diff.con commit diff: document the new --color-moved setting (61e89ea)
   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_BOLD_MAGENTA, /* OLD_MOVED */
  62        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  63        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  64        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  65        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  66        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  69};
  70
  71static NORETURN void die_want_option(const char *option_name)
  72{
  73        die(_("option '%s' requires a value"), option_name);
  74}
  75
  76static int parse_diff_color_slot(const char *var)
  77{
  78        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  79                return DIFF_CONTEXT;
  80        if (!strcasecmp(var, "meta"))
  81                return DIFF_METAINFO;
  82        if (!strcasecmp(var, "frag"))
  83                return DIFF_FRAGINFO;
  84        if (!strcasecmp(var, "old"))
  85                return DIFF_FILE_OLD;
  86        if (!strcasecmp(var, "new"))
  87                return DIFF_FILE_NEW;
  88        if (!strcasecmp(var, "commit"))
  89                return DIFF_COMMIT;
  90        if (!strcasecmp(var, "whitespace"))
  91                return DIFF_WHITESPACE;
  92        if (!strcasecmp(var, "func"))
  93                return DIFF_FUNCINFO;
  94        if (!strcasecmp(var, "oldmoved"))
  95                return DIFF_FILE_OLD_MOVED;
  96        if (!strcasecmp(var, "oldmovedalternative"))
  97                return DIFF_FILE_OLD_MOVED_ALT;
  98        if (!strcasecmp(var, "oldmoveddimmed"))
  99                return DIFF_FILE_OLD_MOVED_DIM;
 100        if (!strcasecmp(var, "oldmovedalternativedimmed"))
 101                return DIFF_FILE_OLD_MOVED_ALT_DIM;
 102        if (!strcasecmp(var, "newmoved"))
 103                return DIFF_FILE_NEW_MOVED;
 104        if (!strcasecmp(var, "newmovedalternative"))
 105                return DIFF_FILE_NEW_MOVED_ALT;
 106        if (!strcasecmp(var, "newmoveddimmed"))
 107                return DIFF_FILE_NEW_MOVED_DIM;
 108        if (!strcasecmp(var, "newmovedalternativedimmed"))
 109                return DIFF_FILE_NEW_MOVED_ALT_DIM;
 110        return -1;
 111}
 112
 113static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 114                                struct strbuf *errmsg)
 115{
 116        char *params_copy = xstrdup(params_string);
 117        struct string_list params = STRING_LIST_INIT_NODUP;
 118        int ret = 0;
 119        int i;
 120
 121        if (*params_copy)
 122                string_list_split_in_place(&params, params_copy, ',', -1);
 123        for (i = 0; i < params.nr; i++) {
 124                const char *p = params.items[i].string;
 125                if (!strcmp(p, "changes")) {
 126                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 127                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 128                } else if (!strcmp(p, "lines")) {
 129                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 130                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 131                } else if (!strcmp(p, "files")) {
 132                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 133                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 134                } else if (!strcmp(p, "noncumulative")) {
 135                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 136                } else if (!strcmp(p, "cumulative")) {
 137                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 138                } else if (isdigit(*p)) {
 139                        char *end;
 140                        int permille = strtoul(p, &end, 10) * 10;
 141                        if (*end == '.' && isdigit(*++end)) {
 142                                /* only use first digit */
 143                                permille += *end - '0';
 144                                /* .. and ignore any further digits */
 145                                while (isdigit(*++end))
 146                                        ; /* nothing */
 147                        }
 148                        if (!*end)
 149                                options->dirstat_permille = permille;
 150                        else {
 151                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 152                                            p);
 153                                ret++;
 154                        }
 155                } else {
 156                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 157                        ret++;
 158                }
 159
 160        }
 161        string_list_clear(&params, 0);
 162        free(params_copy);
 163        return ret;
 164}
 165
 166static int parse_submodule_params(struct diff_options *options, const char *value)
 167{
 168        if (!strcmp(value, "log"))
 169                options->submodule_format = DIFF_SUBMODULE_LOG;
 170        else if (!strcmp(value, "short"))
 171                options->submodule_format = DIFF_SUBMODULE_SHORT;
 172        else if (!strcmp(value, "diff"))
 173                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 174        else
 175                return -1;
 176        return 0;
 177}
 178
 179static int git_config_rename(const char *var, const char *value)
 180{
 181        if (!value)
 182                return DIFF_DETECT_RENAME;
 183        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 184                return  DIFF_DETECT_COPY;
 185        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 186}
 187
 188long parse_algorithm_value(const char *value)
 189{
 190        if (!value)
 191                return -1;
 192        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 193                return 0;
 194        else if (!strcasecmp(value, "minimal"))
 195                return XDF_NEED_MINIMAL;
 196        else if (!strcasecmp(value, "patience"))
 197                return XDF_PATIENCE_DIFF;
 198        else if (!strcasecmp(value, "histogram"))
 199                return XDF_HISTOGRAM_DIFF;
 200        return -1;
 201}
 202
 203static int parse_one_token(const char **arg, const char *token)
 204{
 205        const char *rest;
 206        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 207                *arg = rest;
 208                return 1;
 209        }
 210        return 0;
 211}
 212
 213static int parse_ws_error_highlight(const char *arg)
 214{
 215        const char *orig_arg = arg;
 216        unsigned val = 0;
 217
 218        while (*arg) {
 219                if (parse_one_token(&arg, "none"))
 220                        val = 0;
 221                else if (parse_one_token(&arg, "default"))
 222                        val = WSEH_NEW;
 223                else if (parse_one_token(&arg, "all"))
 224                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 225                else if (parse_one_token(&arg, "new"))
 226                        val |= WSEH_NEW;
 227                else if (parse_one_token(&arg, "old"))
 228                        val |= WSEH_OLD;
 229                else if (parse_one_token(&arg, "context"))
 230                        val |= WSEH_CONTEXT;
 231                else {
 232                        return -1 - (int)(arg - orig_arg);
 233                }
 234                if (*arg)
 235                        arg++;
 236        }
 237        return val;
 238}
 239
 240/*
 241 * These are to give UI layer defaults.
 242 * The core-level commands such as git-diff-files should
 243 * never be affected by the setting of diff.renames
 244 * the user happens to have in the configuration file.
 245 */
 246void init_diff_ui_defaults(void)
 247{
 248        diff_detect_rename_default = 1;
 249}
 250
 251int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 252{
 253        if (!strcmp(var, "diff.indentheuristic"))
 254                diff_indent_heuristic = git_config_bool(var, value);
 255        return 0;
 256}
 257
 258static int parse_color_moved(const char *arg)
 259{
 260        switch (git_parse_maybe_bool(arg)) {
 261        case 0:
 262                return COLOR_MOVED_NO;
 263        case 1:
 264                return COLOR_MOVED_DEFAULT;
 265        default:
 266                break;
 267        }
 268
 269        if (!strcmp(arg, "no"))
 270                return COLOR_MOVED_NO;
 271        else if (!strcmp(arg, "plain"))
 272                return COLOR_MOVED_PLAIN;
 273        else if (!strcmp(arg, "zebra"))
 274                return COLOR_MOVED_ZEBRA;
 275        else if (!strcmp(arg, "default"))
 276                return COLOR_MOVED_DEFAULT;
 277        else if (!strcmp(arg, "dimmed_zebra"))
 278                return COLOR_MOVED_ZEBRA_DIM;
 279        else
 280                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 281}
 282
 283int git_diff_ui_config(const char *var, const char *value, void *cb)
 284{
 285        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 286                diff_use_color_default = git_config_colorbool(var, value);
 287                return 0;
 288        }
 289        if (!strcmp(var, "diff.colormoved")) {
 290                int cm = parse_color_moved(value);
 291                if (cm < 0)
 292                        return -1;
 293                diff_color_moved_default = cm;
 294                return 0;
 295        }
 296        if (!strcmp(var, "diff.context")) {
 297                diff_context_default = git_config_int(var, value);
 298                if (diff_context_default < 0)
 299                        return -1;
 300                return 0;
 301        }
 302        if (!strcmp(var, "diff.interhunkcontext")) {
 303                diff_interhunk_context_default = git_config_int(var, value);
 304                if (diff_interhunk_context_default < 0)
 305                        return -1;
 306                return 0;
 307        }
 308        if (!strcmp(var, "diff.renames")) {
 309                diff_detect_rename_default = git_config_rename(var, value);
 310                return 0;
 311        }
 312        if (!strcmp(var, "diff.autorefreshindex")) {
 313                diff_auto_refresh_index = git_config_bool(var, value);
 314                return 0;
 315        }
 316        if (!strcmp(var, "diff.mnemonicprefix")) {
 317                diff_mnemonic_prefix = git_config_bool(var, value);
 318                return 0;
 319        }
 320        if (!strcmp(var, "diff.noprefix")) {
 321                diff_no_prefix = git_config_bool(var, value);
 322                return 0;
 323        }
 324        if (!strcmp(var, "diff.statgraphwidth")) {
 325                diff_stat_graph_width = git_config_int(var, value);
 326                return 0;
 327        }
 328        if (!strcmp(var, "diff.external"))
 329                return git_config_string(&external_diff_cmd_cfg, var, value);
 330        if (!strcmp(var, "diff.wordregex"))
 331                return git_config_string(&diff_word_regex_cfg, var, value);
 332        if (!strcmp(var, "diff.orderfile"))
 333                return git_config_pathname(&diff_order_file_cfg, var, value);
 334
 335        if (!strcmp(var, "diff.ignoresubmodules"))
 336                handle_ignore_submodules_arg(&default_diff_options, value);
 337
 338        if (!strcmp(var, "diff.submodule")) {
 339                if (parse_submodule_params(&default_diff_options, value))
 340                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 341                                value);
 342                return 0;
 343        }
 344
 345        if (!strcmp(var, "diff.algorithm")) {
 346                diff_algorithm = parse_algorithm_value(value);
 347                if (diff_algorithm < 0)
 348                        return -1;
 349                return 0;
 350        }
 351
 352        if (!strcmp(var, "diff.wserrorhighlight")) {
 353                int val = parse_ws_error_highlight(value);
 354                if (val < 0)
 355                        return -1;
 356                ws_error_highlight_default = val;
 357                return 0;
 358        }
 359
 360        if (git_color_config(var, value, cb) < 0)
 361                return -1;
 362
 363        return git_diff_basic_config(var, value, cb);
 364}
 365
 366int git_diff_basic_config(const char *var, const char *value, void *cb)
 367{
 368        const char *name;
 369
 370        if (!strcmp(var, "diff.renamelimit")) {
 371                diff_rename_limit_default = git_config_int(var, value);
 372                return 0;
 373        }
 374
 375        if (userdiff_config(var, value) < 0)
 376                return -1;
 377
 378        if (skip_prefix(var, "diff.color.", &name) ||
 379            skip_prefix(var, "color.diff.", &name)) {
 380                int slot = parse_diff_color_slot(name);
 381                if (slot < 0)
 382                        return 0;
 383                if (!value)
 384                        return config_error_nonbool(var);
 385                return color_parse(value, diff_colors[slot]);
 386        }
 387
 388        /* like GNU diff's --suppress-blank-empty option  */
 389        if (!strcmp(var, "diff.suppressblankempty") ||
 390                        /* for backwards compatibility */
 391                        !strcmp(var, "diff.suppress-blank-empty")) {
 392                diff_suppress_blank_empty = git_config_bool(var, value);
 393                return 0;
 394        }
 395
 396        if (!strcmp(var, "diff.dirstat")) {
 397                struct strbuf errmsg = STRBUF_INIT;
 398                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 399                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 400                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 401                                errmsg.buf);
 402                strbuf_release(&errmsg);
 403                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 404                return 0;
 405        }
 406
 407        if (starts_with(var, "submodule."))
 408                return parse_submodule_config_option(var, value);
 409
 410        if (git_diff_heuristic_config(var, value, cb) < 0)
 411                return -1;
 412
 413        return git_default_config(var, value, cb);
 414}
 415
 416static char *quote_two(const char *one, const char *two)
 417{
 418        int need_one = quote_c_style(one, NULL, NULL, 1);
 419        int need_two = quote_c_style(two, NULL, NULL, 1);
 420        struct strbuf res = STRBUF_INIT;
 421
 422        if (need_one + need_two) {
 423                strbuf_addch(&res, '"');
 424                quote_c_style(one, &res, NULL, 1);
 425                quote_c_style(two, &res, NULL, 1);
 426                strbuf_addch(&res, '"');
 427        } else {
 428                strbuf_addstr(&res, one);
 429                strbuf_addstr(&res, two);
 430        }
 431        return strbuf_detach(&res, NULL);
 432}
 433
 434static const char *external_diff(void)
 435{
 436        static const char *external_diff_cmd = NULL;
 437        static int done_preparing = 0;
 438
 439        if (done_preparing)
 440                return external_diff_cmd;
 441        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 442        if (!external_diff_cmd)
 443                external_diff_cmd = external_diff_cmd_cfg;
 444        done_preparing = 1;
 445        return external_diff_cmd;
 446}
 447
 448/*
 449 * Keep track of files used for diffing. Sometimes such an entry
 450 * refers to a temporary file, sometimes to an existing file, and
 451 * sometimes to "/dev/null".
 452 */
 453static struct diff_tempfile {
 454        /*
 455         * filename external diff should read from, or NULL if this
 456         * entry is currently not in use:
 457         */
 458        const char *name;
 459
 460        char hex[GIT_MAX_HEXSZ + 1];
 461        char mode[10];
 462
 463        /*
 464         * If this diff_tempfile instance refers to a temporary file,
 465         * this tempfile object is used to manage its lifetime.
 466         */
 467        struct tempfile tempfile;
 468} diff_temp[2];
 469
 470typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 471
 472struct emit_callback {
 473        int color_diff;
 474        unsigned ws_rule;
 475        int blank_at_eof_in_preimage;
 476        int blank_at_eof_in_postimage;
 477        int lno_in_preimage;
 478        int lno_in_postimage;
 479        sane_truncate_fn truncate;
 480        const char **label_path;
 481        struct diff_words_data *diff_words;
 482        struct diff_options *opt;
 483        struct strbuf *header;
 484};
 485
 486static int count_lines(const char *data, int size)
 487{
 488        int count, ch, completely_empty = 1, nl_just_seen = 0;
 489        count = 0;
 490        while (0 < size--) {
 491                ch = *data++;
 492                if (ch == '\n') {
 493                        count++;
 494                        nl_just_seen = 1;
 495                        completely_empty = 0;
 496                }
 497                else {
 498                        nl_just_seen = 0;
 499                        completely_empty = 0;
 500                }
 501        }
 502        if (completely_empty)
 503                return 0;
 504        if (!nl_just_seen)
 505                count++; /* no trailing newline */
 506        return count;
 507}
 508
 509static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 510{
 511        if (!DIFF_FILE_VALID(one)) {
 512                mf->ptr = (char *)""; /* does not matter */
 513                mf->size = 0;
 514                return 0;
 515        }
 516        else if (diff_populate_filespec(one, 0))
 517                return -1;
 518
 519        mf->ptr = one->data;
 520        mf->size = one->size;
 521        return 0;
 522}
 523
 524/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 525static unsigned long diff_filespec_size(struct diff_filespec *one)
 526{
 527        if (!DIFF_FILE_VALID(one))
 528                return 0;
 529        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 530        return one->size;
 531}
 532
 533static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 534{
 535        char *ptr = mf->ptr;
 536        long size = mf->size;
 537        int cnt = 0;
 538
 539        if (!size)
 540                return cnt;
 541        ptr += size - 1; /* pointing at the very end */
 542        if (*ptr != '\n')
 543                ; /* incomplete line */
 544        else
 545                ptr--; /* skip the last LF */
 546        while (mf->ptr < ptr) {
 547                char *prev_eol;
 548                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 549                        if (*prev_eol == '\n')
 550                                break;
 551                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 552                        break;
 553                cnt++;
 554                ptr = prev_eol - 1;
 555        }
 556        return cnt;
 557}
 558
 559static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 560                               struct emit_callback *ecbdata)
 561{
 562        int l1, l2, at;
 563        unsigned ws_rule = ecbdata->ws_rule;
 564        l1 = count_trailing_blank(mf1, ws_rule);
 565        l2 = count_trailing_blank(mf2, ws_rule);
 566        if (l2 <= l1) {
 567                ecbdata->blank_at_eof_in_preimage = 0;
 568                ecbdata->blank_at_eof_in_postimage = 0;
 569                return;
 570        }
 571        at = count_lines(mf1->ptr, mf1->size);
 572        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 573
 574        at = count_lines(mf2->ptr, mf2->size);
 575        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 576}
 577
 578static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 579                        int first, const char *line, int len)
 580{
 581        int has_trailing_newline, has_trailing_carriage_return;
 582        int nofirst;
 583        FILE *file = o->file;
 584
 585        fputs(diff_line_prefix(o), file);
 586
 587        if (len == 0) {
 588                has_trailing_newline = (first == '\n');
 589                has_trailing_carriage_return = (!has_trailing_newline &&
 590                                                (first == '\r'));
 591                nofirst = has_trailing_newline || has_trailing_carriage_return;
 592        } else {
 593                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 594                if (has_trailing_newline)
 595                        len--;
 596                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 597                if (has_trailing_carriage_return)
 598                        len--;
 599                nofirst = 0;
 600        }
 601
 602        if (len || !nofirst) {
 603                fputs(set, file);
 604                if (!nofirst)
 605                        fputc(first, file);
 606                fwrite(line, len, 1, file);
 607                fputs(reset, file);
 608        }
 609        if (has_trailing_carriage_return)
 610                fputc('\r', file);
 611        if (has_trailing_newline)
 612                fputc('\n', file);
 613}
 614
 615static void emit_line(struct diff_options *o, const char *set, const char *reset,
 616                      const char *line, int len)
 617{
 618        emit_line_0(o, set, reset, line[0], line+1, len-1);
 619}
 620
 621enum diff_symbol {
 622        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 623        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 624        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 625        DIFF_SYMBOL_BINARY_DIFF_BODY,
 626        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 627        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 628        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 629        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 630        DIFF_SYMBOL_STATS_LINE,
 631        DIFF_SYMBOL_WORD_DIFF,
 632        DIFF_SYMBOL_STAT_SEP,
 633        DIFF_SYMBOL_SUMMARY,
 634        DIFF_SYMBOL_SUBMODULE_ADD,
 635        DIFF_SYMBOL_SUBMODULE_DEL,
 636        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 637        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 638        DIFF_SYMBOL_SUBMODULE_HEADER,
 639        DIFF_SYMBOL_SUBMODULE_ERROR,
 640        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 641        DIFF_SYMBOL_REWRITE_DIFF,
 642        DIFF_SYMBOL_BINARY_FILES,
 643        DIFF_SYMBOL_HEADER,
 644        DIFF_SYMBOL_FILEPAIR_PLUS,
 645        DIFF_SYMBOL_FILEPAIR_MINUS,
 646        DIFF_SYMBOL_WORDS_PORCELAIN,
 647        DIFF_SYMBOL_WORDS,
 648        DIFF_SYMBOL_CONTEXT,
 649        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 650        DIFF_SYMBOL_PLUS,
 651        DIFF_SYMBOL_MINUS,
 652        DIFF_SYMBOL_NO_LF_EOF,
 653        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 654        DIFF_SYMBOL_CONTEXT_MARKER,
 655        DIFF_SYMBOL_SEPARATOR
 656};
 657/*
 658 * Flags for content lines:
 659 * 0..12 are whitespace rules
 660 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 661 * 16 is marking if the line is blank at EOF
 662 */
 663#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 664#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 665#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 666#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 667#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 668
 669/*
 670 * This struct is used when we need to buffer the output of the diff output.
 671 *
 672 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 673 * into the pre/post image file. This pointer could be a union with the
 674 * line pointer. By storing an offset into the file instead of the literal line,
 675 * we can decrease the memory footprint for the buffered output. At first we
 676 * may want to only have indirection for the content lines, but we could also
 677 * enhance the state for emitting prefabricated lines, e.g. the similarity
 678 * score line or hunk/file headers would only need to store a number or path
 679 * and then the output can be constructed later on depending on state.
 680 */
 681struct emitted_diff_symbol {
 682        const char *line;
 683        int len;
 684        int flags;
 685        enum diff_symbol s;
 686};
 687#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 688
 689struct emitted_diff_symbols {
 690        struct emitted_diff_symbol *buf;
 691        int nr, alloc;
 692};
 693#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 694
 695static void append_emitted_diff_symbol(struct diff_options *o,
 696                                       struct emitted_diff_symbol *e)
 697{
 698        struct emitted_diff_symbol *f;
 699
 700        ALLOC_GROW(o->emitted_symbols->buf,
 701                   o->emitted_symbols->nr + 1,
 702                   o->emitted_symbols->alloc);
 703        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 704
 705        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 706        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 707}
 708
 709struct moved_entry {
 710        struct hashmap_entry ent;
 711        const struct emitted_diff_symbol *es;
 712        struct moved_entry *next_line;
 713};
 714
 715static int next_byte(const char **cp, const char **endp,
 716                     const struct diff_options *diffopt)
 717{
 718        int retval;
 719
 720        if (*cp > *endp)
 721                return -1;
 722
 723        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_CHANGE)) {
 724                while (*cp < *endp && isspace(**cp))
 725                        (*cp)++;
 726                /*
 727                 * After skipping a couple of whitespaces, we still have to
 728                 * account for one space.
