,
2855                                   two->ptr, two->size,
2856                                   &delta_size, deflate_size);
2857                if (delta) {
2858                        void *to_free = delta;
2859                        orig_size = delta_size;
2860                        delta = deflate_it(delta, delta_size, &delta_size);
2861                        free(to_free);
2862                }
2863        }
2864
2865        if (delta && delta_size < deflate_size) {
2866                char *s = xstrfmt("%lu", orig_size);
2867                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2868                                 s, strlen(s), 0);
2869                free(s);
2870                free(deflated);
2871                data = delta;
2872                data_size = delta_size;
2873        } else {
2874                char *s = xstrfmt("%lu", two->size);
2875                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2876                                 s, strlen(s), 0);
2877                free(s);
2878                free(delta);
2879                data = deflated;
2880                data_size = deflate_size;
2881        }
2882
2883        /* emit data encoded in base85 */
2884        cp = data;
2885        while (data_size) {
2886                int len;
2887                int bytes = (52 < data_size) ? 52 : data_size;
2888                char line[71];
2889                data_size -= bytes;
2890                if (bytes <= 26)
2891                        line[0] = bytes + 'A' - 1;
2892                else
2893                        line[0] = bytes - 26 + 'a' - 1;
2894                encode_85(line + 1, cp, bytes);
2895                cp = (char *) cp + bytes;
2896
2897                len = strlen(line);
2898                line[len++] = '\n';
2899                line[len] = '\0';
2900
2901                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2902                                 line, len, 0);
2903        }
2904        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2905        free(data);
2906}
2907
2908static void emit_binary_diff(struct diff_options *o,
2909                             mmfile_t *one, mmfile_t *two)
2910{
2911        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2912        emit_binary_diff_body(o, one, two);
2913        emit_binary_diff_body(o, two, one);
2914}
2915
2916int diff_filespec_is_binary(struct diff_filespec *one)
2917{
2918        if (one->is_binary == -1) {
2919                diff_filespec_load_driver(one);
2920                if (one->driver->binary != -1)
2921                        one->is_binary = one->driver->binary;
2922                else {
2923                        if (!one->data && DIFF_FILE_VALID(one))
2924                                diff_populate_filespec(one, CHECK_BINARY);
2925                        if (one->is_binary == -1 && one->data)
2926                                one->is_binary = buffer_is_binary(one->data,
2927                                                one->size);
2928                        if (one->is_binary == -1)
2929                                one->is_binary = 0;
2930                }
2931        }
2932        return one->is_binary;
2933}
2934
2935static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2936{
2937        diff_filespec_load_driver(one);
2938        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2939}
2940
2941void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2942{
2943        if (!options->a_prefix)
2944                options->a_prefix = a;
2945        if (!options->b_prefix)
2946                options->b_prefix = b;
2947}
2948
2949struct userdiff_driver *get_textconv(struct diff_filespec *one)
2950{
2951        if (!DIFF_FILE_VALID(one))
2952                return NULL;
2953
2954        diff_filespec_load_driver(one);
2955        return userdiff_get_textconv(one->driver);
2956}
2957
2958static void builtin_diff(const char *name_a,
2959                         const char *name_b,
2960                         struct diff_filespec *one,
2961                         struct diff_filespec *two,
2962                         const char *xfrm_msg,
2963                         int must_show_header,
2964                         struct diff_options *o,
2965                         int complete_rewrite)
2966{
2967        mmfile_t mf1, mf2;
2968        const char *lbl[2];
2969        char *a_one, *b_two;
2970        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2971        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2972        const char *a_prefix, *b_prefix;
2973        struct userdiff_driver *textconv_one = NULL;
2974        struct userdiff_driver *textconv_two = NULL;
2975        struct strbuf header = STRBUF_INIT;
2976        const char *line_prefix = diff_line_prefix(o);
2977
2978        diff_set_mnemonic_prefix(o, "a/", "b/");
2979        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2980                a_prefix = o->b_prefix;
2981                b_prefix = o->a_prefix;
2982        } else {
2983                a_prefix = o->a_prefix;
2984                b_prefix = o->b_prefix;
2985        }
2986
2987        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2988            (!one->mode || S_ISGITLINK(one->mode)) &&
2989            (!two->mode || S_ISGITLINK(two->mode))) {
2990                show_submodule_summary(o, one->path ? one->path : two->path,
2991                                &one->oid, &two->oid,
2992                                two->dirty_submodule);
2993                return;
2994        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2995                   (!one->mode || S_ISGITLINK(one->mode)) &&
2996                   (!two->mode || S_ISGITLINK(two->mode))) {
2997                show_submodule_inline_diff(o, one->path ? one->path : two->path,
2998                                &one->oid, &two->oid,
2999                                two->dirty_submodule);
3000                return;
3001        }
3002
3003        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
3004                textconv_one = get_textconv(one);
3005                textconv_two = get_textconv(two);
3006        }
3007
3008        /* Never use a non-valid filename anywhere if at all possible */
3009        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3010        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3011
3012        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3013        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3014        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3015        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3016        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3017        if (lbl[0][0] == '/') {
3018                /* /dev/null */
3019                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3020                if (xfrm_msg)
3021                        strbuf_addstr(&header, xfrm_msg);
3022                must_show_header = 1;
3023        }
3024        else if (lbl[1][0] == '/') {
3025                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3026                if (xfrm_msg)
3027                        strbuf_addstr(&header, xfrm_msg);
3028                must_show_header = 1;
3029        }
3030        else {
3031                if (one->mode != two->mode) {
3032                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3033                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3034                        must_show_header = 1;
3035                }
3036                if (xfrm_msg)
3037                        strbuf_addstr(&header, xfrm_msg);
3038
3039                /*
3040                 * we do not run diff between different kind
3041                 * of objects.
3042                 */
3043                if ((one->mode ^ two->mode) & S_IFMT)
3044                        goto free_ab_and_return;
3045                if (complete_rewrite &&
3046                    (textconv_one || !diff_filespec_is_binary(one)) &&
3047                    (textconv_two || !diff_filespec_is_binary(two))) {
3048                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3049                                         header.buf, header.len, 0);
3050                        strbuf_reset(&header);
3051                        emit_rewrite_diff(name_a, name_b, one, two,
3052                                                textconv_one, textconv_two, o);
3053                        o->found_changes = 1;
3054                        goto free_ab_and_return;
3055                }
3056        }
3057
3058        if (o->irreversible_delete && lbl[1][0] == '/') {
3059                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3060                                 header.len, 0);
3061                strbuf_reset(&header);
3062                goto free_ab_and_return;
3063        } else if (!DIFF_OPT_TST(o, TEXT) &&
3064            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3065              (!textconv_two && diff_filespec_is_binary(two)) )) {
3066                struct strbuf sb = STRBUF_INIT;
3067                if (!one->data && !two->data &&
3068                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3069                    !DIFF_OPT_TST(o, BINARY)) {
3070                        if (!oidcmp(&one->oid, &two->oid)) {
3071                                if (must_show_header)
3072                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3073                                                         header.buf, header.len,
3074                                                         0);
3075                                goto free_ab_and_return;
3076                        }
3077                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3078                                         header.buf, header.len, 0);
3079                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3080                                    diff_line_prefix(o), lbl[0], lbl[1]);
3081                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3082                                         sb.buf, sb.len, 0);
3083                        strbuf_release(&sb);
3084                        goto free_ab_and_return;
3085                }
3086                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3087                        die("unable to read files to diff");
3088                /* Quite common confusing case */
3089                if (mf1.size == mf2.size &&
3090                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3091                        if (must_show_header)
3092                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3093                                                 header.buf, header.len, 0);
3094                        goto free_ab_and_return;
3095                }
3096                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3097                strbuf_reset(&header);
3098                if (DIFF_OPT_TST(o, BINARY))
3099                        emit_binary_diff(o, &mf1, &mf2);
3100                else {
3101                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3102                                    diff_line_prefix(o), lbl[0], lbl[1]);
3103                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3104                                         sb.buf, sb.len, 0);
3105                        strbuf_release(&sb);
3106                }
3107                o->found_changes = 1;
3108        } else {
3109                /* Crazy xdl interfaces.. */
3110                const char *diffopts = getenv("GIT_DIFF_OPTS");
3111                const char *v;
3112                xpparam_t xpp;
3113                xdemitconf_t xecfg;
3114                struct emit_callback ecbdata;
3115                const struct userdiff_funcname *pe;
3116
3117                if (must_show_header) {
3118                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3119                                         header.buf, header.len, 0);
3120                        strbuf_reset(&header);
3121                }
3122
3123                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3124                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3125
3126                pe = diff_funcname_pattern(one);
3127                if (!pe)
3128                        pe = diff_funcname_pattern(two);
3129
3130                memset(&xpp, 0, sizeof(xpp));
3131                memset(&xecfg, 0, sizeof(xecfg));
3132                memset(&ecbdata, 0, sizeof(ecbdata));
3133                ecbdata.label_path = lbl;
3134                ecbdata.color_diff = want_color(o->use_color);
3135                ecbdata.ws_rule = whitespace_rule(name_b);
3136                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3137                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3138                ecbdata.opt = o;
3139                ecbdata.header = header.len ? &header : NULL;
3140                xpp.flags = o->xdl_opts;
3141                xecfg.ctxlen = o->context;
3142                xecfg.interhunkctxlen = o->interhunkcontext;
3143                xecfg.flags = XDL_EMIT_FUNCNAMES;
3144                if (DIFF_OPT_TST(o, FUNCCONTEXT))
3145                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3146                if (pe)
3147                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3148                if (!diffopts)
3149                        ;
3150                else if (skip_prefix(diffopts, "--unified=", &v))
3151                        xecfg.ctxlen = strtoul(v, NULL, 10);
3152                else if (skip_prefix(diffopts, "-u", &v))
3153                        xecfg.ctxlen = strtoul(v, NULL, 10);
3154                if (o->word_diff)
3155                        init_diff_words_data(&ecbdata, o, one, two);
3156                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3157                                  &xpp, &xecfg))
3158                        die("unable to generate diff for %s", one->path);
3159                if (o->word_diff)
3160                        free_diff_words_data(&ecbdata);
3161                if (textconv_one)
3162                        free(mf1.ptr);
3163                if (textconv_two)
3164                        free(mf2.ptr);
3165                xdiff_clear_find_func(&xecfg);
3166        }
3167
3168 free_ab_and_return:
3169        strbuf_release(&header);
3170        diff_free_filespec_data(one);
3171        diff_free_filespec_data(two);
3172        free(a_one);
3173        free(b_two);
3174        return;
3175}
3176
3177static void builtin_diffstat(const char *name_a, const char *name_b,
3178                             struct diff_filespec *one,
3179                             struct diff_filespec *two,
3180                             struct diffstat_t *diffstat,
3181                             struct diff_options *o,
3182                             struct diff_filepair *p)
3183{
3184        mmfile_t mf1, mf2;
3185        struct diffstat_file *data;
3186        int same_contents;
3187        int complete_rewrite = 0;
3188
3189        if (!DIFF_PAIR_UNMERGED(p)) {
3190                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3191                        complete_rewrite = 1;
3192        }
3193
3194        data = diffstat_add(diffstat, name_a, name_b);
3195        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3196
3197        if (!one || !two) {
3198                data->is_unmerged = 1;
3199                return;
3200        }
3201
3202        same_contents = !oidcmp(&one->oid, &two->oid);
3203
3204        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3205                data->is_binary = 1;
3206                if (same_contents) {
3207                        data->added = 0;
3208                        data->deleted = 0;
3209                } else {
3210                        data->added = diff_filespec_size(two);
3211                        data->deleted = diff_filespec_size(one);
3212                }
3213        }
3214
3215        else if (complete_rewrite) {
3216                diff_populate_filespec(one, 0);
3217                diff_populate_filespec(two, 0);
3218                data->deleted = count_lines(one->data, one->size);
3219                data->added = count_lines(two->data, two->size);
3220        }
3221
3222        else if (!same_contents) {
3223                /* Crazy xdl interfaces.. */
3224                xpparam_t xpp;
3225                xdemitconf_t xecfg;
3226
3227                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3228                        die("unable to read files to diff");
3229
3230                memset(&xpp, 0, sizeof(xpp));
3231                memset(&xecfg, 0, sizeof(xecfg));
3232                xpp.flags = o->xdl_opts;
3233                xecfg.ctxlen = o->context;
3234                xecfg.interhunkctxlen = o->interhunkcontext;
3235                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3236                                  &xpp, &xecfg))
3237                        die("unable to generate diffstat for %s", one->path);
3238        }
3239
3240        diff_free_filespec_data(one);
3241        diff_free_filespec_data(two);
3242}
3243
3244static void builtin_checkdiff(const char *name_a, const char *name_b,
3245                              const char *attr_path,
3246                              struct diff_filespec *one,
3247                              struct diff_filespec *two,
3248                              struct diff_options *o)
3249{
3250        mmfile_t mf1, mf2;
3251        struct checkdiff_t data;
3252
3253        if (!two)
3254                return;
3255
3256        memset(&data, 0, sizeof(data));
3257        data.filename = name_b ? name_b : name_a;
3258        data.lineno = 0;
3259        data.o = o;
3260        data.ws_rule = whitespace_rule(attr_path);
3261        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3262
3263        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3264                die("unable to read files to diff");
3265
3266        /*
3267         * All the other codepaths check both sides, but not checking
3268         * the "old" side here is deliberate.  We are checking the newly
3269         * introduced changes, and as long as the "new" side is text, we
3270         * can and should check what it introduces.
