79ea592388375d1e1167382e1d31246cfcd021fb
   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, "plain"))
 260                return COLOR_MOVED_PLAIN;
 261        else if (!strcmp(arg, "zebra"))
 262                return COLOR_MOVED_ZEBRA;
 263        else if (!strcmp(arg, "default"))
 264                return COLOR_MOVED_DEFAULT;
 265        else
 266                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'plain'"));
 267}
 268
 269int git_diff_ui_config(const char *var, const char *value, void *cb)
 270{
 271        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 272                diff_use_color_default = git_config_colorbool(var, value);
 273                return 0;
 274        }
 275        if (!strcmp(var, "diff.colormoved")) {
 276                int cm = parse_color_moved(value);
 277                if (cm < 0)
 278                        return -1;
 279                diff_color_moved_default = cm;
 280                return 0;
 281        }
 282        if (!strcmp(var, "diff.context")) {
 283                diff_context_default = git_config_int(var, value);
 284                if (diff_context_default < 0)
 285                        return -1;
 286                return 0;
 287        }
 288        if (!strcmp(var, "diff.interhunkcontext")) {
 289                diff_interhunk_context_default = git_config_int(var, value);
 290                if (diff_interhunk_context_default < 0)
 291                        return -1;
 292                return 0;
 293        }
 294        if (!strcmp(var, "diff.renames")) {
 295                diff_detect_rename_default = git_config_rename(var, value);
 296                return 0;
 297        }
 298        if (!strcmp(var, "diff.autorefreshindex")) {
 299                diff_auto_refresh_index = git_config_bool(var, value);
 300                return 0;
 301        }
 302        if (!strcmp(var, "diff.mnemonicprefix")) {
 303                diff_mnemonic_prefix = git_config_bool(var, value);
 304                return 0;
 305        }
 306        if (!strcmp(var, "diff.noprefix")) {
 307                diff_no_prefix = git_config_bool(var, value);
 308                return 0;
 309        }
 310        if (!strcmp(var, "diff.statgraphwidth")) {
 311                diff_stat_graph_width = git_config_int(var, value);
 312                return 0;
 313        }
 314        if (!strcmp(var, "diff.external"))
 315                return git_config_string(&external_diff_cmd_cfg, var, value);
 316        if (!strcmp(var, "diff.wordregex"))
 317                return git_config_string(&diff_word_regex_cfg, var, value);
 318        if (!strcmp(var, "diff.orderfile"))
 319                return git_config_pathname(&diff_order_file_cfg, var, value);
 320
 321        if (!strcmp(var, "diff.ignoresubmodules"))
 322                handle_ignore_submodules_arg(&default_diff_options, value);
 323
 324        if (!strcmp(var, "diff.submodule")) {
 325                if (parse_submodule_params(&default_diff_options, value))
 326                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 327                                value);
 328                return 0;
 329        }
 330
 331        if (!strcmp(var, "diff.algorithm")) {
 332                diff_algorithm = parse_algorithm_value(value);
 333                if (diff_algorithm < 0)
 334                        return -1;
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "diff.wserrorhighlight")) {
 339                int val = parse_ws_error_highlight(value);
 340                if (val < 0)
 341                        return -1;
 342                ws_error_highlight_default = val;
 343                return 0;
 344        }
 345
 346        if (git_color_config(var, value, cb) < 0)
 347                return -1;
 348
 349        return git_diff_basic_config(var, value, cb);
 350}
 351
 352int git_diff_basic_config(const char *var, const char *value, void *cb)
 353{
 354        const char *name;
 355
 356        if (!strcmp(var, "diff.renamelimit")) {
 357                diff_rename_limit_default = git_config_int(var, value);
 358                return 0;
 359        }
 360
 361        if (userdiff_config(var, value) < 0)
 362                return -1;
 363
 364        if (skip_prefix(var, "diff.color.", &name) ||
 365            skip_prefix(var, "color.diff.", &name)) {
 366                int slot = parse_diff_color_slot(name);
 367                if (slot < 0)
 368                        return 0;
 369                if (!value)
 370                        return config_error_nonbool(var);
 371                return color_parse(value, diff_colors[slot]);
 372        }
 373
 374        /* like GNU diff's --suppress-blank-empty option  */
 375        if (!strcmp(var, "diff.suppressblankempty") ||
 376                        /* for backwards compatibility */
 377                        !strcmp(var, "diff.suppress-blank-empty")) {
 378                diff_suppress_blank_empty = git_config_bool(var, value);
 379                return 0;
 380        }
 381
 382        if (!strcmp(var, "diff.dirstat")) {
 383                struct strbuf errmsg = STRBUF_INIT;
 384                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 385                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 386                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 387                                errmsg.buf);
 388                strbuf_release(&errmsg);
 389                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 390                return 0;
 391        }
 392
 393        if (starts_with(var, "submodule."))
 394                return parse_submodule_config_option(var, value);
 395
 396        if (git_diff_heuristic_config(var, value, cb) < 0)
 397                return -1;
 398
 399        return git_default_config(var, value, cb);
 400}
 401
 402static char *quote_two(const char *one, const char *two)
 403{
 404        int need_one = quote_c_style(one, NULL, NULL, 1);
 405        int need_two = quote_c_style(two, NULL, NULL, 1);
 406        struct strbuf res = STRBUF_INIT;
 407
 408        if (need_one + need_two) {
 409                strbuf_addch(&res, '"');
 410                quote_c_style(one, &res, NULL, 1);
 411                quote_c_style(two, &res, NULL, 1);
 412                strbuf_addch(&res, '"');
 413        } else {
 414                strbuf_addstr(&res, one);
 415                strbuf_addstr(&res, two);
 416        }
 417        return strbuf_detach(&res, NULL);
 418}
 419
 420static const char *external_diff(void)
 421{
 422        static const char *external_diff_cmd = NULL;
 423        static int done_preparing = 0;
 424
 425        if (done_preparing)
 426                return external_diff_cmd;
 427        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 428        if (!external_diff_cmd)
 429                external_diff_cmd = external_diff_cmd_cfg;
 430        done_preparing = 1;
 431        return external_diff_cmd;
 432}
 433
 434/*
 435 * Keep track of files used for diffing. Sometimes such an entry
 436 * refers to a temporary file, sometimes to an existing file, and
 437 * sometimes to "/dev/null".
 438 */
 439static struct diff_tempfile {
 440        /*
 441         * filename external diff should read from, or NULL if this
 442         * entry is currently not in use:
 443         */
 444        const char *name;
 445
 446        char hex[GIT_MAX_HEXSZ + 1];
 447        char mode[10];
 448
 449        /*
 450         * If this diff_tempfile instance refers to a temporary file,
 451         * this tempfile object is used to manage its lifetime.
 452         */
 453        struct tempfile tempfile;
 454} diff_temp[2];
 455
 456typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 457
 458struct emit_callback {
 459        int color_diff;
 460        unsigned ws_rule;
 461        int blank_at_eof_in_preimage;
 462        int blank_at_eof_in_postimage;
 463        int lno_in_preimage;
 464        int lno_in_postimage;
 465        sane_truncate_fn truncate;
 466        const char **label_path;
 467        struct diff_words_data *diff_words;
 468        struct diff_options *opt;
 469        struct strbuf *header;
 470};
 471
 472static int count_lines(const char *data, int size)
 473{
 474        int count, ch, completely_empty = 1, nl_just_seen = 0;
 475        count = 0;
 476        while (0 < size--) {
 477                ch = *data++;
 478                if (ch == '\n') {
 479                        count++;
 480                        nl_just_seen = 1;
 481                        completely_empty = 0;
 482                }
 483                else {
 484                        nl_just_seen = 0;
 485                        completely_empty = 0;
 486                }
 487        }
 488        if (completely_empty)
 489                return 0;
 490        if (!nl_just_seen)
 491                count++; /* no trailing newline */
 492        return count;
 493}
 494
 495static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 496{
 497        if (!DIFF_FILE_VALID(one)) {
 498                mf->ptr = (char *)""; /* does not matter */
 499                mf->size = 0;
 500                return 0;
 501        }
 502        else if (diff_populate_filespec(one, 0))
 503                return -1;
 504
 505        mf->ptr = one->data;
 506        mf->size = one->size;
 507        return 0;
 508}
 509
 510/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 511static unsigned long diff_filespec_size(struct diff_filespec *one)
 512{
 513        if (!DIFF_FILE_VALID(one))
 514                return 0;
 515        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 516        return one->size;
 517}
 518
 519static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 520{
 521        char *ptr = mf->ptr;
 522        long size = mf->size;
 523        int cnt = 0;
 524
 525        if (!size)
 526                return cnt;
 527        ptr += size - 1; /* pointing at the very end */
 528        if (*ptr != '\n')
 529                ; /* incomplete line */
 530        else
 531                ptr--; /* skip the last LF */
 532        while (mf->ptr < ptr) {
 533                char *prev_eol;
 534                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 535                        if (*prev_eol == '\n')
 536                                break;
 537                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 538                        break;
 539                cnt++;
 540                ptr = prev_eol - 1;
 541        }
 542        return cnt;
 543}
 544
 545static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 546                               struct emit_callback *ecbdata)
 547{
 548        int l1, l2, at;
 549        unsigned ws_rule = ecbdata->ws_rule;
 550        l1 = count_trailing_blank(mf1, ws_rule);
 551        l2 = count_trailing_blank(mf2, ws_rule);
 552        if (l2 <= l1) {
 553                ecbdata->blank_at_eof_in_preimage = 0;
 554                ecbdata->blank_at_eof_in_postimage = 0;
 555                return;
 556        }
 557        at = count_lines(mf1->ptr, mf1->size);
 558        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 559
 560        at = count_lines(mf2->ptr, mf2->size);
 561        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 562}
 563
 564static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 565                        int first, const char *line, int len)
 566{
 567        int has_trailing_newline, has_trailing_carriage_return;
 568        int nofirst;
 569        FILE *file = o->file;
 570
 571        fputs(diff_line_prefix(o), file);
 572
 573        if (len == 0) {
 574                has_trailing_newline = (first == '\n');
 575                has_trailing_carriage_return = (!has_trailing_newline &&
 576                                                (first == '\r'));
 577                nofirst = has_trailing_newline || has_trailing_carriage_return;
 578        } else {
 579                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 580                if (has_trailing_newline)
 581                        len--;
 582                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 583                if (has_trailing_carriage_return)
 584                        len--;
 585                nofirst = 0;
 586        }
 587
 588        if (len || !nofirst) {
 589                fputs(set, file);
 590                if (!nofirst)
 591                        fputc(first, file);
 592                fwrite(line, len, 1, file);
 593                fputs(reset, file);
 594        }
 595        if (has_trailing_carriage_return)
 596                fputc('\r', file);
 597        if (has_trailing_newline)
 598                fputc('\n', file);
 599}
 600
 601static void emit_line(struct diff_options *o, const char *set, const char *reset,
 602                      const char *line, int len)
 603{
 604        emit_line_0(o, set, reset, line[0], line+1, len-1);
 605}
 606
 607enum diff_symbol {
 608        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 609        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 610        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 611        DIFF_SYMBOL_BINARY_DIFF_BODY,
 612        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 613        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 614        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 615        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 616        DIFF_SYMBOL_STATS_LINE,
 617        DIFF_SYMBOL_WORD_DIFF,
 618        DIFF_SYMBOL_STAT_SEP,
 619        DIFF_SYMBOL_SUMMARY,
 620        DIFF_SYMBOL_SUBMODULE_ADD,
 621        DIFF_SYMBOL_SUBMODULE_DEL,
 622        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 623        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 624        DIFF_SYMBOL_SUBMODULE_HEADER,
 625        DIFF_SYMBOL_SUBMODULE_ERROR,
 626        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 627        DIFF_SYMBOL_REWRITE_DIFF,
 628        DIFF_SYMBOL_BINARY_FILES,
 629        DIFF_SYMBOL_HEADER,
 630        DIFF_SYMBOL_FILEPAIR_PLUS,
 631        DIFF_SYMBOL_FILEPAIR_MINUS,
 632        DIFF_SYMBOL_WORDS_PORCELAIN,
 633        DIFF_SYMBOL_WORDS,
 634        DIFF_SYMBOL_CONTEXT,
 635        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 636        DIFF_SYMBOL_PLUS,
 637        DIFF_SYMBOL_MINUS,
 638        DIFF_SYMBOL_NO_LF_EOF,
 639        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 640        DIFF_SYMBOL_CONTEXT_MARKER,
 641        DIFF_SYMBOL_SEPARATOR
 642};
 643/*
 644 * Flags for content lines:
 645 * 0..12 are whitespace rules
 646 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 647 * 16 is marking if the line is blank at EOF
 648 */
 649#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 650#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 651#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 652#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 653
 654/*
 655 * This struct is used when we need to buffer the output of the diff output.
 656 *
 657 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 658 * into the pre/post image file. This pointer could be a union with the
 659 * line pointer. By storing an offset into the file instead of the literal line,
 660 * we can decrease the memory footprint for the buffered output. At first we
 661 * may want to only have indirection for the content lines, but we could also
 662 * enhance the state for emitting prefabricated lines, e.g. the similarity
 663 * score line or hunk/file headers would only need to store a number or path
 664 * and then the output can be constructed later on depending on state.
 665 */
 666struct emitted_diff_symbol {
 667        const char *line;
 668        int len;
 669        int flags;
 670        enum diff_symbol s;
 671};
 672#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 673
 674struct emitted_diff_symbols {
 675        struct emitted_diff_symbol *buf;
 676        int nr, alloc;
 677};
 678#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 679
 680static void append_emitted_diff_symbol(struct diff_options *o,
 681                                       struct emitted_diff_symbol *e)
 682{
 683        struct emitted_diff_symbol *f;
 684
 685        ALLOC_GROW(o->emitted_symbols->buf,
 686                   o->emitted_symbols->nr + 1,
 687                   o->emitted_symbols->alloc);
 688        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 689
 690        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 691        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 692}
 693
 694struct moved_entry {
 695        struct hashmap_entry ent;
 696        const struct emitted_diff_symbol *es;
 697        struct moved_entry *next_line;
 698};
 699
 700static int next_byte(const char **cp, const char **endp,
 701                     const struct diff_options *diffopt)
 702{
 703        int retval;
 704
 705        if (*cp > *endp)
 706                return -1;
 707
 708        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_CHANGE)) {
 709                while (*cp < *endp && isspace(**cp))
 710                        (*cp)++;
 711                /*
 712                 * After skipping a couple of whitespaces, we still have to
 713                 * account for one space.
 714                 */
 715                return (int)' ';
 716        }
 717
 718        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE)) {
 719                while (*cp < *endp && isspace(**cp))
 720                        (*cp)++;
 721                /* return the first non-ws character via the usual below */
 722        }
 723
 724        retval = (unsigned char)(**cp);
 725        (*cp)++;
 726        return retval;
 727}
 728
 729static int moved_entry_cmp(const struct diff_options *diffopt,
 730                           const struct moved_entry *a,
 731                           const struct moved_entry *b,
 732                           const void *keydata)
 733{
 734        const char *ap = a->es->line, *ae = a->es->line + a->es->len;
 735        const char *bp = b->es->line, *be = b->es->line + b->es->len;
 736
 737        if (!(diffopt->xdl_opts & XDF_WHITESPACE_FLAGS))
 738                return a->es->len != b->es->len  || memcmp(ap, bp, a->es->len);
 739
 740        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_AT_EOL)) {
 741                while (ae > ap && isspace(*ae))
 742                        ae--;
 743                while (be > bp && isspace(*be))
 744                        be--;
 745        }
 746
 747        while (1) {
 748                int ca, cb;
 749                ca = next_byte(&ap, &ae, diffopt);
 750                cb = next_byte(&bp, &be, diffopt);
 751                if (ca != cb)
 752                        return 1;
 753                if (ca < 0)
 754                        return 0;
 755        }
 756}
 757
 758static unsigned get_string_hash(struct emitted_diff_symbol *es, struct diff_options *o)
 759{
 760        if (o->xdl_opts & XDF_WHITESPACE_FLAGS) {
 761                static struct strbuf sb = STRBUF_INIT;
 762                const char *ap = es->line, *ae = es->line + es->len;
 763                int c;
 764
 765                strbuf_reset(&sb);
 766                while (ae > ap && isspace(*ae))
 767                        ae--;
 768                while ((c = next_byte(&ap, &ae, o)) > 0)
 769                        strbuf_addch(&sb, c);
 770
 771                return memhash(sb.buf, sb.len);
 772        } else {
 773                return memhash(es->line, es->len);
 774        }
 775}
 776
 777static struct moved_entry *prepare_entry(struct diff_options *o,
 778                                         int line_no)
 779{
 780        struct moved_entry *ret = xmalloc(sizeof(*ret));
 781        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 782
 783        ret->ent.hash = get_string_hash(l, o);
 784        ret->es = l;
 785        ret->next_line = NULL;
 786
 787        return ret;
 788}
 789
 790static void add_lines_to_move_detection(struct diff_options *o,
 791                                        struct hashmap *add_lines,
 792                                        struct hashmap *del_lines)
 793{
 794        struct moved_entry *prev_line = NULL;
 795
 796        int n;
 797        for (n = 0; n < o->emitted_symbols->nr; n++) {
 798                struct hashmap *hm;
 799                struct moved_entry *key;
 800
 801                switch (o->emitted_symbols->buf[n].s) {
 802                case DIFF_SYMBOL_PLUS:
 803                        hm = add_lines;
 804                        break;
 805                case DIFF_SYMBOL_MINUS:
 806                        hm = del_lines;
 807                        break;
 808                default:
 809                        prev_line = NULL;
 810                        continue;
 811                }
 812
 813                key = prepare_entry(o, n);
 814                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 815                        prev_line->next_line = key;
 816
 817                hashmap_add(hm, key);
 818                prev_line = key;
 819        }
 820}
 821
 822static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 823                                         int pmb_nr)
 824{
 825        int lp, rp;
 826
 827        /* Shrink the set of potential block to the remaining running */
 828        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 829                while (lp < pmb_nr && pmb[lp])
 830                        lp++;
 831                /* lp points at the first NULL now */
 832
 833                while (rp > -1 && !pmb[rp])
 834                        rp--;
 835                /* rp points at the last non-NULL */
 836
 837                if (lp < pmb_nr && rp > -1 && lp < rp) {
 838                        pmb[lp] = pmb[rp];
 839                        pmb[rp] = NULL;
 840                        rp--;
 841                        lp++;
 842                }
 843        }
 844
 845        /* Remember the number of running sets */
 846        return rp + 1;
 847}
 848
 849/* Find blocks of moved code, delegate actual coloring decision to helper */
 850static void mark_color_as_moved(struct diff_options *o,
 851                                struct hashmap *add_lines,
 852                                struct hashmap *del_lines)
 853{
 854        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 855        int pmb_nr = 0, pmb_alloc = 0;
 856        int n, flipped_block = 1, block_length = 0;
 857
 858
 859        for (n = 0; n < o->emitted_symbols->nr; n++) {
 860                struct hashmap *hm = NULL;
 861                struct moved_entry *key;
 862                struct moved_entry *match = NULL;
 863                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 864                int i;
 865
 866                switch (l->s) {
 867                case DIFF_SYMBOL_PLUS:
 868                        hm = del_lines;
 869                        key = prepare_entry(o, n);
 870                        match = hashmap_get(hm, key, o);
 871                        free(key);
 872                        break;
 873                case DIFF_SYMBOL_MINUS:
 874                        hm = add_lines;
 875                        key = prepare_entry(o, n);
 876                        match = hashmap_get(hm, key, o);
 877                        free(key);
 878                        break;
 879                default:
 880                        flipped_block = 1;
 881                }
 882
 883                if (!match) {
 884                        if (block_length < COLOR_MOVED_MIN_BLOCK_LENGTH &&
 885                            o->color_moved != COLOR_MOVED_PLAIN) {
 886                                for (i = 0; i < block_length + 1; i++) {
 887                                        l = &o->emitted_symbols->buf[n - i];
 888                                        l->flags &= ~DIFF_SYMBOL_MOVED_LINE;
 889                                }
 890                        }
 891                        pmb_nr = 0;
 892                        block_length = 0;
 893                        continue;
 894                }
 895
 896                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 897                block_length++;
 898
 899                if (o->color_moved == COLOR_MOVED_PLAIN)
 900                        continue;
 901
 902                /* Check any potential block runs, advance each or nullify */
 903                for (i = 0; i < pmb_nr; i++) {
 904                        struct moved_entry *p = pmb[i];
 905                        struct moved_entry *pnext = (p && p->next_line) ?
 906                                        p->next_line : NULL;
 907                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 908                                pmb[i] = p->next_line;
 909                        } else {
 910                                pmb[i] = NULL;
 911                        }
 912                }
 913
 914                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 915
 916                if (pmb_nr == 0) {
 917                        /*
 918                         * The current line is the start of a new block.
 919                         * Setup the set of potential blocks.