 729                 */
 730                return (int)' ';
 731        }
 732
 733        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE)) {
 734                while (*cp < *endp && isspace(**cp))
 735                        (*cp)++;
 736                /* return the first non-ws character via the usual below */
 737        }
 738
 739        retval = (unsigned char)(**cp);
 740        (*cp)++;
 741        return retval;
 742}
 743
 744static int moved_entry_cmp(const struct diff_options *diffopt,
 745                           const struct moved_entry *a,
 746                           const struct moved_entry *b,
 747                           const void *keydata)
 748{
 749        const char *ap = a->es->line, *ae = a->es->line + a->es->len;
 750        const char *bp = b->es->line, *be = b->es->line + b->es->len;
 751
 752        if (!(diffopt->xdl_opts & XDF_WHITESPACE_FLAGS))
 753                return a->es->len != b->es->len  || memcmp(ap, bp, a->es->len);
 754
 755        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_AT_EOL)) {
 756                while (ae > ap && isspace(*ae))
 757                        ae--;
 758                while (be > bp && isspace(*be))
 759                        be--;
 760        }
 761
 762        while (1) {
 763                int ca, cb;
 764                ca = next_byte(&ap, &ae, diffopt);
 765                cb = next_byte(&bp, &be, diffopt);
 766                if (ca != cb)
 767                        return 1;
 768                if (ca < 0)
 769                        return 0;
 770        }
 771}
 772
 773static unsigned get_string_hash(struct emitted_diff_symbol *es, struct diff_options *o)
 774{
 775        if (o->xdl_opts & XDF_WHITESPACE_FLAGS) {
 776                static struct strbuf sb = STRBUF_INIT;
 777                const char *ap = es->line, *ae = es->line + es->len;
 778                int c;
 779
 780                strbuf_reset(&sb);
 781                while (ae > ap && isspace(*ae))
 782                        ae--;
 783                while ((c = next_byte(&ap, &ae, o)) > 0)
 784                        strbuf_addch(&sb, c);
 785
 786                return memhash(sb.buf, sb.len);
 787        } else {
 788                return memhash(es->line, es->len);
 789        }
 790}
 791
 792static struct moved_entry *prepare_entry(struct diff_options *o,
 793                                         int line_no)
 794{
 795        struct moved_entry *ret = xmalloc(sizeof(*ret));
 796        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 797
 798        ret->ent.hash = get_string_hash(l, o);
 799        ret->es = l;
 800        ret->next_line = NULL;
 801
 802        return ret;
 803}
 804
 805static void add_lines_to_move_detection(struct diff_options *o,
 806                                        struct hashmap *add_lines,
 807                                        struct hashmap *del_lines)
 808{
 809        struct moved_entry *prev_line = NULL;
 810
 811        int n;
 812        for (n = 0; n < o->emitted_symbols->nr; n++) {
 813                struct hashmap *hm;
 814                struct moved_entry *key;
 815
 816                switch (o->emitted_symbols->buf[n].s) {
 817                case DIFF_SYMBOL_PLUS:
 818                        hm = add_lines;
 819                        break;
 820                case DIFF_SYMBOL_MINUS:
 821                        hm = del_lines;
 822                        break;
 823                default:
 824                        prev_line = NULL;
 825                        continue;
 826                }
 827
 828                key = prepare_entry(o, n);
 829                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 830                        prev_line->next_line = key;
 831
 832                hashmap_add(hm, key);
 833                prev_line = key;
 834        }
 835}
 836
 837static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 838                                         int pmb_nr)
 839{
 840        int lp, rp;
 841
 842        /* Shrink the set of potential block to the remaining running */
 843        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 844                while (lp < pmb_nr && pmb[lp])
 845                        lp++;
 846                /* lp points at the first NULL now */
 847
 848                while (rp > -1 && !pmb[rp])
 849                        rp--;
 850                /* rp points at the last non-NULL */
 851
 852                if (lp < pmb_nr && rp > -1 && lp < rp) {
 853                        pmb[lp] = pmb[rp];
 854                        pmb[rp] = NULL;
 855                        rp--;
 856                        lp++;
 857                }
 858        }
 859
 860        /* Remember the number of running sets */
 861        return rp + 1;
 862}
 863
 864/* Find blocks of moved code, delegate actual coloring decision to helper */
 865static void mark_color_as_moved(struct diff_options *o,
 866                                struct hashmap *add_lines,
 867                                struct hashmap *del_lines)
 868{
 869        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 870        int pmb_nr = 0, pmb_alloc = 0;
 871        int n, flipped_block = 1, block_length = 0;
 872
 873
 874        for (n = 0; n < o->emitted_symbols->nr; n++) {
 875                struct hashmap *hm = NULL;
 876                struct moved_entry *key;
 877                struct moved_entry *match = NULL;
 878                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 879                int i;
 880
 881                switch (l->s) {
 882                case DIFF_SYMBOL_PLUS:
 883                        hm = del_lines;
 884                        key = prepare_entry(o, n);
 885                        match = hashmap_get(hm, key, o);
 886                        free(key);
 887                        break;
 888                case DIFF_SYMBOL_MINUS:
 889                        hm = add_lines;
 890                        key = prepare_entry(o, n);
 891                        match = hashmap_get(hm, key, o);
 892                        free(key);
 893                        break;
 894                default:
 895                        flipped_block = 1;
 896                }
 897
 898                if (!match) {
 899                        if (block_length < COLOR_MOVED_MIN_BLOCK_LENGTH &&
 900                            o->color_moved != COLOR_MOVED_PLAIN) {
 901                                for (i = 0; i < block_length + 1; i++) {
 902                                        l = &o->emitted_symbols->buf[n - i];
 903                                        l->flags &= ~DIFF_SYMBOL_MOVED_LINE;
 904                                }
 905                        }
 906                        pmb_nr = 0;
 907                        block_length = 0;
 908                        continue;
 909                }
 910
 911                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 912                block_length++;
 913
 914                if (o->color_moved == COLOR_MOVED_PLAIN)
 915                        continue;
 916
 917                /* Check any potential block runs, advance each or nullify */
 918                for (i = 0; i < pmb_nr; i++) {
 919                        struct moved_entry *p = pmb[i];
 920                        struct moved_entry *pnext = (p && p->next_line) ?
 921                                        p->next_line : NULL;
 922                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 923                                pmb[i] = p->next_line;
 924                        } else {
 925                                pmb[i] = NULL;
 926                        }
 927                }
 928
 929                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 930
 931                if (pmb_nr == 0) {
 932                        /*
 933                         * The current line is the start of a new block.
 934                         * Setup the set of potential blocks.
 935                         */
 936                        for (; match; match = hashmap_get_next(hm, match)) {
 937                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 938                                pmb[pmb_nr++] = match;
 939                        }
 940
 941                        flipped_block = (flipped_block + 1) % 2;
 942                }
 943
 944                if (flipped_block)
 945                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 946        }
 947
 948        free(pmb);
 949}
 950
 951#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 952  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 953static void dim_moved_lines(struct diff_options *o)
 954{
 955        int n;
 956        for (n = 0; n < o->emitted_symbols->nr; n++) {
 957                struct emitted_diff_symbol *prev = (n != 0) ?
 958                                &o->emitted_symbols->buf[n - 1] : NULL;
 959                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 960                struct emitted_diff_symbol *next =
 961                                (n < o->emitted_symbols->nr - 1) ?
 962                                &o->emitted_symbols->buf[n + 1] : NULL;
 963
 964                /* Not a plus or minus line? */
 965                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 966                        continue;
 967
 968                /* Not a moved line? */
 969                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 970                        continue;
 971
 972                /*
 973                 * If prev or next are not a plus or minus line,
 974                 * pretend they don't exist
 975                 */
 976                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 977                            prev->s != DIFF_SYMBOL_MINUS)
 978                        prev = NULL;
 979                if (next && next->s != DIFF_SYMBOL_PLUS &&
 980                            next->s != DIFF_SYMBOL_MINUS)
 981                        next = NULL;
 982
 983                /* Inside a block? */
 984                if ((prev &&
 985                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 986                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 987                    (next &&
 988                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 989                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 990                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 991                        continue;
 992                }
 993
 994                /* Check if we are at an interesting bound: */
 995                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 996                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 997                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 998                        continue;
 999                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1000                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1001                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1002                        continue;
1003
1004                /*
1005                 * The boundary to prev and next are not interesting,
1006                 * so this line is not interesting as a whole
1007                 */
1008                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1009        }
1010}
1011
1012static void emit_line_ws_markup(struct diff_options *o,
1013                                const char *set, const char *reset,
1014                                const char *line, int len, char sign,
1015                                unsigned ws_rule, int blank_at_eof)
1016{
1017        const char *ws = NULL;
1018
1019        if (o->ws_error_highlight & ws_rule) {
1020                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1021                if (!*ws)
1022                        ws = NULL;
1023        }
1024
1025        if (!ws)
1026                emit_line_0(o, set, reset, sign, line, len);
1027        else if (blank_at_eof)
1028                /* Blank line at EOF - paint '+' as well */
1029                emit_line_0(o, ws, reset, sign, line, len);
1030        else {
1031                /* Emit just the prefix, then the rest. */
1032                emit_line_0(o, set, reset, sign, "", 0);
1033                ws_check_emit(line, len, ws_rule,
1034                              o->file, set, reset, ws);
1035        }
1036}
1037
1038static void emit_diff_symbol_from_struct(struct diff_options *o,
1039                                         struct emitted_diff_symbol *eds)
1040{
1041        static const char *nneof = " No newline at end of file\n";
1042        const char *context, *reset, *set, *meta, *fraginfo;
1043        struct strbuf sb = STRBUF_INIT;
1044
1045        enum diff_symbol s = eds->s;
1046        const char *line = eds->line;
1047        int len = eds->len;
1048        unsigned flags = eds->flags;
1049
1050        switch (s) {
1051        case DIFF_SYMBOL_NO_LF_EOF:
1052                context = diff_get_color_opt(o, DIFF_CONTEXT);
1053                reset = diff_get_color_opt(o, DIFF_RESET);
1054                putc('\n', o->file);
1055                emit_line_0(o, context, reset, '\\',
1056                            nneof, strlen(nneof));
1057                break;
1058        case DIFF_SYMBOL_SUBMODULE_HEADER:
1059        case DIFF_SYMBOL_SUBMODULE_ERROR:
1060        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1061        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1062        case DIFF_SYMBOL_SUMMARY:
1063        case DIFF_SYMBOL_STATS_LINE:
1064        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1065        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1066                emit_line(o, "", "", line, len);
1067                break;
1068        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1069        case DIFF_SYMBOL_CONTEXT_MARKER:
1070                context = diff_get_color_opt(o, DIFF_CONTEXT);
1071                reset = diff_get_color_opt(o, DIFF_RESET);
1072                emit_line(o, context, reset, line, len);
1073                break;
1074        case DIFF_SYMBOL_SEPARATOR:
1075                fprintf(o->file, "%s%c",
1076                        diff_line_prefix(o),
1077                        o->line_termination);
1078                break;
1079        case DIFF_SYMBOL_CONTEXT:
1080                set = diff_get_color_opt(o, DIFF_CONTEXT);
1081                reset = diff_get_color_opt(o, DIFF_RESET);
1082                emit_line_ws_markup(o, set, reset, line, len, ' ',
1083                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1084                break;
1085        case DIFF_SYMBOL_PLUS:
1086                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1087                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1088                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1089                case DIFF_SYMBOL_MOVED_LINE |
1090                     DIFF_SYMBOL_MOVED_LINE_ALT |
1091                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1092                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1093                        break;
1094                case DIFF_SYMBOL_MOVED_LINE |
1095                     DIFF_SYMBOL_MOVED_LINE_ALT:
1096                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1097                        break;
1098                case DIFF_SYMBOL_MOVED_LINE |
1099                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1100                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1101                        break;
1102                case DIFF_SYMBOL_MOVED_LINE:
1103                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1104                        break;
1105                default:
1106                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1107                }
1108                reset = diff_get_color_opt(o, DIFF_RESET);
1109                emit_line_ws_markup(o, set, reset, line, len, '+',
1110                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1111                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1112                break;
1113        case DIFF_SYMBOL_MINUS:
1114                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1115                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1116                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1117                case DIFF_SYMBOL_MOVED_LINE |
1118                     DIFF_SYMBOL_MOVED_LINE_ALT |
1119                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1120                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1121                        break;
1122                case DIFF_SYMBOL_MOVED_LINE |
1123                     DIFF_SYMBOL_MOVED_LINE_ALT:
1124                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1125                        break;
1126                case DIFF_SYMBOL_MOVED_LINE |
1127                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1128                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1129                        break;
1130                case DIFF_SYMBOL_MOVED_LINE:
1131                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1132                        break;
1133                default:
1134                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1135                }
1136                reset = diff_get_color_opt(o, DIFF_RESET);
1137                emit_line_ws_markup(o, set, reset, line, len, '-',
1138                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1139                break;
1140        case DIFF_SYMBOL_WORDS_PORCELAIN:
1141                context = diff_get_color_opt(o, DIFF_CONTEXT);
1142                reset = diff_get_color_opt(o, DIFF_RESET);
1143                emit_line(o, context, reset, line, len);
1144                fputs("~\n", o->file);
1145                break;
1146        case DIFF_SYMBOL_WORDS:
1147                context = diff_get_color_opt(o, DIFF_CONTEXT);
1148                reset = diff_get_color_opt(o, DIFF_RESET);
1149                /*
1150                 * Skip the prefix character, if any.  With
1151                 * diff_suppress_blank_empty, there may be
1152                 * none.
1153                 */
1154                if (line[0] != '\n') {
1155                        line++;
1156                        len--;
1157                }
1158                emit_line(o, context, reset, line, len);
1159                break;
1160        case DIFF_SYMBOL_FILEPAIR_PLUS:
1161                meta = diff_get_color_opt(o, DIFF_METAINFO);
1162                reset = diff_get_color_opt(o, DIFF_RESET);
1163                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1164                        line, reset,
1165                        strchr(line, ' ') ? "\t" : "");
1166                break;
1167        case DIFF_SYMBOL_FILEPAIR_MINUS:
1168                meta = diff_get_color_opt(o, DIFF_METAINFO);
1169                reset = diff_get_color_opt(o, DIFF_RESET);
1170                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1171                        line, reset,
1172                        strchr(line, ' ') ? "\t" : "");
1173                break;
1174        case DIFF_SYMBOL_BINARY_FILES:
1175        case DIFF_SYMBOL_HEADER:
1176                fprintf(o->file, "%s", line);
1177                break;
1178        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1179                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1180                break;
1181        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1182                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1183                break;
1184        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1185                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1186                break;
1187        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1188                fputs(diff_line_prefix(o), o->file);
1189                fputc('\n', o->file);
1190                break;
1191        case DIFF_SYMBOL_REWRITE_DIFF:
1192                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1193                reset = diff_get_color_opt(o, DIFF_RESET);
1194                emit_line(o, fraginfo, reset, line, len);
1195                break;
1196        case DIFF_SYMBOL_SUBMODULE_ADD:
1197                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1198                reset = diff_get_color_opt(o, DIFF_RESET);
1199                emit_line(o, set, reset, line, len);
1200                break;
1201        case DIFF_SYMBOL_SUBMODULE_DEL:
1202                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1203                reset = diff_get_color_opt(o, DIFF_RESET);
1204                emit_line(o, set, reset, line, len);
1205                break;
1206        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1207                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1208                        diff_line_prefix(o), line);
1209                break;
1210        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1211                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1212                        diff_line_prefix(o), line);
1213                break;
1214        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1215                emit_line(o, "", "", " 0 files changed\n",
1216                          strlen(" 0 files changed\n"));
1217                break;
1218        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1219                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1220                break;
1221        case DIFF_SYMBOL_WORD_DIFF:
1222                fprintf(o->file, "%.*s", len, line);
1223                break;
1224        case DIFF_SYMBOL_STAT_SEP:
1225                fputs(o->stat_sep, o->file);
1226                break;
1227        default:
1228                die("BUG: unknown diff symbol");
1229        }
1230        strbuf_release(&sb);
1231}
1232
1233static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1234                             const char *line, int len, unsigned flags)
1235{
1236        struct emitted_diff_symbol e = {line, len, flags, s};
1237
1238        if (o->emitted_symbols)
1239                append_emitted_diff_symbol(o, &e);
1240        else
1241                emit_diff_symbol_from_struct(o, &e);
1242}
1243
1244void diff_emit_submodule_del(struct diff_options *o, const char *line)
1245{
1246        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1247}
1248
1249void diff_emit_submodule_add(struct diff_options *o, const char *line)
1250{
1251        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1252}
1253
1254void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1255{
1256        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1257                         path, strlen(path), 0);
1258}
1259
1260void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1261{
1262        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1263                         path, strlen(path), 0);
1264}
1265
1266void diff_emit_submodule_header(struct diff_options *o, const char *header)
1267{
1268        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1269                         header, strlen(header), 0);
1270}
1271
1272void diff_emit_submodule_error(struct diff_options *o, const char *err)
1273{
1274        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1275}
1276
1277void diff_emit_submodule_pipethrough(struct diff_options *o,
1278                                     const char *line, int len)
1279{
1280        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1281}
1282
1283static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1284{
1285        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1286              ecbdata->blank_at_eof_in_preimage &&
1287              ecbdata->blank_at_eof_in_postimage &&
1288              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1289              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1290                return 0;
1291        return ws_blank_line(line, len, ecbdata->ws_rule);
1292}
1293
1294static void emit_add_line(const char *reset,
1295                          struct emit_callback *ecbdata,
1296                          const char *line, int len)
1297{
1298        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1299        if (new_blank_line_at_eof(ecbdata, line, len))
1300                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1301
1302        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1303}
1304
1305static void emit_del_line(const char *reset,
1306                          struct emit_callback *ecbdata,
1307                          const char *line, int len)
1308{
1309        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1310        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1311}
1312
1313static void emit_context_line(const char *reset,
1314                              struct emit_callback *ecbdata,
1315                              const char *line, int len)
1316{
1317        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1318        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1319}
1320
1321static void emit_hunk_header(struct emit_callback *ecbdata,
1322                             const char *line, int len)
1323{
1324        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1325        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1326        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1327        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1328        static const char atat[2] = { '@', '@' };
1329        const char *cp, *ep;
1330        struct strbuf msgbuf = STRBUF_INIT;
1331        int org_len = len;
1332        int i = 1;
1333
1334        /*
1335         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1336         * it always is at least 10 bytes long.
1337         */
1338        if (len < 10 ||
1339            memcmp(line, atat, 2) ||
1340            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1341                emit_diff_symbol(ecbdata->opt,
1342                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1343                return;
1344        }
1345        ep += 2; /* skip over @@ */
1346
1347        /* The hunk header in fraginfo color */
1348        strbuf_addstr(&msgbuf, frag);
1349        strbuf_add(&msgbuf, line, ep - line);
1350        strbuf_addstr(&msgbuf, reset);
1351
1352        /*
1353         * trailing "\r\n"
1354         */
1355        for ( ; i < 3; i++)
1356                if (line[len - i] == '\r' || line[len - i] == '\n')
1357                        len--;
1358
1359        /* blank before the func header */
1360        for (cp = ep; ep - line < len; ep++)
1361                if (*ep != ' ' && *ep != '\t')
1362                        break;
1363        if (ep != cp) {
1364                strbuf_addstr(&msgbuf, context);
1365                strbuf_add(&msgbuf, cp, ep - cp);
1366                strbuf_addstr(&msgbuf, reset);
1367        }
1368
1369        if (ep < line + len) {
1370                strbuf_addstr(&msgbuf, func);
1371                strbuf_add(&msgbuf, ep, line + len - ep);
1372                strbuf_addstr(&msgbuf, reset);
1373        }
1374
1375        strbuf_add(&msgbuf, line + len, org_len - len);
1376        strbuf_complete_line(&msgbuf);
1377        emit_diff_symbol(ecbdata->opt,
1378                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1379        strbuf_release(&msgbuf);
1380}
1381
1382static struct diff_tempfile *claim_diff_tempfile(void) {
1383        int i;
1384        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1385                if (!diff_temp[i].name)
1386                        return diff_temp + i;
1387        die("BUG: diff is failing to clean up its tempfiles");
1388}
1389
1390static void remove_tempfile(void)
1391{
1392        int i;
1393        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1394                if (is_tempfile_active(&diff_temp[i].tempfile))
1395                        delete_tempfile(&diff_temp[i].tempfile);
1396                diff_temp[i].name = NULL;
1397        }
1398}
1399
1400static void add_line_count(struct strbuf *out, int count)
1401{
1402        switch (count) {
1403        case 0:
1404                strbuf_addstr(out, "0,0");
1405                break;
1406        case 1:
1407                strbuf_addstr(out, "1");
1408                break;
1409        default:
1410                strbuf_addf(out, "1,%d", count);
1411                break;
1412        }
1413}
1414
1415static void emit_rewrite_lines(struct emit_callback *ecb,
1416                               int prefix, const char *data, int size)
1417{
1418        const char *endp = NULL;
1419        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1420
1421        while (0 < size) {
1422                int len;
1423
1424                endp = memchr(data, '\n', size);
1425                len = endp ? (endp - data + 1) : size;
1426                if (prefix != '+') {
1427                        ecb->lno_in_preimage++;
1428                        emit_del_line(reset, ecb, data, len);
1429                } else {
1430                        ecb->lno_in_postimage++;
1431                        emit_add_line(reset, ecb, data, len);
1432                }
1433                size -= len;
1434                data += len;
1435        }
1436        if (!endp)
1437                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1438}
1439
1440static void emit_rewrite_diff(const char *name_a,
1441                              const char *name_b,
1442                              struct diff_filespec *one,
1443                              struct diff_filespec *two,
1444                              struct userdiff_driver *textconv_one,
1445                              struct userdiff_driver *textconv_two,
1446                              struct diff_options *o)
1447{
1448        int lc_a, lc_b;
1449        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1450        const char *a_prefix, *b_prefix;
1451        char *data_one, *data_two;
1452        size_t size_one, size_two;
1453        struct emit_callback ecbdata;
1454        struct strbuf out = STRBUF_INIT;
1455
1456        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
1457                a_prefix = o->b_prefix;
1458                b_prefix = o->a_prefix;
1459        } else {
1460                a_prefix = o->a_prefix;
1461                b_prefix = o->b_prefix;
1462        }
1463
1464        name_a += (*name_a == '/');
1465        name_b += (*name_b == '/');
1466
1467        strbuf_reset(&a_name);
1468        strbuf_reset(&b_name);
1469        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1470        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1471
1472        size_one = fill_textconv(textconv_one, one, &data_one);
1473        size_two = fill_textconv(textconv_two, two, &data_two);
1474
1475        memset(&ecbdata, 0, sizeof(ecbdata));
1476        ecbdata.color_diff = want_color(o->use_color);
1477        ecbdata.ws_rule = whitespace_rule(name_b);
1478        ecbdata.opt = o;
1479        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1480                mmfile_t mf1, mf2;
1481                mf1.ptr = (char *)data_one;
1482                mf2.ptr = (char *)data_two;
1483                mf1.size = size_one;
1484                mf2.size = size_two;
1485                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1486        }
1487        ecbdata.lno_in_preimage = 1;
1488        ecbdata.lno_in_postimage = 1;
1489
1490        lc_a = count_lines(data_one, size_one);
1491        lc_b = count_lines(data_two, size_two);
1492
1493        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1494                         a_name.buf, a_name.len, 0);
1495        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1496                         b_name.buf, b_name.len, 0);
1497
1498        strbuf_addstr(&out, "@@ -");
1499        if (!o->irreversible_delete)
1500                add_line_count(&out, lc_a);
1501        else
1502                strbuf_addstr(&out, "?,?");
1503        strbuf_addstr(&out, " +");
1504        add_line_count(&out, lc_b);
1505        strbuf_addstr(&out, " @@\n");
1506        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1507        strbuf_release(&out);
1508
1509        if (lc_a && !o->irreversible_delete)
1510                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1511        if (lc_b)
1512                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1513        if (textconv_one)
1514                free((char *)data_one);
1515        if (textconv_two)
1516                free((char *)data_two);
1517}
1518
1519struct diff_words_buffer {
1520        mmfile_t text;
1521        long alloc;
1522        struct diff_words_orig {
1523                const char *begin, *end;
1524        } *orig;
1525        int orig_nr, orig_alloc;
1526};
1527
1528static void diff_words_append(char *line, unsigned long len,
1529                struct diff_words_buffer *buffer)
1530{
1531        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1532        line++;
1533        len--;
1534        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1535        buffer->text.size += len;
1536        buffer->text.ptr[buffer->text.size] = '\0';
1537}
1538
1539struct diff_words_style_elem {
1540        const char *prefix;
1541        const char *suffix;
1542        const char *color; /* NULL; filled in by the setup code if
1543                            * color is enabled */
1544};
1545
1546struct diff_words_style {
1547        enum diff_words_type type;
1548        struct diff_words_style_elem new, old, ctx;
1549        const char *newline;
1550};
1551
1552static struct diff_words_style diff_words_styles[] = {
1553        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1554        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1555        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1556};
1557
1558struct diff_words_data {
1559        struct diff_words_buffer minus, plus;
1560        const char *current_plus;
1561        int last_minus;
1562        struct diff_options *opt;
1563        regex_t *word_regex;
1564        enum diff_words_type type;
1565        struct diff_words_style *style;
1566};
1567
1568static int fn_out_diff_words_write_helper(struct diff_options *o,
1569                                          struct diff_words_style_elem *st_el,
1570                                          const char *newline,
1571                                          size_t count, const char *buf)
1572{
1573        int print = 0;
1574        struct strbuf sb = STRBUF_INIT;
1575
1576        while (count) {
1577                char *p = memchr(buf, '\n', count);
1578                if (print)
1579                        strbuf_addstr(&sb, diff_line_prefix(o));
1580
1581                if (p != buf) {
1582                        const char *reset = st_el->color && *st_el->color ?
1583                                            GIT_COLOR_RESET : NULL;
1584                        if (st_el->color && *st_el->color)
1585                                strbuf_addstr(&sb, st_el->color);
1586                        strbuf_addstr(&sb, st_el->prefix);
1587                        strbuf_add(&sb, buf, p ? p - buf : count);
1588                        strbuf_addstr(&sb, st_el->suffix);
1589                        if (reset)
1590                                strbuf_addstr(&sb, reset);
1591                }
1592                if (!p)
1593                        goto out;
1594
1595                strbuf_addstr(&sb, newline);
1596                count -= p + 1 - buf;
1597                buf = p + 1;
1598                print = 1;
1599                if (count) {
1600                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1601                                         sb.buf, sb.len, 0);
1602                        strbuf_reset(&sb);
1603                }
1604        }
1605
1606out:
1607        if (sb.len)
1608                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1609                                 sb.buf, sb.len, 0);
1610        strbuf_release(&sb);
1611        return 0;
1612}
1613
1614/*
1615 * '--color-words' algorithm can be described as:
1616 *
1617 *   1. collect the minus/plus lines of a diff hunk, divided into
1618 *      minus-lines and plus-lines;
1619 *
1620 *   2. break both minus-lines and plus-lines into words and
1621 *      place them into two mmfile_t with one word for each line;
1622 *
1623 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1624 *
1625 * And for the common parts of the both file, we output the plus side text.
