6f122121344b6043fbe3d996777f6766bfaafb9a
   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 "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed-zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else if (!strcmp(arg, "dimmed_zebra"))
 289                return COLOR_MOVED_ZEBRA_DIM;
 290        else
 291                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 292}
 293
 294static int parse_color_moved_ws(const char *arg)
 295{
 296        int ret = 0;
 297        struct string_list l = STRING_LIST_INIT_DUP;
 298        struct string_list_item *i;
 299
 300        string_list_split(&l, arg, ',', -1);
 301
 302        for_each_string_list_item(i, &l) {
 303                struct strbuf sb = STRBUF_INIT;
 304                strbuf_addstr(&sb, i->string);
 305                strbuf_trim(&sb);
 306
 307                if (!strcmp(sb.buf, "ignore-space-change"))
 308                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 309                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 310                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 311                else if (!strcmp(sb.buf, "ignore-all-space"))
 312                        ret |= XDF_IGNORE_WHITESPACE;
 313                else if (!strcmp(sb.buf, "allow-indentation-change"))
 314                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 315                else
 316                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 317
 318                strbuf_release(&sb);
 319        }
 320
 321        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 322            (ret & XDF_WHITESPACE_FLAGS))
 323                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 324
 325        string_list_clear(&l, 0);
 326
 327        return ret;
 328}
 329
 330int git_diff_ui_config(const char *var, const char *value, void *cb)
 331{
 332        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 333                diff_use_color_default = git_config_colorbool(var, value);
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.colormoved")) {
 337                int cm = parse_color_moved(value);
 338                if (cm < 0)
 339                        return -1;
 340                diff_color_moved_default = cm;
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormovedws")) {
 344                int cm = parse_color_moved_ws(value);
 345                if (cm < 0)
 346                        return -1;
 347                diff_color_moved_ws_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.context")) {
 351                diff_context_default = git_config_int(var, value);
 352                if (diff_context_default < 0)
 353                        return -1;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.interhunkcontext")) {
 357                diff_interhunk_context_default = git_config_int(var, value);
 358                if (diff_interhunk_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.renames")) {
 363                diff_detect_rename_default = git_config_rename(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.autorefreshindex")) {
 367                diff_auto_refresh_index = git_config_bool(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.mnemonicprefix")) {
 371                diff_mnemonic_prefix = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.noprefix")) {
 375                diff_no_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.statgraphwidth")) {
 379                diff_stat_graph_width = git_config_int(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.external"))
 383                return git_config_string(&external_diff_cmd_cfg, var, value);
 384        if (!strcmp(var, "diff.wordregex"))
 385                return git_config_string(&diff_word_regex_cfg, var, value);
 386        if (!strcmp(var, "diff.orderfile"))
 387                return git_config_pathname(&diff_order_file_cfg, var, value);
 388
 389        if (!strcmp(var, "diff.ignoresubmodules"))
 390                handle_ignore_submodules_arg(&default_diff_options, value);
 391
 392        if (!strcmp(var, "diff.submodule")) {
 393                if (parse_submodule_params(&default_diff_options, value))
 394                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 395                                value);
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "diff.algorithm")) {
 400                diff_algorithm = parse_algorithm_value(value);
 401                if (diff_algorithm < 0)
 402                        return -1;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.wserrorhighlight")) {
 407                int val = parse_ws_error_highlight(value);
 408                if (val < 0)
 409                        return -1;
 410                ws_error_highlight_default = val;
 411                return 0;
 412        }
 413
 414        if (git_color_config(var, value, cb) < 0)
 415                return -1;
 416
 417        return git_diff_basic_config(var, value, cb);
 418}
 419
 420int git_diff_basic_config(const char *var, const char *value, void *cb)
 421{
 422        const char *name;
 423
 424        if (!strcmp(var, "diff.renamelimit")) {
 425                diff_rename_limit_default = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (userdiff_config(var, value) < 0)
 430                return -1;
 431
 432        if (skip_prefix(var, "diff.color.", &name) ||
 433            skip_prefix(var, "color.diff.", &name)) {
 434                int slot = parse_diff_color_slot(name);
 435                if (slot < 0)
 436                        return 0;
 437                if (!value)
 438                        return config_error_nonbool(var);
 439                return color_parse(value, diff_colors[slot]);
 440        }
 441
 442        /* like GNU diff's --suppress-blank-empty option  */
 443        if (!strcmp(var, "diff.suppressblankempty") ||
 444                        /* for backwards compatibility */
 445                        !strcmp(var, "diff.suppress-blank-empty")) {
 446                diff_suppress_blank_empty = git_config_bool(var, value);
 447                return 0;
 448        }
 449
 450        if (!strcmp(var, "diff.dirstat")) {
 451                struct strbuf errmsg = STRBUF_INIT;
 452                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 453                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 454                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 455                                errmsg.buf);
 456                strbuf_release(&errmsg);
 457                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 458                return 0;
 459        }
 460
 461        if (git_diff_heuristic_config(var, value, cb) < 0)
 462                return -1;
 463
 464        return git_default_config(var, value, cb);
 465}
 466
 467static char *quote_two(const char *one, const char *two)
 468{
 469        int need_one = quote_c_style(one, NULL, NULL, 1);
 470        int need_two = quote_c_style(two, NULL, NULL, 1);
 471        struct strbuf res = STRBUF_INIT;
 472
 473        if (need_one + need_two) {
 474                strbuf_addch(&res, '"');
 475                quote_c_style(one, &res, NULL, 1);
 476                quote_c_style(two, &res, NULL, 1);
 477                strbuf_addch(&res, '"');
 478        } else {
 479                strbuf_addstr(&res, one);
 480                strbuf_addstr(&res, two);
 481        }
 482        return strbuf_detach(&res, NULL);
 483}
 484
 485static const char *external_diff(void)
 486{
 487        static const char *external_diff_cmd = NULL;
 488        static int done_preparing = 0;
 489
 490        if (done_preparing)
 491                return external_diff_cmd;
 492        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 493        if (!external_diff_cmd)
 494                external_diff_cmd = external_diff_cmd_cfg;
 495        done_preparing = 1;
 496        return external_diff_cmd;
 497}
 498
 499/*
 500 * Keep track of files used for diffing. Sometimes such an entry
 501 * refers to a temporary file, sometimes to an existing file, and
 502 * sometimes to "/dev/null".
 503 */
 504static struct diff_tempfile {
 505        /*
 506         * filename external diff should read from, or NULL if this
 507         * entry is currently not in use:
 508         */
 509        const char *name;
 510
 511        char hex[GIT_MAX_HEXSZ + 1];
 512        char mode[10];
 513
 514        /*
 515         * If this diff_tempfile instance refers to a temporary file,
 516         * this tempfile object is used to manage its lifetime.
 517         */
 518        struct tempfile *tempfile;
 519} diff_temp[2];
 520
 521struct emit_callback {
 522        int color_diff;
 523        unsigned ws_rule;
 524        int blank_at_eof_in_preimage;
 525        int blank_at_eof_in_postimage;
 526        int lno_in_preimage;
 527        int lno_in_postimage;
 528        const char **label_path;
 529        struct diff_words_data *diff_words;
 530        struct diff_options *opt;
 531        struct strbuf *header;
 532};
 533
 534static int count_lines(const char *data, int size)
 535{
 536        int count, ch, completely_empty = 1, nl_just_seen = 0;
 537        count = 0;
 538        while (0 < size--) {
 539                ch = *data++;
 540                if (ch == '\n') {
 541                        count++;
 542                        nl_just_seen = 1;
 543                        completely_empty = 0;
 544                }
 545                else {
 546                        nl_just_seen = 0;
 547                        completely_empty = 0;
 548                }
 549        }
 550        if (completely_empty)
 551                return 0;
 552        if (!nl_just_seen)
 553                count++; /* no trailing newline */
 554        return count;
 555}
 556
 557static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 558{
 559        if (!DIFF_FILE_VALID(one)) {
 560                mf->ptr = (char *)""; /* does not matter */
 561                mf->size = 0;
 562                return 0;
 563        }
 564        else if (diff_populate_filespec(one, 0))
 565                return -1;
 566
 567        mf->ptr = one->data;
 568        mf->size = one->size;
 569        return 0;
 570}
 571
 572/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 573static unsigned long diff_filespec_size(struct diff_filespec *one)
 574{
 575        if (!DIFF_FILE_VALID(one))
 576                return 0;
 577        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 578        return one->size;
 579}
 580
 581static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 582{
 583        char *ptr = mf->ptr;
 584        long size = mf->size;
 585        int cnt = 0;
 586
 587        if (!size)
 588                return cnt;
 589        ptr += size - 1; /* pointing at the very end */
 590        if (*ptr != '\n')
 591                ; /* incomplete line */
 592        else
 593                ptr--; /* skip the last LF */
 594        while (mf->ptr < ptr) {
 595                char *prev_eol;
 596                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 597                        if (*prev_eol == '\n')
 598                                break;
 599                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 600                        break;
 601                cnt++;
 602                ptr = prev_eol - 1;
 603        }
 604        return cnt;
 605}
 606
 607static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 608                               struct emit_callback *ecbdata)
 609{
 610        int l1, l2, at;
 611        unsigned ws_rule = ecbdata->ws_rule;
 612        l1 = count_trailing_blank(mf1, ws_rule);
 613        l2 = count_trailing_blank(mf2, ws_rule);
 614        if (l2 <= l1) {
 615                ecbdata->blank_at_eof_in_preimage = 0;
 616                ecbdata->blank_at_eof_in_postimage = 0;
 617                return;
 618        }
 619        at = count_lines(mf1->ptr, mf1->size);
 620        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 621
 622        at = count_lines(mf2->ptr, mf2->size);
 623        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 624}
 625
 626static void emit_line_0(struct diff_options *o,
 627                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 628                        int first, const char *line, int len)
 629{
 630        int has_trailing_newline, has_trailing_carriage_return;
 631        int needs_reset = 0; /* at the end of the line */
 632        FILE *file = o->file;
 633
 634        fputs(diff_line_prefix(o), file);
 635
 636        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 637        if (has_trailing_newline)
 638                len--;
 639
 640        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 641        if (has_trailing_carriage_return)
 642                len--;
 643
 644        if (!len && !first)
 645                goto end_of_line;
 646
 647        if (reverse && want_color(o->use_color)) {
 648                fputs(GIT_COLOR_REVERSE, file);
 649                needs_reset = 1;
 650        }
 651
 652        if (set_sign) {
 653                fputs(set_sign, file);
 654                needs_reset = 1;
 655        }
 656
 657        if (first)
 658                fputc(first, file);
 659
 660        if (!len)
 661                goto end_of_line;
 662
 663        if (set) {
 664                if (set_sign && set != set_sign)
 665                        fputs(reset, file);
 666                fputs(set, file);
 667                needs_reset = 1;
 668        }
 669        fwrite(line, len, 1, file);
 670        needs_reset = 1; /* 'line' may contain color codes. */
 671
 672end_of_line:
 673        if (needs_reset)
 674                fputs(reset, file);
 675        if (has_trailing_carriage_return)
 676                fputc('\r', file);
 677        if (has_trailing_newline)
 678                fputc('\n', file);
 679}
 680
 681static void emit_line(struct diff_options *o, const char *set, const char *reset,
 682                      const char *line, int len)
 683{
 684        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 685}
 686
 687enum diff_symbol {
 688        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 689        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 690        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 691        DIFF_SYMBOL_BINARY_DIFF_BODY,
 692        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 693        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 694        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 695        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 696        DIFF_SYMBOL_STATS_LINE,
 697        DIFF_SYMBOL_WORD_DIFF,
 698        DIFF_SYMBOL_STAT_SEP,
 699        DIFF_SYMBOL_SUMMARY,
 700        DIFF_SYMBOL_SUBMODULE_ADD,
 701        DIFF_SYMBOL_SUBMODULE_DEL,
 702        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 703        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 704        DIFF_SYMBOL_SUBMODULE_HEADER,
 705        DIFF_SYMBOL_SUBMODULE_ERROR,
 706        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 707        DIFF_SYMBOL_REWRITE_DIFF,
 708        DIFF_SYMBOL_BINARY_FILES,
 709        DIFF_SYMBOL_HEADER,
 710        DIFF_SYMBOL_FILEPAIR_PLUS,
 711        DIFF_SYMBOL_FILEPAIR_MINUS,
 712        DIFF_SYMBOL_WORDS_PORCELAIN,
 713        DIFF_SYMBOL_WORDS,
 714        DIFF_SYMBOL_CONTEXT,
 715        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 716        DIFF_SYMBOL_PLUS,
 717        DIFF_SYMBOL_MINUS,
 718        DIFF_SYMBOL_NO_LF_EOF,
 719        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 720        DIFF_SYMBOL_CONTEXT_MARKER,
 721        DIFF_SYMBOL_SEPARATOR
 722};
 723/*
 724 * Flags for content lines:
 725 * 0..12 are whitespace rules
 726 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 727 * 16 is marking if the line is blank at EOF
 728 */
 729#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 730#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 731#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 732#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 733#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 734
 735/*
 736 * This struct is used when we need to buffer the output of the diff output.
 737 *
 738 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 739 * into the pre/post image file. This pointer could be a union with the
 740 * line pointer. By storing an offset into the file instead of the literal line,
 741 * we can decrease the memory footprint for the buffered output. At first we
 742 * may want to only have indirection for the content lines, but we could also
 743 * enhance the state for emitting prefabricated lines, e.g. the similarity
 744 * score line or hunk/file headers would only need to store a number or path
 745 * and then the output can be constructed later on depending on state.
 746 */
 747struct emitted_diff_symbol {
 748        const char *line;
 749        int len;
 750        int flags;
 751        enum diff_symbol s;
 752};
 753#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 754
 755struct emitted_diff_symbols {
 756        struct emitted_diff_symbol *buf;
 757        int nr, alloc;
 758};
 759#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 760
 761static void append_emitted_diff_symbol(struct diff_options *o,
 762                                       struct emitted_diff_symbol *e)
 763{
 764        struct emitted_diff_symbol *f;
 765
 766        ALLOC_GROW(o->emitted_symbols->buf,
 767                   o->emitted_symbols->nr + 1,
 768                   o->emitted_symbols->alloc);
 769        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 770
 771        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 772        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 773}
 774
 775struct moved_entry {
 776        struct hashmap_entry ent;
 777        const struct emitted_diff_symbol *es;
 778        struct moved_entry *next_line;
 779};
 780
 781/**
 782 * The struct ws_delta holds white space differences between moved lines, i.e.
 783 * between '+' and '-' lines that have been detected to be a move.
 784 * The string contains the difference in leading white spaces, before the
 785 * rest of the line is compared using the white space config for move
 786 * coloring. The current_longer indicates if the first string in the
 787 * comparision is longer than the second.
 788 */
 789struct ws_delta {
 790        char *string;
 791        unsigned int current_longer : 1;
 792};
 793#define WS_DELTA_INIT { NULL, 0 }
 794
 795struct moved_block {
 796        struct moved_entry *match;
 797        struct ws_delta wsd;
 798};
 799
 800static void moved_block_clear(struct moved_block *b)
 801{
 802        FREE_AND_NULL(b->wsd.string);
 803        b->match = NULL;
 804}
 805
 806static int compute_ws_delta(const struct emitted_diff_symbol *a,
 807                             const struct emitted_diff_symbol *b,
 808                             struct ws_delta *out)
 809{
 810        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 811        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 812        int d = longer->len - shorter->len;
 813
 814        out->string = xmemdupz(longer->line, d);
 815        out->current_longer = (a == longer);
 816
 817        return !strncmp(longer->line + d, shorter->line, shorter->len);
 818}
 819
 820static int cmp_in_block_with_wsd(const struct diff_options *o,
 821                                 const struct moved_entry *cur,
 822                                 const struct moved_entry *match,
 823                                 struct moved_block *pmb,
 824                                 int n)
 825{
 826        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 827        int al = cur->es->len, cl = l->len;
 828        const char *a = cur->es->line,
 829                   *b = match->es->line,
 830                   *c = l->line;
 831
 832        int wslen;
 833
 834        /*
 835         * We need to check if 'cur' is equal to 'match'.
 836         * As those are from the same (+/-) side, we do not need to adjust for
 837         * indent changes. However these were found using fuzzy matching
 838         * so we do have to check if they are equal.
 839         */
 840        if (strcmp(a, b))
 841                return 1;
 842
 843        if (!pmb->wsd.string)
 844                /*
 845                 * The white space delta is not active? This can happen
 846                 * when we exit early in this function.
 847                 */
 848                return 1;
 849
 850        /*
 851         * The indent changes of the block are known and stored in
 852         * pmb->wsd; however we need to check if the indent changes of the
 853         * current line are still the same as before.
 854         *
 855         * To do so we need to compare 'l' to 'cur', adjusting the
 856         * one of them for the white spaces, depending which was longer.
 857         */
 858
 859        wslen = strlen(pmb->wsd.string);
 860        if (pmb->wsd.current_longer) {
 861                c += wslen;
 862                cl -= wslen;
 863        } else {
 864                a += wslen;
 865                al -= wslen;
 866        }
 867
 868        if (al != cl || memcmp(a, c, al))
 869                return 1;
 870
 871        return 0;
 872}
 873
 874static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 875                           const void *entry,
 876                           const void *entry_or_key,
 877                           const void *keydata)
 878{
 879        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 880        const struct moved_entry *a = entry;
 881        const struct moved_entry *b = entry_or_key;
 882        unsigned flags = diffopt->color_moved_ws_handling
 883                         & XDF_WHITESPACE_FLAGS;
 884
 885        if (diffopt->color_moved_ws_handling &
 886            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 887                /*
 888                 * As there is not specific white space config given,
 889                 * we'd need to check for a new block, so ignore all
 890                 * white space. The setup of the white space
 891                 * configuration for the next block is done else where
 892                 */
 893                flags |= XDF_IGNORE_WHITESPACE;
 894
 895        return !xdiff_compare_lines(a->es->line, a->es->len,
 896                                    b->es->line, b->es->len,
 897                                    flags);
 898}
 899
 900static struct moved_entry *prepare_entry(struct diff_options *o,
 901                                         int line_no)
 902{
 903        struct moved_entry *ret = xmalloc(sizeof(*ret));
 904        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 905        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 906
 907        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 908        ret->es = l;
 909        ret->next_line = NULL;
 910
 911        return ret;
 912}
 913
 914static void add_lines_to_move_detection(struct diff_options *o,
 915                                        struct hashmap *add_lines,
 916                                        struct hashmap *del_lines)
 917{
 918        struct moved_entry *prev_line = NULL;
 919
 920        int n;
 921        for (n = 0; n < o->emitted_symbols->nr; n++) {
 922                struct hashmap *hm;
 923                struct moved_entry *key;
 924
 925                switch (o->emitted_symbols->buf[n].s) {
 926                case DIFF_SYMBOL_PLUS:
 927                        hm = add_lines;
 928                        break;
 929                case DIFF_SYMBOL_MINUS:
 930                        hm = del_lines;
 931                        break;
 932                default:
 933                        prev_line = NULL;
 934                        continue;
 935                }
 936
 937                key = prepare_entry(o, n);
 938                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 939                        prev_line->next_line = key;
 940
 941                hashmap_add(hm, key);
 942                prev_line = key;
 943        }
 944}
 945
 946static void pmb_advance_or_null(struct diff_options *o,
 947                                struct moved_entry *match,
 948                                struct hashmap *hm,
 949                                struct moved_block *pmb,
 950                                int pmb_nr)
 951{
 952        int i;
 953        for (i = 0; i < pmb_nr; i++) {
 954                struct moved_entry *prev = pmb[i].match;
 955                struct moved_entry *cur = (prev && prev->next_line) ?
 956                                prev->next_line : NULL;
 957                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 958                        pmb[i].match = cur;
 959                } else {
 960                        pmb[i].match = NULL;
 961                }
 962        }
 963}
 964
 965static void pmb_advance_or_null_multi_match(struct diff_options *o,
 966                                            struct moved_entry *match,
 967                                            struct hashmap *hm,
 968                                            struct moved_block *pmb,
 969                                            int pmb_nr, int n)
 970{
 971        int i;
 972        char *got_match = xcalloc(1, pmb_nr);
 973
 974        for (; match; match = hashmap_get_next(hm, match)) {
 975                for (i = 0; i < pmb_nr; i++) {
 976                        struct moved_entry *prev = pmb[i].match;
 977                        struct moved_entry *cur = (prev && prev->next_line) ?
 978                                        prev->next_line : NULL;
 979                        if (!cur)
 980                                continue;
 981                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 982                                got_match[i] |= 1;
 983                }
 984        }
 985
 986        for (i = 0; i < pmb_nr; i++) {
 987                if (got_match[i]) {
 988                        /* Advance to the next line */
 989                        pmb[i].match = pmb[i].match->next_line;
 990                } else {
 991                        moved_block_clear(&pmb[i]);
 992                }
 993        }
 994}
 995
 996static int shrink_potential_moved_blocks(struct moved_block *pmb,
 997                                         int pmb_nr)
 998{
 999        int lp, rp;
1000
1001        /* Shrink the set of potential block to the remaining running */
1002        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1003                while (lp < pmb_nr && pmb[lp].match)
1004                        lp++;
1005                /* lp points at the first NULL now */
1006
1007                while (rp > -1 && !pmb[rp].match)
1008                        rp--;
1009                /* rp points at the last non-NULL */
1010
1011                if (lp < pmb_nr && rp > -1 && lp < rp) {
1012                        pmb[lp] = pmb[rp];
1013                        pmb[rp].match = NULL;
1014                        pmb[rp].wsd.string = NULL;
1015                        rp--;
1016                        lp++;
1017                }
1018        }
1019
1020        /* Remember the number of running sets */
1021        return rp + 1;
1022}
1023
1024/*
1025 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1026 *
1027 * Otherwise, if the last block has fewer alphanumeric characters than
1028 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1029 * that block.
1030 *
1031 * The last block consists of the (n - block_length)'th line up to but not
1032 * including the nth line.
1033 *
1034 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1035 * Think of a way to unify them.
1036 */
1037static void adjust_last_block(struct diff_options *o, int n, int block_length)
1038{
1039        int i, alnum_count = 0;
1040        if (o->color_moved == COLOR_MOVED_PLAIN)
1041                return;
1042        for (i = 1; i < block_length + 1; i++) {
1043                const char *c = o->emitted_symbols->buf[n - i].line;
1044                for (; *c; c++) {
1045                        if (!isalnum(*c))
1046                                continue;
1047                        alnum_count++;
1048                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1049                                return;
1050                }
1051        }
1052        for (i = 1; i < block_length + 1; i++)
1053                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1054}
1055
1056/* Find blocks of moved code, delegate actual coloring decision to helper */
1057static void mark_color_as_moved(struct diff_options *o,
1058                                struct hashmap *add_lines,
1059                                struct hashmap *del_lines)
1060{
1061        struct moved_block *pmb = NULL; /* potentially moved blocks */
1062        int pmb_nr = 0, pmb_alloc = 0;
1063        int n, flipped_block = 1, block_length = 0;
1064
1065
1066        for (n = 0; n < o->emitted_symbols->nr; n++) {
1067                struct hashmap *hm = NULL;
1068                struct moved_entry *key;
1069                struct moved_entry *match = NULL;
1070                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1071
1072                switch (l->s) {
1073                case DIFF_SYMBOL_PLUS:
1074                        hm = del_lines;
1075                        key = prepare_entry(o, n);
1076                        match = hashmap_get(hm, key, NULL);
1077                        free(key);
1078                        break;
1079                case DIFF_SYMBOL_MINUS:
1080                        hm = add_lines;
1081                        key = prepare_entry(o, n);
1082                        match = hashmap_get(hm, key, NULL);
1083                        free(key);
1084                        break;
1085                default:
1086                        flipped_block = 1;
1087                }
1088
1089                if (!match) {
1090                        int i;
1091
1092                        adjust_last_block(o, n, block_length);
1093                        for(i = 0; i < pmb_nr; i++)
1094                                moved_block_clear(&pmb[i]);
1095                        pmb_nr = 0;
1096                        block_length = 0;
1097                        continue;
1098                }
1099
1100                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1101
1102                if (o->color_moved == COLOR_MOVED_PLAIN)
1103                        continue;
1104
1105                if (o->color_moved_ws_handling &
1106                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1107                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1108                else
1109                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1110
1111                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1112
1113                if (pmb_nr == 0) {
1114                        /*
1115                         * The current line is the start of a new block.