 920                         */
 921                        for (; match; match = hashmap_get_next(hm, match)) {
 922                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 923                                pmb[pmb_nr++] = match;
 924                        }
 925
 926                        flipped_block = (flipped_block + 1) % 2;
 927                }
 928
 929                if (flipped_block)
 930                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 931        }
 932
 933        free(pmb);
 934}
 935
 936static void emit_line_ws_markup(struct diff_options *o,
 937                                const char *set, const char *reset,
 938                                const char *line, int len, char sign,
 939                                unsigned ws_rule, int blank_at_eof)
 940{
 941        const char *ws = NULL;
 942
 943        if (o->ws_error_highlight & ws_rule) {
 944                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 945                if (!*ws)
 946                        ws = NULL;
 947        }
 948
 949        if (!ws)
 950                emit_line_0(o, set, reset, sign, line, len);
 951        else if (blank_at_eof)
 952                /* Blank line at EOF - paint '+' as well */
 953                emit_line_0(o, ws, reset, sign, line, len);
 954        else {
 955                /* Emit just the prefix, then the rest. */
 956                emit_line_0(o, set, reset, sign, "", 0);
 957                ws_check_emit(line, len, ws_rule,
 958                              o->file, set, reset, ws);
 959        }
 960}
 961
 962static void emit_diff_symbol_from_struct(struct diff_options *o,
 963                                         struct emitted_diff_symbol *eds)
 964{
 965        static const char *nneof = " No newline at end of file\n";
 966        const char *context, *reset, *set, *meta, *fraginfo;
 967        struct strbuf sb = STRBUF_INIT;
 968
 969        enum diff_symbol s = eds->s;
 970        const char *line = eds->line;
 971        int len = eds->len;
 972        unsigned flags = eds->flags;
 973
 974        switch (s) {
 975        case DIFF_SYMBOL_NO_LF_EOF:
 976                context = diff_get_color_opt(o, DIFF_CONTEXT);
 977                reset = diff_get_color_opt(o, DIFF_RESET);
 978                putc('\n', o->file);
 979                emit_line_0(o, context, reset, '\\',
 980                            nneof, strlen(nneof));
 981                break;
 982        case DIFF_SYMBOL_SUBMODULE_HEADER:
 983        case DIFF_SYMBOL_SUBMODULE_ERROR:
 984        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
 985        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
 986        case DIFF_SYMBOL_SUMMARY:
 987        case DIFF_SYMBOL_STATS_LINE:
 988        case DIFF_SYMBOL_BINARY_DIFF_BODY:
 989        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 990                emit_line(o, "", "", line, len);
 991                break;
 992        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 993        case DIFF_SYMBOL_CONTEXT_MARKER:
 994                context = diff_get_color_opt(o, DIFF_CONTEXT);
 995                reset = diff_get_color_opt(o, DIFF_RESET);
 996                emit_line(o, context, reset, line, len);
 997                break;
 998        case DIFF_SYMBOL_SEPARATOR:
 999                fprintf(o->file, "%s%c",
1000                        diff_line_prefix(o),
1001                        o->line_termination);
1002                break;
1003        case DIFF_SYMBOL_CONTEXT:
1004                set = diff_get_color_opt(o, DIFF_CONTEXT);
1005                reset = diff_get_color_opt(o, DIFF_RESET);
1006                emit_line_ws_markup(o, set, reset, line, len, ' ',
1007                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1008                break;
1009        case DIFF_SYMBOL_PLUS:
1010                if (flags & DIFF_SYMBOL_MOVED_LINE_ALT)
1011                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1012                else if (flags & DIFF_SYMBOL_MOVED_LINE)
1013                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1014                else
1015                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1016                reset = diff_get_color_opt(o, DIFF_RESET);
1017                emit_line_ws_markup(o, set, reset, line, len, '+',
1018                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1019                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1020                break;
1021        case DIFF_SYMBOL_MINUS:
1022                if (flags & DIFF_SYMBOL_MOVED_LINE_ALT)
1023                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1024                else if (flags & DIFF_SYMBOL_MOVED_LINE)
1025                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1026                else
1027                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1028                reset = diff_get_color_opt(o, DIFF_RESET);
1029                emit_line_ws_markup(o, set, reset, line, len, '-',
1030                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1031                break;
1032        case DIFF_SYMBOL_WORDS_PORCELAIN:
1033                context = diff_get_color_opt(o, DIFF_CONTEXT);
1034                reset = diff_get_color_opt(o, DIFF_RESET);
1035                emit_line(o, context, reset, line, len);
1036                fputs("~\n", o->file);
1037                break;
1038        case DIFF_SYMBOL_WORDS:
1039                context = diff_get_color_opt(o, DIFF_CONTEXT);
1040                reset = diff_get_color_opt(o, DIFF_RESET);
1041                /*
1042                 * Skip the prefix character, if any.  With
1043                 * diff_suppress_blank_empty, there may be
1044                 * none.
1045                 */
1046                if (line[0] != '\n') {
1047                        line++;
1048                        len--;
1049                }
1050                emit_line(o, context, reset, line, len);
1051                break;
1052        case DIFF_SYMBOL_FILEPAIR_PLUS:
1053                meta = diff_get_color_opt(o, DIFF_METAINFO);
1054                reset = diff_get_color_opt(o, DIFF_RESET);
1055                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1056                        line, reset,
1057                        strchr(line, ' ') ? "\t" : "");
1058                break;
1059        case DIFF_SYMBOL_FILEPAIR_MINUS:
1060                meta = diff_get_color_opt(o, DIFF_METAINFO);
1061                reset = diff_get_color_opt(o, DIFF_RESET);
1062                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1063                        line, reset,
1064                        strchr(line, ' ') ? "\t" : "");
1065                break;
1066        case DIFF_SYMBOL_BINARY_FILES:
1067        case DIFF_SYMBOL_HEADER:
1068                fprintf(o->file, "%s", line);
1069                break;
1070        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1071                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1072                break;
1073        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1074                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1075                break;
1076        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1077                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1078                break;
1079        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1080                fputs(diff_line_prefix(o), o->file);
1081                fputc('\n', o->file);
1082                break;
1083        case DIFF_SYMBOL_REWRITE_DIFF:
1084                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1085                reset = diff_get_color_opt(o, DIFF_RESET);
1086                emit_line(o, fraginfo, reset, line, len);
1087                break;
1088        case DIFF_SYMBOL_SUBMODULE_ADD:
1089                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1090                reset = diff_get_color_opt(o, DIFF_RESET);
1091                emit_line(o, set, reset, line, len);
1092                break;
1093        case DIFF_SYMBOL_SUBMODULE_DEL:
1094                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1095                reset = diff_get_color_opt(o, DIFF_RESET);
1096                emit_line(o, set, reset, line, len);
1097                break;
1098        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1099                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1100                        diff_line_prefix(o), line);
1101                break;
1102        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1103                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1104                        diff_line_prefix(o), line);
1105                break;
1106        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1107                emit_line(o, "", "", " 0 files changed\n",
1108                          strlen(" 0 files changed\n"));
1109                break;
1110        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1111                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1112                break;
1113        case DIFF_SYMBOL_WORD_DIFF:
1114                fprintf(o->file, "%.*s", len, line);
1115                break;
1116        case DIFF_SYMBOL_STAT_SEP:
1117                fputs(o->stat_sep, o->file);
1118                break;
1119        default:
1120                die("BUG: unknown diff symbol");
1121        }
1122        strbuf_release(&sb);
1123}
1124
1125static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1126                             const char *line, int len, unsigned flags)
1127{
1128        struct emitted_diff_symbol e = {line, len, flags, s};
1129
1130        if (o->emitted_symbols)
1131                append_emitted_diff_symbol(o, &e);
1132        else
1133                emit_diff_symbol_from_struct(o, &e);
1134}
1135
1136void diff_emit_submodule_del(struct diff_options *o, const char *line)
1137{
1138        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1139}
1140
1141void diff_emit_submodule_add(struct diff_options *o, const char *line)
1142{
1143        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1144}
1145
1146void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1147{
1148        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1149                         path, strlen(path), 0);
1150}
1151
1152void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1153{
1154        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1155                         path, strlen(path), 0);
1156}
1157
1158void diff_emit_submodule_header(struct diff_options *o, const char *header)
1159{
1160        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1161                         header, strlen(header), 0);
1162}
1163
1164void diff_emit_submodule_error(struct diff_options *o, const char *err)
1165{
1166        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1167}
1168
1169void diff_emit_submodule_pipethrough(struct diff_options *o,
1170                                     const char *line, int len)
1171{
1172        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1173}
1174
1175static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1176{
1177        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1178              ecbdata->blank_at_eof_in_preimage &&
1179              ecbdata->blank_at_eof_in_postimage &&
1180              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1181              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1182                return 0;
1183        return ws_blank_line(line, len, ecbdata->ws_rule);
1184}
1185
1186static void emit_add_line(const char *reset,
1187                          struct emit_callback *ecbdata,
1188                          const char *line, int len)
1189{
1190        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1191        if (new_blank_line_at_eof(ecbdata, line, len))
1192                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1193
1194        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1195}
1196
1197static void emit_del_line(const char *reset,
1198                          struct emit_callback *ecbdata,
1199                          const char *line, int len)
1200{
1201        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1202        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1203}
1204
1205static void emit_context_line(const char *reset,
1206                              struct emit_callback *ecbdata,
1207                              const char *line, int len)
1208{
1209        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1210        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1211}
1212
1213static void emit_hunk_header(struct emit_callback *ecbdata,
1214                             const char *line, int len)
1215{
1216        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1217        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1218        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1219        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1220        static const char atat[2] = { '@', '@' };
1221        const char *cp, *ep;
1222        struct strbuf msgbuf = STRBUF_INIT;
1223        int org_len = len;
1224        int i = 1;
1225
1226        /*
1227         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1228         * it always is at least 10 bytes long.
1229         */
1230        if (len < 10 ||
1231            memcmp(line, atat, 2) ||
1232            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1233                emit_diff_symbol(ecbdata->opt,
1234                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1235                return;
1236        }
1237        ep += 2; /* skip over @@ */
1238
1239        /* The hunk header in fraginfo color */
1240        strbuf_addstr(&msgbuf, frag);
1241        strbuf_add(&msgbuf, line, ep - line);
1242        strbuf_addstr(&msgbuf, reset);
1243
1244        /*
1245         * trailing "\r\n"
1246         */
1247        for ( ; i < 3; i++)
1248                if (line[len - i] == '\r' || line[len - i] == '\n')
1249                        len--;
1250
1251        /* blank before the func header */
1252        for (cp = ep; ep - line < len; ep++)
1253                if (*ep != ' ' && *ep != '\t')
1254                        break;
1255        if (ep != cp) {
1256                strbuf_addstr(&msgbuf, context);
1257                strbuf_add(&msgbuf, cp, ep - cp);
1258                strbuf_addstr(&msgbuf, reset);
1259        }
1260
1261        if (ep < line + len) {
1262                strbuf_addstr(&msgbuf, func);
1263                strbuf_add(&msgbuf, ep, line + len - ep);
1264                strbuf_addstr(&msgbuf, reset);
1265        }
1266
1267        strbuf_add(&msgbuf, line + len, org_len - len);
1268        strbuf_complete_line(&msgbuf);
1269        emit_diff_symbol(ecbdata->opt,
1270                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1271        strbuf_release(&msgbuf);
1272}
1273
1274static struct diff_tempfile *claim_diff_tempfile(void) {
1275        int i;
1276        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1277                if (!diff_temp[i].name)
1278                        return diff_temp + i;
1279        die("BUG: diff is failing to clean up its tempfiles");
1280}
1281
1282static void remove_tempfile(void)
1283{
1284        int i;
1285        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1286                if (is_tempfile_active(&diff_temp[i].tempfile))
1287                        delete_tempfile(&diff_temp[i].tempfile);
1288                diff_temp[i].name = NULL;
1289        }
1290}
1291
1292static void add_line_count(struct strbuf *out, int count)
1293{
1294        switch (count) {
1295        case 0:
1296                strbuf_addstr(out, "0,0");
1297                break;
1298        case 1:
1299                strbuf_addstr(out, "1");
1300                break;
1301        default:
1302                strbuf_addf(out, "1,%d", count);
1303                break;
1304        }
1305}
1306
1307static void emit_rewrite_lines(struct emit_callback *ecb,
1308                               int prefix, const char *data, int size)
1309{
1310        const char *endp = NULL;
1311        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1312
1313        while (0 < size) {
1314                int len;
1315
1316                endp = memchr(data, '\n', size);
1317                len = endp ? (endp - data + 1) : size;
1318                if (prefix != '+') {
1319                        ecb->lno_in_preimage++;
1320                        emit_del_line(reset, ecb, data, len);
1321                } else {
1322                        ecb->lno_in_postimage++;
1323                        emit_add_line(reset, ecb, data, len);
1324                }
1325                size -= len;
1326                data += len;
1327        }
1328        if (!endp)
1329                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1330}
1331
1332static void emit_rewrite_diff(const char *name_a,
1333                              const char *name_b,
1334                              struct diff_filespec *one,
1335                              struct diff_filespec *two,
1336                              struct userdiff_driver *textconv_one,
1337                              struct userdiff_driver *textconv_two,
1338                              struct diff_options *o)
1339{
1340        int lc_a, lc_b;
1341        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1342        const char *a_prefix, *b_prefix;
1343        char *data_one, *data_two;
1344        size_t size_one, size_two;
1345        struct emit_callback ecbdata;
1346        struct strbuf out = STRBUF_INIT;
1347
1348        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
1349                a_prefix = o->b_prefix;
1350                b_prefix = o->a_prefix;
1351        } else {
1352                a_prefix = o->a_prefix;
1353                b_prefix = o->b_prefix;
1354        }
1355
1356        name_a += (*name_a == '/');
1357        name_b += (*name_b == '/');
1358
1359        strbuf_reset(&a_name);
1360        strbuf_reset(&b_name);
1361        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1362        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1363
1364        size_one = fill_textconv(textconv_one, one, &data_one);
1365        size_two = fill_textconv(textconv_two, two, &data_two);
1366
1367        memset(&ecbdata, 0, sizeof(ecbdata));
1368        ecbdata.color_diff = want_color(o->use_color);
1369        ecbdata.ws_rule = whitespace_rule(name_b);
1370        ecbdata.opt = o;
1371        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1372                mmfile_t mf1, mf2;
1373                mf1.ptr = (char *)data_one;
1374                mf2.ptr = (char *)data_two;
1375                mf1.size = size_one;
1376                mf2.size = size_two;
1377                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1378        }
1379        ecbdata.lno_in_preimage = 1;
1380        ecbdata.lno_in_postimage = 1;
1381
1382        lc_a = count_lines(data_one, size_one);
1383        lc_b = count_lines(data_two, size_two);
1384
1385        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1386                         a_name.buf, a_name.len, 0);
1387        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1388                         b_name.buf, b_name.len, 0);
1389
1390        strbuf_addstr(&out, "@@ -");
1391        if (!o->irreversible_delete)
1392                add_line_count(&out, lc_a);
1393        else
1394                strbuf_addstr(&out, "?,?");
1395        strbuf_addstr(&out, " +");
1396        add_line_count(&out, lc_b);
1397        strbuf_addstr(&out, " @@\n");
1398        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1399        strbuf_release(&out);
1400
1401        if (lc_a && !o->irreversible_delete)
1402                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1403        if (lc_b)
1404                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1405        if (textconv_one)
1406                free((char *)data_one);
1407        if (textconv_two)
1408                free((char *)data_two);
1409}
1410
1411struct diff_words_buffer {
1412        mmfile_t text;
1413        long alloc;
1414        struct diff_words_orig {
1415                const char *begin, *end;
1416        } *orig;
1417        int orig_nr, orig_alloc;
1418};
1419
1420static void diff_words_append(char *line, unsigned long len,
1421                struct diff_words_buffer *buffer)
1422{
1423        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1424        line++;
1425        len--;
1426        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1427        buffer->text.size += len;
1428        buffer->text.ptr[buffer->text.size] = '\0';
1429}
1430
1431struct diff_words_style_elem {
1432        const char *prefix;
1433        const char *suffix;
1434        const char *color; /* NULL; filled in by the setup code if
1435                            * color is enabled */
1436};
1437
1438struct diff_words_style {
1439        enum diff_words_type type;
1440        struct diff_words_style_elem new, old, ctx;
1441        const char *newline;
1442};
1443
1444static struct diff_words_style diff_words_styles[] = {
1445        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1446        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1447        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1448};
1449
1450struct diff_words_data {
1451        struct diff_words_buffer minus, plus;
1452        const char *current_plus;
1453        int last_minus;
1454        struct diff_options *opt;
1455        regex_t *word_regex;
1456        enum diff_words_type type;
1457        struct diff_words_style *style;
1458};
1459
1460static int fn_out_diff_words_write_helper(struct diff_options *o,
1461                                          struct diff_words_style_elem *st_el,
1462                                          const char *newline,
1463                                          size_t count, const char *buf)
1464{
1465        int print = 0;
1466        struct strbuf sb = STRBUF_INIT;
1467
1468        while (count) {
1469                char *p = memchr(buf, '\n', count);
1470                if (print)
1471                        strbuf_addstr(&sb, diff_line_prefix(o));
1472
1473                if (p != buf) {
1474                        const char *reset = st_el->color && *st_el->color ?
1475                                            GIT_COLOR_RESET : NULL;
1476                        if (st_el->color && *st_el->color)
1477                                strbuf_addstr(&sb, st_el->color);
1478                        strbuf_addstr(&sb, st_el->prefix);
1479                        strbuf_add(&sb, buf, p ? p - buf : count);
1480                        strbuf_addstr(&sb, st_el->suffix);
1481                        if (reset)
1482                                strbuf_addstr(&sb, reset);
1483                }
1484                if (!p)
1485                        goto out;
1486
1487                strbuf_addstr(&sb, newline);
1488                count -= p + 1 - buf;
1489                buf = p + 1;
1490                print = 1;
1491                if (count) {
1492                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1493                                         sb.buf, sb.len, 0);
1494                        strbuf_reset(&sb);
1495                }
1496        }
1497
1498out:
1499        if (sb.len)
1500                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1501                                 sb.buf, sb.len, 0);
1502        strbuf_release(&sb);
1503        return 0;
1504}
1505
1506/*
1507 * '--color-words' algorithm can be described as:
1508 *
1509 *   1. collect the minus/plus lines of a diff hunk, divided into
1510 *      minus-lines and plus-lines;
1511 *
1512 *   2. break both minus-lines and plus-lines into words and
1513 *      place them into two mmfile_t with one word for each line;
1514 *
1515 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1516 *
1517 * And for the common parts of the both file, we output the plus side text.
1518 * diff_words->current_plus is used to trace the current position of the plus file
1519 * which printed. diff_words->last_minus is used to trace the last minus word
1520 * printed.
1521 *
1522 * For '--graph' to work with '--color-words', we need to output the graph prefix
1523 * on each line of color words output. Generally, there are two conditions on
1524 * which we should output the prefix.
1525 *
1526 *   1. diff_words->last_minus == 0 &&
1527 *      diff_words->current_plus == diff_words->plus.text.ptr
1528 *
1529 *      that is: the plus text must start as a new line, and if there is no minus
1530 *      word printed, a graph prefix must be printed.
1531 *
1532 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1533 *      *(diff_words->current_plus - 1) == '\n'
1534 *
1535 *      that is: a graph prefix must be printed following a '\n'
1536 */
1537static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1538{
1539        if ((diff_words->last_minus == 0 &&
1540                diff_words->current_plus == diff_words->plus.text.ptr) ||
1541                (diff_words->current_plus > diff_words->plus.text.ptr &&
1542                *(diff_words->current_plus - 1) == '\n')) {
1543                return 1;
1544        } else {
1545                return 0;
1546        }
1547}
1548
1549static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1550{
1551        struct diff_words_data *diff_words = priv;
1552        struct diff_words_style *style = diff_words->style;
1553        int minus_first, minus_len, plus_first, plus_len;
1554        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1555        struct diff_options *opt = diff_words->opt;
1556        const char *line_prefix;
1557
1558        if (line[0] != '@' || parse_hunk_header(line, len,
1559                        &minus_first, &minus_len, &plus_first, &plus_len))
1560                return;
1561
1562        assert(opt);
1563        line_prefix = diff_line_prefix(opt);
1564
1565        /* POSIX requires that first be decremented by one if len == 0... */
1566        if (minus_len) {
1567                minus_begin = diff_words->minus.orig[minus_first].begin;
1568                minus_end =
1569                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1570        } else
1571                minus_begin = minus_end =
1572                        diff_words->minus.orig[minus_first].end;
1573
1574        if (plus_len) {
1575                plus_begin = diff_words->plus.orig[plus_first].begin;
1576                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1577        } else
1578                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1579
1580        if (color_words_output_graph_prefix(diff_words)) {
1581                fputs(line_prefix, diff_words->opt->file);
1582        }
1583        if (diff_words->current_plus != plus_begin) {
1584                fn_out_diff_words_write_helper(diff_words->opt,
1585                                &style->ctx, style->newline,
1586                                plus_begin - diff_words->current_plus,
1587                                diff_words->current_plus);
1588        }
1589        if (minus_begin != minus_end) {
1590                fn_out_diff_words_write_helper(diff_words->opt,
1591                                &style->old, style->newline,
1592                                minus_end - minus_begin, minus_begin);
1593        }
1594        if (plus_begin != plus_end) {
1595                fn_out_diff_words_write_helper(diff_words->opt,
1596                                &style->new, style->newline,
1597                                plus_end - plus_begin, plus_begin);
1598        }
1599
1600        diff_words->current_plus = plus_end;
1601        diff_words->last_minus = minus_first;
1602}
1603
1604/* This function starts looking at *begin, and returns 0 iff a word was found. */
1605static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1606                int *begin, int *end)
1607{
1608        if (word_regex && *begin < buffer->size) {
1609                regmatch_t match[1];
1610                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1611                                 buffer->size - *begin, 1, match, 0)) {
1612                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1613                                        '\n', match[0].rm_eo - match[0].rm_so);
1614                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1615                        *begin += match[0].rm_so;
1616                        return *begin >= *end;
1617                }
1618                return -1;
1619        }
1620
1621        /* find the next word */
1622        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1623                (*begin)++;
1624        if (*begin >= buffer->size)
1625                return -1;
1626
1627        /* find the end of the word */
1628        *end = *begin + 1;
1629        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1630                (*end)++;
1631
1632        return 0;
1633}
1634
1635/*
1636 * This function splits the words in buffer->text, stores the list with
1637 * newline separator into out, and saves the offsets of the original words
1638 * in buffer->orig.
1639 */
1640static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1641                regex_t *word_regex)
1642{
1643        int i, j;
1644        long alloc = 0;
1645
1646        out->size = 0;
1647        out->ptr = NULL;
1648
1649        /* fake an empty "0th" word */
1650        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1651        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1652        buffer->orig_nr = 1;
1653
1654        for (i = 0; i < buffer->text.size; i++) {
1655                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1656                        return;
1657
1658                /* store original boundaries */
1659                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1660                                buffer->orig_alloc);
1661                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1662                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1663                buffer->orig_nr++;
1664
1665                /* store one word */
1666                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1667                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1668                out->ptr[out->size + j - i] = '\n';
1669                out->size += j - i + 1;
1670
1671                i = j - 1;
1672        }
1673}
1674
1675/* this executes the word diff on the accumulated buffers */
1676static void diff_words_show(struct diff_words_data *diff_words)
1677{
1678        xpparam_t xpp;
1679        xdemitconf_t xecfg;
1680        mmfile_t minus, plus;
1681        struct diff_words_style *style = diff_words->style;
1682
1683        struct diff_options *opt = diff_words->opt;
1684        const char *line_prefix;
1685
1686        assert(opt);
1687        line_prefix = diff_line_prefix(opt);
1688
1689        /* special case: only removal */
1690        if (!diff_words->plus.text.size) {
1691                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1692                                 line_prefix, strlen(line_prefix), 0);
1693                fn_out_diff_words_write_helper(diff_words->opt,
1694                        &style->old, style->newline,
1695                        diff_words->minus.text.size,
1696                        diff_words->minus.text.ptr);
1697                diff_words->minus.text.size = 0;
1698                return;
1699        }
1700
1701        diff_words->current_plus = diff_words->plus.text.ptr;
1702        diff_words->last_minus = 0;
1703
1704        memset(&xpp, 0, sizeof(xpp));
1705        memset(&xecfg, 0, sizeof(xecfg));
1706        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1707        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1708        xpp.flags = 0;
1709        /* as only the hunk header will be parsed, we need a 0-context */
1710        xecfg.ctxlen = 0;
1711        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1712                          &xpp, &xecfg))
1713                die("unable to generate word diff");
1714        free(minus.ptr);
1715        free(plus.ptr);
1716        if (diff_words->current_plus != diff_words->plus.text.ptr +
1717                        diff_words->plus.text.size) {
1718                if (color_words_output_graph_prefix(diff_words))
1719                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1720                                         line_prefix, strlen(line_prefix), 0);
1721                fn_out_diff_words_write_helper(diff_words->opt,
1722                        &style->ctx, style->newline,
1723                        diff_words->plus.text.ptr + diff_words->plus.text.size
1724                        - diff_words->current_plus, diff_words->current_plus);
1725        }
1726        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1727}
1728
1729/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1730static void diff_words_flush(struct emit_callback *ecbdata)
1731{
1732        struct diff_options *wo = ecbdata->diff_words->opt;
1733
1734        if (ecbdata->diff_words->minus.text.size ||
1735            ecbdata->diff_words->plus.text.size)
1736                diff_words_show(ecbdata->diff_words);
1737
1738        if (wo->emitted_symbols) {
1739                struct diff_options *o = ecbdata->opt;
1740                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1741                int i;
1742
1743                /*
1744                 * NEEDSWORK:
1745                 * Instead of appending each, concat all words to a line?