3271         */
3272        if (diff_filespec_is_binary(two))
3273                goto free_and_return;
3274        else {
3275                /* Crazy xdl interfaces.. */
3276                xpparam_t xpp;
3277                xdemitconf_t xecfg;
3278
3279                memset(&xpp, 0, sizeof(xpp));
3280                memset(&xecfg, 0, sizeof(xecfg));
3281                xecfg.ctxlen = 1; /* at least one context line */
3282                xpp.flags = 0;
3283                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3284                                  &xpp, &xecfg))
3285                        die("unable to generate checkdiff for %s", one->path);
3286
3287                if (data.ws_rule & WS_BLANK_AT_EOF) {
3288                        struct emit_callback ecbdata;
3289                        int blank_at_eof;
3290
3291                        ecbdata.ws_rule = data.ws_rule;
3292                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3293                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3294
3295                        if (blank_at_eof) {
3296                                static char *err;
3297                                if (!err)
3298                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3299                                fprintf(o->file, "%s:%d: %s.\n",
3300                                        data.filename, blank_at_eof, err);
3301                                data.status = 1; /* report errors */
3302                        }
3303                }
3304        }
3305 free_and_return:
3306        diff_free_filespec_data(one);
3307        diff_free_filespec_data(two);
3308        if (data.status)
3309                DIFF_OPT_SET(o, CHECK_FAILED);
3310}
3311
3312struct diff_filespec *alloc_filespec(const char *path)
3313{
3314        struct diff_filespec *spec;
3315
3316        FLEXPTR_ALLOC_STR(spec, path, path);
3317        spec->count = 1;
3318        spec->is_binary = -1;
3319        return spec;
3320}
3321
3322void free_filespec(struct diff_filespec *spec)
3323{
3324        if (!--spec->count) {
3325                diff_free_filespec_data(spec);
3326                free(spec);
3327        }
3328}
3329
3330void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3331                   int oid_valid, unsigned short mode)
3332{
3333        if (mode) {
3334                spec->mode = canon_mode(mode);
3335                oidcpy(&spec->oid, oid);
3336                spec->oid_valid = oid_valid;
3337        }
3338}
3339
3340/*
3341 * Given a name and sha1 pair, if the index tells us the file in
3342 * the work tree has that object contents, return true, so that
3343 * prepare_temp_file() does not have to inflate and extract.
3344 */
3345static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3346{
3347        const struct cache_entry *ce;
3348        struct stat st;
3349        int pos, len;
3350
3351        /*
3352         * We do not read the cache ourselves here, because the
3353         * benchmark with my previous version that always reads cache
3354         * shows that it makes things worse for diff-tree comparing
3355         * two linux-2.6 kernel trees in an already checked out work
3356         * tree.  This is because most diff-tree comparisons deal with
3357         * only a small number of files, while reading the cache is
3358         * expensive for a large project, and its cost outweighs the
3359         * savings we get by not inflating the object to a temporary
3360         * file.  Practically, this code only helps when we are used
3361         * by diff-cache --cached, which does read the cache before
3362         * calling us.
3363         */
3364        if (!active_cache)
3365                return 0;
3366
3367        /* We want to avoid the working directory if our caller
3368         * doesn't need the data in a normal file, this system
3369         * is rather slow with its stat/open/mmap/close syscalls,
3370         * and the object is contained in a pack file.  The pack
3371         * is probably already open and will be faster to obtain
3372         * the data through than the working directory.  Loose
3373         * objects however would tend to be slower as they need
3374         * to be individually opened and inflated.
3375         */
3376        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3377                return 0;
3378
3379        /*
3380         * Similarly, if we'd have to convert the file contents anyway, that
3381         * makes the optimization not worthwhile.
3382         */
3383        if (!want_file && would_convert_to_git(&the_index, name))
3384                return 0;
3385
3386        len = strlen(name);
3387        pos = cache_name_pos(name, len);
3388        if (pos < 0)
3389                return 0;
3390        ce = active_cache[pos];
3391
3392        /*
3393         * This is not the sha1 we are looking for, or
3394         * unreusable because it is not a regular file.
3395         */
3396        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3397                return 0;
3398
3399        /*
3400         * If ce is marked as "assume unchanged", there is no
3401         * guarantee that work tree matches what we are looking for.
3402         */
3403        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3404                return 0;
3405
3406        /*
3407         * If ce matches the file in the work tree, we can reuse it.
3408         */
3409        if (ce_uptodate(ce) ||
3410            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3411                return 1;
3412
3413        return 0;
3414}
3415
3416static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3417{
3418        struct strbuf buf = STRBUF_INIT;
3419        char *dirty = "";
3420
3421        /* Are we looking at the work tree? */
3422        if (s->dirty_submodule)
3423                dirty = "-dirty";
3424
3425        strbuf_addf(&buf, "Subproject commit %s%s\n",
3426                    oid_to_hex(&s->oid), dirty);
3427        s->size = buf.len;
3428        if (size_only) {
3429                s->data = NULL;
3430                strbuf_release(&buf);
3431        } else {
3432                s->data = strbuf_detach(&buf, NULL);
3433                s->should_free = 1;
3434        }
3435        return 0;
3436}
3437
3438/*
3439 * While doing rename detection and pickaxe operation, we may need to
3440 * grab the data for the blob (or file) for our own in-core comparison.
3441 * diff_filespec has data and size fields for this purpose.
3442 */
3443int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3444{
3445        int size_only = flags & CHECK_SIZE_ONLY;
3446        int err = 0;
3447        /*
3448         * demote FAIL to WARN to allow inspecting the situation
3449         * instead of refusing.
3450         */
3451        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3452                                    ? SAFE_CRLF_WARN
3453                                    : safe_crlf);
3454
3455        if (!DIFF_FILE_VALID(s))
3456                die("internal error: asking to populate invalid file.");
3457        if (S_ISDIR(s->mode))
3458                return -1;
3459
3460        if (s->data)
3461                return 0;
3462
3463        if (size_only && 0 < s->size)
3464                return 0;
3465
3466        if (S_ISGITLINK(s->mode))
3467                return diff_populate_gitlink(s, size_only);
3468
3469        if (!s->oid_valid ||
3470            reuse_worktree_file(s->path, &s->oid, 0)) {
3471                struct strbuf buf = STRBUF_INIT;
3472                struct stat st;
3473                int fd;
3474
3475                if (lstat(s->path, &st) < 0) {
3476                        if (errno == ENOENT) {
3477                        err_empty:
3478                                err = -1;
3479                        empty:
3480                                s->data = (char *)"";
3481                                s->size = 0;
3482                                return err;
3483                        }
3484                }
3485                s->size = xsize_t(st.st_size);
3486                if (!s->size)
3487                        goto empty;
3488                if (S_ISLNK(st.st_mode)) {
3489                        struct strbuf sb = STRBUF_INIT;
3490
3491                        if (strbuf_readlink(&sb, s->path, s->size))
3492                                goto err_empty;
3493                        s->size = sb.len;
3494                        s->data = strbuf_detach(&sb, NULL);
3495                        s->should_free = 1;
3496                        return 0;
3497                }
3498
3499                /*
3500                 * Even if the caller would be happy with getting
3501                 * only the size, we cannot return early at this
3502                 * point if the path requires us to run the content
3503                 * conversion.
3504                 */
3505                if (size_only && !would_convert_to_git(&the_index, s->path))
3506                        return 0;
3507
3508                /*
3509                 * Note: this check uses xsize_t(st.st_size) that may
3510                 * not be the true size of the blob after it goes
3511                 * through convert_to_git().  This may not strictly be
3512                 * correct, but the whole point of big_file_threshold
3513                 * and is_binary check being that we want to avoid
3514                 * opening the file and inspecting the contents, this
3515                 * is probably fine.
3516                 */
3517                if ((flags & CHECK_BINARY) &&
3518                    s->size > big_file_threshold && s->is_binary == -1) {
3519                        s->is_binary = 1;
3520                        return 0;
3521                }
3522                fd = open(s->path, O_RDONLY);
3523                if (fd < 0)
3524                        goto err_empty;
3525                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3526                close(fd);
3527                s->should_munmap = 1;
3528
3529                /*
3530                 * Convert from working tree format to canonical git format
3531                 */
3532                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3533                        size_t size = 0;
3534                        munmap(s->data, s->size);
3535                        s->should_munmap = 0;
3536                        s->data = strbuf_detach(&buf, &size);
3537                        s->size = size;
3538                        s->should_free = 1;
3539                }
3540        }
3541        else {
3542                enum object_type type;
3543                if (size_only || (flags & CHECK_BINARY)) {
3544                        type = sha1_object_info(s->oid.hash, &s->size);
3545                        if (type < 0)
3546                                die("unable to read %s",
3547                                    oid_to_hex(&s->oid));
3548                        if (size_only)
3549                                return 0;
3550                        if (s->size > big_file_threshold && s->is_binary == -1) {
3551                                s->is_binary = 1;
3552                                return 0;
3553                        }
3554                }
3555                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3556                if (!s->data)
3557                        die("unable to read %s", oid_to_hex(&s->oid));
3558                s->should_free = 1;
3559        }
3560        return 0;
3561}
3562
3563void diff_free_filespec_blob(struct diff_filespec *s)
3564{
3565        if (s->should_free)
3566                free(s->data);
3567        else if (s->should_munmap)
3568                munmap(s->data, s->size);
3569
3570        if (s->should_free || s->should_munmap) {
3571                s->should_free = s->should_munmap = 0;
3572                s->data = NULL;
3573        }
3574}
3575
3576void diff_free_filespec_data(struct diff_filespec *s)
3577{
3578        diff_free_filespec_blob(s);
3579        FREE_AND_NULL(s->cnt_data);
3580}
3581
3582static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3583                           void *blob,
3584                           unsigned long size,
3585                           const struct object_id *oid,
3586                           int mode)
3587{
3588        int fd;
3589        struct strbuf buf = STRBUF_INIT;
3590        struct strbuf template = STRBUF_INIT;
3591        char *path_dup = xstrdup(path);
3592        const char *base = basename(path_dup);
3593
3594        /* Generate "XXXXXX_basename.ext" */
3595        strbuf_addstr(&template, "XXXXXX_");
3596        strbuf_addstr(&template, base);
3597
3598        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3599        if (fd < 0)
3600                die_errno("unable to create temp-file");
3601        if (convert_to_working_tree(path,
3602                        (const char *)blob, (size_t)size, &buf)) {
3603                blob = buf.buf;
3604                size = buf.len;
3605        }
3606        if (write_in_full(fd, blob, size) != size)
3607                die_errno("unable to write temp-file");
3608        close_tempfile(&temp->tempfile);
3609        temp->name = get_tempfile_path(&temp->tempfile);
3610        oid_to_hex_r(temp->hex, oid);
3611        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3612        strbuf_release(&buf);
3613        strbuf_release(&template);
3614        free(path_dup);
3615}
3616
3617static struct diff_tempfile *prepare_temp_file(const char *name,
3618                struct diff_filespec *one)
3619{
3620        struct diff_tempfile *temp = claim_diff_tempfile();
3621
3622        if (!DIFF_FILE_VALID(one)) {
3623        not_a_valid_file:
3624                /* A '-' entry produces this for file-2, and
3625                 * a '+' entry produces this for file-1.
3626                 */
3627                temp->name = "/dev/null";
3628                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3629                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3630                return temp;
3631        }
3632
3633        if (!S_ISGITLINK(one->mode) &&
3634            (!one->oid_valid ||
3635             reuse_worktree_file(name, &one->oid, 1))) {
3636                struct stat st;
3637                if (lstat(name, &st) < 0) {
3638                        if (errno == ENOENT)
3639                                goto not_a_valid_file;
3640                        die_errno("stat(%s)", name);
3641                }
3642                if (S_ISLNK(st.st_mode)) {
3643                        struct strbuf sb = STRBUF_INIT;
3644                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3645                                die_errno("readlink(%s)", name);
3646                        prep_temp_blob(name, temp, sb.buf, sb.len,
3647                                       (one->oid_valid ?
3648                                        &one->oid : &null_oid),
3649                                       (one->oid_valid ?
