diff.con commit diff: fix infinite loop with --color-moved --ignore-space-change (fa5ba2c)
   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 (isspace(**cp)) {
 724                if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_CHANGE)) {
 725                        while (*cp < *endp && isspace(**cp))
 726                                (*cp)++;
 727                        /*
 728                         * After skipping a couple of whitespaces,
 729                         * we still have to account for one space.
 730                         */
 731                        return (int)' ';
 732                }
 733
 734                if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE)) {
 735                        while (*cp < *endp && isspace(**cp))
 736                                (*cp)++;
 737                        /* return the first non-ws character via the usual below */
 738                }
 739        }
 740
 741        retval = (unsigned char)(**cp);
 742        (*cp)++;
 743        return retval;
 744}
 745
 746static int moved_entry_cmp(const struct diff_options *diffopt,
 747                           const struct moved_entry *a,
 748                           const struct moved_entry *b,
 749                           const void *keydata)
 750{
 751        const char *ap = a->es->line, *ae = a->es->line + a->es->len;
 752        const char *bp = b->es->line, *be = b->es->line + b->es->len;
 753
 754        if (!(diffopt->xdl_opts & XDF_WHITESPACE_FLAGS))
 755                return a->es->len != b->es->len  || memcmp(ap, bp, a->es->len);
 756
 757        if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_AT_EOL)) {
 758                while (ae > ap && isspace(*ae))
 759                        ae--;
 760                while (be > bp && isspace(*be))
 761                        be--;
 762        }
 763
 764        while (1) {
 765                int ca, cb;
 766                ca = next_byte(&ap, &ae, diffopt);
 767                cb = next_byte(&bp, &be, diffopt);
 768                if (ca != cb)
 769                        return 1;
 770                if (ca < 0)
 771                        return 0;
 772        }
 773}
 774
 775static unsigned get_string_hash(struct emitted_diff_symbol *es, struct diff_options *o)
 776{
 777        if (o->xdl_opts & XDF_WHITESPACE_FLAGS) {
 778                static struct strbuf sb = STRBUF_INIT;
 779                const char *ap = es->line, *ae = es->line + es->len;
 780                int c;
 781
 782                strbuf_reset(&sb);
 783                while (ae > ap && isspace(*ae))
 784                        ae--;
 785                while ((c = next_byte(&ap, &ae, o)) > 0)
 786                        strbuf_addch(&sb, c);
 787
 788                return memhash(sb.buf, sb.len);
 789        } else {
 790                return memhash(es->line, es->len);
 791        }
 792}
 793
 794static struct moved_entry *prepare_entry(struct diff_options *o,
 795                                         int line_no)
 796{
 797        struct moved_entry *ret = xmalloc(sizeof(*ret));
 798        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 799
 800        ret->ent.hash = get_string_hash(l, o);
 801        ret->es = l;
 802        ret->next_line = NULL;
 803
 804        return ret;
 805}
 806
 807static void add_lines_to_move_detection(struct diff_options *o,
 808                                        struct hashmap *add_lines,
 809                                        struct hashmap *del_lines)
 810{
 811        struct moved_entry *prev_line = NULL;
 812
 813        int n;
 814        for (n = 0; n < o->emitted_symbols->nr; n++) {
 815                struct hashmap *hm;
 816                struct moved_entry *key;
 817
 818                switch (o->emitted_symbols->buf[n].s) {
 819                case DIFF_SYMBOL_PLUS:
 820                        hm = add_lines;
 821                        break;
 822                case DIFF_SYMBOL_MINUS:
 823                        hm = del_lines;
 824                        break;
 825                default:
 826                        prev_line = NULL;
 827                        continue;
 828                }
 829
 830                key = prepare_entry(o, n);
 831                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 832                        prev_line->next_line = key;
 833
 834                hashmap_add(hm, key);
 835                prev_line = key;
 836        }
 837}
 838
 839static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 840                                         int pmb_nr)
 841{
 842        int lp, rp;
 843
 844        /* Shrink the set of potential block to the remaining running */
 845        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 846                while (lp < pmb_nr && pmb[lp])
 847                        lp++;
 848                /* lp points at the first NULL now */
 849
 850                while (rp > -1 && !pmb[rp])
 851                        rp--;
 852                /* rp points at the last non-NULL */
 853
 854                if (lp < pmb_nr && rp > -1 && lp < rp) {
 855                        pmb[lp] = pmb[rp];
 856                        pmb[rp] = NULL;
 857                        rp--;
 858                        lp++;
 859                }
 860        }
 861
 862        /* Remember the number of running sets */
 863        return rp + 1;
 864}
 865
 866/* Find blocks of moved code, delegate actual coloring decision to helper */
 867static void mark_color_as_moved(struct diff_options *o,
 868                                struct hashmap *add_lines,
 869                                struct hashmap *del_lines)
 870{
 871        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 872        int pmb_nr = 0, pmb_alloc = 0;
 873        int n, flipped_block = 1, block_length = 0;
 874
 875
 876        for (n = 0; n < o->emitted_symbols->nr; n++) {
 877                struct hashmap *hm = NULL;
 878                struct moved_entry *key;
 879                struct moved_entry *match = NULL;
 880                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 881                int i;
 882
 883                switch (l->s) {
 884                case DIFF_SYMBOL_PLUS:
 885                        hm = del_lines;
 886                        key = prepare_entry(o, n);
 887                        match = hashmap_get(hm, key, o);
 888                        free(key);
 889                        break;
 890                case DIFF_SYMBOL_MINUS:
 891                        hm = add_lines;
 892                        key = prepare_entry(o, n);
 893                        match = hashmap_get(hm, key, o);
 894                        free(key);
 895                        break;
 896                default:
 897                        flipped_block = 1;
 898                }
 899
 900                if (!match) {
 901                        if (block_length < COLOR_MOVED_MIN_BLOCK_LENGTH &&
 902                            o->color_moved != COLOR_MOVED_PLAIN) {
 903                                for (i = 0; i < block_length + 1; i++) {
 904                                        l = &o->emitted_symbols->buf[n - i];
 905                                        l->flags &= ~DIFF_SYMBOL_MOVED_LINE;
 906                                }
 907                        }
 908                        pmb_nr = 0;
 909                        block_length = 0;
 910                        continue;
 911                }
 912
 913                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 914                block_length++;
 915
 916                if (o->color_moved == COLOR_MOVED_PLAIN)
 917                        continue;
 918
 919                /* Check any potential block runs, advance each or nullify */
 920                for (i = 0; i < pmb_nr; i++) {
 921                        struct moved_entry *p = pmb[i];
 922                        struct moved_entry *pnext = (p && p->next_line) ?
 923                                        p->next_line : NULL;
 924                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 925                                pmb[i] = p->next_line;
 926                        } else {
 927                                pmb[i] = NULL;
 928                        }
 929                }
 930
 931                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 932
 933                if (pmb_nr == 0) {
 934                        /*
 935                         * The current line is the start of a new block.
 936                         * Setup the set of potential blocks.
 937                         */
 938                        for (; match; match = hashmap_get_next(hm, match)) {
 939                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 940                                pmb[pmb_nr++] = match;
 941                        }
 942
 943                        flipped_block = (flipped_block + 1) % 2;
 944                }
 945
 946                if (flipped_block)
 947                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 948        }
 949
 950        free(pmb);
 951}
 952
 953#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 954  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 955static void dim_moved_lines(struct diff_options *o)
 956{
 957        int n;
 958        for (n = 0; n < o->emitted_symbols->nr; n++) {
 959                struct emitted_diff_symbol *prev = (n != 0) ?
 960                                &o->emitted_symbols->buf[n - 1] : NULL;
 961                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 962                struct emitted_diff_symbol *next =
 963                                (n < o->emitted_symbols->nr - 1) ?
 964                                &o->emitted_symbols->buf[n + 1] : NULL;
 965
 966                /* Not a plus or minus line? */
 967                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 968                        continue;
 969
 970                /* Not a moved line? */
 971                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 972                        continue;
 973
 974                /*
 975                 * If prev or next are not a plus or minus line,
 976                 * pretend they don't exist
 977                 */
 978                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 979                            prev->s != DIFF_SYMBOL_MINUS)
 980                        prev = NULL;
 981                if (next && next->s != DIFF_SYMBOL_PLUS &&
 982                            next->s != DIFF_SYMBOL_MINUS)
 983                        next = NULL;
 984
 985                /* Inside a block? */
 986                if ((prev &&
 987                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 988                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 989                    (next &&
 990                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 991                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 992                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 993                        continue;
 994                }
 995
 996                /* Check if we are at an interesting bound: */
 997                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 998                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 999                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1000                        continue;
1001                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1002                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1003                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1004                        continue;
1005
1006                /*
1007                 * The boundary to prev and next are not interesting,
1008                 * so this line is not interesting as a whole
1009                 */
1010                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1011        }
1012}
1013
1014static void emit_line_ws_markup(struct diff_options *o,
1015                                const char *set, const char *reset,
1016                                const char *line, int len, char sign,
1017                                unsigned ws_rule, int blank_at_eof)
1018{
1019        const char *ws = NULL;
1020
1021        if (o->ws_error_highlight & ws_rule) {
1022                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1023                if (!*ws)
1024                        ws = NULL;
1025        }
1026
1027        if (!ws)
1028                emit_line_0(o, set, reset, sign, line, len);
1029        else if (blank_at_eof)
1030                /* Blank line at EOF - paint '+' as well */
1031                emit_line_0(o, ws, reset, sign, line, len);
1032        else {
1033                /* Emit just the prefix, then the rest. */
1034                emit_line_0(o, set, reset, sign, "", 0);
1035                ws_check_emit(line, len, ws_rule,
1036                              o->file, set, reset, ws);
1037        }
1038}
1039
1040static void emit_diff_symbol_from_struct(struct diff_options *o,
1041                                         struct emitted_diff_symbol *eds)
1042{
1043        static const char *nneof = " No newline at end of file\n";
1044        const char *context, *reset, *set, *meta, *fraginfo;
1045        struct strbuf sb = STRBUF_INIT;
1046
1047        enum diff_symbol s = eds->s;
1048        const char *line = eds->line;
1049        int len = eds->len;
1050        unsigned flags = eds->flags;
1051
1052        switch (s) {
1053        case DIFF_SYMBOL_NO_LF_EOF:
1054                context = diff_get_color_opt(o, DIFF_CONTEXT);
1055                reset = diff_get_color_opt(o, DIFF_RESET);
1056                putc('\n', o->file);
1057                emit_line_0(o, context, reset, '\\',
1058                            nneof, strlen(nneof));
1059                break;
1060        case DIFF_SYMBOL_SUBMODULE_HEADER:
1061        case DIFF_SYMBOL_SUBMODULE_ERROR:
1062        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1063        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1064        case DIFF_SYMBOL_SUMMARY:
1065        case DIFF_SYMBOL_STATS_LINE:
1066        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1067        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1068                emit_line(o, "", "", line, len);
1069                break;
1070        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1071        case DIFF_SYMBOL_CONTEXT_MARKER:
1072                context = diff_get_color_opt(o, DIFF_CONTEXT);
1073                reset = diff_get_color_opt(o, DIFF_RESET);
1074                emit_line(o, context, reset, line, len);
1075                break;
1076        case DIFF_SYMBOL_SEPARATOR:
1077                fprintf(o->file, "%s%c",
1078                        diff_line_prefix(o),
1079                        o->line_termination);
1080                break;
1081        case DIFF_SYMBOL_CONTEXT:
1082                set = diff_get_color_opt(o, DIFF_CONTEXT);
1083                reset = diff_get_color_opt(o, DIFF_RESET);
1084                emit_line_ws_markup(o, set, reset, line, len, ' ',
1085                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1086                break;
1087        case DIFF_SYMBOL_PLUS:
1088                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1089                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1090                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1091                case DIFF_SYMBOL_MOVED_LINE |
1092                     DIFF_SYMBOL_MOVED_LINE_ALT |
1093                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1094                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1095                        break;
1096                case DIFF_SYMBOL_MOVED_LINE |
1097                     DIFF_SYMBOL_MOVED_LINE_ALT:
1098                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1099                        break;
1100                case DIFF_SYMBOL_MOVED_LINE |
1101                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1102                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1103                        break;
1104                case DIFF_SYMBOL_MOVED_LINE:
1105                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1106                        break;
1107                default:
1108                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1109                }
1110                reset = diff_get_color_opt(o, DIFF_RESET);
1111                emit_line_ws_markup(o, set, reset, line, len, '+',
1112                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1113                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1114                break;
1115        case DIFF_SYMBOL_MINUS:
1116                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1117                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1118                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1119                case DIFF_SYMBOL_MOVED_LINE |
1120                     DIFF_SYMBOL_MOVED_LINE_ALT |
1121                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1122                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1123                        break;
1124                case DIFF_SYMBOL_MOVED_LINE |
1125                     DIFF_SYMBOL_MOVED_LINE_ALT:
1126                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1127                        break;
1128                case DIFF_SYMBOL_MOVED_LINE |
1129                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1130                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1131                        break;
1132                case DIFF_SYMBOL_MOVED_LINE:
1133                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1134                        break;
1135                default:
1136                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1137                }
1138                reset = diff_get_color_opt(o, DIFF_RESET);
1139                emit_line_ws_markup(o, set, reset, line, len, '-',
1140                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1141                break;
1142        case DIFF_SYMBOL_WORDS_PORCELAIN:
1143                context = diff_get_color_opt(o, DIFF_CONTEXT);
1144                reset = diff_get_color_opt(o, DIFF_RESET);
1145                emit_line(o, context, reset, line, len);
1146                fputs("~\n", o->file);
1147                break;
1148        case DIFF_SYMBOL_WORDS:
1149                context = diff_get_color_opt(o, DIFF_CONTEXT);
1150                reset = diff_get_color_opt(o, DIFF_RESET);
1151                /*
1152                 * Skip the prefix character, if any.  With
1153                 * diff_suppress_blank_empty, there may be
1154                 * none.
1155                 */
1156                if (line[0] != '\n') {
1157                        line++;
1158                        len--;
1159                }
1160                emit_line(o, context, reset, line, len);
1161                break;
1162        case DIFF_SYMBOL_FILEPAIR_PLUS:
1163                meta = diff_get_color_opt(o, DIFF_METAINFO);
1164                reset = diff_get_color_opt(o, DIFF_RESET);
1165                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1166                        line, reset,
1167                        strchr(line, ' ') ? "\t" : "");
1168                break;
1169        case DIFF_SYMBOL_FILEPAIR_MINUS:
1170                meta = diff_get_color_opt(o, DIFF_METAINFO);
1171                reset = diff_get_color_opt(o, DIFF_RESET);
1172                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1173                        line, reset,
1174                        strchr(line, ' ') ? "\t" : "");
1175                break;
1176        case DIFF_SYMBOL_BINARY_FILES:
1177        case DIFF_SYMBOL_HEADER:
1178                fprintf(o->file, "%s", line);
1179                break;
1180        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1181                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1182                break;
1183        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1184                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1185                break;
1186        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1187                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1188                break;
1189        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1190                fputs(diff_line_prefix(o), o->file);
1191                fputc('\n', o->file);
1192                break;
1193        case DIFF_SYMBOL_REWRITE_DIFF:
1194                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1195                reset = diff_get_color_opt(o, DIFF_RESET);
1196                emit_line(o, fraginfo, reset, line, len);
1197                break;
1198        case DIFF_SYMBOL_SUBMODULE_ADD:
1199                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1200                reset = diff_get_color_opt(o, DIFF_RESET);
1201                emit_line(o, set, reset, line, len);
1202                break;
1203        case DIFF_SYMBOL_SUBMODULE_DEL:
1204                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1205                reset = diff_get_color_opt(o, DIFF_RESET);
1206                emit_line(o, set, reset, line, len);
1207                break;
1208        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1209                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1210                        diff_line_prefix(o), line);
1211                break;
1212        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1213                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1214                        diff_line_prefix(o), line);
1215                break;
1216        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1217                emit_line(o, "", "", " 0 files changed\n",
1218                          strlen(" 0 files changed\n"));
1219                break;
1220        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1221                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1222                break;
1223        case DIFF_SYMBOL_WORD_DIFF:
1224                fprintf(o->file, "%.*s", len, line);
1225                break;
1226        case DIFF_SYMBOL_STAT_SEP:
1227                fputs(o->stat_sep, o->file);
1228                break;
1229        default:
1230                die("BUG: unknown diff symbol");
1231        }
1232        strbuf_release(&sb);
1233}
1234
1235static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1236                             const char *line, int len, unsigned flags)
1237{
1238        struct emitted_diff_symbol e = {line, len, flags, s};
1239
1240        if (o->emitted_symbols)
1241                append_emitted_diff_symbol(o, &e);
1242        else
1243                emit_diff_symbol_from_struct(o, &e);
1244}
1245
1246void diff_emit_submodule_del(struct diff_options *o, const char *line)
1247{
1248        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1249}
1250
1251void diff_emit_submodule_add(struct diff_options *o, const char *line)
1252{
1253        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1254}
1255
1256void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1257{
1258        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1259                         path, strlen(path), 0);
1260}
1261
1262void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1263{
1264        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1265                         path, strlen(path), 0);
1266}
1267
1268void diff_emit_submodule_header(struct diff_options *o, const char *header)
1269{
1270        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1271                         header, strlen(header), 0);
1272}
1273
1274void diff_emit_submodule_error(struct diff_options *o, const char *err)
1275{
1276        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1277}
1278
1279void diff_emit_submodule_pipethrough(struct diff_options *o,
1280                                     const char *line, int len)
1281{
1282        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1283}
1284
1285static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1286{
1287        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1288              ecbdata->blank_at_eof_in_preimage &&
1289              ecbdata->blank_at_eof_in_postimage &&
1290              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1291              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1292                return 0;
1293        return ws_blank_line(line, len, ecbdata->ws_rule);
1294}
1295
1296static void emit_add_line(const char *reset,
1297                          struct emit_callback *ecbdata,
1298                          const char *line, int len)
1299{
1300        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1301        if (new_blank_line_at_eof(ecbdata, line, len))
1302                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1303
1304        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1305}
1306
1307static void emit_del_line(const char *reset,
1308                          struct emit_callback *ecbdata,
1309                          const char *line, int len)
1310{
1311        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1312        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1313}
1314
1315static void emit_context_line(const char *reset,
1316                              struct emit_callback *ecbdata,
1317                              const char *line, int len)
1318{
1319        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1320        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1321}
1322
1323static void emit_hunk_header(struct emit_callback *ecbdata,
1324                             const char *line, int len)
1325{
1326        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1327        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1328        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1329        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1330        static const char atat[2] = { '@', '@' };
1331        const char *cp, *ep;
1332        struct strbuf msgbuf = STRBUF_INIT;
1333        int org_len = len;
1334        int i = 1;
1335
1336        /*
1337         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1338         * it always is at least 10 bytes long.