1746                 */
1747                for (i = 0; i < wol->nr; i++)
1748                        append_emitted_diff_symbol(o, &wol->buf[i]);
1749
1750                for (i = 0; i < wol->nr; i++)
1751                        free((void *)wol->buf[i].line);
1752
1753                wol->nr = 0;
1754        }
1755}
1756
1757static void diff_filespec_load_driver(struct diff_filespec *one)
1758{
1759        /* Use already-loaded driver */
1760        if (one->driver)
1761                return;
1762
1763        if (S_ISREG(one->mode))
1764                one->driver = userdiff_find_by_path(one->path);
1765
1766        /* Fallback to default settings */
1767        if (!one->driver)
1768                one->driver = userdiff_find_by_name("default");
1769}
1770
1771static const char *userdiff_word_regex(struct diff_filespec *one)
1772{
1773        diff_filespec_load_driver(one);
1774        return one->driver->word_regex;
1775}
1776
1777static void init_diff_words_data(struct emit_callback *ecbdata,
1778                                 struct diff_options *orig_opts,
1779                                 struct diff_filespec *one,
1780                                 struct diff_filespec *two)
1781{
1782        int i;
1783        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1784        memcpy(o, orig_opts, sizeof(struct diff_options));
1785
1786        ecbdata->diff_words =
1787                xcalloc(1, sizeof(struct diff_words_data));
1788        ecbdata->diff_words->type = o->word_diff;
1789        ecbdata->diff_words->opt = o;
1790
1791        if (orig_opts->emitted_symbols)
1792                o->emitted_symbols =
1793                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1794
1795        if (!o->word_regex)
1796                o->word_regex = userdiff_word_regex(one);
1797        if (!o->word_regex)
1798                o->word_regex = userdiff_word_regex(two);
1799        if (!o->word_regex)
1800                o->word_regex = diff_word_regex_cfg;
1801        if (o->word_regex) {
1802                ecbdata->diff_words->word_regex = (regex_t *)
1803                        xmalloc(sizeof(regex_t));
1804                if (regcomp(ecbdata->diff_words->word_regex,
1805                            o->word_regex,
1806                            REG_EXTENDED | REG_NEWLINE))
1807                        die ("Invalid regular expression: %s",
1808                             o->word_regex);
1809        }
1810        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1811                if (o->word_diff == diff_words_styles[i].type) {
1812                        ecbdata->diff_words->style =
1813                                &diff_words_styles[i];
1814                        break;
1815                }
1816        }
1817        if (want_color(o->use_color)) {
1818                struct diff_words_style *st = ecbdata->diff_words->style;
1819                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1820                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1821                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1822        }
1823}
1824
1825static void free_diff_words_data(struct emit_callback *ecbdata)
1826{
1827        if (ecbdata->diff_words) {
1828                diff_words_flush(ecbdata);
1829                free (ecbdata->diff_words->opt->emitted_symbols);
1830                free (ecbdata->diff_words->opt);
1831                free (ecbdata->diff_words->minus.text.ptr);
1832                free (ecbdata->diff_words->minus.orig);
1833                free (ecbdata->diff_words->plus.text.ptr);
1834                free (ecbdata->diff_words->plus.orig);
1835                if (ecbdata->diff_words->word_regex) {
1836                        regfree(ecbdata->diff_words->word_regex);
1837                        free(ecbdata->diff_words->word_regex);
1838                }
1839                FREE_AND_NULL(ecbdata->diff_words);
1840        }
1841}
1842
1843const char *diff_get_color(int diff_use_color, enum color_diff ix)
1844{
1845        if (want_color(diff_use_color))
1846                return diff_colors[ix];
1847        return "";
1848}
1849
1850const char *diff_line_prefix(struct diff_options *opt)
1851{
1852        struct strbuf *msgbuf;
1853        if (!opt->output_prefix)
1854                return "";
1855
1856        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1857        return msgbuf->buf;
1858}
1859
1860static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1861{
1862        const char *cp;
1863        unsigned long allot;
1864        size_t l = len;
1865
1866        if (ecb->truncate)
1867                return ecb->truncate(line, len);
1868        cp = line;
1869        allot = l;
1870        while (0 < l) {
1871                (void) utf8_width(&cp, &l);
1872                if (!cp)
1873                        break; /* truncated in the middle? */
1874        }
1875        return allot - l;
1876}
1877
1878static void find_lno(const char *line, struct emit_callback *ecbdata)
1879{
1880        const char *p;
1881        ecbdata->lno_in_preimage = 0;
1882        ecbdata->lno_in_postimage = 0;
1883        p = strchr(line, '-');
1884        if (!p)
1885                return; /* cannot happen */
1886        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1887        p = strchr(p, '+');
1888        if (!p)
1889                return; /* cannot happen */
1890        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1891}
1892
1893static void fn_out_consume(void *priv, char *line, unsigned long len)
1894{
1895        struct emit_callback *ecbdata = priv;
1896        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1897        struct diff_options *o = ecbdata->opt;
1898
1899        o->found_changes = 1;
1900
1901        if (ecbdata->header) {
1902                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1903                                 ecbdata->header->buf, ecbdata->header->len, 0);
1904                strbuf_reset(ecbdata->header);
1905                ecbdata->header = NULL;
1906        }
1907
1908        if (ecbdata->label_path[0]) {
1909                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1910                                 ecbdata->label_path[0],
1911                                 strlen(ecbdata->label_path[0]), 0);
1912                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1913                                 ecbdata->label_path[1],
1914                                 strlen(ecbdata->label_path[1]), 0);
1915                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1916        }
1917
1918        if (diff_suppress_blank_empty
1919            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1920                line[0] = '\n';
1921                len = 1;
1922        }
1923
1924        if (line[0] == '@') {
1925                if (ecbdata->diff_words)
1926                        diff_words_flush(ecbdata);
1927                len = sane_truncate_line(ecbdata, line, len);
1928                find_lno(line, ecbdata);
1929                emit_hunk_header(ecbdata, line, len);
1930                return;
1931        }
1932
1933        if (ecbdata->diff_words) {
1934                enum diff_symbol s =
1935                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1936                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1937                if (line[0] == '-') {
1938                        diff_words_append(line, len,
1939                                          &ecbdata->diff_words->minus);
1940                        return;
1941                } else if (line[0] == '+') {
1942                        diff_words_append(line, len,
1943                                          &ecbdata->diff_words->plus);
1944                        return;
1945                } else if (starts_with(line, "\\ ")) {
1946                        /*
1947                         * Eat the "no newline at eof" marker as if we
1948                         * saw a "+" or "-" line with nothing on it,
1949                         * and return without diff_words_flush() to
1950                         * defer processing. If this is the end of
1951                         * preimage, more "+" lines may come after it.
1952                         */
1953                        return;
1954                }
1955                diff_words_flush(ecbdata);
1956                emit_diff_symbol(o, s, line, len, 0);
1957                return;
1958        }
1959
1960        switch (line[0]) {
1961        case '+':
1962                ecbdata->lno_in_postimage++;
1963                emit_add_line(reset, ecbdata, line + 1, len - 1);
1964                break;
1965        case '-':
1966                ecbdata->lno_in_preimage++;
1967                emit_del_line(reset, ecbdata, line + 1, len - 1);
1968                break;
1969        case ' ':
1970                ecbdata->lno_in_postimage++;
1971                ecbdata->lno_in_preimage++;
1972                emit_context_line(reset, ecbdata, line + 1, len - 1);
1973                break;
1974        default:
1975                /* incomplete line at the end */
1976                ecbdata->lno_in_preimage++;
1977                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
1978                                 line, len, 0);
1979                break;
1980        }
1981}
1982
1983static char *pprint_rename(const char *a, const char *b)
1984{
1985        const char *old = a;
1986        const char *new = b;
1987        struct strbuf name = STRBUF_INIT;
1988        int pfx_length, sfx_length;
1989        int pfx_adjust_for_slash;
1990        int len_a = strlen(a);
1991        int len_b = strlen(b);
1992        int a_midlen, b_midlen;
1993        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1994        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1995
1996        if (qlen_a || qlen_b) {
1997                quote_c_style(a, &name, NULL, 0);
1998                strbuf_addstr(&name, " => ");
1999                quote_c_style(b, &name, NULL, 0);
2000                return strbuf_detach(&name, NULL);
2001        }
2002
2003        /* Find common prefix */
2004        pfx_length = 0;
2005        while (*old && *new && *old == *new) {
2006                if (*old == '/')
2007                        pfx_length = old - a + 1;
2008                old++;
2009                new++;
2010        }
2011
2012        /* Find common suffix */
2013        old = a + len_a;
2014        new = b + len_b;
2015        sfx_length = 0;
2016        /*
2017         * If there is a common prefix, it must end in a slash.  In
2018         * that case we let this loop run 1 into the prefix to see the
2019         * same slash.
2020         *
2021         * If there is no common prefix, we cannot do this as it would
2022         * underrun the input strings.
2023         */
2024        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2025        while (a + pfx_length - pfx_adjust_for_slash <= old &&
2026               b + pfx_length - pfx_adjust_for_slash <= new &&
2027               *old == *new) {
2028                if (*old == '/')
2029                        sfx_length = len_a - (old - a);
2030                old--;
2031                new--;
2032        }
2033
2034        /*
2035         * pfx{mid-a => mid-b}sfx
2036         * {pfx-a => pfx-b}sfx
2037         * pfx{sfx-a => sfx-b}
2038         * name-a => name-b
2039         */
2040        a_midlen = len_a - pfx_length - sfx_length;
2041        b_midlen = len_b - pfx_length - sfx_length;
2042        if (a_midlen < 0)
2043                a_midlen = 0;
2044        if (b_midlen < 0)
2045                b_midlen = 0;
2046
2047        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2048        if (pfx_length + sfx_length) {
2049                strbuf_add(&name, a, pfx_length);
2050                strbuf_addch(&name, '{');
2051        }
2052        strbuf_add(&name, a + pfx_length, a_midlen);
2053        strbuf_addstr(&name, " => ");
2054        strbuf_add(&name, b + pfx_length, b_midlen);
2055        if (pfx_length + sfx_length) {
2056                strbuf_addch(&name, '}');
2057                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
2058        }
2059        return strbuf_detach(&name, NULL);
2060}
2061
2062struct diffstat_t {
2063        int nr;
2064        int alloc;
2065        struct diffstat_file {
2066                char *from_name;
2067                char *name;
2068                char *print_name;
2069                unsigned is_unmerged:1;
2070                unsigned is_binary:1;
2071                unsigned is_renamed:1;
2072                unsigned is_interesting:1;
2073                uintmax_t added, deleted;
2074        } **files;
2075};
2076
2077static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2078                                          const char *name_a,
2079                                          const char *name_b)
2080{
2081        struct diffstat_file *x;
2082        x = xcalloc(1, sizeof(*x));
2083        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2084        diffstat->files[diffstat->nr++] = x;
2085        if (name_b) {
2086                x->from_name = xstrdup(name_a);
2087                x->name = xstrdup(name_b);
2088                x->is_renamed = 1;
2089        }
2090        else {
2091                x->from_name = NULL;
2092                x->name = xstrdup(name_a);
2093        }
2094        return x;
2095}
2096
2097static void diffstat_consume(void *priv, char *line, unsigned long len)
2098{
2099        struct diffstat_t *diffstat = priv;
2100        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2101
2102        if (line[0] == '+')
2103                x->added++;
2104        else if (line[0] == '-')
2105                x->deleted++;
2106}
2107
2108const char mime_boundary_leader[] = "------------";
2109
2110static int scale_linear(int it, int width, int max_change)
2111{
2112        if (!it)
2113                return 0;
2114        /*
2115         * make sure that at least one '-' or '+' is printed if
2116         * there is any change to this path. The easiest way is to
2117         * scale linearly as if the alloted width is one column shorter
2118         * than it is, and then add 1 to the result.
2119         */
2120        return 1 + (it * (width - 1) / max_change);
2121}
2122
2123static void show_graph(struct strbuf *out, char ch, int cnt,
2124                       const char *set, const char *reset)
2125{
2126        if (cnt <= 0)
2127                return;
2128        strbuf_addstr(out, set);
2129        strbuf_addchars(out, ch, cnt);
2130        strbuf_addstr(out, reset);
2131}
2132
2133static void fill_print_name(struct diffstat_file *file)
2134{
2135        char *pname;
2136
2137        if (file->print_name)
2138                return;
2139
2140        if (!file->is_renamed) {
2141                struct strbuf buf = STRBUF_INIT;
2142                if (quote_c_style(file->name, &buf, NULL, 0)) {
2143                        pname = strbuf_detach(&buf, NULL);
2144                } else {
2145                        pname = file->name;
2146                        strbuf_release(&buf);
2147                }
2148        } else {
2149                pname = pprint_rename(file->from_name, file->name);
2150        }
2151        file->print_name = pname;
2152}
2153
2154static void print_stat_summary_inserts_deletes(struct diff_options *options,
2155                int files, int insertions, int deletions)
2156{
2157        struct strbuf sb = STRBUF_INIT;
2158
2159        if (!files) {
2160                assert(insertions == 0 && deletions == 0);
2161                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2162                                 NULL, 0, 0);
2163                return;
2164        }
2165
2166        strbuf_addf(&sb,
2167                    (files == 1) ? " %d file changed" : " %d files changed",
2168                    files);
2169
2170        /*
2171         * For binary diff, the caller may want to print "x files
2172         * changed" with insertions == 0 && deletions == 0.
2173         *
2174         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2175         * is probably less confusing (i.e skip over "2 files changed
2176         * but nothing about added/removed lines? Is this a bug in Git?").
2177         */
2178        if (insertions || deletions == 0) {
2179                strbuf_addf(&sb,
2180                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2181                            insertions);
2182        }
2183
2184        if (deletions || insertions == 0) {
2185                strbuf_addf(&sb,
2186                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2187                            deletions);
2188        }
2189        strbuf_addch(&sb, '\n');
2190        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2191                         sb.buf, sb.len, 0);
2192        strbuf_release(&sb);
2193}
2194
2195void print_stat_summary(FILE *fp, int files,
2196                        int insertions, int deletions)
2197{
2198        struct diff_options o;
2199        memset(&o, 0, sizeof(o));
2200        o.file = fp;
2201
2202        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2203}
2204
2205static void show_stats(struct diffstat_t *data, struct diff_options *options)
2206{
2207        int i, len, add, del, adds = 0, dels = 0;
2208        uintmax_t max_change = 0, max_len = 0;
2209        int total_files = data->nr, count;
2210        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2211        const char *reset, *add_c, *del_c;
2212        int extra_shown = 0;
2213        const char *line_prefix = diff_line_prefix(options);
2214        struct strbuf out = STRBUF_INIT;
2215
2216        if (data->nr == 0)
2217                return;
2218
2219        count = options->stat_count ? options->stat_count : data->nr;
2220
2221        reset = diff_get_color_opt(options, DIFF_RESET);
2222        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2223        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2224
2225        /*
2226         * Find the longest filename and max number of changes
2227         */
2228        for (i = 0; (i < count) && (i < data->nr); i++) {
2229                struct diffstat_file *file = data->files[i];
2230                uintmax_t change = file->added + file->deleted;
2231
2232                if (!file->is_interesting && (change == 0)) {
2233                        count++; /* not shown == room for one more */
2234                        continue;
2235                }
2236                fill_print_name(file);
2237                len = strlen(file->print_name);
2238                if (max_len < len)
2239                        max_len = len;
2240
2241                if (file->is_unmerged) {
2242                        /* "Unmerged" is 8 characters */
2243                        bin_width = bin_width < 8 ? 8 : bin_width;
2244                        continue;
2245                }
2246                if (file->is_binary) {
2247                        /* "Bin XXX -> YYY bytes" */
2248                        int w = 14 + decimal_width(file->added)
2249                                + decimal_width(file->deleted);
2250                        bin_width = bin_width < w ? w : bin_width;
2251                        /* Display change counts aligned with "Bin" */
2252                        number_width = 3;
2253                        continue;
2254                }
2255
2256                if (max_change < change)
2257                        max_change = change;
2258        }
2259        count = i; /* where we can stop scanning in data->files[] */
2260
2261        /*
2262         * We have width = stat_width or term_columns() columns total.
2263         * We want a maximum of min(max_len, stat_name_width) for the name part.
2264         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2265         * We also need 1 for " " and 4 + decimal_width(max_change)
2266         * for " | NNNN " and one the empty column at the end, altogether
2267         * 6 + decimal_width(max_change).
2268         *
2269         * If there's not enough space, we will use the smaller of
2270         * stat_name_width (if set) and 5/8*width for the filename,
2271         * and the rest for constant elements + graph part, but no more
2272         * than stat_graph_width for the graph part.
2273         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2274         * for the standard terminal size).
2275         *
2276         * In other words: stat_width limits the maximum width, and
2277         * stat_name_width fixes the maximum width of the filename,
2278         * and is also used to divide available columns if there
2279         * aren't enough.
2280         *
2281         * Binary files are displayed with "Bin XXX -> YYY bytes"
2282         * instead of the change count and graph. This part is treated
2283         * similarly to the graph part, except that it is not
2284         * "scaled". If total width is too small to accommodate the
2285         * guaranteed minimum width of the filename part and the
2286         * separators and this message, this message will "overflow"
2287         * making the line longer than the maximum width.
2288         */
2289
2290        if (options->stat_width == -1)
2291                width = term_columns() - strlen(line_prefix);
2292        else
2293                width = options->stat_width ? options->stat_width : 80;
2294        number_width = decimal_width(max_change) > number_width ?
2295                decimal_width(max_change) : number_width;
2296
2297        if (options->stat_graph_width == -1)
2298                options->stat_graph_width = diff_stat_graph_width;
2299
2300        /*
2301         * Guarantee 3/8*16==6 for the graph part
2302         * and 5/8*16==10 for the filename part
2303         */
2304        if (width < 16 + 6 + number_width)
2305                width = 16 + 6 + number_width;
2306
2307        /*
2308         * First assign sizes that are wanted, ignoring available width.
2309         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2310         * starting from "XXX" should fit in graph_width.
2311         */
2312        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2313        if (options->stat_graph_width &&
2314            options->stat_graph_width < graph_width)
2315                graph_width = options->stat_graph_width;
2316
2317        name_width = (options->stat_name_width > 0 &&
2318                      options->stat_name_width < max_len) ?
2319                options->stat_name_width : max_len;
2320
2321        /*
2322         * Adjust adjustable widths not to exceed maximum width
2323         */
2324        if (name_width + number_width + 6 + graph_width > width) {
2325                if (graph_width > width * 3/8 - number_width - 6) {
2326                        graph_width = width * 3/8 - number_width - 6;
2327                        if (graph_width < 6)
2328                                graph_width = 6;
2329                }
2330
2331                if (options->stat_graph_width &&
2332                    graph_width > options->stat_graph_width)
2333                        graph_width = options->stat_graph_width;
2334                if (name_width > width - number_width - 6 - graph_width)
2335                        name_width = width - number_width - 6 - graph_width;
2336                else
2337                        graph_width = width - number_width - 6 - name_width;
2338        }
2339
2340        /*
2341         * From here name_width is the width of the name area,
2342         * and graph_width is the width of the graph area.
2343         * max_change is used to scale graph properly.