1626 * diff_words->current_plus is used to trace the current position of the plus file
1627 * which printed. diff_words->last_minus is used to trace the last minus word
1628 * printed.
1629 *
1630 * For '--graph' to work with '--color-words', we need to output the graph prefix
1631 * on each line of color words output. Generally, there are two conditions on
1632 * which we should output the prefix.
1633 *
1634 *   1. diff_words->last_minus == 0 &&
1635 *      diff_words->current_plus == diff_words->plus.text.ptr
1636 *
1637 *      that is: the plus text must start as a new line, and if there is no minus
1638 *      word printed, a graph prefix must be printed.
1639 *
1640 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1641 *      *(diff_words->current_plus - 1) == '\n'
1642 *
1643 *      that is: a graph prefix must be printed following a '\n'
1644 */
1645static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1646{
1647        if ((diff_words->last_minus == 0 &&
1648                diff_words->current_plus == diff_words->plus.text.ptr) ||
1649                (diff_words->current_plus > diff_words->plus.text.ptr &&
1650                *(diff_words->current_plus - 1) == '\n')) {
1651                return 1;
1652        } else {
1653                return 0;
1654        }
1655}
1656
1657static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1658{
1659        struct diff_words_data *diff_words = priv;
1660        struct diff_words_style *style = diff_words->style;
1661        int minus_first, minus_len, plus_first, plus_len;
1662        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1663        struct diff_options *opt = diff_words->opt;
1664        const char *line_prefix;
1665
1666        if (line[0] != '@' || parse_hunk_header(line, len,
1667                        &minus_first, &minus_len, &plus_first, &plus_len))
1668                return;
1669
1670        assert(opt);
1671        line_prefix = diff_line_prefix(opt);
1672
1673        /* POSIX requires that first be decremented by one if len == 0... */
1674        if (minus_len) {
1675                minus_begin = diff_words->minus.orig[minus_first].begin;
1676                minus_end =
1677                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1678        } else
1679                minus_begin = minus_end =
1680                        diff_words->minus.orig[minus_first].end;
1681
1682        if (plus_len) {
1683                plus_begin = diff_words->plus.orig[plus_first].begin;
1684                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1685        } else
1686                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1687
1688        if (color_words_output_graph_prefix(diff_words)) {
1689                fputs(line_prefix, diff_words->opt->file);
1690        }
1691        if (diff_words->current_plus != plus_begin) {
1692                fn_out_diff_words_write_helper(diff_words->opt,
1693                                &style->ctx, style->newline,
1694                                plus_begin - diff_words->current_plus,
1695                                diff_words->current_plus);
1696        }
1697        if (minus_begin != minus_end) {
1698                fn_out_diff_words_write_helper(diff_words->opt,
1699                                &style->old, style->newline,
1700                                minus_end - minus_begin, minus_begin);
1701        }
1702        if (plus_begin != plus_end) {
1703                fn_out_diff_words_write_helper(diff_words->opt,
1704                                &style->new, style->newline,
1705                                plus_end - plus_begin, plus_begin);
1706        }
1707
1708        diff_words->current_plus = plus_end;
1709        diff_words->last_minus = minus_first;
1710}
1711
1712/* This function starts looking at *begin, and returns 0 iff a word was found. */
1713static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1714                int *begin, int *end)
1715{
1716        if (word_regex && *begin < buffer->size) {
1717                regmatch_t match[1];
1718                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1719                                 buffer->size - *begin, 1, match, 0)) {
1720                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1721                                        '\n', match[0].rm_eo - match[0].rm_so);
1722                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1723                        *begin += match[0].rm_so;
1724                        return *begin >= *end;
1725                }
1726                return -1;
1727        }
1728
1729        /* find the next word */
1730        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1731                (*begin)++;
1732        if (*begin >= buffer->size)
1733                return -1;
1734
1735        /* find the end of the word */
1736        *end = *begin + 1;
1737        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1738                (*end)++;
1739
1740        return 0;
1741}
1742
1743/*
1744 * This function splits the words in buffer->text, stores the list with
1745 * newline separator into out, and saves the offsets of the original words
1746 * in buffer->orig.
1747 */
1748static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1749                regex_t *word_regex)
1750{
1751        int i, j;
1752        long alloc = 0;
1753
1754        out->size = 0;
1755        out->ptr = NULL;
1756
1757        /* fake an empty "0th" word */
1758        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1759        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1760        buffer->orig_nr = 1;
1761
1762        for (i = 0; i < buffer->text.size; i++) {
1763                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1764                        return;
1765
1766                /* store original boundaries */
1767                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1768                                buffer->orig_alloc);
1769                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1770                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1771                buffer->orig_nr++;
1772
1773                /* store one word */
1774                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1775                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1776                out->ptr[out->size + j - i] = '\n';
1777                out->size += j - i + 1;
1778
1779                i = j - 1;
1780        }
1781}
1782
1783/* this executes the word diff on the accumulated buffers */
1784static void diff_words_show(struct diff_words_data *diff_words)
1785{
1786        xpparam_t xpp;
1787        xdemitconf_t xecfg;
1788        mmfile_t minus, plus;
1789        struct diff_words_style *style = diff_words->style;
1790
1791        struct diff_options *opt = diff_words->opt;
1792        const char *line_prefix;
1793
1794        assert(opt);
1795        line_prefix = diff_line_prefix(opt);
1796
1797        /* special case: only removal */
1798        if (!diff_words->plus.text.size) {
1799                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1800                                 line_prefix, strlen(line_prefix), 0);
1801                fn_out_diff_words_write_helper(diff_words->opt,
1802                        &style->old, style->newline,
1803                        diff_words->minus.text.size,
1804                        diff_words->minus.text.ptr);
1805                diff_words->minus.text.size = 0;
1806                return;
1807        }
1808
1809        diff_words->current_plus = diff_words->plus.text.ptr;
1810        diff_words->last_minus = 0;
1811
1812        memset(&xpp, 0, sizeof(xpp));
1813        memset(&xecfg, 0, sizeof(xecfg));
1814        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1815        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1816        xpp.flags = 0;
1817        /* as only the hunk header will be parsed, we need a 0-context */
1818        xecfg.ctxlen = 0;
1819        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1820                          &xpp, &xecfg))
1821                die("unable to generate word diff");
1822        free(minus.ptr);
1823        free(plus.ptr);
1824        if (diff_words->current_plus != diff_words->plus.text.ptr +
1825                        diff_words->plus.text.size) {
1826                if (color_words_output_graph_prefix(diff_words))
1827                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1828                                         line_prefix, strlen(line_prefix), 0);
1829                fn_out_diff_words_write_helper(diff_words->opt,
1830                        &style->ctx, style->newline,
1831                        diff_words->plus.text.ptr + diff_words->plus.text.size
1832                        - diff_words->current_plus, diff_words->current_plus);
1833        }
1834        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1835}
1836
1837/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1838static void diff_words_flush(struct emit_callback *ecbdata)
1839{
1840        struct diff_options *wo = ecbdata->diff_words->opt;
1841
1842        if (ecbdata->diff_words->minus.text.size ||
1843            ecbdata->diff_words->plus.text.size)
1844                diff_words_show(ecbdata->diff_words);
1845
1846        if (wo->emitted_symbols) {
1847                struct diff_options *o = ecbdata->opt;
1848                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1849                int i;
1850
1851                /*
1852                 * NEEDSWORK:
1853                 * Instead of appending each, concat all words to a line?
1854                 */
1855                for (i = 0; i < wol->nr; i++)
1856                        append_emitted_diff_symbol(o, &wol->buf[i]);
1857
1858                for (i = 0; i < wol->nr; i++)
1859                        free((void *)wol->buf[i].line);
1860
1861                wol->nr = 0;
1862        }
1863}
1864
1865static void diff_filespec_load_driver(struct diff_filespec *one)
1866{
1867        /* Use already-loaded driver */
1868        if (one->driver)
1869                return;
1870
1871        if (S_ISREG(one->mode))
1872                one->driver = userdiff_find_by_path(one->path);
1873
1874        /* Fallback to default settings */
1875        if (!one->driver)
1876                one->driver = userdiff_find_by_name("default");
1877}
1878
1879static const char *userdiff_word_regex(struct diff_filespec *one)
1880{
1881        diff_filespec_load_driver(one);
1882        return one->driver->word_regex;
1883}
1884
1885static void init_diff_words_data(struct emit_callback *ecbdata,
1886                                 struct diff_options *orig_opts,
1887                                 struct diff_filespec *one,
1888                                 struct diff_filespec *two)
1889{
1890        int i;
1891        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1892        memcpy(o, orig_opts, sizeof(struct diff_options));
1893
1894        ecbdata->diff_words =
1895                xcalloc(1, sizeof(struct diff_words_data));
1896        ecbdata->diff_words->type = o->word_diff;
1897        ecbdata->diff_words->opt = o;
1898
1899        if (orig_opts->emitted_symbols)
1900                o->emitted_symbols =
1901                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1902
1903        if (!o->word_regex)
1904                o->word_regex = userdiff_word_regex(one);
1905        if (!o->word_regex)
1906                o->word_regex = userdiff_word_regex(two);
1907        if (!o->word_regex)
1908                o->word_regex = diff_word_regex_cfg;
1909        if (o->word_regex) {
1910                ecbdata->diff_words->word_regex = (regex_t *)
1911                        xmalloc(sizeof(regex_t));
1912                if (regcomp(ecbdata->diff_words->word_regex,
1913                            o->word_regex,
1914                            REG_EXTENDED | REG_NEWLINE))
1915                        die ("Invalid regular expression: %s",
1916                             o->word_regex);
1917        }
1918        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1919                if (o->word_diff == diff_words_styles[i].type) {
1920                        ecbdata->diff_words->style =
1921                                &diff_words_styles[i];
1922                        break;
1923                }
1924        }
1925        if (want_color(o->use_color)) {
1926                struct diff_words_style *st = ecbdata->diff_words->style;
1927                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1928                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1929                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1930        }
1931}
1932
1933static void free_diff_words_data(struct emit_callback *ecbdata)
1934{
1935        if (ecbdata->diff_words) {
1936                diff_words_flush(ecbdata);
1937                free (ecbdata->diff_words->opt->emitted_symbols);
1938                free (ecbdata->diff_words->opt);
1939                free (ecbdata->diff_words->minus.text.ptr);
1940                free (ecbdata->diff_words->minus.orig);
1941                free (ecbdata->diff_words->plus.text.ptr);
1942                free (ecbdata->diff_words->plus.orig);
1943                if (ecbdata->diff_words->word_regex) {
1944                        regfree(ecbdata->diff_words->word_regex);
1945                        free(ecbdata->diff_words->word_regex);
1946                }
1947                FREE_AND_NULL(ecbdata->diff_words);
1948        }
1949}
1950
1951const char *diff_get_color(int diff_use_color, enum color_diff ix)
1952{
1953        if (want_color(diff_use_color))
1954                return diff_colors[ix];
1955        return "";
1956}
1957
1958const char *diff_line_prefix(struct diff_options *opt)
1959{
1960        struct strbuf *msgbuf;
1961        if (!opt->output_prefix)
1962                return "";
1963
1964        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1965        return msgbuf->buf;
1966}
1967
1968static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1969{
1970        const char *cp;
1971        unsigned long allot;
1972        size_t l = len;
1973
1974        if (ecb->truncate)
1975                return ecb->truncate(line, len);
1976        cp = line;
1977        allot = l;
1978        while (0 < l) {
1979                (void) utf8_width(&cp, &l);
1980                if (!cp)
1981                        break; /* truncated in the middle? */
1982        }
1983        return allot - l;
1984}
1985
1986static void find_lno(const char *line, struct emit_callback *ecbdata)
1987{
1988        const char *p;
1989        ecbdata->lno_in_preimage = 0;
1990        ecbdata->lno_in_postimage = 0;
1991        p = strchr(line, '-');
1992        if (!p)
1993                return; /* cannot happen */
1994        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1995        p = strchr(p, '+');
1996        if (!p)
1997                return; /* cannot happen */
1998        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1999}
2000
2001static void fn_out_consume(void *priv, char *line, unsigned long len)
2002{
2003        struct emit_callback *ecbdata = priv;
2004        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2005        struct diff_options *o = ecbdata->opt;
2006
2007        o->found_changes = 1;
2008
2009        if (ecbdata->header) {
2010                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2011                                 ecbdata->header->buf, ecbdata->header->len, 0);
2012                strbuf_reset(ecbdata->header);
2013                ecbdata->header = NULL;
2014        }
2015
2016        if (ecbdata->label_path[0]) {
2017                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2018                                 ecbdata->label_path[0],
2019                                 strlen(ecbdata->label_path[0]), 0);
2020                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2021                                 ecbdata->label_path[1],
2022                                 strlen(ecbdata->label_path[1]), 0);
2023                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2024        }
2025
2026        if (diff_suppress_blank_empty
2027            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2028                line[0] = '\n';
2029                len = 1;
2030        }
2031
2032        if (line[0] == '@') {
2033                if (ecbdata->diff_words)
2034                        diff_words_flush(ecbdata);
2035                len = sane_truncate_line(ecbdata, line, len);
2036                find_lno(line, ecbdata);
2037                emit_hunk_header(ecbdata, line, len);
2038                return;
2039        }
2040
2041        if (ecbdata->diff_words) {
2042                enum diff_symbol s =
2043                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2044                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2045                if (line[0] == '-') {
2046                        diff_words_append(line, len,
2047                                          &ecbdata->diff_words->minus);
2048                        return;
2049                } else if (line[0] == '+') {
2050                        diff_words_append(line, len,
2051                                          &ecbdata->diff_words->plus);
2052                        return;
2053                } else if (starts_with(line, "\\ ")) {
2054                        /*
2055                         * Eat the "no newline at eof" marker as if we
2056                         * saw a "+" or "-" line with nothing on it,
2057                         * and return without diff_words_flush() to
2058                         * defer processing. If this is the end of
2059                         * preimage, more "+" lines may come after it.
2060                         */
2061                        return;
2062                }
2063                diff_words_flush(ecbdata);
2064                emit_diff_symbol(o, s, line, len, 0);
2065                return;
2066        }
2067
2068        switch (line[0]) {
2069        case '+':
2070                ecbdata->lno_in_postimage++;
2071                emit_add_line(reset, ecbdata, line + 1, len - 1);
2072                break;
2073        case '-':
2074                ecbdata->lno_in_preimage++;
2075                emit_del_line(reset, ecbdata, line + 1, len - 1);
2076                break;
2077        case ' ':
2078                ecbdata->lno_in_postimage++;
2079                ecbdata->lno_in_preimage++;
2080                emit_context_line(reset, ecbdata, line + 1, len - 1);
2081                break;
2082        default:
2083                /* incomplete line at the end */
2084                ecbdata->lno_in_preimage++;
2085                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2086                                 line, len, 0);
2087                break;
2088        }
2089}
2090
2091static char *pprint_rename(const char *a, const char *b)
2092{
2093        const char *old = a;
2094        const char *new = b;
2095        struct strbuf name = STRBUF_INIT;
2096        int pfx_length, sfx_length;
2097        int pfx_adjust_for_slash;
2098        int len_a = strlen(a);
2099        int len_b = strlen(b);
2100        int a_midlen, b_midlen;
2101        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2102        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2103
2104        if (qlen_a || qlen_b) {
2105                quote_c_style(a, &name, NULL, 0);
2106                strbuf_addstr(&name, " => ");
2107                quote_c_style(b, &name, NULL, 0);
2108                return strbuf_detach(&name, NULL);
2109        }
2110
2111        /* Find common prefix */
2112        pfx_length = 0;
2113        while (*old && *new && *old == *new) {
2114                if (*old == '/')
2115                        pfx_length = old - a + 1;
2116                old++;
2117                new++;
2118        }
2119
2120        /* Find common suffix */
2121        old = a + len_a;
2122        new = b + len_b;
2123        sfx_length = 0;
2124        /*
2125         * If there is a common prefix, it must end in a slash.  In
2126         * that case we let this loop run 1 into the prefix to see the
2127         * same slash.
2128         *
2129         * If there is no common prefix, we cannot do this as it would
2130         * underrun the input strings.
2131         */
2132        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2133        while (a + pfx_length - pfx_adjust_for_slash <= old &&
2134               b + pfx_length - pfx_adjust_for_slash <= new &&
2135               *old == *new) {
2136                if (*old == '/')
2137                        sfx_length = len_a - (old - a);
2138                old--;
2139                new--;
2140        }
2141
2142        /*
2143         * pfx{mid-a => mid-b}sfx
2144         * {pfx-a => pfx-b}sfx
2145         * pfx{sfx-a => sfx-b}
2146         * name-a => name-b
2147         */
2148        a_midlen = len_a - pfx_length - sfx_length;
2149        b_midlen = len_b - pfx_length - sfx_length;
2150        if (a_midlen < 0)
2151                a_midlen = 0;
2152        if (b_midlen < 0)
2153                b_midlen = 0;
2154
2155        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2156        if (pfx_length + sfx_length) {
2157                strbuf_add(&name, a, pfx_length);
2158                strbuf_addch(&name, '{');
2159        }
2160        strbuf_add(&name, a + pfx_length, a_midlen);
2161        strbuf_addstr(&name, " => ");
2162        strbuf_add(&name, b + pfx_length, b_midlen);
2163        if (pfx_length + sfx_length) {
2164                strbuf_addch(&name, '}');
2165                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
2166        }
2167        return strbuf_detach(&name, NULL);
2168}
2169
2170struct diffstat_t {
2171        int nr;
2172        int alloc;
2173        struct diffstat_file {
2174                char *from_name;
2175                char *name;
2176                char *print_name;
2177                unsigned is_unmerged:1;
2178                unsigned is_binary:1;
2179                unsigned is_renamed:1;
2180                unsigned is_interesting:1;
2181                uintmax_t added, deleted;
2182        } **files;
2183};
2184
2185static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2186                                          const char *name_a,
2187                                          const char *name_b)
2188{
2189        struct diffstat_file *x;
2190        x = xcalloc(1, sizeof(*x));
2191        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2192        diffstat->files[diffstat->nr++] = x;
2193        if (name_b) {
2194                x->from_name = xstrdup(name_a);
2195                x->name = xstrdup(name_b);
2196                x->is_renamed = 1;
2197        }
2198        else {
2199                x->from_name = NULL;
2200                x->name = xstrdup(name_a);
2201        }
2202        return x;
2203}
2204
2205static void diffstat_consume(void *priv, char *line, unsigned long len)
2206{
2207        struct diffstat_t *diffstat = priv;
2208        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2209
2210        if (line[0] == '+')
2211                x->added++;
2212        else if (line[0] == '-')
2213                x->deleted++;
2214}
2215
2216const char mime_boundary_leader[] = "------------";
2217
2218static int scale_linear(int it, int width, int max_change)
2219{
2220        if (!it)
2221                return 0;
2222        /*
2223         * make sure that at least one '-' or '+' is printed if
2224         * there is any change to this path. The easiest way is to
2225         * scale linearly as if the alloted width is one column shorter
2226         * than it is, and then add 1 to the result.
2227         */
2228        return 1 + (it * (width - 1) / max_change);
2229}
2230
2231static void show_graph(struct strbuf *out, char ch, int cnt,
2232                       const char *set, const char *reset)
2233{
2234        if (cnt <= 0)
2235                return;
2236        strbuf_addstr(out, set);
2237        strbuf_addchars(out, ch, cnt);
2238        strbuf_addstr(out, reset);
2239}
2240
2241static void fill_print_name(struct diffstat_file *file)
2242{
2243        char *pname;
2244
2245        if (file->print_name)
2246                return;
2247
2248        if (!file->is_renamed) {
2249                struct strbuf buf = STRBUF_INIT;
2250                if (quote_c_style(file->name, &buf, NULL, 0)) {
2251                        pname = strbuf_detach(&buf, NULL);
2252                } else {
2253                        pname = file->name;
2254                        strbuf_release(&buf);
2255                }
2256        } else {
2257                pname = pprint_rename(file->from_name, file->name);
2258        }
2259        file->print_name = pname;
2260}
2261
2262static void print_stat_summary_inserts_deletes(struct diff_options *options,
2263                int files, int insertions, int deletions)
2264{
2265        struct strbuf sb = STRBUF_INIT;
2266
2267        if (!files) {
2268                assert(insertions == 0 && deletions == 0);
2269                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2270                                 NULL, 0, 0);
2271                return;
2272        }
2273
2274        strbuf_addf(&sb,
2275                    (files == 1) ? " %d file changed" : " %d files changed",
2276                    files);
2277
2278        /*
2279         * For binary diff, the caller may want to print "x files
2280         * changed" with insertions == 0 && deletions == 0.
2281         *
2282         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2283         * is probably less confusing (i.e skip over "2 files changed
2284         * but nothing about added/removed lines? Is this a bug in Git?").
2285         */
2286        if (insertions || deletions == 0) {
2287                strbuf_addf(&sb,
2288                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2289                            insertions);
2290        }
2291
2292        if (deletions || insertions == 0) {
2293                strbuf_addf(&sb,
2294                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2295                            deletions);
2296        }
2297        strbuf_addch(&sb, '\n');
2298        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2299                         sb.buf, sb.len, 0);
2300        strbuf_release(&sb);
2301}
2302
2303void print_stat_summary(FILE *fp, int files,
2304                        int insertions, int deletions)
2305{
2306        struct diff_options o;
2307        memset(&o, 0, sizeof(o));
2308        o.file = fp;
2309
2310        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2311}
2312
2313static void show_stats(struct diffstat_t *data, struct diff_options *options)
2314{
2315        int i, len, add, del, adds = 0, dels = 0;
2316        uintmax_t max_change = 0, max_len = 0;
2317        int total_files = data->nr, count;
2318        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2319        const char *reset, *add_c, *del_c;
2320        int extra_shown = 0;
2321        const char *line_prefix = diff_line_prefix(options);
2322        struct strbuf out = STRBUF_INIT;
2323
2324        if (data->nr == 0)
2325                return;
2326
2327        count = options->stat_count ? options->stat_count : data->nr;
2328
2329        reset = diff_get_color_opt(options, DIFF_RESET);
2330        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2331        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2332
2333        /*
2334         * Find the longest filename and max number of changes
2335         */
2336        for (i = 0; (i < count) && (i < data->nr); i++) {
2337                struct diffstat_file *file = data->files[i];
2338                uintmax_t change = file->added + file->deleted;
2339
2340                if (!file->is_interesting && (change == 0)) {
2341                        count++; /* not shown == room for one more */
2342                        continue;
2343                }
2344                fill_print_name(file);
2345                len = strlen(file->print_name);
2346                if (max_len < len)
2347                        max_len = len;
2348
2349                if (file->is_unmerged) {
2350                        /* "Unmerged" is 8 characters */
2351                        bin_width = bin_width < 8 ? 8 : bin_width;
2352                        continue;
2353                }
2354                if (file->is_binary) {
2355                        /* "Bin XXX -> YYY bytes" */
2356                        int w = 14 + decimal_width(file->added)
2357                                + decimal_width(file->deleted);
2358                        bin_width = bin_width < w ? w : bin_width;
2359                        /* Display change counts aligned with "Bin" */
2360                        number_width = 3;
2361                        continue;
2362                }
2363
2364                if (max_change < change)
2365                        max_change = change;
2366        }
2367        count = i; /* where we can stop scanning in data->files[] */
2368
2369        /*
2370         * We have width = stat_width or term_columns() columns total.