3650                                        one->mode : S_IFLNK));
3651                        strbuf_release(&sb);
3652                }
3653                else {
3654                        /* we can borrow from the file in the work tree */
3655                        temp->name = name;
3656                        if (!one->oid_valid)
3657                                oid_to_hex_r(temp->hex, &null_oid);
3658                        else
3659                                oid_to_hex_r(temp->hex, &one->oid);
3660                        /* Even though we may sometimes borrow the
3661                         * contents from the work tree, we always want
3662                         * one->mode.  mode is trustworthy even when
3663                         * !(one->oid_valid), as long as
3664                         * DIFF_FILE_VALID(one).
3665                         */
3666                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3667                }
3668                return temp;
3669        }
3670        else {
3671                if (diff_populate_filespec(one, 0))
3672                        die("cannot read data blob for %s", one->path);
3673                prep_temp_blob(name, temp, one->data, one->size,
3674                               &one->oid, one->mode);
3675        }
3676        return temp;
3677}
3678
3679static void add_external_diff_name(struct argv_array *argv,
3680                                   const char *name,
3681                                   struct diff_filespec *df)
3682{
3683        struct diff_tempfile *temp = prepare_temp_file(name, df);
3684        argv_array_push(argv, temp->name);
3685        argv_array_push(argv, temp->hex);
3686        argv_array_push(argv, temp->mode);
3687}
3688
3689/* An external diff command takes:
3690 *
3691 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3692 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3693 *
3694 */
3695static void run_external_diff(const char *pgm,
3696                              const char *name,
3697                              const char *other,
3698                              struct diff_filespec *one,
3699                              struct diff_filespec *two,
3700                              const char *xfrm_msg,
3701                              int complete_rewrite,
3702                              struct diff_options *o)
3703{
3704        struct argv_array argv = ARGV_ARRAY_INIT;
3705        struct argv_array env = ARGV_ARRAY_INIT;
3706        struct diff_queue_struct *q = &diff_queued_diff;
3707
3708        argv_array_push(&argv, pgm);
3709        argv_array_push(&argv, name);
3710
3711        if (one && two) {
3712                add_external_diff_name(&argv, name, one);
3713                if (!other)
3714                        add_external_diff_name(&argv, name, two);
3715                else {
3716                        add_external_diff_name(&argv, other, two);
3717                        argv_array_push(&argv, other);
3718                        argv_array_push(&argv, xfrm_msg);
3719                }
3720        }
3721
3722        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3723        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3724
3725        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3726                die(_("external diff died, stopping at %s"), name);
3727
3728        remove_tempfile();
3729        argv_array_clear(&argv);
3730        argv_array_clear(&env);
3731}
3732
3733static int similarity_index(struct diff_filepair *p)
3734{
3735        return p->score * 100 / MAX_SCORE;
3736}
3737
3738static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3739{
3740        if (startup_info->have_repository)
3741                return find_unique_abbrev(oid->hash, abbrev);
3742        else {
3743                char *hex = oid_to_hex(oid);
3744                if (abbrev < 0)
3745                        abbrev = FALLBACK_DEFAULT_ABBREV;
3746                if (abbrev > GIT_SHA1_HEXSZ)
3747                        die("BUG: oid abbreviation out of range: %d", abbrev);
3748                if (abbrev)
3749                        hex[abbrev] = '\0';
3750                return hex;
3751        }
3752}
3753
3754static void fill_metainfo(struct strbuf *msg,
3755                          const char *name,
3756                          const char *other,
3757                          struct diff_filespec *one,
3758                          struct diff_filespec *two,
3759                          struct diff_options *o,
3760                          struct diff_filepair *p,
3761                          int *must_show_header,
3762                          int use_color)
3763{
3764        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3765        const char *reset = diff_get_color(use_color, DIFF_RESET);
3766        const char *line_prefix = diff_line_prefix(o);
3767
3768        *must_show_header = 1;
3769        strbuf_init(msg, PATH_MAX * 2 + 300);
3770        switch (p->status) {
3771        case DIFF_STATUS_COPIED:
3772                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3773                            line_prefix, set, similarity_index(p));
3774                strbuf_addf(msg, "%s\n%s%scopy from ",
3775                            reset,  line_prefix, set);
3776                quote_c_style(name, msg, NULL, 0);
3777                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3778                quote_c_style(other, msg, NULL, 0);
3779                strbuf_addf(msg, "%s\n", reset);
3780                break;
3781        case DIFF_STATUS_RENAMED:
3782                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3783                            line_prefix, set, similarity_index(p));
3784                strbuf_addf(msg, "%s\n%s%srename from ",
3785                            reset, line_prefix, set);
3786                quote_c_style(name, msg, NULL, 0);
3787                strbuf_addf(msg, "%s\n%s%srename to ",
3788                            reset, line_prefix, set);
3789                quote_c_style(other, msg, NULL, 0);
3790                strbuf_addf(msg, "%s\n", reset);
3791                break;
3792        case DIFF_STATUS_MODIFIED:
3793                if (p->score) {
3794                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3795                                    line_prefix,
3796                                    set, similarity_index(p), reset);
3797                        break;
3798                }
3799                /* fallthru */
3800        default:
3801                *must_show_header = 0;
3802        }
3803        if (one && two && oidcmp(&one->oid, &two->oid)) {
3804                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3805
3806                if (DIFF_OPT_TST(o, BINARY)) {
3807                        mmfile_t mf;
3808                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3809                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3810                                abbrev = 40;
3811                }
3812                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3813                            diff_abbrev_oid(&one->oid, abbrev),
3814                            diff_abbrev_oid(&two->oid, abbrev));
3815                if (one->mode == two->mode)
3816                        strbuf_addf(msg, " %06o", one->mode);
3817                strbuf_addf(msg, "%s\n", reset);
3818        }
3819}
3820
3821static void run_diff_cmd(const char *pgm,
3822                         const char *name,
3823                         const char *other,
3824                         const char *attr_path,
3825                         struct diff_filespec *one,
3826                         struct diff_filespec *two,
3827                         struct strbuf *msg,
3828                         struct diff_options *o,
3829                         struct diff_filepair *p)
3830{
3831        const char *xfrm_msg = NULL;
3832        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3833        int must_show_header = 0;
3834
3835
3836        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3837                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3838                if (drv && drv->external)
3839                        pgm = drv->external;
3840        }
3841
3842        if (msg) {
3843                /*
3844                 * don't use colors when the header is intended for an
3845                 * external diff driver
3846                 */
3847                fill_metainfo(msg, name, other, one, two, o, p,
3848                              &must_show_header,
3849                              want_color(o->use_color) && !pgm);
3850                xfrm_msg = msg->len ? msg->buf : NULL;
3851        }
3852
3853        if (pgm) {
3854                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3855                                  complete_rewrite, o);
3856                return;
3857        }
3858        if (one && two)
3859                builtin_diff(name, other ? other : name,
3860                             one, two, xfrm_msg, must_show_header,
3861                             o, complete_rewrite);
3862        else
3863                fprintf(o->file, "* Unmerged path %s\n", name);
3864}
3865
3866static void diff_fill_oid_info(struct diff_filespec *one)
3867{
3868        if (DIFF_FILE_VALID(one)) {
3869                if (!one->oid_valid) {
3870                        struct stat st;
3871                        if (one->is_stdin) {
3872                                oidclr(&one->oid);
3873                                return;
3874                        }
3875                        if (lstat(one->path, &st) < 0)
3876                                die_errno("stat '%s'", one->path);
3877                        if (index_path(one->oid.hash, one->path, &st, 0))
3878                                die("cannot hash %s", one->path);
3879                }
3880        }
3881        else
3882                oidclr(&one->oid);
3883}
3884
3885static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3886{
3887        /* Strip the prefix but do not molest /dev/null and absolute paths */
3888        if (*namep && **namep != '/') {
3889                *namep += prefix_length;
3890                if (**namep == '/')
3891                        ++*namep;
3892        }
3893        if (*otherp && **otherp != '/') {
3894                *otherp += prefix_length;
3895                if (**otherp == '/')
3896                        ++*otherp;
3897        }
3898}
3899
3900static void run_diff(struct diff_filepair *p, struct diff_options *o)
3901{
3902        const char *pgm = external_diff();
3903        struct strbuf msg;
3904        struct diff_filespec *one = p->one;
3905        struct diff_filespec *two = p->two;
3906        const char *name;
3907        const char *other;
3908        const char *attr_path;
3909
3910        name  = one->path;
3911        other = (strcmp(name, two->path) ? two->path : NULL);
3912        attr_path = name;
3913        if (o->prefix_length)
3914                strip_prefix(o->prefix_length, &name, &other);
3915
3916        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3917                pgm = NULL;
3918
3919        if (DIFF_PAIR_UNMERGED(p)) {
3920                run_diff_cmd(pgm, name, NULL, attr_path,
3921                             NULL, NULL, NULL, o, p);
3922                return;
3923        }
3924
3925        diff_fill_oid_info(one);
3926        diff_fill_oid_info(two);
3927
3928        if (!pgm &&
3929            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3930            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3931                /*
3932                 * a filepair that changes between file and symlink
3933                 * needs to be split into deletion and creation.
3934                 */
3935                struct diff_filespec *null = alloc_filespec(two->path);
3936                run_diff_cmd(NULL, name, other, attr_path,
3937                             one, null, &msg, o, p);
3938                free(null);
3939                strbuf_release(&msg);
3940
3941                null = alloc_filespec(one->path);
3942                run_diff_cmd(NULL, name, other, attr_path,
3943                             null, two, &msg, o, p);
3944                free(null);
3945        }
3946        else
3947                run_diff_cmd(pgm, name, other, attr_path,
3948                             one, two, &msg, o, p);
3949
3950        strbuf_release(&msg);
3951}
3952
3953static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3954                         struct diffstat_t *diffstat)
3955{
3956        const char *name;
3957        const char *other;
3958
3959        if (DIFF_PAIR_UNMERGED(p)) {
3960                /* unmerged */
3961                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3962                return;
3963        }
3964
3965        name = p->one->path;
3966        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3967
3968        if (o->prefix_length)
3969                strip_prefix(o->prefix_length, &name, &other);
3970
3971        diff_fill_oid_info(p->one);
3972        diff_fill_oid_info(p->two);
3973
3974        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3975}
3976
3977static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3978{
3979        const char *name;
3980        const char *other;
3981        const char *attr_path;
3982
3983        if (DIFF_PAIR_UNMERGED(p)) {
3984                /* unmerged */
3985                return;
3986        }
3987
3988        name = p->one->path;
3989        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3990        attr_path = other ? other : name;
3991
3992        if (o->prefix_length)
3993                strip_prefix(o->prefix_length, &name, &other);
3994
3995        diff_fill_oid_info(p->one);
3996        diff_fill_oid_info(p->two);
3997
3998        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3999}
4000
4001void diff_setup(struct diff_options *options)
4002{
4003        memcpy(options, &default_diff_options, sizeof(*options));
4004
4005        options->file = stdout;
4006
4007        options->abbrev = DEFAULT_ABBREV;
4008        options->line_termination = '\n';
4009        options->break_opt = -1;
4010        options->rename_limit = -1;
4011        options->dirstat_permille = diff_dirstat_permille_default;
4012        options->context = diff_context_default;
4013        options->interhunkcontext = diff_interhunk_context_default;
4014        options->ws_error_highlight = ws_error_highlight_default;
4015        DIFF_OPT_SET(options, RENAME_EMPTY);
4016
4017        /* pathchange left =NULL by default */
4018        options->change = diff_change;
4019        options->add_remove = diff_addremove;
4020        options->use_color = diff_use_color_default;
4021        options->detect_rename = diff_detect_rename_default;
4022        options->xdl_opts |= diff_algorithm;
4023        if (diff_indent_heuristic)
4024                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4025
4026        options->orderfile = diff_order_file_cfg;
4027
4028        if (diff_no_prefix) {
4029                options->a_prefix = options->b_prefix = "";
4030        } else if (!diff_mnemonic_prefix) {
4031                options->a_prefix = "a/";
4032                options->b_prefix = "b/";
4033        }
4034
4035        options->color_moved = diff_color_moved_default;
4036}
4037
4038void diff_setup_done(struct diff_options *options)
4039{
4040        int count = 0;
4041
4042        if (options->set_default)
4043                options->set_default(options);
4044
4045        if (options->output_format & DIFF_FORMAT_NAME)
4046                count++;
4047        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
4048                count++;
4049        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
4050                count++;
4051        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
4052                count++;
4053        if (count > 1)
4054                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4055
4056        /*
4057         * Most of the time we can say "there are changes"
4058         * only by checking if there are changed paths, but
4059         * --ignore-whitespace* options force us to look
4060         * inside contents.