2344         */
2345        for (i = 0; i < count; i++) {
2346                const char *prefix = "";
2347                struct diffstat_file *file = data->files[i];
2348                char *name = file->print_name;
2349                uintmax_t added = file->added;
2350                uintmax_t deleted = file->deleted;
2351                int name_len;
2352
2353                if (!file->is_interesting && (added + deleted == 0))
2354                        continue;
2355
2356                /*
2357                 * "scale" the filename
2358                 */
2359                len = name_width;
2360                name_len = strlen(name);
2361                if (name_width < name_len) {
2362                        char *slash;
2363                        prefix = "...";
2364                        len -= 3;
2365                        name += name_len - len;
2366                        slash = strchr(name, '/');
2367                        if (slash)
2368                                name = slash;
2369                }
2370
2371                if (file->is_binary) {
2372                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2373                        strbuf_addf(&out, " %*s", number_width, "Bin");
2374                        if (!added && !deleted) {
2375                                strbuf_addch(&out, '\n');
2376                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2377                                                 out.buf, out.len, 0);
2378                                strbuf_reset(&out);
2379                                continue;
2380                        }
2381                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2382                                del_c, deleted, reset);
2383                        strbuf_addstr(&out, " -> ");
2384                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2385                                add_c, added, reset);
2386                        strbuf_addstr(&out, " bytes\n");
2387                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2388                                         out.buf, out.len, 0);
2389                        strbuf_reset(&out);
2390                        continue;
2391                }
2392                else if (file->is_unmerged) {
2393                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2394                        strbuf_addstr(&out, " Unmerged\n");
2395                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2396                                         out.buf, out.len, 0);
2397                        strbuf_reset(&out);
2398                        continue;
2399                }
2400
2401                /*
2402                 * scale the add/delete
2403                 */
2404                add = added;
2405                del = deleted;
2406
2407                if (graph_width <= max_change) {
2408                        int total = scale_linear(add + del, graph_width, max_change);
2409                        if (total < 2 && add && del)
2410                                /* width >= 2 due to the sanity check */
2411                                total = 2;
2412                        if (add < del) {
2413                                add = scale_linear(add, graph_width, max_change);
2414                                del = total - add;
2415                        } else {
2416                                del = scale_linear(del, graph_width, max_change);
2417                                add = total - del;
2418                        }
2419                }
2420                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2421                strbuf_addf(&out, " %*"PRIuMAX"%s",
2422                        number_width, added + deleted,
2423                        added + deleted ? " " : "");
2424                show_graph(&out, '+', add, add_c, reset);
2425                show_graph(&out, '-', del, del_c, reset);
2426                strbuf_addch(&out, '\n');
2427                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2428                                 out.buf, out.len, 0);
2429                strbuf_reset(&out);
2430        }
2431
2432        for (i = 0; i < data->nr; i++) {
2433                struct diffstat_file *file = data->files[i];
2434                uintmax_t added = file->added;
2435                uintmax_t deleted = file->deleted;
2436
2437                if (file->is_unmerged ||
2438                    (!file->is_interesting && (added + deleted == 0))) {
2439                        total_files--;
2440                        continue;
2441                }
2442
2443                if (!file->is_binary) {
2444                        adds += added;
2445                        dels += deleted;
2446                }
2447                if (i < count)
2448                        continue;
2449                if (!extra_shown)
2450                        emit_diff_symbol(options,
2451                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2452                                         NULL, 0, 0);
2453                extra_shown = 1;
2454        }
2455
2456        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2457}
2458
2459static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2460{
2461        int i, adds = 0, dels = 0, total_files = data->nr;
2462
2463        if (data->nr == 0)
2464                return;
2465
2466        for (i = 0; i < data->nr; i++) {
2467                int added = data->files[i]->added;
2468                int deleted = data->files[i]->deleted;
2469
2470                if (data->files[i]->is_unmerged ||
2471                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2472                        total_files--;
2473                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2474                        adds += added;
2475                        dels += deleted;
2476                }
2477        }
2478        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2479}
2480
2481static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2482{
2483        int i;
2484
2485        if (data->nr == 0)
2486                return;
2487
2488        for (i = 0; i < data->nr; i++) {
2489                struct diffstat_file *file = data->files[i];
2490
2491                fprintf(options->file, "%s", diff_line_prefix(options));
2492
2493                if (file->is_binary)
2494                        fprintf(options->file, "-\t-\t");
2495                else
2496                        fprintf(options->file,
2497                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2498                                file->added, file->deleted);
2499                if (options->line_termination) {
2500                        fill_print_name(file);
2501                        if (!file->is_renamed)
2502                                write_name_quoted(file->name, options->file,
2503                                                  options->line_termination);
2504                        else {
2505                                fputs(file->print_name, options->file);
2506                                putc(options->line_termination, options->file);
2507                        }
2508                } else {
2509                        if (file->is_renamed) {
2510                                putc('\0', options->file);
2511                                write_name_quoted(file->from_name, options->file, '\0');
2512                        }
2513                        write_name_quoted(file->name, options->file, '\0');
2514                }
2515        }
2516}
2517
2518struct dirstat_file {
2519        const char *name;
2520        unsigned long changed;
2521};
2522
2523struct dirstat_dir {
2524        struct dirstat_file *files;
2525        int alloc, nr, permille, cumulative;
2526};
2527
2528static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2529                unsigned long changed, const char *base, int baselen)
2530{
2531        unsigned long this_dir = 0;
2532        unsigned int sources = 0;
2533        const char *line_prefix = diff_line_prefix(opt);
2534
2535        while (dir->nr) {
2536                struct dirstat_file *f = dir->files;
2537                int namelen = strlen(f->name);
2538                unsigned long this;
2539                char *slash;
2540
2541                if (namelen < baselen)
2542                        break;
2543                if (memcmp(f->name, base, baselen))
2544                        break;
2545                slash = strchr(f->name + baselen, '/');
2546                if (slash) {
2547                        int newbaselen = slash + 1 - f->name;
2548                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2549                        sources++;
2550                } else {
2551                        this = f->changed;
2552                        dir->files++;
2553                        dir->nr--;
2554                        sources += 2;
2555                }
2556                this_dir += this;
2557        }
2558
2559        /*
2560         * We don't report dirstat's for
2561         *  - the top level
2562         *  - or cases where everything came from a single directory
2563         *    under this directory (sources == 1).
2564         */
2565        if (baselen && sources != 1) {
2566                if (this_dir) {
2567                        int permille = this_dir * 1000 / changed;
2568                        if (permille >= dir->permille) {
2569                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2570                                        permille / 10, permille % 10, baselen, base);
2571                                if (!dir->cumulative)
2572                                        return 0;
2573                        }
2574                }
2575        }
2576        return this_dir;
2577}
2578
2579static int dirstat_compare(const void *_a, const void *_b)
2580{
2581        const struct dirstat_file *a = _a;
2582        const struct dirstat_file *b = _b;
2583        return strcmp(a->name, b->name);
2584}
2585
2586static void show_dirstat(struct diff_options *options)
2587{
2588        int i;
2589        unsigned long changed;
2590        struct dirstat_dir dir;
2591        struct diff_queue_struct *q = &diff_queued_diff;
2592
2593        dir.files = NULL;
2594        dir.alloc = 0;
2595        dir.nr = 0;
2596        dir.permille = options->dirstat_permille;
2597        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2598
2599        changed = 0;
2600        for (i = 0; i < q->nr; i++) {
2601                struct diff_filepair *p = q->queue[i];
2602                const char *name;
2603                unsigned long copied, added, damage;
2604                int content_changed;
2605
2606                name = p->two->path ? p->two->path : p->one->path;
2607
2608                if (p->one->oid_valid && p->two->oid_valid)
2609                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2610                else
2611                        content_changed = 1;
2612
2613                if (!content_changed) {
2614                        /*
2615                         * The SHA1 has not changed, so pre-/post-content is
2616                         * identical. We can therefore skip looking at the
2617                         * file contents altogether.
2618                         */
2619                        damage = 0;
2620                        goto found_damage;
2621                }
2622
2623                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2624                        /*
2625                         * In --dirstat-by-file mode, we don't really need to
2626                         * look at the actual file contents at all.
2627                         * The fact that the SHA1 changed is enough for us to
2628                         * add this file to the list of results
2629                         * (with each file contributing equal damage).
2630                         */
2631                        damage = 1;
2632                        goto found_damage;
2633                }
2634
2635                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2636                        diff_populate_filespec(p->one, 0);
2637                        diff_populate_filespec(p->two, 0);
2638                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2639                                               &copied, &added);
2640                        diff_free_filespec_data(p->one);
2641                        diff_free_filespec_data(p->two);
2642                } else if (DIFF_FILE_VALID(p->one)) {
2643                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2644                        copied = added = 0;
2645                        diff_free_filespec_data(p->one);
2646                } else if (DIFF_FILE_VALID(p->two)) {
2647                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2648                        copied = 0;
2649                        added = p->two->size;
2650                        diff_free_filespec_data(p->two);
2651                } else
2652                        continue;
2653
2654                /*
2655                 * Original minus copied is the removed material,
2656                 * added is the new material.  They are both damages
2657                 * made to the preimage.
2658                 * If the resulting damage is zero, we know that
2659                 * diffcore_count_changes() considers the two entries to
2660                 * be identical, but since content_changed is true, we
2661                 * know that there must have been _some_ kind of change,
2662                 * so we force all entries to have damage > 0.
2663                 */
2664                damage = (p->one->size - copied) + added;
2665                if (!damage)
2666                        damage = 1;
2667
2668found_damage:
2669                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2670                dir.files[dir.nr].name = name;
2671                dir.files[dir.nr].changed = damage;
2672                changed += damage;
2673                dir.nr++;
2674        }
2675
2676        /* This can happen even with many files, if everything was renames */
2677        if (!changed)
2678                return;
2679
2680        /* Show all directories with more than x% of the changes */
2681        QSORT(dir.files, dir.nr, dirstat_compare);
2682        gather_dirstat(options, &dir, changed, "", 0);
2683}
2684
2685static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2686{
2687        int i;
2688        unsigned long changed;
2689        struct dirstat_dir dir;
2690
2691        if (data->nr == 0)
2692                return;
2693
2694        dir.files = NULL;
2695        dir.alloc = 0;
2696        dir.nr = 0;
2697        dir.permille = options->dirstat_permille;
2698        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2699
2700        changed = 0;
2701        for (i = 0; i < data->nr; i++) {
2702                struct diffstat_file *file = data->files[i];
2703                unsigned long damage = file->added + file->deleted;
2704                if (file->is_binary)
2705                        /*
2706                         * binary files counts bytes, not lines. Must find some
2707                         * way to normalize binary bytes vs. textual lines.
2708                         * The following heuristic assumes that there are 64
2709                         * bytes per "line".
2710                         * This is stupid and ugly, but very cheap...
2711                         */
2712                        damage = (damage + 63) / 64;
2713                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2714                dir.files[dir.nr].name = file->name;
2715                dir.files[dir.nr].changed = damage;
2716                changed += damage;
2717                dir.nr++;
2718        }
2719
2720        /* This can happen even with many files, if everything was renames */
2721        if (!changed)
2722                return;
2723
2724        /* Show all directories with more than x% of the changes */
2725        QSORT(dir.files, dir.nr, dirstat_compare);
2726        gather_dirstat(options, &dir, changed, "", 0);
2727}
2728
2729static void free_diffstat_info(struct diffstat_t *diffstat)
2730{
2731        int i;
2732        for (i = 0; i < diffstat->nr; i++) {
2733                struct diffstat_file *f = diffstat->files[i];
2734                if (f->name != f->print_name)
2735                        free(f->print_name);
2736                free(f->name);
2737                free(f->from_name);
2738                free(f);
2739        }
2740        free(diffstat->files);
2741}
2742
2743struct checkdiff_t {
2744        const char *filename;
2745        int lineno;
2746        int conflict_marker_size;
2747        struct diff_options *o;
2748        unsigned ws_rule;
2749        unsigned status;
2750};
2751
2752static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2753{
2754        char firstchar;
2755        int cnt;
2756
2757        if (len < marker_size + 1)
2758                return 0;
2759        firstchar = line[0];
2760        switch (firstchar) {
2761        case '=': case '>': case '<': case '|':
2762                break;
2763        default:
2764                return 0;
2765        }
2766        for (cnt = 1; cnt < marker_size; cnt++)
2767                if (line[cnt] != firstchar)
2768                        return 0;
2769        /* line[1] thru line[marker_size-1] are same as firstchar */
2770        if (len < marker_size + 1 || !isspace(line[marker_size]))
2771                return 0;
2772        return 1;
2773}
2774
2775static void checkdiff_consume(void *priv, char *line, unsigned long len)
2776{
2777        struct checkdiff_t *data = priv;
2778        int marker_size = data->conflict_marker_size;
2779        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2780        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2781        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2782        char *err;
2783        const char *line_prefix;
2784
2785        assert(data->o);
2786        line_prefix = diff_line_prefix(data->o);
2787
2788        if (line[0] == '+') {
2789                unsigned bad;
2790                data->lineno++;
2791                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2792                        data->status |= 1;
2793                        fprintf(data->o->file,
2794                                "%s%s:%d: leftover conflict marker\n",
2795                                line_prefix, data->filename, data->lineno);
2796                }
2797                bad = ws_check(line + 1, len - 1, data->ws_rule);
2798                if (!bad)
2799                        return;
2800                data->status |= bad;
2801                err = whitespace_error_string(bad);
2802                fprintf(data->o->file, "%s%s:%d: %s.\n",
2803                        line_prefix, data->filename, data->lineno, err);
2804                free(err);
2805                emit_line(data->o, set, reset, line, 1);
2806                ws_check_emit(line + 1, len - 1, data->ws_rule,
2807                              data->o->file, set, reset, ws);
2808        } else if (line[0] == ' ') {
2809                data->lineno++;
2810        } else if (line[0] == '@') {
2811                char *plus = strchr(line, '+');
2812                if (plus)
2813                        data->lineno = strtol(plus, NULL, 10) - 1;
2814                else
2815                        die("invalid diff");
2816        }
2817}
2818
2819static unsigned char *deflate_it(char *data,
2820                                 unsigned long size,
2821                                 unsigned long *result_size)
2822{
2823        int bound;
2824        unsigned char *deflated;
2825        git_zstream stream;
2826
2827        git_deflate_init(&stream, zlib_compression_level);
2828        bound = git_deflate_bound(&stream, size);
2829        deflated = xmalloc(bound);
2830        stream.next_out = deflated;
2831        stream.avail_out = bound;
2832
2833        stream.next_in = (unsigned char *)data;
2834        stream.avail_in = size;
2835        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2836                ; /* nothing */
2837        git_deflate_end(&stream);
2838        *result_size = stream.total_out;
2839        return deflated;
2840}
2841
2842static void emit_binary_diff_body(struct diff_options *o,
2843                                  mmfile_t *one, mmfile_t *two)
2844{
2845        void *cp;
2846        void *delta;
2847        void *deflated;
2848        void *data;
2849        unsigned long orig_size;
2850        unsigned long delta_size;
2851        unsigned long deflate_size;
2852        unsigned long data_size;
2853
2854        /* We could do deflated delta, or we could do just deflated two,
2855         * whichever is smaller.
2856         */
2857        delta = NULL;
2858        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2859        if (one->size && two->size) {
2860                delta = diff_delta(one->ptr, one->size,
2861                                   two->ptr, two->size,
2862                                   &delta_size, deflate_size);
2863                if (delta) {
2864                        void *to_free = delta;
2865                        orig_size = delta_size;
2866                        delta = deflate_it(delta, delta_size, &delta_size);
2867                        free(to_free);
2868                }
2869        }
2870
2871        if (delta && delta_size < deflate_size) {
2872                char *s = xstrfmt("%lu", orig_size);
2873                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2874                                 s, strlen(s), 0);
2875                free(s);
2876                free(deflated);
2877                data = delta;
2878                data_size = delta_size;
2879        } else {
2880                char *s = xstrfmt("%lu", two->size);
2881                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2882                                 s, strlen(s), 0);
2883                free(s);
2884                free(delta);
2885                data = deflated;
2886                data_size = deflate_size;
2887        }
2888
2889        /* emit data encoded in base85 */
2890        cp = data;
2891        while (data_size) {
2892                int len;
2893                int bytes = (52 < data_size) ? 52 : data_size;
2894                char line[71];
2895                data_size -= bytes;
2896                if (bytes <= 26)
2897                        line[0] = bytes + 'A' - 1;
2898                else
2899                        line[0] = bytes - 26 + 'a' - 1;
2900                encode_85(line + 1, cp, bytes);
2901                cp = (char *) cp + bytes;
2902
2903                len = strlen(line);
2904                line[len++] = '\n';
2905                line[len] = '\0';
2906
2907                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2908                                 line, len, 0);
2909        }
2910        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2911        free(data);
2912}
2913
2914static void emit_binary_diff(struct diff_options *o,
2915                             mmfile_t *one, mmfile_t *two)
2916{
2917        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2918        emit_binary_diff_body(o, one, two);
2919        emit_binary_diff_body(o, two, one);
2920}
2921
2922int diff_filespec_is_binary(struct diff_filespec *one)
2923{
2924        if (one->is_binary == -1) {
2925                diff_filespec_load_driver(one);
2926                if (one->driver->binary != -1)
2927                        one->is_binary = one->driver->binary;
2928                else {
2929                        if (!one->data && DIFF_FILE_VALID(one))
2930                                diff_populate_filespec(one, CHECK_BINARY);
2931                        if (one->is_binary == -1 && one->data)
2932                                one->is_binary = buffer_is_binary(one->data,
2933                                                one->size);
2934                        if (one->is_binary == -1)
2935                                one->is_binary = 0;
2936                }
2937        }
2938        return one->is_binary;
2939}
2940
2941static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2942{
2943        diff_filespec_load_driver(one);
2944        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2945}
2946
2947void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2948{
2949        if (!options->a_prefix)
2950                options->a_prefix = a;
2951        if (!options->b_prefix)
2952                options->b_prefix = b;
2953}
2954
2955struct userdiff_driver *get_textconv(struct diff_filespec *one)
2956{
2957        if (!DIFF_FILE_VALID(one))
2958                return NULL;
2959
2960        diff_filespec_load_driver(one);
2961        return userdiff_get_textconv(one->driver);
2962}
2963
2964static void builtin_diff(const char *name_a,
2965                         const char *name_b,
2966                         struct diff_filespec *one,
2967                         struct diff_filespec *two,
2968                         const char *xfrm_msg,
2969                         int must_show_header,
2970                         struct diff_options *o,
2971                         int complete_rewrite)
2972{
2973        mmfile_t mf1, mf2;
2974        const char *lbl[2];
2975        char *a_one, *b_two;
2976        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2977        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2978        const char *a_prefix, *b_prefix;
2979        struct userdiff_driver *textconv_one = NULL;
2980        struct userdiff_driver *textconv_two = NULL;
2981        struct strbuf header = STRBUF_INIT;
2982        const char *line_prefix = diff_line_prefix(o);
2983
2984        diff_set_mnemonic_prefix(o, "a/", "b/");
2985        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2986                a_prefix = o->b_prefix;
2987                b_prefix = o->a_prefix;
2988        } else {
2989                a_prefix = o->a_prefix;
2990                b_prefix = o->b_prefix;
2991        }
2992
2993        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2994            (!one->mode || S_ISGITLINK(one->mode)) &&
2995            (!two->mode || S_ISGITLINK(two->mode))) {
2996                show_submodule_summary(o, one->path ? one->path : two->path,
2997                                &one->oid, &two->oid,
2998                                two->dirty_submodule);
2999                return;
3000        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3001                   (!one->mode || S_ISGITLINK(one->mode)) &&
3002                   (!two->mode || S_ISGITLINK(two->mode))) {
3003                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3004                                &one->oid, &two->oid,
3005                                two->dirty_submodule);
3006                return;
3007        }
3008
3009        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
3010                textconv_one = get_textconv(one);
3011                textconv_two = get_textconv(two);
3012        }
3013
3014        /* Never use a non-valid filename anywhere if at all possible */
3015        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3016        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3017
3018        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3019        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3020        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3021        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3022        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3023        if (lbl[0][0] == '/') {
3024                /* /dev/null */
3025                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3026                if (xfrm_msg)
3027                        strbuf_addstr(&header, xfrm_msg);
3028                must_show_header = 1;
3029        }
3030        else if (lbl[1][0] == '/') {
3031                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3032                if (xfrm_msg)
3033                        strbuf_addstr(&header, xfrm_msg);
3034                must_show_header = 1;
3035        }
3036        else {
3037                if (one->mode != two->mode) {
3038                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3039                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3040                        must_show_header = 1;
3041                }
3042                if (xfrm_msg)
3043                        strbuf_addstr(&header, xfrm_msg);
3044
3045                /*
3046                 * we do not run diff between different kind
3047                 * of objects.
3048                 */
3049                if ((one->mode ^ two->mode) & S_IFMT)
3050                        goto free_ab_and_return;
3051                if (complete_rewrite &&
3052                    (textconv_one || !diff_filespec_is_binary(one)) &&
3053                    (textconv_two || !diff_filespec_is_binary(two))) {
3054                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3055                                         header.buf, header.len, 0);
3056                        strbuf_reset(&header);
3057                        emit_rewrite_diff(name_a, name_b, one, two,
3058                                                textconv_one, textconv_two, o);
3059                        o->found_changes = 1;
3060                        goto free_ab_and_return;
3061                }
3062        }
3063
3064        if (o->irreversible_delete && lbl[1][0] == '/') {
3065                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3066                                 header.len, 0);
3067                strbuf_reset(&header);
3068                goto free_ab_and_return;
3069        } else if (!DIFF_OPT_TST(o, TEXT) &&
3070            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3071              (!textconv_two && diff_filespec_is_binary(two)) )) {
3072                struct strbuf sb = STRBUF_INIT;
3073                if (!one->data && !two->data &&
3074                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3075                    !DIFF_OPT_TST(o, BINARY)) {
3076                        if (!oidcmp(&one->oid, &two->oid)) {
3077                                if (must_show_header)
3078                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3079                                                         header.buf, header.len,
3080                                                         0);
3081                                goto free_ab_and_return;
3082                        }
3083                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3084                                         header.buf, header.len, 0);
3085                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3086                                    diff_line_prefix(o), lbl[0], lbl[1]);
3087                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3088                                         sb.buf, sb.len, 0);
3089                        strbuf_release(&sb);
3090                        goto free_ab_and_return;
3091                }
3092                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3093                        die("unable to read files to diff");
3094                /* Quite common confusing case */
3095                if (mf1.size == mf2.size &&
3096                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3097                        if (must_show_header)
3098                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3099                                                 header.buf, header.len, 0);
3100                        goto free_ab_and_return;
3101                }
3102                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3103                strbuf_reset(&header);
3104                if (DIFF_OPT_TST(o, BINARY))
3105                        emit_binary_diff(o, &mf1, &mf2);
3106                else {
3107                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3108                                    diff_line_prefix(o), lbl[0], lbl[1]);
3109                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3110                                         sb.buf, sb.len, 0);
3111                        strbuf_release(&sb);
3112                }
3113                o->found_changes = 1;
3114        } else {
3115                /* Crazy xdl interfaces.. */
3116                const char *diffopts = getenv("GIT_DIFF_OPTS");
3117                const char *v;
3118                xpparam_t xpp;
3119                xdemitconf_t xecfg;
3120                struct emit_callback ecbdata;
3121                const struct userdiff_funcname *pe;
3122
3123                if (must_show_header) {
3124                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3125                                         header.buf, header.len, 0);
3126                        strbuf_reset(&header);
3127                }
3128
3129                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3130                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3131
3132                pe = diff_funcname_pattern(one);
3133                if (!pe)
3134                        pe = diff_funcname_pattern(two);
3135
3136                memset(&xpp, 0, sizeof(xpp));
3137                memset(&xecfg, 0, sizeof(xecfg));
3138                memset(&ecbdata, 0, sizeof(ecbdata));
3139                ecbdata.label_path = lbl;
3140                ecbdata.color_diff = want_color(o->use_color);
3141                ecbdata.ws_rule = whitespace_rule(name_b);
3142                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3143                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3144                ecbdata.opt = o;
3145                ecbdata.header = header.len ? &header : NULL;
3146                xpp.flags = o->xdl_opts;
3147                xecfg.ctxlen = o->context;
3148                xecfg.interhunkctxlen = o->interhunkcontext;
3149                xecfg.flags = XDL_EMIT_FUNCNAMES;
3150                if (DIFF_OPT_TST(o, FUNCCONTEXT))
3151                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3152                if (pe)
3153                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3154                if (!diffopts)
3155                        ;
3156                else if (skip_prefix(diffopts, "--unified=", &v))
3157                        xecfg.ctxlen = strtoul(v, NULL, 10);
3158                else if (skip_prefix(diffopts, "-u", &v))
3159                        xecfg.ctxlen = strtoul(v, NULL, 10);
3160                if (o->word_diff)
3161                        init_diff_words_data(&ecbdata, o, one, two);
3162                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3163                                  &xpp, &xecfg))
3164                        die("unable to generate diff for %s", one->path);
3165                if (o->word_diff)
3166                        free_diff_words_data(&ecbdata);
3167                if (textconv_one)
3168                        free(mf1.ptr);
3169                if (textconv_two)
3170                        free(mf2.ptr);
3171                xdiff_clear_find_func(&xecfg);
3172        }
3173
3174 free_ab_and_return:
3175        strbuf_release(&header);
3176        diff_free_filespec_data(one);
3177        diff_free_filespec_data(two);
3178        free(a_one);
3179        free(b_two);
3180        return;
3181}
3182
3183static void builtin_diffstat(const char *name_a, const char *name_b,
3184                             struct diff_filespec *one,
3185                             struct diff_filespec *two,
3186                             struct diffstat_t *diffstat,
3187                             struct diff_options *o,
3188                             struct diff_filepair *p)
3189{
3190        mmfile_t mf1, mf2;
3191        struct diffstat_file *data;
3192        int same_contents;
3193        int complete_rewrite = 0;
3194
3195        if (!DIFF_PAIR_UNMERGED(p)) {
3196                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3197                        complete_rewrite = 1;
3198        }
3199
3200        data = diffstat_add(diffstat, name_a, name_b);
3201        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3202
3203        if (!one || !two) {
3204                data->is_unmerged = 1;
3205                return;
3206        }
3207
3208        same_contents = !oidcmp(&one->oid, &two->oid);
3209
3210        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3211                data->is_binary = 1;
3212                if (same_contents) {
3213                        data->added = 0;
3214                        data->deleted = 0;
3215                } else {
3216                        data->added = diff_filespec_size(two);
3217                        data->deleted = diff_filespec_size(one);
3218                }
3219        }
3220
3221        else if (complete_rewrite) {
3222                diff_populate_filespec(one, 0);
3223                diff_populate_filespec(two, 0);
3224                data->deleted = count_lines(one->data, one->size);
3225                data->added = count_lines(two->data, two->size);
3226        }
3227
3228        else if (!same_contents) {
3229                /* Crazy xdl interfaces.. */
3230                xpparam_t xpp;
3231                xdemitconf_t xecfg;
3232
3233                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3234                        die("unable to read files to diff");
3235
3236                memset(&xpp, 0, sizeof(xpp));
3237                memset(&xecfg, 0, sizeof(xecfg));
3238                xpp.flags = o->xdl_opts;
3239                xecfg.ctxlen = o->context;
3240                xecfg.interhunkctxlen = o->interhunkcontext;
3241                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3242                                  &xpp, &xecfg))
3243                        die("unable to generate diffstat for %s", one->path);
3244        }
3245
3246        diff_free_filespec_data(one);
3247        diff_free_filespec_data(two);
3248}
3249
3250static void builtin_checkdiff(const char *name_a, const char *name_b,
3251                              const char *attr_path,
3252                              struct diff_filespec *one,
3253                              struct diff_filespec *two,
3254                              struct diff_options *o)
3255{
3256        mmfile_t mf1, mf2;
3257        struct checkdiff_t data;
3258
3259        if (!two)
3260                return;
3261
3262        memset(&data, 0, sizeof(data));
3263        data.filename = name_b ? name_b : name_a;
3264        data.lineno = 0;
3265        data.o = o;
3266        data.ws_rule = whitespace_rule(attr_path);
3267        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3268
3269        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3270                die("unable to read files to diff");
3271
3272        /*
3273         * All the other codepaths check both sides, but not checking
3274         * the "old" side here is deliberate.  We are checking the newly
3275         * introduced changes, and as long as the "new" side is text, we
3276         * can and should check what it introduces.