1339         */
1340        if (len < 10 ||
1341            memcmp(line, atat, 2) ||
1342            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1343                emit_diff_symbol(ecbdata->opt,
1344                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1345                return;
1346        }
1347        ep += 2; /* skip over @@ */
1348
1349        /* The hunk header in fraginfo color */
1350        strbuf_addstr(&msgbuf, frag);
1351        strbuf_add(&msgbuf, line, ep - line);
1352        strbuf_addstr(&msgbuf, reset);
1353
1354        /*
1355         * trailing "\r\n"
1356         */
1357        for ( ; i < 3; i++)
1358                if (line[len - i] == '\r' || line[len - i] == '\n')
1359                        len--;
1360
1361        /* blank before the func header */
1362        for (cp = ep; ep - line < len; ep++)
1363                if (*ep != ' ' && *ep != '\t')
1364                        break;
1365        if (ep != cp) {
1366                strbuf_addstr(&msgbuf, context);
1367                strbuf_add(&msgbuf, cp, ep - cp);
1368                strbuf_addstr(&msgbuf, reset);
1369        }
1370
1371        if (ep < line + len) {
1372                strbuf_addstr(&msgbuf, func);
1373                strbuf_add(&msgbuf, ep, line + len - ep);
1374                strbuf_addstr(&msgbuf, reset);
1375        }
1376
1377        strbuf_add(&msgbuf, line + len, org_len - len);
1378        strbuf_complete_line(&msgbuf);
1379        emit_diff_symbol(ecbdata->opt,
1380                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1381        strbuf_release(&msgbuf);
1382}
1383
1384static struct diff_tempfile *claim_diff_tempfile(void) {
1385        int i;
1386        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1387                if (!diff_temp[i].name)
1388                        return diff_temp + i;
1389        die("BUG: diff is failing to clean up its tempfiles");
1390}
1391
1392static void remove_tempfile(void)
1393{
1394        int i;
1395        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1396                if (is_tempfile_active(&diff_temp[i].tempfile))
1397                        delete_tempfile(&diff_temp[i].tempfile);
1398                diff_temp[i].name = NULL;
1399        }
1400}
1401
1402static void add_line_count(struct strbuf *out, int count)
1403{
1404        switch (count) {
1405        case 0:
1406                strbuf_addstr(out, "0,0");
1407                break;
1408        case 1:
1409                strbuf_addstr(out, "1");
1410                break;
1411        default:
1412                strbuf_addf(out, "1,%d", count);
1413                break;
1414        }
1415}
1416
1417static void emit_rewrite_lines(struct emit_callback *ecb,
1418                               int prefix, const char *data, int size)
1419{
1420        const char *endp = NULL;
1421        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1422
1423        while (0 < size) {
1424                int len;
1425
1426                endp = memchr(data, '\n', size);
1427                len = endp ? (endp - data + 1) : size;
1428                if (prefix != '+') {
1429                        ecb->lno_in_preimage++;
1430                        emit_del_line(reset, ecb, data, len);
1431                } else {
1432                        ecb->lno_in_postimage++;
1433                        emit_add_line(reset, ecb, data, len);
1434                }
1435                size -= len;
1436                data += len;
1437        }
1438        if (!endp)
1439                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1440}
1441
1442static void emit_rewrite_diff(const char *name_a,
1443                              const char *name_b,
1444                              struct diff_filespec *one,
1445                              struct diff_filespec *two,
1446                              struct userdiff_driver *textconv_one,
1447                              struct userdiff_driver *textconv_two,
1448                              struct diff_options *o)
1449{
1450        int lc_a, lc_b;
1451        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1452        const char *a_prefix, *b_prefix;
1453        char *data_one, *data_two;
1454        size_t size_one, size_two;
1455        struct emit_callback ecbdata;
1456        struct strbuf out = STRBUF_INIT;
1457
1458        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
1459                a_prefix = o->b_prefix;
1460                b_prefix = o->a_prefix;
1461        } else {
1462                a_prefix = o->a_prefix;
1463                b_prefix = o->b_prefix;
1464        }
1465
1466        name_a += (*name_a == '/');
1467        name_b += (*name_b == '/');
1468
1469        strbuf_reset(&a_name);
1470        strbuf_reset(&b_name);
1471        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1472        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1473
1474        size_one = fill_textconv(textconv_one, one, &data_one);
1475        size_two = fill_textconv(textconv_two, two, &data_two);
1476
1477        memset(&ecbdata, 0, sizeof(ecbdata));
1478        ecbdata.color_diff = want_color(o->use_color);
1479        ecbdata.ws_rule = whitespace_rule(name_b);
1480        ecbdata.opt = o;
1481        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1482                mmfile_t mf1, mf2;
1483                mf1.ptr = (char *)data_one;
1484                mf2.ptr = (char *)data_two;
1485                mf1.size = size_one;
1486                mf2.size = size_two;
1487                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1488        }
1489        ecbdata.lno_in_preimage = 1;
1490        ecbdata.lno_in_postimage = 1;
1491
1492        lc_a = count_lines(data_one, size_one);
1493        lc_b = count_lines(data_two, size_two);
1494
1495        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1496                         a_name.buf, a_name.len, 0);
1497        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1498                         b_name.buf, b_name.len, 0);
1499
1500        strbuf_addstr(&out, "@@ -");
1501        if (!o->irreversible_delete)
1502                add_line_count(&out, lc_a);
1503        else
1504                strbuf_addstr(&out, "?,?");
1505        strbuf_addstr(&out, " +");
1506        add_line_count(&out, lc_b);
1507        strbuf_addstr(&out, " @@\n");
1508        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1509        strbuf_release(&out);
1510
1511        if (lc_a && !o->irreversible_delete)
1512                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1513        if (lc_b)
1514                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1515        if (textconv_one)
1516                free((char *)data_one);
1517        if (textconv_two)
1518                free((char *)data_two);
1519}
1520
1521struct diff_words_buffer {
1522        mmfile_t text;
1523        long alloc;
1524        struct diff_words_orig {
1525                const char *begin, *end;
1526        } *orig;
1527        int orig_nr, orig_alloc;
1528};
1529
1530static void diff_words_append(char *line, unsigned long len,
1531                struct diff_words_buffer *buffer)
1532{
1533        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1534        line++;
1535        len--;
1536        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1537        buffer->text.size += len;
1538        buffer->text.ptr[buffer->text.size] = '\0';
1539}
1540
1541struct diff_words_style_elem {
1542        const char *prefix;
1543        const char *suffix;
1544        const char *color; /* NULL; filled in by the setup code if
1545                            * color is enabled */
1546};
1547
1548struct diff_words_style {
1549        enum diff_words_type type;
1550        struct diff_words_style_elem new, old, ctx;
1551        const char *newline;
1552};
1553
1554static struct diff_words_style diff_words_styles[] = {
1555        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1556        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1557        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1558};
1559
1560struct diff_words_data {
1561        struct diff_words_buffer minus, plus;
1562        const char *current_plus;
1563        int last_minus;
1564        struct diff_options *opt;
1565        regex_t *word_regex;
1566        enum diff_words_type type;
1567        struct diff_words_style *style;
1568};
1569
1570static int fn_out_diff_words_write_helper(struct diff_options *o,
1571                                          struct diff_words_style_elem *st_el,
1572                                          const char *newline,
1573                                          size_t count, const char *buf)
1574{
1575        int print = 0;
1576        struct strbuf sb = STRBUF_INIT;
1577
1578        while (count) {
1579                char *p = memchr(buf, '\n', count);
1580                if (print)
1581                        strbuf_addstr(&sb, diff_line_prefix(o));
1582
1583                if (p != buf) {
1584                        const char *reset = st_el->color && *st_el->color ?
1585                                            GIT_COLOR_RESET : NULL;
1586                        if (st_el->color && *st_el->color)
1587                                strbuf_addstr(&sb, st_el->color);
1588                        strbuf_addstr(&sb, st_el->prefix);
1589                        strbuf_add(&sb, buf, p ? p - buf : count);
1590                        strbuf_addstr(&sb, st_el->suffix);
1591                        if (reset)
1592                                strbuf_addstr(&sb, reset);
1593                }
1594                if (!p)
1595                        goto out;
1596
1597                strbuf_addstr(&sb, newline);
1598                count -= p + 1 - buf;
1599                buf = p + 1;
1600                print = 1;
1601                if (count) {
1602                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1603                                         sb.buf, sb.len, 0);
1604                        strbuf_reset(&sb);
1605                }
1606        }
1607
1608out:
1609        if (sb.len)
1610                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1611                                 sb.buf, sb.len, 0);
1612        strbuf_release(&sb);
1613        return 0;
1614}
1615
1616/*
1617 * '--color-words' algorithm can be described as:
1618 *
1619 *   1. collect the minus/plus lines of a diff hunk, divided into
1620 *      minus-lines and plus-lines;
1621 *
1622 *   2. break both minus-lines and plus-lines into words and
1623 *      place them into two mmfile_t with one word for each line;
1624 *
1625 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1626 *
1627 * And for the common parts of the both file, we output the plus side text.
1628 * diff_words->current_plus is used to trace the current position of the plus file
1629 * which printed. diff_words->last_minus is used to trace the last minus word
1630 * printed.
1631 *
1632 * For '--graph' to work with '--color-words', we need to output the graph prefix
1633 * on each line of color words output. Generally, there are two conditions on
1634 * which we should output the prefix.
1635 *
1636 *   1. diff_words->last_minus == 0 &&
1637 *      diff_words->current_plus == diff_words->plus.text.ptr
1638 *
1639 *      that is: the plus text must start as a new line, and if there is no minus
1640 *      word printed, a graph prefix must be printed.
1641 *
1642 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1643 *      *(diff_words->current_plus - 1) == '\n'
1644 *
1645 *      that is: a graph prefix must be printed following a '\n'
1646 */
1647static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1648{
1649        if ((diff_words->last_minus == 0 &&
1650                diff_words->current_plus == diff_words->plus.text.ptr) ||
1651                (diff_words->current_plus > diff_words->plus.text.ptr &&
1652                *(diff_words->current_plus - 1) == '\n')) {
1653                return 1;
1654        } else {
1655                return 0;
1656        }
1657}
1658
1659static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1660{
1661        struct diff_words_data *diff_words = priv;
1662        struct diff_words_style *style = diff_words->style;
1663        int minus_first, minus_len, plus_first, plus_len;
1664        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1665        struct diff_options *opt = diff_words->opt;
1666        const char *line_prefix;
1667
1668        if (line[0] != '@' || parse_hunk_header(line, len,
1669                        &minus_first, &minus_len, &plus_first, &plus_len))
1670                return;
1671
1672        assert(opt);
1673        line_prefix = diff_line_prefix(opt);
1674
1675        /* POSIX requires that first be decremented by one if len == 0... */
1676        if (minus_len) {
1677                minus_begin = diff_words->minus.orig[minus_first].begin;
1678                minus_end =
1679                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1680        } else
1681                minus_begin = minus_end =
1682                        diff_words->minus.orig[minus_first].end;
1683
1684        if (plus_len) {
1685                plus_begin = diff_words->plus.orig[plus_first].begin;
1686                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1687        } else
1688                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1689
1690        if (color_words_output_graph_prefix(diff_words)) {
1691                fputs(line_prefix, diff_words->opt->file);
1692        }
1693        if (diff_words->current_plus != plus_begin) {
1694                fn_out_diff_words_write_helper(diff_words->opt,
1695                                &style->ctx, style->newline,
1696                                plus_begin - diff_words->current_plus,
1697                                diff_words->current_plus);
1698        }
1699        if (minus_begin != minus_end) {
1700                fn_out_diff_words_write_helper(diff_words->opt,
1701                                &style->old, style->newline,
1702                                minus_end - minus_begin, minus_begin);
1703        }
1704        if (plus_begin != plus_end) {
1705                fn_out_diff_words_write_helper(diff_words->opt,
1706                                &style->new, style->newline,
1707                                plus_end - plus_begin, plus_begin);
1708        }
1709
1710        diff_words->current_plus = plus_end;
1711        diff_words->last_minus = minus_first;
1712}
1713
1714/* This function starts looking at *begin, and returns 0 iff a word was found. */
1715static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1716                int *begin, int *end)
1717{
1718        if (word_regex && *begin < buffer->size) {
1719                regmatch_t match[1];
1720                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1721                                 buffer->size - *begin, 1, match, 0)) {
1722                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1723                                        '\n', match[0].rm_eo - match[0].rm_so);
1724                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1725                        *begin += match[0].rm_so;
1726                        return *begin >= *end;
1727                }
1728                return -1;
1729        }
1730
1731        /* find the next word */
1732        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1733                (*begin)++;
1734        if (*begin >= buffer->size)
1735                return -1;
1736
1737        /* find the end of the word */
1738        *end = *begin + 1;
1739        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1740                (*end)++;
1741
1742        return 0;
1743}
1744
1745/*
1746 * This function splits the words in buffer->text, stores the list with
1747 * newline separator into out, and saves the offsets of the original words
1748 * in buffer->orig.
1749 */
1750static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1751                regex_t *word_regex)
1752{
1753        int i, j;
1754        long alloc = 0;
1755
1756        out->size = 0;
1757        out->ptr = NULL;
1758
1759        /* fake an empty "0th" word */
1760        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1761        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1762        buffer->orig_nr = 1;
1763
1764        for (i = 0; i < buffer->text.size; i++) {
1765                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1766                        return;
1767
1768                /* store original boundaries */
1769                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1770                                buffer->orig_alloc);
1771                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1772                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1773                buffer->orig_nr++;
1774
1775                /* store one word */
1776                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1777                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1778                out->ptr[out->size + j - i] = '\n';
1779                out->size += j - i + 1;
1780
1781                i = j - 1;
1782        }
1783}
1784
1785/* this executes the word diff on the accumulated buffers */
1786static void diff_words_show(struct diff_words_data *diff_words)
1787{
1788        xpparam_t xpp;
1789        xdemitconf_t xecfg;
1790        mmfile_t minus, plus;
1791        struct diff_words_style *style = diff_words->style;
1792
1793        struct diff_options *opt = diff_words->opt;
1794        const char *line_prefix;
1795
1796        assert(opt);
1797        line_prefix = diff_line_prefix(opt);
1798
1799        /* special case: only removal */
1800        if (!diff_words->plus.text.size) {
1801                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1802                                 line_prefix, strlen(line_prefix), 0);
1803                fn_out_diff_words_write_helper(diff_words->opt,
1804                        &style->old, style->newline,
1805                        diff_words->minus.text.size,
1806                        diff_words->minus.text.ptr);
1807                diff_words->minus.text.size = 0;
1808                return;
1809        }
1810
1811        diff_words->current_plus = diff_words->plus.text.ptr;
1812        diff_words->last_minus = 0;
1813
1814        memset(&xpp, 0, sizeof(xpp));
1815        memset(&xecfg, 0, sizeof(xecfg));
1816        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1817        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1818        xpp.flags = 0;
1819        /* as only the hunk header will be parsed, we need a 0-context */
1820        xecfg.ctxlen = 0;
1821        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1822                          &xpp, &xecfg))
1823                die("unable to generate word diff");
1824        free(minus.ptr);
1825        free(plus.ptr);
1826        if (diff_words->current_plus != diff_words->plus.text.ptr +
1827                        diff_words->plus.text.size) {
1828                if (color_words_output_graph_prefix(diff_words))
1829                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1830                                         line_prefix, strlen(line_prefix), 0);
1831                fn_out_diff_words_write_helper(diff_words->opt,
1832                        &style->ctx, style->newline,
1833                        diff_words->plus.text.ptr + diff_words->plus.text.size
1834                        - diff_words->current_plus, diff_words->current_plus);
1835        }
1836        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1837}
1838
1839/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1840static void diff_words_flush(struct emit_callback *ecbdata)
1841{
1842        struct diff_options *wo = ecbdata->diff_words->opt;
1843
1844        if (ecbdata->diff_words->minus.text.size ||
1845            ecbdata->diff_words->plus.text.size)
1846                diff_words_show(ecbdata->diff_words);
1847
1848        if (wo->emitted_symbols) {
1849                struct diff_options *o = ecbdata->opt;
1850                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1851                int i;
1852
1853                /*
1854                 * NEEDSWORK:
1855                 * Instead of appending each, concat all words to a line?
1856                 */
1857                for (i = 0; i < wol->nr; i++)
1858                        append_emitted_diff_symbol(o, &wol->buf[i]);
1859
1860                for (i = 0; i < wol->nr; i++)
1861                        free((void *)wol->buf[i].line);
1862
1863                wol->nr = 0;
1864        }
1865}
1866
1867static void diff_filespec_load_driver(struct diff_filespec *one)
1868{
1869        /* Use already-loaded driver */
1870        if (one->driver)
1871                return;
1872
1873        if (S_ISREG(one->mode))
1874                one->driver = userdiff_find_by_path(one->path);
1875
1876        /* Fallback to default settings */
1877        if (!one->driver)
1878                one->driver = userdiff_find_by_name("default");
1879}
1880
1881static const char *userdiff_word_regex(struct diff_filespec *one)
1882{
1883        diff_filespec_load_driver(one);
1884        return one->driver->word_regex;
1885}
1886
1887static void init_diff_words_data(struct emit_callback *ecbdata,
1888                                 struct diff_options *orig_opts,
1889                                 struct diff_filespec *one,
1890                                 struct diff_filespec *two)
1891{
1892        int i;
1893        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1894        memcpy(o, orig_opts, sizeof(struct diff_options));
1895
1896        ecbdata->diff_words =
1897                xcalloc(1, sizeof(struct diff_words_data));
1898        ecbdata->diff_words->type = o->word_diff;
1899        ecbdata->diff_words->opt = o;
1900
1901        if (orig_opts->emitted_symbols)
1902                o->emitted_symbols =
1903                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1904
1905        if (!o->word_regex)
1906                o->word_regex = userdiff_word_regex(one);
1907        if (!o->word_regex)
1908                o->word_regex = userdiff_word_regex(two);
1909        if (!o->word_regex)
1910                o->word_regex = diff_word_regex_cfg;
1911        if (o->word_regex) {
1912                ecbdata->diff_words->word_regex = (regex_t *)
1913                        xmalloc(sizeof(regex_t));
1914                if (regcomp(ecbdata->diff_words->word_regex,
1915                            o->word_regex,
1916                            REG_EXTENDED | REG_NEWLINE))
1917                        die ("Invalid regular expression: %s",
1918                             o->word_regex);
1919        }
1920        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1921                if (o->word_diff == diff_words_styles[i].type) {
1922                        ecbdata->diff_words->style =
1923                                &diff_words_styles[i];
1924                        break;
1925                }
1926        }
1927        if (want_color(o->use_color)) {
1928                struct diff_words_style *st = ecbdata->diff_words->style;
1929                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1930                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1931                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1932        }
1933}
1934
1935static void free_diff_words_data(struct emit_callback *ecbdata)
1936{
1937        if (ecbdata->diff_words) {
1938                diff_words_flush(ecbdata);
1939                free (ecbdata->diff_words->opt->emitted_symbols);
1940                free (ecbdata->diff_words->opt);
1941                free (ecbdata->diff_words->minus.text.ptr);
1942                free (ecbdata->diff_words->minus.orig);
1943                free (ecbdata->diff_words->plus.text.ptr);
1944                free (ecbdata->diff_words->plus.orig);
1945                if (ecbdata->diff_words->word_regex) {
1946                        regfree(ecbdata->diff_words->word_regex);
1947                        free(ecbdata->diff_words->word_regex);
1948                }
1949                FREE_AND_NULL(ecbdata->diff_words);
1950        }
1951}
1952
1953const char *diff_get_color(int diff_use_color, enum color_diff ix)
1954{
1955        if (want_color(diff_use_color))
1956                return diff_colors[ix];
1957        return "";
1958}
1959
1960const char *diff_line_prefix(struct diff_options *opt)
1961{
1962        struct strbuf *msgbuf;
1963        if (!opt->output_prefix)
1964                return "";
1965
1966        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1967        return msgbuf->buf;
1968}
1969
1970static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1971{
1972        const char *cp;
1973        unsigned long allot;
1974        size_t l = len;
1975
1976        if (ecb->truncate)
1977                return ecb->truncate(line, len);
1978        cp = line;
1979        allot = l;
1980        while (0 < l) {
1981                (void) utf8_width(&cp, &l);
1982                if (!cp)
1983                        break; /* truncated in the middle? */
1984        }
1985        return allot - l;
1986}
1987
1988static void find_lno(const char *line, struct emit_callback *ecbdata)
1989{
1990        const char *p;
1991        ecbdata->lno_in_preimage = 0;
1992        ecbdata->lno_in_postimage = 0;
1993        p = strchr(line, '-');
1994        if (!p)
1995                return; /* cannot happen */
1996        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1997        p = strchr(p, '+');
1998        if (!p)
1999                return; /* cannot happen */
2000        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2001}
2002
2003static void fn_out_consume(void *priv, char *line, unsigned long len)
2004{
2005        struct emit_callback *ecbdata = priv;
2006        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2007        struct diff_options *o = ecbdata->opt;
2008
2009        o->found_changes = 1;
2010
2011        if (ecbdata->header) {
2012                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2013                                 ecbdata->header->buf, ecbdata->header->len, 0);
2014                strbuf_reset(ecbdata->header);
2015                ecbdata->header = NULL;
2016        }
2017
2018        if (ecbdata->label_path[0]) {
2019                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2020                                 ecbdata->label_path[0],
2021                                 strlen(ecbdata->label_path[0]), 0);
2022                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2023                                 ecbdata->label_path[1],
2024                                 strlen(ecbdata->label_path[1]), 0);
2025                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2026        }
2027
2028        if (diff_suppress_blank_empty
2029            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2030                line[0] = '\n';
2031                len = 1;
2032        }
2033
2034        if (line[0] == '@') {
2035                if (ecbdata->diff_words)
2036                        diff_words_flush(ecbdata);
2037                len = sane_truncate_line(ecbdata, line, len);
2038                find_lno(line, ecbdata);
2039                emit_hunk_header(ecbdata, line, len);
2040                return;
2041        }
2042
2043        if (ecbdata->diff_words) {
2044                enum diff_symbol s =
2045                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2046                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2047                if (line[0] == '-') {
2048                        diff_words_append(line, len,
2049                                          &ecbdata->diff_words->minus);
2050                        return;
2051                } else if (line[0] == '+') {
2052                        diff_words_append(line, len,
2053                                          &ecbdata->diff_words->plus);
2054                        return;
2055                } else if (starts_with(line, "\\ ")) {
2056                        /*
2057                         * Eat the "no newline at eof" marker as if we
2058                         * saw a "+" or "-" line with nothing on it,
2059                         * and return without diff_words_flush() to
2060                         * defer processing. If this is the end of
2061                         * preimage, more "+" lines may come after it.
2062                         */
2063                        return;
2064                }
2065                diff_words_flush(ecbdata);
2066                emit_diff_symbol(o, s, line, len, 0);
2067                return;
2068        }
2069
2070        switch (line[0]) {
2071        case '+':
2072                ecbdata->lno_in_postimage++;
2073                emit_add_line(reset, ecbdata, line + 1, len - 1);
2074                break;
2075        case '-':
2076                ecbdata->lno_in_preimage++;
2077                emit_del_line(reset, ecbdata, line + 1, len - 1);
2078                break;
2079        case ' ':
2080                ecbdata->lno_in_postimage++;
2081                ecbdata->lno_in_preimage++;
2082                emit_context_line(reset, ecbdata, line + 1, len - 1);
2083                break;
2084        default:
2085                /* incomplete line at the end */
2086                ecbdata->lno_in_preimage++;
2087                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2088                                 line, len, 0);
2089                break;
2090        }
2091}
2092
2093static char *pprint_rename(const char *a, const char *b)
2094{
2095        const char *old = a;
2096        const char *new = b;
2097        struct strbuf name = STRBUF_INIT;
2098        int pfx_length, sfx_length;
2099        int pfx_adjust_for_slash;
2100        int len_a = strlen(a);
2101        int len_b = strlen(b);
2102        int a_midlen, b_midlen;
2103        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2104        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2105
2106        if (qlen_a || qlen_b) {
2107                quote_c_style(a, &name, NULL, 0);
2108                strbuf_addstr(&name, " => ");
2109                quote_c_style(b, &name, NULL, 0);
2110                return strbuf_detach(&name, NULL);
2111        }
2112
2113        /* Find common prefix */
2114        pfx_length = 0;
2115        while (*old && *new && *old == *new) {
2116                if (*old == '/')
2117                        pfx_length = old - a + 1;
2118                old++;
2119                new++;
2120        }
2121
2122        /* Find common suffix */
2123        old = a + len_a;
2124        new = b + len_b;
2125        sfx_length = 0;
2126        /*
2127         * If there is a common prefix, it must end in a slash.  In
2128         * that case we let this loop run 1 into the prefix to see the
2129         * same slash.