4061         */
4062
4063        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
4064            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
4065            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
4066                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
4067        else
4068                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
4069
4070        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
4071                options->detect_rename = DIFF_DETECT_COPY;
4072
4073        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
4074                options->prefix = NULL;
4075        if (options->prefix)
4076                options->prefix_length = strlen(options->prefix);
4077        else
4078                options->prefix_length = 0;
4079
4080        if (options->output_format & (DIFF_FORMAT_NAME |
4081                                      DIFF_FORMAT_NAME_STATUS |
4082                                      DIFF_FORMAT_CHECKDIFF |
4083                                      DIFF_FORMAT_NO_OUTPUT))
4084                options->output_format &= ~(DIFF_FORMAT_RAW |
4085                                            DIFF_FORMAT_NUMSTAT |
4086                                            DIFF_FORMAT_DIFFSTAT |
4087                                            DIFF_FORMAT_SHORTSTAT |
4088                                            DIFF_FORMAT_DIRSTAT |
4089                                            DIFF_FORMAT_SUMMARY |
4090                                            DIFF_FORMAT_PATCH);
4091
4092        /*
4093         * These cases always need recursive; we do not drop caller-supplied
4094         * recursive bits for other formats here.
4095         */
4096        if (options->output_format & (DIFF_FORMAT_PATCH |
4097                                      DIFF_FORMAT_NUMSTAT |
4098                                      DIFF_FORMAT_DIFFSTAT |
4099                                      DIFF_FORMAT_SHORTSTAT |
4100                                      DIFF_FORMAT_DIRSTAT |
4101                                      DIFF_FORMAT_SUMMARY |
4102                                      DIFF_FORMAT_CHECKDIFF))
4103                DIFF_OPT_SET(options, RECURSIVE);
4104        /*
4105         * Also pickaxe would not work very well if you do not say recursive
4106         */
4107        if (options->pickaxe)
4108                DIFF_OPT_SET(options, RECURSIVE);
4109        /*
4110         * When patches are generated, submodules diffed against the work tree
4111         * must be checked for dirtiness too so it can be shown in the output
4112         */
4113        if (options->output_format & DIFF_FORMAT_PATCH)
4114                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
4115
4116        if (options->detect_rename && options->rename_limit < 0)
4117                options->rename_limit = diff_rename_limit_default;
4118        if (options->setup & DIFF_SETUP_USE_CACHE) {
4119                if (!active_cache)
4120                        /* read-cache does not die even when it fails
4121                         * so it is safe for us to do this here.  Also
4122                         * it does not smudge active_cache or active_nr
4123                         * when it fails, so we do not have to worry about
4124                         * cleaning it up ourselves either.
4125                         */
4126                        read_cache();
4127        }
4128        if (40 < options->abbrev)
4129                options->abbrev = 40; /* full */
4130
4131        /*
4132         * It does not make sense to show the first hit we happened
4133         * to have found.  It does not make sense not to return with
4134         * exit code in such a case either.
4135         */
4136        if (DIFF_OPT_TST(options, QUICK)) {
4137                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4138                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4139        }
4140
4141        options->diff_path_counter = 0;
4142
4143        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
4144                die(_("--follow requires exactly one pathspec"));
4145
4146        if (!options->use_color || external_diff())
4147                options->color_moved = 0;
4148}
4149
4150static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4151{
4152        char c, *eq;
4153        int len;
4154
4155        if (*arg != '-')
4156                return 0;
4157        c = *++arg;
4158        if (!c)
4159                return 0;
4160        if (c == arg_short) {
4161                c = *++arg;
4162                if (!c)
4163                        return 1;
4164                if (val && isdigit(c)) {
4165                        char *end;
4166                        int n = strtoul(arg, &end, 10);
4167                        if (*end)
4168                                return 0;
4169                        *val = n;
4170                        return 1;
4171                }
4172                return 0;
4173        }
4174        if (c != '-')
4175                return 0;
4176        arg++;
4177        eq = strchrnul(arg, '=');
4178        len = eq - arg;
4179        if (!len || strncmp(arg, arg_long, len))
4180                return 0;
4181        if (*eq) {
4182                int n;
4183                char *end;
4184                if (!isdigit(*++eq))
4185                        return 0;
4186                n = strtoul(eq, &end, 10);
4187                if (*end)
4188                        return 0;
4189                *val = n;
4190        }
4191        return 1;
4192}
4193
4194static int diff_scoreopt_parse(const char *opt);
4195
4196static inline int short_opt(char opt, const char **argv,
4197                            const char **optarg)
4198{
4199        const char *arg = argv[0];
4200        if (arg[0] != '-' || arg[1] != opt)
4201                return 0;
4202        if (arg[2] != '\0') {
4203                *optarg = arg + 2;
4204                return 1;
4205        }
4206        if (!argv[1])
4207                die("Option '%c' requires a value", opt);
4208        *optarg = argv[1];
4209        return 2;
4210}
4211
4212int parse_long_opt(const char *opt, const char **argv,
4213                   const char **optarg)
4214{
4215        const char *arg = argv[0];
4216        if (!skip_prefix(arg, "--", &arg))
4217                return 0;
4218        if (!skip_prefix(arg, opt, &arg))
4219                return 0;
4220        if (*arg == '=') { /* stuck form: --option=value */
4221                *optarg = arg + 1;
4222                return 1;
4223        }
4224        if (*arg != '\0')
4225                return 0;
4226        /* separate form: --option value */
4227        if (!argv[1])
4228                die("Option '--%s' requires a value", opt);
4229        *optarg = argv[1];
4230        return 2;
4231}
4232
4233static int stat_opt(struct diff_options *options, const char **av)
4234{
4235        const char *arg = av[0];
4236        char *end;
4237        int width = options->stat_width;
4238        int name_width = options->stat_name_width;
4239        int graph_width = options->stat_graph_width;
4240        int count = options->stat_count;
4241        int argcount = 1;
4242
4243        if (!skip_prefix(arg, "--stat", &arg))
4244                die("BUG: stat option does not begin with --stat: %s", arg);
4245        end = (char *)arg;
4246
4247        switch (*arg) {
4248        case '-':
4249                if (skip_prefix(arg, "-width", &arg)) {
4250                        if (*arg == '=')
4251                                width = strtoul(arg + 1, &end, 10);
4252                        else if (!*arg && !av[1])
4253                                die_want_option("--stat-width");
4254                        else if (!*arg) {
4255                                width = strtoul(av[1], &end, 10);
4256                                argcount = 2;
4257                        }
4258                } else if (skip_prefix(arg, "-name-width", &arg)) {
4259                        if (*arg == '=')
4260                                name_width = strtoul(arg + 1, &end, 10);
4261                        else if (!*arg && !av[1])
4262                                die_want_option("--stat-name-width");
4263                        else if (!*arg) {
4264                                name_width = strtoul(av[1], &end, 10);
4265                                argcount = 2;
4266                        }
4267                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4268                        if (*arg == '=')
4269                                graph_width = strtoul(arg + 1, &end, 10);
4270                        else if (!*arg && !av[1])
4271                                die_want_option("--stat-graph-width");
4272                        else if (!*arg) {
4273                                graph_width = strtoul(av[1], &end, 10);
4274                                argcount = 2;
4275                        }
4276                } else if (skip_prefix(arg, "-count", &arg)) {
4277                        if (*arg == '=')
4278                                count = strtoul(arg + 1, &end, 10);
4279                        else if (!*arg && !av[1])
4280                                die_want_option("--stat-count");
4281                        else if (!*arg) {
4282                                count = strtoul(av[1], &end, 10);
4283                                argcount = 2;
4284                        }
4285                }
4286                break;
4287        case '=':
4288                width = strtoul(arg+1, &end, 10);
4289                if (*end == ',')
4290                        name_width = strtoul(end+1, &end, 10);
4291                if (*end == ',')
4292                        count = strtoul(end+1, &end, 10);
4293        }
4294
4295        /* Important! This checks all the error cases! */
4296        if (*end)
4297                return 0;
4298        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4299        options->stat_name_width = name_width;
4300        options->stat_graph_width = graph_width;
4301        options->stat_width = width;
4302        options->stat_count = count;
4303        return argcount;
4304}
4305
4306static int parse_dirstat_opt(struct diff_options *options, const char *params)
4307{
4308        struct strbuf errmsg = STRBUF_INIT;
4309        if (parse_dirstat_params(options, params, &errmsg))
4310                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4311                    errmsg.buf);
4312        strbuf_release(&errmsg);
4313        /*
4314         * The caller knows a dirstat-related option is given from the command
4315         * line; allow it to say "return this_function();"
4316         */
4317        options->output_format |= DIFF_FORMAT_DIRSTAT;
4318        return 1;
4319}
4320
4321static int parse_submodule_opt(struct diff_options *options, const char *value)
4322{
4323        if (parse_submodule_params(options, value))
4324                die(_("Failed to parse --submodule option parameter: '%s'"),
4325                        value);
4326        return 1;
4327}
4328
4329static const char diff_status_letters[] = {
4330        DIFF_STATUS_ADDED,
4331        DIFF_STATUS_COPIED,
4332        DIFF_STATUS_DELETED,
4333        DIFF_STATUS_MODIFIED,
4334        DIFF_STATUS_RENAMED,
4335        DIFF_STATUS_TYPE_CHANGED,
4336        DIFF_STATUS_UNKNOWN,
4337        DIFF_STATUS_UNMERGED,
4338        DIFF_STATUS_FILTER_AON,
4339        DIFF_STATUS_FILTER_BROKEN,
4340        '\0',
4341};
4342
4343static unsigned int filter_bit['Z' + 1];
4344
4345static void prepare_filter_bits(void)
4346{
4347        int i;
4348
4349        if (!filter_bit[DIFF_STATUS_ADDED]) {
4350                for (i = 0; diff_status_letters[i]; i++)
4351                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4352        }
4353}
4354
4355static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4356{
4357        return opt->filter & filter_bit[(int) status];
4358}
4359
4360static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4361{
4362        int i, optch;
4363
4364        prepare_filter_bits();
4365
4366        /*
4367         * If there is a negation e.g. 'd' in the input, and we haven't
4368         * initialized the filter field with another --diff-filter, start
4369         * from full set of bits, except for AON.