3277         */
3278        if (diff_filespec_is_binary(two))
3279                goto free_and_return;
3280        else {
3281                /* Crazy xdl interfaces.. */
3282                xpparam_t xpp;
3283                xdemitconf_t xecfg;
3284
3285                memset(&xpp, 0, sizeof(xpp));
3286                memset(&xecfg, 0, sizeof(xecfg));
3287                xecfg.ctxlen = 1; /* at least one context line */
3288                xpp.flags = 0;
3289                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3290                                  &xpp, &xecfg))
3291                        die("unable to generate checkdiff for %s", one->path);
3292
3293                if (data.ws_rule & WS_BLANK_AT_EOF) {
3294                        struct emit_callback ecbdata;
3295                        int blank_at_eof;
3296
3297                        ecbdata.ws_rule = data.ws_rule;
3298                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3299                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3300
3301                        if (blank_at_eof) {
3302                                static char *err;
3303                                if (!err)
3304                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3305                                fprintf(o->file, "%s:%d: %s.\n",
3306                                        data.filename, blank_at_eof, err);
3307                                data.status = 1; /* report errors */
3308                        }
3309                }
3310        }
3311 free_and_return:
3312        diff_free_filespec_data(one);
3313        diff_free_filespec_data(two);
3314        if (data.status)
3315                DIFF_OPT_SET(o, CHECK_FAILED);
3316}
3317
3318struct diff_filespec *alloc_filespec(const char *path)
3319{
3320        struct diff_filespec *spec;
3321
3322        FLEXPTR_ALLOC_STR(spec, path, path);
3323        spec->count = 1;
3324        spec->is_binary = -1;
3325        return spec;
3326}
3327
3328void free_filespec(struct diff_filespec *spec)
3329{
3330        if (!--spec->count) {
3331                diff_free_filespec_data(spec);
3332                free(spec);
3333        }
3334}
3335
3336void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3337                   int oid_valid, unsigned short mode)
3338{
3339        if (mode) {
3340                spec->mode = canon_mode(mode);
3341                oidcpy(&spec->oid, oid);
3342                spec->oid_valid = oid_valid;
3343        }
3344}
3345
3346/*
3347 * Given a name and sha1 pair, if the index tells us the file in
3348 * the work tree has that object contents, return true, so that
3349 * prepare_temp_file() does not have to inflate and extract.
3350 */
3351static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3352{
3353        const struct cache_entry *ce;
3354        struct stat st;
3355        int pos, len;
3356
3357        /*
3358         * We do not read the cache ourselves here, because the
3359         * benchmark with my previous version that always reads cache
3360         * shows that it makes things worse for diff-tree comparing
3361         * two linux-2.6 kernel trees in an already checked out work
3362         * tree.  This is because most diff-tree comparisons deal with
3363         * only a small number of files, while reading the cache is
3364         * expensive for a large project, and its cost outweighs the
3365         * savings we get by not inflating the object to a temporary
3366         * file.  Practically, this code only helps when we are used
3367         * by diff-cache --cached, which does read the cache before
3368         * calling us.
3369         */
3370        if (!active_cache)
3371                return 0;
3372
3373        /* We want to avoid the working directory if our caller
3374         * doesn't need the data in a normal file, this system
3375         * is rather slow with its stat/open/mmap/close syscalls,
3376         * and the object is contained in a pack file.  The pack
3377         * is probably already open and will be faster to obtain
3378         * the data through than the working directory.  Loose
3379         * objects however would tend to be slower as they need
3380         * to be individually opened and inflated.
3381         */
3382        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3383                return 0;
3384
3385        /*
3386         * Similarly, if we'd have to convert the file contents anyway, that
3387         * makes the optimization not worthwhile.
3388         */
3389        if (!want_file && would_convert_to_git(&the_index, name))
3390                return 0;
3391
3392        len = strlen(name);
3393        pos = cache_name_pos(name, len);
3394        if (pos < 0)
3395                return 0;
3396        ce = active_cache[pos];
3397
3398        /*
3399         * This is not the sha1 we are looking for, or
3400         * unreusable because it is not a regular file.
3401         */
3402        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3403                return 0;
3404
3405        /*
3406         * If ce is marked as "assume unchanged", there is no
3407         * guarantee that work tree matches what we are looking for.
3408         */
3409        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3410                return 0;
3411
3412        /*
3413         * If ce matches the file in the work tree, we can reuse it.
3414         */
3415        if (ce_uptodate(ce) ||
3416            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3417                return 1;
3418
3419        return 0;
3420}
3421
3422static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3423{
3424        struct strbuf buf = STRBUF_INIT;
3425        char *dirty = "";
3426
3427        /* Are we looking at the work tree? */
3428        if (s->dirty_submodule)
3429                dirty = "-dirty";
3430
3431        strbuf_addf(&buf, "Subproject commit %s%s\n",
3432                    oid_to_hex(&s->oid), dirty);
3433        s->size = buf.len;
3434        if (size_only) {
3435                s->data = NULL;
3436                strbuf_release(&buf);
3437        } else {
3438                s->data = strbuf_detach(&buf, NULL);
3439                s->should_free = 1;
3440        }
3441        return 0;
3442}
3443
3444/*
3445 * While doing rename detection and pickaxe operation, we may need to
3446 * grab the data for the blob (or file) for our own in-core comparison.
3447 * diff_filespec has data and size fields for this purpose.
3448 */
3449int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3450{
3451        int size_only = flags & CHECK_SIZE_ONLY;
3452        int err = 0;
3453        /*
3454         * demote FAIL to WARN to allow inspecting the situation
3455         * instead of refusing.
3456         */
3457        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3458                                    ? SAFE_CRLF_WARN
3459                                    : safe_crlf);
3460
3461        if (!DIFF_FILE_VALID(s))
3462                die("internal error: asking to populate invalid file.");
3463        if (S_ISDIR(s->mode))
3464                return -1;
3465
3466        if (s->data)
3467                return 0;
3468
3469        if (size_only && 0 < s->size)
3470                return 0;
3471
3472        if (S_ISGITLINK(s->mode))
3473                return diff_populate_gitlink(s, size_only);
3474
3475        if (!s->oid_valid ||
3476            reuse_worktree_file(s->path, &s->oid, 0)) {
3477                struct strbuf buf = STRBUF_INIT;
3478                struct stat st;
3479                int fd;
3480
3481                if (lstat(s->path, &st) < 0) {
3482                        if (errno == ENOENT) {
3483                        err_empty:
3484                                err = -1;
3485                        empty:
3486                                s->data = (char *)"";
3487                                s->size = 0;
3488                                return err;
3489                        }
3490                }
3491                s->size = xsize_t(st.st_size);
3492                if (!s->size)
3493                        goto empty;
3494                if (S_ISLNK(st.st_mode)) {
3495                        struct strbuf sb = STRBUF_INIT;
3496
3497                        if (strbuf_readlink(&sb, s->path, s->size))
3498                                goto err_empty;
3499                        s->size = sb.len;
3500                        s->data = strbuf_detach(&sb, NULL);
3501                        s->should_free = 1;
3502                        return 0;
3503                }
3504
3505                /*
3506                 * Even if the caller would be happy with getting
3507                 * only the size, we cannot return early at this
3508                 * point if the path requires us to run the content
3509                 * conversion.
3510                 */
3511                if (size_only && !would_convert_to_git(&the_index, s->path))
3512                        return 0;
3513
3514                /*
3515                 * Note: this check uses xsize_t(st.st_size) that may
3516                 * not be the true size of the blob after it goes
3517                 * through convert_to_git().  This may not strictly be
3518                 * correct, but the whole point of big_file_threshold
3519                 * and is_binary check being that we want to avoid
3520                 * opening the file and inspecting the contents, this
3521                 * is probably fine.
3522                 */
3523                if ((flags & CHECK_BINARY) &&
3524                    s->size > big_file_threshold && s->is_binary == -1) {
3525                        s->is_binary = 1;
3526                        return 0;
3527                }
3528                fd = open(s->path, O_RDONLY);
3529                if (fd < 0)
3530                        goto err_empty;
3531                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3532                close(fd);
3533                s->should_munmap = 1;
3534
3535                /*
3536                 * Convert from working tree format to canonical git format
3537                 */
3538                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3539                        size_t size = 0;
3540                        munmap(s->data, s->size);
3541                        s->should_munmap = 0;
3542                        s->data = strbuf_detach(&buf, &size);
3543                        s->size = size;
3544                        s->should_free = 1;
3545                }
3546        }
3547        else {
3548                enum object_type type;
3549                if (size_only || (flags & CHECK_BINARY)) {
3550                        type = sha1_object_info(s->oid.hash, &s->size);
3551                        if (type < 0)
3552                                die("unable to read %s",
3553                                    oid_to_hex(&s->oid));
3554                        if (size_only)
3555                                return 0;
3556                        if (s->size > big_file_threshold && s->is_binary == -1) {
3557                                s->is_binary = 1;
3558                                return 0;
3559                        }
3560                }
3561                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3562                if (!s->data)
3563                        die("unable to read %s", oid_to_hex(&s->oid));
3564                s->should_free = 1;
3565        }
3566        return 0;
3567}
3568
3569void diff_free_filespec_blob(struct diff_filespec *s)
3570{
3571        if (s->should_free)
3572                free(s->data);
3573        else if (s->should_munmap)
3574                munmap(s->data, s->size);
3575
3576        if (s->should_free || s->should_munmap) {
3577                s->should_free = s->should_munmap = 0;
3578                s->data = NULL;
3579        }
3580}
3581
3582void diff_free_filespec_data(struct diff_filespec *s)
3583{
3584        diff_free_filespec_blob(s);
3585        FREE_AND_NULL(s->cnt_data);
3586}
3587
3588static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3589                           void *blob,
3590                           unsigned long size,
3591                           const struct object_id *oid,
3592                           int mode)
3593{
3594        int fd;
3595        struct strbuf buf = STRBUF_INIT;
3596        struct strbuf template = STRBUF_INIT;
3597        char *path_dup = xstrdup(path);
3598        const char *base = basename(path_dup);
3599
3600        /* Generate "XXXXXX_basename.ext" */
3601        strbuf_addstr(&template, "XXXXXX_");
3602        strbuf_addstr(&template, base);
3603
3604        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3605        if (fd < 0)
3606                die_errno("unable to create temp-file");
3607        if (convert_to_working_tree(path,
3608                        (const char *)blob, (size_t)size, &buf)) {
3609                blob = buf.buf;
3610                size = buf.len;
3611        }
3612        if (write_in_full(fd, blob, size) != size)
3613                die_errno("unable to write temp-file");
3614        close_tempfile(&temp->tempfile);
3615        temp->name = get_tempfile_path(&temp->tempfile);
3616        oid_to_hex_r(temp->hex, oid);
3617        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3618        strbuf_release(&buf);
3619        strbuf_release(&template);
3620        free(path_dup);
3621}
3622
3623static struct diff_tempfile *prepare_temp_file(const char *name,
3624                struct diff_filespec *one)
3625{
3626        struct diff_tempfile *temp = claim_diff_tempfile();
3627
3628        if (!DIFF_FILE_VALID(one)) {
3629        not_a_valid_file:
3630                /* A '-' entry produces this for file-2, and
3631                 * a '+' entry produces this for file-1.
3632                 */
3633                temp->name = "/dev/null";
3634                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3635                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3636                return temp;
3637        }
3638
3639        if (!S_ISGITLINK(one->mode) &&
3640            (!one->oid_valid ||
3641             reuse_worktree_file(name, &one->oid, 1))) {
3642                struct stat st;
3643                if (lstat(name, &st) < 0) {
3644                        if (errno == ENOENT)
3645                                goto not_a_valid_file;
3646                        die_errno("stat(%s)", name);
3647                }
3648                if (S_ISLNK(st.st_mode)) {
3649                        struct strbuf sb = STRBUF_INIT;
3650                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3651                                die_errno("readlink(%s)", name);
3652                        prep_temp_blob(name, temp, sb.buf, sb.len,
3653                                       (one->oid_valid ?
3654                                        &one->oid : &null_oid),
3655                                       (one->oid_valid ?
3656                                        one->mode : S_IFLNK));
3657                        strbuf_release(&sb);
3658                }
3659                else {
3660                        /* we can borrow from the file in the work tree */
3661                        temp->name = name;
3662                        if (!one->oid_valid)
3663                                oid_to_hex_r(temp->hex, &null_oid);
3664                        else
3665                                oid_to_hex_r(temp->hex, &one->oid);
3666                        /* Even though we may sometimes borrow the
3667                         * contents from the work tree, we always want
3668                         * one->mode.  mode is trustworthy even when
3669                         * !(one->oid_valid), as long as
3670                         * DIFF_FILE_VALID(one).
3671                         */
3672                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3673                }
3674                return temp;
3675        }
3676        else {
3677                if (diff_populate_filespec(one, 0))
3678                        die("cannot read data blob for %s", one->path);
3679                prep_temp_blob(name, temp, one->data, one->size,
3680                               &one->oid, one->mode);
3681        }
3682        return temp;
3683}
3684
3685static void add_external_diff_name(struct argv_array *argv,
3686                                   const char *name,
3687                                   struct diff_filespec *df)
3688{
3689        struct diff_tempfile *temp = prepare_temp_file(name, df);
3690        argv_array_push(argv, temp->name);
3691        argv_array_push(argv, temp->hex);
3692        argv_array_push(argv, temp->mode);
3693}
3694
3695/* An external diff command takes:
3696 *
3697 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3698 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3699 *
3700 */
3701static void run_external_diff(const char *pgm,
3702                              const char *name,
3703                              const char *other,
3704                              struct diff_filespec *one,
3705                              struct diff_filespec *two,
3706                              const char *xfrm_msg,
3707                              int complete_rewrite,
3708                              struct diff_options *o)
3709{
3710        struct argv_array argv = ARGV_ARRAY_INIT;
3711        struct argv_array env = ARGV_ARRAY_INIT;
3712        struct diff_queue_struct *q = &diff_queued_diff;
3713
3714        argv_array_push(&argv, pgm);
3715        argv_array_push(&argv, name);
3716
3717        if (one && two) {
3718                add_external_diff_name(&argv, name, one);
3719                if (!other)
3720                        add_external_diff_name(&argv, name, two);
3721                else {
3722                        add_external_diff_name(&argv, other, two);
3723                        argv_array_push(&argv, other);
3724                        argv_array_push(&argv, xfrm_msg);
3725                }
3726        }
3727
3728        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3729        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3730
3731        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3732                die(_("external diff died, stopping at %s"), name);
3733
3734        remove_tempfile();
3735        argv_array_clear(&argv);
3736        argv_array_clear(&env);
3737}
3738
3739static int similarity_index(struct diff_filepair *p)
3740{
3741        return p->score * 100 / MAX_SCORE;
3742}
3743
3744static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3745{
3746        if (startup_info->have_repository)
3747                return find_unique_abbrev(oid->hash, abbrev);
3748        else {
3749                char *hex = oid_to_hex(oid);
3750                if (abbrev < 0)
3751                        abbrev = FALLBACK_DEFAULT_ABBREV;
3752                if (abbrev > GIT_SHA1_HEXSZ)
3753                        die("BUG: oid abbreviation out of range: %d", abbrev);
3754                if (abbrev)
3755                        hex[abbrev] = '\0';
3756                return hex;
3757        }
3758}
3759
3760static void fill_metainfo(struct strbuf *msg,
3761                          const char *name,
3762                          const char *other,
3763                          struct diff_filespec *one,
3764                          struct diff_filespec *two,
3765                          struct diff_options *o,
3766                          struct diff_filepair *p,
3767                          int *must_show_header,
3768                          int use_color)
3769{
3770        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3771        const char *reset = diff_get_color(use_color, DIFF_RESET);
3772        const char *line_prefix = diff_line_prefix(o);
3773
3774        *must_show_header = 1;
3775        strbuf_init(msg, PATH_MAX * 2 + 300);
3776        switch (p->status) {
3777        case DIFF_STATUS_COPIED:
3778                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3779                            line_prefix, set, similarity_index(p));
3780                strbuf_addf(msg, "%s\n%s%scopy from ",
3781                            reset,  line_prefix, set);
3782                quote_c_style(name, msg, NULL, 0);
3783                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3784                quote_c_style(other, msg, NULL, 0);
3785                strbuf_addf(msg, "%s\n", reset);
3786                break;
3787        case DIFF_STATUS_RENAMED:
3788                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3789                            line_prefix, set, similarity_index(p));
3790                strbuf_addf(msg, "%s\n%s%srename from ",
3791                            reset, line_prefix, set);
3792                quote_c_style(name, msg, NULL, 0);
3793                strbuf_addf(msg, "%s\n%s%srename to ",
3794                            reset, line_prefix, set);
3795                quote_c_style(other, msg, NULL, 0);
3796                strbuf_addf(msg, "%s\n", reset);
3797                break;
3798        case DIFF_STATUS_MODIFIED:
3799                if (p->score) {
3800                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3801                                    line_prefix,
3802                                    set, similarity_index(p), reset);
3803                        break;
3804                }
3805                /* fallthru */
3806        default:
3807                *must_show_header = 0;
3808        }
3809        if (one && two && oidcmp(&one->oid, &two->oid)) {
3810                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3811
3812                if (DIFF_OPT_TST(o, BINARY)) {
3813                        mmfile_t mf;
3814                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3815                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3816                                abbrev = 40;
3817                }
3818                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3819                            diff_abbrev_oid(&one->oid, abbrev),
3820                            diff_abbrev_oid(&two->oid, abbrev));
3821                if (one->mode == two->mode)
3822                        strbuf_addf(msg, " %06o", one->mode);
3823                strbuf_addf(msg, "%s\n", reset);
3824        }
3825}
3826
3827static void run_diff_cmd(const char *pgm,
3828                         const char *name,
3829                         const char *other,
3830                         const char *attr_path,
3831                         struct diff_filespec *one,
3832                         struct diff_filespec *two,
3833                         struct strbuf *msg,
3834                         struct diff_options *o,
3835                         struct diff_filepair *p)
3836{
3837        const char *xfrm_msg = NULL;
3838        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3839        int must_show_header = 0;
3840
3841
3842        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3843                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3844                if (drv && drv->external)
3845                        pgm = drv->external;
3846        }
3847
3848        if (msg) {
3849                /*
3850                 * don't use colors when the header is intended for an
3851                 * external diff driver
3852                 */
3853                fill_metainfo(msg, name, other, one, two, o, p,
3854                              &must_show_header,
3855                              want_color(o->use_color) && !pgm);
3856                xfrm_msg = msg->len ? msg->buf : NULL;
3857        }
3858
3859        if (pgm) {
3860                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3861                                  complete_rewrite, o);
3862                return;
3863        }
3864        if (one && two)
3865                builtin_diff(name, other ? other : name,
3866                             one, two, xfrm_msg, must_show_header,
3867                             o, complete_rewrite);
3868        else
3869                fprintf(o->file, "* Unmerged path %s\n", name);
3870}
3871
3872static void diff_fill_oid_info(struct diff_filespec *one)
3873{
3874        if (DIFF_FILE_VALID(one)) {
3875                if (!one->oid_valid) {
3876                        struct stat st;
3877                        if (one->is_stdin) {
3878                                oidclr(&one->oid);
3879                                return;
3880                        }
3881                        if (lstat(one->path, &st) < 0)
3882                                die_errno("stat '%s'", one->path);
3883                        if (index_path(one->oid.hash, one->path, &st, 0))
3884                                die("cannot hash %s", one->path);
3885                }
3886        }
3887        else
3888                oidclr(&one->oid);
3889}
3890
3891static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3892{
3893        /* Strip the prefix but do not molest /dev/null and absolute paths */
3894        if (*namep && **namep != '/') {
3895                *namep += prefix_length;
3896                if (**namep == '/')
3897                        ++*namep;
3898        }
3899        if (*otherp && **otherp != '/') {
3900                *otherp += prefix_length;
3901                if (**otherp == '/')
3902                        ++*otherp;
3903        }
3904}
3905
3906static void run_diff(struct diff_filepair *p, struct diff_options *o)
3907{
3908        const char *pgm = external_diff();
3909        struct strbuf msg;
3910        struct diff_filespec *one = p->one;
3911        struct diff_filespec *two = p->two;
3912        const char *name;
3913        const char *other;
3914        const char *attr_path;
3915
3916        name  = one->path;
3917        other = (strcmp(name, two->path) ? two->path : NULL);
3918        attr_path = name;
3919        if (o->prefix_length)
3920                strip_prefix(o->prefix_length, &name, &other);
3921
3922        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3923                pgm = NULL;
3924
3925        if (DIFF_PAIR_UNMERGED(p)) {
3926                run_diff_cmd(pgm, name, NULL, attr_path,
3927                             NULL, NULL, NULL, o, p);
3928                return;
3929        }
3930
3931        diff_fill_oid_info(one);
3932        diff_fill_oid_info(two);
3933
3934        if (!pgm &&
3935            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3936            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3937                /*
3938                 * a filepair that changes between file and symlink
3939                 * needs to be split into deletion and creation.