2130         *
2131         * If there is no common prefix, we cannot do this as it would
2132         * underrun the input strings.
2133         */
2134        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2135        while (a + pfx_length - pfx_adjust_for_slash <= old &&
2136               b + pfx_length - pfx_adjust_for_slash <= new &&
2137               *old == *new) {
2138                if (*old == '/')
2139                        sfx_length = len_a - (old - a);
2140                old--;
2141                new--;
2142        }
2143
2144        /*
2145         * pfx{mid-a => mid-b}sfx
2146         * {pfx-a => pfx-b}sfx
2147         * pfx{sfx-a => sfx-b}
2148         * name-a => name-b
2149         */
2150        a_midlen = len_a - pfx_length - sfx_length;
2151        b_midlen = len_b - pfx_length - sfx_length;
2152        if (a_midlen < 0)
2153                a_midlen = 0;
2154        if (b_midlen < 0)
2155                b_midlen = 0;
2156
2157        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2158        if (pfx_length + sfx_length) {
2159                strbuf_add(&name, a, pfx_length);
2160                strbuf_addch(&name, '{');
2161        }
2162        strbuf_add(&name, a + pfx_length, a_midlen);
2163        strbuf_addstr(&name, " => ");
2164        strbuf_add(&name, b + pfx_length, b_midlen);
2165        if (pfx_length + sfx_length) {
2166                strbuf_addch(&name, '}');
2167                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
2168        }
2169        return strbuf_detach(&name, NULL);
2170}
2171
2172struct diffstat_t {
2173        int nr;
2174        int alloc;
2175        struct diffstat_file {
2176                char *from_name;
2177                char *name;
2178                char *print_name;
2179                unsigned is_unmerged:1;
2180                unsigned is_binary:1;
2181                unsigned is_renamed:1;
2182                unsigned is_interesting:1;
2183                uintmax_t added, deleted;
2184        } **files;
2185};
2186
2187static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2188                                          const char *name_a,
2189                                          const char *name_b)
2190{
2191        struct diffstat_file *x;
2192        x = xcalloc(1, sizeof(*x));
2193        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2194        diffstat->files[diffstat->nr++] = x;
2195        if (name_b) {
2196                x->from_name = xstrdup(name_a);
2197                x->name = xstrdup(name_b);
2198                x->is_renamed = 1;
2199        }
2200        else {
2201                x->from_name = NULL;
2202                x->name = xstrdup(name_a);
2203        }
2204        return x;
2205}
2206
2207static void diffstat_consume(void *priv, char *line, unsigned long len)
2208{
2209        struct diffstat_t *diffstat = priv;
2210        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2211
2212        if (line[0] == '+')
2213                x->added++;
2214        else if (line[0] == '-')
2215                x->deleted++;
2216}
2217
2218const char mime_boundary_leader[] = "------------";
2219
2220static int scale_linear(int it, int width, int max_change)
2221{
2222        if (!it)
2223                return 0;
2224        /*
2225         * make sure that at least one '-' or '+' is printed if
2226         * there is any change to this path. The easiest way is to
2227         * scale linearly as if the alloted width is one column shorter
2228         * than it is, and then add 1 to the result.
2229         */
2230        return 1 + (it * (width - 1) / max_change);
2231}
2232
2233static void show_graph(struct strbuf *out, char ch, int cnt,
2234                       const char *set, const char *reset)
2235{
2236        if (cnt <= 0)
2237                return;
2238        strbuf_addstr(out, set);
2239        strbuf_addchars(out, ch, cnt);
2240        strbuf_addstr(out, reset);
2241}
2242
2243static void fill_print_name(struct diffstat_file *file)
2244{
2245        char *pname;
2246
2247        if (file->print_name)
2248                return;
2249
2250        if (!file->is_renamed) {
2251                struct strbuf buf = STRBUF_INIT;
2252                if (quote_c_style(file->name, &buf, NULL, 0)) {
2253                        pname = strbuf_detach(&buf, NULL);
2254                } else {
2255                        pname = file->name;
2256                        strbuf_release(&buf);
2257                }
2258        } else {
2259                pname = pprint_rename(file->from_name, file->name);
2260        }
2261        file->print_name = pname;
2262}
2263
2264static void print_stat_summary_inserts_deletes(struct diff_options *options,
2265                int files, int insertions, int deletions)
2266{
2267        struct strbuf sb = STRBUF_INIT;
2268
2269        if (!files) {
2270                assert(insertions == 0 && deletions == 0);
2271                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2272                                 NULL, 0, 0);
2273                return;
2274        }
2275
2276        strbuf_addf(&sb,
2277                    (files == 1) ? " %d file changed" : " %d files changed",
2278                    files);
2279
2280        /*
2281         * For binary diff, the caller may want to print "x files
2282         * changed" with insertions == 0 && deletions == 0.
2283         *
2284         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2285         * is probably less confusing (i.e skip over "2 files changed
2286         * but nothing about added/removed lines? Is this a bug in Git?").
2287         */
2288        if (insertions || deletions == 0) {
2289                strbuf_addf(&sb,
2290                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2291                            insertions);
2292        }
2293
2294        if (deletions || insertions == 0) {
2295                strbuf_addf(&sb,
2296                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2297                            deletions);
2298        }
2299        strbuf_addch(&sb, '\n');
2300        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2301                         sb.buf, sb.len, 0);
2302        strbuf_release(&sb);
2303}
2304
2305void print_stat_summary(FILE *fp, int files,
2306                        int insertions, int deletions)
2307{
2308        struct diff_options o;
2309        memset(&o, 0, sizeof(o));
2310        o.file = fp;
2311
2312        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2313}
2314
2315static void show_stats(struct diffstat_t *data, struct diff_options *options)
2316{
2317        int i, len, add, del, adds = 0, dels = 0;
2318        uintmax_t max_change = 0, max_len = 0;
2319        int total_files = data->nr, count;
2320        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2321        const char *reset, *add_c, *del_c;
2322        int extra_shown = 0;
2323        const char *line_prefix = diff_line_prefix(options);
2324        struct strbuf out = STRBUF_INIT;
2325
2326        if (data->nr == 0)
2327                return;
2328
2329        count = options->stat_count ? options->stat_count : data->nr;
2330
2331        reset = diff_get_color_opt(options, DIFF_RESET);
2332        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2333        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2334
2335        /*
2336         * Find the longest filename and max number of changes
2337         */
2338        for (i = 0; (i < count) && (i < data->nr); i++) {
2339                struct diffstat_file *file = data->files[i];
2340                uintmax_t change = file->added + file->deleted;
2341
2342                if (!file->is_interesting && (change == 0)) {
2343                        count++; /* not shown == room for one more */
2344                        continue;
2345                }
2346                fill_print_name(file);
2347                len = strlen(file->print_name);
2348                if (max_len < len)
2349                        max_len = len;
2350
2351                if (file->is_unmerged) {
2352                        /* "Unmerged" is 8 characters */
2353                        bin_width = bin_width < 8 ? 8 : bin_width;
2354                        continue;
2355                }
2356                if (file->is_binary) {
2357                        /* "Bin XXX -> YYY bytes" */
2358                        int w = 14 + decimal_width(file->added)
2359                                + decimal_width(file->deleted);
2360                        bin_width = bin_width < w ? w : bin_width;
2361                        /* Display change counts aligned with "Bin" */
2362                        number_width = 3;
2363                        continue;
2364                }
2365
2366                if (max_change < change)
2367                        max_change = change;
2368        }
2369        count = i; /* where we can stop scanning in data->files[] */
2370
2371        /*
2372         * We have width = stat_width or term_columns() columns total.
2373         * We want a maximum of min(max_len, stat_name_width) for the name part.
2374         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2375         * We also need 1 for " " and 4 + decimal_width(max_change)
2376         * for " | NNNN " and one the empty column at the end, altogether
2377         * 6 + decimal_width(max_change).
2378         *
2379         * If there's not enough space, we will use the smaller of
2380         * stat_name_width (if set) and 5/8*width for the filename,
2381         * and the rest for constant elements + graph part, but no more
2382         * than stat_graph_width for the graph part.
2383         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2384         * for the standard terminal size).
2385         *
2386         * In other words: stat_width limits the maximum width, and
2387         * stat_name_width fixes the maximum width of the filename,
2388         * and is also used to divide available columns if there
2389         * aren't enough.
2390         *
2391         * Binary files are displayed with "Bin XXX -> YYY bytes"
2392         * instead of the change count and graph. This part is treated
2393         * similarly to the graph part, except that it is not
2394         * "scaled". If total width is too small to accommodate the
2395         * guaranteed minimum width of the filename part and the
2396         * separators and this message, this message will "overflow"
2397         * making the line longer than the maximum width.
2398         */
2399
2400        if (options->stat_width == -1)
2401                width = term_columns() - strlen(line_prefix);
2402        else
2403                width = options->stat_width ? options->stat_width : 80;
2404        number_width = decimal_width(max_change) > number_width ?
2405                decimal_width(max_change) : number_width;
2406
2407        if (options->stat_graph_width == -1)
2408                options->stat_graph_width = diff_stat_graph_width;
2409
2410        /*
2411         * Guarantee 3/8*16==6 for the graph part
2412         * and 5/8*16==10 for the filename part
2413         */
2414        if (width < 16 + 6 + number_width)
2415                width = 16 + 6 + number_width;
2416
2417        /*
2418         * First assign sizes that are wanted, ignoring available width.
2419         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2420         * starting from "XXX" should fit in graph_width.
2421         */
2422        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2423        if (options->stat_graph_width &&
2424            options->stat_graph_width < graph_width)
2425                graph_width = options->stat_graph_width;
2426
2427        name_width = (options->stat_name_width > 0 &&
2428                      options->stat_name_width < max_len) ?
2429                options->stat_name_width : max_len;
2430
2431        /*
2432         * Adjust adjustable widths not to exceed maximum width
2433         */
2434        if (name_width + number_width + 6 + graph_width > width) {
2435                if (graph_width > width * 3/8 - number_width - 6) {
2436                        graph_width = width * 3/8 - number_width - 6;
2437                        if (graph_width < 6)
2438                                graph_width = 6;
2439                }
2440
2441                if (options->stat_graph_width &&
2442                    graph_width > options->stat_graph_width)
2443                        graph_width = options->stat_graph_width;
2444                if (name_width > width - number_width - 6 - graph_width)
2445                        name_width = width - number_width - 6 - graph_width;
2446                else
2447                        graph_width = width - number_width - 6 - name_width;
2448        }
2449
2450        /*
2451         * From here name_width is the width of the name area,
2452         * and graph_width is the width of the graph area.
2453         * max_change is used to scale graph properly.
2454         */
2455        for (i = 0; i < count; i++) {
2456                const char *prefix = "";
2457                struct diffstat_file *file = data->files[i];
2458                char *name = file->print_name;
2459                uintmax_t added = file->added;
2460                uintmax_t deleted = file->deleted;
2461                int name_len;
2462
2463                if (!file->is_interesting && (added + deleted == 0))
2464                        continue;
2465
2466                /*
2467                 * "scale" the filename
2468                 */
2469                len = name_width;
2470                name_len = strlen(name);
2471                if (name_width < name_len) {
2472                        char *slash;
2473                        prefix = "...";
2474                        len -= 3;
2475                        name += name_len - len;
2476                        slash = strchr(name, '/');
2477                        if (slash)
2478                                name = slash;
2479                }
2480
2481                if (file->is_binary) {
2482                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2483                        strbuf_addf(&out, " %*s", number_width, "Bin");
2484                        if (!added && !deleted) {
2485                                strbuf_addch(&out, '\n');
2486                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2487                                                 out.buf, out.len, 0);
2488                                strbuf_reset(&out);
2489                                continue;
2490                        }
2491                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2492                                del_c, deleted, reset);
2493                        strbuf_addstr(&out, " -> ");
2494                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2495                                add_c, added, reset);
2496                        strbuf_addstr(&out, " bytes\n");
2497                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2498                                         out.buf, out.len, 0);
2499                        strbuf_reset(&out);
2500                        continue;
2501                }
2502                else if (file->is_unmerged) {
2503                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2504                        strbuf_addstr(&out, " Unmerged\n");
2505                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2506                                         out.buf, out.len, 0);
2507                        strbuf_reset(&out);
2508                        continue;
2509                }
2510
2511                /*
2512                 * scale the add/delete
2513                 */
2514                add = added;
2515                del = deleted;
2516
2517                if (graph_width <= max_change) {
2518                        int total = scale_linear(add + del, graph_width, max_change);
2519                        if (total < 2 && add && del)
2520                                /* width >= 2 due to the sanity check */
2521                                total = 2;
2522                        if (add < del) {
2523                                add = scale_linear(add, graph_width, max_change);
2524                                del = total - add;
2525                        } else {
2526                                del = scale_linear(del, graph_width, max_change);
2527                                add = total - del;
2528                        }
2529                }
2530                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2531                strbuf_addf(&out, " %*"PRIuMAX"%s",
2532                        number_width, added + deleted,
2533                        added + deleted ? " " : "");
2534                show_graph(&out, '+', add, add_c, reset);
2535                show_graph(&out, '-', del, del_c, reset);
2536                strbuf_addch(&out, '\n');
2537                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2538                                 out.buf, out.len, 0);
2539                strbuf_reset(&out);
2540        }
2541
2542        for (i = 0; i < data->nr; i++) {
2543                struct diffstat_file *file = data->files[i];
2544                uintmax_t added = file->added;
2545                uintmax_t deleted = file->deleted;
2546
2547                if (file->is_unmerged ||
2548                    (!file->is_interesting && (added + deleted == 0))) {
2549                        total_files--;
2550                        continue;
2551                }
2552
2553                if (!file->is_binary) {
2554                        adds += added;
2555                        dels += deleted;
2556                }
2557                if (i < count)
2558                        continue;
2559                if (!extra_shown)
2560                        emit_diff_symbol(options,
2561                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2562                                         NULL, 0, 0);
2563                extra_shown = 1;
2564        }
2565
2566        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2567}
2568
2569static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2570{
2571        int i, adds = 0, dels = 0, total_files = data->nr;
2572
2573        if (data->nr == 0)
2574                return;
2575
2576        for (i = 0; i < data->nr; i++) {
2577                int added = data->files[i]->added;
2578                int deleted = data->files[i]->deleted;
2579
2580                if (data->files[i]->is_unmerged ||
2581                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2582                        total_files--;
2583                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2584                        adds += added;
2585                        dels += deleted;
2586                }
2587        }
2588        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2589}
2590
2591static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2592{
2593        int i;
2594
2595        if (data->nr == 0)
2596                return;
2597
2598        for (i = 0; i < data->nr; i++) {
2599                struct diffstat_file *file = data->files[i];
2600
2601                fprintf(options->file, "%s", diff_line_prefix(options));
2602
2603                if (file->is_binary)
2604                        fprintf(options->file, "-\t-\t");
2605                else
2606                        fprintf(options->file,
2607                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2608                                file->added, file->deleted);
2609                if (options->line_termination) {
2610                        fill_print_name(file);
2611                        if (!file->is_renamed)
2612                                write_name_quoted(file->name, options->file,
2613                                                  options->line_termination);
2614                        else {
2615                                fputs(file->print_name, options->file);
2616                                putc(options->line_termination, options->file);
2617                        }
2618                } else {
2619                        if (file->is_renamed) {
2620                                putc('\0', options->file);
2621                                write_name_quoted(file->from_name, options->file, '\0');
2622                        }
2623                        write_name_quoted(file->name, options->file, '\0');
2624                }
2625        }
2626}
2627
2628struct dirstat_file {
2629        const char *name;
2630        unsigned long changed;
2631};
2632
2633struct dirstat_dir {
2634        struct dirstat_file *files;
2635        int alloc, nr, permille, cumulative;
2636};
2637
2638static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2639                unsigned long changed, const char *base, int baselen)
2640{
2641        unsigned long this_dir = 0;
2642        unsigned int sources = 0;
2643        const char *line_prefix = diff_line_prefix(opt);
2644
2645        while (dir->nr) {
2646                struct dirstat_file *f = dir->files;
2647                int namelen = strlen(f->name);
2648                unsigned long this;
2649                char *slash;
2650
2651                if (namelen < baselen)
2652                        break;
2653                if (memcmp(f->name, base, baselen))
2654                        break;
2655                slash = strchr(f->name + baselen, '/');
2656                if (slash) {
2657                        int newbaselen = slash + 1 - f->name;
2658                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2659                        sources++;
2660                } else {
2661                        this = f->changed;
2662                        dir->files++;
2663                        dir->nr--;
2664                        sources += 2;
2665                }
2666                this_dir += this;
2667        }
2668
2669        /*
2670         * We don't report dirstat's for
2671         *  - the top level
2672         *  - or cases where everything came from a single directory
2673         *    under this directory (sources == 1).
2674         */
2675        if (baselen && sources != 1) {
2676                if (this_dir) {
2677                        int permille = this_dir * 1000 / changed;
2678                        if (permille >= dir->permille) {
2679                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2680                                        permille / 10, permille % 10, baselen, base);
2681                                if (!dir->cumulative)
2682                                        return 0;
2683                        }
2684                }
2685        }
2686        return this_dir;
2687}
2688
2689static int dirstat_compare(const void *_a, const void *_b)
2690{
2691        const struct dirstat_file *a = _a;
2692        const struct dirstat_file *b = _b;
2693        return strcmp(a->name, b->name);
2694}
2695
2696static void show_dirstat(struct diff_options *options)
2697{
2698        int i;
2699        unsigned long changed;
2700        struct dirstat_dir dir;
2701        struct diff_queue_struct *q = &diff_queued_diff;
2702
2703        dir.files = NULL;
2704        dir.alloc = 0;
2705        dir.nr = 0;
2706        dir.permille = options->dirstat_permille;
2707        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2708
2709        changed = 0;
2710        for (i = 0; i < q->nr; i++) {
2711                struct diff_filepair *p = q->queue[i];
2712                const char *name;
2713                unsigned long copied, added, damage;
2714                int content_changed;
2715
2716                name = p->two->path ? p->two->path : p->one->path;
2717
2718                if (p->one->oid_valid && p->two->oid_valid)
2719                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2720                else
2721                        content_changed = 1;
2722
2723                if (!content_changed) {
2724                        /*
2725                         * The SHA1 has not changed, so pre-/post-content is
2726                         * identical. We can therefore skip looking at the
2727                         * file contents altogether.
2728                         */
2729                        damage = 0;
2730                        goto found_damage;
2731                }
2732
2733                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2734                        /*
2735                         * In --dirstat-by-file mode, we don't really need to
2736                         * look at the actual file contents at all.
2737                         * The fact that the SHA1 changed is enough for us to
2738                         * add this file to the list of results
2739                         * (with each file contributing equal damage).
2740                         */
2741                        damage = 1;
2742                        goto found_damage;
2743                }
2744
2745                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2746                        diff_populate_filespec(p->one, 0);
2747                        diff_populate_filespec(p->two, 0);
2748                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2749                                               &copied, &added);
2750                        diff_free_filespec_data(p->one);
2751                        diff_free_filespec_data(p->two);
2752                } else if (DIFF_FILE_VALID(p->one)) {
2753                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2754                        copied = added = 0;
2755                        diff_free_filespec_data(p->one);
2756                } else if (DIFF_FILE_VALID(p->two)) {
2757                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2758                        copied = 0;
2759                        added = p->two->size;
2760                        diff_free_filespec_data(p->two);
2761                } else
2762                        continue;
2763
2764                /*
2765                 * Original minus copied is the removed material,
2766                 * added is the new material.  They are both damages
2767                 * made to the preimage.
2768                 * If the resulting damage is zero, we know that
2769                 * diffcore_count_changes() considers the two entries to
2770                 * be identical, but since content_changed is true, we
2771                 * know that there must have been _some_ kind of change,
2772                 * so we force all entries to have damage > 0.
2773                 */
2774                damage = (p->one->size - copied) + added;
2775                if (!damage)
2776                        damage = 1;
2777
2778found_damage:
2779                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2780                dir.files[dir.nr].name = name;
2781                dir.files[dir.nr].changed = damage;
2782                changed += damage;
2783                dir.nr++;
2784        }
2785
2786        /* This can happen even with many files, if everything was renames */
2787        if (!changed)
2788                return;
2789
2790        /* Show all directories with more than x% of the changes */
2791        QSORT(dir.files, dir.nr, dirstat_compare);
2792        gather_dirstat(options, &dir, changed, "", 0);
2793}
2794
2795static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2796{
2797        int i;
2798        unsigned long changed;
2799        struct dirstat_dir dir;
2800
2801        if (data->nr == 0)
2802                return;
2803
2804        dir.files = NULL;
2805        dir.alloc = 0;
2806        dir.nr = 0;
2807        dir.permille = options->dirstat_permille;
2808        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2809
2810        changed = 0;
2811        for (i = 0; i < data->nr; i++) {
2812                struct diffstat_file *file = data->files[i];
2813                unsigned long damage = file->added + file->deleted;
2814                if (file->is_binary)
2815                        /*
2816                         * binary files counts bytes, not lines. Must find some
2817                         * way to normalize binary bytes vs. textual lines.