1116                         * Setup the set of potential blocks.
1117                         */
1118                        for (; match; match = hashmap_get_next(hm, match)) {
1119                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1120                                if (o->color_moved_ws_handling &
1121                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1122                                        if (compute_ws_delta(l, match->es,
1123                                                             &pmb[pmb_nr].wsd))
1124                                                pmb[pmb_nr++].match = match;
1125                                } else {
1126                                        pmb[pmb_nr].wsd.string = NULL;
1127                                        pmb[pmb_nr++].match = match;
1128                                }
1129                        }
1130
1131                        flipped_block = (flipped_block + 1) % 2;
1132
1133                        adjust_last_block(o, n, block_length);
1134                        block_length = 0;
1135                }
1136
1137                block_length++;
1138
1139                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1140                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1141        }
1142        adjust_last_block(o, n, block_length);
1143
1144        for(n = 0; n < pmb_nr; n++)
1145                moved_block_clear(&pmb[n]);
1146        free(pmb);
1147}
1148
1149#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1150  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1151static void dim_moved_lines(struct diff_options *o)
1152{
1153        int n;
1154        for (n = 0; n < o->emitted_symbols->nr; n++) {
1155                struct emitted_diff_symbol *prev = (n != 0) ?
1156                                &o->emitted_symbols->buf[n - 1] : NULL;
1157                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1158                struct emitted_diff_symbol *next =
1159                                (n < o->emitted_symbols->nr - 1) ?
1160                                &o->emitted_symbols->buf[n + 1] : NULL;
1161
1162                /* Not a plus or minus line? */
1163                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1164                        continue;
1165
1166                /* Not a moved line? */
1167                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1168                        continue;
1169
1170                /*
1171                 * If prev or next are not a plus or minus line,
1172                 * pretend they don't exist
1173                 */
1174                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1175                            prev->s != DIFF_SYMBOL_MINUS)
1176                        prev = NULL;
1177                if (next && next->s != DIFF_SYMBOL_PLUS &&
1178                            next->s != DIFF_SYMBOL_MINUS)
1179                        next = NULL;
1180
1181                /* Inside a block? */
1182                if ((prev &&
1183                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1184                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1185                    (next &&
1186                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1187                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1188                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1189                        continue;
1190                }
1191
1192                /* Check if we are at an interesting bound: */
1193                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1194                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1195                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1196                        continue;
1197                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1198                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1199                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1200                        continue;
1201
1202                /*
1203                 * The boundary to prev and next are not interesting,
1204                 * so this line is not interesting as a whole
1205                 */
1206                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1207        }
1208}
1209
1210static void emit_line_ws_markup(struct diff_options *o,
1211                                const char *set_sign, const char *set,
1212                                const char *reset,
1213                                char sign, const char *line, int len,
1214                                unsigned ws_rule, int blank_at_eof)
1215{
1216        const char *ws = NULL;
1217
1218        if (o->ws_error_highlight & ws_rule) {
1219                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1220                if (!*ws)
1221                        ws = NULL;
1222        }
1223
1224        if (!ws && !set_sign)
1225                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1226        else if (!ws) {
1227                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1228        } else if (blank_at_eof)
1229                /* Blank line at EOF - paint '+' as well */
1230                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1231        else {
1232                /* Emit just the prefix, then the rest. */
1233                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1234                            sign, "", 0);
1235                ws_check_emit(line, len, ws_rule,
1236                              o->file, set, reset, ws);
1237        }
1238}
1239
1240static void emit_diff_symbol_from_struct(struct diff_options *o,
1241                                         struct emitted_diff_symbol *eds)
1242{
1243        static const char *nneof = " No newline at end of file\n";
1244        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1245        struct strbuf sb = STRBUF_INIT;
1246
1247        enum diff_symbol s = eds->s;
1248        const char *line = eds->line;
1249        int len = eds->len;
1250        unsigned flags = eds->flags;
1251
1252        switch (s) {
1253        case DIFF_SYMBOL_NO_LF_EOF:
1254                context = diff_get_color_opt(o, DIFF_CONTEXT);
1255                reset = diff_get_color_opt(o, DIFF_RESET);
1256                putc('\n', o->file);
1257                emit_line_0(o, context, NULL, 0, reset, '\\',
1258                            nneof, strlen(nneof));
1259                break;
1260        case DIFF_SYMBOL_SUBMODULE_HEADER:
1261        case DIFF_SYMBOL_SUBMODULE_ERROR:
1262        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1263        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1264        case DIFF_SYMBOL_SUMMARY:
1265        case DIFF_SYMBOL_STATS_LINE:
1266        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1267        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1268                emit_line(o, "", "", line, len);
1269                break;
1270        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1271        case DIFF_SYMBOL_CONTEXT_MARKER:
1272                context = diff_get_color_opt(o, DIFF_CONTEXT);
1273                reset = diff_get_color_opt(o, DIFF_RESET);
1274                emit_line(o, context, reset, line, len);
1275                break;
1276        case DIFF_SYMBOL_SEPARATOR:
1277                fprintf(o->file, "%s%c",
1278                        diff_line_prefix(o),
1279                        o->line_termination);
1280                break;
1281        case DIFF_SYMBOL_CONTEXT:
1282                set = diff_get_color_opt(o, DIFF_CONTEXT);
1283                reset = diff_get_color_opt(o, DIFF_RESET);
1284                set_sign = NULL;
1285                if (o->flags.dual_color_diffed_diffs) {
1286                        char c = !len ? 0 : line[0];
1287
1288                        if (c == '+')
1289                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1290                        else if (c == '@')
1291                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1292                        else if (c == '-')
1293                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1294                }
1295                emit_line_ws_markup(o, set_sign, set, reset,
1296                                    o->output_indicators[OUTPUT_INDICATOR_CONTEXT],
1297                                    line, len,
1298                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1299                break;
1300        case DIFF_SYMBOL_PLUS:
1301                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1302                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1303                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1304                case DIFF_SYMBOL_MOVED_LINE |
1305                     DIFF_SYMBOL_MOVED_LINE_ALT |
1306                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1307                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1308                        break;
1309                case DIFF_SYMBOL_MOVED_LINE |
1310                     DIFF_SYMBOL_MOVED_LINE_ALT:
1311                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1312                        break;
1313                case DIFF_SYMBOL_MOVED_LINE |
1314                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1315                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1316                        break;
1317                case DIFF_SYMBOL_MOVED_LINE:
1318                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1319                        break;
1320                default:
1321                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1322                }
1323                reset = diff_get_color_opt(o, DIFF_RESET);
1324                if (!o->flags.dual_color_diffed_diffs)
1325                        set_sign = NULL;
1326                else {
1327                        char c = !len ? 0 : line[0];
1328
1329                        set_sign = set;
1330                        if (c == '-')
1331                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1332                        else if (c == '@')
1333                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1334                        else if (c == '+')
1335                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1336                        else
1337                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1338                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1339                }
1340                emit_line_ws_markup(o, set_sign, set, reset,
1341                                    o->output_indicators[OUTPUT_INDICATOR_NEW],
1342                                    line, len,
1343                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1344                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1345                break;
1346        case DIFF_SYMBOL_MINUS:
1347                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1348                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1349                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1350                case DIFF_SYMBOL_MOVED_LINE |
1351                     DIFF_SYMBOL_MOVED_LINE_ALT |
1352                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1353                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1354                        break;
1355                case DIFF_SYMBOL_MOVED_LINE |
1356                     DIFF_SYMBOL_MOVED_LINE_ALT:
1357                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1358                        break;
1359                case DIFF_SYMBOL_MOVED_LINE |
1360                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1361                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1362                        break;
1363                case DIFF_SYMBOL_MOVED_LINE:
1364                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1365                        break;
1366                default:
1367                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1368                }
1369                reset = diff_get_color_opt(o, DIFF_RESET);
1370                if (!o->flags.dual_color_diffed_diffs)
1371                        set_sign = NULL;
1372                else {
1373                        char c = !len ? 0 : line[0];
1374
1375                        set_sign = set;
1376                        if (c == '+')
1377                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1378                        else if (c == '@')
1379                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1380                        else if (c == '-')
1381                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1382                        else
1383                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1384                }
1385                emit_line_ws_markup(o, set_sign, set, reset,
1386                                    o->output_indicators[OUTPUT_INDICATOR_OLD],
1387                                    line, len,
1388                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1389                break;
1390        case DIFF_SYMBOL_WORDS_PORCELAIN:
1391                context = diff_get_color_opt(o, DIFF_CONTEXT);
1392                reset = diff_get_color_opt(o, DIFF_RESET);
1393                emit_line(o, context, reset, line, len);
1394                fputs("~\n", o->file);
1395                break;
1396        case DIFF_SYMBOL_WORDS:
1397                context = diff_get_color_opt(o, DIFF_CONTEXT);
1398                reset = diff_get_color_opt(o, DIFF_RESET);
1399                /*
1400                 * Skip the prefix character, if any.  With
1401                 * diff_suppress_blank_empty, there may be
1402                 * none.
1403                 */
1404                if (line[0] != '\n') {
1405                        line++;
1406                        len--;
1407                }
1408                emit_line(o, context, reset, line, len);
1409                break;
1410        case DIFF_SYMBOL_FILEPAIR_PLUS:
1411                meta = diff_get_color_opt(o, DIFF_METAINFO);
1412                reset = diff_get_color_opt(o, DIFF_RESET);
1413                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1414                        line, reset,
1415                        strchr(line, ' ') ? "\t" : "");
1416                break;
1417        case DIFF_SYMBOL_FILEPAIR_MINUS:
1418                meta = diff_get_color_opt(o, DIFF_METAINFO);
1419                reset = diff_get_color_opt(o, DIFF_RESET);
1420                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1421                        line, reset,
1422                        strchr(line, ' ') ? "\t" : "");
1423                break;
1424        case DIFF_SYMBOL_BINARY_FILES:
1425        case DIFF_SYMBOL_HEADER:
1426                fprintf(o->file, "%s", line);
1427                break;
1428        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1429                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1430                break;
1431        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1432                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1433                break;
1434        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1435                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1436                break;
1437        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1438                fputs(diff_line_prefix(o), o->file);
1439                fputc('\n', o->file);
1440                break;
1441        case DIFF_SYMBOL_REWRITE_DIFF:
1442                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1443                reset = diff_get_color_opt(o, DIFF_RESET);
1444                emit_line(o, fraginfo, reset, line, len);
1445                break;
1446        case DIFF_SYMBOL_SUBMODULE_ADD:
1447                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1448                reset = diff_get_color_opt(o, DIFF_RESET);
1449                emit_line(o, set, reset, line, len);
1450                break;
1451        case DIFF_SYMBOL_SUBMODULE_DEL:
1452                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1453                reset = diff_get_color_opt(o, DIFF_RESET);
1454                emit_line(o, set, reset, line, len);
1455                break;
1456        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1457                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1458                        diff_line_prefix(o), line);
1459                break;
1460        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1461                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1462                        diff_line_prefix(o), line);
1463                break;
1464        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1465                emit_line(o, "", "", " 0 files changed\n",
1466                          strlen(" 0 files changed\n"));
1467                break;
1468        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1469                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1470                break;
1471        case DIFF_SYMBOL_WORD_DIFF:
1472                fprintf(o->file, "%.*s", len, line);
1473                break;
1474        case DIFF_SYMBOL_STAT_SEP:
1475                fputs(o->stat_sep, o->file);
1476                break;
1477        default:
1478                BUG("unknown diff symbol");
1479        }
1480        strbuf_release(&sb);
1481}
1482
1483static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1484                             const char *line, int len, unsigned flags)
1485{
1486        struct emitted_diff_symbol e = {line, len, flags, s};
1487
1488        if (o->emitted_symbols)
1489                append_emitted_diff_symbol(o, &e);
1490        else
1491                emit_diff_symbol_from_struct(o, &e);
1492}
1493
1494void diff_emit_submodule_del(struct diff_options *o, const char *line)
1495{
1496        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1497}
1498
1499void diff_emit_submodule_add(struct diff_options *o, const char *line)
1500{
1501        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1502}
1503
1504void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1507                         path, strlen(path), 0);
1508}
1509
1510void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1511{
1512        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1513                         path, strlen(path), 0);
1514}
1515
1516void diff_emit_submodule_header(struct diff_options *o, const char *header)
1517{
1518        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1519                         header, strlen(header), 0);
1520}
1521
1522void diff_emit_submodule_error(struct diff_options *o, const char *err)
1523{
1524        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1525}
1526
1527void diff_emit_submodule_pipethrough(struct diff_options *o,
1528                                     const char *line, int len)
1529{
1530        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1531}
1532
1533static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1534{
1535        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1536              ecbdata->blank_at_eof_in_preimage &&
1537              ecbdata->blank_at_eof_in_postimage &&
1538              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1539              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1540                return 0;
1541        return ws_blank_line(line, len, ecbdata->ws_rule);
1542}
1543
1544static void emit_add_line(const char *reset,
1545                          struct emit_callback *ecbdata,
1546                          const char *line, int len)
1547{
1548        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1549        if (new_blank_line_at_eof(ecbdata, line, len))
1550                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1551
1552        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1553}
1554
1555static void emit_del_line(const char *reset,
1556                          struct emit_callback *ecbdata,
1557                          const char *line, int len)
1558{
1559        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1560        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1561}
1562
1563static void emit_context_line(const char *reset,
1564                              struct emit_callback *ecbdata,
1565                              const char *line, int len)
1566{
1567        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1568        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1569}
1570
1571static void emit_hunk_header(struct emit_callback *ecbdata,
1572                             const char *line, int len)
1573{
1574        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1575        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1576        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1577        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1578        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1579        static const char atat[2] = { '@', '@' };
1580        const char *cp, *ep;
1581        struct strbuf msgbuf = STRBUF_INIT;
1582        int org_len = len;
1583        int i = 1;
1584
1585        /*
1586         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1587         * it always is at least 10 bytes long.
1588         */
1589        if (len < 10 ||
1590            memcmp(line, atat, 2) ||
1591            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1592                emit_diff_symbol(ecbdata->opt,
1593                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1594                return;
1595        }
1596        ep += 2; /* skip over @@ */
1597
1598        /* The hunk header in fraginfo color */
1599        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1600                strbuf_addstr(&msgbuf, reverse);
1601        strbuf_addstr(&msgbuf, frag);
1602        strbuf_add(&msgbuf, line, ep - line);
1603        strbuf_addstr(&msgbuf, reset);
1604
1605        /*
1606         * trailing "\r\n"
1607         */
1608        for ( ; i < 3; i++)
1609                if (line[len - i] == '\r' || line[len - i] == '\n')
1610                        len--;
1611
1612        /* blank before the func header */
1613        for (cp = ep; ep - line < len; ep++)
1614                if (*ep != ' ' && *ep != '\t')
1615                        break;
1616        if (ep != cp) {
1617                strbuf_addstr(&msgbuf, context);
1618                strbuf_add(&msgbuf, cp, ep - cp);
1619                strbuf_addstr(&msgbuf, reset);
1620        }
1621
1622        if (ep < line + len) {
1623                strbuf_addstr(&msgbuf, func);
1624                strbuf_add(&msgbuf, ep, line + len - ep);
1625                strbuf_addstr(&msgbuf, reset);
1626        }
1627
1628        strbuf_add(&msgbuf, line + len, org_len - len);
1629        strbuf_complete_line(&msgbuf);
1630        emit_diff_symbol(ecbdata->opt,
1631                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1632        strbuf_release(&msgbuf);
1633}
1634
1635static struct diff_tempfile *claim_diff_tempfile(void) {
1636        int i;
1637        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1638                if (!diff_temp[i].name)
1639                        return diff_temp + i;
1640        BUG("diff is failing to clean up its tempfiles");
1641}
1642
1643static void remove_tempfile(void)
1644{
1645        int i;
1646        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1647                if (is_tempfile_active(diff_temp[i].tempfile))
1648                        delete_tempfile(&diff_temp[i].tempfile);
1649                diff_temp[i].name = NULL;
1650        }
1651}
1652
1653static void add_line_count(struct strbuf *out, int count)
1654{
1655        switch (count) {
1656        case 0:
1657                strbuf_addstr(out, "0,0");
1658                break;
1659        case 1:
1660                strbuf_addstr(out, "1");
1661                break;
1662        default:
1663                strbuf_addf(out, "1,%d", count);
1664                break;
1665        }
1666}
1667
1668static void emit_rewrite_lines(struct emit_callback *ecb,
1669                               int prefix, const char *data, int size)
1670{
1671        const char *endp = NULL;
1672        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1673
1674        while (0 < size) {
1675                int len;
1676
1677                endp = memchr(data, '\n', size);
1678                len = endp ? (endp - data + 1) : size;
1679                if (prefix != '+') {
1680                        ecb->lno_in_preimage++;
1681                        emit_del_line(reset, ecb, data, len);
1682                } else {
1683                        ecb->lno_in_postimage++;
1684                        emit_add_line(reset, ecb, data, len);
1685                }
1686                size -= len;
1687                data += len;
1688        }
1689        if (!endp)
1690                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1691}
1692
1693static void emit_rewrite_diff(const char *name_a,
1694                              const char *name_b,
1695                              struct diff_filespec *one,
1696                              struct diff_filespec *two,
1697                              struct userdiff_driver *textconv_one,
1698                              struct userdiff_driver *textconv_two,
1699                              struct diff_options *o)
1700{
1701        int lc_a, lc_b;
1702        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1703        const char *a_prefix, *b_prefix;
1704        char *data_one, *data_two;
1705        size_t size_one, size_two;
1706        struct emit_callback ecbdata;
1707        struct strbuf out = STRBUF_INIT;
1708
1709        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1710                a_prefix = o->b_prefix;
1711                b_prefix = o->a_prefix;
1712        } else {
1713                a_prefix = o->a_prefix;
1714                b_prefix = o->b_prefix;
1715        }
1716
1717        name_a += (*name_a == '/');
1718        name_b += (*name_b == '/');
1719
1720        strbuf_reset(&a_name);
1721        strbuf_reset(&b_name);
1722        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1723        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1724
1725        size_one = fill_textconv(textconv_one, one, &data_one);
1726        size_two = fill_textconv(textconv_two, two, &data_two);
1727
1728        memset(&ecbdata, 0, sizeof(ecbdata));
1729        ecbdata.color_diff = want_color(o->use_color);
1730        ecbdata.ws_rule = whitespace_rule(name_b);
1731        ecbdata.opt = o;
1732        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1733                mmfile_t mf1, mf2;
1734                mf1.ptr = (char *)data_one;
1735                mf2.ptr = (char *)data_two;
1736                mf1.size = size_one;
1737                mf2.size = size_two;
1738                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1739        }
1740        ecbdata.lno_in_preimage = 1;
1741        ecbdata.lno_in_postimage = 1;
1742
1743        lc_a = count_lines(data_one, size_one);
1744        lc_b = count_lines(data_two, size_two);
1745
1746        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1747                         a_name.buf, a_name.len, 0);
1748        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1749                         b_name.buf, b_name.len, 0);
1750
1751        strbuf_addstr(&out, "@@ -");
1752        if (!o->irreversible_delete)
1753                add_line_count(&out, lc_a);
1754        else
1755                strbuf_addstr(&out, "?,?");
1756        strbuf_addstr(&out, " +");
1757        add_line_count(&out, lc_b);
1758        strbuf_addstr(&out, " @@\n");
1759        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1760        strbuf_release(&out);
1761
1762        if (lc_a && !o->irreversible_delete)
1763                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1764        if (lc_b)
1765                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1766        if (textconv_one)
1767                free((char *)data_one);
1768        if (textconv_two)
1769                free((char *)data_two);
1770}
1771
1772struct diff_words_buffer {
1773        mmfile_t text;
1774        unsigned long alloc;
1775        struct diff_words_orig {
1776                const char *begin, *end;
1777        } *orig;
1778        int orig_nr, orig_alloc;
1779};
1780
1781static void diff_words_append(char *line, unsigned long len,
1782                struct diff_words_buffer *buffer)
1783{
1784        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1785        line++;
1786        len--;
1787        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1788        buffer->text.size += len;
1789        buffer->text.ptr[buffer->text.size] = '\0';
1790}
1791
1792struct diff_words_style_elem {
1793        const char *prefix;
1794        const char *suffix;
1795        const char *color; /* NULL; filled in by the setup code if
1796                            * color is enabled */
1797};
1798
1799struct diff_words_style {
1800        enum diff_words_type type;
1801        struct diff_words_style_elem new_word, old_word, ctx;
1802        const char *newline;
1803};
1804
1805static struct diff_words_style diff_words_styles[] = {
1806        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1807        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1808        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1809};
1810
1811struct diff_words_data {
1812        struct diff_words_buffer minus, plus;
1813        const char *current_plus;
1814        int last_minus;
1815        struct diff_options *opt;
1816        regex_t *word_regex;
1817        enum diff_words_type type;
1818        struct diff_words_style *style;
1819};
1820
1821static int fn_out_diff_words_write_helper(struct diff_options *o,
1822                                          struct diff_words_style_elem *st_el,
1823                                          const char *newline,
1824                                          size_t count, const char *buf)
1825{
1826        int print = 0;
1827        struct strbuf sb = STRBUF_INIT;
1828
1829        while (count) {
1830                char *p = memchr(buf, '\n', count);
1831                if (print)
1832                        strbuf_addstr(&sb, diff_line_prefix(o));
1833
1834                if (p != buf) {
1835                        const char *reset = st_el->color && *st_el->color ?
1836                                            GIT_COLOR_RESET : NULL;
1837                        if (st_el->color && *st_el->color)
1838                                strbuf_addstr(&sb, st_el->color);
1839                        strbuf_addstr(&sb, st_el->prefix);
1840                        strbuf_add(&sb, buf, p ? p - buf : count);
1841                        strbuf_addstr(&sb, st_el->suffix);
1842                        if (reset)
1843                                strbuf_addstr(&sb, reset);
1844                }
1845                if (!p)
1846                        goto out;
1847
1848                strbuf_addstr(&sb, newline);
1849                count -= p + 1 - buf;
1850                buf = p + 1;
1851                print = 1;
1852                if (count) {
1853                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1854                                         sb.buf, sb.len, 0);
1855                        strbuf_reset(&sb);
1856                }
1857        }
1858
1859out:
1860        if (sb.len)
1861                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1862                                 sb.buf, sb.len, 0);
1863        strbuf_release(&sb);
1864        return 0;
1865}
1866
1867/*
1868 * '--color-words' algorithm can be described as:
1869 *
1870 *   1. collect the minus/plus lines of a diff hunk, divided into
1871 *      minus-lines and plus-lines;
1872 *
1873 *   2. break both minus-lines and plus-lines into words and
1874 *      place them into two mmfile_t with one word for each line;
1875 *
1876 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1877 *
1878 * And for the common parts of the both file, we output the plus side text.
1879 * diff_words->current_plus is used to trace the current position of the plus file
1880 * which printed. diff_words->last_minus is used to trace the last minus word
1881 * printed.
1882 *
1883 * For '--graph' to work with '--color-words', we need to output the graph prefix
1884 * on each line of color words output. Generally, there are two conditions on
1885 * which we should output the prefix.
1886 *
1887 *   1. diff_words->last_minus == 0 &&
1888 *      diff_words->current_plus == diff_words->plus.text.ptr
1889 *
1890 *      that is: the plus text must start as a new line, and if there is no minus
1891 *      word printed, a graph prefix must be printed.