4370         */
4371        if (!opt->filter) {
4372                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4373                        if (optch < 'a' || 'z' < optch)
4374                                continue;
4375                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4376                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4377                        break;
4378                }
4379        }
4380
4381        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4382                unsigned int bit;
4383                int negate;
4384
4385                if ('a' <= optch && optch <= 'z') {
4386                        negate = 1;
4387                        optch = toupper(optch);
4388                } else {
4389                        negate = 0;
4390                }
4391
4392                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4393                if (!bit)
4394                        return optarg[i];
4395                if (negate)
4396                        opt->filter &= ~bit;
4397                else
4398                        opt->filter |= bit;
4399        }
4400        return 0;
4401}
4402
4403static void enable_patch_output(int *fmt) {
4404        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4405        *fmt |= DIFF_FORMAT_PATCH;
4406}
4407
4408static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4409{
4410        int val = parse_ws_error_highlight(arg);
4411
4412        if (val < 0) {
4413                error("unknown value after ws-error-highlight=%.*s",
4414                      -1 - val, arg);
4415                return 0;
4416        }
4417        opt->ws_error_highlight = val;
4418        return 1;
4419}
4420
4421int diff_opt_parse(struct diff_options *options,
4422                   const char **av, int ac, const char *prefix)
4423{
4424        const char *arg = av[0];
4425        const char *optarg;
4426        int argcount;
4427
4428        if (!prefix)
4429                prefix = "";
4430
4431        /* Output format options */
4432        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4433            || opt_arg(arg, 'U', "unified", &options->context))
4434                enable_patch_output(&options->output_format);
4435        else if (!strcmp(arg, "--raw"))
4436                options->output_format |= DIFF_FORMAT_RAW;
4437        else if (!strcmp(arg, "--patch-with-raw")) {
4438                enable_patch_output(&options->output_format);
4439                options->output_format |= DIFF_FORMAT_RAW;
4440        } else if (!strcmp(arg, "--numstat"))
4441                options->output_format |= DIFF_FORMAT_NUMSTAT;
4442        else if (!strcmp(arg, "--shortstat"))
4443                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4444        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4445                return parse_dirstat_opt(options, "");
4446        else if (skip_prefix(arg, "-X", &arg))
4447                return parse_dirstat_opt(options, arg);
4448        else if (skip_prefix(arg, "--dirstat=", &arg))
4449                return parse_dirstat_opt(options, arg);
4450        else if (!strcmp(arg, "--cumulative"))
4451                return parse_dirstat_opt(options, "cumulative");
4452        else if (!strcmp(arg, "--dirstat-by-file"))
4453                return parse_dirstat_opt(options, "files");
4454        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4455                parse_dirstat_opt(options, "files");
4456                return parse_dirstat_opt(options, arg);
4457        }
4458        else if (!strcmp(arg, "--check"))
4459                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4460        else if (!strcmp(arg, "--summary"))
4461                options->output_format |= DIFF_FORMAT_SUMMARY;
4462        else if (!strcmp(arg, "--patch-with-stat")) {
4463                enable_patch_output(&options->output_format);
4464                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4465        } else if (!strcmp(arg, "--name-only"))
4466                options->output_format |= DIFF_FORMAT_NAME;
4467        else if (!strcmp(arg, "--name-status"))
4468                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4469        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4470                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4471        else if (starts_with(arg, "--stat"))
4472                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4473                return stat_opt(options, av);
4474
4475        /* renames options */
4476        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4477                 !strcmp(arg, "--break-rewrites")) {
4478                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4479                        return error("invalid argument to -B: %s", arg+2);
4480        }
4481        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4482                 !strcmp(arg, "--find-renames")) {
4483                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4484                        return error("invalid argument to -M: %s", arg+2);
4485                options->detect_rename = DIFF_DETECT_RENAME;
4486        }
4487        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4488                options->irreversible_delete = 1;
4489        }
4490        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4491                 !strcmp(arg, "--find-copies")) {
4492                if (options->detect_rename == DIFF_DETECT_COPY)
4493                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4494                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4495                        return error("invalid argument to -C: %s", arg+2);
4496                options->detect_rename = DIFF_DETECT_COPY;
4497        }
4498        else if (!strcmp(arg, "--no-renames"))
4499                options->detect_rename = 0;
4500        else if (!strcmp(arg, "--rename-empty"))
4501                DIFF_OPT_SET(options, RENAME_EMPTY);
4502        else if (!strcmp(arg, "--no-rename-empty"))
4503                DIFF_OPT_CLR(options, RENAME_EMPTY);
4504        else if (!strcmp(arg, "--relative"))
4505                DIFF_OPT_SET(options, RELATIVE_NAME);
4506        else if (skip_prefix(arg, "--relative=", &arg)) {
4507                DIFF_OPT_SET(options, RELATIVE_NAME);
4508                options->prefix = arg;
4509        }
4510
4511        /* xdiff options */
4512        else if (!strcmp(arg, "--minimal"))
4513                DIFF_XDL_SET(options, NEED_MINIMAL);
4514        else if (!strcmp(arg, "--no-minimal"))
4515                DIFF_XDL_CLR(options, NEED_MINIMAL);
4516        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4517                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4518        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4519                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4520        else if (!strcmp(arg, "--ignore-space-at-eol"))
4521                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4522        else if (!strcmp(arg, "--ignore-blank-lines"))
4523                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4524        else if (!strcmp(arg, "--indent-heuristic"))
4525                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4526        else if (!strcmp(arg, "--no-indent-heuristic"))
4527                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4528        else if (!strcmp(arg, "--patience"))
4529                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4530        else if (!strcmp(arg, "--histogram"))
4531                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4532        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4533                long value = parse_algorithm_value(optarg);
4534                if (value < 0)
4535                        return error("option diff-algorithm accepts \"myers\", "
4536                                     "\"minimal\", \"patience\" and \"histogram\"");
4537                /* clear out previous settings */
4538                DIFF_XDL_CLR(options, NEED_MINIMAL);
4539                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4540                options->xdl_opts |= value;
4541                return argcount;
4542        }
4543
4544        /* flags options */
4545        else if (!strcmp(arg, "--binary")) {
4546                enable_patch_output(&options->output_format);
4547                DIFF_OPT_SET(options, BINARY);
4548        }
4549        else if (!strcmp(arg, "--full-index"))
4550                DIFF_OPT_SET(options, FULL_INDEX);
4551        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4552                DIFF_OPT_SET(options, TEXT);
4553        else if (!strcmp(arg, "-R"))
4554                DIFF_OPT_SET(options, REVERSE_DIFF);
4555        else if (!strcmp(arg, "--find-copies-harder"))
4556                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4557        else if (!strcmp(arg, "--follow"))
4558                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4559        else if (!strcmp(arg, "--no-follow")) {
4560                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4561                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4562        } else if (!strcmp(arg, "--color"))
4563                options->use_color = 1;
4564        else if (skip_prefix(arg, "--color=", &arg)) {
4565                int value = git_config_colorbool(NULL, arg);
4566                if (value < 0)
4567                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4568                options->use_color = value;
4569        }
4570        else if (!strcmp(arg, "--no-color"))
4571                options->use_color = 0;
4572        else if (!strcmp(arg, "--color-moved")) {
4573                if (diff_color_moved_default)
4574                        options->color_moved = diff_color_moved_default;
4575                if (options->color_moved == COLOR_MOVED_NO)
4576                        options->color_moved = COLOR_MOVED_DEFAULT;
4577        } else if (!strcmp(arg, "--no-color-moved"))
4578                options->color_moved = COLOR_MOVED_NO;
4579        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4580                int cm = parse_color_moved(arg);
4581                if (cm < 0)
4582                        die("bad --color-moved argument: %s", arg);
4583                options->color_moved = cm;
4584        } else if (!strcmp(arg, "--color-words")) {
4585                options->use_color = 1;
4586                options->word_diff = DIFF_WORDS_COLOR;
4587        }
4588        else if (skip_prefix(arg, "--color-words=", &arg)) {
4589                options->use_color = 1;
4590                options->word_diff = DIFF_WORDS_COLOR;
4591                options->word_regex = arg;
4592        }
4593        else if (!strcmp(arg, "--word-diff")) {
4594                if (options->word_diff == DIFF_WORDS_NONE)
4595                        options->word_diff = DIFF_WORDS_PLAIN;
4596        }
4597        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4598                if (!strcmp(arg, "plain"))
4599                        options->word_diff = DIFF_WORDS_PLAIN;
4600                else if (!strcmp(arg, "color")) {
4601                        options->use_color = 1;
4602                        options->word_diff = DIFF_WORDS_COLOR;
4603                }
4604                else if (!strcmp(arg, "porcelain"))
4605                        options->word_diff = DIFF_WORDS_PORCELAIN;
4606                else if (!strcmp(arg, "none"))
4607                        options->word_diff = DIFF_WORDS_NONE;
4608                else
4609                        die("bad --word-diff argument: %s", arg);
4610        }
4611        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4612                if (options->word_diff == DIFF_WORDS_NONE)
4613                        options->word_diff = DIFF_WORDS_PLAIN;
4614                options->word_regex = optarg;
4615                return argcount;
4616        }
4617        else if (!strcmp(arg, "--exit-code"))
4618                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4619        else if (!strcmp(arg, "--quiet"))
4620                DIFF_OPT_SET(options, QUICK);
4621        else if (!strcmp(arg, "--ext-diff"))
4622                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4623        else if (!strcmp(arg, "--no-ext-diff"))
4624                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4625        else if (!strcmp(arg, "--textconv"))
4626                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4627        else if (!strcmp(arg, "--no-textconv"))
4628                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4629        else if (!strcmp(arg, "--ignore-submodules")) {
4630                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4631                handle_ignore_submodules_arg(options, "all");
4632        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4633                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4634                handle_ignore_submodules_arg(options, arg);
4635        } else if (!strcmp(arg, "--submodule"))
4636                options->submodule_format = DIFF_SUBMODULE_LOG;
4637        else if (skip_prefix(arg, "--submodule=", &arg))
4638                return parse_submodule_opt(options, arg);
4639        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4640                return parse_ws_error_highlight_opt(options, arg);
4641        else if (!strcmp(arg, "--ita-invisible-in-index"))
4642                options->ita_invisible_in_index = 1;
4643        else if (!strcmp(arg, "--ita-visible-in-index"))
4644                options->ita_invisible_in_index = 0;
4645
4646        /* misc options */
4647        else if (!strcmp(arg, "-z"))
4648                options->line_termination = 0;
4649        else if ((argcount = short_opt('l', av, &optarg))) {
4650                options->rename_limit = strtoul(optarg, NULL, 10);
4651                return argcount;
4652        }
4653        else if ((argcount = short_opt('S', av, &optarg))) {
4654                options->pickaxe = optarg;
4655                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4656                return argcount;
4657        } else if ((argcount = short_opt('G', av, &optarg))) {
4658                options->pickaxe = optarg;
4659                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4660                return argcount;
4661        }
4662        else if (!strcmp(arg, "--pickaxe-all"))
4663                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4664        else if (!strcmp(arg, "--pickaxe-regex"))
4665                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4666        else if ((argcount = short_opt('O', av, &optarg))) {
4667                options->orderfile = prefix_filename(prefix, optarg);
4668                return argcount;
4669        }
4670        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4671                int offending = parse_diff_filter_opt(optarg, options);
4672                if (offending)
4673                        die("unknown change class '%c' in --diff-filter=%s",
4674                            offending, optarg);
4675                return argcount;
4676        }
4677        else if (!strcmp(arg, "--no-abbrev"))
4678                options->abbrev = 0;
4679        else if (!strcmp(arg, "--abbrev"))
4680                options->abbrev = DEFAULT_ABBREV;
4681        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4682                options->abbrev = strtoul(arg, NULL, 10);
4683                if (options->abbrev < MINIMUM_ABBREV)
4684                        options->abbrev = MINIMUM_ABBREV;
4685                else if (40 < options->abbrev)
4686                        options->abbrev = 40;
4687        }
4688        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4689                options->a_prefix = optarg;
4690                return argcount;
4691        }
4692        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4693                options->line_prefix = optarg;
4694                options->line_prefix_length = strlen(options->line_prefix);
4695                graph_setup_line_prefix(options);
4696                return argcount;
4697        }
4698        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4699                options->b_prefix = optarg;
4700                return argcount;
4701        }
4702        else if (!strcmp(arg, "--no-prefix"))
4703                options->a_prefix = options->b_prefix = "";
4704        else if (opt_arg(arg, '\0', "inter-hunk-context",
4705                         &options->interhunkcontext))
4706                ;
4707        else if (!strcmp(arg, "-W"))
4708                DIFF_OPT_SET(options, FUNCCONTEXT);
4709        else if (!strcmp(arg, "--function-context"))
4710                DIFF_OPT_SET(options, FUNCCONTEXT);
4711        else if (!strcmp(arg, "--no-function-context"))
4712                DIFF_OPT_CLR(options, FUNCCONTEXT);
4713        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4714                char *path = prefix_filename(prefix, optarg);
4715                options->file = xfopen(path, "w");
4716                options->close_file = 1;
4717                if (options->use_color != GIT_COLOR_ALWAYS)
4718                        options->use_color = GIT_COLOR_NEVER;
4719                free(path);
4720                return argcount;
4721        } else
4722                return 0;
4723        return 1;
4724}
4725
4726int parse_rename_score(const char **cp_p)
4727{
4728        unsigned long num, scale;
4729        int ch, dot;
4730        const char *cp = *cp_p;
4731
4732        num = 0;
4733        scale = 1;
4734        dot = 0;
4735        for (;;) {
4736                ch = *cp;
4737                if ( !dot && ch == '.' ) {
4738                        scale = 1;
4739                        dot = 1;
4740                } else if ( ch == '%' ) {
4741                        scale = dot ? scale*100 : 100;
4742                        cp++;   /* % is always at the end */
4743                        break;
4744                } else if ( ch >= '0' && ch <= '9' ) {
4745                        if ( scale < 100000 ) {
4746                                scale *= 10;
4747                                num = (num*10) + (ch-'0');
4748                        }
4749                } else {
4750                        break;
4751                }
4752                cp++;
4753        }
4754        *cp_p = cp;
4755
4756        /* user says num divided by scale and we say internally that
4757         * is MAX_SCORE * num / scale.