2818                         * The following heuristic assumes that there are 64
2819                         * bytes per "line".
2820                         * This is stupid and ugly, but very cheap...
2821                         */
2822                        damage = (damage + 63) / 64;
2823                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2824                dir.files[dir.nr].name = file->name;
2825                dir.files[dir.nr].changed = damage;
2826                changed += damage;
2827                dir.nr++;
2828        }
2829
2830        /* This can happen even with many files, if everything was renames */
2831        if (!changed)
2832                return;
2833
2834        /* Show all directories with more than x% of the changes */
2835        QSORT(dir.files, dir.nr, dirstat_compare);
2836        gather_dirstat(options, &dir, changed, "", 0);
2837}
2838
2839static void free_diffstat_info(struct diffstat_t *diffstat)
2840{
2841        int i;
2842        for (i = 0; i < diffstat->nr; i++) {
2843                struct diffstat_file *f = diffstat->files[i];
2844                if (f->name != f->print_name)
2845                        free(f->print_name);
2846                free(f->name);
2847                free(f->from_name);
2848                free(f);
2849        }
2850        free(diffstat->files);
2851}
2852
2853struct checkdiff_t {
2854        const char *filename;
2855        int lineno;
2856        int conflict_marker_size;
2857        struct diff_options *o;
2858        unsigned ws_rule;
2859        unsigned status;
2860};
2861
2862static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2863{
2864        char firstchar;
2865        int cnt;
2866
2867        if (len < marker_size + 1)
2868                return 0;
2869        firstchar = line[0];
2870        switch (firstchar) {
2871        case '=': case '>': case '<': case '|':
2872                break;
2873        default:
2874                return 0;
2875        }
2876        for (cnt = 1; cnt < marker_size; cnt++)
2877                if (line[cnt] != firstchar)
2878                        return 0;
2879        /* line[1] thru line[marker_size-1] are same as firstchar */
2880        if (len < marker_size + 1 || !isspace(line[marker_size]))
2881                return 0;
2882        return 1;
2883}
2884
2885static void checkdiff_consume(void *priv, char *line, unsigned long len)
2886{
2887        struct checkdiff_t *data = priv;
2888        int marker_size = data->conflict_marker_size;
2889        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2890        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2891        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2892        char *err;
2893        const char *line_prefix;
2894
2895        assert(data->o);
2896        line_prefix = diff_line_prefix(data->o);
2897
2898        if (line[0] == '+') {
2899                unsigned bad;
2900                data->lineno++;
2901                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2902                        data->status |= 1;
2903                        fprintf(data->o->file,
2904                                "%s%s:%d: leftover conflict marker\n",
2905                                line_prefix, data->filename, data->lineno);
2906                }
2907                bad = ws_check(line + 1, len - 1, data->ws_rule);
2908                if (!bad)
2909                        return;
2910                data->status |= bad;
2911                err = whitespace_error_string(bad);
2912                fprintf(data->o->file, "%s%s:%d: %s.\n",
2913                        line_prefix, data->filename, data->lineno, err);
2914                free(err);
2915                emit_line(data->o, set, reset, line, 1);
2916                ws_check_emit(line + 1, len - 1, data->ws_rule,
2917                              data->o->file, set, reset, ws);
2918        } else if (line[0] == ' ') {
2919                data->lineno++;
2920        } else if (line[0] == '@') {
2921                char *plus = strchr(line, '+');
2922                if (plus)
2923                        data->lineno = strtol(plus, NULL, 10) - 1;
2924                else
2925                        die("invalid diff");
2926        }
2927}
2928
2929static unsigned char *deflate_it(char *data,
2930                                 unsigned long size,
2931                                 unsigned long *result_size)
2932{
2933        int bound;
2934        unsigned char *deflated;
2935        git_zstream stream;
2936
2937        git_deflate_init(&stream, zlib_compression_level);
2938        bound = git_deflate_bound(&stream, size);
2939        deflated = xmalloc(bound);
2940        stream.next_out = deflated;
2941        stream.avail_out = bound;
2942
2943        stream.next_in = (unsigned char *)data;
2944        stream.avail_in = size;
2945        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2946                ; /* nothing */
2947        git_deflate_end(&stream);
2948        *result_size = stream.total_out;
2949        return deflated;
2950}
2951
2952static void emit_binary_diff_body(struct diff_options *o,
2953                                  mmfile_t *one, mmfile_t *two)
2954{
2955        void *cp;
2956        void *delta;
2957        void *deflated;
2958        void *data;
2959        unsigned long orig_size;
2960        unsigned long delta_size;
2961        unsigned long deflate_size;
2962        unsigned long data_size;
2963
2964        /* We could do deflated delta, or we could do just deflated two,
2965         * whichever is smaller.
2966         */
2967        delta = NULL;
2968        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2969        if (one->size && two->size) {
2970                delta = diff_delta(one->ptr, one->size,
2971                                   two->ptr, two->size,
2972                                   &delta_size, deflate_size);
2973                if (delta) {
2974                        void *to_free = delta;
2975                        orig_size = delta_size;
2976                        delta = deflate_it(delta, delta_size, &delta_size);
2977                        free(to_free);
2978                }
2979        }
2980
2981        if (delta && delta_size < deflate_size) {
2982                char *s = xstrfmt("%lu", orig_size);
2983                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2984                                 s, strlen(s), 0);
2985                free(s);
2986                free(deflated);
2987                data = delta;
2988                data_size = delta_size;
2989        } else {
2990                char *s = xstrfmt("%lu", two->size);
2991                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2992                                 s, strlen(s), 0);
2993                free(s);
2994                free(delta);
2995                data = deflated;
2996                data_size = deflate_size;
2997        }
2998
2999        /* emit data encoded in base85 */
3000        cp = data;
3001        while (data_size) {
3002                int len;
3003                int bytes = (52 < data_size) ? 52 : data_size;
3004                char line[71];
3005                data_size -= bytes;
3006                if (bytes <= 26)
3007                        line[0] = bytes + 'A' - 1;
3008                else
3009                        line[0] = bytes - 26 + 'a' - 1;
3010                encode_85(line + 1, cp, bytes);
3011                cp = (char *) cp + bytes;
3012
3013                len = strlen(line);
3014                line[len++] = '\n';
3015                line[len] = '\0';
3016
3017                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3018                                 line, len, 0);
3019        }
3020        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3021        free(data);
3022}
3023
3024static void emit_binary_diff(struct diff_options *o,
3025                             mmfile_t *one, mmfile_t *two)
3026{
3027        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3028        emit_binary_diff_body(o, one, two);
3029        emit_binary_diff_body(o, two, one);
3030}
3031
3032int diff_filespec_is_binary(struct diff_filespec *one)
3033{
3034        if (one->is_binary == -1) {
3035                diff_filespec_load_driver(one);
3036                if (one->driver->binary != -1)
3037                        one->is_binary = one->driver->binary;
3038                else {
3039                        if (!one->data && DIFF_FILE_VALID(one))
3040                                diff_populate_filespec(one, CHECK_BINARY);
3041                        if (one->is_binary == -1 && one->data)
3042                                one->is_binary = buffer_is_binary(one->data,
3043                                                one->size);
3044                        if (one->is_binary == -1)
3045                                one->is_binary = 0;
3046                }
3047        }
3048        return one->is_binary;
3049}
3050
3051static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3052{
3053        diff_filespec_load_driver(one);
3054        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3055}
3056
3057void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3058{
3059        if (!options->a_prefix)
3060                options->a_prefix = a;
3061        if (!options->b_prefix)
3062                options->b_prefix = b;
3063}
3064
3065struct userdiff_driver *get_textconv(struct diff_filespec *one)
3066{
3067        if (!DIFF_FILE_VALID(one))
3068                return NULL;
3069
3070        diff_filespec_load_driver(one);
3071        return userdiff_get_textconv(one->driver);
3072}
3073
3074static void builtin_diff(const char *name_a,
3075                         const char *name_b,
3076                         struct diff_filespec *one,
3077                         struct diff_filespec *two,
3078                         const char *xfrm_msg,
3079                         int must_show_header,
3080                         struct diff_options *o,
3081                         int complete_rewrite)
3082{
3083        mmfile_t mf1, mf2;
3084        const char *lbl[2];
3085        char *a_one, *b_two;
3086        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3087        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3088        const char *a_prefix, *b_prefix;
3089        struct userdiff_driver *textconv_one = NULL;
3090        struct userdiff_driver *textconv_two = NULL;
3091        struct strbuf header = STRBUF_INIT;
3092        const char *line_prefix = diff_line_prefix(o);
3093
3094        diff_set_mnemonic_prefix(o, "a/", "b/");
3095        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
3096                a_prefix = o->b_prefix;
3097                b_prefix = o->a_prefix;
3098        } else {
3099                a_prefix = o->a_prefix;
3100                b_prefix = o->b_prefix;
3101        }
3102
3103        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3104            (!one->mode || S_ISGITLINK(one->mode)) &&
3105            (!two->mode || S_ISGITLINK(two->mode))) {
3106                show_submodule_summary(o, one->path ? one->path : two->path,
3107                                &one->oid, &two->oid,
3108                                two->dirty_submodule);
3109                return;
3110        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3111                   (!one->mode || S_ISGITLINK(one->mode)) &&
3112                   (!two->mode || S_ISGITLINK(two->mode))) {
3113                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3114                                &one->oid, &two->oid,
3115                                two->dirty_submodule);
3116                return;
3117        }
3118
3119        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
3120                textconv_one = get_textconv(one);
3121                textconv_two = get_textconv(two);
3122        }
3123
3124        /* Never use a non-valid filename anywhere if at all possible */
3125        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3126        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3127
3128        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3129        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3130        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3131        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3132        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3133        if (lbl[0][0] == '/') {
3134                /* /dev/null */
3135                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3136                if (xfrm_msg)
3137                        strbuf_addstr(&header, xfrm_msg);
3138                must_show_header = 1;
3139        }
3140        else if (lbl[1][0] == '/') {
3141                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3142                if (xfrm_msg)
3143                        strbuf_addstr(&header, xfrm_msg);
3144                must_show_header = 1;
3145        }
3146        else {
3147                if (one->mode != two->mode) {
3148                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3149                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3150                        must_show_header = 1;
3151                }
3152                if (xfrm_msg)
3153                        strbuf_addstr(&header, xfrm_msg);
3154
3155                /*
3156                 * we do not run diff between different kind
3157                 * of objects.
3158                 */
3159                if ((one->mode ^ two->mode) & S_IFMT)
3160                        goto free_ab_and_return;
3161                if (complete_rewrite &&
3162                    (textconv_one || !diff_filespec_is_binary(one)) &&
3163                    (textconv_two || !diff_filespec_is_binary(two))) {
3164                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3165                                         header.buf, header.len, 0);
3166                        strbuf_reset(&header);
3167                        emit_rewrite_diff(name_a, name_b, one, two,
3168                                                textconv_one, textconv_two, o);
3169                        o->found_changes = 1;
3170                        goto free_ab_and_return;
3171                }
3172        }
3173
3174        if (o->irreversible_delete && lbl[1][0] == '/') {
3175                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3176                                 header.len, 0);
3177                strbuf_reset(&header);
3178                goto free_ab_and_return;
3179        } else if (!DIFF_OPT_TST(o, TEXT) &&
3180            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3181              (!textconv_two && diff_filespec_is_binary(two)) )) {
3182                struct strbuf sb = STRBUF_INIT;
3183                if (!one->data && !two->data &&
3184                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3185                    !DIFF_OPT_TST(o, BINARY)) {
3186                        if (!oidcmp(&one->oid, &two->oid)) {
3187                                if (must_show_header)
3188                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3189                                                         header.buf, header.len,
3190                                                         0);
3191                                goto free_ab_and_return;
3192                        }
3193                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3194                                         header.buf, header.len, 0);
3195                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3196                                    diff_line_prefix(o), lbl[0], lbl[1]);
3197                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3198                                         sb.buf, sb.len, 0);
3199                        strbuf_release(&sb);
3200                        goto free_ab_and_return;
3201                }
3202                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3203                        die("unable to read files to diff");
3204                /* Quite common confusing case */
3205                if (mf1.size == mf2.size &&
3206                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3207                        if (must_show_header)
3208                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3209                                                 header.buf, header.len, 0);
3210                        goto free_ab_and_return;
3211                }
3212                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3213                strbuf_reset(&header);
3214                if (DIFF_OPT_TST(o, BINARY))
3215                        emit_binary_diff(o, &mf1, &mf2);
3216                else {
3217                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3218                                    diff_line_prefix(o), lbl[0], lbl[1]);
3219                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3220                                         sb.buf, sb.len, 0);
3221                        strbuf_release(&sb);
3222                }
3223                o->found_changes = 1;
3224        } else {
3225                /* Crazy xdl interfaces.. */
3226                const char *diffopts = getenv("GIT_DIFF_OPTS");
3227                const char *v;
3228                xpparam_t xpp;
3229                xdemitconf_t xecfg;
3230                struct emit_callback ecbdata;
3231                const struct userdiff_funcname *pe;
3232
3233                if (must_show_header) {
3234                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3235                                         header.buf, header.len, 0);
3236                        strbuf_reset(&header);
3237                }
3238
3239                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3240                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3241
3242                pe = diff_funcname_pattern(one);
3243                if (!pe)
3244                        pe = diff_funcname_pattern(two);
3245
3246                memset(&xpp, 0, sizeof(xpp));
3247                memset(&xecfg, 0, sizeof(xecfg));
3248                memset(&ecbdata, 0, sizeof(ecbdata));
3249                ecbdata.label_path = lbl;
3250                ecbdata.color_diff = want_color(o->use_color);
3251                ecbdata.ws_rule = whitespace_rule(name_b);
3252                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3253                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3254                ecbdata.opt = o;
3255                ecbdata.header = header.len ? &header : NULL;
3256                xpp.flags = o->xdl_opts;
3257                xecfg.ctxlen = o->context;
3258                xecfg.interhunkctxlen = o->interhunkcontext;
3259                xecfg.flags = XDL_EMIT_FUNCNAMES;
3260                if (DIFF_OPT_TST(o, FUNCCONTEXT))
3261                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3262                if (pe)
3263                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3264                if (!diffopts)
3265                        ;
3266                else if (skip_prefix(diffopts, "--unified=", &v))
3267                        xecfg.ctxlen = strtoul(v, NULL, 10);
3268                else if (skip_prefix(diffopts, "-u", &v))
3269                        xecfg.ctxlen = strtoul(v, NULL, 10);
3270                if (o->word_diff)
3271                        init_diff_words_data(&ecbdata, o, one, two);
3272                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3273                                  &xpp, &xecfg))
3274                        die("unable to generate diff for %s", one->path);
3275                if (o->word_diff)
3276                        free_diff_words_data(&ecbdata);
3277                if (textconv_one)
3278                        free(mf1.ptr);
3279                if (textconv_two)
3280                        free(mf2.ptr);
3281                xdiff_clear_find_func(&xecfg);
3282        }
3283
3284 free_ab_and_return:
3285        strbuf_release(&header);
3286        diff_free_filespec_data(one);
3287        diff_free_filespec_data(two);
3288        free(a_one);
3289        free(b_two);
3290        return;
3291}
3292
3293static void builtin_diffstat(const char *name_a, const char *name_b,
3294                             struct diff_filespec *one,
3295                             struct diff_filespec *two,
3296                             struct diffstat_t *diffstat,
3297                             struct diff_options *o,
3298                             struct diff_filepair *p)
3299{
3300        mmfile_t mf1, mf2;
3301        struct diffstat_file *data;
3302        int same_contents;
3303        int complete_rewrite = 0;
3304
3305        if (!DIFF_PAIR_UNMERGED(p)) {
3306                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3307                        complete_rewrite = 1;
3308        }
3309
3310        data = diffstat_add(diffstat, name_a, name_b);
3311        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3312
3313        if (!one || !two) {
3314                data->is_unmerged = 1;
3315                return;
3316        }
3317
3318        same_contents = !oidcmp(&one->oid, &two->oid);
3319
3320        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3321                data->is_binary = 1;
3322                if (same_contents) {
3323                        data->added = 0;
3324                        data->deleted = 0;
3325                } else {
3326                        data->added = diff_filespec_size(two);
3327                        data->deleted = diff_filespec_size(one);
3328                }
3329        }
3330
3331        else if (complete_rewrite) {
3332                diff_populate_filespec(one, 0);
3333                diff_populate_filespec(two, 0);
3334                data->deleted = count_lines(one->data, one->size);
3335                data->added = count_lines(two->data, two->size);
3336        }
3337
3338        else if (!same_contents) {
3339                /* Crazy xdl interfaces.. */
3340                xpparam_t xpp;
3341                xdemitconf_t xecfg;
3342
3343                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3344                        die("unable to read files to diff");
3345
3346                memset(&xpp, 0, sizeof(xpp));
3347                memset(&xecfg, 0, sizeof(xecfg));
3348                xpp.flags = o->xdl_opts;
3349                xecfg.ctxlen = o->context;
3350                xecfg.interhunkctxlen = o->interhunkcontext;
3351                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3352                                  &xpp, &xecfg))
3353                        die("unable to generate diffstat for %s", one->path);
3354        }
3355
3356        diff_free_filespec_data(one);
3357        diff_free_filespec_data(two);
3358}
3359
3360static void builtin_checkdiff(const char *name_a, const char *name_b,
3361                              const char *attr_path,
3362                              struct diff_filespec *one,
3363                              struct diff_filespec *two,
3364                              struct diff_options *o)
3365{
3366        mmfile_t mf1, mf2;
3367        struct checkdiff_t data;
3368
3369        if (!two)
3370                return;
3371
3372        memset(&data, 0, sizeof(data));
3373        data.filename = name_b ? name_b : name_a;
3374        data.lineno = 0;
3375        data.o = o;
3376        data.ws_rule = whitespace_rule(attr_path);
3377        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3378
3379        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3380                die("unable to read files to diff");
3381
3382        /*
3383         * All the other codepaths check both sides, but not checking
3384         * the "old" side here is deliberate.  We are checking the newly
3385         * introduced changes, and as long as the "new" side is text, we
3386         * can and should check what it introduces.
3387         */
3388        if (diff_filespec_is_binary(two))
3389                goto free_and_return;
3390        else {
3391                /* Crazy xdl interfaces.. */
3392                xpparam_t xpp;
3393                xdemitconf_t xecfg;
3394
3395                memset(&xpp, 0, sizeof(xpp));
3396                memset(&xecfg, 0, sizeof(xecfg));
3397                xecfg.ctxlen = 1; /* at least one context line */
3398                xpp.flags = 0;
3399                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3400                                  &xpp, &xecfg))
3401                        die("unable to generate checkdiff for %s", one->path);
3402
3403                if (data.ws_rule & WS_BLANK_AT_EOF) {
3404                        struct emit_callback ecbdata;
3405                        int blank_at_eof;
3406
3407                        ecbdata.ws_rule = data.ws_rule;
3408                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3409                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3410
3411                        if (blank_at_eof) {
3412                                static char *err;
3413                                if (!err)
3414                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3415                                fprintf(o->file, "%s:%d: %s.\n",
3416                                        data.filename, blank_at_eof, err);
3417                                data.status = 1; /* report errors */
3418                        }
3419                }
3420        }
3421 free_and_return:
3422        diff_free_filespec_data(one);
3423        diff_free_filespec_data(two);
3424        if (data.status)
3425                DIFF_OPT_SET(o, CHECK_FAILED);
3426}
3427
3428struct diff_filespec *alloc_filespec(const char *path)
3429{
3430        struct diff_filespec *spec;
3431
3432        FLEXPTR_ALLOC_STR(spec, path, path);
3433        spec->count = 1;
3434        spec->is_binary = -1;
3435        return spec;
3436}
3437
3438void free_filespec(struct diff_filespec *spec)
3439{
3440        if (!--spec->count) {
3441                diff_free_filespec_data(spec);
3442                free(spec);
3443        }
3444}
3445
3446void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3447                   int oid_valid, unsigned short mode)
3448{
3449        if (mode) {
3450                spec->mode = canon_mode(mode);
3451                oidcpy(&spec->oid, oid);
3452                spec->oid_valid = oid_valid;
3453        }
3454}
3455
3456/*
3457 * Given a name and sha1 pair, if the index tells us the file in
3458 * the work tree has that object contents, return true, so that
3459 * prepare_temp_file() does not have to inflate and extract.
3460 */
3461static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3462{
3463        const struct cache_entry *ce;
3464        struct stat st;
3465        int pos, len;
3466
3467        /*
3468         * We do not read the cache ourselves here, because the
3469         * benchmark with my previous version that always reads cache
3470         * shows that it makes things worse for diff-tree comparing
3471         * two linux-2.6 kernel trees in an already checked out work
3472         * tree.  This is because most diff-tree comparisons deal with
3473         * only a small number of files, while reading the cache is
3474         * expensive for a large project, and its cost outweighs the
3475         * savings we get by not inflating the object to a temporary
3476         * file.  Practically, this code only helps when we are used
3477         * by diff-cache --cached, which does read the cache before
3478         * calling us.