2371         * We want a maximum of min(max_len, stat_name_width) for the name part.
2372         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2373         * We also need 1 for " " and 4 + decimal_width(max_change)
2374         * for " | NNNN " and one the empty column at the end, altogether
2375         * 6 + decimal_width(max_change).
2376         *
2377         * If there's not enough space, we will use the smaller of
2378         * stat_name_width (if set) and 5/8*width for the filename,
2379         * and the rest for constant elements + graph part, but no more
2380         * than stat_graph_width for the graph part.
2381         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2382         * for the standard terminal size).
2383         *
2384         * In other words: stat_width limits the maximum width, and
2385         * stat_name_width fixes the maximum width of the filename,
2386         * and is also used to divide available columns if there
2387         * aren't enough.
2388         *
2389         * Binary files are displayed with "Bin XXX -> YYY bytes"
2390         * instead of the change count and graph. This part is treated
2391         * similarly to the graph part, except that it is not
2392         * "scaled". If total width is too small to accommodate the
2393         * guaranteed minimum width of the filename part and the
2394         * separators and this message, this message will "overflow"
2395         * making the line longer than the maximum width.
2396         */
2397
2398        if (options->stat_width == -1)
2399                width = term_columns() - strlen(line_prefix);
2400        else
2401                width = options->stat_width ? options->stat_width : 80;
2402        number_width = decimal_width(max_change) > number_width ?
2403                decimal_width(max_change) : number_width;
2404
2405        if (options->stat_graph_width == -1)
2406                options->stat_graph_width = diff_stat_graph_width;
2407
2408        /*
2409         * Guarantee 3/8*16==6 for the graph part
2410         * and 5/8*16==10 for the filename part
2411         */
2412        if (width < 16 + 6 + number_width)
2413                width = 16 + 6 + number_width;
2414
2415        /*
2416         * First assign sizes that are wanted, ignoring available width.
2417         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2418         * starting from "XXX" should fit in graph_width.
2419         */
2420        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2421        if (options->stat_graph_width &&
2422            options->stat_graph_width < graph_width)
2423                graph_width = options->stat_graph_width;
2424
2425        name_width = (options->stat_name_width > 0 &&
2426                      options->stat_name_width < max_len) ?
2427                options->stat_name_width : max_len;
2428
2429        /*
2430         * Adjust adjustable widths not to exceed maximum width
2431         */
2432        if (name_width + number_width + 6 + graph_width > width) {
2433                if (graph_width > width * 3/8 - number_width - 6) {
2434                        graph_width = width * 3/8 - number_width - 6;
2435                        if (graph_width < 6)
2436                                graph_width = 6;
2437                }
2438
2439                if (options->stat_graph_width &&
2440                    graph_width > options->stat_graph_width)
2441                        graph_width = options->stat_graph_width;
2442                if (name_width > width - number_width - 6 - graph_width)
2443                        name_width = width - number_width - 6 - graph_width;
2444                else
2445                        graph_width = width - number_width - 6 - name_width;
2446        }
2447
2448        /*
2449         * From here name_width is the width of the name area,
2450         * and graph_width is the width of the graph area.
2451         * max_change is used to scale graph properly.
2452         */
2453        for (i = 0; i < count; i++) {
2454                const char *prefix = "";
2455                struct diffstat_file *file = data->files[i];
2456                char *name = file->print_name;
2457                uintmax_t added = file->added;
2458                uintmax_t deleted = file->deleted;
2459                int name_len;
2460
2461                if (!file->is_interesting && (added + deleted == 0))
2462                        continue;
2463
2464                /*
2465                 * "scale" the filename
2466                 */
2467                len = name_width;
2468                name_len = strlen(name);
2469                if (name_width < name_len) {
2470                        char *slash;
2471                        prefix = "...";
2472                        len -= 3;
2473                        name += name_len - len;
2474                        slash = strchr(name, '/');
2475                        if (slash)
2476                                name = slash;
2477                }
2478
2479                if (file->is_binary) {
2480                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2481                        strbuf_addf(&out, " %*s", number_width, "Bin");
2482                        if (!added && !deleted) {
2483                                strbuf_addch(&out, '\n');
2484                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2485                                                 out.buf, out.len, 0);
2486                                strbuf_reset(&out);
2487                                continue;
2488                        }
2489                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2490                                del_c, deleted, reset);
2491                        strbuf_addstr(&out, " -> ");
2492                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2493                                add_c, added, reset);
2494                        strbuf_addstr(&out, " bytes\n");
2495                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2496                                         out.buf, out.len, 0);
2497                        strbuf_reset(&out);
2498                        continue;
2499                }
2500                else if (file->is_unmerged) {
2501                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2502                        strbuf_addstr(&out, " Unmerged\n");
2503                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2504                                         out.buf, out.len, 0);
2505                        strbuf_reset(&out);
2506                        continue;
2507                }
2508
2509                /*
2510                 * scale the add/delete
2511                 */
2512                add = added;
2513                del = deleted;
2514
2515                if (graph_width <= max_change) {
2516                        int total = scale_linear(add + del, graph_width, max_change);
2517                        if (total < 2 && add && del)
2518                                /* width >= 2 due to the sanity check */
2519                                total = 2;
2520                        if (add < del) {
2521                                add = scale_linear(add, graph_width, max_change);
2522                                del = total - add;
2523                        } else {
2524                                del = scale_linear(del, graph_width, max_change);
2525                                add = total - del;
2526                        }
2527                }
2528                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2529                strbuf_addf(&out, " %*"PRIuMAX"%s",
2530                        number_width, added + deleted,
2531                        added + deleted ? " " : "");
2532                show_graph(&out, '+', add, add_c, reset);
2533                show_graph(&out, '-', del, del_c, reset);
2534                strbuf_addch(&out, '\n');
2535                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2536                                 out.buf, out.len, 0);
2537                strbuf_reset(&out);
2538        }
2539
2540        for (i = 0; i < data->nr; i++) {
2541                struct diffstat_file *file = data->files[i];
2542                uintmax_t added = file->added;
2543                uintmax_t deleted = file->deleted;
2544
2545                if (file->is_unmerged ||
2546                    (!file->is_interesting && (added + deleted == 0))) {
2547                        total_files--;
2548                        continue;
2549                }
2550
2551                if (!file->is_binary) {
2552                        adds += added;
2553                        dels += deleted;
2554                }
2555                if (i < count)
2556                        continue;
2557                if (!extra_shown)
2558                        emit_diff_symbol(options,
2559                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2560                                         NULL, 0, 0);
2561                extra_shown = 1;
2562        }
2563
2564        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2565}
2566
2567static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2568{
2569        int i, adds = 0, dels = 0, total_files = data->nr;
2570
2571        if (data->nr == 0)
2572                return;
2573
2574        for (i = 0; i < data->nr; i++) {
2575                int added = data->files[i]->added;
2576                int deleted = data->files[i]->deleted;
2577
2578                if (data->files[i]->is_unmerged ||
2579                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2580                        total_files--;
2581                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2582                        adds += added;
2583                        dels += deleted;
2584                }
2585        }
2586        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2587}
2588
2589static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2590{
2591        int i;
2592
2593        if (data->nr == 0)
2594                return;
2595
2596        for (i = 0; i < data->nr; i++) {
2597                struct diffstat_file *file = data->files[i];
2598
2599                fprintf(options->file, "%s", diff_line_prefix(options));
2600
2601                if (file->is_binary)
2602                        fprintf(options->file, "-\t-\t");
2603                else
2604                        fprintf(options->file,
2605                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2606                                file->added, file->deleted);
2607                if (options->line_termination) {
2608                        fill_print_name(file);
2609                        if (!file->is_renamed)
2610                                write_name_quoted(file->name, options->file,
2611                                                  options->line_termination);
2612                        else {
2613                                fputs(file->print_name, options->file);
2614                                putc(options->line_termination, options->file);
2615                        }
2616                } else {
2617                        if (file->is_renamed) {
2618                                putc('\0', options->file);
2619                                write_name_quoted(file->from_name, options->file, '\0');
2620                        }
2621                        write_name_quoted(file->name, options->file, '\0');
2622                }
2623        }
2624}
2625
2626struct dirstat_file {
2627        const char *name;
2628        unsigned long changed;
2629};
2630
2631struct dirstat_dir {
2632        struct dirstat_file *files;
2633        int alloc, nr, permille, cumulative;
2634};
2635
2636static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2637                unsigned long changed, const char *base, int baselen)
2638{
2639        unsigned long this_dir = 0;
2640        unsigned int sources = 0;
2641        const char *line_prefix = diff_line_prefix(opt);
2642
2643        while (dir->nr) {
2644                struct dirstat_file *f = dir->files;
2645                int namelen = strlen(f->name);
2646                unsigned long this;
2647                char *slash;
2648
2649                if (namelen < baselen)
2650                        break;
2651                if (memcmp(f->name, base, baselen))
2652                        break;
2653                slash = strchr(f->name + baselen, '/');
2654                if (slash) {
2655                        int newbaselen = slash + 1 - f->name;
2656                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2657                        sources++;
2658                } else {
2659                        this = f->changed;
2660                        dir->files++;
2661                        dir->nr--;
2662                        sources += 2;
2663                }
2664                this_dir += this;
2665        }
2666
2667        /*
2668         * We don't report dirstat's for
2669         *  - the top level
2670         *  - or cases where everything came from a single directory
2671         *    under this directory (sources == 1).
2672         */
2673        if (baselen && sources != 1) {
2674                if (this_dir) {
2675                        int permille = this_dir * 1000 / changed;
2676                        if (permille >= dir->permille) {
2677                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2678                                        permille / 10, permille % 10, baselen, base);
2679                                if (!dir->cumulative)
2680                                        return 0;
2681                        }
2682                }
2683        }
2684        return this_dir;
2685}
2686
2687static int dirstat_compare(const void *_a, const void *_b)
2688{
2689        const struct dirstat_file *a = _a;
2690        const struct dirstat_file *b = _b;
2691        return strcmp(a->name, b->name);
2692}
2693
2694static void show_dirstat(struct diff_options *options)
2695{
2696        int i;
2697        unsigned long changed;
2698        struct dirstat_dir dir;
2699        struct diff_queue_struct *q = &diff_queued_diff;
2700
2701        dir.files = NULL;
2702        dir.alloc = 0;
2703        dir.nr = 0;
2704        dir.permille = options->dirstat_permille;
2705        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2706
2707        changed = 0;
2708        for (i = 0; i < q->nr; i++) {
2709                struct diff_filepair *p = q->queue[i];
2710                const char *name;
2711                unsigned long copied, added, damage;
2712                int content_changed;
2713
2714                name = p->two->path ? p->two->path : p->one->path;
2715
2716                if (p->one->oid_valid && p->two->oid_valid)
2717                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2718                else
2719                        content_changed = 1;
2720
2721                if (!content_changed) {
2722                        /*
2723                         * The SHA1 has not changed, so pre-/post-content is
2724                         * identical. We can therefore skip looking at the
2725                         * file contents altogether.
2726                         */
2727                        damage = 0;
2728                        goto found_damage;
2729                }
2730
2731                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2732                        /*
2733                         * In --dirstat-by-file mode, we don't really need to
2734                         * look at the actual file contents at all.
2735                         * The fact that the SHA1 changed is enough for us to
2736                         * add this file to the list of results
2737                         * (with each file contributing equal damage).
2738                         */
2739                        damage = 1;
2740                        goto found_damage;
2741                }
2742
2743                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2744                        diff_populate_filespec(p->one, 0);
2745                        diff_populate_filespec(p->two, 0);
2746                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2747                                               &copied, &added);
2748                        diff_free_filespec_data(p->one);
2749                        diff_free_filespec_data(p->two);
2750                } else if (DIFF_FILE_VALID(p->one)) {
2751                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2752                        copied = added = 0;
2753                        diff_free_filespec_data(p->one);
2754                } else if (DIFF_FILE_VALID(p->two)) {
2755                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2756                        copied = 0;
2757                        added = p->two->size;
2758                        diff_free_filespec_data(p->two);
2759                } else
2760                        continue;
2761
2762                /*
2763                 * Original minus copied is the removed material,
2764                 * added is the new material.  They are both damages
2765                 * made to the preimage.
2766                 * If the resulting damage is zero, we know that
2767                 * diffcore_count_changes() considers the two entries to
2768                 * be identical, but since content_changed is true, we
2769                 * know that there must have been _some_ kind of change,
2770                 * so we force all entries to have damage > 0.
2771                 */
2772                damage = (p->one->size - copied) + added;
2773                if (!damage)
2774                        damage = 1;
2775
2776found_damage:
2777                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2778                dir.files[dir.nr].name = name;
2779                dir.files[dir.nr].changed = damage;
2780                changed += damage;
2781                dir.nr++;
2782        }
2783
2784        /* This can happen even with many files, if everything was renames */
2785        if (!changed)
2786                return;
2787
2788        /* Show all directories with more than x% of the changes */
2789        QSORT(dir.files, dir.nr, dirstat_compare);
2790        gather_dirstat(options, &dir, changed, "", 0);
2791}
2792
2793static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2794{
2795        int i;
2796        unsigned long changed;
2797        struct dirstat_dir dir;
2798
2799        if (data->nr == 0)
2800                return;
2801
2802        dir.files = NULL;
2803        dir.alloc = 0;
2804        dir.nr = 0;
2805        dir.permille = options->dirstat_permille;
2806        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2807
2808        changed = 0;
2809        for (i = 0; i < data->nr; i++) {
2810                struct diffstat_file *file = data->files[i];
2811                unsigned long damage = file->added + file->deleted;
2812                if (file->is_binary)
2813                        /*
2814                         * binary files counts bytes, not lines. Must find some
2815                         * way to normalize binary bytes vs. textual lines.
2816                         * The following heuristic assumes that there are 64
2817                         * bytes per "line".
2818                         * This is stupid and ugly, but very cheap...
2819                         */
2820                        damage = (damage + 63) / 64;
2821                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2822                dir.files[dir.nr].name = file->name;
2823                dir.files[dir.nr].changed = damage;
2824                changed += damage;
2825                dir.nr++;
2826        }
2827
2828        /* This can happen even with many files, if everything was renames */
2829        if (!changed)
2830                return;
2831
2832        /* Show all directories with more than x% of the changes */
2833        QSORT(dir.files, dir.nr, dirstat_compare);
2834        gather_dirstat(options, &dir, changed, "", 0);
2835}
2836
2837static void free_diffstat_info(struct diffstat_t *diffstat)
2838{
2839        int i;
2840        for (i = 0; i < diffstat->nr; i++) {
2841                struct diffstat_file *f = diffstat->files[i];
2842                if (f->name != f->print_name)
2843                        free(f->print_name);
2844                free(f->name);
2845                free(f->from_name);
2846                free(f);
2847        }
2848        free(diffstat->files);
2849}
2850
2851struct checkdiff_t {
2852        const char *filename;
2853        int lineno;
2854        int conflict_marker_size;
2855        struct diff_options *o;
2856        unsigned ws_rule;
2857        unsigned status;
2858};
2859
2860static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2861{
2862        char firstchar;
2863        int cnt;
2864
2865        if (len < marker_size + 1)
2866                return 0;
2867        firstchar = line[0];
2868        switch (firstchar) {
2869        case '=': case '>': case '<': case '|':
2870                break;
2871        default:
2872                return 0;
2873        }
2874        for (cnt = 1; cnt < marker_size; cnt++)
2875                if (line[cnt] != firstchar)
2876                        return 0;
2877        /* line[1] thru line[marker_size-1] are same as firstchar */
2878        if (len < marker_size + 1 || !isspace(line[marker_size]))
2879                return 0;
2880        return 1;
2881}
2882
2883static void checkdiff_consume(void *priv, char *line, unsigned long len)
2884{
2885        struct checkdiff_t *data = priv;
2886        int marker_size = data->conflict_marker_size;
2887        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2888        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2889        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2890        char *err;
2891        const char *line_prefix;
2892
2893        assert(data->o);
2894        line_prefix = diff_line_prefix(data->o);
2895
2896        if (line[0] == '+') {
2897                unsigned bad;
2898                data->lineno++;
2899                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2900                        data->status |= 1;
2901                        fprintf(data->o->file,
2902                                "%s%s:%d: leftover conflict marker\n",
2903                                line_prefix, data->filename, data->lineno);
2904                }
2905                bad = ws_check(line + 1, len - 1, data->ws_rule);
2906                if (!bad)
2907                        return;
2908                data->status |= bad;
2909                err = whitespace_error_string(bad);
2910                fprintf(data->o->file, "%s%s:%d: %s.\n",
2911                        line_prefix, data->filename, data->lineno, err);
2912                free(err);
2913                emit_line(data->o, set, reset, line, 1);
2914                ws_check_emit(line + 1, len - 1, data->ws_rule,
2915                              data->o->file, set, reset, ws);
2916        } else if (line[0] == ' ') {
2917                data->lineno++;
2918        } else if (line[0] == '@') {
2919                char *plus = strchr(line, '+');
2920                if (plus)
2921                        data->lineno = strtol(plus, NULL, 10) - 1;
2922                else
2923                        die("invalid diff");
2924        }
2925}
2926
2927static unsigned char *deflate_it(char *data,
2928                                 unsigned long size,
2929                                 unsigned long *result_size)
2930{
2931        int bound;
2932        unsigned char *deflated;
2933        git_zstream stream;
2934
2935        git_deflate_init(&stream, zlib_compression_level);
2936        bound = git_deflate_bound(&stream, size);
2937        deflated = xmalloc(bound);
2938        stream.next_out = deflated;
2939        stream.avail_out = bound;
2940
2941        stream.next_in = (unsigned char *)data;
2942        stream.avail_in = size;
2943        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2944                ; /* nothing */
2945        git_deflate_end(&stream);
2946        *result_size = stream.total_out;
2947        return deflated;
2948}
2949
2950static void emit_binary_diff_body(struct diff_options *o,
2951                                  mmfile_t *one, mmfile_t *two)
2952{
2953        void *cp;
2954        void *delta;
2955        void *deflated;
2956        void *data;
2957        unsigned long orig_size;
2958        unsigned long delta_size;
2959        unsigned long deflate_size;
2960        unsigned long data_size;
2961
2962        /* We could do deflated delta, or we could do just deflated two,
2963         * whichever is smaller.
2964         */
2965        delta = NULL;
2966        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2967        if (one->size && two->size) {
2968                delta = diff_delta(one->ptr, one->size,
2969                                   two->ptr, two->size,
2970                                   &delta_size, deflate_size);
2971                if (delta) {
2972                        void *to_free = delta;
2973                        orig_size = delta_size;
2974                        delta = deflate_it(delta, delta_size, &delta_size);
2975                        free(to_free);
2976                }
2977        }
2978
2979        if (delta && delta_size < deflate_size) {
2980                char *s = xstrfmt("%lu", orig_size);
2981                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2982                                 s, strlen(s), 0);
2983                free(s);
2984                free(deflated);
2985                data = delta;
2986                data_size = delta_size;
2987        } else {
2988                char *s = xstrfmt("%lu", two->size);
2989                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2990                                 s, strlen(s), 0);
2991                free(s);
2992                free(delta);
2993                data = deflated;
2994                data_size = deflate_size;
2995        }
2996
2997        /* emit data encoded in base85 */
2998        cp = data;
2999        while (data_size) {
3000                int len;
3001                int bytes = (52 < data_size) ? 52 : data_size;
3002                char line[71];
3003                data_size -= bytes;
3004                if (bytes <= 26)
3005                        line[0] = bytes + 'A' - 1;
3006                else
3007                        line[0] = bytes - 26 + 'a' - 1;
3008                encode_85(line + 1, cp, bytes);
3009                cp = (char *) cp + bytes;
3010
3011                len = strlen(line);
3012                line[len++] = '\n';
3013                line[len] = '\0';
3014
3015                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3016                                 line, len, 0);
3017        }
3018        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3019        free(data);
3020}
3021
3022static void emit_binary_diff(struct diff_options *o,
3023                             mmfile_t *one, mmfile_t *two)
3024{
3025        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3026        emit_binary_diff_body(o, one, two);
3027        emit_binary_diff_body(o, two, one);
3028}
3029
3030int diff_filespec_is_binary(struct diff_filespec *one)
3031{
3032        if (one->is_binary == -1) {
3033                diff_filespec_load_driver(one);
3034                if (one->driver->binary != -1)
3035                        one->is_binary = one->driver->binary;
3036                else {
3037                        if (!one->data && DIFF_FILE_VALID(one))
3038                                diff_populate_filespec(one, CHECK_BINARY);
3039                        if (one->is_binary == -1 && one->data)
3040                                one->is_binary = buffer_is_binary(one->data,
3041                                                one->size);
3042                        if (one->is_binary == -1)
3043                                one->is_binary = 0;
3044                }
3045        }
3046        return one->is_binary;
3047}
3048
3049static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3050{
3051        diff_filespec_load_driver(one);
3052        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3053}
3054
3055void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3056{
3057        if (!options->a_prefix)
3058                options->a_prefix = a;
3059        if (!options->b_prefix)
3060                options->b_prefix = b;
3061}
3062
3063struct userdiff_driver *get_textconv(struct diff_filespec *one)
3064{
3065        if (!DIFF_FILE_VALID(one))
3066                return NULL;
3067
3068        diff_filespec_load_driver(one);
3069        return userdiff_get_textconv(one->driver);
3070}
3071
3072static void builtin_diff(const char *name_a,
3073                         const char *name_b,
3074                         struct diff_filespec *one,
3075                         struct diff_filespec *two,
3076                         const char *xfrm_msg,
3077                         int must_show_header,
3078                         struct diff_options *o,
3079                         int complete_rewrite)
3080{
3081        mmfile_t mf1, mf2;
3082        const char *lbl[2];
3083        char *a_one, *b_two;
3084        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3085        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3086        const char *a_prefix, *b_prefix;
3087        struct userdiff_driver *textconv_one = NULL;
3088        struct userdiff_driver *textconv_two = NULL;
3089        struct strbuf header = STRBUF_INIT;
3090        const char *line_prefix = diff_line_prefix(o);
3091
3092        diff_set_mnemonic_prefix(o, "a/", "b/");
3093        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
3094                a_prefix = o->b_prefix;
3095                b_prefix = o->a_prefix;
3096        } else {
3097                a_prefix = o->a_prefix;
3098                b_prefix = o->b_prefix;
3099        }
3100
3101        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3102            (!one->mode || S_ISGITLINK(one->mode)) &&
3103            (!two->mode || S_ISGITLINK(two->mode))) {
3104                show_submodule_summary(o, one->path ? one->path : two->path,
3105                                &one->oid, &two->oid,
3106                                two->dirty_submodule);
3107                return;
3108        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3109                   (!one->mode || S_ISGITLINK(one->mode)) &&
3110                   (!two->mode || S_ISGITLINK(two->mode))) {
3111                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3112                                &one->oid, &two->oid,
3113                                two->dirty_submodule);
3114                return;
3115        }
3116
3117        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
3118                textconv_one = get_textconv(one);
3119                textconv_two = get_textconv(two);
3120        }
3121
3122        /* Never use a non-valid filename anywhere if at all possible */
3123        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3124        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3125
3126        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3127        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3128        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3129        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3130        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3131        if (lbl[0][0] == '/') {
3132                /* /dev/null */
3133                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3134                if (xfrm_msg)
3135                        strbuf_addstr(&header, xfrm_msg);
3136                must_show_header = 1;
3137        }
3138        else if (lbl[1][0] == '/') {
3139                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3140                if (xfrm_msg)
3141                        strbuf_addstr(&header, xfrm_msg);
3142                must_show_header = 1;
3143        }
3144        else {
3145                if (one->mode != two->mode) {
3146                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3147                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3148                        must_show_header = 1;
3149                }
3150                if (xfrm_msg)
3151                        strbuf_addstr(&header, xfrm_msg);
3152
3153                /*
3154                 * we do not run diff between different kind
3155                 * of objects.