1892 *
1893 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1894 *      *(diff_words->current_plus - 1) == '\n'
1895 *
1896 *      that is: a graph prefix must be printed following a '\n'
1897 */
1898static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1899{
1900        if ((diff_words->last_minus == 0 &&
1901                diff_words->current_plus == diff_words->plus.text.ptr) ||
1902                (diff_words->current_plus > diff_words->plus.text.ptr &&
1903                *(diff_words->current_plus - 1) == '\n')) {
1904                return 1;
1905        } else {
1906                return 0;
1907        }
1908}
1909
1910static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1911{
1912        struct diff_words_data *diff_words = priv;
1913        struct diff_words_style *style = diff_words->style;
1914        int minus_first, minus_len, plus_first, plus_len;
1915        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1916        struct diff_options *opt = diff_words->opt;
1917        const char *line_prefix;
1918
1919        if (line[0] != '@' || parse_hunk_header(line, len,
1920                        &minus_first, &minus_len, &plus_first, &plus_len))
1921                return;
1922
1923        assert(opt);
1924        line_prefix = diff_line_prefix(opt);
1925
1926        /* POSIX requires that first be decremented by one if len == 0... */
1927        if (minus_len) {
1928                minus_begin = diff_words->minus.orig[minus_first].begin;
1929                minus_end =
1930                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1931        } else
1932                minus_begin = minus_end =
1933                        diff_words->minus.orig[minus_first].end;
1934
1935        if (plus_len) {
1936                plus_begin = diff_words->plus.orig[plus_first].begin;
1937                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1938        } else
1939                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1940
1941        if (color_words_output_graph_prefix(diff_words)) {
1942                fputs(line_prefix, diff_words->opt->file);
1943        }
1944        if (diff_words->current_plus != plus_begin) {
1945                fn_out_diff_words_write_helper(diff_words->opt,
1946                                &style->ctx, style->newline,
1947                                plus_begin - diff_words->current_plus,
1948                                diff_words->current_plus);
1949        }
1950        if (minus_begin != minus_end) {
1951                fn_out_diff_words_write_helper(diff_words->opt,
1952                                &style->old_word, style->newline,
1953                                minus_end - minus_begin, minus_begin);
1954        }
1955        if (plus_begin != plus_end) {
1956                fn_out_diff_words_write_helper(diff_words->opt,
1957                                &style->new_word, style->newline,
1958                                plus_end - plus_begin, plus_begin);
1959        }
1960
1961        diff_words->current_plus = plus_end;
1962        diff_words->last_minus = minus_first;
1963}
1964
1965/* This function starts looking at *begin, and returns 0 iff a word was found. */
1966static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1967                int *begin, int *end)
1968{
1969        if (word_regex && *begin < buffer->size) {
1970                regmatch_t match[1];
1971                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1972                                 buffer->size - *begin, 1, match, 0)) {
1973                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1974                                        '\n', match[0].rm_eo - match[0].rm_so);
1975                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1976                        *begin += match[0].rm_so;
1977                        return *begin >= *end;
1978                }
1979                return -1;
1980        }
1981
1982        /* find the next word */
1983        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1984                (*begin)++;
1985        if (*begin >= buffer->size)
1986                return -1;
1987
1988        /* find the end of the word */
1989        *end = *begin + 1;
1990        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1991                (*end)++;
1992
1993        return 0;
1994}
1995
1996/*
1997 * This function splits the words in buffer->text, stores the list with
1998 * newline separator into out, and saves the offsets of the original words
1999 * in buffer->orig.
2000 */
2001static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2002                regex_t *word_regex)
2003{
2004        int i, j;
2005        long alloc = 0;
2006
2007        out->size = 0;
2008        out->ptr = NULL;
2009
2010        /* fake an empty "0th" word */
2011        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2012        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2013        buffer->orig_nr = 1;
2014
2015        for (i = 0; i < buffer->text.size; i++) {
2016                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2017                        return;
2018
2019                /* store original boundaries */
2020                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2021                                buffer->orig_alloc);
2022                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2023                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2024                buffer->orig_nr++;
2025
2026                /* store one word */
2027                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2028                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2029                out->ptr[out->size + j - i] = '\n';
2030                out->size += j - i + 1;
2031
2032                i = j - 1;
2033        }
2034}
2035
2036/* this executes the word diff on the accumulated buffers */
2037static void diff_words_show(struct diff_words_data *diff_words)
2038{
2039        xpparam_t xpp;
2040        xdemitconf_t xecfg;
2041        mmfile_t minus, plus;
2042        struct diff_words_style *style = diff_words->style;
2043
2044        struct diff_options *opt = diff_words->opt;
2045        const char *line_prefix;
2046
2047        assert(opt);
2048        line_prefix = diff_line_prefix(opt);
2049
2050        /* special case: only removal */
2051        if (!diff_words->plus.text.size) {
2052                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2053                                 line_prefix, strlen(line_prefix), 0);
2054                fn_out_diff_words_write_helper(diff_words->opt,
2055                        &style->old_word, style->newline,
2056                        diff_words->minus.text.size,
2057                        diff_words->minus.text.ptr);
2058                diff_words->minus.text.size = 0;
2059                return;
2060        }
2061
2062        diff_words->current_plus = diff_words->plus.text.ptr;
2063        diff_words->last_minus = 0;
2064
2065        memset(&xpp, 0, sizeof(xpp));
2066        memset(&xecfg, 0, sizeof(xecfg));
2067        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2068        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2069        xpp.flags = 0;
2070        /* as only the hunk header will be parsed, we need a 0-context */
2071        xecfg.ctxlen = 0;
2072        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2073                          &xpp, &xecfg))
2074                die("unable to generate word diff");
2075        free(minus.ptr);
2076        free(plus.ptr);
2077        if (diff_words->current_plus != diff_words->plus.text.ptr +
2078                        diff_words->plus.text.size) {
2079                if (color_words_output_graph_prefix(diff_words))
2080                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2081                                         line_prefix, strlen(line_prefix), 0);
2082                fn_out_diff_words_write_helper(diff_words->opt,
2083                        &style->ctx, style->newline,
2084                        diff_words->plus.text.ptr + diff_words->plus.text.size
2085                        - diff_words->current_plus, diff_words->current_plus);
2086        }
2087        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2088}
2089
2090/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2091static void diff_words_flush(struct emit_callback *ecbdata)
2092{
2093        struct diff_options *wo = ecbdata->diff_words->opt;
2094
2095        if (ecbdata->diff_words->minus.text.size ||
2096            ecbdata->diff_words->plus.text.size)
2097                diff_words_show(ecbdata->diff_words);
2098
2099        if (wo->emitted_symbols) {
2100                struct diff_options *o = ecbdata->opt;
2101                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2102                int i;
2103
2104                /*
2105                 * NEEDSWORK:
2106                 * Instead of appending each, concat all words to a line?
2107                 */
2108                for (i = 0; i < wol->nr; i++)
2109                        append_emitted_diff_symbol(o, &wol->buf[i]);
2110
2111                for (i = 0; i < wol->nr; i++)
2112                        free((void *)wol->buf[i].line);
2113
2114                wol->nr = 0;
2115        }
2116}
2117
2118static void diff_filespec_load_driver(struct diff_filespec *one)
2119{
2120        /* Use already-loaded driver */
2121        if (one->driver)
2122                return;
2123
2124        if (S_ISREG(one->mode))
2125                one->driver = userdiff_find_by_path(one->path);
2126
2127        /* Fallback to default settings */
2128        if (!one->driver)
2129                one->driver = userdiff_find_by_name("default");
2130}
2131
2132static const char *userdiff_word_regex(struct diff_filespec *one)
2133{
2134        diff_filespec_load_driver(one);
2135        return one->driver->word_regex;
2136}
2137
2138static void init_diff_words_data(struct emit_callback *ecbdata,
2139                                 struct diff_options *orig_opts,
2140                                 struct diff_filespec *one,
2141                                 struct diff_filespec *two)
2142{
2143        int i;
2144        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2145        memcpy(o, orig_opts, sizeof(struct diff_options));
2146
2147        ecbdata->diff_words =
2148                xcalloc(1, sizeof(struct diff_words_data));
2149        ecbdata->diff_words->type = o->word_diff;
2150        ecbdata->diff_words->opt = o;
2151
2152        if (orig_opts->emitted_symbols)
2153                o->emitted_symbols =
2154                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2155
2156        if (!o->word_regex)
2157                o->word_regex = userdiff_word_regex(one);
2158        if (!o->word_regex)
2159                o->word_regex = userdiff_word_regex(two);
2160        if (!o->word_regex)
2161                o->word_regex = diff_word_regex_cfg;
2162        if (o->word_regex) {
2163                ecbdata->diff_words->word_regex = (regex_t *)
2164                        xmalloc(sizeof(regex_t));
2165                if (regcomp(ecbdata->diff_words->word_regex,
2166                            o->word_regex,
2167                            REG_EXTENDED | REG_NEWLINE))
2168                        die("invalid regular expression: %s",
2169                            o->word_regex);
2170        }
2171        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2172                if (o->word_diff == diff_words_styles[i].type) {
2173                        ecbdata->diff_words->style =
2174                                &diff_words_styles[i];
2175                        break;
2176                }
2177        }
2178        if (want_color(o->use_color)) {
2179                struct diff_words_style *st = ecbdata->diff_words->style;
2180                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2181                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2182                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2183        }
2184}
2185
2186static void free_diff_words_data(struct emit_callback *ecbdata)
2187{
2188        if (ecbdata->diff_words) {
2189                diff_words_flush(ecbdata);
2190                free (ecbdata->diff_words->opt->emitted_symbols);
2191                free (ecbdata->diff_words->opt);
2192                free (ecbdata->diff_words->minus.text.ptr);
2193                free (ecbdata->diff_words->minus.orig);
2194                free (ecbdata->diff_words->plus.text.ptr);
2195                free (ecbdata->diff_words->plus.orig);
2196                if (ecbdata->diff_words->word_regex) {
2197                        regfree(ecbdata->diff_words->word_regex);
2198                        free(ecbdata->diff_words->word_regex);
2199                }
2200                FREE_AND_NULL(ecbdata->diff_words);
2201        }
2202}
2203
2204const char *diff_get_color(int diff_use_color, enum color_diff ix)
2205{
2206        if (want_color(diff_use_color))
2207                return diff_colors[ix];
2208        return "";
2209}
2210
2211const char *diff_line_prefix(struct diff_options *opt)
2212{
2213        struct strbuf *msgbuf;
2214        if (!opt->output_prefix)
2215                return "";
2216
2217        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2218        return msgbuf->buf;
2219}
2220
2221static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2222{
2223        const char *cp;
2224        unsigned long allot;
2225        size_t l = len;
2226
2227        cp = line;
2228        allot = l;
2229        while (0 < l) {
2230                (void) utf8_width(&cp, &l);
2231                if (!cp)
2232                        break; /* truncated in the middle? */
2233        }
2234        return allot - l;
2235}
2236
2237static void find_lno(const char *line, struct emit_callback *ecbdata)
2238{
2239        const char *p;
2240        ecbdata->lno_in_preimage = 0;
2241        ecbdata->lno_in_postimage = 0;
2242        p = strchr(line, '-');
2243        if (!p)
2244                return; /* cannot happen */
2245        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2246        p = strchr(p, '+');
2247        if (!p)
2248                return; /* cannot happen */
2249        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2250}
2251
2252static void fn_out_consume(void *priv, char *line, unsigned long len)
2253{
2254        struct emit_callback *ecbdata = priv;
2255        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2256        struct diff_options *o = ecbdata->opt;
2257
2258        o->found_changes = 1;
2259
2260        if (ecbdata->header) {
2261                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2262                                 ecbdata->header->buf, ecbdata->header->len, 0);
2263                strbuf_reset(ecbdata->header);
2264                ecbdata->header = NULL;
2265        }
2266
2267        if (ecbdata->label_path[0]) {
2268                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2269                                 ecbdata->label_path[0],
2270                                 strlen(ecbdata->label_path[0]), 0);
2271                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2272                                 ecbdata->label_path[1],
2273                                 strlen(ecbdata->label_path[1]), 0);
2274                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2275        }
2276
2277        if (diff_suppress_blank_empty
2278            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2279                line[0] = '\n';
2280                len = 1;
2281        }
2282
2283        if (line[0] == '@') {
2284                if (ecbdata->diff_words)
2285                        diff_words_flush(ecbdata);
2286                len = sane_truncate_line(ecbdata, line, len);
2287                find_lno(line, ecbdata);
2288                emit_hunk_header(ecbdata, line, len);
2289                return;
2290        }
2291
2292        if (ecbdata->diff_words) {
2293                enum diff_symbol s =
2294                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2295                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2296                if (line[0] == '-') {
2297                        diff_words_append(line, len,
2298                                          &ecbdata->diff_words->minus);
2299                        return;
2300                } else if (line[0] == '+') {
2301                        diff_words_append(line, len,
2302                                          &ecbdata->diff_words->plus);
2303                        return;
2304                } else if (starts_with(line, "\\ ")) {
2305                        /*
2306                         * Eat the "no newline at eof" marker as if we
2307                         * saw a "+" or "-" line with nothing on it,
2308                         * and return without diff_words_flush() to
2309                         * defer processing. If this is the end of
2310                         * preimage, more "+" lines may come after it.
2311                         */
2312                        return;
2313                }
2314                diff_words_flush(ecbdata);
2315                emit_diff_symbol(o, s, line, len, 0);
2316                return;
2317        }
2318
2319        switch (line[0]) {
2320        case '+':
2321                ecbdata->lno_in_postimage++;
2322                emit_add_line(reset, ecbdata, line + 1, len - 1);
2323                break;
2324        case '-':
2325                ecbdata->lno_in_preimage++;
2326                emit_del_line(reset, ecbdata, line + 1, len - 1);
2327                break;
2328        case ' ':
2329                ecbdata->lno_in_postimage++;
2330                ecbdata->lno_in_preimage++;
2331                emit_context_line(reset, ecbdata, line + 1, len - 1);
2332                break;
2333        default:
2334                /* incomplete line at the end */
2335                ecbdata->lno_in_preimage++;
2336                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2337                                 line, len, 0);
2338                break;
2339        }
2340}
2341
2342static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2343{
2344        const char *old_name = a;
2345        const char *new_name = b;
2346        int pfx_length, sfx_length;
2347        int pfx_adjust_for_slash;
2348        int len_a = strlen(a);
2349        int len_b = strlen(b);
2350        int a_midlen, b_midlen;
2351        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2352        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2353
2354        if (qlen_a || qlen_b) {
2355                quote_c_style(a, name, NULL, 0);
2356                strbuf_addstr(name, " => ");
2357                quote_c_style(b, name, NULL, 0);
2358                return;
2359        }
2360
2361        /* Find common prefix */
2362        pfx_length = 0;
2363        while (*old_name && *new_name && *old_name == *new_name) {
2364                if (*old_name == '/')
2365                        pfx_length = old_name - a + 1;
2366                old_name++;
2367                new_name++;
2368        }
2369
2370        /* Find common suffix */
2371        old_name = a + len_a;
2372        new_name = b + len_b;
2373        sfx_length = 0;
2374        /*
2375         * If there is a common prefix, it must end in a slash.  In
2376         * that case we let this loop run 1 into the prefix to see the
2377         * same slash.
2378         *
2379         * If there is no common prefix, we cannot do this as it would
2380         * underrun the input strings.
2381         */
2382        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2383        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2384               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2385               *old_name == *new_name) {
2386                if (*old_name == '/')
2387                        sfx_length = len_a - (old_name - a);
2388                old_name--;
2389                new_name--;
2390        }
2391
2392        /*
2393         * pfx{mid-a => mid-b}sfx
2394         * {pfx-a => pfx-b}sfx
2395         * pfx{sfx-a => sfx-b}
2396         * name-a => name-b
2397         */
2398        a_midlen = len_a - pfx_length - sfx_length;
2399        b_midlen = len_b - pfx_length - sfx_length;
2400        if (a_midlen < 0)
2401                a_midlen = 0;
2402        if (b_midlen < 0)
2403                b_midlen = 0;
2404
2405        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2406        if (pfx_length + sfx_length) {
2407                strbuf_add(name, a, pfx_length);
2408                strbuf_addch(name, '{');
2409        }
2410        strbuf_add(name, a + pfx_length, a_midlen);
2411        strbuf_addstr(name, " => ");
2412        strbuf_add(name, b + pfx_length, b_midlen);
2413        if (pfx_length + sfx_length) {
2414                strbuf_addch(name, '}');
2415                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2416        }
2417}
2418
2419struct diffstat_t {
2420        int nr;
2421        int alloc;
2422        struct diffstat_file {
2423                char *from_name;
2424                char *name;
2425                char *print_name;
2426                const char *comments;
2427                unsigned is_unmerged:1;
2428                unsigned is_binary:1;
2429                unsigned is_renamed:1;
2430                unsigned is_interesting:1;
2431                uintmax_t added, deleted;
2432        } **files;
2433};
2434
2435static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2436                                          const char *name_a,
2437                                          const char *name_b)
2438{
2439        struct diffstat_file *x;
2440        x = xcalloc(1, sizeof(*x));
2441        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2442        diffstat->files[diffstat->nr++] = x;
2443        if (name_b) {
2444                x->from_name = xstrdup(name_a);
2445                x->name = xstrdup(name_b);
2446                x->is_renamed = 1;
2447        }
2448        else {
2449                x->from_name = NULL;
2450                x->name = xstrdup(name_a);
2451        }
2452        return x;
2453}
2454
2455static void diffstat_consume(void *priv, char *line, unsigned long len)
2456{
2457        struct diffstat_t *diffstat = priv;
2458        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2459
2460        if (line[0] == '+')
2461                x->added++;
2462        else if (line[0] == '-')
2463                x->deleted++;
2464}
2465
2466const char mime_boundary_leader[] = "------------";
2467
2468static int scale_linear(int it, int width, int max_change)
2469{
2470        if (!it)
2471                return 0;
2472        /*
2473         * make sure that at least one '-' or '+' is printed if
2474         * there is any change to this path. The easiest way is to
2475         * scale linearly as if the alloted width is one column shorter
2476         * than it is, and then add 1 to the result.
2477         */
2478        return 1 + (it * (width - 1) / max_change);
2479}
2480
2481static void show_graph(struct strbuf *out, char ch, int cnt,
2482                       const char *set, const char *reset)
2483{
2484        if (cnt <= 0)
2485                return;
2486        strbuf_addstr(out, set);
2487        strbuf_addchars(out, ch, cnt);
2488        strbuf_addstr(out, reset);
2489}
2490
2491static void fill_print_name(struct diffstat_file *file)
2492{
2493        struct strbuf pname = STRBUF_INIT;
2494
2495        if (file->print_name)
2496                return;
2497
2498        if (file->is_renamed)
2499                pprint_rename(&pname, file->from_name, file->name);
2500        else
2501                quote_c_style(file->name, &pname, NULL, 0);
2502
2503        if (file->comments)
2504                strbuf_addf(&pname, " (%s)", file->comments);
2505
2506        file->print_name = strbuf_detach(&pname, NULL);
2507}
2508
2509static void print_stat_summary_inserts_deletes(struct diff_options *options,
2510                int files, int insertions, int deletions)
2511{
2512        struct strbuf sb = STRBUF_INIT;
2513
2514        if (!files) {
2515                assert(insertions == 0 && deletions == 0);
2516                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2517                                 NULL, 0, 0);
2518                return;
2519        }
2520
2521        strbuf_addf(&sb,
2522                    (files == 1) ? " %d file changed" : " %d files changed",
2523                    files);
2524
2525        /*
2526         * For binary diff, the caller may want to print "x files
2527         * changed" with insertions == 0 && deletions == 0.
2528         *
2529         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2530         * is probably less confusing (i.e skip over "2 files changed
2531         * but nothing about added/removed lines? Is this a bug in Git?").
2532         */
2533        if (insertions || deletions == 0) {
2534                strbuf_addf(&sb,
2535                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2536                            insertions);
2537        }
2538
2539        if (deletions || insertions == 0) {
2540                strbuf_addf(&sb,
2541                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2542                            deletions);
2543        }
2544        strbuf_addch(&sb, '\n');
2545        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2546                         sb.buf, sb.len, 0);
2547        strbuf_release(&sb);
2548}
2549
2550void print_stat_summary(FILE *fp, int files,
2551                        int insertions, int deletions)
2552{
2553        struct diff_options o;
2554        memset(&o, 0, sizeof(o));
2555        o.file = fp;
2556
2557        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2558}
2559
2560static void show_stats(struct diffstat_t *data, struct diff_options *options)
2561{
2562        int i, len, add, del, adds = 0, dels = 0;
2563        uintmax_t max_change = 0, max_len = 0;
2564        int total_files = data->nr, count;
2565        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2566        const char *reset, *add_c, *del_c;
2567        int extra_shown = 0;
2568        const char *line_prefix = diff_line_prefix(options);
2569        struct strbuf out = STRBUF_INIT;
2570
2571        if (data->nr == 0)
2572                return;
2573
2574        count = options->stat_count ? options->stat_count : data->nr;
2575
2576        reset = diff_get_color_opt(options, DIFF_RESET);
2577        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2578        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2579
2580        /*
2581         * Find the longest filename and max number of changes
2582         */
2583        for (i = 0; (i < count) && (i < data->nr); i++) {
2584                struct diffstat_file *file = data->files[i];
2585                uintmax_t change = file->added + file->deleted;
2586
2587                if (!file->is_interesting && (change == 0)) {
2588                        count++; /* not shown == room for one more */
2589                        continue;
2590                }
2591                fill_print_name(file);
2592                len = strlen(file->print_name);
2593                if (max_len < len)
2594                        max_len = len;
2595
2596                if (file->is_unmerged) {
2597                        /* "Unmerged" is 8 characters */
2598                        bin_width = bin_width < 8 ? 8 : bin_width;
2599                        continue;
2600                }
2601                if (file->is_binary) {
2602                        /* "Bin XXX -> YYY bytes" */
2603                        int w = 14 + decimal_width(file->added)
2604                                + decimal_width(file->deleted);
2605                        bin_width = bin_width < w ? w : bin_width;
2606                        /* Display change counts aligned with "Bin" */
2607                        number_width = 3;
2608                        continue;
2609                }
2610
2611                if (max_change < change)
2612                        max_change = change;
2613        }
2614        count = i; /* where we can stop scanning in data->files[] */
2615
2616        /*
2617         * We have width = stat_width or term_columns() columns total.
2618         * We want a maximum of min(max_len, stat_name_width) for the name part.
2619         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2620         * We also need 1 for " " and 4 + decimal_width(max_change)
2621         * for " | NNNN " and one the empty column at the end, altogether
2622         * 6 + decimal_width(max_change).
2623         *
2624         * If there's not enough space, we will use the smaller of
2625         * stat_name_width (if set) and 5/8*width for the filename,
2626         * and the rest for constant elements + graph part, but no more
2627         * than stat_graph_width for the graph part.
2628         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2629         * for the standard terminal size).
2630         *
2631         * In other words: stat_width limits the maximum width, and
2632         * stat_name_width fixes the maximum width of the filename,
2633         * and is also used to divide available columns if there
2634         * aren't enough.
2635         *
2636         * Binary files are displayed with "Bin XXX -> YYY bytes"
2637         * instead of the change count and graph. This part is treated
2638         * similarly to the graph part, except that it is not
2639         * "scaled". If total width is too small to accommodate the
2640         * guaranteed minimum width of the filename part and the
2641         * separators and this message, this message will "overflow"
2642         * making the line longer than the maximum width.
2643         */
2644
2645        if (options->stat_width == -1)
2646                width = term_columns() - strlen(line_prefix);
2647        else
2648                width = options->stat_width ? options->stat_width : 80;
2649        number_width = decimal_width(max_change) > number_width ?
2650                decimal_width(max_change) : number_width;
2651
2652        if (options->stat_graph_width == -1)
2653                options->stat_graph_width = diff_stat_graph_width;
2654
2655        /*
2656         * Guarantee 3/8*16==6 for the graph part
2657         * and 5/8*16==10 for the filename part
2658         */
2659        if (width < 16 + 6 + number_width)
2660                width = 16 + 6 + number_width;
2661
2662        /*
2663         * First assign sizes that are wanted, ignoring available width.
2664         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2665         * starting from "XXX" should fit in graph_width.
2666         */
2667        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2668        if (options->stat_graph_width &&
2669            options->stat_graph_width < graph_width)
2670                graph_width = options->stat_graph_width;
2671
2672        name_width = (options->stat_name_width > 0 &&
2673                      options->stat_name_width < max_len) ?