3479         */
3480        if (!active_cache)
3481                return 0;
3482
3483        /* We want to avoid the working directory if our caller
3484         * doesn't need the data in a normal file, this system
3485         * is rather slow with its stat/open/mmap/close syscalls,
3486         * and the object is contained in a pack file.  The pack
3487         * is probably already open and will be faster to obtain
3488         * the data through than the working directory.  Loose
3489         * objects however would tend to be slower as they need
3490         * to be individually opened and inflated.
3491         */
3492        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3493                return 0;
3494
3495        /*
3496         * Similarly, if we'd have to convert the file contents anyway, that
3497         * makes the optimization not worthwhile.
3498         */
3499        if (!want_file && would_convert_to_git(&the_index, name))
3500                return 0;
3501
3502        len = strlen(name);
3503        pos = cache_name_pos(name, len);
3504        if (pos < 0)
3505                return 0;
3506        ce = active_cache[pos];
3507
3508        /*
3509         * This is not the sha1 we are looking for, or
3510         * unreusable because it is not a regular file.
3511         */
3512        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3513                return 0;
3514
3515        /*
3516         * If ce is marked as "assume unchanged", there is no
3517         * guarantee that work tree matches what we are looking for.
3518         */
3519        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3520                return 0;
3521
3522        /*
3523         * If ce matches the file in the work tree, we can reuse it.
3524         */
3525        if (ce_uptodate(ce) ||
3526            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3527                return 1;
3528
3529        return 0;
3530}
3531
3532static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3533{
3534        struct strbuf buf = STRBUF_INIT;
3535        char *dirty = "";
3536
3537        /* Are we looking at the work tree? */
3538        if (s->dirty_submodule)
3539                dirty = "-dirty";
3540
3541        strbuf_addf(&buf, "Subproject commit %s%s\n",
3542                    oid_to_hex(&s->oid), dirty);
3543        s->size = buf.len;
3544        if (size_only) {
3545                s->data = NULL;
3546                strbuf_release(&buf);
3547        } else {
3548                s->data = strbuf_detach(&buf, NULL);
3549                s->should_free = 1;
3550        }
3551        return 0;
3552}
3553
3554/*
3555 * While doing rename detection and pickaxe operation, we may need to
3556 * grab the data for the blob (or file) for our own in-core comparison.
3557 * diff_filespec has data and size fields for this purpose.
3558 */
3559int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3560{
3561        int size_only = flags & CHECK_SIZE_ONLY;
3562        int err = 0;
3563        /*
3564         * demote FAIL to WARN to allow inspecting the situation
3565         * instead of refusing.
3566         */
3567        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3568                                    ? SAFE_CRLF_WARN
3569                                    : safe_crlf);
3570
3571        if (!DIFF_FILE_VALID(s))
3572                die("internal error: asking to populate invalid file.");
3573        if (S_ISDIR(s->mode))
3574                return -1;
3575
3576        if (s->data)
3577                return 0;
3578
3579        if (size_only && 0 < s->size)
3580                return 0;
3581
3582        if (S_ISGITLINK(s->mode))
3583                return diff_populate_gitlink(s, size_only);
3584
3585        if (!s->oid_valid ||
3586            reuse_worktree_file(s->path, &s->oid, 0)) {
3587                struct strbuf buf = STRBUF_INIT;
3588                struct stat st;
3589                int fd;
3590
3591                if (lstat(s->path, &st) < 0) {
3592                        if (errno == ENOENT) {
3593                        err_empty:
3594                                err = -1;
3595                        empty:
3596                                s->data = (char *)"";
3597                                s->size = 0;
3598                                return err;
3599                        }
3600                }
3601                s->size = xsize_t(st.st_size);
3602                if (!s->size)
3603                        goto empty;
3604                if (S_ISLNK(st.st_mode)) {
3605                        struct strbuf sb = STRBUF_INIT;
3606
3607                        if (strbuf_readlink(&sb, s->path, s->size))
3608                                goto err_empty;
3609                        s->size = sb.len;
3610                        s->data = strbuf_detach(&sb, NULL);
3611                        s->should_free = 1;
3612                        return 0;
3613                }
3614
3615                /*
3616                 * Even if the caller would be happy with getting
3617                 * only the size, we cannot return early at this
3618                 * point if the path requires us to run the content
3619                 * conversion.
3620                 */
3621                if (size_only && !would_convert_to_git(&the_index, s->path))
3622                        return 0;
3623
3624                /*
3625                 * Note: this check uses xsize_t(st.st_size) that may
3626                 * not be the true size of the blob after it goes
3627                 * through convert_to_git().  This may not strictly be
3628                 * correct, but the whole point of big_file_threshold
3629                 * and is_binary check being that we want to avoid
3630                 * opening the file and inspecting the contents, this
3631                 * is probably fine.
3632                 */
3633                if ((flags & CHECK_BINARY) &&
3634                    s->size > big_file_threshold && s->is_binary == -1) {
3635                        s->is_binary = 1;
3636                        return 0;
3637                }
3638                fd = open(s->path, O_RDONLY);
3639                if (fd < 0)
3640                        goto err_empty;
3641                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3642                close(fd);
3643                s->should_munmap = 1;
3644
3645                /*
3646                 * Convert from working tree format to canonical git format
3647                 */
3648                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3649                        size_t size = 0;
3650                        munmap(s->data, s->size);
3651                        s->should_munmap = 0;
3652                        s->data = strbuf_detach(&buf, &size);
3653                        s->size = size;
3654                        s->should_free = 1;
3655                }
3656        }
3657        else {
3658                enum object_type type;
3659                if (size_only || (flags & CHECK_BINARY)) {
3660                        type = sha1_object_info(s->oid.hash, &s->size);
3661                        if (type < 0)
3662                                die("unable to read %s",
3663                                    oid_to_hex(&s->oid));
3664                        if (size_only)
3665                                return 0;
3666                        if (s->size > big_file_threshold && s->is_binary == -1) {
3667                                s->is_binary = 1;
3668                                return 0;
3669                        }
3670                }
3671                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3672                if (!s->data)
3673                        die("unable to read %s", oid_to_hex(&s->oid));
3674                s->should_free = 1;
3675        }
3676        return 0;
3677}
3678
3679void diff_free_filespec_blob(struct diff_filespec *s)
3680{
3681        if (s->should_free)
3682                free(s->data);
3683        else if (s->should_munmap)
3684                munmap(s->data, s->size);
3685
3686        if (s->should_free || s->should_munmap) {
3687                s->should_free = s->should_munmap = 0;
3688                s->data = NULL;
3689        }
3690}
3691
3692void diff_free_filespec_data(struct diff_filespec *s)
3693{
3694        diff_free_filespec_blob(s);
3695        FREE_AND_NULL(s->cnt_data);
3696}
3697
3698static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3699                           void *blob,
3700                           unsigned long size,
3701                           const struct object_id *oid,
3702                           int mode)
3703{
3704        int fd;
3705        struct strbuf buf = STRBUF_INIT;
3706        struct strbuf template = STRBUF_INIT;
3707        char *path_dup = xstrdup(path);
3708        const char *base = basename(path_dup);
3709
3710        /* Generate "XXXXXX_basename.ext" */
3711        strbuf_addstr(&template, "XXXXXX_");
3712        strbuf_addstr(&template, base);
3713
3714        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3715        if (fd < 0)
3716                die_errno("unable to create temp-file");
3717        if (convert_to_working_tree(path,
3718                        (const char *)blob, (size_t)size, &buf)) {
3719                blob = buf.buf;
3720                size = buf.len;
3721        }
3722        if (write_in_full(fd, blob, size) != size)
3723                die_errno("unable to write temp-file");
3724        close_tempfile(&temp->tempfile);
3725        temp->name = get_tempfile_path(&temp->tempfile);
3726        oid_to_hex_r(temp->hex, oid);
3727        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3728        strbuf_release(&buf);
3729        strbuf_release(&template);
3730        free(path_dup);
3731}
3732
3733static struct diff_tempfile *prepare_temp_file(const char *name,
3734                struct diff_filespec *one)
3735{
3736        struct diff_tempfile *temp = claim_diff_tempfile();
3737
3738        if (!DIFF_FILE_VALID(one)) {
3739        not_a_valid_file:
3740                /* A '-' entry produces this for file-2, and
3741                 * a '+' entry produces this for file-1.
3742                 */
3743                temp->name = "/dev/null";
3744                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3745                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3746                return temp;
3747        }
3748
3749        if (!S_ISGITLINK(one->mode) &&
3750            (!one->oid_valid ||
3751             reuse_worktree_file(name, &one->oid, 1))) {
3752                struct stat st;
3753                if (lstat(name, &st) < 0) {
3754                        if (errno == ENOENT)
3755                                goto not_a_valid_file;
3756                        die_errno("stat(%s)", name);
3757                }
3758                if (S_ISLNK(st.st_mode)) {
3759                        struct strbuf sb = STRBUF_INIT;
3760                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3761                                die_errno("readlink(%s)", name);
3762                        prep_temp_blob(name, temp, sb.buf, sb.len,
3763                                       (one->oid_valid ?
3764                                        &one->oid : &null_oid),
3765                                       (one->oid_valid ?
3766                                        one->mode : S_IFLNK));
3767                        strbuf_release(&sb);
3768                }
3769                else {
3770                        /* we can borrow from the file in the work tree */
3771                        temp->name = name;
3772                        if (!one->oid_valid)
3773                                oid_to_hex_r(temp->hex, &null_oid);
3774                        else
3775                                oid_to_hex_r(temp->hex, &one->oid);
3776                        /* Even though we may sometimes borrow the
3777                         * contents from the work tree, we always want
3778                         * one->mode.  mode is trustworthy even when
3779                         * !(one->oid_valid), as long as
3780                         * DIFF_FILE_VALID(one).
3781                         */
3782                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3783                }
3784                return temp;
3785        }
3786        else {
3787                if (diff_populate_filespec(one, 0))
3788                        die("cannot read data blob for %s", one->path);
3789                prep_temp_blob(name, temp, one->data, one->size,
3790                               &one->oid, one->mode);
3791        }
3792        return temp;
3793}
3794
3795static void add_external_diff_name(struct argv_array *argv,
3796                                   const char *name,
3797                                   struct diff_filespec *df)
3798{
3799        struct diff_tempfile *temp = prepare_temp_file(name, df);
3800        argv_array_push(argv, temp->name);
3801        argv_array_push(argv, temp->hex);
3802        argv_array_push(argv, temp->mode);
3803}
3804
3805/* An external diff command takes:
3806 *
3807 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3808 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3809 *
3810 */
3811static void run_external_diff(const char *pgm,
3812                              const char *name,
3813                              const char *other,
3814                              struct diff_filespec *one,
3815                              struct diff_filespec *two,
3816                              const char *xfrm_msg,
3817                              int complete_rewrite,
3818                              struct diff_options *o)
3819{
3820        struct argv_array argv = ARGV_ARRAY_INIT;
3821        struct argv_array env = ARGV_ARRAY_INIT;
3822        struct diff_queue_struct *q = &diff_queued_diff;
3823
3824        argv_array_push(&argv, pgm);
3825        argv_array_push(&argv, name);
3826
3827        if (one && two) {
3828                add_external_diff_name(&argv, name, one);
3829                if (!other)
3830                        add_external_diff_name(&argv, name, two);
3831                else {
3832                        add_external_diff_name(&argv, other, two);
3833                        argv_array_push(&argv, other);
3834                        argv_array_push(&argv, xfrm_msg);
3835                }
3836        }
3837
3838        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3839        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3840
3841        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3842                die(_("external diff died, stopping at %s"), name);
3843
3844        remove_tempfile();
3845        argv_array_clear(&argv);
3846        argv_array_clear(&env);
3847}
3848
3849static int similarity_index(struct diff_filepair *p)
3850{
3851        return p->score * 100 / MAX_SCORE;
3852}
3853
3854static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3855{
3856        if (startup_info->have_repository)
3857                return find_unique_abbrev(oid->hash, abbrev);
3858        else {
3859                char *hex = oid_to_hex(oid);
3860                if (abbrev < 0)
3861                        abbrev = FALLBACK_DEFAULT_ABBREV;
3862                if (abbrev > GIT_SHA1_HEXSZ)
3863                        die("BUG: oid abbreviation out of range: %d", abbrev);
3864                if (abbrev)
3865                        hex[abbrev] = '\0';
3866                return hex;
3867        }
3868}
3869
3870static void fill_metainfo(struct strbuf *msg,
3871                          const char *name,
3872                          const char *other,
3873                          struct diff_filespec *one,
3874                          struct diff_filespec *two,
3875                          struct diff_options *o,
3876                          struct diff_filepair *p,
3877                          int *must_show_header,
3878                          int use_color)
3879{
3880        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3881        const char *reset = diff_get_color(use_color, DIFF_RESET);
3882        const char *line_prefix = diff_line_prefix(o);
3883
3884        *must_show_header = 1;
3885        strbuf_init(msg, PATH_MAX * 2 + 300);
3886        switch (p->status) {
3887        case DIFF_STATUS_COPIED:
3888                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3889                            line_prefix, set, similarity_index(p));
3890                strbuf_addf(msg, "%s\n%s%scopy from ",
3891                            reset,  line_prefix, set);
3892                quote_c_style(name, msg, NULL, 0);
3893                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3894                quote_c_style(other, msg, NULL, 0);
3895                strbuf_addf(msg, "%s\n", reset);
3896                break;
3897        case DIFF_STATUS_RENAMED:
3898                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3899                            line_prefix, set, similarity_index(p));
3900                strbuf_addf(msg, "%s\n%s%srename from ",
3901                            reset, line_prefix, set);
3902                quote_c_style(name, msg, NULL, 0);
3903                strbuf_addf(msg, "%s\n%s%srename to ",
3904                            reset, line_prefix, set);
3905                quote_c_style(other, msg, NULL, 0);
3906                strbuf_addf(msg, "%s\n", reset);
3907                break;
3908        case DIFF_STATUS_MODIFIED:
3909                if (p->score) {
3910                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3911                                    line_prefix,
3912                                    set, similarity_index(p), reset);
3913                        break;
3914                }
3915                /* fallthru */
3916        default:
3917                *must_show_header = 0;
3918        }
3919        if (one && two && oidcmp(&one->oid, &two->oid)) {
3920                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3921
3922                if (DIFF_OPT_TST(o, BINARY)) {
3923                        mmfile_t mf;
3924                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3925                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3926                                abbrev = 40;
3927                }
3928                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3929                            diff_abbrev_oid(&one->oid, abbrev),
3930                            diff_abbrev_oid(&two->oid, abbrev));
3931                if (one->mode == two->mode)
3932                        strbuf_addf(msg, " %06o", one->mode);
3933                strbuf_addf(msg, "%s\n", reset);
3934        }
3935}
3936
3937static void run_diff_cmd(const char *pgm,
3938                         const char *name,
3939                         const char *other,
3940                         const char *attr_path,
3941                         struct diff_filespec *one,
3942                         struct diff_filespec *two,
3943                         struct strbuf *msg,
3944                         struct diff_options *o,
3945                         struct diff_filepair *p)
3946{
3947        const char *xfrm_msg = NULL;
3948        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3949        int must_show_header = 0;
3950
3951
3952        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3953                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3954                if (drv && drv->external)
3955                        pgm = drv->external;
3956        }
3957
3958        if (msg) {
3959                /*
3960                 * don't use colors when the header is intended for an
3961                 * external diff driver
3962                 */
3963                fill_metainfo(msg, name, other, one, two, o, p,
3964                              &must_show_header,
3965                              want_color(o->use_color) && !pgm);
3966                xfrm_msg = msg->len ? msg->buf : NULL;
3967        }
3968
3969        if (pgm) {
3970                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3971                                  complete_rewrite, o);
3972                return;
3973        }
3974        if (one && two)
3975                builtin_diff(name, other ? other : name,
3976                             one, two, xfrm_msg, must_show_header,
3977                             o, complete_rewrite);
3978        else
3979                fprintf(o->file, "* Unmerged path %s\n", name);
3980}
3981
3982static void diff_fill_oid_info(struct diff_filespec *one)
3983{
3984        if (DIFF_FILE_VALID(one)) {
3985                if (!one->oid_valid) {
3986                        struct stat st;
3987                        if (one->is_stdin) {
3988                                oidclr(&one->oid);
3989                                return;
3990                        }
3991                        if (lstat(one->path, &st) < 0)
3992                                die_errno("stat '%s'", one->path);
3993                        if (index_path(one->oid.hash, one->path, &st, 0))
3994                                die("cannot hash %s", one->path);
3995                }
3996        }
3997        else
3998                oidclr(&one->oid);
3999}
4000
4001static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4002{
4003        /* Strip the prefix but do not molest /dev/null and absolute paths */
4004        if (*namep && **namep != '/') {
4005                *namep += prefix_length;
4006                if (**namep == '/')
4007                        ++*namep;
4008        }
4009        if (*otherp && **otherp != '/') {
4010                *otherp += prefix_length;
4011                if (**otherp == '/')
4012                        ++*otherp;
4013        }
4014}
4015
4016static void run_diff(struct diff_filepair *p, struct diff_options *o)
4017{
4018        const char *pgm = external_diff();
4019        struct strbuf msg;
4020        struct diff_filespec *one = p->one;
4021        struct diff_filespec *two = p->two;
4022        const char *name;
4023        const char *other;
4024        const char *attr_path;
4025
4026        name  = one->path;
4027        other = (strcmp(name, two->path) ? two->path : NULL);
4028        attr_path = name;
4029        if (o->prefix_length)
4030                strip_prefix(o->prefix_length, &name, &other);
4031
4032        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
4033                pgm = NULL;
4034
4035        if (DIFF_PAIR_UNMERGED(p)) {
4036                run_diff_cmd(pgm, name, NULL, attr_path,
4037                             NULL, NULL, NULL, o, p);
4038                return;
4039        }
4040
4041        diff_fill_oid_info(one);
4042        diff_fill_oid_info(two);
4043
4044        if (!pgm &&
4045            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4046            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4047                /*
4048                 * a filepair that changes between file and symlink
4049                 * needs to be split into deletion and creation.
4050                 */
4051                struct diff_filespec *null = alloc_filespec(two->path);
4052                run_diff_cmd(NULL, name, other, attr_path,
4053                             one, null, &msg, o, p);
4054                free(null);
4055                strbuf_release(&msg);
4056
4057                null = alloc_filespec(one->path);
4058                run_diff_cmd(NULL, name, other, attr_path,
4059                             null, two, &msg, o, p);
4060                free(null);
4061        }
4062        else
4063                run_diff_cmd(pgm, name, other, attr_path,
4064                             one, two, &msg, o, p);
4065
4066        strbuf_release(&msg);
4067}
4068
4069static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4070                         struct diffstat_t *diffstat)
4071{
4072        const char *name;
4073        const char *other;
4074
4075        if (DIFF_PAIR_UNMERGED(p)) {
4076                /* unmerged */
4077                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4078                return;
4079        }
4080
4081        name = p->one->path;
4082        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4083
4084        if (o->prefix_length)
4085                strip_prefix(o->prefix_length, &name, &other);
4086
4087        diff_fill_oid_info(p->one);
4088        diff_fill_oid_info(p->two);
4089
4090        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4091}
4092
4093static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4094{
4095        const char *name;
4096        const char *other;
4097        const char *attr_path;
4098
4099        if (DIFF_PAIR_UNMERGED(p)) {
4100                /* unmerged */
4101                return;
4102        }
4103
4104        name = p->one->path;
4105        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4106        attr_path = other ? other : name;
4107
4108        if (o->prefix_length)
4109                strip_prefix(o->prefix_length, &name, &other);
4110
4111        diff_fill_oid_info(p->one);
4112        diff_fill_oid_info(p->two);
4113
4114        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4115}
4116
4117void diff_setup(struct diff_options *options)
4118{
4119        memcpy(options, &default_diff_options, sizeof(*options));
4120
4121        options->file = stdout;
4122
4123        options->abbrev = DEFAULT_ABBREV;
4124        options->line_termination = '\n';
4125        options->break_opt = -1;
4126        options->rename_limit = -1;
4127        options->dirstat_permille = diff_dirstat_permille_default;
4128        options->context = diff_context_default;
4129        options->interhunkcontext = diff_interhunk_context_default;
4130        options->ws_error_highlight = ws_error_highlight_default;
4131        DIFF_OPT_SET(options, RENAME_EMPTY);
4132
4133        /* pathchange left =NULL by default */
4134        options->change = diff_change;
4135        options->add_remove = diff_addremove;
4136        options->use_color = diff_use_color_default;
4137        options->detect_rename = diff_detect_rename_default;
4138        options->xdl_opts |= diff_algorithm;
4139        if (diff_indent_heuristic)
4140                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4141
4142        options->orderfile = diff_order_file_cfg;
4143
4144        if (diff_no_prefix) {
4145                options->a_prefix = options->b_prefix = "";
4146        } else if (!diff_mnemonic_prefix) {
4147                options->a_prefix = "a/";
4148                options->b_prefix = "b/";
4149        }
4150
4151        options->color_moved = diff_color_moved_default;
4152}
4153
4154void diff_setup_done(struct diff_options *options)
4155{
4156        int count = 0;
4157
4158        if (options->set_default)
4159                options->set_default(options);
4160
4161        if (options->output_format & DIFF_FORMAT_NAME)
4162                count++;
4163        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
4164                count++;
4165        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
4166                count++;
4167        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
4168                count++;
4169        if (count > 1)
4170                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4171
4172        /*
4173         * Most of the time we can say "there are changes"
4174         * only by checking if there are changed paths, but
4175         * --ignore-whitespace* options force us to look
4176         * inside contents.