3156                 */
3157                if ((one->mode ^ two->mode) & S_IFMT)
3158                        goto free_ab_and_return;
3159                if (complete_rewrite &&
3160                    (textconv_one || !diff_filespec_is_binary(one)) &&
3161                    (textconv_two || !diff_filespec_is_binary(two))) {
3162                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3163                                         header.buf, header.len, 0);
3164                        strbuf_reset(&header);
3165                        emit_rewrite_diff(name_a, name_b, one, two,
3166                                                textconv_one, textconv_two, o);
3167                        o->found_changes = 1;
3168                        goto free_ab_and_return;
3169                }
3170        }
3171
3172        if (o->irreversible_delete && lbl[1][0] == '/') {
3173                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3174                                 header.len, 0);
3175                strbuf_reset(&header);
3176                goto free_ab_and_return;
3177        } else if (!DIFF_OPT_TST(o, TEXT) &&
3178            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3179              (!textconv_two && diff_filespec_is_binary(two)) )) {
3180                struct strbuf sb = STRBUF_INIT;
3181                if (!one->data && !two->data &&
3182                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3183                    !DIFF_OPT_TST(o, BINARY)) {
3184                        if (!oidcmp(&one->oid, &two->oid)) {
3185                                if (must_show_header)
3186                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3187                                                         header.buf, header.len,
3188                                                         0);
3189                                goto free_ab_and_return;
3190                        }
3191                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3192                                         header.buf, header.len, 0);
3193                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3194                                    diff_line_prefix(o), lbl[0], lbl[1]);
3195                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3196                                         sb.buf, sb.len, 0);
3197                        strbuf_release(&sb);
3198                        goto free_ab_and_return;
3199                }
3200                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3201                        die("unable to read files to diff");
3202                /* Quite common confusing case */
3203                if (mf1.size == mf2.size &&
3204                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3205                        if (must_show_header)
3206                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3207                                                 header.buf, header.len, 0);
3208                        goto free_ab_and_return;
3209                }
3210                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3211                strbuf_reset(&header);
3212                if (DIFF_OPT_TST(o, BINARY))
3213                        emit_binary_diff(o, &mf1, &mf2);
3214                else {
3215                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3216                                    diff_line_prefix(o), lbl[0], lbl[1]);
3217                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3218                                         sb.buf, sb.len, 0);
3219                        strbuf_release(&sb);
3220                }
3221                o->found_changes = 1;
3222        } else {
3223                /* Crazy xdl interfaces.. */
3224                const char *diffopts = getenv("GIT_DIFF_OPTS");
3225                const char *v;
3226                xpparam_t xpp;
3227                xdemitconf_t xecfg;
3228                struct emit_callback ecbdata;
3229                const struct userdiff_funcname *pe;
3230
3231                if (must_show_header) {
3232                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3233                                         header.buf, header.len, 0);
3234                        strbuf_reset(&header);
3235                }
3236
3237                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3238                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3239
3240                pe = diff_funcname_pattern(one);
3241                if (!pe)
3242                        pe = diff_funcname_pattern(two);
3243
3244                memset(&xpp, 0, sizeof(xpp));
3245                memset(&xecfg, 0, sizeof(xecfg));
3246                memset(&ecbdata, 0, sizeof(ecbdata));
3247                ecbdata.label_path = lbl;
3248                ecbdata.color_diff = want_color(o->use_color);
3249                ecbdata.ws_rule = whitespace_rule(name_b);
3250                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3251                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3252                ecbdata.opt = o;
3253                ecbdata.header = header.len ? &header : NULL;
3254                xpp.flags = o->xdl_opts;
3255                xecfg.ctxlen = o->context;
3256                xecfg.interhunkctxlen = o->interhunkcontext;
3257                xecfg.flags = XDL_EMIT_FUNCNAMES;
3258                if (DIFF_OPT_TST(o, FUNCCONTEXT))
3259                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3260                if (pe)
3261                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3262                if (!diffopts)
3263                        ;
3264                else if (skip_prefix(diffopts, "--unified=", &v))
3265                        xecfg.ctxlen = strtoul(v, NULL, 10);
3266                else if (skip_prefix(diffopts, "-u", &v))
3267                        xecfg.ctxlen = strtoul(v, NULL, 10);
3268                if (o->word_diff)
3269                        init_diff_words_data(&ecbdata, o, one, two);
3270                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3271                                  &xpp, &xecfg))
3272                        die("unable to generate diff for %s", one->path);
3273                if (o->word_diff)
3274                        free_diff_words_data(&ecbdata);
3275                if (textconv_one)
3276                        free(mf1.ptr);
3277                if (textconv_two)
3278                        free(mf2.ptr);
3279                xdiff_clear_find_func(&xecfg);
3280        }
3281
3282 free_ab_and_return:
3283        strbuf_release(&header);
3284        diff_free_filespec_data(one);
3285        diff_free_filespec_data(two);
3286        free(a_one);
3287        free(b_two);
3288        return;
3289}
3290
3291static void builtin_diffstat(const char *name_a, const char *name_b,
3292                             struct diff_filespec *one,
3293                             struct diff_filespec *two,
3294                             struct diffstat_t *diffstat,
3295                             struct diff_options *o,
3296                             struct diff_filepair *p)
3297{
3298        mmfile_t mf1, mf2;
3299        struct diffstat_file *data;
3300        int same_contents;
3301        int complete_rewrite = 0;
3302
3303        if (!DIFF_PAIR_UNMERGED(p)) {
3304                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3305                        complete_rewrite = 1;
3306        }
3307
3308        data = diffstat_add(diffstat, name_a, name_b);
3309        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3310
3311        if (!one || !two) {
3312                data->is_unmerged = 1;
3313                return;
3314        }
3315
3316        same_contents = !oidcmp(&one->oid, &two->oid);
3317
3318        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3319                data->is_binary = 1;
3320                if (same_contents) {
3321                        data->added = 0;
3322                        data->deleted = 0;
3323                } else {
3324                        data->added = diff_filespec_size(two);
3325                        data->deleted = diff_filespec_size(one);
3326                }
3327        }
3328
3329        else if (complete_rewrite) {
3330                diff_populate_filespec(one, 0);
3331                diff_populate_filespec(two, 0);
3332                data->deleted = count_lines(one->data, one->size);
3333                data->added = count_lines(two->data, two->size);
3334        }
3335
3336        else if (!same_contents) {
3337                /* Crazy xdl interfaces.. */
3338                xpparam_t xpp;
3339                xdemitconf_t xecfg;
3340
3341                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3342                        die("unable to read files to diff");
3343
3344                memset(&xpp, 0, sizeof(xpp));
3345                memset(&xecfg, 0, sizeof(xecfg));
3346                xpp.flags = o->xdl_opts;
3347                xecfg.ctxlen = o->context;
3348                xecfg.interhunkctxlen = o->interhunkcontext;
3349                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3350                                  &xpp, &xecfg))
3351                        die("unable to generate diffstat for %s", one->path);
3352        }
3353
3354        diff_free_filespec_data(one);
3355        diff_free_filespec_data(two);
3356}
3357
3358static void builtin_checkdiff(const char *name_a, const char *name_b,
3359                              const char *attr_path,
3360                              struct diff_filespec *one,
3361                              struct diff_filespec *two,
3362                              struct diff_options *o)
3363{
3364        mmfile_t mf1, mf2;
3365        struct checkdiff_t data;
3366
3367        if (!two)
3368                return;
3369
3370        memset(&data, 0, sizeof(data));
3371        data.filename = name_b ? name_b : name_a;
3372        data.lineno = 0;
3373        data.o = o;
3374        data.ws_rule = whitespace_rule(attr_path);
3375        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3376
3377        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3378                die("unable to read files to diff");
3379
3380        /*
3381         * All the other codepaths check both sides, but not checking
3382         * the "old" side here is deliberate.  We are checking the newly
3383         * introduced changes, and as long as the "new" side is text, we
3384         * can and should check what it introduces.
3385         */
3386        if (diff_filespec_is_binary(two))
3387                goto free_and_return;
3388        else {
3389                /* Crazy xdl interfaces.. */
3390                xpparam_t xpp;
3391                xdemitconf_t xecfg;
3392
3393                memset(&xpp, 0, sizeof(xpp));
3394                memset(&xecfg, 0, sizeof(xecfg));
3395                xecfg.ctxlen = 1; /* at least one context line */
3396                xpp.flags = 0;
3397                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3398                                  &xpp, &xecfg))
3399                        die("unable to generate checkdiff for %s", one->path);
3400
3401                if (data.ws_rule & WS_BLANK_AT_EOF) {
3402                        struct emit_callback ecbdata;
3403                        int blank_at_eof;
3404
3405                        ecbdata.ws_rule = data.ws_rule;
3406                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3407                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3408
3409                        if (blank_at_eof) {
3410                                static char *err;
3411                                if (!err)
3412                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3413                                fprintf(o->file, "%s:%d: %s.\n",
3414                                        data.filename, blank_at_eof, err);
3415                                data.status = 1; /* report errors */
3416                        }
3417                }
3418        }
3419 free_and_return:
3420        diff_free_filespec_data(one);
3421        diff_free_filespec_data(two);
3422        if (data.status)
3423                DIFF_OPT_SET(o, CHECK_FAILED);
3424}
3425
3426struct diff_filespec *alloc_filespec(const char *path)
3427{
3428        struct diff_filespec *spec;
3429
3430        FLEXPTR_ALLOC_STR(spec, path, path);
3431        spec->count = 1;
3432        spec->is_binary = -1;
3433        return spec;
3434}
3435
3436void free_filespec(struct diff_filespec *spec)
3437{
3438        if (!--spec->count) {
3439                diff_free_filespec_data(spec);
3440                free(spec);
3441        }
3442}
3443
3444void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3445                   int oid_valid, unsigned short mode)
3446{
3447        if (mode) {
3448                spec->mode = canon_mode(mode);
3449                oidcpy(&spec->oid, oid);
3450                spec->oid_valid = oid_valid;
3451        }
3452}
3453
3454/*
3455 * Given a name and sha1 pair, if the index tells us the file in
3456 * the work tree has that object contents, return true, so that
3457 * prepare_temp_file() does not have to inflate and extract.
3458 */
3459static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3460{
3461        const struct cache_entry *ce;
3462        struct stat st;
3463        int pos, len;
3464
3465        /*
3466         * We do not read the cache ourselves here, because the
3467         * benchmark with my previous version that always reads cache
3468         * shows that it makes things worse for diff-tree comparing
3469         * two linux-2.6 kernel trees in an already checked out work
3470         * tree.  This is because most diff-tree comparisons deal with
3471         * only a small number of files, while reading the cache is
3472         * expensive for a large project, and its cost outweighs the
3473         * savings we get by not inflating the object to a temporary
3474         * file.  Practically, this code only helps when we are used
3475         * by diff-cache --cached, which does read the cache before
3476         * calling us.
3477         */
3478        if (!active_cache)
3479                return 0;
3480
3481        /* We want to avoid the working directory if our caller
3482         * doesn't need the data in a normal file, this system
3483         * is rather slow with its stat/open/mmap/close syscalls,
3484         * and the object is contained in a pack file.  The pack
3485         * is probably already open and will be faster to obtain
3486         * the data through than the working directory.  Loose
3487         * objects however would tend to be slower as they need
3488         * to be individually opened and inflated.
3489         */
3490        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3491                return 0;
3492
3493        /*
3494         * Similarly, if we'd have to convert the file contents anyway, that
3495         * makes the optimization not worthwhile.
3496         */
3497        if (!want_file && would_convert_to_git(&the_index, name))
3498                return 0;
3499
3500        len = strlen(name);
3501        pos = cache_name_pos(name, len);
3502        if (pos < 0)
3503                return 0;
3504        ce = active_cache[pos];
3505
3506        /*
3507         * This is not the sha1 we are looking for, or
3508         * unreusable because it is not a regular file.
3509         */
3510        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3511                return 0;
3512
3513        /*
3514         * If ce is marked as "assume unchanged", there is no
3515         * guarantee that work tree matches what we are looking for.
3516         */
3517        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3518                return 0;
3519
3520        /*
3521         * If ce matches the file in the work tree, we can reuse it.
3522         */
3523        if (ce_uptodate(ce) ||
3524            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3525                return 1;
3526
3527        return 0;
3528}
3529
3530static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3531{
3532        struct strbuf buf = STRBUF_INIT;
3533        char *dirty = "";
3534
3535        /* Are we looking at the work tree? */
3536        if (s->dirty_submodule)
3537                dirty = "-dirty";
3538
3539        strbuf_addf(&buf, "Subproject commit %s%s\n",
3540                    oid_to_hex(&s->oid), dirty);
3541        s->size = buf.len;
3542        if (size_only) {
3543                s->data = NULL;
3544                strbuf_release(&buf);
3545        } else {
3546                s->data = strbuf_detach(&buf, NULL);
3547                s->should_free = 1;
3548        }
3549        return 0;
3550}
3551
3552/*
3553 * While doing rename detection and pickaxe operation, we may need to
3554 * grab the data for the blob (or file) for our own in-core comparison.
3555 * diff_filespec has data and size fields for this purpose.
3556 */
3557int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3558{
3559        int size_only = flags & CHECK_SIZE_ONLY;
3560        int err = 0;
3561        /*
3562         * demote FAIL to WARN to allow inspecting the situation
3563         * instead of refusing.
3564         */
3565        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3566                                    ? SAFE_CRLF_WARN
3567                                    : safe_crlf);
3568
3569        if (!DIFF_FILE_VALID(s))
3570                die("internal error: asking to populate invalid file.");
3571        if (S_ISDIR(s->mode))
3572                return -1;
3573
3574        if (s->data)
3575                return 0;
3576
3577        if (size_only && 0 < s->size)
3578                return 0;
3579
3580        if (S_ISGITLINK(s->mode))
3581                return diff_populate_gitlink(s, size_only);
3582
3583        if (!s->oid_valid ||
3584            reuse_worktree_file(s->path, &s->oid, 0)) {
3585                struct strbuf buf = STRBUF_INIT;
3586                struct stat st;
3587                int fd;
3588
3589                if (lstat(s->path, &st) < 0) {
3590                        if (errno == ENOENT) {
3591                        err_empty:
3592                                err = -1;
3593                        empty:
3594                                s->data = (char *)"";
3595                                s->size = 0;
3596                                return err;
3597                        }
3598                }
3599                s->size = xsize_t(st.st_size);
3600                if (!s->size)
3601                        goto empty;
3602                if (S_ISLNK(st.st_mode)) {
3603                        struct strbuf sb = STRBUF_INIT;
3604
3605                        if (strbuf_readlink(&sb, s->path, s->size))
3606                                goto err_empty;
3607                        s->size = sb.len;
3608                        s->data = strbuf_detach(&sb, NULL);
3609                        s->should_free = 1;
3610                        return 0;
3611                }
3612
3613                /*
3614                 * Even if the caller would be happy with getting
3615                 * only the size, we cannot return early at this
3616                 * point if the path requires us to run the content
3617                 * conversion.
3618                 */
3619                if (size_only && !would_convert_to_git(&the_index, s->path))
3620                        return 0;
3621
3622                /*
3623                 * Note: this check uses xsize_t(st.st_size) that may
3624                 * not be the true size of the blob after it goes
3625                 * through convert_to_git().  This may not strictly be
3626                 * correct, but the whole point of big_file_threshold
3627                 * and is_binary check being that we want to avoid
3628                 * opening the file and inspecting the contents, this
3629                 * is probably fine.
3630                 */
3631                if ((flags & CHECK_BINARY) &&
3632                    s->size > big_file_threshold && s->is_binary == -1) {
3633                        s->is_binary = 1;
3634                        return 0;
3635                }
3636                fd = open(s->path, O_RDONLY);
3637                if (fd < 0)
3638                        goto err_empty;
3639                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3640                close(fd);
3641                s->should_munmap = 1;
3642
3643                /*
3644                 * Convert from working tree format to canonical git format
3645                 */
3646                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3647                        size_t size = 0;
3648                        munmap(s->data, s->size);
3649                        s->should_munmap = 0;
3650                        s->data = strbuf_detach(&buf, &size);
3651                        s->size = size;
3652                        s->should_free = 1;
3653                }
3654        }
3655        else {
3656                enum object_type type;
3657                if (size_only || (flags & CHECK_BINARY)) {
3658                        type = sha1_object_info(s->oid.hash, &s->size);
3659                        if (type < 0)
3660                                die("unable to read %s",
3661                                    oid_to_hex(&s->oid));
3662                        if (size_only)
3663                                return 0;
3664                        if (s->size > big_file_threshold && s->is_binary == -1) {
3665                                s->is_binary = 1;
3666                                return 0;
3667                        }
3668                }
3669                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3670                if (!s->data)
3671                        die("unable to read %s", oid_to_hex(&s->oid));
3672                s->should_free = 1;
3673        }
3674        return 0;
3675}
3676
3677void diff_free_filespec_blob(struct diff_filespec *s)
3678{
3679        if (s->should_free)
3680                free(s->data);
3681        else if (s->should_munmap)
3682                munmap(s->data, s->size);
3683
3684        if (s->should_free || s->should_munmap) {
3685                s->should_free = s->should_munmap = 0;
3686                s->data = NULL;
3687        }
3688}
3689
3690void diff_free_filespec_data(struct diff_filespec *s)
3691{
3692        diff_free_filespec_blob(s);
3693        FREE_AND_NULL(s->cnt_data);
3694}
3695
3696static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3697                           void *blob,
3698                           unsigned long size,
3699                           const struct object_id *oid,
3700                           int mode)
3701{
3702        int fd;
3703        struct strbuf buf = STRBUF_INIT;
3704        struct strbuf template = STRBUF_INIT;
3705        char *path_dup = xstrdup(path);
3706        const char *base = basename(path_dup);
3707
3708        /* Generate "XXXXXX_basename.ext" */
3709        strbuf_addstr(&template, "XXXXXX_");
3710        strbuf_addstr(&template, base);
3711
3712        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3713        if (fd < 0)
3714                die_errno("unable to create temp-file");
3715        if (convert_to_working_tree(path,
3716                        (const char *)blob, (size_t)size, &buf)) {
3717                blob = buf.buf;
3718                size = buf.len;
3719        }
3720        if (write_in_full(fd, blob, size) != size)
3721                die_errno("unable to write temp-file");
3722        close_tempfile(&temp->tempfile);
3723        temp->name = get_tempfile_path(&temp->tempfile);
3724        oid_to_hex_r(temp->hex, oid);
3725        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3726        strbuf_release(&buf);
3727        strbuf_release(&template);
3728        free(path_dup);
3729}
3730
3731static struct diff_tempfile *prepare_temp_file(const char *name,
3732                struct diff_filespec *one)
3733{
3734        struct diff_tempfile *temp = claim_diff_tempfile();
3735
3736        if (!DIFF_FILE_VALID(one)) {
3737        not_a_valid_file:
3738                /* A '-' entry produces this for file-2, and
3739                 * a '+' entry produces this for file-1.
3740                 */
3741                temp->name = "/dev/null";
3742                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3743                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3744                return temp;
3745        }
3746
3747        if (!S_ISGITLINK(one->mode) &&
3748            (!one->oid_valid ||
3749             reuse_worktree_file(name, &one->oid, 1))) {
3750                struct stat st;
3751                if (lstat(name, &st) < 0) {
3752                        if (errno == ENOENT)
3753                                goto not_a_valid_file;
3754                        die_errno("stat(%s)", name);
3755                }
3756                if (S_ISLNK(st.st_mode)) {
3757                        struct strbuf sb = STRBUF_INIT;
3758                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3759                                die_errno("readlink(%s)", name);
3760                        prep_temp_blob(name, temp, sb.buf, sb.len,
3761                                       (one->oid_valid ?
3762                                        &one->oid : &null_oid),
3763                                       (one->oid_valid ?
3764                                        one->mode : S_IFLNK));
3765                        strbuf_release(&sb);
3766                }
3767                else {
3768                        /* we can borrow from the file in the work tree */
3769                        temp->name = name;
3770                        if (!one->oid_valid)
3771                                oid_to_hex_r(temp->hex, &null_oid);
3772                        else
3773                                oid_to_hex_r(temp->hex, &one->oid);
3774                        /* Even though we may sometimes borrow the
3775                         * contents from the work tree, we always want
3776                         * one->mode.  mode is trustworthy even when
3777                         * !(one->oid_valid), as long as
3778                         * DIFF_FILE_VALID(one).