2674                options->stat_name_width : max_len;
2675
2676        /*
2677         * Adjust adjustable widths not to exceed maximum width
2678         */
2679        if (name_width + number_width + 6 + graph_width > width) {
2680                if (graph_width > width * 3/8 - number_width - 6) {
2681                        graph_width = width * 3/8 - number_width - 6;
2682                        if (graph_width < 6)
2683                                graph_width = 6;
2684                }
2685
2686                if (options->stat_graph_width &&
2687                    graph_width > options->stat_graph_width)
2688                        graph_width = options->stat_graph_width;
2689                if (name_width > width - number_width - 6 - graph_width)
2690                        name_width = width - number_width - 6 - graph_width;
2691                else
2692                        graph_width = width - number_width - 6 - name_width;
2693        }
2694
2695        /*
2696         * From here name_width is the width of the name area,
2697         * and graph_width is the width of the graph area.
2698         * max_change is used to scale graph properly.
2699         */
2700        for (i = 0; i < count; i++) {
2701                const char *prefix = "";
2702                struct diffstat_file *file = data->files[i];
2703                char *name = file->print_name;
2704                uintmax_t added = file->added;
2705                uintmax_t deleted = file->deleted;
2706                int name_len;
2707
2708                if (!file->is_interesting && (added + deleted == 0))
2709                        continue;
2710
2711                /*
2712                 * "scale" the filename
2713                 */
2714                len = name_width;
2715                name_len = strlen(name);
2716                if (name_width < name_len) {
2717                        char *slash;
2718                        prefix = "...";
2719                        len -= 3;
2720                        name += name_len - len;
2721                        slash = strchr(name, '/');
2722                        if (slash)
2723                                name = slash;
2724                }
2725
2726                if (file->is_binary) {
2727                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2728                        strbuf_addf(&out, " %*s", number_width, "Bin");
2729                        if (!added && !deleted) {
2730                                strbuf_addch(&out, '\n');
2731                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2732                                                 out.buf, out.len, 0);
2733                                strbuf_reset(&out);
2734                                continue;
2735                        }
2736                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2737                                del_c, deleted, reset);
2738                        strbuf_addstr(&out, " -> ");
2739                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2740                                add_c, added, reset);
2741                        strbuf_addstr(&out, " bytes\n");
2742                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2743                                         out.buf, out.len, 0);
2744                        strbuf_reset(&out);
2745                        continue;
2746                }
2747                else if (file->is_unmerged) {
2748                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2749                        strbuf_addstr(&out, " Unmerged\n");
2750                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2751                                         out.buf, out.len, 0);
2752                        strbuf_reset(&out);
2753                        continue;
2754                }
2755
2756                /*
2757                 * scale the add/delete
2758                 */
2759                add = added;
2760                del = deleted;
2761
2762                if (graph_width <= max_change) {
2763                        int total = scale_linear(add + del, graph_width, max_change);
2764                        if (total < 2 && add && del)
2765                                /* width >= 2 due to the sanity check */
2766                                total = 2;
2767                        if (add < del) {
2768                                add = scale_linear(add, graph_width, max_change);
2769                                del = total - add;
2770                        } else {
2771                                del = scale_linear(del, graph_width, max_change);
2772                                add = total - del;
2773                        }
2774                }
2775                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2776                strbuf_addf(&out, " %*"PRIuMAX"%s",
2777                        number_width, added + deleted,
2778                        added + deleted ? " " : "");
2779                show_graph(&out, '+', add, add_c, reset);
2780                show_graph(&out, '-', del, del_c, reset);
2781                strbuf_addch(&out, '\n');
2782                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2783                                 out.buf, out.len, 0);
2784                strbuf_reset(&out);
2785        }
2786
2787        for (i = 0; i < data->nr; i++) {
2788                struct diffstat_file *file = data->files[i];
2789                uintmax_t added = file->added;
2790                uintmax_t deleted = file->deleted;
2791
2792                if (file->is_unmerged ||
2793                    (!file->is_interesting && (added + deleted == 0))) {
2794                        total_files--;
2795                        continue;
2796                }
2797
2798                if (!file->is_binary) {
2799                        adds += added;
2800                        dels += deleted;
2801                }
2802                if (i < count)
2803                        continue;
2804                if (!extra_shown)
2805                        emit_diff_symbol(options,
2806                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2807                                         NULL, 0, 0);
2808                extra_shown = 1;
2809        }
2810
2811        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2812        strbuf_release(&out);
2813}
2814
2815static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2816{
2817        int i, adds = 0, dels = 0, total_files = data->nr;
2818
2819        if (data->nr == 0)
2820                return;
2821
2822        for (i = 0; i < data->nr; i++) {
2823                int added = data->files[i]->added;
2824                int deleted = data->files[i]->deleted;
2825
2826                if (data->files[i]->is_unmerged ||
2827                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2828                        total_files--;
2829                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2830                        adds += added;
2831                        dels += deleted;
2832                }
2833        }
2834        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2835}
2836
2837static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2838{
2839        int i;
2840
2841        if (data->nr == 0)
2842                return;
2843
2844        for (i = 0; i < data->nr; i++) {
2845                struct diffstat_file *file = data->files[i];
2846
2847                fprintf(options->file, "%s", diff_line_prefix(options));
2848
2849                if (file->is_binary)
2850                        fprintf(options->file, "-\t-\t");
2851                else
2852                        fprintf(options->file,
2853                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2854                                file->added, file->deleted);
2855                if (options->line_termination) {
2856                        fill_print_name(file);
2857                        if (!file->is_renamed)
2858                                write_name_quoted(file->name, options->file,
2859                                                  options->line_termination);
2860                        else {
2861                                fputs(file->print_name, options->file);
2862                                putc(options->line_termination, options->file);
2863                        }
2864                } else {
2865                        if (file->is_renamed) {
2866                                putc('\0', options->file);
2867                                write_name_quoted(file->from_name, options->file, '\0');
2868                        }
2869                        write_name_quoted(file->name, options->file, '\0');
2870                }
2871        }
2872}
2873
2874struct dirstat_file {
2875        const char *name;
2876        unsigned long changed;
2877};
2878
2879struct dirstat_dir {
2880        struct dirstat_file *files;
2881        int alloc, nr, permille, cumulative;
2882};
2883
2884static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2885                unsigned long changed, const char *base, int baselen)
2886{
2887        unsigned long sum_changes = 0;
2888        unsigned int sources = 0;
2889        const char *line_prefix = diff_line_prefix(opt);
2890
2891        while (dir->nr) {
2892                struct dirstat_file *f = dir->files;
2893                int namelen = strlen(f->name);
2894                unsigned long changes;
2895                char *slash;
2896
2897                if (namelen < baselen)
2898                        break;
2899                if (memcmp(f->name, base, baselen))
2900                        break;
2901                slash = strchr(f->name + baselen, '/');
2902                if (slash) {
2903                        int newbaselen = slash + 1 - f->name;
2904                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2905                        sources++;
2906                } else {
2907                        changes = f->changed;
2908                        dir->files++;
2909                        dir->nr--;
2910                        sources += 2;
2911                }
2912                sum_changes += changes;
2913        }
2914
2915        /*
2916         * We don't report dirstat's for
2917         *  - the top level
2918         *  - or cases where everything came from a single directory
2919         *    under this directory (sources == 1).
2920         */
2921        if (baselen && sources != 1) {
2922                if (sum_changes) {
2923                        int permille = sum_changes * 1000 / changed;
2924                        if (permille >= dir->permille) {
2925                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2926                                        permille / 10, permille % 10, baselen, base);
2927                                if (!dir->cumulative)
2928                                        return 0;
2929                        }
2930                }
2931        }
2932        return sum_changes;
2933}
2934
2935static int dirstat_compare(const void *_a, const void *_b)
2936{
2937        const struct dirstat_file *a = _a;
2938        const struct dirstat_file *b = _b;
2939        return strcmp(a->name, b->name);
2940}
2941
2942static void show_dirstat(struct diff_options *options)
2943{
2944        int i;
2945        unsigned long changed;
2946        struct dirstat_dir dir;
2947        struct diff_queue_struct *q = &diff_queued_diff;
2948
2949        dir.files = NULL;
2950        dir.alloc = 0;
2951        dir.nr = 0;
2952        dir.permille = options->dirstat_permille;
2953        dir.cumulative = options->flags.dirstat_cumulative;
2954
2955        changed = 0;
2956        for (i = 0; i < q->nr; i++) {
2957                struct diff_filepair *p = q->queue[i];
2958                const char *name;
2959                unsigned long copied, added, damage;
2960
2961                name = p->two->path ? p->two->path : p->one->path;
2962
2963                if (p->one->oid_valid && p->two->oid_valid &&
2964                    oideq(&p->one->oid, &p->two->oid)) {
2965                        /*
2966                         * The SHA1 has not changed, so pre-/post-content is
2967                         * identical. We can therefore skip looking at the
2968                         * file contents altogether.
2969                         */
2970                        damage = 0;
2971                        goto found_damage;
2972                }
2973
2974                if (options->flags.dirstat_by_file) {
2975                        /*
2976                         * In --dirstat-by-file mode, we don't really need to
2977                         * look at the actual file contents at all.
2978                         * The fact that the SHA1 changed is enough for us to
2979                         * add this file to the list of results
2980                         * (with each file contributing equal damage).
2981                         */
2982                        damage = 1;
2983                        goto found_damage;
2984                }
2985
2986                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2987                        diff_populate_filespec(p->one, 0);
2988                        diff_populate_filespec(p->two, 0);
2989                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2990                                               &copied, &added);
2991                        diff_free_filespec_data(p->one);
2992                        diff_free_filespec_data(p->two);
2993                } else if (DIFF_FILE_VALID(p->one)) {
2994                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2995                        copied = added = 0;
2996                        diff_free_filespec_data(p->one);
2997                } else if (DIFF_FILE_VALID(p->two)) {
2998                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2999                        copied = 0;
3000                        added = p->two->size;
3001                        diff_free_filespec_data(p->two);
3002                } else
3003                        continue;
3004
3005                /*
3006                 * Original minus copied is the removed material,
3007                 * added is the new material.  They are both damages
3008                 * made to the preimage.
3009                 * If the resulting damage is zero, we know that
3010                 * diffcore_count_changes() considers the two entries to
3011                 * be identical, but since the oid changed, we
3012                 * know that there must have been _some_ kind of change,
3013                 * so we force all entries to have damage > 0.
3014                 */
3015                damage = (p->one->size - copied) + added;
3016                if (!damage)
3017                        damage = 1;
3018
3019found_damage:
3020                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3021                dir.files[dir.nr].name = name;
3022                dir.files[dir.nr].changed = damage;
3023                changed += damage;
3024                dir.nr++;
3025        }
3026
3027        /* This can happen even with many files, if everything was renames */
3028        if (!changed)
3029                return;
3030
3031        /* Show all directories with more than x% of the changes */
3032        QSORT(dir.files, dir.nr, dirstat_compare);
3033        gather_dirstat(options, &dir, changed, "", 0);
3034}
3035
3036static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3037{
3038        int i;
3039        unsigned long changed;
3040        struct dirstat_dir dir;
3041
3042        if (data->nr == 0)
3043                return;
3044
3045        dir.files = NULL;
3046        dir.alloc = 0;
3047        dir.nr = 0;
3048        dir.permille = options->dirstat_permille;
3049        dir.cumulative = options->flags.dirstat_cumulative;
3050
3051        changed = 0;
3052        for (i = 0; i < data->nr; i++) {
3053                struct diffstat_file *file = data->files[i];
3054                unsigned long damage = file->added + file->deleted;
3055                if (file->is_binary)
3056                        /*
3057                         * binary files counts bytes, not lines. Must find some
3058                         * way to normalize binary bytes vs. textual lines.
3059                         * The following heuristic assumes that there are 64
3060                         * bytes per "line".
3061                         * This is stupid and ugly, but very cheap...
3062                         */
3063                        damage = DIV_ROUND_UP(damage, 64);
3064                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3065                dir.files[dir.nr].name = file->name;
3066                dir.files[dir.nr].changed = damage;
3067                changed += damage;
3068                dir.nr++;
3069        }
3070
3071        /* This can happen even with many files, if everything was renames */
3072        if (!changed)
3073                return;
3074
3075        /* Show all directories with more than x% of the changes */
3076        QSORT(dir.files, dir.nr, dirstat_compare);
3077        gather_dirstat(options, &dir, changed, "", 0);
3078}
3079
3080static void free_diffstat_info(struct diffstat_t *diffstat)
3081{
3082        int i;
3083        for (i = 0; i < diffstat->nr; i++) {
3084                struct diffstat_file *f = diffstat->files[i];
3085                free(f->print_name);
3086                free(f->name);
3087                free(f->from_name);
3088                free(f);
3089        }
3090        free(diffstat->files);
3091}
3092
3093struct checkdiff_t {
3094        const char *filename;
3095        int lineno;
3096        int conflict_marker_size;
3097        struct diff_options *o;
3098        unsigned ws_rule;
3099        unsigned status;
3100};
3101
3102static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3103{
3104        char firstchar;
3105        int cnt;
3106
3107        if (len < marker_size + 1)
3108                return 0;
3109        firstchar = line[0];
3110        switch (firstchar) {
3111        case '=': case '>': case '<': case '|':
3112                break;
3113        default:
3114                return 0;
3115        }
3116        for (cnt = 1; cnt < marker_size; cnt++)
3117                if (line[cnt] != firstchar)
3118                        return 0;
3119        /* line[1] thru line[marker_size-1] are same as firstchar */
3120        if (len < marker_size + 1 || !isspace(line[marker_size]))
3121                return 0;
3122        return 1;
3123}
3124
3125static void checkdiff_consume(void *priv, char *line, unsigned long len)
3126{
3127        struct checkdiff_t *data = priv;
3128        int marker_size = data->conflict_marker_size;
3129        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3130        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3131        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3132        char *err;
3133        const char *line_prefix;
3134
3135        assert(data->o);
3136        line_prefix = diff_line_prefix(data->o);
3137
3138        if (line[0] == '+') {
3139                unsigned bad;
3140                data->lineno++;
3141                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3142                        data->status |= 1;
3143                        fprintf(data->o->file,
3144                                "%s%s:%d: leftover conflict marker\n",
3145                                line_prefix, data->filename, data->lineno);
3146                }
3147                bad = ws_check(line + 1, len - 1, data->ws_rule);
3148                if (!bad)
3149                        return;
3150                data->status |= bad;
3151                err = whitespace_error_string(bad);
3152                fprintf(data->o->file, "%s%s:%d: %s.\n",
3153                        line_prefix, data->filename, data->lineno, err);
3154                free(err);
3155                emit_line(data->o, set, reset, line, 1);
3156                ws_check_emit(line + 1, len - 1, data->ws_rule,
3157                              data->o->file, set, reset, ws);
3158        } else if (line[0] == ' ') {
3159                data->lineno++;
3160        } else if (line[0] == '@') {
3161                char *plus = strchr(line, '+');
3162                if (plus)
3163                        data->lineno = strtol(plus, NULL, 10) - 1;
3164                else
3165                        die("invalid diff");
3166        }
3167}
3168
3169static unsigned char *deflate_it(char *data,
3170                                 unsigned long size,
3171                                 unsigned long *result_size)
3172{
3173        int bound;
3174        unsigned char *deflated;
3175        git_zstream stream;
3176
3177        git_deflate_init(&stream, zlib_compression_level);
3178        bound = git_deflate_bound(&stream, size);
3179        deflated = xmalloc(bound);
3180        stream.next_out = deflated;
3181        stream.avail_out = bound;
3182
3183        stream.next_in = (unsigned char *)data;
3184        stream.avail_in = size;
3185        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3186                ; /* nothing */
3187        git_deflate_end(&stream);
3188        *result_size = stream.total_out;
3189        return deflated;
3190}
3191
3192static void emit_binary_diff_body(struct diff_options *o,
3193                                  mmfile_t *one, mmfile_t *two)
3194{
3195        void *cp;
3196        void *delta;
3197        void *deflated;
3198        void *data;
3199        unsigned long orig_size;
3200        unsigned long delta_size;
3201        unsigned long deflate_size;
3202        unsigned long data_size;
3203
3204        /* We could do deflated delta, or we could do just deflated two,
3205         * whichever is smaller.
3206         */
3207        delta = NULL;
3208        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3209        if (one->size && two->size) {
3210                delta = diff_delta(one->ptr, one->size,
3211                                   two->ptr, two->size,
3212                                   &delta_size, deflate_size);
3213                if (delta) {
3214                        void *to_free = delta;
3215                        orig_size = delta_size;
3216                        delta = deflate_it(delta, delta_size, &delta_size);
3217                        free(to_free);
3218                }
3219        }
3220
3221        if (delta && delta_size < deflate_size) {
3222                char *s = xstrfmt("%lu", orig_size);
3223                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3224                                 s, strlen(s), 0);
3225                free(s);
3226                free(deflated);
3227                data = delta;
3228                data_size = delta_size;
3229        } else {
3230                char *s = xstrfmt("%lu", two->size);
3231                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3232                                 s, strlen(s), 0);
3233                free(s);
3234                free(delta);
3235                data = deflated;
3236                data_size = deflate_size;
3237        }
3238
3239        /* emit data encoded in base85 */
3240        cp = data;
3241        while (data_size) {
3242                int len;
3243                int bytes = (52 < data_size) ? 52 : data_size;
3244                char line[71];
3245                data_size -= bytes;
3246                if (bytes <= 26)
3247                        line[0] = bytes + 'A' - 1;
3248                else
3249                        line[0] = bytes - 26 + 'a' - 1;
3250                encode_85(line + 1, cp, bytes);
3251                cp = (char *) cp + bytes;
3252
3253                len = strlen(line);
3254                line[len++] = '\n';
3255                line[len] = '\0';
3256
3257                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3258                                 line, len, 0);
3259        }
3260        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3261        free(data);
3262}
3263
3264static void emit_binary_diff(struct diff_options *o,
3265                             mmfile_t *one, mmfile_t *two)
3266{
3267        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3268        emit_binary_diff_body(o, one, two);
3269        emit_binary_diff_body(o, two, one);
3270}
3271
3272int diff_filespec_is_binary(struct diff_filespec *one)
3273{
3274        if (one->is_binary == -1) {
3275                diff_filespec_load_driver(one);
3276                if (one->driver->binary != -1)
3277                        one->is_binary = one->driver->binary;
3278                else {
3279                        if (!one->data && DIFF_FILE_VALID(one))
3280                                diff_populate_filespec(one, CHECK_BINARY);
3281                        if (one->is_binary == -1 && one->data)
3282                                one->is_binary = buffer_is_binary(one->data,
3283                                                one->size);
3284                        if (one->is_binary == -1)
3285                                one->is_binary = 0;
3286                }
3287        }
3288        return one->is_binary;
3289}
3290
3291static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3292{
3293        diff_filespec_load_driver(one);
3294        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3295}
3296
3297void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3298{
3299        if (!options->a_prefix)
3300                options->a_prefix = a;
3301        if (!options->b_prefix)
3302                options->b_prefix = b;
3303}
3304
3305struct userdiff_driver *get_textconv(struct diff_filespec *one)
3306{
3307        if (!DIFF_FILE_VALID(one))
3308                return NULL;
3309
3310        diff_filespec_load_driver(one);
3311        return userdiff_get_textconv(one->driver);
3312}
3313
3314static void builtin_diff(const char *name_a,
3315                         const char *name_b,
3316                         struct diff_filespec *one,
3317                         struct diff_filespec *two,
3318                         const char *xfrm_msg,
3319                         int must_show_header,
3320                         struct diff_options *o,
3321                         int complete_rewrite)
3322{
3323        mmfile_t mf1, mf2;
3324        const char *lbl[2];
3325        char *a_one, *b_two;
3326        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3327        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3328        const char *a_prefix, *b_prefix;
3329        struct userdiff_driver *textconv_one = NULL;
3330        struct userdiff_driver *textconv_two = NULL;
3331        struct strbuf header = STRBUF_INIT;
3332        const char *line_prefix = diff_line_prefix(o);
3333
3334        diff_set_mnemonic_prefix(o, "a/", "b/");
3335        if (o->flags.reverse_diff) {
3336                a_prefix = o->b_prefix;
3337                b_prefix = o->a_prefix;
3338        } else {
3339                a_prefix = o->a_prefix;
3340                b_prefix = o->b_prefix;
3341        }
3342
3343        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3344            (!one->mode || S_ISGITLINK(one->mode)) &&
3345            (!two->mode || S_ISGITLINK(two->mode))) {
3346                show_submodule_summary(o, one->path ? one->path : two->path,
3347                                &one->oid, &two->oid,
3348                                two->dirty_submodule);
3349                return;
3350        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3351                   (!one->mode || S_ISGITLINK(one->mode)) &&
3352                   (!two->mode || S_ISGITLINK(two->mode))) {
3353                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3354                                &one->oid, &two->oid,
3355                                two->dirty_submodule);
3356                return;
3357        }
3358
3359        if (o->flags.allow_textconv) {
3360                textconv_one = get_textconv(one);
3361                textconv_two = get_textconv(two);
3362        }
3363
3364        /* Never use a non-valid filename anywhere if at all possible */
3365        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3366        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3367
3368        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3369        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3370        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3371        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3372        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3373        if (lbl[0][0] == '/') {
3374                /* /dev/null */
3375                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3376                if (xfrm_msg)
3377                        strbuf_addstr(&header, xfrm_msg);
3378                must_show_header = 1;
3379        }
3380        else if (lbl[1][0] == '/') {
3381                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3382                if (xfrm_msg)
3383                        strbuf_addstr(&header, xfrm_msg);
3384                must_show_header = 1;
3385        }
3386        else {
3387                if (one->mode != two->mode) {
3388                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3389                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3390                        must_show_header = 1;
3391                }
3392                if (xfrm_msg)
3393                        strbuf_addstr(&header, xfrm_msg);
3394
3395                /*
3396                 * we do not run diff between different kind
3397                 * of objects.