4177         */
4178
4179        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
4180            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
4181            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
4182                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
4183        else
4184                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
4185
4186        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
4187                options->detect_rename = DIFF_DETECT_COPY;
4188
4189        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
4190                options->prefix = NULL;
4191        if (options->prefix)
4192                options->prefix_length = strlen(options->prefix);
4193        else
4194                options->prefix_length = 0;
4195
4196        if (options->output_format & (DIFF_FORMAT_NAME |
4197                                      DIFF_FORMAT_NAME_STATUS |
4198                                      DIFF_FORMAT_CHECKDIFF |
4199                                      DIFF_FORMAT_NO_OUTPUT))
4200                options->output_format &= ~(DIFF_FORMAT_RAW |
4201                                            DIFF_FORMAT_NUMSTAT |
4202                                            DIFF_FORMAT_DIFFSTAT |
4203                                            DIFF_FORMAT_SHORTSTAT |
4204                                            DIFF_FORMAT_DIRSTAT |
4205                                            DIFF_FORMAT_SUMMARY |
4206                                            DIFF_FORMAT_PATCH);
4207
4208        /*
4209         * These cases always need recursive; we do not drop caller-supplied
4210         * recursive bits for other formats here.
4211         */
4212        if (options->output_format & (DIFF_FORMAT_PATCH |
4213                                      DIFF_FORMAT_NUMSTAT |
4214                                      DIFF_FORMAT_DIFFSTAT |
4215                                      DIFF_FORMAT_SHORTSTAT |
4216                                      DIFF_FORMAT_DIRSTAT |
4217                                      DIFF_FORMAT_SUMMARY |
4218                                      DIFF_FORMAT_CHECKDIFF))
4219                DIFF_OPT_SET(options, RECURSIVE);
4220        /*
4221         * Also pickaxe would not work very well if you do not say recursive
4222         */
4223        if (options->pickaxe)
4224                DIFF_OPT_SET(options, RECURSIVE);
4225        /*
4226         * When patches are generated, submodules diffed against the work tree
4227         * must be checked for dirtiness too so it can be shown in the output
4228         */
4229        if (options->output_format & DIFF_FORMAT_PATCH)
4230                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
4231
4232        if (options->detect_rename && options->rename_limit < 0)
4233                options->rename_limit = diff_rename_limit_default;
4234        if (options->setup & DIFF_SETUP_USE_CACHE) {
4235                if (!active_cache)
4236                        /* read-cache does not die even when it fails
4237                         * so it is safe for us to do this here.  Also
4238                         * it does not smudge active_cache or active_nr
4239                         * when it fails, so we do not have to worry about
4240                         * cleaning it up ourselves either.
4241                         */
4242                        read_cache();
4243        }
4244        if (40 < options->abbrev)
4245                options->abbrev = 40; /* full */
4246
4247        /*
4248         * It does not make sense to show the first hit we happened
4249         * to have found.  It does not make sense not to return with
4250         * exit code in such a case either.
4251         */
4252        if (DIFF_OPT_TST(options, QUICK)) {
4253                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4254                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4255        }
4256
4257        options->diff_path_counter = 0;
4258
4259        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
4260                die(_("--follow requires exactly one pathspec"));
4261
4262        if (!options->use_color || external_diff())
4263                options->color_moved = 0;
4264}
4265
4266static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4267{
4268        char c, *eq;
4269        int len;
4270
4271        if (*arg != '-')
4272                return 0;
4273        c = *++arg;
4274        if (!c)
4275                return 0;
4276        if (c == arg_short) {
4277                c = *++arg;
4278                if (!c)
4279                        return 1;
4280                if (val && isdigit(c)) {
4281                        char *end;
4282                        int n = strtoul(arg, &end, 10);
4283                        if (*end)
4284                                return 0;
4285                        *val = n;
4286                        return 1;
4287                }
4288                return 0;
4289        }
4290        if (c != '-')
4291                return 0;
4292        arg++;
4293        eq = strchrnul(arg, '=');
4294        len = eq - arg;
4295        if (!len || strncmp(arg, arg_long, len))
4296                return 0;
4297        if (*eq) {
4298                int n;
4299                char *end;
4300                if (!isdigit(*++eq))
4301                        return 0;
4302                n = strtoul(eq, &end, 10);
4303                if (*end)
4304                        return 0;
4305                *val = n;
4306        }
4307        return 1;
4308}
4309
4310static int diff_scoreopt_parse(const char *opt);
4311
4312static inline int short_opt(char opt, const char **argv,
4313                            const char **optarg)
4314{
4315        const char *arg = argv[0];
4316        if (arg[0] != '-' || arg[1] != opt)
4317                return 0;
4318        if (arg[2] != '\0') {
4319                *optarg = arg + 2;
4320                return 1;
4321        }
4322        if (!argv[1])
4323                die("Option '%c' requires a value", opt);
4324        *optarg = argv[1];
4325        return 2;
4326}
4327
4328int parse_long_opt(const char *opt, const char **argv,
4329                   const char **optarg)
4330{
4331        const char *arg = argv[0];
4332        if (!skip_prefix(arg, "--", &arg))
4333                return 0;
4334        if (!skip_prefix(arg, opt, &arg))
4335                return 0;
4336        if (*arg == '=') { /* stuck form: --option=value */
4337                *optarg = arg + 1;
4338                return 1;
4339        }
4340        if (*arg != '\0')
4341                return 0;
4342        /* separate form: --option value */
4343        if (!argv[1])
4344                die("Option '--%s' requires a value", opt);
4345        *optarg = argv[1];
4346        return 2;
4347}
4348
4349static int stat_opt(struct diff_options *options, const char **av)
4350{
4351        const char *arg = av[0];
4352        char *end;
4353        int width = options->stat_width;
4354        int name_width = options->stat_name_width;
4355        int graph_width = options->stat_graph_width;
4356        int count = options->stat_count;
4357        int argcount = 1;
4358
4359        if (!skip_prefix(arg, "--stat", &arg))
4360                die("BUG: stat option does not begin with --stat: %s", arg);
4361        end = (char *)arg;
4362
4363        switch (*arg) {
4364        case '-':
4365                if (skip_prefix(arg, "-width", &arg)) {
4366                        if (*arg == '=')
4367                                width = strtoul(arg + 1, &end, 10);
4368                        else if (!*arg && !av[1])
4369                                die_want_option("--stat-width");
4370                        else if (!*arg) {
4371                                width = strtoul(av[1], &end, 10);
4372                                argcount = 2;
4373                        }
4374                } else if (skip_prefix(arg, "-name-width", &arg)) {
4375                        if (*arg == '=')
4376                                name_width = strtoul(arg + 1, &end, 10);
4377                        else if (!*arg && !av[1])
4378                                die_want_option("--stat-name-width");
4379                        else if (!*arg) {
4380                                name_width = strtoul(av[1], &end, 10);
4381                                argcount = 2;
4382                        }
4383                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4384                        if (*arg == '=')
4385                                graph_width = strtoul(arg + 1, &end, 10);
4386                        else if (!*arg && !av[1])
4387                                die_want_option("--stat-graph-width");
4388                        else if (!*arg) {
4389                                graph_width = strtoul(av[1], &end, 10);
4390                                argcount = 2;
4391                        }
4392                } else if (skip_prefix(arg, "-count", &arg)) {
4393                        if (*arg == '=')
4394                                count = strtoul(arg + 1, &end, 10);
4395                        else if (!*arg && !av[1])
4396                                die_want_option("--stat-count");
4397                        else if (!*arg) {
4398                                count = strtoul(av[1], &end, 10);
4399                                argcount = 2;
4400                        }
4401                }
4402                break;
4403        case '=':
4404                width = strtoul(arg+1, &end, 10);
4405                if (*end == ',')
4406                        name_width = strtoul(end+1, &end, 10);
4407                if (*end == ',')
4408                        count = strtoul(end+1, &end, 10);
4409        }
4410
4411        /* Important! This checks all the error cases! */
4412        if (*end)
4413                return 0;
4414        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4415        options->stat_name_width = name_width;
4416        options->stat_graph_width = graph_width;
4417        options->stat_width = width;
4418        options->stat_count = count;
4419        return argcount;
4420}
4421
4422static int parse_dirstat_opt(struct diff_options *options, const char *params)
4423{
4424        struct strbuf errmsg = STRBUF_INIT;
4425        if (parse_dirstat_params(options, params, &errmsg))
4426                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4427                    errmsg.buf);
4428        strbuf_release(&errmsg);
4429        /*
4430         * The caller knows a dirstat-related option is given from the command
4431         * line; allow it to say "return this_function();"
4432         */
4433        options->output_format |= DIFF_FORMAT_DIRSTAT;
4434        return 1;
4435}
4436
4437static int parse_submodule_opt(struct diff_options *options, const char *value)
4438{
4439        if (parse_submodule_params(options, value))
4440                die(_("Failed to parse --submodule option parameter: '%s'"),
4441                        value);
4442        return 1;
4443}
4444
4445static const char diff_status_letters[] = {
4446        DIFF_STATUS_ADDED,
4447        DIFF_STATUS_COPIED,
4448        DIFF_STATUS_DELETED,
4449        DIFF_STATUS_MODIFIED,
4450        DIFF_STATUS_RENAMED,
4451        DIFF_STATUS_TYPE_CHANGED,
4452        DIFF_STATUS_UNKNOWN,
4453        DIFF_STATUS_UNMERGED,
4454        DIFF_STATUS_FILTER_AON,
4455        DIFF_STATUS_FILTER_BROKEN,
4456        '\0',
4457};
4458
4459static unsigned int filter_bit['Z' + 1];
4460
4461static void prepare_filter_bits(void)
4462{
4463        int i;
4464
4465        if (!filter_bit[DIFF_STATUS_ADDED]) {
4466                for (i = 0; diff_status_letters[i]; i++)
4467                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4468        }
4469}
4470
4471static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4472{
4473        return opt->filter & filter_bit[(int) status];
4474}
4475
4476static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4477{
4478        int i, optch;
4479
4480        prepare_filter_bits();
4481
4482        /*
4483         * If there is a negation e.g. 'd' in the input, and we haven't
4484         * initialized the filter field with another --diff-filter, start
4485         * from full set of bits, except for AON.
4486         */
4487        if (!opt->filter) {
4488                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4489                        if (optch < 'a' || 'z' < optch)
4490                                continue;
4491                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4492                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4493                        break;
4494                }
4495        }
4496
4497        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4498                unsigned int bit;
4499                int negate;
4500
4501                if ('a' <= optch && optch <= 'z') {
4502                        negate = 1;
4503                        optch = toupper(optch);
4504                } else {
4505                        negate = 0;
4506                }
4507
4508                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4509                if (!bit)
4510                        return optarg[i];
4511                if (negate)
4512                        opt->filter &= ~bit;
4513                else
4514                        opt->filter |= bit;
4515        }
4516        return 0;
4517}
4518
4519static void enable_patch_output(int *fmt) {
4520        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4521        *fmt |= DIFF_FORMAT_PATCH;
4522}
4523
4524static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4525{
4526        int val = parse_ws_error_highlight(arg);
4527
4528        if (val < 0) {
4529                error("unknown value after ws-error-highlight=%.*s",
4530                      -1 - val, arg);
4531                return 0;
4532        }
4533        opt->ws_error_highlight = val;
4534        return 1;
4535}
4536
4537int diff_opt_parse(struct diff_options *options,
4538                   const char **av, int ac, const char *prefix)
4539{
4540        const char *arg = av[0];
4541        const char *optarg;
4542        int argcount;
4543
4544        if (!prefix)
4545                prefix = "";
4546
4547        /* Output format options */
4548        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4549            || opt_arg(arg, 'U', "unified", &options->context))
4550                enable_patch_output(&options->output_format);
4551        else if (!strcmp(arg, "--raw"))
4552                options->output_format |= DIFF_FORMAT_RAW;
4553        else if (!strcmp(arg, "--patch-with-raw")) {
4554                enable_patch_output(&options->output_format);
4555                options->output_format |= DIFF_FORMAT_RAW;
4556        } else if (!strcmp(arg, "--numstat"))
4557                options->output_format |= DIFF_FORMAT_NUMSTAT;
4558        else if (!strcmp(arg, "--shortstat"))
4559                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4560        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4561                return parse_dirstat_opt(options, "");
4562        else if (skip_prefix(arg, "-X", &arg))
4563                return parse_dirstat_opt(options, arg);
4564        else if (skip_prefix(arg, "--dirstat=", &arg))
4565                return parse_dirstat_opt(options, arg);
4566        else if (!strcmp(arg, "--cumulative"))
4567                return parse_dirstat_opt(options, "cumulative");
4568        else if (!strcmp(arg, "--dirstat-by-file"))
4569                return parse_dirstat_opt(options, "files");
4570        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4571                parse_dirstat_opt(options, "files");
4572                return parse_dirstat_opt(options, arg);
4573        }
4574        else if (!strcmp(arg, "--check"))
4575                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4576        else if (!strcmp(arg, "--summary"))
4577                options->output_format |= DIFF_FORMAT_SUMMARY;
4578        else if (!strcmp(arg, "--patch-with-stat")) {
4579                enable_patch_output(&options->output_format);
4580                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4581        } else if (!strcmp(arg, "--name-only"))
4582                options->output_format |= DIFF_FORMAT_NAME;
4583        else if (!strcmp(arg, "--name-status"))
4584                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4585        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4586                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4587        else if (starts_with(arg, "--stat"))
4588                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4589                return stat_opt(options, av);
4590
4591        /* renames options */
4592        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4593                 !strcmp(arg, "--break-rewrites")) {
4594                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4595                        return error("invalid argument to -B: %s", arg+2);
4596        }
4597        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4598                 !strcmp(arg, "--find-renames")) {
4599                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4600                        return error("invalid argument to -M: %s", arg+2);
4601                options->detect_rename = DIFF_DETECT_RENAME;
4602        }
4603        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4604                options->irreversible_delete = 1;
4605        }
4606        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4607                 !strcmp(arg, "--find-copies")) {
4608                if (options->detect_rename == DIFF_DETECT_COPY)
4609                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4610                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4611                        return error("invalid argument to -C: %s", arg+2);
4612                options->detect_rename = DIFF_DETECT_COPY;
4613        }
4614        else if (!strcmp(arg, "--no-renames"))
4615                options->detect_rename = 0;
4616        else if (!strcmp(arg, "--rename-empty"))
4617                DIFF_OPT_SET(options, RENAME_EMPTY);
4618        else if (!strcmp(arg, "--no-rename-empty"))
4619                DIFF_OPT_CLR(options, RENAME_EMPTY);
4620        else if (!strcmp(arg, "--relative"))
4621                DIFF_OPT_SET(options, RELATIVE_NAME);
4622        else if (skip_prefix(arg, "--relative=", &arg)) {
4623                DIFF_OPT_SET(options, RELATIVE_NAME);
4624                options->prefix = arg;
4625        }
4626
4627        /* xdiff options */
4628        else if (!strcmp(arg, "--minimal"))
4629                DIFF_XDL_SET(options, NEED_MINIMAL);
4630        else if (!strcmp(arg, "--no-minimal"))
4631                DIFF_XDL_CLR(options, NEED_MINIMAL);
4632        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4633                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4634        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4635                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4636        else if (!strcmp(arg, "--ignore-space-at-eol"))
4637                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4638        else if (!strcmp(arg, "--ignore-blank-lines"))
4639                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4640        else if (!strcmp(arg, "--indent-heuristic"))
4641                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4642        else if (!strcmp(arg, "--no-indent-heuristic"))
4643                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4644        else if (!strcmp(arg, "--patience"))
4645                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4646        else if (!strcmp(arg, "--histogram"))
4647                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4648        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4649                long value = parse_algorithm_value(optarg);
4650                if (value < 0)
4651                        return error("option diff-algorithm accepts \"myers\", "
4652                                     "\"minimal\", \"patience\" and \"histogram\"");
4653                /* clear out previous settings */
4654                DIFF_XDL_CLR(options, NEED_MINIMAL);
4655                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4656                options->xdl_opts |= value;
4657                return argcount;
4658        }
4659
4660        /* flags options */
4661        else if (!strcmp(arg, "--binary")) {
4662                enable_patch_output(&options->output_format);
4663                DIFF_OPT_SET(options, BINARY);
4664        }
4665        else if (!strcmp(arg, "--full-index"))
4666                DIFF_OPT_SET(options, FULL_INDEX);
4667        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4668                DIFF_OPT_SET(options, TEXT);
4669        else if (!strcmp(arg, "-R"))
4670                DIFF_OPT_SET(options, REVERSE_DIFF);
4671        else if (!strcmp(arg, "--find-copies-harder"))
4672                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4673        else if (!strcmp(arg, "--follow"))
4674                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4675        else if (!strcmp(arg, "--no-follow")) {
4676                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4677                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4678        } else if (!strcmp(arg, "--color"))
4679                options->use_color = 1;
4680        else if (skip_prefix(arg, "--color=", &arg)) {
4681                int value = git_config_colorbool(NULL, arg);
4682                if (value < 0)
4683                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4684                options->use_color = value;
4685        }
4686        else if (!strcmp(arg, "--no-color"))
4687                options->use_color = 0;
4688        else if (!strcmp(arg, "--color-moved")) {
4689                if (diff_color_moved_default)
4690                        options->color_moved = diff_color_moved_default;
4691                if (options->color_moved == COLOR_MOVED_NO)
4692                        options->color_moved = COLOR_MOVED_DEFAULT;
4693        } else if (!strcmp(arg, "--no-color-moved"))
4694                options->color_moved = COLOR_MOVED_NO;
4695        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4696                int cm = parse_color_moved(arg);
4697                if (cm < 0)
4698                        die("bad --color-moved argument: %s", arg);
4699                options->color_moved = cm;
4700        } else if (!strcmp(arg, "--color-words")) {
4701                options->use_color = 1;
4702                options->word_diff = DIFF_WORDS_COLOR;
4703        }
4704        else if (skip_prefix(arg, "--color-words=", &arg)) {
4705                options->use_color = 1;
4706                options->word_diff = DIFF_WORDS_COLOR;
4707                options->word_regex = arg;
4708        }
4709        else if (!strcmp(arg, "--word-diff")) {
4710                if (options->word_diff == DIFF_WORDS_NONE)
4711                        options->word_diff = DIFF_WORDS_PLAIN;
4712        }
4713        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4714                if (!strcmp(arg, "plain"))
4715                        options->word_diff = DIFF_WORDS_PLAIN;
4716                else if (!strcmp(arg, "color")) {
4717                        options->use_color = 1;
4718                        options->word_diff = DIFF_WORDS_COLOR;
4719                }
4720                else if (!strcmp(arg, "porcelain"))
4721                        options->word_diff = DIFF_WORDS_PORCELAIN;
4722                else if (!strcmp(arg, "none"))
4723                        options->word_diff = DIFF_WORDS_NONE;
4724                else
4725                        die("bad --word-diff argument: %s", arg);
4726        }
4727        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4728                if (options->word_diff == DIFF_WORDS_NONE)
4729                        options->word_diff = DIFF_WORDS_PLAIN;
4730                options->word_regex = optarg;
4731                return argcount;
4732        }
4733        else if (!strcmp(arg, "--exit-code"))
4734                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4735        else if (!strcmp(arg, "--quiet"))
4736                DIFF_OPT_SET(options, QUICK);
4737        else if (!strcmp(arg, "--ext-diff"))
4738                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4739        else if (!strcmp(arg, "--no-ext-diff"))
4740                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4741        else if (!strcmp(arg, "--textconv"))
4742                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4743        else if (!strcmp(arg, "--no-textconv"))
4744                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4745        else if (!strcmp(arg, "--ignore-submodules")) {
4746                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4747                handle_ignore_submodules_arg(options, "all");
4748        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4749                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4750                handle_ignore_submodules_arg(options, arg);
4751        } else if (!strcmp(arg, "--submodule"))
4752                options->submodule_format = DIFF_SUBMODULE_LOG;
4753        else if (skip_prefix(arg, "--submodule=", &arg))
4754                return parse_submodule_opt(options, arg);
4755        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4756                return parse_ws_error_highlight_opt(options, arg);
4757        else if (!strcmp(arg, "--ita-invisible-in-index"))
4758                options->ita_invisible_in_index = 1;
4759        else if (!strcmp(arg, "--ita-visible-in-index"))
4760                options->ita_invisible_in_index = 0;
4761
4762        /* misc options */
4763        else if (!strcmp(arg, "-z"))
4764                options->line_termination = 0;
4765        else if ((argcount = short_opt('l', av, &optarg))) {
4766                options->rename_limit = strtoul(optarg, NULL, 10);
4767                return argcount;
4768        }
4769        else if ((argcount = short_opt('S', av, &optarg))) {
4770                options->pickaxe = optarg;
4771                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4772                return argcount;
4773        } else if ((argcount = short_opt('G', av, &optarg))) {
4774                options->pickaxe = optarg;
4775                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4776                return argcount;
4777        }
4778        else if (!strcmp(arg, "--pickaxe-all"))
4779                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4780        else if (!strcmp(arg, "--pickaxe-regex"))
4781                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4782        else if ((argcount = short_opt('O', av, &optarg))) {
4783                options->orderfile = prefix_filename(prefix, optarg);
4784                return argcount;
4785        }
4786        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4787                int offending = parse_diff_filter_opt(optarg, options);
4788                if (offending)
4789                        die("unknown change class '%c' in --diff-filter=%s",
4790                            offending, optarg);
4791                return argcount;
4792        }
4793        else if (!strcmp(arg, "--no-abbrev"))
4794                options->abbrev = 0;
4795        else if (!strcmp(arg, "--abbrev"))
4796                options->abbrev = DEFAULT_ABBREV;
4797        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4798                options->abbrev = strtoul(arg, NULL, 10);
4799                if (options->abbrev < MINIMUM_ABBREV)
4800                        options->abbrev = MINIMUM_ABBREV;
4801                else if (40 < options->abbrev)
4802                        options->abbrev = 40;
4803        }
4804        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4805                options->a_prefix = optarg;
4806                return argcount;
4807        }
4808        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4809                options->line_prefix = optarg;
4810                options->line_prefix_length = strlen(options->line_prefix);
4811                graph_setup_line_prefix(options);
4812                return argcount;
4813        }
4814        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4815                options->b_prefix = optarg;
4816                return argcount;
4817        }
4818        else if (!strcmp(arg, "--no-prefix"))
4819                options->a_prefix = options->b_prefix = "";
4820        else if (opt_arg(arg, '\0', "inter-hunk-context",
4821                         &options->interhunkcontext))
4822                ;
4823        else if (!strcmp(arg, "-W"))
4824                DIFF_OPT_SET(options, FUNCCONTEXT);
4825        else if (!strcmp(arg, "--function-context"))
4826                DIFF_OPT_SET(options, FUNCCONTEXT);
4827        else if (!strcmp(arg, "--no-function-context"))
4828                DIFF_OPT_CLR(options, FUNCCONTEXT);
4829        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4830                char *path = prefix_filename(prefix, optarg);
4831                options->file = xfopen(path, "w");
4832                options->close_file = 1;
4833                if (options->use_color != GIT_COLOR_ALWAYS)
4834                        options->use_color = GIT_COLOR_NEVER;
4835                free(path);
4836                return argcount;
4837        } else
4838                return 0;
4839        return 1;
4840}
4841
4842int parse_rename_score(const char **cp_p)
4843{
4844        unsigned long num, scale;
4845        int ch, dot;
4846        const char *cp = *cp_p;
4847
4848        num = 0;
4849        scale = 1;
4850        dot = 0;
4851        for (;;) {
4852                ch = *cp;
4853                if ( !dot && ch == '.' ) {
4854                        scale = 1;
4855                        dot = 1;
4856                } else if ( ch == '%' ) {
4857                        scale = dot ? scale*100 : 100;
4858                        cp++;   /* % is always at the end */
4859                        break;
4860                } else if ( ch >= '0' && ch <= '9' ) {
4861                        if ( scale < 100000 ) {
4862                                scale *= 10;
4863                                num = (num*10) + (ch-'0');
4864                        }
4865                } else {
4866                        break;
4867                }
4868                cp++;
4869        }
4870        *cp_p = cp;
4871
4872        /* user says num divided by scale and we say internally that
4873         * is MAX_SCORE * num / scale.