3779                         */
3780                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3781                }
3782                return temp;
3783        }
3784        else {
3785                if (diff_populate_filespec(one, 0))
3786                        die("cannot read data blob for %s", one->path);
3787                prep_temp_blob(name, temp, one->data, one->size,
3788                               &one->oid, one->mode);
3789        }
3790        return temp;
3791}
3792
3793static void add_external_diff_name(struct argv_array *argv,
3794                                   const char *name,
3795                                   struct diff_filespec *df)
3796{
3797        struct diff_tempfile *temp = prepare_temp_file(name, df);
3798        argv_array_push(argv, temp->name);
3799        argv_array_push(argv, temp->hex);
3800        argv_array_push(argv, temp->mode);
3801}
3802
3803/* An external diff command takes:
3804 *
3805 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3806 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3807 *
3808 */
3809static void run_external_diff(const char *pgm,
3810                              const char *name,
3811                              const char *other,
3812                              struct diff_filespec *one,
3813                              struct diff_filespec *two,
3814                              const char *xfrm_msg,
3815                              int complete_rewrite,
3816                              struct diff_options *o)
3817{
3818        struct argv_array argv = ARGV_ARRAY_INIT;
3819        struct argv_array env = ARGV_ARRAY_INIT;
3820        struct diff_queue_struct *q = &diff_queued_diff;
3821
3822        argv_array_push(&argv, pgm);
3823        argv_array_push(&argv, name);
3824
3825        if (one && two) {
3826                add_external_diff_name(&argv, name, one);
3827                if (!other)
3828                        add_external_diff_name(&argv, name, two);
3829                else {
3830                        add_external_diff_name(&argv, other, two);
3831                        argv_array_push(&argv, other);
3832                        argv_array_push(&argv, xfrm_msg);
3833                }
3834        }
3835
3836        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3837        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3838
3839        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3840                die(_("external diff died, stopping at %s"), name);
3841
3842        remove_tempfile();
3843        argv_array_clear(&argv);
3844        argv_array_clear(&env);
3845}
3846
3847static int similarity_index(struct diff_filepair *p)
3848{
3849        return p->score * 100 / MAX_SCORE;
3850}
3851
3852static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3853{
3854        if (startup_info->have_repository)
3855                return find_unique_abbrev(oid->hash, abbrev);
3856        else {
3857                char *hex = oid_to_hex(oid);
3858                if (abbrev < 0)
3859                        abbrev = FALLBACK_DEFAULT_ABBREV;
3860                if (abbrev > GIT_SHA1_HEXSZ)
3861                        die("BUG: oid abbreviation out of range: %d", abbrev);
3862                if (abbrev)
3863                        hex[abbrev] = '\0';
3864                return hex;
3865        }
3866}
3867
3868static void fill_metainfo(struct strbuf *msg,
3869                          const char *name,
3870                          const char *other,
3871                          struct diff_filespec *one,
3872                          struct diff_filespec *two,
3873                          struct diff_options *o,
3874                          struct diff_filepair *p,
3875                          int *must_show_header,
3876                          int use_color)
3877{
3878        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3879        const char *reset = diff_get_color(use_color, DIFF_RESET);
3880        const char *line_prefix = diff_line_prefix(o);
3881
3882        *must_show_header = 1;
3883        strbuf_init(msg, PATH_MAX * 2 + 300);
3884        switch (p->status) {
3885        case DIFF_STATUS_COPIED:
3886                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3887                            line_prefix, set, similarity_index(p));
3888                strbuf_addf(msg, "%s\n%s%scopy from ",
3889                            reset,  line_prefix, set);
3890                quote_c_style(name, msg, NULL, 0);
3891                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3892                quote_c_style(other, msg, NULL, 0);
3893                strbuf_addf(msg, "%s\n", reset);
3894                break;
3895        case DIFF_STATUS_RENAMED:
3896                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3897                            line_prefix, set, similarity_index(p));
3898                strbuf_addf(msg, "%s\n%s%srename from ",
3899                            reset, line_prefix, set);
3900                quote_c_style(name, msg, NULL, 0);
3901                strbuf_addf(msg, "%s\n%s%srename to ",
3902                            reset, line_prefix, set);
3903                quote_c_style(other, msg, NULL, 0);
3904                strbuf_addf(msg, "%s\n", reset);
3905                break;
3906        case DIFF_STATUS_MODIFIED:
3907                if (p->score) {
3908                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3909                                    line_prefix,
3910                                    set, similarity_index(p), reset);
3911                        break;
3912                }
3913                /* fallthru */
3914        default:
3915                *must_show_header = 0;
3916        }
3917        if (one && two && oidcmp(&one->oid, &two->oid)) {
3918                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3919
3920                if (DIFF_OPT_TST(o, BINARY)) {
3921                        mmfile_t mf;
3922                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3923                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3924                                abbrev = 40;
3925                }
3926                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3927                            diff_abbrev_oid(&one->oid, abbrev),
3928                            diff_abbrev_oid(&two->oid, abbrev));
3929                if (one->mode == two->mode)
3930                        strbuf_addf(msg, " %06o", one->mode);
3931                strbuf_addf(msg, "%s\n", reset);
3932        }
3933}
3934
3935static void run_diff_cmd(const char *pgm,
3936                         const char *name,
3937                         const char *other,
3938                         const char *attr_path,
3939                         struct diff_filespec *one,
3940                         struct diff_filespec *two,
3941                         struct strbuf *msg,
3942                         struct diff_options *o,
3943                         struct diff_filepair *p)
3944{
3945        const char *xfrm_msg = NULL;
3946        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3947        int must_show_header = 0;
3948
3949
3950        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3951                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3952                if (drv && drv->external)
3953                        pgm = drv->external;
3954        }
3955
3956        if (msg) {
3957                /*
3958                 * don't use colors when the header is intended for an
3959                 * external diff driver
3960                 */
3961                fill_metainfo(msg, name, other, one, two, o, p,
3962                              &must_show_header,
3963                              want_color(o->use_color) && !pgm);
3964                xfrm_msg = msg->len ? msg->buf : NULL;
3965        }
3966
3967        if (pgm) {
3968                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3969                                  complete_rewrite, o);
3970                return;
3971        }
3972        if (one && two)
3973                builtin_diff(name, other ? other : name,
3974                             one, two, xfrm_msg, must_show_header,
3975                             o, complete_rewrite);
3976        else
3977                fprintf(o->file, "* Unmerged path %s\n", name);
3978}
3979
3980static void diff_fill_oid_info(struct diff_filespec *one)
3981{
3982        if (DIFF_FILE_VALID(one)) {
3983                if (!one->oid_valid) {
3984                        struct stat st;
3985                        if (one->is_stdin) {
3986                                oidclr(&one->oid);
3987                                return;
3988                        }
3989                        if (lstat(one->path, &st) < 0)
3990                                die_errno("stat '%s'", one->path);
3991                        if (index_path(one->oid.hash, one->path, &st, 0))
3992                                die("cannot hash %s", one->path);
3993                }
3994        }
3995        else
3996                oidclr(&one->oid);
3997}
3998
3999static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4000{
4001        /* Strip the prefix but do not molest /dev/null and absolute paths */
4002        if (*namep && **namep != '/') {
4003                *namep += prefix_length;
4004                if (**namep == '/')
4005                        ++*namep;
4006        }
4007        if (*otherp && **otherp != '/') {
4008                *otherp += prefix_length;
4009                if (**otherp == '/')
4010                        ++*otherp;
4011        }
4012}
4013
4014static void run_diff(struct diff_filepair *p, struct diff_options *o)
4015{
4016        const char *pgm = external_diff();
4017        struct strbuf msg;
4018        struct diff_filespec *one = p->one;
4019        struct diff_filespec *two = p->two;
4020        const char *name;
4021        const char *other;
4022        const char *attr_path;
4023
4024        name  = one->path;
4025        other = (strcmp(name, two->path) ? two->path : NULL);
4026        attr_path = name;
4027        if (o->prefix_length)
4028                strip_prefix(o->prefix_length, &name, &other);
4029
4030        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
4031                pgm = NULL;
4032
4033        if (DIFF_PAIR_UNMERGED(p)) {
4034                run_diff_cmd(pgm, name, NULL, attr_path,
4035                             NULL, NULL, NULL, o, p);
4036                return;
4037        }
4038
4039        diff_fill_oid_info(one);
4040        diff_fill_oid_info(two);
4041
4042        if (!pgm &&
4043            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4044            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4045                /*
4046                 * a filepair that changes between file and symlink
4047                 * needs to be split into deletion and creation.
4048                 */
4049                struct diff_filespec *null = alloc_filespec(two->path);
4050                run_diff_cmd(NULL, name, other, attr_path,
4051                             one, null, &msg, o, p);
4052                free(null);
4053                strbuf_release(&msg);
4054
4055                null = alloc_filespec(one->path);
4056                run_diff_cmd(NULL, name, other, attr_path,
4057                             null, two, &msg, o, p);
4058                free(null);
4059        }
4060        else
4061                run_diff_cmd(pgm, name, other, attr_path,
4062                             one, two, &msg, o, p);
4063
4064        strbuf_release(&msg);
4065}
4066
4067static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4068                         struct diffstat_t *diffstat)
4069{
4070        const char *name;
4071        const char *other;
4072
4073        if (DIFF_PAIR_UNMERGED(p)) {
4074                /* unmerged */
4075                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4076                return;
4077        }
4078
4079        name = p->one->path;
4080        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4081
4082        if (o->prefix_length)
4083                strip_prefix(o->prefix_length, &name, &other);
4084
4085        diff_fill_oid_info(p->one);
4086        diff_fill_oid_info(p->two);
4087
4088        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4089}
4090
4091static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4092{
4093        const char *name;
4094        const char *other;
4095        const char *attr_path;
4096
4097        if (DIFF_PAIR_UNMERGED(p)) {
4098                /* unmerged */
4099                return;
4100        }
4101
4102        name = p->one->path;
4103        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4104        attr_path = other ? other : name;
4105
4106        if (o->prefix_length)
4107                strip_prefix(o->prefix_length, &name, &other);
4108
4109        diff_fill_oid_info(p->one);
4110        diff_fill_oid_info(p->two);
4111
4112        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4113}
4114
4115void diff_setup(struct diff_options *options)
4116{
4117        memcpy(options, &default_diff_options, sizeof(*options));
4118
4119        options->file = stdout;
4120
4121        options->abbrev = DEFAULT_ABBREV;
4122        options->line_termination = '\n';
4123        options->break_opt = -1;
4124        options->rename_limit = -1;
4125        options->dirstat_permille = diff_dirstat_permille_default;
4126        options->context = diff_context_default;
4127        options->interhunkcontext = diff_interhunk_context_default;
4128        options->ws_error_highlight = ws_error_highlight_default;
4129        DIFF_OPT_SET(options, RENAME_EMPTY);
4130
4131        /* pathchange left =NULL by default */
4132        options->change = diff_change;
4133        options->add_remove = diff_addremove;
4134        options->use_color = diff_use_color_default;
4135        options->detect_rename = diff_detect_rename_default;
4136        options->xdl_opts |= diff_algorithm;
4137        if (diff_indent_heuristic)
4138                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4139
4140        options->orderfile = diff_order_file_cfg;
4141
4142        if (diff_no_prefix) {
4143                options->a_prefix = options->b_prefix = "";
4144        } else if (!diff_mnemonic_prefix) {
4145                options->a_prefix = "a/";
4146                options->b_prefix = "b/";
4147        }
4148
4149        options->color_moved = diff_color_moved_default;
4150}
4151
4152void diff_setup_done(struct diff_options *options)
4153{
4154        int count = 0;
4155
4156        if (options->set_default)
4157                options->set_default(options);
4158
4159        if (options->output_format & DIFF_FORMAT_NAME)
4160                count++;
4161        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
4162                count++;
4163        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
4164                count++;
4165        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
4166                count++;
4167        if (count > 1)
4168                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4169
4170        /*
4171         * Most of the time we can say "there are changes"
4172         * only by checking if there are changed paths, but
4173         * --ignore-whitespace* options force us to look
4174         * inside contents.
4175         */
4176
4177        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
4178            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
4179            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
4180                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
4181        else
4182                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
4183
4184        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
4185                options->detect_rename = DIFF_DETECT_COPY;
4186
4187        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
4188                options->prefix = NULL;
4189        if (options->prefix)
4190                options->prefix_length = strlen(options->prefix);
4191        else
4192                options->prefix_length = 0;
4193
4194        if (options->output_format & (DIFF_FORMAT_NAME |
4195                                      DIFF_FORMAT_NAME_STATUS |
4196                                      DIFF_FORMAT_CHECKDIFF |
4197                                      DIFF_FORMAT_NO_OUTPUT))
4198                options->output_format &= ~(DIFF_FORMAT_RAW |
4199                                            DIFF_FORMAT_NUMSTAT |
4200                                            DIFF_FORMAT_DIFFSTAT |
4201                                            DIFF_FORMAT_SHORTSTAT |
4202                                            DIFF_FORMAT_DIRSTAT |
4203                                            DIFF_FORMAT_SUMMARY |
4204                                            DIFF_FORMAT_PATCH);
4205
4206        /*
4207         * These cases always need recursive; we do not drop caller-supplied
4208         * recursive bits for other formats here.
4209         */
4210        if (options->output_format & (DIFF_FORMAT_PATCH |
4211                                      DIFF_FORMAT_NUMSTAT |
4212                                      DIFF_FORMAT_DIFFSTAT |
4213                                      DIFF_FORMAT_SHORTSTAT |
4214                                      DIFF_FORMAT_DIRSTAT |
4215                                      DIFF_FORMAT_SUMMARY |
4216                                      DIFF_FORMAT_CHECKDIFF))
4217                DIFF_OPT_SET(options, RECURSIVE);
4218        /*
4219         * Also pickaxe would not work very well if you do not say recursive
4220         */
4221        if (options->pickaxe)
4222                DIFF_OPT_SET(options, RECURSIVE);
4223        /*
4224         * When patches are generated, submodules diffed against the work tree
4225         * must be checked for dirtiness too so it can be shown in the output
4226         */
4227        if (options->output_format & DIFF_FORMAT_PATCH)
4228                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
4229
4230        if (options->detect_rename && options->rename_limit < 0)
4231                options->rename_limit = diff_rename_limit_default;
4232        if (options->setup & DIFF_SETUP_USE_CACHE) {
4233                if (!active_cache)
4234                        /* read-cache does not die even when it fails
4235                         * so it is safe for us to do this here.  Also
4236                         * it does not smudge active_cache or active_nr
4237                         * when it fails, so we do not have to worry about
4238                         * cleaning it up ourselves either.
4239                         */
4240                        read_cache();
4241        }
4242        if (40 < options->abbrev)
4243                options->abbrev = 40; /* full */
4244
4245        /*
4246         * It does not make sense to show the first hit we happened
4247         * to have found.  It does not make sense not to return with
4248         * exit code in such a case either.
4249         */
4250        if (DIFF_OPT_TST(options, QUICK)) {
4251                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4252                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4253        }
4254
4255        options->diff_path_counter = 0;
4256
4257        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
4258                die(_("--follow requires exactly one pathspec"));
4259
4260        if (!options->use_color || external_diff())
4261                options->color_moved = 0;
4262}
4263
4264static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4265{
4266        char c, *eq;
4267        int len;
4268
4269        if (*arg != '-')
4270                return 0;
4271        c = *++arg;
4272        if (!c)
4273                return 0;
4274        if (c == arg_short) {
4275                c = *++arg;
4276                if (!c)
4277                        return 1;
4278                if (val && isdigit(c)) {
4279                        char *end;
4280                        int n = strtoul(arg, &end, 10);
4281                        if (*end)
4282                                return 0;
4283                        *val = n;
4284                        return 1;
4285                }
4286                return 0;
4287        }
4288        if (c != '-')
4289                return 0;
4290        arg++;
4291        eq = strchrnul(arg, '=');
4292        len = eq - arg;
4293        if (!len || strncmp(arg, arg_long, len))
4294                return 0;
4295        if (*eq) {
4296                int n;
4297                char *end;
4298                if (!isdigit(*++eq))
4299                        return 0;
4300                n = strtoul(eq, &end, 10);
4301                if (*end)
4302                        return 0;
4303                *val = n;
4304        }
4305        return 1;
4306}
4307
4308static int diff_scoreopt_parse(const char *opt);
4309
4310static inline int short_opt(char opt, const char **argv,
4311                            const char **optarg)
4312{
4313        const char *arg = argv[0];
4314        if (arg[0] != '-' || arg[1] != opt)
4315                return 0;
4316        if (arg[2] != '\0') {
4317                *optarg = arg + 2;
4318                return 1;
4319        }
4320        if (!argv[1])
4321                die("Option '%c' requires a value", opt);
4322        *optarg = argv[1];
4323        return 2;
4324}
4325
4326int parse_long_opt(const char *opt, const char **argv,
4327                   const char **optarg)
4328{
4329        const char *arg = argv[0];
4330        if (!skip_prefix(arg, "--", &arg))
4331                return 0;
4332        if (!skip_prefix(arg, opt, &arg))
4333                return 0;
4334        if (*arg == '=') { /* stuck form: --option=value */
4335                *optarg = arg + 1;
4336                return 1;
4337        }
4338        if (*arg != '\0')
4339                return 0;
4340        /* separate form: --option value */
4341        if (!argv[1])
4342                die("Option '--%s' requires a value", opt);
4343        *optarg = argv[1];
4344        return 2;
4345}
4346
4347static int stat_opt(struct diff_options *options, const char **av)
4348{
4349        const char *arg = av[0];
4350        char *end;
4351        int width = options->stat_width;
4352        int name_width = options->stat_name_width;
4353        int graph_width = options->stat_graph_width;
4354        int count = options->stat_count;
4355        int argcount = 1;
4356
4357        if (!skip_prefix(arg, "--stat", &arg))
4358                die("BUG: stat option does not begin with --stat: %s", arg);
4359        end = (char *)arg;
4360
4361        switch (*arg) {
4362        case '-':
4363                if (skip_prefix(arg, "-width", &arg)) {
4364                        if (*arg == '=')
4365                                width = strtoul(arg + 1, &end, 10);
4366                        else if (!*arg && !av[1])
4367                                die_want_option("--stat-width");
4368                        else if (!*arg) {
4369                                width = strtoul(av[1], &end, 10);
4370                                argcount = 2;
4371                        }
4372                } else if (skip_prefix(arg, "-name-width", &arg)) {
4373                        if (*arg == '=')
4374                                name_width = strtoul(arg + 1, &end, 10);
4375                        else if (!*arg && !av[1])
4376                                die_want_option("--stat-name-width");
4377                        else if (!*arg) {
4378                                name_width = strtoul(av[1], &end, 10);
4379                                argcount = 2;
4380                        }
4381                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4382                        if (*arg == '=')
4383                                graph_width = strtoul(arg + 1, &end, 10);
4384                        else if (!*arg && !av[1])
4385                                die_want_option("--stat-graph-width");
4386                        else if (!*arg) {
4387                                graph_width = strtoul(av[1], &end, 10);
4388                                argcount = 2;
4389                        }
4390                } else if (skip_prefix(arg, "-count", &arg)) {
4391                        if (*arg == '=')
4392                                count = strtoul(arg + 1, &end, 10);
4393                        else if (!*arg && !av[1])
4394                                die_want_option("--stat-count");
4395                        else if (!*arg) {
4396                                count = strtoul(av[1], &end, 10);
4397                                argcount = 2;
4398                        }
4399                }
4400                break;
4401        case '=':
4402                width = strtoul(arg+1, &end, 10);
4403                if (*end == ',')
4404                        name_width = strtoul(end+1, &end, 10);
4405                if (*end == ',')
4406                        count = strtoul(end+1, &end, 10);
4407        }
4408
4409        /* Important! This checks all the error cases! */
4410        if (*end)
4411                return 0;
4412        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4413        options->stat_name_width = name_width;
4414        options->stat_graph_width = graph_width;
4415        options->stat_width = width;
4416        options->stat_count = count;
4417        return argcount;
4418}
4419
4420static int parse_dirstat_opt(struct diff_options *options, const char *params)
4421{
4422        struct strbuf errmsg = STRBUF_INIT;
4423        if (parse_dirstat_params(options, params, &errmsg))
4424                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4425                    errmsg.buf);
4426        strbuf_release(&errmsg);
4427        /*
4428         * The caller knows a dirstat-related option is given from the command
4429         * line; allow it to say "return this_function();"
4430         */
4431        options->output_format |= DIFF_FORMAT_DIRSTAT;
4432        return 1;
4433}
4434
4435static int parse_submodule_opt(struct diff_options *options, const char *value)
4436{
4437        if (parse_submodule_params(options, value))
4438                die(_("Failed to parse --submodule option parameter: '%s'"),
4439                        value);
4440        return 1;
4441}
4442
4443static const char diff_status_letters[] = {
4444        DIFF_STATUS_ADDED,
4445        DIFF_STATUS_COPIED,
4446        DIFF_STATUS_DELETED,
4447        DIFF_STATUS_MODIFIED,
4448        DIFF_STATUS_RENAMED,
4449        DIFF_STATUS_TYPE_CHANGED,
4450        DIFF_STATUS_UNKNOWN,
4451        DIFF_STATUS_UNMERGED,
4452        DIFF_STATUS_FILTER_AON,
4453        DIFF_STATUS_FILTER_BROKEN,
4454        '\0',
4455};
4456
4457static unsigned int filter_bit['Z' + 1];
4458
4459static void prepare_filter_bits(void)
4460{
4461        int i;
4462
4463        if (!filter_bit[DIFF_STATUS_ADDED]) {
4464                for (i = 0; diff_status_letters[i]; i++)
4465                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4466        }
4467}
4468
4469static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4470{
4471        return opt->filter & filter_bit[(int) status];
4472}
4473
4474static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4475{
4476        int i, optch;
4477
4478        prepare_filter_bits();
4479
4480        /*
4481         * If there is a negation e.g. 'd' in the input, and we haven't
4482         * initialized the filter field with another --diff-filter, start
4483         * from full set of bits, except for AON.