3398                 */
3399                if ((one->mode ^ two->mode) & S_IFMT)
3400                        goto free_ab_and_return;
3401                if (complete_rewrite &&
3402                    (textconv_one || !diff_filespec_is_binary(one)) &&
3403                    (textconv_two || !diff_filespec_is_binary(two))) {
3404                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3405                                         header.buf, header.len, 0);
3406                        strbuf_reset(&header);
3407                        emit_rewrite_diff(name_a, name_b, one, two,
3408                                                textconv_one, textconv_two, o);
3409                        o->found_changes = 1;
3410                        goto free_ab_and_return;
3411                }
3412        }
3413
3414        if (o->irreversible_delete && lbl[1][0] == '/') {
3415                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3416                                 header.len, 0);
3417                strbuf_reset(&header);
3418                goto free_ab_and_return;
3419        } else if (!o->flags.text &&
3420            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3421              (!textconv_two && diff_filespec_is_binary(two)) )) {
3422                struct strbuf sb = STRBUF_INIT;
3423                if (!one->data && !two->data &&
3424                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3425                    !o->flags.binary) {
3426                        if (oideq(&one->oid, &two->oid)) {
3427                                if (must_show_header)
3428                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3429                                                         header.buf, header.len,
3430                                                         0);
3431                                goto free_ab_and_return;
3432                        }
3433                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3434                                         header.buf, header.len, 0);
3435                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3436                                    diff_line_prefix(o), lbl[0], lbl[1]);
3437                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3438                                         sb.buf, sb.len, 0);
3439                        strbuf_release(&sb);
3440                        goto free_ab_and_return;
3441                }
3442                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3443                        die("unable to read files to diff");
3444                /* Quite common confusing case */
3445                if (mf1.size == mf2.size &&
3446                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3447                        if (must_show_header)
3448                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3449                                                 header.buf, header.len, 0);
3450                        goto free_ab_and_return;
3451                }
3452                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3453                strbuf_reset(&header);
3454                if (o->flags.binary)
3455                        emit_binary_diff(o, &mf1, &mf2);
3456                else {
3457                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3458                                    diff_line_prefix(o), lbl[0], lbl[1]);
3459                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3460                                         sb.buf, sb.len, 0);
3461                        strbuf_release(&sb);
3462                }
3463                o->found_changes = 1;
3464        } else {
3465                /* Crazy xdl interfaces.. */
3466                const char *diffopts = getenv("GIT_DIFF_OPTS");
3467                const char *v;
3468                xpparam_t xpp;
3469                xdemitconf_t xecfg;
3470                struct emit_callback ecbdata;
3471                const struct userdiff_funcname *pe;
3472
3473                if (must_show_header) {
3474                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3475                                         header.buf, header.len, 0);
3476                        strbuf_reset(&header);
3477                }
3478
3479                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3480                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3481
3482                pe = diff_funcname_pattern(one);
3483                if (!pe)
3484                        pe = diff_funcname_pattern(two);
3485
3486                memset(&xpp, 0, sizeof(xpp));
3487                memset(&xecfg, 0, sizeof(xecfg));
3488                memset(&ecbdata, 0, sizeof(ecbdata));
3489                if (o->flags.suppress_diff_headers)
3490                        lbl[0] = NULL;
3491                ecbdata.label_path = lbl;
3492                ecbdata.color_diff = want_color(o->use_color);
3493                ecbdata.ws_rule = whitespace_rule(name_b);
3494                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3495                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3496                ecbdata.opt = o;
3497                if (header.len && !o->flags.suppress_diff_headers)
3498                        ecbdata.header = &header;
3499                xpp.flags = o->xdl_opts;
3500                xpp.anchors = o->anchors;
3501                xpp.anchors_nr = o->anchors_nr;
3502                xecfg.ctxlen = o->context;
3503                xecfg.interhunkctxlen = o->interhunkcontext;
3504                xecfg.flags = XDL_EMIT_FUNCNAMES;
3505                if (o->flags.funccontext)
3506                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3507                if (pe)
3508                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3509                if (!diffopts)
3510                        ;
3511                else if (skip_prefix(diffopts, "--unified=", &v))
3512                        xecfg.ctxlen = strtoul(v, NULL, 10);
3513                else if (skip_prefix(diffopts, "-u", &v))
3514                        xecfg.ctxlen = strtoul(v, NULL, 10);
3515                if (o->word_diff)
3516                        init_diff_words_data(&ecbdata, o, one, two);
3517                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3518                                  &xpp, &xecfg))
3519                        die("unable to generate diff for %s", one->path);
3520                if (o->word_diff)
3521                        free_diff_words_data(&ecbdata);
3522                if (textconv_one)
3523                        free(mf1.ptr);
3524                if (textconv_two)
3525                        free(mf2.ptr);
3526                xdiff_clear_find_func(&xecfg);
3527        }
3528
3529 free_ab_and_return:
3530        strbuf_release(&header);
3531        diff_free_filespec_data(one);
3532        diff_free_filespec_data(two);
3533        free(a_one);
3534        free(b_two);
3535        return;
3536}
3537
3538static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3539{
3540        if (!is_renamed) {
3541                if (p->status == DIFF_STATUS_ADDED) {
3542                        if (S_ISLNK(p->two->mode))
3543                                return "new +l";
3544                        else if ((p->two->mode & 0777) == 0755)
3545                                return "new +x";
3546                        else
3547                                return "new";
3548                } else if (p->status == DIFF_STATUS_DELETED)
3549                        return "gone";
3550        }
3551        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3552                return "mode -l";
3553        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3554                return "mode +l";
3555        else if ((p->one->mode & 0777) == 0644 &&
3556                 (p->two->mode & 0777) == 0755)
3557                return "mode +x";
3558        else if ((p->one->mode & 0777) == 0755 &&
3559                 (p->two->mode & 0777) == 0644)
3560                return "mode -x";
3561        return NULL;
3562}
3563
3564static void builtin_diffstat(const char *name_a, const char *name_b,
3565                             struct diff_filespec *one,
3566                             struct diff_filespec *two,
3567                             struct diffstat_t *diffstat,
3568                             struct diff_options *o,
3569                             struct diff_filepair *p)
3570{
3571        mmfile_t mf1, mf2;
3572        struct diffstat_file *data;
3573        int same_contents;
3574        int complete_rewrite = 0;
3575
3576        if (!DIFF_PAIR_UNMERGED(p)) {
3577                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3578                        complete_rewrite = 1;
3579        }
3580
3581        data = diffstat_add(diffstat, name_a, name_b);
3582        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3583        if (o->flags.stat_with_summary)
3584                data->comments = get_compact_summary(p, data->is_renamed);
3585
3586        if (!one || !two) {
3587                data->is_unmerged = 1;
3588                return;
3589        }
3590
3591        same_contents = oideq(&one->oid, &two->oid);
3592
3593        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3594                data->is_binary = 1;
3595                if (same_contents) {
3596                        data->added = 0;
3597                        data->deleted = 0;
3598                } else {
3599                        data->added = diff_filespec_size(two);
3600                        data->deleted = diff_filespec_size(one);
3601                }
3602        }
3603
3604        else if (complete_rewrite) {
3605                diff_populate_filespec(one, 0);
3606                diff_populate_filespec(two, 0);
3607                data->deleted = count_lines(one->data, one->size);
3608                data->added = count_lines(two->data, two->size);
3609        }
3610
3611        else if (!same_contents) {
3612                /* Crazy xdl interfaces.. */
3613                xpparam_t xpp;
3614                xdemitconf_t xecfg;
3615
3616                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3617                        die("unable to read files to diff");
3618
3619                memset(&xpp, 0, sizeof(xpp));
3620                memset(&xecfg, 0, sizeof(xecfg));
3621                xpp.flags = o->xdl_opts;
3622                xpp.anchors = o->anchors;
3623                xpp.anchors_nr = o->anchors_nr;
3624                xecfg.ctxlen = o->context;
3625                xecfg.interhunkctxlen = o->interhunkcontext;
3626                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3627                                  &xpp, &xecfg))
3628                        die("unable to generate diffstat for %s", one->path);
3629        }
3630
3631        diff_free_filespec_data(one);
3632        diff_free_filespec_data(two);
3633}
3634
3635static void builtin_checkdiff(const char *name_a, const char *name_b,
3636                              const char *attr_path,
3637                              struct diff_filespec *one,
3638                              struct diff_filespec *two,
3639                              struct diff_options *o)
3640{
3641        mmfile_t mf1, mf2;
3642        struct checkdiff_t data;
3643
3644        if (!two)
3645                return;
3646
3647        memset(&data, 0, sizeof(data));
3648        data.filename = name_b ? name_b : name_a;
3649        data.lineno = 0;
3650        data.o = o;
3651        data.ws_rule = whitespace_rule(attr_path);
3652        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3653
3654        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3655                die("unable to read files to diff");
3656
3657        /*
3658         * All the other codepaths check both sides, but not checking
3659         * the "old" side here is deliberate.  We are checking the newly
3660         * introduced changes, and as long as the "new" side is text, we
3661         * can and should check what it introduces.
3662         */
3663        if (diff_filespec_is_binary(two))
3664                goto free_and_return;
3665        else {
3666                /* Crazy xdl interfaces.. */
3667                xpparam_t xpp;
3668                xdemitconf_t xecfg;
3669
3670                memset(&xpp, 0, sizeof(xpp));
3671                memset(&xecfg, 0, sizeof(xecfg));
3672                xecfg.ctxlen = 1; /* at least one context line */
3673                xpp.flags = 0;
3674                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3675                                  &xpp, &xecfg))
3676                        die("unable to generate checkdiff for %s", one->path);
3677
3678                if (data.ws_rule & WS_BLANK_AT_EOF) {
3679                        struct emit_callback ecbdata;
3680                        int blank_at_eof;
3681
3682                        ecbdata.ws_rule = data.ws_rule;
3683                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3684                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3685
3686                        if (blank_at_eof) {
3687                                static char *err;
3688                                if (!err)
3689                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3690                                fprintf(o->file, "%s:%d: %s.\n",
3691                                        data.filename, blank_at_eof, err);
3692                                data.status = 1; /* report errors */
3693                        }
3694                }
3695        }
3696 free_and_return:
3697        diff_free_filespec_data(one);
3698        diff_free_filespec_data(two);
3699        if (data.status)
3700                o->flags.check_failed = 1;
3701}
3702
3703struct diff_filespec *alloc_filespec(const char *path)
3704{
3705        struct diff_filespec *spec;
3706
3707        FLEXPTR_ALLOC_STR(spec, path, path);
3708        spec->count = 1;
3709        spec->is_binary = -1;
3710        return spec;
3711}
3712
3713void free_filespec(struct diff_filespec *spec)
3714{
3715        if (!--spec->count) {
3716                diff_free_filespec_data(spec);
3717                free(spec);
3718        }
3719}
3720
3721void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3722                   int oid_valid, unsigned short mode)
3723{
3724        if (mode) {
3725                spec->mode = canon_mode(mode);
3726                oidcpy(&spec->oid, oid);
3727                spec->oid_valid = oid_valid;
3728        }
3729}
3730
3731/*
3732 * Given a name and sha1 pair, if the index tells us the file in
3733 * the work tree has that object contents, return true, so that
3734 * prepare_temp_file() does not have to inflate and extract.
3735 */
3736static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3737{
3738        const struct cache_entry *ce;
3739        struct stat st;
3740        int pos, len;
3741
3742        /*
3743         * We do not read the cache ourselves here, because the
3744         * benchmark with my previous version that always reads cache
3745         * shows that it makes things worse for diff-tree comparing
3746         * two linux-2.6 kernel trees in an already checked out work
3747         * tree.  This is because most diff-tree comparisons deal with
3748         * only a small number of files, while reading the cache is
3749         * expensive for a large project, and its cost outweighs the
3750         * savings we get by not inflating the object to a temporary
3751         * file.  Practically, this code only helps when we are used
3752         * by diff-cache --cached, which does read the cache before
3753         * calling us.
3754         */
3755        if (!active_cache)
3756                return 0;
3757
3758        /* We want to avoid the working directory if our caller
3759         * doesn't need the data in a normal file, this system
3760         * is rather slow with its stat/open/mmap/close syscalls,
3761         * and the object is contained in a pack file.  The pack
3762         * is probably already open and will be faster to obtain
3763         * the data through than the working directory.  Loose
3764         * objects however would tend to be slower as they need
3765         * to be individually opened and inflated.
3766         */
3767        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3768                return 0;
3769
3770        /*
3771         * Similarly, if we'd have to convert the file contents anyway, that
3772         * makes the optimization not worthwhile.
3773         */
3774        if (!want_file && would_convert_to_git(&the_index, name))
3775                return 0;
3776
3777        len = strlen(name);
3778        pos = cache_name_pos(name, len);
3779        if (pos < 0)
3780                return 0;
3781        ce = active_cache[pos];
3782
3783        /*
3784         * This is not the sha1 we are looking for, or
3785         * unreusable because it is not a regular file.
3786         */
3787        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3788                return 0;
3789
3790        /*
3791         * If ce is marked as "assume unchanged", there is no
3792         * guarantee that work tree matches what we are looking for.
3793         */
3794        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3795                return 0;
3796
3797        /*
3798         * If ce matches the file in the work tree, we can reuse it.
3799         */
3800        if (ce_uptodate(ce) ||
3801            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3802                return 1;
3803
3804        return 0;
3805}
3806
3807static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3808{
3809        struct strbuf buf = STRBUF_INIT;
3810        char *dirty = "";
3811
3812        /* Are we looking at the work tree? */
3813        if (s->dirty_submodule)
3814                dirty = "-dirty";
3815
3816        strbuf_addf(&buf, "Subproject commit %s%s\n",
3817                    oid_to_hex(&s->oid), dirty);
3818        s->size = buf.len;
3819        if (size_only) {
3820                s->data = NULL;
3821                strbuf_release(&buf);
3822        } else {
3823                s->data = strbuf_detach(&buf, NULL);
3824                s->should_free = 1;
3825        }
3826        return 0;
3827}
3828
3829/*
3830 * While doing rename detection and pickaxe operation, we may need to
3831 * grab the data for the blob (or file) for our own in-core comparison.
3832 * diff_filespec has data and size fields for this purpose.
3833 */
3834int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3835{
3836        int size_only = flags & CHECK_SIZE_ONLY;
3837        int err = 0;
3838        int conv_flags = global_conv_flags_eol;
3839        /*
3840         * demote FAIL to WARN to allow inspecting the situation
3841         * instead of refusing.
3842         */
3843        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3844                conv_flags = CONV_EOL_RNDTRP_WARN;
3845
3846        if (!DIFF_FILE_VALID(s))
3847                die("internal error: asking to populate invalid file.");
3848        if (S_ISDIR(s->mode))
3849                return -1;
3850
3851        if (s->data)
3852                return 0;
3853
3854        if (size_only && 0 < s->size)
3855                return 0;
3856
3857        if (S_ISGITLINK(s->mode))
3858                return diff_populate_gitlink(s, size_only);
3859
3860        if (!s->oid_valid ||
3861            reuse_worktree_file(s->path, &s->oid, 0)) {
3862                struct strbuf buf = STRBUF_INIT;
3863                struct stat st;
3864                int fd;
3865
3866                if (lstat(s->path, &st) < 0) {
3867                err_empty:
3868                        err = -1;
3869                empty:
3870                        s->data = (char *)"";
3871                        s->size = 0;
3872                        return err;
3873                }
3874                s->size = xsize_t(st.st_size);
3875                if (!s->size)
3876                        goto empty;
3877                if (S_ISLNK(st.st_mode)) {
3878                        struct strbuf sb = STRBUF_INIT;
3879
3880                        if (strbuf_readlink(&sb, s->path, s->size))
3881                                goto err_empty;
3882                        s->size = sb.len;
3883                        s->data = strbuf_detach(&sb, NULL);
3884                        s->should_free = 1;
3885                        return 0;
3886                }
3887
3888                /*
3889                 * Even if the caller would be happy with getting
3890                 * only the size, we cannot return early at this
3891                 * point if the path requires us to run the content
3892                 * conversion.
3893                 */
3894                if (size_only && !would_convert_to_git(&the_index, s->path))
3895                        return 0;
3896
3897                /*
3898                 * Note: this check uses xsize_t(st.st_size) that may
3899                 * not be the true size of the blob after it goes
3900                 * through convert_to_git().  This may not strictly be
3901                 * correct, but the whole point of big_file_threshold
3902                 * and is_binary check being that we want to avoid
3903                 * opening the file and inspecting the contents, this
3904                 * is probably fine.
3905                 */
3906                if ((flags & CHECK_BINARY) &&
3907                    s->size > big_file_threshold && s->is_binary == -1) {
3908                        s->is_binary = 1;
3909                        return 0;
3910                }
3911                fd = open(s->path, O_RDONLY);
3912                if (fd < 0)
3913                        goto err_empty;
3914                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3915                close(fd);
3916                s->should_munmap = 1;
3917
3918                /*
3919                 * Convert from working tree format to canonical git format
3920                 */
3921                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3922                        size_t size = 0;
3923                        munmap(s->data, s->size);
3924                        s->should_munmap = 0;
3925                        s->data = strbuf_detach(&buf, &size);
3926                        s->size = size;
3927                        s->should_free = 1;
3928                }
3929        }
3930        else {
3931                enum object_type type;
3932                if (size_only || (flags & CHECK_BINARY)) {
3933                        type = oid_object_info(the_repository, &s->oid,
3934                                               &s->size);
3935                        if (type < 0)
3936                                die("unable to read %s",
3937                                    oid_to_hex(&s->oid));
3938                        if (size_only)
3939                                return 0;
3940                        if (s->size > big_file_threshold && s->is_binary == -1) {
3941                                s->is_binary = 1;
3942                                return 0;
3943                        }
3944                }
3945                s->data = read_object_file(&s->oid, &type, &s->size);
3946                if (!s->data)
3947                        die("unable to read %s", oid_to_hex(&s->oid));
3948                s->should_free = 1;
3949        }
3950        return 0;
3951}
3952
3953void diff_free_filespec_blob(struct diff_filespec *s)
3954{
3955        if (s->should_free)
3956                free(s->data);
3957        else if (s->should_munmap)
3958                munmap(s->data, s->size);
3959
3960        if (s->should_free || s->should_munmap) {
3961                s->should_free = s->should_munmap = 0;
3962                s->data = NULL;
3963        }
3964}
3965
3966void diff_free_filespec_data(struct diff_filespec *s)
3967{
3968        diff_free_filespec_blob(s);
3969        FREE_AND_NULL(s->cnt_data);
3970}
3971
3972static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3973                           void *blob,
3974                           unsigned long size,
3975                           const struct object_id *oid,
3976                           int mode)
3977{
3978        struct strbuf buf = STRBUF_INIT;
3979        struct strbuf tempfile = STRBUF_INIT;
3980        char *path_dup = xstrdup(path);
3981        const char *base = basename(path_dup);
3982
3983        /* Generate "XXXXXX_basename.ext" */
3984        strbuf_addstr(&tempfile, "XXXXXX_");
3985        strbuf_addstr(&tempfile, base);
3986
3987        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3988        if (!temp->tempfile)
3989                die_errno("unable to create temp-file");
3990        if (convert_to_working_tree(&the_index, path,
3991                        (const char *)blob, (size_t)size, &buf)) {
3992                blob = buf.buf;
3993                size = buf.len;
3994        }
3995        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3996            close_tempfile_gently(temp->tempfile))
3997                die_errno("unable to write temp-file");
3998        temp->name = get_tempfile_path(temp->tempfile);
3999        oid_to_hex_r(temp->hex, oid);
4000        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4001        strbuf_release(&buf);
4002        strbuf_release(&tempfile);
4003        free(path_dup);
4004}
4005
4006static struct diff_tempfile *prepare_temp_file(const char *name,
4007                struct diff_filespec *one)
4008{
4009        struct diff_tempfile *temp = claim_diff_tempfile();
4010
4011        if (!DIFF_FILE_VALID(one)) {
4012        not_a_valid_file:
4013                /* A '-' entry produces this for file-2, and
4014                 * a '+' entry produces this for file-1.
4015                 */
4016                temp->name = "/dev/null";
4017                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4018                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4019                return temp;
4020        }
4021
4022        if (!S_ISGITLINK(one->mode) &&
4023            (!one->oid_valid ||
4024             reuse_worktree_file(name, &one->oid, 1))) {
4025                struct stat st;
4026                if (lstat(name, &st) < 0) {
4027                        if (errno == ENOENT)
4028                                goto not_a_valid_file;
4029                        die_errno("stat(%s)", name);
4030                }
4031                if (S_ISLNK(st.st_mode)) {
4032                        struct strbuf sb = STRBUF_INIT;
4033                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4034                                die_errno("readlink(%s)", name);
4035                        prep_temp_blob(name, temp, sb.buf, sb.len,
4036                                       (one->oid_valid ?
4037                                        &one->oid : &null_oid),
4038                                       (one->oid_valid ?
4039                                        one->mode : S_IFLNK));
4040                        strbuf_release(&sb);
4041                }
4042                else {
4043                        /* we can borrow from the file in the work tree */
4044                        temp->name = name;
4045                        if (!one->oid_valid)
4046                                oid_to_hex_r(temp->hex, &null_oid);
4047                        else
4048                                oid_to_hex_r(temp->hex, &one->oid);
4049                        /* Even though we may sometimes borrow the
4050                         * contents from the work tree, we always want
4051                         * one->mode.  mode is trustworthy even when
4052                         * !(one->oid_valid), as long as
4053                         * DIFF_FILE_VALID(one).
4054                         */
4055                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4056                }
4057                return temp;
4058        }
4059        else {
4060                if (diff_populate_filespec(one, 0))
4061                        die("cannot read data blob for %s", one->path);
4062                prep_temp_blob(name, temp, one->data, one->size,
4063                               &one->oid, one->mode);
4064        }
4065        return temp;
4066}
4067
4068static void add_external_diff_name(struct argv_array *argv,
4069                                   const char *name,
4070                                   struct diff_filespec *df)
4071{
4072        struct diff_tempfile *temp = prepare_temp_file(name, df);
4073        argv_array_push(argv, temp->name);
4074        argv_array_push(argv, temp->hex);
4075        argv_array_push(argv, temp->mode);
4076}
4077
4078/* An external diff command takes:
4079 *
4080 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4081 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4082 *
4083 */
4084static void run_external_diff(const char *pgm,
4085                              const char *name,
4086                              const char *other,
4087                              struct diff_filespec *one,
4088                              struct diff_filespec *two,
4089                              const char *xfrm_msg,
4090                              int complete_rewrite,
4091                              struct diff_options *o)
4092{
4093        struct argv_array argv = ARGV_ARRAY_INIT;
4094        struct argv_array env = ARGV_ARRAY_INIT;
4095        struct diff_queue_struct *q = &diff_queued_diff;
4096
4097        argv_array_push(&argv, pgm);
4098        argv_array_push(&argv, name);
4099
4100        if (one && two) {
4101                add_external_diff_name(&argv, name, one);
4102                if (!other)
4103                        add_external_diff_name(&argv, name, two);
4104                else {
4105                        add_external_diff_name(&argv, other, two);
4106                        argv_array_push(&argv, other);
4107                        argv_array_push(&argv, xfrm_msg);
4108                }
4109        }
4110
4111        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4112        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4113
4114        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4115                die(_("external diff died, stopping at %s"), name);
4116
4117        remove_tempfile();
4118        argv_array_clear(&argv);
4119        argv_array_clear(&env);
4120}
4121
4122static int similarity_index(struct diff_filepair *p)
4123{
4124        return p->score * 100 / MAX_SCORE;
4125}
4126
4127static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4128{
4129        if (startup_info->have_repository)
4130                return find_unique_abbrev(oid, abbrev);
4131        else {
4132                char *hex = oid_to_hex(oid);
4133                if (abbrev < 0)
4134                        abbrev = FALLBACK_DEFAULT_ABBREV;
4135                if (abbrev > the_hash_algo->hexsz)
4136                        BUG("oid abbreviation out of range: %d", abbrev);
4137                if (abbrev)
4138                        hex[abbrev] = '\0';
4139                return hex;
4140        }
4141}
4142
4143static void fill_metainfo(struct strbuf *msg,
4144                          const char *name,
4145                          const char *other,
4146                          struct diff_filespec *one,
4147                          struct diff_filespec *two,
4148                          struct diff_options *o,
4149                          struct diff_filepair *p,
4150                          int *must_show_header,
4151                          int use_color)
4152{
4153        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4154        const char *reset = diff_get_color(use_color, DIFF_RESET);
4155        const char *line_prefix = diff_line_prefix(o);
4156
4157        *must_show_header = 1;
4158        strbuf_init(msg, PATH_MAX * 2 + 300);
4159        switch (p->status) {
4160        case DIFF_STATUS_COPIED:
4161                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4162                            line_prefix, set, similarity_index(p));
4163                strbuf_addf(msg, "%s\n%s%scopy from ",
4164                            reset,  line_prefix, set);
4165                quote_c_style(name, msg, NULL, 0);
4166                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4167                quote_c_style(other, msg, NULL, 0);
4168                strbuf_addf(msg, "%s\n", reset);
4169                break;
4170        case DIFF_STATUS_RENAMED:
4171                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4172                            line_prefix, set, similarity_index(p));
4173                strbuf_addf(msg, "%s\n%s%srename from ",
4174                            reset, line_prefix, set);
4175                quote_c_style(name, msg, NULL, 0);
4176                strbuf_addf(msg, "%s\n%s%srename to ",
4177                            reset, line_prefix, set);
4178                quote_c_style(other, msg, NULL, 0);
4179                strbuf_addf(msg, "%s\n", reset);
4180                break;
4181        case DIFF_STATUS_MODIFIED:
4182                if (p->score) {
4183                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4184                                    line_prefix,
4185                                    set, similarity_index(p), reset);
4186                        break;
4187                }
4188                /* fallthru */
4189        default:
4190                *must_show_header = 0;
4191        }
4192        if (one && two && !oideq(&one->oid, &two->oid)) {
4193                const unsigned hexsz = the_hash_algo->hexsz;
4194                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4195
4196                if (o->flags.binary) {
4197                        mmfile_t mf;
4198                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4199                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4200                                abbrev = hexsz;
4201                }
4202                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4203                            diff_abbrev_oid(&one->oid, abbrev),
4204                            diff_abbrev_oid(&two->oid, abbrev));
4205                if (one->mode == two->mode)
4206                        strbuf_addf(msg, " %06o", one->mode);
4207                strbuf_addf(msg, "%s\n", reset);
4208        }
4209}
4210
4211static void run_diff_cmd(const char *pgm,
4212                         const char *name,
4213                         const char *other,
4214                         const char *attr_path,
4215                         struct diff_filespec *one,
4216                         struct diff_filespec *two,
4217                         struct strbuf *msg,
4218                         struct diff_options *o,
4219                         struct diff_filepair *p)
4220{
4221        const char *xfrm_msg = NULL;
4222        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4223        int must_show_header = 0;
4224
4225
4226        if (o->flags.allow_external) {
4227                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4228                if (drv && drv->external)
4229                        pgm = drv->external;
4230        }
4231
4232        if (msg) {
4233                /*
4234                 * don't use colors when the header is intended for an
4235                 * external diff driver
4236                 */
4237                fill_metainfo(msg, name, other, one, two, o, p,
4238                              &must_show_header,
4239                              want_color(o->use_color) && !pgm);
4240                xfrm_msg = msg->len ? msg->buf : NULL;
4241        }
4242
4243        if (pgm) {
4244                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4245                                  complete_rewrite, o);
4246                return;
4247        }
4248        if (one && two)
4249                builtin_diff(name, other ? other : name,
4250                             one, two, xfrm_msg, must_show_header,
4251                             o, complete_rewrite);
4252        else
4253                fprintf(o->file, "* Unmerged path %s\n", name);
4254}
4255
4256static void diff_fill_oid_info(struct diff_filespec *one)
4257{
4258        if (DIFF_FILE_VALID(one)) {
4259                if (!one->oid_valid) {
4260                        struct stat st;
4261                        if (one->is_stdin) {
4262                                oidclr(&one->oid);
4263                                return;
4264                        }
4265                        if (lstat(one->path, &st) < 0)
4266                                die_errno("stat '%s'", one->path);
4267                        if (index_path(&one->oid, one->path, &st, 0))
4268                                die("cannot hash %s", one->path);
4269                }
4270        }
4271        else
4272                oidclr(&one->oid);
4273}
4274
4275static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4276{
4277        /* Strip the prefix but do not molest /dev/null and absolute paths */
4278        if (*namep && **namep != '/') {
4279                *namep += prefix_length;
4280                if (**namep == '/')
4281                        ++*namep;
4282        }
4283        if (*otherp && **otherp != '/') {
4284                *otherp += prefix_length;
4285                if (**otherp == '/')
4286                        ++*otherp;
4287        }
4288}
4289
4290static void run_diff(struct diff_filepair *p, struct diff_options *o)
4291{
4292        const char *pgm = external_diff();
4293        struct strbuf msg;
4294        struct diff_filespec *one = p->one;
4295        struct diff_filespec *two = p->two;
4296        const char *name;
4297        const char *other;
4298        const char *attr_path;
4299
4300        name  = one->path;
4301        other = (strcmp(name, two->path) ? two->path : NULL);
4302        attr_path = name;
4303        if (o->prefix_length)
4304                strip_prefix(o->prefix_length, &name, &other);
4305
4306        if (!o->flags.allow_external)
4307                pgm = NULL;
4308
4309        if (DIFF_PAIR_UNMERGED(p)) {
4310                run_diff_cmd(pgm, name, NULL, attr_path,
4311                             NULL, NULL, NULL, o, p);
4312                return;
4313        }
4314
4315        diff_fill_oid_info(one);
4316        diff_fill_oid_info(two);
4317
4318        if (!pgm &&
4319            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4320            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4321                /*
4322                 * a filepair that changes between file and symlink
4323                 * needs to be split into deletion and creation.