4874         */
4875        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4876}
4877
4878static int diff_scoreopt_parse(const char *opt)
4879{
4880        int opt1, opt2, cmd;
4881
4882        if (*opt++ != '-')
4883                return -1;
4884        cmd = *opt++;
4885        if (cmd == '-') {
4886                /* convert the long-form arguments into short-form versions */
4887                if (skip_prefix(opt, "break-rewrites", &opt)) {
4888                        if (*opt == 0 || *opt++ == '=')
4889                                cmd = 'B';
4890                } else if (skip_prefix(opt, "find-copies", &opt)) {
4891                        if (*opt == 0 || *opt++ == '=')
4892                                cmd = 'C';
4893                } else if (skip_prefix(opt, "find-renames", &opt)) {
4894                        if (*opt == 0 || *opt++ == '=')
4895                                cmd = 'M';
4896                }
4897        }
4898        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4899                return -1; /* that is not a -M, -C, or -B option */
4900
4901        opt1 = parse_rename_score(&opt);
4902        if (cmd != 'B')
4903                opt2 = 0;
4904        else {
4905                if (*opt == 0)
4906                        opt2 = 0;
4907                else if (*opt != '/')
4908                        return -1; /* we expect -B80/99 or -B80 */
4909                else {
4910                        opt++;
4911                        opt2 = parse_rename_score(&opt);
4912                }
4913        }
4914        if (*opt != 0)
4915                return -1;
4916        return opt1 | (opt2 << 16);
4917}
4918
4919struct diff_queue_struct diff_queued_diff;
4920
4921void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4922{
4923        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4924        queue->queue[queue->nr++] = dp;
4925}
4926
4927struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4928                                 struct diff_filespec *one,
4929                                 struct diff_filespec *two)
4930{
4931        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4932        dp->one = one;
4933        dp->two = two;
4934        if (queue)
4935                diff_q(queue, dp);
4936        return dp;
4937}
4938
4939void diff_free_filepair(struct diff_filepair *p)
4940{
4941        free_filespec(p->one);
4942        free_filespec(p->two);
4943        free(p);
4944}
4945
4946const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4947{
4948        int abblen;
4949        const char *abbrev;
4950
4951        if (len == GIT_SHA1_HEXSZ)
4952                return oid_to_hex(oid);
4953
4954        abbrev = diff_abbrev_oid(oid, len);
4955        abblen = strlen(abbrev);
4956
4957        /*
4958         * In well-behaved cases, where the abbbreviated result is the
4959         * same as the requested length, append three dots after the
4960         * abbreviation (hence the whole logic is limited to the case
4961         * where abblen < 37); when the actual abbreviated result is a
4962         * bit longer than the requested length, we reduce the number
4963         * of dots so that they match the well-behaved ones.  However,
4964         * if the actual abbreviation is longer than the requested
4965         * length by more than three, we give up on aligning, and add
4966         * three dots anyway, to indicate that the output is not the
4967         * full object name.  Yes, this may be suboptimal, but this
4968         * appears only in "diff --raw --abbrev" output and it is not
4969         * worth the effort to change it now.  Note that this would
4970         * likely to work fine when the automatic sizing of default
4971         * abbreviation length is used--we would be fed -1 in "len" in
4972         * that case, and will end up always appending three-dots, but
4973         * the automatic sizing is supposed to give abblen that ensures
4974         * uniqueness across all objects (statistically speaking).
4975         */
4976        if (abblen < GIT_SHA1_HEXSZ - 3) {
4977                static char hex[GIT_MAX_HEXSZ + 1];
4978                if (len < abblen && abblen <= len + 2)
4979                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4980                else
4981                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4982                return hex;
4983        }
4984
4985        return oid_to_hex(oid);
4986}
4987
4988static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4989{
4990        int line_termination = opt->line_termination;
4991        int inter_name_termination = line_termination ? '\t' : '\0';
4992
4993        fprintf(opt->file, "%s", diff_line_prefix(opt));
4994        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4995                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4996                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4997                fprintf(opt->file, "%s ",
4998                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4999        }
5000        if (p->score) {
5001                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5002                        inter_name_termination);
5003        } else {
5004                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5005        }
5006
5007        if (p->status == DIFF_STATUS_COPIED ||
5008            p->status == DIFF_STATUS_RENAMED) {
5009                const char *name_a, *name_b;
5010                name_a = p->one->path;
5011                name_b = p->two->path;
5012                strip_prefix(opt->prefix_length, &name_a, &name_b);
5013                write_name_quoted(name_a, opt->file, inter_name_termination);
5014                write_name_quoted(name_b, opt->file, line_termination);
5015        } else {
5016                const char *name_a, *name_b;
5017                name_a = p->one->mode ? p->one->path : p->two->path;
5018                name_b = NULL;
5019                strip_prefix(opt->prefix_length, &name_a, &name_b);
5020                write_name_quoted(name_a, opt->file, line_termination);
5021        }
5022}
5023
5024int diff_unmodified_pair(struct diff_filepair *p)
5025{
5026        /* This function is written stricter than necessary to support
5027         * the currently implemented transformers, but the idea is to
5028         * let transformers to produce diff_filepairs any way they want,
5029         * and filter and clean them up here before producing the output.
5030         */
5031        struct diff_filespec *one = p->one, *two = p->two;
5032
5033        if (DIFF_PAIR_UNMERGED(p))
5034                return 0; /* unmerged is interesting */
5035
5036        /* deletion, addition, mode or type change
5037         * and rename are all interesting.
5038         */
5039        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5040            DIFF_PAIR_MODE_CHANGED(p) ||
5041            strcmp(one->path, two->path))
5042                return 0;
5043
5044        /* both are valid and point at the same path.  that is, we are
5045         * dealing with a change.
5046         */
5047        if (one->oid_valid && two->oid_valid &&
5048            !oidcmp(&one->oid, &two->oid) &&
5049            !one->dirty_submodule && !two->dirty_submodule)
5050                return 1; /* no change */
5051        if (!one->oid_valid && !two->oid_valid)
5052                return 1; /* both look at the same file on the filesystem. */
5053        return 0;
5054}
5055
5056static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5057{
5058        if (diff_unmodified_pair(p))
5059                return;
5060
5061        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5062            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5063                return; /* no tree diffs in patch format */
5064
5065        run_diff(p, o);
5066}
5067
5068static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5069                            struct diffstat_t *diffstat)
5070{
5071        if (diff_unmodified_pair(p))
5072                return;
5073
5074        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5075            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5076                return; /* no useful stat for tree diffs */
5077
5078        run_diffstat(p, o, diffstat);
5079}
5080
5081static void diff_flush_checkdiff(struct diff_filepair *p,
5082                struct diff_options *o)
5083{
5084        if (diff_unmodified_pair(p))
5085                return;
5086
5087        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5088            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5089                return; /* nothing to check in tree diffs */
5090
5091        run_checkdiff(p, o);
5092}
5093
5094int diff_queue_is_empty(void)
5095{
5096        struct diff_queue_struct *q = &diff_queued_diff;
5097        int i;
5098        for (i = 0; i < q->nr; i++)
5099                if (!diff_unmodified_pair(q->queue[i]))
5100                        return 0;
5101        return 1;
5102}
5103
5104#if DIFF_DEBUG
5105void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5106{
5107        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5108                x, one ? one : "",
5109                s->path,
5110                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5111                s->mode,
5112                s->oid_valid ? oid_to_hex(&s->oid) : "");
5113        fprintf(stderr, "queue[%d] %s size %lu\n",
5114                x, one ? one : "",
5115                s->size);
5116}
5117
5118void diff_debug_filepair(const struct diff_filepair *p, int i)
5119{
5120        diff_debug_filespec(p->one, i, "one");
5121        diff_debug_filespec(p->two, i, "two");
5122        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5123                p->score, p->status ? p->status : '?',
5124                p->one->rename_used, p->broken_pair);
5125}
5126
5127void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5128{
5129        int i;
5130        if (msg)
5131                fprintf(stderr, "%s\n", msg);
5132        fprintf(stderr, "q->nr = %d\n", q->nr);
5133        for (i = 0; i < q->nr; i++) {
5134                struct diff_filepair *p = q->queue[i];
5135                diff_debug_filepair(p, i);
5136        }
5137}
5138#endif
5139
5140static void diff_resolve_rename_copy(void)
5141{
5142        int i;
5143        struct diff_filepair *p;
5144        struct diff_queue_struct *q = &diff_queued_diff;
5145
5146        diff_debug_queue("resolve-rename-copy", q);
5147
5148        for (i = 0; i < q->nr; i++) {
5149                p = q->queue[i];
5150                p->status = 0; /* undecided */
5151                if (DIFF_PAIR_UNMERGED(p))
5152                        p->status = DIFF_STATUS_UNMERGED;
5153                else if (!DIFF_FILE_VALID(p->one))
5154                        p->status = DIFF_STATUS_ADDED;
5155                else if (!DIFF_FILE_VALID(p->two))
5156                        p->status = DIFF_STATUS_DELETED;
5157                else if (DIFF_PAIR_TYPE_CHANGED(p))
5158                        p->status = DIFF_STATUS_TYPE_CHANGED;
5159
5160                /* from this point on, we are dealing with a pair
5161                 * whose both sides are valid and of the same type, i.e.
5162                 * either in-place edit or rename/copy edit.
5163                 */
5164                else if (DIFF_PAIR_RENAME(p)) {
5165                        /*
5166                         * A rename might have re-connected a broken
5167                         * pair up, causing the pathnames to be the
5168                         * same again. If so, that's not a rename at
5169                         * all, just a modification..
5170                         *
5171                         * Otherwise, see if this source was used for
5172                         * multiple renames, in which case we decrement
5173                         * the count, and call it a copy.
5174                         */
5175                        if (!strcmp(p->one->path, p->two->path))
5176                                p->status = DIFF_STATUS_MODIFIED;
5177                        else if (--p->one->rename_used > 0)
5178                                p->status = DIFF_STATUS_COPIED;
5179                        else
5180                                p->status = DIFF_STATUS_RENAMED;
5181                }
5182                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5183                         p->one->mode != p->two->mode ||
5184                         p->one->dirty_submodule ||
5185                         p->two->dirty_submodule ||
5186                         is_null_oid(&p->one->oid))
5187                        p->status = DIFF_STATUS_MODIFIED;
5188                else {
5189                        /* This is a "no-change" entry and should not
5190                         * happen anymore, but prepare for broken callers.
5191                         */
5192                        error("feeding unmodified %s to diffcore",
5193                              p->one->path);
5194                        p->status = DIFF_STATUS_UNKNOWN;
5195                }
5196        }
5197        diff_debug_queue("resolve-rename-copy done", q);
5198}
5199
5200static int check_pair_status(struct diff_filepair *p)
5201{
5202        switch (p->status) {
5203        case DIFF_STATUS_UNKNOWN:
5204                return 0;
5205        case 0:
5206                die("internal error in diff-resolve-rename-copy");
5207        default:
5208                return 1;
5209        }
5210}
5211
5212static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5213{
5214        int fmt = opt->output_format;
5215
5216        if (fmt & DIFF_FORMAT_CHECKDIFF)
5217                diff_flush_checkdiff(p, opt);
5218        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5219                diff_flush_raw(p, opt);
5220        else if (fmt & DIFF_FORMAT_NAME) {
5221                const char *name_a, *name_b;
5222                name_a = p->two->path;
5223                name_b = NULL;
5224                strip_prefix(opt->prefix_length, &name_a, &name_b);
5225                fprintf(opt->file, "%s", diff_line_prefix(opt));
5226                write_name_quoted(name_a, opt->file, opt->line_termination);
5227        }
5228}
5229
5230static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5231{
5232        struct strbuf sb = STRBUF_INIT;
5233        if (fs->mode)
5234                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5235        else
5236                strbuf_addf(&sb, " %s ", newdelete);
5237
5238        quote_c_style(fs->path, &sb, NULL, 0);
5239        strbuf_addch(&sb, '\n');
5240        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5241                         sb.buf, sb.len, 0);
5242        strbuf_release(&sb);
5243}
5244
5245static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5246                int show_name)
5247{
5248        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5249                struct strbuf sb = STRBUF_INIT;
5250                strbuf_addf(&sb, " mode change %06o => %06o",
5251                            p->one->mode, p->two->mode);
5252                if (show_name) {
5253                        strbuf_addch(&sb, ' ');
5254                        quote_c_style(p->two->path, &sb, NULL, 0);
5255                }
5256                strbuf_addch(&sb, '\n');
5257                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5258                                 sb.buf, sb.len, 0);
5259                strbuf_release(&sb);
5260        }
5261}
5262
5263static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5264                struct diff_filepair *p)
5265{
5266        struct strbuf sb = STRBUF_INIT;
5267        char *names = pprint_rename(p->one->path, p->two->path);
5268        strbuf_addf(&sb, " %s %s (%d%%)\n",
5269                        renamecopy, names, similarity_index(p));
5270        free(names);
5271        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5272                                 sb.buf, sb.len, 0);
5273        show_mode_change(opt, p, 0);
5274}
5275
5276static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5277{
5278        switch(p->status) {
5279        case DIFF_STATUS_DELETED:
5280                show_file_mode_name(opt, "delete", p->one);
5281                break;
5282        case DIFF_STATUS_ADDED:
5283                show_file_mode_name(opt, "create", p->two);
5284                break;
5285        case DIFF_STATUS_COPIED:
5286                show_rename_copy(opt, "copy", p);
5287                break;
5288        case DIFF_STATUS_RENAMED:
5289                show_rename_copy(opt, "rename", p);
5290                break;
5291        default:
5292                if (p->score) {
5293                        struct strbuf sb = STRBUF_INIT;
5294                        strbuf_addstr(&sb, " rewrite ");
5295                        quote_c_style(p->two->path, &sb, NULL, 0);
5296                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5297                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5298                                         sb.buf, sb.len, 0);
5299                }
5300                show_mode_change(opt, p, !p->score);
5301                break;
5302        }
5303}
5304
5305struct patch_id_t {
5306        git_SHA_CTX *ctx;
5307        int patchlen;
5308};
5309
5310static int remove_space(char *line, int len)
5311{
5312        int i;
5313        char *dst = line;
5314        unsigned char c;
5315
5316        for (i = 0; i < len; i++)
5317                if (!isspace((c = line[i])))
5318                        *dst++ = c;
5319
5320        return dst - line;
5321}
5322
5323static void patch_id_consume(void *priv, char *line, unsigned long len)
5324{
5325        struct patch_id_t *data = priv;
5326        int new_len;
5327
5328        /* Ignore line numbers when computing the SHA1 of the patch */
5329        if (starts_with(line, "@@ -"))
5330                return;
5331
5332        new_len = remove_space(line, len);
5333
5334        git_SHA1_Update(data->ctx, line, new_len);
5335        data->patchlen += new_len;
5336}
5337
5338static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5339{
5340        git_SHA1_Update(ctx, str, strlen(str));
5341}
5342
5343static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5344{
5345        /* large enough for 2^32 in octal */
5346        char buf[12];
5347        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5348        git_SHA1_Update(ctx, buf, len);
5349}
5350
5351/* returns 0 upon success, and writes result into sha1 */
5352static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5353{
5354        struct diff_queue_struct *q = &diff_queued_diff;
5355        int i;
5356        git_SHA_CTX ctx;
5357        struct patch_id_t data;
5358
5359        git_SHA1_Init(&ctx);
5360        memset(&data, 0, sizeof(struct patch_id_t));
5361        data.ctx = &ctx;
5362
5363        for (i = 0; i < q->nr; i++) {
5364                xpparam_t xpp;
5365                xdemitconf_t xecfg;
5366                mmfile_t mf1, mf2;
5367                struct diff_filepair *p = q->queue[i];
5368                int len1, len2;
5369
5370                memset(&xpp, 0, sizeof(xpp));
5371                memset(&xecfg, 0, sizeof(xecfg));
5372                if (p->status == 0)
5373                        return error("internal diff status error");
5374                if (p->status == DIFF_STATUS_UNKNOWN)
5375                        continue;
5376                if (diff_unmodified_pair(p))
5377                        continue;
5378                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5379                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5380                        continue;
5381                if (DIFF_PAIR_UNMERGED(p))
5382                        continue;
5383
5384                diff_fill_oid_info(p->one);
5385                diff_fill_oid_info(p->two);
5386
5387                len1 = remove_space(p->one->path, strlen(p->one->path));
5388                len2 = remove_space(p->two->path, strlen(p->two->path));
5389                patch_id_add_string(&ctx, "diff--git");
5390                patch_id_add_string(&ctx, "a/");
5391                git_SHA1_Update(&ctx, p->one->path, len1);
5392                patch_id_add_string(&ctx, "b/");
5393                git_SHA1_Update(&ctx, p->two->path, len2);
5394
5395                if (p->one->mode == 0) {
5396                        patch_id_add_string(&ctx, "newfilemode");
5397                        patch_id_add_mode(&ctx, p->two->mode);
5398                        patch_id_add_string(&ctx, "---/dev/null");
5399                        patch_id_add_string(&ctx, "+++b/");
5400                        git_SHA1_Update(&ctx, p->two->path, len2);
5401                } else if (p->two->mode == 0) {
5402                        patch_id_add_string(&ctx, "deletedfilemode");
5403                        patch_id_add_mode(&ctx, p->one->mode);
5404                        patch_id_add_string(&ctx, "---a/");
5405                        git_SHA1_Update(&ctx, p->one->path, len1);
5406                        patch_id_add_string(&ctx, "+++/dev/null");
5407                } else {
5408                        patch_id_add_string(&ctx, "---a/");
5409                        git_SHA1_Update(&ctx, p->one->path, len1);
5410                        patch_id_add_string(&ctx, "+++b/");
5411                        git_SHA1_Update(&ctx, p->two->path, len2);
5412                }
5413
5414                if (diff_header_only)
5415                        continue;
5416
5417                if (fill_mmfile(&mf1, p->one) < 0 ||
5418                    fill_mmfile(&mf2, p->two) < 0)
5419                        return error("unable to read files to diff");
5420
5421                if (diff_filespec_is_binary(p->one) ||
5422                    diff_filespec_is_binary(p->two)) {
5423                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5424                                        GIT_SHA1_HEXSZ);
5425                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5426                                        GIT_SHA1_HEXSZ);
5427                        continue;
5428                }
5429
5430                xpp.flags = 0;
5431                xecfg.ctxlen = 3;
5432                xecfg.flags = 0;
5433                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5434                                  &xpp, &xecfg))
5435                        return error("unable to generate patch-id diff for %s",
5436                                     p->one->path);
5437        }
5438
5439        git_SHA1_Final(oid->hash, &ctx);
5440        return 0;
5441}
5442
5443int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5444{
5445        struct diff_queue_struct *q = &diff_queued_diff;
5446        int i;
5447        int result = diff_get_patch_id(options, oid, diff_header_only);
5448
5449        for (i = 0; i < q->nr; i++)
5450                diff_free_filepair(q->queue[i]);
5451
5452        free(q->queue);
5453        DIFF_QUEUE_CLEAR(q);
5454
5455        return result;
5456}
5457
5458static int is_summary_empty(const struct diff_queue_struct *q)
5459{
5460        int i;
5461
5462        for (i = 0; i < q->nr; i++) {
5463                const struct diff_filepair *p = q->queue[i];
5464
5465                switch (p->status) {
5466                case DIFF_STATUS_DELETED:
5467                case DIFF_STATUS_ADDED:
5468                case DIFF_STATUS_COPIED:
5469                case DIFF_STATUS_RENAMED:
5470                        return 0;
5471                default:
5472                        if (p->score)
5473                                return 0;
5474                        if (p->one->mode && p->two->mode &&
5475                            p->one->mode != p->two->mode)
5476                                return 0;
5477                        break;
5478                }
5479        }
5480        return 1;
5481}
5482
5483static const char rename_limit_warning[] =
5484N_("inexact rename detection was skipped due to too many files.");
5485
5486static const char degrade_cc_to_c_warning[] =
5487N_("only found copies from modified paths due to too many files.");
5488
5489static const char rename_limit_advice[] =
5490N_("you may want to set your %s variable to at least "
5491   "%d and retry the command.");
5492
5493void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5494{
5495        if (degraded_cc)
5496                warning(_(degrade_cc_to_c_warning));
5497        else if (needed)
5498                warning(_(rename_limit_warning));
5499        else
5500                return;
5501        if (0 < needed && needed < 32767)
5502                warning(_(rename_limit_advice), varname, needed);
5503}
5504
5505static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5506{
5507        int i;
5508        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5509        struct diff_queue_struct *q = &diff_queued_diff;
5510
5511        if (WSEH_NEW & WS_RULE_MASK)
5512                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5513
5514        if (o->color_moved)
5515                o->emitted_symbols = &esm;
5516
5517        for (i = 0; i < q->nr; i++) {
5518                struct diff_filepair *p = q->queue[i];
5519                if (check_pair_status(p))
5520                        diff_flush_patch(p, o);
5521        }
5522
5523        if (o->emitted_symbols) {
5524                if (o->color_moved) {
5525                        struct hashmap add_lines, del_lines;
5526
5527                        hashmap_init(&del_lines,
5528                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5529                        hashmap_init(&add_lines,
5530                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5531
5532                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5533                        mark_color_as_moved(o, &add_lines, &del_lines);
5534                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5535                                dim_moved_lines(o);
5536
5537                        hashmap_free(&add_lines, 0);
5538                        hashmap_free(&del_lines, 0);
5539                }
5540
5541                for (i = 0; i < esm.nr; i++)
5542                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5543
5544                for (i = 0; i < esm.nr; i++)
5545                        free((void *)esm.buf[i].line);
5546        }
5547        esm.nr = 0;
5548}
5549
5550void diff_flush(struct diff_options *options)
5551{
5552        struct diff_queue_struct *q = &diff_queued_diff;
5553        int i, output_format = options->output_format;
5554        int separator = 0;
5555        int dirstat_by_line = 0;
5556
5557        /*
5558         * Order: raw, stat, summary, patch
5559         * or:    name/name-status/checkdiff (other bits clear)
5560         */
5561        if (!q->nr)
5562                goto free_queue;
5563
5564        if (output_format & (DIFF_FORMAT_RAW |
5565                             DIFF_FORMAT_NAME |
5566                             DIFF_FORMAT_NAME_STATUS |
5567                             DIFF_FORMAT_CHECKDIFF)) {
5568                for (i = 0; i < q->nr; i++) {
5569                        struct diff_filepair *p = q->queue[i];
5570                        if (check_pair_status(p))
5571                                flush_one_pair(p, options);
5572                }
5573                separator++;
5574        }
5575
5576        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
5577                dirstat_by_line = 1;
5578
5579        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5580            dirstat_by_line) {
5581                struct diffstat_t diffstat;
5582
5583                memset(&diffstat, 0, sizeof(struct diffstat_t));
5584                for (i = 0; i < q->nr; i++) {
5585                        struct diff_filepair *p = q->queue[i];
5586                        if (check_pair_status(p))
5587                                diff_flush_stat(p, options, &diffstat);
5588                }
5589                if (output_format & DIFF_FORMAT_NUMSTAT)
5590                        show_numstat(&diffstat, options);
5591                if (output_format & DIFF_FORMAT_DIFFSTAT)
5592                        show_stats(&diffstat, options);
5593                if (output_format & DIFF_FORMAT_SHORTSTAT)
5594                        show_shortstats(&diffstat, options);
5595                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5596                        show_dirstat_by_line(&diffstat, options);
5597                free_diffstat_info(&diffstat);
5598                separator++;
5599        }
5600        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5601                show_dirstat(options);
5602
5603        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5604                for (i = 0; i < q->nr; i++) {
5605                        diff_summary(options, q->queue[i]);
5606                }
5607                separator++;
5608        }
5609
5610        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5611            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5612            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5613                /*
5614                 * run diff_flush_patch for the exit status. setting
5615                 * options->file to /dev/null should be safe, because we
5616                 * aren't supposed to produce any output anyway.