4484         */
4485        if (!opt->filter) {
4486                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4487                        if (optch < 'a' || 'z' < optch)
4488                                continue;
4489                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4490                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4491                        break;
4492                }
4493        }
4494
4495        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4496                unsigned int bit;
4497                int negate;
4498
4499                if ('a' <= optch && optch <= 'z') {
4500                        negate = 1;
4501                        optch = toupper(optch);
4502                } else {
4503                        negate = 0;
4504                }
4505
4506                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4507                if (!bit)
4508                        return optarg[i];
4509                if (negate)
4510                        opt->filter &= ~bit;
4511                else
4512                        opt->filter |= bit;
4513        }
4514        return 0;
4515}
4516
4517static void enable_patch_output(int *fmt) {
4518        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4519        *fmt |= DIFF_FORMAT_PATCH;
4520}
4521
4522static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4523{
4524        int val = parse_ws_error_highlight(arg);
4525
4526        if (val < 0) {
4527                error("unknown value after ws-error-highlight=%.*s",
4528                      -1 - val, arg);
4529                return 0;
4530        }
4531        opt->ws_error_highlight = val;
4532        return 1;
4533}
4534
4535int diff_opt_parse(struct diff_options *options,
4536                   const char **av, int ac, const char *prefix)
4537{
4538        const char *arg = av[0];
4539        const char *optarg;
4540        int argcount;
4541
4542        if (!prefix)
4543                prefix = "";
4544
4545        /* Output format options */
4546        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4547            || opt_arg(arg, 'U', "unified", &options->context))
4548                enable_patch_output(&options->output_format);
4549        else if (!strcmp(arg, "--raw"))
4550                options->output_format |= DIFF_FORMAT_RAW;
4551        else if (!strcmp(arg, "--patch-with-raw")) {
4552                enable_patch_output(&options->output_format);
4553                options->output_format |= DIFF_FORMAT_RAW;
4554        } else if (!strcmp(arg, "--numstat"))
4555                options->output_format |= DIFF_FORMAT_NUMSTAT;
4556        else if (!strcmp(arg, "--shortstat"))
4557                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4558        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4559                return parse_dirstat_opt(options, "");
4560        else if (skip_prefix(arg, "-X", &arg))
4561                return parse_dirstat_opt(options, arg);
4562        else if (skip_prefix(arg, "--dirstat=", &arg))
4563                return parse_dirstat_opt(options, arg);
4564        else if (!strcmp(arg, "--cumulative"))
4565                return parse_dirstat_opt(options, "cumulative");
4566        else if (!strcmp(arg, "--dirstat-by-file"))
4567                return parse_dirstat_opt(options, "files");
4568        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4569                parse_dirstat_opt(options, "files");
4570                return parse_dirstat_opt(options, arg);
4571        }
4572        else if (!strcmp(arg, "--check"))
4573                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4574        else if (!strcmp(arg, "--summary"))
4575                options->output_format |= DIFF_FORMAT_SUMMARY;
4576        else if (!strcmp(arg, "--patch-with-stat")) {
4577                enable_patch_output(&options->output_format);
4578                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4579        } else if (!strcmp(arg, "--name-only"))
4580                options->output_format |= DIFF_FORMAT_NAME;
4581        else if (!strcmp(arg, "--name-status"))
4582                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4583        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4584                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4585        else if (starts_with(arg, "--stat"))
4586                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4587                return stat_opt(options, av);
4588
4589        /* renames options */
4590        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4591                 !strcmp(arg, "--break-rewrites")) {
4592                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4593                        return error("invalid argument to -B: %s", arg+2);
4594        }
4595        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4596                 !strcmp(arg, "--find-renames")) {
4597                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4598                        return error("invalid argument to -M: %s", arg+2);
4599                options->detect_rename = DIFF_DETECT_RENAME;
4600        }
4601        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4602                options->irreversible_delete = 1;
4603        }
4604        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4605                 !strcmp(arg, "--find-copies")) {
4606                if (options->detect_rename == DIFF_DETECT_COPY)
4607                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4608                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4609                        return error("invalid argument to -C: %s", arg+2);
4610                options->detect_rename = DIFF_DETECT_COPY;
4611        }
4612        else if (!strcmp(arg, "--no-renames"))
4613                options->detect_rename = 0;
4614        else if (!strcmp(arg, "--rename-empty"))
4615                DIFF_OPT_SET(options, RENAME_EMPTY);
4616        else if (!strcmp(arg, "--no-rename-empty"))
4617                DIFF_OPT_CLR(options, RENAME_EMPTY);
4618        else if (!strcmp(arg, "--relative"))
4619                DIFF_OPT_SET(options, RELATIVE_NAME);
4620        else if (skip_prefix(arg, "--relative=", &arg)) {
4621                DIFF_OPT_SET(options, RELATIVE_NAME);
4622                options->prefix = arg;
4623        }
4624
4625        /* xdiff options */
4626        else if (!strcmp(arg, "--minimal"))
4627                DIFF_XDL_SET(options, NEED_MINIMAL);
4628        else if (!strcmp(arg, "--no-minimal"))
4629                DIFF_XDL_CLR(options, NEED_MINIMAL);
4630        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4631                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4632        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4633                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4634        else if (!strcmp(arg, "--ignore-space-at-eol"))
4635                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4636        else if (!strcmp(arg, "--ignore-blank-lines"))
4637                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4638        else if (!strcmp(arg, "--indent-heuristic"))
4639                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4640        else if (!strcmp(arg, "--no-indent-heuristic"))
4641                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4642        else if (!strcmp(arg, "--patience"))
4643                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4644        else if (!strcmp(arg, "--histogram"))
4645                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4646        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4647                long value = parse_algorithm_value(optarg);
4648                if (value < 0)
4649                        return error("option diff-algorithm accepts \"myers\", "
4650                                     "\"minimal\", \"patience\" and \"histogram\"");
4651                /* clear out previous settings */
4652                DIFF_XDL_CLR(options, NEED_MINIMAL);
4653                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4654                options->xdl_opts |= value;
4655                return argcount;
4656        }
4657
4658        /* flags options */
4659        else if (!strcmp(arg, "--binary")) {
4660                enable_patch_output(&options->output_format);
4661                DIFF_OPT_SET(options, BINARY);
4662        }
4663        else if (!strcmp(arg, "--full-index"))
4664                DIFF_OPT_SET(options, FULL_INDEX);
4665        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4666                DIFF_OPT_SET(options, TEXT);
4667        else if (!strcmp(arg, "-R"))
4668                DIFF_OPT_SET(options, REVERSE_DIFF);
4669        else if (!strcmp(arg, "--find-copies-harder"))
4670                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4671        else if (!strcmp(arg, "--follow"))
4672                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4673        else if (!strcmp(arg, "--no-follow")) {
4674                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4675                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4676        } else if (!strcmp(arg, "--color"))
4677                options->use_color = 1;
4678        else if (skip_prefix(arg, "--color=", &arg)) {
4679                int value = git_config_colorbool(NULL, arg);
4680                if (value < 0)
4681                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4682                options->use_color = value;
4683        }
4684        else if (!strcmp(arg, "--no-color"))
4685                options->use_color = 0;
4686        else if (!strcmp(arg, "--color-moved")) {
4687                if (diff_color_moved_default)
4688                        options->color_moved = diff_color_moved_default;
4689                if (options->color_moved == COLOR_MOVED_NO)
4690                        options->color_moved = COLOR_MOVED_DEFAULT;
4691        } else if (!strcmp(arg, "--no-color-moved"))
4692                options->color_moved = COLOR_MOVED_NO;
4693        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4694                int cm = parse_color_moved(arg);
4695                if (cm < 0)
4696                        die("bad --color-moved argument: %s", arg);
4697                options->color_moved = cm;
4698        } else if (!strcmp(arg, "--color-words")) {
4699                options->use_color = 1;
4700                options->word_diff = DIFF_WORDS_COLOR;
4701        }
4702        else if (skip_prefix(arg, "--color-words=", &arg)) {
4703                options->use_color = 1;
4704                options->word_diff = DIFF_WORDS_COLOR;
4705                options->word_regex = arg;
4706        }
4707        else if (!strcmp(arg, "--word-diff")) {
4708                if (options->word_diff == DIFF_WORDS_NONE)
4709                        options->word_diff = DIFF_WORDS_PLAIN;
4710        }
4711        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4712                if (!strcmp(arg, "plain"))
4713                        options->word_diff = DIFF_WORDS_PLAIN;
4714                else if (!strcmp(arg, "color")) {
4715                        options->use_color = 1;
4716                        options->word_diff = DIFF_WORDS_COLOR;
4717                }
4718                else if (!strcmp(arg, "porcelain"))
4719                        options->word_diff = DIFF_WORDS_PORCELAIN;
4720                else if (!strcmp(arg, "none"))
4721                        options->word_diff = DIFF_WORDS_NONE;
4722                else
4723                        die("bad --word-diff argument: %s", arg);
4724        }
4725        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4726                if (options->word_diff == DIFF_WORDS_NONE)
4727                        options->word_diff = DIFF_WORDS_PLAIN;
4728                options->word_regex = optarg;
4729                return argcount;
4730        }
4731        else if (!strcmp(arg, "--exit-code"))
4732                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4733        else if (!strcmp(arg, "--quiet"))
4734                DIFF_OPT_SET(options, QUICK);
4735        else if (!strcmp(arg, "--ext-diff"))
4736                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4737        else if (!strcmp(arg, "--no-ext-diff"))
4738                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4739        else if (!strcmp(arg, "--textconv"))
4740                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4741        else if (!strcmp(arg, "--no-textconv"))
4742                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4743        else if (!strcmp(arg, "--ignore-submodules")) {
4744                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4745                handle_ignore_submodules_arg(options, "all");
4746        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4747                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4748                handle_ignore_submodules_arg(options, arg);
4749        } else if (!strcmp(arg, "--submodule"))
4750                options->submodule_format = DIFF_SUBMODULE_LOG;
4751        else if (skip_prefix(arg, "--submodule=", &arg))
4752                return parse_submodule_opt(options, arg);
4753        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4754                return parse_ws_error_highlight_opt(options, arg);
4755        else if (!strcmp(arg, "--ita-invisible-in-index"))
4756                options->ita_invisible_in_index = 1;
4757        else if (!strcmp(arg, "--ita-visible-in-index"))
4758                options->ita_invisible_in_index = 0;
4759
4760        /* misc options */
4761        else if (!strcmp(arg, "-z"))
4762                options->line_termination = 0;
4763        else if ((argcount = short_opt('l', av, &optarg))) {
4764                options->rename_limit = strtoul(optarg, NULL, 10);
4765                return argcount;
4766        }
4767        else if ((argcount = short_opt('S', av, &optarg))) {
4768                options->pickaxe = optarg;
4769                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4770                return argcount;
4771        } else if ((argcount = short_opt('G', av, &optarg))) {
4772                options->pickaxe = optarg;
4773                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4774                return argcount;
4775        }
4776        else if (!strcmp(arg, "--pickaxe-all"))
4777                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4778        else if (!strcmp(arg, "--pickaxe-regex"))
4779                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4780        else if ((argcount = short_opt('O', av, &optarg))) {
4781                options->orderfile = prefix_filename(prefix, optarg);
4782                return argcount;
4783        }
4784        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4785                int offending = parse_diff_filter_opt(optarg, options);
4786                if (offending)
4787                        die("unknown change class '%c' in --diff-filter=%s",
4788                            offending, optarg);
4789                return argcount;
4790        }
4791        else if (!strcmp(arg, "--no-abbrev"))
4792                options->abbrev = 0;
4793        else if (!strcmp(arg, "--abbrev"))
4794                options->abbrev = DEFAULT_ABBREV;
4795        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4796                options->abbrev = strtoul(arg, NULL, 10);
4797                if (options->abbrev < MINIMUM_ABBREV)
4798                        options->abbrev = MINIMUM_ABBREV;
4799                else if (40 < options->abbrev)
4800                        options->abbrev = 40;
4801        }
4802        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4803                options->a_prefix = optarg;
4804                return argcount;
4805        }
4806        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4807                options->line_prefix = optarg;
4808                options->line_prefix_length = strlen(options->line_prefix);
4809                graph_setup_line_prefix(options);
4810                return argcount;
4811        }
4812        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4813                options->b_prefix = optarg;
4814                return argcount;
4815        }
4816        else if (!strcmp(arg, "--no-prefix"))
4817                options->a_prefix = options->b_prefix = "";
4818        else if (opt_arg(arg, '\0', "inter-hunk-context",
4819                         &options->interhunkcontext))
4820                ;
4821        else if (!strcmp(arg, "-W"))
4822                DIFF_OPT_SET(options, FUNCCONTEXT);
4823        else if (!strcmp(arg, "--function-context"))
4824                DIFF_OPT_SET(options, FUNCCONTEXT);
4825        else if (!strcmp(arg, "--no-function-context"))
4826                DIFF_OPT_CLR(options, FUNCCONTEXT);
4827        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4828                char *path = prefix_filename(prefix, optarg);
4829                options->file = xfopen(path, "w");
4830                options->close_file = 1;
4831                if (options->use_color != GIT_COLOR_ALWAYS)
4832                        options->use_color = GIT_COLOR_NEVER;
4833                free(path);
4834                return argcount;
4835        } else
4836                return 0;
4837        return 1;
4838}
4839
4840int parse_rename_score(const char **cp_p)
4841{
4842        unsigned long num, scale;
4843        int ch, dot;
4844        const char *cp = *cp_p;
4845
4846        num = 0;
4847        scale = 1;
4848        dot = 0;
4849        for (;;) {
4850                ch = *cp;
4851                if ( !dot && ch == '.' ) {
4852                        scale = 1;
4853                        dot = 1;
4854                } else if ( ch == '%' ) {
4855                        scale = dot ? scale*100 : 100;
4856                        cp++;   /* % is always at the end */
4857                        break;
4858                } else if ( ch >= '0' && ch <= '9' ) {
4859                        if ( scale < 100000 ) {
4860                                scale *= 10;
4861                                num = (num*10) + (ch-'0');
4862                        }
4863                } else {
4864                        break;
4865                }
4866                cp++;
4867        }
4868        *cp_p = cp;
4869
4870        /* user says num divided by scale and we say internally that
4871         * is MAX_SCORE * num / scale.
4872         */
4873        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4874}
4875
4876static int diff_scoreopt_parse(const char *opt)
4877{
4878        int opt1, opt2, cmd;
4879
4880        if (*opt++ != '-')
4881                return -1;
4882        cmd = *opt++;
4883        if (cmd == '-') {
4884                /* convert the long-form arguments into short-form versions */
4885                if (skip_prefix(opt, "break-rewrites", &opt)) {
4886                        if (*opt == 0 || *opt++ == '=')
4887                                cmd = 'B';
4888                } else if (skip_prefix(opt, "find-copies", &opt)) {
4889                        if (*opt == 0 || *opt++ == '=')
4890                                cmd = 'C';
4891                } else if (skip_prefix(opt, "find-renames", &opt)) {
4892                        if (*opt == 0 || *opt++ == '=')
4893                                cmd = 'M';
4894                }
4895        }
4896        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4897                return -1; /* that is not a -M, -C, or -B option */
4898
4899        opt1 = parse_rename_score(&opt);
4900        if (cmd != 'B')
4901                opt2 = 0;
4902        else {
4903                if (*opt == 0)
4904                        opt2 = 0;
4905                else if (*opt != '/')
4906                        return -1; /* we expect -B80/99 or -B80 */
4907                else {
4908                        opt++;
4909                        opt2 = parse_rename_score(&opt);
4910                }
4911        }
4912        if (*opt != 0)
4913                return -1;
4914        return opt1 | (opt2 << 16);
4915}
4916
4917struct diff_queue_struct diff_queued_diff;
4918
4919void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4920{
4921        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4922        queue->queue[queue->nr++] = dp;
4923}
4924
4925struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4926                                 struct diff_filespec *one,
4927                                 struct diff_filespec *two)
4928{
4929        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4930        dp->one = one;
4931        dp->two = two;
4932        if (queue)
4933                diff_q(queue, dp);
4934        return dp;
4935}
4936
4937void diff_free_filepair(struct diff_filepair *p)
4938{
4939        free_filespec(p->one);
4940        free_filespec(p->two);
4941        free(p);
4942}
4943
4944const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4945{
4946        int abblen;
4947        const char *abbrev;
4948
4949        if (len == GIT_SHA1_HEXSZ)
4950                return oid_to_hex(oid);
4951
4952        abbrev = diff_abbrev_oid(oid, len);
4953        abblen = strlen(abbrev);
4954
4955        /*
4956         * In well-behaved cases, where the abbbreviated result is the
4957         * same as the requested length, append three dots after the
4958         * abbreviation (hence the whole logic is limited to the case
4959         * where abblen < 37); when the actual abbreviated result is a
4960         * bit longer than the requested length, we reduce the number
4961         * of dots so that they match the well-behaved ones.  However,
4962         * if the actual abbreviation is longer than the requested
4963         * length by more than three, we give up on aligning, and add
4964         * three dots anyway, to indicate that the output is not the
4965         * full object name.  Yes, this may be suboptimal, but this
4966         * appears only in "diff --raw --abbrev" output and it is not
4967         * worth the effort to change it now.  Note that this would
4968         * likely to work fine when the automatic sizing of default
4969         * abbreviation length is used--we would be fed -1 in "len" in
4970         * that case, and will end up always appending three-dots, but
4971         * the automatic sizing is supposed to give abblen that ensures
4972         * uniqueness across all objects (statistically speaking).
4973         */
4974        if (abblen < GIT_SHA1_HEXSZ - 3) {
4975                static char hex[GIT_MAX_HEXSZ + 1];
4976                if (len < abblen && abblen <= len + 2)
4977                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4978                else
4979                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4980                return hex;
4981        }
4982
4983        return oid_to_hex(oid);
4984}
4985
4986static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4987{
4988        int line_termination = opt->line_termination;
4989        int inter_name_termination = line_termination ? '\t' : '\0';
4990
4991        fprintf(opt->file, "%s", diff_line_prefix(opt));
4992        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4993                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4994                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4995                fprintf(opt->file, "%s ",
4996                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4997        }
4998        if (p->score) {
4999                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5000                        inter_name_termination);
5001        } else {
5002                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5003        }
5004
5005        if (p->status == DIFF_STATUS_COPIED ||
5006            p->status == DIFF_STATUS_RENAMED) {
5007                const char *name_a, *name_b;
5008                name_a = p->one->path;
5009                name_b = p->two->path;
5010                strip_prefix(opt->prefix_length, &name_a, &name_b);
5011                write_name_quoted(name_a, opt->file, inter_name_termination);
5012                write_name_quoted(name_b, opt->file, line_termination);
5013        } else {
5014                const char *name_a, *name_b;
5015                name_a = p->one->mode ? p->one->path : p->two->path;
5016                name_b = NULL;
5017                strip_prefix(opt->prefix_length, &name_a, &name_b);
5018                write_name_quoted(name_a, opt->file, line_termination);
5019        }
5020}
5021
5022int diff_unmodified_pair(struct diff_filepair *p)
5023{
5024        /* This function is written stricter than necessary to support
5025         * the currently implemented transformers, but the idea is to
5026         * let transformers to produce diff_filepairs any way they want,
5027         * and filter and clean them up here before producing the output.
5028         */
5029        struct diff_filespec *one = p->one, *two = p->two;
5030
5031        if (DIFF_PAIR_UNMERGED(p))
5032                return 0; /* unmerged is interesting */
5033
5034        /* deletion, addition, mode or type change
5035         * and rename are all interesting.
5036         */
5037        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5038            DIFF_PAIR_MODE_CHANGED(p) ||
5039            strcmp(one->path, two->path))
5040                return 0;
5041
5042        /* both are valid and point at the same path.  that is, we are
5043         * dealing with a change.
5044         */
5045        if (one->oid_valid && two->oid_valid &&
5046            !oidcmp(&one->oid, &two->oid) &&
5047            !one->dirty_submodule && !two->dirty_submodule)
5048                return 1; /* no change */
5049        if (!one->oid_valid && !two->oid_valid)
5050                return 1; /* both look at the same file on the filesystem. */
5051        return 0;
5052}
5053
5054static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5055{
5056        if (diff_unmodified_pair(p))
5057                return;
5058
5059        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5060            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5061                return; /* no tree diffs in patch format */
5062
5063        run_diff(p, o);
5064}
5065
5066static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5067                            struct diffstat_t *diffstat)
5068{
5069        if (diff_unmodified_pair(p))
5070                return;
5071
5072        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5073            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5074                return; /* no useful stat for tree diffs */
5075
5076        run_diffstat(p, o, diffstat);
5077}
5078
5079static void diff_flush_checkdiff(struct diff_filepair *p,
5080                struct diff_options *o)
5081{
5082        if (diff_unmodified_pair(p))
5083                return;
5084
5085        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5086            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5087                return; /* nothing to check in tree diffs */
5088
5089        run_checkdiff(p, o);
5090}
5091
5092int diff_queue_is_empty(void)
5093{
5094        struct diff_queue_struct *q = &diff_queued_diff;
5095        int i;
5096        for (i = 0; i < q->nr; i++)
5097                if (!diff_unmodified_pair(q->queue[i]))
5098                        return 0;
5099        return 1;
5100}
5101
5102#if DIFF_DEBUG
5103void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5104{
5105        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5106                x, one ? one : "",
5107                s->path,
5108                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5109                s->mode,
5110                s->oid_valid ? oid_to_hex(&s->oid) : "");
5111        fprintf(stderr, "queue[%d] %s size %lu\n",
5112                x, one ? one : "",
5113                s->size);
5114}
5115
5116void diff_debug_filepair(const struct diff_filepair *p, int i)
5117{
5118        diff_debug_filespec(p->one, i, "one");
5119        diff_debug_filespec(p->two, i, "two");
5120        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5121                p->score, p->status ? p->status : '?',
5122                p->one->rename_used, p->broken_pair);
5123}
5124
5125void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5126{
5127        int i;
5128        if (msg)
5129                fprintf(stderr, "%s\n", msg);
5130        fprintf(stderr, "q->nr = %d\n", q->nr);
5131        for (i = 0; i < q->nr; i++) {
5132                struct diff_filepair *p = q->queue[i];
5133                diff_debug_filepair(p, i);
5134        }
5135}
5136#endif
5137
5138static void diff_resolve_rename_copy(void)
5139{
5140        int i;
5141        struct diff_filepair *p;
5142        struct diff_queue_struct *q = &diff_queued_diff;
5143
5144        diff_debug_queue("resolve-rename-copy", q);
5145
5146        for (i = 0; i < q->nr; i++) {
5147                p = q->queue[i];
5148                p->status = 0; /* undecided */
5149                if (DIFF_PAIR_UNMERGED(p))
5150                        p->status = DIFF_STATUS_UNMERGED;
5151                else if (!DIFF_FILE_VALID(p->one))
5152                        p->status = DIFF_STATUS_ADDED;
5153                else if (!DIFF_FILE_VALID(p->two))
5154                        p->status = DIFF_STATUS_DELETED;
5155                else if (DIFF_PAIR_TYPE_CHANGED(p))
5156                        p->status = DIFF_STATUS_TYPE_CHANGED;
5157
5158                /* from this point on, we are dealing with a pair
5159                 * whose both sides are valid and of the same type, i.e.
5160                 * either in-place edit or rename/copy edit.
5161                 */
5162                else if (DIFF_PAIR_RENAME(p)) {
5163                        /*
5164                         * A rename might have re-connected a broken
5165                         * pair up, causing the pathnames to be the
5166                         * same again. If so, that's not a rename at
5167                         * all, just a modification..
5168                         *
5169                         * Otherwise, see if this source was used for
5170                         * multiple renames, in which case we decrement
5171                         * the count, and call it a copy.
5172                         */
5173                        if (!strcmp(p->one->path, p->two->path))
5174                                p->status = DIFF_STATUS_MODIFIED;
5175                        else if (--p->one->rename_used > 0)
5176                                p->status = DIFF_STATUS_COPIED;
5177                        else
5178                                p->status = DIFF_STATUS_RENAMED;
5179                }
5180                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5181                         p->one->mode != p->two->mode ||
5182                         p->one->dirty_submodule ||
5183                         p->two->dirty_submodule ||
5184                         is_null_oid(&p->one->oid))
5185                        p->status = DIFF_STATUS_MODIFIED;
5186                else {
5187                        /* This is a "no-change" entry and should not
5188                         * happen anymore, but prepare for broken callers.