4324                 */
4325                struct diff_filespec *null = alloc_filespec(two->path);
4326                run_diff_cmd(NULL, name, other, attr_path,
4327                             one, null, &msg, o, p);
4328                free(null);
4329                strbuf_release(&msg);
4330
4331                null = alloc_filespec(one->path);
4332                run_diff_cmd(NULL, name, other, attr_path,
4333                             null, two, &msg, o, p);
4334                free(null);
4335        }
4336        else
4337                run_diff_cmd(pgm, name, other, attr_path,
4338                             one, two, &msg, o, p);
4339
4340        strbuf_release(&msg);
4341}
4342
4343static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4344                         struct diffstat_t *diffstat)
4345{
4346        const char *name;
4347        const char *other;
4348
4349        if (DIFF_PAIR_UNMERGED(p)) {
4350                /* unmerged */
4351                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4352                return;
4353        }
4354
4355        name = p->one->path;
4356        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4357
4358        if (o->prefix_length)
4359                strip_prefix(o->prefix_length, &name, &other);
4360
4361        diff_fill_oid_info(p->one);
4362        diff_fill_oid_info(p->two);
4363
4364        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4365}
4366
4367static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4368{
4369        const char *name;
4370        const char *other;
4371        const char *attr_path;
4372
4373        if (DIFF_PAIR_UNMERGED(p)) {
4374                /* unmerged */
4375                return;
4376        }
4377
4378        name = p->one->path;
4379        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4380        attr_path = other ? other : name;
4381
4382        if (o->prefix_length)
4383                strip_prefix(o->prefix_length, &name, &other);
4384
4385        diff_fill_oid_info(p->one);
4386        diff_fill_oid_info(p->two);
4387
4388        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4389}
4390
4391void diff_setup(struct diff_options *options)
4392{
4393        memcpy(options, &default_diff_options, sizeof(*options));
4394
4395        options->file = stdout;
4396
4397        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4398        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4399        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4400        options->abbrev = DEFAULT_ABBREV;
4401        options->line_termination = '\n';
4402        options->break_opt = -1;
4403        options->rename_limit = -1;
4404        options->dirstat_permille = diff_dirstat_permille_default;
4405        options->context = diff_context_default;
4406        options->interhunkcontext = diff_interhunk_context_default;
4407        options->ws_error_highlight = ws_error_highlight_default;
4408        options->flags.rename_empty = 1;
4409        options->objfind = NULL;
4410
4411        /* pathchange left =NULL by default */
4412        options->change = diff_change;
4413        options->add_remove = diff_addremove;
4414        options->use_color = diff_use_color_default;
4415        options->detect_rename = diff_detect_rename_default;
4416        options->xdl_opts |= diff_algorithm;
4417        if (diff_indent_heuristic)
4418                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4419
4420        options->orderfile = diff_order_file_cfg;
4421
4422        if (diff_no_prefix) {
4423                options->a_prefix = options->b_prefix = "";
4424        } else if (!diff_mnemonic_prefix) {
4425                options->a_prefix = "a/";
4426                options->b_prefix = "b/";
4427        }
4428
4429        options->color_moved = diff_color_moved_default;
4430        options->color_moved_ws_handling = diff_color_moved_ws_default;
4431}
4432
4433void diff_setup_done(struct diff_options *options)
4434{
4435        unsigned check_mask = DIFF_FORMAT_NAME |
4436                              DIFF_FORMAT_NAME_STATUS |
4437                              DIFF_FORMAT_CHECKDIFF |
4438                              DIFF_FORMAT_NO_OUTPUT;
4439        /*
4440         * This must be signed because we're comparing against a potentially
4441         * negative value.
4442         */
4443        const int hexsz = the_hash_algo->hexsz;
4444
4445        if (options->set_default)
4446                options->set_default(options);
4447
4448        if (HAS_MULTI_BITS(options->output_format & check_mask))
4449                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4450
4451        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4452                die(_("-G, -S and --find-object are mutually exclusive"));
4453
4454        /*
4455         * Most of the time we can say "there are changes"
4456         * only by checking if there are changed paths, but
4457         * --ignore-whitespace* options force us to look
4458         * inside contents.
4459         */
4460
4461        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4462                options->flags.diff_from_contents = 1;
4463        else
4464                options->flags.diff_from_contents = 0;
4465
4466        if (options->flags.find_copies_harder)
4467                options->detect_rename = DIFF_DETECT_COPY;
4468
4469        if (!options->flags.relative_name)
4470                options->prefix = NULL;
4471        if (options->prefix)
4472                options->prefix_length = strlen(options->prefix);
4473        else
4474                options->prefix_length = 0;
4475
4476        if (options->output_format & (DIFF_FORMAT_NAME |
4477                                      DIFF_FORMAT_NAME_STATUS |
4478                                      DIFF_FORMAT_CHECKDIFF |
4479                                      DIFF_FORMAT_NO_OUTPUT))
4480                options->output_format &= ~(DIFF_FORMAT_RAW |
4481                                            DIFF_FORMAT_NUMSTAT |
4482                                            DIFF_FORMAT_DIFFSTAT |
4483                                            DIFF_FORMAT_SHORTSTAT |
4484                                            DIFF_FORMAT_DIRSTAT |
4485                                            DIFF_FORMAT_SUMMARY |
4486                                            DIFF_FORMAT_PATCH);
4487
4488        /*
4489         * These cases always need recursive; we do not drop caller-supplied
4490         * recursive bits for other formats here.
4491         */
4492        if (options->output_format & (DIFF_FORMAT_PATCH |
4493                                      DIFF_FORMAT_NUMSTAT |
4494                                      DIFF_FORMAT_DIFFSTAT |
4495                                      DIFF_FORMAT_SHORTSTAT |
4496                                      DIFF_FORMAT_DIRSTAT |
4497                                      DIFF_FORMAT_SUMMARY |
4498                                      DIFF_FORMAT_CHECKDIFF))
4499                options->flags.recursive = 1;
4500        /*
4501         * Also pickaxe would not work very well if you do not say recursive
4502         */
4503        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4504                options->flags.recursive = 1;
4505        /*
4506         * When patches are generated, submodules diffed against the work tree
4507         * must be checked for dirtiness too so it can be shown in the output
4508         */
4509        if (options->output_format & DIFF_FORMAT_PATCH)
4510                options->flags.dirty_submodules = 1;
4511
4512        if (options->detect_rename && options->rename_limit < 0)
4513                options->rename_limit = diff_rename_limit_default;
4514        if (hexsz < options->abbrev)
4515                options->abbrev = hexsz; /* full */
4516
4517        /*
4518         * It does not make sense to show the first hit we happened
4519         * to have found.  It does not make sense not to return with
4520         * exit code in such a case either.
4521         */
4522        if (options->flags.quick) {
4523                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4524                options->flags.exit_with_status = 1;
4525        }
4526
4527        options->diff_path_counter = 0;
4528
4529        if (options->flags.follow_renames && options->pathspec.nr != 1)
4530                die(_("--follow requires exactly one pathspec"));
4531
4532        if (!options->use_color || external_diff())
4533                options->color_moved = 0;
4534}
4535
4536static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4537{
4538        char c, *eq;
4539        int len;
4540
4541        if (*arg != '-')
4542                return 0;
4543        c = *++arg;
4544        if (!c)
4545                return 0;
4546        if (c == arg_short) {
4547                c = *++arg;
4548                if (!c)
4549                        return 1;
4550                if (val && isdigit(c)) {
4551                        char *end;
4552                        int n = strtoul(arg, &end, 10);
4553                        if (*end)
4554                                return 0;
4555                        *val = n;
4556                        return 1;
4557                }
4558                return 0;
4559        }
4560        if (c != '-')
4561                return 0;
4562        arg++;
4563        eq = strchrnul(arg, '=');
4564        len = eq - arg;
4565        if (!len || strncmp(arg, arg_long, len))
4566                return 0;
4567        if (*eq) {
4568                int n;
4569                char *end;
4570                if (!isdigit(*++eq))
4571                        return 0;
4572                n = strtoul(eq, &end, 10);
4573                if (*end)
4574                        return 0;
4575                *val = n;
4576        }
4577        return 1;
4578}
4579
4580static int diff_scoreopt_parse(const char *opt);
4581
4582static inline int short_opt(char opt, const char **argv,
4583                            const char **optarg)
4584{
4585        const char *arg = argv[0];
4586        if (arg[0] != '-' || arg[1] != opt)
4587                return 0;
4588        if (arg[2] != '\0') {
4589                *optarg = arg + 2;
4590                return 1;
4591        }
4592        if (!argv[1])
4593                die("Option '%c' requires a value", opt);
4594        *optarg = argv[1];
4595        return 2;
4596}
4597
4598int parse_long_opt(const char *opt, const char **argv,
4599                   const char **optarg)
4600{
4601        const char *arg = argv[0];
4602        if (!skip_prefix(arg, "--", &arg))
4603                return 0;
4604        if (!skip_prefix(arg, opt, &arg))
4605                return 0;
4606        if (*arg == '=') { /* stuck form: --option=value */
4607                *optarg = arg + 1;
4608                return 1;
4609        }
4610        if (*arg != '\0')
4611                return 0;
4612        /* separate form: --option value */
4613        if (!argv[1])
4614                die("Option '--%s' requires a value", opt);
4615        *optarg = argv[1];
4616        return 2;
4617}
4618
4619static int stat_opt(struct diff_options *options, const char **av)
4620{
4621        const char *arg = av[0];
4622        char *end;
4623        int width = options->stat_width;
4624        int name_width = options->stat_name_width;
4625        int graph_width = options->stat_graph_width;
4626        int count = options->stat_count;
4627        int argcount = 1;
4628
4629        if (!skip_prefix(arg, "--stat", &arg))
4630                BUG("stat option does not begin with --stat: %s", arg);
4631        end = (char *)arg;
4632
4633        switch (*arg) {
4634        case '-':
4635                if (skip_prefix(arg, "-width", &arg)) {
4636                        if (*arg == '=')
4637                                width = strtoul(arg + 1, &end, 10);
4638                        else if (!*arg && !av[1])
4639                                die_want_option("--stat-width");
4640                        else if (!*arg) {
4641                                width = strtoul(av[1], &end, 10);
4642                                argcount = 2;
4643                        }
4644                } else if (skip_prefix(arg, "-name-width", &arg)) {
4645                        if (*arg == '=')
4646                                name_width = strtoul(arg + 1, &end, 10);
4647                        else if (!*arg && !av[1])
4648                                die_want_option("--stat-name-width");
4649                        else if (!*arg) {
4650                                name_width = strtoul(av[1], &end, 10);
4651                                argcount = 2;
4652                        }
4653                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4654                        if (*arg == '=')
4655                                graph_width = strtoul(arg + 1, &end, 10);
4656                        else if (!*arg && !av[1])
4657                                die_want_option("--stat-graph-width");
4658                        else if (!*arg) {
4659                                graph_width = strtoul(av[1], &end, 10);
4660                                argcount = 2;
4661                        }
4662                } else if (skip_prefix(arg, "-count", &arg)) {
4663                        if (*arg == '=')
4664                                count = strtoul(arg + 1, &end, 10);
4665                        else if (!*arg && !av[1])
4666                                die_want_option("--stat-count");
4667                        else if (!*arg) {
4668                                count = strtoul(av[1], &end, 10);
4669                                argcount = 2;
4670                        }
4671                }
4672                break;
4673        case '=':
4674                width = strtoul(arg+1, &end, 10);
4675                if (*end == ',')
4676                        name_width = strtoul(end+1, &end, 10);
4677                if (*end == ',')
4678                        count = strtoul(end+1, &end, 10);
4679        }
4680
4681        /* Important! This checks all the error cases! */
4682        if (*end)
4683                return 0;
4684        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4685        options->stat_name_width = name_width;
4686        options->stat_graph_width = graph_width;
4687        options->stat_width = width;
4688        options->stat_count = count;
4689        return argcount;
4690}
4691
4692static int parse_dirstat_opt(struct diff_options *options, const char *params)
4693{
4694        struct strbuf errmsg = STRBUF_INIT;
4695        if (parse_dirstat_params(options, params, &errmsg))
4696                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4697                    errmsg.buf);
4698        strbuf_release(&errmsg);
4699        /*
4700         * The caller knows a dirstat-related option is given from the command
4701         * line; allow it to say "return this_function();"
4702         */
4703        options->output_format |= DIFF_FORMAT_DIRSTAT;
4704        return 1;
4705}
4706
4707static int parse_submodule_opt(struct diff_options *options, const char *value)
4708{
4709        if (parse_submodule_params(options, value))
4710                die(_("Failed to parse --submodule option parameter: '%s'"),
4711                        value);
4712        return 1;
4713}
4714
4715static const char diff_status_letters[] = {
4716        DIFF_STATUS_ADDED,
4717        DIFF_STATUS_COPIED,
4718        DIFF_STATUS_DELETED,
4719        DIFF_STATUS_MODIFIED,
4720        DIFF_STATUS_RENAMED,
4721        DIFF_STATUS_TYPE_CHANGED,
4722        DIFF_STATUS_UNKNOWN,
4723        DIFF_STATUS_UNMERGED,
4724        DIFF_STATUS_FILTER_AON,
4725        DIFF_STATUS_FILTER_BROKEN,
4726        '\0',
4727};
4728
4729static unsigned int filter_bit['Z' + 1];
4730
4731static void prepare_filter_bits(void)
4732{
4733        int i;
4734
4735        if (!filter_bit[DIFF_STATUS_ADDED]) {
4736                for (i = 0; diff_status_letters[i]; i++)
4737                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4738        }
4739}
4740
4741static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4742{
4743        return opt->filter & filter_bit[(int) status];
4744}
4745
4746static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4747{
4748        int i, optch;
4749
4750        prepare_filter_bits();
4751
4752        /*
4753         * If there is a negation e.g. 'd' in the input, and we haven't
4754         * initialized the filter field with another --diff-filter, start
4755         * from full set of bits, except for AON.
4756         */
4757        if (!opt->filter) {
4758                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4759                        if (optch < 'a' || 'z' < optch)
4760                                continue;
4761                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4762                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4763                        break;
4764                }
4765        }
4766
4767        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4768                unsigned int bit;
4769                int negate;
4770
4771                if ('a' <= optch && optch <= 'z') {
4772                        negate = 1;
4773                        optch = toupper(optch);
4774                } else {
4775                        negate = 0;
4776                }
4777
4778                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4779                if (!bit)
4780                        return optarg[i];
4781                if (negate)
4782                        opt->filter &= ~bit;
4783                else
4784                        opt->filter |= bit;
4785        }
4786        return 0;
4787}
4788
4789static void enable_patch_output(int *fmt) {
4790        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4791        *fmt |= DIFF_FORMAT_PATCH;
4792}
4793
4794static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4795{
4796        int val = parse_ws_error_highlight(arg);
4797
4798        if (val < 0) {
4799                error("unknown value after ws-error-highlight=%.*s",
4800                      -1 - val, arg);
4801                return 0;
4802        }
4803        opt->ws_error_highlight = val;
4804        return 1;
4805}
4806
4807static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4808{
4809        struct object_id oid;
4810
4811        if (get_oid(arg, &oid))
4812                return error("unable to resolve '%s'", arg);
4813
4814        if (!opt->objfind)
4815                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4816
4817        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4818        opt->flags.recursive = 1;
4819        opt->flags.tree_in_recursive = 1;
4820        oidset_insert(opt->objfind, &oid);
4821        return 1;
4822}
4823
4824int diff_opt_parse(struct diff_options *options,
4825                   const char **av, int ac, const char *prefix)
4826{
4827        const char *arg = av[0];
4828        const char *optarg;
4829        int argcount;
4830
4831        if (!prefix)
4832                prefix = "";
4833
4834        /* Output format options */
4835        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4836            || opt_arg(arg, 'U', "unified", &options->context))
4837                enable_patch_output(&options->output_format);
4838        else if (!strcmp(arg, "--raw"))
4839                options->output_format |= DIFF_FORMAT_RAW;
4840        else if (!strcmp(arg, "--patch-with-raw")) {
4841                enable_patch_output(&options->output_format);
4842                options->output_format |= DIFF_FORMAT_RAW;
4843        } else if (!strcmp(arg, "--numstat"))
4844                options->output_format |= DIFF_FORMAT_NUMSTAT;
4845        else if (!strcmp(arg, "--shortstat"))
4846                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4847        else if (skip_prefix(arg, "-X", &arg) ||
4848                 skip_to_optional_arg(arg, "--dirstat", &arg))
4849                return parse_dirstat_opt(options, arg);
4850        else if (!strcmp(arg, "--cumulative"))
4851                return parse_dirstat_opt(options, "cumulative");
4852        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4853                parse_dirstat_opt(options, "files");
4854                return parse_dirstat_opt(options, arg);
4855        }
4856        else if (!strcmp(arg, "--check"))
4857                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4858        else if (!strcmp(arg, "--summary"))
4859                options->output_format |= DIFF_FORMAT_SUMMARY;
4860        else if (!strcmp(arg, "--patch-with-stat")) {
4861                enable_patch_output(&options->output_format);
4862                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4863        } else if (!strcmp(arg, "--name-only"))
4864                options->output_format |= DIFF_FORMAT_NAME;
4865        else if (!strcmp(arg, "--name-status"))
4866                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4867        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4868                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4869        else if (starts_with(arg, "--stat"))
4870                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4871                return stat_opt(options, av);
4872        else if (!strcmp(arg, "--compact-summary")) {
4873                 options->flags.stat_with_summary = 1;
4874                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4875        } else if (!strcmp(arg, "--no-compact-summary"))
4876                 options->flags.stat_with_summary = 0;
4877        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4878                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4879        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4880                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4881        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4882                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4883
4884        /* renames options */
4885        else if (starts_with(arg, "-B") ||
4886                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4887                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4888                        return error("invalid argument to -B: %s", arg+2);
4889        }
4890        else if (starts_with(arg, "-M") ||
4891                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4892                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4893                        return error("invalid argument to -M: %s", arg+2);
4894                options->detect_rename = DIFF_DETECT_RENAME;
4895        }
4896        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4897                options->irreversible_delete = 1;
4898        }
4899        else if (starts_with(arg, "-C") ||
4900                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4901                if (options->detect_rename == DIFF_DETECT_COPY)
4902                        options->flags.find_copies_harder = 1;
4903                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4904                        return error("invalid argument to -C: %s", arg+2);
4905                options->detect_rename = DIFF_DETECT_COPY;
4906        }
4907        else if (!strcmp(arg, "--no-renames"))
4908                options->detect_rename = 0;
4909        else if (!strcmp(arg, "--rename-empty"))
4910                options->flags.rename_empty = 1;
4911        else if (!strcmp(arg, "--no-rename-empty"))
4912                options->flags.rename_empty = 0;
4913        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4914                options->flags.relative_name = 1;
4915                if (arg)
4916                        options->prefix = arg;
4917        }
4918
4919        /* xdiff options */
4920        else if (!strcmp(arg, "--minimal"))
4921                DIFF_XDL_SET(options, NEED_MINIMAL);
4922        else if (!strcmp(arg, "--no-minimal"))
4923                DIFF_XDL_CLR(options, NEED_MINIMAL);
4924        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4925                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4926        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4927                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4928        else if (!strcmp(arg, "--ignore-space-at-eol"))
4929                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4930        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4931                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4932        else if (!strcmp(arg, "--ignore-blank-lines"))
4933                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4934        else if (!strcmp(arg, "--indent-heuristic"))
4935                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4936        else if (!strcmp(arg, "--no-indent-heuristic"))
4937                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4938        else if (!strcmp(arg, "--patience")) {
4939                int i;
4940                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4941                /*
4942                 * Both --patience and --anchored use PATIENCE_DIFF
4943                 * internally, so remove any anchors previously
4944                 * specified.