4758         */
4759        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4760}
4761
4762static int diff_scoreopt_parse(const char *opt)
4763{
4764        int opt1, opt2, cmd;
4765
4766        if (*opt++ != '-')
4767                return -1;
4768        cmd = *opt++;
4769        if (cmd == '-') {
4770                /* convert the long-form arguments into short-form versions */
4771                if (skip_prefix(opt, "break-rewrites", &opt)) {
4772                        if (*opt == 0 || *opt++ == '=')
4773                                cmd = 'B';
4774                } else if (skip_prefix(opt, "find-copies", &opt)) {
4775                        if (*opt == 0 || *opt++ == '=')
4776                                cmd = 'C';
4777                } else if (skip_prefix(opt, "find-renames", &opt)) {
4778                        if (*opt == 0 || *opt++ == '=')
4779                                cmd = 'M';
4780                }
4781        }
4782        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4783                return -1; /* that is not a -M, -C, or -B option */
4784
4785        opt1 = parse_rename_score(&opt);
4786        if (cmd != 'B')
4787                opt2 = 0;
4788        else {
4789                if (*opt == 0)
4790                        opt2 = 0;
4791                else if (*opt != '/')
4792                        return -1; /* we expect -B80/99 or -B80 */
4793                else {
4794                        opt++;
4795                        opt2 = parse_rename_score(&opt);
4796                }
4797        }
4798        if (*opt != 0)
4799                return -1;
4800        return opt1 | (opt2 << 16);
4801}
4802
4803struct diff_queue_struct diff_queued_diff;
4804
4805void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4806{
4807        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4808        queue->queue[queue->nr++] = dp;
4809}
4810
4811struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4812                                 struct diff_filespec *one,
4813                                 struct diff_filespec *two)
4814{
4815        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4816        dp->one = one;
4817        dp->two = two;
4818        if (queue)
4819                diff_q(queue, dp);
4820        return dp;
4821}
4822
4823void diff_free_filepair(struct diff_filepair *p)
4824{
4825        free_filespec(p->one);
4826        free_filespec(p->two);
4827        free(p);
4828}
4829
4830const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4831{
4832        int abblen;
4833        const char *abbrev;
4834
4835        if (len == GIT_SHA1_HEXSZ)
4836                return oid_to_hex(oid);
4837
4838        abbrev = diff_abbrev_oid(oid, len);
4839        abblen = strlen(abbrev);
4840
4841        /*
4842         * In well-behaved cases, where the abbbreviated result is the
4843         * same as the requested length, append three dots after the
4844         * abbreviation (hence the whole logic is limited to the case
4845         * where abblen < 37); when the actual abbreviated result is a
4846         * bit longer than the requested length, we reduce the number
4847         * of dots so that they match the well-behaved ones.  However,
4848         * if the actual abbreviation is longer than the requested
4849         * length by more than three, we give up on aligning, and add
4850         * three dots anyway, to indicate that the output is not the
4851         * full object name.  Yes, this may be suboptimal, but this
4852         * appears only in "diff --raw --abbrev" output and it is not
4853         * worth the effort to change it now.  Note that this would
4854         * likely to work fine when the automatic sizing of default
4855         * abbreviation length is used--we would be fed -1 in "len" in
4856         * that case, and will end up always appending three-dots, but
4857         * the automatic sizing is supposed to give abblen that ensures
4858         * uniqueness across all objects (statistically speaking).
4859         */
4860        if (abblen < GIT_SHA1_HEXSZ - 3) {
4861                static char hex[GIT_MAX_HEXSZ + 1];
4862                if (len < abblen && abblen <= len + 2)
4863                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4864                else
4865                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4866                return hex;
4867        }
4868
4869        return oid_to_hex(oid);
4870}
4871
4872static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4873{
4874        int line_termination = opt->line_termination;
4875        int inter_name_termination = line_termination ? '\t' : '\0';
4876
4877        fprintf(opt->file, "%s", diff_line_prefix(opt));
4878        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4879                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4880                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4881                fprintf(opt->file, "%s ",
4882                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4883        }
4884        if (p->score) {
4885                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4886                        inter_name_termination);
4887        } else {
4888                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4889        }
4890
4891        if (p->status == DIFF_STATUS_COPIED ||
4892            p->status == DIFF_STATUS_RENAMED) {
4893                const char *name_a, *name_b;
4894                name_a = p->one->path;
4895                name_b = p->two->path;
4896                strip_prefix(opt->prefix_length, &name_a, &name_b);
4897                write_name_quoted(name_a, opt->file, inter_name_termination);
4898                write_name_quoted(name_b, opt->file, line_termination);
4899        } else {
4900                const char *name_a, *name_b;
4901                name_a = p->one->mode ? p->one->path : p->two->path;
4902                name_b = NULL;
4903                strip_prefix(opt->prefix_length, &name_a, &name_b);
4904                write_name_quoted(name_a, opt->file, line_termination);
4905        }
4906}
4907
4908int diff_unmodified_pair(struct diff_filepair *p)
4909{
4910        /* This function is written stricter than necessary to support
4911         * the currently implemented transformers, but the idea is to
4912         * let transformers to produce diff_filepairs any way they want,
4913         * and filter and clean them up here before producing the output.
4914         */
4915        struct diff_filespec *one = p->one, *two = p->two;
4916
4917        if (DIFF_PAIR_UNMERGED(p))
4918                return 0; /* unmerged is interesting */
4919
4920        /* deletion, addition, mode or type change
4921         * and rename are all interesting.
4922         */
4923        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4924            DIFF_PAIR_MODE_CHANGED(p) ||
4925            strcmp(one->path, two->path))
4926                return 0;
4927
4928        /* both are valid and point at the same path.  that is, we are
4929         * dealing with a change.
4930         */
4931        if (one->oid_valid && two->oid_valid &&
4932            !oidcmp(&one->oid, &two->oid) &&
4933            !one->dirty_submodule && !two->dirty_submodule)
4934                return 1; /* no change */
4935        if (!one->oid_valid && !two->oid_valid)
4936                return 1; /* both look at the same file on the filesystem. */
4937        return 0;
4938}
4939
4940static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4941{
4942        if (diff_unmodified_pair(p))
4943                return;
4944
4945        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4946            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4947                return; /* no tree diffs in patch format */
4948
4949        run_diff(p, o);
4950}
4951
4952static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4953                            struct diffstat_t *diffstat)
4954{
4955        if (diff_unmodified_pair(p))
4956                return;
4957
4958        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4959            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4960                return; /* no useful stat for tree diffs */
4961
4962        run_diffstat(p, o, diffstat);
4963}
4964
4965static void diff_flush_checkdiff(struct diff_filepair *p,
4966                struct diff_options *o)
4967{
4968        if (diff_unmodified_pair(p))
4969                return;
4970
4971        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4972            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4973                return; /* nothing to check in tree diffs */
4974
4975        run_checkdiff(p, o);
4976}
4977
4978int diff_queue_is_empty(void)
4979{
4980        struct diff_queue_struct *q = &diff_queued_diff;
4981        int i;
4982        for (i = 0; i < q->nr; i++)
4983                if (!diff_unmodified_pair(q->queue[i]))
4984                        return 0;
4985        return 1;
4986}
4987
4988#if DIFF_DEBUG
4989void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4990{
4991        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4992                x, one ? one : "",
4993                s->path,
4994                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4995                s->mode,
4996                s->oid_valid ? oid_to_hex(&s->oid) : "");
4997        fprintf(stderr, "queue[%d] %s size %lu\n",
4998                x, one ? one : "",
4999                s->size);
5000}
5001
5002void diff_debug_filepair(const struct diff_filepair *p, int i)
5003{
5004        diff_debug_filespec(p->one, i, "one");
5005        diff_debug_filespec(p->two, i, "two");
5006        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5007                p->score, p->status ? p->status : '?',
5008                p->one->rename_used, p->broken_pair);
5009}
5010
5011void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5012{
5013        int i;
5014        if (msg)
5015                fprintf(stderr, "%s\n", msg);
5016        fprintf(stderr, "q->nr = %d\n", q->nr);
5017        for (i = 0; i < q->nr; i++) {
5018                struct diff_filepair *p = q->queue[i];
5019                diff_debug_filepair(p, i);
5020        }
5021}
5022#endif
5023
5024static void diff_resolve_rename_copy(void)
5025{
5026        int i;
5027        struct diff_filepair *p;
5028        struct diff_queue_struct *q = &diff_queued_diff;
5029
5030        diff_debug_queue("resolve-rename-copy", q);
5031
5032        for (i = 0; i < q->nr; i++) {
5033                p = q->queue[i];
5034                p->status = 0; /* undecided */
5035                if (DIFF_PAIR_UNMERGED(p))
5036                        p->status = DIFF_STATUS_UNMERGED;
5037                else if (!DIFF_FILE_VALID(p->one))
5038                        p->status = DIFF_STATUS_ADDED;
5039                else if (!DIFF_FILE_VALID(p->two))
5040                        p->status = DIFF_STATUS_DELETED;
5041                else if (DIFF_PAIR_TYPE_CHANGED(p))
5042                        p->status = DIFF_STATUS_TYPE_CHANGED;
5043
5044                /* from this point on, we are dealing with a pair
5045                 * whose both sides are valid and of the same type, i.e.
5046                 * either in-place edit or rename/copy edit.
5047                 */
5048                else if (DIFF_PAIR_RENAME(p)) {
5049                        /*
5050                         * A rename might have re-connected a broken
5051                         * pair up, causing the pathnames to be the
5052                         * same again. If so, that's not a rename at
5053                         * all, just a modification..
5054                         *
5055                         * Otherwise, see if this source was used for
5056                         * multiple renames, in which case we decrement
5057                         * the count, and call it a copy.
5058                         */
5059                        if (!strcmp(p->one->path, p->two->path))
5060                                p->status = DIFF_STATUS_MODIFIED;
5061                        else if (--p->one->rename_used > 0)
5062                                p->status = DIFF_STATUS_COPIED;
5063                        else
5064                                p->status = DIFF_STATUS_RENAMED;
5065                }
5066                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5067                         p->one->mode != p->two->mode ||
5068                         p->one->dirty_submodule ||
5069                         p->two->dirty_submodule ||
5070                         is_null_oid(&p->one->oid))
5071                        p->status = DIFF_STATUS_MODIFIED;
5072                else {
5073                        /* This is a "no-change" entry and should not
5074                         * happen anymore, but prepare for broken callers.