3940                 */
3941                struct diff_filespec *null = alloc_filespec(two->path);
3942                run_diff_cmd(NULL, name, other, attr_path,
3943                             one, null, &msg, o, p);
3944                free(null);
3945                strbuf_release(&msg);
3946
3947                null = alloc_filespec(one->path);
3948                run_diff_cmd(NULL, name, other, attr_path,
3949                             null, two, &msg, o, p);
3950                free(null);
3951        }
3952        else
3953                run_diff_cmd(pgm, name, other, attr_path,
3954                             one, two, &msg, o, p);
3955
3956        strbuf_release(&msg);
3957}
3958
3959static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3960                         struct diffstat_t *diffstat)
3961{
3962        const char *name;
3963        const char *other;
3964
3965        if (DIFF_PAIR_UNMERGED(p)) {
3966                /* unmerged */
3967                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3968                return;
3969        }
3970
3971        name = p->one->path;
3972        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3973
3974        if (o->prefix_length)
3975                strip_prefix(o->prefix_length, &name, &other);
3976
3977        diff_fill_oid_info(p->one);
3978        diff_fill_oid_info(p->two);
3979
3980        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3981}
3982
3983static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3984{
3985        const char *name;
3986        const char *other;
3987        const char *attr_path;
3988
3989        if (DIFF_PAIR_UNMERGED(p)) {
3990                /* unmerged */
3991                return;
3992        }
3993
3994        name = p->one->path;
3995        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3996        attr_path = other ? other : name;
3997
3998        if (o->prefix_length)
3999                strip_prefix(o->prefix_length, &name, &other);
4000
4001        diff_fill_oid_info(p->one);
4002        diff_fill_oid_info(p->two);
4003
4004        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4005}
4006
4007void diff_setup(struct diff_options *options)
4008{
4009        memcpy(options, &default_diff_options, sizeof(*options));
4010
4011        options->file = stdout;
4012
4013        options->abbrev = DEFAULT_ABBREV;
4014        options->line_termination = '\n';
4015        options->break_opt = -1;
4016        options->rename_limit = -1;
4017        options->dirstat_permille = diff_dirstat_permille_default;
4018        options->context = diff_context_default;
4019        options->interhunkcontext = diff_interhunk_context_default;
4020        options->ws_error_highlight = ws_error_highlight_default;
4021        DIFF_OPT_SET(options, RENAME_EMPTY);
4022
4023        /* pathchange left =NULL by default */
4024        options->change = diff_change;
4025        options->add_remove = diff_addremove;
4026        options->use_color = diff_use_color_default;
4027        options->detect_rename = diff_detect_rename_default;
4028        options->xdl_opts |= diff_algorithm;
4029        if (diff_indent_heuristic)
4030                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4031
4032        options->orderfile = diff_order_file_cfg;
4033
4034        if (diff_no_prefix) {
4035                options->a_prefix = options->b_prefix = "";
4036        } else if (!diff_mnemonic_prefix) {
4037                options->a_prefix = "a/";
4038                options->b_prefix = "b/";
4039        }
4040
4041        options->color_moved = diff_color_moved_default;
4042}
4043
4044void diff_setup_done(struct diff_options *options)
4045{
4046        int count = 0;
4047
4048        if (options->set_default)
4049                options->set_default(options);
4050
4051        if (options->output_format & DIFF_FORMAT_NAME)
4052                count++;
4053        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
4054                count++;
4055        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
4056                count++;
4057        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
4058                count++;
4059        if (count > 1)
4060                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4061
4062        /*
4063         * Most of the time we can say "there are changes"
4064         * only by checking if there are changed paths, but
4065         * --ignore-whitespace* options force us to look
4066         * inside contents.
4067         */
4068
4069        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
4070            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
4071            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
4072                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
4073        else
4074                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
4075
4076        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
4077                options->detect_rename = DIFF_DETECT_COPY;
4078
4079        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
4080                options->prefix = NULL;
4081        if (options->prefix)
4082                options->prefix_length = strlen(options->prefix);
4083        else
4084                options->prefix_length = 0;
4085
4086        if (options->output_format & (DIFF_FORMAT_NAME |
4087                                      DIFF_FORMAT_NAME_STATUS |
4088                                      DIFF_FORMAT_CHECKDIFF |
4089                                      DIFF_FORMAT_NO_OUTPUT))
4090                options->output_format &= ~(DIFF_FORMAT_RAW |
4091                                            DIFF_FORMAT_NUMSTAT |
4092                                            DIFF_FORMAT_DIFFSTAT |
4093                                            DIFF_FORMAT_SHORTSTAT |
4094                                            DIFF_FORMAT_DIRSTAT |
4095                                            DIFF_FORMAT_SUMMARY |
4096                                            DIFF_FORMAT_PATCH);
4097
4098        /*
4099         * These cases always need recursive; we do not drop caller-supplied
4100         * recursive bits for other formats here.
4101         */
4102        if (options->output_format & (DIFF_FORMAT_PATCH |
4103                                      DIFF_FORMAT_NUMSTAT |
4104                                      DIFF_FORMAT_DIFFSTAT |
4105                                      DIFF_FORMAT_SHORTSTAT |
4106                                      DIFF_FORMAT_DIRSTAT |
4107                                      DIFF_FORMAT_SUMMARY |
4108                                      DIFF_FORMAT_CHECKDIFF))
4109                DIFF_OPT_SET(options, RECURSIVE);
4110        /*
4111         * Also pickaxe would not work very well if you do not say recursive
4112         */
4113        if (options->pickaxe)
4114                DIFF_OPT_SET(options, RECURSIVE);
4115        /*
4116         * When patches are generated, submodules diffed against the work tree
4117         * must be checked for dirtiness too so it can be shown in the output
4118         */
4119        if (options->output_format & DIFF_FORMAT_PATCH)
4120                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
4121
4122        if (options->detect_rename && options->rename_limit < 0)
4123                options->rename_limit = diff_rename_limit_default;
4124        if (options->setup & DIFF_SETUP_USE_CACHE) {
4125                if (!active_cache)
4126                        /* read-cache does not die even when it fails
4127                         * so it is safe for us to do this here.  Also
4128                         * it does not smudge active_cache or active_nr
4129                         * when it fails, so we do not have to worry about
4130                         * cleaning it up ourselves either.
4131                         */
4132                        read_cache();
4133        }
4134        if (40 < options->abbrev)
4135                options->abbrev = 40; /* full */
4136
4137        /*
4138         * It does not make sense to show the first hit we happened
4139         * to have found.  It does not make sense not to return with
4140         * exit code in such a case either.
4141         */
4142        if (DIFF_OPT_TST(options, QUICK)) {
4143                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4144                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4145        }
4146
4147        options->diff_path_counter = 0;
4148
4149        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
4150                die(_("--follow requires exactly one pathspec"));
4151
4152        if (!options->use_color || external_diff())
4153                options->color_moved = 0;
4154}
4155
4156static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4157{
4158        char c, *eq;
4159        int len;
4160
4161        if (*arg != '-')
4162                return 0;
4163        c = *++arg;
4164        if (!c)
4165                return 0;
4166        if (c == arg_short) {
4167                c = *++arg;
4168                if (!c)
4169                        return 1;
4170                if (val && isdigit(c)) {
4171                        char *end;
4172                        int n = strtoul(arg, &end, 10);
4173                        if (*end)
4174                                return 0;
4175                        *val = n;
4176                        return 1;
4177                }
4178                return 0;
4179        }
4180        if (c != '-')
4181                return 0;
4182        arg++;
4183        eq = strchrnul(arg, '=');
4184        len = eq - arg;
4185        if (!len || strncmp(arg, arg_long, len))
4186                return 0;
4187        if (*eq) {
4188                int n;
4189                char *end;
4190                if (!isdigit(*++eq))
4191                        return 0;
4192                n = strtoul(eq, &end, 10);
4193                if (*end)
4194                        return 0;
4195                *val = n;
4196        }
4197        return 1;
4198}
4199
4200static int diff_scoreopt_parse(const char *opt);
4201
4202static inline int short_opt(char opt, const char **argv,
4203                            const char **optarg)
4204{
4205        const char *arg = argv[0];
4206        if (arg[0] != '-' || arg[1] != opt)
4207                return 0;
4208        if (arg[2] != '\0') {
4209                *optarg = arg + 2;
4210                return 1;
4211        }
4212        if (!argv[1])
4213                die("Option '%c' requires a value", opt);
4214        *optarg = argv[1];
4215        return 2;
4216}
4217
4218int parse_long_opt(const char *opt, const char **argv,
4219                   const char **optarg)
4220{
4221        const char *arg = argv[0];
4222        if (!skip_prefix(arg, "--", &arg))
4223                return 0;
4224        if (!skip_prefix(arg, opt, &arg))
4225                return 0;
4226        if (*arg == '=') { /* stuck form: --option=value */
4227                *optarg = arg + 1;
4228                return 1;
4229        }
4230        if (*arg != '\0')
4231                return 0;
4232        /* separate form: --option value */
4233        if (!argv[1])
4234                die("Option '--%s' requires a value", opt);
4235        *optarg = argv[1];
4236        return 2;
4237}
4238
4239static int stat_opt(struct diff_options *options, const char **av)
4240{
4241        const char *arg = av[0];
4242        char *end;
4243        int width = options->stat_width;
4244        int name_width = options->stat_name_width;
4245        int graph_width = options->stat_graph_width;
4246        int count = options->stat_count;
4247        int argcount = 1;
4248
4249        if (!skip_prefix(arg, "--stat", &arg))
4250                die("BUG: stat option does not begin with --stat: %s", arg);
4251        end = (char *)arg;
4252
4253        switch (*arg) {
4254        case '-':
4255                if (skip_prefix(arg, "-width", &arg)) {
4256                        if (*arg == '=')
4257                                width = strtoul(arg + 1, &end, 10);
4258                        else if (!*arg && !av[1])
4259                                die_want_option("--stat-width");
4260                        else if (!*arg) {
4261                                width = strtoul(av[1], &end, 10);
4262                                argcount = 2;
4263                        }
4264                } else if (skip_prefix(arg, "-name-width", &arg)) {
4265                        if (*arg == '=')
4266                                name_width = strtoul(arg + 1, &end, 10);
4267                        else if (!*arg && !av[1])
4268                                die_want_option("--stat-name-width");
4269                        else if (!*arg) {
4270                                name_width = strtoul(av[1], &end, 10);
4271                                argcount = 2;
4272                        }
4273                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4274                        if (*arg == '=')
4275                                graph_width = strtoul(arg + 1, &end, 10);
4276                        else if (!*arg && !av[1])
4277                                die_want_option("--stat-graph-width");
4278                        else if (!*arg) {
4279                                graph_width = strtoul(av[1], &end, 10);
4280                                argcount = 2;
4281                        }
4282                } else if (skip_prefix(arg, "-count", &arg)) {
4283                        if (*arg == '=')
4284                                count = strtoul(arg + 1, &end, 10);
4285                        else if (!*arg && !av[1])
4286                                die_want_option("--stat-count");
4287                        else if (!*arg) {
4288                                count = strtoul(av[1], &end, 10);
4289                                argcount = 2;
4290                        }
4291                }
4292                break;
4293        case '=':
4294                width = strtoul(arg+1, &end, 10);
4295                if (*end == ',')
4296                        name_width = strtoul(end+1, &end, 10);
4297                if (*end == ',')
4298                        count = strtoul(end+1, &end, 10);
4299        }
4300
4301        /* Important! This checks all the error cases! */
4302        if (*end)
4303                return 0;
4304        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4305        options->stat_name_width = name_width;
4306        options->stat_graph_width = graph_width;
4307        options->stat_width = width;
4308        options->stat_count = count;
4309        return argcount;
4310}
4311
4312static int parse_dirstat_opt(struct diff_options *options, const char *params)
4313{
4314        struct strbuf errmsg = STRBUF_INIT;
4315        if (parse_dirstat_params(options, params, &errmsg))
4316                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4317                    errmsg.buf);
4318        strbuf_release(&errmsg);
4319        /*
4320         * The caller knows a dirstat-related option is given from the command
4321         * line; allow it to say "return this_function();"
4322         */
4323        options->output_format |= DIFF_FORMAT_DIRSTAT;
4324        return 1;
4325}
4326
4327static int parse_submodule_opt(struct diff_options *options, const char *value)
4328{
4329        if (parse_submodule_params(options, value))
4330                die(_("Failed to parse --submodule option parameter: '%s'"),
4331                        value);
4332        return 1;
4333}
4334
4335static const char diff_status_letters[] = {
4336        DIFF_STATUS_ADDED,
4337        DIFF_STATUS_COPIED,
4338        DIFF_STATUS_DELETED,
4339        DIFF_STATUS_MODIFIED,
4340        DIFF_STATUS_RENAMED,
4341        DIFF_STATUS_TYPE_CHANGED,
4342        DIFF_STATUS_UNKNOWN,
4343        DIFF_STATUS_UNMERGED,
4344        DIFF_STATUS_FILTER_AON,
4345        DIFF_STATUS_FILTER_BROKEN,
4346        '\0',
4347};
4348
4349static unsigned int filter_bit['Z' + 1];
4350
4351static void prepare_filter_bits(void)
4352{
4353        int i;
4354
4355        if (!filter_bit[DIFF_STATUS_ADDED]) {
4356                for (i = 0; diff_status_letters[i]; i++)
4357                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4358        }
4359}
4360
4361static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4362{
4363        return opt->filter & filter_bit[(int) status];
4364}
4365
4366static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4367{
4368        int i, optch;
4369
4370        prepare_filter_bits();
4371
4372        /*
4373         * If there is a negation e.g. 'd' in the input, and we haven't
4374         * initialized the filter field with another --diff-filter, start
4375         * from full set of bits, except for AON.
4376         */
4377        if (!opt->filter) {
4378                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4379                        if (optch < 'a' || 'z' < optch)
4380                                continue;
4381                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4382                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4383                        break;
4384                }
4385        }
4386
4387        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4388                unsigned int bit;
4389                int negate;
4390
4391                if ('a' <= optch && optch <= 'z') {
4392                        negate = 1;
4393                        optch = toupper(optch);
4394                } else {
4395                        negate = 0;
4396                }
4397
4398                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4399                if (!bit)
4400                        return optarg[i];
4401                if (negate)
4402                        opt->filter &= ~bit;
4403                else
4404                        opt->filter |= bit;
4405        }
4406        return 0;
4407}
4408
4409static void enable_patch_output(int *fmt) {
4410        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4411        *fmt |= DIFF_FORMAT_PATCH;
4412}
4413
4414static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4415{
4416        int val = parse_ws_error_highlight(arg);
4417
4418        if (val < 0) {
4419                error("unknown value after ws-error-highlight=%.*s",
4420                      -1 - val, arg);
4421                return 0;
4422        }
4423        opt->ws_error_highlight = val;
4424        return 1;
4425}
4426
4427int diff_opt_parse(struct diff_options *options,
4428                   const char **av, int ac, const char *prefix)
4429{
4430        const char *arg = av[0];
4431        const char *optarg;
4432        int argcount;
4433
4434        if (!prefix)
4435                prefix = "";
4436
4437        /* Output format options */
4438        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4439            || opt_arg(arg, 'U', "unified", &options->context))
4440                enable_patch_output(&options->output_format);
4441        else if (!strcmp(arg, "--raw"))
4442                options->output_format |= DIFF_FORMAT_RAW;
4443        else if (!strcmp(arg, "--patch-with-raw")) {
4444                enable_patch_output(&options->output_format);
4445                options->output_format |= DIFF_FORMAT_RAW;
4446        } else if (!strcmp(arg, "--numstat"))
4447                options->output_format |= DIFF_FORMAT_NUMSTAT;
4448        else if (!strcmp(arg, "--shortstat"))
4449                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4450        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4451                return parse_dirstat_opt(options, "");
4452        else if (skip_prefix(arg, "-X", &arg))
4453                return parse_dirstat_opt(options, arg);
4454        else if (skip_prefix(arg, "--dirstat=", &arg))
4455                return parse_dirstat_opt(options, arg);
4456        else if (!strcmp(arg, "--cumulative"))
4457                return parse_dirstat_opt(options, "cumulative");
4458        else if (!strcmp(arg, "--dirstat-by-file"))
4459                return parse_dirstat_opt(options, "files");
4460        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4461                parse_dirstat_opt(options, "files");
4462                return parse_dirstat_opt(options, arg);
4463        }
4464        else if (!strcmp(arg, "--check"))
4465                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4466        else if (!strcmp(arg, "--summary"))
4467                options->output_format |= DIFF_FORMAT_SUMMARY;
4468        else if (!strcmp(arg, "--patch-with-stat")) {
4469                enable_patch_output(&options->output_format);
4470                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4471        } else if (!strcmp(arg, "--name-only"))
4472                options->output_format |= DIFF_FORMAT_NAME;
4473        else if (!strcmp(arg, "--name-status"))
4474                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4475        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4476                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4477        else if (starts_with(arg, "--stat"))
4478                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4479                return stat_opt(options, av);
4480
4481        /* renames options */
4482        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4483                 !strcmp(arg, "--break-rewrites")) {
4484                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4485                        return error("invalid argument to -B: %s", arg+2);
4486        }
4487        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4488                 !strcmp(arg, "--find-renames")) {
4489                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4490                        return error("invalid argument to -M: %s", arg+2);
4491                options->detect_rename = DIFF_DETECT_RENAME;
4492        }
4493        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4494                options->irreversible_delete = 1;
4495        }
4496        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4497                 !strcmp(arg, "--find-copies")) {
4498                if (options->detect_rename == DIFF_DETECT_COPY)
4499                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4500                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4501                        return error("invalid argument to -C: %s", arg+2);
4502                options->detect_rename = DIFF_DETECT_COPY;
4503        }
4504        else if (!strcmp(arg, "--no-renames"))
4505                options->detect_rename = 0;
4506        else if (!strcmp(arg, "--rename-empty"))
4507                DIFF_OPT_SET(options, RENAME_EMPTY);
4508        else if (!strcmp(arg, "--no-rename-empty"))
4509                DIFF_OPT_CLR(options, RENAME_EMPTY);
4510        else if (!strcmp(arg, "--relative"))
4511                DIFF_OPT_SET(options, RELATIVE_NAME);
4512        else if (skip_prefix(arg, "--relative=", &arg)) {
4513                DIFF_OPT_SET(options, RELATIVE_NAME);
4514                options->prefix = arg;
4515        }
4516
4517        /* xdiff options */
4518        else if (!strcmp(arg, "--minimal"))
4519                DIFF_XDL_SET(options, NEED_MINIMAL);
4520        else if (!strcmp(arg, "--no-minimal"))
4521                DIFF_XDL_CLR(options, NEED_MINIMAL);
4522        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4523                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4524        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4525                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4526        else if (!strcmp(arg, "--ignore-space-at-eol"))
4527                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4528        else if (!strcmp(arg, "--ignore-blank-lines"))
4529                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4530        else if (!strcmp(arg, "--indent-heuristic"))
4531                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4532        else if (!strcmp(arg, "--no-indent-heuristic"))
4533                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4534        else if (!strcmp(arg, "--patience"))
4535                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4536        else if (!strcmp(arg, "--histogram"))
4537                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4538        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4539                long value = parse_algorithm_value(optarg);
4540                if (value < 0)
4541                        return error("option diff-algorithm accepts \"myers\", "
4542                                     "\"minimal\", \"patience\" and \"histogram\"");
4543                /* clear out previous settings */
4544                DIFF_XDL_CLR(options, NEED_MINIMAL);
4545                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4546                options->xdl_opts |= value;
4547                return argcount;
4548        }
4549
4550        /* flags options */
4551        else if (!strcmp(arg, "--binary")) {
4552                enable_patch_output(&options->output_format);
4553                DIFF_OPT_SET(options, BINARY);
4554        }
4555        else if (!strcmp(arg, "--full-index"))
4556                DIFF_OPT_SET(options, FULL_INDEX);
4557        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4558                DIFF_OPT_SET(options, TEXT);
4559        else if (!strcmp(arg, "-R"))
4560                DIFF_OPT_SET(options, REVERSE_DIFF);
4561        else if (!strcmp(arg, "--find-copies-harder"))
4562                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4563        else if (!strcmp(arg, "--follow"))
4564                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4565        else if (!strcmp(arg, "--no-follow")) {
4566                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4567                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4568        } else if (!strcmp(arg, "--color"))
4569                options->use_color = 1;
4570        else if (skip_prefix(arg, "--color=", &arg)) {
4571                int value = git_config_colorbool(NULL, arg);
4572                if (value < 0)
4573                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4574                options->use_color = value;
4575        }
4576        else if (!strcmp(arg, "--no-color"))
4577                options->use_color = 0;
4578        else if (!strcmp(arg, "--color-moved")) {
4579                if (diff_color_moved_default)
4580                        options->color_moved = diff_color_moved_default;
4581                if (options->color_moved == COLOR_MOVED_NO)
4582                        options->color_moved = COLOR_MOVED_DEFAULT;
4583        } else if (!strcmp(arg, "--no-color-moved"))
4584                options->color_moved = COLOR_MOVED_NO;
4585        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4586                int cm = parse_color_moved(arg);
4587                if (cm < 0)
4588                        die("bad --color-moved argument: %s", arg);
4589                options->color_moved = cm;
4590        } else if (!strcmp(arg, "--color-words")) {
4591                options->use_color = 1;
4592                options->word_diff = DIFF_WORDS_COLOR;
4593        }
4594        else if (skip_prefix(arg, "--color-words=", &arg)) {
4595                options->use_color = 1;
4596                options->word_diff = DIFF_WORDS_COLOR;
4597                options->word_regex = arg;
4598        }
4599        else if (!strcmp(arg, "--word-diff")) {
4600                if (options->word_diff == DIFF_WORDS_NONE)
4601                        options->word_diff = DIFF_WORDS_PLAIN;
4602        }
4603        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4604                if (!strcmp(arg, "plain"))
4605                        options->word_diff = DIFF_WORDS_PLAIN;
4606                else if (!strcmp(arg, "color")) {
4607                        options->use_color = 1;
4608                        options->word_diff = DIFF_WORDS_COLOR;
4609                }
4610                else if (!strcmp(arg, "porcelain"))
4611                        options->word_diff = DIFF_WORDS_PORCELAIN;
4612                else if (!strcmp(arg, "none"))
4613                        options->word_diff = DIFF_WORDS_NONE;
4614                else
4615                        die("bad --word-diff argument: %s", arg);
4616        }
4617        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4618                if (options->word_diff == DIFF_WORDS_NONE)
4619                        options->word_diff = DIFF_WORDS_PLAIN;
4620                options->word_regex = optarg;
4621                return argcount;
4622        }
4623        else if (!strcmp(arg, "--exit-code"))
4624                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4625        else if (!strcmp(arg, "--quiet"))
4626                DIFF_OPT_SET(options, QUICK);
4627        else if (!strcmp(arg, "--ext-diff"))
4628                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4629        else if (!strcmp(arg, "--no-ext-diff"))
4630                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4631        else if (!strcmp(arg, "--textconv"))
4632                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4633        else if (!strcmp(arg, "--no-textconv"))
4634                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4635        else if (!strcmp(arg, "--ignore-submodules")) {
4636                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4637                handle_ignore_submodules_arg(options, "all");
4638        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4639                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4640                handle_ignore_submodules_arg(options, arg);
4641        } else if (!strcmp(arg, "--submodule"))
4642                options->submodule_format = DIFF_SUBMODULE_LOG;
4643        else if (skip_prefix(arg, "--submodule=", &arg))
4644                return parse_submodule_opt(options, arg);
4645        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4646                return parse_ws_error_highlight_opt(options, arg);
4647        else if (!strcmp(arg, "--ita-invisible-in-index"))
4648                options->ita_invisible_in_index = 1;
4649        else if (!strcmp(arg, "--ita-visible-in-index"))
4650                options->ita_invisible_in_index = 0;
4651
4652        /* misc options */
4653        else if (!strcmp(arg, "-z"))
4654                options->line_termination = 0;
4655        else if ((argcount = short_opt('l', av, &optarg))) {
4656                options->rename_limit = strtoul(optarg, NULL, 10);
4657                return argcount;
4658        }
4659        else if ((argcount = short_opt('S', av, &optarg))) {
4660                options->pickaxe = optarg;
4661                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4662                return argcount;
4663        } else if ((argcount = short_opt('G', av, &optarg))) {
4664                options->pickaxe = optarg;
4665                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4666                return argcount;
4667        }
4668        else if (!strcmp(arg, "--pickaxe-all"))
4669                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4670        else if (!strcmp(arg, "--pickaxe-regex"))
4671                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4672        else if ((argcount = short_opt('O', av, &optarg))) {
4673                options->orderfile = prefix_filename(prefix, optarg);
4674                return argcount;
4675        }
4676        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4677                int offending = parse_diff_filter_opt(optarg, options);
4678                if (offending)
4679                        die("unknown change class '%c' in --diff-filter=%s",
4680                            offending, optarg);
4681                return argcount;
4682        }
4683        else if (!strcmp(arg, "--no-abbrev"))
4684                options->abbrev = 0;
4685        else if (!strcmp(arg, "--abbrev"))
4686                options->abbrev = DEFAULT_ABBREV;
4687        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4688                options->abbrev = strtoul(arg, NULL, 10);
4689                if (options->abbrev < MINIMUM_ABBREV)
4690                        options->abbrev = MINIMUM_ABBREV;
4691                else if (40 < options->abbrev)
4692                        options->abbrev = 40;
4693        }
4694        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4695                options->a_prefix = optarg;
4696                return argcount;
4697        }
4698        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4699                options->line_prefix = optarg;
4700                options->line_prefix_length = strlen(options->line_prefix);
4701                graph_setup_line_prefix(options);
4702                return argcount;
4703        }
4704        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4705                options->b_prefix = optarg;
4706                return argcount;
4707        }
4708        else if (!strcmp(arg, "--no-prefix"))
4709                options->a_prefix = options->b_prefix = "";
4710        else if (opt_arg(arg, '\0', "inter-hunk-context",
4711                         &options->interhunkcontext))
4712                ;
4713        else if (!strcmp(arg, "-W"))
4714                DIFF_OPT_SET(options, FUNCCONTEXT);
4715        else if (!strcmp(arg, "--function-context"))
4716                DIFF_OPT_SET(options, FUNCCONTEXT);
4717        else if (!strcmp(arg, "--no-function-context"))
4718                DIFF_OPT_CLR(options, FUNCCONTEXT);
4719        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4720                char *path = prefix_filename(prefix, optarg);
4721                options->file = xfopen(path, "w");
4722                options->close_file = 1;
4723                if (options->use_color != GIT_COLOR_ALWAYS)
4724                        options->use_color = GIT_COLOR_NEVER;
4725                free(path);
4726                return argcount;
4727        } else
4728                return 0;
4729        return 1;
4730}
4731
4732int parse_rename_score(const char **cp_p)
4733{
4734        unsigned long num, scale;
4735        int ch, dot;
4736        const char *cp = *cp_p;
4737
4738        num = 0;
4739        scale = 1;
4740        dot = 0;
4741        for (;;) {
4742                ch = *cp;
4743                if ( !dot && ch == '.' ) {
4744                        scale = 1;
4745                        dot = 1;
4746                } else if ( ch == '%' ) {
4747                        scale = dot ? scale*100 : 100;
4748                        cp++;   /* % is always at the end */
4749                        break;
4750                } else if ( ch >= '0' && ch <= '9' ) {
4751                        if ( scale < 100000 ) {
4752                                scale *= 10;
4753                                num = (num*10) + (ch-'0');
4754                        }
4755                } else {
4756                        break;
4757                }
4758                cp++;
4759        }
4760        *cp_p = cp;
4761
4762        /* user says num divided by scale and we say internally that
4763         * is MAX_SCORE * num / scale.