4945                 */
4946                for (i = 0; i < options->anchors_nr; i++)
4947                        free(options->anchors[i]);
4948                options->anchors_nr = 0;
4949        } else if (!strcmp(arg, "--histogram"))
4950                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4951        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4952                long value = parse_algorithm_value(optarg);
4953                if (value < 0)
4954                        return error("option diff-algorithm accepts \"myers\", "
4955                                     "\"minimal\", \"patience\" and \"histogram\"");
4956                /* clear out previous settings */
4957                DIFF_XDL_CLR(options, NEED_MINIMAL);
4958                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4959                options->xdl_opts |= value;
4960                return argcount;
4961        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4962                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4963                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4964                           options->anchors_alloc);
4965                options->anchors[options->anchors_nr++] = xstrdup(arg);
4966        }
4967
4968        /* flags options */
4969        else if (!strcmp(arg, "--binary")) {
4970                enable_patch_output(&options->output_format);
4971                options->flags.binary = 1;
4972        }
4973        else if (!strcmp(arg, "--full-index"))
4974                options->flags.full_index = 1;
4975        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4976                options->flags.text = 1;
4977        else if (!strcmp(arg, "-R"))
4978                options->flags.reverse_diff = 1;
4979        else if (!strcmp(arg, "--find-copies-harder"))
4980                options->flags.find_copies_harder = 1;
4981        else if (!strcmp(arg, "--follow"))
4982                options->flags.follow_renames = 1;
4983        else if (!strcmp(arg, "--no-follow")) {
4984                options->flags.follow_renames = 0;
4985                options->flags.default_follow_renames = 0;
4986        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4987                int value = git_config_colorbool(NULL, arg);
4988                if (value < 0)
4989                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4990                options->use_color = value;
4991        }
4992        else if (!strcmp(arg, "--no-color"))
4993                options->use_color = 0;
4994        else if (!strcmp(arg, "--color-moved")) {
4995                if (diff_color_moved_default)
4996                        options->color_moved = diff_color_moved_default;
4997                if (options->color_moved == COLOR_MOVED_NO)
4998                        options->color_moved = COLOR_MOVED_DEFAULT;
4999        } else if (!strcmp(arg, "--no-color-moved"))
5000                options->color_moved = COLOR_MOVED_NO;
5001        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5002                int cm = parse_color_moved(arg);
5003                if (cm < 0)
5004                        die("bad --color-moved argument: %s", arg);
5005                options->color_moved = cm;
5006        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5007                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5008        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5009                options->use_color = 1;
5010                options->word_diff = DIFF_WORDS_COLOR;
5011        }
5012        else if (!strcmp(arg, "--word-diff")) {
5013                if (options->word_diff == DIFF_WORDS_NONE)
5014                        options->word_diff = DIFF_WORDS_PLAIN;
5015        }
5016        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5017                if (!strcmp(arg, "plain"))
5018                        options->word_diff = DIFF_WORDS_PLAIN;
5019                else if (!strcmp(arg, "color")) {
5020                        options->use_color = 1;
5021                        options->word_diff = DIFF_WORDS_COLOR;
5022                }
5023                else if (!strcmp(arg, "porcelain"))
5024                        options->word_diff = DIFF_WORDS_PORCELAIN;
5025                else if (!strcmp(arg, "none"))
5026                        options->word_diff = DIFF_WORDS_NONE;
5027                else
5028                        die("bad --word-diff argument: %s", arg);
5029        }
5030        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5031                if (options->word_diff == DIFF_WORDS_NONE)
5032                        options->word_diff = DIFF_WORDS_PLAIN;
5033                options->word_regex = optarg;
5034                return argcount;
5035        }
5036        else if (!strcmp(arg, "--exit-code"))
5037                options->flags.exit_with_status = 1;
5038        else if (!strcmp(arg, "--quiet"))
5039                options->flags.quick = 1;
5040        else if (!strcmp(arg, "--ext-diff"))
5041                options->flags.allow_external = 1;
5042        else if (!strcmp(arg, "--no-ext-diff"))
5043                options->flags.allow_external = 0;
5044        else if (!strcmp(arg, "--textconv")) {
5045                options->flags.allow_textconv = 1;
5046                options->flags.textconv_set_via_cmdline = 1;
5047        } else if (!strcmp(arg, "--no-textconv"))
5048                options->flags.allow_textconv = 0;
5049        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5050                options->flags.override_submodule_config = 1;
5051                handle_ignore_submodules_arg(options, arg);
5052        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5053                return parse_submodule_opt(options, arg);
5054        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5055                return parse_ws_error_highlight_opt(options, arg);
5056        else if (!strcmp(arg, "--ita-invisible-in-index"))
5057                options->ita_invisible_in_index = 1;
5058        else if (!strcmp(arg, "--ita-visible-in-index"))
5059                options->ita_invisible_in_index = 0;
5060
5061        /* misc options */
5062        else if (!strcmp(arg, "-z"))
5063                options->line_termination = 0;
5064        else if ((argcount = short_opt('l', av, &optarg))) {
5065                options->rename_limit = strtoul(optarg, NULL, 10);
5066                return argcount;
5067        }
5068        else if ((argcount = short_opt('S', av, &optarg))) {
5069                options->pickaxe = optarg;
5070                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5071                return argcount;
5072        } else if ((argcount = short_opt('G', av, &optarg))) {
5073                options->pickaxe = optarg;
5074                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5075                return argcount;
5076        }
5077        else if (!strcmp(arg, "--pickaxe-all"))
5078                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5079        else if (!strcmp(arg, "--pickaxe-regex"))
5080                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5081        else if ((argcount = short_opt('O', av, &optarg))) {
5082                options->orderfile = prefix_filename(prefix, optarg);
5083                return argcount;
5084        } else if (skip_prefix(arg, "--find-object=", &arg))
5085                return parse_objfind_opt(options, arg);
5086        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5087                int offending = parse_diff_filter_opt(optarg, options);
5088                if (offending)
5089                        die("unknown change class '%c' in --diff-filter=%s",
5090                            offending, optarg);
5091                return argcount;
5092        }
5093        else if (!strcmp(arg, "--no-abbrev"))
5094                options->abbrev = 0;
5095        else if (!strcmp(arg, "--abbrev"))
5096                options->abbrev = DEFAULT_ABBREV;
5097        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5098                options->abbrev = strtoul(arg, NULL, 10);
5099                if (options->abbrev < MINIMUM_ABBREV)
5100                        options->abbrev = MINIMUM_ABBREV;
5101                else if (the_hash_algo->hexsz < options->abbrev)
5102                        options->abbrev = the_hash_algo->hexsz;
5103        }
5104        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5105                options->a_prefix = optarg;
5106                return argcount;
5107        }
5108        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5109                options->line_prefix = optarg;
5110                options->line_prefix_length = strlen(options->line_prefix);
5111                graph_setup_line_prefix(options);
5112                return argcount;
5113        }
5114        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5115                options->b_prefix = optarg;
5116                return argcount;
5117        }
5118        else if (!strcmp(arg, "--no-prefix"))
5119                options->a_prefix = options->b_prefix = "";
5120        else if (opt_arg(arg, '\0', "inter-hunk-context",
5121                         &options->interhunkcontext))
5122                ;
5123        else if (!strcmp(arg, "-W"))
5124                options->flags.funccontext = 1;
5125        else if (!strcmp(arg, "--function-context"))
5126                options->flags.funccontext = 1;
5127        else if (!strcmp(arg, "--no-function-context"))
5128                options->flags.funccontext = 0;
5129        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5130                char *path = prefix_filename(prefix, optarg);
5131                options->file = xfopen(path, "w");
5132                options->close_file = 1;
5133                if (options->use_color != GIT_COLOR_ALWAYS)
5134                        options->use_color = GIT_COLOR_NEVER;
5135                free(path);
5136                return argcount;
5137        } else
5138                return 0;
5139        return 1;
5140}
5141
5142int parse_rename_score(const char **cp_p)
5143{
5144        unsigned long num, scale;
5145        int ch, dot;
5146        const char *cp = *cp_p;
5147
5148        num = 0;
5149        scale = 1;
5150        dot = 0;
5151        for (;;) {
5152                ch = *cp;
5153                if ( !dot && ch == '.' ) {
5154                        scale = 1;
5155                        dot = 1;
5156                } else if ( ch == '%' ) {
5157                        scale = dot ? scale*100 : 100;
5158                        cp++;   /* % is always at the end */
5159                        break;
5160                } else if ( ch >= '0' && ch <= '9' ) {
5161                        if ( scale < 100000 ) {
5162                                scale *= 10;
5163                                num = (num*10) + (ch-'0');
5164                        }
5165                } else {
5166                        break;
5167                }
5168                cp++;
5169        }
5170        *cp_p = cp;
5171
5172        /* user says num divided by scale and we say internally that
5173         * is MAX_SCORE * num / scale.
5174         */
5175        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5176}
5177
5178static int diff_scoreopt_parse(const char *opt)
5179{
5180        int opt1, opt2, cmd;
5181
5182        if (*opt++ != '-')
5183                return -1;
5184        cmd = *opt++;
5185        if (cmd == '-') {
5186                /* convert the long-form arguments into short-form versions */
5187                if (skip_prefix(opt, "break-rewrites", &opt)) {
5188                        if (*opt == 0 || *opt++ == '=')
5189                                cmd = 'B';
5190                } else if (skip_prefix(opt, "find-copies", &opt)) {
5191                        if (*opt == 0 || *opt++ == '=')
5192                                cmd = 'C';
5193                } else if (skip_prefix(opt, "find-renames", &opt)) {
5194                        if (*opt == 0 || *opt++ == '=')
5195                                cmd = 'M';
5196                }
5197        }
5198        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5199                return -1; /* that is not a -M, -C, or -B option */
5200
5201        opt1 = parse_rename_score(&opt);
5202        if (cmd != 'B')
5203                opt2 = 0;
5204        else {
5205                if (*opt == 0)
5206                        opt2 = 0;
5207                else if (*opt != '/')
5208                        return -1; /* we expect -B80/99 or -B80 */
5209                else {
5210                        opt++;
5211                        opt2 = parse_rename_score(&opt);
5212                }
5213        }
5214        if (*opt != 0)
5215                return -1;
5216        return opt1 | (opt2 << 16);
5217}
5218
5219struct diff_queue_struct diff_queued_diff;
5220
5221void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5222{
5223        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5224        queue->queue[queue->nr++] = dp;
5225}
5226
5227struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5228                                 struct diff_filespec *one,
5229                                 struct diff_filespec *two)
5230{
5231        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5232        dp->one = one;
5233        dp->two = two;
5234        if (queue)
5235                diff_q(queue, dp);
5236        return dp;
5237}
5238
5239void diff_free_filepair(struct diff_filepair *p)
5240{
5241        free_filespec(p->one);
5242        free_filespec(p->two);
5243        free(p);
5244}
5245
5246const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5247{
5248        int abblen;
5249        const char *abbrev;
5250
5251        /* Do we want all 40 hex characters? */
5252        if (len == the_hash_algo->hexsz)
5253                return oid_to_hex(oid);
5254
5255        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5256        abbrev = diff_abbrev_oid(oid, len);
5257
5258        if (!print_sha1_ellipsis())
5259                return abbrev;
5260
5261        abblen = strlen(abbrev);
5262
5263        /*
5264         * In well-behaved cases, where the abbreviated result is the
5265         * same as the requested length, append three dots after the
5266         * abbreviation (hence the whole logic is limited to the case
5267         * where abblen < 37); when the actual abbreviated result is a
5268         * bit longer than the requested length, we reduce the number
5269         * of dots so that they match the well-behaved ones.  However,
5270         * if the actual abbreviation is longer than the requested
5271         * length by more than three, we give up on aligning, and add
5272         * three dots anyway, to indicate that the output is not the
5273         * full object name.  Yes, this may be suboptimal, but this
5274         * appears only in "diff --raw --abbrev" output and it is not
5275         * worth the effort to change it now.  Note that this would
5276         * likely to work fine when the automatic sizing of default
5277         * abbreviation length is used--we would be fed -1 in "len" in
5278         * that case, and will end up always appending three-dots, but
5279         * the automatic sizing is supposed to give abblen that ensures
5280         * uniqueness across all objects (statistically speaking).
5281         */
5282        if (abblen < the_hash_algo->hexsz - 3) {
5283                static char hex[GIT_MAX_HEXSZ + 1];
5284                if (len < abblen && abblen <= len + 2)
5285                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5286                else
5287                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5288                return hex;
5289        }
5290
5291        return oid_to_hex(oid);
5292}
5293
5294static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5295{
5296        int line_termination = opt->line_termination;
5297        int inter_name_termination = line_termination ? '\t' : '\0';
5298
5299        fprintf(opt->file, "%s", diff_line_prefix(opt));
5300        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5301                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5302                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5303                fprintf(opt->file, "%s ",
5304                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5305        }
5306        if (p->score) {
5307                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5308                        inter_name_termination);
5309        } else {
5310                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5311        }
5312
5313        if (p->status == DIFF_STATUS_COPIED ||
5314            p->status == DIFF_STATUS_RENAMED) {
5315                const char *name_a, *name_b;
5316                name_a = p->one->path;
5317                name_b = p->two->path;
5318                strip_prefix(opt->prefix_length, &name_a, &name_b);
5319                write_name_quoted(name_a, opt->file, inter_name_termination);
5320                write_name_quoted(name_b, opt->file, line_termination);
5321        } else {
5322                const char *name_a, *name_b;
5323                name_a = p->one->mode ? p->one->path : p->two->path;
5324                name_b = NULL;
5325                strip_prefix(opt->prefix_length, &name_a, &name_b);
5326                write_name_quoted(name_a, opt->file, line_termination);
5327        }
5328}
5329
5330int diff_unmodified_pair(struct diff_filepair *p)
5331{
5332        /* This function is written stricter than necessary to support
5333         * the currently implemented transformers, but the idea is to
5334         * let transformers to produce diff_filepairs any way they want,
5335         * and filter and clean them up here before producing the output.
5336         */
5337        struct diff_filespec *one = p->one, *two = p->two;
5338
5339        if (DIFF_PAIR_UNMERGED(p))
5340                return 0; /* unmerged is interesting */
5341
5342        /* deletion, addition, mode or type change
5343         * and rename are all interesting.
5344         */
5345        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5346            DIFF_PAIR_MODE_CHANGED(p) ||
5347            strcmp(one->path, two->path))
5348                return 0;
5349
5350        /* both are valid and point at the same path.  that is, we are
5351         * dealing with a change.
5352         */
5353        if (one->oid_valid && two->oid_valid &&
5354            oideq(&one->oid, &two->oid) &&
5355            !one->dirty_submodule && !two->dirty_submodule)
5356                return 1; /* no change */
5357        if (!one->oid_valid && !two->oid_valid)
5358                return 1; /* both look at the same file on the filesystem. */
5359        return 0;
5360}
5361
5362static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5363{
5364        if (diff_unmodified_pair(p))
5365                return;
5366
5367        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5368            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5369                return; /* no tree diffs in patch format */
5370
5371        run_diff(p, o);
5372}
5373
5374static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5375                            struct diffstat_t *diffstat)
5376{
5377        if (diff_unmodified_pair(p))
5378                return;
5379
5380        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5381            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5382                return; /* no useful stat for tree diffs */
5383
5384        run_diffstat(p, o, diffstat);
5385}
5386
5387static void diff_flush_checkdiff(struct diff_filepair *p,
5388                struct diff_options *o)
5389{
5390        if (diff_unmodified_pair(p))
5391                return;
5392
5393        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5394            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5395                return; /* nothing to check in tree diffs */
5396
5397        run_checkdiff(p, o);
5398}
5399
5400int diff_queue_is_empty(void)
5401{
5402        struct diff_queue_struct *q = &diff_queued_diff;
5403        int i;
5404        for (i = 0; i < q->nr; i++)
5405                if (!diff_unmodified_pair(q->queue[i]))
5406                        return 0;
5407        return 1;
5408}
5409
5410#if DIFF_DEBUG
5411void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5412{
5413        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5414                x, one ? one : "",
5415                s->path,
5416                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5417                s->mode,
5418                s->oid_valid ? oid_to_hex(&s->oid) : "");
5419        fprintf(stderr, "queue[%d] %s size %lu\n",
5420                x, one ? one : "",
5421                s->size);
5422}
5423
5424void diff_debug_filepair(const struct diff_filepair *p, int i)
5425{
5426        diff_debug_filespec(p->one, i, "one");
5427        diff_debug_filespec(p->two, i, "two");
5428        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5429                p->score, p->status ? p->status : '?',
5430                p->one->rename_used, p->broken_pair);
5431}
5432
5433void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5434{
5435        int i;
5436        if (msg)
5437                fprintf(stderr, "%s\n", msg);
5438        fprintf(stderr, "q->nr = %d\n", q->nr);
5439        for (i = 0; i < q->nr; i++) {
5440                struct diff_filepair *p = q->queue[i];
5441                diff_debug_filepair(p, i);
5442        }
5443}
5444#endif
5445
5446static void diff_resolve_rename_copy(void)
5447{
5448        int i;
5449        struct diff_filepair *p;
5450        struct diff_queue_struct *q = &diff_queued_diff;
5451
5452        diff_debug_queue("resolve-rename-copy", q);
5453
5454        for (i = 0; i < q->nr; i++) {
5455                p = q->queue[i];
5456                p->status = 0; /* undecided */
5457                if (DIFF_PAIR_UNMERGED(p))
5458                        p->status = DIFF_STATUS_UNMERGED;
5459                else if (!DIFF_FILE_VALID(p->one))
5460                        p->status = DIFF_STATUS_ADDED;
5461                else if (!DIFF_FILE_VALID(p->two))
5462                        p->status = DIFF_STATUS_DELETED;
5463                else if (DIFF_PAIR_TYPE_CHANGED(p))
5464                        p->status = DIFF_STATUS_TYPE_CHANGED;
5465
5466                /* from this point on, we are dealing with a pair
5467                 * whose both sides are valid and of the same type, i.e.
5468                 * either in-place edit or rename/copy edit.
5469                 */
5470                else if (DIFF_PAIR_RENAME(p)) {
5471                        /*
5472                         * A rename might have re-connected a broken
5473                         * pair up, causing the pathnames to be the
5474                         * same again. If so, that's not a rename at
5475                         * all, just a modification..
5476                         *
5477                         * Otherwise, see if this source was used for
5478                         * multiple renames, in which case we decrement
5479                         * the count, and call it a copy.
5480                         */
5481                        if (!strcmp(p->one->path, p->two->path))
5482                                p->status = DIFF_STATUS_MODIFIED;
5483                        else if (--p->one->rename_used > 0)
5484                                p->status = DIFF_STATUS_COPIED;
5485                        else
5486                                p->status = DIFF_STATUS_RENAMED;
5487                }
5488                else if (!oideq(&p->one->oid, &p->two->oid) ||
5489                         p->one->mode != p->two->mode ||
5490                         p->one->dirty_submodule ||
5491                         p->two->dirty_submodule ||
5492                         is_null_oid(&p->one->oid))
5493                        p->status = DIFF_STATUS_MODIFIED;
5494                else {
5495                        /* This is a "no-change" entry and should not
5496                         * happen anymore, but prepare for broken callers.