5075                         */
5076                        error("feeding unmodified %s to diffcore",
5077                              p->one->path);
5078                        p->status = DIFF_STATUS_UNKNOWN;
5079                }
5080        }
5081        diff_debug_queue("resolve-rename-copy done", q);
5082}
5083
5084static int check_pair_status(struct diff_filepair *p)
5085{
5086        switch (p->status) {
5087        case DIFF_STATUS_UNKNOWN:
5088                return 0;
5089        case 0:
5090                die("internal error in diff-resolve-rename-copy");
5091        default:
5092                return 1;
5093        }
5094}
5095
5096static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5097{
5098        int fmt = opt->output_format;
5099
5100        if (fmt & DIFF_FORMAT_CHECKDIFF)
5101                diff_flush_checkdiff(p, opt);
5102        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5103                diff_flush_raw(p, opt);
5104        else if (fmt & DIFF_FORMAT_NAME) {
5105                const char *name_a, *name_b;
5106                name_a = p->two->path;
5107                name_b = NULL;
5108                strip_prefix(opt->prefix_length, &name_a, &name_b);
5109                fprintf(opt->file, "%s", diff_line_prefix(opt));
5110                write_name_quoted(name_a, opt->file, opt->line_termination);
5111        }
5112}
5113
5114static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5115{
5116        struct strbuf sb = STRBUF_INIT;
5117        if (fs->mode)
5118                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5119        else
5120                strbuf_addf(&sb, " %s ", newdelete);
5121
5122        quote_c_style(fs->path, &sb, NULL, 0);
5123        strbuf_addch(&sb, '\n');
5124        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5125                         sb.buf, sb.len, 0);
5126        strbuf_release(&sb);
5127}
5128
5129static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5130                int show_name)
5131{
5132        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5133                struct strbuf sb = STRBUF_INIT;
5134                strbuf_addf(&sb, " mode change %06o => %06o",
5135                            p->one->mode, p->two->mode);
5136                if (show_name) {
5137                        strbuf_addch(&sb, ' ');
5138                        quote_c_style(p->two->path, &sb, NULL, 0);
5139                }
5140                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5141                                 sb.buf, sb.len, 0);
5142                strbuf_release(&sb);
5143        }
5144}
5145
5146static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5147                struct diff_filepair *p)
5148{
5149        struct strbuf sb = STRBUF_INIT;
5150        char *names = pprint_rename(p->one->path, p->two->path);
5151        strbuf_addf(&sb, " %s %s (%d%%)\n",
5152                        renamecopy, names, similarity_index(p));
5153        free(names);
5154        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5155                                 sb.buf, sb.len, 0);
5156        show_mode_change(opt, p, 0);
5157}
5158
5159static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5160{
5161        switch(p->status) {
5162        case DIFF_STATUS_DELETED:
5163                show_file_mode_name(opt, "delete", p->one);
5164                break;
5165        case DIFF_STATUS_ADDED:
5166                show_file_mode_name(opt, "create", p->two);
5167                break;
5168        case DIFF_STATUS_COPIED:
5169                show_rename_copy(opt, "copy", p);
5170                break;
5171        case DIFF_STATUS_RENAMED:
5172                show_rename_copy(opt, "rename", p);
5173                break;
5174        default:
5175                if (p->score) {
5176                        struct strbuf sb = STRBUF_INIT;
5177                        strbuf_addstr(&sb, " rewrite ");
5178                        quote_c_style(p->two->path, &sb, NULL, 0);
5179                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5180                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5181                                         sb.buf, sb.len, 0);
5182                }
5183                show_mode_change(opt, p, !p->score);
5184                break;
5185        }
5186}
5187
5188struct patch_id_t {
5189        git_SHA_CTX *ctx;
5190        int patchlen;
5191};
5192
5193static int remove_space(char *line, int len)
5194{
5195        int i;
5196        char *dst = line;
5197        unsigned char c;
5198
5199        for (i = 0; i < len; i++)
5200                if (!isspace((c = line[i])))
5201                        *dst++ = c;
5202
5203        return dst - line;
5204}
5205
5206static void patch_id_consume(void *priv, char *line, unsigned long len)
5207{
5208        struct patch_id_t *data = priv;
5209        int new_len;
5210
5211        /* Ignore line numbers when computing the SHA1 of the patch */
5212        if (starts_with(line, "@@ -"))
5213                return;
5214
5215        new_len = remove_space(line, len);
5216
5217        git_SHA1_Update(data->ctx, line, new_len);
5218        data->patchlen += new_len;
5219}
5220
5221static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5222{
5223        git_SHA1_Update(ctx, str, strlen(str));
5224}
5225
5226static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5227{
5228        /* large enough for 2^32 in octal */
5229        char buf[12];
5230        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5231        git_SHA1_Update(ctx, buf, len);
5232}
5233
5234/* returns 0 upon success, and writes result into sha1 */
5235static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5236{
5237        struct diff_queue_struct *q = &diff_queued_diff;
5238        int i;
5239        git_SHA_CTX ctx;
5240        struct patch_id_t data;
5241
5242        git_SHA1_Init(&ctx);
5243        memset(&data, 0, sizeof(struct patch_id_t));
5244        data.ctx = &ctx;
5245
5246        for (i = 0; i < q->nr; i++) {
5247                xpparam_t xpp;
5248                xdemitconf_t xecfg;
5249                mmfile_t mf1, mf2;
5250                struct diff_filepair *p = q->queue[i];
5251                int len1, len2;
5252
5253                memset(&xpp, 0, sizeof(xpp));
5254                memset(&xecfg, 0, sizeof(xecfg));
5255                if (p->status == 0)
5256                        return error("internal diff status error");
5257                if (p->status == DIFF_STATUS_UNKNOWN)
5258                        continue;
5259                if (diff_unmodified_pair(p))
5260                        continue;
5261                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5262                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5263                        continue;
5264                if (DIFF_PAIR_UNMERGED(p))
5265                        continue;
5266
5267                diff_fill_oid_info(p->one);
5268                diff_fill_oid_info(p->two);
5269
5270                len1 = remove_space(p->one->path, strlen(p->one->path));
5271                len2 = remove_space(p->two->path, strlen(p->two->path));
5272                patch_id_add_string(&ctx, "diff--git");
5273                patch_id_add_string(&ctx, "a/");
5274                git_SHA1_Update(&ctx, p->one->path, len1);
5275                patch_id_add_string(&ctx, "b/");
5276                git_SHA1_Update(&ctx, p->two->path, len2);
5277
5278                if (p->one->mode == 0) {
5279                        patch_id_add_string(&ctx, "newfilemode");
5280                        patch_id_add_mode(&ctx, p->two->mode);
5281                        patch_id_add_string(&ctx, "---/dev/null");
5282                        patch_id_add_string(&ctx, "+++b/");
5283                        git_SHA1_Update(&ctx, p->two->path, len2);
5284                } else if (p->two->mode == 0) {
5285                        patch_id_add_string(&ctx, "deletedfilemode");
5286                        patch_id_add_mode(&ctx, p->one->mode);
5287                        patch_id_add_string(&ctx, "---a/");
5288                        git_SHA1_Update(&ctx, p->one->path, len1);
5289                        patch_id_add_string(&ctx, "+++/dev/null");
5290                } else {
5291                        patch_id_add_string(&ctx, "---a/");
5292                        git_SHA1_Update(&ctx, p->one->path, len1);
5293                        patch_id_add_string(&ctx, "+++b/");
5294                        git_SHA1_Update(&ctx, p->two->path, len2);
5295                }
5296
5297                if (diff_header_only)
5298                        continue;
5299
5300                if (fill_mmfile(&mf1, p->one) < 0 ||
5301                    fill_mmfile(&mf2, p->two) < 0)
5302                        return error("unable to read files to diff");
5303
5304                if (diff_filespec_is_binary(p->one) ||
5305                    diff_filespec_is_binary(p->two)) {
5306                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5307                                        GIT_SHA1_HEXSZ);
5308                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5309                                        GIT_SHA1_HEXSZ);
5310                        continue;
5311                }
5312
5313                xpp.flags = 0;
5314                xecfg.ctxlen = 3;
5315                xecfg.flags = 0;
5316                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5317                                  &xpp, &xecfg))
5318                        return error("unable to generate patch-id diff for %s",
5319                                     p->one->path);
5320        }
5321
5322        git_SHA1_Final(oid->hash, &ctx);
5323        return 0;
5324}
5325
5326int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5327{
5328        struct diff_queue_struct *q = &diff_queued_diff;
5329        int i;
5330        int result = diff_get_patch_id(options, oid, diff_header_only);
5331
5332        for (i = 0; i < q->nr; i++)
5333                diff_free_filepair(q->queue[i]);
5334
5335        free(q->queue);
5336        DIFF_QUEUE_CLEAR(q);
5337
5338        return result;
5339}
5340
5341static int is_summary_empty(const struct diff_queue_struct *q)
5342{
5343        int i;
5344
5345        for (i = 0; i < q->nr; i++) {
5346                const struct diff_filepair *p = q->queue[i];
5347
5348                switch (p->status) {
5349                case DIFF_STATUS_DELETED:
5350                case DIFF_STATUS_ADDED:
5351                case DIFF_STATUS_COPIED:
5352                case DIFF_STATUS_RENAMED:
5353                        return 0;
5354                default:
5355                        if (p->score)
5356                                return 0;
5357                        if (p->one->mode && p->two->mode &&
5358                            p->one->mode != p->two->mode)
5359                                return 0;
5360                        break;
5361                }
5362        }
5363        return 1;
5364}
5365
5366static const char rename_limit_warning[] =
5367N_("inexact rename detection was skipped due to too many files.");
5368
5369static const char degrade_cc_to_c_warning[] =
5370N_("only found copies from modified paths due to too many files.");
5371
5372static const char rename_limit_advice[] =
5373N_("you may want to set your %s variable to at least "
5374   "%d and retry the command.");
5375
5376void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5377{
5378        if (degraded_cc)
5379                warning(_(degrade_cc_to_c_warning));
5380        else if (needed)
5381                warning(_(rename_limit_warning));
5382        else
5383                return;
5384        if (0 < needed && needed < 32767)
5385                warning(_(rename_limit_advice), varname, needed);
5386}
5387
5388static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5389{
5390        int i;
5391        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5392        struct diff_queue_struct *q = &diff_queued_diff;
5393
5394        if (WSEH_NEW & WS_RULE_MASK)
5395                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5396
5397        if (o->color_moved)
5398                o->emitted_symbols = &esm;
5399
5400        for (i = 0; i < q->nr; i++) {
5401                struct diff_filepair *p = q->queue[i];
5402                if (check_pair_status(p))
5403                        diff_flush_patch(p, o);
5404        }
5405
5406        if (o->emitted_symbols) {
5407                if (o->color_moved) {
5408                        struct hashmap add_lines, del_lines;
5409
5410                        hashmap_init(&del_lines,
5411                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5412                        hashmap_init(&add_lines,
5413                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5414
5415                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5416                        mark_color_as_moved(o, &add_lines, &del_lines);
5417
5418                        hashmap_free(&add_lines, 0);
5419                        hashmap_free(&del_lines, 0);
5420                }
5421
5422                for (i = 0; i < esm.nr; i++)
5423                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5424
5425                for (i = 0; i < esm.nr; i++)
5426                        free((void *)esm.buf[i].line);
5427        }
5428        esm.nr = 0;
5429}
5430
5431void diff_flush(struct diff_options *options)
5432{
5433        struct diff_queue_struct *q = &diff_queued_diff;
5434        int i, output_format = options->output_format;
5435        int separator = 0;
5436        int dirstat_by_line = 0;
5437
5438        /*
5439         * Order: raw, stat, summary, patch
5440         * or:    name/name-status/checkdiff (other bits clear)
5441         */
5442        if (!q->nr)
5443                goto free_queue;
5444
5445        if (output_format & (DIFF_FORMAT_RAW |
5446                             DIFF_FORMAT_NAME |
5447                             DIFF_FORMAT_NAME_STATUS |
5448                             DIFF_FORMAT_CHECKDIFF)) {
5449                for (i = 0; i < q->nr; i++) {
5450                        struct diff_filepair *p = q->queue[i];
5451                        if (check_pair_status(p))
5452                                flush_one_pair(p, options);
5453                }
5454                separator++;
5455        }
5456
5457        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
5458                dirstat_by_line = 1;
5459
5460        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5461            dirstat_by_line) {
5462                struct diffstat_t diffstat;
5463
5464                memset(&diffstat, 0, sizeof(struct diffstat_t));
5465                for (i = 0; i < q->nr; i++) {
5466                        struct diff_filepair *p = q->queue[i];
5467                        if (check_pair_status(p))
5468                                diff_flush_stat(p, options, &diffstat);
5469                }
5470                if (output_format & DIFF_FORMAT_NUMSTAT)
5471                        show_numstat(&diffstat, options);
5472                if (output_format & DIFF_FORMAT_DIFFSTAT)
5473                        show_stats(&diffstat, options);
5474                if (output_format & DIFF_FORMAT_SHORTSTAT)
5475                        show_shortstats(&diffstat, options);
5476                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5477                        show_dirstat_by_line(&diffstat, options);
5478                free_diffstat_info(&diffstat);
5479                separator++;
5480        }
5481        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5482                show_dirstat(options);
5483
5484        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5485                for (i = 0; i < q->nr; i++) {
5486                        diff_summary(options, q->queue[i]);
5487                }
5488                separator++;
5489        }
5490
5491        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5492            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5493            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5494                /*
5495                 * run diff_flush_patch for the exit status. setting
5496                 * options->file to /dev/null should be safe, because we
5497                 * aren't supposed to produce any output anyway.
5498                 */
5499                if (options->close_file)
5500                        fclose(options->file);
5501                options->file = xfopen("/dev/null", "w");
5502                options->close_file = 1;
5503                options->color_moved = 0;
5504                for (i = 0; i < q->nr; i++) {
5505                        struct diff_filepair *p = q->queue[i];
5506                        if (check_pair_status(p))
5507                                diff_flush_patch(p, options);
5508                        if (options->found_changes)
5509                                break;
5510                }
5511        }
5512
5513        if (output_format & DIFF_FORMAT_PATCH) {
5514                if (separator) {
5515                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5516                        if (options->stat_sep)
5517                                /* attach patch instead of inline */
5518                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5519                                                 NULL, 0, 0);
5520                }
5521
5522                diff_flush_patch_all_file_pairs(options);
5523        }
5524
5525        if (output_format & DIFF_FORMAT_CALLBACK)
5526                options->format_callback(q, options, options->format_callback_data);
5527
5528        for (i = 0; i < q->nr; i++)
5529                diff_free_filepair(q->queue[i]);
5530free_queue:
5531        free(q->queue);
5532        DIFF_QUEUE_CLEAR(q);
5533        if (options->close_file)
5534                fclose(options->file);
5535
5536        /*
5537         * Report the content-level differences with HAS_CHANGES;
5538         * diff_addremove/diff_change does not set the bit when
5539         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5540         */
5541        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5542                if (options->found_changes)
5543                        DIFF_OPT_SET(options, HAS_CHANGES);
5544                else
5545                        DIFF_OPT_CLR(options, HAS_CHANGES);
5546        }
5547}
5548
5549static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5550{
5551        return (((p->status == DIFF_STATUS_MODIFIED) &&
5552                 ((p->score &&
5553                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5554                  (!p->score &&
5555                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5556                ((p->status != DIFF_STATUS_MODIFIED) &&
5557                 filter_bit_tst(p->status, options)));
5558}
5559
5560static void diffcore_apply_filter(struct diff_options *options)
5561{
5562        int i;
5563        struct diff_queue_struct *q = &diff_queued_diff;
5564        struct diff_queue_struct outq;
5565
5566        DIFF_QUEUE_CLEAR(&outq);
5567
5568        if (!options->filter)
5569                return;
5570
5571        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5572                int found;
5573                for (i = found = 0; !found && i < q->nr; i++) {
5574                        if (match_filter(options, q->queue[i]))
5575                                found++;
5576                }
5577                if (found)
5578                        return;
5579
5580                /* otherwise we will clear the whole queue
5581                 * by copying the empty outq at the end of this
5582                 * function, but first clear the current entries
5583                 * in the queue.