4764         */
4765        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4766}
4767
4768static int diff_scoreopt_parse(const char *opt)
4769{
4770        int opt1, opt2, cmd;
4771
4772        if (*opt++ != '-')
4773                return -1;
4774        cmd = *opt++;
4775        if (cmd == '-') {
4776                /* convert the long-form arguments into short-form versions */
4777                if (skip_prefix(opt, "break-rewrites", &opt)) {
4778                        if (*opt == 0 || *opt++ == '=')
4779                                cmd = 'B';
4780                } else if (skip_prefix(opt, "find-copies", &opt)) {
4781                        if (*opt == 0 || *opt++ == '=')
4782                                cmd = 'C';
4783                } else if (skip_prefix(opt, "find-renames", &opt)) {
4784                        if (*opt == 0 || *opt++ == '=')
4785                                cmd = 'M';
4786                }
4787        }
4788        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4789                return -1; /* that is not a -M, -C, or -B option */
4790
4791        opt1 = parse_rename_score(&opt);
4792        if (cmd != 'B')
4793                opt2 = 0;
4794        else {
4795                if (*opt == 0)
4796                        opt2 = 0;
4797                else if (*opt != '/')
4798                        return -1; /* we expect -B80/99 or -B80 */
4799                else {
4800                        opt++;
4801                        opt2 = parse_rename_score(&opt);
4802                }
4803        }
4804        if (*opt != 0)
4805                return -1;
4806        return opt1 | (opt2 << 16);
4807}
4808
4809struct diff_queue_struct diff_queued_diff;
4810
4811void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4812{
4813        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4814        queue->queue[queue->nr++] = dp;
4815}
4816
4817struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4818                                 struct diff_filespec *one,
4819                                 struct diff_filespec *two)
4820{
4821        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4822        dp->one = one;
4823        dp->two = two;
4824        if (queue)
4825                diff_q(queue, dp);
4826        return dp;
4827}
4828
4829void diff_free_filepair(struct diff_filepair *p)
4830{
4831        free_filespec(p->one);
4832        free_filespec(p->two);
4833        free(p);
4834}
4835
4836const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4837{
4838        int abblen;
4839        const char *abbrev;
4840
4841        if (len == GIT_SHA1_HEXSZ)
4842                return oid_to_hex(oid);
4843
4844        abbrev = diff_abbrev_oid(oid, len);
4845        abblen = strlen(abbrev);
4846
4847        /*
4848         * In well-behaved cases, where the abbbreviated result is the
4849         * same as the requested length, append three dots after the
4850         * abbreviation (hence the whole logic is limited to the case
4851         * where abblen < 37); when the actual abbreviated result is a
4852         * bit longer than the requested length, we reduce the number
4853         * of dots so that they match the well-behaved ones.  However,
4854         * if the actual abbreviation is longer than the requested
4855         * length by more than three, we give up on aligning, and add
4856         * three dots anyway, to indicate that the output is not the
4857         * full object name.  Yes, this may be suboptimal, but this
4858         * appears only in "diff --raw --abbrev" output and it is not
4859         * worth the effort to change it now.  Note that this would
4860         * likely to work fine when the automatic sizing of default
4861         * abbreviation length is used--we would be fed -1 in "len" in
4862         * that case, and will end up always appending three-dots, but
4863         * the automatic sizing is supposed to give abblen that ensures
4864         * uniqueness across all objects (statistically speaking).
4865         */
4866        if (abblen < GIT_SHA1_HEXSZ - 3) {
4867                static char hex[GIT_MAX_HEXSZ + 1];
4868                if (len < abblen && abblen <= len + 2)
4869                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4870                else
4871                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4872                return hex;
4873        }
4874
4875        return oid_to_hex(oid);
4876}
4877
4878static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4879{
4880        int line_termination = opt->line_termination;
4881        int inter_name_termination = line_termination ? '\t' : '\0';
4882
4883        fprintf(opt->file, "%s", diff_line_prefix(opt));
4884        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4885                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4886                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4887                fprintf(opt->file, "%s ",
4888                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4889        }
4890        if (p->score) {
4891                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4892                        inter_name_termination);
4893        } else {
4894                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4895        }
4896
4897        if (p->status == DIFF_STATUS_COPIED ||
4898            p->status == DIFF_STATUS_RENAMED) {
4899                const char *name_a, *name_b;
4900                name_a = p->one->path;
4901                name_b = p->two->path;
4902                strip_prefix(opt->prefix_length, &name_a, &name_b);
4903                write_name_quoted(name_a, opt->file, inter_name_termination);
4904                write_name_quoted(name_b, opt->file, line_termination);
4905        } else {
4906                const char *name_a, *name_b;
4907                name_a = p->one->mode ? p->one->path : p->two->path;
4908                name_b = NULL;
4909                strip_prefix(opt->prefix_length, &name_a, &name_b);
4910                write_name_quoted(name_a, opt->file, line_termination);
4911        }
4912}
4913
4914int diff_unmodified_pair(struct diff_filepair *p)
4915{
4916        /* This function is written stricter than necessary to support
4917         * the currently implemented transformers, but the idea is to
4918         * let transformers to produce diff_filepairs any way they want,
4919         * and filter and clean them up here before producing the output.
4920         */
4921        struct diff_filespec *one = p->one, *two = p->two;
4922
4923        if (DIFF_PAIR_UNMERGED(p))
4924                return 0; /* unmerged is interesting */
4925
4926        /* deletion, addition, mode or type change
4927         * and rename are all interesting.
4928         */
4929        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4930            DIFF_PAIR_MODE_CHANGED(p) ||
4931            strcmp(one->path, two->path))
4932                return 0;
4933
4934        /* both are valid and point at the same path.  that is, we are
4935         * dealing with a change.
4936         */
4937        if (one->oid_valid && two->oid_valid &&
4938            !oidcmp(&one->oid, &two->oid) &&
4939            !one->dirty_submodule && !two->dirty_submodule)
4940                return 1; /* no change */
4941        if (!one->oid_valid && !two->oid_valid)
4942                return 1; /* both look at the same file on the filesystem. */
4943        return 0;
4944}
4945
4946static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4947{
4948        if (diff_unmodified_pair(p))
4949                return;
4950
4951        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4952            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4953                return; /* no tree diffs in patch format */
4954
4955        run_diff(p, o);
4956}
4957
4958static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4959                            struct diffstat_t *diffstat)
4960{
4961        if (diff_unmodified_pair(p))
4962                return;
4963
4964        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4965            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4966                return; /* no useful stat for tree diffs */
4967
4968        run_diffstat(p, o, diffstat);
4969}
4970
4971static void diff_flush_checkdiff(struct diff_filepair *p,
4972                struct diff_options *o)
4973{
4974        if (diff_unmodified_pair(p))
4975                return;
4976
4977        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4978            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4979                return; /* nothing to check in tree diffs */
4980
4981        run_checkdiff(p, o);
4982}
4983
4984int diff_queue_is_empty(void)
4985{
4986        struct diff_queue_struct *q = &diff_queued_diff;
4987        int i;
4988        for (i = 0; i < q->nr; i++)
4989                if (!diff_unmodified_pair(q->queue[i]))
4990                        return 0;
4991        return 1;
4992}
4993
4994#if DIFF_DEBUG
4995void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4996{
4997        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4998                x, one ? one : "",
4999                s->path,
5000                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5001                s->mode,
5002                s->oid_valid ? oid_to_hex(&s->oid) : "");
5003        fprintf(stderr, "queue[%d] %s size %lu\n",
5004                x, one ? one : "",
5005                s->size);
5006}
5007
5008void diff_debug_filepair(const struct diff_filepair *p, int i)
5009{
5010        diff_debug_filespec(p->one, i, "one");
5011        diff_debug_filespec(p->two, i, "two");
5012        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5013                p->score, p->status ? p->status : '?',
5014                p->one->rename_used, p->broken_pair);
5015}
5016
5017void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5018{
5019        int i;
5020        if (msg)
5021                fprintf(stderr, "%s\n", msg);
5022        fprintf(stderr, "q->nr = %d\n", q->nr);
5023        for (i = 0; i < q->nr; i++) {
5024                struct diff_filepair *p = q->queue[i];
5025                diff_debug_filepair(p, i);
5026        }
5027}
5028#endif
5029
5030static void diff_resolve_rename_copy(void)
5031{
5032        int i;
5033        struct diff_filepair *p;
5034        struct diff_queue_struct *q = &diff_queued_diff;
5035
5036        diff_debug_queue("resolve-rename-copy", q);
5037
5038        for (i = 0; i < q->nr; i++) {
5039                p = q->queue[i];
5040                p->status = 0; /* undecided */
5041                if (DIFF_PAIR_UNMERGED(p))
5042                        p->status = DIFF_STATUS_UNMERGED;
5043                else if (!DIFF_FILE_VALID(p->one))
5044                        p->status = DIFF_STATUS_ADDED;
5045                else if (!DIFF_FILE_VALID(p->two))
5046                        p->status = DIFF_STATUS_DELETED;
5047                else if (DIFF_PAIR_TYPE_CHANGED(p))
5048                        p->status = DIFF_STATUS_TYPE_CHANGED;
5049
5050                /* from this point on, we are dealing with a pair
5051                 * whose both sides are valid and of the same type, i.e.
5052                 * either in-place edit or rename/copy edit.
5053                 */
5054                else if (DIFF_PAIR_RENAME(p)) {
5055                        /*
5056                         * A rename might have re-connected a broken
5057                         * pair up, causing the pathnames to be the
5058                         * same again. If so, that's not a rename at
5059                         * all, just a modification..
5060                         *
5061                         * Otherwise, see if this source was used for
5062                         * multiple renames, in which case we decrement
5063                         * the count, and call it a copy.
5064                         */
5065                        if (!strcmp(p->one->path, p->two->path))
5066                                p->status = DIFF_STATUS_MODIFIED;
5067                        else if (--p->one->rename_used > 0)
5068                                p->status = DIFF_STATUS_COPIED;
5069                        else
5070                                p->status = DIFF_STATUS_RENAMED;
5071                }
5072                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5073                         p->one->mode != p->two->mode ||
5074                         p->one->dirty_submodule ||
5075                         p->two->dirty_submodule ||
5076                         is_null_oid(&p->one->oid))
5077                        p->status = DIFF_STATUS_MODIFIED;
5078                else {
5079                        /* This is a "no-change" entry and should not
5080                         * happen anymore, but prepare for broken callers.