5617                 */
5618                if (options->close_file)
5619                        fclose(options->file);
5620                options->file = xfopen("/dev/null", "w");
5621                options->close_file = 1;
5622                options->color_moved = 0;
5623                for (i = 0; i < q->nr; i++) {
5624                        struct diff_filepair *p = q->queue[i];
5625                        if (check_pair_status(p))
5626                                diff_flush_patch(p, options);
5627                        if (options->found_changes)
5628                                break;
5629                }
5630        }
5631
5632        if (output_format & DIFF_FORMAT_PATCH) {
5633                if (separator) {
5634                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5635                        if (options->stat_sep)
5636                                /* attach patch instead of inline */
5637                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5638                                                 NULL, 0, 0);
5639                }
5640
5641                diff_flush_patch_all_file_pairs(options);
5642        }
5643
5644        if (output_format & DIFF_FORMAT_CALLBACK)
5645                options->format_callback(q, options, options->format_callback_data);
5646
5647        for (i = 0; i < q->nr; i++)
5648                diff_free_filepair(q->queue[i]);
5649free_queue:
5650        free(q->queue);
5651        DIFF_QUEUE_CLEAR(q);
5652        if (options->close_file)
5653                fclose(options->file);
5654
5655        /*
5656         * Report the content-level differences with HAS_CHANGES;
5657         * diff_addremove/diff_change does not set the bit when
5658         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5659         */
5660        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5661                if (options->found_changes)
5662                        DIFF_OPT_SET(options, HAS_CHANGES);
5663                else
5664                        DIFF_OPT_CLR(options, HAS_CHANGES);
5665        }
5666}
5667
5668static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5669{
5670        return (((p->status == DIFF_STATUS_MODIFIED) &&
5671                 ((p->score &&
5672                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5673                  (!p->score &&
5674                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5675                ((p->status != DIFF_STATUS_MODIFIED) &&
5676                 filter_bit_tst(p->status, options)));
5677}
5678
5679static void diffcore_apply_filter(struct diff_options *options)
5680{
5681        int i;
5682        struct diff_queue_struct *q = &diff_queued_diff;
5683        struct diff_queue_struct outq;
5684
5685        DIFF_QUEUE_CLEAR(&outq);
5686
5687        if (!options->filter)
5688                return;
5689
5690        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5691                int found;
5692                for (i = found = 0; !found && i < q->nr; i++) {
5693                        if (match_filter(options, q->queue[i]))
5694                                found++;
5695                }
5696                if (found)
5697                        return;
5698
5699                /* otherwise we will clear the whole queue
5700                 * by copying the empty outq at the end of this
5701                 * function, but first clear the current entries
5702                 * in the queue.
5703                 */
5704                for (i = 0; i < q->nr; i++)
5705                        diff_free_filepair(q->queue[i]);
5706        }
5707        else {
5708                /* Only the matching ones */
5709                for (i = 0; i < q->nr; i++) {
5710                        struct diff_filepair *p = q->queue[i];
5711                        if (match_filter(options, p))
5712                                diff_q(&outq, p);
5713                        else
5714                                diff_free_filepair(p);
5715                }
5716        }
5717        free(q->queue);
5718        *q = outq;
5719}
5720
5721/* Check whether two filespecs with the same mode and size are identical */
5722static int diff_filespec_is_identical(struct diff_filespec *one,
5723                                      struct diff_filespec *two)
5724{
5725        if (S_ISGITLINK(one->mode))
5726                return 0;
5727        if (diff_populate_filespec(one, 0))
5728                return 0;
5729        if (diff_populate_filespec(two, 0))
5730                return 0;
5731        return !memcmp(one->data, two->data, one->size);
5732}
5733
5734static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5735{
5736        if (p->done_skip_stat_unmatch)
5737                return p->skip_stat_unmatch_result;
5738
5739        p->done_skip_stat_unmatch = 1;
5740        p->skip_stat_unmatch_result = 0;
5741        /*
5742         * 1. Entries that come from stat info dirtiness
5743         *    always have both sides (iow, not create/delete),
5744         *    one side of the object name is unknown, with
5745         *    the same mode and size.  Keep the ones that
5746         *    do not match these criteria.  They have real
5747         *    differences.
5748         *
5749         * 2. At this point, the file is known to be modified,
5750         *    with the same mode and size, and the object
5751         *    name of one side is unknown.  Need to inspect
5752         *    the identical contents.
5753         */
5754        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5755            !DIFF_FILE_VALID(p->two) ||
5756            (p->one->oid_valid && p->two->oid_valid) ||
5757            (p->one->mode != p->two->mode) ||
5758            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5759            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5760            (p->one->size != p->two->size) ||
5761            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5762                p->skip_stat_unmatch_result = 1;
5763        return p->skip_stat_unmatch_result;
5764}
5765
5766static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5767{
5768        int i;
5769        struct diff_queue_struct *q = &diff_queued_diff;
5770        struct diff_queue_struct outq;
5771        DIFF_QUEUE_CLEAR(&outq);
5772
5773        for (i = 0; i < q->nr; i++) {
5774                struct diff_filepair *p = q->queue[i];
5775
5776                if (diff_filespec_check_stat_unmatch(p))
5777                        diff_q(&outq, p);
5778                else {
5779                        /*
5780                         * The caller can subtract 1 from skip_stat_unmatch
5781                         * to determine how many paths were dirty only
5782                         * due to stat info mismatch.
5783                         */
5784                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5785                                diffopt->skip_stat_unmatch++;
5786                        diff_free_filepair(p);
5787                }
5788        }
5789        free(q->queue);
5790        *q = outq;
5791}
5792
5793static int diffnamecmp(const void *a_, const void *b_)
5794{
5795        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5796        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5797        const char *name_a, *name_b;
5798
5799        name_a = a->one ? a->one->path : a->two->path;
5800        name_b = b->one ? b->one->path : b->two->path;
5801        return strcmp(name_a, name_b);
5802}
5803
5804void diffcore_fix_diff_index(struct diff_options *options)
5805{
5806        struct diff_queue_struct *q = &diff_queued_diff;
5807        QSORT(q->queue, q->nr, diffnamecmp);
5808}
5809
5810void diffcore_std(struct diff_options *options)
5811{
5812        /* NOTE please keep the following in sync with diff_tree_combined() */
5813        if (options->skip_stat_unmatch)
5814                diffcore_skip_stat_unmatch(options);
5815        if (!options->found_follow) {
5816                /* See try_to_follow_renames() in tree-diff.c */
5817                if (options->break_opt != -1)
5818                        diffcore_break(options->break_opt);
5819                if (options->detect_rename)
5820                        diffcore_rename(options);
5821                if (options->break_opt != -1)
5822                        diffcore_merge_broken();
5823        }
5824        if (options->pickaxe)
5825                diffcore_pickaxe(options);
5826        if (options->orderfile)
5827                diffcore_order(options->orderfile);
5828        if (!options->found_follow)
5829                /* See try_to_follow_renames() in tree-diff.c */
5830                diff_resolve_rename_copy();
5831        diffcore_apply_filter(options);
5832
5833        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5834                DIFF_OPT_SET(options, HAS_CHANGES);
5835        else
5836                DIFF_OPT_CLR(options, HAS_CHANGES);
5837
5838        options->found_follow = 0;
5839}
5840
5841int diff_result_code(struct diff_options *opt, int status)
5842{
5843        int result = 0;
5844
5845        diff_warn_rename_limit("diff.renameLimit",
5846                               opt->needed_rename_limit,
5847                               opt->degraded_cc_to_c);
5848        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5849            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5850                return status;
5851        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5852            DIFF_OPT_TST(opt, HAS_CHANGES))
5853                result |= 01;
5854        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5855            DIFF_OPT_TST(opt, CHECK_FAILED))
5856                result |= 02;
5857        return result;
5858}
5859
5860int diff_can_quit_early(struct diff_options *opt)
5861{
5862        return (DIFF_OPT_TST(opt, QUICK) &&
5863                !opt->filter &&
5864                DIFF_OPT_TST(opt, HAS_CHANGES));
5865}
5866
5867/*
5868 * Shall changes to this submodule be ignored?
5869 *
5870 * Submodule changes can be configured to be ignored separately for each path,
5871 * but that configuration can be overridden from the command line.
5872 */
5873static int is_submodule_ignored(const char *path, struct diff_options *options)
5874{
5875        int ignored = 0;
5876        unsigned orig_flags = options->flags;
5877        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5878                set_diffopt_flags_from_submodule_config(options, path);
5879        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5880                ignored = 1;
5881        options->flags = orig_flags;
5882        return ignored;
5883}
5884
5885void diff_addremove(struct diff_options *options,
5886                    int addremove, unsigned mode,
5887                    const struct object_id *oid,
5888                    int oid_valid,
5889                    const char *concatpath, unsigned dirty_submodule)
5890{
5891        struct diff_filespec *one, *two;
5892
5893        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5894                return;
5895
5896        /* This may look odd, but it is a preparation for
5897         * feeding "there are unchanged files which should
5898         * not produce diffs, but when you are doing copy
5899         * detection you would need them, so here they are"
5900         * entries to the diff-core.  They will be prefixed
5901         * with something like '=' or '*' (I haven't decided
5902         * which but should not make any difference).
5903         * Feeding the same new and old to diff_change()
5904         * also has the same effect.
5905         * Before the final output happens, they are pruned after
5906         * merged into rename/copy pairs as appropriate.
5907         */
5908        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5909                addremove = (addremove == '+' ? '-' :
5910                             addremove == '-' ? '+' : addremove);
5911
5912        if (options->prefix &&
5913            strncmp(concatpath, options->prefix, options->prefix_length))
5914                return;
5915
5916        one = alloc_filespec(concatpath);
5917        two = alloc_filespec(concatpath);
5918
5919        if (addremove != '+')
5920                fill_filespec(one, oid, oid_valid, mode);
5921        if (addremove != '-') {
5922                fill_filespec(two, oid, oid_valid, mode);
5923                two->dirty_submodule = dirty_submodule;
5924        }
5925
5926        diff_queue(&diff_queued_diff, one, two);
5927        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5928                DIFF_OPT_SET(options, HAS_CHANGES);
5929}
5930
5931void diff_change(struct diff_options *options,
5932                 unsigned old_mode, unsigned new_mode,
5933                 const struct object_id *old_oid,
5934                 const struct object_id *new_oid,
5935                 int old_oid_valid, int new_oid_valid,
5936                 const char *concatpath,
5937                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5938{
5939        struct diff_filespec *one, *two;
5940        struct diff_filepair *p;
5941
5942        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5943            is_submodule_ignored(concatpath, options))
5944                return;
5945
5946        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5947                SWAP(old_mode, new_mode);
5948                SWAP(old_oid, new_oid);
5949                SWAP(old_oid_valid, new_oid_valid);
5950                SWAP(old_dirty_submodule, new_dirty_submodule);
5951        }
5952
5953        if (options->prefix &&
5954            strncmp(concatpath, options->prefix, options->prefix_length))
5955                return;
5956
5957        one = alloc_filespec(concatpath);
5958        two = alloc_filespec(concatpath);
5959        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5960        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5961        one->dirty_submodule = old_dirty_submodule;
5962        two->dirty_submodule = new_dirty_submodule;
5963        p = diff_queue(&diff_queued_diff, one, two);
5964
5965        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5966                return;
5967
5968        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5969            !diff_filespec_check_stat_unmatch(p))
5970                return;
5971
5972        DIFF_OPT_SET(options, HAS_CHANGES);
5973}
5974
5975struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5976{
5977        struct diff_filepair *pair;
5978        struct diff_filespec *one, *two;
5979
5980        if (options->prefix &&
5981            strncmp(path, options->prefix, options->prefix_length))
5982                return NULL;
5983
5984        one = alloc_filespec(path);
5985        two = alloc_filespec(path);
5986        pair = diff_queue(&diff_queued_diff, one, two);
5987        pair->is_unmerged = 1;
5988        return pair;
5989}
5990
5991static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5992                size_t *outsize)
5993{
5994        struct diff_tempfile *temp;
5995        const char *argv[3];
5996        const char **arg = argv;
5997        struct child_process child = CHILD_PROCESS_INIT;
5998        struct strbuf buf = STRBUF_INIT;
5999        int err = 0;
6000
6001        temp = prepare_temp_file(spec->path, spec);
6002        *arg++ = pgm;
6003        *arg++ = temp->name;
6004        *arg = NULL;
6005
6006        child.use_shell = 1;
6007        child.argv = argv;
6008        child.out = -1;
6009        if (start_command(&child)) {
6010                remove_tempfile();
6011                return NULL;
6012        }
6013
6014        if (strbuf_read(&buf, child.out, 0) < 0)
6015                err = error("error reading from textconv command '%s'", pgm);
6016        close(child.out);
6017
6018        if (finish_command(&child) || err) {
6019                strbuf_release(&buf);
6020                remove_tempfile();
6021                return NULL;
6022        }
6023        remove_tempfile();
6024
6025        return strbuf_detach(&buf, outsize);
6026}
6027
6028size_t fill_textconv(struct userdiff_driver *driver,
6029                     struct diff_filespec *df,
6030                     char **outbuf)
6031{
6032        size_t size;
6033
6034        if (!driver) {
6035                if (!DIFF_FILE_VALID(df)) {
6036                        *outbuf = "";
6037                        return 0;
6038                }
6039                if (diff_populate_filespec(df, 0))
6040                        die("unable to read files to diff");
6041                *outbuf = df->data;
6042                return df->size;
6043        }
6044
6045        if (!driver->textconv)
6046                die("BUG: fill_textconv called with non-textconv driver");
6047
6048        if (driver->textconv_cache && df->oid_valid) {
6049                *outbuf = notes_cache_get(driver->textconv_cache,
6050                                          &df->oid,
6051                                          &size);
6052                if (*outbuf)
6053                        return size;
6054        }
6055
6056        *outbuf = run_textconv(driver->textconv, df, &size);
6057        if (!*outbuf)
6058                die("unable to read files to diff");
6059
6060        if (driver->textconv_cache && df->oid_valid) {
6061                /* ignore errors, as we might be in a readonly repository */
6062                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6063                                size);
6064                /*
6065                 * we could save up changes and flush them all at the end,
6066                 * but we would need an extra call after all diffing is done.
6067                 * Since generating a cache entry is the slow path anyway,
6068                 * this extra overhead probably isn't a big deal.
6069                 */
6070                notes_cache_write(driver->textconv_cache);
6071        }
6072
6073        return size;
6074}
6075
6076int textconv_object(const char *path,
6077                    unsigned mode,
6078                    const struct object_id *oid,
6079                    int oid_valid,
6080                    char **buf,
6081                    unsigned long *buf_size)
6082{
6083        struct diff_filespec *df;
6084        struct userdiff_driver *textconv;
6085
6086        df = alloc_filespec(path);
6087        fill_filespec(df, oid, oid_valid, mode);
6088        textconv = get_textconv(df);
6089        if (!textconv) {
6090                free_filespec(df);
6091                return 0;
6092        }
6093
6094        *buf_size = fill_textconv(textconv, df, buf);
6095        free_filespec(df);
6096        return 1;
6097}
6098
6099void setup_diff_pager(struct diff_options *opt)
6100{
6101        /*
6102         * If the user asked for our exit code, then either they want --quiet
6103         * or --exit-code. We should definitely not bother with a pager in the
6104         * former case, as we will generate no output. Since we still properly
6105         * report our exit code even when a pager is run, we _could_ run a
6106         * pager with --exit-code. But since we have not done so historically,
6107         * and because it is easy to find people oneline advising "git diff
6108         * --exit-code" in hooks and other scripts, we do not do so.
6109         */
6110        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
6111            check_pager_config("diff") != 0)
6112                setup_pager();
6113}