5584                 */
5585                for (i = 0; i < q->nr; i++)
5586                        diff_free_filepair(q->queue[i]);
5587        }
5588        else {
5589                /* Only the matching ones */
5590                for (i = 0; i < q->nr; i++) {
5591                        struct diff_filepair *p = q->queue[i];
5592                        if (match_filter(options, p))
5593                                diff_q(&outq, p);
5594                        else
5595                                diff_free_filepair(p);
5596                }
5597        }
5598        free(q->queue);
5599        *q = outq;
5600}
5601
5602/* Check whether two filespecs with the same mode and size are identical */
5603static int diff_filespec_is_identical(struct diff_filespec *one,
5604                                      struct diff_filespec *two)
5605{
5606        if (S_ISGITLINK(one->mode))
5607                return 0;
5608        if (diff_populate_filespec(one, 0))
5609                return 0;
5610        if (diff_populate_filespec(two, 0))
5611                return 0;
5612        return !memcmp(one->data, two->data, one->size);
5613}
5614
5615static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5616{
5617        if (p->done_skip_stat_unmatch)
5618                return p->skip_stat_unmatch_result;
5619
5620        p->done_skip_stat_unmatch = 1;
5621        p->skip_stat_unmatch_result = 0;
5622        /*
5623         * 1. Entries that come from stat info dirtiness
5624         *    always have both sides (iow, not create/delete),
5625         *    one side of the object name is unknown, with
5626         *    the same mode and size.  Keep the ones that
5627         *    do not match these criteria.  They have real
5628         *    differences.
5629         *
5630         * 2. At this point, the file is known to be modified,
5631         *    with the same mode and size, and the object
5632         *    name of one side is unknown.  Need to inspect
5633         *    the identical contents.
5634         */
5635        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5636            !DIFF_FILE_VALID(p->two) ||
5637            (p->one->oid_valid && p->two->oid_valid) ||
5638            (p->one->mode != p->two->mode) ||
5639            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5640            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5641            (p->one->size != p->two->size) ||
5642            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5643                p->skip_stat_unmatch_result = 1;
5644        return p->skip_stat_unmatch_result;
5645}
5646
5647static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5648{
5649        int i;
5650        struct diff_queue_struct *q = &diff_queued_diff;
5651        struct diff_queue_struct outq;
5652        DIFF_QUEUE_CLEAR(&outq);
5653
5654        for (i = 0; i < q->nr; i++) {
5655                struct diff_filepair *p = q->queue[i];
5656
5657                if (diff_filespec_check_stat_unmatch(p))
5658                        diff_q(&outq, p);
5659                else {
5660                        /*
5661                         * The caller can subtract 1 from skip_stat_unmatch
5662                         * to determine how many paths were dirty only
5663                         * due to stat info mismatch.
5664                         */
5665                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5666                                diffopt->skip_stat_unmatch++;
5667                        diff_free_filepair(p);
5668                }
5669        }
5670        free(q->queue);
5671        *q = outq;
5672}
5673
5674static int diffnamecmp(const void *a_, const void *b_)
5675{
5676        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5677        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5678        const char *name_a, *name_b;
5679
5680        name_a = a->one ? a->one->path : a->two->path;
5681        name_b = b->one ? b->one->path : b->two->path;
5682        return strcmp(name_a, name_b);
5683}
5684
5685void diffcore_fix_diff_index(struct diff_options *options)
5686{
5687        struct diff_queue_struct *q = &diff_queued_diff;
5688        QSORT(q->queue, q->nr, diffnamecmp);
5689}
5690
5691void diffcore_std(struct diff_options *options)
5692{
5693        /* NOTE please keep the following in sync with diff_tree_combined() */
5694        if (options->skip_stat_unmatch)
5695                diffcore_skip_stat_unmatch(options);
5696        if (!options->found_follow) {
5697                /* See try_to_follow_renames() in tree-diff.c */
5698                if (options->break_opt != -1)
5699                        diffcore_break(options->break_opt);
5700                if (options->detect_rename)
5701                        diffcore_rename(options);
5702                if (options->break_opt != -1)
5703                        diffcore_merge_broken();
5704        }
5705        if (options->pickaxe)
5706                diffcore_pickaxe(options);
5707        if (options->orderfile)
5708                diffcore_order(options->orderfile);
5709        if (!options->found_follow)
5710                /* See try_to_follow_renames() in tree-diff.c */
5711                diff_resolve_rename_copy();
5712        diffcore_apply_filter(options);
5713
5714        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5715                DIFF_OPT_SET(options, HAS_CHANGES);
5716        else
5717                DIFF_OPT_CLR(options, HAS_CHANGES);
5718
5719        options->found_follow = 0;
5720}
5721
5722int diff_result_code(struct diff_options *opt, int status)
5723{
5724        int result = 0;
5725
5726        diff_warn_rename_limit("diff.renameLimit",
5727                               opt->needed_rename_limit,
5728                               opt->degraded_cc_to_c);
5729        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5730            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5731                return status;
5732        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5733            DIFF_OPT_TST(opt, HAS_CHANGES))
5734                result |= 01;
5735        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5736            DIFF_OPT_TST(opt, CHECK_FAILED))
5737                result |= 02;
5738        return result;
5739}
5740
5741int diff_can_quit_early(struct diff_options *opt)
5742{
5743        return (DIFF_OPT_TST(opt, QUICK) &&
5744                !opt->filter &&
5745                DIFF_OPT_TST(opt, HAS_CHANGES));
5746}
5747
5748/*
5749 * Shall changes to this submodule be ignored?
5750 *
5751 * Submodule changes can be configured to be ignored separately for each path,
5752 * but that configuration can be overridden from the command line.
5753 */
5754static int is_submodule_ignored(const char *path, struct diff_options *options)
5755{
5756        int ignored = 0;
5757        unsigned orig_flags = options->flags;
5758        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5759                set_diffopt_flags_from_submodule_config(options, path);
5760        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5761                ignored = 1;
5762        options->flags = orig_flags;
5763        return ignored;
5764}
5765
5766void diff_addremove(struct diff_options *options,
5767                    int addremove, unsigned mode,
5768                    const struct object_id *oid,
5769                    int oid_valid,
5770                    const char *concatpath, unsigned dirty_submodule)
5771{
5772        struct diff_filespec *one, *two;
5773
5774        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5775                return;
5776
5777        /* This may look odd, but it is a preparation for
5778         * feeding "there are unchanged files which should
5779         * not produce diffs, but when you are doing copy
5780         * detection you would need them, so here they are"
5781         * entries to the diff-core.  They will be prefixed
5782         * with something like '=' or '*' (I haven't decided
5783         * which but should not make any difference).
5784         * Feeding the same new and old to diff_change()
5785         * also has the same effect.
5786         * Before the final output happens, they are pruned after
5787         * merged into rename/copy pairs as appropriate.
5788         */
5789        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5790                addremove = (addremove == '+' ? '-' :
5791                             addremove == '-' ? '+' : addremove);
5792
5793        if (options->prefix &&
5794            strncmp(concatpath, options->prefix, options->prefix_length))
5795                return;
5796
5797        one = alloc_filespec(concatpath);
5798        two = alloc_filespec(concatpath);
5799
5800        if (addremove != '+')
5801                fill_filespec(one, oid, oid_valid, mode);
5802        if (addremove != '-') {
5803                fill_filespec(two, oid, oid_valid, mode);
5804                two->dirty_submodule = dirty_submodule;
5805        }
5806
5807        diff_queue(&diff_queued_diff, one, two);
5808        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5809                DIFF_OPT_SET(options, HAS_CHANGES);
5810}
5811
5812void diff_change(struct diff_options *options,
5813                 unsigned old_mode, unsigned new_mode,
5814                 const struct object_id *old_oid,
5815                 const struct object_id *new_oid,
5816                 int old_oid_valid, int new_oid_valid,
5817                 const char *concatpath,
5818                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5819{
5820        struct diff_filespec *one, *two;
5821        struct diff_filepair *p;
5822
5823        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5824            is_submodule_ignored(concatpath, options))
5825                return;
5826
5827        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5828                SWAP(old_mode, new_mode);
5829                SWAP(old_oid, new_oid);
5830                SWAP(old_oid_valid, new_oid_valid);
5831                SWAP(old_dirty_submodule, new_dirty_submodule);
5832        }
5833
5834        if (options->prefix &&
5835            strncmp(concatpath, options->prefix, options->prefix_length))
5836                return;
5837
5838        one = alloc_filespec(concatpath);
5839        two = alloc_filespec(concatpath);
5840        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5841        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5842        one->dirty_submodule = old_dirty_submodule;
5843        two->dirty_submodule = new_dirty_submodule;
5844        p = diff_queue(&diff_queued_diff, one, two);
5845
5846        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5847                return;
5848
5849        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5850            !diff_filespec_check_stat_unmatch(p))
5851                return;
5852
5853        DIFF_OPT_SET(options, HAS_CHANGES);
5854}
5855
5856struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5857{
5858        struct diff_filepair *pair;
5859        struct diff_filespec *one, *two;
5860
5861        if (options->prefix &&
5862            strncmp(path, options->prefix, options->prefix_length))
5863                return NULL;
5864
5865        one = alloc_filespec(path);
5866        two = alloc_filespec(path);
5867        pair = diff_queue(&diff_queued_diff, one, two);
5868        pair->is_unmerged = 1;
5869        return pair;
5870}
5871
5872static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5873                size_t *outsize)
5874{
5875        struct diff_tempfile *temp;
5876        const char *argv[3];
5877        const char **arg = argv;
5878        struct child_process child = CHILD_PROCESS_INIT;
5879        struct strbuf buf = STRBUF_INIT;
5880        int err = 0;
5881
5882        temp = prepare_temp_file(spec->path, spec);
5883        *arg++ = pgm;
5884        *arg++ = temp->name;
5885        *arg = NULL;
5886
5887        child.use_shell = 1;
5888        child.argv = argv;
5889        child.out = -1;
5890        if (start_command(&child)) {
5891                remove_tempfile();
5892                return NULL;
5893        }
5894
5895        if (strbuf_read(&buf, child.out, 0) < 0)
5896                err = error("error reading from textconv command '%s'", pgm);
5897        close(child.out);
5898
5899        if (finish_command(&child) || err) {
5900                strbuf_release(&buf);
5901                remove_tempfile();
5902                return NULL;
5903        }
5904        remove_tempfile();
5905
5906        return strbuf_detach(&buf, outsize);
5907}
5908
5909size_t fill_textconv(struct userdiff_driver *driver,
5910                     struct diff_filespec *df,
5911                     char **outbuf)
5912{
5913        size_t size;
5914
5915        if (!driver) {
5916                if (!DIFF_FILE_VALID(df)) {
5917                        *outbuf = "";
5918                        return 0;
5919                }
5920                if (diff_populate_filespec(df, 0))
5921                        die("unable to read files to diff");
5922                *outbuf = df->data;
5923                return df->size;
5924        }
5925
5926        if (!driver->textconv)
5927                die("BUG: fill_textconv called with non-textconv driver");
5928
5929        if (driver->textconv_cache && df->oid_valid) {
5930                *outbuf = notes_cache_get(driver->textconv_cache,
5931                                          &df->oid,
5932                                          &size);
5933                if (*outbuf)
5934                        return size;
5935        }
5936
5937        *outbuf = run_textconv(driver->textconv, df, &size);
5938        if (!*outbuf)
5939                die("unable to read files to diff");
5940
5941        if (driver->textconv_cache && df->oid_valid) {
5942                /* ignore errors, as we might be in a readonly repository */
5943                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5944                                size);
5945                /*
5946                 * we could save up changes and flush them all at the end,
5947                 * but we would need an extra call after all diffing is done.
5948                 * Since generating a cache entry is the slow path anyway,
5949                 * this extra overhead probably isn't a big deal.
5950                 */
5951                notes_cache_write(driver->textconv_cache);
5952        }
5953
5954        return size;
5955}
5956
5957int textconv_object(const char *path,
5958                    unsigned mode,
5959                    const struct object_id *oid,
5960                    int oid_valid,
5961                    char **buf,
5962                    unsigned long *buf_size)
5963{
5964        struct diff_filespec *df;
5965        struct userdiff_driver *textconv;
5966
5967        df = alloc_filespec(path);
5968        fill_filespec(df, oid, oid_valid, mode);
5969        textconv = get_textconv(df);
5970        if (!textconv) {
5971                free_filespec(df);
5972                return 0;
5973        }
5974
5975        *buf_size = fill_textconv(textconv, df, buf);
5976        free_filespec(df);
5977        return 1;
5978}
5979
5980void setup_diff_pager(struct diff_options *opt)
5981{
5982        /*
5983         * If the user asked for our exit code, then either they want --quiet
5984         * or --exit-code. We should definitely not bother with a pager in the
5985         * former case, as we will generate no output. Since we still properly
5986         * report our exit code even when a pager is run, we _could_ run a
5987         * pager with --exit-code. But since we have not done so historically,
5988         * and because it is easy to find people oneline advising "git diff
5989         * --exit-code" in hooks and other scripts, we do not do so.
5990         */
5991        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5992            check_pager_config("diff") != 0)
5993                setup_pager();
5994}