5189                         */
5190                        error("feeding unmodified %s to diffcore",
5191                              p->one->path);
5192                        p->status = DIFF_STATUS_UNKNOWN;
5193                }
5194        }
5195        diff_debug_queue("resolve-rename-copy done", q);
5196}
5197
5198static int check_pair_status(struct diff_filepair *p)
5199{
5200        switch (p->status) {
5201        case DIFF_STATUS_UNKNOWN:
5202                return 0;
5203        case 0:
5204                die("internal error in diff-resolve-rename-copy");
5205        default:
5206                return 1;
5207        }
5208}
5209
5210static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5211{
5212        int fmt = opt->output_format;
5213
5214        if (fmt & DIFF_FORMAT_CHECKDIFF)
5215                diff_flush_checkdiff(p, opt);
5216        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5217                diff_flush_raw(p, opt);
5218        else if (fmt & DIFF_FORMAT_NAME) {
5219                const char *name_a, *name_b;
5220                name_a = p->two->path;
5221                name_b = NULL;
5222                strip_prefix(opt->prefix_length, &name_a, &name_b);
5223                fprintf(opt->file, "%s", diff_line_prefix(opt));
5224                write_name_quoted(name_a, opt->file, opt->line_termination);
5225        }
5226}
5227
5228static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5229{
5230        struct strbuf sb = STRBUF_INIT;
5231        if (fs->mode)
5232                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5233        else
5234                strbuf_addf(&sb, " %s ", newdelete);
5235
5236        quote_c_style(fs->path, &sb, NULL, 0);
5237        strbuf_addch(&sb, '\n');
5238        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5239                         sb.buf, sb.len, 0);
5240        strbuf_release(&sb);
5241}
5242
5243static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5244                int show_name)
5245{
5246        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5247                struct strbuf sb = STRBUF_INIT;
5248                strbuf_addf(&sb, " mode change %06o => %06o",
5249                            p->one->mode, p->two->mode);
5250                if (show_name) {
5251                        strbuf_addch(&sb, ' ');
5252                        quote_c_style(p->two->path, &sb, NULL, 0);
5253                }
5254                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5255                                 sb.buf, sb.len, 0);
5256                strbuf_release(&sb);
5257        }
5258}
5259
5260static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5261                struct diff_filepair *p)
5262{
5263        struct strbuf sb = STRBUF_INIT;
5264        char *names = pprint_rename(p->one->path, p->two->path);
5265        strbuf_addf(&sb, " %s %s (%d%%)\n",
5266                        renamecopy, names, similarity_index(p));
5267        free(names);
5268        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5269                                 sb.buf, sb.len, 0);
5270        show_mode_change(opt, p, 0);
5271}
5272
5273static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5274{
5275        switch(p->status) {
5276        case DIFF_STATUS_DELETED:
5277                show_file_mode_name(opt, "delete", p->one);
5278                break;
5279        case DIFF_STATUS_ADDED:
5280                show_file_mode_name(opt, "create", p->two);
5281                break;
5282        case DIFF_STATUS_COPIED:
5283                show_rename_copy(opt, "copy", p);
5284                break;
5285        case DIFF_STATUS_RENAMED:
5286                show_rename_copy(opt, "rename", p);
5287                break;
5288        default:
5289                if (p->score) {
5290                        struct strbuf sb = STRBUF_INIT;
5291                        strbuf_addstr(&sb, " rewrite ");
5292                        quote_c_style(p->two->path, &sb, NULL, 0);
5293                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5294                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5295                                         sb.buf, sb.len, 0);
5296                }
5297                show_mode_change(opt, p, !p->score);
5298                break;
5299        }
5300}
5301
5302struct patch_id_t {
5303        git_SHA_CTX *ctx;
5304        int patchlen;
5305};
5306
5307static int remove_space(char *line, int len)
5308{
5309        int i;
5310        char *dst = line;
5311        unsigned char c;
5312
5313        for (i = 0; i < len; i++)
5314                if (!isspace((c = line[i])))
5315                        *dst++ = c;
5316
5317        return dst - line;
5318}
5319
5320static void patch_id_consume(void *priv, char *line, unsigned long len)
5321{
5322        struct patch_id_t *data = priv;
5323        int new_len;
5324
5325        /* Ignore line numbers when computing the SHA1 of the patch */
5326        if (starts_with(line, "@@ -"))
5327                return;
5328
5329        new_len = remove_space(line, len);
5330
5331        git_SHA1_Update(data->ctx, line, new_len);
5332        data->patchlen += new_len;
5333}
5334
5335static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5336{
5337        git_SHA1_Update(ctx, str, strlen(str));
5338}
5339
5340static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5341{
5342        /* large enough for 2^32 in octal */
5343        char buf[12];
5344        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5345        git_SHA1_Update(ctx, buf, len);
5346}
5347
5348/* returns 0 upon success, and writes result into sha1 */
5349static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5350{
5351        struct diff_queue_struct *q = &diff_queued_diff;
5352        int i;
5353        git_SHA_CTX ctx;
5354        struct patch_id_t data;
5355
5356        git_SHA1_Init(&ctx);
5357        memset(&data, 0, sizeof(struct patch_id_t));
5358        data.ctx = &ctx;
5359
5360        for (i = 0; i < q->nr; i++) {
5361                xpparam_t xpp;
5362                xdemitconf_t xecfg;
5363                mmfile_t mf1, mf2;
5364                struct diff_filepair *p = q->queue[i];
5365                int len1, len2;
5366
5367                memset(&xpp, 0, sizeof(xpp));
5368                memset(&xecfg, 0, sizeof(xecfg));
5369                if (p->status == 0)
5370                        return error("internal diff status error");
5371                if (p->status == DIFF_STATUS_UNKNOWN)
5372                        continue;
5373                if (diff_unmodified_pair(p))
5374                        continue;
5375                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5376                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5377                        continue;
5378                if (DIFF_PAIR_UNMERGED(p))
5379                        continue;
5380
5381                diff_fill_oid_info(p->one);
5382                diff_fill_oid_info(p->two);
5383
5384                len1 = remove_space(p->one->path, strlen(p->one->path));
5385                len2 = remove_space(p->two->path, strlen(p->two->path));
5386                patch_id_add_string(&ctx, "diff--git");
5387                patch_id_add_string(&ctx, "a/");
5388                git_SHA1_Update(&ctx, p->one->path, len1);
5389                patch_id_add_string(&ctx, "b/");
5390                git_SHA1_Update(&ctx, p->two->path, len2);
5391
5392                if (p->one->mode == 0) {
5393                        patch_id_add_string(&ctx, "newfilemode");
5394                        patch_id_add_mode(&ctx, p->two->mode);
5395                        patch_id_add_string(&ctx, "---/dev/null");
5396                        patch_id_add_string(&ctx, "+++b/");
5397                        git_SHA1_Update(&ctx, p->two->path, len2);
5398                } else if (p->two->mode == 0) {
5399                        patch_id_add_string(&ctx, "deletedfilemode");
5400                        patch_id_add_mode(&ctx, p->one->mode);
5401                        patch_id_add_string(&ctx, "---a/");
5402                        git_SHA1_Update(&ctx, p->one->path, len1);
5403                        patch_id_add_string(&ctx, "+++/dev/null");
5404                } else {
5405                        patch_id_add_string(&ctx, "---a/");
5406                        git_SHA1_Update(&ctx, p->one->path, len1);
5407                        patch_id_add_string(&ctx, "+++b/");
5408                        git_SHA1_Update(&ctx, p->two->path, len2);
5409                }
5410
5411                if (diff_header_only)
5412                        continue;
5413
5414                if (fill_mmfile(&mf1, p->one) < 0 ||
5415                    fill_mmfile(&mf2, p->two) < 0)
5416                        return error("unable to read files to diff");
5417
5418                if (diff_filespec_is_binary(p->one) ||
5419                    diff_filespec_is_binary(p->two)) {
5420                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5421                                        GIT_SHA1_HEXSZ);
5422                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5423                                        GIT_SHA1_HEXSZ);
5424                        continue;
5425                }
5426
5427                xpp.flags = 0;
5428                xecfg.ctxlen = 3;
5429                xecfg.flags = 0;
5430                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5431                                  &xpp, &xecfg))
5432                        return error("unable to generate patch-id diff for %s",
5433                                     p->one->path);
5434        }
5435
5436        git_SHA1_Final(oid->hash, &ctx);
5437        return 0;
5438}
5439
5440int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5441{
5442        struct diff_queue_struct *q = &diff_queued_diff;
5443        int i;
5444        int result = diff_get_patch_id(options, oid, diff_header_only);
5445
5446        for (i = 0; i < q->nr; i++)
5447                diff_free_filepair(q->queue[i]);
5448
5449        free(q->queue);
5450        DIFF_QUEUE_CLEAR(q);
5451
5452        return result;
5453}
5454
5455static int is_summary_empty(const struct diff_queue_struct *q)
5456{
5457        int i;
5458
5459        for (i = 0; i < q->nr; i++) {
5460                const struct diff_filepair *p = q->queue[i];
5461
5462                switch (p->status) {
5463                case DIFF_STATUS_DELETED:
5464                case DIFF_STATUS_ADDED:
5465                case DIFF_STATUS_COPIED:
5466                case DIFF_STATUS_RENAMED:
5467                        return 0;
5468                default:
5469                        if (p->score)
5470                                return 0;
5471                        if (p->one->mode && p->two->mode &&
5472                            p->one->mode != p->two->mode)
5473                                return 0;
5474                        break;
5475                }
5476        }
5477        return 1;
5478}
5479
5480static const char rename_limit_warning[] =
5481N_("inexact rename detection was skipped due to too many files.");
5482
5483static const char degrade_cc_to_c_warning[] =
5484N_("only found copies from modified paths due to too many files.");
5485
5486static const char rename_limit_advice[] =
5487N_("you may want to set your %s variable to at least "
5488   "%d and retry the command.");
5489
5490void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5491{
5492        if (degraded_cc)
5493                warning(_(degrade_cc_to_c_warning));
5494        else if (needed)
5495                warning(_(rename_limit_warning));
5496        else
5497                return;
5498        if (0 < needed && needed < 32767)
5499                warning(_(rename_limit_advice), varname, needed);
5500}
5501
5502static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5503{
5504        int i;
5505        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5506        struct diff_queue_struct *q = &diff_queued_diff;
5507
5508        if (WSEH_NEW & WS_RULE_MASK)
5509                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5510
5511        if (o->color_moved)
5512                o->emitted_symbols = &esm;
5513
5514        for (i = 0; i < q->nr; i++) {
5515                struct diff_filepair *p = q->queue[i];
5516                if (check_pair_status(p))
5517                        diff_flush_patch(p, o);
5518        }
5519
5520        if (o->emitted_symbols) {
5521                if (o->color_moved) {
5522                        struct hashmap add_lines, del_lines;
5523
5524                        hashmap_init(&del_lines,
5525                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5526                        hashmap_init(&add_lines,
5527                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5528
5529                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5530                        mark_color_as_moved(o, &add_lines, &del_lines);
5531                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5532                                dim_moved_lines(o);
5533
5534                        hashmap_free(&add_lines, 0);
5535                        hashmap_free(&del_lines, 0);
5536                }
5537
5538                for (i = 0; i < esm.nr; i++)
5539                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5540
5541                for (i = 0; i < esm.nr; i++)
5542                        free((void *)esm.buf[i].line);
5543        }
5544        esm.nr = 0;
5545}
5546
5547void diff_flush(struct diff_options *options)
5548{
5549        struct diff_queue_struct *q = &diff_queued_diff;
5550        int i, output_format = options->output_format;
5551        int separator = 0;
5552        int dirstat_by_line = 0;
5553
5554        /*
5555         * Order: raw, stat, summary, patch
5556         * or:    name/name-status/checkdiff (other bits clear)
5557         */
5558        if (!q->nr)
5559                goto free_queue;
5560
5561        if (output_format & (DIFF_FORMAT_RAW |
5562                             DIFF_FORMAT_NAME |
5563                             DIFF_FORMAT_NAME_STATUS |
5564                             DIFF_FORMAT_CHECKDIFF)) {
5565                for (i = 0; i < q->nr; i++) {
5566                        struct diff_filepair *p = q->queue[i];
5567                        if (check_pair_status(p))
5568                                flush_one_pair(p, options);
5569                }
5570                separator++;
5571        }
5572
5573        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
5574                dirstat_by_line = 1;
5575
5576        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5577            dirstat_by_line) {
5578                struct diffstat_t diffstat;
5579
5580                memset(&diffstat, 0, sizeof(struct diffstat_t));
5581                for (i = 0; i < q->nr; i++) {
5582                        struct diff_filepair *p = q->queue[i];
5583                        if (check_pair_status(p))
5584                                diff_flush_stat(p, options, &diffstat);
5585                }
5586                if (output_format & DIFF_FORMAT_NUMSTAT)
5587                        show_numstat(&diffstat, options);
5588                if (output_format & DIFF_FORMAT_DIFFSTAT)
5589                        show_stats(&diffstat, options);
5590                if (output_format & DIFF_FORMAT_SHORTSTAT)
5591                        show_shortstats(&diffstat, options);
5592                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5593                        show_dirstat_by_line(&diffstat, options);
5594                free_diffstat_info(&diffstat);
5595                separator++;
5596        }
5597        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5598                show_dirstat(options);
5599
5600        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5601                for (i = 0; i < q->nr; i++) {
5602                        diff_summary(options, q->queue[i]);
5603                }
5604                separator++;
5605        }
5606
5607        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5608            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5609            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5610                /*
5611                 * run diff_flush_patch for the exit status. setting
5612                 * options->file to /dev/null should be safe, because we
5613                 * aren't supposed to produce any output anyway.
5614                 */
5615                if (options->close_file)
5616                        fclose(options->file);
5617                options->file = xfopen("/dev/null", "w");
5618                options->close_file = 1;
5619                options->color_moved = 0;
5620                for (i = 0; i < q->nr; i++) {
5621                        struct diff_filepair *p = q->queue[i];
5622                        if (check_pair_status(p))
5623                                diff_flush_patch(p, options);
5624                        if (options->found_changes)
5625                                break;
5626                }
5627        }
5628
5629        if (output_format & DIFF_FORMAT_PATCH) {
5630                if (separator) {
5631                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5632                        if (options->stat_sep)
5633                                /* attach patch instead of inline */
5634                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5635                                                 NULL, 0, 0);
5636                }
5637
5638                diff_flush_patch_all_file_pairs(options);
5639        }
5640
5641        if (output_format & DIFF_FORMAT_CALLBACK)
5642                options->format_callback(q, options, options->format_callback_data);
5643
5644        for (i = 0; i < q->nr; i++)
5645                diff_free_filepair(q->queue[i]);
5646free_queue:
5647        free(q->queue);
5648        DIFF_QUEUE_CLEAR(q);
5649        if (options->close_file)
5650                fclose(options->file);
5651
5652        /*
5653         * Report the content-level differences with HAS_CHANGES;
5654         * diff_addremove/diff_change does not set the bit when
5655         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5656         */
5657        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5658                if (options->found_changes)
5659                        DIFF_OPT_SET(options, HAS_CHANGES);
5660                else
5661                        DIFF_OPT_CLR(options, HAS_CHANGES);
5662        }
5663}
5664
5665static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5666{
5667        return (((p->status == DIFF_STATUS_MODIFIED) &&
5668                 ((p->score &&
5669                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5670                  (!p->score &&
5671                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5672                ((p->status != DIFF_STATUS_MODIFIED) &&
5673                 filter_bit_tst(p->status, options)));
5674}
5675
5676static void diffcore_apply_filter(struct diff_options *options)
5677{
5678        int i;
5679        struct diff_queue_struct *q = &diff_queued_diff;
5680        struct diff_queue_struct outq;
5681
5682        DIFF_QUEUE_CLEAR(&outq);
5683
5684        if (!options->filter)
5685                return;
5686
5687        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5688                int found;
5689                for (i = found = 0; !found && i < q->nr; i++) {
5690                        if (match_filter(options, q->queue[i]))
5691                                found++;
5692                }
5693                if (found)
5694                        return;
5695
5696                /* otherwise we will clear the whole queue
5697                 * by copying the empty outq at the end of this
5698                 * function, but first clear the current entries
5699                 * in the queue.
5700                 */
5701                for (i = 0; i < q->nr; i++)
5702                        diff_free_filepair(q->queue[i]);
5703        }
5704        else {
5705                /* Only the matching ones */
5706                for (i = 0; i < q->nr; i++) {
5707                        struct diff_filepair *p = q->queue[i];
5708                        if (match_filter(options, p))
5709                                diff_q(&outq, p);
5710                        else
5711                                diff_free_filepair(p);
5712                }
5713        }
5714        free(q->queue);
5715        *q = outq;
5716}
5717
5718/* Check whether two filespecs with the same mode and size are identical */
5719static int diff_filespec_is_identical(struct diff_filespec *one,
5720                                      struct diff_filespec *two)
5721{
5722        if (S_ISGITLINK(one->mode))
5723                return 0;
5724        if (diff_populate_filespec(one, 0))
5725                return 0;
5726        if (diff_populate_filespec(two, 0))
5727                return 0;
5728        return !memcmp(one->data, two->data, one->size);
5729}
5730
5731static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5732{
5733        if (p->done_skip_stat_unmatch)
5734                return p->skip_stat_unmatch_result;
5735
5736        p->done_skip_stat_unmatch = 1;
5737        p->skip_stat_unmatch_result = 0;
5738        /*
5739         * 1. Entries that come from stat info dirtiness
5740         *    always have both sides (iow, not create/delete),
5741         *    one side of the object name is unknown, with
5742         *    the same mode and size.  Keep the ones that
5743         *    do not match these criteria.  They have real
5744         *    differences.
5745         *
5746         * 2. At this point, the file is known to be modified,
5747         *    with the same mode and size, and the object
5748         *    name of one side is unknown.  Need to inspect
5749         *    the identical contents.
5750         */
5751        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5752            !DIFF_FILE_VALID(p->two) ||
5753            (p->one->oid_valid && p->two->oid_valid) ||
5754            (p->one->mode != p->two->mode) ||
5755            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5756            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5757            (p->one->size != p->two->size) ||
5758            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5759                p->skip_stat_unmatch_result = 1;
5760        return p->skip_stat_unmatch_result;
5761}
5762
5763static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5764{
5765        int i;
5766        struct diff_queue_struct *q = &diff_queued_diff;
5767        struct diff_queue_struct outq;
5768        DIFF_QUEUE_CLEAR(&outq);
5769
5770        for (i = 0; i < q->nr; i++) {
5771                struct diff_filepair *p = q->queue[i];
5772
5773                if (diff_filespec_check_stat_unmatch(p))
5774                        diff_q(&outq, p);
5775                else {
5776                        /*
5777                         * The caller can subtract 1 from skip_stat_unmatch
5778                         * to determine how many paths were dirty only
5779                         * due to stat info mismatch.
5780                         */
5781                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5782                                diffopt->skip_stat_unmatch++;
5783                        diff_free_filepair(p);
5784                }
5785        }
5786        free(q->queue);
5787        *q = outq;
5788}
5789
5790static int diffnamecmp(const void *a_, const void *b_)
5791{
5792        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5793        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5794        const char *name_a, *name_b;
5795
5796        name_a = a->one ? a->one->path : a->two->path;
5797        name_b = b->one ? b->one->path : b->two->path;
5798        return strcmp(name_a, name_b);
5799}
5800
5801void diffcore_fix_diff_index(struct diff_options *options)
5802{
5803        struct diff_queue_struct *q = &diff_queued_diff;
5804        QSORT(q->queue, q->nr, diffnamecmp);
5805}
5806
5807void diffcore_std(struct diff_options *options)
5808{
5809        /* NOTE please keep the following in sync with diff_tree_combined() */
5810        if (options->skip_stat_unmatch)
5811                diffcore_skip_stat_unmatch(options);
5812        if (!options->found_follow) {
5813                /* See try_to_follow_renames() in tree-diff.c */
5814                if (options->break_opt != -1)
5815                        diffcore_break(options->break_opt);
5816                if (options->detect_rename)
5817                        diffcore_rename(options);
5818                if (options->break_opt != -1)
5819                        diffcore_merge_broken();
5820        }
5821        if (options->pickaxe)
5822                diffcore_pickaxe(options);
5823        if (options->orderfile)
5824                diffcore_order(options->orderfile);
5825        if (!options->found_follow)
5826                /* See try_to_follow_renames() in tree-diff.c */
5827                diff_resolve_rename_copy();
5828        diffcore_apply_filter(options);
5829
5830        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5831                DIFF_OPT_SET(options, HAS_CHANGES);
5832        else
5833                DIFF_OPT_CLR(options, HAS_CHANGES);
5834
5835        options->found_follow = 0;
5836}
5837
5838int diff_result_code(struct diff_options *opt, int status)
5839{
5840        int result = 0;
5841
5842        diff_warn_rename_limit("diff.renameLimit",
5843                               opt->needed_rename_limit,
5844                               opt->degraded_cc_to_c);
5845        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5846            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5847                return status;
5848        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5849            DIFF_OPT_TST(opt, HAS_CHANGES))
5850                result |= 01;
5851        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5852            DIFF_OPT_TST(opt, CHECK_FAILED))
5853                result |= 02;
5854        return result;
5855}
5856
5857int diff_can_quit_early(struct diff_options *opt)
5858{
5859        return (DIFF_OPT_TST(opt, QUICK) &&
5860                !opt->filter &&
5861                DIFF_OPT_TST(opt, HAS_CHANGES));
5862}
5863
5864/*
5865 * Shall changes to this submodule be ignored?
5866 *
5867 * Submodule changes can be configured to be ignored separately for each path,
5868 * but that configuration can be overridden from the command line.
5869 */
5870static int is_submodule_ignored(const char *path, struct diff_options *options)
5871{
5872        int ignored = 0;
5873        unsigned orig_flags = options->flags;
5874        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5875                set_diffopt_flags_from_submodule_config(options, path);
5876        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5877                ignored = 1;
5878        options->flags = orig_flags;
5879        return ignored;
5880}
5881
5882void diff_addremove(struct diff_options *options,
5883                    int addremove, unsigned mode,
5884                    const struct object_id *oid,
5885                    int oid_valid,
5886                    const char *concatpath, unsigned dirty_submodule)
5887{
5888        struct diff_filespec *one, *two;
5889
5890        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5891                return;
5892
5893        /* This may look odd, but it is a preparation for
5894         * feeding "there are unchanged files which should
5895         * not produce diffs, but when you are doing copy
5896         * detection you would need them, so here they are"
5897         * entries to the diff-core.  They will be prefixed
5898         * with something like '=' or '*' (I haven't decided
5899         * which but should not make any difference).
5900         * Feeding the same new and old to diff_change()
5901         * also has the same effect.
5902         * Before the final output happens, they are pruned after
5903         * merged into rename/copy pairs as appropriate.
5904         */
5905        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5906                addremove = (addremove == '+' ? '-' :
5907                             addremove == '-' ? '+' : addremove);
5908
5909        if (options->prefix &&
5910            strncmp(concatpath, options->prefix, options->prefix_length))
5911                return;
5912
5913        one = alloc_filespec(concatpath);
5914        two = alloc_filespec(concatpath);
5915
5916        if (addremove != '+')
5917                fill_filespec(one, oid, oid_valid, mode);
5918        if (addremove != '-') {
5919                fill_filespec(two, oid, oid_valid, mode);
5920                two->dirty_submodule = dirty_submodule;
5921        }
5922
5923        diff_queue(&diff_queued_diff, one, two);
5924        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5925                DIFF_OPT_SET(options, HAS_CHANGES);
5926}
5927
5928void diff_change(struct diff_options *options,
5929                 unsigned old_mode, unsigned new_mode,
5930                 const struct object_id *old_oid,
5931                 const struct object_id *new_oid,
5932                 int old_oid_valid, int new_oid_valid,
5933                 const char *concatpath,
5934                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5935{
5936        struct diff_filespec *one, *two;
5937        struct diff_filepair *p;
5938
5939        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5940            is_submodule_ignored(concatpath, options))
5941                return;
5942
5943        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5944                SWAP(old_mode, new_mode);
5945                SWAP(old_oid, new_oid);
5946                SWAP(old_oid_valid, new_oid_valid);
5947                SWAP(old_dirty_submodule, new_dirty_submodule);
5948        }
5949
5950        if (options->prefix &&
5951            strncmp(concatpath, options->prefix, options->prefix_length))
5952                return;
5953
5954        one = alloc_filespec(concatpath);
5955        two = alloc_filespec(concatpath);
5956        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5957        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5958        one->dirty_submodule = old_dirty_submodule;
5959        two->dirty_submodule = new_dirty_submodule;
5960        p = diff_queue(&diff_queued_diff, one, two);
5961
5962        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5963                return;
5964
5965        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5966            !diff_filespec_check_stat_unmatch(p))
5967                return;
5968
5969        DIFF_OPT_SET(options, HAS_CHANGES);
5970}
5971
5972struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5973{
5974        struct diff_filepair *pair;
5975        struct diff_filespec *one, *two;
5976
5977        if (options->prefix &&
5978            strncmp(path, options->prefix, options->prefix_length))
5979                return NULL;
5980
5981        one = alloc_filespec(path);
5982        two = alloc_filespec(path);
5983        pair = diff_queue(&diff_queued_diff, one, two);
5984        pair->is_unmerged = 1;
5985        return pair;
5986}
5987
5988static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5989                size_t *outsize)
5990{
5991        struct diff_tempfile *temp;
5992        const char *argv[3];
5993        const char **arg = argv;
5994        struct child_process child = CHILD_PROCESS_INIT;
5995        struct strbuf buf = STRBUF_INIT;
5996        int err = 0;
5997
5998        temp = prepare_temp_file(spec->path, spec);
5999        *arg++ = pgm;
6000        *arg++ = temp->name;
6001        *arg = NULL;
6002
6003        child.use_shell = 1;
6004        child.argv = argv;
6005        child.out = -1;
6006        if (start_command(&child)) {
6007                remove_tempfile();
6008                return NULL;
6009        }
6010
6011        if (strbuf_read(&buf, child.out, 0) < 0)
6012                err = error("error reading from textconv command '%s'", pgm);
6013        close(child.out);
6014
6015        if (finish_command(&child) || err) {
6016                strbuf_release(&buf);
6017                remove_tempfile();
6018                return NULL;
6019        }
6020        remove_tempfile();
6021
6022        return strbuf_detach(&buf, outsize);
6023}
6024
6025size_t fill_textconv(struct userdiff_driver *driver,
6026                     struct diff_filespec *df,
6027                     char **outbuf)
6028{
6029        size_t size;
6030
6031        if (!driver) {
6032                if (!DIFF_FILE_VALID(df)) {
6033                        *outbuf = "";
6034                        return 0;
6035                }
6036                if (diff_populate_filespec(df, 0))
6037                        die("unable to read files to diff");
6038                *outbuf = df->data;
6039                return df->size;
6040        }
6041
6042        if (!driver->textconv)
6043                die("BUG: fill_textconv called with non-textconv driver");
6044
6045        if (driver->textconv_cache && df->oid_valid) {
6046                *outbuf = notes_cache_get(driver->textconv_cache,
6047                                          &df->oid,
6048                                          &size);
6049                if (*outbuf)
6050                        return size;
6051        }
6052
6053        *outbuf = run_textconv(driver->textconv, df, &size);
6054        if (!*outbuf)
6055                die("unable to read files to diff");
6056
6057        if (driver->textconv_cache && df->oid_valid) {
6058                /* ignore errors, as we might be in a readonly repository */
6059                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6060                                size);
6061                /*
6062                 * we could save up changes and flush them all at the end,
6063                 * but we would need an extra call after all diffing is done.
6064                 * Since generating a cache entry is the slow path anyway,
6065                 * this extra overhead probably isn't a big deal.
6066                 */
6067                notes_cache_write(driver->textconv_cache);
6068        }
6069
6070        return size;
6071}
6072
6073int textconv_object(const char *path,
6074                    unsigned mode,
6075                    const struct object_id *oid,
6076                    int oid_valid,
6077                    char **buf,
6078                    unsigned long *buf_size)
6079{
6080        struct diff_filespec *df;
6081        struct userdiff_driver *textconv;
6082
6083        df = alloc_filespec(path);
6084        fill_filespec(df, oid, oid_valid, mode);
6085        textconv = get_textconv(df);
6086        if (!textconv) {
6087                free_filespec(df);
6088                return 0;
6089        }
6090
6091        *buf_size = fill_textconv(textconv, df, buf);
6092        free_filespec(df);
6093        return 1;
6094}
6095
6096void setup_diff_pager(struct diff_options *opt)
6097{
6098        /*
6099         * If the user asked for our exit code, then either they want --quiet
6100         * or --exit-code. We should definitely not bother with a pager in the
6101         * former case, as we will generate no output. Since we still properly
6102         * report our exit code even when a pager is run, we _could_ run a
6103         * pager with --exit-code. But since we have not done so historically,
6104         * and because it is easy to find people oneline advising "git diff
6105         * --exit-code" in hooks and other scripts, we do not do so.
6106         */
6107        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
6108            check_pager_config("diff") != 0)
6109                setup_pager();
6110}