5497                         */
5498                        error("feeding unmodified %s to diffcore",
5499                              p->one->path);
5500                        p->status = DIFF_STATUS_UNKNOWN;
5501                }
5502        }
5503        diff_debug_queue("resolve-rename-copy done", q);
5504}
5505
5506static int check_pair_status(struct diff_filepair *p)
5507{
5508        switch (p->status) {
5509        case DIFF_STATUS_UNKNOWN:
5510                return 0;
5511        case 0:
5512                die("internal error in diff-resolve-rename-copy");
5513        default:
5514                return 1;
5515        }
5516}
5517
5518static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5519{
5520        int fmt = opt->output_format;
5521
5522        if (fmt & DIFF_FORMAT_CHECKDIFF)
5523                diff_flush_checkdiff(p, opt);
5524        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5525                diff_flush_raw(p, opt);
5526        else if (fmt & DIFF_FORMAT_NAME) {
5527                const char *name_a, *name_b;
5528                name_a = p->two->path;
5529                name_b = NULL;
5530                strip_prefix(opt->prefix_length, &name_a, &name_b);
5531                fprintf(opt->file, "%s", diff_line_prefix(opt));
5532                write_name_quoted(name_a, opt->file, opt->line_termination);
5533        }
5534}
5535
5536static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5537{
5538        struct strbuf sb = STRBUF_INIT;
5539        if (fs->mode)
5540                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5541        else
5542                strbuf_addf(&sb, " %s ", newdelete);
5543
5544        quote_c_style(fs->path, &sb, NULL, 0);
5545        strbuf_addch(&sb, '\n');
5546        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5547                         sb.buf, sb.len, 0);
5548        strbuf_release(&sb);
5549}
5550
5551static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5552                int show_name)
5553{
5554        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5555                struct strbuf sb = STRBUF_INIT;
5556                strbuf_addf(&sb, " mode change %06o => %06o",
5557                            p->one->mode, p->two->mode);
5558                if (show_name) {
5559                        strbuf_addch(&sb, ' ');
5560                        quote_c_style(p->two->path, &sb, NULL, 0);
5561                }
5562                strbuf_addch(&sb, '\n');
5563                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5564                                 sb.buf, sb.len, 0);
5565                strbuf_release(&sb);
5566        }
5567}
5568
5569static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5570                struct diff_filepair *p)
5571{
5572        struct strbuf sb = STRBUF_INIT;
5573        struct strbuf names = STRBUF_INIT;
5574
5575        pprint_rename(&names, p->one->path, p->two->path);
5576        strbuf_addf(&sb, " %s %s (%d%%)\n",
5577                    renamecopy, names.buf, similarity_index(p));
5578        strbuf_release(&names);
5579        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5580                                 sb.buf, sb.len, 0);
5581        show_mode_change(opt, p, 0);
5582        strbuf_release(&sb);
5583}
5584
5585static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5586{
5587        switch(p->status) {
5588        case DIFF_STATUS_DELETED:
5589                show_file_mode_name(opt, "delete", p->one);
5590                break;
5591        case DIFF_STATUS_ADDED:
5592                show_file_mode_name(opt, "create", p->two);
5593                break;
5594        case DIFF_STATUS_COPIED:
5595                show_rename_copy(opt, "copy", p);
5596                break;
5597        case DIFF_STATUS_RENAMED:
5598                show_rename_copy(opt, "rename", p);
5599                break;
5600        default:
5601                if (p->score) {
5602                        struct strbuf sb = STRBUF_INIT;
5603                        strbuf_addstr(&sb, " rewrite ");
5604                        quote_c_style(p->two->path, &sb, NULL, 0);
5605                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5606                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5607                                         sb.buf, sb.len, 0);
5608                        strbuf_release(&sb);
5609                }
5610                show_mode_change(opt, p, !p->score);
5611                break;
5612        }
5613}
5614
5615struct patch_id_t {
5616        git_SHA_CTX *ctx;
5617        int patchlen;
5618};
5619
5620static int remove_space(char *line, int len)
5621{
5622        int i;
5623        char *dst = line;
5624        unsigned char c;
5625
5626        for (i = 0; i < len; i++)
5627                if (!isspace((c = line[i])))
5628                        *dst++ = c;
5629
5630        return dst - line;
5631}
5632
5633static void patch_id_consume(void *priv, char *line, unsigned long len)
5634{
5635        struct patch_id_t *data = priv;
5636        int new_len;
5637
5638        /* Ignore line numbers when computing the SHA1 of the patch */
5639        if (starts_with(line, "@@ -"))
5640                return;
5641
5642        new_len = remove_space(line, len);
5643
5644        git_SHA1_Update(data->ctx, line, new_len);
5645        data->patchlen += new_len;
5646}
5647
5648static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5649{
5650        git_SHA1_Update(ctx, str, strlen(str));
5651}
5652
5653static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5654{
5655        /* large enough for 2^32 in octal */
5656        char buf[12];
5657        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5658        git_SHA1_Update(ctx, buf, len);
5659}
5660
5661/* returns 0 upon success, and writes result into sha1 */
5662static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5663{
5664        struct diff_queue_struct *q = &diff_queued_diff;
5665        int i;
5666        git_SHA_CTX ctx;
5667        struct patch_id_t data;
5668
5669        git_SHA1_Init(&ctx);
5670        memset(&data, 0, sizeof(struct patch_id_t));
5671        data.ctx = &ctx;
5672
5673        for (i = 0; i < q->nr; i++) {
5674                xpparam_t xpp;
5675                xdemitconf_t xecfg;
5676                mmfile_t mf1, mf2;
5677                struct diff_filepair *p = q->queue[i];
5678                int len1, len2;
5679
5680                memset(&xpp, 0, sizeof(xpp));
5681                memset(&xecfg, 0, sizeof(xecfg));
5682                if (p->status == 0)
5683                        return error("internal diff status error");
5684                if (p->status == DIFF_STATUS_UNKNOWN)
5685                        continue;
5686                if (diff_unmodified_pair(p))
5687                        continue;
5688                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5689                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5690                        continue;
5691                if (DIFF_PAIR_UNMERGED(p))
5692                        continue;
5693
5694                diff_fill_oid_info(p->one);
5695                diff_fill_oid_info(p->two);
5696
5697                len1 = remove_space(p->one->path, strlen(p->one->path));
5698                len2 = remove_space(p->two->path, strlen(p->two->path));
5699                patch_id_add_string(&ctx, "diff--git");
5700                patch_id_add_string(&ctx, "a/");
5701                git_SHA1_Update(&ctx, p->one->path, len1);
5702                patch_id_add_string(&ctx, "b/");
5703                git_SHA1_Update(&ctx, p->two->path, len2);
5704
5705                if (p->one->mode == 0) {
5706                        patch_id_add_string(&ctx, "newfilemode");
5707                        patch_id_add_mode(&ctx, p->two->mode);
5708                        patch_id_add_string(&ctx, "---/dev/null");
5709                        patch_id_add_string(&ctx, "+++b/");
5710                        git_SHA1_Update(&ctx, p->two->path, len2);
5711                } else if (p->two->mode == 0) {
5712                        patch_id_add_string(&ctx, "deletedfilemode");
5713                        patch_id_add_mode(&ctx, p->one->mode);
5714                        patch_id_add_string(&ctx, "---a/");
5715                        git_SHA1_Update(&ctx, p->one->path, len1);
5716                        patch_id_add_string(&ctx, "+++/dev/null");
5717                } else {
5718                        patch_id_add_string(&ctx, "---a/");
5719                        git_SHA1_Update(&ctx, p->one->path, len1);
5720                        patch_id_add_string(&ctx, "+++b/");
5721                        git_SHA1_Update(&ctx, p->two->path, len2);
5722                }
5723
5724                if (diff_header_only)
5725                        continue;
5726
5727                if (fill_mmfile(&mf1, p->one) < 0 ||
5728                    fill_mmfile(&mf2, p->two) < 0)
5729                        return error("unable to read files to diff");
5730
5731                if (diff_filespec_is_binary(p->one) ||
5732                    diff_filespec_is_binary(p->two)) {
5733                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5734                                        GIT_SHA1_HEXSZ);
5735                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5736                                        GIT_SHA1_HEXSZ);
5737                        continue;
5738                }
5739
5740                xpp.flags = 0;
5741                xecfg.ctxlen = 3;
5742                xecfg.flags = 0;
5743                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5744                                  &xpp, &xecfg))
5745                        return error("unable to generate patch-id diff for %s",
5746                                     p->one->path);
5747        }
5748
5749        git_SHA1_Final(oid->hash, &ctx);
5750        return 0;
5751}
5752
5753int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5754{
5755        struct diff_queue_struct *q = &diff_queued_diff;
5756        int i;
5757        int result = diff_get_patch_id(options, oid, diff_header_only);
5758
5759        for (i = 0; i < q->nr; i++)
5760                diff_free_filepair(q->queue[i]);
5761
5762        free(q->queue);
5763        DIFF_QUEUE_CLEAR(q);
5764
5765        return result;
5766}
5767
5768static int is_summary_empty(const struct diff_queue_struct *q)
5769{
5770        int i;
5771
5772        for (i = 0; i < q->nr; i++) {
5773                const struct diff_filepair *p = q->queue[i];
5774
5775                switch (p->status) {
5776                case DIFF_STATUS_DELETED:
5777                case DIFF_STATUS_ADDED:
5778                case DIFF_STATUS_COPIED:
5779                case DIFF_STATUS_RENAMED:
5780                        return 0;
5781                default:
5782                        if (p->score)
5783                                return 0;
5784                        if (p->one->mode && p->two->mode &&
5785                            p->one->mode != p->two->mode)
5786                                return 0;
5787                        break;
5788                }
5789        }
5790        return 1;
5791}
5792
5793static const char rename_limit_warning[] =
5794N_("inexact rename detection was skipped due to too many files.");
5795
5796static const char degrade_cc_to_c_warning[] =
5797N_("only found copies from modified paths due to too many files.");
5798
5799static const char rename_limit_advice[] =
5800N_("you may want to set your %s variable to at least "
5801   "%d and retry the command.");
5802
5803void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5804{
5805        fflush(stdout);
5806        if (degraded_cc)
5807                warning(_(degrade_cc_to_c_warning));
5808        else if (needed)
5809                warning(_(rename_limit_warning));
5810        else
5811                return;
5812        if (0 < needed)
5813                warning(_(rename_limit_advice), varname, needed);
5814}
5815
5816static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5817{
5818        int i;
5819        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5820        struct diff_queue_struct *q = &diff_queued_diff;
5821
5822        if (WSEH_NEW & WS_RULE_MASK)
5823                BUG("WS rules bit mask overlaps with diff symbol flags");
5824
5825        if (o->color_moved)
5826                o->emitted_symbols = &esm;
5827
5828        for (i = 0; i < q->nr; i++) {
5829                struct diff_filepair *p = q->queue[i];
5830                if (check_pair_status(p))
5831                        diff_flush_patch(p, o);
5832        }
5833
5834        if (o->emitted_symbols) {
5835                if (o->color_moved) {
5836                        struct hashmap add_lines, del_lines;
5837
5838                        if (o->color_moved_ws_handling &
5839                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5840                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5841
5842                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5843                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5844
5845                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5846                        mark_color_as_moved(o, &add_lines, &del_lines);
5847                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5848                                dim_moved_lines(o);
5849
5850                        hashmap_free(&add_lines, 0);
5851                        hashmap_free(&del_lines, 0);
5852                }
5853
5854                for (i = 0; i < esm.nr; i++)
5855                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5856
5857                for (i = 0; i < esm.nr; i++)
5858                        free((void *)esm.buf[i].line);
5859        }
5860        esm.nr = 0;
5861}
5862
5863void diff_flush(struct diff_options *options)
5864{
5865        struct diff_queue_struct *q = &diff_queued_diff;
5866        int i, output_format = options->output_format;
5867        int separator = 0;
5868        int dirstat_by_line = 0;
5869
5870        /*
5871         * Order: raw, stat, summary, patch
5872         * or:    name/name-status/checkdiff (other bits clear)
5873         */
5874        if (!q->nr)
5875                goto free_queue;
5876
5877        if (output_format & (DIFF_FORMAT_RAW |
5878                             DIFF_FORMAT_NAME |
5879                             DIFF_FORMAT_NAME_STATUS |
5880                             DIFF_FORMAT_CHECKDIFF)) {
5881                for (i = 0; i < q->nr; i++) {
5882                        struct diff_filepair *p = q->queue[i];
5883                        if (check_pair_status(p))
5884                                flush_one_pair(p, options);
5885                }
5886                separator++;
5887        }
5888
5889        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5890                dirstat_by_line = 1;
5891
5892        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5893            dirstat_by_line) {
5894                struct diffstat_t diffstat;
5895
5896                memset(&diffstat, 0, sizeof(struct diffstat_t));
5897                for (i = 0; i < q->nr; i++) {
5898                        struct diff_filepair *p = q->queue[i];
5899                        if (check_pair_status(p))
5900                                diff_flush_stat(p, options, &diffstat);
5901                }
5902                if (output_format & DIFF_FORMAT_NUMSTAT)
5903                        show_numstat(&diffstat, options);
5904                if (output_format & DIFF_FORMAT_DIFFSTAT)
5905                        show_stats(&diffstat, options);
5906                if (output_format & DIFF_FORMAT_SHORTSTAT)
5907                        show_shortstats(&diffstat, options);
5908                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5909                        show_dirstat_by_line(&diffstat, options);
5910                free_diffstat_info(&diffstat);
5911                separator++;
5912        }
5913        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5914                show_dirstat(options);
5915
5916        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5917                for (i = 0; i < q->nr; i++) {
5918                        diff_summary(options, q->queue[i]);
5919                }
5920                separator++;
5921        }
5922
5923        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5924            options->flags.exit_with_status &&
5925            options->flags.diff_from_contents) {
5926                /*
5927                 * run diff_flush_patch for the exit status. setting
5928                 * options->file to /dev/null should be safe, because we
5929                 * aren't supposed to produce any output anyway.
5930                 */
5931                if (options->close_file)
5932                        fclose(options->file);
5933                options->file = xfopen("/dev/null", "w");
5934                options->close_file = 1;
5935                options->color_moved = 0;
5936                for (i = 0; i < q->nr; i++) {
5937                        struct diff_filepair *p = q->queue[i];
5938                        if (check_pair_status(p))
5939                                diff_flush_patch(p, options);
5940                        if (options->found_changes)
5941                                break;
5942                }
5943        }
5944
5945        if (output_format & DIFF_FORMAT_PATCH) {
5946                if (separator) {
5947                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5948                        if (options->stat_sep)
5949                                /* attach patch instead of inline */
5950                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5951                                                 NULL, 0, 0);
5952                }
5953
5954                diff_flush_patch_all_file_pairs(options);
5955        }
5956
5957        if (output_format & DIFF_FORMAT_CALLBACK)
5958                options->format_callback(q, options, options->format_callback_data);
5959
5960        for (i = 0; i < q->nr; i++)
5961                diff_free_filepair(q->queue[i]);
5962free_queue:
5963        free(q->queue);
5964        DIFF_QUEUE_CLEAR(q);
5965        if (options->close_file)
5966                fclose(options->file);
5967
5968        /*
5969         * Report the content-level differences with HAS_CHANGES;
5970         * diff_addremove/diff_change does not set the bit when
5971         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5972         */
5973        if (options->flags.diff_from_contents) {
5974                if (options->found_changes)
5975                        options->flags.has_changes = 1;
5976                else
5977                        options->flags.has_changes = 0;
5978        }
5979}
5980
5981static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5982{
5983        return (((p->status == DIFF_STATUS_MODIFIED) &&
5984                 ((p->score &&
5985                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5986                  (!p->score &&
5987                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5988                ((p->status != DIFF_STATUS_MODIFIED) &&
5989                 filter_bit_tst(p->status, options)));
5990}
5991
5992static void diffcore_apply_filter(struct diff_options *options)
5993{
5994        int i;
5995        struct diff_queue_struct *q = &diff_queued_diff;
5996        struct diff_queue_struct outq;
5997
5998        DIFF_QUEUE_CLEAR(&outq);
5999
6000        if (!options->filter)
6001                return;
6002
6003        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6004                int found;
6005                for (i = found = 0; !found && i < q->nr; i++) {
6006                        if (match_filter(options, q->queue[i]))
6007                                found++;
6008                }
6009                if (found)
6010                        return;
6011
6012                /* otherwise we will clear the whole queue
6013                 * by copying the empty outq at the end of this
6014                 * function, but first clear the current entries
6015                 * in the queue.
6016                 */
6017                for (i = 0; i < q->nr; i++)
6018                        diff_free_filepair(q->queue[i]);
6019        }
6020        else {
6021                /* Only the matching ones */
6022                for (i = 0; i < q->nr; i++) {
6023                        struct diff_filepair *p = q->queue[i];
6024                        if (match_filter(options, p))
6025                                diff_q(&outq, p);
6026                        else
6027                                diff_free_filepair(p);
6028                }
6029        }
6030        free(q->queue);
6031        *q = outq;
6032}
6033
6034/* Check whether two filespecs with the same mode and size are identical */
6035static int diff_filespec_is_identical(struct diff_filespec *one,
6036                                      struct diff_filespec *two)
6037{
6038        if (S_ISGITLINK(one->mode))
6039                return 0;
6040        if (diff_populate_filespec(one, 0))
6041                return 0;
6042        if (diff_populate_filespec(two, 0))
6043                return 0;
6044        return !memcmp(one->data, two->data, one->size);
6045}
6046
6047static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6048{
6049        if (p->done_skip_stat_unmatch)
6050                return p->skip_stat_unmatch_result;
6051
6052        p->done_skip_stat_unmatch = 1;
6053        p->skip_stat_unmatch_result = 0;
6054        /*
6055         * 1. Entries that come from stat info dirtiness
6056         *    always have both sides (iow, not create/delete),
6057         *    one side of the object name is unknown, with
6058         *    the same mode and size.  Keep the ones that
6059         *    do not match these criteria.  They have real
6060         *    differences.
6061         *
6062         * 2. At this point, the file is known to be modified,
6063         *    with the same mode and size, and the object
6064         *    name of one side is unknown.  Need to inspect
6065         *    the identical contents.
6066         */
6067        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6068            !DIFF_FILE_VALID(p->two) ||
6069            (p->one->oid_valid && p->two->oid_valid) ||
6070            (p->one->mode != p->two->mode) ||
6071            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6072            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6073            (p->one->size != p->two->size) ||
6074            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6075                p->skip_stat_unmatch_result = 1;
6076        return p->skip_stat_unmatch_result;
6077}
6078
6079static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6080{
6081        int i;
6082        struct diff_queue_struct *q = &diff_queued_diff;
6083        struct diff_queue_struct outq;
6084        DIFF_QUEUE_CLEAR(&outq);
6085
6086        for (i = 0; i < q->nr; i++) {
6087                struct diff_filepair *p = q->queue[i];
6088
6089                if (diff_filespec_check_stat_unmatch(p))
6090                        diff_q(&outq, p);
6091                else {
6092                        /*
6093                         * The caller can subtract 1 from skip_stat_unmatch
6094                         * to determine how many paths were dirty only
6095                         * due to stat info mismatch.
6096                         */
6097                        if (!diffopt->flags.no_index)
6098                                diffopt->skip_stat_unmatch++;
6099                        diff_free_filepair(p);
6100                }
6101        }
6102        free(q->queue);
6103        *q = outq;
6104}
6105
6106static int diffnamecmp(const void *a_, const void *b_)
6107{
6108        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6109        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6110        const char *name_a, *name_b;
6111
6112        name_a = a->one ? a->one->path : a->two->path;
6113        name_b = b->one ? b->one->path : b->two->path;
6114        return strcmp(name_a, name_b);
6115}
6116
6117void diffcore_fix_diff_index(struct diff_options *options)
6118{
6119        struct diff_queue_struct *q = &diff_queued_diff;
6120        QSORT(q->queue, q->nr, diffnamecmp);
6121}
6122
6123void diffcore_std(struct diff_options *options)
6124{
6125        /* NOTE please keep the following in sync with diff_tree_combined() */
6126        if (options->skip_stat_unmatch)
6127                diffcore_skip_stat_unmatch(options);
6128        if (!options->found_follow) {
6129                /* See try_to_follow_renames() in tree-diff.c */
6130                if (options->break_opt != -1)
6131                        diffcore_break(options->break_opt);
6132                if (options->detect_rename)
6133                        diffcore_rename(options);
6134                if (options->break_opt != -1)
6135                        diffcore_merge_broken();
6136        }
6137        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6138                diffcore_pickaxe(options);
6139        if (options->orderfile)
6140                diffcore_order(options->orderfile);
6141        if (!options->found_follow)
6142                /* See try_to_follow_renames() in tree-diff.c */
6143                diff_resolve_rename_copy();
6144        diffcore_apply_filter(options);
6145
6146        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6147                options->flags.has_changes = 1;
6148        else
6149                options->flags.has_changes = 0;
6150
6151        options->found_follow = 0;
6152}
6153
6154int diff_result_code(struct diff_options *opt, int status)
6155{
6156        int result = 0;
6157
6158        diff_warn_rename_limit("diff.renameLimit",
6159                               opt->needed_rename_limit,
6160                               opt->degraded_cc_to_c);
6161        if (!opt->flags.exit_with_status &&
6162            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6163                return status;
6164        if (opt->flags.exit_with_status &&
6165            opt->flags.has_changes)
6166                result |= 01;
6167        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6168            opt->flags.check_failed)
6169                result |= 02;
6170        return result;
6171}
6172
6173int diff_can_quit_early(struct diff_options *opt)
6174{
6175        return (opt->flags.quick &&
6176                !opt->filter &&
6177                opt->flags.has_changes);
6178}
6179
6180/*
6181 * Shall changes to this submodule be ignored?
6182 *
6183 * Submodule changes can be configured to be ignored separately for each path,
6184 * but that configuration can be overridden from the command line.
6185 */
6186static int is_submodule_ignored(const char *path, struct diff_options *options)
6187{
6188        int ignored = 0;
6189        struct diff_flags orig_flags = options->flags;
6190        if (!options->flags.override_submodule_config)
6191                set_diffopt_flags_from_submodule_config(options, path);
6192        if (options->flags.ignore_submodules)
6193                ignored = 1;
6194        options->flags = orig_flags;
6195        return ignored;
6196}
6197
6198void diff_addremove(struct diff_options *options,
6199                    int addremove, unsigned mode,
6200                    const struct object_id *oid,
6201                    int oid_valid,
6202                    const char *concatpath, unsigned dirty_submodule)
6203{
6204        struct diff_filespec *one, *two;
6205
6206        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6207                return;
6208
6209        /* This may look odd, but it is a preparation for
6210         * feeding "there are unchanged files which should
6211         * not produce diffs, but when you are doing copy
6212         * detection you would need them, so here they are"
6213         * entries to the diff-core.  They will be prefixed
6214         * with something like '=' or '*' (I haven't decided
6215         * which but should not make any difference).
6216         * Feeding the same new and old to diff_change()
6217         * also has the same effect.
6218         * Before the final output happens, they are pruned after
6219         * merged into rename/copy pairs as appropriate.
6220         */
6221        if (options->flags.reverse_diff)
6222                addremove = (addremove == '+' ? '-' :
6223                             addremove == '-' ? '+' : addremove);
6224
6225        if (options->prefix &&
6226            strncmp(concatpath, options->prefix, options->prefix_length))
6227                return;
6228
6229        one = alloc_filespec(concatpath);
6230        two = alloc_filespec(concatpath);
6231
6232        if (addremove != '+')
6233                fill_filespec(one, oid, oid_valid, mode);
6234        if (addremove != '-') {
6235                fill_filespec(two, oid, oid_valid, mode);
6236                two->dirty_submodule = dirty_submodule;
6237        }
6238
6239        diff_queue(&diff_queued_diff, one, two);
6240        if (!options->flags.diff_from_contents)
6241                options->flags.has_changes = 1;
6242}
6243
6244void diff_change(struct diff_options *options,
6245                 unsigned old_mode, unsigned new_mode,
6246                 const struct object_id *old_oid,
6247                 const struct object_id *new_oid,
6248                 int old_oid_valid, int new_oid_valid,
6249                 const char *concatpath,
6250                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6251{
6252        struct diff_filespec *one, *two;
6253        struct diff_filepair *p;
6254
6255        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6256            is_submodule_ignored(concatpath, options))
6257                return;
6258
6259        if (options->flags.reverse_diff) {
6260                SWAP(old_mode, new_mode);
6261                SWAP(old_oid, new_oid);
6262                SWAP(old_oid_valid, new_oid_valid);
6263                SWAP(old_dirty_submodule, new_dirty_submodule);
6264        }
6265
6266        if (options->prefix &&
6267            strncmp(concatpath, options->prefix, options->prefix_length))
6268                return;
6269
6270        one = alloc_filespec(concatpath);
6271        two = alloc_filespec(concatpath);
6272        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6273        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6274        one->dirty_submodule = old_dirty_submodule;
6275        two->dirty_submodule = new_dirty_submodule;
6276        p = diff_queue(&diff_queued_diff, one, two);
6277
6278        if (options->flags.diff_from_contents)
6279                return;
6280
6281        if (options->flags.quick && options->skip_stat_unmatch &&
6282            !diff_filespec_check_stat_unmatch(p))
6283                return;
6284
6285        options->flags.has_changes = 1;
6286}
6287
6288struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6289{
6290        struct diff_filepair *pair;
6291        struct diff_filespec *one, *two;
6292
6293        if (options->prefix &&
6294            strncmp(path, options->prefix, options->prefix_length))
6295                return NULL;
6296
6297        one = alloc_filespec(path);
6298        two = alloc_filespec(path);
6299        pair = diff_queue(&diff_queued_diff, one, two);
6300        pair->is_unmerged = 1;
6301        return pair;
6302}
6303
6304static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6305                size_t *outsize)
6306{
6307        struct diff_tempfile *temp;
6308        const char *argv[3];
6309        const char **arg = argv;
6310        struct child_process child = CHILD_PROCESS_INIT;
6311        struct strbuf buf = STRBUF_INIT;
6312        int err = 0;
6313
6314        temp = prepare_temp_file(spec->path, spec);
6315        *arg++ = pgm;
6316        *arg++ = temp->name;
6317        *arg = NULL;
6318
6319        child.use_shell = 1;
6320        child.argv = argv;
6321        child.out = -1;
6322        if (start_command(&child)) {
6323                remove_tempfile();
6324                return NULL;
6325        }
6326
6327        if (strbuf_read(&buf, child.out, 0) < 0)
6328                err = error("error reading from textconv command '%s'", pgm);
6329        close(child.out);
6330
6331        if (finish_command(&child) || err) {
6332                strbuf_release(&buf);
6333                remove_tempfile();
6334                return NULL;
6335        }
6336        remove_tempfile();
6337
6338        return strbuf_detach(&buf, outsize);
6339}
6340
6341size_t fill_textconv(struct userdiff_driver *driver,
6342                     struct diff_filespec *df,
6343                     char **outbuf)
6344{
6345        size_t size;
6346
6347        if (!driver) {
6348                if (!DIFF_FILE_VALID(df)) {
6349                        *outbuf = "";
6350                        return 0;
6351                }
6352                if (diff_populate_filespec(df, 0))
6353                        die("unable to read files to diff");
6354                *outbuf = df->data;
6355                return df->size;
6356        }
6357
6358        if (!driver->textconv)
6359                BUG("fill_textconv called with non-textconv driver");
6360
6361        if (driver->textconv_cache && df->oid_valid) {
6362                *outbuf = notes_cache_get(driver->textconv_cache,
6363                                          &df->oid,
6364                                          &size);
6365                if (*outbuf)
6366                        return size;
6367        }
6368
6369        *outbuf = run_textconv(driver->textconv, df, &size);
6370        if (!*outbuf)
6371                die("unable to read files to diff");
6372
6373        if (driver->textconv_cache && df->oid_valid) {
6374                /* ignore errors, as we might be in a readonly repository */
6375                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6376                                size);
6377                /*
6378                 * we could save up changes and flush them all at the end,
6379                 * but we would need an extra call after all diffing is done.
6380                 * Since generating a cache entry is the slow path anyway,
6381                 * this extra overhead probably isn't a big deal.
6382                 */
6383                notes_cache_write(driver->textconv_cache);
6384        }
6385
6386        return size;
6387}
6388
6389int textconv_object(const char *path,
6390                    unsigned mode,
6391                    const struct object_id *oid,
6392                    int oid_valid,
6393                    char **buf,
6394                    unsigned long *buf_size)
6395{
6396        struct diff_filespec *df;
6397        struct userdiff_driver *textconv;
6398
6399        df = alloc_filespec(path);
6400        fill_filespec(df, oid, oid_valid, mode);
6401        textconv = get_textconv(df);
6402        if (!textconv) {
6403                free_filespec(df);
6404                return 0;
6405        }
6406
6407        *buf_size = fill_textconv(textconv, df, buf);
6408        free_filespec(df);
6409        return 1;
6410}
6411
6412void setup_diff_pager(struct diff_options *opt)
6413{
6414        /*
6415         * If the user asked for our exit code, then either they want --quiet
6416         * or --exit-code. We should definitely not bother with a pager in the
6417         * former case, as we will generate no output. Since we still properly
6418         * report our exit code even when a pager is run, we _could_ run a
6419         * pager with --exit-code. But since we have not done so historically,
6420         * and because it is easy to find people oneline advising "git diff
6421         * --exit-code" in hooks and other scripts, we do not do so.
6422         */
6423        if (!opt->flags.exit_with_status &&
6424            check_pager_config("diff") != 0)
6425                setup_pager();
6426}