5081                         */
5082                        error("feeding unmodified %s to diffcore",
5083                              p->one->path);
5084                        p->status = DIFF_STATUS_UNKNOWN;
5085                }
5086        }
5087        diff_debug_queue("resolve-rename-copy done", q);
5088}
5089
5090static int check_pair_status(struct diff_filepair *p)
5091{
5092        switch (p->status) {
5093        case DIFF_STATUS_UNKNOWN:
5094                return 0;
5095        case 0:
5096                die("internal error in diff-resolve-rename-copy");
5097        default:
5098                return 1;
5099        }
5100}
5101
5102static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5103{
5104        int fmt = opt->output_format;
5105
5106        if (fmt & DIFF_FORMAT_CHECKDIFF)
5107                diff_flush_checkdiff(p, opt);
5108        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5109                diff_flush_raw(p, opt);
5110        else if (fmt & DIFF_FORMAT_NAME) {
5111                const char *name_a, *name_b;
5112                name_a = p->two->path;
5113                name_b = NULL;
5114                strip_prefix(opt->prefix_length, &name_a, &name_b);
5115                fprintf(opt->file, "%s", diff_line_prefix(opt));
5116                write_name_quoted(name_a, opt->file, opt->line_termination);
5117        }
5118}
5119
5120static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5121{
5122        struct strbuf sb = STRBUF_INIT;
5123        if (fs->mode)
5124                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5125        else
5126                strbuf_addf(&sb, " %s ", newdelete);
5127
5128        quote_c_style(fs->path, &sb, NULL, 0);
5129        strbuf_addch(&sb, '\n');
5130        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5131                         sb.buf, sb.len, 0);
5132        strbuf_release(&sb);
5133}
5134
5135static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5136                int show_name)
5137{
5138        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5139                struct strbuf sb = STRBUF_INIT;
5140                strbuf_addf(&sb, " mode change %06o => %06o",
5141                            p->one->mode, p->two->mode);
5142                if (show_name) {
5143                        strbuf_addch(&sb, ' ');
5144                        quote_c_style(p->two->path, &sb, NULL, 0);
5145                }
5146                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5147                                 sb.buf, sb.len, 0);
5148                strbuf_release(&sb);
5149        }
5150}
5151
5152static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5153                struct diff_filepair *p)
5154{
5155        struct strbuf sb = STRBUF_INIT;
5156        char *names = pprint_rename(p->one->path, p->two->path);
5157        strbuf_addf(&sb, " %s %s (%d%%)\n",
5158                        renamecopy, names, similarity_index(p));
5159        free(names);
5160        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5161                                 sb.buf, sb.len, 0);
5162        show_mode_change(opt, p, 0);
5163}
5164
5165static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5166{
5167        switch(p->status) {
5168        case DIFF_STATUS_DELETED:
5169                show_file_mode_name(opt, "delete", p->one);
5170                break;
5171        case DIFF_STATUS_ADDED:
5172                show_file_mode_name(opt, "create", p->two);
5173                break;
5174        case DIFF_STATUS_COPIED:
5175                show_rename_copy(opt, "copy", p);
5176                break;
5177        case DIFF_STATUS_RENAMED:
5178                show_rename_copy(opt, "rename", p);
5179                break;
5180        default:
5181                if (p->score) {
5182                        struct strbuf sb = STRBUF_INIT;
5183                        strbuf_addstr(&sb, " rewrite ");
5184                        quote_c_style(p->two->path, &sb, NULL, 0);
5185                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5186                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5187                                         sb.buf, sb.len, 0);
5188                }
5189                show_mode_change(opt, p, !p->score);
5190                break;
5191        }
5192}
5193
5194struct patch_id_t {
5195        git_SHA_CTX *ctx;
5196        int patchlen;
5197};
5198
5199static int remove_space(char *line, int len)
5200{
5201        int i;
5202        char *dst = line;
5203        unsigned char c;
5204
5205        for (i = 0; i < len; i++)
5206                if (!isspace((c = line[i])))
5207                        *dst++ = c;
5208
5209        return dst - line;
5210}
5211
5212static void patch_id_consume(void *priv, char *line, unsigned long len)
5213{
5214        struct patch_id_t *data = priv;
5215        int new_len;
5216
5217        /* Ignore line numbers when computing the SHA1 of the patch */
5218        if (starts_with(line, "@@ -"))
5219                return;
5220
5221        new_len = remove_space(line, len);
5222
5223        git_SHA1_Update(data->ctx, line, new_len);
5224        data->patchlen += new_len;
5225}
5226
5227static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5228{
5229        git_SHA1_Update(ctx, str, strlen(str));
5230}
5231
5232static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5233{
5234        /* large enough for 2^32 in octal */
5235        char buf[12];
5236        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5237        git_SHA1_Update(ctx, buf, len);
5238}
5239
5240/* returns 0 upon success, and writes result into sha1 */
5241static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5242{
5243        struct diff_queue_struct *q = &diff_queued_diff;
5244        int i;
5245        git_SHA_CTX ctx;
5246        struct patch_id_t data;
5247
5248        git_SHA1_Init(&ctx);
5249        memset(&data, 0, sizeof(struct patch_id_t));
5250        data.ctx = &ctx;
5251
5252        for (i = 0; i < q->nr; i++) {
5253                xpparam_t xpp;
5254                xdemitconf_t xecfg;
5255                mmfile_t mf1, mf2;
5256                struct diff_filepair *p = q->queue[i];
5257                int len1, len2;
5258
5259                memset(&xpp, 0, sizeof(xpp));
5260                memset(&xecfg, 0, sizeof(xecfg));
5261                if (p->status == 0)
5262                        return error("internal diff status error");
5263                if (p->status == DIFF_STATUS_UNKNOWN)
5264                        continue;
5265                if (diff_unmodified_pair(p))
5266                        continue;
5267                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5268                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5269                        continue;
5270                if (DIFF_PAIR_UNMERGED(p))
5271                        continue;
5272
5273                diff_fill_oid_info(p->one);
5274                diff_fill_oid_info(p->two);
5275
5276                len1 = remove_space(p->one->path, strlen(p->one->path));
5277                len2 = remove_space(p->two->path, strlen(p->two->path));
5278                patch_id_add_string(&ctx, "diff--git");
5279                patch_id_add_string(&ctx, "a/");
5280                git_SHA1_Update(&ctx, p->one->path, len1);
5281                patch_id_add_string(&ctx, "b/");
5282                git_SHA1_Update(&ctx, p->two->path, len2);
5283
5284                if (p->one->mode == 0) {
5285                        patch_id_add_string(&ctx, "newfilemode");
5286                        patch_id_add_mode(&ctx, p->two->mode);
5287                        patch_id_add_string(&ctx, "---/dev/null");
5288                        patch_id_add_string(&ctx, "+++b/");
5289                        git_SHA1_Update(&ctx, p->two->path, len2);
5290                } else if (p->two->mode == 0) {
5291                        patch_id_add_string(&ctx, "deletedfilemode");
5292                        patch_id_add_mode(&ctx, p->one->mode);
5293                        patch_id_add_string(&ctx, "---a/");
5294                        git_SHA1_Update(&ctx, p->one->path, len1);
5295                        patch_id_add_string(&ctx, "+++/dev/null");
5296                } else {
5297                        patch_id_add_string(&ctx, "---a/");
5298                        git_SHA1_Update(&ctx, p->one->path, len1);
5299                        patch_id_add_string(&ctx, "+++b/");
5300                        git_SHA1_Update(&ctx, p->two->path, len2);
5301                }
5302
5303                if (diff_header_only)
5304                        continue;
5305
5306                if (fill_mmfile(&mf1, p->one) < 0 ||
5307                    fill_mmfile(&mf2, p->two) < 0)
5308                        return error("unable to read files to diff");
5309
5310                if (diff_filespec_is_binary(p->one) ||
5311                    diff_filespec_is_binary(p->two)) {
5312                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5313                                        GIT_SHA1_HEXSZ);
5314                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5315                                        GIT_SHA1_HEXSZ);
5316                        continue;
5317                }
5318
5319                xpp.flags = 0;
5320                xecfg.ctxlen = 3;
5321                xecfg.flags = 0;
5322                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5323                                  &xpp, &xecfg))
5324                        return error("unable to generate patch-id diff for %s",
5325                                     p->one->path);
5326        }
5327
5328        git_SHA1_Final(oid->hash, &ctx);
5329        return 0;
5330}
5331
5332int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5333{
5334        struct diff_queue_struct *q = &diff_queued_diff;
5335        int i;
5336        int result = diff_get_patch_id(options, oid, diff_header_only);
5337
5338        for (i = 0; i < q->nr; i++)
5339                diff_free_filepair(q->queue[i]);
5340
5341        free(q->queue);
5342        DIFF_QUEUE_CLEAR(q);
5343
5344        return result;
5345}
5346
5347static int is_summary_empty(const struct diff_queue_struct *q)
5348{
5349        int i;
5350
5351        for (i = 0; i < q->nr; i++) {
5352                const struct diff_filepair *p = q->queue[i];
5353
5354                switch (p->status) {
5355                case DIFF_STATUS_DELETED:
5356                case DIFF_STATUS_ADDED:
5357                case DIFF_STATUS_COPIED:
5358                case DIFF_STATUS_RENAMED:
5359                        return 0;
5360                default:
5361                        if (p->score)
5362                                return 0;
5363                        if (p->one->mode && p->two->mode &&
5364                            p->one->mode != p->two->mode)
5365                                return 0;
5366                        break;
5367                }
5368        }
5369        return 1;
5370}
5371
5372static const char rename_limit_warning[] =
5373N_("inexact rename detection was skipped due to too many files.");
5374
5375static const char degrade_cc_to_c_warning[] =
5376N_("only found copies from modified paths due to too many files.");
5377
5378static const char rename_limit_advice[] =
5379N_("you may want to set your %s variable to at least "
5380   "%d and retry the command.");
5381
5382void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5383{
5384        if (degraded_cc)
5385                warning(_(degrade_cc_to_c_warning));
5386        else if (needed)
5387                warning(_(rename_limit_warning));
5388        else
5389                return;
5390        if (0 < needed && needed < 32767)
5391                warning(_(rename_limit_advice), varname, needed);
5392}
5393
5394static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5395{
5396        int i;
5397        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5398        struct diff_queue_struct *q = &diff_queued_diff;
5399
5400        if (WSEH_NEW & WS_RULE_MASK)
5401                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5402
5403        if (o->color_moved)
5404                o->emitted_symbols = &esm;
5405
5406        for (i = 0; i < q->nr; i++) {
5407                struct diff_filepair *p = q->queue[i];
5408                if (check_pair_status(p))
5409                        diff_flush_patch(p, o);
5410        }
5411
5412        if (o->emitted_symbols) {
5413                if (o->color_moved) {
5414                        struct hashmap add_lines, del_lines;
5415
5416                        hashmap_init(&del_lines,
5417                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5418                        hashmap_init(&add_lines,
5419                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5420
5421                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5422                        mark_color_as_moved(o, &add_lines, &del_lines);
5423
5424                        hashmap_free(&add_lines, 0);
5425                        hashmap_free(&del_lines, 0);
5426                }
5427
5428                for (i = 0; i < esm.nr; i++)
5429                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5430
5431                for (i = 0; i < esm.nr; i++)
5432                        free((void *)esm.buf[i].line);
5433        }
5434        esm.nr = 0;
5435}
5436
5437void diff_flush(struct diff_options *options)
5438{
5439        struct diff_queue_struct *q = &diff_queued_diff;
5440        int i, output_format = options->output_format;
5441        int separator = 0;
5442        int dirstat_by_line = 0;
5443
5444        /*
5445         * Order: raw, stat, summary, patch
5446         * or:    name/name-status/checkdiff (other bits clear)
5447         */
5448        if (!q->nr)
5449                goto free_queue;
5450
5451        if (output_format & (DIFF_FORMAT_RAW |
5452                             DIFF_FORMAT_NAME |
5453                             DIFF_FORMAT_NAME_STATUS |
5454                             DIFF_FORMAT_CHECKDIFF)) {
5455                for (i = 0; i < q->nr; i++) {
5456                        struct diff_filepair *p = q->queue[i];
5457                        if (check_pair_status(p))
5458                                flush_one_pair(p, options);
5459                }
5460                separator++;
5461        }
5462
5463        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
5464                dirstat_by_line = 1;
5465
5466        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5467            dirstat_by_line) {
5468                struct diffstat_t diffstat;
5469
5470                memset(&diffstat, 0, sizeof(struct diffstat_t));
5471                for (i = 0; i < q->nr; i++) {
5472                        struct diff_filepair *p = q->queue[i];
5473                        if (check_pair_status(p))
5474                                diff_flush_stat(p, options, &diffstat);
5475                }
5476                if (output_format & DIFF_FORMAT_NUMSTAT)
5477                        show_numstat(&diffstat, options);
5478                if (output_format & DIFF_FORMAT_DIFFSTAT)
5479                        show_stats(&diffstat, options);
5480                if (output_format & DIFF_FORMAT_SHORTSTAT)
5481                        show_shortstats(&diffstat, options);
5482                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5483                        show_dirstat_by_line(&diffstat, options);
5484                free_diffstat_info(&diffstat);
5485                separator++;
5486        }
5487        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5488                show_dirstat(options);
5489
5490        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5491                for (i = 0; i < q->nr; i++) {
5492                        diff_summary(options, q->queue[i]);
5493                }
5494                separator++;
5495        }
5496
5497        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5498            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5499            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5500                /*
5501                 * run diff_flush_patch for the exit status. setting
5502                 * options->file to /dev/null should be safe, because we
5503                 * aren't supposed to produce any output anyway.
5504                 */
5505                if (options->close_file)
5506                        fclose(options->file);
5507                options->file = xfopen("/dev/null", "w");
5508                options->close_file = 1;
5509                options->color_moved = 0;
5510                for (i = 0; i < q->nr; i++) {
5511                        struct diff_filepair *p = q->queue[i];
5512                        if (check_pair_status(p))
5513                                diff_flush_patch(p, options);
5514                        if (options->found_changes)
5515                                break;
5516                }
5517        }
5518
5519        if (output_format & DIFF_FORMAT_PATCH) {
5520                if (separator) {
5521                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5522                        if (options->stat_sep)
5523                                /* attach patch instead of inline */
5524                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5525                                                 NULL, 0, 0);
5526                }
5527
5528                diff_flush_patch_all_file_pairs(options);
5529        }
5530
5531        if (output_format & DIFF_FORMAT_CALLBACK)
5532                options->format_callback(q, options, options->format_callback_data);
5533
5534        for (i = 0; i < q->nr; i++)
5535                diff_free_filepair(q->queue[i]);
5536free_queue:
5537        free(q->queue);
5538        DIFF_QUEUE_CLEAR(q);
5539        if (options->close_file)
5540                fclose(options->file);
5541
5542        /*
5543         * Report the content-level differences with HAS_CHANGES;
5544         * diff_addremove/diff_change does not set the bit when
5545         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5546         */
5547        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5548                if (options->found_changes)
5549                        DIFF_OPT_SET(options, HAS_CHANGES);
5550                else
5551                        DIFF_OPT_CLR(options, HAS_CHANGES);
5552        }
5553}
5554
5555static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5556{
5557        return (((p->status == DIFF_STATUS_MODIFIED) &&
5558                 ((p->score &&
5559                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5560                  (!p->score &&
5561                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5562                ((p->status != DIFF_STATUS_MODIFIED) &&
5563                 filter_bit_tst(p->status, options)));
5564}
5565
5566static void diffcore_apply_filter(struct diff_options *options)
5567{
5568        int i;
5569        struct diff_queue_struct *q = &diff_queued_diff;
5570        struct diff_queue_struct outq;
5571
5572        DIFF_QUEUE_CLEAR(&outq);
5573
5574        if (!options->filter)
5575                return;
5576
5577        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5578                int found;
5579                for (i = found = 0; !found && i < q->nr; i++) {
5580                        if (match_filter(options, q->queue[i]))
5581                                found++;
5582                }
5583                if (found)
5584                        return;
5585
5586                /* otherwise we will clear the whole queue
5587                 * by copying the empty outq at the end of this
5588                 * function, but first clear the current entries
5589                 * in the queue.
5590                 */
5591                for (i = 0; i < q->nr; i++)
5592                        diff_free_filepair(q->queue[i]);
5593        }
5594        else {
5595                /* Only the matching ones */
5596                for (i = 0; i < q->nr; i++) {
5597                        struct diff_filepair *p = q->queue[i];
5598                        if (match_filter(options, p))
5599                                diff_q(&outq, p);
5600                        else
5601                                diff_free_filepair(p);
5602                }
5603        }
5604        free(q->queue);
5605        *q = outq;
5606}
5607
5608/* Check whether two filespecs with the same mode and size are identical */
5609static int diff_filespec_is_identical(struct diff_filespec *one,
5610                                      struct diff_filespec *two)
5611{
5612        if (S_ISGITLINK(one->mode))
5613                return 0;
5614        if (diff_populate_filespec(one, 0))
5615                return 0;
5616        if (diff_populate_filespec(two, 0))
5617                return 0;
5618        return !memcmp(one->data, two->data, one->size);
5619}
5620
5621static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5622{
5623        if (p->done_skip_stat_unmatch)
5624                return p->skip_stat_unmatch_result;
5625
5626        p->done_skip_stat_unmatch = 1;
5627        p->skip_stat_unmatch_result = 0;
5628        /*
5629         * 1. Entries that come from stat info dirtiness
5630         *    always have both sides (iow, not create/delete),
5631         *    one side of the object name is unknown, with
5632         *    the same mode and size.  Keep the ones that
5633         *    do not match these criteria.  They have real
5634         *    differences.
5635         *
5636         * 2. At this point, the file is known to be modified,
5637         *    with the same mode and size, and the object
5638         *    name of one side is unknown.  Need to inspect
5639         *    the identical contents.
5640         */
5641        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5642            !DIFF_FILE_VALID(p->two) ||
5643            (p->one->oid_valid && p->two->oid_valid) ||
5644            (p->one->mode != p->two->mode) ||
5645            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5646            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5647            (p->one->size != p->two->size) ||
5648            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5649                p->skip_stat_unmatch_result = 1;
5650        return p->skip_stat_unmatch_result;
5651}
5652
5653static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5654{
5655        int i;
5656        struct diff_queue_struct *q = &diff_queued_diff;
5657        struct diff_queue_struct outq;
5658        DIFF_QUEUE_CLEAR(&outq);
5659
5660        for (i = 0; i < q->nr; i++) {
5661                struct diff_filepair *p = q->queue[i];
5662
5663                if (diff_filespec_check_stat_unmatch(p))
5664                        diff_q(&outq, p);
5665                else {
5666                        /*
5667                         * The caller can subtract 1 from skip_stat_unmatch
5668                         * to determine how many paths were dirty only
5669                         * due to stat info mismatch.
5670                         */
5671                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5672                                diffopt->skip_stat_unmatch++;
5673                        diff_free_filepair(p);
5674                }
5675        }
5676        free(q->queue);
5677        *q = outq;
5678}
5679
5680static int diffnamecmp(const void *a_, const void *b_)
5681{
5682        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5683        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5684        const char *name_a, *name_b;
5685
5686        name_a = a->one ? a->one->path : a->two->path;
5687        name_b = b->one ? b->one->path : b->two->path;
5688        return strcmp(name_a, name_b);
5689}
5690
5691void diffcore_fix_diff_index(struct diff_options *options)
5692{
5693        struct diff_queue_struct *q = &diff_queued_diff;
5694        QSORT(q->queue, q->nr, diffnamecmp);
5695}
5696
5697void diffcore_std(struct diff_options *options)
5698{
5699        /* NOTE please keep the following in sync with diff_tree_combined() */
5700        if (options->skip_stat_unmatch)
5701                diffcore_skip_stat_unmatch(options);
5702        if (!options->found_follow) {
5703                /* See try_to_follow_renames() in tree-diff.c */
5704                if (options->break_opt != -1)
5705                        diffcore_break(options->break_opt);
5706                if (options->detect_rename)
5707                        diffcore_rename(options);
5708                if (options->break_opt != -1)
5709                        diffcore_merge_broken();
5710        }
5711        if (options->pickaxe)
5712                diffcore_pickaxe(options);
5713        if (options->orderfile)
5714                diffcore_order(options->orderfile);
5715        if (!options->found_follow)
5716                /* See try_to_follow_renames() in tree-diff.c */
5717                diff_resolve_rename_copy();
5718        diffcore_apply_filter(options);
5719
5720        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5721                DIFF_OPT_SET(options, HAS_CHANGES);
5722        else
5723                DIFF_OPT_CLR(options, HAS_CHANGES);
5724
5725        options->found_follow = 0;
5726}
5727
5728int diff_result_code(struct diff_options *opt, int status)
5729{
5730        int result = 0;
5731
5732        diff_warn_rename_limit("diff.renameLimit",
5733                               opt->needed_rename_limit,
5734                               opt->degraded_cc_to_c);
5735        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5736            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5737                return status;
5738        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5739            DIFF_OPT_TST(opt, HAS_CHANGES))
5740                result |= 01;
5741        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5742            DIFF_OPT_TST(opt, CHECK_FAILED))
5743                result |= 02;
5744        return result;
5745}
5746
5747int diff_can_quit_early(struct diff_options *opt)
5748{
5749        return (DIFF_OPT_TST(opt, QUICK) &&
5750                !opt->filter &&
5751                DIFF_OPT_TST(opt, HAS_CHANGES));
5752}
5753
5754/*
5755 * Shall changes to this submodule be ignored?
5756 *
5757 * Submodule changes can be configured to be ignored separately for each path,
5758 * but that configuration can be overridden from the command line.
5759 */
5760static int is_submodule_ignored(const char *path, struct diff_options *options)
5761{
5762        int ignored = 0;
5763        unsigned orig_flags = options->flags;
5764        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5765                set_diffopt_flags_from_submodule_config(options, path);
5766        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5767                ignored = 1;
5768        options->flags = orig_flags;
5769        return ignored;
5770}
5771
5772void diff_addremove(struct diff_options *options,
5773                    int addremove, unsigned mode,
5774                    const struct object_id *oid,
5775                    int oid_valid,
5776                    const char *concatpath, unsigned dirty_submodule)
5777{
5778        struct diff_filespec *one, *two;
5779
5780        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5781                return;
5782
5783        /* This may look odd, but it is a preparation for
5784         * feeding "there are unchanged files which should
5785         * not produce diffs, but when you are doing copy
5786         * detection you would need them, so here they are"
5787         * entries to the diff-core.  They will be prefixed
5788         * with something like '=' or '*' (I haven't decided
5789         * which but should not make any difference).
5790         * Feeding the same new and old to diff_change()
5791         * also has the same effect.
5792         * Before the final output happens, they are pruned after
5793         * merged into rename/copy pairs as appropriate.
5794         */
5795        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5796                addremove = (addremove == '+' ? '-' :
5797                             addremove == '-' ? '+' : addremove);
5798
5799        if (options->prefix &&
5800            strncmp(concatpath, options->prefix, options->prefix_length))
5801                return;
5802
5803        one = alloc_filespec(concatpath);
5804        two = alloc_filespec(concatpath);
5805
5806        if (addremove != '+')
5807                fill_filespec(one, oid, oid_valid, mode);
5808        if (addremove != '-') {
5809                fill_filespec(two, oid, oid_valid, mode);
5810                two->dirty_submodule = dirty_submodule;
5811        }
5812
5813        diff_queue(&diff_queued_diff, one, two);
5814        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5815                DIFF_OPT_SET(options, HAS_CHANGES);
5816}
5817
5818void diff_change(struct diff_options *options,
5819                 unsigned old_mode, unsigned new_mode,
5820                 const struct object_id *old_oid,
5821                 const struct object_id *new_oid,
5822                 int old_oid_valid, int new_oid_valid,
5823                 const char *concatpath,
5824                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5825{
5826        struct diff_filespec *one, *two;
5827        struct diff_filepair *p;
5828
5829        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5830            is_submodule_ignored(concatpath, options))
5831                return;
5832
5833        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5834                SWAP(old_mode, new_mode);
5835                SWAP(old_oid, new_oid);
5836                SWAP(old_oid_valid, new_oid_valid);
5837                SWAP(old_dirty_submodule, new_dirty_submodule);
5838        }
5839
5840        if (options->prefix &&
5841            strncmp(concatpath, options->prefix, options->prefix_length))
5842                return;
5843
5844        one = alloc_filespec(concatpath);
5845        two = alloc_filespec(concatpath);
5846        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5847        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5848        one->dirty_submodule = old_dirty_submodule;
5849        two->dirty_submodule = new_dirty_submodule;
5850        p = diff_queue(&diff_queued_diff, one, two);
5851
5852        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5853                return;
5854
5855        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5856            !diff_filespec_check_stat_unmatch(p))
5857                return;
5858
5859        DIFF_OPT_SET(options, HAS_CHANGES);
5860}
5861
5862struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5863{
5864        struct diff_filepair *pair;
5865        struct diff_filespec *one, *two;
5866
5867        if (options->prefix &&
5868            strncmp(path, options->prefix, options->prefix_length))
5869                return NULL;
5870
5871        one = alloc_filespec(path);
5872        two = alloc_filespec(path);
5873        pair = diff_queue(&diff_queued_diff, one, two);
5874        pair->is_unmerged = 1;
5875        return pair;
5876}
5877
5878static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5879                size_t *outsize)
5880{
5881        struct diff_tempfile *temp;
5882        const char *argv[3];
5883        const char **arg = argv;
5884        struct child_process child = CHILD_PROCESS_INIT;
5885        struct strbuf buf = STRBUF_INIT;
5886        int err = 0;
5887
5888        temp = prepare_temp_file(spec->path, spec);
5889        *arg++ = pgm;
5890        *arg++ = temp->name;
5891        *arg = NULL;
5892
5893        child.use_shell = 1;
5894        child.argv = argv;
5895        child.out = -1;
5896        if (start_command(&child)) {
5897                remove_tempfile();
5898                return NULL;
5899        }
5900
5901        if (strbuf_read(&buf, child.out, 0) < 0)
5902                err = error("error reading from textconv command '%s'", pgm);
5903        close(child.out);
5904
5905        if (finish_command(&child) || err) {
5906                strbuf_release(&buf);
5907                remove_tempfile();
5908                return NULL;
5909        }
5910        remove_tempfile();
5911
5912        return strbuf_detach(&buf, outsize);
5913}
5914
5915size_t fill_textconv(struct userdiff_driver *driver,
5916                     struct diff_filespec *df,
5917                     char **outbuf)
5918{
5919        size_t size;
5920
5921        if (!driver) {
5922                if (!DIFF_FILE_VALID(df)) {
5923                        *outbuf = "";
5924                        return 0;
5925                }
5926                if (diff_populate_filespec(df, 0))
5927                        die("unable to read files to diff");
5928                *outbuf = df->data;
5929                return df->size;
5930        }
5931
5932        if (!driver->textconv)
5933                die("BUG: fill_textconv called with non-textconv driver");
5934
5935        if (driver->textconv_cache && df->oid_valid) {
5936                *outbuf = notes_cache_get(driver->textconv_cache,
5937                                          &df->oid,
5938                                          &size);
5939                if (*outbuf)
5940                        return size;
5941        }
5942
5943        *outbuf = run_textconv(driver->textconv, df, &size);
5944        if (!*outbuf)
5945                die("unable to read files to diff");
5946
5947        if (driver->textconv_cache && df->oid_valid) {
5948                /* ignore errors, as we might be in a readonly repository */
5949                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5950                                size);
5951                /*
5952                 * we could save up changes and flush them all at the end,
5953                 * but we would need an extra call after all diffing is done.
5954                 * Since generating a cache entry is the slow path anyway,
5955                 * this extra overhead probably isn't a big deal.
5956                 */
5957                notes_cache_write(driver->textconv_cache);
5958        }
5959
5960        return size;
5961}
5962
5963int textconv_object(const char *path,
5964                    unsigned mode,
5965                    const struct object_id *oid,
5966                    int oid_valid,
5967                    char **buf,
5968                    unsigned long *buf_size)
5969{
5970        struct diff_filespec *df;
5971        struct userdiff_driver *textconv;
5972
5973        df = alloc_filespec(path);
5974        fill_filespec(df, oid, oid_valid, mode);
5975        textconv = get_textconv(df);
5976        if (!textconv) {
5977                free_filespec(df);
5978                return 0;
5979        }
5980
5981        *buf_size = fill_textconv(textconv, df, buf);
5982        free_filespec(df);
5983        return 1;
5984}
5985
5986void setup_diff_pager(struct diff_options *opt)
5987{
5988        /*
5989         * If the user asked for our exit code, then either they want --quiet
5990         * or --exit-code. We should definitely not bother with a pager in the
5991         * former case, as we will generate no output. Since we still properly
5992         * report our exit code even when a pager is run, we _could_ run a
5993         * pager with --exit-code. But since we have not done so historically,
5994         * and because it is easy to find people oneline advising "git diff
5995         * --exit-code" in hooks and other scripts, we do not do so.
5996         */
5997        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5998            check_pager_config("diff") != 0)
5999                setup_pager();
6000}